Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

32 files changed, 19755 insertions, 0 deletions

diff --git a/net/ceph/Kconfig b/net/ceph/Kconfig
new file mode 100644
index 000000000..cd2d5b930
--- /dev/null
+++ b/net/ceph/Kconfig
@@ -0,0 +1,43 @@
+config CEPH_LIB
+	tristate "Ceph core library"
+	depends on INET
+	select LIBCRC32C
+	select CRYPTO_AES
+	select CRYPTO_CBC
+	select CRYPTO
+	select KEYS
+	default n
+	help
+	  Choose Y or M here to include cephlib, which provides the
+	  common functionality to both the Ceph filesystem and
+	  to the rados block device (rbd).
+
+	  More information at http://ceph.newdream.net/.
+
+	  If unsure, say N.
+
+config CEPH_LIB_PRETTYDEBUG
+	bool "Include file:line in ceph debug output"
+	depends on CEPH_LIB
+	default n
+	help
+	  If you say Y here, debug output will include a filename and
+	  line to aid debugging.  This increases kernel size and slows
+	  execution slightly when debug call sites are enabled (e.g.,
+	  via CONFIG_DYNAMIC_DEBUG).
+
+	  If unsure, say N.
+
+config CEPH_LIB_USE_DNS_RESOLVER
+	bool "Use in-kernel support for DNS lookup"
+	depends on CEPH_LIB
+	select DNS_RESOLVER
+	default n
+	help
+	  If you say Y here, hostnames (e.g. monitor addresses) will
+	  be resolved using the CONFIG_DNS_RESOLVER facility.
+
+	  For information on how to use CONFIG_DNS_RESOLVER consult
+	  Documentation/networking/dns_resolver.txt
+
+	  If unsure, say N.
diff --git a/net/ceph/Makefile b/net/ceph/Makefile
new file mode 100644
index 000000000..db09defe2
--- /dev/null
+++ b/net/ceph/Makefile
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for CEPH filesystem.
+#
+obj-$(CONFIG_CEPH_LIB) += libceph.o
+
+libceph-y := ceph_common.o messenger.o msgpool.o buffer.o pagelist.o \
+	mon_client.o \
+	cls_lock_client.o \
+	osd_client.o osdmap.o crush/crush.o crush/mapper.o crush/hash.o \
+	striper.o \
+	debugfs.o \
+	auth.o auth_none.o \
+	crypto.o armor.o \
+	auth_x.o \
+	ceph_fs.o ceph_strings.o ceph_hash.o \
+	pagevec.o snapshot.o string_table.o
diff --git a/net/ceph/armor.c b/net/ceph/armor.c
new file mode 100644
index 000000000..0db806592
--- /dev/null
+++ b/net/ceph/armor.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/errno.h>
+
+int ceph_armor(char *dst, const char *src, const char *end);
+int ceph_unarmor(char *dst, const char *src, const char *end);
+
+/*
+ * base64 encode/decode.
+ */
+
+static const char *pem_key =
+	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+static int encode_bits(int c)
+{
+	return pem_key[c];
+}
+
+static int decode_bits(char c)
+{
+	if (c >= 'A' && c <= 'Z')
+		return c - 'A';
+	if (c >= 'a' && c <= 'z')
+		return c - 'a' + 26;
+	if (c >= '0' && c <= '9')
+		return c - '0' + 52;
+	if (c == '+')
+		return 62;
+	if (c == '/')
+		return 63;
+	if (c == '=')
+		return 0; /* just non-negative, please */
+	return -EINVAL;
+}
+
+int ceph_armor(char *dst, const char *src, const char *end)
+{
+	int olen = 0;
+	int line = 0;
+
+	while (src < end) {
+		unsigned char a, b, c;
+
+		a = *src++;
+		*dst++ = encode_bits(a >> 2);
+		if (src < end) {
+			b = *src++;
+			*dst++ = encode_bits(((a & 3) << 4) | (b >> 4));
+			if (src < end) {
+				c = *src++;
+				*dst++ = encode_bits(((b & 15) << 2) |
+						     (c >> 6));
+				*dst++ = encode_bits(c & 63);
+			} else {
+				*dst++ = encode_bits((b & 15) << 2);
+				*dst++ = '=';
+			}
+		} else {
+			*dst++ = encode_bits(((a & 3) << 4));
+			*dst++ = '=';
+			*dst++ = '=';
+		}
+		olen += 4;
+		line += 4;
+		if (line == 64) {
+			line = 0;
+			*(dst++) = '\n';
+			olen++;
+		}
+	}
+	return olen;
+}
+
+int ceph_unarmor(char *dst, const char *src, const char *end)
+{
+	int olen = 0;
+
+	while (src < end) {
+		int a, b, c, d;
+
+		if (src[0] == '\n') {
+			src++;
+			continue;
+		}
+		if (src + 4 > end)
+			return -EINVAL;
+		a = decode_bits(src[0]);
+		b = decode_bits(src[1]);
+		c = decode_bits(src[2]);
+		d = decode_bits(src[3]);
+		if (a < 0 || b < 0 || c < 0 || d < 0)
+			return -EINVAL;
+
+		*dst++ = (a << 2) | (b >> 4);
+		if (src[2] == '=')
+			return olen + 1;
+		*dst++ = ((b & 15) << 4) | (c >> 2);
+		if (src[3] == '=')
+			return olen + 2;
+		*dst++ = ((c & 3) << 6) | d;
+		olen += 3;
+		src += 4;
+	}
+	return olen;
+}
diff --git a/net/ceph/auth.c b/net/ceph/auth.c
new file mode 100644
index 000000000..fbeee068e
--- /dev/null
+++ b/net/ceph/auth.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+
+#include <linux/ceph/types.h>
+#include <linux/ceph/decode.h>
+#include <linux/ceph/libceph.h>
+#include <linux/ceph/messenger.h>
+#include "auth_none.h"
+#include "auth_x.h"
+
+
+/*
+ * get protocol handler
+ */
+static u32 supported_protocols[] = {
+	CEPH_AUTH_NONE,
+	CEPH_AUTH_CEPHX
+};
+
+static int ceph_auth_init_protocol(struct ceph_auth_client *ac, int protocol)
+{
+	switch (protocol) {
+	case CEPH_AUTH_NONE:
+		return ceph_auth_none_init(ac);
+	case CEPH_AUTH_CEPHX:
+		return ceph_x_init(ac);
+	default:
+		return -ENOENT;
+	}
+}
+
+/*
+ * setup, teardown.
+ */
+struct ceph_auth_client *ceph_auth_init(const char *name, const struct ceph_crypto_key *key)
+{
+	struct ceph_auth_client *ac;
+	int ret;
+
+	dout("auth_init name '%s'\n", name);
+
+	ret = -ENOMEM;
+	ac = kzalloc(sizeof(*ac), GFP_NOFS);
+	if (!ac)
+		goto out;
+
+	mutex_init(&ac->mutex);
+	ac->negotiating = true;
+	if (name)
+		ac->name = name;
+	else
+		ac->name = CEPH_AUTH_NAME_DEFAULT;
+	dout("auth_init name %s\n", ac->name);
+	ac->key = key;
+	return ac;
+
+out:
+	return ERR_PTR(ret);
+}
+
+void ceph_auth_destroy(struct ceph_auth_client *ac)
+{
+	dout("auth_destroy %p\n", ac);
+	if (ac->ops)
+		ac->ops->destroy(ac);
+	kfree(ac);
+}
+
+/*
+ * Reset occurs when reconnecting to the monitor.
+ */
+void ceph_auth_reset(struct ceph_auth_client *ac)
+{
+	mutex_lock(&ac->mutex);
+	dout("auth_reset %p\n", ac);
+	if (ac->ops && !ac->negotiating)
+		ac->ops->reset(ac);
+	ac->negotiating = true;
+	mutex_unlock(&ac->mutex);
+}
+
+/*
+ * EntityName, not to be confused with entity_name_t
+ */
+int ceph_auth_entity_name_encode(const char *name, void **p, void *end)
+{
+	int len = strlen(name);
+
+	if (*p + 2*sizeof(u32) + len > end)
+		return -ERANGE;
+	ceph_encode_32(p, CEPH_ENTITY_TYPE_CLIENT);
+	ceph_encode_32(p, len);
+	ceph_encode_copy(p, name, len);
+	return 0;
+}
+
+/*
+ * Initiate protocol negotiation with monitor.  Include entity name
+ * and list supported protocols.
+ */
+int ceph_auth_build_hello(struct ceph_auth_client *ac, void *buf, size_t len)
+{
+	struct ceph_mon_request_header *monhdr = buf;
+	void *p = monhdr + 1, *end = buf + len, *lenp;
+	int i, num;
+	int ret;
+
+	mutex_lock(&ac->mutex);
+	dout("auth_build_hello\n");
+	monhdr->have_version = 0;
+	monhdr->session_mon = cpu_to_le16(-1);
+	monhdr->session_mon_tid = 0;
+
+	ceph_encode_32(&p, CEPH_AUTH_UNKNOWN);  /* no protocol, yet */
+
+	lenp = p;
+	p += sizeof(u32);
+
+	ceph_decode_need(&p, end, 1 + sizeof(u32), bad);
+	ceph_encode_8(&p, 1);
+	num = ARRAY_SIZE(supported_protocols);
+	ceph_encode_32(&p, num);
+	ceph_decode_need(&p, end, num * sizeof(u32), bad);
+	for (i = 0; i < num; i++)
+		ceph_encode_32(&p, supported_protocols[i]);
+
+	ret = ceph_auth_entity_name_encode(ac->name, &p, end);
+	if (ret < 0)
+		goto out;
+	ceph_decode_need(&p, end, sizeof(u64), bad);
+	ceph_encode_64(&p, ac->global_id);
+
+	ceph_encode_32(&lenp, p - lenp - sizeof(u32));
+	ret = p - buf;
+out:
+	mutex_unlock(&ac->mutex);
+	return ret;
+
+bad:
+	ret = -ERANGE;
+	goto out;
+}
+
+static int ceph_build_auth_request(struct ceph_auth_client *ac,
+				   void *msg_buf, size_t msg_len)
+{
+	struct ceph_mon_request_header *monhdr = msg_buf;
+	void *p = monhdr + 1;
+	void *end = msg_buf + msg_len;
+	int ret;
+
+	monhdr->have_version = 0;
+	monhdr->session_mon = cpu_to_le16(-1);
+	monhdr->session_mon_tid = 0;
+
+	ceph_encode_32(&p, ac->protocol);
+
+	ret = ac->ops->build_request(ac, p + sizeof(u32), end);
+	if (ret < 0) {
+		pr_err("error %d building auth method %s request\n", ret,
+		       ac->ops->name);
+		goto out;
+	}
+	dout(" built request %d bytes\n", ret);
+	ceph_encode_32(&p, ret);
+	ret = p + ret - msg_buf;
+out:
+	return ret;
+}
+
+/*
+ * Handle auth message from monitor.
+ */
+int ceph_handle_auth_reply(struct ceph_auth_client *ac,
+			   void *buf, size_t len,
+			   void *reply_buf, size_t reply_len)
+{
+	void *p = buf;
+	void *end = buf + len;
+	int protocol;
+	s32 result;
+	u64 global_id;
+	void *payload, *payload_end;
+	int payload_len;
+	char *result_msg;
+	int result_msg_len;
+	int ret = -EINVAL;
+
+	mutex_lock(&ac->mutex);
+	dout("handle_auth_reply %p %p\n", p, end);
+	ceph_decode_need(&p, end, sizeof(u32) * 3 + sizeof(u64), bad);
+	protocol = ceph_decode_32(&p);
+	result = ceph_decode_32(&p);
+	global_id = ceph_decode_64(&p);
+	payload_len = ceph_decode_32(&p);
+	payload = p;
+	p += payload_len;
+	ceph_decode_need(&p, end, sizeof(u32), bad);
+	result_msg_len = ceph_decode_32(&p);
+	result_msg = p;
+	p += result_msg_len;
+	if (p != end)
+		goto bad;
+
+	dout(" result %d '%.*s' gid %llu len %d\n", result, result_msg_len,
+	     result_msg, global_id, payload_len);
+
+	payload_end = payload + payload_len;
+
+	if (global_id && ac->global_id != global_id) {
+		dout(" set global_id %lld -> %lld\n", ac->global_id, global_id);
+		ac->global_id = global_id;
+	}
+
+	if (ac->negotiating) {
+		/* server does not support our protocols? */
+		if (!protocol && result < 0) {
+			ret = result;
+			goto out;
+		}
+		/* set up (new) protocol handler? */
+		if (ac->protocol && ac->protocol != protocol) {
+			ac->ops->destroy(ac);
+			ac->protocol = 0;
+			ac->ops = NULL;
+		}
+		if (ac->protocol != protocol) {
+			ret = ceph_auth_init_protocol(ac, protocol);
+			if (ret) {
+				pr_err("error %d on auth protocol %d init\n",
+				       ret, protocol);
+				goto out;
+			}
+		}
+
+		ac->negotiating = false;
+	}
+
+	ret = ac->ops->handle_reply(ac, result, payload, payload_end);
+	if (ret == -EAGAIN) {
+		ret = ceph_build_auth_request(ac, reply_buf, reply_len);
+	} else if (ret) {
+		pr_err("auth method '%s' error %d\n", ac->ops->name, ret);
+	}
+
+out:
+	mutex_unlock(&ac->mutex);
+	return ret;
+
+bad:
+	pr_err("failed to decode auth msg\n");
+	ret = -EINVAL;
+	goto out;
+}
+
+int ceph_build_auth(struct ceph_auth_client *ac,
+		    void *msg_buf, size_t msg_len)
+{
+	int ret = 0;
+
+	mutex_lock(&ac->mutex);
+	if (ac->ops->should_authenticate(ac))
+		ret = ceph_build_auth_request(ac, msg_buf, msg_len);
+	mutex_unlock(&ac->mutex);
+	return ret;
+}
+
+int ceph_auth_is_authenticated(struct ceph_auth_client *ac)
+{
+	int ret = 0;
+
+	mutex_lock(&ac->mutex);
+	if (ac->ops)
+		ret = ac->ops->is_authenticated(ac);
+	mutex_unlock(&ac->mutex);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_auth_is_authenticated);
+
+int ceph_auth_create_authorizer(struct ceph_auth_client *ac,
+				int peer_type,
+				struct ceph_auth_handshake *auth)
+{
+	int ret = 0;
+
+	mutex_lock(&ac->mutex);
+	if (ac->ops && ac->ops->create_authorizer)
+		ret = ac->ops->create_authorizer(ac, peer_type, auth);
+	mutex_unlock(&ac->mutex);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_auth_create_authorizer);
+
+void ceph_auth_destroy_authorizer(struct ceph_authorizer *a)
+{
+	a->destroy(a);
+}
+EXPORT_SYMBOL(ceph_auth_destroy_authorizer);
+
+int ceph_auth_update_authorizer(struct ceph_auth_client *ac,
+				int peer_type,
+				struct ceph_auth_handshake *a)
+{
+	int ret = 0;
+
+	mutex_lock(&ac->mutex);
+	if (ac->ops && ac->ops->update_authorizer)
+		ret = ac->ops->update_authorizer(ac, peer_type, a);
+	mutex_unlock(&ac->mutex);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_auth_update_authorizer);
+
+int ceph_auth_add_authorizer_challenge(struct ceph_auth_client *ac,
+				       struct ceph_authorizer *a,
+				       void *challenge_buf,
+				       int challenge_buf_len)
+{
+	int ret = 0;
+
+	mutex_lock(&ac->mutex);
+	if (ac->ops && ac->ops->add_authorizer_challenge)
+		ret = ac->ops->add_authorizer_challenge(ac, a, challenge_buf,
+							challenge_buf_len);
+	mutex_unlock(&ac->mutex);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_auth_add_authorizer_challenge);
+
+int ceph_auth_verify_authorizer_reply(struct ceph_auth_client *ac,
+				      struct ceph_authorizer *a)
+{
+	int ret = 0;
+
+	mutex_lock(&ac->mutex);
+	if (ac->ops && ac->ops->verify_authorizer_reply)
+		ret = ac->ops->verify_authorizer_reply(ac, a);
+	mutex_unlock(&ac->mutex);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_auth_verify_authorizer_reply);
+
+void ceph_auth_invalidate_authorizer(struct ceph_auth_client *ac, int peer_type)
+{
+	mutex_lock(&ac->mutex);
+	if (ac->ops && ac->ops->invalidate_authorizer)
+		ac->ops->invalidate_authorizer(ac, peer_type);
+	mutex_unlock(&ac->mutex);
+}
+EXPORT_SYMBOL(ceph_auth_invalidate_authorizer);
diff --git a/net/ceph/auth_none.c b/net/ceph/auth_none.c
new file mode 100644
index 000000000..edb704247
--- /dev/null
+++ b/net/ceph/auth_none.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+
+#include <linux/ceph/decode.h>
+#include <linux/ceph/auth.h>
+
+#include "auth_none.h"
+
+static void reset(struct ceph_auth_client *ac)
+{
+	struct ceph_auth_none_info *xi = ac->private;
+
+	xi->starting = true;
+}
+
+static void destroy(struct ceph_auth_client *ac)
+{
+	kfree(ac->private);
+	ac->private = NULL;
+}
+
+static int is_authenticated(struct ceph_auth_client *ac)
+{
+	struct ceph_auth_none_info *xi = ac->private;
+
+	return !xi->starting;
+}
+
+static int should_authenticate(struct ceph_auth_client *ac)
+{
+	struct ceph_auth_none_info *xi = ac->private;
+
+	return xi->starting;
+}
+
+static int ceph_auth_none_build_authorizer(struct ceph_auth_client *ac,
+					   struct ceph_none_authorizer *au)
+{
+	void *p = au->buf;
+	void *const end = p + sizeof(au->buf);
+	int ret;
+
+	ceph_encode_8_safe(&p, end, 1, e_range);
+	ret = ceph_auth_entity_name_encode(ac->name, &p, end);
+	if (ret < 0)
+		return ret;
+
+	ceph_encode_64_safe(&p, end, ac->global_id, e_range);
+	au->buf_len = p - (void *)au->buf;
+	dout("%s built authorizer len %d\n", __func__, au->buf_len);
+	return 0;
+
+e_range:
+	return -ERANGE;
+}
+
+static int build_request(struct ceph_auth_client *ac, void *buf, void *end)
+{
+	return 0;
+}
+
+/*
+ * the generic auth code decode the global_id, and we carry no actual
+ * authenticate state, so nothing happens here.
+ */
+static int handle_reply(struct ceph_auth_client *ac, int result,
+			void *buf, void *end)
+{
+	struct ceph_auth_none_info *xi = ac->private;
+
+	xi->starting = false;
+	return result;
+}
+
+static void ceph_auth_none_destroy_authorizer(struct ceph_authorizer *a)
+{
+	kfree(a);
+}
+
+/*
+ * build an 'authorizer' with our entity_name and global_id.  it is
+ * identical for all services we connect to.
+ */
+static int ceph_auth_none_create_authorizer(
+	struct ceph_auth_client *ac, int peer_type,
+	struct ceph_auth_handshake *auth)
+{
+	struct ceph_none_authorizer *au;
+	int ret;
+
+	au = kmalloc(sizeof(*au), GFP_NOFS);
+	if (!au)
+		return -ENOMEM;
+
+	au->base.destroy = ceph_auth_none_destroy_authorizer;
+
+	ret = ceph_auth_none_build_authorizer(ac, au);
+	if (ret) {
+		kfree(au);
+		return ret;
+	}
+
+	auth->authorizer = (struct ceph_authorizer *) au;
+	auth->authorizer_buf = au->buf;
+	auth->authorizer_buf_len = au->buf_len;
+	auth->authorizer_reply_buf = au->reply_buf;
+	auth->authorizer_reply_buf_len = sizeof (au->reply_buf);
+
+	return 0;
+}
+
+static const struct ceph_auth_client_ops ceph_auth_none_ops = {
+	.name = "none",
+	.reset = reset,
+	.destroy = destroy,
+	.is_authenticated = is_authenticated,
+	.should_authenticate = should_authenticate,
+	.build_request = build_request,
+	.handle_reply = handle_reply,
+	.create_authorizer = ceph_auth_none_create_authorizer,
+};
+
+int ceph_auth_none_init(struct ceph_auth_client *ac)
+{
+	struct ceph_auth_none_info *xi;
+
+	dout("ceph_auth_none_init %p\n", ac);
+	xi = kzalloc(sizeof(*xi), GFP_NOFS);
+	if (!xi)
+		return -ENOMEM;
+
+	xi->starting = true;
+
+	ac->protocol = CEPH_AUTH_NONE;
+	ac->private = xi;
+	ac->ops = &ceph_auth_none_ops;
+	return 0;
+}
diff --git a/net/ceph/auth_none.h b/net/ceph/auth_none.h
new file mode 100644
index 000000000..4158f0643
--- /dev/null
+++ b/net/ceph/auth_none.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _FS_CEPH_AUTH_NONE_H
+#define _FS_CEPH_AUTH_NONE_H
+
+#include <linux/slab.h>
+#include <linux/ceph/auth.h>
+
+/*
+ * null security mode.
+ *
+ * we use a single static authorizer that simply encodes our entity name
+ * and global id.
+ */
+
+struct ceph_none_authorizer {
+	struct ceph_authorizer base;
+	char buf[128];
+	int buf_len;
+	char reply_buf[0];
+};
+
+struct ceph_auth_none_info {
+	bool starting;
+};
+
+int ceph_auth_none_init(struct ceph_auth_client *ac);
+
+#endif
diff --git a/net/ceph/auth_x.c b/net/ceph/auth_x.c
new file mode 100644
index 000000000..b52732337
--- /dev/null
+++ b/net/ceph/auth_x.c
@@ -0,0 +1,966 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+
+#include <linux/ceph/decode.h>
+#include <linux/ceph/auth.h>
+#include <linux/ceph/ceph_features.h>
+#include <linux/ceph/libceph.h>
+#include <linux/ceph/messenger.h>
+
+#include "crypto.h"
+#include "auth_x.h"
+#include "auth_x_protocol.h"
+
+static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed);
+
+static int ceph_x_is_authenticated(struct ceph_auth_client *ac)
+{
+	struct ceph_x_info *xi = ac->private;
+	int need;
+
+	ceph_x_validate_tickets(ac, &need);
+	dout("ceph_x_is_authenticated want=%d need=%d have=%d\n",
+	     ac->want_keys, need, xi->have_keys);
+	return (ac->want_keys & xi->have_keys) == ac->want_keys;
+}
+
+static int ceph_x_should_authenticate(struct ceph_auth_client *ac)
+{
+	struct ceph_x_info *xi = ac->private;
+	int need;
+
+	ceph_x_validate_tickets(ac, &need);
+	dout("ceph_x_should_authenticate want=%d need=%d have=%d\n",
+	     ac->want_keys, need, xi->have_keys);
+	return need != 0;
+}
+
+static int ceph_x_encrypt_offset(void)
+{
+	return sizeof(u32) + sizeof(struct ceph_x_encrypt_header);
+}
+
+static int ceph_x_encrypt_buflen(int ilen)
+{
+	return ceph_x_encrypt_offset() + ilen + 16;
+}
+
+static int ceph_x_encrypt(struct ceph_crypto_key *secret, void *buf,
+			  int buf_len, int plaintext_len)
+{
+	struct ceph_x_encrypt_header *hdr = buf + sizeof(u32);
+	int ciphertext_len;
+	int ret;
+
+	hdr->struct_v = 1;
+	hdr->magic = cpu_to_le64(CEPHX_ENC_MAGIC);
+
+	ret = ceph_crypt(secret, true, buf + sizeof(u32), buf_len - sizeof(u32),
+			 plaintext_len + sizeof(struct ceph_x_encrypt_header),
+			 &ciphertext_len);
+	if (ret)
+		return ret;
+
+	ceph_encode_32(&buf, ciphertext_len);
+	return sizeof(u32) + ciphertext_len;
+}
+
+static int __ceph_x_decrypt(struct ceph_crypto_key *secret, void *p,
+			    int ciphertext_len)
+{
+	struct ceph_x_encrypt_header *hdr = p;
+	int plaintext_len;
+	int ret;
+
+	ret = ceph_crypt(secret, false, p, ciphertext_len, ciphertext_len,
+			 &plaintext_len);
+	if (ret)
+		return ret;
+
+	if (le64_to_cpu(hdr->magic) != CEPHX_ENC_MAGIC) {
+		pr_err("%s bad magic\n", __func__);
+		return -EINVAL;
+	}
+
+	return plaintext_len - sizeof(*hdr);
+}
+
+static int ceph_x_decrypt(struct ceph_crypto_key *secret, void **p, void *end)
+{
+	int ciphertext_len;
+	int ret;
+
+	ceph_decode_32_safe(p, end, ciphertext_len, e_inval);
+	ceph_decode_need(p, end, ciphertext_len, e_inval);
+
+	ret = __ceph_x_decrypt(secret, *p, ciphertext_len);
+	if (ret < 0)
+		return ret;
+
+	*p += ciphertext_len;
+	return ret;
+
+e_inval:
+	return -EINVAL;
+}
+
+/*
+ * get existing (or insert new) ticket handler
+ */
+static struct ceph_x_ticket_handler *
+get_ticket_handler(struct ceph_auth_client *ac, int service)
+{
+	struct ceph_x_ticket_handler *th;
+	struct ceph_x_info *xi = ac->private;
+	struct rb_node *parent = NULL, **p = &xi->ticket_handlers.rb_node;
+
+	while (*p) {
+		parent = *p;
+		th = rb_entry(parent, struct ceph_x_ticket_handler, node);
+		if (service < th->service)
+			p = &(*p)->rb_left;
+		else if (service > th->service)
+			p = &(*p)->rb_right;
+		else
+			return th;
+	}
+
+	/* add it */
+	th = kzalloc(sizeof(*th), GFP_NOFS);
+	if (!th)
+		return ERR_PTR(-ENOMEM);
+	th->service = service;
+	rb_link_node(&th->node, parent, p);
+	rb_insert_color(&th->node, &xi->ticket_handlers);
+	return th;
+}
+
+static void remove_ticket_handler(struct ceph_auth_client *ac,
+				  struct ceph_x_ticket_handler *th)
+{
+	struct ceph_x_info *xi = ac->private;
+
+	dout("remove_ticket_handler %p %d\n", th, th->service);
+	rb_erase(&th->node, &xi->ticket_handlers);
+	ceph_crypto_key_destroy(&th->session_key);
+	if (th->ticket_blob)
+		ceph_buffer_put(th->ticket_blob);
+	kfree(th);
+}
+
+static int process_one_ticket(struct ceph_auth_client *ac,
+			      struct ceph_crypto_key *secret,
+			      void **p, void *end)
+{
+	struct ceph_x_info *xi = ac->private;
+	int type;
+	u8 tkt_struct_v, blob_struct_v;
+	struct ceph_x_ticket_handler *th;
+	void *dp, *dend;
+	int dlen;
+	char is_enc;
+	struct timespec64 validity;
+	void *tp, *tpend;
+	void **ptp;
+	struct ceph_crypto_key new_session_key = { 0 };
+	struct ceph_buffer *new_ticket_blob;
+	time64_t new_expires, new_renew_after;
+	u64 new_secret_id;
+	int ret;
+
+	ceph_decode_need(p, end, sizeof(u32) + 1, bad);
+
+	type = ceph_decode_32(p);
+	dout(" ticket type %d %s\n", type, ceph_entity_type_name(type));
+
+	tkt_struct_v = ceph_decode_8(p);
+	if (tkt_struct_v != 1)
+		goto bad;
+
+	th = get_ticket_handler(ac, type);
+	if (IS_ERR(th)) {
+		ret = PTR_ERR(th);
+		goto out;
+	}
+
+	/* blob for me */
+	dp = *p + ceph_x_encrypt_offset();
+	ret = ceph_x_decrypt(secret, p, end);
+	if (ret < 0)
+		goto out;
+	dout(" decrypted %d bytes\n", ret);
+	dend = dp + ret;
+
+	tkt_struct_v = ceph_decode_8(&dp);
+	if (tkt_struct_v != 1)
+		goto bad;
+
+	ret = ceph_crypto_key_decode(&new_session_key, &dp, dend);
+	if (ret)
+		goto out;
+
+	ceph_decode_timespec64(&validity, dp);
+	dp += sizeof(struct ceph_timespec);
+	new_expires = ktime_get_real_seconds() + validity.tv_sec;
+	new_renew_after = new_expires - (validity.tv_sec / 4);
+	dout(" expires=%llu renew_after=%llu\n", new_expires,
+	     new_renew_after);
+
+	/* ticket blob for service */
+	ceph_decode_8_safe(p, end, is_enc, bad);
+	if (is_enc) {
+		/* encrypted */
+		tp = *p + ceph_x_encrypt_offset();
+		ret = ceph_x_decrypt(&th->session_key, p, end);
+		if (ret < 0)
+			goto out;
+		dout(" encrypted ticket, decrypted %d bytes\n", ret);
+		ptp = &tp;
+		tpend = tp + ret;
+	} else {
+		/* unencrypted */
+		ptp = p;
+		tpend = end;
+	}
+	ceph_decode_32_safe(ptp, tpend, dlen, bad);
+	dout(" ticket blob is %d bytes\n", dlen);
+	ceph_decode_need(ptp, tpend, 1 + sizeof(u64), bad);
+	blob_struct_v = ceph_decode_8(ptp);
+	if (blob_struct_v != 1)
+		goto bad;
+
+	new_secret_id = ceph_decode_64(ptp);
+	ret = ceph_decode_buffer(&new_ticket_blob, ptp, tpend);
+	if (ret)
+		goto out;
+
+	/* all is well, update our ticket */
+	ceph_crypto_key_destroy(&th->session_key);
+	if (th->ticket_blob)
+		ceph_buffer_put(th->ticket_blob);
+	th->session_key = new_session_key;
+	th->ticket_blob = new_ticket_blob;
+	th->secret_id = new_secret_id;
+	th->expires = new_expires;
+	th->renew_after = new_renew_after;
+	th->have_key = true;
+	dout(" got ticket service %d (%s) secret_id %lld len %d\n",
+	     type, ceph_entity_type_name(type), th->secret_id,
+	     (int)th->ticket_blob->vec.iov_len);
+	xi->have_keys |= th->service;
+	return 0;
+
+bad:
+	ret = -EINVAL;
+out:
+	ceph_crypto_key_destroy(&new_session_key);
+	return ret;
+}
+
+static int ceph_x_proc_ticket_reply(struct ceph_auth_client *ac,
+				    struct ceph_crypto_key *secret,
+				    void *buf, void *end)
+{
+	void *p = buf;
+	u8 reply_struct_v;
+	u32 num;
+	int ret;
+
+	ceph_decode_8_safe(&p, end, reply_struct_v, bad);
+	if (reply_struct_v != 1)
+		return -EINVAL;
+
+	ceph_decode_32_safe(&p, end, num, bad);
+	dout("%d tickets\n", num);
+
+	while (num--) {
+		ret = process_one_ticket(ac, secret, &p, end);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+
+bad:
+	return -EINVAL;
+}
+
+/*
+ * Encode and encrypt the second part (ceph_x_authorize_b) of the
+ * authorizer.  The first part (ceph_x_authorize_a) should already be
+ * encoded.
+ */
+static int encrypt_authorizer(struct ceph_x_authorizer *au,
+			      u64 *server_challenge)
+{
+	struct ceph_x_authorize_a *msg_a;
+	struct ceph_x_authorize_b *msg_b;
+	void *p, *end;
+	int ret;
+
+	msg_a = au->buf->vec.iov_base;
+	WARN_ON(msg_a->ticket_blob.secret_id != cpu_to_le64(au->secret_id));
+	p = (void *)(msg_a + 1) + le32_to_cpu(msg_a->ticket_blob.blob_len);
+	end = au->buf->vec.iov_base + au->buf->vec.iov_len;
+
+	msg_b = p + ceph_x_encrypt_offset();
+	msg_b->struct_v = 2;
+	msg_b->nonce = cpu_to_le64(au->nonce);
+	if (server_challenge) {
+		msg_b->have_challenge = 1;
+		msg_b->server_challenge_plus_one =
+		    cpu_to_le64(*server_challenge + 1);
+	} else {
+		msg_b->have_challenge = 0;
+		msg_b->server_challenge_plus_one = 0;
+	}
+
+	ret = ceph_x_encrypt(&au->session_key, p, end - p, sizeof(*msg_b));
+	if (ret < 0)
+		return ret;
+
+	p += ret;
+	if (server_challenge) {
+		WARN_ON(p != end);
+	} else {
+		WARN_ON(p > end);
+		au->buf->vec.iov_len = p - au->buf->vec.iov_base;
+	}
+
+	return 0;
+}
+
+static void ceph_x_authorizer_cleanup(struct ceph_x_authorizer *au)
+{
+	ceph_crypto_key_destroy(&au->session_key);
+	if (au->buf) {
+		ceph_buffer_put(au->buf);
+		au->buf = NULL;
+	}
+}
+
+static int ceph_x_build_authorizer(struct ceph_auth_client *ac,
+				   struct ceph_x_ticket_handler *th,
+				   struct ceph_x_authorizer *au)
+{
+	int maxlen;
+	struct ceph_x_authorize_a *msg_a;
+	struct ceph_x_authorize_b *msg_b;
+	int ret;
+	int ticket_blob_len =
+		(th->ticket_blob ? th->ticket_blob->vec.iov_len : 0);
+
+	dout("build_authorizer for %s %p\n",
+	     ceph_entity_type_name(th->service), au);
+
+	ceph_crypto_key_destroy(&au->session_key);
+	ret = ceph_crypto_key_clone(&au->session_key, &th->session_key);
+	if (ret)
+		goto out_au;
+
+	maxlen = sizeof(*msg_a) + ticket_blob_len +
+		ceph_x_encrypt_buflen(sizeof(*msg_b));
+	dout("  need len %d\n", maxlen);
+	if (au->buf && au->buf->alloc_len < maxlen) {
+		ceph_buffer_put(au->buf);
+		au->buf = NULL;
+	}
+	if (!au->buf) {
+		au->buf = ceph_buffer_new(maxlen, GFP_NOFS);
+		if (!au->buf) {
+			ret = -ENOMEM;
+			goto out_au;
+		}
+	}
+	au->service = th->service;
+	au->secret_id = th->secret_id;
+
+	msg_a = au->buf->vec.iov_base;
+	msg_a->struct_v = 1;
+	msg_a->global_id = cpu_to_le64(ac->global_id);
+	msg_a->service_id = cpu_to_le32(th->service);
+	msg_a->ticket_blob.struct_v = 1;
+	msg_a->ticket_blob.secret_id = cpu_to_le64(th->secret_id);
+	msg_a->ticket_blob.blob_len = cpu_to_le32(ticket_blob_len);
+	if (ticket_blob_len) {
+		memcpy(msg_a->ticket_blob.blob, th->ticket_blob->vec.iov_base,
+		       th->ticket_blob->vec.iov_len);
+	}
+	dout(" th %p secret_id %lld %lld\n", th, th->secret_id,
+	     le64_to_cpu(msg_a->ticket_blob.secret_id));
+
+	get_random_bytes(&au->nonce, sizeof(au->nonce));
+	ret = encrypt_authorizer(au, NULL);
+	if (ret) {
+		pr_err("failed to encrypt authorizer: %d", ret);
+		goto out_au;
+	}
+
+	dout(" built authorizer nonce %llx len %d\n", au->nonce,
+	     (int)au->buf->vec.iov_len);
+	return 0;
+
+out_au:
+	ceph_x_authorizer_cleanup(au);
+	return ret;
+}
+
+static int ceph_x_encode_ticket(struct ceph_x_ticket_handler *th,
+				void **p, void *end)
+{
+	ceph_decode_need(p, end, 1 + sizeof(u64), bad);
+	ceph_encode_8(p, 1);
+	ceph_encode_64(p, th->secret_id);
+	if (th->ticket_blob) {
+		const char *buf = th->ticket_blob->vec.iov_base;
+		u32 len = th->ticket_blob->vec.iov_len;
+
+		ceph_encode_32_safe(p, end, len, bad);
+		ceph_encode_copy_safe(p, end, buf, len, bad);
+	} else {
+		ceph_encode_32_safe(p, end, 0, bad);
+	}
+
+	return 0;
+bad:
+	return -ERANGE;
+}
+
+static bool need_key(struct ceph_x_ticket_handler *th)
+{
+	if (!th->have_key)
+		return true;
+
+	return ktime_get_real_seconds() >= th->renew_after;
+}
+
+static bool have_key(struct ceph_x_ticket_handler *th)
+{
+	if (th->have_key) {
+		if (ktime_get_real_seconds() >= th->expires)
+			th->have_key = false;
+	}
+
+	return th->have_key;
+}
+
+static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed)
+{
+	int want = ac->want_keys;
+	struct ceph_x_info *xi = ac->private;
+	int service;
+
+	*pneed = ac->want_keys & ~(xi->have_keys);
+
+	for (service = 1; service <= want; service <<= 1) {
+		struct ceph_x_ticket_handler *th;
+
+		if (!(ac->want_keys & service))
+			continue;
+
+		if (*pneed & service)
+			continue;
+
+		th = get_ticket_handler(ac, service);
+		if (IS_ERR(th)) {
+			*pneed |= service;
+			continue;
+		}
+
+		if (need_key(th))
+			*pneed |= service;
+		if (!have_key(th))
+			xi->have_keys &= ~service;
+	}
+}
+
+static int ceph_x_build_request(struct ceph_auth_client *ac,
+				void *buf, void *end)
+{
+	struct ceph_x_info *xi = ac->private;
+	int need;
+	struct ceph_x_request_header *head = buf;
+	int ret;
+	struct ceph_x_ticket_handler *th =
+		get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
+
+	if (IS_ERR(th))
+		return PTR_ERR(th);
+
+	ceph_x_validate_tickets(ac, &need);
+
+	dout("build_request want %x have %x need %x\n",
+	     ac->want_keys, xi->have_keys, need);
+
+	if (need & CEPH_ENTITY_TYPE_AUTH) {
+		struct ceph_x_authenticate *auth = (void *)(head + 1);
+		void *p = auth + 1;
+		void *enc_buf = xi->auth_authorizer.enc_buf;
+		struct ceph_x_challenge_blob *blob = enc_buf +
+							ceph_x_encrypt_offset();
+		u64 *u;
+
+		if (p > end)
+			return -ERANGE;
+
+		dout(" get_auth_session_key\n");
+		head->op = cpu_to_le16(CEPHX_GET_AUTH_SESSION_KEY);
+
+		/* encrypt and hash */
+		get_random_bytes(&auth->client_challenge, sizeof(u64));
+		blob->client_challenge = auth->client_challenge;
+		blob->server_challenge = cpu_to_le64(xi->server_challenge);
+		ret = ceph_x_encrypt(&xi->secret, enc_buf, CEPHX_AU_ENC_BUF_LEN,
+				     sizeof(*blob));
+		if (ret < 0)
+			return ret;
+
+		auth->struct_v = 1;
+		auth->key = 0;
+		for (u = (u64 *)enc_buf; u + 1 <= (u64 *)(enc_buf + ret); u++)
+			auth->key ^= *(__le64 *)u;
+		dout(" server_challenge %llx client_challenge %llx key %llx\n",
+		     xi->server_challenge, le64_to_cpu(auth->client_challenge),
+		     le64_to_cpu(auth->key));
+
+		/* now encode the old ticket if exists */
+		ret = ceph_x_encode_ticket(th, &p, end);
+		if (ret < 0)
+			return ret;
+
+		return p - buf;
+	}
+
+	if (need) {
+		void *p = head + 1;
+		struct ceph_x_service_ticket_request *req;
+
+		if (p > end)
+			return -ERANGE;
+		head->op = cpu_to_le16(CEPHX_GET_PRINCIPAL_SESSION_KEY);
+
+		ret = ceph_x_build_authorizer(ac, th, &xi->auth_authorizer);
+		if (ret)
+			return ret;
+		ceph_encode_copy(&p, xi->auth_authorizer.buf->vec.iov_base,
+				 xi->auth_authorizer.buf->vec.iov_len);
+
+		req = p;
+		req->keys = cpu_to_le32(need);
+		p += sizeof(*req);
+		return p - buf;
+	}
+
+	return 0;
+}
+
+static int ceph_x_handle_reply(struct ceph_auth_client *ac, int result,
+			       void *buf, void *end)
+{
+	struct ceph_x_info *xi = ac->private;
+	struct ceph_x_reply_header *head = buf;
+	struct ceph_x_ticket_handler *th;
+	int len = end - buf;
+	int op;
+	int ret;
+
+	if (result)
+		return result;  /* XXX hmm? */
+
+	if (xi->starting) {
+		/* it's a hello */
+		struct ceph_x_server_challenge *sc = buf;
+
+		if (len != sizeof(*sc))
+			return -EINVAL;
+		xi->server_challenge = le64_to_cpu(sc->server_challenge);
+		dout("handle_reply got server challenge %llx\n",
+		     xi->server_challenge);
+		xi->starting = false;
+		xi->have_keys &= ~CEPH_ENTITY_TYPE_AUTH;
+		return -EAGAIN;
+	}
+
+	op = le16_to_cpu(head->op);
+	result = le32_to_cpu(head->result);
+	dout("handle_reply op %d result %d\n", op, result);
+	switch (op) {
+	case CEPHX_GET_AUTH_SESSION_KEY:
+		/* verify auth key */
+		ret = ceph_x_proc_ticket_reply(ac, &xi->secret,
+					       buf + sizeof(*head), end);
+		break;
+
+	case CEPHX_GET_PRINCIPAL_SESSION_KEY:
+		th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
+		if (IS_ERR(th))
+			return PTR_ERR(th);
+		ret = ceph_x_proc_ticket_reply(ac, &th->session_key,
+					       buf + sizeof(*head), end);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+	if (ret)
+		return ret;
+	if (ac->want_keys == xi->have_keys)
+		return 0;
+	return -EAGAIN;
+}
+
+static void ceph_x_destroy_authorizer(struct ceph_authorizer *a)
+{
+	struct ceph_x_authorizer *au = (void *)a;
+
+	ceph_x_authorizer_cleanup(au);
+	kfree(au);
+}
+
+static int ceph_x_create_authorizer(
+	struct ceph_auth_client *ac, int peer_type,
+	struct ceph_auth_handshake *auth)
+{
+	struct ceph_x_authorizer *au;
+	struct ceph_x_ticket_handler *th;
+	int ret;
+
+	th = get_ticket_handler(ac, peer_type);
+	if (IS_ERR(th))
+		return PTR_ERR(th);
+
+	au = kzalloc(sizeof(*au), GFP_NOFS);
+	if (!au)
+		return -ENOMEM;
+
+	au->base.destroy = ceph_x_destroy_authorizer;
+
+	ret = ceph_x_build_authorizer(ac, th, au);
+	if (ret) {
+		kfree(au);
+		return ret;
+	}
+
+	auth->authorizer = (struct ceph_authorizer *) au;
+	auth->authorizer_buf = au->buf->vec.iov_base;
+	auth->authorizer_buf_len = au->buf->vec.iov_len;
+	auth->authorizer_reply_buf = au->enc_buf;
+	auth->authorizer_reply_buf_len = CEPHX_AU_ENC_BUF_LEN;
+	auth->sign_message = ac->ops->sign_message;
+	auth->check_message_signature = ac->ops->check_message_signature;
+
+	return 0;
+}
+
+static int ceph_x_update_authorizer(
+	struct ceph_auth_client *ac, int peer_type,
+	struct ceph_auth_handshake *auth)
+{
+	struct ceph_x_authorizer *au;
+	struct ceph_x_ticket_handler *th;
+
+	th = get_ticket_handler(ac, peer_type);
+	if (IS_ERR(th))
+		return PTR_ERR(th);
+
+	au = (struct ceph_x_authorizer *)auth->authorizer;
+	if (au->secret_id < th->secret_id) {
+		dout("ceph_x_update_authorizer service %u secret %llu < %llu\n",
+		     au->service, au->secret_id, th->secret_id);
+		return ceph_x_build_authorizer(ac, th, au);
+	}
+	return 0;
+}
+
+static int decrypt_authorize_challenge(struct ceph_x_authorizer *au,
+				       void *challenge_buf,
+				       int challenge_buf_len,
+				       u64 *server_challenge)
+{
+	struct ceph_x_authorize_challenge *ch =
+	    challenge_buf + sizeof(struct ceph_x_encrypt_header);
+	int ret;
+
+	/* no leading len */
+	ret = __ceph_x_decrypt(&au->session_key, challenge_buf,
+			       challenge_buf_len);
+	if (ret < 0)
+		return ret;
+	if (ret < sizeof(*ch)) {
+		pr_err("bad size %d for ceph_x_authorize_challenge\n", ret);
+		return -EINVAL;
+	}
+
+	*server_challenge = le64_to_cpu(ch->server_challenge);
+	return 0;
+}
+
+static int ceph_x_add_authorizer_challenge(struct ceph_auth_client *ac,
+					   struct ceph_authorizer *a,
+					   void *challenge_buf,
+					   int challenge_buf_len)
+{
+	struct ceph_x_authorizer *au = (void *)a;
+	u64 server_challenge;
+	int ret;
+
+	ret = decrypt_authorize_challenge(au, challenge_buf, challenge_buf_len,
+					  &server_challenge);
+	if (ret) {
+		pr_err("failed to decrypt authorize challenge: %d", ret);
+		return ret;
+	}
+
+	ret = encrypt_authorizer(au, &server_challenge);
+	if (ret) {
+		pr_err("failed to encrypt authorizer w/ challenge: %d", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ceph_x_verify_authorizer_reply(struct ceph_auth_client *ac,
+					  struct ceph_authorizer *a)
+{
+	struct ceph_x_authorizer *au = (void *)a;
+	void *p = au->enc_buf;
+	struct ceph_x_authorize_reply *reply = p + ceph_x_encrypt_offset();
+	int ret;
+
+	ret = ceph_x_decrypt(&au->session_key, &p, p + CEPHX_AU_ENC_BUF_LEN);
+	if (ret < 0)
+		return ret;
+	if (ret < sizeof(*reply)) {
+		pr_err("bad size %d for ceph_x_authorize_reply\n", ret);
+		return -EINVAL;
+	}
+
+	if (au->nonce + 1 != le64_to_cpu(reply->nonce_plus_one))
+		ret = -EPERM;
+	else
+		ret = 0;
+	dout("verify_authorizer_reply nonce %llx got %llx ret %d\n",
+	     au->nonce, le64_to_cpu(reply->nonce_plus_one), ret);
+	return ret;
+}
+
+static void ceph_x_reset(struct ceph_auth_client *ac)
+{
+	struct ceph_x_info *xi = ac->private;
+
+	dout("reset\n");
+	xi->starting = true;
+	xi->server_challenge = 0;
+}
+
+static void ceph_x_destroy(struct ceph_auth_client *ac)
+{
+	struct ceph_x_info *xi = ac->private;
+	struct rb_node *p;
+
+	dout("ceph_x_destroy %p\n", ac);
+	ceph_crypto_key_destroy(&xi->secret);
+
+	while ((p = rb_first(&xi->ticket_handlers)) != NULL) {
+		struct ceph_x_ticket_handler *th =
+			rb_entry(p, struct ceph_x_ticket_handler, node);
+		remove_ticket_handler(ac, th);
+	}
+
+	ceph_x_authorizer_cleanup(&xi->auth_authorizer);
+
+	kfree(ac->private);
+	ac->private = NULL;
+}
+
+static void invalidate_ticket(struct ceph_auth_client *ac, int peer_type)
+{
+	struct ceph_x_ticket_handler *th;
+
+	th = get_ticket_handler(ac, peer_type);
+	if (!IS_ERR(th))
+		th->have_key = false;
+}
+
+static void ceph_x_invalidate_authorizer(struct ceph_auth_client *ac,
+					 int peer_type)
+{
+	/*
+	 * We are to invalidate a service ticket in the hopes of
+	 * getting a new, hopefully more valid, one.  But, we won't get
+	 * it unless our AUTH ticket is good, so invalidate AUTH ticket
+	 * as well, just in case.
+	 */
+	invalidate_ticket(ac, peer_type);
+	invalidate_ticket(ac, CEPH_ENTITY_TYPE_AUTH);
+}
+
+static int calc_signature(struct ceph_x_authorizer *au, struct ceph_msg *msg,
+			  __le64 *psig)
+{
+	void *enc_buf = au->enc_buf;
+	int ret;
+
+	if (!CEPH_HAVE_FEATURE(msg->con->peer_features, CEPHX_V2)) {
+		struct {
+			__le32 len;
+			__le32 header_crc;
+			__le32 front_crc;
+			__le32 middle_crc;
+			__le32 data_crc;
+		} __packed *sigblock = enc_buf + ceph_x_encrypt_offset();
+
+		sigblock->len = cpu_to_le32(4*sizeof(u32));
+		sigblock->header_crc = msg->hdr.crc;
+		sigblock->front_crc = msg->footer.front_crc;
+		sigblock->middle_crc = msg->footer.middle_crc;
+		sigblock->data_crc =  msg->footer.data_crc;
+
+		ret = ceph_x_encrypt(&au->session_key, enc_buf,
+				     CEPHX_AU_ENC_BUF_LEN, sizeof(*sigblock));
+		if (ret < 0)
+			return ret;
+
+		*psig = *(__le64 *)(enc_buf + sizeof(u32));
+	} else {
+		struct {
+			__le32 header_crc;
+			__le32 front_crc;
+			__le32 front_len;
+			__le32 middle_crc;
+			__le32 middle_len;
+			__le32 data_crc;
+			__le32 data_len;
+			__le32 seq_lower_word;
+		} __packed *sigblock = enc_buf;
+		struct {
+			__le64 a, b, c, d;
+		} __packed *penc = enc_buf;
+		int ciphertext_len;
+
+		sigblock->header_crc = msg->hdr.crc;
+		sigblock->front_crc = msg->footer.front_crc;
+		sigblock->front_len = msg->hdr.front_len;
+		sigblock->middle_crc = msg->footer.middle_crc;
+		sigblock->middle_len = msg->hdr.middle_len;
+		sigblock->data_crc =  msg->footer.data_crc;
+		sigblock->data_len = msg->hdr.data_len;
+		sigblock->seq_lower_word = *(__le32 *)&msg->hdr.seq;
+
+		/* no leading len, no ceph_x_encrypt_header */
+		ret = ceph_crypt(&au->session_key, true, enc_buf,
+				 CEPHX_AU_ENC_BUF_LEN, sizeof(*sigblock),
+				 &ciphertext_len);
+		if (ret)
+			return ret;
+
+		*psig = penc->a ^ penc->b ^ penc->c ^ penc->d;
+	}
+
+	return 0;
+}
+
+static int ceph_x_sign_message(struct ceph_auth_handshake *auth,
+			       struct ceph_msg *msg)
+{
+	__le64 sig;
+	int ret;
+
+	if (ceph_test_opt(from_msgr(msg->con->msgr), NOMSGSIGN))
+		return 0;
+
+	ret = calc_signature((struct ceph_x_authorizer *)auth->authorizer,
+			     msg, &sig);
+	if (ret)
+		return ret;
+
+	msg->footer.sig = sig;
+	msg->footer.flags |= CEPH_MSG_FOOTER_SIGNED;
+	return 0;
+}
+
+static int ceph_x_check_message_signature(struct ceph_auth_handshake *auth,
+					  struct ceph_msg *msg)
+{
+	__le64 sig_check;
+	int ret;
+
+	if (ceph_test_opt(from_msgr(msg->con->msgr), NOMSGSIGN))
+		return 0;
+
+	ret = calc_signature((struct ceph_x_authorizer *)auth->authorizer,
+			     msg, &sig_check);
+	if (ret)
+		return ret;
+	if (sig_check == msg->footer.sig)
+		return 0;
+	if (msg->footer.flags & CEPH_MSG_FOOTER_SIGNED)
+		dout("ceph_x_check_message_signature %p has signature %llx "
+		     "expect %llx\n", msg, msg->footer.sig, sig_check);
+	else
+		dout("ceph_x_check_message_signature %p sender did not set "
+		     "CEPH_MSG_FOOTER_SIGNED\n", msg);
+	return -EBADMSG;
+}
+
+static const struct ceph_auth_client_ops ceph_x_ops = {
+	.name = "x",
+	.is_authenticated = ceph_x_is_authenticated,
+	.should_authenticate = ceph_x_should_authenticate,
+	.build_request = ceph_x_build_request,
+	.handle_reply = ceph_x_handle_reply,
+	.create_authorizer = ceph_x_create_authorizer,
+	.update_authorizer = ceph_x_update_authorizer,
+	.add_authorizer_challenge = ceph_x_add_authorizer_challenge,
+	.verify_authorizer_reply = ceph_x_verify_authorizer_reply,
+	.invalidate_authorizer = ceph_x_invalidate_authorizer,
+	.reset =  ceph_x_reset,
+	.destroy = ceph_x_destroy,
+	.sign_message = ceph_x_sign_message,
+	.check_message_signature = ceph_x_check_message_signature,
+};
+
+
+int ceph_x_init(struct ceph_auth_client *ac)
+{
+	struct ceph_x_info *xi;
+	int ret;
+
+	dout("ceph_x_init %p\n", ac);
+	ret = -ENOMEM;
+	xi = kzalloc(sizeof(*xi), GFP_NOFS);
+	if (!xi)
+		goto out;
+
+	ret = -EINVAL;
+	if (!ac->key) {
+		pr_err("no secret set (for auth_x protocol)\n");
+		goto out_nomem;
+	}
+
+	ret = ceph_crypto_key_clone(&xi->secret, ac->key);
+	if (ret < 0) {
+		pr_err("cannot clone key: %d\n", ret);
+		goto out_nomem;
+	}
+
+	xi->starting = true;
+	xi->ticket_handlers = RB_ROOT;
+
+	ac->protocol = CEPH_AUTH_CEPHX;
+	ac->private = xi;
+	ac->ops = &ceph_x_ops;
+	return 0;
+
+out_nomem:
+	kfree(xi);
+out:
+	return ret;
+}
diff --git a/net/ceph/auth_x.h b/net/ceph/auth_x.h
new file mode 100644
index 000000000..c03735f96
--- /dev/null
+++ b/net/ceph/auth_x.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _FS_CEPH_AUTH_X_H
+#define _FS_CEPH_AUTH_X_H
+
+#include <linux/rbtree.h>
+
+#include <linux/ceph/auth.h>
+
+#include "crypto.h"
+#include "auth_x_protocol.h"
+
+/*
+ * Handle ticket for a single service.
+ */
+struct ceph_x_ticket_handler {
+	struct rb_node node;
+	unsigned int service;
+
+	struct ceph_crypto_key session_key;
+	bool have_key;
+
+	u64 secret_id;
+	struct ceph_buffer *ticket_blob;
+
+	time64_t renew_after, expires;
+};
+
+#define CEPHX_AU_ENC_BUF_LEN	128  /* big enough for encrypted blob */
+
+struct ceph_x_authorizer {
+	struct ceph_authorizer base;
+	struct ceph_crypto_key session_key;
+	struct ceph_buffer *buf;
+	unsigned int service;
+	u64 nonce;
+	u64 secret_id;
+	char enc_buf[CEPHX_AU_ENC_BUF_LEN] __aligned(8);
+};
+
+struct ceph_x_info {
+	struct ceph_crypto_key secret;
+
+	bool starting;
+	u64 server_challenge;
+
+	unsigned int have_keys;
+	struct rb_root ticket_handlers;
+
+	struct ceph_x_authorizer auth_authorizer;
+};
+
+int ceph_x_init(struct ceph_auth_client *ac);
+
+#endif
diff --git a/net/ceph/auth_x_protocol.h b/net/ceph/auth_x_protocol.h
new file mode 100644
index 000000000..24b0b7456
--- /dev/null
+++ b/net/ceph/auth_x_protocol.h
@@ -0,0 +1,98 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __FS_CEPH_AUTH_X_PROTOCOL
+#define __FS_CEPH_AUTH_X_PROTOCOL
+
+#define CEPHX_GET_AUTH_SESSION_KEY      0x0100
+#define CEPHX_GET_PRINCIPAL_SESSION_KEY 0x0200
+#define CEPHX_GET_ROTATING_KEY          0x0400
+
+/* common bits */
+struct ceph_x_ticket_blob {
+	__u8 struct_v;
+	__le64 secret_id;
+	__le32 blob_len;
+	char blob[];
+} __attribute__ ((packed));
+
+
+/* common request/reply headers */
+struct ceph_x_request_header {
+	__le16 op;
+} __attribute__ ((packed));
+
+struct ceph_x_reply_header {
+	__le16 op;
+	__le32 result;
+} __attribute__ ((packed));
+
+
+/* authenticate handshake */
+
+/* initial hello (no reply header) */
+struct ceph_x_server_challenge {
+	__u8 struct_v;
+	__le64 server_challenge;
+} __attribute__ ((packed));
+
+struct ceph_x_authenticate {
+	__u8 struct_v;
+	__le64 client_challenge;
+	__le64 key;
+	/* ticket blob */
+} __attribute__ ((packed));
+
+struct ceph_x_service_ticket_request {
+	__u8 struct_v;
+	__le32 keys;
+} __attribute__ ((packed));
+
+struct ceph_x_challenge_blob {
+	__le64 server_challenge;
+	__le64 client_challenge;
+} __attribute__ ((packed));
+
+
+
+/* authorize handshake */
+
+/*
+ * The authorizer consists of two pieces:
+ *  a - service id, ticket blob
+ *  b - encrypted with session key
+ */
+struct ceph_x_authorize_a {
+	__u8 struct_v;
+	__le64 global_id;
+	__le32 service_id;
+	struct ceph_x_ticket_blob ticket_blob;
+} __attribute__ ((packed));
+
+struct ceph_x_authorize_b {
+	__u8 struct_v;
+	__le64 nonce;
+	__u8 have_challenge;
+	__le64 server_challenge_plus_one;
+} __attribute__ ((packed));
+
+struct ceph_x_authorize_challenge {
+	__u8 struct_v;
+	__le64 server_challenge;
+} __attribute__ ((packed));
+
+struct ceph_x_authorize_reply {
+	__u8 struct_v;
+	__le64 nonce_plus_one;
+} __attribute__ ((packed));
+
+
+/*
+ * encyption bundle
+ */
+#define CEPHX_ENC_MAGIC 0xff009cad8826aa55ull
+
+struct ceph_x_encrypt_header {
+	__u8 struct_v;
+	__le64 magic;
+} __attribute__ ((packed));
+
+#endif
diff --git a/net/ceph/buffer.c b/net/ceph/buffer.c
new file mode 100644
index 000000000..5622763ad
--- /dev/null
+++ b/net/ceph/buffer.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <linux/ceph/buffer.h>
+#include <linux/ceph/decode.h>
+#include <linux/ceph/libceph.h> /* for ceph_kvmalloc */
+
+struct ceph_buffer *ceph_buffer_new(size_t len, gfp_t gfp)
+{
+	struct ceph_buffer *b;
+
+	b = kmalloc(sizeof(*b), gfp);
+	if (!b)
+		return NULL;
+
+	b->vec.iov_base = ceph_kvmalloc(len, gfp);
+	if (!b->vec.iov_base) {
+		kfree(b);
+		return NULL;
+	}
+
+	kref_init(&b->kref);
+	b->alloc_len = len;
+	b->vec.iov_len = len;
+	dout("buffer_new %p\n", b);
+	return b;
+}
+EXPORT_SYMBOL(ceph_buffer_new);
+
+void ceph_buffer_release(struct kref *kref)
+{
+	struct ceph_buffer *b = container_of(kref, struct ceph_buffer, kref);
+
+	dout("buffer_release %p\n", b);
+	kvfree(b->vec.iov_base);
+	kfree(b);
+}
+EXPORT_SYMBOL(ceph_buffer_release);
+
+int ceph_decode_buffer(struct ceph_buffer **b, void **p, void *end)
+{
+	size_t len;
+
+	ceph_decode_need(p, end, sizeof(u32), bad);
+	len = ceph_decode_32(p);
+	dout("decode_buffer len %d\n", (int)len);
+	ceph_decode_need(p, end, len, bad);
+	*b = ceph_buffer_new(len, GFP_NOFS);
+	if (!*b)
+		return -ENOMEM;
+	ceph_decode_copy(p, (*b)->vec.iov_base, len);
+	return 0;
+bad:
+	return -EINVAL;
+}
diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
new file mode 100644
index 000000000..20f0c3d7e
--- /dev/null
+++ b/net/ceph/ceph_common.c
@@ -0,0 +1,818 @@
+
+#include <linux/ceph/ceph_debug.h>
+#include <linux/backing-dev.h>
+#include <linux/ctype.h>
+#include <linux/fs.h>
+#include <linux/inet.h>
+#include <linux/in6.h>
+#include <linux/key.h>
+#include <keys/ceph-type.h>
+#include <linux/module.h>
+#include <linux/mount.h>
+#include <linux/nsproxy.h>
+#include <linux/parser.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/statfs.h>
+#include <linux/string.h>
+#include <linux/vmalloc.h>
+
+
+#include <linux/ceph/ceph_features.h>
+#include <linux/ceph/libceph.h>
+#include <linux/ceph/debugfs.h>
+#include <linux/ceph/decode.h>
+#include <linux/ceph/mon_client.h>
+#include <linux/ceph/auth.h>
+#include "crypto.h"
+
+
+/*
+ * Module compatibility interface.  For now it doesn't do anything,
+ * but its existence signals a certain level of functionality.
+ *
+ * The data buffer is used to pass information both to and from
+ * libceph.  The return value indicates whether libceph determines
+ * it is compatible with the caller (from another kernel module),
+ * given the provided data.
+ *
+ * The data pointer can be null.
+ */
+bool libceph_compatible(void *data)
+{
+	return true;
+}
+EXPORT_SYMBOL(libceph_compatible);
+
+static int param_get_supported_features(char *buffer,
+					const struct kernel_param *kp)
+{
+	return sprintf(buffer, "0x%llx", CEPH_FEATURES_SUPPORTED_DEFAULT);
+}
+static const struct kernel_param_ops param_ops_supported_features = {
+	.get = param_get_supported_features,
+};
+module_param_cb(supported_features, &param_ops_supported_features, NULL,
+		0444);
+
+const char *ceph_msg_type_name(int type)
+{
+	switch (type) {
+	case CEPH_MSG_SHUTDOWN: return "shutdown";
+	case CEPH_MSG_PING: return "ping";
+	case CEPH_MSG_AUTH: return "auth";
+	case CEPH_MSG_AUTH_REPLY: return "auth_reply";
+	case CEPH_MSG_MON_MAP: return "mon_map";
+	case CEPH_MSG_MON_GET_MAP: return "mon_get_map";
+	case CEPH_MSG_MON_SUBSCRIBE: return "mon_subscribe";
+	case CEPH_MSG_MON_SUBSCRIBE_ACK: return "mon_subscribe_ack";
+	case CEPH_MSG_STATFS: return "statfs";
+	case CEPH_MSG_STATFS_REPLY: return "statfs_reply";
+	case CEPH_MSG_MON_GET_VERSION: return "mon_get_version";
+	case CEPH_MSG_MON_GET_VERSION_REPLY: return "mon_get_version_reply";
+	case CEPH_MSG_MDS_MAP: return "mds_map";
+	case CEPH_MSG_FS_MAP_USER: return "fs_map_user";
+	case CEPH_MSG_CLIENT_SESSION: return "client_session";
+	case CEPH_MSG_CLIENT_RECONNECT: return "client_reconnect";
+	case CEPH_MSG_CLIENT_REQUEST: return "client_request";
+	case CEPH_MSG_CLIENT_REQUEST_FORWARD: return "client_request_forward";
+	case CEPH_MSG_CLIENT_REPLY: return "client_reply";
+	case CEPH_MSG_CLIENT_CAPS: return "client_caps";
+	case CEPH_MSG_CLIENT_CAPRELEASE: return "client_cap_release";
+	case CEPH_MSG_CLIENT_QUOTA: return "client_quota";
+	case CEPH_MSG_CLIENT_SNAP: return "client_snap";
+	case CEPH_MSG_CLIENT_LEASE: return "client_lease";
+	case CEPH_MSG_POOLOP_REPLY: return "poolop_reply";
+	case CEPH_MSG_POOLOP: return "poolop";
+	case CEPH_MSG_MON_COMMAND: return "mon_command";
+	case CEPH_MSG_MON_COMMAND_ACK: return "mon_command_ack";
+	case CEPH_MSG_OSD_MAP: return "osd_map";
+	case CEPH_MSG_OSD_OP: return "osd_op";
+	case CEPH_MSG_OSD_OPREPLY: return "osd_opreply";
+	case CEPH_MSG_WATCH_NOTIFY: return "watch_notify";
+	case CEPH_MSG_OSD_BACKOFF: return "osd_backoff";
+	default: return "unknown";
+	}
+}
+EXPORT_SYMBOL(ceph_msg_type_name);
+
+/*
+ * Initially learn our fsid, or verify an fsid matches.
+ */
+int ceph_check_fsid(struct ceph_client *client, struct ceph_fsid *fsid)
+{
+	if (client->have_fsid) {
+		if (ceph_fsid_compare(&client->fsid, fsid)) {
+			pr_err("bad fsid, had %pU got %pU",
+			       &client->fsid, fsid);
+			return -1;
+		}
+	} else {
+		memcpy(&client->fsid, fsid, sizeof(*fsid));
+	}
+	return 0;
+}
+EXPORT_SYMBOL(ceph_check_fsid);
+
+static int strcmp_null(const char *s1, const char *s2)
+{
+	if (!s1 && !s2)
+		return 0;
+	if (s1 && !s2)
+		return -1;
+	if (!s1 && s2)
+		return 1;
+	return strcmp(s1, s2);
+}
+
+int ceph_compare_options(struct ceph_options *new_opt,
+			 struct ceph_client *client)
+{
+	struct ceph_options *opt1 = new_opt;
+	struct ceph_options *opt2 = client->options;
+	int ofs = offsetof(struct ceph_options, mon_addr);
+	int i;
+	int ret;
+
+	/*
+	 * Don't bother comparing options if network namespaces don't
+	 * match.
+	 */
+	if (!net_eq(current->nsproxy->net_ns, read_pnet(&client->msgr.net)))
+		return -1;
+
+	ret = memcmp(opt1, opt2, ofs);
+	if (ret)
+		return ret;
+
+	ret = strcmp_null(opt1->name, opt2->name);
+	if (ret)
+		return ret;
+
+	if (opt1->key && !opt2->key)
+		return -1;
+	if (!opt1->key && opt2->key)
+		return 1;
+	if (opt1->key && opt2->key) {
+		if (opt1->key->type != opt2->key->type)
+			return -1;
+		if (opt1->key->created.tv_sec != opt2->key->created.tv_sec)
+			return -1;
+		if (opt1->key->created.tv_nsec != opt2->key->created.tv_nsec)
+			return -1;
+		if (opt1->key->len != opt2->key->len)
+			return -1;
+		if (opt1->key->key && !opt2->key->key)
+			return -1;
+		if (!opt1->key->key && opt2->key->key)
+			return 1;
+		if (opt1->key->key && opt2->key->key) {
+			ret = memcmp(opt1->key->key, opt2->key->key, opt1->key->len);
+			if (ret)
+				return ret;
+		}
+	}
+
+	/* any matching mon ip implies a match */
+	for (i = 0; i < opt1->num_mon; i++) {
+		if (ceph_monmap_contains(client->monc.monmap,
+				 &opt1->mon_addr[i]))
+			return 0;
+	}
+	return -1;
+}
+EXPORT_SYMBOL(ceph_compare_options);
+
+void *ceph_kvmalloc(size_t size, gfp_t flags)
+{
+	if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
+		void *ptr = kmalloc(size, flags | __GFP_NOWARN);
+		if (ptr)
+			return ptr;
+	}
+
+	return __vmalloc(size, flags, PAGE_KERNEL);
+}
+
+
+static int parse_fsid(const char *str, struct ceph_fsid *fsid)
+{
+	int i = 0;
+	char tmp[3];
+	int err = -EINVAL;
+	int d;
+
+	dout("parse_fsid '%s'\n", str);
+	tmp[2] = 0;
+	while (*str && i < 16) {
+		if (ispunct(*str)) {
+			str++;
+			continue;
+		}
+		if (!isxdigit(str[0]) || !isxdigit(str[1]))
+			break;
+		tmp[0] = str[0];
+		tmp[1] = str[1];
+		if (sscanf(tmp, "%x", &d) < 1)
+			break;
+		fsid->fsid[i] = d & 0xff;
+		i++;
+		str += 2;
+	}
+
+	if (i == 16)
+		err = 0;
+	dout("parse_fsid ret %d got fsid %pU\n", err, fsid);
+	return err;
+}
+
+/*
+ * ceph options
+ */
+enum {
+	Opt_osdtimeout,
+	Opt_osdkeepalivetimeout,
+	Opt_mount_timeout,
+	Opt_osd_idle_ttl,
+	Opt_osd_request_timeout,
+	Opt_last_int,
+	/* int args above */
+	Opt_fsid,
+	Opt_name,
+	Opt_secret,
+	Opt_key,
+	Opt_ip,
+	Opt_last_string,
+	/* string args above */
+	Opt_share,
+	Opt_noshare,
+	Opt_crc,
+	Opt_nocrc,
+	Opt_cephx_require_signatures,
+	Opt_nocephx_require_signatures,
+	Opt_cephx_sign_messages,
+	Opt_nocephx_sign_messages,
+	Opt_tcp_nodelay,
+	Opt_notcp_nodelay,
+};
+
+static match_table_t opt_tokens = {
+	{Opt_osdtimeout, "osdtimeout=%d"},
+	{Opt_osdkeepalivetimeout, "osdkeepalive=%d"},
+	{Opt_mount_timeout, "mount_timeout=%d"},
+	{Opt_osd_idle_ttl, "osd_idle_ttl=%d"},
+	{Opt_osd_request_timeout, "osd_request_timeout=%d"},
+	/* int args above */
+	{Opt_fsid, "fsid=%s"},
+	{Opt_name, "name=%s"},
+	{Opt_secret, "secret=%s"},
+	{Opt_key, "key=%s"},
+	{Opt_ip, "ip=%s"},
+	/* string args above */
+	{Opt_share, "share"},
+	{Opt_noshare, "noshare"},
+	{Opt_crc, "crc"},
+	{Opt_nocrc, "nocrc"},
+	{Opt_cephx_require_signatures, "cephx_require_signatures"},
+	{Opt_nocephx_require_signatures, "nocephx_require_signatures"},
+	{Opt_cephx_sign_messages, "cephx_sign_messages"},
+	{Opt_nocephx_sign_messages, "nocephx_sign_messages"},
+	{Opt_tcp_nodelay, "tcp_nodelay"},
+	{Opt_notcp_nodelay, "notcp_nodelay"},
+	{-1, NULL}
+};
+
+void ceph_destroy_options(struct ceph_options *opt)
+{
+	dout("destroy_options %p\n", opt);
+	kfree(opt->name);
+	if (opt->key) {
+		ceph_crypto_key_destroy(opt->key);
+		kfree(opt->key);
+	}
+	kfree(opt->mon_addr);
+	kfree(opt);
+}
+EXPORT_SYMBOL(ceph_destroy_options);
+
+/* get secret from key store */
+static int get_secret(struct ceph_crypto_key *dst, const char *name) {
+	struct key *ukey;
+	int key_err;
+	int err = 0;
+	struct ceph_crypto_key *ckey;
+
+	ukey = request_key(&key_type_ceph, name, NULL);
+	if (IS_ERR(ukey)) {
+		/* request_key errors don't map nicely to mount(2)
+		   errors; don't even try, but still printk */
+		key_err = PTR_ERR(ukey);
+		switch (key_err) {
+		case -ENOKEY:
+			pr_warn("ceph: Mount failed due to key not found: %s\n",
+				name);
+			break;
+		case -EKEYEXPIRED:
+			pr_warn("ceph: Mount failed due to expired key: %s\n",
+				name);
+			break;
+		case -EKEYREVOKED:
+			pr_warn("ceph: Mount failed due to revoked key: %s\n",
+				name);
+			break;
+		default:
+			pr_warn("ceph: Mount failed due to unknown key error %d: %s\n",
+				key_err, name);
+		}
+		err = -EPERM;
+		goto out;
+	}
+
+	ckey = ukey->payload.data[0];
+	err = ceph_crypto_key_clone(dst, ckey);
+	if (err)
+		goto out_key;
+	/* pass through, err is 0 */
+
+out_key:
+	key_put(ukey);
+out:
+	return err;
+}
+
+struct ceph_options *
+ceph_parse_options(char *options, const char *dev_name,
+			const char *dev_name_end,
+			int (*parse_extra_token)(char *c, void *private),
+			void *private)
+{
+	struct ceph_options *opt;
+	const char *c;
+	int err = -ENOMEM;
+	substring_t argstr[MAX_OPT_ARGS];
+
+	opt = kzalloc(sizeof(*opt), GFP_KERNEL);
+	if (!opt)
+		return ERR_PTR(-ENOMEM);
+	opt->mon_addr = kcalloc(CEPH_MAX_MON, sizeof(*opt->mon_addr),
+				GFP_KERNEL);
+	if (!opt->mon_addr)
+		goto out;
+
+	dout("parse_options %p options '%s' dev_name '%s'\n", opt, options,
+	     dev_name);
+
+	/* start with defaults */
+	opt->flags = CEPH_OPT_DEFAULT;
+	opt->osd_keepalive_timeout = CEPH_OSD_KEEPALIVE_DEFAULT;
+	opt->mount_timeout = CEPH_MOUNT_TIMEOUT_DEFAULT;
+	opt->osd_idle_ttl = CEPH_OSD_IDLE_TTL_DEFAULT;
+	opt->osd_request_timeout = CEPH_OSD_REQUEST_TIMEOUT_DEFAULT;
+
+	/* get mon ip(s) */
+	/* ip1[:port1][,ip2[:port2]...] */
+	err = ceph_parse_ips(dev_name, dev_name_end, opt->mon_addr,
+			     CEPH_MAX_MON, &opt->num_mon);
+	if (err < 0)
+		goto out;
+
+	/* parse mount options */
+	while ((c = strsep(&options, ",")) != NULL) {
+		int token, intval;
+		if (!*c)
+			continue;
+		err = -EINVAL;
+		token = match_token((char *)c, opt_tokens, argstr);
+		if (token < 0 && parse_extra_token) {
+			/* extra? */
+			err = parse_extra_token((char *)c, private);
+			if (err < 0) {
+				pr_err("bad option at '%s'\n", c);
+				goto out;
+			}
+			continue;
+		}
+		if (token < Opt_last_int) {
+			err = match_int(&argstr[0], &intval);
+			if (err < 0) {
+				pr_err("bad option arg (not int) at '%s'\n", c);
+				goto out;
+			}
+			dout("got int token %d val %d\n", token, intval);
+		} else if (token > Opt_last_int && token < Opt_last_string) {
+			dout("got string token %d val %s\n", token,
+			     argstr[0].from);
+		} else {
+			dout("got token %d\n", token);
+		}
+		switch (token) {
+		case Opt_ip:
+			err = ceph_parse_ips(argstr[0].from,
+					     argstr[0].to,
+					     &opt->my_addr,
+					     1, NULL);
+			if (err < 0)
+				goto out;
+			opt->flags |= CEPH_OPT_MYIP;
+			break;
+
+		case Opt_fsid:
+			err = parse_fsid(argstr[0].from, &opt->fsid);
+			if (err == 0)
+				opt->flags |= CEPH_OPT_FSID;
+			break;
+		case Opt_name:
+			kfree(opt->name);
+			opt->name = kstrndup(argstr[0].from,
+					      argstr[0].to-argstr[0].from,
+					      GFP_KERNEL);
+			if (!opt->name) {
+				err = -ENOMEM;
+				goto out;
+			}
+			break;
+		case Opt_secret:
+			ceph_crypto_key_destroy(opt->key);
+			kfree(opt->key);
+
+		        opt->key = kzalloc(sizeof(*opt->key), GFP_KERNEL);
+			if (!opt->key) {
+				err = -ENOMEM;
+				goto out;
+			}
+			err = ceph_crypto_key_unarmor(opt->key, argstr[0].from);
+			if (err < 0)
+				goto out;
+			break;
+		case Opt_key:
+			ceph_crypto_key_destroy(opt->key);
+			kfree(opt->key);
+
+		        opt->key = kzalloc(sizeof(*opt->key), GFP_KERNEL);
+			if (!opt->key) {
+				err = -ENOMEM;
+				goto out;
+			}
+			err = get_secret(opt->key, argstr[0].from);
+			if (err < 0)
+				goto out;
+			break;
+
+			/* misc */
+		case Opt_osdtimeout:
+			pr_warn("ignoring deprecated osdtimeout option\n");
+			break;
+		case Opt_osdkeepalivetimeout:
+			/* 0 isn't well defined right now, reject it */
+			if (intval < 1 || intval > INT_MAX / 1000) {
+				pr_err("osdkeepalive out of range\n");
+				err = -EINVAL;
+				goto out;
+			}
+			opt->osd_keepalive_timeout =
+					msecs_to_jiffies(intval * 1000);
+			break;
+		case Opt_osd_idle_ttl:
+			/* 0 isn't well defined right now, reject it */
+			if (intval < 1 || intval > INT_MAX / 1000) {
+				pr_err("osd_idle_ttl out of range\n");
+				err = -EINVAL;
+				goto out;
+			}
+			opt->osd_idle_ttl = msecs_to_jiffies(intval * 1000);
+			break;
+		case Opt_mount_timeout:
+			/* 0 is "wait forever" (i.e. infinite timeout) */
+			if (intval < 0 || intval > INT_MAX / 1000) {
+				pr_err("mount_timeout out of range\n");
+				err = -EINVAL;
+				goto out;
+			}
+			opt->mount_timeout = msecs_to_jiffies(intval * 1000);
+			break;
+		case Opt_osd_request_timeout:
+			/* 0 is "wait forever" (i.e. infinite timeout) */
+			if (intval < 0 || intval > INT_MAX / 1000) {
+				pr_err("osd_request_timeout out of range\n");
+				err = -EINVAL;
+				goto out;
+			}
+			opt->osd_request_timeout = msecs_to_jiffies(intval * 1000);
+			break;
+
+		case Opt_share:
+			opt->flags &= ~CEPH_OPT_NOSHARE;
+			break;
+		case Opt_noshare:
+			opt->flags |= CEPH_OPT_NOSHARE;
+			break;
+
+		case Opt_crc:
+			opt->flags &= ~CEPH_OPT_NOCRC;
+			break;
+		case Opt_nocrc:
+			opt->flags |= CEPH_OPT_NOCRC;
+			break;
+
+		case Opt_cephx_require_signatures:
+			opt->flags &= ~CEPH_OPT_NOMSGAUTH;
+			break;
+		case Opt_nocephx_require_signatures:
+			opt->flags |= CEPH_OPT_NOMSGAUTH;
+			break;
+		case Opt_cephx_sign_messages:
+			opt->flags &= ~CEPH_OPT_NOMSGSIGN;
+			break;
+		case Opt_nocephx_sign_messages:
+			opt->flags |= CEPH_OPT_NOMSGSIGN;
+			break;
+
+		case Opt_tcp_nodelay:
+			opt->flags |= CEPH_OPT_TCP_NODELAY;
+			break;
+		case Opt_notcp_nodelay:
+			opt->flags &= ~CEPH_OPT_TCP_NODELAY;
+			break;
+
+		default:
+			BUG_ON(token);
+		}
+	}
+
+	/* success */
+	return opt;
+
+out:
+	ceph_destroy_options(opt);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL(ceph_parse_options);
+
+int ceph_print_client_options(struct seq_file *m, struct ceph_client *client)
+{
+	struct ceph_options *opt = client->options;
+	size_t pos = m->count;
+
+	if (opt->name) {
+		seq_puts(m, "name=");
+		seq_escape(m, opt->name, ", \t\n\\");
+		seq_putc(m, ',');
+	}
+	if (opt->key)
+		seq_puts(m, "secret=<hidden>,");
+
+	if (opt->flags & CEPH_OPT_FSID)
+		seq_printf(m, "fsid=%pU,", &opt->fsid);
+	if (opt->flags & CEPH_OPT_NOSHARE)
+		seq_puts(m, "noshare,");
+	if (opt->flags & CEPH_OPT_NOCRC)
+		seq_puts(m, "nocrc,");
+	if (opt->flags & CEPH_OPT_NOMSGAUTH)
+		seq_puts(m, "nocephx_require_signatures,");
+	if (opt->flags & CEPH_OPT_NOMSGSIGN)
+		seq_puts(m, "nocephx_sign_messages,");
+	if ((opt->flags & CEPH_OPT_TCP_NODELAY) == 0)
+		seq_puts(m, "notcp_nodelay,");
+
+	if (opt->mount_timeout != CEPH_MOUNT_TIMEOUT_DEFAULT)
+		seq_printf(m, "mount_timeout=%d,",
+			   jiffies_to_msecs(opt->mount_timeout) / 1000);
+	if (opt->osd_idle_ttl != CEPH_OSD_IDLE_TTL_DEFAULT)
+		seq_printf(m, "osd_idle_ttl=%d,",
+			   jiffies_to_msecs(opt->osd_idle_ttl) / 1000);
+	if (opt->osd_keepalive_timeout != CEPH_OSD_KEEPALIVE_DEFAULT)
+		seq_printf(m, "osdkeepalivetimeout=%d,",
+		    jiffies_to_msecs(opt->osd_keepalive_timeout) / 1000);
+	if (opt->osd_request_timeout != CEPH_OSD_REQUEST_TIMEOUT_DEFAULT)
+		seq_printf(m, "osd_request_timeout=%d,",
+			   jiffies_to_msecs(opt->osd_request_timeout) / 1000);
+
+	/* drop redundant comma */
+	if (m->count != pos)
+		m->count--;
+
+	return 0;
+}
+EXPORT_SYMBOL(ceph_print_client_options);
+
+struct ceph_entity_addr *ceph_client_addr(struct ceph_client *client)
+{
+	return &client->msgr.inst.addr;
+}
+EXPORT_SYMBOL(ceph_client_addr);
+
+u64 ceph_client_gid(struct ceph_client *client)
+{
+	return client->monc.auth->global_id;
+}
+EXPORT_SYMBOL(ceph_client_gid);
+
+/*
+ * create a fresh client instance
+ */
+struct ceph_client *ceph_create_client(struct ceph_options *opt, void *private)
+{
+	struct ceph_client *client;
+	struct ceph_entity_addr *myaddr = NULL;
+	int err;
+
+	err = wait_for_random_bytes();
+	if (err < 0)
+		return ERR_PTR(err);
+
+	client = kzalloc(sizeof(*client), GFP_KERNEL);
+	if (client == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	client->private = private;
+	client->options = opt;
+
+	mutex_init(&client->mount_mutex);
+	init_waitqueue_head(&client->auth_wq);
+	client->auth_err = 0;
+
+	client->extra_mon_dispatch = NULL;
+	client->supported_features = CEPH_FEATURES_SUPPORTED_DEFAULT;
+	client->required_features = CEPH_FEATURES_REQUIRED_DEFAULT;
+
+	if (!ceph_test_opt(client, NOMSGAUTH))
+		client->required_features |= CEPH_FEATURE_MSG_AUTH;
+
+	/* msgr */
+	if (ceph_test_opt(client, MYIP))
+		myaddr = &client->options->my_addr;
+
+	ceph_messenger_init(&client->msgr, myaddr);
+
+	/* subsystems */
+	err = ceph_monc_init(&client->monc, client);
+	if (err < 0)
+		goto fail;
+	err = ceph_osdc_init(&client->osdc, client);
+	if (err < 0)
+		goto fail_monc;
+
+	return client;
+
+fail_monc:
+	ceph_monc_stop(&client->monc);
+fail:
+	ceph_messenger_fini(&client->msgr);
+	kfree(client);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL(ceph_create_client);
+
+void ceph_destroy_client(struct ceph_client *client)
+{
+	dout("destroy_client %p\n", client);
+
+	atomic_set(&client->msgr.stopping, 1);
+
+	/* unmount */
+	ceph_osdc_stop(&client->osdc);
+	ceph_monc_stop(&client->monc);
+	ceph_messenger_fini(&client->msgr);
+
+	ceph_debugfs_client_cleanup(client);
+
+	ceph_destroy_options(client->options);
+
+	kfree(client);
+	dout("destroy_client %p done\n", client);
+}
+EXPORT_SYMBOL(ceph_destroy_client);
+
+/*
+ * true if we have the mon map (and have thus joined the cluster)
+ */
+static bool have_mon_and_osd_map(struct ceph_client *client)
+{
+	return client->monc.monmap && client->monc.monmap->epoch &&
+	       client->osdc.osdmap && client->osdc.osdmap->epoch;
+}
+
+/*
+ * mount: join the ceph cluster, and open root directory.
+ */
+int __ceph_open_session(struct ceph_client *client, unsigned long started)
+{
+	unsigned long timeout = client->options->mount_timeout;
+	long err;
+
+	/* open session, and wait for mon and osd maps */
+	err = ceph_monc_open_session(&client->monc);
+	if (err < 0)
+		return err;
+
+	while (!have_mon_and_osd_map(client)) {
+		if (timeout && time_after_eq(jiffies, started + timeout))
+			return -ETIMEDOUT;
+
+		/* wait */
+		dout("mount waiting for mon_map\n");
+		err = wait_event_interruptible_timeout(client->auth_wq,
+			have_mon_and_osd_map(client) || (client->auth_err < 0),
+			ceph_timeout_jiffies(timeout));
+		if (err < 0)
+			return err;
+		if (client->auth_err < 0)
+			return client->auth_err;
+	}
+
+	pr_info("client%llu fsid %pU\n", ceph_client_gid(client),
+		&client->fsid);
+	ceph_debugfs_client_init(client);
+
+	return 0;
+}
+EXPORT_SYMBOL(__ceph_open_session);
+
+int ceph_open_session(struct ceph_client *client)
+{
+	int ret;
+	unsigned long started = jiffies;  /* note the start time */
+
+	dout("open_session start\n");
+	mutex_lock(&client->mount_mutex);
+
+	ret = __ceph_open_session(client, started);
+
+	mutex_unlock(&client->mount_mutex);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_open_session);
+
+int ceph_wait_for_latest_osdmap(struct ceph_client *client,
+				unsigned long timeout)
+{
+	u64 newest_epoch;
+	int ret;
+
+	ret = ceph_monc_get_version(&client->monc, "osdmap", &newest_epoch);
+	if (ret)
+		return ret;
+
+	if (client->osdc.osdmap->epoch >= newest_epoch)
+		return 0;
+
+	ceph_osdc_maybe_request_map(&client->osdc);
+	return ceph_monc_wait_osdmap(&client->monc, newest_epoch, timeout);
+}
+EXPORT_SYMBOL(ceph_wait_for_latest_osdmap);
+
+static int __init init_ceph_lib(void)
+{
+	int ret = 0;
+
+	ret = ceph_debugfs_init();
+	if (ret < 0)
+		goto out;
+
+	ret = ceph_crypto_init();
+	if (ret < 0)
+		goto out_debugfs;
+
+	ret = ceph_msgr_init();
+	if (ret < 0)
+		goto out_crypto;
+
+	ret = ceph_osdc_setup();
+	if (ret < 0)
+		goto out_msgr;
+
+	pr_info("loaded (mon/osd proto %d/%d)\n",
+		CEPH_MONC_PROTOCOL, CEPH_OSDC_PROTOCOL);
+
+	return 0;
+
+out_msgr:
+	ceph_msgr_exit();
+out_crypto:
+	ceph_crypto_shutdown();
+out_debugfs:
+	ceph_debugfs_cleanup();
+out:
+	return ret;
+}
+
+static void __exit exit_ceph_lib(void)
+{
+	dout("exit_ceph_lib\n");
+	WARN_ON(!ceph_strings_empty());
+
+	ceph_osdc_cleanup();
+	ceph_msgr_exit();
+	ceph_crypto_shutdown();
+	ceph_debugfs_cleanup();
+}
+
+module_init(init_ceph_lib);
+module_exit(exit_ceph_lib);
+
+MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
+MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
+MODULE_AUTHOR("Patience Warnick <patience@newdream.net>");
+MODULE_DESCRIPTION("Ceph core library");
+MODULE_LICENSE("GPL");
diff --git a/net/ceph/ceph_fs.c b/net/ceph/ceph_fs.c
new file mode 100644
index 000000000..756a2dc10
--- /dev/null
+++ b/net/ceph/ceph_fs.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Some non-inline ceph helpers
+ */
+#include <linux/module.h>
+#include <linux/ceph/types.h>
+
+/*
+ * return true if @layout appears to be valid
+ */
+int ceph_file_layout_is_valid(const struct ceph_file_layout *layout)
+{
+	__u32 su = layout->stripe_unit;
+	__u32 sc = layout->stripe_count;
+	__u32 os = layout->object_size;
+
+	/* stripe unit, object size must be non-zero, 64k increment */
+	if (!su || (su & (CEPH_MIN_STRIPE_UNIT-1)))
+		return 0;
+	if (!os || (os & (CEPH_MIN_STRIPE_UNIT-1)))
+		return 0;
+	/* object size must be a multiple of stripe unit */
+	if (os < su || os % su)
+		return 0;
+	/* stripe count must be non-zero */
+	if (!sc)
+		return 0;
+	return 1;
+}
+
+void ceph_file_layout_from_legacy(struct ceph_file_layout *fl,
+				  struct ceph_file_layout_legacy *legacy)
+{
+	fl->stripe_unit = le32_to_cpu(legacy->fl_stripe_unit);
+	fl->stripe_count = le32_to_cpu(legacy->fl_stripe_count);
+	fl->object_size = le32_to_cpu(legacy->fl_object_size);
+	fl->pool_id = le32_to_cpu(legacy->fl_pg_pool);
+	if (fl->pool_id == 0 && fl->stripe_unit == 0 &&
+	    fl->stripe_count == 0 && fl->object_size == 0)
+		fl->pool_id = -1;
+}
+EXPORT_SYMBOL(ceph_file_layout_from_legacy);
+
+void ceph_file_layout_to_legacy(struct ceph_file_layout *fl,
+				struct ceph_file_layout_legacy *legacy)
+{
+	legacy->fl_stripe_unit = cpu_to_le32(fl->stripe_unit);
+	legacy->fl_stripe_count = cpu_to_le32(fl->stripe_count);
+	legacy->fl_object_size = cpu_to_le32(fl->object_size);
+	if (fl->pool_id >= 0)
+		legacy->fl_pg_pool = cpu_to_le32(fl->pool_id);
+	else
+		legacy->fl_pg_pool = 0;
+}
+EXPORT_SYMBOL(ceph_file_layout_to_legacy);
+
+int ceph_flags_to_mode(int flags)
+{
+	int mode;
+
+#ifdef O_DIRECTORY  /* fixme */
+	if ((flags & O_DIRECTORY) == O_DIRECTORY)
+		return CEPH_FILE_MODE_PIN;
+#endif
+
+	switch (flags & O_ACCMODE) {
+	case O_WRONLY:
+		mode = CEPH_FILE_MODE_WR;
+		break;
+	case O_RDONLY:
+		mode = CEPH_FILE_MODE_RD;
+		break;
+	case O_RDWR:
+	case O_ACCMODE: /* this is what the VFS does */
+		mode = CEPH_FILE_MODE_RDWR;
+		break;
+	}
+#ifdef O_LAZY
+	if (flags & O_LAZY)
+		mode |= CEPH_FILE_MODE_LAZY;
+#endif
+
+	return mode;
+}
+EXPORT_SYMBOL(ceph_flags_to_mode);
+
+int ceph_caps_for_mode(int mode)
+{
+	int caps = CEPH_CAP_PIN;
+
+	if (mode & CEPH_FILE_MODE_RD)
+		caps |= CEPH_CAP_FILE_SHARED |
+			CEPH_CAP_FILE_RD | CEPH_CAP_FILE_CACHE;
+	if (mode & CEPH_FILE_MODE_WR)
+		caps |= CEPH_CAP_FILE_EXCL |
+			CEPH_CAP_FILE_WR | CEPH_CAP_FILE_BUFFER |
+			CEPH_CAP_AUTH_SHARED | CEPH_CAP_AUTH_EXCL |
+			CEPH_CAP_XATTR_SHARED | CEPH_CAP_XATTR_EXCL;
+	if (mode & CEPH_FILE_MODE_LAZY)
+		caps |= CEPH_CAP_FILE_LAZYIO;
+
+	return caps;
+}
+EXPORT_SYMBOL(ceph_caps_for_mode);
diff --git a/net/ceph/ceph_hash.c b/net/ceph/ceph_hash.c
new file mode 100644
index 000000000..9a5850f26
--- /dev/null
+++ b/net/ceph/ceph_hash.c
@@ -0,0 +1,131 @@
+
+#include <linux/ceph/types.h>
+#include <linux/module.h>
+
+/*
+ * Robert Jenkin's hash function.
+ * http://burtleburtle.net/bob/hash/evahash.html
+ * This is in the public domain.
+ */
+#define mix(a, b, c)						\
+	do {							\
+		a = a - b;  a = a - c;  a = a ^ (c >> 13);	\
+		b = b - c;  b = b - a;  b = b ^ (a << 8);	\
+		c = c - a;  c = c - b;  c = c ^ (b >> 13);	\
+		a = a - b;  a = a - c;  a = a ^ (c >> 12);	\
+		b = b - c;  b = b - a;  b = b ^ (a << 16);	\
+		c = c - a;  c = c - b;  c = c ^ (b >> 5);	\
+		a = a - b;  a = a - c;  a = a ^ (c >> 3);	\
+		b = b - c;  b = b - a;  b = b ^ (a << 10);	\
+		c = c - a;  c = c - b;  c = c ^ (b >> 15);	\
+	} while (0)
+
+unsigned int ceph_str_hash_rjenkins(const char *str, unsigned int length)
+{
+	const unsigned char *k = (const unsigned char *)str;
+	__u32 a, b, c;  /* the internal state */
+	__u32 len;      /* how many key bytes still need mixing */
+
+	/* Set up the internal state */
+	len = length;
+	a = 0x9e3779b9;      /* the golden ratio; an arbitrary value */
+	b = a;
+	c = 0;               /* variable initialization of internal state */
+
+	/* handle most of the key */
+	while (len >= 12) {
+		a = a + (k[0] + ((__u32)k[1] << 8) + ((__u32)k[2] << 16) +
+			 ((__u32)k[3] << 24));
+		b = b + (k[4] + ((__u32)k[5] << 8) + ((__u32)k[6] << 16) +
+			 ((__u32)k[7] << 24));
+		c = c + (k[8] + ((__u32)k[9] << 8) + ((__u32)k[10] << 16) +
+			 ((__u32)k[11] << 24));
+		mix(a, b, c);
+		k = k + 12;
+		len = len - 12;
+	}
+
+	/* handle the last 11 bytes */
+	c = c + length;
+	switch (len) {
+	case 11:
+		c = c + ((__u32)k[10] << 24);
+		/* fall through */
+	case 10:
+		c = c + ((__u32)k[9] << 16);
+		/* fall through */
+	case 9:
+		c = c + ((__u32)k[8] << 8);
+		/* the first byte of c is reserved for the length */
+		/* fall through */
+	case 8:
+		b = b + ((__u32)k[7] << 24);
+		/* fall through */
+	case 7:
+		b = b + ((__u32)k[6] << 16);
+		/* fall through */
+	case 6:
+		b = b + ((__u32)k[5] << 8);
+		/* fall through */
+	case 5:
+		b = b + k[4];
+		/* fall through */
+	case 4:
+		a = a + ((__u32)k[3] << 24);
+		/* fall through */
+	case 3:
+		a = a + ((__u32)k[2] << 16);
+		/* fall through */
+	case 2:
+		a = a + ((__u32)k[1] << 8);
+		/* fall through */
+	case 1:
+		a = a + k[0];
+		/* case 0: nothing left to add */
+	}
+	mix(a, b, c);
+
+	return c;
+}
+
+/*
+ * linux dcache hash
+ */
+unsigned int ceph_str_hash_linux(const char *str, unsigned int length)
+{
+	unsigned long hash = 0;
+	unsigned char c;
+
+	while (length--) {
+		c = *str++;
+		hash = (hash + (c << 4) + (c >> 4)) * 11;
+	}
+	return hash;
+}
+
+
+unsigned int ceph_str_hash(int type, const char *s, unsigned int len)
+{
+	switch (type) {
+	case CEPH_STR_HASH_LINUX:
+		return ceph_str_hash_linux(s, len);
+	case CEPH_STR_HASH_RJENKINS:
+		return ceph_str_hash_rjenkins(s, len);
+	default:
+		return -1;
+	}
+}
+EXPORT_SYMBOL(ceph_str_hash);
+
+const char *ceph_str_hash_name(int type)
+{
+	switch (type) {
+	case CEPH_STR_HASH_LINUX:
+		return "linux";
+	case CEPH_STR_HASH_RJENKINS:
+		return "rjenkins";
+	default:
+		return "unknown";
+	}
+}
+EXPORT_SYMBOL(ceph_str_hash_name);
diff --git a/net/ceph/ceph_strings.c b/net/ceph/ceph_strings.c
new file mode 100644
index 000000000..10e014949
--- /dev/null
+++ b/net/ceph/ceph_strings.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Ceph string constants
+ */
+#include <linux/module.h>
+#include <linux/ceph/types.h>
+
+const char *ceph_entity_type_name(int type)
+{
+	switch (type) {
+	case CEPH_ENTITY_TYPE_MDS: return "mds";
+	case CEPH_ENTITY_TYPE_OSD: return "osd";
+	case CEPH_ENTITY_TYPE_MON: return "mon";
+	case CEPH_ENTITY_TYPE_CLIENT: return "client";
+	case CEPH_ENTITY_TYPE_AUTH: return "auth";
+	default: return "unknown";
+	}
+}
+EXPORT_SYMBOL(ceph_entity_type_name);
+
+const char *ceph_osd_op_name(int op)
+{
+	switch (op) {
+#define GENERATE_CASE(op, opcode, str)	case CEPH_OSD_OP_##op: return (str);
+__CEPH_FORALL_OSD_OPS(GENERATE_CASE)
+#undef GENERATE_CASE
+	default:
+		return "???";
+	}
+}
+
+const char *ceph_osd_watch_op_name(int o)
+{
+	switch (o) {
+	case CEPH_OSD_WATCH_OP_UNWATCH:
+		return "unwatch";
+	case CEPH_OSD_WATCH_OP_WATCH:
+		return "watch";
+	case CEPH_OSD_WATCH_OP_RECONNECT:
+		return "reconnect";
+	case CEPH_OSD_WATCH_OP_PING:
+		return "ping";
+	default:
+		return "???";
+	}
+}
+
+const char *ceph_osd_state_name(int s)
+{
+	switch (s) {
+	case CEPH_OSD_EXISTS:
+		return "exists";
+	case CEPH_OSD_UP:
+		return "up";
+	case CEPH_OSD_AUTOOUT:
+		return "autoout";
+	case CEPH_OSD_NEW:
+		return "new";
+	default:
+		return "???";
+	}
+}
diff --git a/net/ceph/cls_lock_client.c b/net/ceph/cls_lock_client.c
new file mode 100644
index 000000000..2105a6eaa
--- /dev/null
+++ b/net/ceph/cls_lock_client.c
@@ -0,0 +1,377 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/types.h>
+#include <linux/slab.h>
+
+#include <linux/ceph/cls_lock_client.h>
+#include <linux/ceph/decode.h>
+
+/**
+ * ceph_cls_lock - grab rados lock for object
+ * @oid, @oloc: object to lock
+ * @lock_name: the name of the lock
+ * @type: lock type (CEPH_CLS_LOCK_EXCLUSIVE or CEPH_CLS_LOCK_SHARED)
+ * @cookie: user-defined identifier for this instance of the lock
+ * @tag: user-defined tag
+ * @desc: user-defined lock description
+ * @flags: lock flags
+ *
+ * All operations on the same lock should use the same tag.
+ */
+int ceph_cls_lock(struct ceph_osd_client *osdc,
+		  struct ceph_object_id *oid,
+		  struct ceph_object_locator *oloc,
+		  char *lock_name, u8 type, char *cookie,
+		  char *tag, char *desc, u8 flags)
+{
+	int lock_op_buf_size;
+	int name_len = strlen(lock_name);
+	int cookie_len = strlen(cookie);
+	int tag_len = strlen(tag);
+	int desc_len = strlen(desc);
+	void *p, *end;
+	struct page *lock_op_page;
+	struct timespec64 mtime;
+	int ret;
+
+	lock_op_buf_size = name_len + sizeof(__le32) +
+			   cookie_len + sizeof(__le32) +
+			   tag_len + sizeof(__le32) +
+			   desc_len + sizeof(__le32) +
+			   sizeof(struct ceph_timespec) +
+			   /* flag and type */
+			   sizeof(u8) + sizeof(u8) +
+			   CEPH_ENCODING_START_BLK_LEN;
+	if (lock_op_buf_size > PAGE_SIZE)
+		return -E2BIG;
+
+	lock_op_page = alloc_page(GFP_NOIO);
+	if (!lock_op_page)
+		return -ENOMEM;
+
+	p = page_address(lock_op_page);
+	end = p + lock_op_buf_size;
+
+	/* encode cls_lock_lock_op struct */
+	ceph_start_encoding(&p, 1, 1,
+			    lock_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
+	ceph_encode_string(&p, end, lock_name, name_len);
+	ceph_encode_8(&p, type);
+	ceph_encode_string(&p, end, cookie, cookie_len);
+	ceph_encode_string(&p, end, tag, tag_len);
+	ceph_encode_string(&p, end, desc, desc_len);
+	/* only support infinite duration */
+	memset(&mtime, 0, sizeof(mtime));
+	ceph_encode_timespec64(p, &mtime);
+	p += sizeof(struct ceph_timespec);
+	ceph_encode_8(&p, flags);
+
+	dout("%s lock_name %s type %d cookie %s tag %s desc %s flags 0x%x\n",
+	     __func__, lock_name, type, cookie, tag, desc, flags);
+	ret = ceph_osdc_call(osdc, oid, oloc, "lock", "lock",
+			     CEPH_OSD_FLAG_WRITE, lock_op_page,
+			     lock_op_buf_size, NULL, NULL);
+
+	dout("%s: status %d\n", __func__, ret);
+	__free_page(lock_op_page);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_cls_lock);
+
+/**
+ * ceph_cls_unlock - release rados lock for object
+ * @oid, @oloc: object to lock
+ * @lock_name: the name of the lock
+ * @cookie: user-defined identifier for this instance of the lock
+ */
+int ceph_cls_unlock(struct ceph_osd_client *osdc,
+		    struct ceph_object_id *oid,
+		    struct ceph_object_locator *oloc,
+		    char *lock_name, char *cookie)
+{
+	int unlock_op_buf_size;
+	int name_len = strlen(lock_name);
+	int cookie_len = strlen(cookie);
+	void *p, *end;
+	struct page *unlock_op_page;
+	int ret;
+
+	unlock_op_buf_size = name_len + sizeof(__le32) +
+			     cookie_len + sizeof(__le32) +
+			     CEPH_ENCODING_START_BLK_LEN;
+	if (unlock_op_buf_size > PAGE_SIZE)
+		return -E2BIG;
+
+	unlock_op_page = alloc_page(GFP_NOIO);
+	if (!unlock_op_page)
+		return -ENOMEM;
+
+	p = page_address(unlock_op_page);
+	end = p + unlock_op_buf_size;
+
+	/* encode cls_lock_unlock_op struct */
+	ceph_start_encoding(&p, 1, 1,
+			    unlock_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
+	ceph_encode_string(&p, end, lock_name, name_len);
+	ceph_encode_string(&p, end, cookie, cookie_len);
+
+	dout("%s lock_name %s cookie %s\n", __func__, lock_name, cookie);
+	ret = ceph_osdc_call(osdc, oid, oloc, "lock", "unlock",
+			     CEPH_OSD_FLAG_WRITE, unlock_op_page,
+			     unlock_op_buf_size, NULL, NULL);
+
+	dout("%s: status %d\n", __func__, ret);
+	__free_page(unlock_op_page);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_cls_unlock);
+
+/**
+ * ceph_cls_break_lock - release rados lock for object for specified client
+ * @oid, @oloc: object to lock
+ * @lock_name: the name of the lock
+ * @cookie: user-defined identifier for this instance of the lock
+ * @locker: current lock owner
+ */
+int ceph_cls_break_lock(struct ceph_osd_client *osdc,
+			struct ceph_object_id *oid,
+			struct ceph_object_locator *oloc,
+			char *lock_name, char *cookie,
+			struct ceph_entity_name *locker)
+{
+	int break_op_buf_size;
+	int name_len = strlen(lock_name);
+	int cookie_len = strlen(cookie);
+	struct page *break_op_page;
+	void *p, *end;
+	int ret;
+
+	break_op_buf_size = name_len + sizeof(__le32) +
+			    cookie_len + sizeof(__le32) +
+			    sizeof(u8) + sizeof(__le64) +
+			    CEPH_ENCODING_START_BLK_LEN;
+	if (break_op_buf_size > PAGE_SIZE)
+		return -E2BIG;
+
+	break_op_page = alloc_page(GFP_NOIO);
+	if (!break_op_page)
+		return -ENOMEM;
+
+	p = page_address(break_op_page);
+	end = p + break_op_buf_size;
+
+	/* encode cls_lock_break_op struct */
+	ceph_start_encoding(&p, 1, 1,
+			    break_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
+	ceph_encode_string(&p, end, lock_name, name_len);
+	ceph_encode_copy(&p, locker, sizeof(*locker));
+	ceph_encode_string(&p, end, cookie, cookie_len);
+
+	dout("%s lock_name %s cookie %s locker %s%llu\n", __func__, lock_name,
+	     cookie, ENTITY_NAME(*locker));
+	ret = ceph_osdc_call(osdc, oid, oloc, "lock", "break_lock",
+			     CEPH_OSD_FLAG_WRITE, break_op_page,
+			     break_op_buf_size, NULL, NULL);
+
+	dout("%s: status %d\n", __func__, ret);
+	__free_page(break_op_page);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_cls_break_lock);
+
+int ceph_cls_set_cookie(struct ceph_osd_client *osdc,
+			struct ceph_object_id *oid,
+			struct ceph_object_locator *oloc,
+			char *lock_name, u8 type, char *old_cookie,
+			char *tag, char *new_cookie)
+{
+	int cookie_op_buf_size;
+	int name_len = strlen(lock_name);
+	int old_cookie_len = strlen(old_cookie);
+	int tag_len = strlen(tag);
+	int new_cookie_len = strlen(new_cookie);
+	void *p, *end;
+	struct page *cookie_op_page;
+	int ret;
+
+	cookie_op_buf_size = name_len + sizeof(__le32) +
+			     old_cookie_len + sizeof(__le32) +
+			     tag_len + sizeof(__le32) +
+			     new_cookie_len + sizeof(__le32) +
+			     sizeof(u8) + CEPH_ENCODING_START_BLK_LEN;
+	if (cookie_op_buf_size > PAGE_SIZE)
+		return -E2BIG;
+
+	cookie_op_page = alloc_page(GFP_NOIO);
+	if (!cookie_op_page)
+		return -ENOMEM;
+
+	p = page_address(cookie_op_page);
+	end = p + cookie_op_buf_size;
+
+	/* encode cls_lock_set_cookie_op struct */
+	ceph_start_encoding(&p, 1, 1,
+			    cookie_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
+	ceph_encode_string(&p, end, lock_name, name_len);
+	ceph_encode_8(&p, type);
+	ceph_encode_string(&p, end, old_cookie, old_cookie_len);
+	ceph_encode_string(&p, end, tag, tag_len);
+	ceph_encode_string(&p, end, new_cookie, new_cookie_len);
+
+	dout("%s lock_name %s type %d old_cookie %s tag %s new_cookie %s\n",
+	     __func__, lock_name, type, old_cookie, tag, new_cookie);
+	ret = ceph_osdc_call(osdc, oid, oloc, "lock", "set_cookie",
+			     CEPH_OSD_FLAG_WRITE, cookie_op_page,
+			     cookie_op_buf_size, NULL, NULL);
+
+	dout("%s: status %d\n", __func__, ret);
+	__free_page(cookie_op_page);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_cls_set_cookie);
+
+void ceph_free_lockers(struct ceph_locker *lockers, u32 num_lockers)
+{
+	int i;
+
+	for (i = 0; i < num_lockers; i++)
+		kfree(lockers[i].id.cookie);
+	kfree(lockers);
+}
+EXPORT_SYMBOL(ceph_free_lockers);
+
+static int decode_locker(void **p, void *end, struct ceph_locker *locker)
+{
+	u8 struct_v;
+	u32 len;
+	char *s;
+	int ret;
+
+	ret = ceph_start_decoding(p, end, 1, "locker_id_t", &struct_v, &len);
+	if (ret)
+		return ret;
+
+	ceph_decode_copy(p, &locker->id.name, sizeof(locker->id.name));
+	s = ceph_extract_encoded_string(p, end, NULL, GFP_NOIO);
+	if (IS_ERR(s))
+		return PTR_ERR(s);
+
+	locker->id.cookie = s;
+
+	ret = ceph_start_decoding(p, end, 1, "locker_info_t", &struct_v, &len);
+	if (ret)
+		return ret;
+
+	*p += sizeof(struct ceph_timespec); /* skip expiration */
+	ceph_decode_copy(p, &locker->info.addr, sizeof(locker->info.addr));
+	ceph_decode_addr(&locker->info.addr);
+	len = ceph_decode_32(p);
+	*p += len; /* skip description */
+
+	dout("%s %s%llu cookie %s addr %s\n", __func__,
+	     ENTITY_NAME(locker->id.name), locker->id.cookie,
+	     ceph_pr_addr(&locker->info.addr.in_addr));
+	return 0;
+}
+
+static int decode_lockers(void **p, void *end, u8 *type, char **tag,
+			  struct ceph_locker **lockers, u32 *num_lockers)
+{
+	u8 struct_v;
+	u32 struct_len;
+	char *s;
+	int i;
+	int ret;
+
+	ret = ceph_start_decoding(p, end, 1, "cls_lock_get_info_reply",
+				  &struct_v, &struct_len);
+	if (ret)
+		return ret;
+
+	*num_lockers = ceph_decode_32(p);
+	*lockers = kcalloc(*num_lockers, sizeof(**lockers), GFP_NOIO);
+	if (!*lockers)
+		return -ENOMEM;
+
+	for (i = 0; i < *num_lockers; i++) {
+		ret = decode_locker(p, end, *lockers + i);
+		if (ret)
+			goto err_free_lockers;
+	}
+
+	*type = ceph_decode_8(p);
+	s = ceph_extract_encoded_string(p, end, NULL, GFP_NOIO);
+	if (IS_ERR(s)) {
+		ret = PTR_ERR(s);
+		goto err_free_lockers;
+	}
+
+	*tag = s;
+	return 0;
+
+err_free_lockers:
+	ceph_free_lockers(*lockers, *num_lockers);
+	return ret;
+}
+
+/*
+ * On success, the caller is responsible for:
+ *
+ *     kfree(tag);
+ *     ceph_free_lockers(lockers, num_lockers);
+ */
+int ceph_cls_lock_info(struct ceph_osd_client *osdc,
+		       struct ceph_object_id *oid,
+		       struct ceph_object_locator *oloc,
+		       char *lock_name, u8 *type, char **tag,
+		       struct ceph_locker **lockers, u32 *num_lockers)
+{
+	int get_info_op_buf_size;
+	int name_len = strlen(lock_name);
+	struct page *get_info_op_page, *reply_page;
+	size_t reply_len = PAGE_SIZE;
+	void *p, *end;
+	int ret;
+
+	get_info_op_buf_size = name_len + sizeof(__le32) +
+			       CEPH_ENCODING_START_BLK_LEN;
+	if (get_info_op_buf_size > PAGE_SIZE)
+		return -E2BIG;
+
+	get_info_op_page = alloc_page(GFP_NOIO);
+	if (!get_info_op_page)
+		return -ENOMEM;
+
+	reply_page = alloc_page(GFP_NOIO);
+	if (!reply_page) {
+		__free_page(get_info_op_page);
+		return -ENOMEM;
+	}
+
+	p = page_address(get_info_op_page);
+	end = p + get_info_op_buf_size;
+
+	/* encode cls_lock_get_info_op struct */
+	ceph_start_encoding(&p, 1, 1,
+			    get_info_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
+	ceph_encode_string(&p, end, lock_name, name_len);
+
+	dout("%s lock_name %s\n", __func__, lock_name);
+	ret = ceph_osdc_call(osdc, oid, oloc, "lock", "get_info",
+			     CEPH_OSD_FLAG_READ, get_info_op_page,
+			     get_info_op_buf_size, reply_page, &reply_len);
+
+	dout("%s: status %d\n", __func__, ret);
+	if (ret >= 0) {
+		p = page_address(reply_page);
+		end = p + reply_len;
+
+		ret = decode_lockers(&p, end, type, tag, lockers, num_lockers);
+	}
+
+	__free_page(get_info_op_page);
+	__free_page(reply_page);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_cls_lock_info);
diff --git a/net/ceph/crush/crush.c b/net/ceph/crush/crush.c
new file mode 100644
index 000000000..3d70244bc
--- /dev/null
+++ b/net/ceph/crush/crush.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifdef __KERNEL__
+# include <linux/slab.h>
+# include <linux/crush/crush.h>
+void clear_choose_args(struct crush_map *c);
+#else
+# include "crush_compat.h"
+# include "crush.h"
+#endif
+
+const char *crush_bucket_alg_name(int alg)
+{
+	switch (alg) {
+	case CRUSH_BUCKET_UNIFORM: return "uniform";
+	case CRUSH_BUCKET_LIST: return "list";
+	case CRUSH_BUCKET_TREE: return "tree";
+	case CRUSH_BUCKET_STRAW: return "straw";
+	case CRUSH_BUCKET_STRAW2: return "straw2";
+	default: return "unknown";
+	}
+}
+
+/**
+ * crush_get_bucket_item_weight - Get weight of an item in given bucket
+ * @b: bucket pointer
+ * @p: item index in bucket
+ */
+int crush_get_bucket_item_weight(const struct crush_bucket *b, int p)
+{
+	if ((__u32)p >= b->size)
+		return 0;
+
+	switch (b->alg) {
+	case CRUSH_BUCKET_UNIFORM:
+		return ((struct crush_bucket_uniform *)b)->item_weight;
+	case CRUSH_BUCKET_LIST:
+		return ((struct crush_bucket_list *)b)->item_weights[p];
+	case CRUSH_BUCKET_TREE:
+		return ((struct crush_bucket_tree *)b)->node_weights[crush_calc_tree_node(p)];
+	case CRUSH_BUCKET_STRAW:
+		return ((struct crush_bucket_straw *)b)->item_weights[p];
+	case CRUSH_BUCKET_STRAW2:
+		return ((struct crush_bucket_straw2 *)b)->item_weights[p];
+	}
+	return 0;
+}
+
+void crush_destroy_bucket_uniform(struct crush_bucket_uniform *b)
+{
+	kfree(b->h.items);
+	kfree(b);
+}
+
+void crush_destroy_bucket_list(struct crush_bucket_list *b)
+{
+	kfree(b->item_weights);
+	kfree(b->sum_weights);
+	kfree(b->h.items);
+	kfree(b);
+}
+
+void crush_destroy_bucket_tree(struct crush_bucket_tree *b)
+{
+	kfree(b->h.items);
+	kfree(b->node_weights);
+	kfree(b);
+}
+
+void crush_destroy_bucket_straw(struct crush_bucket_straw *b)
+{
+	kfree(b->straws);
+	kfree(b->item_weights);
+	kfree(b->h.items);
+	kfree(b);
+}
+
+void crush_destroy_bucket_straw2(struct crush_bucket_straw2 *b)
+{
+	kfree(b->item_weights);
+	kfree(b->h.items);
+	kfree(b);
+}
+
+void crush_destroy_bucket(struct crush_bucket *b)
+{
+	switch (b->alg) {
+	case CRUSH_BUCKET_UNIFORM:
+		crush_destroy_bucket_uniform((struct crush_bucket_uniform *)b);
+		break;
+	case CRUSH_BUCKET_LIST:
+		crush_destroy_bucket_list((struct crush_bucket_list *)b);
+		break;
+	case CRUSH_BUCKET_TREE:
+		crush_destroy_bucket_tree((struct crush_bucket_tree *)b);
+		break;
+	case CRUSH_BUCKET_STRAW:
+		crush_destroy_bucket_straw((struct crush_bucket_straw *)b);
+		break;
+	case CRUSH_BUCKET_STRAW2:
+		crush_destroy_bucket_straw2((struct crush_bucket_straw2 *)b);
+		break;
+	}
+}
+
+/**
+ * crush_destroy - Destroy a crush_map
+ * @map: crush_map pointer
+ */
+void crush_destroy(struct crush_map *map)
+{
+	/* buckets */
+	if (map->buckets) {
+		__s32 b;
+		for (b = 0; b < map->max_buckets; b++) {
+			if (map->buckets[b] == NULL)
+				continue;
+			crush_destroy_bucket(map->buckets[b]);
+		}
+		kfree(map->buckets);
+	}
+
+	/* rules */
+	if (map->rules) {
+		__u32 b;
+		for (b = 0; b < map->max_rules; b++)
+			crush_destroy_rule(map->rules[b]);
+		kfree(map->rules);
+	}
+
+#ifndef __KERNEL__
+	kfree(map->choose_tries);
+#else
+	clear_choose_args(map);
+#endif
+	kfree(map);
+}
+
+void crush_destroy_rule(struct crush_rule *rule)
+{
+	kfree(rule);
+}
diff --git a/net/ceph/crush/crush_ln_table.h b/net/ceph/crush/crush_ln_table.h
new file mode 100644
index 000000000..aae534c90
--- /dev/null
+++ b/net/ceph/crush/crush_ln_table.h
@@ -0,0 +1,164 @@
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2015 Intel Corporation All Rights Reserved
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ *
+ */
+
+#ifndef CEPH_CRUSH_LN_H
+#define CEPH_CRUSH_LN_H
+
+#ifdef __KERNEL__
+# include <linux/types.h>
+#else
+# include "crush_compat.h"
+#endif
+
+/*
+ * RH_LH_tbl[2*k] = 2^48/(1.0+k/128.0)
+ * RH_LH_tbl[2*k+1] = 2^48*log2(1.0+k/128.0)
+ */
+static __s64 __RH_LH_tbl[128*2+2] = {
+  0x0001000000000000ll, 0x0000000000000000ll, 0x0000fe03f80fe040ll, 0x000002dfca16dde1ll,
+  0x0000fc0fc0fc0fc1ll, 0x000005b9e5a170b4ll, 0x0000fa232cf25214ll, 0x0000088e68ea899all,
+  0x0000f83e0f83e0f9ll, 0x00000b5d69bac77ell, 0x0000f6603d980f67ll, 0x00000e26fd5c8555ll,
+  0x0000f4898d5f85bcll, 0x000010eb389fa29fll, 0x0000f2b9d6480f2cll, 0x000013aa2fdd27f1ll,
+  0x0000f0f0f0f0f0f1ll, 0x00001663f6fac913ll, 0x0000ef2eb71fc435ll, 0x00001918a16e4633ll,
+  0x0000ed7303b5cc0fll, 0x00001bc84240adabll, 0x0000ebbdb2a5c162ll, 0x00001e72ec117fa5ll,
+  0x0000ea0ea0ea0ea1ll, 0x00002118b119b4f3ll, 0x0000e865ac7b7604ll, 0x000023b9a32eaa56ll,
+  0x0000e6c2b4481cd9ll, 0x00002655d3c4f15cll, 0x0000e525982af70dll, 0x000028ed53f307eell,
+  0x0000e38e38e38e39ll, 0x00002b803473f7adll, 0x0000e1fc780e1fc8ll, 0x00002e0e85a9de04ll,
+  0x0000e070381c0e08ll, 0x0000309857a05e07ll, 0x0000dee95c4ca038ll, 0x0000331dba0efce1ll,
+  0x0000dd67c8a60dd7ll, 0x0000359ebc5b69d9ll, 0x0000dbeb61eed19dll, 0x0000381b6d9bb29bll,
+  0x0000da740da740dbll, 0x00003a93dc9864b2ll, 0x0000d901b2036407ll, 0x00003d0817ce9cd4ll,
+  0x0000d79435e50d7all, 0x00003f782d7204d0ll, 0x0000d62b80d62b81ll, 0x000041e42b6ec0c0ll,
+  0x0000d4c77b03531ell, 0x0000444c1f6b4c2dll, 0x0000d3680d3680d4ll, 0x000046b016ca47c1ll,
+  0x0000d20d20d20d21ll, 0x000049101eac381cll, 0x0000d0b69fcbd259ll, 0x00004b6c43f1366all,
+  0x0000cf6474a8819fll, 0x00004dc4933a9337ll, 0x0000ce168a772509ll, 0x0000501918ec6c11ll,
+  0x0000cccccccccccdll, 0x00005269e12f346ell, 0x0000cb8727c065c4ll, 0x000054b6f7f1325all,
+  0x0000ca4587e6b750ll, 0x0000570068e7ef5all, 0x0000c907da4e8712ll, 0x000059463f919deell,
+  0x0000c7ce0c7ce0c8ll, 0x00005b8887367433ll, 0x0000c6980c6980c7ll, 0x00005dc74ae9fbecll,
+  0x0000c565c87b5f9ell, 0x00006002958c5871ll, 0x0000c4372f855d83ll, 0x0000623a71cb82c8ll,
+  0x0000c30c30c30c31ll, 0x0000646eea247c5cll, 0x0000c1e4bbd595f7ll, 0x000066a008e4788cll,
+  0x0000c0c0c0c0c0c1ll, 0x000068cdd829fd81ll, 0x0000bfa02fe80bfbll, 0x00006af861e5fc7dll,
+  0x0000be82fa0be830ll, 0x00006d1fafdce20all, 0x0000bd6910470767ll, 0x00006f43cba79e40ll,
+  0x0000bc52640bc527ll, 0x00007164beb4a56dll, 0x0000bb3ee721a54ell, 0x000073829248e961ll,
+  0x0000ba2e8ba2e8bbll, 0x0000759d4f80cba8ll, 0x0000b92143fa36f6ll, 0x000077b4ff5108d9ll,
+  0x0000b81702e05c0cll, 0x000079c9aa879d53ll, 0x0000b70fbb5a19bfll, 0x00007bdb59cca388ll,
+  0x0000b60b60b60b61ll, 0x00007dea15a32c1bll, 0x0000b509e68a9b95ll, 0x00007ff5e66a0ffell,
+  0x0000b40b40b40b41ll, 0x000081fed45cbccbll, 0x0000b30f63528918ll, 0x00008404e793fb81ll,
+  0x0000b21642c8590cll, 0x000086082806b1d5ll, 0x0000b11fd3b80b12ll, 0x000088089d8a9e47ll,
+  0x0000b02c0b02c0b1ll, 0x00008a064fd50f2all, 0x0000af3addc680b0ll, 0x00008c01467b94bbll,
+  0x0000ae4c415c9883ll, 0x00008df988f4ae80ll, 0x0000ad602b580ad7ll, 0x00008fef1e987409ll,
+  0x0000ac7691840ac8ll, 0x000091e20ea1393ell, 0x0000ab8f69e2835all, 0x000093d2602c2e5fll,
+  0x0000aaaaaaaaaaabll, 0x000095c01a39fbd6ll, 0x0000a9c84a47a080ll, 0x000097ab43af59f9ll,
+  0x0000a8e83f5717c1ll, 0x00009993e355a4e5ll, 0x0000a80a80a80a81ll, 0x00009b79ffdb6c8bll,
+  0x0000a72f0539782all, 0x00009d5d9fd5010bll, 0x0000a655c4392d7cll, 0x00009f3ec9bcfb80ll,
+  0x0000a57eb50295fbll, 0x0000a11d83f4c355ll, 0x0000a4a9cf1d9684ll, 0x0000a2f9d4c51039ll,
+  0x0000a3d70a3d70a4ll, 0x0000a4d3c25e68dcll, 0x0000a3065e3fae7dll, 0x0000a6ab52d99e76ll,
+  0x0000a237c32b16d0ll, 0x0000a8808c384547ll, 0x0000a16b312ea8fdll, 0x0000aa5374652a1cll,
+  0x0000a0a0a0a0a0a1ll, 0x0000ac241134c4e9ll, 0x00009fd809fd80a0ll, 0x0000adf26865a8a1ll,
+  0x00009f1165e72549ll, 0x0000afbe7fa0f04dll, 0x00009e4cad23dd60ll, 0x0000b1885c7aa982ll,
+  0x00009d89d89d89d9ll, 0x0000b35004723c46ll, 0x00009cc8e160c3fcll, 0x0000b5157cf2d078ll,
+  0x00009c09c09c09c1ll, 0x0000b6d8cb53b0call, 0x00009b4c6f9ef03bll, 0x0000b899f4d8ab63ll,
+  0x00009a90e7d95bc7ll, 0x0000ba58feb2703all, 0x000099d722dabde6ll, 0x0000bc15edfeed32ll,
+  0x0000991f1a515886ll, 0x0000bdd0c7c9a817ll, 0x00009868c809868dll, 0x0000bf89910c1678ll,
+  0x000097b425ed097cll, 0x0000c1404eadf383ll, 0x000097012e025c05ll, 0x0000c2f5058593d9ll,
+  0x0000964fda6c0965ll, 0x0000c4a7ba58377cll, 0x000095a02568095bll, 0x0000c65871da59ddll,
+  0x000094f2094f2095ll, 0x0000c80730b00016ll, 0x0000944580944581ll, 0x0000c9b3fb6d0559ll,
+  0x0000939a85c4093all, 0x0000cb5ed69565afll, 0x000092f113840498ll, 0x0000cd07c69d8702ll,
+  0x0000924924924925ll, 0x0000ceaecfea8085ll, 0x000091a2b3c4d5e7ll, 0x0000d053f6d26089ll,
+  0x000090fdbc090fdcll, 0x0000d1f73f9c70c0ll, 0x0000905a38633e07ll, 0x0000d398ae817906ll,
+  0x00008fb823ee08fcll, 0x0000d53847ac00a6ll, 0x00008f1779d9fdc4ll, 0x0000d6d60f388e41ll,
+  0x00008e78356d1409ll, 0x0000d8720935e643ll, 0x00008dda5202376all, 0x0000da0c39a54804ll,
+  0x00008d3dcb08d3ddll, 0x0000dba4a47aa996ll, 0x00008ca29c046515ll, 0x0000dd3b4d9cf24bll,
+  0x00008c08c08c08c1ll, 0x0000ded038e633f3ll, 0x00008b70344a139cll, 0x0000e0636a23e2eell,
+  0x00008ad8f2fba939ll, 0x0000e1f4e5170d02ll, 0x00008a42f870566all, 0x0000e384ad748f0ell,
+  0x000089ae4089ae41ll, 0x0000e512c6e54998ll, 0x0000891ac73ae982ll, 0x0000e69f35065448ll,
+  0x0000888888888889ll, 0x0000e829fb693044ll, 0x000087f78087f781ll, 0x0000e9b31d93f98ell,
+  0x00008767ab5f34e5ll, 0x0000eb3a9f019750ll, 0x000086d905447a35ll, 0x0000ecc08321eb30ll,
+  0x0000864b8a7de6d2ll, 0x0000ee44cd59ffabll, 0x000085bf37612cefll, 0x0000efc781043579ll,
+  0x0000853408534086ll, 0x0000f148a170700all, 0x000084a9f9c8084bll, 0x0000f2c831e44116ll,
+  0x0000842108421085ll, 0x0000f446359b1353ll, 0x0000839930523fbfll, 0x0000f5c2afc65447ll,
+  0x000083126e978d50ll, 0x0000f73da38d9d4all, 0x0000828cbfbeb9a1ll, 0x0000f8b7140edbb1ll,
+  0x0000820820820821ll, 0x0000fa2f045e7832ll, 0x000081848da8faf1ll, 0x0000fba577877d7dll,
+  0x0000810204081021ll, 0x0000fd1a708bbe11ll, 0x0000808080808081ll, 0x0000fe8df263f957ll,
+  0x0000800000000000ll, 0x0000ffff00000000ll,
+};
+
+/*
+ * LL_tbl[k] = 2^48*log2(1.0+k/2^15)
+ */
+static __s64 __LL_tbl[256] = {
+  0x0000000000000000ull, 0x00000002e2a60a00ull, 0x000000070cb64ec5ull, 0x00000009ef50ce67ull,
+  0x0000000cd1e588fdull, 0x0000000fb4747e9cull, 0x0000001296fdaf5eull, 0x0000001579811b58ull,
+  0x000000185bfec2a1ull, 0x0000001b3e76a552ull, 0x0000001e20e8c380ull, 0x0000002103551d43ull,
+  0x00000023e5bbb2b2ull, 0x00000026c81c83e4ull, 0x00000029aa7790f0ull, 0x0000002c8cccd9edull,
+  0x0000002f6f1c5ef2ull, 0x0000003251662017ull, 0x0000003533aa1d71ull, 0x0000003815e8571aull,
+  0x0000003af820cd26ull, 0x0000003dda537faeull, 0x00000040bc806ec8ull, 0x000000439ea79a8cull,
+  0x0000004680c90310ull, 0x0000004962e4a86cull, 0x0000004c44fa8ab6ull, 0x0000004f270aaa06ull,
+  0x0000005209150672ull, 0x00000054eb19a013ull, 0x00000057cd1876fdull, 0x0000005aaf118b4aull,
+  0x0000005d9104dd0full, 0x0000006072f26c64ull, 0x0000006354da3960ull, 0x0000006636bc441aull,
+  0x0000006918988ca8ull, 0x0000006bfa6f1322ull, 0x0000006edc3fd79full, 0x00000071be0ada35ull,
+  0x000000749fd01afdull, 0x00000077818f9a0cull, 0x0000007a6349577aull, 0x0000007d44fd535eull,
+  0x0000008026ab8dceull, 0x00000083085406e3ull, 0x00000085e9f6beb2ull, 0x00000088cb93b552ull,
+  0x0000008bad2aeadcull, 0x0000008e8ebc5f65ull, 0x0000009170481305ull, 0x0000009451ce05d3ull,
+  0x00000097334e37e5ull, 0x0000009a14c8a953ull, 0x0000009cf63d5a33ull, 0x0000009fd7ac4a9dull,
+  0x000000a2b07f3458ull, 0x000000a59a78ea6aull, 0x000000a87bd699fbull, 0x000000ab5d2e8970ull,
+  0x000000ae3e80b8e3ull, 0x000000b11fcd2869ull, 0x000000b40113d818ull, 0x000000b6e254c80aull,
+  0x000000b9c38ff853ull, 0x000000bca4c5690cull, 0x000000bf85f51a4aull, 0x000000c2671f0c26ull,
+  0x000000c548433eb6ull, 0x000000c82961b211ull, 0x000000cb0a7a664dull, 0x000000cdeb8d5b82ull,
+  0x000000d0cc9a91c8ull, 0x000000d3ada20933ull, 0x000000d68ea3c1ddull, 0x000000d96f9fbbdbull,
+  0x000000dc5095f744ull, 0x000000df31867430ull, 0x000000e2127132b5ull, 0x000000e4f35632eaull,
+  0x000000e7d43574e6ull, 0x000000eab50ef8c1ull, 0x000000ed95e2be90ull, 0x000000f076b0c66cull,
+  0x000000f35779106aull, 0x000000f6383b9ca2ull, 0x000000f918f86b2aull, 0x000000fbf9af7c1aull,
+  0x000000feda60cf88ull, 0x00000101bb0c658cull, 0x000001049bb23e3cull, 0x000001077c5259afull,
+  0x0000010a5cecb7fcull, 0x0000010d3d81593aull, 0x000001101e103d7full, 0x00000112fe9964e4ull,
+  0x00000115df1ccf7eull, 0x00000118bf9a7d64ull, 0x0000011ba0126eadull, 0x0000011e8084a371ull,
+  0x0000012160f11bc6ull, 0x000001244157d7c3ull, 0x0000012721b8d77full, 0x0000012a02141b10ull,
+  0x0000012ce269a28eull, 0x0000012fc2b96e0full, 0x00000132a3037daaull, 0x000001358347d177ull,
+  0x000001386386698cull, 0x0000013b43bf45ffull, 0x0000013e23f266e9ull, 0x00000141041fcc5eull,
+  0x00000143e4477678ull, 0x00000146c469654bull, 0x00000149a48598f0ull, 0x0000014c849c117cull,
+  0x0000014f64accf08ull, 0x0000015244b7d1a9ull, 0x0000015524bd1976ull, 0x0000015804bca687ull,
+  0x0000015ae4b678f2ull, 0x0000015dc4aa90ceull, 0x00000160a498ee31ull, 0x0000016384819134ull,
+  0x00000166646479ecull, 0x000001694441a870ull, 0x0000016c24191cd7ull, 0x0000016df6ca19bdull,
+  0x00000171e3b6d7aaull, 0x00000174c37d1e44ull, 0x00000177a33dab1cull, 0x0000017a82f87e49ull,
+  0x0000017d62ad97e2ull, 0x00000180425cf7feull, 0x00000182b07f3458ull, 0x0000018601aa8c19ull,
+  0x00000188e148c046ull, 0x0000018bc0e13b52ull, 0x0000018ea073fd52ull, 0x000001918001065dull,
+  0x000001945f88568bull, 0x000001973f09edf2ull, 0x0000019a1e85ccaaull, 0x0000019cfdfbf2c8ull,
+  0x0000019fdd6c6063ull, 0x000001a2bcd71593ull, 0x000001a59c3c126eull, 0x000001a87b9b570bull,
+  0x000001ab5af4e380ull, 0x000001ae3a48b7e5ull, 0x000001b11996d450ull, 0x000001b3f8df38d9ull,
+  0x000001b6d821e595ull, 0x000001b9b75eda9bull, 0x000001bc96961803ull, 0x000001bf75c79de3ull,
+  0x000001c254f36c51ull, 0x000001c534198365ull, 0x000001c81339e336ull, 0x000001caf2548bd9ull,
+  0x000001cdd1697d67ull, 0x000001d0b078b7f5ull, 0x000001d38f823b9aull, 0x000001d66e86086dull,
+  0x000001d94d841e86ull, 0x000001dc2c7c7df9ull, 0x000001df0b6f26dfull, 0x000001e1ea5c194eull,
+  0x000001e4c943555dull, 0x000001e7a824db23ull, 0x000001ea8700aab5ull, 0x000001ed65d6c42bull,
+  0x000001f044a7279dull, 0x000001f32371d51full, 0x000001f60236cccaull, 0x000001f8e0f60eb3ull,
+  0x000001fbbfaf9af3ull, 0x000001fe9e63719eull, 0x000002017d1192ccull, 0x000002045bb9fe94ull,
+  0x000002073a5cb50dull, 0x00000209c06e6212ull, 0x0000020cf791026aull, 0x0000020fd622997cull,
+  0x00000212b07f3458ull, 0x000002159334a8d8ull, 0x0000021871b52150ull, 0x0000021b502fe517ull,
+  0x0000021d6a73a78full, 0x000002210d144eeeull, 0x00000223eb7df52cull, 0x00000226c9e1e713ull,
+  0x00000229a84024bbull, 0x0000022c23679b4eull, 0x0000022f64eb83a8ull, 0x000002324338a51bull,
+  0x00000235218012a9ull, 0x00000237ffc1cc69ull, 0x0000023a2c3b0ea4ull, 0x0000023d13ee805bull,
+  0x0000024035e9221full, 0x00000243788faf25ull, 0x0000024656b4e735ull, 0x00000247ed646bfeull,
+  0x0000024c12ee3d98ull, 0x0000024ef1025c1aull, 0x00000251cf10c799ull, 0x0000025492644d65ull,
+  0x000002578b1c85eeull, 0x0000025a6919d8f0ull, 0x0000025d13ee805bull, 0x0000026025036716ull,
+  0x0000026296453882ull, 0x00000265e0d62b53ull, 0x00000268beb701f3ull, 0x0000026b9c92265eull,
+  0x0000026d32f798a9ull, 0x00000271583758ebull, 0x000002743601673bull, 0x0000027713c5c3b0ull,
+  0x00000279f1846e5full, 0x0000027ccf3d6761ull, 0x0000027e6580aecbull, 0x000002828a9e44b3ull,
+  0x0000028568462932ull, 0x00000287bdbf5255ull, 0x0000028b2384de4aull, 0x0000028d13ee805bull,
+  0x0000029035e9221full, 0x0000029296453882ull, 0x0000029699bdfb61ull, 0x0000029902a37aabull,
+  0x0000029c54b864c9ull, 0x0000029deabd1083ull, 0x000002a20f9c0bb5ull, 0x000002a4c7605d61ull,
+  0x000002a7bdbf5255ull, 0x000002a96056dafcull, 0x000002ac3daf14efull, 0x000002af1b019ecaull,
+  0x000002b296453882ull, 0x000002b5d022d80full, 0x000002b8fa471cb3ull, 0x000002ba9012e713ull,
+  0x000002bd6d4901ccull, 0x000002c04a796cf6ull, 0x000002c327a428a6ull, 0x000002c61a5e8f4cull,
+  0x000002c8e1e891f6ull, 0x000002cbbf023fc2ull, 0x000002ce9c163e6eull, 0x000002d179248e13ull,
+  0x000002d4562d2ec6ull, 0x000002d73330209dull, 0x000002da102d63b0ull, 0x000002dced24f814ull,
+};
+
+#endif
diff --git a/net/ceph/crush/hash.c b/net/ceph/crush/hash.c
new file mode 100644
index 000000000..e5cc603cd
--- /dev/null
+++ b/net/ceph/crush/hash.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifdef __KERNEL__
+# include <linux/crush/hash.h>
+#else
+# include "hash.h"
+#endif
+
+/*
+ * Robert Jenkins' function for mixing 32-bit values
+ * http://burtleburtle.net/bob/hash/evahash.html
+ * a, b = random bits, c = input and output
+ */
+#define crush_hashmix(a, b, c) do {			\
+		a = a-b;  a = a-c;  a = a^(c>>13);	\
+		b = b-c;  b = b-a;  b = b^(a<<8);	\
+		c = c-a;  c = c-b;  c = c^(b>>13);	\
+		a = a-b;  a = a-c;  a = a^(c>>12);	\
+		b = b-c;  b = b-a;  b = b^(a<<16);	\
+		c = c-a;  c = c-b;  c = c^(b>>5);	\
+		a = a-b;  a = a-c;  a = a^(c>>3);	\
+		b = b-c;  b = b-a;  b = b^(a<<10);	\
+		c = c-a;  c = c-b;  c = c^(b>>15);	\
+	} while (0)
+
+#define crush_hash_seed 1315423911
+
+static __u32 crush_hash32_rjenkins1(__u32 a)
+{
+	__u32 hash = crush_hash_seed ^ a;
+	__u32 b = a;
+	__u32 x = 231232;
+	__u32 y = 1232;
+	crush_hashmix(b, x, hash);
+	crush_hashmix(y, a, hash);
+	return hash;
+}
+
+static __u32 crush_hash32_rjenkins1_2(__u32 a, __u32 b)
+{
+	__u32 hash = crush_hash_seed ^ a ^ b;
+	__u32 x = 231232;
+	__u32 y = 1232;
+	crush_hashmix(a, b, hash);
+	crush_hashmix(x, a, hash);
+	crush_hashmix(b, y, hash);
+	return hash;
+}
+
+static __u32 crush_hash32_rjenkins1_3(__u32 a, __u32 b, __u32 c)
+{
+	__u32 hash = crush_hash_seed ^ a ^ b ^ c;
+	__u32 x = 231232;
+	__u32 y = 1232;
+	crush_hashmix(a, b, hash);
+	crush_hashmix(c, x, hash);
+	crush_hashmix(y, a, hash);
+	crush_hashmix(b, x, hash);
+	crush_hashmix(y, c, hash);
+	return hash;
+}
+
+static __u32 crush_hash32_rjenkins1_4(__u32 a, __u32 b, __u32 c, __u32 d)
+{
+	__u32 hash = crush_hash_seed ^ a ^ b ^ c ^ d;
+	__u32 x = 231232;
+	__u32 y = 1232;
+	crush_hashmix(a, b, hash);
+	crush_hashmix(c, d, hash);
+	crush_hashmix(a, x, hash);
+	crush_hashmix(y, b, hash);
+	crush_hashmix(c, x, hash);
+	crush_hashmix(y, d, hash);
+	return hash;
+}
+
+static __u32 crush_hash32_rjenkins1_5(__u32 a, __u32 b, __u32 c, __u32 d,
+				      __u32 e)
+{
+	__u32 hash = crush_hash_seed ^ a ^ b ^ c ^ d ^ e;
+	__u32 x = 231232;
+	__u32 y = 1232;
+	crush_hashmix(a, b, hash);
+	crush_hashmix(c, d, hash);
+	crush_hashmix(e, x, hash);
+	crush_hashmix(y, a, hash);
+	crush_hashmix(b, x, hash);
+	crush_hashmix(y, c, hash);
+	crush_hashmix(d, x, hash);
+	crush_hashmix(y, e, hash);
+	return hash;
+}
+
+
+__u32 crush_hash32(int type, __u32 a)
+{
+	switch (type) {
+	case CRUSH_HASH_RJENKINS1:
+		return crush_hash32_rjenkins1(a);
+	default:
+		return 0;
+	}
+}
+
+__u32 crush_hash32_2(int type, __u32 a, __u32 b)
+{
+	switch (type) {
+	case CRUSH_HASH_RJENKINS1:
+		return crush_hash32_rjenkins1_2(a, b);
+	default:
+		return 0;
+	}
+}
+
+__u32 crush_hash32_3(int type, __u32 a, __u32 b, __u32 c)
+{
+	switch (type) {
+	case CRUSH_HASH_RJENKINS1:
+		return crush_hash32_rjenkins1_3(a, b, c);
+	default:
+		return 0;
+	}
+}
+
+__u32 crush_hash32_4(int type, __u32 a, __u32 b, __u32 c, __u32 d)
+{
+	switch (type) {
+	case CRUSH_HASH_RJENKINS1:
+		return crush_hash32_rjenkins1_4(a, b, c, d);
+	default:
+		return 0;
+	}
+}
+
+__u32 crush_hash32_5(int type, __u32 a, __u32 b, __u32 c, __u32 d, __u32 e)
+{
+	switch (type) {
+	case CRUSH_HASH_RJENKINS1:
+		return crush_hash32_rjenkins1_5(a, b, c, d, e);
+	default:
+		return 0;
+	}
+}
+
+const char *crush_hash_name(int type)
+{
+	switch (type) {
+	case CRUSH_HASH_RJENKINS1:
+		return "rjenkins1";
+	default:
+		return "unknown";
+	}
+}
diff --git a/net/ceph/crush/mapper.c b/net/ceph/crush/mapper.c
new file mode 100644
index 000000000..3f323ed9d
--- /dev/null
+++ b/net/ceph/crush/mapper.c
@@ -0,0 +1,1099 @@
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2015 Intel Corporation All Rights Reserved
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ *
+ */
+
+#ifdef __KERNEL__
+# include <linux/string.h>
+# include <linux/slab.h>
+# include <linux/bug.h>
+# include <linux/kernel.h>
+# include <linux/crush/crush.h>
+# include <linux/crush/hash.h>
+# include <linux/crush/mapper.h>
+#else
+# include "crush_compat.h"
+# include "crush.h"
+# include "hash.h"
+# include "mapper.h"
+#endif
+#include "crush_ln_table.h"
+
+#define dprintk(args...) /* printf(args) */
+
+/*
+ * Implement the core CRUSH mapping algorithm.
+ */
+
+/**
+ * crush_find_rule - find a crush_rule id for a given ruleset, type, and size.
+ * @map: the crush_map
+ * @ruleset: the storage ruleset id (user defined)
+ * @type: storage ruleset type (user defined)
+ * @size: output set size
+ */
+int crush_find_rule(const struct crush_map *map, int ruleset, int type, int size)
+{
+	__u32 i;
+
+	for (i = 0; i < map->max_rules; i++) {
+		if (map->rules[i] &&
+		    map->rules[i]->mask.ruleset == ruleset &&
+		    map->rules[i]->mask.type == type &&
+		    map->rules[i]->mask.min_size <= size &&
+		    map->rules[i]->mask.max_size >= size)
+			return i;
+	}
+	return -1;
+}
+
+/*
+ * bucket choose methods
+ *
+ * For each bucket algorithm, we have a "choose" method that, given a
+ * crush input @x and replica position (usually, position in output set) @r,
+ * will produce an item in the bucket.
+ */
+
+/*
+ * Choose based on a random permutation of the bucket.
+ *
+ * We used to use some prime number arithmetic to do this, but it
+ * wasn't very random, and had some other bad behaviors.  Instead, we
+ * calculate an actual random permutation of the bucket members.
+ * Since this is expensive, we optimize for the r=0 case, which
+ * captures the vast majority of calls.
+ */
+static int bucket_perm_choose(const struct crush_bucket *bucket,
+			      struct crush_work_bucket *work,
+			      int x, int r)
+{
+	unsigned int pr = r % bucket->size;
+	unsigned int i, s;
+
+	/* start a new permutation if @x has changed */
+	if (work->perm_x != (__u32)x || work->perm_n == 0) {
+		dprintk("bucket %d new x=%d\n", bucket->id, x);
+		work->perm_x = x;
+
+		/* optimize common r=0 case */
+		if (pr == 0) {
+			s = crush_hash32_3(bucket->hash, x, bucket->id, 0) %
+				bucket->size;
+			work->perm[0] = s;
+			work->perm_n = 0xffff;   /* magic value, see below */
+			goto out;
+		}
+
+		for (i = 0; i < bucket->size; i++)
+			work->perm[i] = i;
+		work->perm_n = 0;
+	} else if (work->perm_n == 0xffff) {
+		/* clean up after the r=0 case above */
+		for (i = 1; i < bucket->size; i++)
+			work->perm[i] = i;
+		work->perm[work->perm[0]] = 0;
+		work->perm_n = 1;
+	}
+
+	/* calculate permutation up to pr */
+	for (i = 0; i < work->perm_n; i++)
+		dprintk(" perm_choose have %d: %d\n", i, work->perm[i]);
+	while (work->perm_n <= pr) {
+		unsigned int p = work->perm_n;
+		/* no point in swapping the final entry */
+		if (p < bucket->size - 1) {
+			i = crush_hash32_3(bucket->hash, x, bucket->id, p) %
+				(bucket->size - p);
+			if (i) {
+				unsigned int t = work->perm[p + i];
+				work->perm[p + i] = work->perm[p];
+				work->perm[p] = t;
+			}
+			dprintk(" perm_choose swap %d with %d\n", p, p+i);
+		}
+		work->perm_n++;
+	}
+	for (i = 0; i < bucket->size; i++)
+		dprintk(" perm_choose  %d: %d\n", i, work->perm[i]);
+
+	s = work->perm[pr];
+out:
+	dprintk(" perm_choose %d sz=%d x=%d r=%d (%d) s=%d\n", bucket->id,
+		bucket->size, x, r, pr, s);
+	return bucket->items[s];
+}
+
+/* uniform */
+static int bucket_uniform_choose(const struct crush_bucket_uniform *bucket,
+				 struct crush_work_bucket *work, int x, int r)
+{
+	return bucket_perm_choose(&bucket->h, work, x, r);
+}
+
+/* list */
+static int bucket_list_choose(const struct crush_bucket_list *bucket,
+			      int x, int r)
+{
+	int i;
+
+	for (i = bucket->h.size-1; i >= 0; i--) {
+		__u64 w = crush_hash32_4(bucket->h.hash, x, bucket->h.items[i],
+					 r, bucket->h.id);
+		w &= 0xffff;
+		dprintk("list_choose i=%d x=%d r=%d item %d weight %x "
+			"sw %x rand %llx",
+			i, x, r, bucket->h.items[i], bucket->item_weights[i],
+			bucket->sum_weights[i], w);
+		w *= bucket->sum_weights[i];
+		w = w >> 16;
+		/*dprintk(" scaled %llx\n", w);*/
+		if (w < bucket->item_weights[i]) {
+			return bucket->h.items[i];
+		}
+	}
+
+	dprintk("bad list sums for bucket %d\n", bucket->h.id);
+	return bucket->h.items[0];
+}
+
+
+/* (binary) tree */
+static int height(int n)
+{
+	int h = 0;
+	while ((n & 1) == 0) {
+		h++;
+		n = n >> 1;
+	}
+	return h;
+}
+
+static int left(int x)
+{
+	int h = height(x);
+	return x - (1 << (h-1));
+}
+
+static int right(int x)
+{
+	int h = height(x);
+	return x + (1 << (h-1));
+}
+
+static int terminal(int x)
+{
+	return x & 1;
+}
+
+static int bucket_tree_choose(const struct crush_bucket_tree *bucket,
+			      int x, int r)
+{
+	int n;
+	__u32 w;
+	__u64 t;
+
+	/* start at root */
+	n = bucket->num_nodes >> 1;
+
+	while (!terminal(n)) {
+		int l;
+		/* pick point in [0, w) */
+		w = bucket->node_weights[n];
+		t = (__u64)crush_hash32_4(bucket->h.hash, x, n, r,
+					  bucket->h.id) * (__u64)w;
+		t = t >> 32;
+
+		/* descend to the left or right? */
+		l = left(n);
+		if (t < bucket->node_weights[l])
+			n = l;
+		else
+			n = right(n);
+	}
+
+	return bucket->h.items[n >> 1];
+}
+
+
+/* straw */
+
+static int bucket_straw_choose(const struct crush_bucket_straw *bucket,
+			       int x, int r)
+{
+	__u32 i;
+	int high = 0;
+	__u64 high_draw = 0;
+	__u64 draw;
+
+	for (i = 0; i < bucket->h.size; i++) {
+		draw = crush_hash32_3(bucket->h.hash, x, bucket->h.items[i], r);
+		draw &= 0xffff;
+		draw *= bucket->straws[i];
+		if (i == 0 || draw > high_draw) {
+			high = i;
+			high_draw = draw;
+		}
+	}
+	return bucket->h.items[high];
+}
+
+/* compute 2^44*log2(input+1) */
+static __u64 crush_ln(unsigned int xin)
+{
+	unsigned int x = xin;
+	int iexpon, index1, index2;
+	__u64 RH, LH, LL, xl64, result;
+
+	x++;
+
+	/* normalize input */
+	iexpon = 15;
+
+	/*
+	 * figure out number of bits we need to shift and
+	 * do it in one step instead of iteratively
+	 */
+	if (!(x & 0x18000)) {
+		int bits = __builtin_clz(x & 0x1FFFF) - 16;
+		x <<= bits;
+		iexpon = 15 - bits;
+	}
+
+	index1 = (x >> 8) << 1;
+	/* RH ~ 2^56/index1 */
+	RH = __RH_LH_tbl[index1 - 256];
+	/* LH ~ 2^48 * log2(index1/256) */
+	LH = __RH_LH_tbl[index1 + 1 - 256];
+
+	/* RH*x ~ 2^48 * (2^15 + xf), xf<2^8 */
+	xl64 = (__s64)x * RH;
+	xl64 >>= 48;
+
+	result = iexpon;
+	result <<= (12 + 32);
+
+	index2 = xl64 & 0xff;
+	/* LL ~ 2^48*log2(1.0+index2/2^15) */
+	LL = __LL_tbl[index2];
+
+	LH = LH + LL;
+
+	LH >>= (48 - 12 - 32);
+	result += LH;
+
+	return result;
+}
+
+
+/*
+ * straw2
+ *
+ * for reference, see:
+ *
+ * http://en.wikipedia.org/wiki/Exponential_distribution#Distribution_of_the_minimum_of_exponential_random_variables
+ *
+ */
+
+static __u32 *get_choose_arg_weights(const struct crush_bucket_straw2 *bucket,
+				     const struct crush_choose_arg *arg,
+				     int position)
+{
+	if (!arg || !arg->weight_set)
+		return bucket->item_weights;
+
+	if (position >= arg->weight_set_size)
+		position = arg->weight_set_size - 1;
+	return arg->weight_set[position].weights;
+}
+
+static __s32 *get_choose_arg_ids(const struct crush_bucket_straw2 *bucket,
+				 const struct crush_choose_arg *arg)
+{
+	if (!arg || !arg->ids)
+		return bucket->h.items;
+
+	return arg->ids;
+}
+
+static int bucket_straw2_choose(const struct crush_bucket_straw2 *bucket,
+				int x, int r,
+				const struct crush_choose_arg *arg,
+				int position)
+{
+	unsigned int i, high = 0;
+	unsigned int u;
+	__s64 ln, draw, high_draw = 0;
+	__u32 *weights = get_choose_arg_weights(bucket, arg, position);
+	__s32 *ids = get_choose_arg_ids(bucket, arg);
+
+	for (i = 0; i < bucket->h.size; i++) {
+		dprintk("weight 0x%x item %d\n", weights[i], ids[i]);
+		if (weights[i]) {
+			u = crush_hash32_3(bucket->h.hash, x, ids[i], r);
+			u &= 0xffff;
+
+			/*
+			 * for some reason slightly less than 0x10000 produces
+			 * a slightly more accurate distribution... probably a
+			 * rounding effect.
+			 *
+			 * the natural log lookup table maps [0,0xffff]
+			 * (corresponding to real numbers [1/0x10000, 1] to
+			 * [0, 0xffffffffffff] (corresponding to real numbers
+			 * [-11.090355,0]).
+			 */
+			ln = crush_ln(u) - 0x1000000000000ll;
+
+			/*
+			 * divide by 16.16 fixed-point weight.  note
+			 * that the ln value is negative, so a larger
+			 * weight means a larger (less negative) value
+			 * for draw.
+			 */
+			draw = div64_s64(ln, weights[i]);
+		} else {
+			draw = S64_MIN;
+		}
+
+		if (i == 0 || draw > high_draw) {
+			high = i;
+			high_draw = draw;
+		}
+	}
+
+	return bucket->h.items[high];
+}
+
+
+static int crush_bucket_choose(const struct crush_bucket *in,
+			       struct crush_work_bucket *work,
+			       int x, int r,
+			       const struct crush_choose_arg *arg,
+			       int position)
+{
+	dprintk(" crush_bucket_choose %d x=%d r=%d\n", in->id, x, r);
+	BUG_ON(in->size == 0);
+	switch (in->alg) {
+	case CRUSH_BUCKET_UNIFORM:
+		return bucket_uniform_choose(
+			(const struct crush_bucket_uniform *)in,
+			work, x, r);
+	case CRUSH_BUCKET_LIST:
+		return bucket_list_choose((const struct crush_bucket_list *)in,
+					  x, r);
+	case CRUSH_BUCKET_TREE:
+		return bucket_tree_choose((const struct crush_bucket_tree *)in,
+					  x, r);
+	case CRUSH_BUCKET_STRAW:
+		return bucket_straw_choose(
+			(const struct crush_bucket_straw *)in,
+			x, r);
+	case CRUSH_BUCKET_STRAW2:
+		return bucket_straw2_choose(
+			(const struct crush_bucket_straw2 *)in,
+			x, r, arg, position);
+	default:
+		dprintk("unknown bucket %d alg %d\n", in->id, in->alg);
+		return in->items[0];
+	}
+}
+
+/*
+ * true if device is marked "out" (failed, fully offloaded)
+ * of the cluster
+ */
+static int is_out(const struct crush_map *map,
+		  const __u32 *weight, int weight_max,
+		  int item, int x)
+{
+	if (item >= weight_max)
+		return 1;
+	if (weight[item] >= 0x10000)
+		return 0;
+	if (weight[item] == 0)
+		return 1;
+	if ((crush_hash32_2(CRUSH_HASH_RJENKINS1, x, item) & 0xffff)
+	    < weight[item])
+		return 0;
+	return 1;
+}
+
+/**
+ * crush_choose_firstn - choose numrep distinct items of given type
+ * @map: the crush_map
+ * @bucket: the bucket we are choose an item from
+ * @x: crush input value
+ * @numrep: the number of items to choose
+ * @type: the type of item to choose
+ * @out: pointer to output vector
+ * @outpos: our position in that vector
+ * @out_size: size of the out vector
+ * @tries: number of attempts to make
+ * @recurse_tries: number of attempts to have recursive chooseleaf make
+ * @local_retries: localized retries
+ * @local_fallback_retries: localized fallback retries
+ * @recurse_to_leaf: true if we want one device under each item of given type (chooseleaf instead of choose)
+ * @stable: stable mode starts rep=0 in the recursive call for all replicas
+ * @vary_r: pass r to recursive calls
+ * @out2: second output vector for leaf items (if @recurse_to_leaf)
+ * @parent_r: r value passed from the parent
+ */
+static int crush_choose_firstn(const struct crush_map *map,
+			       struct crush_work *work,
+			       const struct crush_bucket *bucket,
+			       const __u32 *weight, int weight_max,
+			       int x, int numrep, int type,
+			       int *out, int outpos,
+			       int out_size,
+			       unsigned int tries,
+			       unsigned int recurse_tries,
+			       unsigned int local_retries,
+			       unsigned int local_fallback_retries,
+			       int recurse_to_leaf,
+			       unsigned int vary_r,
+			       unsigned int stable,
+			       int *out2,
+			       int parent_r,
+			       const struct crush_choose_arg *choose_args)
+{
+	int rep;
+	unsigned int ftotal, flocal;
+	int retry_descent, retry_bucket, skip_rep;
+	const struct crush_bucket *in = bucket;
+	int r;
+	int i;
+	int item = 0;
+	int itemtype;
+	int collide, reject;
+	int count = out_size;
+
+	dprintk("CHOOSE%s bucket %d x %d outpos %d numrep %d tries %d recurse_tries %d local_retries %d local_fallback_retries %d parent_r %d stable %d\n",
+		recurse_to_leaf ? "_LEAF" : "",
+		bucket->id, x, outpos, numrep,
+		tries, recurse_tries, local_retries, local_fallback_retries,
+		parent_r, stable);
+
+	for (rep = stable ? 0 : outpos; rep < numrep && count > 0 ; rep++) {
+		/* keep trying until we get a non-out, non-colliding item */
+		ftotal = 0;
+		skip_rep = 0;
+		do {
+			retry_descent = 0;
+			in = bucket;               /* initial bucket */
+
+			/* choose through intervening buckets */
+			flocal = 0;
+			do {
+				collide = 0;
+				retry_bucket = 0;
+				r = rep + parent_r;
+				/* r' = r + f_total */
+				r += ftotal;
+
+				/* bucket choose */
+				if (in->size == 0) {
+					reject = 1;
+					goto reject;
+				}
+				if (local_fallback_retries > 0 &&
+				    flocal >= (in->size>>1) &&
+				    flocal > local_fallback_retries)
+					item = bucket_perm_choose(
+						in, work->work[-1-in->id],
+						x, r);
+				else
+					item = crush_bucket_choose(
+						in, work->work[-1-in->id],
+						x, r,
+						(choose_args ?
+						 &choose_args[-1-in->id] : NULL),
+						outpos);
+				if (item >= map->max_devices) {
+					dprintk("   bad item %d\n", item);
+					skip_rep = 1;
+					break;
+				}
+
+				/* desired type? */
+				if (item < 0)
+					itemtype = map->buckets[-1-item]->type;
+				else
+					itemtype = 0;
+				dprintk("  item %d type %d\n", item, itemtype);
+
+				/* keep going? */
+				if (itemtype != type) {
+					if (item >= 0 ||
+					    (-1-item) >= map->max_buckets) {
+						dprintk("   bad item type %d\n", type);
+						skip_rep = 1;
+						break;
+					}
+					in = map->buckets[-1-item];
+					retry_bucket = 1;
+					continue;
+				}
+
+				/* collision? */
+				for (i = 0; i < outpos; i++) {
+					if (out[i] == item) {
+						collide = 1;
+						break;
+					}
+				}
+
+				reject = 0;
+				if (!collide && recurse_to_leaf) {
+					if (item < 0) {
+						int sub_r;
+						if (vary_r)
+							sub_r = r >> (vary_r-1);
+						else
+							sub_r = 0;
+						if (crush_choose_firstn(
+							    map,
+							    work,
+							    map->buckets[-1-item],
+							    weight, weight_max,
+							    x, stable ? 1 : outpos+1, 0,
+							    out2, outpos, count,
+							    recurse_tries, 0,
+							    local_retries,
+							    local_fallback_retries,
+							    0,
+							    vary_r,
+							    stable,
+							    NULL,
+							    sub_r,
+							    choose_args) <= outpos)
+							/* didn't get leaf */
+							reject = 1;
+					} else {
+						/* we already have a leaf! */
+						out2[outpos] = item;
+					}
+				}
+
+				if (!reject && !collide) {
+					/* out? */
+					if (itemtype == 0)
+						reject = is_out(map, weight,
+								weight_max,
+								item, x);
+				}
+
+reject:
+				if (reject || collide) {
+					ftotal++;
+					flocal++;
+
+					if (collide && flocal <= local_retries)
+						/* retry locally a few times */
+						retry_bucket = 1;
+					else if (local_fallback_retries > 0 &&
+						 flocal <= in->size + local_fallback_retries)
+						/* exhaustive bucket search */
+						retry_bucket = 1;
+					else if (ftotal < tries)
+						/* then retry descent */
+						retry_descent = 1;
+					else
+						/* else give up */
+						skip_rep = 1;
+					dprintk("  reject %d  collide %d  "
+						"ftotal %u  flocal %u\n",
+						reject, collide, ftotal,
+						flocal);
+				}
+			} while (retry_bucket);
+		} while (retry_descent);
+
+		if (skip_rep) {
+			dprintk("skip rep\n");
+			continue;
+		}
+
+		dprintk("CHOOSE got %d\n", item);
+		out[outpos] = item;
+		outpos++;
+		count--;
+#ifndef __KERNEL__
+		if (map->choose_tries && ftotal <= map->choose_total_tries)
+			map->choose_tries[ftotal]++;
+#endif
+	}
+
+	dprintk("CHOOSE returns %d\n", outpos);
+	return outpos;
+}
+
+
+/**
+ * crush_choose_indep: alternative breadth-first positionally stable mapping
+ *
+ */
+static void crush_choose_indep(const struct crush_map *map,
+			       struct crush_work *work,
+			       const struct crush_bucket *bucket,
+			       const __u32 *weight, int weight_max,
+			       int x, int left, int numrep, int type,
+			       int *out, int outpos,
+			       unsigned int tries,
+			       unsigned int recurse_tries,
+			       int recurse_to_leaf,
+			       int *out2,
+			       int parent_r,
+			       const struct crush_choose_arg *choose_args)
+{
+	const struct crush_bucket *in = bucket;
+	int endpos = outpos + left;
+	int rep;
+	unsigned int ftotal;
+	int r;
+	int i;
+	int item = 0;
+	int itemtype;
+	int collide;
+
+	dprintk("CHOOSE%s INDEP bucket %d x %d outpos %d numrep %d\n", recurse_to_leaf ? "_LEAF" : "",
+		bucket->id, x, outpos, numrep);
+
+	/* initially my result is undefined */
+	for (rep = outpos; rep < endpos; rep++) {
+		out[rep] = CRUSH_ITEM_UNDEF;
+		if (out2)
+			out2[rep] = CRUSH_ITEM_UNDEF;
+	}
+
+	for (ftotal = 0; left > 0 && ftotal < tries; ftotal++) {
+#ifdef DEBUG_INDEP
+		if (out2 && ftotal) {
+			dprintk("%u %d a: ", ftotal, left);
+			for (rep = outpos; rep < endpos; rep++) {
+				dprintk(" %d", out[rep]);
+			}
+			dprintk("\n");
+			dprintk("%u %d b: ", ftotal, left);
+			for (rep = outpos; rep < endpos; rep++) {
+				dprintk(" %d", out2[rep]);
+			}
+			dprintk("\n");
+		}
+#endif
+		for (rep = outpos; rep < endpos; rep++) {
+			if (out[rep] != CRUSH_ITEM_UNDEF)
+				continue;
+
+			in = bucket;  /* initial bucket */
+
+			/* choose through intervening buckets */
+			for (;;) {
+				/* note: we base the choice on the position
+				 * even in the nested call.  that means that
+				 * if the first layer chooses the same bucket
+				 * in a different position, we will tend to
+				 * choose a different item in that bucket.
+				 * this will involve more devices in data
+				 * movement and tend to distribute the load.
+				 */
+				r = rep + parent_r;
+
+				/* be careful */
+				if (in->alg == CRUSH_BUCKET_UNIFORM &&
+				    in->size % numrep == 0)
+					/* r'=r+(n+1)*f_total */
+					r += (numrep+1) * ftotal;
+				else
+					/* r' = r + n*f_total */
+					r += numrep * ftotal;
+
+				/* bucket choose */
+				if (in->size == 0) {
+					dprintk("   empty bucket\n");
+					break;
+				}
+
+				item = crush_bucket_choose(
+					in, work->work[-1-in->id],
+					x, r,
+					(choose_args ?
+					 &choose_args[-1-in->id] : NULL),
+					outpos);
+				if (item >= map->max_devices) {
+					dprintk("   bad item %d\n", item);
+					out[rep] = CRUSH_ITEM_NONE;
+					if (out2)
+						out2[rep] = CRUSH_ITEM_NONE;
+					left--;
+					break;
+				}
+
+				/* desired type? */
+				if (item < 0)
+					itemtype = map->buckets[-1-item]->type;
+				else
+					itemtype = 0;
+				dprintk("  item %d type %d\n", item, itemtype);
+
+				/* keep going? */
+				if (itemtype != type) {
+					if (item >= 0 ||
+					    (-1-item) >= map->max_buckets) {
+						dprintk("   bad item type %d\n", type);
+						out[rep] = CRUSH_ITEM_NONE;
+						if (out2)
+							out2[rep] =
+								CRUSH_ITEM_NONE;
+						left--;
+						break;
+					}
+					in = map->buckets[-1-item];
+					continue;
+				}
+
+				/* collision? */
+				collide = 0;
+				for (i = outpos; i < endpos; i++) {
+					if (out[i] == item) {
+						collide = 1;
+						break;
+					}
+				}
+				if (collide)
+					break;
+
+				if (recurse_to_leaf) {
+					if (item < 0) {
+						crush_choose_indep(
+							map,
+							work,
+							map->buckets[-1-item],
+							weight, weight_max,
+							x, 1, numrep, 0,
+							out2, rep,
+							recurse_tries, 0,
+							0, NULL, r,
+							choose_args);
+						if (out2[rep] == CRUSH_ITEM_NONE) {
+							/* placed nothing; no leaf */
+							break;
+						}
+					} else {
+						/* we already have a leaf! */
+						out2[rep] = item;
+					}
+				}
+
+				/* out? */
+				if (itemtype == 0 &&
+				    is_out(map, weight, weight_max, item, x))
+					break;
+
+				/* yay! */
+				out[rep] = item;
+				left--;
+				break;
+			}
+		}
+	}
+	for (rep = outpos; rep < endpos; rep++) {
+		if (out[rep] == CRUSH_ITEM_UNDEF) {
+			out[rep] = CRUSH_ITEM_NONE;
+		}
+		if (out2 && out2[rep] == CRUSH_ITEM_UNDEF) {
+			out2[rep] = CRUSH_ITEM_NONE;
+		}
+	}
+#ifndef __KERNEL__
+	if (map->choose_tries && ftotal <= map->choose_total_tries)
+		map->choose_tries[ftotal]++;
+#endif
+#ifdef DEBUG_INDEP
+	if (out2) {
+		dprintk("%u %d a: ", ftotal, left);
+		for (rep = outpos; rep < endpos; rep++) {
+			dprintk(" %d", out[rep]);
+		}
+		dprintk("\n");
+		dprintk("%u %d b: ", ftotal, left);
+		for (rep = outpos; rep < endpos; rep++) {
+			dprintk(" %d", out2[rep]);
+		}
+		dprintk("\n");
+	}
+#endif
+}
+
+
+/*
+ * This takes a chunk of memory and sets it up to be a shiny new
+ * working area for a CRUSH placement computation. It must be called
+ * on any newly allocated memory before passing it in to
+ * crush_do_rule. It may be used repeatedly after that, so long as the
+ * map has not changed. If the map /has/ changed, you must make sure
+ * the working size is no smaller than what was allocated and re-run
+ * crush_init_workspace.
+ *
+ * If you do retain the working space between calls to crush, make it
+ * thread-local.
+ */
+void crush_init_workspace(const struct crush_map *map, void *v)
+{
+	struct crush_work *w = v;
+	__s32 b;
+
+	/*
+	 * We work by moving through the available space and setting
+	 * values and pointers as we go.
+	 *
+	 * It's a bit like Forth's use of the 'allot' word since we
+	 * set the pointer first and then reserve the space for it to
+	 * point to by incrementing the point.
+	 */
+	v += sizeof(struct crush_work);
+	w->work = v;
+	v += map->max_buckets * sizeof(struct crush_work_bucket *);
+	for (b = 0; b < map->max_buckets; ++b) {
+		if (!map->buckets[b])
+			continue;
+
+		w->work[b] = v;
+		switch (map->buckets[b]->alg) {
+		default:
+			v += sizeof(struct crush_work_bucket);
+			break;
+		}
+		w->work[b]->perm_x = 0;
+		w->work[b]->perm_n = 0;
+		w->work[b]->perm = v;
+		v += map->buckets[b]->size * sizeof(__u32);
+	}
+	BUG_ON(v - (void *)w != map->working_size);
+}
+
+/**
+ * crush_do_rule - calculate a mapping with the given input and rule
+ * @map: the crush_map
+ * @ruleno: the rule id
+ * @x: hash input
+ * @result: pointer to result vector
+ * @result_max: maximum result size
+ * @weight: weight vector (for map leaves)
+ * @weight_max: size of weight vector
+ * @cwin: pointer to at least crush_work_size() bytes of memory
+ * @choose_args: weights and ids for each known bucket
+ */
+int crush_do_rule(const struct crush_map *map,
+		  int ruleno, int x, int *result, int result_max,
+		  const __u32 *weight, int weight_max,
+		  void *cwin, const struct crush_choose_arg *choose_args)
+{
+	int result_len;
+	struct crush_work *cw = cwin;
+	int *a = cwin + map->working_size;
+	int *b = a + result_max;
+	int *c = b + result_max;
+	int *w = a;
+	int *o = b;
+	int recurse_to_leaf;
+	int wsize = 0;
+	int osize;
+	int *tmp;
+	const struct crush_rule *rule;
+	__u32 step;
+	int i, j;
+	int numrep;
+	int out_size;
+	/*
+	 * the original choose_total_tries value was off by one (it
+	 * counted "retries" and not "tries").  add one.
+	 */
+	int choose_tries = map->choose_total_tries + 1;
+	int choose_leaf_tries = 0;
+	/*
+	 * the local tries values were counted as "retries", though,
+	 * and need no adjustment
+	 */
+	int choose_local_retries = map->choose_local_tries;
+	int choose_local_fallback_retries = map->choose_local_fallback_tries;
+
+	int vary_r = map->chooseleaf_vary_r;
+	int stable = map->chooseleaf_stable;
+
+	if ((__u32)ruleno >= map->max_rules) {
+		dprintk(" bad ruleno %d\n", ruleno);
+		return 0;
+	}
+
+	rule = map->rules[ruleno];
+	result_len = 0;
+
+	for (step = 0; step < rule->len; step++) {
+		int firstn = 0;
+		const struct crush_rule_step *curstep = &rule->steps[step];
+
+		switch (curstep->op) {
+		case CRUSH_RULE_TAKE:
+			if ((curstep->arg1 >= 0 &&
+			     curstep->arg1 < map->max_devices) ||
+			    (-1-curstep->arg1 >= 0 &&
+			     -1-curstep->arg1 < map->max_buckets &&
+			     map->buckets[-1-curstep->arg1])) {
+				w[0] = curstep->arg1;
+				wsize = 1;
+			} else {
+				dprintk(" bad take value %d\n", curstep->arg1);
+			}
+			break;
+
+		case CRUSH_RULE_SET_CHOOSE_TRIES:
+			if (curstep->arg1 > 0)
+				choose_tries = curstep->arg1;
+			break;
+
+		case CRUSH_RULE_SET_CHOOSELEAF_TRIES:
+			if (curstep->arg1 > 0)
+				choose_leaf_tries = curstep->arg1;
+			break;
+
+		case CRUSH_RULE_SET_CHOOSE_LOCAL_TRIES:
+			if (curstep->arg1 >= 0)
+				choose_local_retries = curstep->arg1;
+			break;
+
+		case CRUSH_RULE_SET_CHOOSE_LOCAL_FALLBACK_TRIES:
+			if (curstep->arg1 >= 0)
+				choose_local_fallback_retries = curstep->arg1;
+			break;
+
+		case CRUSH_RULE_SET_CHOOSELEAF_VARY_R:
+			if (curstep->arg1 >= 0)
+				vary_r = curstep->arg1;
+			break;
+
+		case CRUSH_RULE_SET_CHOOSELEAF_STABLE:
+			if (curstep->arg1 >= 0)
+				stable = curstep->arg1;
+			break;
+
+		case CRUSH_RULE_CHOOSELEAF_FIRSTN:
+		case CRUSH_RULE_CHOOSE_FIRSTN:
+			firstn = 1;
+			/* fall through */
+		case CRUSH_RULE_CHOOSELEAF_INDEP:
+		case CRUSH_RULE_CHOOSE_INDEP:
+			if (wsize == 0)
+				break;
+
+			recurse_to_leaf =
+				curstep->op ==
+				 CRUSH_RULE_CHOOSELEAF_FIRSTN ||
+				curstep->op ==
+				CRUSH_RULE_CHOOSELEAF_INDEP;
+
+			/* reset output */
+			osize = 0;
+
+			for (i = 0; i < wsize; i++) {
+				int bno;
+				numrep = curstep->arg1;
+				if (numrep <= 0) {
+					numrep += result_max;
+					if (numrep <= 0)
+						continue;
+				}
+				j = 0;
+				/* make sure bucket id is valid */
+				bno = -1 - w[i];
+				if (bno < 0 || bno >= map->max_buckets) {
+					/* w[i] is probably CRUSH_ITEM_NONE */
+					dprintk("  bad w[i] %d\n", w[i]);
+					continue;
+				}
+				if (firstn) {
+					int recurse_tries;
+					if (choose_leaf_tries)
+						recurse_tries =
+							choose_leaf_tries;
+					else if (map->chooseleaf_descend_once)
+						recurse_tries = 1;
+					else
+						recurse_tries = choose_tries;
+					osize += crush_choose_firstn(
+						map,
+						cw,
+						map->buckets[bno],
+						weight, weight_max,
+						x, numrep,
+						curstep->arg2,
+						o+osize, j,
+						result_max-osize,
+						choose_tries,
+						recurse_tries,
+						choose_local_retries,
+						choose_local_fallback_retries,
+						recurse_to_leaf,
+						vary_r,
+						stable,
+						c+osize,
+						0,
+						choose_args);
+				} else {
+					out_size = ((numrep < (result_max-osize)) ?
+						    numrep : (result_max-osize));
+					crush_choose_indep(
+						map,
+						cw,
+						map->buckets[bno],
+						weight, weight_max,
+						x, out_size, numrep,
+						curstep->arg2,
+						o+osize, j,
+						choose_tries,
+						choose_leaf_tries ?
+						   choose_leaf_tries : 1,
+						recurse_to_leaf,
+						c+osize,
+						0,
+						choose_args);
+					osize += out_size;
+				}
+			}
+
+			if (recurse_to_leaf)
+				/* copy final _leaf_ values to output set */
+				memcpy(o, c, osize*sizeof(*o));
+
+			/* swap o and w arrays */
+			tmp = o;
+			o = w;
+			w = tmp;
+			wsize = osize;
+			break;
+
+
+		case CRUSH_RULE_EMIT:
+			for (i = 0; i < wsize && result_len < result_max; i++) {
+				result[result_len] = w[i];
+				result_len++;
+			}
+			wsize = 0;
+			break;
+
+		default:
+			dprintk(" unknown op %d at step %d\n",
+				curstep->op, step);
+			break;
+		}
+	}
+
+	return result_len;
+}
diff --git a/net/ceph/crypto.c b/net/ceph/crypto.c
new file mode 100644
index 000000000..02172c408
--- /dev/null
+++ b/net/ceph/crypto.c
@@ -0,0 +1,358 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/err.h>
+#include <linux/scatterlist.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <crypto/aes.h>
+#include <crypto/skcipher.h>
+#include <linux/key-type.h>
+#include <linux/sched/mm.h>
+
+#include <keys/ceph-type.h>
+#include <keys/user-type.h>
+#include <linux/ceph/decode.h>
+#include "crypto.h"
+
+/*
+ * Set ->key and ->tfm.  The rest of the key should be filled in before
+ * this function is called.
+ */
+static int set_secret(struct ceph_crypto_key *key, void *buf)
+{
+	unsigned int noio_flag;
+	int ret;
+
+	key->key = NULL;
+	key->tfm = NULL;
+
+	switch (key->type) {
+	case CEPH_CRYPTO_NONE:
+		return 0; /* nothing to do */
+	case CEPH_CRYPTO_AES:
+		break;
+	default:
+		return -ENOTSUPP;
+	}
+
+	if (!key->len)
+		return -EINVAL;
+
+	key->key = kmemdup(buf, key->len, GFP_NOIO);
+	if (!key->key) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	/* crypto_alloc_skcipher() allocates with GFP_KERNEL */
+	noio_flag = memalloc_noio_save();
+	key->tfm = crypto_alloc_skcipher("cbc(aes)", 0, CRYPTO_ALG_ASYNC);
+	memalloc_noio_restore(noio_flag);
+	if (IS_ERR(key->tfm)) {
+		ret = PTR_ERR(key->tfm);
+		key->tfm = NULL;
+		goto fail;
+	}
+
+	ret = crypto_skcipher_setkey(key->tfm, key->key, key->len);
+	if (ret)
+		goto fail;
+
+	return 0;
+
+fail:
+	ceph_crypto_key_destroy(key);
+	return ret;
+}
+
+int ceph_crypto_key_clone(struct ceph_crypto_key *dst,
+			  const struct ceph_crypto_key *src)
+{
+	memcpy(dst, src, sizeof(struct ceph_crypto_key));
+	return set_secret(dst, src->key);
+}
+
+int ceph_crypto_key_encode(struct ceph_crypto_key *key, void **p, void *end)
+{
+	if (*p + sizeof(u16) + sizeof(key->created) +
+	    sizeof(u16) + key->len > end)
+		return -ERANGE;
+	ceph_encode_16(p, key->type);
+	ceph_encode_copy(p, &key->created, sizeof(key->created));
+	ceph_encode_16(p, key->len);
+	ceph_encode_copy(p, key->key, key->len);
+	return 0;
+}
+
+int ceph_crypto_key_decode(struct ceph_crypto_key *key, void **p, void *end)
+{
+	int ret;
+
+	ceph_decode_need(p, end, 2*sizeof(u16) + sizeof(key->created), bad);
+	key->type = ceph_decode_16(p);
+	ceph_decode_copy(p, &key->created, sizeof(key->created));
+	key->len = ceph_decode_16(p);
+	ceph_decode_need(p, end, key->len, bad);
+	ret = set_secret(key, *p);
+	*p += key->len;
+	return ret;
+
+bad:
+	dout("failed to decode crypto key\n");
+	return -EINVAL;
+}
+
+int ceph_crypto_key_unarmor(struct ceph_crypto_key *key, const char *inkey)
+{
+	int inlen = strlen(inkey);
+	int blen = inlen * 3 / 4;
+	void *buf, *p;
+	int ret;
+
+	dout("crypto_key_unarmor %s\n", inkey);
+	buf = kmalloc(blen, GFP_NOFS);
+	if (!buf)
+		return -ENOMEM;
+	blen = ceph_unarmor(buf, inkey, inkey+inlen);
+	if (blen < 0) {
+		kfree(buf);
+		return blen;
+	}
+
+	p = buf;
+	ret = ceph_crypto_key_decode(key, &p, p + blen);
+	kfree(buf);
+	if (ret)
+		return ret;
+	dout("crypto_key_unarmor key %p type %d len %d\n", key,
+	     key->type, key->len);
+	return 0;
+}
+
+void ceph_crypto_key_destroy(struct ceph_crypto_key *key)
+{
+	if (key) {
+		kfree(key->key);
+		key->key = NULL;
+		crypto_free_skcipher(key->tfm);
+		key->tfm = NULL;
+	}
+}
+
+static const u8 *aes_iv = (u8 *)CEPH_AES_IV;
+
+/*
+ * Should be used for buffers allocated with ceph_kvmalloc().
+ * Currently these are encrypt out-buffer (ceph_buffer) and decrypt
+ * in-buffer (msg front).
+ *
+ * Dispose of @sgt with teardown_sgtable().
+ *
+ * @prealloc_sg is to avoid memory allocation inside sg_alloc_table()
+ * in cases where a single sg is sufficient.  No attempt to reduce the
+ * number of sgs by squeezing physically contiguous pages together is
+ * made though, for simplicity.
+ */
+static int setup_sgtable(struct sg_table *sgt, struct scatterlist *prealloc_sg,
+			 const void *buf, unsigned int buf_len)
+{
+	struct scatterlist *sg;
+	const bool is_vmalloc = is_vmalloc_addr(buf);
+	unsigned int off = offset_in_page(buf);
+	unsigned int chunk_cnt = 1;
+	unsigned int chunk_len = PAGE_ALIGN(off + buf_len);
+	int i;
+	int ret;
+
+	if (buf_len == 0) {
+		memset(sgt, 0, sizeof(*sgt));
+		return -EINVAL;
+	}
+
+	if (is_vmalloc) {
+		chunk_cnt = chunk_len >> PAGE_SHIFT;
+		chunk_len = PAGE_SIZE;
+	}
+
+	if (chunk_cnt > 1) {
+		ret = sg_alloc_table(sgt, chunk_cnt, GFP_NOFS);
+		if (ret)
+			return ret;
+	} else {
+		WARN_ON(chunk_cnt != 1);
+		sg_init_table(prealloc_sg, 1);
+		sgt->sgl = prealloc_sg;
+		sgt->nents = sgt->orig_nents = 1;
+	}
+
+	for_each_sg(sgt->sgl, sg, sgt->orig_nents, i) {
+		struct page *page;
+		unsigned int len = min(chunk_len - off, buf_len);
+
+		if (is_vmalloc)
+			page = vmalloc_to_page(buf);
+		else
+			page = virt_to_page(buf);
+
+		sg_set_page(sg, page, len, off);
+
+		off = 0;
+		buf += len;
+		buf_len -= len;
+	}
+	WARN_ON(buf_len != 0);
+
+	return 0;
+}
+
+static void teardown_sgtable(struct sg_table *sgt)
+{
+	if (sgt->orig_nents > 1)
+		sg_free_table(sgt);
+}
+
+static int ceph_aes_crypt(const struct ceph_crypto_key *key, bool encrypt,
+			  void *buf, int buf_len, int in_len, int *pout_len)
+{
+	SKCIPHER_REQUEST_ON_STACK(req, key->tfm);
+	struct sg_table sgt;
+	struct scatterlist prealloc_sg;
+	char iv[AES_BLOCK_SIZE] __aligned(8);
+	int pad_byte = AES_BLOCK_SIZE - (in_len & (AES_BLOCK_SIZE - 1));
+	int crypt_len = encrypt ? in_len + pad_byte : in_len;
+	int ret;
+
+	WARN_ON(crypt_len > buf_len);
+	if (encrypt)
+		memset(buf + in_len, pad_byte, pad_byte);
+	ret = setup_sgtable(&sgt, &prealloc_sg, buf, crypt_len);
+	if (ret)
+		return ret;
+
+	memcpy(iv, aes_iv, AES_BLOCK_SIZE);
+	skcipher_request_set_tfm(req, key->tfm);
+	skcipher_request_set_callback(req, 0, NULL, NULL);
+	skcipher_request_set_crypt(req, sgt.sgl, sgt.sgl, crypt_len, iv);
+
+	/*
+	print_hex_dump(KERN_ERR, "key: ", DUMP_PREFIX_NONE, 16, 1,
+		       key->key, key->len, 1);
+	print_hex_dump(KERN_ERR, " in: ", DUMP_PREFIX_NONE, 16, 1,
+		       buf, crypt_len, 1);
+	*/
+	if (encrypt)
+		ret = crypto_skcipher_encrypt(req);
+	else
+		ret = crypto_skcipher_decrypt(req);
+	skcipher_request_zero(req);
+	if (ret) {
+		pr_err("%s %scrypt failed: %d\n", __func__,
+		       encrypt ? "en" : "de", ret);
+		goto out_sgt;
+	}
+	/*
+	print_hex_dump(KERN_ERR, "out: ", DUMP_PREFIX_NONE, 16, 1,
+		       buf, crypt_len, 1);
+	*/
+
+	if (encrypt) {
+		*pout_len = crypt_len;
+	} else {
+		pad_byte = *(char *)(buf + in_len - 1);
+		if (pad_byte > 0 && pad_byte <= AES_BLOCK_SIZE &&
+		    in_len >= pad_byte) {
+			*pout_len = in_len - pad_byte;
+		} else {
+			pr_err("%s got bad padding %d on in_len %d\n",
+			       __func__, pad_byte, in_len);
+			ret = -EPERM;
+			goto out_sgt;
+		}
+	}
+
+out_sgt:
+	teardown_sgtable(&sgt);
+	return ret;
+}
+
+int ceph_crypt(const struct ceph_crypto_key *key, bool encrypt,
+	       void *buf, int buf_len, int in_len, int *pout_len)
+{
+	switch (key->type) {
+	case CEPH_CRYPTO_NONE:
+		*pout_len = in_len;
+		return 0;
+	case CEPH_CRYPTO_AES:
+		return ceph_aes_crypt(key, encrypt, buf, buf_len, in_len,
+				      pout_len);
+	default:
+		return -ENOTSUPP;
+	}
+}
+
+static int ceph_key_preparse(struct key_preparsed_payload *prep)
+{
+	struct ceph_crypto_key *ckey;
+	size_t datalen = prep->datalen;
+	int ret;
+	void *p;
+
+	ret = -EINVAL;
+	if (datalen <= 0 || datalen > 32767 || !prep->data)
+		goto err;
+
+	ret = -ENOMEM;
+	ckey = kmalloc(sizeof(*ckey), GFP_KERNEL);
+	if (!ckey)
+		goto err;
+
+	/* TODO ceph_crypto_key_decode should really take const input */
+	p = (void *)prep->data;
+	ret = ceph_crypto_key_decode(ckey, &p, (char*)prep->data+datalen);
+	if (ret < 0)
+		goto err_ckey;
+
+	prep->payload.data[0] = ckey;
+	prep->quotalen = datalen;
+	return 0;
+
+err_ckey:
+	kfree(ckey);
+err:
+	return ret;
+}
+
+static void ceph_key_free_preparse(struct key_preparsed_payload *prep)
+{
+	struct ceph_crypto_key *ckey = prep->payload.data[0];
+	ceph_crypto_key_destroy(ckey);
+	kfree(ckey);
+}
+
+static void ceph_key_destroy(struct key *key)
+{
+	struct ceph_crypto_key *ckey = key->payload.data[0];
+
+	ceph_crypto_key_destroy(ckey);
+	kfree(ckey);
+}
+
+struct key_type key_type_ceph = {
+	.name		= "ceph",
+	.preparse	= ceph_key_preparse,
+	.free_preparse	= ceph_key_free_preparse,
+	.instantiate	= generic_key_instantiate,
+	.destroy	= ceph_key_destroy,
+};
+
+int __init ceph_crypto_init(void)
+{
+	return register_key_type(&key_type_ceph);
+}
+
+void ceph_crypto_shutdown(void)
+{
+	unregister_key_type(&key_type_ceph);
+}
diff --git a/net/ceph/crypto.h b/net/ceph/crypto.h
new file mode 100644
index 000000000..bb45c7d43
--- /dev/null
+++ b/net/ceph/crypto.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _FS_CEPH_CRYPTO_H
+#define _FS_CEPH_CRYPTO_H
+
+#include <linux/ceph/types.h>
+#include <linux/ceph/buffer.h>
+
+/*
+ * cryptographic secret
+ */
+struct ceph_crypto_key {
+	int type;
+	struct ceph_timespec created;
+	int len;
+	void *key;
+	struct crypto_skcipher *tfm;
+};
+
+int ceph_crypto_key_clone(struct ceph_crypto_key *dst,
+			  const struct ceph_crypto_key *src);
+int ceph_crypto_key_encode(struct ceph_crypto_key *key, void **p, void *end);
+int ceph_crypto_key_decode(struct ceph_crypto_key *key, void **p, void *end);
+int ceph_crypto_key_unarmor(struct ceph_crypto_key *key, const char *in);
+void ceph_crypto_key_destroy(struct ceph_crypto_key *key);
+
+/* crypto.c */
+int ceph_crypt(const struct ceph_crypto_key *key, bool encrypt,
+	       void *buf, int buf_len, int in_len, int *pout_len);
+int ceph_crypto_init(void);
+void ceph_crypto_shutdown(void);
+
+/* armor.c */
+int ceph_armor(char *dst, const char *src, const char *end);
+int ceph_unarmor(char *dst, const char *src, const char *end);
+
+#endif
diff --git a/net/ceph/debugfs.c b/net/ceph/debugfs.c
new file mode 100644
index 000000000..02952605d
--- /dev/null
+++ b/net/ceph/debugfs.c
@@ -0,0 +1,498 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/ctype.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#include <linux/ceph/libceph.h>
+#include <linux/ceph/mon_client.h>
+#include <linux/ceph/auth.h>
+#include <linux/ceph/debugfs.h>
+
+#ifdef CONFIG_DEBUG_FS
+
+/*
+ * Implement /sys/kernel/debug/ceph fun
+ *
+ * /sys/kernel/debug/ceph/client*  - an instance of the ceph client
+ *      .../osdmap      - current osdmap
+ *      .../monmap      - current monmap
+ *      .../osdc        - active osd requests
+ *      .../monc        - mon client state
+ *      .../client_options - libceph-only (i.e. not rbd or cephfs) options
+ *      .../dentry_lru  - dump contents of dentry lru
+ *      .../caps        - expose cap (reservation) stats
+ *      .../bdi         - symlink to ../../bdi/something
+ */
+
+static struct dentry *ceph_debugfs_dir;
+
+static int monmap_show(struct seq_file *s, void *p)
+{
+	int i;
+	struct ceph_client *client = s->private;
+
+	if (client->monc.monmap == NULL)
+		return 0;
+
+	seq_printf(s, "epoch %d\n", client->monc.monmap->epoch);
+	for (i = 0; i < client->monc.monmap->num_mon; i++) {
+		struct ceph_entity_inst *inst =
+			&client->monc.monmap->mon_inst[i];
+
+		seq_printf(s, "\t%s%lld\t%s\n",
+			   ENTITY_NAME(inst->name),
+			   ceph_pr_addr(&inst->addr.in_addr));
+	}
+	return 0;
+}
+
+static int osdmap_show(struct seq_file *s, void *p)
+{
+	int i;
+	struct ceph_client *client = s->private;
+	struct ceph_osd_client *osdc = &client->osdc;
+	struct ceph_osdmap *map = osdc->osdmap;
+	struct rb_node *n;
+
+	if (map == NULL)
+		return 0;
+
+	down_read(&osdc->lock);
+	seq_printf(s, "epoch %u barrier %u flags 0x%x\n", map->epoch,
+			osdc->epoch_barrier, map->flags);
+
+	for (n = rb_first(&map->pg_pools); n; n = rb_next(n)) {
+		struct ceph_pg_pool_info *pi =
+			rb_entry(n, struct ceph_pg_pool_info, node);
+
+		seq_printf(s, "pool %lld '%s' type %d size %d min_size %d pg_num %u pg_num_mask %d flags 0x%llx lfor %u read_tier %lld write_tier %lld\n",
+			   pi->id, pi->name, pi->type, pi->size, pi->min_size,
+			   pi->pg_num, pi->pg_num_mask, pi->flags,
+			   pi->last_force_request_resend, pi->read_tier,
+			   pi->write_tier);
+	}
+	for (i = 0; i < map->max_osd; i++) {
+		struct ceph_entity_addr *addr = &map->osd_addr[i];
+		u32 state = map->osd_state[i];
+		char sb[64];
+
+		seq_printf(s, "osd%d\t%s\t%3d%%\t(%s)\t%3d%%\n",
+			   i, ceph_pr_addr(&addr->in_addr),
+			   ((map->osd_weight[i]*100) >> 16),
+			   ceph_osdmap_state_str(sb, sizeof(sb), state),
+			   ((ceph_get_primary_affinity(map, i)*100) >> 16));
+	}
+	for (n = rb_first(&map->pg_temp); n; n = rb_next(n)) {
+		struct ceph_pg_mapping *pg =
+			rb_entry(n, struct ceph_pg_mapping, node);
+
+		seq_printf(s, "pg_temp %llu.%x [", pg->pgid.pool,
+			   pg->pgid.seed);
+		for (i = 0; i < pg->pg_temp.len; i++)
+			seq_printf(s, "%s%d", (i == 0 ? "" : ","),
+				   pg->pg_temp.osds[i]);
+		seq_printf(s, "]\n");
+	}
+	for (n = rb_first(&map->primary_temp); n; n = rb_next(n)) {
+		struct ceph_pg_mapping *pg =
+			rb_entry(n, struct ceph_pg_mapping, node);
+
+		seq_printf(s, "primary_temp %llu.%x %d\n", pg->pgid.pool,
+			   pg->pgid.seed, pg->primary_temp.osd);
+	}
+	for (n = rb_first(&map->pg_upmap); n; n = rb_next(n)) {
+		struct ceph_pg_mapping *pg =
+			rb_entry(n, struct ceph_pg_mapping, node);
+
+		seq_printf(s, "pg_upmap %llu.%x [", pg->pgid.pool,
+			   pg->pgid.seed);
+		for (i = 0; i < pg->pg_upmap.len; i++)
+			seq_printf(s, "%s%d", (i == 0 ? "" : ","),
+				   pg->pg_upmap.osds[i]);
+		seq_printf(s, "]\n");
+	}
+	for (n = rb_first(&map->pg_upmap_items); n; n = rb_next(n)) {
+		struct ceph_pg_mapping *pg =
+			rb_entry(n, struct ceph_pg_mapping, node);
+
+		seq_printf(s, "pg_upmap_items %llu.%x [", pg->pgid.pool,
+			   pg->pgid.seed);
+		for (i = 0; i < pg->pg_upmap_items.len; i++)
+			seq_printf(s, "%s%d->%d", (i == 0 ? "" : ","),
+				   pg->pg_upmap_items.from_to[i][0],
+				   pg->pg_upmap_items.from_to[i][1]);
+		seq_printf(s, "]\n");
+	}
+
+	up_read(&osdc->lock);
+	return 0;
+}
+
+static int monc_show(struct seq_file *s, void *p)
+{
+	struct ceph_client *client = s->private;
+	struct ceph_mon_generic_request *req;
+	struct ceph_mon_client *monc = &client->monc;
+	struct rb_node *rp;
+	int i;
+
+	mutex_lock(&monc->mutex);
+
+	for (i = 0; i < ARRAY_SIZE(monc->subs); i++) {
+		seq_printf(s, "have %s %u", ceph_sub_str[i],
+			   monc->subs[i].have);
+		if (monc->subs[i].want)
+			seq_printf(s, " want %llu%s",
+				   le64_to_cpu(monc->subs[i].item.start),
+				   (monc->subs[i].item.flags &
+					CEPH_SUBSCRIBE_ONETIME ?  "" : "+"));
+		seq_putc(s, '\n');
+	}
+	seq_printf(s, "fs_cluster_id %d\n", monc->fs_cluster_id);
+
+	for (rp = rb_first(&monc->generic_request_tree); rp; rp = rb_next(rp)) {
+		__u16 op;
+		req = rb_entry(rp, struct ceph_mon_generic_request, node);
+		op = le16_to_cpu(req->request->hdr.type);
+		if (op == CEPH_MSG_STATFS)
+			seq_printf(s, "%llu statfs\n", req->tid);
+		else if (op == CEPH_MSG_MON_GET_VERSION)
+			seq_printf(s, "%llu mon_get_version", req->tid);
+		else
+			seq_printf(s, "%llu unknown\n", req->tid);
+	}
+
+	mutex_unlock(&monc->mutex);
+	return 0;
+}
+
+static void dump_spgid(struct seq_file *s, const struct ceph_spg *spgid)
+{
+	seq_printf(s, "%llu.%x", spgid->pgid.pool, spgid->pgid.seed);
+	if (spgid->shard != CEPH_SPG_NOSHARD)
+		seq_printf(s, "s%d", spgid->shard);
+}
+
+static void dump_target(struct seq_file *s, struct ceph_osd_request_target *t)
+{
+	int i;
+
+	seq_printf(s, "osd%d\t%llu.%x\t", t->osd, t->pgid.pool, t->pgid.seed);
+	dump_spgid(s, &t->spgid);
+	seq_puts(s, "\t[");
+	for (i = 0; i < t->up.size; i++)
+		seq_printf(s, "%s%d", (!i ? "" : ","), t->up.osds[i]);
+	seq_printf(s, "]/%d\t[", t->up.primary);
+	for (i = 0; i < t->acting.size; i++)
+		seq_printf(s, "%s%d", (!i ? "" : ","), t->acting.osds[i]);
+	seq_printf(s, "]/%d\te%u\t", t->acting.primary, t->epoch);
+	if (t->target_oloc.pool_ns) {
+		seq_printf(s, "%*pE/%*pE\t0x%x",
+			(int)t->target_oloc.pool_ns->len,
+			t->target_oloc.pool_ns->str,
+			t->target_oid.name_len, t->target_oid.name, t->flags);
+	} else {
+		seq_printf(s, "%*pE\t0x%x", t->target_oid.name_len,
+			t->target_oid.name, t->flags);
+	}
+	if (t->paused)
+		seq_puts(s, "\tP");
+}
+
+static void dump_request(struct seq_file *s, struct ceph_osd_request *req)
+{
+	int i;
+
+	seq_printf(s, "%llu\t", req->r_tid);
+	dump_target(s, &req->r_t);
+
+	seq_printf(s, "\t%d", req->r_attempts);
+
+	for (i = 0; i < req->r_num_ops; i++) {
+		struct ceph_osd_req_op *op = &req->r_ops[i];
+
+		seq_printf(s, "%s%s", (i == 0 ? "\t" : ","),
+			   ceph_osd_op_name(op->op));
+		if (op->op == CEPH_OSD_OP_WATCH)
+			seq_printf(s, "-%s",
+				   ceph_osd_watch_op_name(op->watch.op));
+	}
+
+	seq_putc(s, '\n');
+}
+
+static void dump_requests(struct seq_file *s, struct ceph_osd *osd)
+{
+	struct rb_node *n;
+
+	mutex_lock(&osd->lock);
+	for (n = rb_first(&osd->o_requests); n; n = rb_next(n)) {
+		struct ceph_osd_request *req =
+		    rb_entry(n, struct ceph_osd_request, r_node);
+
+		dump_request(s, req);
+	}
+
+	mutex_unlock(&osd->lock);
+}
+
+static void dump_linger_request(struct seq_file *s,
+				struct ceph_osd_linger_request *lreq)
+{
+	seq_printf(s, "%llu\t", lreq->linger_id);
+	dump_target(s, &lreq->t);
+
+	seq_printf(s, "\t%u\t%s%s/%d\n", lreq->register_gen,
+		   lreq->is_watch ? "W" : "N", lreq->committed ? "C" : "",
+		   lreq->last_error);
+}
+
+static void dump_linger_requests(struct seq_file *s, struct ceph_osd *osd)
+{
+	struct rb_node *n;
+
+	mutex_lock(&osd->lock);
+	for (n = rb_first(&osd->o_linger_requests); n; n = rb_next(n)) {
+		struct ceph_osd_linger_request *lreq =
+		    rb_entry(n, struct ceph_osd_linger_request, node);
+
+		dump_linger_request(s, lreq);
+	}
+
+	mutex_unlock(&osd->lock);
+}
+
+static void dump_snapid(struct seq_file *s, u64 snapid)
+{
+	if (snapid == CEPH_NOSNAP)
+		seq_puts(s, "head");
+	else if (snapid == CEPH_SNAPDIR)
+		seq_puts(s, "snapdir");
+	else
+		seq_printf(s, "%llx", snapid);
+}
+
+static void dump_name_escaped(struct seq_file *s, unsigned char *name,
+			      size_t len)
+{
+	size_t i;
+
+	for (i = 0; i < len; i++) {
+		if (name[i] == '%' || name[i] == ':' || name[i] == '/' ||
+		    name[i] < 32 || name[i] >= 127) {
+			seq_printf(s, "%%%02x", name[i]);
+		} else {
+			seq_putc(s, name[i]);
+		}
+	}
+}
+
+static void dump_hoid(struct seq_file *s, const struct ceph_hobject_id *hoid)
+{
+	if (hoid->snapid == 0 && hoid->hash == 0 && !hoid->is_max &&
+	    hoid->pool == S64_MIN) {
+		seq_puts(s, "MIN");
+		return;
+	}
+	if (hoid->is_max) {
+		seq_puts(s, "MAX");
+		return;
+	}
+	seq_printf(s, "%lld:%08x:", hoid->pool, hoid->hash_reverse_bits);
+	dump_name_escaped(s, hoid->nspace, hoid->nspace_len);
+	seq_putc(s, ':');
+	dump_name_escaped(s, hoid->key, hoid->key_len);
+	seq_putc(s, ':');
+	dump_name_escaped(s, hoid->oid, hoid->oid_len);
+	seq_putc(s, ':');
+	dump_snapid(s, hoid->snapid);
+}
+
+static void dump_backoffs(struct seq_file *s, struct ceph_osd *osd)
+{
+	struct rb_node *n;
+
+	mutex_lock(&osd->lock);
+	for (n = rb_first(&osd->o_backoffs_by_id); n; n = rb_next(n)) {
+		struct ceph_osd_backoff *backoff =
+		    rb_entry(n, struct ceph_osd_backoff, id_node);
+
+		seq_printf(s, "osd%d\t", osd->o_osd);
+		dump_spgid(s, &backoff->spgid);
+		seq_printf(s, "\t%llu\t", backoff->id);
+		dump_hoid(s, backoff->begin);
+		seq_putc(s, '\t');
+		dump_hoid(s, backoff->end);
+		seq_putc(s, '\n');
+	}
+
+	mutex_unlock(&osd->lock);
+}
+
+static int osdc_show(struct seq_file *s, void *pp)
+{
+	struct ceph_client *client = s->private;
+	struct ceph_osd_client *osdc = &client->osdc;
+	struct rb_node *n;
+
+	down_read(&osdc->lock);
+	seq_printf(s, "REQUESTS %d homeless %d\n",
+		   atomic_read(&osdc->num_requests),
+		   atomic_read(&osdc->num_homeless));
+	for (n = rb_first(&osdc->osds); n; n = rb_next(n)) {
+		struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
+
+		dump_requests(s, osd);
+	}
+	dump_requests(s, &osdc->homeless_osd);
+
+	seq_puts(s, "LINGER REQUESTS\n");
+	for (n = rb_first(&osdc->osds); n; n = rb_next(n)) {
+		struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
+
+		dump_linger_requests(s, osd);
+	}
+	dump_linger_requests(s, &osdc->homeless_osd);
+
+	seq_puts(s, "BACKOFFS\n");
+	for (n = rb_first(&osdc->osds); n; n = rb_next(n)) {
+		struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
+
+		dump_backoffs(s, osd);
+	}
+
+	up_read(&osdc->lock);
+	return 0;
+}
+
+static int client_options_show(struct seq_file *s, void *p)
+{
+	struct ceph_client *client = s->private;
+	int ret;
+
+	ret = ceph_print_client_options(s, client);
+	if (ret)
+		return ret;
+
+	seq_putc(s, '\n');
+	return 0;
+}
+
+CEPH_DEFINE_SHOW_FUNC(monmap_show)
+CEPH_DEFINE_SHOW_FUNC(osdmap_show)
+CEPH_DEFINE_SHOW_FUNC(monc_show)
+CEPH_DEFINE_SHOW_FUNC(osdc_show)
+CEPH_DEFINE_SHOW_FUNC(client_options_show)
+
+int __init ceph_debugfs_init(void)
+{
+	ceph_debugfs_dir = debugfs_create_dir("ceph", NULL);
+	if (!ceph_debugfs_dir)
+		return -ENOMEM;
+	return 0;
+}
+
+void ceph_debugfs_cleanup(void)
+{
+	debugfs_remove(ceph_debugfs_dir);
+}
+
+int ceph_debugfs_client_init(struct ceph_client *client)
+{
+	int ret = -ENOMEM;
+	char name[80];
+
+	snprintf(name, sizeof(name), "%pU.client%lld", &client->fsid,
+		 client->monc.auth->global_id);
+
+	dout("ceph_debugfs_client_init %p %s\n", client, name);
+
+	BUG_ON(client->debugfs_dir);
+	client->debugfs_dir = debugfs_create_dir(name, ceph_debugfs_dir);
+	if (!client->debugfs_dir)
+		goto out;
+
+	client->monc.debugfs_file = debugfs_create_file("monc",
+						      0400,
+						      client->debugfs_dir,
+						      client,
+						      &monc_show_fops);
+	if (!client->monc.debugfs_file)
+		goto out;
+
+	client->osdc.debugfs_file = debugfs_create_file("osdc",
+						      0400,
+						      client->debugfs_dir,
+						      client,
+						      &osdc_show_fops);
+	if (!client->osdc.debugfs_file)
+		goto out;
+
+	client->debugfs_monmap = debugfs_create_file("monmap",
+					0400,
+					client->debugfs_dir,
+					client,
+					&monmap_show_fops);
+	if (!client->debugfs_monmap)
+		goto out;
+
+	client->debugfs_osdmap = debugfs_create_file("osdmap",
+					0400,
+					client->debugfs_dir,
+					client,
+					&osdmap_show_fops);
+	if (!client->debugfs_osdmap)
+		goto out;
+
+	client->debugfs_options = debugfs_create_file("client_options",
+					0400,
+					client->debugfs_dir,
+					client,
+					&client_options_show_fops);
+	if (!client->debugfs_options)
+		goto out;
+
+	return 0;
+
+out:
+	ceph_debugfs_client_cleanup(client);
+	return ret;
+}
+
+void ceph_debugfs_client_cleanup(struct ceph_client *client)
+{
+	dout("ceph_debugfs_client_cleanup %p\n", client);
+	debugfs_remove(client->debugfs_options);
+	debugfs_remove(client->debugfs_osdmap);
+	debugfs_remove(client->debugfs_monmap);
+	debugfs_remove(client->osdc.debugfs_file);
+	debugfs_remove(client->monc.debugfs_file);
+	debugfs_remove(client->debugfs_dir);
+}
+
+#else  /* CONFIG_DEBUG_FS */
+
+int __init ceph_debugfs_init(void)
+{
+	return 0;
+}
+
+void ceph_debugfs_cleanup(void)
+{
+}
+
+int ceph_debugfs_client_init(struct ceph_client *client)
+{
+	return 0;
+}
+
+void ceph_debugfs_client_cleanup(struct ceph_client *client)
+{
+}
+
+#endif  /* CONFIG_DEBUG_FS */
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
new file mode 100644
index 000000000..21bd37ec5
--- /dev/null
+++ b/net/ceph/messenger.c
@@ -0,0 +1,3581 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/crc32c.h>
+#include <linux/ctype.h>
+#include <linux/highmem.h>
+#include <linux/inet.h>
+#include <linux/kthread.h>
+#include <linux/net.h>
+#include <linux/nsproxy.h>
+#include <linux/sched/mm.h>
+#include <linux/slab.h>
+#include <linux/socket.h>
+#include <linux/string.h>
+#ifdef	CONFIG_BLOCK
+#include <linux/bio.h>
+#endif	/* CONFIG_BLOCK */
+#include <linux/dns_resolver.h>
+#include <net/tcp.h>
+
+#include <linux/ceph/ceph_features.h>
+#include <linux/ceph/libceph.h>
+#include <linux/ceph/messenger.h>
+#include <linux/ceph/decode.h>
+#include <linux/ceph/pagelist.h>
+#include <linux/export.h>
+
+/*
+ * Ceph uses the messenger to exchange ceph_msg messages with other
+ * hosts in the system.  The messenger provides ordered and reliable
+ * delivery.  We tolerate TCP disconnects by reconnecting (with
+ * exponential backoff) in the case of a fault (disconnection, bad
+ * crc, protocol error).  Acks allow sent messages to be discarded by
+ * the sender.
+ */
+
+/*
+ * We track the state of the socket on a given connection using
+ * values defined below.  The transition to a new socket state is
+ * handled by a function which verifies we aren't coming from an
+ * unexpected state.
+ *
+ *      --------
+ *      | NEW* |  transient initial state
+ *      --------
+ *          | con_sock_state_init()
+ *          v
+ *      ----------
+ *      | CLOSED |  initialized, but no socket (and no
+ *      ----------  TCP connection)
+ *       ^      \
+ *       |       \ con_sock_state_connecting()
+ *       |        ----------------------
+ *       |                              \
+ *       + con_sock_state_closed()       \
+ *       |+---------------------------    \
+ *       | \                          \    \
+ *       |  -----------                \    \
+ *       |  | CLOSING |  socket event;  \    \
+ *       |  -----------  await close     \    \
+ *       |       ^                        \   |
+ *       |       |                         \  |
+ *       |       + con_sock_state_closing() \ |
+ *       |      / \                         | |
+ *       |     /   ---------------          | |
+ *       |    /                   \         v v
+ *       |   /                    --------------
+ *       |  /    -----------------| CONNECTING |  socket created, TCP
+ *       |  |   /                 --------------  connect initiated
+ *       |  |   | con_sock_state_connected()
+ *       |  |   v
+ *      -------------
+ *      | CONNECTED |  TCP connection established
+ *      -------------
+ *
+ * State values for ceph_connection->sock_state; NEW is assumed to be 0.
+ */
+
+#define CON_SOCK_STATE_NEW		0	/* -> CLOSED */
+#define CON_SOCK_STATE_CLOSED		1	/* -> CONNECTING */
+#define CON_SOCK_STATE_CONNECTING	2	/* -> CONNECTED or -> CLOSING */
+#define CON_SOCK_STATE_CONNECTED	3	/* -> CLOSING or -> CLOSED */
+#define CON_SOCK_STATE_CLOSING		4	/* -> CLOSED */
+
+/*
+ * connection states
+ */
+#define CON_STATE_CLOSED        1  /* -> PREOPEN */
+#define CON_STATE_PREOPEN       2  /* -> CONNECTING, CLOSED */
+#define CON_STATE_CONNECTING    3  /* -> NEGOTIATING, CLOSED */
+#define CON_STATE_NEGOTIATING   4  /* -> OPEN, CLOSED */
+#define CON_STATE_OPEN          5  /* -> STANDBY, CLOSED */
+#define CON_STATE_STANDBY       6  /* -> PREOPEN, CLOSED */
+
+/*
+ * ceph_connection flag bits
+ */
+#define CON_FLAG_LOSSYTX           0  /* we can close channel or drop
+				       * messages on errors */
+#define CON_FLAG_KEEPALIVE_PENDING 1  /* we need to send a keepalive */
+#define CON_FLAG_WRITE_PENDING	   2  /* we have data ready to send */
+#define CON_FLAG_SOCK_CLOSED	   3  /* socket state changed to closed */
+#define CON_FLAG_BACKOFF           4  /* need to retry queuing delayed work */
+
+static bool con_flag_valid(unsigned long con_flag)
+{
+	switch (con_flag) {
+	case CON_FLAG_LOSSYTX:
+	case CON_FLAG_KEEPALIVE_PENDING:
+	case CON_FLAG_WRITE_PENDING:
+	case CON_FLAG_SOCK_CLOSED:
+	case CON_FLAG_BACKOFF:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static void con_flag_clear(struct ceph_connection *con, unsigned long con_flag)
+{
+	BUG_ON(!con_flag_valid(con_flag));
+
+	clear_bit(con_flag, &con->flags);
+}
+
+static void con_flag_set(struct ceph_connection *con, unsigned long con_flag)
+{
+	BUG_ON(!con_flag_valid(con_flag));
+
+	set_bit(con_flag, &con->flags);
+}
+
+static bool con_flag_test(struct ceph_connection *con, unsigned long con_flag)
+{
+	BUG_ON(!con_flag_valid(con_flag));
+
+	return test_bit(con_flag, &con->flags);
+}
+
+static bool con_flag_test_and_clear(struct ceph_connection *con,
+					unsigned long con_flag)
+{
+	BUG_ON(!con_flag_valid(con_flag));
+
+	return test_and_clear_bit(con_flag, &con->flags);
+}
+
+static bool con_flag_test_and_set(struct ceph_connection *con,
+					unsigned long con_flag)
+{
+	BUG_ON(!con_flag_valid(con_flag));
+
+	return test_and_set_bit(con_flag, &con->flags);
+}
+
+/* Slab caches for frequently-allocated structures */
+
+static struct kmem_cache	*ceph_msg_cache;
+static struct kmem_cache	*ceph_msg_data_cache;
+
+/* static tag bytes (protocol control messages) */
+static char tag_msg = CEPH_MSGR_TAG_MSG;
+static char tag_ack = CEPH_MSGR_TAG_ACK;
+static char tag_keepalive = CEPH_MSGR_TAG_KEEPALIVE;
+static char tag_keepalive2 = CEPH_MSGR_TAG_KEEPALIVE2;
+
+#ifdef CONFIG_LOCKDEP
+static struct lock_class_key socket_class;
+#endif
+
+static void queue_con(struct ceph_connection *con);
+static void cancel_con(struct ceph_connection *con);
+static void ceph_con_workfn(struct work_struct *);
+static void con_fault(struct ceph_connection *con);
+
+/*
+ * Nicely render a sockaddr as a string.  An array of formatted
+ * strings is used, to approximate reentrancy.
+ */
+#define ADDR_STR_COUNT_LOG	5	/* log2(# address strings in array) */
+#define ADDR_STR_COUNT		(1 << ADDR_STR_COUNT_LOG)
+#define ADDR_STR_COUNT_MASK	(ADDR_STR_COUNT - 1)
+#define MAX_ADDR_STR_LEN	64	/* 54 is enough */
+
+static char addr_str[ADDR_STR_COUNT][MAX_ADDR_STR_LEN];
+static atomic_t addr_str_seq = ATOMIC_INIT(0);
+
+static struct page *zero_page;		/* used in certain error cases */
+
+const char *ceph_pr_addr(const struct sockaddr_storage *ss)
+{
+	int i;
+	char *s;
+	struct sockaddr_in *in4 = (struct sockaddr_in *) ss;
+	struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) ss;
+
+	i = atomic_inc_return(&addr_str_seq) & ADDR_STR_COUNT_MASK;
+	s = addr_str[i];
+
+	switch (ss->ss_family) {
+	case AF_INET:
+		snprintf(s, MAX_ADDR_STR_LEN, "%pI4:%hu", &in4->sin_addr,
+			 ntohs(in4->sin_port));
+		break;
+
+	case AF_INET6:
+		snprintf(s, MAX_ADDR_STR_LEN, "[%pI6c]:%hu", &in6->sin6_addr,
+			 ntohs(in6->sin6_port));
+		break;
+
+	default:
+		snprintf(s, MAX_ADDR_STR_LEN, "(unknown sockaddr family %hu)",
+			 ss->ss_family);
+	}
+
+	return s;
+}
+EXPORT_SYMBOL(ceph_pr_addr);
+
+static void encode_my_addr(struct ceph_messenger *msgr)
+{
+	memcpy(&msgr->my_enc_addr, &msgr->inst.addr, sizeof(msgr->my_enc_addr));
+	ceph_encode_addr(&msgr->my_enc_addr);
+}
+
+/*
+ * work queue for all reading and writing to/from the socket.
+ */
+static struct workqueue_struct *ceph_msgr_wq;
+
+static int ceph_msgr_slab_init(void)
+{
+	BUG_ON(ceph_msg_cache);
+	ceph_msg_cache = KMEM_CACHE(ceph_msg, 0);
+	if (!ceph_msg_cache)
+		return -ENOMEM;
+
+	BUG_ON(ceph_msg_data_cache);
+	ceph_msg_data_cache = KMEM_CACHE(ceph_msg_data, 0);
+	if (ceph_msg_data_cache)
+		return 0;
+
+	kmem_cache_destroy(ceph_msg_cache);
+	ceph_msg_cache = NULL;
+
+	return -ENOMEM;
+}
+
+static void ceph_msgr_slab_exit(void)
+{
+	BUG_ON(!ceph_msg_data_cache);
+	kmem_cache_destroy(ceph_msg_data_cache);
+	ceph_msg_data_cache = NULL;
+
+	BUG_ON(!ceph_msg_cache);
+	kmem_cache_destroy(ceph_msg_cache);
+	ceph_msg_cache = NULL;
+}
+
+static void _ceph_msgr_exit(void)
+{
+	if (ceph_msgr_wq) {
+		destroy_workqueue(ceph_msgr_wq);
+		ceph_msgr_wq = NULL;
+	}
+
+	BUG_ON(zero_page == NULL);
+	put_page(zero_page);
+	zero_page = NULL;
+
+	ceph_msgr_slab_exit();
+}
+
+int __init ceph_msgr_init(void)
+{
+	if (ceph_msgr_slab_init())
+		return -ENOMEM;
+
+	BUG_ON(zero_page != NULL);
+	zero_page = ZERO_PAGE(0);
+	get_page(zero_page);
+
+	/*
+	 * The number of active work items is limited by the number of
+	 * connections, so leave @max_active at default.
+	 */
+	ceph_msgr_wq = alloc_workqueue("ceph-msgr", WQ_MEM_RECLAIM, 0);
+	if (ceph_msgr_wq)
+		return 0;
+
+	pr_err("msgr_init failed to create workqueue\n");
+	_ceph_msgr_exit();
+
+	return -ENOMEM;
+}
+
+void ceph_msgr_exit(void)
+{
+	BUG_ON(ceph_msgr_wq == NULL);
+
+	_ceph_msgr_exit();
+}
+
+void ceph_msgr_flush(void)
+{
+	flush_workqueue(ceph_msgr_wq);
+}
+EXPORT_SYMBOL(ceph_msgr_flush);
+
+/* Connection socket state transition functions */
+
+static void con_sock_state_init(struct ceph_connection *con)
+{
+	int old_state;
+
+	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSED);
+	if (WARN_ON(old_state != CON_SOCK_STATE_NEW))
+		printk("%s: unexpected old state %d\n", __func__, old_state);
+	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
+	     CON_SOCK_STATE_CLOSED);
+}
+
+static void con_sock_state_connecting(struct ceph_connection *con)
+{
+	int old_state;
+
+	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CONNECTING);
+	if (WARN_ON(old_state != CON_SOCK_STATE_CLOSED))
+		printk("%s: unexpected old state %d\n", __func__, old_state);
+	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
+	     CON_SOCK_STATE_CONNECTING);
+}
+
+static void con_sock_state_connected(struct ceph_connection *con)
+{
+	int old_state;
+
+	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CONNECTED);
+	if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTING))
+		printk("%s: unexpected old state %d\n", __func__, old_state);
+	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
+	     CON_SOCK_STATE_CONNECTED);
+}
+
+static void con_sock_state_closing(struct ceph_connection *con)
+{
+	int old_state;
+
+	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSING);
+	if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTING &&
+			old_state != CON_SOCK_STATE_CONNECTED &&
+			old_state != CON_SOCK_STATE_CLOSING))
+		printk("%s: unexpected old state %d\n", __func__, old_state);
+	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
+	     CON_SOCK_STATE_CLOSING);
+}
+
+static void con_sock_state_closed(struct ceph_connection *con)
+{
+	int old_state;
+
+	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSED);
+	if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTED &&
+		    old_state != CON_SOCK_STATE_CLOSING &&
+		    old_state != CON_SOCK_STATE_CONNECTING &&
+		    old_state != CON_SOCK_STATE_CLOSED))
+		printk("%s: unexpected old state %d\n", __func__, old_state);
+	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
+	     CON_SOCK_STATE_CLOSED);
+}
+
+/*
+ * socket callback functions
+ */
+
+/* data available on socket, or listen socket received a connect */
+static void ceph_sock_data_ready(struct sock *sk)
+{
+	struct ceph_connection *con = sk->sk_user_data;
+	if (atomic_read(&con->msgr->stopping)) {
+		return;
+	}
+
+	if (sk->sk_state != TCP_CLOSE_WAIT) {
+		dout("%s on %p state = %lu, queueing work\n", __func__,
+		     con, con->state);
+		queue_con(con);
+	}
+}
+
+/* socket has buffer space for writing */
+static void ceph_sock_write_space(struct sock *sk)
+{
+	struct ceph_connection *con = sk->sk_user_data;
+
+	/* only queue to workqueue if there is data we want to write,
+	 * and there is sufficient space in the socket buffer to accept
+	 * more data.  clear SOCK_NOSPACE so that ceph_sock_write_space()
+	 * doesn't get called again until try_write() fills the socket
+	 * buffer. See net/ipv4/tcp_input.c:tcp_check_space()
+	 * and net/core/stream.c:sk_stream_write_space().
+	 */
+	if (con_flag_test(con, CON_FLAG_WRITE_PENDING)) {
+		if (sk_stream_is_writeable(sk)) {
+			dout("%s %p queueing write work\n", __func__, con);
+			clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
+			queue_con(con);
+		}
+	} else {
+		dout("%s %p nothing to write\n", __func__, con);
+	}
+}
+
+/* socket's state has changed */
+static void ceph_sock_state_change(struct sock *sk)
+{
+	struct ceph_connection *con = sk->sk_user_data;
+
+	dout("%s %p state = %lu sk_state = %u\n", __func__,
+	     con, con->state, sk->sk_state);
+
+	switch (sk->sk_state) {
+	case TCP_CLOSE:
+		dout("%s TCP_CLOSE\n", __func__);
+		/* fall through */
+	case TCP_CLOSE_WAIT:
+		dout("%s TCP_CLOSE_WAIT\n", __func__);
+		con_sock_state_closing(con);
+		con_flag_set(con, CON_FLAG_SOCK_CLOSED);
+		queue_con(con);
+		break;
+	case TCP_ESTABLISHED:
+		dout("%s TCP_ESTABLISHED\n", __func__);
+		con_sock_state_connected(con);
+		queue_con(con);
+		break;
+	default:	/* Everything else is uninteresting */
+		break;
+	}
+}
+
+/*
+ * set up socket callbacks
+ */
+static void set_sock_callbacks(struct socket *sock,
+			       struct ceph_connection *con)
+{
+	struct sock *sk = sock->sk;
+	sk->sk_user_data = con;
+	sk->sk_data_ready = ceph_sock_data_ready;
+	sk->sk_write_space = ceph_sock_write_space;
+	sk->sk_state_change = ceph_sock_state_change;
+}
+
+
+/*
+ * socket helpers
+ */
+
+/*
+ * initiate connection to a remote socket.
+ */
+static int ceph_tcp_connect(struct ceph_connection *con)
+{
+	struct sockaddr_storage *paddr = &con->peer_addr.in_addr;
+	struct socket *sock;
+	unsigned int noio_flag;
+	int ret;
+
+	BUG_ON(con->sock);
+
+	/* sock_create_kern() allocates with GFP_KERNEL */
+	noio_flag = memalloc_noio_save();
+	ret = sock_create_kern(read_pnet(&con->msgr->net), paddr->ss_family,
+			       SOCK_STREAM, IPPROTO_TCP, &sock);
+	memalloc_noio_restore(noio_flag);
+	if (ret)
+		return ret;
+	sock->sk->sk_allocation = GFP_NOFS;
+
+#ifdef CONFIG_LOCKDEP
+	lockdep_set_class(&sock->sk->sk_lock, &socket_class);
+#endif
+
+	set_sock_callbacks(sock, con);
+
+	dout("connect %s\n", ceph_pr_addr(&con->peer_addr.in_addr));
+
+	con_sock_state_connecting(con);
+	ret = sock->ops->connect(sock, (struct sockaddr *)paddr, sizeof(*paddr),
+				 O_NONBLOCK);
+	if (ret == -EINPROGRESS) {
+		dout("connect %s EINPROGRESS sk_state = %u\n",
+		     ceph_pr_addr(&con->peer_addr.in_addr),
+		     sock->sk->sk_state);
+	} else if (ret < 0) {
+		pr_err("connect %s error %d\n",
+		       ceph_pr_addr(&con->peer_addr.in_addr), ret);
+		sock_release(sock);
+		return ret;
+	}
+
+	if (ceph_test_opt(from_msgr(con->msgr), TCP_NODELAY)) {
+		int optval = 1;
+
+		ret = kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY,
+					(char *)&optval, sizeof(optval));
+		if (ret)
+			pr_err("kernel_setsockopt(TCP_NODELAY) failed: %d",
+			       ret);
+	}
+
+	con->sock = sock;
+	return 0;
+}
+
+/*
+ * If @buf is NULL, discard up to @len bytes.
+ */
+static int ceph_tcp_recvmsg(struct socket *sock, void *buf, size_t len)
+{
+	struct kvec iov = {buf, len};
+	struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
+	int r;
+
+	if (!buf)
+		msg.msg_flags |= MSG_TRUNC;
+
+	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1, len);
+	r = sock_recvmsg(sock, &msg, msg.msg_flags);
+	if (r == -EAGAIN)
+		r = 0;
+	return r;
+}
+
+static int ceph_tcp_recvpage(struct socket *sock, struct page *page,
+		     int page_offset, size_t length)
+{
+	struct bio_vec bvec = {
+		.bv_page = page,
+		.bv_offset = page_offset,
+		.bv_len = length
+	};
+	struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
+	int r;
+
+	BUG_ON(page_offset + length > PAGE_SIZE);
+	iov_iter_bvec(&msg.msg_iter, READ | ITER_BVEC, &bvec, 1, length);
+	r = sock_recvmsg(sock, &msg, msg.msg_flags);
+	if (r == -EAGAIN)
+		r = 0;
+	return r;
+}
+
+/*
+ * write something.  @more is true if caller will be sending more data
+ * shortly.
+ */
+static int ceph_tcp_sendmsg(struct socket *sock, struct kvec *iov,
+		     size_t kvlen, size_t len, int more)
+{
+	struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
+	int r;
+
+	if (more)
+		msg.msg_flags |= MSG_MORE;
+	else
+		msg.msg_flags |= MSG_EOR;  /* superfluous, but what the hell */
+
+	r = kernel_sendmsg(sock, &msg, iov, kvlen, len);
+	if (r == -EAGAIN)
+		r = 0;
+	return r;
+}
+
+static int __ceph_tcp_sendpage(struct socket *sock, struct page *page,
+		     int offset, size_t size, bool more)
+{
+	int flags = MSG_DONTWAIT | MSG_NOSIGNAL | (more ? MSG_MORE : MSG_EOR);
+	int ret;
+
+	ret = kernel_sendpage(sock, page, offset, size, flags);
+	if (ret == -EAGAIN)
+		ret = 0;
+
+	return ret;
+}
+
+static int ceph_tcp_sendpage(struct socket *sock, struct page *page,
+		     int offset, size_t size, bool more)
+{
+	struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
+	struct bio_vec bvec;
+	int ret;
+
+	/*
+	 * sendpage cannot properly handle pages with page_count == 0,
+	 * we need to fall back to sendmsg if that's the case.
+	 *
+	 * Same goes for slab pages: skb_can_coalesce() allows
+	 * coalescing neighboring slab objects into a single frag which
+	 * triggers one of hardened usercopy checks.
+	 */
+	if (page_count(page) >= 1 && !PageSlab(page))
+		return __ceph_tcp_sendpage(sock, page, offset, size, more);
+
+	bvec.bv_page = page;
+	bvec.bv_offset = offset;
+	bvec.bv_len = size;
+
+	if (more)
+		msg.msg_flags |= MSG_MORE;
+	else
+		msg.msg_flags |= MSG_EOR;  /* superfluous, but what the hell */
+
+	iov_iter_bvec(&msg.msg_iter, WRITE | ITER_BVEC, &bvec, 1, size);
+	ret = sock_sendmsg(sock, &msg);
+	if (ret == -EAGAIN)
+		ret = 0;
+
+	return ret;
+}
+
+/*
+ * Shutdown/close the socket for the given connection.
+ */
+static int con_close_socket(struct ceph_connection *con)
+{
+	int rc = 0;
+
+	dout("con_close_socket on %p sock %p\n", con, con->sock);
+	if (con->sock) {
+		rc = con->sock->ops->shutdown(con->sock, SHUT_RDWR);
+		sock_release(con->sock);
+		con->sock = NULL;
+	}
+
+	/*
+	 * Forcibly clear the SOCK_CLOSED flag.  It gets set
+	 * independent of the connection mutex, and we could have
+	 * received a socket close event before we had the chance to
+	 * shut the socket down.
+	 */
+	con_flag_clear(con, CON_FLAG_SOCK_CLOSED);
+
+	con_sock_state_closed(con);
+	return rc;
+}
+
+/*
+ * Reset a connection.  Discard all incoming and outgoing messages
+ * and clear *_seq state.
+ */
+static void ceph_msg_remove(struct ceph_msg *msg)
+{
+	list_del_init(&msg->list_head);
+
+	ceph_msg_put(msg);
+}
+static void ceph_msg_remove_list(struct list_head *head)
+{
+	while (!list_empty(head)) {
+		struct ceph_msg *msg = list_first_entry(head, struct ceph_msg,
+							list_head);
+		ceph_msg_remove(msg);
+	}
+}
+
+static void reset_connection(struct ceph_connection *con)
+{
+	/* reset connection, out_queue, msg_ and connect_seq */
+	/* discard existing out_queue and msg_seq */
+	dout("reset_connection %p\n", con);
+	ceph_msg_remove_list(&con->out_queue);
+	ceph_msg_remove_list(&con->out_sent);
+
+	if (con->in_msg) {
+		BUG_ON(con->in_msg->con != con);
+		ceph_msg_put(con->in_msg);
+		con->in_msg = NULL;
+	}
+
+	con->connect_seq = 0;
+	con->out_seq = 0;
+	if (con->out_msg) {
+		BUG_ON(con->out_msg->con != con);
+		ceph_msg_put(con->out_msg);
+		con->out_msg = NULL;
+	}
+	con->in_seq = 0;
+	con->in_seq_acked = 0;
+
+	con->out_skip = 0;
+}
+
+/*
+ * mark a peer down.  drop any open connections.
+ */
+void ceph_con_close(struct ceph_connection *con)
+{
+	mutex_lock(&con->mutex);
+	dout("con_close %p peer %s\n", con,
+	     ceph_pr_addr(&con->peer_addr.in_addr));
+	con->state = CON_STATE_CLOSED;
+
+	con_flag_clear(con, CON_FLAG_LOSSYTX);	/* so we retry next connect */
+	con_flag_clear(con, CON_FLAG_KEEPALIVE_PENDING);
+	con_flag_clear(con, CON_FLAG_WRITE_PENDING);
+	con_flag_clear(con, CON_FLAG_BACKOFF);
+
+	reset_connection(con);
+	con->peer_global_seq = 0;
+	cancel_con(con);
+	con_close_socket(con);
+	mutex_unlock(&con->mutex);
+}
+EXPORT_SYMBOL(ceph_con_close);
+
+/*
+ * Reopen a closed connection, with a new peer address.
+ */
+void ceph_con_open(struct ceph_connection *con,
+		   __u8 entity_type, __u64 entity_num,
+		   struct ceph_entity_addr *addr)
+{
+	mutex_lock(&con->mutex);
+	dout("con_open %p %s\n", con, ceph_pr_addr(&addr->in_addr));
+
+	WARN_ON(con->state != CON_STATE_CLOSED);
+	con->state = CON_STATE_PREOPEN;
+
+	con->peer_name.type = (__u8) entity_type;
+	con->peer_name.num = cpu_to_le64(entity_num);
+
+	memcpy(&con->peer_addr, addr, sizeof(*addr));
+	con->delay = 0;      /* reset backoff memory */
+	mutex_unlock(&con->mutex);
+	queue_con(con);
+}
+EXPORT_SYMBOL(ceph_con_open);
+
+/*
+ * return true if this connection ever successfully opened
+ */
+bool ceph_con_opened(struct ceph_connection *con)
+{
+	return con->connect_seq > 0;
+}
+
+/*
+ * initialize a new connection.
+ */
+void ceph_con_init(struct ceph_connection *con, void *private,
+	const struct ceph_connection_operations *ops,
+	struct ceph_messenger *msgr)
+{
+	dout("con_init %p\n", con);
+	memset(con, 0, sizeof(*con));
+	con->private = private;
+	con->ops = ops;
+	con->msgr = msgr;
+
+	con_sock_state_init(con);
+
+	mutex_init(&con->mutex);
+	INIT_LIST_HEAD(&con->out_queue);
+	INIT_LIST_HEAD(&con->out_sent);
+	INIT_DELAYED_WORK(&con->work, ceph_con_workfn);
+
+	con->state = CON_STATE_CLOSED;
+}
+EXPORT_SYMBOL(ceph_con_init);
+
+
+/*
+ * We maintain a global counter to order connection attempts.  Get
+ * a unique seq greater than @gt.
+ */
+static u32 get_global_seq(struct ceph_messenger *msgr, u32 gt)
+{
+	u32 ret;
+
+	spin_lock(&msgr->global_seq_lock);
+	if (msgr->global_seq < gt)
+		msgr->global_seq = gt;
+	ret = ++msgr->global_seq;
+	spin_unlock(&msgr->global_seq_lock);
+	return ret;
+}
+
+static void con_out_kvec_reset(struct ceph_connection *con)
+{
+	BUG_ON(con->out_skip);
+
+	con->out_kvec_left = 0;
+	con->out_kvec_bytes = 0;
+	con->out_kvec_cur = &con->out_kvec[0];
+}
+
+static void con_out_kvec_add(struct ceph_connection *con,
+				size_t size, void *data)
+{
+	int index = con->out_kvec_left;
+
+	BUG_ON(con->out_skip);
+	BUG_ON(index >= ARRAY_SIZE(con->out_kvec));
+
+	con->out_kvec[index].iov_len = size;
+	con->out_kvec[index].iov_base = data;
+	con->out_kvec_left++;
+	con->out_kvec_bytes += size;
+}
+
+/*
+ * Chop off a kvec from the end.  Return residual number of bytes for
+ * that kvec, i.e. how many bytes would have been written if the kvec
+ * hadn't been nuked.
+ */
+static int con_out_kvec_skip(struct ceph_connection *con)
+{
+	int off = con->out_kvec_cur - con->out_kvec;
+	int skip = 0;
+
+	if (con->out_kvec_bytes > 0) {
+		skip = con->out_kvec[off + con->out_kvec_left - 1].iov_len;
+		BUG_ON(con->out_kvec_bytes < skip);
+		BUG_ON(!con->out_kvec_left);
+		con->out_kvec_bytes -= skip;
+		con->out_kvec_left--;
+	}
+
+	return skip;
+}
+
+#ifdef CONFIG_BLOCK
+
+/*
+ * For a bio data item, a piece is whatever remains of the next
+ * entry in the current bio iovec, or the first entry in the next
+ * bio in the list.
+ */
+static void ceph_msg_data_bio_cursor_init(struct ceph_msg_data_cursor *cursor,
+					size_t length)
+{
+	struct ceph_msg_data *data = cursor->data;
+	struct ceph_bio_iter *it = &cursor->bio_iter;
+
+	cursor->resid = min_t(size_t, length, data->bio_length);
+	*it = data->bio_pos;
+	if (cursor->resid < it->iter.bi_size)
+		it->iter.bi_size = cursor->resid;
+
+	BUG_ON(cursor->resid < bio_iter_len(it->bio, it->iter));
+	cursor->last_piece = cursor->resid == bio_iter_len(it->bio, it->iter);
+}
+
+static struct page *ceph_msg_data_bio_next(struct ceph_msg_data_cursor *cursor,
+						size_t *page_offset,
+						size_t *length)
+{
+	struct bio_vec bv = bio_iter_iovec(cursor->bio_iter.bio,
+					   cursor->bio_iter.iter);
+
+	*page_offset = bv.bv_offset;
+	*length = bv.bv_len;
+	return bv.bv_page;
+}
+
+static bool ceph_msg_data_bio_advance(struct ceph_msg_data_cursor *cursor,
+					size_t bytes)
+{
+	struct ceph_bio_iter *it = &cursor->bio_iter;
+
+	BUG_ON(bytes > cursor->resid);
+	BUG_ON(bytes > bio_iter_len(it->bio, it->iter));
+	cursor->resid -= bytes;
+	bio_advance_iter(it->bio, &it->iter, bytes);
+
+	if (!cursor->resid) {
+		BUG_ON(!cursor->last_piece);
+		return false;   /* no more data */
+	}
+
+	if (!bytes || (it->iter.bi_size && it->iter.bi_bvec_done))
+		return false;	/* more bytes to process in this segment */
+
+	if (!it->iter.bi_size) {
+		it->bio = it->bio->bi_next;
+		it->iter = it->bio->bi_iter;
+		if (cursor->resid < it->iter.bi_size)
+			it->iter.bi_size = cursor->resid;
+	}
+
+	BUG_ON(cursor->last_piece);
+	BUG_ON(cursor->resid < bio_iter_len(it->bio, it->iter));
+	cursor->last_piece = cursor->resid == bio_iter_len(it->bio, it->iter);
+	return true;
+}
+#endif /* CONFIG_BLOCK */
+
+static void ceph_msg_data_bvecs_cursor_init(struct ceph_msg_data_cursor *cursor,
+					size_t length)
+{
+	struct ceph_msg_data *data = cursor->data;
+	struct bio_vec *bvecs = data->bvec_pos.bvecs;
+
+	cursor->resid = min_t(size_t, length, data->bvec_pos.iter.bi_size);
+	cursor->bvec_iter = data->bvec_pos.iter;
+	cursor->bvec_iter.bi_size = cursor->resid;
+
+	BUG_ON(cursor->resid < bvec_iter_len(bvecs, cursor->bvec_iter));
+	cursor->last_piece =
+	    cursor->resid == bvec_iter_len(bvecs, cursor->bvec_iter);
+}
+
+static struct page *ceph_msg_data_bvecs_next(struct ceph_msg_data_cursor *cursor,
+						size_t *page_offset,
+						size_t *length)
+{
+	struct bio_vec bv = bvec_iter_bvec(cursor->data->bvec_pos.bvecs,
+					   cursor->bvec_iter);
+
+	*page_offset = bv.bv_offset;
+	*length = bv.bv_len;
+	return bv.bv_page;
+}
+
+static bool ceph_msg_data_bvecs_advance(struct ceph_msg_data_cursor *cursor,
+					size_t bytes)
+{
+	struct bio_vec *bvecs = cursor->data->bvec_pos.bvecs;
+
+	BUG_ON(bytes > cursor->resid);
+	BUG_ON(bytes > bvec_iter_len(bvecs, cursor->bvec_iter));
+	cursor->resid -= bytes;
+	bvec_iter_advance(bvecs, &cursor->bvec_iter, bytes);
+
+	if (!cursor->resid) {
+		BUG_ON(!cursor->last_piece);
+		return false;   /* no more data */
+	}
+
+	if (!bytes || cursor->bvec_iter.bi_bvec_done)
+		return false;	/* more bytes to process in this segment */
+
+	BUG_ON(cursor->last_piece);
+	BUG_ON(cursor->resid < bvec_iter_len(bvecs, cursor->bvec_iter));
+	cursor->last_piece =
+	    cursor->resid == bvec_iter_len(bvecs, cursor->bvec_iter);
+	return true;
+}
+
+/*
+ * For a page array, a piece comes from the first page in the array
+ * that has not already been fully consumed.
+ */
+static void ceph_msg_data_pages_cursor_init(struct ceph_msg_data_cursor *cursor,
+					size_t length)
+{
+	struct ceph_msg_data *data = cursor->data;
+	int page_count;
+
+	BUG_ON(data->type != CEPH_MSG_DATA_PAGES);
+
+	BUG_ON(!data->pages);
+	BUG_ON(!data->length);
+
+	cursor->resid = min(length, data->length);
+	page_count = calc_pages_for(data->alignment, (u64)data->length);
+	cursor->page_offset = data->alignment & ~PAGE_MASK;
+	cursor->page_index = 0;
+	BUG_ON(page_count > (int)USHRT_MAX);
+	cursor->page_count = (unsigned short)page_count;
+	BUG_ON(length > SIZE_MAX - cursor->page_offset);
+	cursor->last_piece = cursor->page_offset + cursor->resid <= PAGE_SIZE;
+}
+
+static struct page *
+ceph_msg_data_pages_next(struct ceph_msg_data_cursor *cursor,
+					size_t *page_offset, size_t *length)
+{
+	struct ceph_msg_data *data = cursor->data;
+
+	BUG_ON(data->type != CEPH_MSG_DATA_PAGES);
+
+	BUG_ON(cursor->page_index >= cursor->page_count);
+	BUG_ON(cursor->page_offset >= PAGE_SIZE);
+
+	*page_offset = cursor->page_offset;
+	if (cursor->last_piece)
+		*length = cursor->resid;
+	else
+		*length = PAGE_SIZE - *page_offset;
+
+	return data->pages[cursor->page_index];
+}
+
+static bool ceph_msg_data_pages_advance(struct ceph_msg_data_cursor *cursor,
+						size_t bytes)
+{
+	BUG_ON(cursor->data->type != CEPH_MSG_DATA_PAGES);
+
+	BUG_ON(cursor->page_offset + bytes > PAGE_SIZE);
+
+	/* Advance the cursor page offset */
+
+	cursor->resid -= bytes;
+	cursor->page_offset = (cursor->page_offset + bytes) & ~PAGE_MASK;
+	if (!bytes || cursor->page_offset)
+		return false;	/* more bytes to process in the current page */
+
+	if (!cursor->resid)
+		return false;   /* no more data */
+
+	/* Move on to the next page; offset is already at 0 */
+
+	BUG_ON(cursor->page_index >= cursor->page_count);
+	cursor->page_index++;
+	cursor->last_piece = cursor->resid <= PAGE_SIZE;
+
+	return true;
+}
+
+/*
+ * For a pagelist, a piece is whatever remains to be consumed in the
+ * first page in the list, or the front of the next page.
+ */
+static void
+ceph_msg_data_pagelist_cursor_init(struct ceph_msg_data_cursor *cursor,
+					size_t length)
+{
+	struct ceph_msg_data *data = cursor->data;
+	struct ceph_pagelist *pagelist;
+	struct page *page;
+
+	BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
+
+	pagelist = data->pagelist;
+	BUG_ON(!pagelist);
+
+	if (!length)
+		return;		/* pagelist can be assigned but empty */
+
+	BUG_ON(list_empty(&pagelist->head));
+	page = list_first_entry(&pagelist->head, struct page, lru);
+
+	cursor->resid = min(length, pagelist->length);
+	cursor->page = page;
+	cursor->offset = 0;
+	cursor->last_piece = cursor->resid <= PAGE_SIZE;
+}
+
+static struct page *
+ceph_msg_data_pagelist_next(struct ceph_msg_data_cursor *cursor,
+				size_t *page_offset, size_t *length)
+{
+	struct ceph_msg_data *data = cursor->data;
+	struct ceph_pagelist *pagelist;
+
+	BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
+
+	pagelist = data->pagelist;
+	BUG_ON(!pagelist);
+
+	BUG_ON(!cursor->page);
+	BUG_ON(cursor->offset + cursor->resid != pagelist->length);
+
+	/* offset of first page in pagelist is always 0 */
+	*page_offset = cursor->offset & ~PAGE_MASK;
+	if (cursor->last_piece)
+		*length = cursor->resid;
+	else
+		*length = PAGE_SIZE - *page_offset;
+
+	return cursor->page;
+}
+
+static bool ceph_msg_data_pagelist_advance(struct ceph_msg_data_cursor *cursor,
+						size_t bytes)
+{
+	struct ceph_msg_data *data = cursor->data;
+	struct ceph_pagelist *pagelist;
+
+	BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
+
+	pagelist = data->pagelist;
+	BUG_ON(!pagelist);
+
+	BUG_ON(cursor->offset + cursor->resid != pagelist->length);
+	BUG_ON((cursor->offset & ~PAGE_MASK) + bytes > PAGE_SIZE);
+
+	/* Advance the cursor offset */
+
+	cursor->resid -= bytes;
+	cursor->offset += bytes;
+	/* offset of first page in pagelist is always 0 */
+	if (!bytes || cursor->offset & ~PAGE_MASK)
+		return false;	/* more bytes to process in the current page */
+
+	if (!cursor->resid)
+		return false;   /* no more data */
+
+	/* Move on to the next page */
+
+	BUG_ON(list_is_last(&cursor->page->lru, &pagelist->head));
+	cursor->page = list_next_entry(cursor->page, lru);
+	cursor->last_piece = cursor->resid <= PAGE_SIZE;
+
+	return true;
+}
+
+/*
+ * Message data is handled (sent or received) in pieces, where each
+ * piece resides on a single page.  The network layer might not
+ * consume an entire piece at once.  A data item's cursor keeps
+ * track of which piece is next to process and how much remains to
+ * be processed in that piece.  It also tracks whether the current
+ * piece is the last one in the data item.
+ */
+static void __ceph_msg_data_cursor_init(struct ceph_msg_data_cursor *cursor)
+{
+	size_t length = cursor->total_resid;
+
+	switch (cursor->data->type) {
+	case CEPH_MSG_DATA_PAGELIST:
+		ceph_msg_data_pagelist_cursor_init(cursor, length);
+		break;
+	case CEPH_MSG_DATA_PAGES:
+		ceph_msg_data_pages_cursor_init(cursor, length);
+		break;
+#ifdef CONFIG_BLOCK
+	case CEPH_MSG_DATA_BIO:
+		ceph_msg_data_bio_cursor_init(cursor, length);
+		break;
+#endif /* CONFIG_BLOCK */
+	case CEPH_MSG_DATA_BVECS:
+		ceph_msg_data_bvecs_cursor_init(cursor, length);
+		break;
+	case CEPH_MSG_DATA_NONE:
+	default:
+		/* BUG(); */
+		break;
+	}
+	cursor->need_crc = true;
+}
+
+static void ceph_msg_data_cursor_init(struct ceph_msg *msg, size_t length)
+{
+	struct ceph_msg_data_cursor *cursor = &msg->cursor;
+	struct ceph_msg_data *data;
+
+	BUG_ON(!length);
+	BUG_ON(length > msg->data_length);
+	BUG_ON(list_empty(&msg->data));
+
+	cursor->data_head = &msg->data;
+	cursor->total_resid = length;
+	data = list_first_entry(&msg->data, struct ceph_msg_data, links);
+	cursor->data = data;
+
+	__ceph_msg_data_cursor_init(cursor);
+}
+
+/*
+ * Return the page containing the next piece to process for a given
+ * data item, and supply the page offset and length of that piece.
+ * Indicate whether this is the last piece in this data item.
+ */
+static struct page *ceph_msg_data_next(struct ceph_msg_data_cursor *cursor,
+					size_t *page_offset, size_t *length,
+					bool *last_piece)
+{
+	struct page *page;
+
+	switch (cursor->data->type) {
+	case CEPH_MSG_DATA_PAGELIST:
+		page = ceph_msg_data_pagelist_next(cursor, page_offset, length);
+		break;
+	case CEPH_MSG_DATA_PAGES:
+		page = ceph_msg_data_pages_next(cursor, page_offset, length);
+		break;
+#ifdef CONFIG_BLOCK
+	case CEPH_MSG_DATA_BIO:
+		page = ceph_msg_data_bio_next(cursor, page_offset, length);
+		break;
+#endif /* CONFIG_BLOCK */
+	case CEPH_MSG_DATA_BVECS:
+		page = ceph_msg_data_bvecs_next(cursor, page_offset, length);
+		break;
+	case CEPH_MSG_DATA_NONE:
+	default:
+		page = NULL;
+		break;
+	}
+
+	BUG_ON(!page);
+	BUG_ON(*page_offset + *length > PAGE_SIZE);
+	BUG_ON(!*length);
+	BUG_ON(*length > cursor->resid);
+	if (last_piece)
+		*last_piece = cursor->last_piece;
+
+	return page;
+}
+
+/*
+ * Returns true if the result moves the cursor on to the next piece
+ * of the data item.
+ */
+static void ceph_msg_data_advance(struct ceph_msg_data_cursor *cursor,
+				  size_t bytes)
+{
+	bool new_piece;
+
+	BUG_ON(bytes > cursor->resid);
+	switch (cursor->data->type) {
+	case CEPH_MSG_DATA_PAGELIST:
+		new_piece = ceph_msg_data_pagelist_advance(cursor, bytes);
+		break;
+	case CEPH_MSG_DATA_PAGES:
+		new_piece = ceph_msg_data_pages_advance(cursor, bytes);
+		break;
+#ifdef CONFIG_BLOCK
+	case CEPH_MSG_DATA_BIO:
+		new_piece = ceph_msg_data_bio_advance(cursor, bytes);
+		break;
+#endif /* CONFIG_BLOCK */
+	case CEPH_MSG_DATA_BVECS:
+		new_piece = ceph_msg_data_bvecs_advance(cursor, bytes);
+		break;
+	case CEPH_MSG_DATA_NONE:
+	default:
+		BUG();
+		break;
+	}
+	cursor->total_resid -= bytes;
+
+	if (!cursor->resid && cursor->total_resid) {
+		WARN_ON(!cursor->last_piece);
+		BUG_ON(list_is_last(&cursor->data->links, cursor->data_head));
+		cursor->data = list_next_entry(cursor->data, links);
+		__ceph_msg_data_cursor_init(cursor);
+		new_piece = true;
+	}
+	cursor->need_crc = new_piece;
+}
+
+static size_t sizeof_footer(struct ceph_connection *con)
+{
+	return (con->peer_features & CEPH_FEATURE_MSG_AUTH) ?
+	    sizeof(struct ceph_msg_footer) :
+	    sizeof(struct ceph_msg_footer_old);
+}
+
+static void prepare_message_data(struct ceph_msg *msg, u32 data_len)
+{
+	BUG_ON(!msg);
+	BUG_ON(!data_len);
+
+	/* Initialize data cursor */
+
+	ceph_msg_data_cursor_init(msg, (size_t)data_len);
+}
+
+/*
+ * Prepare footer for currently outgoing message, and finish things
+ * off.  Assumes out_kvec* are already valid.. we just add on to the end.
+ */
+static void prepare_write_message_footer(struct ceph_connection *con)
+{
+	struct ceph_msg *m = con->out_msg;
+
+	m->footer.flags |= CEPH_MSG_FOOTER_COMPLETE;
+
+	dout("prepare_write_message_footer %p\n", con);
+	con_out_kvec_add(con, sizeof_footer(con), &m->footer);
+	if (con->peer_features & CEPH_FEATURE_MSG_AUTH) {
+		if (con->ops->sign_message)
+			con->ops->sign_message(m);
+		else
+			m->footer.sig = 0;
+	} else {
+		m->old_footer.flags = m->footer.flags;
+	}
+	con->out_more = m->more_to_follow;
+	con->out_msg_done = true;
+}
+
+/*
+ * Prepare headers for the next outgoing message.
+ */
+static void prepare_write_message(struct ceph_connection *con)
+{
+	struct ceph_msg *m;
+	u32 crc;
+
+	con_out_kvec_reset(con);
+	con->out_msg_done = false;
+
+	/* Sneak an ack in there first?  If we can get it into the same
+	 * TCP packet that's a good thing. */
+	if (con->in_seq > con->in_seq_acked) {
+		con->in_seq_acked = con->in_seq;
+		con_out_kvec_add(con, sizeof (tag_ack), &tag_ack);
+		con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
+		con_out_kvec_add(con, sizeof (con->out_temp_ack),
+			&con->out_temp_ack);
+	}
+
+	BUG_ON(list_empty(&con->out_queue));
+	m = list_first_entry(&con->out_queue, struct ceph_msg, list_head);
+	con->out_msg = m;
+	BUG_ON(m->con != con);
+
+	/* put message on sent list */
+	ceph_msg_get(m);
+	list_move_tail(&m->list_head, &con->out_sent);
+
+	/*
+	 * only assign outgoing seq # if we haven't sent this message
+	 * yet.  if it is requeued, resend with it's original seq.
+	 */
+	if (m->needs_out_seq) {
+		m->hdr.seq = cpu_to_le64(++con->out_seq);
+		m->needs_out_seq = false;
+
+		if (con->ops->reencode_message)
+			con->ops->reencode_message(m);
+	}
+
+	dout("prepare_write_message %p seq %lld type %d len %d+%d+%zd\n",
+	     m, con->out_seq, le16_to_cpu(m->hdr.type),
+	     le32_to_cpu(m->hdr.front_len), le32_to_cpu(m->hdr.middle_len),
+	     m->data_length);
+	WARN_ON(m->front.iov_len != le32_to_cpu(m->hdr.front_len));
+	WARN_ON(m->data_length != le32_to_cpu(m->hdr.data_len));
+
+	/* tag + hdr + front + middle */
+	con_out_kvec_add(con, sizeof (tag_msg), &tag_msg);
+	con_out_kvec_add(con, sizeof(con->out_hdr), &con->out_hdr);
+	con_out_kvec_add(con, m->front.iov_len, m->front.iov_base);
+
+	if (m->middle)
+		con_out_kvec_add(con, m->middle->vec.iov_len,
+			m->middle->vec.iov_base);
+
+	/* fill in hdr crc and finalize hdr */
+	crc = crc32c(0, &m->hdr, offsetof(struct ceph_msg_header, crc));
+	con->out_msg->hdr.crc = cpu_to_le32(crc);
+	memcpy(&con->out_hdr, &con->out_msg->hdr, sizeof(con->out_hdr));
+
+	/* fill in front and middle crc, footer */
+	crc = crc32c(0, m->front.iov_base, m->front.iov_len);
+	con->out_msg->footer.front_crc = cpu_to_le32(crc);
+	if (m->middle) {
+		crc = crc32c(0, m->middle->vec.iov_base,
+				m->middle->vec.iov_len);
+		con->out_msg->footer.middle_crc = cpu_to_le32(crc);
+	} else
+		con->out_msg->footer.middle_crc = 0;
+	dout("%s front_crc %u middle_crc %u\n", __func__,
+	     le32_to_cpu(con->out_msg->footer.front_crc),
+	     le32_to_cpu(con->out_msg->footer.middle_crc));
+	con->out_msg->footer.flags = 0;
+
+	/* is there a data payload? */
+	con->out_msg->footer.data_crc = 0;
+	if (m->data_length) {
+		prepare_message_data(con->out_msg, m->data_length);
+		con->out_more = 1;  /* data + footer will follow */
+	} else {
+		/* no, queue up footer too and be done */
+		prepare_write_message_footer(con);
+	}
+
+	con_flag_set(con, CON_FLAG_WRITE_PENDING);
+}
+
+/*
+ * Prepare an ack.
+ */
+static void prepare_write_ack(struct ceph_connection *con)
+{
+	dout("prepare_write_ack %p %llu -> %llu\n", con,
+	     con->in_seq_acked, con->in_seq);
+	con->in_seq_acked = con->in_seq;
+
+	con_out_kvec_reset(con);
+
+	con_out_kvec_add(con, sizeof (tag_ack), &tag_ack);
+
+	con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
+	con_out_kvec_add(con, sizeof (con->out_temp_ack),
+				&con->out_temp_ack);
+
+	con->out_more = 1;  /* more will follow.. eventually.. */
+	con_flag_set(con, CON_FLAG_WRITE_PENDING);
+}
+
+/*
+ * Prepare to share the seq during handshake
+ */
+static void prepare_write_seq(struct ceph_connection *con)
+{
+	dout("prepare_write_seq %p %llu -> %llu\n", con,
+	     con->in_seq_acked, con->in_seq);
+	con->in_seq_acked = con->in_seq;
+
+	con_out_kvec_reset(con);
+
+	con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
+	con_out_kvec_add(con, sizeof (con->out_temp_ack),
+			 &con->out_temp_ack);
+
+	con_flag_set(con, CON_FLAG_WRITE_PENDING);
+}
+
+/*
+ * Prepare to write keepalive byte.
+ */
+static void prepare_write_keepalive(struct ceph_connection *con)
+{
+	dout("prepare_write_keepalive %p\n", con);
+	con_out_kvec_reset(con);
+	if (con->peer_features & CEPH_FEATURE_MSGR_KEEPALIVE2) {
+		struct timespec64 now;
+
+		ktime_get_real_ts64(&now);
+		con_out_kvec_add(con, sizeof(tag_keepalive2), &tag_keepalive2);
+		ceph_encode_timespec64(&con->out_temp_keepalive2, &now);
+		con_out_kvec_add(con, sizeof(con->out_temp_keepalive2),
+				 &con->out_temp_keepalive2);
+	} else {
+		con_out_kvec_add(con, sizeof(tag_keepalive), &tag_keepalive);
+	}
+	con_flag_set(con, CON_FLAG_WRITE_PENDING);
+}
+
+/*
+ * Connection negotiation.
+ */
+
+static int get_connect_authorizer(struct ceph_connection *con)
+{
+	struct ceph_auth_handshake *auth;
+	int auth_proto;
+
+	if (!con->ops->get_authorizer) {
+		con->auth = NULL;
+		con->out_connect.authorizer_protocol = CEPH_AUTH_UNKNOWN;
+		con->out_connect.authorizer_len = 0;
+		return 0;
+	}
+
+	auth = con->ops->get_authorizer(con, &auth_proto, con->auth_retry);
+	if (IS_ERR(auth))
+		return PTR_ERR(auth);
+
+	con->auth = auth;
+	con->out_connect.authorizer_protocol = cpu_to_le32(auth_proto);
+	con->out_connect.authorizer_len = cpu_to_le32(auth->authorizer_buf_len);
+	return 0;
+}
+
+/*
+ * We connected to a peer and are saying hello.
+ */
+static void prepare_write_banner(struct ceph_connection *con)
+{
+	con_out_kvec_add(con, strlen(CEPH_BANNER), CEPH_BANNER);
+	con_out_kvec_add(con, sizeof (con->msgr->my_enc_addr),
+					&con->msgr->my_enc_addr);
+
+	con->out_more = 0;
+	con_flag_set(con, CON_FLAG_WRITE_PENDING);
+}
+
+static void __prepare_write_connect(struct ceph_connection *con)
+{
+	con_out_kvec_add(con, sizeof(con->out_connect), &con->out_connect);
+	if (con->auth)
+		con_out_kvec_add(con, con->auth->authorizer_buf_len,
+				 con->auth->authorizer_buf);
+
+	con->out_more = 0;
+	con_flag_set(con, CON_FLAG_WRITE_PENDING);
+}
+
+static int prepare_write_connect(struct ceph_connection *con)
+{
+	unsigned int global_seq = get_global_seq(con->msgr, 0);
+	int proto;
+	int ret;
+
+	switch (con->peer_name.type) {
+	case CEPH_ENTITY_TYPE_MON:
+		proto = CEPH_MONC_PROTOCOL;
+		break;
+	case CEPH_ENTITY_TYPE_OSD:
+		proto = CEPH_OSDC_PROTOCOL;
+		break;
+	case CEPH_ENTITY_TYPE_MDS:
+		proto = CEPH_MDSC_PROTOCOL;
+		break;
+	default:
+		BUG();
+	}
+
+	dout("prepare_write_connect %p cseq=%d gseq=%d proto=%d\n", con,
+	     con->connect_seq, global_seq, proto);
+
+	con->out_connect.features =
+	    cpu_to_le64(from_msgr(con->msgr)->supported_features);
+	con->out_connect.host_type = cpu_to_le32(CEPH_ENTITY_TYPE_CLIENT);
+	con->out_connect.connect_seq = cpu_to_le32(con->connect_seq);
+	con->out_connect.global_seq = cpu_to_le32(global_seq);
+	con->out_connect.protocol_version = cpu_to_le32(proto);
+	con->out_connect.flags = 0;
+
+	ret = get_connect_authorizer(con);
+	if (ret)
+		return ret;
+
+	__prepare_write_connect(con);
+	return 0;
+}
+
+/*
+ * write as much of pending kvecs to the socket as we can.
+ *  1 -> done
+ *  0 -> socket full, but more to do
+ * <0 -> error
+ */
+static int write_partial_kvec(struct ceph_connection *con)
+{
+	int ret;
+
+	dout("write_partial_kvec %p %d left\n", con, con->out_kvec_bytes);
+	while (con->out_kvec_bytes > 0) {
+		ret = ceph_tcp_sendmsg(con->sock, con->out_kvec_cur,
+				       con->out_kvec_left, con->out_kvec_bytes,
+				       con->out_more);
+		if (ret <= 0)
+			goto out;
+		con->out_kvec_bytes -= ret;
+		if (con->out_kvec_bytes == 0)
+			break;            /* done */
+
+		/* account for full iov entries consumed */
+		while (ret >= con->out_kvec_cur->iov_len) {
+			BUG_ON(!con->out_kvec_left);
+			ret -= con->out_kvec_cur->iov_len;
+			con->out_kvec_cur++;
+			con->out_kvec_left--;
+		}
+		/* and for a partially-consumed entry */
+		if (ret) {
+			con->out_kvec_cur->iov_len -= ret;
+			con->out_kvec_cur->iov_base += ret;
+		}
+	}
+	con->out_kvec_left = 0;
+	ret = 1;
+out:
+	dout("write_partial_kvec %p %d left in %d kvecs ret = %d\n", con,
+	     con->out_kvec_bytes, con->out_kvec_left, ret);
+	return ret;  /* done! */
+}
+
+static u32 ceph_crc32c_page(u32 crc, struct page *page,
+				unsigned int page_offset,
+				unsigned int length)
+{
+	char *kaddr;
+
+	kaddr = kmap(page);
+	BUG_ON(kaddr == NULL);
+	crc = crc32c(crc, kaddr + page_offset, length);
+	kunmap(page);
+
+	return crc;
+}
+/*
+ * Write as much message data payload as we can.  If we finish, queue
+ * up the footer.
+ *  1 -> done, footer is now queued in out_kvec[].
+ *  0 -> socket full, but more to do
+ * <0 -> error
+ */
+static int write_partial_message_data(struct ceph_connection *con)
+{
+	struct ceph_msg *msg = con->out_msg;
+	struct ceph_msg_data_cursor *cursor = &msg->cursor;
+	bool do_datacrc = !ceph_test_opt(from_msgr(con->msgr), NOCRC);
+	u32 crc;
+
+	dout("%s %p msg %p\n", __func__, con, msg);
+
+	if (list_empty(&msg->data))
+		return -EINVAL;
+
+	/*
+	 * Iterate through each page that contains data to be
+	 * written, and send as much as possible for each.
+	 *
+	 * If we are calculating the data crc (the default), we will
+	 * need to map the page.  If we have no pages, they have
+	 * been revoked, so use the zero page.
+	 */
+	crc = do_datacrc ? le32_to_cpu(msg->footer.data_crc) : 0;
+	while (cursor->total_resid) {
+		struct page *page;
+		size_t page_offset;
+		size_t length;
+		bool last_piece;
+		int ret;
+
+		if (!cursor->resid) {
+			ceph_msg_data_advance(cursor, 0);
+			continue;
+		}
+
+		page = ceph_msg_data_next(cursor, &page_offset, &length,
+					  &last_piece);
+		ret = ceph_tcp_sendpage(con->sock, page, page_offset,
+					length, !last_piece);
+		if (ret <= 0) {
+			if (do_datacrc)
+				msg->footer.data_crc = cpu_to_le32(crc);
+
+			return ret;
+		}
+		if (do_datacrc && cursor->need_crc)
+			crc = ceph_crc32c_page(crc, page, page_offset, length);
+		ceph_msg_data_advance(cursor, (size_t)ret);
+	}
+
+	dout("%s %p msg %p done\n", __func__, con, msg);
+
+	/* prepare and queue up footer, too */
+	if (do_datacrc)
+		msg->footer.data_crc = cpu_to_le32(crc);
+	else
+		msg->footer.flags |= CEPH_MSG_FOOTER_NOCRC;
+	con_out_kvec_reset(con);
+	prepare_write_message_footer(con);
+
+	return 1;	/* must return > 0 to indicate success */
+}
+
+/*
+ * write some zeros
+ */
+static int write_partial_skip(struct ceph_connection *con)
+{
+	int ret;
+
+	dout("%s %p %d left\n", __func__, con, con->out_skip);
+	while (con->out_skip > 0) {
+		size_t size = min(con->out_skip, (int) PAGE_SIZE);
+
+		ret = ceph_tcp_sendpage(con->sock, zero_page, 0, size, true);
+		if (ret <= 0)
+			goto out;
+		con->out_skip -= ret;
+	}
+	ret = 1;
+out:
+	return ret;
+}
+
+/*
+ * Prepare to read connection handshake, or an ack.
+ */
+static void prepare_read_banner(struct ceph_connection *con)
+{
+	dout("prepare_read_banner %p\n", con);
+	con->in_base_pos = 0;
+}
+
+static void prepare_read_connect(struct ceph_connection *con)
+{
+	dout("prepare_read_connect %p\n", con);
+	con->in_base_pos = 0;
+}
+
+static void prepare_read_ack(struct ceph_connection *con)
+{
+	dout("prepare_read_ack %p\n", con);
+	con->in_base_pos = 0;
+}
+
+static void prepare_read_seq(struct ceph_connection *con)
+{
+	dout("prepare_read_seq %p\n", con);
+	con->in_base_pos = 0;
+	con->in_tag = CEPH_MSGR_TAG_SEQ;
+}
+
+static void prepare_read_tag(struct ceph_connection *con)
+{
+	dout("prepare_read_tag %p\n", con);
+	con->in_base_pos = 0;
+	con->in_tag = CEPH_MSGR_TAG_READY;
+}
+
+static void prepare_read_keepalive_ack(struct ceph_connection *con)
+{
+	dout("prepare_read_keepalive_ack %p\n", con);
+	con->in_base_pos = 0;
+}
+
+/*
+ * Prepare to read a message.
+ */
+static int prepare_read_message(struct ceph_connection *con)
+{
+	dout("prepare_read_message %p\n", con);
+	BUG_ON(con->in_msg != NULL);
+	con->in_base_pos = 0;
+	con->in_front_crc = con->in_middle_crc = con->in_data_crc = 0;
+	return 0;
+}
+
+
+static int read_partial(struct ceph_connection *con,
+			int end, int size, void *object)
+{
+	while (con->in_base_pos < end) {
+		int left = end - con->in_base_pos;
+		int have = size - left;
+		int ret = ceph_tcp_recvmsg(con->sock, object + have, left);
+		if (ret <= 0)
+			return ret;
+		con->in_base_pos += ret;
+	}
+	return 1;
+}
+
+
+/*
+ * Read all or part of the connect-side handshake on a new connection
+ */
+static int read_partial_banner(struct ceph_connection *con)
+{
+	int size;
+	int end;
+	int ret;
+
+	dout("read_partial_banner %p at %d\n", con, con->in_base_pos);
+
+	/* peer's banner */
+	size = strlen(CEPH_BANNER);
+	end = size;
+	ret = read_partial(con, end, size, con->in_banner);
+	if (ret <= 0)
+		goto out;
+
+	size = sizeof (con->actual_peer_addr);
+	end += size;
+	ret = read_partial(con, end, size, &con->actual_peer_addr);
+	if (ret <= 0)
+		goto out;
+
+	size = sizeof (con->peer_addr_for_me);
+	end += size;
+	ret = read_partial(con, end, size, &con->peer_addr_for_me);
+	if (ret <= 0)
+		goto out;
+
+out:
+	return ret;
+}
+
+static int read_partial_connect(struct ceph_connection *con)
+{
+	int size;
+	int end;
+	int ret;
+
+	dout("read_partial_connect %p at %d\n", con, con->in_base_pos);
+
+	size = sizeof (con->in_reply);
+	end = size;
+	ret = read_partial(con, end, size, &con->in_reply);
+	if (ret <= 0)
+		goto out;
+
+	if (con->auth) {
+		size = le32_to_cpu(con->in_reply.authorizer_len);
+		if (size > con->auth->authorizer_reply_buf_len) {
+			pr_err("authorizer reply too big: %d > %zu\n", size,
+			       con->auth->authorizer_reply_buf_len);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		end += size;
+		ret = read_partial(con, end, size,
+				   con->auth->authorizer_reply_buf);
+		if (ret <= 0)
+			goto out;
+	}
+
+	dout("read_partial_connect %p tag %d, con_seq = %u, g_seq = %u\n",
+	     con, (int)con->in_reply.tag,
+	     le32_to_cpu(con->in_reply.connect_seq),
+	     le32_to_cpu(con->in_reply.global_seq));
+out:
+	return ret;
+}
+
+/*
+ * Verify the hello banner looks okay.
+ */
+static int verify_hello(struct ceph_connection *con)
+{
+	if (memcmp(con->in_banner, CEPH_BANNER, strlen(CEPH_BANNER))) {
+		pr_err("connect to %s got bad banner\n",
+		       ceph_pr_addr(&con->peer_addr.in_addr));
+		con->error_msg = "protocol error, bad banner";
+		return -1;
+	}
+	return 0;
+}
+
+static bool addr_is_blank(struct sockaddr_storage *ss)
+{
+	struct in_addr *addr = &((struct sockaddr_in *)ss)->sin_addr;
+	struct in6_addr *addr6 = &((struct sockaddr_in6 *)ss)->sin6_addr;
+
+	switch (ss->ss_family) {
+	case AF_INET:
+		return addr->s_addr == htonl(INADDR_ANY);
+	case AF_INET6:
+		return ipv6_addr_any(addr6);
+	default:
+		return true;
+	}
+}
+
+static int addr_port(struct sockaddr_storage *ss)
+{
+	switch (ss->ss_family) {
+	case AF_INET:
+		return ntohs(((struct sockaddr_in *)ss)->sin_port);
+	case AF_INET6:
+		return ntohs(((struct sockaddr_in6 *)ss)->sin6_port);
+	}
+	return 0;
+}
+
+static void addr_set_port(struct sockaddr_storage *ss, int p)
+{
+	switch (ss->ss_family) {
+	case AF_INET:
+		((struct sockaddr_in *)ss)->sin_port = htons(p);
+		break;
+	case AF_INET6:
+		((struct sockaddr_in6 *)ss)->sin6_port = htons(p);
+		break;
+	}
+}
+
+/*
+ * Unlike other *_pton function semantics, zero indicates success.
+ */
+static int ceph_pton(const char *str, size_t len, struct sockaddr_storage *ss,
+		char delim, const char **ipend)
+{
+	struct sockaddr_in *in4 = (struct sockaddr_in *) ss;
+	struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) ss;
+
+	memset(ss, 0, sizeof(*ss));
+
+	if (in4_pton(str, len, (u8 *)&in4->sin_addr.s_addr, delim, ipend)) {
+		ss->ss_family = AF_INET;
+		return 0;
+	}
+
+	if (in6_pton(str, len, (u8 *)&in6->sin6_addr.s6_addr, delim, ipend)) {
+		ss->ss_family = AF_INET6;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+/*
+ * Extract hostname string and resolve using kernel DNS facility.
+ */
+#ifdef CONFIG_CEPH_LIB_USE_DNS_RESOLVER
+static int ceph_dns_resolve_name(const char *name, size_t namelen,
+		struct sockaddr_storage *ss, char delim, const char **ipend)
+{
+	const char *end, *delim_p;
+	char *colon_p, *ip_addr = NULL;
+	int ip_len, ret;
+
+	/*
+	 * The end of the hostname occurs immediately preceding the delimiter or
+	 * the port marker (':') where the delimiter takes precedence.
+	 */
+	delim_p = memchr(name, delim, namelen);
+	colon_p = memchr(name, ':', namelen);
+
+	if (delim_p && colon_p)
+		end = delim_p < colon_p ? delim_p : colon_p;
+	else if (!delim_p && colon_p)
+		end = colon_p;
+	else {
+		end = delim_p;
+		if (!end) /* case: hostname:/ */
+			end = name + namelen;
+	}
+
+	if (end <= name)
+		return -EINVAL;
+
+	/* do dns_resolve upcall */
+	ip_len = dns_query(NULL, name, end - name, NULL, &ip_addr, NULL);
+	if (ip_len > 0)
+		ret = ceph_pton(ip_addr, ip_len, ss, -1, NULL);
+	else
+		ret = -ESRCH;
+
+	kfree(ip_addr);
+
+	*ipend = end;
+
+	pr_info("resolve '%.*s' (ret=%d): %s\n", (int)(end - name), name,
+			ret, ret ? "failed" : ceph_pr_addr(ss));
+
+	return ret;
+}
+#else
+static inline int ceph_dns_resolve_name(const char *name, size_t namelen,
+		struct sockaddr_storage *ss, char delim, const char **ipend)
+{
+	return -EINVAL;
+}
+#endif
+
+/*
+ * Parse a server name (IP or hostname). If a valid IP address is not found
+ * then try to extract a hostname to resolve using userspace DNS upcall.
+ */
+static int ceph_parse_server_name(const char *name, size_t namelen,
+			struct sockaddr_storage *ss, char delim, const char **ipend)
+{
+	int ret;
+
+	ret = ceph_pton(name, namelen, ss, delim, ipend);
+	if (ret)
+		ret = ceph_dns_resolve_name(name, namelen, ss, delim, ipend);
+
+	return ret;
+}
+
+/*
+ * Parse an ip[:port] list into an addr array.  Use the default
+ * monitor port if a port isn't specified.
+ */
+int ceph_parse_ips(const char *c, const char *end,
+		   struct ceph_entity_addr *addr,
+		   int max_count, int *count)
+{
+	int i, ret = -EINVAL;
+	const char *p = c;
+
+	dout("parse_ips on '%.*s'\n", (int)(end-c), c);
+	for (i = 0; i < max_count; i++) {
+		const char *ipend;
+		struct sockaddr_storage *ss = &addr[i].in_addr;
+		int port;
+		char delim = ',';
+
+		if (*p == '[') {
+			delim = ']';
+			p++;
+		}
+
+		ret = ceph_parse_server_name(p, end - p, ss, delim, &ipend);
+		if (ret)
+			goto bad;
+		ret = -EINVAL;
+
+		p = ipend;
+
+		if (delim == ']') {
+			if (*p != ']') {
+				dout("missing matching ']'\n");
+				goto bad;
+			}
+			p++;
+		}
+
+		/* port? */
+		if (p < end && *p == ':') {
+			port = 0;
+			p++;
+			while (p < end && *p >= '0' && *p <= '9') {
+				port = (port * 10) + (*p - '0');
+				p++;
+			}
+			if (port == 0)
+				port = CEPH_MON_PORT;
+			else if (port > 65535)
+				goto bad;
+		} else {
+			port = CEPH_MON_PORT;
+		}
+
+		addr_set_port(ss, port);
+
+		dout("parse_ips got %s\n", ceph_pr_addr(ss));
+
+		if (p == end)
+			break;
+		if (*p != ',')
+			goto bad;
+		p++;
+	}
+
+	if (p != end)
+		goto bad;
+
+	if (count)
+		*count = i + 1;
+	return 0;
+
+bad:
+	pr_err("parse_ips bad ip '%.*s'\n", (int)(end - c), c);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_parse_ips);
+
+static int process_banner(struct ceph_connection *con)
+{
+	dout("process_banner on %p\n", con);
+
+	if (verify_hello(con) < 0)
+		return -1;
+
+	ceph_decode_addr(&con->actual_peer_addr);
+	ceph_decode_addr(&con->peer_addr_for_me);
+
+	/*
+	 * Make sure the other end is who we wanted.  note that the other
+	 * end may not yet know their ip address, so if it's 0.0.0.0, give
+	 * them the benefit of the doubt.
+	 */
+	if (memcmp(&con->peer_addr, &con->actual_peer_addr,
+		   sizeof(con->peer_addr)) != 0 &&
+	    !(addr_is_blank(&con->actual_peer_addr.in_addr) &&
+	      con->actual_peer_addr.nonce == con->peer_addr.nonce)) {
+		pr_warn("wrong peer, want %s/%d, got %s/%d\n",
+			ceph_pr_addr(&con->peer_addr.in_addr),
+			(int)le32_to_cpu(con->peer_addr.nonce),
+			ceph_pr_addr(&con->actual_peer_addr.in_addr),
+			(int)le32_to_cpu(con->actual_peer_addr.nonce));
+		con->error_msg = "wrong peer at address";
+		return -1;
+	}
+
+	/*
+	 * did we learn our address?
+	 */
+	if (addr_is_blank(&con->msgr->inst.addr.in_addr)) {
+		int port = addr_port(&con->msgr->inst.addr.in_addr);
+
+		memcpy(&con->msgr->inst.addr.in_addr,
+		       &con->peer_addr_for_me.in_addr,
+		       sizeof(con->peer_addr_for_me.in_addr));
+		addr_set_port(&con->msgr->inst.addr.in_addr, port);
+		encode_my_addr(con->msgr);
+		dout("process_banner learned my addr is %s\n",
+		     ceph_pr_addr(&con->msgr->inst.addr.in_addr));
+	}
+
+	return 0;
+}
+
+static int process_connect(struct ceph_connection *con)
+{
+	u64 sup_feat = from_msgr(con->msgr)->supported_features;
+	u64 req_feat = from_msgr(con->msgr)->required_features;
+	u64 server_feat = le64_to_cpu(con->in_reply.features);
+	int ret;
+
+	dout("process_connect on %p tag %d\n", con, (int)con->in_tag);
+
+	if (con->auth) {
+		int len = le32_to_cpu(con->in_reply.authorizer_len);
+
+		/*
+		 * Any connection that defines ->get_authorizer()
+		 * should also define ->add_authorizer_challenge() and
+		 * ->verify_authorizer_reply().
+		 *
+		 * See get_connect_authorizer().
+		 */
+		if (con->in_reply.tag == CEPH_MSGR_TAG_CHALLENGE_AUTHORIZER) {
+			ret = con->ops->add_authorizer_challenge(
+				    con, con->auth->authorizer_reply_buf, len);
+			if (ret < 0)
+				return ret;
+
+			con_out_kvec_reset(con);
+			__prepare_write_connect(con);
+			prepare_read_connect(con);
+			return 0;
+		}
+
+		if (len) {
+			ret = con->ops->verify_authorizer_reply(con);
+			if (ret < 0) {
+				con->error_msg = "bad authorize reply";
+				return ret;
+			}
+		}
+	}
+
+	switch (con->in_reply.tag) {
+	case CEPH_MSGR_TAG_FEATURES:
+		pr_err("%s%lld %s feature set mismatch,"
+		       " my %llx < server's %llx, missing %llx\n",
+		       ENTITY_NAME(con->peer_name),
+		       ceph_pr_addr(&con->peer_addr.in_addr),
+		       sup_feat, server_feat, server_feat & ~sup_feat);
+		con->error_msg = "missing required protocol features";
+		reset_connection(con);
+		return -1;
+
+	case CEPH_MSGR_TAG_BADPROTOVER:
+		pr_err("%s%lld %s protocol version mismatch,"
+		       " my %d != server's %d\n",
+		       ENTITY_NAME(con->peer_name),
+		       ceph_pr_addr(&con->peer_addr.in_addr),
+		       le32_to_cpu(con->out_connect.protocol_version),
+		       le32_to_cpu(con->in_reply.protocol_version));
+		con->error_msg = "protocol version mismatch";
+		reset_connection(con);
+		return -1;
+
+	case CEPH_MSGR_TAG_BADAUTHORIZER:
+		con->auth_retry++;
+		dout("process_connect %p got BADAUTHORIZER attempt %d\n", con,
+		     con->auth_retry);
+		if (con->auth_retry == 2) {
+			con->error_msg = "connect authorization failure";
+			return -1;
+		}
+		con_out_kvec_reset(con);
+		ret = prepare_write_connect(con);
+		if (ret < 0)
+			return ret;
+		prepare_read_connect(con);
+		break;
+
+	case CEPH_MSGR_TAG_RESETSESSION:
+		/*
+		 * If we connected with a large connect_seq but the peer
+		 * has no record of a session with us (no connection, or
+		 * connect_seq == 0), they will send RESETSESION to indicate
+		 * that they must have reset their session, and may have
+		 * dropped messages.
+		 */
+		dout("process_connect got RESET peer seq %u\n",
+		     le32_to_cpu(con->in_reply.connect_seq));
+		pr_err("%s%lld %s connection reset\n",
+		       ENTITY_NAME(con->peer_name),
+		       ceph_pr_addr(&con->peer_addr.in_addr));
+		reset_connection(con);
+		con_out_kvec_reset(con);
+		ret = prepare_write_connect(con);
+		if (ret < 0)
+			return ret;
+		prepare_read_connect(con);
+
+		/* Tell ceph about it. */
+		mutex_unlock(&con->mutex);
+		pr_info("reset on %s%lld\n", ENTITY_NAME(con->peer_name));
+		if (con->ops->peer_reset)
+			con->ops->peer_reset(con);
+		mutex_lock(&con->mutex);
+		if (con->state != CON_STATE_NEGOTIATING)
+			return -EAGAIN;
+		break;
+
+	case CEPH_MSGR_TAG_RETRY_SESSION:
+		/*
+		 * If we sent a smaller connect_seq than the peer has, try
+		 * again with a larger value.
+		 */
+		dout("process_connect got RETRY_SESSION my seq %u, peer %u\n",
+		     le32_to_cpu(con->out_connect.connect_seq),
+		     le32_to_cpu(con->in_reply.connect_seq));
+		con->connect_seq = le32_to_cpu(con->in_reply.connect_seq);
+		con_out_kvec_reset(con);
+		ret = prepare_write_connect(con);
+		if (ret < 0)
+			return ret;
+		prepare_read_connect(con);
+		break;
+
+	case CEPH_MSGR_TAG_RETRY_GLOBAL:
+		/*
+		 * If we sent a smaller global_seq than the peer has, try
+		 * again with a larger value.
+		 */
+		dout("process_connect got RETRY_GLOBAL my %u peer_gseq %u\n",
+		     con->peer_global_seq,
+		     le32_to_cpu(con->in_reply.global_seq));
+		get_global_seq(con->msgr,
+			       le32_to_cpu(con->in_reply.global_seq));
+		con_out_kvec_reset(con);
+		ret = prepare_write_connect(con);
+		if (ret < 0)
+			return ret;
+		prepare_read_connect(con);
+		break;
+
+	case CEPH_MSGR_TAG_SEQ:
+	case CEPH_MSGR_TAG_READY:
+		if (req_feat & ~server_feat) {
+			pr_err("%s%lld %s protocol feature mismatch,"
+			       " my required %llx > server's %llx, need %llx\n",
+			       ENTITY_NAME(con->peer_name),
+			       ceph_pr_addr(&con->peer_addr.in_addr),
+			       req_feat, server_feat, req_feat & ~server_feat);
+			con->error_msg = "missing required protocol features";
+			reset_connection(con);
+			return -1;
+		}
+
+		WARN_ON(con->state != CON_STATE_NEGOTIATING);
+		con->state = CON_STATE_OPEN;
+		con->auth_retry = 0;    /* we authenticated; clear flag */
+		con->peer_global_seq = le32_to_cpu(con->in_reply.global_seq);
+		con->connect_seq++;
+		con->peer_features = server_feat;
+		dout("process_connect got READY gseq %d cseq %d (%d)\n",
+		     con->peer_global_seq,
+		     le32_to_cpu(con->in_reply.connect_seq),
+		     con->connect_seq);
+		WARN_ON(con->connect_seq !=
+			le32_to_cpu(con->in_reply.connect_seq));
+
+		if (con->in_reply.flags & CEPH_MSG_CONNECT_LOSSY)
+			con_flag_set(con, CON_FLAG_LOSSYTX);
+
+		con->delay = 0;      /* reset backoff memory */
+
+		if (con->in_reply.tag == CEPH_MSGR_TAG_SEQ) {
+			prepare_write_seq(con);
+			prepare_read_seq(con);
+		} else {
+			prepare_read_tag(con);
+		}
+		break;
+
+	case CEPH_MSGR_TAG_WAIT:
+		/*
+		 * If there is a connection race (we are opening
+		 * connections to each other), one of us may just have
+		 * to WAIT.  This shouldn't happen if we are the
+		 * client.
+		 */
+		con->error_msg = "protocol error, got WAIT as client";
+		return -1;
+
+	default:
+		con->error_msg = "protocol error, garbage tag during connect";
+		return -1;
+	}
+	return 0;
+}
+
+
+/*
+ * read (part of) an ack
+ */
+static int read_partial_ack(struct ceph_connection *con)
+{
+	int size = sizeof (con->in_temp_ack);
+	int end = size;
+
+	return read_partial(con, end, size, &con->in_temp_ack);
+}
+
+/*
+ * We can finally discard anything that's been acked.
+ */
+static void process_ack(struct ceph_connection *con)
+{
+	struct ceph_msg *m;
+	u64 ack = le64_to_cpu(con->in_temp_ack);
+	u64 seq;
+	bool reconnect = (con->in_tag == CEPH_MSGR_TAG_SEQ);
+	struct list_head *list = reconnect ? &con->out_queue : &con->out_sent;
+
+	/*
+	 * In the reconnect case, con_fault() has requeued messages
+	 * in out_sent. We should cleanup old messages according to
+	 * the reconnect seq.
+	 */
+	while (!list_empty(list)) {
+		m = list_first_entry(list, struct ceph_msg, list_head);
+		if (reconnect && m->needs_out_seq)
+			break;
+		seq = le64_to_cpu(m->hdr.seq);
+		if (seq > ack)
+			break;
+		dout("got ack for seq %llu type %d at %p\n", seq,
+		     le16_to_cpu(m->hdr.type), m);
+		m->ack_stamp = jiffies;
+		ceph_msg_remove(m);
+	}
+
+	prepare_read_tag(con);
+}
+
+
+static int read_partial_message_section(struct ceph_connection *con,
+					struct kvec *section,
+					unsigned int sec_len, u32 *crc)
+{
+	int ret, left;
+
+	BUG_ON(!section);
+
+	while (section->iov_len < sec_len) {
+		BUG_ON(section->iov_base == NULL);
+		left = sec_len - section->iov_len;
+		ret = ceph_tcp_recvmsg(con->sock, (char *)section->iov_base +
+				       section->iov_len, left);
+		if (ret <= 0)
+			return ret;
+		section->iov_len += ret;
+	}
+	if (section->iov_len == sec_len)
+		*crc = crc32c(0, section->iov_base, section->iov_len);
+
+	return 1;
+}
+
+static int read_partial_msg_data(struct ceph_connection *con)
+{
+	struct ceph_msg *msg = con->in_msg;
+	struct ceph_msg_data_cursor *cursor = &msg->cursor;
+	bool do_datacrc = !ceph_test_opt(from_msgr(con->msgr), NOCRC);
+	struct page *page;
+	size_t page_offset;
+	size_t length;
+	u32 crc = 0;
+	int ret;
+
+	BUG_ON(!msg);
+	if (list_empty(&msg->data))
+		return -EIO;
+
+	if (do_datacrc)
+		crc = con->in_data_crc;
+	while (cursor->total_resid) {
+		if (!cursor->resid) {
+			ceph_msg_data_advance(cursor, 0);
+			continue;
+		}
+
+		page = ceph_msg_data_next(cursor, &page_offset, &length, NULL);
+		ret = ceph_tcp_recvpage(con->sock, page, page_offset, length);
+		if (ret <= 0) {
+			if (do_datacrc)
+				con->in_data_crc = crc;
+
+			return ret;
+		}
+
+		if (do_datacrc)
+			crc = ceph_crc32c_page(crc, page, page_offset, ret);
+		ceph_msg_data_advance(cursor, (size_t)ret);
+	}
+	if (do_datacrc)
+		con->in_data_crc = crc;
+
+	return 1;	/* must return > 0 to indicate success */
+}
+
+/*
+ * read (part of) a message.
+ */
+static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip);
+
+static int read_partial_message(struct ceph_connection *con)
+{
+	struct ceph_msg *m = con->in_msg;
+	int size;
+	int end;
+	int ret;
+	unsigned int front_len, middle_len, data_len;
+	bool do_datacrc = !ceph_test_opt(from_msgr(con->msgr), NOCRC);
+	bool need_sign = (con->peer_features & CEPH_FEATURE_MSG_AUTH);
+	u64 seq;
+	u32 crc;
+
+	dout("read_partial_message con %p msg %p\n", con, m);
+
+	/* header */
+	size = sizeof (con->in_hdr);
+	end = size;
+	ret = read_partial(con, end, size, &con->in_hdr);
+	if (ret <= 0)
+		return ret;
+
+	crc = crc32c(0, &con->in_hdr, offsetof(struct ceph_msg_header, crc));
+	if (cpu_to_le32(crc) != con->in_hdr.crc) {
+		pr_err("read_partial_message bad hdr crc %u != expected %u\n",
+		       crc, con->in_hdr.crc);
+		return -EBADMSG;
+	}
+
+	front_len = le32_to_cpu(con->in_hdr.front_len);
+	if (front_len > CEPH_MSG_MAX_FRONT_LEN)
+		return -EIO;
+	middle_len = le32_to_cpu(con->in_hdr.middle_len);
+	if (middle_len > CEPH_MSG_MAX_MIDDLE_LEN)
+		return -EIO;
+	data_len = le32_to_cpu(con->in_hdr.data_len);
+	if (data_len > CEPH_MSG_MAX_DATA_LEN)
+		return -EIO;
+
+	/* verify seq# */
+	seq = le64_to_cpu(con->in_hdr.seq);
+	if ((s64)seq - (s64)con->in_seq < 1) {
+		pr_info("skipping %s%lld %s seq %lld expected %lld\n",
+			ENTITY_NAME(con->peer_name),
+			ceph_pr_addr(&con->peer_addr.in_addr),
+			seq, con->in_seq + 1);
+		con->in_base_pos = -front_len - middle_len - data_len -
+			sizeof_footer(con);
+		con->in_tag = CEPH_MSGR_TAG_READY;
+		return 1;
+	} else if ((s64)seq - (s64)con->in_seq > 1) {
+		pr_err("read_partial_message bad seq %lld expected %lld\n",
+		       seq, con->in_seq + 1);
+		con->error_msg = "bad message sequence # for incoming message";
+		return -EBADE;
+	}
+
+	/* allocate message? */
+	if (!con->in_msg) {
+		int skip = 0;
+
+		dout("got hdr type %d front %d data %d\n", con->in_hdr.type,
+		     front_len, data_len);
+		ret = ceph_con_in_msg_alloc(con, &skip);
+		if (ret < 0)
+			return ret;
+
+		BUG_ON(!con->in_msg ^ skip);
+		if (skip) {
+			/* skip this message */
+			dout("alloc_msg said skip message\n");
+			con->in_base_pos = -front_len - middle_len - data_len -
+				sizeof_footer(con);
+			con->in_tag = CEPH_MSGR_TAG_READY;
+			con->in_seq++;
+			return 1;
+		}
+
+		BUG_ON(!con->in_msg);
+		BUG_ON(con->in_msg->con != con);
+		m = con->in_msg;
+		m->front.iov_len = 0;    /* haven't read it yet */
+		if (m->middle)
+			m->middle->vec.iov_len = 0;
+
+		/* prepare for data payload, if any */
+
+		if (data_len)
+			prepare_message_data(con->in_msg, data_len);
+	}
+
+	/* front */
+	ret = read_partial_message_section(con, &m->front, front_len,
+					   &con->in_front_crc);
+	if (ret <= 0)
+		return ret;
+
+	/* middle */
+	if (m->middle) {
+		ret = read_partial_message_section(con, &m->middle->vec,
+						   middle_len,
+						   &con->in_middle_crc);
+		if (ret <= 0)
+			return ret;
+	}
+
+	/* (page) data */
+	if (data_len) {
+		ret = read_partial_msg_data(con);
+		if (ret <= 0)
+			return ret;
+	}
+
+	/* footer */
+	size = sizeof_footer(con);
+	end += size;
+	ret = read_partial(con, end, size, &m->footer);
+	if (ret <= 0)
+		return ret;
+
+	if (!need_sign) {
+		m->footer.flags = m->old_footer.flags;
+		m->footer.sig = 0;
+	}
+
+	dout("read_partial_message got msg %p %d (%u) + %d (%u) + %d (%u)\n",
+	     m, front_len, m->footer.front_crc, middle_len,
+	     m->footer.middle_crc, data_len, m->footer.data_crc);
+
+	/* crc ok? */
+	if (con->in_front_crc != le32_to_cpu(m->footer.front_crc)) {
+		pr_err("read_partial_message %p front crc %u != exp. %u\n",
+		       m, con->in_front_crc, m->footer.front_crc);
+		return -EBADMSG;
+	}
+	if (con->in_middle_crc != le32_to_cpu(m->footer.middle_crc)) {
+		pr_err("read_partial_message %p middle crc %u != exp %u\n",
+		       m, con->in_middle_crc, m->footer.middle_crc);
+		return -EBADMSG;
+	}
+	if (do_datacrc &&
+	    (m->footer.flags & CEPH_MSG_FOOTER_NOCRC) == 0 &&
+	    con->in_data_crc != le32_to_cpu(m->footer.data_crc)) {
+		pr_err("read_partial_message %p data crc %u != exp. %u\n", m,
+		       con->in_data_crc, le32_to_cpu(m->footer.data_crc));
+		return -EBADMSG;
+	}
+
+	if (need_sign && con->ops->check_message_signature &&
+	    con->ops->check_message_signature(m)) {
+		pr_err("read_partial_message %p signature check failed\n", m);
+		return -EBADMSG;
+	}
+
+	return 1; /* done! */
+}
+
+/*
+ * Process message.  This happens in the worker thread.  The callback should
+ * be careful not to do anything that waits on other incoming messages or it
+ * may deadlock.
+ */
+static void process_message(struct ceph_connection *con)
+{
+	struct ceph_msg *msg = con->in_msg;
+
+	BUG_ON(con->in_msg->con != con);
+	con->in_msg = NULL;
+
+	/* if first message, set peer_name */
+	if (con->peer_name.type == 0)
+		con->peer_name = msg->hdr.src;
+
+	con->in_seq++;
+	mutex_unlock(&con->mutex);
+
+	dout("===== %p %llu from %s%lld %d=%s len %d+%d (%u %u %u) =====\n",
+	     msg, le64_to_cpu(msg->hdr.seq),
+	     ENTITY_NAME(msg->hdr.src),
+	     le16_to_cpu(msg->hdr.type),
+	     ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
+	     le32_to_cpu(msg->hdr.front_len),
+	     le32_to_cpu(msg->hdr.data_len),
+	     con->in_front_crc, con->in_middle_crc, con->in_data_crc);
+	con->ops->dispatch(con, msg);
+
+	mutex_lock(&con->mutex);
+}
+
+static int read_keepalive_ack(struct ceph_connection *con)
+{
+	struct ceph_timespec ceph_ts;
+	size_t size = sizeof(ceph_ts);
+	int ret = read_partial(con, size, size, &ceph_ts);
+	if (ret <= 0)
+		return ret;
+	ceph_decode_timespec64(&con->last_keepalive_ack, &ceph_ts);
+	prepare_read_tag(con);
+	return 1;
+}
+
+/*
+ * Write something to the socket.  Called in a worker thread when the
+ * socket appears to be writeable and we have something ready to send.
+ */
+static int try_write(struct ceph_connection *con)
+{
+	int ret = 1;
+
+	dout("try_write start %p state %lu\n", con, con->state);
+	if (con->state != CON_STATE_PREOPEN &&
+	    con->state != CON_STATE_CONNECTING &&
+	    con->state != CON_STATE_NEGOTIATING &&
+	    con->state != CON_STATE_OPEN)
+		return 0;
+
+	/* open the socket first? */
+	if (con->state == CON_STATE_PREOPEN) {
+		BUG_ON(con->sock);
+		con->state = CON_STATE_CONNECTING;
+
+		con_out_kvec_reset(con);
+		prepare_write_banner(con);
+		prepare_read_banner(con);
+
+		BUG_ON(con->in_msg);
+		con->in_tag = CEPH_MSGR_TAG_READY;
+		dout("try_write initiating connect on %p new state %lu\n",
+		     con, con->state);
+		ret = ceph_tcp_connect(con);
+		if (ret < 0) {
+			con->error_msg = "connect error";
+			goto out;
+		}
+	}
+
+more:
+	dout("try_write out_kvec_bytes %d\n", con->out_kvec_bytes);
+	BUG_ON(!con->sock);
+
+	/* kvec data queued? */
+	if (con->out_kvec_left) {
+		ret = write_partial_kvec(con);
+		if (ret <= 0)
+			goto out;
+	}
+	if (con->out_skip) {
+		ret = write_partial_skip(con);
+		if (ret <= 0)
+			goto out;
+	}
+
+	/* msg pages? */
+	if (con->out_msg) {
+		if (con->out_msg_done) {
+			ceph_msg_put(con->out_msg);
+			con->out_msg = NULL;   /* we're done with this one */
+			goto do_next;
+		}
+
+		ret = write_partial_message_data(con);
+		if (ret == 1)
+			goto more;  /* we need to send the footer, too! */
+		if (ret == 0)
+			goto out;
+		if (ret < 0) {
+			dout("try_write write_partial_message_data err %d\n",
+			     ret);
+			goto out;
+		}
+	}
+
+do_next:
+	if (con->state == CON_STATE_OPEN) {
+		if (con_flag_test_and_clear(con, CON_FLAG_KEEPALIVE_PENDING)) {
+			prepare_write_keepalive(con);
+			goto more;
+		}
+		/* is anything else pending? */
+		if (!list_empty(&con->out_queue)) {
+			prepare_write_message(con);
+			goto more;
+		}
+		if (con->in_seq > con->in_seq_acked) {
+			prepare_write_ack(con);
+			goto more;
+		}
+	}
+
+	/* Nothing to do! */
+	con_flag_clear(con, CON_FLAG_WRITE_PENDING);
+	dout("try_write nothing else to write.\n");
+	ret = 0;
+out:
+	dout("try_write done on %p ret %d\n", con, ret);
+	return ret;
+}
+
+/*
+ * Read what we can from the socket.
+ */
+static int try_read(struct ceph_connection *con)
+{
+	int ret = -1;
+
+more:
+	dout("try_read start on %p state %lu\n", con, con->state);
+	if (con->state != CON_STATE_CONNECTING &&
+	    con->state != CON_STATE_NEGOTIATING &&
+	    con->state != CON_STATE_OPEN)
+		return 0;
+
+	BUG_ON(!con->sock);
+
+	dout("try_read tag %d in_base_pos %d\n", (int)con->in_tag,
+	     con->in_base_pos);
+
+	if (con->state == CON_STATE_CONNECTING) {
+		dout("try_read connecting\n");
+		ret = read_partial_banner(con);
+		if (ret <= 0)
+			goto out;
+		ret = process_banner(con);
+		if (ret < 0)
+			goto out;
+
+		con->state = CON_STATE_NEGOTIATING;
+
+		/*
+		 * Received banner is good, exchange connection info.
+		 * Do not reset out_kvec, as sending our banner raced
+		 * with receiving peer banner after connect completed.
+		 */
+		ret = prepare_write_connect(con);
+		if (ret < 0)
+			goto out;
+		prepare_read_connect(con);
+
+		/* Send connection info before awaiting response */
+		goto out;
+	}
+
+	if (con->state == CON_STATE_NEGOTIATING) {
+		dout("try_read negotiating\n");
+		ret = read_partial_connect(con);
+		if (ret <= 0)
+			goto out;
+		ret = process_connect(con);
+		if (ret < 0)
+			goto out;
+		goto more;
+	}
+
+	WARN_ON(con->state != CON_STATE_OPEN);
+
+	if (con->in_base_pos < 0) {
+		/*
+		 * skipping + discarding content.
+		 */
+		ret = ceph_tcp_recvmsg(con->sock, NULL, -con->in_base_pos);
+		if (ret <= 0)
+			goto out;
+		dout("skipped %d / %d bytes\n", ret, -con->in_base_pos);
+		con->in_base_pos += ret;
+		if (con->in_base_pos)
+			goto more;
+	}
+	if (con->in_tag == CEPH_MSGR_TAG_READY) {
+		/*
+		 * what's next?
+		 */
+		ret = ceph_tcp_recvmsg(con->sock, &con->in_tag, 1);
+		if (ret <= 0)
+			goto out;
+		dout("try_read got tag %d\n", (int)con->in_tag);
+		switch (con->in_tag) {
+		case CEPH_MSGR_TAG_MSG:
+			prepare_read_message(con);
+			break;
+		case CEPH_MSGR_TAG_ACK:
+			prepare_read_ack(con);
+			break;
+		case CEPH_MSGR_TAG_KEEPALIVE2_ACK:
+			prepare_read_keepalive_ack(con);
+			break;
+		case CEPH_MSGR_TAG_CLOSE:
+			con_close_socket(con);
+			con->state = CON_STATE_CLOSED;
+			goto out;
+		default:
+			goto bad_tag;
+		}
+	}
+	if (con->in_tag == CEPH_MSGR_TAG_MSG) {
+		ret = read_partial_message(con);
+		if (ret <= 0) {
+			switch (ret) {
+			case -EBADMSG:
+				con->error_msg = "bad crc/signature";
+				/* fall through */
+			case -EBADE:
+				ret = -EIO;
+				break;
+			case -EIO:
+				con->error_msg = "io error";
+				break;
+			}
+			goto out;
+		}
+		if (con->in_tag == CEPH_MSGR_TAG_READY)
+			goto more;
+		process_message(con);
+		if (con->state == CON_STATE_OPEN)
+			prepare_read_tag(con);
+		goto more;
+	}
+	if (con->in_tag == CEPH_MSGR_TAG_ACK ||
+	    con->in_tag == CEPH_MSGR_TAG_SEQ) {
+		/*
+		 * the final handshake seq exchange is semantically
+		 * equivalent to an ACK
+		 */
+		ret = read_partial_ack(con);
+		if (ret <= 0)
+			goto out;
+		process_ack(con);
+		goto more;
+	}
+	if (con->in_tag == CEPH_MSGR_TAG_KEEPALIVE2_ACK) {
+		ret = read_keepalive_ack(con);
+		if (ret <= 0)
+			goto out;
+		goto more;
+	}
+
+out:
+	dout("try_read done on %p ret %d\n", con, ret);
+	return ret;
+
+bad_tag:
+	pr_err("try_read bad con->in_tag = %d\n", (int)con->in_tag);
+	con->error_msg = "protocol error, garbage tag";
+	ret = -1;
+	goto out;
+}
+
+
+/*
+ * Atomically queue work on a connection after the specified delay.
+ * Bump @con reference to avoid races with connection teardown.
+ * Returns 0 if work was queued, or an error code otherwise.
+ */
+static int queue_con_delay(struct ceph_connection *con, unsigned long delay)
+{
+	if (!con->ops->get(con)) {
+		dout("%s %p ref count 0\n", __func__, con);
+		return -ENOENT;
+	}
+
+	if (!queue_delayed_work(ceph_msgr_wq, &con->work, delay)) {
+		dout("%s %p - already queued\n", __func__, con);
+		con->ops->put(con);
+		return -EBUSY;
+	}
+
+	dout("%s %p %lu\n", __func__, con, delay);
+	return 0;
+}
+
+static void queue_con(struct ceph_connection *con)
+{
+	(void) queue_con_delay(con, 0);
+}
+
+static void cancel_con(struct ceph_connection *con)
+{
+	if (cancel_delayed_work(&con->work)) {
+		dout("%s %p\n", __func__, con);
+		con->ops->put(con);
+	}
+}
+
+static bool con_sock_closed(struct ceph_connection *con)
+{
+	if (!con_flag_test_and_clear(con, CON_FLAG_SOCK_CLOSED))
+		return false;
+
+#define CASE(x)								\
+	case CON_STATE_ ## x:						\
+		con->error_msg = "socket closed (con state " #x ")";	\
+		break;
+
+	switch (con->state) {
+	CASE(CLOSED);
+	CASE(PREOPEN);
+	CASE(CONNECTING);
+	CASE(NEGOTIATING);
+	CASE(OPEN);
+	CASE(STANDBY);
+	default:
+		pr_warn("%s con %p unrecognized state %lu\n",
+			__func__, con, con->state);
+		con->error_msg = "unrecognized con state";
+		BUG();
+		break;
+	}
+#undef CASE
+
+	return true;
+}
+
+static bool con_backoff(struct ceph_connection *con)
+{
+	int ret;
+
+	if (!con_flag_test_and_clear(con, CON_FLAG_BACKOFF))
+		return false;
+
+	ret = queue_con_delay(con, round_jiffies_relative(con->delay));
+	if (ret) {
+		dout("%s: con %p FAILED to back off %lu\n", __func__,
+			con, con->delay);
+		BUG_ON(ret == -ENOENT);
+		con_flag_set(con, CON_FLAG_BACKOFF);
+	}
+
+	return true;
+}
+
+/* Finish fault handling; con->mutex must *not* be held here */
+
+static void con_fault_finish(struct ceph_connection *con)
+{
+	dout("%s %p\n", __func__, con);
+
+	/*
+	 * in case we faulted due to authentication, invalidate our
+	 * current tickets so that we can get new ones.
+	 */
+	if (con->auth_retry) {
+		dout("auth_retry %d, invalidating\n", con->auth_retry);
+		if (con->ops->invalidate_authorizer)
+			con->ops->invalidate_authorizer(con);
+		con->auth_retry = 0;
+	}
+
+	if (con->ops->fault)
+		con->ops->fault(con);
+}
+
+/*
+ * Do some work on a connection.  Drop a connection ref when we're done.
+ */
+static void ceph_con_workfn(struct work_struct *work)
+{
+	struct ceph_connection *con = container_of(work, struct ceph_connection,
+						   work.work);
+	bool fault;
+
+	mutex_lock(&con->mutex);
+	while (true) {
+		int ret;
+
+		if ((fault = con_sock_closed(con))) {
+			dout("%s: con %p SOCK_CLOSED\n", __func__, con);
+			break;
+		}
+		if (con_backoff(con)) {
+			dout("%s: con %p BACKOFF\n", __func__, con);
+			break;
+		}
+		if (con->state == CON_STATE_STANDBY) {
+			dout("%s: con %p STANDBY\n", __func__, con);
+			break;
+		}
+		if (con->state == CON_STATE_CLOSED) {
+			dout("%s: con %p CLOSED\n", __func__, con);
+			BUG_ON(con->sock);
+			break;
+		}
+		if (con->state == CON_STATE_PREOPEN) {
+			dout("%s: con %p PREOPEN\n", __func__, con);
+			BUG_ON(con->sock);
+		}
+
+		ret = try_read(con);
+		if (ret < 0) {
+			if (ret == -EAGAIN)
+				continue;
+			if (!con->error_msg)
+				con->error_msg = "socket error on read";
+			fault = true;
+			break;
+		}
+
+		ret = try_write(con);
+		if (ret < 0) {
+			if (ret == -EAGAIN)
+				continue;
+			if (!con->error_msg)
+				con->error_msg = "socket error on write";
+			fault = true;
+		}
+
+		break;	/* If we make it to here, we're done */
+	}
+	if (fault)
+		con_fault(con);
+	mutex_unlock(&con->mutex);
+
+	if (fault)
+		con_fault_finish(con);
+
+	con->ops->put(con);
+}
+
+/*
+ * Generic error/fault handler.  A retry mechanism is used with
+ * exponential backoff
+ */
+static void con_fault(struct ceph_connection *con)
+{
+	dout("fault %p state %lu to peer %s\n",
+	     con, con->state, ceph_pr_addr(&con->peer_addr.in_addr));
+
+	pr_warn("%s%lld %s %s\n", ENTITY_NAME(con->peer_name),
+		ceph_pr_addr(&con->peer_addr.in_addr), con->error_msg);
+	con->error_msg = NULL;
+
+	WARN_ON(con->state != CON_STATE_CONNECTING &&
+	       con->state != CON_STATE_NEGOTIATING &&
+	       con->state != CON_STATE_OPEN);
+
+	con_close_socket(con);
+
+	if (con_flag_test(con, CON_FLAG_LOSSYTX)) {
+		dout("fault on LOSSYTX channel, marking CLOSED\n");
+		con->state = CON_STATE_CLOSED;
+		return;
+	}
+
+	if (con->in_msg) {
+		BUG_ON(con->in_msg->con != con);
+		ceph_msg_put(con->in_msg);
+		con->in_msg = NULL;
+	}
+	if (con->out_msg) {
+		BUG_ON(con->out_msg->con != con);
+		ceph_msg_put(con->out_msg);
+		con->out_msg = NULL;
+	}
+
+	/* Requeue anything that hasn't been acked */
+	list_splice_init(&con->out_sent, &con->out_queue);
+
+	/* If there are no messages queued or keepalive pending, place
+	 * the connection in a STANDBY state */
+	if (list_empty(&con->out_queue) &&
+	    !con_flag_test(con, CON_FLAG_KEEPALIVE_PENDING)) {
+		dout("fault %p setting STANDBY clearing WRITE_PENDING\n", con);
+		con_flag_clear(con, CON_FLAG_WRITE_PENDING);
+		con->state = CON_STATE_STANDBY;
+	} else {
+		/* retry after a delay. */
+		con->state = CON_STATE_PREOPEN;
+		if (con->delay == 0)
+			con->delay = BASE_DELAY_INTERVAL;
+		else if (con->delay < MAX_DELAY_INTERVAL)
+			con->delay *= 2;
+		con_flag_set(con, CON_FLAG_BACKOFF);
+		queue_con(con);
+	}
+}
+
+
+
+/*
+ * initialize a new messenger instance
+ */
+void ceph_messenger_init(struct ceph_messenger *msgr,
+			 struct ceph_entity_addr *myaddr)
+{
+	spin_lock_init(&msgr->global_seq_lock);
+
+	if (myaddr)
+		msgr->inst.addr = *myaddr;
+
+	/* select a random nonce */
+	msgr->inst.addr.type = 0;
+	get_random_bytes(&msgr->inst.addr.nonce, sizeof(msgr->inst.addr.nonce));
+	encode_my_addr(msgr);
+
+	atomic_set(&msgr->stopping, 0);
+	write_pnet(&msgr->net, get_net(current->nsproxy->net_ns));
+
+	dout("%s %p\n", __func__, msgr);
+}
+EXPORT_SYMBOL(ceph_messenger_init);
+
+void ceph_messenger_fini(struct ceph_messenger *msgr)
+{
+	put_net(read_pnet(&msgr->net));
+}
+EXPORT_SYMBOL(ceph_messenger_fini);
+
+static void msg_con_set(struct ceph_msg *msg, struct ceph_connection *con)
+{
+	if (msg->con)
+		msg->con->ops->put(msg->con);
+
+	msg->con = con ? con->ops->get(con) : NULL;
+	BUG_ON(msg->con != con);
+}
+
+static void clear_standby(struct ceph_connection *con)
+{
+	/* come back from STANDBY? */
+	if (con->state == CON_STATE_STANDBY) {
+		dout("clear_standby %p and ++connect_seq\n", con);
+		con->state = CON_STATE_PREOPEN;
+		con->connect_seq++;
+		WARN_ON(con_flag_test(con, CON_FLAG_WRITE_PENDING));
+		WARN_ON(con_flag_test(con, CON_FLAG_KEEPALIVE_PENDING));
+	}
+}
+
+/*
+ * Queue up an outgoing message on the given connection.
+ */
+void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg)
+{
+	/* set src+dst */
+	msg->hdr.src = con->msgr->inst.name;
+	BUG_ON(msg->front.iov_len != le32_to_cpu(msg->hdr.front_len));
+	msg->needs_out_seq = true;
+
+	mutex_lock(&con->mutex);
+
+	if (con->state == CON_STATE_CLOSED) {
+		dout("con_send %p closed, dropping %p\n", con, msg);
+		ceph_msg_put(msg);
+		mutex_unlock(&con->mutex);
+		return;
+	}
+
+	msg_con_set(msg, con);
+
+	BUG_ON(!list_empty(&msg->list_head));
+	list_add_tail(&msg->list_head, &con->out_queue);
+	dout("----- %p to %s%lld %d=%s len %d+%d+%d -----\n", msg,
+	     ENTITY_NAME(con->peer_name), le16_to_cpu(msg->hdr.type),
+	     ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
+	     le32_to_cpu(msg->hdr.front_len),
+	     le32_to_cpu(msg->hdr.middle_len),
+	     le32_to_cpu(msg->hdr.data_len));
+
+	clear_standby(con);
+	mutex_unlock(&con->mutex);
+
+	/* if there wasn't anything waiting to send before, queue
+	 * new work */
+	if (con_flag_test_and_set(con, CON_FLAG_WRITE_PENDING) == 0)
+		queue_con(con);
+}
+EXPORT_SYMBOL(ceph_con_send);
+
+/*
+ * Revoke a message that was previously queued for send
+ */
+void ceph_msg_revoke(struct ceph_msg *msg)
+{
+	struct ceph_connection *con = msg->con;
+
+	if (!con) {
+		dout("%s msg %p null con\n", __func__, msg);
+		return;		/* Message not in our possession */
+	}
+
+	mutex_lock(&con->mutex);
+	if (!list_empty(&msg->list_head)) {
+		dout("%s %p msg %p - was on queue\n", __func__, con, msg);
+		list_del_init(&msg->list_head);
+		msg->hdr.seq = 0;
+
+		ceph_msg_put(msg);
+	}
+	if (con->out_msg == msg) {
+		BUG_ON(con->out_skip);
+		/* footer */
+		if (con->out_msg_done) {
+			con->out_skip += con_out_kvec_skip(con);
+		} else {
+			BUG_ON(!msg->data_length);
+			con->out_skip += sizeof_footer(con);
+		}
+		/* data, middle, front */
+		if (msg->data_length)
+			con->out_skip += msg->cursor.total_resid;
+		if (msg->middle)
+			con->out_skip += con_out_kvec_skip(con);
+		con->out_skip += con_out_kvec_skip(con);
+
+		dout("%s %p msg %p - was sending, will write %d skip %d\n",
+		     __func__, con, msg, con->out_kvec_bytes, con->out_skip);
+		msg->hdr.seq = 0;
+		con->out_msg = NULL;
+		ceph_msg_put(msg);
+	}
+
+	mutex_unlock(&con->mutex);
+}
+
+/*
+ * Revoke a message that we may be reading data into
+ */
+void ceph_msg_revoke_incoming(struct ceph_msg *msg)
+{
+	struct ceph_connection *con = msg->con;
+
+	if (!con) {
+		dout("%s msg %p null con\n", __func__, msg);
+		return;		/* Message not in our possession */
+	}
+
+	mutex_lock(&con->mutex);
+	if (con->in_msg == msg) {
+		unsigned int front_len = le32_to_cpu(con->in_hdr.front_len);
+		unsigned int middle_len = le32_to_cpu(con->in_hdr.middle_len);
+		unsigned int data_len = le32_to_cpu(con->in_hdr.data_len);
+
+		/* skip rest of message */
+		dout("%s %p msg %p revoked\n", __func__, con, msg);
+		con->in_base_pos = con->in_base_pos -
+				sizeof(struct ceph_msg_header) -
+				front_len -
+				middle_len -
+				data_len -
+				sizeof(struct ceph_msg_footer);
+		ceph_msg_put(con->in_msg);
+		con->in_msg = NULL;
+		con->in_tag = CEPH_MSGR_TAG_READY;
+		con->in_seq++;
+	} else {
+		dout("%s %p in_msg %p msg %p no-op\n",
+		     __func__, con, con->in_msg, msg);
+	}
+	mutex_unlock(&con->mutex);
+}
+
+/*
+ * Queue a keepalive byte to ensure the tcp connection is alive.
+ */
+void ceph_con_keepalive(struct ceph_connection *con)
+{
+	dout("con_keepalive %p\n", con);
+	mutex_lock(&con->mutex);
+	clear_standby(con);
+	con_flag_set(con, CON_FLAG_KEEPALIVE_PENDING);
+	mutex_unlock(&con->mutex);
+
+	if (con_flag_test_and_set(con, CON_FLAG_WRITE_PENDING) == 0)
+		queue_con(con);
+}
+EXPORT_SYMBOL(ceph_con_keepalive);
+
+bool ceph_con_keepalive_expired(struct ceph_connection *con,
+			       unsigned long interval)
+{
+	if (interval > 0 &&
+	    (con->peer_features & CEPH_FEATURE_MSGR_KEEPALIVE2)) {
+		struct timespec64 now;
+		struct timespec64 ts;
+		ktime_get_real_ts64(&now);
+		jiffies_to_timespec64(interval, &ts);
+		ts = timespec64_add(con->last_keepalive_ack, ts);
+		return timespec64_compare(&now, &ts) >= 0;
+	}
+	return false;
+}
+
+static struct ceph_msg_data *ceph_msg_data_create(enum ceph_msg_data_type type)
+{
+	struct ceph_msg_data *data;
+
+	if (WARN_ON(!ceph_msg_data_type_valid(type)))
+		return NULL;
+
+	data = kmem_cache_zalloc(ceph_msg_data_cache, GFP_NOFS);
+	if (!data)
+		return NULL;
+
+	data->type = type;
+	INIT_LIST_HEAD(&data->links);
+
+	return data;
+}
+
+static void ceph_msg_data_destroy(struct ceph_msg_data *data)
+{
+	if (!data)
+		return;
+
+	WARN_ON(!list_empty(&data->links));
+	if (data->type == CEPH_MSG_DATA_PAGELIST)
+		ceph_pagelist_release(data->pagelist);
+	kmem_cache_free(ceph_msg_data_cache, data);
+}
+
+void ceph_msg_data_add_pages(struct ceph_msg *msg, struct page **pages,
+		size_t length, size_t alignment)
+{
+	struct ceph_msg_data *data;
+
+	BUG_ON(!pages);
+	BUG_ON(!length);
+
+	data = ceph_msg_data_create(CEPH_MSG_DATA_PAGES);
+	BUG_ON(!data);
+	data->pages = pages;
+	data->length = length;
+	data->alignment = alignment & ~PAGE_MASK;
+
+	list_add_tail(&data->links, &msg->data);
+	msg->data_length += length;
+}
+EXPORT_SYMBOL(ceph_msg_data_add_pages);
+
+void ceph_msg_data_add_pagelist(struct ceph_msg *msg,
+				struct ceph_pagelist *pagelist)
+{
+	struct ceph_msg_data *data;
+
+	BUG_ON(!pagelist);
+	BUG_ON(!pagelist->length);
+
+	data = ceph_msg_data_create(CEPH_MSG_DATA_PAGELIST);
+	BUG_ON(!data);
+	data->pagelist = pagelist;
+
+	list_add_tail(&data->links, &msg->data);
+	msg->data_length += pagelist->length;
+}
+EXPORT_SYMBOL(ceph_msg_data_add_pagelist);
+
+#ifdef	CONFIG_BLOCK
+void ceph_msg_data_add_bio(struct ceph_msg *msg, struct ceph_bio_iter *bio_pos,
+			   u32 length)
+{
+	struct ceph_msg_data *data;
+
+	data = ceph_msg_data_create(CEPH_MSG_DATA_BIO);
+	BUG_ON(!data);
+	data->bio_pos = *bio_pos;
+	data->bio_length = length;
+
+	list_add_tail(&data->links, &msg->data);
+	msg->data_length += length;
+}
+EXPORT_SYMBOL(ceph_msg_data_add_bio);
+#endif	/* CONFIG_BLOCK */
+
+void ceph_msg_data_add_bvecs(struct ceph_msg *msg,
+			     struct ceph_bvec_iter *bvec_pos)
+{
+	struct ceph_msg_data *data;
+
+	data = ceph_msg_data_create(CEPH_MSG_DATA_BVECS);
+	BUG_ON(!data);
+	data->bvec_pos = *bvec_pos;
+
+	list_add_tail(&data->links, &msg->data);
+	msg->data_length += bvec_pos->iter.bi_size;
+}
+EXPORT_SYMBOL(ceph_msg_data_add_bvecs);
+
+/*
+ * construct a new message with given type, size
+ * the new msg has a ref count of 1.
+ */
+struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
+			      bool can_fail)
+{
+	struct ceph_msg *m;
+
+	m = kmem_cache_zalloc(ceph_msg_cache, flags);
+	if (m == NULL)
+		goto out;
+
+	m->hdr.type = cpu_to_le16(type);
+	m->hdr.priority = cpu_to_le16(CEPH_MSG_PRIO_DEFAULT);
+	m->hdr.front_len = cpu_to_le32(front_len);
+
+	INIT_LIST_HEAD(&m->list_head);
+	kref_init(&m->kref);
+	INIT_LIST_HEAD(&m->data);
+
+	/* front */
+	if (front_len) {
+		m->front.iov_base = ceph_kvmalloc(front_len, flags);
+		if (m->front.iov_base == NULL) {
+			dout("ceph_msg_new can't allocate %d bytes\n",
+			     front_len);
+			goto out2;
+		}
+	} else {
+		m->front.iov_base = NULL;
+	}
+	m->front_alloc_len = m->front.iov_len = front_len;
+
+	dout("ceph_msg_new %p front %d\n", m, front_len);
+	return m;
+
+out2:
+	ceph_msg_put(m);
+out:
+	if (!can_fail) {
+		pr_err("msg_new can't create type %d front %d\n", type,
+		       front_len);
+		WARN_ON(1);
+	} else {
+		dout("msg_new can't create type %d front %d\n", type,
+		     front_len);
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(ceph_msg_new);
+
+/*
+ * Allocate "middle" portion of a message, if it is needed and wasn't
+ * allocated by alloc_msg.  This allows us to read a small fixed-size
+ * per-type header in the front and then gracefully fail (i.e.,
+ * propagate the error to the caller based on info in the front) when
+ * the middle is too large.
+ */
+static int ceph_alloc_middle(struct ceph_connection *con, struct ceph_msg *msg)
+{
+	int type = le16_to_cpu(msg->hdr.type);
+	int middle_len = le32_to_cpu(msg->hdr.middle_len);
+
+	dout("alloc_middle %p type %d %s middle_len %d\n", msg, type,
+	     ceph_msg_type_name(type), middle_len);
+	BUG_ON(!middle_len);
+	BUG_ON(msg->middle);
+
+	msg->middle = ceph_buffer_new(middle_len, GFP_NOFS);
+	if (!msg->middle)
+		return -ENOMEM;
+	return 0;
+}
+
+/*
+ * Allocate a message for receiving an incoming message on a
+ * connection, and save the result in con->in_msg.  Uses the
+ * connection's private alloc_msg op if available.
+ *
+ * Returns 0 on success, or a negative error code.
+ *
+ * On success, if we set *skip = 1:
+ *  - the next message should be skipped and ignored.
+ *  - con->in_msg == NULL
+ * or if we set *skip = 0:
+ *  - con->in_msg is non-null.
+ * On error (ENOMEM, EAGAIN, ...),
+ *  - con->in_msg == NULL
+ */
+static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip)
+{
+	struct ceph_msg_header *hdr = &con->in_hdr;
+	int middle_len = le32_to_cpu(hdr->middle_len);
+	struct ceph_msg *msg;
+	int ret = 0;
+
+	BUG_ON(con->in_msg != NULL);
+	BUG_ON(!con->ops->alloc_msg);
+
+	mutex_unlock(&con->mutex);
+	msg = con->ops->alloc_msg(con, hdr, skip);
+	mutex_lock(&con->mutex);
+	if (con->state != CON_STATE_OPEN) {
+		if (msg)
+			ceph_msg_put(msg);
+		return -EAGAIN;
+	}
+	if (msg) {
+		BUG_ON(*skip);
+		msg_con_set(msg, con);
+		con->in_msg = msg;
+	} else {
+		/*
+		 * Null message pointer means either we should skip
+		 * this message or we couldn't allocate memory.  The
+		 * former is not an error.
+		 */
+		if (*skip)
+			return 0;
+
+		con->error_msg = "error allocating memory for incoming message";
+		return -ENOMEM;
+	}
+	memcpy(&con->in_msg->hdr, &con->in_hdr, sizeof(con->in_hdr));
+
+	if (middle_len && !con->in_msg->middle) {
+		ret = ceph_alloc_middle(con, con->in_msg);
+		if (ret < 0) {
+			ceph_msg_put(con->in_msg);
+			con->in_msg = NULL;
+		}
+	}
+
+	return ret;
+}
+
+
+/*
+ * Free a generically kmalloc'd message.
+ */
+static void ceph_msg_free(struct ceph_msg *m)
+{
+	dout("%s %p\n", __func__, m);
+	kvfree(m->front.iov_base);
+	kmem_cache_free(ceph_msg_cache, m);
+}
+
+static void ceph_msg_release(struct kref *kref)
+{
+	struct ceph_msg *m = container_of(kref, struct ceph_msg, kref);
+	struct ceph_msg_data *data, *next;
+
+	dout("%s %p\n", __func__, m);
+	WARN_ON(!list_empty(&m->list_head));
+
+	msg_con_set(m, NULL);
+
+	/* drop middle, data, if any */
+	if (m->middle) {
+		ceph_buffer_put(m->middle);
+		m->middle = NULL;
+	}
+
+	list_for_each_entry_safe(data, next, &m->data, links) {
+		list_del_init(&data->links);
+		ceph_msg_data_destroy(data);
+	}
+	m->data_length = 0;
+
+	if (m->pool)
+		ceph_msgpool_put(m->pool, m);
+	else
+		ceph_msg_free(m);
+}
+
+struct ceph_msg *ceph_msg_get(struct ceph_msg *msg)
+{
+	dout("%s %p (was %d)\n", __func__, msg,
+	     kref_read(&msg->kref));
+	kref_get(&msg->kref);
+	return msg;
+}
+EXPORT_SYMBOL(ceph_msg_get);
+
+void ceph_msg_put(struct ceph_msg *msg)
+{
+	dout("%s %p (was %d)\n", __func__, msg,
+	     kref_read(&msg->kref));
+	kref_put(&msg->kref, ceph_msg_release);
+}
+EXPORT_SYMBOL(ceph_msg_put);
+
+void ceph_msg_dump(struct ceph_msg *msg)
+{
+	pr_debug("msg_dump %p (front_alloc_len %d length %zd)\n", msg,
+		 msg->front_alloc_len, msg->data_length);
+	print_hex_dump(KERN_DEBUG, "header: ",
+		       DUMP_PREFIX_OFFSET, 16, 1,
+		       &msg->hdr, sizeof(msg->hdr), true);
+	print_hex_dump(KERN_DEBUG, " front: ",
+		       DUMP_PREFIX_OFFSET, 16, 1,
+		       msg->front.iov_base, msg->front.iov_len, true);
+	if (msg->middle)
+		print_hex_dump(KERN_DEBUG, "middle: ",
+			       DUMP_PREFIX_OFFSET, 16, 1,
+			       msg->middle->vec.iov_base,
+			       msg->middle->vec.iov_len, true);
+	print_hex_dump(KERN_DEBUG, "footer: ",
+		       DUMP_PREFIX_OFFSET, 16, 1,
+		       &msg->footer, sizeof(msg->footer), true);
+}
+EXPORT_SYMBOL(ceph_msg_dump);
diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
new file mode 100644
index 000000000..a53e4fbb6
--- /dev/null
+++ b/net/ceph/mon_client.c
@@ -0,0 +1,1369 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/random.h>
+#include <linux/sched.h>
+
+#include <linux/ceph/ceph_features.h>
+#include <linux/ceph/mon_client.h>
+#include <linux/ceph/libceph.h>
+#include <linux/ceph/debugfs.h>
+#include <linux/ceph/decode.h>
+#include <linux/ceph/auth.h>
+
+/*
+ * Interact with Ceph monitor cluster.  Handle requests for new map
+ * versions, and periodically resend as needed.  Also implement
+ * statfs() and umount().
+ *
+ * A small cluster of Ceph "monitors" are responsible for managing critical
+ * cluster configuration and state information.  An odd number (e.g., 3, 5)
+ * of cmon daemons use a modified version of the Paxos part-time parliament
+ * algorithm to manage the MDS map (mds cluster membership), OSD map, and
+ * list of clients who have mounted the file system.
+ *
+ * We maintain an open, active session with a monitor at all times in order to
+ * receive timely MDSMap updates.  We periodically send a keepalive byte on the
+ * TCP socket to ensure we detect a failure.  If the connection does break, we
+ * randomly hunt for a new monitor.  Once the connection is reestablished, we
+ * resend any outstanding requests.
+ */
+
+static const struct ceph_connection_operations mon_con_ops;
+
+static int __validate_auth(struct ceph_mon_client *monc);
+
+/*
+ * Decode a monmap blob (e.g., during mount).
+ */
+struct ceph_monmap *ceph_monmap_decode(void *p, void *end)
+{
+	struct ceph_monmap *m = NULL;
+	int i, err = -EINVAL;
+	struct ceph_fsid fsid;
+	u32 epoch, num_mon;
+	u32 len;
+
+	ceph_decode_32_safe(&p, end, len, bad);
+	ceph_decode_need(&p, end, len, bad);
+
+	dout("monmap_decode %p %p len %d\n", p, end, (int)(end-p));
+	p += sizeof(u16);  /* skip version */
+
+	ceph_decode_need(&p, end, sizeof(fsid) + 2*sizeof(u32), bad);
+	ceph_decode_copy(&p, &fsid, sizeof(fsid));
+	epoch = ceph_decode_32(&p);
+
+	num_mon = ceph_decode_32(&p);
+	ceph_decode_need(&p, end, num_mon*sizeof(m->mon_inst[0]), bad);
+
+	if (num_mon > CEPH_MAX_MON)
+		goto bad;
+	m = kmalloc(struct_size(m, mon_inst, num_mon), GFP_NOFS);
+	if (m == NULL)
+		return ERR_PTR(-ENOMEM);
+	m->fsid = fsid;
+	m->epoch = epoch;
+	m->num_mon = num_mon;
+	ceph_decode_copy(&p, m->mon_inst, num_mon*sizeof(m->mon_inst[0]));
+	for (i = 0; i < num_mon; i++)
+		ceph_decode_addr(&m->mon_inst[i].addr);
+
+	dout("monmap_decode epoch %d, num_mon %d\n", m->epoch,
+	     m->num_mon);
+	for (i = 0; i < m->num_mon; i++)
+		dout("monmap_decode  mon%d is %s\n", i,
+		     ceph_pr_addr(&m->mon_inst[i].addr.in_addr));
+	return m;
+
+bad:
+	dout("monmap_decode failed with %d\n", err);
+	kfree(m);
+	return ERR_PTR(err);
+}
+
+/*
+ * return true if *addr is included in the monmap.
+ */
+int ceph_monmap_contains(struct ceph_monmap *m, struct ceph_entity_addr *addr)
+{
+	int i;
+
+	for (i = 0; i < m->num_mon; i++)
+		if (memcmp(addr, &m->mon_inst[i].addr, sizeof(*addr)) == 0)
+			return 1;
+	return 0;
+}
+
+/*
+ * Send an auth request.
+ */
+static void __send_prepared_auth_request(struct ceph_mon_client *monc, int len)
+{
+	monc->pending_auth = 1;
+	monc->m_auth->front.iov_len = len;
+	monc->m_auth->hdr.front_len = cpu_to_le32(len);
+	ceph_msg_revoke(monc->m_auth);
+	ceph_msg_get(monc->m_auth);  /* keep our ref */
+	ceph_con_send(&monc->con, monc->m_auth);
+}
+
+/*
+ * Close monitor session, if any.
+ */
+static void __close_session(struct ceph_mon_client *monc)
+{
+	dout("__close_session closing mon%d\n", monc->cur_mon);
+	ceph_msg_revoke(monc->m_auth);
+	ceph_msg_revoke_incoming(monc->m_auth_reply);
+	ceph_msg_revoke(monc->m_subscribe);
+	ceph_msg_revoke_incoming(monc->m_subscribe_ack);
+	ceph_con_close(&monc->con);
+
+	monc->pending_auth = 0;
+	ceph_auth_reset(monc->auth);
+}
+
+/*
+ * Pick a new monitor at random and set cur_mon.  If we are repicking
+ * (i.e. cur_mon is already set), be sure to pick a different one.
+ */
+static void pick_new_mon(struct ceph_mon_client *monc)
+{
+	int old_mon = monc->cur_mon;
+
+	BUG_ON(monc->monmap->num_mon < 1);
+
+	if (monc->monmap->num_mon == 1) {
+		monc->cur_mon = 0;
+	} else {
+		int max = monc->monmap->num_mon;
+		int o = -1;
+		int n;
+
+		if (monc->cur_mon >= 0) {
+			if (monc->cur_mon < monc->monmap->num_mon)
+				o = monc->cur_mon;
+			if (o >= 0)
+				max--;
+		}
+
+		n = prandom_u32() % max;
+		if (o >= 0 && n >= o)
+			n++;
+
+		monc->cur_mon = n;
+	}
+
+	dout("%s mon%d -> mon%d out of %d mons\n", __func__, old_mon,
+	     monc->cur_mon, monc->monmap->num_mon);
+}
+
+/*
+ * Open a session with a new monitor.
+ */
+static void __open_session(struct ceph_mon_client *monc)
+{
+	int ret;
+
+	pick_new_mon(monc);
+
+	monc->hunting = true;
+	if (monc->had_a_connection) {
+		monc->hunt_mult *= CEPH_MONC_HUNT_BACKOFF;
+		if (monc->hunt_mult > CEPH_MONC_HUNT_MAX_MULT)
+			monc->hunt_mult = CEPH_MONC_HUNT_MAX_MULT;
+	}
+
+	monc->sub_renew_after = jiffies; /* i.e., expired */
+	monc->sub_renew_sent = 0;
+
+	dout("%s opening mon%d\n", __func__, monc->cur_mon);
+	ceph_con_open(&monc->con, CEPH_ENTITY_TYPE_MON, monc->cur_mon,
+		      &monc->monmap->mon_inst[monc->cur_mon].addr);
+
+	/*
+	 * send an initial keepalive to ensure our timestamp is valid
+	 * by the time we are in an OPENED state
+	 */
+	ceph_con_keepalive(&monc->con);
+
+	/* initiate authentication handshake */
+	ret = ceph_auth_build_hello(monc->auth,
+				    monc->m_auth->front.iov_base,
+				    monc->m_auth->front_alloc_len);
+	BUG_ON(ret <= 0);
+	__send_prepared_auth_request(monc, ret);
+}
+
+static void reopen_session(struct ceph_mon_client *monc)
+{
+	if (!monc->hunting)
+		pr_info("mon%d %s session lost, hunting for new mon\n",
+		    monc->cur_mon, ceph_pr_addr(&monc->con.peer_addr.in_addr));
+
+	__close_session(monc);
+	__open_session(monc);
+}
+
+static void un_backoff(struct ceph_mon_client *monc)
+{
+	monc->hunt_mult /= 2; /* reduce by 50% */
+	if (monc->hunt_mult < 1)
+		monc->hunt_mult = 1;
+	dout("%s hunt_mult now %d\n", __func__, monc->hunt_mult);
+}
+
+/*
+ * Reschedule delayed work timer.
+ */
+static void __schedule_delayed(struct ceph_mon_client *monc)
+{
+	unsigned long delay;
+
+	if (monc->hunting)
+		delay = CEPH_MONC_HUNT_INTERVAL * monc->hunt_mult;
+	else
+		delay = CEPH_MONC_PING_INTERVAL;
+
+	dout("__schedule_delayed after %lu\n", delay);
+	mod_delayed_work(system_wq, &monc->delayed_work,
+			 round_jiffies_relative(delay));
+}
+
+const char *ceph_sub_str[] = {
+	[CEPH_SUB_MONMAP] = "monmap",
+	[CEPH_SUB_OSDMAP] = "osdmap",
+	[CEPH_SUB_FSMAP]  = "fsmap.user",
+	[CEPH_SUB_MDSMAP] = "mdsmap",
+};
+
+/*
+ * Send subscribe request for one or more maps, according to
+ * monc->subs.
+ */
+static void __send_subscribe(struct ceph_mon_client *monc)
+{
+	struct ceph_msg *msg = monc->m_subscribe;
+	void *p = msg->front.iov_base;
+	void *const end = p + msg->front_alloc_len;
+	int num = 0;
+	int i;
+
+	dout("%s sent %lu\n", __func__, monc->sub_renew_sent);
+
+	BUG_ON(monc->cur_mon < 0);
+
+	if (!monc->sub_renew_sent)
+		monc->sub_renew_sent = jiffies | 1; /* never 0 */
+
+	msg->hdr.version = cpu_to_le16(2);
+
+	for (i = 0; i < ARRAY_SIZE(monc->subs); i++) {
+		if (monc->subs[i].want)
+			num++;
+	}
+	BUG_ON(num < 1); /* monmap sub is always there */
+	ceph_encode_32(&p, num);
+	for (i = 0; i < ARRAY_SIZE(monc->subs); i++) {
+		char buf[32];
+		int len;
+
+		if (!monc->subs[i].want)
+			continue;
+
+		len = sprintf(buf, "%s", ceph_sub_str[i]);
+		if (i == CEPH_SUB_MDSMAP &&
+		    monc->fs_cluster_id != CEPH_FS_CLUSTER_ID_NONE)
+			len += sprintf(buf + len, ".%d", monc->fs_cluster_id);
+
+		dout("%s %s start %llu flags 0x%x\n", __func__, buf,
+		     le64_to_cpu(monc->subs[i].item.start),
+		     monc->subs[i].item.flags);
+		ceph_encode_string(&p, end, buf, len);
+		memcpy(p, &monc->subs[i].item, sizeof(monc->subs[i].item));
+		p += sizeof(monc->subs[i].item);
+	}
+
+	BUG_ON(p > end);
+	msg->front.iov_len = p - msg->front.iov_base;
+	msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
+	ceph_msg_revoke(msg);
+	ceph_con_send(&monc->con, ceph_msg_get(msg));
+}
+
+static void handle_subscribe_ack(struct ceph_mon_client *monc,
+				 struct ceph_msg *msg)
+{
+	unsigned int seconds;
+	struct ceph_mon_subscribe_ack *h = msg->front.iov_base;
+
+	if (msg->front.iov_len < sizeof(*h))
+		goto bad;
+	seconds = le32_to_cpu(h->duration);
+
+	mutex_lock(&monc->mutex);
+	if (monc->sub_renew_sent) {
+		/*
+		 * This is only needed for legacy (infernalis or older)
+		 * MONs -- see delayed_work().
+		 */
+		monc->sub_renew_after = monc->sub_renew_sent +
+					    (seconds >> 1) * HZ - 1;
+		dout("%s sent %lu duration %d renew after %lu\n", __func__,
+		     monc->sub_renew_sent, seconds, monc->sub_renew_after);
+		monc->sub_renew_sent = 0;
+	} else {
+		dout("%s sent %lu renew after %lu, ignoring\n", __func__,
+		     monc->sub_renew_sent, monc->sub_renew_after);
+	}
+	mutex_unlock(&monc->mutex);
+	return;
+bad:
+	pr_err("got corrupt subscribe-ack msg\n");
+	ceph_msg_dump(msg);
+}
+
+/*
+ * Register interest in a map
+ *
+ * @sub: one of CEPH_SUB_*
+ * @epoch: X for "every map since X", or 0 for "just the latest"
+ */
+static bool __ceph_monc_want_map(struct ceph_mon_client *monc, int sub,
+				 u32 epoch, bool continuous)
+{
+	__le64 start = cpu_to_le64(epoch);
+	u8 flags = !continuous ? CEPH_SUBSCRIBE_ONETIME : 0;
+
+	dout("%s %s epoch %u continuous %d\n", __func__, ceph_sub_str[sub],
+	     epoch, continuous);
+
+	if (monc->subs[sub].want &&
+	    monc->subs[sub].item.start == start &&
+	    monc->subs[sub].item.flags == flags)
+		return false;
+
+	monc->subs[sub].item.start = start;
+	monc->subs[sub].item.flags = flags;
+	monc->subs[sub].want = true;
+
+	return true;
+}
+
+bool ceph_monc_want_map(struct ceph_mon_client *monc, int sub, u32 epoch,
+			bool continuous)
+{
+	bool need_request;
+
+	mutex_lock(&monc->mutex);
+	need_request = __ceph_monc_want_map(monc, sub, epoch, continuous);
+	mutex_unlock(&monc->mutex);
+
+	return need_request;
+}
+EXPORT_SYMBOL(ceph_monc_want_map);
+
+/*
+ * Keep track of which maps we have
+ *
+ * @sub: one of CEPH_SUB_*
+ */
+static void __ceph_monc_got_map(struct ceph_mon_client *monc, int sub,
+				u32 epoch)
+{
+	dout("%s %s epoch %u\n", __func__, ceph_sub_str[sub], epoch);
+
+	if (monc->subs[sub].want) {
+		if (monc->subs[sub].item.flags & CEPH_SUBSCRIBE_ONETIME)
+			monc->subs[sub].want = false;
+		else
+			monc->subs[sub].item.start = cpu_to_le64(epoch + 1);
+	}
+
+	monc->subs[sub].have = epoch;
+}
+
+void ceph_monc_got_map(struct ceph_mon_client *monc, int sub, u32 epoch)
+{
+	mutex_lock(&monc->mutex);
+	__ceph_monc_got_map(monc, sub, epoch);
+	mutex_unlock(&monc->mutex);
+}
+EXPORT_SYMBOL(ceph_monc_got_map);
+
+void ceph_monc_renew_subs(struct ceph_mon_client *monc)
+{
+	mutex_lock(&monc->mutex);
+	__send_subscribe(monc);
+	mutex_unlock(&monc->mutex);
+}
+EXPORT_SYMBOL(ceph_monc_renew_subs);
+
+/*
+ * Wait for an osdmap with a given epoch.
+ *
+ * @epoch: epoch to wait for
+ * @timeout: in jiffies, 0 means "wait forever"
+ */
+int ceph_monc_wait_osdmap(struct ceph_mon_client *monc, u32 epoch,
+			  unsigned long timeout)
+{
+	unsigned long started = jiffies;
+	long ret;
+
+	mutex_lock(&monc->mutex);
+	while (monc->subs[CEPH_SUB_OSDMAP].have < epoch) {
+		mutex_unlock(&monc->mutex);
+
+		if (timeout && time_after_eq(jiffies, started + timeout))
+			return -ETIMEDOUT;
+
+		ret = wait_event_interruptible_timeout(monc->client->auth_wq,
+				     monc->subs[CEPH_SUB_OSDMAP].have >= epoch,
+				     ceph_timeout_jiffies(timeout));
+		if (ret < 0)
+			return ret;
+
+		mutex_lock(&monc->mutex);
+	}
+
+	mutex_unlock(&monc->mutex);
+	return 0;
+}
+EXPORT_SYMBOL(ceph_monc_wait_osdmap);
+
+/*
+ * Open a session with a random monitor.  Request monmap and osdmap,
+ * which are waited upon in __ceph_open_session().
+ */
+int ceph_monc_open_session(struct ceph_mon_client *monc)
+{
+	mutex_lock(&monc->mutex);
+	__ceph_monc_want_map(monc, CEPH_SUB_MONMAP, 0, true);
+	__ceph_monc_want_map(monc, CEPH_SUB_OSDMAP, 0, false);
+	__open_session(monc);
+	__schedule_delayed(monc);
+	mutex_unlock(&monc->mutex);
+	return 0;
+}
+EXPORT_SYMBOL(ceph_monc_open_session);
+
+static void ceph_monc_handle_map(struct ceph_mon_client *monc,
+				 struct ceph_msg *msg)
+{
+	struct ceph_client *client = monc->client;
+	struct ceph_monmap *monmap = NULL, *old = monc->monmap;
+	void *p, *end;
+
+	mutex_lock(&monc->mutex);
+
+	dout("handle_monmap\n");
+	p = msg->front.iov_base;
+	end = p + msg->front.iov_len;
+
+	monmap = ceph_monmap_decode(p, end);
+	if (IS_ERR(monmap)) {
+		pr_err("problem decoding monmap, %d\n",
+		       (int)PTR_ERR(monmap));
+		goto out;
+	}
+
+	if (ceph_check_fsid(monc->client, &monmap->fsid) < 0) {
+		kfree(monmap);
+		goto out;
+	}
+
+	client->monc.monmap = monmap;
+	kfree(old);
+
+	__ceph_monc_got_map(monc, CEPH_SUB_MONMAP, monc->monmap->epoch);
+	client->have_fsid = true;
+
+out:
+	mutex_unlock(&monc->mutex);
+	wake_up_all(&client->auth_wq);
+}
+
+/*
+ * generic requests (currently statfs, mon_get_version)
+ */
+DEFINE_RB_FUNCS(generic_request, struct ceph_mon_generic_request, tid, node)
+
+static void release_generic_request(struct kref *kref)
+{
+	struct ceph_mon_generic_request *req =
+		container_of(kref, struct ceph_mon_generic_request, kref);
+
+	dout("%s greq %p request %p reply %p\n", __func__, req, req->request,
+	     req->reply);
+	WARN_ON(!RB_EMPTY_NODE(&req->node));
+
+	if (req->reply)
+		ceph_msg_put(req->reply);
+	if (req->request)
+		ceph_msg_put(req->request);
+
+	kfree(req);
+}
+
+static void put_generic_request(struct ceph_mon_generic_request *req)
+{
+	if (req)
+		kref_put(&req->kref, release_generic_request);
+}
+
+static void get_generic_request(struct ceph_mon_generic_request *req)
+{
+	kref_get(&req->kref);
+}
+
+static struct ceph_mon_generic_request *
+alloc_generic_request(struct ceph_mon_client *monc, gfp_t gfp)
+{
+	struct ceph_mon_generic_request *req;
+
+	req = kzalloc(sizeof(*req), gfp);
+	if (!req)
+		return NULL;
+
+	req->monc = monc;
+	kref_init(&req->kref);
+	RB_CLEAR_NODE(&req->node);
+	init_completion(&req->completion);
+
+	dout("%s greq %p\n", __func__, req);
+	return req;
+}
+
+static void register_generic_request(struct ceph_mon_generic_request *req)
+{
+	struct ceph_mon_client *monc = req->monc;
+
+	WARN_ON(req->tid);
+
+	get_generic_request(req);
+	req->tid = ++monc->last_tid;
+	insert_generic_request(&monc->generic_request_tree, req);
+}
+
+static void send_generic_request(struct ceph_mon_client *monc,
+				 struct ceph_mon_generic_request *req)
+{
+	WARN_ON(!req->tid);
+
+	dout("%s greq %p tid %llu\n", __func__, req, req->tid);
+	req->request->hdr.tid = cpu_to_le64(req->tid);
+	ceph_con_send(&monc->con, ceph_msg_get(req->request));
+}
+
+static void __finish_generic_request(struct ceph_mon_generic_request *req)
+{
+	struct ceph_mon_client *monc = req->monc;
+
+	dout("%s greq %p tid %llu\n", __func__, req, req->tid);
+	erase_generic_request(&monc->generic_request_tree, req);
+
+	ceph_msg_revoke(req->request);
+	ceph_msg_revoke_incoming(req->reply);
+}
+
+static void finish_generic_request(struct ceph_mon_generic_request *req)
+{
+	__finish_generic_request(req);
+	put_generic_request(req);
+}
+
+static void complete_generic_request(struct ceph_mon_generic_request *req)
+{
+	if (req->complete_cb)
+		req->complete_cb(req);
+	else
+		complete_all(&req->completion);
+	put_generic_request(req);
+}
+
+static void cancel_generic_request(struct ceph_mon_generic_request *req)
+{
+	struct ceph_mon_client *monc = req->monc;
+	struct ceph_mon_generic_request *lookup_req;
+
+	dout("%s greq %p tid %llu\n", __func__, req, req->tid);
+
+	mutex_lock(&monc->mutex);
+	lookup_req = lookup_generic_request(&monc->generic_request_tree,
+					    req->tid);
+	if (lookup_req) {
+		WARN_ON(lookup_req != req);
+		finish_generic_request(req);
+	}
+
+	mutex_unlock(&monc->mutex);
+}
+
+static int wait_generic_request(struct ceph_mon_generic_request *req)
+{
+	int ret;
+
+	dout("%s greq %p tid %llu\n", __func__, req, req->tid);
+	ret = wait_for_completion_interruptible(&req->completion);
+	if (ret)
+		cancel_generic_request(req);
+	else
+		ret = req->result; /* completed */
+
+	return ret;
+}
+
+static struct ceph_msg *get_generic_reply(struct ceph_connection *con,
+					 struct ceph_msg_header *hdr,
+					 int *skip)
+{
+	struct ceph_mon_client *monc = con->private;
+	struct ceph_mon_generic_request *req;
+	u64 tid = le64_to_cpu(hdr->tid);
+	struct ceph_msg *m;
+
+	mutex_lock(&monc->mutex);
+	req = lookup_generic_request(&monc->generic_request_tree, tid);
+	if (!req) {
+		dout("get_generic_reply %lld dne\n", tid);
+		*skip = 1;
+		m = NULL;
+	} else {
+		dout("get_generic_reply %lld got %p\n", tid, req->reply);
+		*skip = 0;
+		m = ceph_msg_get(req->reply);
+		/*
+		 * we don't need to track the connection reading into
+		 * this reply because we only have one open connection
+		 * at a time, ever.
+		 */
+	}
+	mutex_unlock(&monc->mutex);
+	return m;
+}
+
+/*
+ * statfs
+ */
+static void handle_statfs_reply(struct ceph_mon_client *monc,
+				struct ceph_msg *msg)
+{
+	struct ceph_mon_generic_request *req;
+	struct ceph_mon_statfs_reply *reply = msg->front.iov_base;
+	u64 tid = le64_to_cpu(msg->hdr.tid);
+
+	dout("%s msg %p tid %llu\n", __func__, msg, tid);
+
+	if (msg->front.iov_len != sizeof(*reply))
+		goto bad;
+
+	mutex_lock(&monc->mutex);
+	req = lookup_generic_request(&monc->generic_request_tree, tid);
+	if (!req) {
+		mutex_unlock(&monc->mutex);
+		return;
+	}
+
+	req->result = 0;
+	*req->u.st = reply->st; /* struct */
+	__finish_generic_request(req);
+	mutex_unlock(&monc->mutex);
+
+	complete_generic_request(req);
+	return;
+
+bad:
+	pr_err("corrupt statfs reply, tid %llu\n", tid);
+	ceph_msg_dump(msg);
+}
+
+/*
+ * Do a synchronous statfs().
+ */
+int ceph_monc_do_statfs(struct ceph_mon_client *monc, u64 data_pool,
+			struct ceph_statfs *buf)
+{
+	struct ceph_mon_generic_request *req;
+	struct ceph_mon_statfs *h;
+	int ret = -ENOMEM;
+
+	req = alloc_generic_request(monc, GFP_NOFS);
+	if (!req)
+		goto out;
+
+	req->request = ceph_msg_new(CEPH_MSG_STATFS, sizeof(*h), GFP_NOFS,
+				    true);
+	if (!req->request)
+		goto out;
+
+	req->reply = ceph_msg_new(CEPH_MSG_STATFS_REPLY, 64, GFP_NOFS, true);
+	if (!req->reply)
+		goto out;
+
+	req->u.st = buf;
+	req->request->hdr.version = cpu_to_le16(2);
+
+	mutex_lock(&monc->mutex);
+	register_generic_request(req);
+	/* fill out request */
+	h = req->request->front.iov_base;
+	h->monhdr.have_version = 0;
+	h->monhdr.session_mon = cpu_to_le16(-1);
+	h->monhdr.session_mon_tid = 0;
+	h->fsid = monc->monmap->fsid;
+	h->contains_data_pool = (data_pool != CEPH_NOPOOL);
+	h->data_pool = cpu_to_le64(data_pool);
+	send_generic_request(monc, req);
+	mutex_unlock(&monc->mutex);
+
+	ret = wait_generic_request(req);
+out:
+	put_generic_request(req);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_monc_do_statfs);
+
+static void handle_get_version_reply(struct ceph_mon_client *monc,
+				     struct ceph_msg *msg)
+{
+	struct ceph_mon_generic_request *req;
+	u64 tid = le64_to_cpu(msg->hdr.tid);
+	void *p = msg->front.iov_base;
+	void *end = p + msg->front_alloc_len;
+	u64 handle;
+
+	dout("%s msg %p tid %llu\n", __func__, msg, tid);
+
+	ceph_decode_need(&p, end, 2*sizeof(u64), bad);
+	handle = ceph_decode_64(&p);
+	if (tid != 0 && tid != handle)
+		goto bad;
+
+	mutex_lock(&monc->mutex);
+	req = lookup_generic_request(&monc->generic_request_tree, handle);
+	if (!req) {
+		mutex_unlock(&monc->mutex);
+		return;
+	}
+
+	req->result = 0;
+	req->u.newest = ceph_decode_64(&p);
+	__finish_generic_request(req);
+	mutex_unlock(&monc->mutex);
+
+	complete_generic_request(req);
+	return;
+
+bad:
+	pr_err("corrupt mon_get_version reply, tid %llu\n", tid);
+	ceph_msg_dump(msg);
+}
+
+static struct ceph_mon_generic_request *
+__ceph_monc_get_version(struct ceph_mon_client *monc, const char *what,
+			ceph_monc_callback_t cb, u64 private_data)
+{
+	struct ceph_mon_generic_request *req;
+
+	req = alloc_generic_request(monc, GFP_NOIO);
+	if (!req)
+		goto err_put_req;
+
+	req->request = ceph_msg_new(CEPH_MSG_MON_GET_VERSION,
+				    sizeof(u64) + sizeof(u32) + strlen(what),
+				    GFP_NOIO, true);
+	if (!req->request)
+		goto err_put_req;
+
+	req->reply = ceph_msg_new(CEPH_MSG_MON_GET_VERSION_REPLY, 32, GFP_NOIO,
+				  true);
+	if (!req->reply)
+		goto err_put_req;
+
+	req->complete_cb = cb;
+	req->private_data = private_data;
+
+	mutex_lock(&monc->mutex);
+	register_generic_request(req);
+	{
+		void *p = req->request->front.iov_base;
+		void *const end = p + req->request->front_alloc_len;
+
+		ceph_encode_64(&p, req->tid); /* handle */
+		ceph_encode_string(&p, end, what, strlen(what));
+		WARN_ON(p != end);
+	}
+	send_generic_request(monc, req);
+	mutex_unlock(&monc->mutex);
+
+	return req;
+
+err_put_req:
+	put_generic_request(req);
+	return ERR_PTR(-ENOMEM);
+}
+
+/*
+ * Send MMonGetVersion and wait for the reply.
+ *
+ * @what: one of "mdsmap", "osdmap" or "monmap"
+ */
+int ceph_monc_get_version(struct ceph_mon_client *monc, const char *what,
+			  u64 *newest)
+{
+	struct ceph_mon_generic_request *req;
+	int ret;
+
+	req = __ceph_monc_get_version(monc, what, NULL, 0);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+
+	ret = wait_generic_request(req);
+	if (!ret)
+		*newest = req->u.newest;
+
+	put_generic_request(req);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_monc_get_version);
+
+/*
+ * Send MMonGetVersion,
+ *
+ * @what: one of "mdsmap", "osdmap" or "monmap"
+ */
+int ceph_monc_get_version_async(struct ceph_mon_client *monc, const char *what,
+				ceph_monc_callback_t cb, u64 private_data)
+{
+	struct ceph_mon_generic_request *req;
+
+	req = __ceph_monc_get_version(monc, what, cb, private_data);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+
+	put_generic_request(req);
+	return 0;
+}
+EXPORT_SYMBOL(ceph_monc_get_version_async);
+
+static void handle_command_ack(struct ceph_mon_client *monc,
+			       struct ceph_msg *msg)
+{
+	struct ceph_mon_generic_request *req;
+	void *p = msg->front.iov_base;
+	void *const end = p + msg->front_alloc_len;
+	u64 tid = le64_to_cpu(msg->hdr.tid);
+
+	dout("%s msg %p tid %llu\n", __func__, msg, tid);
+
+	ceph_decode_need(&p, end, sizeof(struct ceph_mon_request_header) +
+							    sizeof(u32), bad);
+	p += sizeof(struct ceph_mon_request_header);
+
+	mutex_lock(&monc->mutex);
+	req = lookup_generic_request(&monc->generic_request_tree, tid);
+	if (!req) {
+		mutex_unlock(&monc->mutex);
+		return;
+	}
+
+	req->result = ceph_decode_32(&p);
+	__finish_generic_request(req);
+	mutex_unlock(&monc->mutex);
+
+	complete_generic_request(req);
+	return;
+
+bad:
+	pr_err("corrupt mon_command ack, tid %llu\n", tid);
+	ceph_msg_dump(msg);
+}
+
+int ceph_monc_blacklist_add(struct ceph_mon_client *monc,
+			    struct ceph_entity_addr *client_addr)
+{
+	struct ceph_mon_generic_request *req;
+	struct ceph_mon_command *h;
+	int ret = -ENOMEM;
+	int len;
+
+	req = alloc_generic_request(monc, GFP_NOIO);
+	if (!req)
+		goto out;
+
+	req->request = ceph_msg_new(CEPH_MSG_MON_COMMAND, 256, GFP_NOIO, true);
+	if (!req->request)
+		goto out;
+
+	req->reply = ceph_msg_new(CEPH_MSG_MON_COMMAND_ACK, 512, GFP_NOIO,
+				  true);
+	if (!req->reply)
+		goto out;
+
+	mutex_lock(&monc->mutex);
+	register_generic_request(req);
+	h = req->request->front.iov_base;
+	h->monhdr.have_version = 0;
+	h->monhdr.session_mon = cpu_to_le16(-1);
+	h->monhdr.session_mon_tid = 0;
+	h->fsid = monc->monmap->fsid;
+	h->num_strs = cpu_to_le32(1);
+	len = sprintf(h->str, "{ \"prefix\": \"osd blacklist\", \
+		                 \"blacklistop\": \"add\", \
+				 \"addr\": \"%pISpc/%u\" }",
+		      &client_addr->in_addr, le32_to_cpu(client_addr->nonce));
+	h->str_len = cpu_to_le32(len);
+	send_generic_request(monc, req);
+	mutex_unlock(&monc->mutex);
+
+	ret = wait_generic_request(req);
+	if (!ret)
+		/*
+		 * Make sure we have the osdmap that includes the blacklist
+		 * entry.  This is needed to ensure that the OSDs pick up the
+		 * new blacklist before processing any future requests from
+		 * this client.
+		 */
+		ret = ceph_wait_for_latest_osdmap(monc->client, 0);
+
+out:
+	put_generic_request(req);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_monc_blacklist_add);
+
+/*
+ * Resend pending generic requests.
+ */
+static void __resend_generic_request(struct ceph_mon_client *monc)
+{
+	struct ceph_mon_generic_request *req;
+	struct rb_node *p;
+
+	for (p = rb_first(&monc->generic_request_tree); p; p = rb_next(p)) {
+		req = rb_entry(p, struct ceph_mon_generic_request, node);
+		ceph_msg_revoke(req->request);
+		ceph_msg_revoke_incoming(req->reply);
+		ceph_con_send(&monc->con, ceph_msg_get(req->request));
+	}
+}
+
+/*
+ * Delayed work.  If we haven't mounted yet, retry.  Otherwise,
+ * renew/retry subscription as needed (in case it is timing out, or we
+ * got an ENOMEM).  And keep the monitor connection alive.
+ */
+static void delayed_work(struct work_struct *work)
+{
+	struct ceph_mon_client *monc =
+		container_of(work, struct ceph_mon_client, delayed_work.work);
+
+	dout("monc delayed_work\n");
+	mutex_lock(&monc->mutex);
+	if (monc->hunting) {
+		dout("%s continuing hunt\n", __func__);
+		reopen_session(monc);
+	} else {
+		int is_auth = ceph_auth_is_authenticated(monc->auth);
+		if (ceph_con_keepalive_expired(&monc->con,
+					       CEPH_MONC_PING_TIMEOUT)) {
+			dout("monc keepalive timeout\n");
+			is_auth = 0;
+			reopen_session(monc);
+		}
+
+		if (!monc->hunting) {
+			ceph_con_keepalive(&monc->con);
+			__validate_auth(monc);
+			un_backoff(monc);
+		}
+
+		if (is_auth &&
+		    !(monc->con.peer_features & CEPH_FEATURE_MON_STATEFUL_SUB)) {
+			unsigned long now = jiffies;
+
+			dout("%s renew subs? now %lu renew after %lu\n",
+			     __func__, now, monc->sub_renew_after);
+			if (time_after_eq(now, monc->sub_renew_after))
+				__send_subscribe(monc);
+		}
+	}
+	__schedule_delayed(monc);
+	mutex_unlock(&monc->mutex);
+}
+
+/*
+ * On startup, we build a temporary monmap populated with the IPs
+ * provided by mount(2).
+ */
+static int build_initial_monmap(struct ceph_mon_client *monc)
+{
+	struct ceph_options *opt = monc->client->options;
+	struct ceph_entity_addr *mon_addr = opt->mon_addr;
+	int num_mon = opt->num_mon;
+	int i;
+
+	/* build initial monmap */
+	monc->monmap = kzalloc(struct_size(monc->monmap, mon_inst, num_mon),
+			       GFP_KERNEL);
+	if (!monc->monmap)
+		return -ENOMEM;
+	for (i = 0; i < num_mon; i++) {
+		monc->monmap->mon_inst[i].addr = mon_addr[i];
+		monc->monmap->mon_inst[i].addr.nonce = 0;
+		monc->monmap->mon_inst[i].name.type =
+			CEPH_ENTITY_TYPE_MON;
+		monc->monmap->mon_inst[i].name.num = cpu_to_le64(i);
+	}
+	monc->monmap->num_mon = num_mon;
+	return 0;
+}
+
+int ceph_monc_init(struct ceph_mon_client *monc, struct ceph_client *cl)
+{
+	int err = 0;
+
+	dout("init\n");
+	memset(monc, 0, sizeof(*monc));
+	monc->client = cl;
+	monc->monmap = NULL;
+	mutex_init(&monc->mutex);
+
+	err = build_initial_monmap(monc);
+	if (err)
+		goto out;
+
+	/* connection */
+	/* authentication */
+	monc->auth = ceph_auth_init(cl->options->name,
+				    cl->options->key);
+	if (IS_ERR(monc->auth)) {
+		err = PTR_ERR(monc->auth);
+		goto out_monmap;
+	}
+	monc->auth->want_keys =
+		CEPH_ENTITY_TYPE_AUTH | CEPH_ENTITY_TYPE_MON |
+		CEPH_ENTITY_TYPE_OSD | CEPH_ENTITY_TYPE_MDS;
+
+	/* msgs */
+	err = -ENOMEM;
+	monc->m_subscribe_ack = ceph_msg_new(CEPH_MSG_MON_SUBSCRIBE_ACK,
+				     sizeof(struct ceph_mon_subscribe_ack),
+				     GFP_KERNEL, true);
+	if (!monc->m_subscribe_ack)
+		goto out_auth;
+
+	monc->m_subscribe = ceph_msg_new(CEPH_MSG_MON_SUBSCRIBE, 128,
+					 GFP_KERNEL, true);
+	if (!monc->m_subscribe)
+		goto out_subscribe_ack;
+
+	monc->m_auth_reply = ceph_msg_new(CEPH_MSG_AUTH_REPLY, 4096,
+					  GFP_KERNEL, true);
+	if (!monc->m_auth_reply)
+		goto out_subscribe;
+
+	monc->m_auth = ceph_msg_new(CEPH_MSG_AUTH, 4096, GFP_KERNEL, true);
+	monc->pending_auth = 0;
+	if (!monc->m_auth)
+		goto out_auth_reply;
+
+	ceph_con_init(&monc->con, monc, &mon_con_ops,
+		      &monc->client->msgr);
+
+	monc->cur_mon = -1;
+	monc->had_a_connection = false;
+	monc->hunt_mult = 1;
+
+	INIT_DELAYED_WORK(&monc->delayed_work, delayed_work);
+	monc->generic_request_tree = RB_ROOT;
+	monc->last_tid = 0;
+
+	monc->fs_cluster_id = CEPH_FS_CLUSTER_ID_NONE;
+
+	return 0;
+
+out_auth_reply:
+	ceph_msg_put(monc->m_auth_reply);
+out_subscribe:
+	ceph_msg_put(monc->m_subscribe);
+out_subscribe_ack:
+	ceph_msg_put(monc->m_subscribe_ack);
+out_auth:
+	ceph_auth_destroy(monc->auth);
+out_monmap:
+	kfree(monc->monmap);
+out:
+	return err;
+}
+EXPORT_SYMBOL(ceph_monc_init);
+
+void ceph_monc_stop(struct ceph_mon_client *monc)
+{
+	dout("stop\n");
+	cancel_delayed_work_sync(&monc->delayed_work);
+
+	mutex_lock(&monc->mutex);
+	__close_session(monc);
+	monc->cur_mon = -1;
+	mutex_unlock(&monc->mutex);
+
+	/*
+	 * flush msgr queue before we destroy ourselves to ensure that:
+	 *  - any work that references our embedded con is finished.
+	 *  - any osd_client or other work that may reference an authorizer
+	 *    finishes before we shut down the auth subsystem.
+	 */
+	ceph_msgr_flush();
+
+	ceph_auth_destroy(monc->auth);
+
+	WARN_ON(!RB_EMPTY_ROOT(&monc->generic_request_tree));
+
+	ceph_msg_put(monc->m_auth);
+	ceph_msg_put(monc->m_auth_reply);
+	ceph_msg_put(monc->m_subscribe);
+	ceph_msg_put(monc->m_subscribe_ack);
+
+	kfree(monc->monmap);
+}
+EXPORT_SYMBOL(ceph_monc_stop);
+
+static void finish_hunting(struct ceph_mon_client *monc)
+{
+	if (monc->hunting) {
+		dout("%s found mon%d\n", __func__, monc->cur_mon);
+		monc->hunting = false;
+		monc->had_a_connection = true;
+		un_backoff(monc);
+		__schedule_delayed(monc);
+	}
+}
+
+static void handle_auth_reply(struct ceph_mon_client *monc,
+			      struct ceph_msg *msg)
+{
+	int ret;
+	int was_auth = 0;
+
+	mutex_lock(&monc->mutex);
+	was_auth = ceph_auth_is_authenticated(monc->auth);
+	monc->pending_auth = 0;
+	ret = ceph_handle_auth_reply(monc->auth, msg->front.iov_base,
+				     msg->front.iov_len,
+				     monc->m_auth->front.iov_base,
+				     monc->m_auth->front_alloc_len);
+	if (ret > 0) {
+		__send_prepared_auth_request(monc, ret);
+		goto out;
+	}
+
+	finish_hunting(monc);
+
+	if (ret < 0) {
+		monc->client->auth_err = ret;
+	} else if (!was_auth && ceph_auth_is_authenticated(monc->auth)) {
+		dout("authenticated, starting session\n");
+
+		monc->client->msgr.inst.name.type = CEPH_ENTITY_TYPE_CLIENT;
+		monc->client->msgr.inst.name.num =
+					cpu_to_le64(monc->auth->global_id);
+
+		__send_subscribe(monc);
+		__resend_generic_request(monc);
+
+		pr_info("mon%d %s session established\n", monc->cur_mon,
+			ceph_pr_addr(&monc->con.peer_addr.in_addr));
+	}
+
+out:
+	mutex_unlock(&monc->mutex);
+	if (monc->client->auth_err < 0)
+		wake_up_all(&monc->client->auth_wq);
+}
+
+static int __validate_auth(struct ceph_mon_client *monc)
+{
+	int ret;
+
+	if (monc->pending_auth)
+		return 0;
+
+	ret = ceph_build_auth(monc->auth, monc->m_auth->front.iov_base,
+			      monc->m_auth->front_alloc_len);
+	if (ret <= 0)
+		return ret; /* either an error, or no need to authenticate */
+	__send_prepared_auth_request(monc, ret);
+	return 0;
+}
+
+int ceph_monc_validate_auth(struct ceph_mon_client *monc)
+{
+	int ret;
+
+	mutex_lock(&monc->mutex);
+	ret = __validate_auth(monc);
+	mutex_unlock(&monc->mutex);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_monc_validate_auth);
+
+/*
+ * handle incoming message
+ */
+static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
+{
+	struct ceph_mon_client *monc = con->private;
+	int type = le16_to_cpu(msg->hdr.type);
+
+	if (!monc)
+		return;
+
+	switch (type) {
+	case CEPH_MSG_AUTH_REPLY:
+		handle_auth_reply(monc, msg);
+		break;
+
+	case CEPH_MSG_MON_SUBSCRIBE_ACK:
+		handle_subscribe_ack(monc, msg);
+		break;
+
+	case CEPH_MSG_STATFS_REPLY:
+		handle_statfs_reply(monc, msg);
+		break;
+
+	case CEPH_MSG_MON_GET_VERSION_REPLY:
+		handle_get_version_reply(monc, msg);
+		break;
+
+	case CEPH_MSG_MON_COMMAND_ACK:
+		handle_command_ack(monc, msg);
+		break;
+
+	case CEPH_MSG_MON_MAP:
+		ceph_monc_handle_map(monc, msg);
+		break;
+
+	case CEPH_MSG_OSD_MAP:
+		ceph_osdc_handle_map(&monc->client->osdc, msg);
+		break;
+
+	default:
+		/* can the chained handler handle it? */
+		if (monc->client->extra_mon_dispatch &&
+		    monc->client->extra_mon_dispatch(monc->client, msg) == 0)
+			break;
+
+		pr_err("received unknown message type %d %s\n", type,
+		       ceph_msg_type_name(type));
+	}
+	ceph_msg_put(msg);
+}
+
+/*
+ * Allocate memory for incoming message
+ */
+static struct ceph_msg *mon_alloc_msg(struct ceph_connection *con,
+				      struct ceph_msg_header *hdr,
+				      int *skip)
+{
+	struct ceph_mon_client *monc = con->private;
+	int type = le16_to_cpu(hdr->type);
+	int front_len = le32_to_cpu(hdr->front_len);
+	struct ceph_msg *m = NULL;
+
+	*skip = 0;
+
+	switch (type) {
+	case CEPH_MSG_MON_SUBSCRIBE_ACK:
+		m = ceph_msg_get(monc->m_subscribe_ack);
+		break;
+	case CEPH_MSG_STATFS_REPLY:
+	case CEPH_MSG_MON_COMMAND_ACK:
+		return get_generic_reply(con, hdr, skip);
+	case CEPH_MSG_AUTH_REPLY:
+		m = ceph_msg_get(monc->m_auth_reply);
+		break;
+	case CEPH_MSG_MON_GET_VERSION_REPLY:
+		if (le64_to_cpu(hdr->tid) != 0)
+			return get_generic_reply(con, hdr, skip);
+
+		/*
+		 * Older OSDs don't set reply tid even if the orignal
+		 * request had a non-zero tid.  Work around this weirdness
+		 * by allocating a new message.
+		 */
+		/* fall through */
+	case CEPH_MSG_MON_MAP:
+	case CEPH_MSG_MDS_MAP:
+	case CEPH_MSG_OSD_MAP:
+	case CEPH_MSG_FS_MAP_USER:
+		m = ceph_msg_new(type, front_len, GFP_NOFS, false);
+		if (!m)
+			return NULL;	/* ENOMEM--return skip == 0 */
+		break;
+	}
+
+	if (!m) {
+		pr_info("alloc_msg unknown type %d\n", type);
+		*skip = 1;
+	} else if (front_len > m->front_alloc_len) {
+		pr_warn("mon_alloc_msg front %d > prealloc %d (%u#%llu)\n",
+			front_len, m->front_alloc_len,
+			(unsigned int)con->peer_name.type,
+			le64_to_cpu(con->peer_name.num));
+		ceph_msg_put(m);
+		m = ceph_msg_new(type, front_len, GFP_NOFS, false);
+	}
+
+	return m;
+}
+
+/*
+ * If the monitor connection resets, pick a new monitor and resubmit
+ * any pending requests.
+ */
+static void mon_fault(struct ceph_connection *con)
+{
+	struct ceph_mon_client *monc = con->private;
+
+	mutex_lock(&monc->mutex);
+	dout("%s mon%d\n", __func__, monc->cur_mon);
+	if (monc->cur_mon >= 0) {
+		if (!monc->hunting) {
+			dout("%s hunting for new mon\n", __func__);
+			reopen_session(monc);
+			__schedule_delayed(monc);
+		} else {
+			dout("%s already hunting\n", __func__);
+		}
+	}
+	mutex_unlock(&monc->mutex);
+}
+
+/*
+ * We can ignore refcounting on the connection struct, as all references
+ * will come from the messenger workqueue, which is drained prior to
+ * mon_client destruction.
+ */
+static struct ceph_connection *con_get(struct ceph_connection *con)
+{
+	return con;
+}
+
+static void con_put(struct ceph_connection *con)
+{
+}
+
+static const struct ceph_connection_operations mon_con_ops = {
+	.get = con_get,
+	.put = con_put,
+	.dispatch = dispatch,
+	.fault = mon_fault,
+	.alloc_msg = mon_alloc_msg,
+};
diff --git a/net/ceph/msgpool.c b/net/ceph/msgpool.c
new file mode 100644
index 000000000..725715358
--- /dev/null
+++ b/net/ceph/msgpool.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/vmalloc.h>
+
+#include <linux/ceph/messenger.h>
+#include <linux/ceph/msgpool.h>
+
+static void *msgpool_alloc(gfp_t gfp_mask, void *arg)
+{
+	struct ceph_msgpool *pool = arg;
+	struct ceph_msg *msg;
+
+	msg = ceph_msg_new(pool->type, pool->front_len, gfp_mask, true);
+	if (!msg) {
+		dout("msgpool_alloc %s failed\n", pool->name);
+	} else {
+		dout("msgpool_alloc %s %p\n", pool->name, msg);
+		msg->pool = pool;
+	}
+	return msg;
+}
+
+static void msgpool_free(void *element, void *arg)
+{
+	struct ceph_msgpool *pool = arg;
+	struct ceph_msg *msg = element;
+
+	dout("msgpool_release %s %p\n", pool->name, msg);
+	msg->pool = NULL;
+	ceph_msg_put(msg);
+}
+
+int ceph_msgpool_init(struct ceph_msgpool *pool, int type,
+		      int front_len, int size, bool blocking, const char *name)
+{
+	dout("msgpool %s init\n", name);
+	pool->type = type;
+	pool->front_len = front_len;
+	pool->pool = mempool_create(size, msgpool_alloc, msgpool_free, pool);
+	if (!pool->pool)
+		return -ENOMEM;
+	pool->name = name;
+	return 0;
+}
+
+void ceph_msgpool_destroy(struct ceph_msgpool *pool)
+{
+	dout("msgpool %s destroy\n", pool->name);
+	mempool_destroy(pool->pool);
+}
+
+struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *pool,
+				  int front_len)
+{
+	struct ceph_msg *msg;
+
+	if (front_len > pool->front_len) {
+		dout("msgpool_get %s need front %d, pool size is %d\n",
+		       pool->name, front_len, pool->front_len);
+		WARN_ON(1);
+
+		/* try to alloc a fresh message */
+		return ceph_msg_new(pool->type, front_len, GFP_NOFS, false);
+	}
+
+	msg = mempool_alloc(pool->pool, GFP_NOFS);
+	dout("msgpool_get %s %p\n", pool->name, msg);
+	return msg;
+}
+
+void ceph_msgpool_put(struct ceph_msgpool *pool, struct ceph_msg *msg)
+{
+	dout("msgpool_put %s %p\n", pool->name, msg);
+
+	/* reset msg front_len; user may have changed it */
+	msg->front.iov_len = pool->front_len;
+	msg->hdr.front_len = cpu_to_le32(pool->front_len);
+
+	kref_init(&msg->kref);  /* retake single ref */
+	mempool_free(msg, pool->pool);
+}
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
new file mode 100644
index 000000000..713fe1fbc
--- /dev/null
+++ b/net/ceph/osd_client.c
@@ -0,0 +1,5465 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#ifdef CONFIG_BLOCK
+#include <linux/bio.h>
+#endif
+
+#include <linux/ceph/ceph_features.h>
+#include <linux/ceph/libceph.h>
+#include <linux/ceph/osd_client.h>
+#include <linux/ceph/messenger.h>
+#include <linux/ceph/decode.h>
+#include <linux/ceph/auth.h>
+#include <linux/ceph/pagelist.h>
+#include <linux/ceph/striper.h>
+
+#define OSD_OPREPLY_FRONT_LEN	512
+
+static struct kmem_cache	*ceph_osd_request_cache;
+
+static const struct ceph_connection_operations osd_con_ops;
+
+/*
+ * Implement client access to distributed object storage cluster.
+ *
+ * All data objects are stored within a cluster/cloud of OSDs, or
+ * "object storage devices."  (Note that Ceph OSDs have _nothing_ to
+ * do with the T10 OSD extensions to SCSI.)  Ceph OSDs are simply
+ * remote daemons serving up and coordinating consistent and safe
+ * access to storage.
+ *
+ * Cluster membership and the mapping of data objects onto storage devices
+ * are described by the osd map.
+ *
+ * We keep track of pending OSD requests (read, write), resubmit
+ * requests to different OSDs when the cluster topology/data layout
+ * change, or retry the affected requests when the communications
+ * channel with an OSD is reset.
+ */
+
+static void link_request(struct ceph_osd *osd, struct ceph_osd_request *req);
+static void unlink_request(struct ceph_osd *osd, struct ceph_osd_request *req);
+static void link_linger(struct ceph_osd *osd,
+			struct ceph_osd_linger_request *lreq);
+static void unlink_linger(struct ceph_osd *osd,
+			  struct ceph_osd_linger_request *lreq);
+static void clear_backoffs(struct ceph_osd *osd);
+
+#if 1
+static inline bool rwsem_is_wrlocked(struct rw_semaphore *sem)
+{
+	bool wrlocked = true;
+
+	if (unlikely(down_read_trylock(sem))) {
+		wrlocked = false;
+		up_read(sem);
+	}
+
+	return wrlocked;
+}
+static inline void verify_osdc_locked(struct ceph_osd_client *osdc)
+{
+	WARN_ON(!rwsem_is_locked(&osdc->lock));
+}
+static inline void verify_osdc_wrlocked(struct ceph_osd_client *osdc)
+{
+	WARN_ON(!rwsem_is_wrlocked(&osdc->lock));
+}
+static inline void verify_osd_locked(struct ceph_osd *osd)
+{
+	struct ceph_osd_client *osdc = osd->o_osdc;
+
+	WARN_ON(!(mutex_is_locked(&osd->lock) &&
+		  rwsem_is_locked(&osdc->lock)) &&
+		!rwsem_is_wrlocked(&osdc->lock));
+}
+static inline void verify_lreq_locked(struct ceph_osd_linger_request *lreq)
+{
+	WARN_ON(!mutex_is_locked(&lreq->lock));
+}
+#else
+static inline void verify_osdc_locked(struct ceph_osd_client *osdc) { }
+static inline void verify_osdc_wrlocked(struct ceph_osd_client *osdc) { }
+static inline void verify_osd_locked(struct ceph_osd *osd) { }
+static inline void verify_lreq_locked(struct ceph_osd_linger_request *lreq) { }
+#endif
+
+/*
+ * calculate the mapping of a file extent onto an object, and fill out the
+ * request accordingly.  shorten extent as necessary if it crosses an
+ * object boundary.
+ *
+ * fill osd op in request message.
+ */
+static int calc_layout(struct ceph_file_layout *layout, u64 off, u64 *plen,
+			u64 *objnum, u64 *objoff, u64 *objlen)
+{
+	u64 orig_len = *plen;
+	u32 xlen;
+
+	/* object extent? */
+	ceph_calc_file_object_mapping(layout, off, orig_len, objnum,
+					  objoff, &xlen);
+	*objlen = xlen;
+	if (*objlen < orig_len) {
+		*plen = *objlen;
+		dout(" skipping last %llu, final file extent %llu~%llu\n",
+		     orig_len - *plen, off, *plen);
+	}
+
+	dout("calc_layout objnum=%llx %llu~%llu\n", *objnum, *objoff, *objlen);
+	return 0;
+}
+
+static void ceph_osd_data_init(struct ceph_osd_data *osd_data)
+{
+	memset(osd_data, 0, sizeof (*osd_data));
+	osd_data->type = CEPH_OSD_DATA_TYPE_NONE;
+}
+
+static void ceph_osd_data_pages_init(struct ceph_osd_data *osd_data,
+			struct page **pages, u64 length, u32 alignment,
+			bool pages_from_pool, bool own_pages)
+{
+	osd_data->type = CEPH_OSD_DATA_TYPE_PAGES;
+	osd_data->pages = pages;
+	osd_data->length = length;
+	osd_data->alignment = alignment;
+	osd_data->pages_from_pool = pages_from_pool;
+	osd_data->own_pages = own_pages;
+}
+
+static void ceph_osd_data_pagelist_init(struct ceph_osd_data *osd_data,
+			struct ceph_pagelist *pagelist)
+{
+	osd_data->type = CEPH_OSD_DATA_TYPE_PAGELIST;
+	osd_data->pagelist = pagelist;
+}
+
+#ifdef CONFIG_BLOCK
+static void ceph_osd_data_bio_init(struct ceph_osd_data *osd_data,
+				   struct ceph_bio_iter *bio_pos,
+				   u32 bio_length)
+{
+	osd_data->type = CEPH_OSD_DATA_TYPE_BIO;
+	osd_data->bio_pos = *bio_pos;
+	osd_data->bio_length = bio_length;
+}
+#endif /* CONFIG_BLOCK */
+
+static void ceph_osd_data_bvecs_init(struct ceph_osd_data *osd_data,
+				     struct ceph_bvec_iter *bvec_pos,
+				     u32 num_bvecs)
+{
+	osd_data->type = CEPH_OSD_DATA_TYPE_BVECS;
+	osd_data->bvec_pos = *bvec_pos;
+	osd_data->num_bvecs = num_bvecs;
+}
+
+#define osd_req_op_data(oreq, whch, typ, fld)				\
+({									\
+	struct ceph_osd_request *__oreq = (oreq);			\
+	unsigned int __whch = (whch);					\
+	BUG_ON(__whch >= __oreq->r_num_ops);				\
+	&__oreq->r_ops[__whch].typ.fld;					\
+})
+
+static struct ceph_osd_data *
+osd_req_op_raw_data_in(struct ceph_osd_request *osd_req, unsigned int which)
+{
+	BUG_ON(which >= osd_req->r_num_ops);
+
+	return &osd_req->r_ops[which].raw_data_in;
+}
+
+struct ceph_osd_data *
+osd_req_op_extent_osd_data(struct ceph_osd_request *osd_req,
+			unsigned int which)
+{
+	return osd_req_op_data(osd_req, which, extent, osd_data);
+}
+EXPORT_SYMBOL(osd_req_op_extent_osd_data);
+
+void osd_req_op_raw_data_in_pages(struct ceph_osd_request *osd_req,
+			unsigned int which, struct page **pages,
+			u64 length, u32 alignment,
+			bool pages_from_pool, bool own_pages)
+{
+	struct ceph_osd_data *osd_data;
+
+	osd_data = osd_req_op_raw_data_in(osd_req, which);
+	ceph_osd_data_pages_init(osd_data, pages, length, alignment,
+				pages_from_pool, own_pages);
+}
+EXPORT_SYMBOL(osd_req_op_raw_data_in_pages);
+
+void osd_req_op_extent_osd_data_pages(struct ceph_osd_request *osd_req,
+			unsigned int which, struct page **pages,
+			u64 length, u32 alignment,
+			bool pages_from_pool, bool own_pages)
+{
+	struct ceph_osd_data *osd_data;
+
+	osd_data = osd_req_op_data(osd_req, which, extent, osd_data);
+	ceph_osd_data_pages_init(osd_data, pages, length, alignment,
+				pages_from_pool, own_pages);
+}
+EXPORT_SYMBOL(osd_req_op_extent_osd_data_pages);
+
+void osd_req_op_extent_osd_data_pagelist(struct ceph_osd_request *osd_req,
+			unsigned int which, struct ceph_pagelist *pagelist)
+{
+	struct ceph_osd_data *osd_data;
+
+	osd_data = osd_req_op_data(osd_req, which, extent, osd_data);
+	ceph_osd_data_pagelist_init(osd_data, pagelist);
+}
+EXPORT_SYMBOL(osd_req_op_extent_osd_data_pagelist);
+
+#ifdef CONFIG_BLOCK
+void osd_req_op_extent_osd_data_bio(struct ceph_osd_request *osd_req,
+				    unsigned int which,
+				    struct ceph_bio_iter *bio_pos,
+				    u32 bio_length)
+{
+	struct ceph_osd_data *osd_data;
+
+	osd_data = osd_req_op_data(osd_req, which, extent, osd_data);
+	ceph_osd_data_bio_init(osd_data, bio_pos, bio_length);
+}
+EXPORT_SYMBOL(osd_req_op_extent_osd_data_bio);
+#endif /* CONFIG_BLOCK */
+
+void osd_req_op_extent_osd_data_bvecs(struct ceph_osd_request *osd_req,
+				      unsigned int which,
+				      struct bio_vec *bvecs, u32 num_bvecs,
+				      u32 bytes)
+{
+	struct ceph_osd_data *osd_data;
+	struct ceph_bvec_iter it = {
+		.bvecs = bvecs,
+		.iter = { .bi_size = bytes },
+	};
+
+	osd_data = osd_req_op_data(osd_req, which, extent, osd_data);
+	ceph_osd_data_bvecs_init(osd_data, &it, num_bvecs);
+}
+EXPORT_SYMBOL(osd_req_op_extent_osd_data_bvecs);
+
+void osd_req_op_extent_osd_data_bvec_pos(struct ceph_osd_request *osd_req,
+					 unsigned int which,
+					 struct ceph_bvec_iter *bvec_pos)
+{
+	struct ceph_osd_data *osd_data;
+
+	osd_data = osd_req_op_data(osd_req, which, extent, osd_data);
+	ceph_osd_data_bvecs_init(osd_data, bvec_pos, 0);
+}
+EXPORT_SYMBOL(osd_req_op_extent_osd_data_bvec_pos);
+
+static void osd_req_op_cls_request_info_pagelist(
+			struct ceph_osd_request *osd_req,
+			unsigned int which, struct ceph_pagelist *pagelist)
+{
+	struct ceph_osd_data *osd_data;
+
+	osd_data = osd_req_op_data(osd_req, which, cls, request_info);
+	ceph_osd_data_pagelist_init(osd_data, pagelist);
+}
+
+void osd_req_op_cls_request_data_pagelist(
+			struct ceph_osd_request *osd_req,
+			unsigned int which, struct ceph_pagelist *pagelist)
+{
+	struct ceph_osd_data *osd_data;
+
+	osd_data = osd_req_op_data(osd_req, which, cls, request_data);
+	ceph_osd_data_pagelist_init(osd_data, pagelist);
+	osd_req->r_ops[which].cls.indata_len += pagelist->length;
+	osd_req->r_ops[which].indata_len += pagelist->length;
+}
+EXPORT_SYMBOL(osd_req_op_cls_request_data_pagelist);
+
+void osd_req_op_cls_request_data_pages(struct ceph_osd_request *osd_req,
+			unsigned int which, struct page **pages, u64 length,
+			u32 alignment, bool pages_from_pool, bool own_pages)
+{
+	struct ceph_osd_data *osd_data;
+
+	osd_data = osd_req_op_data(osd_req, which, cls, request_data);
+	ceph_osd_data_pages_init(osd_data, pages, length, alignment,
+				pages_from_pool, own_pages);
+	osd_req->r_ops[which].cls.indata_len += length;
+	osd_req->r_ops[which].indata_len += length;
+}
+EXPORT_SYMBOL(osd_req_op_cls_request_data_pages);
+
+void osd_req_op_cls_request_data_bvecs(struct ceph_osd_request *osd_req,
+				       unsigned int which,
+				       struct bio_vec *bvecs, u32 num_bvecs,
+				       u32 bytes)
+{
+	struct ceph_osd_data *osd_data;
+	struct ceph_bvec_iter it = {
+		.bvecs = bvecs,
+		.iter = { .bi_size = bytes },
+	};
+
+	osd_data = osd_req_op_data(osd_req, which, cls, request_data);
+	ceph_osd_data_bvecs_init(osd_data, &it, num_bvecs);
+	osd_req->r_ops[which].cls.indata_len += bytes;
+	osd_req->r_ops[which].indata_len += bytes;
+}
+EXPORT_SYMBOL(osd_req_op_cls_request_data_bvecs);
+
+void osd_req_op_cls_response_data_pages(struct ceph_osd_request *osd_req,
+			unsigned int which, struct page **pages, u64 length,
+			u32 alignment, bool pages_from_pool, bool own_pages)
+{
+	struct ceph_osd_data *osd_data;
+
+	osd_data = osd_req_op_data(osd_req, which, cls, response_data);
+	ceph_osd_data_pages_init(osd_data, pages, length, alignment,
+				pages_from_pool, own_pages);
+}
+EXPORT_SYMBOL(osd_req_op_cls_response_data_pages);
+
+static u64 ceph_osd_data_length(struct ceph_osd_data *osd_data)
+{
+	switch (osd_data->type) {
+	case CEPH_OSD_DATA_TYPE_NONE:
+		return 0;
+	case CEPH_OSD_DATA_TYPE_PAGES:
+		return osd_data->length;
+	case CEPH_OSD_DATA_TYPE_PAGELIST:
+		return (u64)osd_data->pagelist->length;
+#ifdef CONFIG_BLOCK
+	case CEPH_OSD_DATA_TYPE_BIO:
+		return (u64)osd_data->bio_length;
+#endif /* CONFIG_BLOCK */
+	case CEPH_OSD_DATA_TYPE_BVECS:
+		return osd_data->bvec_pos.iter.bi_size;
+	default:
+		WARN(true, "unrecognized data type %d\n", (int)osd_data->type);
+		return 0;
+	}
+}
+
+static void ceph_osd_data_release(struct ceph_osd_data *osd_data)
+{
+	if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGES && osd_data->own_pages) {
+		int num_pages;
+
+		num_pages = calc_pages_for((u64)osd_data->alignment,
+						(u64)osd_data->length);
+		ceph_release_page_vector(osd_data->pages, num_pages);
+	}
+	ceph_osd_data_init(osd_data);
+}
+
+static void osd_req_op_data_release(struct ceph_osd_request *osd_req,
+			unsigned int which)
+{
+	struct ceph_osd_req_op *op;
+
+	BUG_ON(which >= osd_req->r_num_ops);
+	op = &osd_req->r_ops[which];
+
+	switch (op->op) {
+	case CEPH_OSD_OP_READ:
+	case CEPH_OSD_OP_WRITE:
+	case CEPH_OSD_OP_WRITEFULL:
+		ceph_osd_data_release(&op->extent.osd_data);
+		break;
+	case CEPH_OSD_OP_CALL:
+		ceph_osd_data_release(&op->cls.request_info);
+		ceph_osd_data_release(&op->cls.request_data);
+		ceph_osd_data_release(&op->cls.response_data);
+		break;
+	case CEPH_OSD_OP_SETXATTR:
+	case CEPH_OSD_OP_CMPXATTR:
+		ceph_osd_data_release(&op->xattr.osd_data);
+		break;
+	case CEPH_OSD_OP_STAT:
+		ceph_osd_data_release(&op->raw_data_in);
+		break;
+	case CEPH_OSD_OP_NOTIFY_ACK:
+		ceph_osd_data_release(&op->notify_ack.request_data);
+		break;
+	case CEPH_OSD_OP_NOTIFY:
+		ceph_osd_data_release(&op->notify.request_data);
+		ceph_osd_data_release(&op->notify.response_data);
+		break;
+	case CEPH_OSD_OP_LIST_WATCHERS:
+		ceph_osd_data_release(&op->list_watchers.response_data);
+		break;
+	default:
+		break;
+	}
+}
+
+/*
+ * Assumes @t is zero-initialized.
+ */
+static void target_init(struct ceph_osd_request_target *t)
+{
+	ceph_oid_init(&t->base_oid);
+	ceph_oloc_init(&t->base_oloc);
+	ceph_oid_init(&t->target_oid);
+	ceph_oloc_init(&t->target_oloc);
+
+	ceph_osds_init(&t->acting);
+	ceph_osds_init(&t->up);
+	t->size = -1;
+	t->min_size = -1;
+
+	t->osd = CEPH_HOMELESS_OSD;
+}
+
+static void target_copy(struct ceph_osd_request_target *dest,
+			const struct ceph_osd_request_target *src)
+{
+	ceph_oid_copy(&dest->base_oid, &src->base_oid);
+	ceph_oloc_copy(&dest->base_oloc, &src->base_oloc);
+	ceph_oid_copy(&dest->target_oid, &src->target_oid);
+	ceph_oloc_copy(&dest->target_oloc, &src->target_oloc);
+
+	dest->pgid = src->pgid; /* struct */
+	dest->spgid = src->spgid; /* struct */
+	dest->pg_num = src->pg_num;
+	dest->pg_num_mask = src->pg_num_mask;
+	ceph_osds_copy(&dest->acting, &src->acting);
+	ceph_osds_copy(&dest->up, &src->up);
+	dest->size = src->size;
+	dest->min_size = src->min_size;
+	dest->sort_bitwise = src->sort_bitwise;
+	dest->recovery_deletes = src->recovery_deletes;
+
+	dest->flags = src->flags;
+	dest->paused = src->paused;
+
+	dest->epoch = src->epoch;
+	dest->last_force_resend = src->last_force_resend;
+
+	dest->osd = src->osd;
+}
+
+static void target_destroy(struct ceph_osd_request_target *t)
+{
+	ceph_oid_destroy(&t->base_oid);
+	ceph_oloc_destroy(&t->base_oloc);
+	ceph_oid_destroy(&t->target_oid);
+	ceph_oloc_destroy(&t->target_oloc);
+}
+
+/*
+ * requests
+ */
+static void request_release_checks(struct ceph_osd_request *req)
+{
+	WARN_ON(!RB_EMPTY_NODE(&req->r_node));
+	WARN_ON(!RB_EMPTY_NODE(&req->r_mc_node));
+	WARN_ON(!list_empty(&req->r_unsafe_item));
+	WARN_ON(req->r_osd);
+}
+
+static void ceph_osdc_release_request(struct kref *kref)
+{
+	struct ceph_osd_request *req = container_of(kref,
+					    struct ceph_osd_request, r_kref);
+	unsigned int which;
+
+	dout("%s %p (r_request %p r_reply %p)\n", __func__, req,
+	     req->r_request, req->r_reply);
+	request_release_checks(req);
+
+	if (req->r_request)
+		ceph_msg_put(req->r_request);
+	if (req->r_reply)
+		ceph_msg_put(req->r_reply);
+
+	for (which = 0; which < req->r_num_ops; which++)
+		osd_req_op_data_release(req, which);
+
+	target_destroy(&req->r_t);
+	ceph_put_snap_context(req->r_snapc);
+
+	if (req->r_mempool)
+		mempool_free(req, req->r_osdc->req_mempool);
+	else if (req->r_num_ops <= CEPH_OSD_SLAB_OPS)
+		kmem_cache_free(ceph_osd_request_cache, req);
+	else
+		kfree(req);
+}
+
+void ceph_osdc_get_request(struct ceph_osd_request *req)
+{
+	dout("%s %p (was %d)\n", __func__, req,
+	     kref_read(&req->r_kref));
+	kref_get(&req->r_kref);
+}
+EXPORT_SYMBOL(ceph_osdc_get_request);
+
+void ceph_osdc_put_request(struct ceph_osd_request *req)
+{
+	if (req) {
+		dout("%s %p (was %d)\n", __func__, req,
+		     kref_read(&req->r_kref));
+		kref_put(&req->r_kref, ceph_osdc_release_request);
+	}
+}
+EXPORT_SYMBOL(ceph_osdc_put_request);
+
+static void request_init(struct ceph_osd_request *req)
+{
+	/* req only, each op is zeroed in _osd_req_op_init() */
+	memset(req, 0, sizeof(*req));
+
+	kref_init(&req->r_kref);
+	init_completion(&req->r_completion);
+	RB_CLEAR_NODE(&req->r_node);
+	RB_CLEAR_NODE(&req->r_mc_node);
+	INIT_LIST_HEAD(&req->r_unsafe_item);
+
+	target_init(&req->r_t);
+}
+
+/*
+ * This is ugly, but it allows us to reuse linger registration and ping
+ * requests, keeping the structure of the code around send_linger{_ping}()
+ * reasonable.  Setting up a min_nr=2 mempool for each linger request
+ * and dealing with copying ops (this blasts req only, watch op remains
+ * intact) isn't any better.
+ */
+static void request_reinit(struct ceph_osd_request *req)
+{
+	struct ceph_osd_client *osdc = req->r_osdc;
+	bool mempool = req->r_mempool;
+	unsigned int num_ops = req->r_num_ops;
+	u64 snapid = req->r_snapid;
+	struct ceph_snap_context *snapc = req->r_snapc;
+	bool linger = req->r_linger;
+	struct ceph_msg *request_msg = req->r_request;
+	struct ceph_msg *reply_msg = req->r_reply;
+
+	dout("%s req %p\n", __func__, req);
+	WARN_ON(kref_read(&req->r_kref) != 1);
+	request_release_checks(req);
+
+	WARN_ON(kref_read(&request_msg->kref) != 1);
+	WARN_ON(kref_read(&reply_msg->kref) != 1);
+	target_destroy(&req->r_t);
+
+	request_init(req);
+	req->r_osdc = osdc;
+	req->r_mempool = mempool;
+	req->r_num_ops = num_ops;
+	req->r_snapid = snapid;
+	req->r_snapc = snapc;
+	req->r_linger = linger;
+	req->r_request = request_msg;
+	req->r_reply = reply_msg;
+}
+
+struct ceph_osd_request *ceph_osdc_alloc_request(struct ceph_osd_client *osdc,
+					       struct ceph_snap_context *snapc,
+					       unsigned int num_ops,
+					       bool use_mempool,
+					       gfp_t gfp_flags)
+{
+	struct ceph_osd_request *req;
+
+	if (use_mempool) {
+		BUG_ON(num_ops > CEPH_OSD_SLAB_OPS);
+		req = mempool_alloc(osdc->req_mempool, gfp_flags);
+	} else if (num_ops <= CEPH_OSD_SLAB_OPS) {
+		req = kmem_cache_alloc(ceph_osd_request_cache, gfp_flags);
+	} else {
+		BUG_ON(num_ops > CEPH_OSD_MAX_OPS);
+		req = kmalloc(struct_size(req, r_ops, num_ops), gfp_flags);
+	}
+	if (unlikely(!req))
+		return NULL;
+
+	request_init(req);
+	req->r_osdc = osdc;
+	req->r_mempool = use_mempool;
+	req->r_num_ops = num_ops;
+	req->r_snapid = CEPH_NOSNAP;
+	req->r_snapc = ceph_get_snap_context(snapc);
+
+	dout("%s req %p\n", __func__, req);
+	return req;
+}
+EXPORT_SYMBOL(ceph_osdc_alloc_request);
+
+static int ceph_oloc_encoding_size(const struct ceph_object_locator *oloc)
+{
+	return 8 + 4 + 4 + 4 + (oloc->pool_ns ? oloc->pool_ns->len : 0);
+}
+
+int ceph_osdc_alloc_messages(struct ceph_osd_request *req, gfp_t gfp)
+{
+	struct ceph_osd_client *osdc = req->r_osdc;
+	struct ceph_msg *msg;
+	int msg_size;
+
+	WARN_ON(ceph_oid_empty(&req->r_base_oid));
+	WARN_ON(ceph_oloc_empty(&req->r_base_oloc));
+
+	/* create request message */
+	msg_size = CEPH_ENCODING_START_BLK_LEN +
+			CEPH_PGID_ENCODING_LEN + 1; /* spgid */
+	msg_size += 4 + 4 + 4; /* hash, osdmap_epoch, flags */
+	msg_size += CEPH_ENCODING_START_BLK_LEN +
+			sizeof(struct ceph_osd_reqid); /* reqid */
+	msg_size += sizeof(struct ceph_blkin_trace_info); /* trace */
+	msg_size += 4 + sizeof(struct ceph_timespec); /* client_inc, mtime */
+	msg_size += CEPH_ENCODING_START_BLK_LEN +
+			ceph_oloc_encoding_size(&req->r_base_oloc); /* oloc */
+	msg_size += 4 + req->r_base_oid.name_len; /* oid */
+	msg_size += 2 + req->r_num_ops * sizeof(struct ceph_osd_op);
+	msg_size += 8; /* snapid */
+	msg_size += 8; /* snap_seq */
+	msg_size += 4 + 8 * (req->r_snapc ? req->r_snapc->num_snaps : 0);
+	msg_size += 4 + 8; /* retry_attempt, features */
+
+	if (req->r_mempool)
+		msg = ceph_msgpool_get(&osdc->msgpool_op, 0);
+	else
+		msg = ceph_msg_new(CEPH_MSG_OSD_OP, msg_size, gfp, true);
+	if (!msg)
+		return -ENOMEM;
+
+	memset(msg->front.iov_base, 0, msg->front.iov_len);
+	req->r_request = msg;
+
+	/* create reply message */
+	msg_size = OSD_OPREPLY_FRONT_LEN;
+	msg_size += req->r_base_oid.name_len;
+	msg_size += req->r_num_ops * sizeof(struct ceph_osd_op);
+
+	if (req->r_mempool)
+		msg = ceph_msgpool_get(&osdc->msgpool_op_reply, 0);
+	else
+		msg = ceph_msg_new(CEPH_MSG_OSD_OPREPLY, msg_size, gfp, true);
+	if (!msg)
+		return -ENOMEM;
+
+	req->r_reply = msg;
+
+	return 0;
+}
+EXPORT_SYMBOL(ceph_osdc_alloc_messages);
+
+static bool osd_req_opcode_valid(u16 opcode)
+{
+	switch (opcode) {
+#define GENERATE_CASE(op, opcode, str)	case CEPH_OSD_OP_##op: return true;
+__CEPH_FORALL_OSD_OPS(GENERATE_CASE)
+#undef GENERATE_CASE
+	default:
+		return false;
+	}
+}
+
+/*
+ * This is an osd op init function for opcodes that have no data or
+ * other information associated with them.  It also serves as a
+ * common init routine for all the other init functions, below.
+ */
+static struct ceph_osd_req_op *
+_osd_req_op_init(struct ceph_osd_request *osd_req, unsigned int which,
+		 u16 opcode, u32 flags)
+{
+	struct ceph_osd_req_op *op;
+
+	BUG_ON(which >= osd_req->r_num_ops);
+	BUG_ON(!osd_req_opcode_valid(opcode));
+
+	op = &osd_req->r_ops[which];
+	memset(op, 0, sizeof (*op));
+	op->op = opcode;
+	op->flags = flags;
+
+	return op;
+}
+
+void osd_req_op_init(struct ceph_osd_request *osd_req,
+		     unsigned int which, u16 opcode, u32 flags)
+{
+	(void)_osd_req_op_init(osd_req, which, opcode, flags);
+}
+EXPORT_SYMBOL(osd_req_op_init);
+
+void osd_req_op_extent_init(struct ceph_osd_request *osd_req,
+				unsigned int which, u16 opcode,
+				u64 offset, u64 length,
+				u64 truncate_size, u32 truncate_seq)
+{
+	struct ceph_osd_req_op *op = _osd_req_op_init(osd_req, which,
+						      opcode, 0);
+	size_t payload_len = 0;
+
+	BUG_ON(opcode != CEPH_OSD_OP_READ && opcode != CEPH_OSD_OP_WRITE &&
+	       opcode != CEPH_OSD_OP_WRITEFULL && opcode != CEPH_OSD_OP_ZERO &&
+	       opcode != CEPH_OSD_OP_TRUNCATE);
+
+	op->extent.offset = offset;
+	op->extent.length = length;
+	op->extent.truncate_size = truncate_size;
+	op->extent.truncate_seq = truncate_seq;
+	if (opcode == CEPH_OSD_OP_WRITE || opcode == CEPH_OSD_OP_WRITEFULL)
+		payload_len += length;
+
+	op->indata_len = payload_len;
+}
+EXPORT_SYMBOL(osd_req_op_extent_init);
+
+void osd_req_op_extent_update(struct ceph_osd_request *osd_req,
+				unsigned int which, u64 length)
+{
+	struct ceph_osd_req_op *op;
+	u64 previous;
+
+	BUG_ON(which >= osd_req->r_num_ops);
+	op = &osd_req->r_ops[which];
+	previous = op->extent.length;
+
+	if (length == previous)
+		return;		/* Nothing to do */
+	BUG_ON(length > previous);
+
+	op->extent.length = length;
+	if (op->op == CEPH_OSD_OP_WRITE || op->op == CEPH_OSD_OP_WRITEFULL)
+		op->indata_len -= previous - length;
+}
+EXPORT_SYMBOL(osd_req_op_extent_update);
+
+void osd_req_op_extent_dup_last(struct ceph_osd_request *osd_req,
+				unsigned int which, u64 offset_inc)
+{
+	struct ceph_osd_req_op *op, *prev_op;
+
+	BUG_ON(which + 1 >= osd_req->r_num_ops);
+
+	prev_op = &osd_req->r_ops[which];
+	op = _osd_req_op_init(osd_req, which + 1, prev_op->op, prev_op->flags);
+	/* dup previous one */
+	op->indata_len = prev_op->indata_len;
+	op->outdata_len = prev_op->outdata_len;
+	op->extent = prev_op->extent;
+	/* adjust offset */
+	op->extent.offset += offset_inc;
+	op->extent.length -= offset_inc;
+
+	if (op->op == CEPH_OSD_OP_WRITE || op->op == CEPH_OSD_OP_WRITEFULL)
+		op->indata_len -= offset_inc;
+}
+EXPORT_SYMBOL(osd_req_op_extent_dup_last);
+
+int osd_req_op_cls_init(struct ceph_osd_request *osd_req, unsigned int which,
+			u16 opcode, const char *class, const char *method)
+{
+	struct ceph_osd_req_op *op = _osd_req_op_init(osd_req, which,
+						      opcode, 0);
+	struct ceph_pagelist *pagelist;
+	size_t payload_len = 0;
+	size_t size;
+
+	BUG_ON(opcode != CEPH_OSD_OP_CALL);
+
+	pagelist = kmalloc(sizeof (*pagelist), GFP_NOFS);
+	if (!pagelist)
+		return -ENOMEM;
+
+	ceph_pagelist_init(pagelist);
+
+	op->cls.class_name = class;
+	size = strlen(class);
+	BUG_ON(size > (size_t) U8_MAX);
+	op->cls.class_len = size;
+	ceph_pagelist_append(pagelist, class, size);
+	payload_len += size;
+
+	op->cls.method_name = method;
+	size = strlen(method);
+	BUG_ON(size > (size_t) U8_MAX);
+	op->cls.method_len = size;
+	ceph_pagelist_append(pagelist, method, size);
+	payload_len += size;
+
+	osd_req_op_cls_request_info_pagelist(osd_req, which, pagelist);
+
+	op->indata_len = payload_len;
+	return 0;
+}
+EXPORT_SYMBOL(osd_req_op_cls_init);
+
+int osd_req_op_xattr_init(struct ceph_osd_request *osd_req, unsigned int which,
+			  u16 opcode, const char *name, const void *value,
+			  size_t size, u8 cmp_op, u8 cmp_mode)
+{
+	struct ceph_osd_req_op *op = _osd_req_op_init(osd_req, which,
+						      opcode, 0);
+	struct ceph_pagelist *pagelist;
+	size_t payload_len;
+
+	BUG_ON(opcode != CEPH_OSD_OP_SETXATTR && opcode != CEPH_OSD_OP_CMPXATTR);
+
+	pagelist = kmalloc(sizeof(*pagelist), GFP_NOFS);
+	if (!pagelist)
+		return -ENOMEM;
+
+	ceph_pagelist_init(pagelist);
+
+	payload_len = strlen(name);
+	op->xattr.name_len = payload_len;
+	ceph_pagelist_append(pagelist, name, payload_len);
+
+	op->xattr.value_len = size;
+	ceph_pagelist_append(pagelist, value, size);
+	payload_len += size;
+
+	op->xattr.cmp_op = cmp_op;
+	op->xattr.cmp_mode = cmp_mode;
+
+	ceph_osd_data_pagelist_init(&op->xattr.osd_data, pagelist);
+	op->indata_len = payload_len;
+	return 0;
+}
+EXPORT_SYMBOL(osd_req_op_xattr_init);
+
+/*
+ * @watch_opcode: CEPH_OSD_WATCH_OP_*
+ */
+static void osd_req_op_watch_init(struct ceph_osd_request *req, int which,
+				  u64 cookie, u8 watch_opcode)
+{
+	struct ceph_osd_req_op *op;
+
+	op = _osd_req_op_init(req, which, CEPH_OSD_OP_WATCH, 0);
+	op->watch.cookie = cookie;
+	op->watch.op = watch_opcode;
+	op->watch.gen = 0;
+}
+
+void osd_req_op_alloc_hint_init(struct ceph_osd_request *osd_req,
+				unsigned int which,
+				u64 expected_object_size,
+				u64 expected_write_size)
+{
+	struct ceph_osd_req_op *op = _osd_req_op_init(osd_req, which,
+						      CEPH_OSD_OP_SETALLOCHINT,
+						      0);
+
+	op->alloc_hint.expected_object_size = expected_object_size;
+	op->alloc_hint.expected_write_size = expected_write_size;
+
+	/*
+	 * CEPH_OSD_OP_SETALLOCHINT op is advisory and therefore deemed
+	 * not worth a feature bit.  Set FAILOK per-op flag to make
+	 * sure older osds don't trip over an unsupported opcode.
+	 */
+	op->flags |= CEPH_OSD_OP_FLAG_FAILOK;
+}
+EXPORT_SYMBOL(osd_req_op_alloc_hint_init);
+
+static void ceph_osdc_msg_data_add(struct ceph_msg *msg,
+				struct ceph_osd_data *osd_data)
+{
+	u64 length = ceph_osd_data_length(osd_data);
+
+	if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGES) {
+		BUG_ON(length > (u64) SIZE_MAX);
+		if (length)
+			ceph_msg_data_add_pages(msg, osd_data->pages,
+					length, osd_data->alignment);
+	} else if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGELIST) {
+		BUG_ON(!length);
+		ceph_msg_data_add_pagelist(msg, osd_data->pagelist);
+#ifdef CONFIG_BLOCK
+	} else if (osd_data->type == CEPH_OSD_DATA_TYPE_BIO) {
+		ceph_msg_data_add_bio(msg, &osd_data->bio_pos, length);
+#endif
+	} else if (osd_data->type == CEPH_OSD_DATA_TYPE_BVECS) {
+		ceph_msg_data_add_bvecs(msg, &osd_data->bvec_pos);
+	} else {
+		BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_NONE);
+	}
+}
+
+static u32 osd_req_encode_op(struct ceph_osd_op *dst,
+			     const struct ceph_osd_req_op *src)
+{
+	if (WARN_ON(!osd_req_opcode_valid(src->op))) {
+		pr_err("unrecognized osd opcode %d\n", src->op);
+
+		return 0;
+	}
+
+	switch (src->op) {
+	case CEPH_OSD_OP_STAT:
+		break;
+	case CEPH_OSD_OP_READ:
+	case CEPH_OSD_OP_WRITE:
+	case CEPH_OSD_OP_WRITEFULL:
+	case CEPH_OSD_OP_ZERO:
+	case CEPH_OSD_OP_TRUNCATE:
+		dst->extent.offset = cpu_to_le64(src->extent.offset);
+		dst->extent.length = cpu_to_le64(src->extent.length);
+		dst->extent.truncate_size =
+			cpu_to_le64(src->extent.truncate_size);
+		dst->extent.truncate_seq =
+			cpu_to_le32(src->extent.truncate_seq);
+		break;
+	case CEPH_OSD_OP_CALL:
+		dst->cls.class_len = src->cls.class_len;
+		dst->cls.method_len = src->cls.method_len;
+		dst->cls.indata_len = cpu_to_le32(src->cls.indata_len);
+		break;
+	case CEPH_OSD_OP_WATCH:
+		dst->watch.cookie = cpu_to_le64(src->watch.cookie);
+		dst->watch.ver = cpu_to_le64(0);
+		dst->watch.op = src->watch.op;
+		dst->watch.gen = cpu_to_le32(src->watch.gen);
+		break;
+	case CEPH_OSD_OP_NOTIFY_ACK:
+		break;
+	case CEPH_OSD_OP_NOTIFY:
+		dst->notify.cookie = cpu_to_le64(src->notify.cookie);
+		break;
+	case CEPH_OSD_OP_LIST_WATCHERS:
+		break;
+	case CEPH_OSD_OP_SETALLOCHINT:
+		dst->alloc_hint.expected_object_size =
+		    cpu_to_le64(src->alloc_hint.expected_object_size);
+		dst->alloc_hint.expected_write_size =
+		    cpu_to_le64(src->alloc_hint.expected_write_size);
+		break;
+	case CEPH_OSD_OP_SETXATTR:
+	case CEPH_OSD_OP_CMPXATTR:
+		dst->xattr.name_len = cpu_to_le32(src->xattr.name_len);
+		dst->xattr.value_len = cpu_to_le32(src->xattr.value_len);
+		dst->xattr.cmp_op = src->xattr.cmp_op;
+		dst->xattr.cmp_mode = src->xattr.cmp_mode;
+		break;
+	case CEPH_OSD_OP_CREATE:
+	case CEPH_OSD_OP_DELETE:
+		break;
+	default:
+		pr_err("unsupported osd opcode %s\n",
+			ceph_osd_op_name(src->op));
+		WARN_ON(1);
+
+		return 0;
+	}
+
+	dst->op = cpu_to_le16(src->op);
+	dst->flags = cpu_to_le32(src->flags);
+	dst->payload_len = cpu_to_le32(src->indata_len);
+
+	return src->indata_len;
+}
+
+/*
+ * build new request AND message, calculate layout, and adjust file
+ * extent as needed.
+ *
+ * if the file was recently truncated, we include information about its
+ * old and new size so that the object can be updated appropriately.  (we
+ * avoid synchronously deleting truncated objects because it's slow.)
+ */
+struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *osdc,
+					       struct ceph_file_layout *layout,
+					       struct ceph_vino vino,
+					       u64 off, u64 *plen,
+					       unsigned int which, int num_ops,
+					       int opcode, int flags,
+					       struct ceph_snap_context *snapc,
+					       u32 truncate_seq,
+					       u64 truncate_size,
+					       bool use_mempool)
+{
+	struct ceph_osd_request *req;
+	u64 objnum = 0;
+	u64 objoff = 0;
+	u64 objlen = 0;
+	int r;
+
+	BUG_ON(opcode != CEPH_OSD_OP_READ && opcode != CEPH_OSD_OP_WRITE &&
+	       opcode != CEPH_OSD_OP_ZERO && opcode != CEPH_OSD_OP_TRUNCATE &&
+	       opcode != CEPH_OSD_OP_CREATE && opcode != CEPH_OSD_OP_DELETE);
+
+	req = ceph_osdc_alloc_request(osdc, snapc, num_ops, use_mempool,
+					GFP_NOFS);
+	if (!req) {
+		r = -ENOMEM;
+		goto fail;
+	}
+
+	/* calculate max write size */
+	r = calc_layout(layout, off, plen, &objnum, &objoff, &objlen);
+	if (r)
+		goto fail;
+
+	if (opcode == CEPH_OSD_OP_CREATE || opcode == CEPH_OSD_OP_DELETE) {
+		osd_req_op_init(req, which, opcode, 0);
+	} else {
+		u32 object_size = layout->object_size;
+		u32 object_base = off - objoff;
+		if (!(truncate_seq == 1 && truncate_size == -1ULL)) {
+			if (truncate_size <= object_base) {
+				truncate_size = 0;
+			} else {
+				truncate_size -= object_base;
+				if (truncate_size > object_size)
+					truncate_size = object_size;
+			}
+		}
+		osd_req_op_extent_init(req, which, opcode, objoff, objlen,
+				       truncate_size, truncate_seq);
+	}
+
+	req->r_flags = flags;
+	req->r_base_oloc.pool = layout->pool_id;
+	req->r_base_oloc.pool_ns = ceph_try_get_string(layout->pool_ns);
+	ceph_oid_printf(&req->r_base_oid, "%llx.%08llx", vino.ino, objnum);
+
+	req->r_snapid = vino.snap;
+	if (flags & CEPH_OSD_FLAG_WRITE)
+		req->r_data_offset = off;
+
+	r = ceph_osdc_alloc_messages(req, GFP_NOFS);
+	if (r)
+		goto fail;
+
+	return req;
+
+fail:
+	ceph_osdc_put_request(req);
+	return ERR_PTR(r);
+}
+EXPORT_SYMBOL(ceph_osdc_new_request);
+
+/*
+ * We keep osd requests in an rbtree, sorted by ->r_tid.
+ */
+DEFINE_RB_FUNCS(request, struct ceph_osd_request, r_tid, r_node)
+DEFINE_RB_FUNCS(request_mc, struct ceph_osd_request, r_tid, r_mc_node)
+
+/*
+ * Call @fn on each OSD request as long as @fn returns 0.
+ */
+static void for_each_request(struct ceph_osd_client *osdc,
+			int (*fn)(struct ceph_osd_request *req, void *arg),
+			void *arg)
+{
+	struct rb_node *n, *p;
+
+	for (n = rb_first(&osdc->osds); n; n = rb_next(n)) {
+		struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
+
+		for (p = rb_first(&osd->o_requests); p; ) {
+			struct ceph_osd_request *req =
+			    rb_entry(p, struct ceph_osd_request, r_node);
+
+			p = rb_next(p);
+			if (fn(req, arg))
+				return;
+		}
+	}
+
+	for (p = rb_first(&osdc->homeless_osd.o_requests); p; ) {
+		struct ceph_osd_request *req =
+		    rb_entry(p, struct ceph_osd_request, r_node);
+
+		p = rb_next(p);
+		if (fn(req, arg))
+			return;
+	}
+}
+
+static bool osd_homeless(struct ceph_osd *osd)
+{
+	return osd->o_osd == CEPH_HOMELESS_OSD;
+}
+
+static bool osd_registered(struct ceph_osd *osd)
+{
+	verify_osdc_locked(osd->o_osdc);
+
+	return !RB_EMPTY_NODE(&osd->o_node);
+}
+
+/*
+ * Assumes @osd is zero-initialized.
+ */
+static void osd_init(struct ceph_osd *osd)
+{
+	refcount_set(&osd->o_ref, 1);
+	RB_CLEAR_NODE(&osd->o_node);
+	osd->o_requests = RB_ROOT;
+	osd->o_linger_requests = RB_ROOT;
+	osd->o_backoff_mappings = RB_ROOT;
+	osd->o_backoffs_by_id = RB_ROOT;
+	INIT_LIST_HEAD(&osd->o_osd_lru);
+	INIT_LIST_HEAD(&osd->o_keepalive_item);
+	osd->o_incarnation = 1;
+	mutex_init(&osd->lock);
+}
+
+static void osd_cleanup(struct ceph_osd *osd)
+{
+	WARN_ON(!RB_EMPTY_NODE(&osd->o_node));
+	WARN_ON(!RB_EMPTY_ROOT(&osd->o_requests));
+	WARN_ON(!RB_EMPTY_ROOT(&osd->o_linger_requests));
+	WARN_ON(!RB_EMPTY_ROOT(&osd->o_backoff_mappings));
+	WARN_ON(!RB_EMPTY_ROOT(&osd->o_backoffs_by_id));
+	WARN_ON(!list_empty(&osd->o_osd_lru));
+	WARN_ON(!list_empty(&osd->o_keepalive_item));
+
+	if (osd->o_auth.authorizer) {
+		WARN_ON(osd_homeless(osd));
+		ceph_auth_destroy_authorizer(osd->o_auth.authorizer);
+	}
+}
+
+/*
+ * Track open sessions with osds.
+ */
+static struct ceph_osd *create_osd(struct ceph_osd_client *osdc, int onum)
+{
+	struct ceph_osd *osd;
+
+	WARN_ON(onum == CEPH_HOMELESS_OSD);
+
+	osd = kzalloc(sizeof(*osd), GFP_NOIO | __GFP_NOFAIL);
+	osd_init(osd);
+	osd->o_osdc = osdc;
+	osd->o_osd = onum;
+
+	ceph_con_init(&osd->o_con, osd, &osd_con_ops, &osdc->client->msgr);
+
+	return osd;
+}
+
+static struct ceph_osd *get_osd(struct ceph_osd *osd)
+{
+	if (refcount_inc_not_zero(&osd->o_ref)) {
+		dout("get_osd %p %d -> %d\n", osd, refcount_read(&osd->o_ref)-1,
+		     refcount_read(&osd->o_ref));
+		return osd;
+	} else {
+		dout("get_osd %p FAIL\n", osd);
+		return NULL;
+	}
+}
+
+static void put_osd(struct ceph_osd *osd)
+{
+	dout("put_osd %p %d -> %d\n", osd, refcount_read(&osd->o_ref),
+	     refcount_read(&osd->o_ref) - 1);
+	if (refcount_dec_and_test(&osd->o_ref)) {
+		osd_cleanup(osd);
+		kfree(osd);
+	}
+}
+
+DEFINE_RB_FUNCS(osd, struct ceph_osd, o_osd, o_node)
+
+static void __move_osd_to_lru(struct ceph_osd *osd)
+{
+	struct ceph_osd_client *osdc = osd->o_osdc;
+
+	dout("%s osd %p osd%d\n", __func__, osd, osd->o_osd);
+	BUG_ON(!list_empty(&osd->o_osd_lru));
+
+	spin_lock(&osdc->osd_lru_lock);
+	list_add_tail(&osd->o_osd_lru, &osdc->osd_lru);
+	spin_unlock(&osdc->osd_lru_lock);
+
+	osd->lru_ttl = jiffies + osdc->client->options->osd_idle_ttl;
+}
+
+static void maybe_move_osd_to_lru(struct ceph_osd *osd)
+{
+	if (RB_EMPTY_ROOT(&osd->o_requests) &&
+	    RB_EMPTY_ROOT(&osd->o_linger_requests))
+		__move_osd_to_lru(osd);
+}
+
+static void __remove_osd_from_lru(struct ceph_osd *osd)
+{
+	struct ceph_osd_client *osdc = osd->o_osdc;
+
+	dout("%s osd %p osd%d\n", __func__, osd, osd->o_osd);
+
+	spin_lock(&osdc->osd_lru_lock);
+	if (!list_empty(&osd->o_osd_lru))
+		list_del_init(&osd->o_osd_lru);
+	spin_unlock(&osdc->osd_lru_lock);
+}
+
+/*
+ * Close the connection and assign any leftover requests to the
+ * homeless session.
+ */
+static void close_osd(struct ceph_osd *osd)
+{
+	struct ceph_osd_client *osdc = osd->o_osdc;
+	struct rb_node *n;
+
+	verify_osdc_wrlocked(osdc);
+	dout("%s osd %p osd%d\n", __func__, osd, osd->o_osd);
+
+	ceph_con_close(&osd->o_con);
+
+	for (n = rb_first(&osd->o_requests); n; ) {
+		struct ceph_osd_request *req =
+		    rb_entry(n, struct ceph_osd_request, r_node);
+
+		n = rb_next(n); /* unlink_request() */
+
+		dout(" reassigning req %p tid %llu\n", req, req->r_tid);
+		unlink_request(osd, req);
+		link_request(&osdc->homeless_osd, req);
+	}
+	for (n = rb_first(&osd->o_linger_requests); n; ) {
+		struct ceph_osd_linger_request *lreq =
+		    rb_entry(n, struct ceph_osd_linger_request, node);
+
+		n = rb_next(n); /* unlink_linger() */
+
+		dout(" reassigning lreq %p linger_id %llu\n", lreq,
+		     lreq->linger_id);
+		unlink_linger(osd, lreq);
+		link_linger(&osdc->homeless_osd, lreq);
+	}
+	clear_backoffs(osd);
+
+	__remove_osd_from_lru(osd);
+	erase_osd(&osdc->osds, osd);
+	put_osd(osd);
+}
+
+/*
+ * reset osd connect
+ */
+static int reopen_osd(struct ceph_osd *osd)
+{
+	struct ceph_entity_addr *peer_addr;
+
+	dout("%s osd %p osd%d\n", __func__, osd, osd->o_osd);
+
+	if (RB_EMPTY_ROOT(&osd->o_requests) &&
+	    RB_EMPTY_ROOT(&osd->o_linger_requests)) {
+		close_osd(osd);
+		return -ENODEV;
+	}
+
+	peer_addr = &osd->o_osdc->osdmap->osd_addr[osd->o_osd];
+	if (!memcmp(peer_addr, &osd->o_con.peer_addr, sizeof (*peer_addr)) &&
+			!ceph_con_opened(&osd->o_con)) {
+		struct rb_node *n;
+
+		dout("osd addr hasn't changed and connection never opened, "
+		     "letting msgr retry\n");
+		/* touch each r_stamp for handle_timeout()'s benfit */
+		for (n = rb_first(&osd->o_requests); n; n = rb_next(n)) {
+			struct ceph_osd_request *req =
+			    rb_entry(n, struct ceph_osd_request, r_node);
+			req->r_stamp = jiffies;
+		}
+
+		return -EAGAIN;
+	}
+
+	ceph_con_close(&osd->o_con);
+	ceph_con_open(&osd->o_con, CEPH_ENTITY_TYPE_OSD, osd->o_osd, peer_addr);
+	osd->o_incarnation++;
+
+	return 0;
+}
+
+static struct ceph_osd *lookup_create_osd(struct ceph_osd_client *osdc, int o,
+					  bool wrlocked)
+{
+	struct ceph_osd *osd;
+
+	if (wrlocked)
+		verify_osdc_wrlocked(osdc);
+	else
+		verify_osdc_locked(osdc);
+
+	if (o != CEPH_HOMELESS_OSD)
+		osd = lookup_osd(&osdc->osds, o);
+	else
+		osd = &osdc->homeless_osd;
+	if (!osd) {
+		if (!wrlocked)
+			return ERR_PTR(-EAGAIN);
+
+		osd = create_osd(osdc, o);
+		insert_osd(&osdc->osds, osd);
+		ceph_con_open(&osd->o_con, CEPH_ENTITY_TYPE_OSD, osd->o_osd,
+			      &osdc->osdmap->osd_addr[osd->o_osd]);
+	}
+
+	dout("%s osdc %p osd%d -> osd %p\n", __func__, osdc, o, osd);
+	return osd;
+}
+
+/*
+ * Create request <-> OSD session relation.
+ *
+ * @req has to be assigned a tid, @osd may be homeless.
+ */
+static void link_request(struct ceph_osd *osd, struct ceph_osd_request *req)
+{
+	verify_osd_locked(osd);
+	WARN_ON(!req->r_tid || req->r_osd);
+	dout("%s osd %p osd%d req %p tid %llu\n", __func__, osd, osd->o_osd,
+	     req, req->r_tid);
+
+	if (!osd_homeless(osd))
+		__remove_osd_from_lru(osd);
+	else
+		atomic_inc(&osd->o_osdc->num_homeless);
+
+	get_osd(osd);
+	insert_request(&osd->o_requests, req);
+	req->r_osd = osd;
+}
+
+static void unlink_request(struct ceph_osd *osd, struct ceph_osd_request *req)
+{
+	verify_osd_locked(osd);
+	WARN_ON(req->r_osd != osd);
+	dout("%s osd %p osd%d req %p tid %llu\n", __func__, osd, osd->o_osd,
+	     req, req->r_tid);
+
+	req->r_osd = NULL;
+	erase_request(&osd->o_requests, req);
+	put_osd(osd);
+
+	if (!osd_homeless(osd))
+		maybe_move_osd_to_lru(osd);
+	else
+		atomic_dec(&osd->o_osdc->num_homeless);
+}
+
+static bool __pool_full(struct ceph_pg_pool_info *pi)
+{
+	return pi->flags & CEPH_POOL_FLAG_FULL;
+}
+
+static bool have_pool_full(struct ceph_osd_client *osdc)
+{
+	struct rb_node *n;
+
+	for (n = rb_first(&osdc->osdmap->pg_pools); n; n = rb_next(n)) {
+		struct ceph_pg_pool_info *pi =
+		    rb_entry(n, struct ceph_pg_pool_info, node);
+
+		if (__pool_full(pi))
+			return true;
+	}
+
+	return false;
+}
+
+static bool pool_full(struct ceph_osd_client *osdc, s64 pool_id)
+{
+	struct ceph_pg_pool_info *pi;
+
+	pi = ceph_pg_pool_by_id(osdc->osdmap, pool_id);
+	if (!pi)
+		return false;
+
+	return __pool_full(pi);
+}
+
+/*
+ * Returns whether a request should be blocked from being sent
+ * based on the current osdmap and osd_client settings.
+ */
+static bool target_should_be_paused(struct ceph_osd_client *osdc,
+				    const struct ceph_osd_request_target *t,
+				    struct ceph_pg_pool_info *pi)
+{
+	bool pauserd = ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSERD);
+	bool pausewr = ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSEWR) ||
+		       ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL) ||
+		       __pool_full(pi);
+
+	WARN_ON(pi->id != t->target_oloc.pool);
+	return ((t->flags & CEPH_OSD_FLAG_READ) && pauserd) ||
+	       ((t->flags & CEPH_OSD_FLAG_WRITE) && pausewr) ||
+	       (osdc->osdmap->epoch < osdc->epoch_barrier);
+}
+
+enum calc_target_result {
+	CALC_TARGET_NO_ACTION = 0,
+	CALC_TARGET_NEED_RESEND,
+	CALC_TARGET_POOL_DNE,
+};
+
+static enum calc_target_result calc_target(struct ceph_osd_client *osdc,
+					   struct ceph_osd_request_target *t,
+					   struct ceph_connection *con,
+					   bool any_change)
+{
+	struct ceph_pg_pool_info *pi;
+	struct ceph_pg pgid, last_pgid;
+	struct ceph_osds up, acting;
+	bool force_resend = false;
+	bool unpaused = false;
+	bool legacy_change = false;
+	bool split = false;
+	bool sort_bitwise = ceph_osdmap_flag(osdc, CEPH_OSDMAP_SORTBITWISE);
+	bool recovery_deletes = ceph_osdmap_flag(osdc,
+						 CEPH_OSDMAP_RECOVERY_DELETES);
+	enum calc_target_result ct_res;
+
+	t->epoch = osdc->osdmap->epoch;
+	pi = ceph_pg_pool_by_id(osdc->osdmap, t->base_oloc.pool);
+	if (!pi) {
+		t->osd = CEPH_HOMELESS_OSD;
+		ct_res = CALC_TARGET_POOL_DNE;
+		goto out;
+	}
+
+	if (osdc->osdmap->epoch == pi->last_force_request_resend) {
+		if (t->last_force_resend < pi->last_force_request_resend) {
+			t->last_force_resend = pi->last_force_request_resend;
+			force_resend = true;
+		} else if (t->last_force_resend == 0) {
+			force_resend = true;
+		}
+	}
+
+	/* apply tiering */
+	ceph_oid_copy(&t->target_oid, &t->base_oid);
+	ceph_oloc_copy(&t->target_oloc, &t->base_oloc);
+	if ((t->flags & CEPH_OSD_FLAG_IGNORE_OVERLAY) == 0) {
+		if (t->flags & CEPH_OSD_FLAG_READ && pi->read_tier >= 0)
+			t->target_oloc.pool = pi->read_tier;
+		if (t->flags & CEPH_OSD_FLAG_WRITE && pi->write_tier >= 0)
+			t->target_oloc.pool = pi->write_tier;
+
+		pi = ceph_pg_pool_by_id(osdc->osdmap, t->target_oloc.pool);
+		if (!pi) {
+			t->osd = CEPH_HOMELESS_OSD;
+			ct_res = CALC_TARGET_POOL_DNE;
+			goto out;
+		}
+	}
+
+	__ceph_object_locator_to_pg(pi, &t->target_oid, &t->target_oloc, &pgid);
+	last_pgid.pool = pgid.pool;
+	last_pgid.seed = ceph_stable_mod(pgid.seed, t->pg_num, t->pg_num_mask);
+
+	ceph_pg_to_up_acting_osds(osdc->osdmap, pi, &pgid, &up, &acting);
+	if (any_change &&
+	    ceph_is_new_interval(&t->acting,
+				 &acting,
+				 &t->up,
+				 &up,
+				 t->size,
+				 pi->size,
+				 t->min_size,
+				 pi->min_size,
+				 t->pg_num,
+				 pi->pg_num,
+				 t->sort_bitwise,
+				 sort_bitwise,
+				 t->recovery_deletes,
+				 recovery_deletes,
+				 &last_pgid))
+		force_resend = true;
+
+	if (t->paused && !target_should_be_paused(osdc, t, pi)) {
+		t->paused = false;
+		unpaused = true;
+	}
+	legacy_change = ceph_pg_compare(&t->pgid, &pgid) ||
+			ceph_osds_changed(&t->acting, &acting, any_change);
+	if (t->pg_num)
+		split = ceph_pg_is_split(&last_pgid, t->pg_num, pi->pg_num);
+
+	if (legacy_change || force_resend || split) {
+		t->pgid = pgid; /* struct */
+		ceph_pg_to_primary_shard(osdc->osdmap, pi, &pgid, &t->spgid);
+		ceph_osds_copy(&t->acting, &acting);
+		ceph_osds_copy(&t->up, &up);
+		t->size = pi->size;
+		t->min_size = pi->min_size;
+		t->pg_num = pi->pg_num;
+		t->pg_num_mask = pi->pg_num_mask;
+		t->sort_bitwise = sort_bitwise;
+		t->recovery_deletes = recovery_deletes;
+
+		t->osd = acting.primary;
+	}
+
+	if (unpaused || legacy_change || force_resend || split)
+		ct_res = CALC_TARGET_NEED_RESEND;
+	else
+		ct_res = CALC_TARGET_NO_ACTION;
+
+out:
+	dout("%s t %p -> %d%d%d%d ct_res %d osd%d\n", __func__, t, unpaused,
+	     legacy_change, force_resend, split, ct_res, t->osd);
+	return ct_res;
+}
+
+static struct ceph_spg_mapping *alloc_spg_mapping(void)
+{
+	struct ceph_spg_mapping *spg;
+
+	spg = kmalloc(sizeof(*spg), GFP_NOIO);
+	if (!spg)
+		return NULL;
+
+	RB_CLEAR_NODE(&spg->node);
+	spg->backoffs = RB_ROOT;
+	return spg;
+}
+
+static void free_spg_mapping(struct ceph_spg_mapping *spg)
+{
+	WARN_ON(!RB_EMPTY_NODE(&spg->node));
+	WARN_ON(!RB_EMPTY_ROOT(&spg->backoffs));
+
+	kfree(spg);
+}
+
+/*
+ * rbtree of ceph_spg_mapping for handling map<spg_t, ...>, similar to
+ * ceph_pg_mapping.  Used to track OSD backoffs -- a backoff [range] is
+ * defined only within a specific spgid; it does not pass anything to
+ * children on split, or to another primary.
+ */
+DEFINE_RB_FUNCS2(spg_mapping, struct ceph_spg_mapping, spgid, ceph_spg_compare,
+		 RB_BYPTR, const struct ceph_spg *, node)
+
+static u64 hoid_get_bitwise_key(const struct ceph_hobject_id *hoid)
+{
+	return hoid->is_max ? 0x100000000ull : hoid->hash_reverse_bits;
+}
+
+static void hoid_get_effective_key(const struct ceph_hobject_id *hoid,
+				   void **pkey, size_t *pkey_len)
+{
+	if (hoid->key_len) {
+		*pkey = hoid->key;
+		*pkey_len = hoid->key_len;
+	} else {
+		*pkey = hoid->oid;
+		*pkey_len = hoid->oid_len;
+	}
+}
+
+static int compare_names(const void *name1, size_t name1_len,
+			 const void *name2, size_t name2_len)
+{
+	int ret;
+
+	ret = memcmp(name1, name2, min(name1_len, name2_len));
+	if (!ret) {
+		if (name1_len < name2_len)
+			ret = -1;
+		else if (name1_len > name2_len)
+			ret = 1;
+	}
+	return ret;
+}
+
+static int hoid_compare(const struct ceph_hobject_id *lhs,
+			const struct ceph_hobject_id *rhs)
+{
+	void *effective_key1, *effective_key2;
+	size_t effective_key1_len, effective_key2_len;
+	int ret;
+
+	if (lhs->is_max < rhs->is_max)
+		return -1;
+	if (lhs->is_max > rhs->is_max)
+		return 1;
+
+	if (lhs->pool < rhs->pool)
+		return -1;
+	if (lhs->pool > rhs->pool)
+		return 1;
+
+	if (hoid_get_bitwise_key(lhs) < hoid_get_bitwise_key(rhs))
+		return -1;
+	if (hoid_get_bitwise_key(lhs) > hoid_get_bitwise_key(rhs))
+		return 1;
+
+	ret = compare_names(lhs->nspace, lhs->nspace_len,
+			    rhs->nspace, rhs->nspace_len);
+	if (ret)
+		return ret;
+
+	hoid_get_effective_key(lhs, &effective_key1, &effective_key1_len);
+	hoid_get_effective_key(rhs, &effective_key2, &effective_key2_len);
+	ret = compare_names(effective_key1, effective_key1_len,
+			    effective_key2, effective_key2_len);
+	if (ret)
+		return ret;
+
+	ret = compare_names(lhs->oid, lhs->oid_len, rhs->oid, rhs->oid_len);
+	if (ret)
+		return ret;
+
+	if (lhs->snapid < rhs->snapid)
+		return -1;
+	if (lhs->snapid > rhs->snapid)
+		return 1;
+
+	return 0;
+}
+
+/*
+ * For decoding ->begin and ->end of MOSDBackoff only -- no MIN/MAX
+ * compat stuff here.
+ *
+ * Assumes @hoid is zero-initialized.
+ */
+static int decode_hoid(void **p, void *end, struct ceph_hobject_id *hoid)
+{
+	u8 struct_v;
+	u32 struct_len;
+	int ret;
+
+	ret = ceph_start_decoding(p, end, 4, "hobject_t", &struct_v,
+				  &struct_len);
+	if (ret)
+		return ret;
+
+	if (struct_v < 4) {
+		pr_err("got struct_v %d < 4 of hobject_t\n", struct_v);
+		goto e_inval;
+	}
+
+	hoid->key = ceph_extract_encoded_string(p, end, &hoid->key_len,
+						GFP_NOIO);
+	if (IS_ERR(hoid->key)) {
+		ret = PTR_ERR(hoid->key);
+		hoid->key = NULL;
+		return ret;
+	}
+
+	hoid->oid = ceph_extract_encoded_string(p, end, &hoid->oid_len,
+						GFP_NOIO);
+	if (IS_ERR(hoid->oid)) {
+		ret = PTR_ERR(hoid->oid);
+		hoid->oid = NULL;
+		return ret;
+	}
+
+	ceph_decode_64_safe(p, end, hoid->snapid, e_inval);
+	ceph_decode_32_safe(p, end, hoid->hash, e_inval);
+	ceph_decode_8_safe(p, end, hoid->is_max, e_inval);
+
+	hoid->nspace = ceph_extract_encoded_string(p, end, &hoid->nspace_len,
+						   GFP_NOIO);
+	if (IS_ERR(hoid->nspace)) {
+		ret = PTR_ERR(hoid->nspace);
+		hoid->nspace = NULL;
+		return ret;
+	}
+
+	ceph_decode_64_safe(p, end, hoid->pool, e_inval);
+
+	ceph_hoid_build_hash_cache(hoid);
+	return 0;
+
+e_inval:
+	return -EINVAL;
+}
+
+static int hoid_encoding_size(const struct ceph_hobject_id *hoid)
+{
+	return 8 + 4 + 1 + 8 + /* snapid, hash, is_max, pool */
+	       4 + hoid->key_len + 4 + hoid->oid_len + 4 + hoid->nspace_len;
+}
+
+static void encode_hoid(void **p, void *end, const struct ceph_hobject_id *hoid)
+{
+	ceph_start_encoding(p, 4, 3, hoid_encoding_size(hoid));
+	ceph_encode_string(p, end, hoid->key, hoid->key_len);
+	ceph_encode_string(p, end, hoid->oid, hoid->oid_len);
+	ceph_encode_64(p, hoid->snapid);
+	ceph_encode_32(p, hoid->hash);
+	ceph_encode_8(p, hoid->is_max);
+	ceph_encode_string(p, end, hoid->nspace, hoid->nspace_len);
+	ceph_encode_64(p, hoid->pool);
+}
+
+static void free_hoid(struct ceph_hobject_id *hoid)
+{
+	if (hoid) {
+		kfree(hoid->key);
+		kfree(hoid->oid);
+		kfree(hoid->nspace);
+		kfree(hoid);
+	}
+}
+
+static struct ceph_osd_backoff *alloc_backoff(void)
+{
+	struct ceph_osd_backoff *backoff;
+
+	backoff = kzalloc(sizeof(*backoff), GFP_NOIO);
+	if (!backoff)
+		return NULL;
+
+	RB_CLEAR_NODE(&backoff->spg_node);
+	RB_CLEAR_NODE(&backoff->id_node);
+	return backoff;
+}
+
+static void free_backoff(struct ceph_osd_backoff *backoff)
+{
+	WARN_ON(!RB_EMPTY_NODE(&backoff->spg_node));
+	WARN_ON(!RB_EMPTY_NODE(&backoff->id_node));
+
+	free_hoid(backoff->begin);
+	free_hoid(backoff->end);
+	kfree(backoff);
+}
+
+/*
+ * Within a specific spgid, backoffs are managed by ->begin hoid.
+ */
+DEFINE_RB_INSDEL_FUNCS2(backoff, struct ceph_osd_backoff, begin, hoid_compare,
+			RB_BYVAL, spg_node);
+
+static struct ceph_osd_backoff *lookup_containing_backoff(struct rb_root *root,
+					    const struct ceph_hobject_id *hoid)
+{
+	struct rb_node *n = root->rb_node;
+
+	while (n) {
+		struct ceph_osd_backoff *cur =
+		    rb_entry(n, struct ceph_osd_backoff, spg_node);
+		int cmp;
+
+		cmp = hoid_compare(hoid, cur->begin);
+		if (cmp < 0) {
+			n = n->rb_left;
+		} else if (cmp > 0) {
+			if (hoid_compare(hoid, cur->end) < 0)
+				return cur;
+
+			n = n->rb_right;
+		} else {
+			return cur;
+		}
+	}
+
+	return NULL;
+}
+
+/*
+ * Each backoff has a unique id within its OSD session.
+ */
+DEFINE_RB_FUNCS(backoff_by_id, struct ceph_osd_backoff, id, id_node)
+
+static void clear_backoffs(struct ceph_osd *osd)
+{
+	while (!RB_EMPTY_ROOT(&osd->o_backoff_mappings)) {
+		struct ceph_spg_mapping *spg =
+		    rb_entry(rb_first(&osd->o_backoff_mappings),
+			     struct ceph_spg_mapping, node);
+
+		while (!RB_EMPTY_ROOT(&spg->backoffs)) {
+			struct ceph_osd_backoff *backoff =
+			    rb_entry(rb_first(&spg->backoffs),
+				     struct ceph_osd_backoff, spg_node);
+
+			erase_backoff(&spg->backoffs, backoff);
+			erase_backoff_by_id(&osd->o_backoffs_by_id, backoff);
+			free_backoff(backoff);
+		}
+		erase_spg_mapping(&osd->o_backoff_mappings, spg);
+		free_spg_mapping(spg);
+	}
+}
+
+/*
+ * Set up a temporary, non-owning view into @t.
+ */
+static void hoid_fill_from_target(struct ceph_hobject_id *hoid,
+				  const struct ceph_osd_request_target *t)
+{
+	hoid->key = NULL;
+	hoid->key_len = 0;
+	hoid->oid = t->target_oid.name;
+	hoid->oid_len = t->target_oid.name_len;
+	hoid->snapid = CEPH_NOSNAP;
+	hoid->hash = t->pgid.seed;
+	hoid->is_max = false;
+	if (t->target_oloc.pool_ns) {
+		hoid->nspace = t->target_oloc.pool_ns->str;
+		hoid->nspace_len = t->target_oloc.pool_ns->len;
+	} else {
+		hoid->nspace = NULL;
+		hoid->nspace_len = 0;
+	}
+	hoid->pool = t->target_oloc.pool;
+	ceph_hoid_build_hash_cache(hoid);
+}
+
+static bool should_plug_request(struct ceph_osd_request *req)
+{
+	struct ceph_osd *osd = req->r_osd;
+	struct ceph_spg_mapping *spg;
+	struct ceph_osd_backoff *backoff;
+	struct ceph_hobject_id hoid;
+
+	spg = lookup_spg_mapping(&osd->o_backoff_mappings, &req->r_t.spgid);
+	if (!spg)
+		return false;
+
+	hoid_fill_from_target(&hoid, &req->r_t);
+	backoff = lookup_containing_backoff(&spg->backoffs, &hoid);
+	if (!backoff)
+		return false;
+
+	dout("%s req %p tid %llu backoff osd%d spgid %llu.%xs%d id %llu\n",
+	     __func__, req, req->r_tid, osd->o_osd, backoff->spgid.pgid.pool,
+	     backoff->spgid.pgid.seed, backoff->spgid.shard, backoff->id);
+	return true;
+}
+
+static void setup_request_data(struct ceph_osd_request *req,
+			       struct ceph_msg *msg)
+{
+	u32 data_len = 0;
+	int i;
+
+	if (!list_empty(&msg->data))
+		return;
+
+	WARN_ON(msg->data_length);
+	for (i = 0; i < req->r_num_ops; i++) {
+		struct ceph_osd_req_op *op = &req->r_ops[i];
+
+		switch (op->op) {
+		/* request */
+		case CEPH_OSD_OP_WRITE:
+		case CEPH_OSD_OP_WRITEFULL:
+			WARN_ON(op->indata_len != op->extent.length);
+			ceph_osdc_msg_data_add(msg, &op->extent.osd_data);
+			break;
+		case CEPH_OSD_OP_SETXATTR:
+		case CEPH_OSD_OP_CMPXATTR:
+			WARN_ON(op->indata_len != op->xattr.name_len +
+						  op->xattr.value_len);
+			ceph_osdc_msg_data_add(msg, &op->xattr.osd_data);
+			break;
+		case CEPH_OSD_OP_NOTIFY_ACK:
+			ceph_osdc_msg_data_add(msg,
+					       &op->notify_ack.request_data);
+			break;
+
+		/* reply */
+		case CEPH_OSD_OP_STAT:
+			ceph_osdc_msg_data_add(req->r_reply,
+					       &op->raw_data_in);
+			break;
+		case CEPH_OSD_OP_READ:
+			ceph_osdc_msg_data_add(req->r_reply,
+					       &op->extent.osd_data);
+			break;
+		case CEPH_OSD_OP_LIST_WATCHERS:
+			ceph_osdc_msg_data_add(req->r_reply,
+					       &op->list_watchers.response_data);
+			break;
+
+		/* both */
+		case CEPH_OSD_OP_CALL:
+			WARN_ON(op->indata_len != op->cls.class_len +
+						  op->cls.method_len +
+						  op->cls.indata_len);
+			ceph_osdc_msg_data_add(msg, &op->cls.request_info);
+			/* optional, can be NONE */
+			ceph_osdc_msg_data_add(msg, &op->cls.request_data);
+			/* optional, can be NONE */
+			ceph_osdc_msg_data_add(req->r_reply,
+					       &op->cls.response_data);
+			break;
+		case CEPH_OSD_OP_NOTIFY:
+			ceph_osdc_msg_data_add(msg,
+					       &op->notify.request_data);
+			ceph_osdc_msg_data_add(req->r_reply,
+					       &op->notify.response_data);
+			break;
+		}
+
+		data_len += op->indata_len;
+	}
+
+	WARN_ON(data_len != msg->data_length);
+}
+
+static void encode_pgid(void **p, const struct ceph_pg *pgid)
+{
+	ceph_encode_8(p, 1);
+	ceph_encode_64(p, pgid->pool);
+	ceph_encode_32(p, pgid->seed);
+	ceph_encode_32(p, -1); /* preferred */
+}
+
+static void encode_spgid(void **p, const struct ceph_spg *spgid)
+{
+	ceph_start_encoding(p, 1, 1, CEPH_PGID_ENCODING_LEN + 1);
+	encode_pgid(p, &spgid->pgid);
+	ceph_encode_8(p, spgid->shard);
+}
+
+static void encode_oloc(void **p, void *end,
+			const struct ceph_object_locator *oloc)
+{
+	ceph_start_encoding(p, 5, 4, ceph_oloc_encoding_size(oloc));
+	ceph_encode_64(p, oloc->pool);
+	ceph_encode_32(p, -1); /* preferred */
+	ceph_encode_32(p, 0);  /* key len */
+	if (oloc->pool_ns)
+		ceph_encode_string(p, end, oloc->pool_ns->str,
+				   oloc->pool_ns->len);
+	else
+		ceph_encode_32(p, 0);
+}
+
+static void encode_request_partial(struct ceph_osd_request *req,
+				   struct ceph_msg *msg)
+{
+	void *p = msg->front.iov_base;
+	void *const end = p + msg->front_alloc_len;
+	u32 data_len = 0;
+	int i;
+
+	if (req->r_flags & CEPH_OSD_FLAG_WRITE) {
+		/* snapshots aren't writeable */
+		WARN_ON(req->r_snapid != CEPH_NOSNAP);
+	} else {
+		WARN_ON(req->r_mtime.tv_sec || req->r_mtime.tv_nsec ||
+			req->r_data_offset || req->r_snapc);
+	}
+
+	setup_request_data(req, msg);
+
+	encode_spgid(&p, &req->r_t.spgid); /* actual spg */
+	ceph_encode_32(&p, req->r_t.pgid.seed); /* raw hash */
+	ceph_encode_32(&p, req->r_osdc->osdmap->epoch);
+	ceph_encode_32(&p, req->r_flags);
+
+	/* reqid */
+	ceph_start_encoding(&p, 2, 2, sizeof(struct ceph_osd_reqid));
+	memset(p, 0, sizeof(struct ceph_osd_reqid));
+	p += sizeof(struct ceph_osd_reqid);
+
+	/* trace */
+	memset(p, 0, sizeof(struct ceph_blkin_trace_info));
+	p += sizeof(struct ceph_blkin_trace_info);
+
+	ceph_encode_32(&p, 0); /* client_inc, always 0 */
+	ceph_encode_timespec64(p, &req->r_mtime);
+	p += sizeof(struct ceph_timespec);
+
+	encode_oloc(&p, end, &req->r_t.target_oloc);
+	ceph_encode_string(&p, end, req->r_t.target_oid.name,
+			   req->r_t.target_oid.name_len);
+
+	/* ops, can imply data */
+	ceph_encode_16(&p, req->r_num_ops);
+	for (i = 0; i < req->r_num_ops; i++) {
+		data_len += osd_req_encode_op(p, &req->r_ops[i]);
+		p += sizeof(struct ceph_osd_op);
+	}
+
+	ceph_encode_64(&p, req->r_snapid); /* snapid */
+	if (req->r_snapc) {
+		ceph_encode_64(&p, req->r_snapc->seq);
+		ceph_encode_32(&p, req->r_snapc->num_snaps);
+		for (i = 0; i < req->r_snapc->num_snaps; i++)
+			ceph_encode_64(&p, req->r_snapc->snaps[i]);
+	} else {
+		ceph_encode_64(&p, 0); /* snap_seq */
+		ceph_encode_32(&p, 0); /* snaps len */
+	}
+
+	ceph_encode_32(&p, req->r_attempts); /* retry_attempt */
+	BUG_ON(p > end - 8); /* space for features */
+
+	msg->hdr.version = cpu_to_le16(8); /* MOSDOp v8 */
+	/* front_len is finalized in encode_request_finish() */
+	msg->front.iov_len = p - msg->front.iov_base;
+	msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
+	msg->hdr.data_len = cpu_to_le32(data_len);
+	/*
+	 * The header "data_off" is a hint to the receiver allowing it
+	 * to align received data into its buffers such that there's no
+	 * need to re-copy it before writing it to disk (direct I/O).
+	 */
+	msg->hdr.data_off = cpu_to_le16(req->r_data_offset);
+
+	dout("%s req %p msg %p oid %s oid_len %d\n", __func__, req, msg,
+	     req->r_t.target_oid.name, req->r_t.target_oid.name_len);
+}
+
+static void encode_request_finish(struct ceph_msg *msg)
+{
+	void *p = msg->front.iov_base;
+	void *const partial_end = p + msg->front.iov_len;
+	void *const end = p + msg->front_alloc_len;
+
+	if (CEPH_HAVE_FEATURE(msg->con->peer_features, RESEND_ON_SPLIT)) {
+		/* luminous OSD -- encode features and be done */
+		p = partial_end;
+		ceph_encode_64(&p, msg->con->peer_features);
+	} else {
+		struct {
+			char spgid[CEPH_ENCODING_START_BLK_LEN +
+				   CEPH_PGID_ENCODING_LEN + 1];
+			__le32 hash;
+			__le32 epoch;
+			__le32 flags;
+			char reqid[CEPH_ENCODING_START_BLK_LEN +
+				   sizeof(struct ceph_osd_reqid)];
+			char trace[sizeof(struct ceph_blkin_trace_info)];
+			__le32 client_inc;
+			struct ceph_timespec mtime;
+		} __packed head;
+		struct ceph_pg pgid;
+		void *oloc, *oid, *tail;
+		int oloc_len, oid_len, tail_len;
+		int len;
+
+		/*
+		 * Pre-luminous OSD -- reencode v8 into v4 using @head
+		 * as a temporary buffer.  Encode the raw PG; the rest
+		 * is just a matter of moving oloc, oid and tail blobs
+		 * around.
+		 */
+		memcpy(&head, p, sizeof(head));
+		p += sizeof(head);
+
+		oloc = p;
+		p += CEPH_ENCODING_START_BLK_LEN;
+		pgid.pool = ceph_decode_64(&p);
+		p += 4 + 4; /* preferred, key len */
+		len = ceph_decode_32(&p);
+		p += len;   /* nspace */
+		oloc_len = p - oloc;
+
+		oid = p;
+		len = ceph_decode_32(&p);
+		p += len;
+		oid_len = p - oid;
+
+		tail = p;
+		tail_len = partial_end - p;
+
+		p = msg->front.iov_base;
+		ceph_encode_copy(&p, &head.client_inc, sizeof(head.client_inc));
+		ceph_encode_copy(&p, &head.epoch, sizeof(head.epoch));
+		ceph_encode_copy(&p, &head.flags, sizeof(head.flags));
+		ceph_encode_copy(&p, &head.mtime, sizeof(head.mtime));
+
+		/* reassert_version */
+		memset(p, 0, sizeof(struct ceph_eversion));
+		p += sizeof(struct ceph_eversion);
+
+		BUG_ON(p >= oloc);
+		memmove(p, oloc, oloc_len);
+		p += oloc_len;
+
+		pgid.seed = le32_to_cpu(head.hash);
+		encode_pgid(&p, &pgid); /* raw pg */
+
+		BUG_ON(p >= oid);
+		memmove(p, oid, oid_len);
+		p += oid_len;
+
+		/* tail -- ops, snapid, snapc, retry_attempt */
+		BUG_ON(p >= tail);
+		memmove(p, tail, tail_len);
+		p += tail_len;
+
+		msg->hdr.version = cpu_to_le16(4); /* MOSDOp v4 */
+	}
+
+	BUG_ON(p > end);
+	msg->front.iov_len = p - msg->front.iov_base;
+	msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
+
+	dout("%s msg %p tid %llu %u+%u+%u v%d\n", __func__, msg,
+	     le64_to_cpu(msg->hdr.tid), le32_to_cpu(msg->hdr.front_len),
+	     le32_to_cpu(msg->hdr.middle_len), le32_to_cpu(msg->hdr.data_len),
+	     le16_to_cpu(msg->hdr.version));
+}
+
+/*
+ * @req has to be assigned a tid and registered.
+ */
+static void send_request(struct ceph_osd_request *req)
+{
+	struct ceph_osd *osd = req->r_osd;
+
+	verify_osd_locked(osd);
+	WARN_ON(osd->o_osd != req->r_t.osd);
+
+	/* backoff? */
+	if (should_plug_request(req))
+		return;
+
+	/*
+	 * We may have a previously queued request message hanging
+	 * around.  Cancel it to avoid corrupting the msgr.
+	 */
+	if (req->r_sent)
+		ceph_msg_revoke(req->r_request);
+
+	req->r_flags |= CEPH_OSD_FLAG_KNOWN_REDIR;
+	if (req->r_attempts)
+		req->r_flags |= CEPH_OSD_FLAG_RETRY;
+	else
+		WARN_ON(req->r_flags & CEPH_OSD_FLAG_RETRY);
+
+	encode_request_partial(req, req->r_request);
+
+	dout("%s req %p tid %llu to pgid %llu.%x spgid %llu.%xs%d osd%d e%u flags 0x%x attempt %d\n",
+	     __func__, req, req->r_tid, req->r_t.pgid.pool, req->r_t.pgid.seed,
+	     req->r_t.spgid.pgid.pool, req->r_t.spgid.pgid.seed,
+	     req->r_t.spgid.shard, osd->o_osd, req->r_t.epoch, req->r_flags,
+	     req->r_attempts);
+
+	req->r_t.paused = false;
+	req->r_stamp = jiffies;
+	req->r_attempts++;
+
+	req->r_sent = osd->o_incarnation;
+	req->r_request->hdr.tid = cpu_to_le64(req->r_tid);
+	ceph_con_send(&osd->o_con, ceph_msg_get(req->r_request));
+}
+
+static void maybe_request_map(struct ceph_osd_client *osdc)
+{
+	bool continuous = false;
+
+	verify_osdc_locked(osdc);
+	WARN_ON(!osdc->osdmap->epoch);
+
+	if (ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL) ||
+	    ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSERD) ||
+	    ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSEWR)) {
+		dout("%s osdc %p continuous\n", __func__, osdc);
+		continuous = true;
+	} else {
+		dout("%s osdc %p onetime\n", __func__, osdc);
+	}
+
+	if (ceph_monc_want_map(&osdc->client->monc, CEPH_SUB_OSDMAP,
+			       osdc->osdmap->epoch + 1, continuous))
+		ceph_monc_renew_subs(&osdc->client->monc);
+}
+
+static void complete_request(struct ceph_osd_request *req, int err);
+static void send_map_check(struct ceph_osd_request *req);
+
+static void __submit_request(struct ceph_osd_request *req, bool wrlocked)
+{
+	struct ceph_osd_client *osdc = req->r_osdc;
+	struct ceph_osd *osd;
+	enum calc_target_result ct_res;
+	int err = 0;
+	bool need_send = false;
+	bool promoted = false;
+
+	WARN_ON(req->r_tid);
+	dout("%s req %p wrlocked %d\n", __func__, req, wrlocked);
+
+again:
+	ct_res = calc_target(osdc, &req->r_t, NULL, false);
+	if (ct_res == CALC_TARGET_POOL_DNE && !wrlocked)
+		goto promote;
+
+	osd = lookup_create_osd(osdc, req->r_t.osd, wrlocked);
+	if (IS_ERR(osd)) {
+		WARN_ON(PTR_ERR(osd) != -EAGAIN || wrlocked);
+		goto promote;
+	}
+
+	if (osdc->abort_err) {
+		dout("req %p abort_err %d\n", req, osdc->abort_err);
+		err = osdc->abort_err;
+	} else if (osdc->osdmap->epoch < osdc->epoch_barrier) {
+		dout("req %p epoch %u barrier %u\n", req, osdc->osdmap->epoch,
+		     osdc->epoch_barrier);
+		req->r_t.paused = true;
+		maybe_request_map(osdc);
+	} else if ((req->r_flags & CEPH_OSD_FLAG_WRITE) &&
+		   ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSEWR)) {
+		dout("req %p pausewr\n", req);
+		req->r_t.paused = true;
+		maybe_request_map(osdc);
+	} else if ((req->r_flags & CEPH_OSD_FLAG_READ) &&
+		   ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSERD)) {
+		dout("req %p pauserd\n", req);
+		req->r_t.paused = true;
+		maybe_request_map(osdc);
+	} else if ((req->r_flags & CEPH_OSD_FLAG_WRITE) &&
+		   !(req->r_flags & (CEPH_OSD_FLAG_FULL_TRY |
+				     CEPH_OSD_FLAG_FULL_FORCE)) &&
+		   (ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL) ||
+		    pool_full(osdc, req->r_t.base_oloc.pool))) {
+		dout("req %p full/pool_full\n", req);
+		if (osdc->abort_on_full) {
+			err = -ENOSPC;
+		} else {
+			pr_warn_ratelimited("FULL or reached pool quota\n");
+			req->r_t.paused = true;
+			maybe_request_map(osdc);
+		}
+	} else if (!osd_homeless(osd)) {
+		need_send = true;
+	} else {
+		maybe_request_map(osdc);
+	}
+
+	mutex_lock(&osd->lock);
+	/*
+	 * Assign the tid atomically with send_request() to protect
+	 * multiple writes to the same object from racing with each
+	 * other, resulting in out of order ops on the OSDs.
+	 */
+	req->r_tid = atomic64_inc_return(&osdc->last_tid);
+	link_request(osd, req);
+	if (need_send)
+		send_request(req);
+	else if (err)
+		complete_request(req, err);
+	mutex_unlock(&osd->lock);
+
+	if (!err && ct_res == CALC_TARGET_POOL_DNE)
+		send_map_check(req);
+
+	if (promoted)
+		downgrade_write(&osdc->lock);
+	return;
+
+promote:
+	up_read(&osdc->lock);
+	down_write(&osdc->lock);
+	wrlocked = true;
+	promoted = true;
+	goto again;
+}
+
+static void account_request(struct ceph_osd_request *req)
+{
+	WARN_ON(req->r_flags & (CEPH_OSD_FLAG_ACK | CEPH_OSD_FLAG_ONDISK));
+	WARN_ON(!(req->r_flags & (CEPH_OSD_FLAG_READ | CEPH_OSD_FLAG_WRITE)));
+
+	req->r_flags |= CEPH_OSD_FLAG_ONDISK;
+	atomic_inc(&req->r_osdc->num_requests);
+
+	req->r_start_stamp = jiffies;
+}
+
+static void submit_request(struct ceph_osd_request *req, bool wrlocked)
+{
+	ceph_osdc_get_request(req);
+	account_request(req);
+	__submit_request(req, wrlocked);
+}
+
+static void finish_request(struct ceph_osd_request *req)
+{
+	struct ceph_osd_client *osdc = req->r_osdc;
+
+	WARN_ON(lookup_request_mc(&osdc->map_checks, req->r_tid));
+	dout("%s req %p tid %llu\n", __func__, req, req->r_tid);
+
+	if (req->r_osd)
+		unlink_request(req->r_osd, req);
+	atomic_dec(&osdc->num_requests);
+
+	/*
+	 * If an OSD has failed or returned and a request has been sent
+	 * twice, it's possible to get a reply and end up here while the
+	 * request message is queued for delivery.  We will ignore the
+	 * reply, so not a big deal, but better to try and catch it.
+	 */
+	ceph_msg_revoke(req->r_request);
+	ceph_msg_revoke_incoming(req->r_reply);
+}
+
+static void __complete_request(struct ceph_osd_request *req)
+{
+	dout("%s req %p tid %llu cb %pf result %d\n", __func__, req,
+	     req->r_tid, req->r_callback, req->r_result);
+
+	if (req->r_callback)
+		req->r_callback(req);
+	complete_all(&req->r_completion);
+	ceph_osdc_put_request(req);
+}
+
+static void complete_request_workfn(struct work_struct *work)
+{
+	struct ceph_osd_request *req =
+	    container_of(work, struct ceph_osd_request, r_complete_work);
+
+	__complete_request(req);
+}
+
+/*
+ * This is open-coded in handle_reply().
+ */
+static void complete_request(struct ceph_osd_request *req, int err)
+{
+	dout("%s req %p tid %llu err %d\n", __func__, req, req->r_tid, err);
+
+	req->r_result = err;
+	finish_request(req);
+
+	INIT_WORK(&req->r_complete_work, complete_request_workfn);
+	queue_work(req->r_osdc->completion_wq, &req->r_complete_work);
+}
+
+static void cancel_map_check(struct ceph_osd_request *req)
+{
+	struct ceph_osd_client *osdc = req->r_osdc;
+	struct ceph_osd_request *lookup_req;
+
+	verify_osdc_wrlocked(osdc);
+
+	lookup_req = lookup_request_mc(&osdc->map_checks, req->r_tid);
+	if (!lookup_req)
+		return;
+
+	WARN_ON(lookup_req != req);
+	erase_request_mc(&osdc->map_checks, req);
+	ceph_osdc_put_request(req);
+}
+
+static void cancel_request(struct ceph_osd_request *req)
+{
+	dout("%s req %p tid %llu\n", __func__, req, req->r_tid);
+
+	cancel_map_check(req);
+	finish_request(req);
+	complete_all(&req->r_completion);
+	ceph_osdc_put_request(req);
+}
+
+static void abort_request(struct ceph_osd_request *req, int err)
+{
+	dout("%s req %p tid %llu err %d\n", __func__, req, req->r_tid, err);
+
+	cancel_map_check(req);
+	complete_request(req, err);
+}
+
+static int abort_fn(struct ceph_osd_request *req, void *arg)
+{
+	int err = *(int *)arg;
+
+	abort_request(req, err);
+	return 0; /* continue iteration */
+}
+
+/*
+ * Abort all in-flight requests with @err and arrange for all future
+ * requests to be failed immediately.
+ */
+void ceph_osdc_abort_requests(struct ceph_osd_client *osdc, int err)
+{
+	dout("%s osdc %p err %d\n", __func__, osdc, err);
+	down_write(&osdc->lock);
+	for_each_request(osdc, abort_fn, &err);
+	osdc->abort_err = err;
+	up_write(&osdc->lock);
+}
+EXPORT_SYMBOL(ceph_osdc_abort_requests);
+
+static void update_epoch_barrier(struct ceph_osd_client *osdc, u32 eb)
+{
+	if (likely(eb > osdc->epoch_barrier)) {
+		dout("updating epoch_barrier from %u to %u\n",
+				osdc->epoch_barrier, eb);
+		osdc->epoch_barrier = eb;
+		/* Request map if we're not to the barrier yet */
+		if (eb > osdc->osdmap->epoch)
+			maybe_request_map(osdc);
+	}
+}
+
+void ceph_osdc_update_epoch_barrier(struct ceph_osd_client *osdc, u32 eb)
+{
+	down_read(&osdc->lock);
+	if (unlikely(eb > osdc->epoch_barrier)) {
+		up_read(&osdc->lock);
+		down_write(&osdc->lock);
+		update_epoch_barrier(osdc, eb);
+		up_write(&osdc->lock);
+	} else {
+		up_read(&osdc->lock);
+	}
+}
+EXPORT_SYMBOL(ceph_osdc_update_epoch_barrier);
+
+/*
+ * We can end up releasing caps as a result of abort_request().
+ * In that case, we probably want to ensure that the cap release message
+ * has an updated epoch barrier in it, so set the epoch barrier prior to
+ * aborting the first request.
+ */
+static int abort_on_full_fn(struct ceph_osd_request *req, void *arg)
+{
+	struct ceph_osd_client *osdc = req->r_osdc;
+	bool *victims = arg;
+
+	if ((req->r_flags & CEPH_OSD_FLAG_WRITE) &&
+	    (ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL) ||
+	     pool_full(osdc, req->r_t.base_oloc.pool))) {
+		if (!*victims) {
+			update_epoch_barrier(osdc, osdc->osdmap->epoch);
+			*victims = true;
+		}
+		abort_request(req, -ENOSPC);
+	}
+
+	return 0; /* continue iteration */
+}
+
+/*
+ * Drop all pending requests that are stalled waiting on a full condition to
+ * clear, and complete them with ENOSPC as the return code. Set the
+ * osdc->epoch_barrier to the latest map epoch that we've seen if any were
+ * cancelled.
+ */
+static void ceph_osdc_abort_on_full(struct ceph_osd_client *osdc)
+{
+	bool victims = false;
+
+	if (osdc->abort_on_full &&
+	    (ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL) || have_pool_full(osdc)))
+		for_each_request(osdc, abort_on_full_fn, &victims);
+}
+
+static void check_pool_dne(struct ceph_osd_request *req)
+{
+	struct ceph_osd_client *osdc = req->r_osdc;
+	struct ceph_osdmap *map = osdc->osdmap;
+
+	verify_osdc_wrlocked(osdc);
+	WARN_ON(!map->epoch);
+
+	if (req->r_attempts) {
+		/*
+		 * We sent a request earlier, which means that
+		 * previously the pool existed, and now it does not
+		 * (i.e., it was deleted).
+		 */
+		req->r_map_dne_bound = map->epoch;
+		dout("%s req %p tid %llu pool disappeared\n", __func__, req,
+		     req->r_tid);
+	} else {
+		dout("%s req %p tid %llu map_dne_bound %u have %u\n", __func__,
+		     req, req->r_tid, req->r_map_dne_bound, map->epoch);
+	}
+
+	if (req->r_map_dne_bound) {
+		if (map->epoch >= req->r_map_dne_bound) {
+			/* we had a new enough map */
+			pr_info_ratelimited("tid %llu pool does not exist\n",
+					    req->r_tid);
+			complete_request(req, -ENOENT);
+		}
+	} else {
+		send_map_check(req);
+	}
+}
+
+static void map_check_cb(struct ceph_mon_generic_request *greq)
+{
+	struct ceph_osd_client *osdc = &greq->monc->client->osdc;
+	struct ceph_osd_request *req;
+	u64 tid = greq->private_data;
+
+	WARN_ON(greq->result || !greq->u.newest);
+
+	down_write(&osdc->lock);
+	req = lookup_request_mc(&osdc->map_checks, tid);
+	if (!req) {
+		dout("%s tid %llu dne\n", __func__, tid);
+		goto out_unlock;
+	}
+
+	dout("%s req %p tid %llu map_dne_bound %u newest %llu\n", __func__,
+	     req, req->r_tid, req->r_map_dne_bound, greq->u.newest);
+	if (!req->r_map_dne_bound)
+		req->r_map_dne_bound = greq->u.newest;
+	erase_request_mc(&osdc->map_checks, req);
+	check_pool_dne(req);
+
+	ceph_osdc_put_request(req);
+out_unlock:
+	up_write(&osdc->lock);
+}
+
+static void send_map_check(struct ceph_osd_request *req)
+{
+	struct ceph_osd_client *osdc = req->r_osdc;
+	struct ceph_osd_request *lookup_req;
+	int ret;
+
+	verify_osdc_wrlocked(osdc);
+
+	lookup_req = lookup_request_mc(&osdc->map_checks, req->r_tid);
+	if (lookup_req) {
+		WARN_ON(lookup_req != req);
+		return;
+	}
+
+	ceph_osdc_get_request(req);
+	insert_request_mc(&osdc->map_checks, req);
+	ret = ceph_monc_get_version_async(&osdc->client->monc, "osdmap",
+					  map_check_cb, req->r_tid);
+	WARN_ON(ret);
+}
+
+/*
+ * lingering requests, watch/notify v2 infrastructure
+ */
+static void linger_release(struct kref *kref)
+{
+	struct ceph_osd_linger_request *lreq =
+	    container_of(kref, struct ceph_osd_linger_request, kref);
+
+	dout("%s lreq %p reg_req %p ping_req %p\n", __func__, lreq,
+	     lreq->reg_req, lreq->ping_req);
+	WARN_ON(!RB_EMPTY_NODE(&lreq->node));
+	WARN_ON(!RB_EMPTY_NODE(&lreq->osdc_node));
+	WARN_ON(!RB_EMPTY_NODE(&lreq->mc_node));
+	WARN_ON(!list_empty(&lreq->scan_item));
+	WARN_ON(!list_empty(&lreq->pending_lworks));
+	WARN_ON(lreq->osd);
+
+	if (lreq->reg_req)
+		ceph_osdc_put_request(lreq->reg_req);
+	if (lreq->ping_req)
+		ceph_osdc_put_request(lreq->ping_req);
+	target_destroy(&lreq->t);
+	kfree(lreq);
+}
+
+static void linger_put(struct ceph_osd_linger_request *lreq)
+{
+	if (lreq)
+		kref_put(&lreq->kref, linger_release);
+}
+
+static struct ceph_osd_linger_request *
+linger_get(struct ceph_osd_linger_request *lreq)
+{
+	kref_get(&lreq->kref);
+	return lreq;
+}
+
+static struct ceph_osd_linger_request *
+linger_alloc(struct ceph_osd_client *osdc)
+{
+	struct ceph_osd_linger_request *lreq;
+
+	lreq = kzalloc(sizeof(*lreq), GFP_NOIO);
+	if (!lreq)
+		return NULL;
+
+	kref_init(&lreq->kref);
+	mutex_init(&lreq->lock);
+	RB_CLEAR_NODE(&lreq->node);
+	RB_CLEAR_NODE(&lreq->osdc_node);
+	RB_CLEAR_NODE(&lreq->mc_node);
+	INIT_LIST_HEAD(&lreq->scan_item);
+	INIT_LIST_HEAD(&lreq->pending_lworks);
+	init_completion(&lreq->reg_commit_wait);
+	init_completion(&lreq->notify_finish_wait);
+
+	lreq->osdc = osdc;
+	target_init(&lreq->t);
+
+	dout("%s lreq %p\n", __func__, lreq);
+	return lreq;
+}
+
+DEFINE_RB_INSDEL_FUNCS(linger, struct ceph_osd_linger_request, linger_id, node)
+DEFINE_RB_FUNCS(linger_osdc, struct ceph_osd_linger_request, linger_id, osdc_node)
+DEFINE_RB_FUNCS(linger_mc, struct ceph_osd_linger_request, linger_id, mc_node)
+
+/*
+ * Create linger request <-> OSD session relation.
+ *
+ * @lreq has to be registered, @osd may be homeless.
+ */
+static void link_linger(struct ceph_osd *osd,
+			struct ceph_osd_linger_request *lreq)
+{
+	verify_osd_locked(osd);
+	WARN_ON(!lreq->linger_id || lreq->osd);
+	dout("%s osd %p osd%d lreq %p linger_id %llu\n", __func__, osd,
+	     osd->o_osd, lreq, lreq->linger_id);
+
+	if (!osd_homeless(osd))
+		__remove_osd_from_lru(osd);
+	else
+		atomic_inc(&osd->o_osdc->num_homeless);
+
+	get_osd(osd);
+	insert_linger(&osd->o_linger_requests, lreq);
+	lreq->osd = osd;
+}
+
+static void unlink_linger(struct ceph_osd *osd,
+			  struct ceph_osd_linger_request *lreq)
+{
+	verify_osd_locked(osd);
+	WARN_ON(lreq->osd != osd);
+	dout("%s osd %p osd%d lreq %p linger_id %llu\n", __func__, osd,
+	     osd->o_osd, lreq, lreq->linger_id);
+
+	lreq->osd = NULL;
+	erase_linger(&osd->o_linger_requests, lreq);
+	put_osd(osd);
+
+	if (!osd_homeless(osd))
+		maybe_move_osd_to_lru(osd);
+	else
+		atomic_dec(&osd->o_osdc->num_homeless);
+}
+
+static bool __linger_registered(struct ceph_osd_linger_request *lreq)
+{
+	verify_osdc_locked(lreq->osdc);
+
+	return !RB_EMPTY_NODE(&lreq->osdc_node);
+}
+
+static bool linger_registered(struct ceph_osd_linger_request *lreq)
+{
+	struct ceph_osd_client *osdc = lreq->osdc;
+	bool registered;
+
+	down_read(&osdc->lock);
+	registered = __linger_registered(lreq);
+	up_read(&osdc->lock);
+
+	return registered;
+}
+
+static void linger_register(struct ceph_osd_linger_request *lreq)
+{
+	struct ceph_osd_client *osdc = lreq->osdc;
+
+	verify_osdc_wrlocked(osdc);
+	WARN_ON(lreq->linger_id);
+
+	linger_get(lreq);
+	lreq->linger_id = ++osdc->last_linger_id;
+	insert_linger_osdc(&osdc->linger_requests, lreq);
+}
+
+static void linger_unregister(struct ceph_osd_linger_request *lreq)
+{
+	struct ceph_osd_client *osdc = lreq->osdc;
+
+	verify_osdc_wrlocked(osdc);
+
+	erase_linger_osdc(&osdc->linger_requests, lreq);
+	linger_put(lreq);
+}
+
+static void cancel_linger_request(struct ceph_osd_request *req)
+{
+	struct ceph_osd_linger_request *lreq = req->r_priv;
+
+	WARN_ON(!req->r_linger);
+	cancel_request(req);
+	linger_put(lreq);
+}
+
+struct linger_work {
+	struct work_struct work;
+	struct ceph_osd_linger_request *lreq;
+	struct list_head pending_item;
+	unsigned long queued_stamp;
+
+	union {
+		struct {
+			u64 notify_id;
+			u64 notifier_id;
+			void *payload; /* points into @msg front */
+			size_t payload_len;
+
+			struct ceph_msg *msg; /* for ceph_msg_put() */
+		} notify;
+		struct {
+			int err;
+		} error;
+	};
+};
+
+static struct linger_work *lwork_alloc(struct ceph_osd_linger_request *lreq,
+				       work_func_t workfn)
+{
+	struct linger_work *lwork;
+
+	lwork = kzalloc(sizeof(*lwork), GFP_NOIO);
+	if (!lwork)
+		return NULL;
+
+	INIT_WORK(&lwork->work, workfn);
+	INIT_LIST_HEAD(&lwork->pending_item);
+	lwork->lreq = linger_get(lreq);
+
+	return lwork;
+}
+
+static void lwork_free(struct linger_work *lwork)
+{
+	struct ceph_osd_linger_request *lreq = lwork->lreq;
+
+	mutex_lock(&lreq->lock);
+	list_del(&lwork->pending_item);
+	mutex_unlock(&lreq->lock);
+
+	linger_put(lreq);
+	kfree(lwork);
+}
+
+static void lwork_queue(struct linger_work *lwork)
+{
+	struct ceph_osd_linger_request *lreq = lwork->lreq;
+	struct ceph_osd_client *osdc = lreq->osdc;
+
+	verify_lreq_locked(lreq);
+	WARN_ON(!list_empty(&lwork->pending_item));
+
+	lwork->queued_stamp = jiffies;
+	list_add_tail(&lwork->pending_item, &lreq->pending_lworks);
+	queue_work(osdc->notify_wq, &lwork->work);
+}
+
+static void do_watch_notify(struct work_struct *w)
+{
+	struct linger_work *lwork = container_of(w, struct linger_work, work);
+	struct ceph_osd_linger_request *lreq = lwork->lreq;
+
+	if (!linger_registered(lreq)) {
+		dout("%s lreq %p not registered\n", __func__, lreq);
+		goto out;
+	}
+
+	WARN_ON(!lreq->is_watch);
+	dout("%s lreq %p notify_id %llu notifier_id %llu payload_len %zu\n",
+	     __func__, lreq, lwork->notify.notify_id, lwork->notify.notifier_id,
+	     lwork->notify.payload_len);
+	lreq->wcb(lreq->data, lwork->notify.notify_id, lreq->linger_id,
+		  lwork->notify.notifier_id, lwork->notify.payload,
+		  lwork->notify.payload_len);
+
+out:
+	ceph_msg_put(lwork->notify.msg);
+	lwork_free(lwork);
+}
+
+static void do_watch_error(struct work_struct *w)
+{
+	struct linger_work *lwork = container_of(w, struct linger_work, work);
+	struct ceph_osd_linger_request *lreq = lwork->lreq;
+
+	if (!linger_registered(lreq)) {
+		dout("%s lreq %p not registered\n", __func__, lreq);
+		goto out;
+	}
+
+	dout("%s lreq %p err %d\n", __func__, lreq, lwork->error.err);
+	lreq->errcb(lreq->data, lreq->linger_id, lwork->error.err);
+
+out:
+	lwork_free(lwork);
+}
+
+static void queue_watch_error(struct ceph_osd_linger_request *lreq)
+{
+	struct linger_work *lwork;
+
+	lwork = lwork_alloc(lreq, do_watch_error);
+	if (!lwork) {
+		pr_err("failed to allocate error-lwork\n");
+		return;
+	}
+
+	lwork->error.err = lreq->last_error;
+	lwork_queue(lwork);
+}
+
+static void linger_reg_commit_complete(struct ceph_osd_linger_request *lreq,
+				       int result)
+{
+	if (!completion_done(&lreq->reg_commit_wait)) {
+		lreq->reg_commit_error = (result <= 0 ? result : 0);
+		complete_all(&lreq->reg_commit_wait);
+	}
+}
+
+static void linger_commit_cb(struct ceph_osd_request *req)
+{
+	struct ceph_osd_linger_request *lreq = req->r_priv;
+
+	mutex_lock(&lreq->lock);
+	dout("%s lreq %p linger_id %llu result %d\n", __func__, lreq,
+	     lreq->linger_id, req->r_result);
+	linger_reg_commit_complete(lreq, req->r_result);
+	lreq->committed = true;
+
+	if (!lreq->is_watch) {
+		struct ceph_osd_data *osd_data =
+		    osd_req_op_data(req, 0, notify, response_data);
+		void *p = page_address(osd_data->pages[0]);
+
+		WARN_ON(req->r_ops[0].op != CEPH_OSD_OP_NOTIFY ||
+			osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
+
+		/* make note of the notify_id */
+		if (req->r_ops[0].outdata_len >= sizeof(u64)) {
+			lreq->notify_id = ceph_decode_64(&p);
+			dout("lreq %p notify_id %llu\n", lreq,
+			     lreq->notify_id);
+		} else {
+			dout("lreq %p no notify_id\n", lreq);
+		}
+	}
+
+	mutex_unlock(&lreq->lock);
+	linger_put(lreq);
+}
+
+static int normalize_watch_error(int err)
+{
+	/*
+	 * Translate ENOENT -> ENOTCONN so that a delete->disconnection
+	 * notification and a failure to reconnect because we raced with
+	 * the delete appear the same to the user.
+	 */
+	if (err == -ENOENT)
+		err = -ENOTCONN;
+
+	return err;
+}
+
+static void linger_reconnect_cb(struct ceph_osd_request *req)
+{
+	struct ceph_osd_linger_request *lreq = req->r_priv;
+
+	mutex_lock(&lreq->lock);
+	dout("%s lreq %p linger_id %llu result %d last_error %d\n", __func__,
+	     lreq, lreq->linger_id, req->r_result, lreq->last_error);
+	if (req->r_result < 0) {
+		if (!lreq->last_error) {
+			lreq->last_error = normalize_watch_error(req->r_result);
+			queue_watch_error(lreq);
+		}
+	}
+
+	mutex_unlock(&lreq->lock);
+	linger_put(lreq);
+}
+
+static void send_linger(struct ceph_osd_linger_request *lreq)
+{
+	struct ceph_osd_request *req = lreq->reg_req;
+	struct ceph_osd_req_op *op = &req->r_ops[0];
+
+	verify_osdc_wrlocked(req->r_osdc);
+	dout("%s lreq %p linger_id %llu\n", __func__, lreq, lreq->linger_id);
+
+	if (req->r_osd)
+		cancel_linger_request(req);
+
+	request_reinit(req);
+	ceph_oid_copy(&req->r_base_oid, &lreq->t.base_oid);
+	ceph_oloc_copy(&req->r_base_oloc, &lreq->t.base_oloc);
+	req->r_flags = lreq->t.flags;
+	req->r_mtime = lreq->mtime;
+
+	mutex_lock(&lreq->lock);
+	if (lreq->is_watch && lreq->committed) {
+		WARN_ON(op->op != CEPH_OSD_OP_WATCH ||
+			op->watch.cookie != lreq->linger_id);
+		op->watch.op = CEPH_OSD_WATCH_OP_RECONNECT;
+		op->watch.gen = ++lreq->register_gen;
+		dout("lreq %p reconnect register_gen %u\n", lreq,
+		     op->watch.gen);
+		req->r_callback = linger_reconnect_cb;
+	} else {
+		if (!lreq->is_watch)
+			lreq->notify_id = 0;
+		else
+			WARN_ON(op->watch.op != CEPH_OSD_WATCH_OP_WATCH);
+		dout("lreq %p register\n", lreq);
+		req->r_callback = linger_commit_cb;
+	}
+	mutex_unlock(&lreq->lock);
+
+	req->r_priv = linger_get(lreq);
+	req->r_linger = true;
+
+	submit_request(req, true);
+}
+
+static void linger_ping_cb(struct ceph_osd_request *req)
+{
+	struct ceph_osd_linger_request *lreq = req->r_priv;
+
+	mutex_lock(&lreq->lock);
+	dout("%s lreq %p linger_id %llu result %d ping_sent %lu last_error %d\n",
+	     __func__, lreq, lreq->linger_id, req->r_result, lreq->ping_sent,
+	     lreq->last_error);
+	if (lreq->register_gen == req->r_ops[0].watch.gen) {
+		if (!req->r_result) {
+			lreq->watch_valid_thru = lreq->ping_sent;
+		} else if (!lreq->last_error) {
+			lreq->last_error = normalize_watch_error(req->r_result);
+			queue_watch_error(lreq);
+		}
+	} else {
+		dout("lreq %p register_gen %u ignoring old pong %u\n", lreq,
+		     lreq->register_gen, req->r_ops[0].watch.gen);
+	}
+
+	mutex_unlock(&lreq->lock);
+	linger_put(lreq);
+}
+
+static void send_linger_ping(struct ceph_osd_linger_request *lreq)
+{
+	struct ceph_osd_client *osdc = lreq->osdc;
+	struct ceph_osd_request *req = lreq->ping_req;
+	struct ceph_osd_req_op *op = &req->r_ops[0];
+
+	if (ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSERD)) {
+		dout("%s PAUSERD\n", __func__);
+		return;
+	}
+
+	lreq->ping_sent = jiffies;
+	dout("%s lreq %p linger_id %llu ping_sent %lu register_gen %u\n",
+	     __func__, lreq, lreq->linger_id, lreq->ping_sent,
+	     lreq->register_gen);
+
+	if (req->r_osd)
+		cancel_linger_request(req);
+
+	request_reinit(req);
+	target_copy(&req->r_t, &lreq->t);
+
+	WARN_ON(op->op != CEPH_OSD_OP_WATCH ||
+		op->watch.cookie != lreq->linger_id ||
+		op->watch.op != CEPH_OSD_WATCH_OP_PING);
+	op->watch.gen = lreq->register_gen;
+	req->r_callback = linger_ping_cb;
+	req->r_priv = linger_get(lreq);
+	req->r_linger = true;
+
+	ceph_osdc_get_request(req);
+	account_request(req);
+	req->r_tid = atomic64_inc_return(&osdc->last_tid);
+	link_request(lreq->osd, req);
+	send_request(req);
+}
+
+static void linger_submit(struct ceph_osd_linger_request *lreq)
+{
+	struct ceph_osd_client *osdc = lreq->osdc;
+	struct ceph_osd *osd;
+
+	calc_target(osdc, &lreq->t, NULL, false);
+	osd = lookup_create_osd(osdc, lreq->t.osd, true);
+	link_linger(osd, lreq);
+
+	send_linger(lreq);
+}
+
+static void cancel_linger_map_check(struct ceph_osd_linger_request *lreq)
+{
+	struct ceph_osd_client *osdc = lreq->osdc;
+	struct ceph_osd_linger_request *lookup_lreq;
+
+	verify_osdc_wrlocked(osdc);
+
+	lookup_lreq = lookup_linger_mc(&osdc->linger_map_checks,
+				       lreq->linger_id);
+	if (!lookup_lreq)
+		return;
+
+	WARN_ON(lookup_lreq != lreq);
+	erase_linger_mc(&osdc->linger_map_checks, lreq);
+	linger_put(lreq);
+}
+
+/*
+ * @lreq has to be both registered and linked.
+ */
+static void __linger_cancel(struct ceph_osd_linger_request *lreq)
+{
+	if (lreq->is_watch && lreq->ping_req->r_osd)
+		cancel_linger_request(lreq->ping_req);
+	if (lreq->reg_req->r_osd)
+		cancel_linger_request(lreq->reg_req);
+	cancel_linger_map_check(lreq);
+	unlink_linger(lreq->osd, lreq);
+	linger_unregister(lreq);
+}
+
+static void linger_cancel(struct ceph_osd_linger_request *lreq)
+{
+	struct ceph_osd_client *osdc = lreq->osdc;
+
+	down_write(&osdc->lock);
+	if (__linger_registered(lreq))
+		__linger_cancel(lreq);
+	up_write(&osdc->lock);
+}
+
+static void send_linger_map_check(struct ceph_osd_linger_request *lreq);
+
+static void check_linger_pool_dne(struct ceph_osd_linger_request *lreq)
+{
+	struct ceph_osd_client *osdc = lreq->osdc;
+	struct ceph_osdmap *map = osdc->osdmap;
+
+	verify_osdc_wrlocked(osdc);
+	WARN_ON(!map->epoch);
+
+	if (lreq->register_gen) {
+		lreq->map_dne_bound = map->epoch;
+		dout("%s lreq %p linger_id %llu pool disappeared\n", __func__,
+		     lreq, lreq->linger_id);
+	} else {
+		dout("%s lreq %p linger_id %llu map_dne_bound %u have %u\n",
+		     __func__, lreq, lreq->linger_id, lreq->map_dne_bound,
+		     map->epoch);
+	}
+
+	if (lreq->map_dne_bound) {
+		if (map->epoch >= lreq->map_dne_bound) {
+			/* we had a new enough map */
+			pr_info("linger_id %llu pool does not exist\n",
+				lreq->linger_id);
+			linger_reg_commit_complete(lreq, -ENOENT);
+			__linger_cancel(lreq);
+		}
+	} else {
+		send_linger_map_check(lreq);
+	}
+}
+
+static void linger_map_check_cb(struct ceph_mon_generic_request *greq)
+{
+	struct ceph_osd_client *osdc = &greq->monc->client->osdc;
+	struct ceph_osd_linger_request *lreq;
+	u64 linger_id = greq->private_data;
+
+	WARN_ON(greq->result || !greq->u.newest);
+
+	down_write(&osdc->lock);
+	lreq = lookup_linger_mc(&osdc->linger_map_checks, linger_id);
+	if (!lreq) {
+		dout("%s linger_id %llu dne\n", __func__, linger_id);
+		goto out_unlock;
+	}
+
+	dout("%s lreq %p linger_id %llu map_dne_bound %u newest %llu\n",
+	     __func__, lreq, lreq->linger_id, lreq->map_dne_bound,
+	     greq->u.newest);
+	if (!lreq->map_dne_bound)
+		lreq->map_dne_bound = greq->u.newest;
+	erase_linger_mc(&osdc->linger_map_checks, lreq);
+	check_linger_pool_dne(lreq);
+
+	linger_put(lreq);
+out_unlock:
+	up_write(&osdc->lock);
+}
+
+static void send_linger_map_check(struct ceph_osd_linger_request *lreq)
+{
+	struct ceph_osd_client *osdc = lreq->osdc;
+	struct ceph_osd_linger_request *lookup_lreq;
+	int ret;
+
+	verify_osdc_wrlocked(osdc);
+
+	lookup_lreq = lookup_linger_mc(&osdc->linger_map_checks,
+				       lreq->linger_id);
+	if (lookup_lreq) {
+		WARN_ON(lookup_lreq != lreq);
+		return;
+	}
+
+	linger_get(lreq);
+	insert_linger_mc(&osdc->linger_map_checks, lreq);
+	ret = ceph_monc_get_version_async(&osdc->client->monc, "osdmap",
+					  linger_map_check_cb, lreq->linger_id);
+	WARN_ON(ret);
+}
+
+static int linger_reg_commit_wait(struct ceph_osd_linger_request *lreq)
+{
+	int ret;
+
+	dout("%s lreq %p linger_id %llu\n", __func__, lreq, lreq->linger_id);
+	ret = wait_for_completion_interruptible(&lreq->reg_commit_wait);
+	return ret ?: lreq->reg_commit_error;
+}
+
+static int linger_notify_finish_wait(struct ceph_osd_linger_request *lreq)
+{
+	int ret;
+
+	dout("%s lreq %p linger_id %llu\n", __func__, lreq, lreq->linger_id);
+	ret = wait_for_completion_interruptible(&lreq->notify_finish_wait);
+	return ret ?: lreq->notify_finish_error;
+}
+
+/*
+ * Timeout callback, called every N seconds.  When 1 or more OSD
+ * requests has been active for more than N seconds, we send a keepalive
+ * (tag + timestamp) to its OSD to ensure any communications channel
+ * reset is detected.
+ */
+static void handle_timeout(struct work_struct *work)
+{
+	struct ceph_osd_client *osdc =
+		container_of(work, struct ceph_osd_client, timeout_work.work);
+	struct ceph_options *opts = osdc->client->options;
+	unsigned long cutoff = jiffies - opts->osd_keepalive_timeout;
+	unsigned long expiry_cutoff = jiffies - opts->osd_request_timeout;
+	LIST_HEAD(slow_osds);
+	struct rb_node *n, *p;
+
+	dout("%s osdc %p\n", __func__, osdc);
+	down_write(&osdc->lock);
+
+	/*
+	 * ping osds that are a bit slow.  this ensures that if there
+	 * is a break in the TCP connection we will notice, and reopen
+	 * a connection with that osd (from the fault callback).
+	 */
+	for (n = rb_first(&osdc->osds); n; n = rb_next(n)) {
+		struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
+		bool found = false;
+
+		for (p = rb_first(&osd->o_requests); p; ) {
+			struct ceph_osd_request *req =
+			    rb_entry(p, struct ceph_osd_request, r_node);
+
+			p = rb_next(p); /* abort_request() */
+
+			if (time_before(req->r_stamp, cutoff)) {
+				dout(" req %p tid %llu on osd%d is laggy\n",
+				     req, req->r_tid, osd->o_osd);
+				found = true;
+			}
+			if (opts->osd_request_timeout &&
+			    time_before(req->r_start_stamp, expiry_cutoff)) {
+				pr_err_ratelimited("tid %llu on osd%d timeout\n",
+				       req->r_tid, osd->o_osd);
+				abort_request(req, -ETIMEDOUT);
+			}
+		}
+		for (p = rb_first(&osd->o_linger_requests); p; p = rb_next(p)) {
+			struct ceph_osd_linger_request *lreq =
+			    rb_entry(p, struct ceph_osd_linger_request, node);
+
+			dout(" lreq %p linger_id %llu is served by osd%d\n",
+			     lreq, lreq->linger_id, osd->o_osd);
+			found = true;
+
+			mutex_lock(&lreq->lock);
+			if (lreq->is_watch && lreq->committed && !lreq->last_error)
+				send_linger_ping(lreq);
+			mutex_unlock(&lreq->lock);
+		}
+
+		if (found)
+			list_move_tail(&osd->o_keepalive_item, &slow_osds);
+	}
+
+	if (opts->osd_request_timeout) {
+		for (p = rb_first(&osdc->homeless_osd.o_requests); p; ) {
+			struct ceph_osd_request *req =
+			    rb_entry(p, struct ceph_osd_request, r_node);
+
+			p = rb_next(p); /* abort_request() */
+
+			if (time_before(req->r_start_stamp, expiry_cutoff)) {
+				pr_err_ratelimited("tid %llu on osd%d timeout\n",
+				       req->r_tid, osdc->homeless_osd.o_osd);
+				abort_request(req, -ETIMEDOUT);
+			}
+		}
+	}
+
+	if (atomic_read(&osdc->num_homeless) || !list_empty(&slow_osds))
+		maybe_request_map(osdc);
+
+	while (!list_empty(&slow_osds)) {
+		struct ceph_osd *osd = list_first_entry(&slow_osds,
+							struct ceph_osd,
+							o_keepalive_item);
+		list_del_init(&osd->o_keepalive_item);
+		ceph_con_keepalive(&osd->o_con);
+	}
+
+	up_write(&osdc->lock);
+	schedule_delayed_work(&osdc->timeout_work,
+			      osdc->client->options->osd_keepalive_timeout);
+}
+
+static void handle_osds_timeout(struct work_struct *work)
+{
+	struct ceph_osd_client *osdc =
+		container_of(work, struct ceph_osd_client,
+			     osds_timeout_work.work);
+	unsigned long delay = osdc->client->options->osd_idle_ttl / 4;
+	struct ceph_osd *osd, *nosd;
+
+	dout("%s osdc %p\n", __func__, osdc);
+	down_write(&osdc->lock);
+	list_for_each_entry_safe(osd, nosd, &osdc->osd_lru, o_osd_lru) {
+		if (time_before(jiffies, osd->lru_ttl))
+			break;
+
+		WARN_ON(!RB_EMPTY_ROOT(&osd->o_requests));
+		WARN_ON(!RB_EMPTY_ROOT(&osd->o_linger_requests));
+		close_osd(osd);
+	}
+
+	up_write(&osdc->lock);
+	schedule_delayed_work(&osdc->osds_timeout_work,
+			      round_jiffies_relative(delay));
+}
+
+static int ceph_oloc_decode(void **p, void *end,
+			    struct ceph_object_locator *oloc)
+{
+	u8 struct_v, struct_cv;
+	u32 len;
+	void *struct_end;
+	int ret = 0;
+
+	ceph_decode_need(p, end, 1 + 1 + 4, e_inval);
+	struct_v = ceph_decode_8(p);
+	struct_cv = ceph_decode_8(p);
+	if (struct_v < 3) {
+		pr_warn("got v %d < 3 cv %d of ceph_object_locator\n",
+			struct_v, struct_cv);
+		goto e_inval;
+	}
+	if (struct_cv > 6) {
+		pr_warn("got v %d cv %d > 6 of ceph_object_locator\n",
+			struct_v, struct_cv);
+		goto e_inval;
+	}
+	len = ceph_decode_32(p);
+	ceph_decode_need(p, end, len, e_inval);
+	struct_end = *p + len;
+
+	oloc->pool = ceph_decode_64(p);
+	*p += 4; /* skip preferred */
+
+	len = ceph_decode_32(p);
+	if (len > 0) {
+		pr_warn("ceph_object_locator::key is set\n");
+		goto e_inval;
+	}
+
+	if (struct_v >= 5) {
+		bool changed = false;
+
+		len = ceph_decode_32(p);
+		if (len > 0) {
+			ceph_decode_need(p, end, len, e_inval);
+			if (!oloc->pool_ns ||
+			    ceph_compare_string(oloc->pool_ns, *p, len))
+				changed = true;
+			*p += len;
+		} else {
+			if (oloc->pool_ns)
+				changed = true;
+		}
+		if (changed) {
+			/* redirect changes namespace */
+			pr_warn("ceph_object_locator::nspace is changed\n");
+			goto e_inval;
+		}
+	}
+
+	if (struct_v >= 6) {
+		s64 hash = ceph_decode_64(p);
+		if (hash != -1) {
+			pr_warn("ceph_object_locator::hash is set\n");
+			goto e_inval;
+		}
+	}
+
+	/* skip the rest */
+	*p = struct_end;
+out:
+	return ret;
+
+e_inval:
+	ret = -EINVAL;
+	goto out;
+}
+
+static int ceph_redirect_decode(void **p, void *end,
+				struct ceph_request_redirect *redir)
+{
+	u8 struct_v, struct_cv;
+	u32 len;
+	void *struct_end;
+	int ret;
+
+	ceph_decode_need(p, end, 1 + 1 + 4, e_inval);
+	struct_v = ceph_decode_8(p);
+	struct_cv = ceph_decode_8(p);
+	if (struct_cv > 1) {
+		pr_warn("got v %d cv %d > 1 of ceph_request_redirect\n",
+			struct_v, struct_cv);
+		goto e_inval;
+	}
+	len = ceph_decode_32(p);
+	ceph_decode_need(p, end, len, e_inval);
+	struct_end = *p + len;
+
+	ret = ceph_oloc_decode(p, end, &redir->oloc);
+	if (ret)
+		goto out;
+
+	len = ceph_decode_32(p);
+	if (len > 0) {
+		pr_warn("ceph_request_redirect::object_name is set\n");
+		goto e_inval;
+	}
+
+	len = ceph_decode_32(p);
+	*p += len; /* skip osd_instructions */
+
+	/* skip the rest */
+	*p = struct_end;
+out:
+	return ret;
+
+e_inval:
+	ret = -EINVAL;
+	goto out;
+}
+
+struct MOSDOpReply {
+	struct ceph_pg pgid;
+	u64 flags;
+	int result;
+	u32 epoch;
+	int num_ops;
+	u32 outdata_len[CEPH_OSD_MAX_OPS];
+	s32 rval[CEPH_OSD_MAX_OPS];
+	int retry_attempt;
+	struct ceph_eversion replay_version;
+	u64 user_version;
+	struct ceph_request_redirect redirect;
+};
+
+static int decode_MOSDOpReply(const struct ceph_msg *msg, struct MOSDOpReply *m)
+{
+	void *p = msg->front.iov_base;
+	void *const end = p + msg->front.iov_len;
+	u16 version = le16_to_cpu(msg->hdr.version);
+	struct ceph_eversion bad_replay_version;
+	u8 decode_redir;
+	u32 len;
+	int ret;
+	int i;
+
+	ceph_decode_32_safe(&p, end, len, e_inval);
+	ceph_decode_need(&p, end, len, e_inval);
+	p += len; /* skip oid */
+
+	ret = ceph_decode_pgid(&p, end, &m->pgid);
+	if (ret)
+		return ret;
+
+	ceph_decode_64_safe(&p, end, m->flags, e_inval);
+	ceph_decode_32_safe(&p, end, m->result, e_inval);
+	ceph_decode_need(&p, end, sizeof(bad_replay_version), e_inval);
+	memcpy(&bad_replay_version, p, sizeof(bad_replay_version));
+	p += sizeof(bad_replay_version);
+	ceph_decode_32_safe(&p, end, m->epoch, e_inval);
+
+	ceph_decode_32_safe(&p, end, m->num_ops, e_inval);
+	if (m->num_ops > ARRAY_SIZE(m->outdata_len))
+		goto e_inval;
+
+	ceph_decode_need(&p, end, m->num_ops * sizeof(struct ceph_osd_op),
+			 e_inval);
+	for (i = 0; i < m->num_ops; i++) {
+		struct ceph_osd_op *op = p;
+
+		m->outdata_len[i] = le32_to_cpu(op->payload_len);
+		p += sizeof(*op);
+	}
+
+	ceph_decode_32_safe(&p, end, m->retry_attempt, e_inval);
+	for (i = 0; i < m->num_ops; i++)
+		ceph_decode_32_safe(&p, end, m->rval[i], e_inval);
+
+	if (version >= 5) {
+		ceph_decode_need(&p, end, sizeof(m->replay_version), e_inval);
+		memcpy(&m->replay_version, p, sizeof(m->replay_version));
+		p += sizeof(m->replay_version);
+		ceph_decode_64_safe(&p, end, m->user_version, e_inval);
+	} else {
+		m->replay_version = bad_replay_version; /* struct */
+		m->user_version = le64_to_cpu(m->replay_version.version);
+	}
+
+	if (version >= 6) {
+		if (version >= 7)
+			ceph_decode_8_safe(&p, end, decode_redir, e_inval);
+		else
+			decode_redir = 1;
+	} else {
+		decode_redir = 0;
+	}
+
+	if (decode_redir) {
+		ret = ceph_redirect_decode(&p, end, &m->redirect);
+		if (ret)
+			return ret;
+	} else {
+		ceph_oloc_init(&m->redirect.oloc);
+	}
+
+	return 0;
+
+e_inval:
+	return -EINVAL;
+}
+
+/*
+ * Handle MOSDOpReply.  Set ->r_result and call the callback if it is
+ * specified.
+ */
+static void handle_reply(struct ceph_osd *osd, struct ceph_msg *msg)
+{
+	struct ceph_osd_client *osdc = osd->o_osdc;
+	struct ceph_osd_request *req;
+	struct MOSDOpReply m;
+	u64 tid = le64_to_cpu(msg->hdr.tid);
+	u32 data_len = 0;
+	int ret;
+	int i;
+
+	dout("%s msg %p tid %llu\n", __func__, msg, tid);
+
+	down_read(&osdc->lock);
+	if (!osd_registered(osd)) {
+		dout("%s osd%d unknown\n", __func__, osd->o_osd);
+		goto out_unlock_osdc;
+	}
+	WARN_ON(osd->o_osd != le64_to_cpu(msg->hdr.src.num));
+
+	mutex_lock(&osd->lock);
+	req = lookup_request(&osd->o_requests, tid);
+	if (!req) {
+		dout("%s osd%d tid %llu unknown\n", __func__, osd->o_osd, tid);
+		goto out_unlock_session;
+	}
+
+	m.redirect.oloc.pool_ns = req->r_t.target_oloc.pool_ns;
+	ret = decode_MOSDOpReply(msg, &m);
+	m.redirect.oloc.pool_ns = NULL;
+	if (ret) {
+		pr_err("failed to decode MOSDOpReply for tid %llu: %d\n",
+		       req->r_tid, ret);
+		ceph_msg_dump(msg);
+		goto fail_request;
+	}
+	dout("%s req %p tid %llu flags 0x%llx pgid %llu.%x epoch %u attempt %d v %u'%llu uv %llu\n",
+	     __func__, req, req->r_tid, m.flags, m.pgid.pool, m.pgid.seed,
+	     m.epoch, m.retry_attempt, le32_to_cpu(m.replay_version.epoch),
+	     le64_to_cpu(m.replay_version.version), m.user_version);
+
+	if (m.retry_attempt >= 0) {
+		if (m.retry_attempt != req->r_attempts - 1) {
+			dout("req %p tid %llu retry_attempt %d != %d, ignoring\n",
+			     req, req->r_tid, m.retry_attempt,
+			     req->r_attempts - 1);
+			goto out_unlock_session;
+		}
+	} else {
+		WARN_ON(1); /* MOSDOpReply v4 is assumed */
+	}
+
+	if (!ceph_oloc_empty(&m.redirect.oloc)) {
+		dout("req %p tid %llu redirect pool %lld\n", req, req->r_tid,
+		     m.redirect.oloc.pool);
+		unlink_request(osd, req);
+		mutex_unlock(&osd->lock);
+
+		/*
+		 * Not ceph_oloc_copy() - changing pool_ns is not
+		 * supported.
+		 */
+		req->r_t.target_oloc.pool = m.redirect.oloc.pool;
+		req->r_flags |= CEPH_OSD_FLAG_REDIRECTED |
+				CEPH_OSD_FLAG_IGNORE_OVERLAY |
+				CEPH_OSD_FLAG_IGNORE_CACHE;
+		req->r_tid = 0;
+		__submit_request(req, false);
+		goto out_unlock_osdc;
+	}
+
+	if (m.num_ops != req->r_num_ops) {
+		pr_err("num_ops %d != %d for tid %llu\n", m.num_ops,
+		       req->r_num_ops, req->r_tid);
+		goto fail_request;
+	}
+	for (i = 0; i < req->r_num_ops; i++) {
+		dout(" req %p tid %llu op %d rval %d len %u\n", req,
+		     req->r_tid, i, m.rval[i], m.outdata_len[i]);
+		req->r_ops[i].rval = m.rval[i];
+		req->r_ops[i].outdata_len = m.outdata_len[i];
+		data_len += m.outdata_len[i];
+	}
+	if (data_len != le32_to_cpu(msg->hdr.data_len)) {
+		pr_err("sum of lens %u != %u for tid %llu\n", data_len,
+		       le32_to_cpu(msg->hdr.data_len), req->r_tid);
+		goto fail_request;
+	}
+	dout("%s req %p tid %llu result %d data_len %u\n", __func__,
+	     req, req->r_tid, m.result, data_len);
+
+	/*
+	 * Since we only ever request ONDISK, we should only ever get
+	 * one (type of) reply back.
+	 */
+	WARN_ON(!(m.flags & CEPH_OSD_FLAG_ONDISK));
+	req->r_result = m.result ?: data_len;
+	finish_request(req);
+	mutex_unlock(&osd->lock);
+	up_read(&osdc->lock);
+
+	__complete_request(req);
+	return;
+
+fail_request:
+	complete_request(req, -EIO);
+out_unlock_session:
+	mutex_unlock(&osd->lock);
+out_unlock_osdc:
+	up_read(&osdc->lock);
+}
+
+static void set_pool_was_full(struct ceph_osd_client *osdc)
+{
+	struct rb_node *n;
+
+	for (n = rb_first(&osdc->osdmap->pg_pools); n; n = rb_next(n)) {
+		struct ceph_pg_pool_info *pi =
+		    rb_entry(n, struct ceph_pg_pool_info, node);
+
+		pi->was_full = __pool_full(pi);
+	}
+}
+
+static bool pool_cleared_full(struct ceph_osd_client *osdc, s64 pool_id)
+{
+	struct ceph_pg_pool_info *pi;
+
+	pi = ceph_pg_pool_by_id(osdc->osdmap, pool_id);
+	if (!pi)
+		return false;
+
+	return pi->was_full && !__pool_full(pi);
+}
+
+static enum calc_target_result
+recalc_linger_target(struct ceph_osd_linger_request *lreq)
+{
+	struct ceph_osd_client *osdc = lreq->osdc;
+	enum calc_target_result ct_res;
+
+	ct_res = calc_target(osdc, &lreq->t, NULL, true);
+	if (ct_res == CALC_TARGET_NEED_RESEND) {
+		struct ceph_osd *osd;
+
+		osd = lookup_create_osd(osdc, lreq->t.osd, true);
+		if (osd != lreq->osd) {
+			unlink_linger(lreq->osd, lreq);
+			link_linger(osd, lreq);
+		}
+	}
+
+	return ct_res;
+}
+
+/*
+ * Requeue requests whose mapping to an OSD has changed.
+ */
+static void scan_requests(struct ceph_osd *osd,
+			  bool force_resend,
+			  bool cleared_full,
+			  bool check_pool_cleared_full,
+			  struct rb_root *need_resend,
+			  struct list_head *need_resend_linger)
+{
+	struct ceph_osd_client *osdc = osd->o_osdc;
+	struct rb_node *n;
+	bool force_resend_writes;
+
+	for (n = rb_first(&osd->o_linger_requests); n; ) {
+		struct ceph_osd_linger_request *lreq =
+		    rb_entry(n, struct ceph_osd_linger_request, node);
+		enum calc_target_result ct_res;
+
+		n = rb_next(n); /* recalc_linger_target() */
+
+		dout("%s lreq %p linger_id %llu\n", __func__, lreq,
+		     lreq->linger_id);
+		ct_res = recalc_linger_target(lreq);
+		switch (ct_res) {
+		case CALC_TARGET_NO_ACTION:
+			force_resend_writes = cleared_full ||
+			    (check_pool_cleared_full &&
+			     pool_cleared_full(osdc, lreq->t.base_oloc.pool));
+			if (!force_resend && !force_resend_writes)
+				break;
+
+			/* fall through */
+		case CALC_TARGET_NEED_RESEND:
+			cancel_linger_map_check(lreq);
+			/*
+			 * scan_requests() for the previous epoch(s)
+			 * may have already added it to the list, since
+			 * it's not unlinked here.
+			 */
+			if (list_empty(&lreq->scan_item))
+				list_add_tail(&lreq->scan_item, need_resend_linger);
+			break;
+		case CALC_TARGET_POOL_DNE:
+			list_del_init(&lreq->scan_item);
+			check_linger_pool_dne(lreq);
+			break;
+		}
+	}
+
+	for (n = rb_first(&osd->o_requests); n; ) {
+		struct ceph_osd_request *req =
+		    rb_entry(n, struct ceph_osd_request, r_node);
+		enum calc_target_result ct_res;
+
+		n = rb_next(n); /* unlink_request(), check_pool_dne() */
+
+		dout("%s req %p tid %llu\n", __func__, req, req->r_tid);
+		ct_res = calc_target(osdc, &req->r_t, &req->r_osd->o_con,
+				     false);
+		switch (ct_res) {
+		case CALC_TARGET_NO_ACTION:
+			force_resend_writes = cleared_full ||
+			    (check_pool_cleared_full &&
+			     pool_cleared_full(osdc, req->r_t.base_oloc.pool));
+			if (!force_resend &&
+			    (!(req->r_flags & CEPH_OSD_FLAG_WRITE) ||
+			     !force_resend_writes))
+				break;
+
+			/* fall through */
+		case CALC_TARGET_NEED_RESEND:
+			cancel_map_check(req);
+			unlink_request(osd, req);
+			insert_request(need_resend, req);
+			break;
+		case CALC_TARGET_POOL_DNE:
+			check_pool_dne(req);
+			break;
+		}
+	}
+}
+
+static int handle_one_map(struct ceph_osd_client *osdc,
+			  void *p, void *end, bool incremental,
+			  struct rb_root *need_resend,
+			  struct list_head *need_resend_linger)
+{
+	struct ceph_osdmap *newmap;
+	struct rb_node *n;
+	bool skipped_map = false;
+	bool was_full;
+
+	was_full = ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL);
+	set_pool_was_full(osdc);
+
+	if (incremental)
+		newmap = osdmap_apply_incremental(&p, end, osdc->osdmap);
+	else
+		newmap = ceph_osdmap_decode(&p, end);
+	if (IS_ERR(newmap))
+		return PTR_ERR(newmap);
+
+	if (newmap != osdc->osdmap) {
+		/*
+		 * Preserve ->was_full before destroying the old map.
+		 * For pools that weren't in the old map, ->was_full
+		 * should be false.
+		 */
+		for (n = rb_first(&newmap->pg_pools); n; n = rb_next(n)) {
+			struct ceph_pg_pool_info *pi =
+			    rb_entry(n, struct ceph_pg_pool_info, node);
+			struct ceph_pg_pool_info *old_pi;
+
+			old_pi = ceph_pg_pool_by_id(osdc->osdmap, pi->id);
+			if (old_pi)
+				pi->was_full = old_pi->was_full;
+			else
+				WARN_ON(pi->was_full);
+		}
+
+		if (osdc->osdmap->epoch &&
+		    osdc->osdmap->epoch + 1 < newmap->epoch) {
+			WARN_ON(incremental);
+			skipped_map = true;
+		}
+
+		ceph_osdmap_destroy(osdc->osdmap);
+		osdc->osdmap = newmap;
+	}
+
+	was_full &= !ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL);
+	scan_requests(&osdc->homeless_osd, skipped_map, was_full, true,
+		      need_resend, need_resend_linger);
+
+	for (n = rb_first(&osdc->osds); n; ) {
+		struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
+
+		n = rb_next(n); /* close_osd() */
+
+		scan_requests(osd, skipped_map, was_full, true, need_resend,
+			      need_resend_linger);
+		if (!ceph_osd_is_up(osdc->osdmap, osd->o_osd) ||
+		    memcmp(&osd->o_con.peer_addr,
+			   ceph_osd_addr(osdc->osdmap, osd->o_osd),
+			   sizeof(struct ceph_entity_addr)))
+			close_osd(osd);
+	}
+
+	return 0;
+}
+
+static void kick_requests(struct ceph_osd_client *osdc,
+			  struct rb_root *need_resend,
+			  struct list_head *need_resend_linger)
+{
+	struct ceph_osd_linger_request *lreq, *nlreq;
+	enum calc_target_result ct_res;
+	struct rb_node *n;
+
+	/* make sure need_resend targets reflect latest map */
+	for (n = rb_first(need_resend); n; ) {
+		struct ceph_osd_request *req =
+		    rb_entry(n, struct ceph_osd_request, r_node);
+
+		n = rb_next(n);
+
+		if (req->r_t.epoch < osdc->osdmap->epoch) {
+			ct_res = calc_target(osdc, &req->r_t, NULL, false);
+			if (ct_res == CALC_TARGET_POOL_DNE) {
+				erase_request(need_resend, req);
+				check_pool_dne(req);
+			}
+		}
+	}
+
+	for (n = rb_first(need_resend); n; ) {
+		struct ceph_osd_request *req =
+		    rb_entry(n, struct ceph_osd_request, r_node);
+		struct ceph_osd *osd;
+
+		n = rb_next(n);
+		erase_request(need_resend, req); /* before link_request() */
+
+		osd = lookup_create_osd(osdc, req->r_t.osd, true);
+		link_request(osd, req);
+		if (!req->r_linger) {
+			if (!osd_homeless(osd) && !req->r_t.paused)
+				send_request(req);
+		} else {
+			cancel_linger_request(req);
+		}
+	}
+
+	list_for_each_entry_safe(lreq, nlreq, need_resend_linger, scan_item) {
+		if (!osd_homeless(lreq->osd))
+			send_linger(lreq);
+
+		list_del_init(&lreq->scan_item);
+	}
+}
+
+/*
+ * Process updated osd map.
+ *
+ * The message contains any number of incremental and full maps, normally
+ * indicating some sort of topology change in the cluster.  Kick requests
+ * off to different OSDs as needed.
+ */
+void ceph_osdc_handle_map(struct ceph_osd_client *osdc, struct ceph_msg *msg)
+{
+	void *p = msg->front.iov_base;
+	void *const end = p + msg->front.iov_len;
+	u32 nr_maps, maplen;
+	u32 epoch;
+	struct ceph_fsid fsid;
+	struct rb_root need_resend = RB_ROOT;
+	LIST_HEAD(need_resend_linger);
+	bool handled_incremental = false;
+	bool was_pauserd, was_pausewr;
+	bool pauserd, pausewr;
+	int err;
+
+	dout("%s have %u\n", __func__, osdc->osdmap->epoch);
+	down_write(&osdc->lock);
+
+	/* verify fsid */
+	ceph_decode_need(&p, end, sizeof(fsid), bad);
+	ceph_decode_copy(&p, &fsid, sizeof(fsid));
+	if (ceph_check_fsid(osdc->client, &fsid) < 0)
+		goto bad;
+
+	was_pauserd = ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSERD);
+	was_pausewr = ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSEWR) ||
+		      ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL) ||
+		      have_pool_full(osdc);
+
+	/* incremental maps */
+	ceph_decode_32_safe(&p, end, nr_maps, bad);
+	dout(" %d inc maps\n", nr_maps);
+	while (nr_maps > 0) {
+		ceph_decode_need(&p, end, 2*sizeof(u32), bad);
+		epoch = ceph_decode_32(&p);
+		maplen = ceph_decode_32(&p);
+		ceph_decode_need(&p, end, maplen, bad);
+		if (osdc->osdmap->epoch &&
+		    osdc->osdmap->epoch + 1 == epoch) {
+			dout("applying incremental map %u len %d\n",
+			     epoch, maplen);
+			err = handle_one_map(osdc, p, p + maplen, true,
+					     &need_resend, &need_resend_linger);
+			if (err)
+				goto bad;
+			handled_incremental = true;
+		} else {
+			dout("ignoring incremental map %u len %d\n",
+			     epoch, maplen);
+		}
+		p += maplen;
+		nr_maps--;
+	}
+	if (handled_incremental)
+		goto done;
+
+	/* full maps */
+	ceph_decode_32_safe(&p, end, nr_maps, bad);
+	dout(" %d full maps\n", nr_maps);
+	while (nr_maps) {
+		ceph_decode_need(&p, end, 2*sizeof(u32), bad);
+		epoch = ceph_decode_32(&p);
+		maplen = ceph_decode_32(&p);
+		ceph_decode_need(&p, end, maplen, bad);
+		if (nr_maps > 1) {
+			dout("skipping non-latest full map %u len %d\n",
+			     epoch, maplen);
+		} else if (osdc->osdmap->epoch >= epoch) {
+			dout("skipping full map %u len %d, "
+			     "older than our %u\n", epoch, maplen,
+			     osdc->osdmap->epoch);
+		} else {
+			dout("taking full map %u len %d\n", epoch, maplen);
+			err = handle_one_map(osdc, p, p + maplen, false,
+					     &need_resend, &need_resend_linger);
+			if (err)
+				goto bad;
+		}
+		p += maplen;
+		nr_maps--;
+	}
+
+done:
+	/*
+	 * subscribe to subsequent osdmap updates if full to ensure
+	 * we find out when we are no longer full and stop returning
+	 * ENOSPC.
+	 */
+	pauserd = ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSERD);
+	pausewr = ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSEWR) ||
+		  ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL) ||
+		  have_pool_full(osdc);
+	if (was_pauserd || was_pausewr || pauserd || pausewr ||
+	    osdc->osdmap->epoch < osdc->epoch_barrier)
+		maybe_request_map(osdc);
+
+	kick_requests(osdc, &need_resend, &need_resend_linger);
+
+	ceph_osdc_abort_on_full(osdc);
+	ceph_monc_got_map(&osdc->client->monc, CEPH_SUB_OSDMAP,
+			  osdc->osdmap->epoch);
+	up_write(&osdc->lock);
+	wake_up_all(&osdc->client->auth_wq);
+	return;
+
+bad:
+	pr_err("osdc handle_map corrupt msg\n");
+	ceph_msg_dump(msg);
+	up_write(&osdc->lock);
+}
+
+/*
+ * Resubmit requests pending on the given osd.
+ */
+static void kick_osd_requests(struct ceph_osd *osd)
+{
+	struct rb_node *n;
+
+	clear_backoffs(osd);
+
+	for (n = rb_first(&osd->o_requests); n; ) {
+		struct ceph_osd_request *req =
+		    rb_entry(n, struct ceph_osd_request, r_node);
+
+		n = rb_next(n); /* cancel_linger_request() */
+
+		if (!req->r_linger) {
+			if (!req->r_t.paused)
+				send_request(req);
+		} else {
+			cancel_linger_request(req);
+		}
+	}
+	for (n = rb_first(&osd->o_linger_requests); n; n = rb_next(n)) {
+		struct ceph_osd_linger_request *lreq =
+		    rb_entry(n, struct ceph_osd_linger_request, node);
+
+		send_linger(lreq);
+	}
+}
+
+/*
+ * If the osd connection drops, we need to resubmit all requests.
+ */
+static void osd_fault(struct ceph_connection *con)
+{
+	struct ceph_osd *osd = con->private;
+	struct ceph_osd_client *osdc = osd->o_osdc;
+
+	dout("%s osd %p osd%d\n", __func__, osd, osd->o_osd);
+
+	down_write(&osdc->lock);
+	if (!osd_registered(osd)) {
+		dout("%s osd%d unknown\n", __func__, osd->o_osd);
+		goto out_unlock;
+	}
+
+	if (!reopen_osd(osd))
+		kick_osd_requests(osd);
+	maybe_request_map(osdc);
+
+out_unlock:
+	up_write(&osdc->lock);
+}
+
+struct MOSDBackoff {
+	struct ceph_spg spgid;
+	u32 map_epoch;
+	u8 op;
+	u64 id;
+	struct ceph_hobject_id *begin;
+	struct ceph_hobject_id *end;
+};
+
+static int decode_MOSDBackoff(const struct ceph_msg *msg, struct MOSDBackoff *m)
+{
+	void *p = msg->front.iov_base;
+	void *const end = p + msg->front.iov_len;
+	u8 struct_v;
+	u32 struct_len;
+	int ret;
+
+	ret = ceph_start_decoding(&p, end, 1, "spg_t", &struct_v, &struct_len);
+	if (ret)
+		return ret;
+
+	ret = ceph_decode_pgid(&p, end, &m->spgid.pgid);
+	if (ret)
+		return ret;
+
+	ceph_decode_8_safe(&p, end, m->spgid.shard, e_inval);
+	ceph_decode_32_safe(&p, end, m->map_epoch, e_inval);
+	ceph_decode_8_safe(&p, end, m->op, e_inval);
+	ceph_decode_64_safe(&p, end, m->id, e_inval);
+
+	m->begin = kzalloc(sizeof(*m->begin), GFP_NOIO);
+	if (!m->begin)
+		return -ENOMEM;
+
+	ret = decode_hoid(&p, end, m->begin);
+	if (ret) {
+		free_hoid(m->begin);
+		return ret;
+	}
+
+	m->end = kzalloc(sizeof(*m->end), GFP_NOIO);
+	if (!m->end) {
+		free_hoid(m->begin);
+		return -ENOMEM;
+	}
+
+	ret = decode_hoid(&p, end, m->end);
+	if (ret) {
+		free_hoid(m->begin);
+		free_hoid(m->end);
+		return ret;
+	}
+
+	return 0;
+
+e_inval:
+	return -EINVAL;
+}
+
+static struct ceph_msg *create_backoff_message(
+				const struct ceph_osd_backoff *backoff,
+				u32 map_epoch)
+{
+	struct ceph_msg *msg;
+	void *p, *end;
+	int msg_size;
+
+	msg_size = CEPH_ENCODING_START_BLK_LEN +
+			CEPH_PGID_ENCODING_LEN + 1; /* spgid */
+	msg_size += 4 + 1 + 8; /* map_epoch, op, id */
+	msg_size += CEPH_ENCODING_START_BLK_LEN +
+			hoid_encoding_size(backoff->begin);
+	msg_size += CEPH_ENCODING_START_BLK_LEN +
+			hoid_encoding_size(backoff->end);
+
+	msg = ceph_msg_new(CEPH_MSG_OSD_BACKOFF, msg_size, GFP_NOIO, true);
+	if (!msg)
+		return NULL;
+
+	p = msg->front.iov_base;
+	end = p + msg->front_alloc_len;
+
+	encode_spgid(&p, &backoff->spgid);
+	ceph_encode_32(&p, map_epoch);
+	ceph_encode_8(&p, CEPH_OSD_BACKOFF_OP_ACK_BLOCK);
+	ceph_encode_64(&p, backoff->id);
+	encode_hoid(&p, end, backoff->begin);
+	encode_hoid(&p, end, backoff->end);
+	BUG_ON(p != end);
+
+	msg->front.iov_len = p - msg->front.iov_base;
+	msg->hdr.version = cpu_to_le16(1); /* MOSDBackoff v1 */
+	msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
+
+	return msg;
+}
+
+static void handle_backoff_block(struct ceph_osd *osd, struct MOSDBackoff *m)
+{
+	struct ceph_spg_mapping *spg;
+	struct ceph_osd_backoff *backoff;
+	struct ceph_msg *msg;
+
+	dout("%s osd%d spgid %llu.%xs%d id %llu\n", __func__, osd->o_osd,
+	     m->spgid.pgid.pool, m->spgid.pgid.seed, m->spgid.shard, m->id);
+
+	spg = lookup_spg_mapping(&osd->o_backoff_mappings, &m->spgid);
+	if (!spg) {
+		spg = alloc_spg_mapping();
+		if (!spg) {
+			pr_err("%s failed to allocate spg\n", __func__);
+			return;
+		}
+		spg->spgid = m->spgid; /* struct */
+		insert_spg_mapping(&osd->o_backoff_mappings, spg);
+	}
+
+	backoff = alloc_backoff();
+	if (!backoff) {
+		pr_err("%s failed to allocate backoff\n", __func__);
+		return;
+	}
+	backoff->spgid = m->spgid; /* struct */
+	backoff->id = m->id;
+	backoff->begin = m->begin;
+	m->begin = NULL; /* backoff now owns this */
+	backoff->end = m->end;
+	m->end = NULL;   /* ditto */
+
+	insert_backoff(&spg->backoffs, backoff);
+	insert_backoff_by_id(&osd->o_backoffs_by_id, backoff);
+
+	/*
+	 * Ack with original backoff's epoch so that the OSD can
+	 * discard this if there was a PG split.
+	 */
+	msg = create_backoff_message(backoff, m->map_epoch);
+	if (!msg) {
+		pr_err("%s failed to allocate msg\n", __func__);
+		return;
+	}
+	ceph_con_send(&osd->o_con, msg);
+}
+
+static bool target_contained_by(const struct ceph_osd_request_target *t,
+				const struct ceph_hobject_id *begin,
+				const struct ceph_hobject_id *end)
+{
+	struct ceph_hobject_id hoid;
+	int cmp;
+
+	hoid_fill_from_target(&hoid, t);
+	cmp = hoid_compare(&hoid, begin);
+	return !cmp || (cmp > 0 && hoid_compare(&hoid, end) < 0);
+}
+
+static void handle_backoff_unblock(struct ceph_osd *osd,
+				   const struct MOSDBackoff *m)
+{
+	struct ceph_spg_mapping *spg;
+	struct ceph_osd_backoff *backoff;
+	struct rb_node *n;
+
+	dout("%s osd%d spgid %llu.%xs%d id %llu\n", __func__, osd->o_osd,
+	     m->spgid.pgid.pool, m->spgid.pgid.seed, m->spgid.shard, m->id);
+
+	backoff = lookup_backoff_by_id(&osd->o_backoffs_by_id, m->id);
+	if (!backoff) {
+		pr_err("%s osd%d spgid %llu.%xs%d id %llu backoff dne\n",
+		       __func__, osd->o_osd, m->spgid.pgid.pool,
+		       m->spgid.pgid.seed, m->spgid.shard, m->id);
+		return;
+	}
+
+	if (hoid_compare(backoff->begin, m->begin) &&
+	    hoid_compare(backoff->end, m->end)) {
+		pr_err("%s osd%d spgid %llu.%xs%d id %llu bad range?\n",
+		       __func__, osd->o_osd, m->spgid.pgid.pool,
+		       m->spgid.pgid.seed, m->spgid.shard, m->id);
+		/* unblock it anyway... */
+	}
+
+	spg = lookup_spg_mapping(&osd->o_backoff_mappings, &backoff->spgid);
+	BUG_ON(!spg);
+
+	erase_backoff(&spg->backoffs, backoff);
+	erase_backoff_by_id(&osd->o_backoffs_by_id, backoff);
+	free_backoff(backoff);
+
+	if (RB_EMPTY_ROOT(&spg->backoffs)) {
+		erase_spg_mapping(&osd->o_backoff_mappings, spg);
+		free_spg_mapping(spg);
+	}
+
+	for (n = rb_first(&osd->o_requests); n; n = rb_next(n)) {
+		struct ceph_osd_request *req =
+		    rb_entry(n, struct ceph_osd_request, r_node);
+
+		if (!ceph_spg_compare(&req->r_t.spgid, &m->spgid)) {
+			/*
+			 * Match against @m, not @backoff -- the PG may
+			 * have split on the OSD.
+			 */
+			if (target_contained_by(&req->r_t, m->begin, m->end)) {
+				/*
+				 * If no other installed backoff applies,
+				 * resend.
+				 */
+				send_request(req);
+			}
+		}
+	}
+}
+
+static void handle_backoff(struct ceph_osd *osd, struct ceph_msg *msg)
+{
+	struct ceph_osd_client *osdc = osd->o_osdc;
+	struct MOSDBackoff m;
+	int ret;
+
+	down_read(&osdc->lock);
+	if (!osd_registered(osd)) {
+		dout("%s osd%d unknown\n", __func__, osd->o_osd);
+		up_read(&osdc->lock);
+		return;
+	}
+	WARN_ON(osd->o_osd != le64_to_cpu(msg->hdr.src.num));
+
+	mutex_lock(&osd->lock);
+	ret = decode_MOSDBackoff(msg, &m);
+	if (ret) {
+		pr_err("failed to decode MOSDBackoff: %d\n", ret);
+		ceph_msg_dump(msg);
+		goto out_unlock;
+	}
+
+	switch (m.op) {
+	case CEPH_OSD_BACKOFF_OP_BLOCK:
+		handle_backoff_block(osd, &m);
+		break;
+	case CEPH_OSD_BACKOFF_OP_UNBLOCK:
+		handle_backoff_unblock(osd, &m);
+		break;
+	default:
+		pr_err("%s osd%d unknown op %d\n", __func__, osd->o_osd, m.op);
+	}
+
+	free_hoid(m.begin);
+	free_hoid(m.end);
+
+out_unlock:
+	mutex_unlock(&osd->lock);
+	up_read(&osdc->lock);
+}
+
+/*
+ * Process osd watch notifications
+ */
+static void handle_watch_notify(struct ceph_osd_client *osdc,
+				struct ceph_msg *msg)
+{
+	void *p = msg->front.iov_base;
+	void *const end = p + msg->front.iov_len;
+	struct ceph_osd_linger_request *lreq;
+	struct linger_work *lwork;
+	u8 proto_ver, opcode;
+	u64 cookie, notify_id;
+	u64 notifier_id = 0;
+	s32 return_code = 0;
+	void *payload = NULL;
+	u32 payload_len = 0;
+
+	ceph_decode_8_safe(&p, end, proto_ver, bad);
+	ceph_decode_8_safe(&p, end, opcode, bad);
+	ceph_decode_64_safe(&p, end, cookie, bad);
+	p += 8; /* skip ver */
+	ceph_decode_64_safe(&p, end, notify_id, bad);
+
+	if (proto_ver >= 1) {
+		ceph_decode_32_safe(&p, end, payload_len, bad);
+		ceph_decode_need(&p, end, payload_len, bad);
+		payload = p;
+		p += payload_len;
+	}
+
+	if (le16_to_cpu(msg->hdr.version) >= 2)
+		ceph_decode_32_safe(&p, end, return_code, bad);
+
+	if (le16_to_cpu(msg->hdr.version) >= 3)
+		ceph_decode_64_safe(&p, end, notifier_id, bad);
+
+	down_read(&osdc->lock);
+	lreq = lookup_linger_osdc(&osdc->linger_requests, cookie);
+	if (!lreq) {
+		dout("%s opcode %d cookie %llu dne\n", __func__, opcode,
+		     cookie);
+		goto out_unlock_osdc;
+	}
+
+	mutex_lock(&lreq->lock);
+	dout("%s opcode %d cookie %llu lreq %p is_watch %d\n", __func__,
+	     opcode, cookie, lreq, lreq->is_watch);
+	if (opcode == CEPH_WATCH_EVENT_DISCONNECT) {
+		if (!lreq->last_error) {
+			lreq->last_error = -ENOTCONN;
+			queue_watch_error(lreq);
+		}
+	} else if (!lreq->is_watch) {
+		/* CEPH_WATCH_EVENT_NOTIFY_COMPLETE */
+		if (lreq->notify_id && lreq->notify_id != notify_id) {
+			dout("lreq %p notify_id %llu != %llu, ignoring\n", lreq,
+			     lreq->notify_id, notify_id);
+		} else if (!completion_done(&lreq->notify_finish_wait)) {
+			struct ceph_msg_data *data =
+			    list_first_entry_or_null(&msg->data,
+						     struct ceph_msg_data,
+						     links);
+
+			if (data) {
+				if (lreq->preply_pages) {
+					WARN_ON(data->type !=
+							CEPH_MSG_DATA_PAGES);
+					*lreq->preply_pages = data->pages;
+					*lreq->preply_len = data->length;
+				} else {
+					ceph_release_page_vector(data->pages,
+					       calc_pages_for(0, data->length));
+				}
+			}
+			lreq->notify_finish_error = return_code;
+			complete_all(&lreq->notify_finish_wait);
+		}
+	} else {
+		/* CEPH_WATCH_EVENT_NOTIFY */
+		lwork = lwork_alloc(lreq, do_watch_notify);
+		if (!lwork) {
+			pr_err("failed to allocate notify-lwork\n");
+			goto out_unlock_lreq;
+		}
+
+		lwork->notify.notify_id = notify_id;
+		lwork->notify.notifier_id = notifier_id;
+		lwork->notify.payload = payload;
+		lwork->notify.payload_len = payload_len;
+		lwork->notify.msg = ceph_msg_get(msg);
+		lwork_queue(lwork);
+	}
+
+out_unlock_lreq:
+	mutex_unlock(&lreq->lock);
+out_unlock_osdc:
+	up_read(&osdc->lock);
+	return;
+
+bad:
+	pr_err("osdc handle_watch_notify corrupt msg\n");
+}
+
+/*
+ * Register request, send initial attempt.
+ */
+int ceph_osdc_start_request(struct ceph_osd_client *osdc,
+			    struct ceph_osd_request *req,
+			    bool nofail)
+{
+	down_read(&osdc->lock);
+	submit_request(req, false);
+	up_read(&osdc->lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(ceph_osdc_start_request);
+
+/*
+ * Unregister a registered request.  The request is not completed:
+ * ->r_result isn't set and __complete_request() isn't called.
+ */
+void ceph_osdc_cancel_request(struct ceph_osd_request *req)
+{
+	struct ceph_osd_client *osdc = req->r_osdc;
+
+	down_write(&osdc->lock);
+	if (req->r_osd)
+		cancel_request(req);
+	up_write(&osdc->lock);
+}
+EXPORT_SYMBOL(ceph_osdc_cancel_request);
+
+/*
+ * @timeout: in jiffies, 0 means "wait forever"
+ */
+static int wait_request_timeout(struct ceph_osd_request *req,
+				unsigned long timeout)
+{
+	long left;
+
+	dout("%s req %p tid %llu\n", __func__, req, req->r_tid);
+	left = wait_for_completion_killable_timeout(&req->r_completion,
+						ceph_timeout_jiffies(timeout));
+	if (left <= 0) {
+		left = left ?: -ETIMEDOUT;
+		ceph_osdc_cancel_request(req);
+	} else {
+		left = req->r_result; /* completed */
+	}
+
+	return left;
+}
+
+/*
+ * wait for a request to complete
+ */
+int ceph_osdc_wait_request(struct ceph_osd_client *osdc,
+			   struct ceph_osd_request *req)
+{
+	return wait_request_timeout(req, 0);
+}
+EXPORT_SYMBOL(ceph_osdc_wait_request);
+
+/*
+ * sync - wait for all in-flight requests to flush.  avoid starvation.
+ */
+void ceph_osdc_sync(struct ceph_osd_client *osdc)
+{
+	struct rb_node *n, *p;
+	u64 last_tid = atomic64_read(&osdc->last_tid);
+
+again:
+	down_read(&osdc->lock);
+	for (n = rb_first(&osdc->osds); n; n = rb_next(n)) {
+		struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
+
+		mutex_lock(&osd->lock);
+		for (p = rb_first(&osd->o_requests); p; p = rb_next(p)) {
+			struct ceph_osd_request *req =
+			    rb_entry(p, struct ceph_osd_request, r_node);
+
+			if (req->r_tid > last_tid)
+				break;
+
+			if (!(req->r_flags & CEPH_OSD_FLAG_WRITE))
+				continue;
+
+			ceph_osdc_get_request(req);
+			mutex_unlock(&osd->lock);
+			up_read(&osdc->lock);
+			dout("%s waiting on req %p tid %llu last_tid %llu\n",
+			     __func__, req, req->r_tid, last_tid);
+			wait_for_completion(&req->r_completion);
+			ceph_osdc_put_request(req);
+			goto again;
+		}
+
+		mutex_unlock(&osd->lock);
+	}
+
+	up_read(&osdc->lock);
+	dout("%s done last_tid %llu\n", __func__, last_tid);
+}
+EXPORT_SYMBOL(ceph_osdc_sync);
+
+static struct ceph_osd_request *
+alloc_linger_request(struct ceph_osd_linger_request *lreq)
+{
+	struct ceph_osd_request *req;
+
+	req = ceph_osdc_alloc_request(lreq->osdc, NULL, 1, false, GFP_NOIO);
+	if (!req)
+		return NULL;
+
+	ceph_oid_copy(&req->r_base_oid, &lreq->t.base_oid);
+	ceph_oloc_copy(&req->r_base_oloc, &lreq->t.base_oloc);
+
+	if (ceph_osdc_alloc_messages(req, GFP_NOIO)) {
+		ceph_osdc_put_request(req);
+		return NULL;
+	}
+
+	return req;
+}
+
+/*
+ * Returns a handle, caller owns a ref.
+ */
+struct ceph_osd_linger_request *
+ceph_osdc_watch(struct ceph_osd_client *osdc,
+		struct ceph_object_id *oid,
+		struct ceph_object_locator *oloc,
+		rados_watchcb2_t wcb,
+		rados_watcherrcb_t errcb,
+		void *data)
+{
+	struct ceph_osd_linger_request *lreq;
+	int ret;
+
+	lreq = linger_alloc(osdc);
+	if (!lreq)
+		return ERR_PTR(-ENOMEM);
+
+	lreq->is_watch = true;
+	lreq->wcb = wcb;
+	lreq->errcb = errcb;
+	lreq->data = data;
+	lreq->watch_valid_thru = jiffies;
+
+	ceph_oid_copy(&lreq->t.base_oid, oid);
+	ceph_oloc_copy(&lreq->t.base_oloc, oloc);
+	lreq->t.flags = CEPH_OSD_FLAG_WRITE;
+	ktime_get_real_ts64(&lreq->mtime);
+
+	lreq->reg_req = alloc_linger_request(lreq);
+	if (!lreq->reg_req) {
+		ret = -ENOMEM;
+		goto err_put_lreq;
+	}
+
+	lreq->ping_req = alloc_linger_request(lreq);
+	if (!lreq->ping_req) {
+		ret = -ENOMEM;
+		goto err_put_lreq;
+	}
+
+	down_write(&osdc->lock);
+	linger_register(lreq); /* before osd_req_op_* */
+	osd_req_op_watch_init(lreq->reg_req, 0, lreq->linger_id,
+			      CEPH_OSD_WATCH_OP_WATCH);
+	osd_req_op_watch_init(lreq->ping_req, 0, lreq->linger_id,
+			      CEPH_OSD_WATCH_OP_PING);
+	linger_submit(lreq);
+	up_write(&osdc->lock);
+
+	ret = linger_reg_commit_wait(lreq);
+	if (ret) {
+		linger_cancel(lreq);
+		goto err_put_lreq;
+	}
+
+	return lreq;
+
+err_put_lreq:
+	linger_put(lreq);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL(ceph_osdc_watch);
+
+/*
+ * Releases a ref.
+ *
+ * Times out after mount_timeout to preserve rbd unmap behaviour
+ * introduced in 2894e1d76974 ("rbd: timeout watch teardown on unmap
+ * with mount_timeout").
+ */
+int ceph_osdc_unwatch(struct ceph_osd_client *osdc,
+		      struct ceph_osd_linger_request *lreq)
+{
+	struct ceph_options *opts = osdc->client->options;
+	struct ceph_osd_request *req;
+	int ret;
+
+	req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_NOIO);
+	if (!req)
+		return -ENOMEM;
+
+	ceph_oid_copy(&req->r_base_oid, &lreq->t.base_oid);
+	ceph_oloc_copy(&req->r_base_oloc, &lreq->t.base_oloc);
+	req->r_flags = CEPH_OSD_FLAG_WRITE;
+	ktime_get_real_ts64(&req->r_mtime);
+	osd_req_op_watch_init(req, 0, lreq->linger_id,
+			      CEPH_OSD_WATCH_OP_UNWATCH);
+
+	ret = ceph_osdc_alloc_messages(req, GFP_NOIO);
+	if (ret)
+		goto out_put_req;
+
+	ceph_osdc_start_request(osdc, req, false);
+	linger_cancel(lreq);
+	linger_put(lreq);
+	ret = wait_request_timeout(req, opts->mount_timeout);
+
+out_put_req:
+	ceph_osdc_put_request(req);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_osdc_unwatch);
+
+static int osd_req_op_notify_ack_init(struct ceph_osd_request *req, int which,
+				      u64 notify_id, u64 cookie, void *payload,
+				      u32 payload_len)
+{
+	struct ceph_osd_req_op *op;
+	struct ceph_pagelist *pl;
+	int ret;
+
+	op = _osd_req_op_init(req, which, CEPH_OSD_OP_NOTIFY_ACK, 0);
+
+	pl = kmalloc(sizeof(*pl), GFP_NOIO);
+	if (!pl)
+		return -ENOMEM;
+
+	ceph_pagelist_init(pl);
+	ret = ceph_pagelist_encode_64(pl, notify_id);
+	ret |= ceph_pagelist_encode_64(pl, cookie);
+	if (payload) {
+		ret |= ceph_pagelist_encode_32(pl, payload_len);
+		ret |= ceph_pagelist_append(pl, payload, payload_len);
+	} else {
+		ret |= ceph_pagelist_encode_32(pl, 0);
+	}
+	if (ret) {
+		ceph_pagelist_release(pl);
+		return -ENOMEM;
+	}
+
+	ceph_osd_data_pagelist_init(&op->notify_ack.request_data, pl);
+	op->indata_len = pl->length;
+	return 0;
+}
+
+int ceph_osdc_notify_ack(struct ceph_osd_client *osdc,
+			 struct ceph_object_id *oid,
+			 struct ceph_object_locator *oloc,
+			 u64 notify_id,
+			 u64 cookie,
+			 void *payload,
+			 u32 payload_len)
+{
+	struct ceph_osd_request *req;
+	int ret;
+
+	req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_NOIO);
+	if (!req)
+		return -ENOMEM;
+
+	ceph_oid_copy(&req->r_base_oid, oid);
+	ceph_oloc_copy(&req->r_base_oloc, oloc);
+	req->r_flags = CEPH_OSD_FLAG_READ;
+
+	ret = ceph_osdc_alloc_messages(req, GFP_NOIO);
+	if (ret)
+		goto out_put_req;
+
+	ret = osd_req_op_notify_ack_init(req, 0, notify_id, cookie, payload,
+					 payload_len);
+	if (ret)
+		goto out_put_req;
+
+	ceph_osdc_start_request(osdc, req, false);
+	ret = ceph_osdc_wait_request(osdc, req);
+
+out_put_req:
+	ceph_osdc_put_request(req);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_osdc_notify_ack);
+
+static int osd_req_op_notify_init(struct ceph_osd_request *req, int which,
+				  u64 cookie, u32 prot_ver, u32 timeout,
+				  void *payload, u32 payload_len)
+{
+	struct ceph_osd_req_op *op;
+	struct ceph_pagelist *pl;
+	int ret;
+
+	op = _osd_req_op_init(req, which, CEPH_OSD_OP_NOTIFY, 0);
+	op->notify.cookie = cookie;
+
+	pl = kmalloc(sizeof(*pl), GFP_NOIO);
+	if (!pl)
+		return -ENOMEM;
+
+	ceph_pagelist_init(pl);
+	ret = ceph_pagelist_encode_32(pl, 1); /* prot_ver */
+	ret |= ceph_pagelist_encode_32(pl, timeout);
+	ret |= ceph_pagelist_encode_32(pl, payload_len);
+	ret |= ceph_pagelist_append(pl, payload, payload_len);
+	if (ret) {
+		ceph_pagelist_release(pl);
+		return -ENOMEM;
+	}
+
+	ceph_osd_data_pagelist_init(&op->notify.request_data, pl);
+	op->indata_len = pl->length;
+	return 0;
+}
+
+/*
+ * @timeout: in seconds
+ *
+ * @preply_{pages,len} are initialized both on success and error.
+ * The caller is responsible for:
+ *
+ *     ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len))
+ */
+int ceph_osdc_notify(struct ceph_osd_client *osdc,
+		     struct ceph_object_id *oid,
+		     struct ceph_object_locator *oloc,
+		     void *payload,
+		     u32 payload_len,
+		     u32 timeout,
+		     struct page ***preply_pages,
+		     size_t *preply_len)
+{
+	struct ceph_osd_linger_request *lreq;
+	struct page **pages;
+	int ret;
+
+	WARN_ON(!timeout);
+	if (preply_pages) {
+		*preply_pages = NULL;
+		*preply_len = 0;
+	}
+
+	lreq = linger_alloc(osdc);
+	if (!lreq)
+		return -ENOMEM;
+
+	lreq->preply_pages = preply_pages;
+	lreq->preply_len = preply_len;
+
+	ceph_oid_copy(&lreq->t.base_oid, oid);
+	ceph_oloc_copy(&lreq->t.base_oloc, oloc);
+	lreq->t.flags = CEPH_OSD_FLAG_READ;
+
+	lreq->reg_req = alloc_linger_request(lreq);
+	if (!lreq->reg_req) {
+		ret = -ENOMEM;
+		goto out_put_lreq;
+	}
+
+	/* for notify_id */
+	pages = ceph_alloc_page_vector(1, GFP_NOIO);
+	if (IS_ERR(pages)) {
+		ret = PTR_ERR(pages);
+		goto out_put_lreq;
+	}
+
+	down_write(&osdc->lock);
+	linger_register(lreq); /* before osd_req_op_* */
+	ret = osd_req_op_notify_init(lreq->reg_req, 0, lreq->linger_id, 1,
+				     timeout, payload, payload_len);
+	if (ret) {
+		linger_unregister(lreq);
+		up_write(&osdc->lock);
+		ceph_release_page_vector(pages, 1);
+		goto out_put_lreq;
+	}
+	ceph_osd_data_pages_init(osd_req_op_data(lreq->reg_req, 0, notify,
+						 response_data),
+				 pages, PAGE_SIZE, 0, false, true);
+	linger_submit(lreq);
+	up_write(&osdc->lock);
+
+	ret = linger_reg_commit_wait(lreq);
+	if (!ret)
+		ret = linger_notify_finish_wait(lreq);
+	else
+		dout("lreq %p failed to initiate notify %d\n", lreq, ret);
+
+	linger_cancel(lreq);
+out_put_lreq:
+	linger_put(lreq);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_osdc_notify);
+
+/*
+ * Return the number of milliseconds since the watch was last
+ * confirmed, or an error.  If there is an error, the watch is no
+ * longer valid, and should be destroyed with ceph_osdc_unwatch().
+ */
+int ceph_osdc_watch_check(struct ceph_osd_client *osdc,
+			  struct ceph_osd_linger_request *lreq)
+{
+	unsigned long stamp, age;
+	int ret;
+
+	down_read(&osdc->lock);
+	mutex_lock(&lreq->lock);
+	stamp = lreq->watch_valid_thru;
+	if (!list_empty(&lreq->pending_lworks)) {
+		struct linger_work *lwork =
+		    list_first_entry(&lreq->pending_lworks,
+				     struct linger_work,
+				     pending_item);
+
+		if (time_before(lwork->queued_stamp, stamp))
+			stamp = lwork->queued_stamp;
+	}
+	age = jiffies - stamp;
+	dout("%s lreq %p linger_id %llu age %lu last_error %d\n", __func__,
+	     lreq, lreq->linger_id, age, lreq->last_error);
+	/* we are truncating to msecs, so return a safe upper bound */
+	ret = lreq->last_error ?: 1 + jiffies_to_msecs(age);
+
+	mutex_unlock(&lreq->lock);
+	up_read(&osdc->lock);
+	return ret;
+}
+
+static int decode_watcher(void **p, void *end, struct ceph_watch_item *item)
+{
+	u8 struct_v;
+	u32 struct_len;
+	int ret;
+
+	ret = ceph_start_decoding(p, end, 2, "watch_item_t",
+				  &struct_v, &struct_len);
+	if (ret)
+		return ret;
+
+	ceph_decode_copy(p, &item->name, sizeof(item->name));
+	item->cookie = ceph_decode_64(p);
+	*p += 4; /* skip timeout_seconds */
+	if (struct_v >= 2) {
+		ceph_decode_copy(p, &item->addr, sizeof(item->addr));
+		ceph_decode_addr(&item->addr);
+	}
+
+	dout("%s %s%llu cookie %llu addr %s\n", __func__,
+	     ENTITY_NAME(item->name), item->cookie,
+	     ceph_pr_addr(&item->addr.in_addr));
+	return 0;
+}
+
+static int decode_watchers(void **p, void *end,
+			   struct ceph_watch_item **watchers,
+			   u32 *num_watchers)
+{
+	u8 struct_v;
+	u32 struct_len;
+	int i;
+	int ret;
+
+	ret = ceph_start_decoding(p, end, 1, "obj_list_watch_response_t",
+				  &struct_v, &struct_len);
+	if (ret)
+		return ret;
+
+	*num_watchers = ceph_decode_32(p);
+	*watchers = kcalloc(*num_watchers, sizeof(**watchers), GFP_NOIO);
+	if (!*watchers)
+		return -ENOMEM;
+
+	for (i = 0; i < *num_watchers; i++) {
+		ret = decode_watcher(p, end, *watchers + i);
+		if (ret) {
+			kfree(*watchers);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * On success, the caller is responsible for:
+ *
+ *     kfree(watchers);
+ */
+int ceph_osdc_list_watchers(struct ceph_osd_client *osdc,
+			    struct ceph_object_id *oid,
+			    struct ceph_object_locator *oloc,
+			    struct ceph_watch_item **watchers,
+			    u32 *num_watchers)
+{
+	struct ceph_osd_request *req;
+	struct page **pages;
+	int ret;
+
+	req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_NOIO);
+	if (!req)
+		return -ENOMEM;
+
+	ceph_oid_copy(&req->r_base_oid, oid);
+	ceph_oloc_copy(&req->r_base_oloc, oloc);
+	req->r_flags = CEPH_OSD_FLAG_READ;
+
+	ret = ceph_osdc_alloc_messages(req, GFP_NOIO);
+	if (ret)
+		goto out_put_req;
+
+	pages = ceph_alloc_page_vector(1, GFP_NOIO);
+	if (IS_ERR(pages)) {
+		ret = PTR_ERR(pages);
+		goto out_put_req;
+	}
+
+	osd_req_op_init(req, 0, CEPH_OSD_OP_LIST_WATCHERS, 0);
+	ceph_osd_data_pages_init(osd_req_op_data(req, 0, list_watchers,
+						 response_data),
+				 pages, PAGE_SIZE, 0, false, true);
+
+	ceph_osdc_start_request(osdc, req, false);
+	ret = ceph_osdc_wait_request(osdc, req);
+	if (ret >= 0) {
+		void *p = page_address(pages[0]);
+		void *const end = p + req->r_ops[0].outdata_len;
+
+		ret = decode_watchers(&p, end, watchers, num_watchers);
+	}
+
+out_put_req:
+	ceph_osdc_put_request(req);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_osdc_list_watchers);
+
+/*
+ * Call all pending notify callbacks - for use after a watch is
+ * unregistered, to make sure no more callbacks for it will be invoked
+ */
+void ceph_osdc_flush_notifies(struct ceph_osd_client *osdc)
+{
+	dout("%s osdc %p\n", __func__, osdc);
+	flush_workqueue(osdc->notify_wq);
+}
+EXPORT_SYMBOL(ceph_osdc_flush_notifies);
+
+void ceph_osdc_maybe_request_map(struct ceph_osd_client *osdc)
+{
+	down_read(&osdc->lock);
+	maybe_request_map(osdc);
+	up_read(&osdc->lock);
+}
+EXPORT_SYMBOL(ceph_osdc_maybe_request_map);
+
+/*
+ * Execute an OSD class method on an object.
+ *
+ * @flags: CEPH_OSD_FLAG_*
+ * @resp_len: in/out param for reply length
+ */
+int ceph_osdc_call(struct ceph_osd_client *osdc,
+		   struct ceph_object_id *oid,
+		   struct ceph_object_locator *oloc,
+		   const char *class, const char *method,
+		   unsigned int flags,
+		   struct page *req_page, size_t req_len,
+		   struct page *resp_page, size_t *resp_len)
+{
+	struct ceph_osd_request *req;
+	int ret;
+
+	if (req_len > PAGE_SIZE || (resp_page && *resp_len > PAGE_SIZE))
+		return -E2BIG;
+
+	req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_NOIO);
+	if (!req)
+		return -ENOMEM;
+
+	ceph_oid_copy(&req->r_base_oid, oid);
+	ceph_oloc_copy(&req->r_base_oloc, oloc);
+	req->r_flags = flags;
+
+	ret = ceph_osdc_alloc_messages(req, GFP_NOIO);
+	if (ret)
+		goto out_put_req;
+
+	ret = osd_req_op_cls_init(req, 0, CEPH_OSD_OP_CALL, class, method);
+	if (ret)
+		goto out_put_req;
+
+	if (req_page)
+		osd_req_op_cls_request_data_pages(req, 0, &req_page, req_len,
+						  0, false, false);
+	if (resp_page)
+		osd_req_op_cls_response_data_pages(req, 0, &resp_page,
+						   *resp_len, 0, false, false);
+
+	ceph_osdc_start_request(osdc, req, false);
+	ret = ceph_osdc_wait_request(osdc, req);
+	if (ret >= 0) {
+		ret = req->r_ops[0].rval;
+		if (resp_page)
+			*resp_len = req->r_ops[0].outdata_len;
+	}
+
+out_put_req:
+	ceph_osdc_put_request(req);
+	return ret;
+}
+EXPORT_SYMBOL(ceph_osdc_call);
+
+/*
+ * init, shutdown
+ */
+int ceph_osdc_init(struct ceph_osd_client *osdc, struct ceph_client *client)
+{
+	int err;
+
+	dout("init\n");
+	osdc->client = client;
+	init_rwsem(&osdc->lock);
+	osdc->osds = RB_ROOT;
+	INIT_LIST_HEAD(&osdc->osd_lru);
+	spin_lock_init(&osdc->osd_lru_lock);
+	osd_init(&osdc->homeless_osd);
+	osdc->homeless_osd.o_osdc = osdc;
+	osdc->homeless_osd.o_osd = CEPH_HOMELESS_OSD;
+	osdc->last_linger_id = CEPH_LINGER_ID_START;
+	osdc->linger_requests = RB_ROOT;
+	osdc->map_checks = RB_ROOT;
+	osdc->linger_map_checks = RB_ROOT;
+	INIT_DELAYED_WORK(&osdc->timeout_work, handle_timeout);
+	INIT_DELAYED_WORK(&osdc->osds_timeout_work, handle_osds_timeout);
+
+	err = -ENOMEM;
+	osdc->osdmap = ceph_osdmap_alloc();
+	if (!osdc->osdmap)
+		goto out;
+
+	osdc->req_mempool = mempool_create_slab_pool(10,
+						     ceph_osd_request_cache);
+	if (!osdc->req_mempool)
+		goto out_map;
+
+	err = ceph_msgpool_init(&osdc->msgpool_op, CEPH_MSG_OSD_OP,
+				PAGE_SIZE, 10, true, "osd_op");
+	if (err < 0)
+		goto out_mempool;
+	err = ceph_msgpool_init(&osdc->msgpool_op_reply, CEPH_MSG_OSD_OPREPLY,
+				PAGE_SIZE, 10, true, "osd_op_reply");
+	if (err < 0)
+		goto out_msgpool;
+
+	err = -ENOMEM;
+	osdc->notify_wq = create_singlethread_workqueue("ceph-watch-notify");
+	if (!osdc->notify_wq)
+		goto out_msgpool_reply;
+
+	osdc->completion_wq = create_singlethread_workqueue("ceph-completion");
+	if (!osdc->completion_wq)
+		goto out_notify_wq;
+
+	schedule_delayed_work(&osdc->timeout_work,
+			      osdc->client->options->osd_keepalive_timeout);
+	schedule_delayed_work(&osdc->osds_timeout_work,
+	    round_jiffies_relative(osdc->client->options->osd_idle_ttl));
+
+	return 0;
+
+out_notify_wq:
+	destroy_workqueue(osdc->notify_wq);
+out_msgpool_reply:
+	ceph_msgpool_destroy(&osdc->msgpool_op_reply);
+out_msgpool:
+	ceph_msgpool_destroy(&osdc->msgpool_op);
+out_mempool:
+	mempool_destroy(osdc->req_mempool);
+out_map:
+	ceph_osdmap_destroy(osdc->osdmap);
+out:
+	return err;
+}
+
+void ceph_osdc_stop(struct ceph_osd_client *osdc)
+{
+	destroy_workqueue(osdc->completion_wq);
+	destroy_workqueue(osdc->notify_wq);
+	cancel_delayed_work_sync(&osdc->timeout_work);
+	cancel_delayed_work_sync(&osdc->osds_timeout_work);
+
+	down_write(&osdc->lock);
+	while (!RB_EMPTY_ROOT(&osdc->osds)) {
+		struct ceph_osd *osd = rb_entry(rb_first(&osdc->osds),
+						struct ceph_osd, o_node);
+		close_osd(osd);
+	}
+	up_write(&osdc->lock);
+	WARN_ON(refcount_read(&osdc->homeless_osd.o_ref) != 1);
+	osd_cleanup(&osdc->homeless_osd);
+
+	WARN_ON(!list_empty(&osdc->osd_lru));
+	WARN_ON(!RB_EMPTY_ROOT(&osdc->linger_requests));
+	WARN_ON(!RB_EMPTY_ROOT(&osdc->map_checks));
+	WARN_ON(!RB_EMPTY_ROOT(&osdc->linger_map_checks));
+	WARN_ON(atomic_read(&osdc->num_requests));
+	WARN_ON(atomic_read(&osdc->num_homeless));
+
+	ceph_osdmap_destroy(osdc->osdmap);
+	mempool_destroy(osdc->req_mempool);
+	ceph_msgpool_destroy(&osdc->msgpool_op);
+	ceph_msgpool_destroy(&osdc->msgpool_op_reply);
+}
+
+/*
+ * Read some contiguous pages.  If we cross a stripe boundary, shorten
+ * *plen.  Return number of bytes read, or error.
+ */
+int ceph_osdc_readpages(struct ceph_osd_client *osdc,
+			struct ceph_vino vino, struct ceph_file_layout *layout,
+			u64 off, u64 *plen,
+			u32 truncate_seq, u64 truncate_size,
+			struct page **pages, int num_pages, int page_align)
+{
+	struct ceph_osd_request *req;
+	int rc = 0;
+
+	dout("readpages on ino %llx.%llx on %llu~%llu\n", vino.ino,
+	     vino.snap, off, *plen);
+	req = ceph_osdc_new_request(osdc, layout, vino, off, plen, 0, 1,
+				    CEPH_OSD_OP_READ, CEPH_OSD_FLAG_READ,
+				    NULL, truncate_seq, truncate_size,
+				    false);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+
+	/* it may be a short read due to an object boundary */
+	osd_req_op_extent_osd_data_pages(req, 0,
+				pages, *plen, page_align, false, false);
+
+	dout("readpages  final extent is %llu~%llu (%llu bytes align %d)\n",
+	     off, *plen, *plen, page_align);
+
+	rc = ceph_osdc_start_request(osdc, req, false);
+	if (!rc)
+		rc = ceph_osdc_wait_request(osdc, req);
+
+	ceph_osdc_put_request(req);
+	dout("readpages result %d\n", rc);
+	return rc;
+}
+EXPORT_SYMBOL(ceph_osdc_readpages);
+
+/*
+ * do a synchronous write on N pages
+ */
+int ceph_osdc_writepages(struct ceph_osd_client *osdc, struct ceph_vino vino,
+			 struct ceph_file_layout *layout,
+			 struct ceph_snap_context *snapc,
+			 u64 off, u64 len,
+			 u32 truncate_seq, u64 truncate_size,
+			 struct timespec64 *mtime,
+			 struct page **pages, int num_pages)
+{
+	struct ceph_osd_request *req;
+	int rc = 0;
+	int page_align = off & ~PAGE_MASK;
+
+	req = ceph_osdc_new_request(osdc, layout, vino, off, &len, 0, 1,
+				    CEPH_OSD_OP_WRITE, CEPH_OSD_FLAG_WRITE,
+				    snapc, truncate_seq, truncate_size,
+				    true);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+
+	/* it may be a short write due to an object boundary */
+	osd_req_op_extent_osd_data_pages(req, 0, pages, len, page_align,
+				false, false);
+	dout("writepages %llu~%llu (%llu bytes)\n", off, len, len);
+
+	req->r_mtime = *mtime;
+	rc = ceph_osdc_start_request(osdc, req, true);
+	if (!rc)
+		rc = ceph_osdc_wait_request(osdc, req);
+
+	ceph_osdc_put_request(req);
+	if (rc == 0)
+		rc = len;
+	dout("writepages result %d\n", rc);
+	return rc;
+}
+EXPORT_SYMBOL(ceph_osdc_writepages);
+
+int __init ceph_osdc_setup(void)
+{
+	size_t size = sizeof(struct ceph_osd_request) +
+	    CEPH_OSD_SLAB_OPS * sizeof(struct ceph_osd_req_op);
+
+	BUG_ON(ceph_osd_request_cache);
+	ceph_osd_request_cache = kmem_cache_create("ceph_osd_request", size,
+						   0, 0, NULL);
+
+	return ceph_osd_request_cache ? 0 : -ENOMEM;
+}
+
+void ceph_osdc_cleanup(void)
+{
+	BUG_ON(!ceph_osd_request_cache);
+	kmem_cache_destroy(ceph_osd_request_cache);
+	ceph_osd_request_cache = NULL;
+}
+
+/*
+ * handle incoming message
+ */
+static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
+{
+	struct ceph_osd *osd = con->private;
+	struct ceph_osd_client *osdc = osd->o_osdc;
+	int type = le16_to_cpu(msg->hdr.type);
+
+	switch (type) {
+	case CEPH_MSG_OSD_MAP:
+		ceph_osdc_handle_map(osdc, msg);
+		break;
+	case CEPH_MSG_OSD_OPREPLY:
+		handle_reply(osd, msg);
+		break;
+	case CEPH_MSG_OSD_BACKOFF:
+		handle_backoff(osd, msg);
+		break;
+	case CEPH_MSG_WATCH_NOTIFY:
+		handle_watch_notify(osdc, msg);
+		break;
+
+	default:
+		pr_err("received unknown message type %d %s\n", type,
+		       ceph_msg_type_name(type));
+	}
+
+	ceph_msg_put(msg);
+}
+
+/*
+ * Lookup and return message for incoming reply.  Don't try to do
+ * anything about a larger than preallocated data portion of the
+ * message at the moment - for now, just skip the message.
+ */
+static struct ceph_msg *get_reply(struct ceph_connection *con,
+				  struct ceph_msg_header *hdr,
+				  int *skip)
+{
+	struct ceph_osd *osd = con->private;
+	struct ceph_osd_client *osdc = osd->o_osdc;
+	struct ceph_msg *m = NULL;
+	struct ceph_osd_request *req;
+	int front_len = le32_to_cpu(hdr->front_len);
+	int data_len = le32_to_cpu(hdr->data_len);
+	u64 tid = le64_to_cpu(hdr->tid);
+
+	down_read(&osdc->lock);
+	if (!osd_registered(osd)) {
+		dout("%s osd%d unknown, skipping\n", __func__, osd->o_osd);
+		*skip = 1;
+		goto out_unlock_osdc;
+	}
+	WARN_ON(osd->o_osd != le64_to_cpu(hdr->src.num));
+
+	mutex_lock(&osd->lock);
+	req = lookup_request(&osd->o_requests, tid);
+	if (!req) {
+		dout("%s osd%d tid %llu unknown, skipping\n", __func__,
+		     osd->o_osd, tid);
+		*skip = 1;
+		goto out_unlock_session;
+	}
+
+	ceph_msg_revoke_incoming(req->r_reply);
+
+	if (front_len > req->r_reply->front_alloc_len) {
+		pr_warn("%s osd%d tid %llu front %d > preallocated %d\n",
+			__func__, osd->o_osd, req->r_tid, front_len,
+			req->r_reply->front_alloc_len);
+		m = ceph_msg_new(CEPH_MSG_OSD_OPREPLY, front_len, GFP_NOFS,
+				 false);
+		if (!m)
+			goto out_unlock_session;
+		ceph_msg_put(req->r_reply);
+		req->r_reply = m;
+	}
+
+	if (data_len > req->r_reply->data_length) {
+		pr_warn("%s osd%d tid %llu data %d > preallocated %zu, skipping\n",
+			__func__, osd->o_osd, req->r_tid, data_len,
+			req->r_reply->data_length);
+		m = NULL;
+		*skip = 1;
+		goto out_unlock_session;
+	}
+
+	m = ceph_msg_get(req->r_reply);
+	dout("get_reply tid %lld %p\n", tid, m);
+
+out_unlock_session:
+	mutex_unlock(&osd->lock);
+out_unlock_osdc:
+	up_read(&osdc->lock);
+	return m;
+}
+
+/*
+ * TODO: switch to a msg-owned pagelist
+ */
+static struct ceph_msg *alloc_msg_with_page_vector(struct ceph_msg_header *hdr)
+{
+	struct ceph_msg *m;
+	int type = le16_to_cpu(hdr->type);
+	u32 front_len = le32_to_cpu(hdr->front_len);
+	u32 data_len = le32_to_cpu(hdr->data_len);
+
+	m = ceph_msg_new(type, front_len, GFP_NOIO, false);
+	if (!m)
+		return NULL;
+
+	if (data_len) {
+		struct page **pages;
+		struct ceph_osd_data osd_data;
+
+		pages = ceph_alloc_page_vector(calc_pages_for(0, data_len),
+					       GFP_NOIO);
+		if (IS_ERR(pages)) {
+			ceph_msg_put(m);
+			return NULL;
+		}
+
+		ceph_osd_data_pages_init(&osd_data, pages, data_len, 0, false,
+					 false);
+		ceph_osdc_msg_data_add(m, &osd_data);
+	}
+
+	return m;
+}
+
+static struct ceph_msg *alloc_msg(struct ceph_connection *con,
+				  struct ceph_msg_header *hdr,
+				  int *skip)
+{
+	struct ceph_osd *osd = con->private;
+	int type = le16_to_cpu(hdr->type);
+
+	*skip = 0;
+	switch (type) {
+	case CEPH_MSG_OSD_MAP:
+	case CEPH_MSG_OSD_BACKOFF:
+	case CEPH_MSG_WATCH_NOTIFY:
+		return alloc_msg_with_page_vector(hdr);
+	case CEPH_MSG_OSD_OPREPLY:
+		return get_reply(con, hdr, skip);
+	default:
+		pr_warn("%s osd%d unknown msg type %d, skipping\n", __func__,
+			osd->o_osd, type);
+		*skip = 1;
+		return NULL;
+	}
+}
+
+/*
+ * Wrappers to refcount containing ceph_osd struct
+ */
+static struct ceph_connection *get_osd_con(struct ceph_connection *con)
+{
+	struct ceph_osd *osd = con->private;
+	if (get_osd(osd))
+		return con;
+	return NULL;
+}
+
+static void put_osd_con(struct ceph_connection *con)
+{
+	struct ceph_osd *osd = con->private;
+	put_osd(osd);
+}
+
+/*
+ * authentication
+ */
+/*
+ * Note: returned pointer is the address of a structure that's
+ * managed separately.  Caller must *not* attempt to free it.
+ */
+static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
+					int *proto, int force_new)
+{
+	struct ceph_osd *o = con->private;
+	struct ceph_osd_client *osdc = o->o_osdc;
+	struct ceph_auth_client *ac = osdc->client->monc.auth;
+	struct ceph_auth_handshake *auth = &o->o_auth;
+
+	if (force_new && auth->authorizer) {
+		ceph_auth_destroy_authorizer(auth->authorizer);
+		auth->authorizer = NULL;
+	}
+	if (!auth->authorizer) {
+		int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_OSD,
+						      auth);
+		if (ret)
+			return ERR_PTR(ret);
+	} else {
+		int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_OSD,
+						     auth);
+		if (ret)
+			return ERR_PTR(ret);
+	}
+	*proto = ac->protocol;
+
+	return auth;
+}
+
+static int add_authorizer_challenge(struct ceph_connection *con,
+				    void *challenge_buf, int challenge_buf_len)
+{
+	struct ceph_osd *o = con->private;
+	struct ceph_osd_client *osdc = o->o_osdc;
+	struct ceph_auth_client *ac = osdc->client->monc.auth;
+
+	return ceph_auth_add_authorizer_challenge(ac, o->o_auth.authorizer,
+					    challenge_buf, challenge_buf_len);
+}
+
+static int verify_authorizer_reply(struct ceph_connection *con)
+{
+	struct ceph_osd *o = con->private;
+	struct ceph_osd_client *osdc = o->o_osdc;
+	struct ceph_auth_client *ac = osdc->client->monc.auth;
+
+	return ceph_auth_verify_authorizer_reply(ac, o->o_auth.authorizer);
+}
+
+static int invalidate_authorizer(struct ceph_connection *con)
+{
+	struct ceph_osd *o = con->private;
+	struct ceph_osd_client *osdc = o->o_osdc;
+	struct ceph_auth_client *ac = osdc->client->monc.auth;
+
+	ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_OSD);
+	return ceph_monc_validate_auth(&osdc->client->monc);
+}
+
+static void osd_reencode_message(struct ceph_msg *msg)
+{
+	int type = le16_to_cpu(msg->hdr.type);
+
+	if (type == CEPH_MSG_OSD_OP)
+		encode_request_finish(msg);
+}
+
+static int osd_sign_message(struct ceph_msg *msg)
+{
+	struct ceph_osd *o = msg->con->private;
+	struct ceph_auth_handshake *auth = &o->o_auth;
+
+	return ceph_auth_sign_message(auth, msg);
+}
+
+static int osd_check_message_signature(struct ceph_msg *msg)
+{
+	struct ceph_osd *o = msg->con->private;
+	struct ceph_auth_handshake *auth = &o->o_auth;
+
+	return ceph_auth_check_message_signature(auth, msg);
+}
+
+static const struct ceph_connection_operations osd_con_ops = {
+	.get = get_osd_con,
+	.put = put_osd_con,
+	.dispatch = dispatch,
+	.get_authorizer = get_authorizer,
+	.add_authorizer_challenge = add_authorizer_challenge,
+	.verify_authorizer_reply = verify_authorizer_reply,
+	.invalidate_authorizer = invalidate_authorizer,
+	.alloc_msg = alloc_msg,
+	.reencode_message = osd_reencode_message,
+	.sign_message = osd_sign_message,
+	.check_message_signature = osd_check_message_signature,
+	.fault = osd_fault,
+};
diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
new file mode 100644
index 000000000..7cb6025fe
--- /dev/null
+++ b/net/ceph/osdmap.c
@@ -0,0 +1,2653 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <linux/ceph/libceph.h>
+#include <linux/ceph/osdmap.h>
+#include <linux/ceph/decode.h>
+#include <linux/crush/hash.h>
+#include <linux/crush/mapper.h>
+
+char *ceph_osdmap_state_str(char *str, int len, u32 state)
+{
+	if (!len)
+		return str;
+
+	if ((state & CEPH_OSD_EXISTS) && (state & CEPH_OSD_UP))
+		snprintf(str, len, "exists, up");
+	else if (state & CEPH_OSD_EXISTS)
+		snprintf(str, len, "exists");
+	else if (state & CEPH_OSD_UP)
+		snprintf(str, len, "up");
+	else
+		snprintf(str, len, "doesn't exist");
+
+	return str;
+}
+
+/* maps */
+
+static int calc_bits_of(unsigned int t)
+{
+	int b = 0;
+	while (t) {
+		t = t >> 1;
+		b++;
+	}
+	return b;
+}
+
+/*
+ * the foo_mask is the smallest value 2^n-1 that is >= foo.
+ */
+static void calc_pg_masks(struct ceph_pg_pool_info *pi)
+{
+	pi->pg_num_mask = (1 << calc_bits_of(pi->pg_num-1)) - 1;
+	pi->pgp_num_mask = (1 << calc_bits_of(pi->pgp_num-1)) - 1;
+}
+
+/*
+ * decode crush map
+ */
+static int crush_decode_uniform_bucket(void **p, void *end,
+				       struct crush_bucket_uniform *b)
+{
+	dout("crush_decode_uniform_bucket %p to %p\n", *p, end);
+	ceph_decode_need(p, end, (1+b->h.size) * sizeof(u32), bad);
+	b->item_weight = ceph_decode_32(p);
+	return 0;
+bad:
+	return -EINVAL;
+}
+
+static int crush_decode_list_bucket(void **p, void *end,
+				    struct crush_bucket_list *b)
+{
+	int j;
+	dout("crush_decode_list_bucket %p to %p\n", *p, end);
+	b->item_weights = kcalloc(b->h.size, sizeof(u32), GFP_NOFS);
+	if (b->item_weights == NULL)
+		return -ENOMEM;
+	b->sum_weights = kcalloc(b->h.size, sizeof(u32), GFP_NOFS);
+	if (b->sum_weights == NULL)
+		return -ENOMEM;
+	ceph_decode_need(p, end, 2 * b->h.size * sizeof(u32), bad);
+	for (j = 0; j < b->h.size; j++) {
+		b->item_weights[j] = ceph_decode_32(p);
+		b->sum_weights[j] = ceph_decode_32(p);
+	}
+	return 0;
+bad:
+	return -EINVAL;
+}
+
+static int crush_decode_tree_bucket(void **p, void *end,
+				    struct crush_bucket_tree *b)
+{
+	int j;
+	dout("crush_decode_tree_bucket %p to %p\n", *p, end);
+	ceph_decode_8_safe(p, end, b->num_nodes, bad);
+	b->node_weights = kcalloc(b->num_nodes, sizeof(u32), GFP_NOFS);
+	if (b->node_weights == NULL)
+		return -ENOMEM;
+	ceph_decode_need(p, end, b->num_nodes * sizeof(u32), bad);
+	for (j = 0; j < b->num_nodes; j++)
+		b->node_weights[j] = ceph_decode_32(p);
+	return 0;
+bad:
+	return -EINVAL;
+}
+
+static int crush_decode_straw_bucket(void **p, void *end,
+				     struct crush_bucket_straw *b)
+{
+	int j;
+	dout("crush_decode_straw_bucket %p to %p\n", *p, end);
+	b->item_weights = kcalloc(b->h.size, sizeof(u32), GFP_NOFS);
+	if (b->item_weights == NULL)
+		return -ENOMEM;
+	b->straws = kcalloc(b->h.size, sizeof(u32), GFP_NOFS);
+	if (b->straws == NULL)
+		return -ENOMEM;
+	ceph_decode_need(p, end, 2 * b->h.size * sizeof(u32), bad);
+	for (j = 0; j < b->h.size; j++) {
+		b->item_weights[j] = ceph_decode_32(p);
+		b->straws[j] = ceph_decode_32(p);
+	}
+	return 0;
+bad:
+	return -EINVAL;
+}
+
+static int crush_decode_straw2_bucket(void **p, void *end,
+				      struct crush_bucket_straw2 *b)
+{
+	int j;
+	dout("crush_decode_straw2_bucket %p to %p\n", *p, end);
+	b->item_weights = kcalloc(b->h.size, sizeof(u32), GFP_NOFS);
+	if (b->item_weights == NULL)
+		return -ENOMEM;
+	ceph_decode_need(p, end, b->h.size * sizeof(u32), bad);
+	for (j = 0; j < b->h.size; j++)
+		b->item_weights[j] = ceph_decode_32(p);
+	return 0;
+bad:
+	return -EINVAL;
+}
+
+static struct crush_choose_arg_map *alloc_choose_arg_map(void)
+{
+	struct crush_choose_arg_map *arg_map;
+
+	arg_map = kzalloc(sizeof(*arg_map), GFP_NOIO);
+	if (!arg_map)
+		return NULL;
+
+	RB_CLEAR_NODE(&arg_map->node);
+	return arg_map;
+}
+
+static void free_choose_arg_map(struct crush_choose_arg_map *arg_map)
+{
+	if (arg_map) {
+		int i, j;
+
+		WARN_ON(!RB_EMPTY_NODE(&arg_map->node));
+
+		for (i = 0; i < arg_map->size; i++) {
+			struct crush_choose_arg *arg = &arg_map->args[i];
+
+			for (j = 0; j < arg->weight_set_size; j++)
+				kfree(arg->weight_set[j].weights);
+			kfree(arg->weight_set);
+			kfree(arg->ids);
+		}
+		kfree(arg_map->args);
+		kfree(arg_map);
+	}
+}
+
+DEFINE_RB_FUNCS(choose_arg_map, struct crush_choose_arg_map, choose_args_index,
+		node);
+
+void clear_choose_args(struct crush_map *c)
+{
+	while (!RB_EMPTY_ROOT(&c->choose_args)) {
+		struct crush_choose_arg_map *arg_map =
+		    rb_entry(rb_first(&c->choose_args),
+			     struct crush_choose_arg_map, node);
+
+		erase_choose_arg_map(&c->choose_args, arg_map);
+		free_choose_arg_map(arg_map);
+	}
+}
+
+static u32 *decode_array_32_alloc(void **p, void *end, u32 *plen)
+{
+	u32 *a = NULL;
+	u32 len;
+	int ret;
+
+	ceph_decode_32_safe(p, end, len, e_inval);
+	if (len) {
+		u32 i;
+
+		a = kmalloc_array(len, sizeof(u32), GFP_NOIO);
+		if (!a) {
+			ret = -ENOMEM;
+			goto fail;
+		}
+
+		ceph_decode_need(p, end, len * sizeof(u32), e_inval);
+		for (i = 0; i < len; i++)
+			a[i] = ceph_decode_32(p);
+	}
+
+	*plen = len;
+	return a;
+
+e_inval:
+	ret = -EINVAL;
+fail:
+	kfree(a);
+	return ERR_PTR(ret);
+}
+
+/*
+ * Assumes @arg is zero-initialized.
+ */
+static int decode_choose_arg(void **p, void *end, struct crush_choose_arg *arg)
+{
+	int ret;
+
+	ceph_decode_32_safe(p, end, arg->weight_set_size, e_inval);
+	if (arg->weight_set_size) {
+		u32 i;
+
+		arg->weight_set = kmalloc_array(arg->weight_set_size,
+						sizeof(*arg->weight_set),
+						GFP_NOIO);
+		if (!arg->weight_set)
+			return -ENOMEM;
+
+		for (i = 0; i < arg->weight_set_size; i++) {
+			struct crush_weight_set *w = &arg->weight_set[i];
+
+			w->weights = decode_array_32_alloc(p, end, &w->size);
+			if (IS_ERR(w->weights)) {
+				ret = PTR_ERR(w->weights);
+				w->weights = NULL;
+				return ret;
+			}
+		}
+	}
+
+	arg->ids = decode_array_32_alloc(p, end, &arg->ids_size);
+	if (IS_ERR(arg->ids)) {
+		ret = PTR_ERR(arg->ids);
+		arg->ids = NULL;
+		return ret;
+	}
+
+	return 0;
+
+e_inval:
+	return -EINVAL;
+}
+
+static int decode_choose_args(void **p, void *end, struct crush_map *c)
+{
+	struct crush_choose_arg_map *arg_map = NULL;
+	u32 num_choose_arg_maps, num_buckets;
+	int ret;
+
+	ceph_decode_32_safe(p, end, num_choose_arg_maps, e_inval);
+	while (num_choose_arg_maps--) {
+		arg_map = alloc_choose_arg_map();
+		if (!arg_map) {
+			ret = -ENOMEM;
+			goto fail;
+		}
+
+		ceph_decode_64_safe(p, end, arg_map->choose_args_index,
+				    e_inval);
+		arg_map->size = c->max_buckets;
+		arg_map->args = kcalloc(arg_map->size, sizeof(*arg_map->args),
+					GFP_NOIO);
+		if (!arg_map->args) {
+			ret = -ENOMEM;
+			goto fail;
+		}
+
+		ceph_decode_32_safe(p, end, num_buckets, e_inval);
+		while (num_buckets--) {
+			struct crush_choose_arg *arg;
+			u32 bucket_index;
+
+			ceph_decode_32_safe(p, end, bucket_index, e_inval);
+			if (bucket_index >= arg_map->size)
+				goto e_inval;
+
+			arg = &arg_map->args[bucket_index];
+			ret = decode_choose_arg(p, end, arg);
+			if (ret)
+				goto fail;
+
+			if (arg->ids_size &&
+			    arg->ids_size != c->buckets[bucket_index]->size)
+				goto e_inval;
+		}
+
+		insert_choose_arg_map(&c->choose_args, arg_map);
+	}
+
+	return 0;
+
+e_inval:
+	ret = -EINVAL;
+fail:
+	free_choose_arg_map(arg_map);
+	return ret;
+}
+
+static void crush_finalize(struct crush_map *c)
+{
+	__s32 b;
+
+	/* Space for the array of pointers to per-bucket workspace */
+	c->working_size = sizeof(struct crush_work) +
+	    c->max_buckets * sizeof(struct crush_work_bucket *);
+
+	for (b = 0; b < c->max_buckets; b++) {
+		if (!c->buckets[b])
+			continue;
+
+		switch (c->buckets[b]->alg) {
+		default:
+			/*
+			 * The base case, permutation variables and
+			 * the pointer to the permutation array.
+			 */
+			c->working_size += sizeof(struct crush_work_bucket);
+			break;
+		}
+		/* Every bucket has a permutation array. */
+		c->working_size += c->buckets[b]->size * sizeof(__u32);
+	}
+}
+
+static struct crush_map *crush_decode(void *pbyval, void *end)
+{
+	struct crush_map *c;
+	int err;
+	int i, j;
+	void **p = &pbyval;
+	void *start = pbyval;
+	u32 magic;
+
+	dout("crush_decode %p to %p len %d\n", *p, end, (int)(end - *p));
+
+	c = kzalloc(sizeof(*c), GFP_NOFS);
+	if (c == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	c->choose_args = RB_ROOT;
+
+        /* set tunables to default values */
+        c->choose_local_tries = 2;
+        c->choose_local_fallback_tries = 5;
+        c->choose_total_tries = 19;
+	c->chooseleaf_descend_once = 0;
+
+	ceph_decode_need(p, end, 4*sizeof(u32), bad);
+	magic = ceph_decode_32(p);
+	if (magic != CRUSH_MAGIC) {
+		pr_err("crush_decode magic %x != current %x\n",
+		       (unsigned int)magic, (unsigned int)CRUSH_MAGIC);
+		goto bad;
+	}
+	c->max_buckets = ceph_decode_32(p);
+	c->max_rules = ceph_decode_32(p);
+	c->max_devices = ceph_decode_32(p);
+
+	c->buckets = kcalloc(c->max_buckets, sizeof(*c->buckets), GFP_NOFS);
+	if (c->buckets == NULL)
+		goto badmem;
+	c->rules = kcalloc(c->max_rules, sizeof(*c->rules), GFP_NOFS);
+	if (c->rules == NULL)
+		goto badmem;
+
+	/* buckets */
+	for (i = 0; i < c->max_buckets; i++) {
+		int size = 0;
+		u32 alg;
+		struct crush_bucket *b;
+
+		ceph_decode_32_safe(p, end, alg, bad);
+		if (alg == 0) {
+			c->buckets[i] = NULL;
+			continue;
+		}
+		dout("crush_decode bucket %d off %x %p to %p\n",
+		     i, (int)(*p-start), *p, end);
+
+		switch (alg) {
+		case CRUSH_BUCKET_UNIFORM:
+			size = sizeof(struct crush_bucket_uniform);
+			break;
+		case CRUSH_BUCKET_LIST:
+			size = sizeof(struct crush_bucket_list);
+			break;
+		case CRUSH_BUCKET_TREE:
+			size = sizeof(struct crush_bucket_tree);
+			break;
+		case CRUSH_BUCKET_STRAW:
+			size = sizeof(struct crush_bucket_straw);
+			break;
+		case CRUSH_BUCKET_STRAW2:
+			size = sizeof(struct crush_bucket_straw2);
+			break;
+		default:
+			goto bad;
+		}
+		BUG_ON(size == 0);
+		b = c->buckets[i] = kzalloc(size, GFP_NOFS);
+		if (b == NULL)
+			goto badmem;
+
+		ceph_decode_need(p, end, 4*sizeof(u32), bad);
+		b->id = ceph_decode_32(p);
+		b->type = ceph_decode_16(p);
+		b->alg = ceph_decode_8(p);
+		b->hash = ceph_decode_8(p);
+		b->weight = ceph_decode_32(p);
+		b->size = ceph_decode_32(p);
+
+		dout("crush_decode bucket size %d off %x %p to %p\n",
+		     b->size, (int)(*p-start), *p, end);
+
+		b->items = kcalloc(b->size, sizeof(__s32), GFP_NOFS);
+		if (b->items == NULL)
+			goto badmem;
+
+		ceph_decode_need(p, end, b->size*sizeof(u32), bad);
+		for (j = 0; j < b->size; j++)
+			b->items[j] = ceph_decode_32(p);
+
+		switch (b->alg) {
+		case CRUSH_BUCKET_UNIFORM:
+			err = crush_decode_uniform_bucket(p, end,
+				  (struct crush_bucket_uniform *)b);
+			if (err < 0)
+				goto fail;
+			break;
+		case CRUSH_BUCKET_LIST:
+			err = crush_decode_list_bucket(p, end,
+			       (struct crush_bucket_list *)b);
+			if (err < 0)
+				goto fail;
+			break;
+		case CRUSH_BUCKET_TREE:
+			err = crush_decode_tree_bucket(p, end,
+				(struct crush_bucket_tree *)b);
+			if (err < 0)
+				goto fail;
+			break;
+		case CRUSH_BUCKET_STRAW:
+			err = crush_decode_straw_bucket(p, end,
+				(struct crush_bucket_straw *)b);
+			if (err < 0)
+				goto fail;
+			break;
+		case CRUSH_BUCKET_STRAW2:
+			err = crush_decode_straw2_bucket(p, end,
+				(struct crush_bucket_straw2 *)b);
+			if (err < 0)
+				goto fail;
+			break;
+		}
+	}
+
+	/* rules */
+	dout("rule vec is %p\n", c->rules);
+	for (i = 0; i < c->max_rules; i++) {
+		u32 yes;
+		struct crush_rule *r;
+
+		ceph_decode_32_safe(p, end, yes, bad);
+		if (!yes) {
+			dout("crush_decode NO rule %d off %x %p to %p\n",
+			     i, (int)(*p-start), *p, end);
+			c->rules[i] = NULL;
+			continue;
+		}
+
+		dout("crush_decode rule %d off %x %p to %p\n",
+		     i, (int)(*p-start), *p, end);
+
+		/* len */
+		ceph_decode_32_safe(p, end, yes, bad);
+#if BITS_PER_LONG == 32
+		if (yes > (ULONG_MAX - sizeof(*r))
+			  / sizeof(struct crush_rule_step))
+			goto bad;
+#endif
+		r = c->rules[i] = kmalloc(sizeof(*r) +
+					  yes*sizeof(struct crush_rule_step),
+					  GFP_NOFS);
+		if (r == NULL)
+			goto badmem;
+		dout(" rule %d is at %p\n", i, r);
+		r->len = yes;
+		ceph_decode_copy_safe(p, end, &r->mask, 4, bad); /* 4 u8's */
+		ceph_decode_need(p, end, r->len*3*sizeof(u32), bad);
+		for (j = 0; j < r->len; j++) {
+			r->steps[j].op = ceph_decode_32(p);
+			r->steps[j].arg1 = ceph_decode_32(p);
+			r->steps[j].arg2 = ceph_decode_32(p);
+		}
+	}
+
+	ceph_decode_skip_map(p, end, 32, string, bad); /* type_map */
+	ceph_decode_skip_map(p, end, 32, string, bad); /* name_map */
+	ceph_decode_skip_map(p, end, 32, string, bad); /* rule_name_map */
+
+        /* tunables */
+        ceph_decode_need(p, end, 3*sizeof(u32), done);
+        c->choose_local_tries = ceph_decode_32(p);
+        c->choose_local_fallback_tries =  ceph_decode_32(p);
+        c->choose_total_tries = ceph_decode_32(p);
+        dout("crush decode tunable choose_local_tries = %d\n",
+             c->choose_local_tries);
+        dout("crush decode tunable choose_local_fallback_tries = %d\n",
+             c->choose_local_fallback_tries);
+        dout("crush decode tunable choose_total_tries = %d\n",
+             c->choose_total_tries);
+
+	ceph_decode_need(p, end, sizeof(u32), done);
+	c->chooseleaf_descend_once = ceph_decode_32(p);
+	dout("crush decode tunable chooseleaf_descend_once = %d\n",
+	     c->chooseleaf_descend_once);
+
+	ceph_decode_need(p, end, sizeof(u8), done);
+	c->chooseleaf_vary_r = ceph_decode_8(p);
+	dout("crush decode tunable chooseleaf_vary_r = %d\n",
+	     c->chooseleaf_vary_r);
+
+	/* skip straw_calc_version, allowed_bucket_algs */
+	ceph_decode_need(p, end, sizeof(u8) + sizeof(u32), done);
+	*p += sizeof(u8) + sizeof(u32);
+
+	ceph_decode_need(p, end, sizeof(u8), done);
+	c->chooseleaf_stable = ceph_decode_8(p);
+	dout("crush decode tunable chooseleaf_stable = %d\n",
+	     c->chooseleaf_stable);
+
+	if (*p != end) {
+		/* class_map */
+		ceph_decode_skip_map(p, end, 32, 32, bad);
+		/* class_name */
+		ceph_decode_skip_map(p, end, 32, string, bad);
+		/* class_bucket */
+		ceph_decode_skip_map_of_map(p, end, 32, 32, 32, bad);
+	}
+
+	if (*p != end) {
+		err = decode_choose_args(p, end, c);
+		if (err)
+			goto fail;
+	}
+
+done:
+	crush_finalize(c);
+	dout("crush_decode success\n");
+	return c;
+
+badmem:
+	err = -ENOMEM;
+fail:
+	dout("crush_decode fail %d\n", err);
+	crush_destroy(c);
+	return ERR_PTR(err);
+
+bad:
+	err = -EINVAL;
+	goto fail;
+}
+
+int ceph_pg_compare(const struct ceph_pg *lhs, const struct ceph_pg *rhs)
+{
+	if (lhs->pool < rhs->pool)
+		return -1;
+	if (lhs->pool > rhs->pool)
+		return 1;
+	if (lhs->seed < rhs->seed)
+		return -1;
+	if (lhs->seed > rhs->seed)
+		return 1;
+
+	return 0;
+}
+
+int ceph_spg_compare(const struct ceph_spg *lhs, const struct ceph_spg *rhs)
+{
+	int ret;
+
+	ret = ceph_pg_compare(&lhs->pgid, &rhs->pgid);
+	if (ret)
+		return ret;
+
+	if (lhs->shard < rhs->shard)
+		return -1;
+	if (lhs->shard > rhs->shard)
+		return 1;
+
+	return 0;
+}
+
+static struct ceph_pg_mapping *alloc_pg_mapping(size_t payload_len)
+{
+	struct ceph_pg_mapping *pg;
+
+	pg = kmalloc(sizeof(*pg) + payload_len, GFP_NOIO);
+	if (!pg)
+		return NULL;
+
+	RB_CLEAR_NODE(&pg->node);
+	return pg;
+}
+
+static void free_pg_mapping(struct ceph_pg_mapping *pg)
+{
+	WARN_ON(!RB_EMPTY_NODE(&pg->node));
+
+	kfree(pg);
+}
+
+/*
+ * rbtree of pg_mapping for handling pg_temp (explicit mapping of pgid
+ * to a set of osds) and primary_temp (explicit primary setting)
+ */
+DEFINE_RB_FUNCS2(pg_mapping, struct ceph_pg_mapping, pgid, ceph_pg_compare,
+		 RB_BYPTR, const struct ceph_pg *, node)
+
+/*
+ * rbtree of pg pool info
+ */
+static int __insert_pg_pool(struct rb_root *root, struct ceph_pg_pool_info *new)
+{
+	struct rb_node **p = &root->rb_node;
+	struct rb_node *parent = NULL;
+	struct ceph_pg_pool_info *pi = NULL;
+
+	while (*p) {
+		parent = *p;
+		pi = rb_entry(parent, struct ceph_pg_pool_info, node);
+		if (new->id < pi->id)
+			p = &(*p)->rb_left;
+		else if (new->id > pi->id)
+			p = &(*p)->rb_right;
+		else
+			return -EEXIST;
+	}
+
+	rb_link_node(&new->node, parent, p);
+	rb_insert_color(&new->node, root);
+	return 0;
+}
+
+static struct ceph_pg_pool_info *__lookup_pg_pool(struct rb_root *root, u64 id)
+{
+	struct ceph_pg_pool_info *pi;
+	struct rb_node *n = root->rb_node;
+
+	while (n) {
+		pi = rb_entry(n, struct ceph_pg_pool_info, node);
+		if (id < pi->id)
+			n = n->rb_left;
+		else if (id > pi->id)
+			n = n->rb_right;
+		else
+			return pi;
+	}
+	return NULL;
+}
+
+struct ceph_pg_pool_info *ceph_pg_pool_by_id(struct ceph_osdmap *map, u64 id)
+{
+	return __lookup_pg_pool(&map->pg_pools, id);
+}
+
+const char *ceph_pg_pool_name_by_id(struct ceph_osdmap *map, u64 id)
+{
+	struct ceph_pg_pool_info *pi;
+
+	if (id == CEPH_NOPOOL)
+		return NULL;
+
+	if (WARN_ON_ONCE(id > (u64) INT_MAX))
+		return NULL;
+
+	pi = __lookup_pg_pool(&map->pg_pools, (int) id);
+
+	return pi ? pi->name : NULL;
+}
+EXPORT_SYMBOL(ceph_pg_pool_name_by_id);
+
+int ceph_pg_poolid_by_name(struct ceph_osdmap *map, const char *name)
+{
+	struct rb_node *rbp;
+
+	for (rbp = rb_first(&map->pg_pools); rbp; rbp = rb_next(rbp)) {
+		struct ceph_pg_pool_info *pi =
+			rb_entry(rbp, struct ceph_pg_pool_info, node);
+		if (pi->name && strcmp(pi->name, name) == 0)
+			return pi->id;
+	}
+	return -ENOENT;
+}
+EXPORT_SYMBOL(ceph_pg_poolid_by_name);
+
+u64 ceph_pg_pool_flags(struct ceph_osdmap *map, u64 id)
+{
+	struct ceph_pg_pool_info *pi;
+
+	pi = __lookup_pg_pool(&map->pg_pools, id);
+	return pi ? pi->flags : 0;
+}
+EXPORT_SYMBOL(ceph_pg_pool_flags);
+
+static void __remove_pg_pool(struct rb_root *root, struct ceph_pg_pool_info *pi)
+{
+	rb_erase(&pi->node, root);
+	kfree(pi->name);
+	kfree(pi);
+}
+
+static int decode_pool(void **p, void *end, struct ceph_pg_pool_info *pi)
+{
+	u8 ev, cv;
+	unsigned len, num;
+	void *pool_end;
+
+	ceph_decode_need(p, end, 2 + 4, bad);
+	ev = ceph_decode_8(p);  /* encoding version */
+	cv = ceph_decode_8(p); /* compat version */
+	if (ev < 5) {
+		pr_warn("got v %d < 5 cv %d of ceph_pg_pool\n", ev, cv);
+		return -EINVAL;
+	}
+	if (cv > 9) {
+		pr_warn("got v %d cv %d > 9 of ceph_pg_pool\n", ev, cv);
+		return -EINVAL;
+	}
+	len = ceph_decode_32(p);
+	ceph_decode_need(p, end, len, bad);
+	pool_end = *p + len;
+
+	pi->type = ceph_decode_8(p);
+	pi->size = ceph_decode_8(p);
+	pi->crush_ruleset = ceph_decode_8(p);
+	pi->object_hash = ceph_decode_8(p);
+
+	pi->pg_num = ceph_decode_32(p);
+	pi->pgp_num = ceph_decode_32(p);
+
+	*p += 4 + 4;  /* skip lpg* */
+	*p += 4;      /* skip last_change */
+	*p += 8 + 4;  /* skip snap_seq, snap_epoch */
+
+	/* skip snaps */
+	num = ceph_decode_32(p);
+	while (num--) {
+		*p += 8;  /* snapid key */
+		*p += 1 + 1; /* versions */
+		len = ceph_decode_32(p);
+		*p += len;
+	}
+
+	/* skip removed_snaps */
+	num = ceph_decode_32(p);
+	*p += num * (8 + 8);
+
+	*p += 8;  /* skip auid */
+	pi->flags = ceph_decode_64(p);
+	*p += 4;  /* skip crash_replay_interval */
+
+	if (ev >= 7)
+		pi->min_size = ceph_decode_8(p);
+	else
+		pi->min_size = pi->size - pi->size / 2;
+
+	if (ev >= 8)
+		*p += 8 + 8;  /* skip quota_max_* */
+
+	if (ev >= 9) {
+		/* skip tiers */
+		num = ceph_decode_32(p);
+		*p += num * 8;
+
+		*p += 8;  /* skip tier_of */
+		*p += 1;  /* skip cache_mode */
+
+		pi->read_tier = ceph_decode_64(p);
+		pi->write_tier = ceph_decode_64(p);
+	} else {
+		pi->read_tier = -1;
+		pi->write_tier = -1;
+	}
+
+	if (ev >= 10) {
+		/* skip properties */
+		num = ceph_decode_32(p);
+		while (num--) {
+			len = ceph_decode_32(p);
+			*p += len; /* key */
+			len = ceph_decode_32(p);
+			*p += len; /* val */
+		}
+	}
+
+	if (ev >= 11) {
+		/* skip hit_set_params */
+		*p += 1 + 1; /* versions */
+		len = ceph_decode_32(p);
+		*p += len;
+
+		*p += 4; /* skip hit_set_period */
+		*p += 4; /* skip hit_set_count */
+	}
+
+	if (ev >= 12)
+		*p += 4; /* skip stripe_width */
+
+	if (ev >= 13) {
+		*p += 8; /* skip target_max_bytes */
+		*p += 8; /* skip target_max_objects */
+		*p += 4; /* skip cache_target_dirty_ratio_micro */
+		*p += 4; /* skip cache_target_full_ratio_micro */
+		*p += 4; /* skip cache_min_flush_age */
+		*p += 4; /* skip cache_min_evict_age */
+	}
+
+	if (ev >=  14) {
+		/* skip erasure_code_profile */
+		len = ceph_decode_32(p);
+		*p += len;
+	}
+
+	/*
+	 * last_force_op_resend_preluminous, will be overridden if the
+	 * map was encoded with RESEND_ON_SPLIT
+	 */
+	if (ev >= 15)
+		pi->last_force_request_resend = ceph_decode_32(p);
+	else
+		pi->last_force_request_resend = 0;
+
+	if (ev >= 16)
+		*p += 4; /* skip min_read_recency_for_promote */
+
+	if (ev >= 17)
+		*p += 8; /* skip expected_num_objects */
+
+	if (ev >= 19)
+		*p += 4; /* skip cache_target_dirty_high_ratio_micro */
+
+	if (ev >= 20)
+		*p += 4; /* skip min_write_recency_for_promote */
+
+	if (ev >= 21)
+		*p += 1; /* skip use_gmt_hitset */
+
+	if (ev >= 22)
+		*p += 1; /* skip fast_read */
+
+	if (ev >= 23) {
+		*p += 4; /* skip hit_set_grade_decay_rate */
+		*p += 4; /* skip hit_set_search_last_n */
+	}
+
+	if (ev >= 24) {
+		/* skip opts */
+		*p += 1 + 1; /* versions */
+		len = ceph_decode_32(p);
+		*p += len;
+	}
+
+	if (ev >= 25)
+		pi->last_force_request_resend = ceph_decode_32(p);
+
+	/* ignore the rest */
+
+	*p = pool_end;
+	calc_pg_masks(pi);
+	return 0;
+
+bad:
+	return -EINVAL;
+}
+
+static int decode_pool_names(void **p, void *end, struct ceph_osdmap *map)
+{
+	struct ceph_pg_pool_info *pi;
+	u32 num, len;
+	u64 pool;
+
+	ceph_decode_32_safe(p, end, num, bad);
+	dout(" %d pool names\n", num);
+	while (num--) {
+		ceph_decode_64_safe(p, end, pool, bad);
+		ceph_decode_32_safe(p, end, len, bad);
+		dout("  pool %llu len %d\n", pool, len);
+		ceph_decode_need(p, end, len, bad);
+		pi = __lookup_pg_pool(&map->pg_pools, pool);
+		if (pi) {
+			char *name = kstrndup(*p, len, GFP_NOFS);
+
+			if (!name)
+				return -ENOMEM;
+			kfree(pi->name);
+			pi->name = name;
+			dout("  name is %s\n", pi->name);
+		}
+		*p += len;
+	}
+	return 0;
+
+bad:
+	return -EINVAL;
+}
+
+/*
+ * osd map
+ */
+struct ceph_osdmap *ceph_osdmap_alloc(void)
+{
+	struct ceph_osdmap *map;
+
+	map = kzalloc(sizeof(*map), GFP_NOIO);
+	if (!map)
+		return NULL;
+
+	map->pg_pools = RB_ROOT;
+	map->pool_max = -1;
+	map->pg_temp = RB_ROOT;
+	map->primary_temp = RB_ROOT;
+	map->pg_upmap = RB_ROOT;
+	map->pg_upmap_items = RB_ROOT;
+	mutex_init(&map->crush_workspace_mutex);
+
+	return map;
+}
+
+void ceph_osdmap_destroy(struct ceph_osdmap *map)
+{
+	dout("osdmap_destroy %p\n", map);
+	if (map->crush)
+		crush_destroy(map->crush);
+	while (!RB_EMPTY_ROOT(&map->pg_temp)) {
+		struct ceph_pg_mapping *pg =
+			rb_entry(rb_first(&map->pg_temp),
+				 struct ceph_pg_mapping, node);
+		erase_pg_mapping(&map->pg_temp, pg);
+		free_pg_mapping(pg);
+	}
+	while (!RB_EMPTY_ROOT(&map->primary_temp)) {
+		struct ceph_pg_mapping *pg =
+			rb_entry(rb_first(&map->primary_temp),
+				 struct ceph_pg_mapping, node);
+		erase_pg_mapping(&map->primary_temp, pg);
+		free_pg_mapping(pg);
+	}
+	while (!RB_EMPTY_ROOT(&map->pg_upmap)) {
+		struct ceph_pg_mapping *pg =
+			rb_entry(rb_first(&map->pg_upmap),
+				 struct ceph_pg_mapping, node);
+		rb_erase(&pg->node, &map->pg_upmap);
+		kfree(pg);
+	}
+	while (!RB_EMPTY_ROOT(&map->pg_upmap_items)) {
+		struct ceph_pg_mapping *pg =
+			rb_entry(rb_first(&map->pg_upmap_items),
+				 struct ceph_pg_mapping, node);
+		rb_erase(&pg->node, &map->pg_upmap_items);
+		kfree(pg);
+	}
+	while (!RB_EMPTY_ROOT(&map->pg_pools)) {
+		struct ceph_pg_pool_info *pi =
+			rb_entry(rb_first(&map->pg_pools),
+				 struct ceph_pg_pool_info, node);
+		__remove_pg_pool(&map->pg_pools, pi);
+	}
+	kfree(map->osd_state);
+	kfree(map->osd_weight);
+	kfree(map->osd_addr);
+	kfree(map->osd_primary_affinity);
+	kfree(map->crush_workspace);
+	kfree(map);
+}
+
+/*
+ * Adjust max_osd value, (re)allocate arrays.
+ *
+ * The new elements are properly initialized.
+ */
+static int osdmap_set_max_osd(struct ceph_osdmap *map, int max)
+{
+	u32 *state;
+	u32 *weight;
+	struct ceph_entity_addr *addr;
+	int i;
+
+	state = krealloc(map->osd_state, max*sizeof(*state), GFP_NOFS);
+	if (!state)
+		return -ENOMEM;
+	map->osd_state = state;
+
+	weight = krealloc(map->osd_weight, max*sizeof(*weight), GFP_NOFS);
+	if (!weight)
+		return -ENOMEM;
+	map->osd_weight = weight;
+
+	addr = krealloc(map->osd_addr, max*sizeof(*addr), GFP_NOFS);
+	if (!addr)
+		return -ENOMEM;
+	map->osd_addr = addr;
+
+	for (i = map->max_osd; i < max; i++) {
+		map->osd_state[i] = 0;
+		map->osd_weight[i] = CEPH_OSD_OUT;
+		memset(map->osd_addr + i, 0, sizeof(*map->osd_addr));
+	}
+
+	if (map->osd_primary_affinity) {
+		u32 *affinity;
+
+		affinity = krealloc(map->osd_primary_affinity,
+				    max*sizeof(*affinity), GFP_NOFS);
+		if (!affinity)
+			return -ENOMEM;
+		map->osd_primary_affinity = affinity;
+
+		for (i = map->max_osd; i < max; i++)
+			map->osd_primary_affinity[i] =
+			    CEPH_OSD_DEFAULT_PRIMARY_AFFINITY;
+	}
+
+	map->max_osd = max;
+
+	return 0;
+}
+
+static int osdmap_set_crush(struct ceph_osdmap *map, struct crush_map *crush)
+{
+	void *workspace;
+	size_t work_size;
+
+	if (IS_ERR(crush))
+		return PTR_ERR(crush);
+
+	work_size = crush_work_size(crush, CEPH_PG_MAX_SIZE);
+	dout("%s work_size %zu bytes\n", __func__, work_size);
+	workspace = kmalloc(work_size, GFP_NOIO);
+	if (!workspace) {
+		crush_destroy(crush);
+		return -ENOMEM;
+	}
+	crush_init_workspace(crush, workspace);
+
+	if (map->crush)
+		crush_destroy(map->crush);
+	kfree(map->crush_workspace);
+	map->crush = crush;
+	map->crush_workspace = workspace;
+	return 0;
+}
+
+#define OSDMAP_WRAPPER_COMPAT_VER	7
+#define OSDMAP_CLIENT_DATA_COMPAT_VER	1
+
+/*
+ * Return 0 or error.  On success, *v is set to 0 for old (v6) osdmaps,
+ * to struct_v of the client_data section for new (v7 and above)
+ * osdmaps.
+ */
+static int get_osdmap_client_data_v(void **p, void *end,
+				    const char *prefix, u8 *v)
+{
+	u8 struct_v;
+
+	ceph_decode_8_safe(p, end, struct_v, e_inval);
+	if (struct_v >= 7) {
+		u8 struct_compat;
+
+		ceph_decode_8_safe(p, end, struct_compat, e_inval);
+		if (struct_compat > OSDMAP_WRAPPER_COMPAT_VER) {
+			pr_warn("got v %d cv %d > %d of %s ceph_osdmap\n",
+				struct_v, struct_compat,
+				OSDMAP_WRAPPER_COMPAT_VER, prefix);
+			return -EINVAL;
+		}
+		*p += 4; /* ignore wrapper struct_len */
+
+		ceph_decode_8_safe(p, end, struct_v, e_inval);
+		ceph_decode_8_safe(p, end, struct_compat, e_inval);
+		if (struct_compat > OSDMAP_CLIENT_DATA_COMPAT_VER) {
+			pr_warn("got v %d cv %d > %d of %s ceph_osdmap client data\n",
+				struct_v, struct_compat,
+				OSDMAP_CLIENT_DATA_COMPAT_VER, prefix);
+			return -EINVAL;
+		}
+		*p += 4; /* ignore client data struct_len */
+	} else {
+		u16 version;
+
+		*p -= 1;
+		ceph_decode_16_safe(p, end, version, e_inval);
+		if (version < 6) {
+			pr_warn("got v %d < 6 of %s ceph_osdmap\n",
+				version, prefix);
+			return -EINVAL;
+		}
+
+		/* old osdmap enconding */
+		struct_v = 0;
+	}
+
+	*v = struct_v;
+	return 0;
+
+e_inval:
+	return -EINVAL;
+}
+
+static int __decode_pools(void **p, void *end, struct ceph_osdmap *map,
+			  bool incremental)
+{
+	u32 n;
+
+	ceph_decode_32_safe(p, end, n, e_inval);
+	while (n--) {
+		struct ceph_pg_pool_info *pi;
+		u64 pool;
+		int ret;
+
+		ceph_decode_64_safe(p, end, pool, e_inval);
+
+		pi = __lookup_pg_pool(&map->pg_pools, pool);
+		if (!incremental || !pi) {
+			pi = kzalloc(sizeof(*pi), GFP_NOFS);
+			if (!pi)
+				return -ENOMEM;
+
+			pi->id = pool;
+
+			ret = __insert_pg_pool(&map->pg_pools, pi);
+			if (ret) {
+				kfree(pi);
+				return ret;
+			}
+		}
+
+		ret = decode_pool(p, end, pi);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+
+e_inval:
+	return -EINVAL;
+}
+
+static int decode_pools(void **p, void *end, struct ceph_osdmap *map)
+{
+	return __decode_pools(p, end, map, false);
+}
+
+static int decode_new_pools(void **p, void *end, struct ceph_osdmap *map)
+{
+	return __decode_pools(p, end, map, true);
+}
+
+typedef struct ceph_pg_mapping *(*decode_mapping_fn_t)(void **, void *, bool);
+
+static int decode_pg_mapping(void **p, void *end, struct rb_root *mapping_root,
+			     decode_mapping_fn_t fn, bool incremental)
+{
+	u32 n;
+
+	WARN_ON(!incremental && !fn);
+
+	ceph_decode_32_safe(p, end, n, e_inval);
+	while (n--) {
+		struct ceph_pg_mapping *pg;
+		struct ceph_pg pgid;
+		int ret;
+
+		ret = ceph_decode_pgid(p, end, &pgid);
+		if (ret)
+			return ret;
+
+		pg = lookup_pg_mapping(mapping_root, &pgid);
+		if (pg) {
+			WARN_ON(!incremental);
+			erase_pg_mapping(mapping_root, pg);
+			free_pg_mapping(pg);
+		}
+
+		if (fn) {
+			pg = fn(p, end, incremental);
+			if (IS_ERR(pg))
+				return PTR_ERR(pg);
+
+			if (pg) {
+				pg->pgid = pgid; /* struct */
+				insert_pg_mapping(mapping_root, pg);
+			}
+		}
+	}
+
+	return 0;
+
+e_inval:
+	return -EINVAL;
+}
+
+static struct ceph_pg_mapping *__decode_pg_temp(void **p, void *end,
+						bool incremental)
+{
+	struct ceph_pg_mapping *pg;
+	u32 len, i;
+
+	ceph_decode_32_safe(p, end, len, e_inval);
+	if (len == 0 && incremental)
+		return NULL;	/* new_pg_temp: [] to remove */
+	if (len > (SIZE_MAX - sizeof(*pg)) / sizeof(u32))
+		return ERR_PTR(-EINVAL);
+
+	ceph_decode_need(p, end, len * sizeof(u32), e_inval);
+	pg = alloc_pg_mapping(len * sizeof(u32));
+	if (!pg)
+		return ERR_PTR(-ENOMEM);
+
+	pg->pg_temp.len = len;
+	for (i = 0; i < len; i++)
+		pg->pg_temp.osds[i] = ceph_decode_32(p);
+
+	return pg;
+
+e_inval:
+	return ERR_PTR(-EINVAL);
+}
+
+static int decode_pg_temp(void **p, void *end, struct ceph_osdmap *map)
+{
+	return decode_pg_mapping(p, end, &map->pg_temp, __decode_pg_temp,
+				 false);
+}
+
+static int decode_new_pg_temp(void **p, void *end, struct ceph_osdmap *map)
+{
+	return decode_pg_mapping(p, end, &map->pg_temp, __decode_pg_temp,
+				 true);
+}
+
+static struct ceph_pg_mapping *__decode_primary_temp(void **p, void *end,
+						     bool incremental)
+{
+	struct ceph_pg_mapping *pg;
+	u32 osd;
+
+	ceph_decode_32_safe(p, end, osd, e_inval);
+	if (osd == (u32)-1 && incremental)
+		return NULL;	/* new_primary_temp: -1 to remove */
+
+	pg = alloc_pg_mapping(0);
+	if (!pg)
+		return ERR_PTR(-ENOMEM);
+
+	pg->primary_temp.osd = osd;
+	return pg;
+
+e_inval:
+	return ERR_PTR(-EINVAL);
+}
+
+static int decode_primary_temp(void **p, void *end, struct ceph_osdmap *map)
+{
+	return decode_pg_mapping(p, end, &map->primary_temp,
+				 __decode_primary_temp, false);
+}
+
+static int decode_new_primary_temp(void **p, void *end,
+				   struct ceph_osdmap *map)
+{
+	return decode_pg_mapping(p, end, &map->primary_temp,
+				 __decode_primary_temp, true);
+}
+
+u32 ceph_get_primary_affinity(struct ceph_osdmap *map, int osd)
+{
+	BUG_ON(osd >= map->max_osd);
+
+	if (!map->osd_primary_affinity)
+		return CEPH_OSD_DEFAULT_PRIMARY_AFFINITY;
+
+	return map->osd_primary_affinity[osd];
+}
+
+static int set_primary_affinity(struct ceph_osdmap *map, int osd, u32 aff)
+{
+	BUG_ON(osd >= map->max_osd);
+
+	if (!map->osd_primary_affinity) {
+		int i;
+
+		map->osd_primary_affinity = kmalloc_array(map->max_osd,
+							  sizeof(u32),
+							  GFP_NOFS);
+		if (!map->osd_primary_affinity)
+			return -ENOMEM;
+
+		for (i = 0; i < map->max_osd; i++)
+			map->osd_primary_affinity[i] =
+			    CEPH_OSD_DEFAULT_PRIMARY_AFFINITY;
+	}
+
+	map->osd_primary_affinity[osd] = aff;
+
+	return 0;
+}
+
+static int decode_primary_affinity(void **p, void *end,
+				   struct ceph_osdmap *map)
+{
+	u32 len, i;
+
+	ceph_decode_32_safe(p, end, len, e_inval);
+	if (len == 0) {
+		kfree(map->osd_primary_affinity);
+		map->osd_primary_affinity = NULL;
+		return 0;
+	}
+	if (len != map->max_osd)
+		goto e_inval;
+
+	ceph_decode_need(p, end, map->max_osd*sizeof(u32), e_inval);
+
+	for (i = 0; i < map->max_osd; i++) {
+		int ret;
+
+		ret = set_primary_affinity(map, i, ceph_decode_32(p));
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+
+e_inval:
+	return -EINVAL;
+}
+
+static int decode_new_primary_affinity(void **p, void *end,
+				       struct ceph_osdmap *map)
+{
+	u32 n;
+
+	ceph_decode_32_safe(p, end, n, e_inval);
+	while (n--) {
+		u32 osd, aff;
+		int ret;
+
+		ceph_decode_32_safe(p, end, osd, e_inval);
+		ceph_decode_32_safe(p, end, aff, e_inval);
+
+		ret = set_primary_affinity(map, osd, aff);
+		if (ret)
+			return ret;
+
+		pr_info("osd%d primary-affinity 0x%x\n", osd, aff);
+	}
+
+	return 0;
+
+e_inval:
+	return -EINVAL;
+}
+
+static struct ceph_pg_mapping *__decode_pg_upmap(void **p, void *end,
+						 bool __unused)
+{
+	return __decode_pg_temp(p, end, false);
+}
+
+static int decode_pg_upmap(void **p, void *end, struct ceph_osdmap *map)
+{
+	return decode_pg_mapping(p, end, &map->pg_upmap, __decode_pg_upmap,
+				 false);
+}
+
+static int decode_new_pg_upmap(void **p, void *end, struct ceph_osdmap *map)
+{
+	return decode_pg_mapping(p, end, &map->pg_upmap, __decode_pg_upmap,
+				 true);
+}
+
+static int decode_old_pg_upmap(void **p, void *end, struct ceph_osdmap *map)
+{
+	return decode_pg_mapping(p, end, &map->pg_upmap, NULL, true);
+}
+
+static struct ceph_pg_mapping *__decode_pg_upmap_items(void **p, void *end,
+						       bool __unused)
+{
+	struct ceph_pg_mapping *pg;
+	u32 len, i;
+
+	ceph_decode_32_safe(p, end, len, e_inval);
+	if (len > (SIZE_MAX - sizeof(*pg)) / (2 * sizeof(u32)))
+		return ERR_PTR(-EINVAL);
+
+	ceph_decode_need(p, end, 2 * len * sizeof(u32), e_inval);
+	pg = alloc_pg_mapping(2 * len * sizeof(u32));
+	if (!pg)
+		return ERR_PTR(-ENOMEM);
+
+	pg->pg_upmap_items.len = len;
+	for (i = 0; i < len; i++) {
+		pg->pg_upmap_items.from_to[i][0] = ceph_decode_32(p);
+		pg->pg_upmap_items.from_to[i][1] = ceph_decode_32(p);
+	}
+
+	return pg;
+
+e_inval:
+	return ERR_PTR(-EINVAL);
+}
+
+static int decode_pg_upmap_items(void **p, void *end, struct ceph_osdmap *map)
+{
+	return decode_pg_mapping(p, end, &map->pg_upmap_items,
+				 __decode_pg_upmap_items, false);
+}
+
+static int decode_new_pg_upmap_items(void **p, void *end,
+				     struct ceph_osdmap *map)
+{
+	return decode_pg_mapping(p, end, &map->pg_upmap_items,
+				 __decode_pg_upmap_items, true);
+}
+
+static int decode_old_pg_upmap_items(void **p, void *end,
+				     struct ceph_osdmap *map)
+{
+	return decode_pg_mapping(p, end, &map->pg_upmap_items, NULL, true);
+}
+
+/*
+ * decode a full map.
+ */
+static int osdmap_decode(void **p, void *end, struct ceph_osdmap *map)
+{
+	u8 struct_v;
+	u32 epoch = 0;
+	void *start = *p;
+	u32 max;
+	u32 len, i;
+	int err;
+
+	dout("%s %p to %p len %d\n", __func__, *p, end, (int)(end - *p));
+
+	err = get_osdmap_client_data_v(p, end, "full", &struct_v);
+	if (err)
+		goto bad;
+
+	/* fsid, epoch, created, modified */
+	ceph_decode_need(p, end, sizeof(map->fsid) + sizeof(u32) +
+			 sizeof(map->created) + sizeof(map->modified), e_inval);
+	ceph_decode_copy(p, &map->fsid, sizeof(map->fsid));
+	epoch = map->epoch = ceph_decode_32(p);
+	ceph_decode_copy(p, &map->created, sizeof(map->created));
+	ceph_decode_copy(p, &map->modified, sizeof(map->modified));
+
+	/* pools */
+	err = decode_pools(p, end, map);
+	if (err)
+		goto bad;
+
+	/* pool_name */
+	err = decode_pool_names(p, end, map);
+	if (err)
+		goto bad;
+
+	ceph_decode_32_safe(p, end, map->pool_max, e_inval);
+
+	ceph_decode_32_safe(p, end, map->flags, e_inval);
+
+	/* max_osd */
+	ceph_decode_32_safe(p, end, max, e_inval);
+
+	/* (re)alloc osd arrays */
+	err = osdmap_set_max_osd(map, max);
+	if (err)
+		goto bad;
+
+	/* osd_state, osd_weight, osd_addrs->client_addr */
+	ceph_decode_need(p, end, 3*sizeof(u32) +
+			 map->max_osd*((struct_v >= 5 ? sizeof(u32) :
+							sizeof(u8)) +
+				       sizeof(*map->osd_weight) +
+				       sizeof(*map->osd_addr)), e_inval);
+
+	if (ceph_decode_32(p) != map->max_osd)
+		goto e_inval;
+
+	if (struct_v >= 5) {
+		for (i = 0; i < map->max_osd; i++)
+			map->osd_state[i] = ceph_decode_32(p);
+	} else {
+		for (i = 0; i < map->max_osd; i++)
+			map->osd_state[i] = ceph_decode_8(p);
+	}
+
+	if (ceph_decode_32(p) != map->max_osd)
+		goto e_inval;
+
+	for (i = 0; i < map->max_osd; i++)
+		map->osd_weight[i] = ceph_decode_32(p);
+
+	if (ceph_decode_32(p) != map->max_osd)
+		goto e_inval;
+
+	ceph_decode_copy(p, map->osd_addr, map->max_osd*sizeof(*map->osd_addr));
+	for (i = 0; i < map->max_osd; i++)
+		ceph_decode_addr(&map->osd_addr[i]);
+
+	/* pg_temp */
+	err = decode_pg_temp(p, end, map);
+	if (err)
+		goto bad;
+
+	/* primary_temp */
+	if (struct_v >= 1) {
+		err = decode_primary_temp(p, end, map);
+		if (err)
+			goto bad;
+	}
+
+	/* primary_affinity */
+	if (struct_v >= 2) {
+		err = decode_primary_affinity(p, end, map);
+		if (err)
+			goto bad;
+	} else {
+		WARN_ON(map->osd_primary_affinity);
+	}
+
+	/* crush */
+	ceph_decode_32_safe(p, end, len, e_inval);
+	err = osdmap_set_crush(map, crush_decode(*p, min(*p + len, end)));
+	if (err)
+		goto bad;
+
+	*p += len;
+	if (struct_v >= 3) {
+		/* erasure_code_profiles */
+		ceph_decode_skip_map_of_map(p, end, string, string, string,
+					    e_inval);
+	}
+
+	if (struct_v >= 4) {
+		err = decode_pg_upmap(p, end, map);
+		if (err)
+			goto bad;
+
+		err = decode_pg_upmap_items(p, end, map);
+		if (err)
+			goto bad;
+	} else {
+		WARN_ON(!RB_EMPTY_ROOT(&map->pg_upmap));
+		WARN_ON(!RB_EMPTY_ROOT(&map->pg_upmap_items));
+	}
+
+	/* ignore the rest */
+	*p = end;
+
+	dout("full osdmap epoch %d max_osd %d\n", map->epoch, map->max_osd);
+	return 0;
+
+e_inval:
+	err = -EINVAL;
+bad:
+	pr_err("corrupt full osdmap (%d) epoch %d off %d (%p of %p-%p)\n",
+	       err, epoch, (int)(*p - start), *p, start, end);
+	print_hex_dump(KERN_DEBUG, "osdmap: ",
+		       DUMP_PREFIX_OFFSET, 16, 1,
+		       start, end - start, true);
+	return err;
+}
+
+/*
+ * Allocate and decode a full map.
+ */
+struct ceph_osdmap *ceph_osdmap_decode(void **p, void *end)
+{
+	struct ceph_osdmap *map;
+	int ret;
+
+	map = ceph_osdmap_alloc();
+	if (!map)
+		return ERR_PTR(-ENOMEM);
+
+	ret = osdmap_decode(p, end, map);
+	if (ret) {
+		ceph_osdmap_destroy(map);
+		return ERR_PTR(ret);
+	}
+
+	return map;
+}
+
+/*
+ * Encoding order is (new_up_client, new_state, new_weight).  Need to
+ * apply in the (new_weight, new_state, new_up_client) order, because
+ * an incremental map may look like e.g.
+ *
+ *     new_up_client: { osd=6, addr=... } # set osd_state and addr
+ *     new_state: { osd=6, xorstate=EXISTS } # clear osd_state
+ */
+static int decode_new_up_state_weight(void **p, void *end, u8 struct_v,
+				      struct ceph_osdmap *map)
+{
+	void *new_up_client;
+	void *new_state;
+	void *new_weight_end;
+	u32 len;
+
+	new_up_client = *p;
+	ceph_decode_32_safe(p, end, len, e_inval);
+	len *= sizeof(u32) + sizeof(struct ceph_entity_addr);
+	ceph_decode_need(p, end, len, e_inval);
+	*p += len;
+
+	new_state = *p;
+	ceph_decode_32_safe(p, end, len, e_inval);
+	len *= sizeof(u32) + (struct_v >= 5 ? sizeof(u32) : sizeof(u8));
+	ceph_decode_need(p, end, len, e_inval);
+	*p += len;
+
+	/* new_weight */
+	ceph_decode_32_safe(p, end, len, e_inval);
+	while (len--) {
+		s32 osd;
+		u32 w;
+
+		ceph_decode_need(p, end, 2*sizeof(u32), e_inval);
+		osd = ceph_decode_32(p);
+		w = ceph_decode_32(p);
+		BUG_ON(osd >= map->max_osd);
+		pr_info("osd%d weight 0x%x %s\n", osd, w,
+		     w == CEPH_OSD_IN ? "(in)" :
+		     (w == CEPH_OSD_OUT ? "(out)" : ""));
+		map->osd_weight[osd] = w;
+
+		/*
+		 * If we are marking in, set the EXISTS, and clear the
+		 * AUTOOUT and NEW bits.
+		 */
+		if (w) {
+			map->osd_state[osd] |= CEPH_OSD_EXISTS;
+			map->osd_state[osd] &= ~(CEPH_OSD_AUTOOUT |
+						 CEPH_OSD_NEW);
+		}
+	}
+	new_weight_end = *p;
+
+	/* new_state (up/down) */
+	*p = new_state;
+	len = ceph_decode_32(p);
+	while (len--) {
+		s32 osd;
+		u32 xorstate;
+		int ret;
+
+		osd = ceph_decode_32(p);
+		if (struct_v >= 5)
+			xorstate = ceph_decode_32(p);
+		else
+			xorstate = ceph_decode_8(p);
+		if (xorstate == 0)
+			xorstate = CEPH_OSD_UP;
+		BUG_ON(osd >= map->max_osd);
+		if ((map->osd_state[osd] & CEPH_OSD_UP) &&
+		    (xorstate & CEPH_OSD_UP))
+			pr_info("osd%d down\n", osd);
+		if ((map->osd_state[osd] & CEPH_OSD_EXISTS) &&
+		    (xorstate & CEPH_OSD_EXISTS)) {
+			pr_info("osd%d does not exist\n", osd);
+			ret = set_primary_affinity(map, osd,
+						   CEPH_OSD_DEFAULT_PRIMARY_AFFINITY);
+			if (ret)
+				return ret;
+			memset(map->osd_addr + osd, 0, sizeof(*map->osd_addr));
+			map->osd_state[osd] = 0;
+		} else {
+			map->osd_state[osd] ^= xorstate;
+		}
+	}
+
+	/* new_up_client */
+	*p = new_up_client;
+	len = ceph_decode_32(p);
+	while (len--) {
+		s32 osd;
+		struct ceph_entity_addr addr;
+
+		osd = ceph_decode_32(p);
+		ceph_decode_copy(p, &addr, sizeof(addr));
+		ceph_decode_addr(&addr);
+		BUG_ON(osd >= map->max_osd);
+		pr_info("osd%d up\n", osd);
+		map->osd_state[osd] |= CEPH_OSD_EXISTS | CEPH_OSD_UP;
+		map->osd_addr[osd] = addr;
+	}
+
+	*p = new_weight_end;
+	return 0;
+
+e_inval:
+	return -EINVAL;
+}
+
+/*
+ * decode and apply an incremental map update.
+ */
+struct ceph_osdmap *osdmap_apply_incremental(void **p, void *end,
+					     struct ceph_osdmap *map)
+{
+	struct ceph_fsid fsid;
+	u32 epoch = 0;
+	struct ceph_timespec modified;
+	s32 len;
+	u64 pool;
+	__s64 new_pool_max;
+	__s32 new_flags, max;
+	void *start = *p;
+	int err;
+	u8 struct_v;
+
+	dout("%s %p to %p len %d\n", __func__, *p, end, (int)(end - *p));
+
+	err = get_osdmap_client_data_v(p, end, "inc", &struct_v);
+	if (err)
+		goto bad;
+
+	/* fsid, epoch, modified, new_pool_max, new_flags */
+	ceph_decode_need(p, end, sizeof(fsid) + sizeof(u32) + sizeof(modified) +
+			 sizeof(u64) + sizeof(u32), e_inval);
+	ceph_decode_copy(p, &fsid, sizeof(fsid));
+	epoch = ceph_decode_32(p);
+	BUG_ON(epoch != map->epoch+1);
+	ceph_decode_copy(p, &modified, sizeof(modified));
+	new_pool_max = ceph_decode_64(p);
+	new_flags = ceph_decode_32(p);
+
+	/* full map? */
+	ceph_decode_32_safe(p, end, len, e_inval);
+	if (len > 0) {
+		dout("apply_incremental full map len %d, %p to %p\n",
+		     len, *p, end);
+		return ceph_osdmap_decode(p, min(*p+len, end));
+	}
+
+	/* new crush? */
+	ceph_decode_32_safe(p, end, len, e_inval);
+	if (len > 0) {
+		err = osdmap_set_crush(map,
+				       crush_decode(*p, min(*p + len, end)));
+		if (err)
+			goto bad;
+		*p += len;
+	}
+
+	/* new flags? */
+	if (new_flags >= 0)
+		map->flags = new_flags;
+	if (new_pool_max >= 0)
+		map->pool_max = new_pool_max;
+
+	/* new max? */
+	ceph_decode_32_safe(p, end, max, e_inval);
+	if (max >= 0) {
+		err = osdmap_set_max_osd(map, max);
+		if (err)
+			goto bad;
+	}
+
+	map->epoch++;
+	map->modified = modified;
+
+	/* new_pools */
+	err = decode_new_pools(p, end, map);
+	if (err)
+		goto bad;
+
+	/* new_pool_names */
+	err = decode_pool_names(p, end, map);
+	if (err)
+		goto bad;
+
+	/* old_pool */
+	ceph_decode_32_safe(p, end, len, e_inval);
+	while (len--) {
+		struct ceph_pg_pool_info *pi;
+
+		ceph_decode_64_safe(p, end, pool, e_inval);
+		pi = __lookup_pg_pool(&map->pg_pools, pool);
+		if (pi)
+			__remove_pg_pool(&map->pg_pools, pi);
+	}
+
+	/* new_up_client, new_state, new_weight */
+	err = decode_new_up_state_weight(p, end, struct_v, map);
+	if (err)
+		goto bad;
+
+	/* new_pg_temp */
+	err = decode_new_pg_temp(p, end, map);
+	if (err)
+		goto bad;
+
+	/* new_primary_temp */
+	if (struct_v >= 1) {
+		err = decode_new_primary_temp(p, end, map);
+		if (err)
+			goto bad;
+	}
+
+	/* new_primary_affinity */
+	if (struct_v >= 2) {
+		err = decode_new_primary_affinity(p, end, map);
+		if (err)
+			goto bad;
+	}
+
+	if (struct_v >= 3) {
+		/* new_erasure_code_profiles */
+		ceph_decode_skip_map_of_map(p, end, string, string, string,
+					    e_inval);
+		/* old_erasure_code_profiles */
+		ceph_decode_skip_set(p, end, string, e_inval);
+	}
+
+	if (struct_v >= 4) {
+		err = decode_new_pg_upmap(p, end, map);
+		if (err)
+			goto bad;
+
+		err = decode_old_pg_upmap(p, end, map);
+		if (err)
+			goto bad;
+
+		err = decode_new_pg_upmap_items(p, end, map);
+		if (err)
+			goto bad;
+
+		err = decode_old_pg_upmap_items(p, end, map);
+		if (err)
+			goto bad;
+	}
+
+	/* ignore the rest */
+	*p = end;
+
+	dout("inc osdmap epoch %d max_osd %d\n", map->epoch, map->max_osd);
+	return map;
+
+e_inval:
+	err = -EINVAL;
+bad:
+	pr_err("corrupt inc osdmap (%d) epoch %d off %d (%p of %p-%p)\n",
+	       err, epoch, (int)(*p - start), *p, start, end);
+	print_hex_dump(KERN_DEBUG, "osdmap: ",
+		       DUMP_PREFIX_OFFSET, 16, 1,
+		       start, end - start, true);
+	return ERR_PTR(err);
+}
+
+void ceph_oloc_copy(struct ceph_object_locator *dest,
+		    const struct ceph_object_locator *src)
+{
+	ceph_oloc_destroy(dest);
+
+	dest->pool = src->pool;
+	if (src->pool_ns)
+		dest->pool_ns = ceph_get_string(src->pool_ns);
+	else
+		dest->pool_ns = NULL;
+}
+EXPORT_SYMBOL(ceph_oloc_copy);
+
+void ceph_oloc_destroy(struct ceph_object_locator *oloc)
+{
+	ceph_put_string(oloc->pool_ns);
+}
+EXPORT_SYMBOL(ceph_oloc_destroy);
+
+void ceph_oid_copy(struct ceph_object_id *dest,
+		   const struct ceph_object_id *src)
+{
+	ceph_oid_destroy(dest);
+
+	if (src->name != src->inline_name) {
+		/* very rare, see ceph_object_id definition */
+		dest->name = kmalloc(src->name_len + 1,
+				     GFP_NOIO | __GFP_NOFAIL);
+	} else {
+		dest->name = dest->inline_name;
+	}
+	memcpy(dest->name, src->name, src->name_len + 1);
+	dest->name_len = src->name_len;
+}
+EXPORT_SYMBOL(ceph_oid_copy);
+
+static __printf(2, 0)
+int oid_printf_vargs(struct ceph_object_id *oid, const char *fmt, va_list ap)
+{
+	int len;
+
+	WARN_ON(!ceph_oid_empty(oid));
+
+	len = vsnprintf(oid->inline_name, sizeof(oid->inline_name), fmt, ap);
+	if (len >= sizeof(oid->inline_name))
+		return len;
+
+	oid->name_len = len;
+	return 0;
+}
+
+/*
+ * If oid doesn't fit into inline buffer, BUG.
+ */
+void ceph_oid_printf(struct ceph_object_id *oid, const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	BUG_ON(oid_printf_vargs(oid, fmt, ap));
+	va_end(ap);
+}
+EXPORT_SYMBOL(ceph_oid_printf);
+
+static __printf(3, 0)
+int oid_aprintf_vargs(struct ceph_object_id *oid, gfp_t gfp,
+		      const char *fmt, va_list ap)
+{
+	va_list aq;
+	int len;
+
+	va_copy(aq, ap);
+	len = oid_printf_vargs(oid, fmt, aq);
+	va_end(aq);
+
+	if (len) {
+		char *external_name;
+
+		external_name = kmalloc(len + 1, gfp);
+		if (!external_name)
+			return -ENOMEM;
+
+		oid->name = external_name;
+		WARN_ON(vsnprintf(oid->name, len + 1, fmt, ap) != len);
+		oid->name_len = len;
+	}
+
+	return 0;
+}
+
+/*
+ * If oid doesn't fit into inline buffer, allocate.
+ */
+int ceph_oid_aprintf(struct ceph_object_id *oid, gfp_t gfp,
+		     const char *fmt, ...)
+{
+	va_list ap;
+	int ret;
+
+	va_start(ap, fmt);
+	ret = oid_aprintf_vargs(oid, gfp, fmt, ap);
+	va_end(ap);
+
+	return ret;
+}
+EXPORT_SYMBOL(ceph_oid_aprintf);
+
+void ceph_oid_destroy(struct ceph_object_id *oid)
+{
+	if (oid->name != oid->inline_name)
+		kfree(oid->name);
+}
+EXPORT_SYMBOL(ceph_oid_destroy);
+
+/*
+ * osds only
+ */
+static bool __osds_equal(const struct ceph_osds *lhs,
+			 const struct ceph_osds *rhs)
+{
+	if (lhs->size == rhs->size &&
+	    !memcmp(lhs->osds, rhs->osds, rhs->size * sizeof(rhs->osds[0])))
+		return true;
+
+	return false;
+}
+
+/*
+ * osds + primary
+ */
+static bool osds_equal(const struct ceph_osds *lhs,
+		       const struct ceph_osds *rhs)
+{
+	if (__osds_equal(lhs, rhs) &&
+	    lhs->primary == rhs->primary)
+		return true;
+
+	return false;
+}
+
+static bool osds_valid(const struct ceph_osds *set)
+{
+	/* non-empty set */
+	if (set->size > 0 && set->primary >= 0)
+		return true;
+
+	/* empty can_shift_osds set */
+	if (!set->size && set->primary == -1)
+		return true;
+
+	/* empty !can_shift_osds set - all NONE */
+	if (set->size > 0 && set->primary == -1) {
+		int i;
+
+		for (i = 0; i < set->size; i++) {
+			if (set->osds[i] != CRUSH_ITEM_NONE)
+				break;
+		}
+		if (i == set->size)
+			return true;
+	}
+
+	return false;
+}
+
+void ceph_osds_copy(struct ceph_osds *dest, const struct ceph_osds *src)
+{
+	memcpy(dest->osds, src->osds, src->size * sizeof(src->osds[0]));
+	dest->size = src->size;
+	dest->primary = src->primary;
+}
+
+bool ceph_pg_is_split(const struct ceph_pg *pgid, u32 old_pg_num,
+		      u32 new_pg_num)
+{
+	int old_bits = calc_bits_of(old_pg_num);
+	int old_mask = (1 << old_bits) - 1;
+	int n;
+
+	WARN_ON(pgid->seed >= old_pg_num);
+	if (new_pg_num <= old_pg_num)
+		return false;
+
+	for (n = 1; ; n++) {
+		int next_bit = n << (old_bits - 1);
+		u32 s = next_bit | pgid->seed;
+
+		if (s < old_pg_num || s == pgid->seed)
+			continue;
+		if (s >= new_pg_num)
+			break;
+
+		s = ceph_stable_mod(s, old_pg_num, old_mask);
+		if (s == pgid->seed)
+			return true;
+	}
+
+	return false;
+}
+
+bool ceph_is_new_interval(const struct ceph_osds *old_acting,
+			  const struct ceph_osds *new_acting,
+			  const struct ceph_osds *old_up,
+			  const struct ceph_osds *new_up,
+			  int old_size,
+			  int new_size,
+			  int old_min_size,
+			  int new_min_size,
+			  u32 old_pg_num,
+			  u32 new_pg_num,
+			  bool old_sort_bitwise,
+			  bool new_sort_bitwise,
+			  bool old_recovery_deletes,
+			  bool new_recovery_deletes,
+			  const struct ceph_pg *pgid)
+{
+	return !osds_equal(old_acting, new_acting) ||
+	       !osds_equal(old_up, new_up) ||
+	       old_size != new_size ||
+	       old_min_size != new_min_size ||
+	       ceph_pg_is_split(pgid, old_pg_num, new_pg_num) ||
+	       old_sort_bitwise != new_sort_bitwise ||
+	       old_recovery_deletes != new_recovery_deletes;
+}
+
+static int calc_pg_rank(int osd, const struct ceph_osds *acting)
+{
+	int i;
+
+	for (i = 0; i < acting->size; i++) {
+		if (acting->osds[i] == osd)
+			return i;
+	}
+
+	return -1;
+}
+
+static bool primary_changed(const struct ceph_osds *old_acting,
+			    const struct ceph_osds *new_acting)
+{
+	if (!old_acting->size && !new_acting->size)
+		return false; /* both still empty */
+
+	if (!old_acting->size ^ !new_acting->size)
+		return true; /* was empty, now not, or vice versa */
+
+	if (old_acting->primary != new_acting->primary)
+		return true; /* primary changed */
+
+	if (calc_pg_rank(old_acting->primary, old_acting) !=
+	    calc_pg_rank(new_acting->primary, new_acting))
+		return true;
+
+	return false; /* same primary (tho replicas may have changed) */
+}
+
+bool ceph_osds_changed(const struct ceph_osds *old_acting,
+		       const struct ceph_osds *new_acting,
+		       bool any_change)
+{
+	if (primary_changed(old_acting, new_acting))
+		return true;
+
+	if (any_change && !__osds_equal(old_acting, new_acting))
+		return true;
+
+	return false;
+}
+
+/*
+ * Map an object into a PG.
+ *
+ * Should only be called with target_oid and target_oloc (as opposed to
+ * base_oid and base_oloc), since tiering isn't taken into account.
+ */
+void __ceph_object_locator_to_pg(struct ceph_pg_pool_info *pi,
+				 const struct ceph_object_id *oid,
+				 const struct ceph_object_locator *oloc,
+				 struct ceph_pg *raw_pgid)
+{
+	WARN_ON(pi->id != oloc->pool);
+
+	if (!oloc->pool_ns) {
+		raw_pgid->pool = oloc->pool;
+		raw_pgid->seed = ceph_str_hash(pi->object_hash, oid->name,
+					     oid->name_len);
+		dout("%s %s -> raw_pgid %llu.%x\n", __func__, oid->name,
+		     raw_pgid->pool, raw_pgid->seed);
+	} else {
+		char stack_buf[256];
+		char *buf = stack_buf;
+		int nsl = oloc->pool_ns->len;
+		size_t total = nsl + 1 + oid->name_len;
+
+		if (total > sizeof(stack_buf))
+			buf = kmalloc(total, GFP_NOIO | __GFP_NOFAIL);
+		memcpy(buf, oloc->pool_ns->str, nsl);
+		buf[nsl] = '\037';
+		memcpy(buf + nsl + 1, oid->name, oid->name_len);
+		raw_pgid->pool = oloc->pool;
+		raw_pgid->seed = ceph_str_hash(pi->object_hash, buf, total);
+		if (buf != stack_buf)
+			kfree(buf);
+		dout("%s %s ns %.*s -> raw_pgid %llu.%x\n", __func__,
+		     oid->name, nsl, oloc->pool_ns->str,
+		     raw_pgid->pool, raw_pgid->seed);
+	}
+}
+
+int ceph_object_locator_to_pg(struct ceph_osdmap *osdmap,
+			      const struct ceph_object_id *oid,
+			      const struct ceph_object_locator *oloc,
+			      struct ceph_pg *raw_pgid)
+{
+	struct ceph_pg_pool_info *pi;
+
+	pi = ceph_pg_pool_by_id(osdmap, oloc->pool);
+	if (!pi)
+		return -ENOENT;
+
+	__ceph_object_locator_to_pg(pi, oid, oloc, raw_pgid);
+	return 0;
+}
+EXPORT_SYMBOL(ceph_object_locator_to_pg);
+
+/*
+ * Map a raw PG (full precision ps) into an actual PG.
+ */
+static void raw_pg_to_pg(struct ceph_pg_pool_info *pi,
+			 const struct ceph_pg *raw_pgid,
+			 struct ceph_pg *pgid)
+{
+	pgid->pool = raw_pgid->pool;
+	pgid->seed = ceph_stable_mod(raw_pgid->seed, pi->pg_num,
+				     pi->pg_num_mask);
+}
+
+/*
+ * Map a raw PG (full precision ps) into a placement ps (placement
+ * seed).  Include pool id in that value so that different pools don't
+ * use the same seeds.
+ */
+static u32 raw_pg_to_pps(struct ceph_pg_pool_info *pi,
+			 const struct ceph_pg *raw_pgid)
+{
+	if (pi->flags & CEPH_POOL_FLAG_HASHPSPOOL) {
+		/* hash pool id and seed so that pool PGs do not overlap */
+		return crush_hash32_2(CRUSH_HASH_RJENKINS1,
+				      ceph_stable_mod(raw_pgid->seed,
+						      pi->pgp_num,
+						      pi->pgp_num_mask),
+				      raw_pgid->pool);
+	} else {
+		/*
+		 * legacy behavior: add ps and pool together.  this is
+		 * not a great approach because the PGs from each pool
+		 * will overlap on top of each other: 0.5 == 1.4 ==
+		 * 2.3 == ...
+		 */
+		return ceph_stable_mod(raw_pgid->seed, pi->pgp_num,
+				       pi->pgp_num_mask) +
+		       (unsigned)raw_pgid->pool;
+	}
+}
+
+/*
+ * Magic value used for a "default" fallback choose_args, used if the
+ * crush_choose_arg_map passed to do_crush() does not exist.  If this
+ * also doesn't exist, fall back to canonical weights.
+ */
+#define CEPH_DEFAULT_CHOOSE_ARGS	-1
+
+static int do_crush(struct ceph_osdmap *map, int ruleno, int x,
+		    int *result, int result_max,
+		    const __u32 *weight, int weight_max,
+		    s64 choose_args_index)
+{
+	struct crush_choose_arg_map *arg_map;
+	int r;
+
+	BUG_ON(result_max > CEPH_PG_MAX_SIZE);
+
+	arg_map = lookup_choose_arg_map(&map->crush->choose_args,
+					choose_args_index);
+	if (!arg_map)
+		arg_map = lookup_choose_arg_map(&map->crush->choose_args,
+						CEPH_DEFAULT_CHOOSE_ARGS);
+
+	mutex_lock(&map->crush_workspace_mutex);
+	r = crush_do_rule(map->crush, ruleno, x, result, result_max,
+			  weight, weight_max, map->crush_workspace,
+			  arg_map ? arg_map->args : NULL);
+	mutex_unlock(&map->crush_workspace_mutex);
+
+	return r;
+}
+
+static void remove_nonexistent_osds(struct ceph_osdmap *osdmap,
+				    struct ceph_pg_pool_info *pi,
+				    struct ceph_osds *set)
+{
+	int i;
+
+	if (ceph_can_shift_osds(pi)) {
+		int removed = 0;
+
+		/* shift left */
+		for (i = 0; i < set->size; i++) {
+			if (!ceph_osd_exists(osdmap, set->osds[i])) {
+				removed++;
+				continue;
+			}
+			if (removed)
+				set->osds[i - removed] = set->osds[i];
+		}
+		set->size -= removed;
+	} else {
+		/* set dne devices to NONE */
+		for (i = 0; i < set->size; i++) {
+			if (!ceph_osd_exists(osdmap, set->osds[i]))
+				set->osds[i] = CRUSH_ITEM_NONE;
+		}
+	}
+}
+
+/*
+ * Calculate raw set (CRUSH output) for given PG and filter out
+ * nonexistent OSDs.  ->primary is undefined for a raw set.
+ *
+ * Placement seed (CRUSH input) is returned through @ppps.
+ */
+static void pg_to_raw_osds(struct ceph_osdmap *osdmap,
+			   struct ceph_pg_pool_info *pi,
+			   const struct ceph_pg *raw_pgid,
+			   struct ceph_osds *raw,
+			   u32 *ppps)
+{
+	u32 pps = raw_pg_to_pps(pi, raw_pgid);
+	int ruleno;
+	int len;
+
+	ceph_osds_init(raw);
+	if (ppps)
+		*ppps = pps;
+
+	ruleno = crush_find_rule(osdmap->crush, pi->crush_ruleset, pi->type,
+				 pi->size);
+	if (ruleno < 0) {
+		pr_err("no crush rule: pool %lld ruleset %d type %d size %d\n",
+		       pi->id, pi->crush_ruleset, pi->type, pi->size);
+		return;
+	}
+
+	if (pi->size > ARRAY_SIZE(raw->osds)) {
+		pr_err_ratelimited("pool %lld ruleset %d type %d too wide: size %d > %zu\n",
+		       pi->id, pi->crush_ruleset, pi->type, pi->size,
+		       ARRAY_SIZE(raw->osds));
+		return;
+	}
+
+	len = do_crush(osdmap, ruleno, pps, raw->osds, pi->size,
+		       osdmap->osd_weight, osdmap->max_osd, pi->id);
+	if (len < 0) {
+		pr_err("error %d from crush rule %d: pool %lld ruleset %d type %d size %d\n",
+		       len, ruleno, pi->id, pi->crush_ruleset, pi->type,
+		       pi->size);
+		return;
+	}
+
+	raw->size = len;
+	remove_nonexistent_osds(osdmap, pi, raw);
+}
+
+/* apply pg_upmap[_items] mappings */
+static void apply_upmap(struct ceph_osdmap *osdmap,
+			const struct ceph_pg *pgid,
+			struct ceph_osds *raw)
+{
+	struct ceph_pg_mapping *pg;
+	int i, j;
+
+	pg = lookup_pg_mapping(&osdmap->pg_upmap, pgid);
+	if (pg) {
+		/* make sure targets aren't marked out */
+		for (i = 0; i < pg->pg_upmap.len; i++) {
+			int osd = pg->pg_upmap.osds[i];
+
+			if (osd != CRUSH_ITEM_NONE &&
+			    osd < osdmap->max_osd &&
+			    osdmap->osd_weight[osd] == 0) {
+				/* reject/ignore explicit mapping */
+				return;
+			}
+		}
+		for (i = 0; i < pg->pg_upmap.len; i++)
+			raw->osds[i] = pg->pg_upmap.osds[i];
+		raw->size = pg->pg_upmap.len;
+		/* check and apply pg_upmap_items, if any */
+	}
+
+	pg = lookup_pg_mapping(&osdmap->pg_upmap_items, pgid);
+	if (pg) {
+		/*
+		 * Note: this approach does not allow a bidirectional swap,
+		 * e.g., [[1,2],[2,1]] applied to [0,1,2] -> [0,2,1].
+		 */
+		for (i = 0; i < pg->pg_upmap_items.len; i++) {
+			int from = pg->pg_upmap_items.from_to[i][0];
+			int to = pg->pg_upmap_items.from_to[i][1];
+			int pos = -1;
+			bool exists = false;
+
+			/* make sure replacement doesn't already appear */
+			for (j = 0; j < raw->size; j++) {
+				int osd = raw->osds[j];
+
+				if (osd == to) {
+					exists = true;
+					break;
+				}
+				/* ignore mapping if target is marked out */
+				if (osd == from && pos < 0 &&
+				    !(to != CRUSH_ITEM_NONE &&
+				      to < osdmap->max_osd &&
+				      osdmap->osd_weight[to] == 0)) {
+					pos = j;
+				}
+			}
+			if (!exists && pos >= 0)
+				raw->osds[pos] = to;
+		}
+	}
+}
+
+/*
+ * Given raw set, calculate up set and up primary.  By definition of an
+ * up set, the result won't contain nonexistent or down OSDs.
+ *
+ * This is done in-place - on return @set is the up set.  If it's
+ * empty, ->primary will remain undefined.
+ */
+static void raw_to_up_osds(struct ceph_osdmap *osdmap,
+			   struct ceph_pg_pool_info *pi,
+			   struct ceph_osds *set)
+{
+	int i;
+
+	/* ->primary is undefined for a raw set */
+	BUG_ON(set->primary != -1);
+
+	if (ceph_can_shift_osds(pi)) {
+		int removed = 0;
+
+		/* shift left */
+		for (i = 0; i < set->size; i++) {
+			if (ceph_osd_is_down(osdmap, set->osds[i])) {
+				removed++;
+				continue;
+			}
+			if (removed)
+				set->osds[i - removed] = set->osds[i];
+		}
+		set->size -= removed;
+		if (set->size > 0)
+			set->primary = set->osds[0];
+	} else {
+		/* set down/dne devices to NONE */
+		for (i = set->size - 1; i >= 0; i--) {
+			if (ceph_osd_is_down(osdmap, set->osds[i]))
+				set->osds[i] = CRUSH_ITEM_NONE;
+			else
+				set->primary = set->osds[i];
+		}
+	}
+}
+
+static void apply_primary_affinity(struct ceph_osdmap *osdmap,
+				   struct ceph_pg_pool_info *pi,
+				   u32 pps,
+				   struct ceph_osds *up)
+{
+	int i;
+	int pos = -1;
+
+	/*
+	 * Do we have any non-default primary_affinity values for these
+	 * osds?
+	 */
+	if (!osdmap->osd_primary_affinity)
+		return;
+
+	for (i = 0; i < up->size; i++) {
+		int osd = up->osds[i];
+
+		if (osd != CRUSH_ITEM_NONE &&
+		    osdmap->osd_primary_affinity[osd] !=
+					CEPH_OSD_DEFAULT_PRIMARY_AFFINITY) {
+			break;
+		}
+	}
+	if (i == up->size)
+		return;
+
+	/*
+	 * Pick the primary.  Feed both the seed (for the pg) and the
+	 * osd into the hash/rng so that a proportional fraction of an
+	 * osd's pgs get rejected as primary.
+	 */
+	for (i = 0; i < up->size; i++) {
+		int osd = up->osds[i];
+		u32 aff;
+
+		if (osd == CRUSH_ITEM_NONE)
+			continue;
+
+		aff = osdmap->osd_primary_affinity[osd];
+		if (aff < CEPH_OSD_MAX_PRIMARY_AFFINITY &&
+		    (crush_hash32_2(CRUSH_HASH_RJENKINS1,
+				    pps, osd) >> 16) >= aff) {
+			/*
+			 * We chose not to use this primary.  Note it
+			 * anyway as a fallback in case we don't pick
+			 * anyone else, but keep looking.
+			 */
+			if (pos < 0)
+				pos = i;
+		} else {
+			pos = i;
+			break;
+		}
+	}
+	if (pos < 0)
+		return;
+
+	up->primary = up->osds[pos];
+
+	if (ceph_can_shift_osds(pi) && pos > 0) {
+		/* move the new primary to the front */
+		for (i = pos; i > 0; i--)
+			up->osds[i] = up->osds[i - 1];
+		up->osds[0] = up->primary;
+	}
+}
+
+/*
+ * Get pg_temp and primary_temp mappings for given PG.
+ *
+ * Note that a PG may have none, only pg_temp, only primary_temp or
+ * both pg_temp and primary_temp mappings.  This means @temp isn't
+ * always a valid OSD set on return: in the "only primary_temp" case,
+ * @temp will have its ->primary >= 0 but ->size == 0.
+ */
+static void get_temp_osds(struct ceph_osdmap *osdmap,
+			  struct ceph_pg_pool_info *pi,
+			  const struct ceph_pg *pgid,
+			  struct ceph_osds *temp)
+{
+	struct ceph_pg_mapping *pg;
+	int i;
+
+	ceph_osds_init(temp);
+
+	/* pg_temp? */
+	pg = lookup_pg_mapping(&osdmap->pg_temp, pgid);
+	if (pg) {
+		for (i = 0; i < pg->pg_temp.len; i++) {
+			if (ceph_osd_is_down(osdmap, pg->pg_temp.osds[i])) {
+				if (ceph_can_shift_osds(pi))
+					continue;
+
+				temp->osds[temp->size++] = CRUSH_ITEM_NONE;
+			} else {
+				temp->osds[temp->size++] = pg->pg_temp.osds[i];
+			}
+		}
+
+		/* apply pg_temp's primary */
+		for (i = 0; i < temp->size; i++) {
+			if (temp->osds[i] != CRUSH_ITEM_NONE) {
+				temp->primary = temp->osds[i];
+				break;
+			}
+		}
+	}
+
+	/* primary_temp? */
+	pg = lookup_pg_mapping(&osdmap->primary_temp, pgid);
+	if (pg)
+		temp->primary = pg->primary_temp.osd;
+}
+
+/*
+ * Map a PG to its acting set as well as its up set.
+ *
+ * Acting set is used for data mapping purposes, while up set can be
+ * recorded for detecting interval changes and deciding whether to
+ * resend a request.
+ */
+void ceph_pg_to_up_acting_osds(struct ceph_osdmap *osdmap,
+			       struct ceph_pg_pool_info *pi,
+			       const struct ceph_pg *raw_pgid,
+			       struct ceph_osds *up,
+			       struct ceph_osds *acting)
+{
+	struct ceph_pg pgid;
+	u32 pps;
+
+	WARN_ON(pi->id != raw_pgid->pool);
+	raw_pg_to_pg(pi, raw_pgid, &pgid);
+
+	pg_to_raw_osds(osdmap, pi, raw_pgid, up, &pps);
+	apply_upmap(osdmap, &pgid, up);
+	raw_to_up_osds(osdmap, pi, up);
+	apply_primary_affinity(osdmap, pi, pps, up);
+	get_temp_osds(osdmap, pi, &pgid, acting);
+	if (!acting->size) {
+		memcpy(acting->osds, up->osds, up->size * sizeof(up->osds[0]));
+		acting->size = up->size;
+		if (acting->primary == -1)
+			acting->primary = up->primary;
+	}
+	WARN_ON(!osds_valid(up) || !osds_valid(acting));
+}
+
+bool ceph_pg_to_primary_shard(struct ceph_osdmap *osdmap,
+			      struct ceph_pg_pool_info *pi,
+			      const struct ceph_pg *raw_pgid,
+			      struct ceph_spg *spgid)
+{
+	struct ceph_pg pgid;
+	struct ceph_osds up, acting;
+	int i;
+
+	WARN_ON(pi->id != raw_pgid->pool);
+	raw_pg_to_pg(pi, raw_pgid, &pgid);
+
+	if (ceph_can_shift_osds(pi)) {
+		spgid->pgid = pgid; /* struct */
+		spgid->shard = CEPH_SPG_NOSHARD;
+		return true;
+	}
+
+	ceph_pg_to_up_acting_osds(osdmap, pi, &pgid, &up, &acting);
+	for (i = 0; i < acting.size; i++) {
+		if (acting.osds[i] == acting.primary) {
+			spgid->pgid = pgid; /* struct */
+			spgid->shard = i;
+			return true;
+		}
+	}
+
+	return false;
+}
+
+/*
+ * Return acting primary for given PG, or -1 if none.
+ */
+int ceph_pg_to_acting_primary(struct ceph_osdmap *osdmap,
+			      const struct ceph_pg *raw_pgid)
+{
+	struct ceph_pg_pool_info *pi;
+	struct ceph_osds up, acting;
+
+	pi = ceph_pg_pool_by_id(osdmap, raw_pgid->pool);
+	if (!pi)
+		return -1;
+
+	ceph_pg_to_up_acting_osds(osdmap, pi, raw_pgid, &up, &acting);
+	return acting.primary;
+}
+EXPORT_SYMBOL(ceph_pg_to_acting_primary);
diff --git a/net/ceph/pagelist.c b/net/ceph/pagelist.c
new file mode 100644
index 000000000..2ea056477
--- /dev/null
+++ b/net/ceph/pagelist.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/module.h>
+#include <linux/gfp.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/ceph/pagelist.h>
+
+static void ceph_pagelist_unmap_tail(struct ceph_pagelist *pl)
+{
+	if (pl->mapped_tail) {
+		struct page *page = list_entry(pl->head.prev, struct page, lru);
+		kunmap(page);
+		pl->mapped_tail = NULL;
+	}
+}
+
+void ceph_pagelist_release(struct ceph_pagelist *pl)
+{
+	if (!refcount_dec_and_test(&pl->refcnt))
+		return;
+	ceph_pagelist_unmap_tail(pl);
+	while (!list_empty(&pl->head)) {
+		struct page *page = list_first_entry(&pl->head, struct page,
+						     lru);
+		list_del(&page->lru);
+		__free_page(page);
+	}
+	ceph_pagelist_free_reserve(pl);
+	kfree(pl);
+}
+EXPORT_SYMBOL(ceph_pagelist_release);
+
+static int ceph_pagelist_addpage(struct ceph_pagelist *pl)
+{
+	struct page *page;
+
+	if (!pl->num_pages_free) {
+		page = __page_cache_alloc(GFP_NOFS);
+	} else {
+		page = list_first_entry(&pl->free_list, struct page, lru);
+		list_del(&page->lru);
+		--pl->num_pages_free;
+	}
+	if (!page)
+		return -ENOMEM;
+	pl->room += PAGE_SIZE;
+	ceph_pagelist_unmap_tail(pl);
+	list_add_tail(&page->lru, &pl->head);
+	pl->mapped_tail = kmap(page);
+	return 0;
+}
+
+int ceph_pagelist_append(struct ceph_pagelist *pl, const void *buf, size_t len)
+{
+	while (pl->room < len) {
+		size_t bit = pl->room;
+		int ret;
+
+		memcpy(pl->mapped_tail + (pl->length & ~PAGE_MASK),
+		       buf, bit);
+		pl->length += bit;
+		pl->room -= bit;
+		buf += bit;
+		len -= bit;
+		ret = ceph_pagelist_addpage(pl);
+		if (ret)
+			return ret;
+	}
+
+	memcpy(pl->mapped_tail + (pl->length & ~PAGE_MASK), buf, len);
+	pl->length += len;
+	pl->room -= len;
+	return 0;
+}
+EXPORT_SYMBOL(ceph_pagelist_append);
+
+/* Allocate enough pages for a pagelist to append the given amount
+ * of data without without allocating.
+ * Returns: 0 on success, -ENOMEM on error.
+ */
+int ceph_pagelist_reserve(struct ceph_pagelist *pl, size_t space)
+{
+	if (space <= pl->room)
+		return 0;
+	space -= pl->room;
+	space = (space + PAGE_SIZE - 1) >> PAGE_SHIFT;   /* conv to num pages */
+
+	while (space > pl->num_pages_free) {
+		struct page *page = __page_cache_alloc(GFP_NOFS);
+		if (!page)
+			return -ENOMEM;
+		list_add_tail(&page->lru, &pl->free_list);
+		++pl->num_pages_free;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(ceph_pagelist_reserve);
+
+/* Free any pages that have been preallocated. */
+int ceph_pagelist_free_reserve(struct ceph_pagelist *pl)
+{
+	while (!list_empty(&pl->free_list)) {
+		struct page *page = list_first_entry(&pl->free_list,
+						     struct page, lru);
+		list_del(&page->lru);
+		__free_page(page);
+		--pl->num_pages_free;
+	}
+	BUG_ON(pl->num_pages_free);
+	return 0;
+}
+EXPORT_SYMBOL(ceph_pagelist_free_reserve);
+
+/* Create a truncation point. */
+void ceph_pagelist_set_cursor(struct ceph_pagelist *pl,
+			      struct ceph_pagelist_cursor *c)
+{
+	c->pl = pl;
+	c->page_lru = pl->head.prev;
+	c->room = pl->room;
+}
+EXPORT_SYMBOL(ceph_pagelist_set_cursor);
+
+/* Truncate a pagelist to the given point. Move extra pages to reserve.
+ * This won't sleep.
+ * Returns: 0 on success,
+ *          -EINVAL if the pagelist doesn't match the trunc point pagelist
+ */
+int ceph_pagelist_truncate(struct ceph_pagelist *pl,
+			   struct ceph_pagelist_cursor *c)
+{
+	struct page *page;
+
+	if (pl != c->pl)
+		return -EINVAL;
+	ceph_pagelist_unmap_tail(pl);
+	while (pl->head.prev != c->page_lru) {
+		page = list_entry(pl->head.prev, struct page, lru);
+		/* move from pagelist to reserve */
+		list_move_tail(&page->lru, &pl->free_list);
+		++pl->num_pages_free;
+	}
+	pl->room = c->room;
+	if (!list_empty(&pl->head)) {
+		page = list_entry(pl->head.prev, struct page, lru);
+		pl->mapped_tail = kmap(page);
+	}
+	return 0;
+}
+EXPORT_SYMBOL(ceph_pagelist_truncate);
diff --git a/net/ceph/pagevec.c b/net/ceph/pagevec.c
new file mode 100644
index 000000000..d3736f5bf
--- /dev/null
+++ b/net/ceph/pagevec.c
@@ -0,0 +1,199 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/namei.h>
+#include <linux/writeback.h>
+
+#include <linux/ceph/libceph.h>
+
+/*
+ * build a vector of user pages
+ */
+struct page **ceph_get_direct_page_vector(const void __user *data,
+					  int num_pages, bool write_page)
+{
+	struct page **pages;
+	int got = 0;
+	int rc = 0;
+
+	pages = kmalloc_array(num_pages, sizeof(*pages), GFP_NOFS);
+	if (!pages)
+		return ERR_PTR(-ENOMEM);
+
+	while (got < num_pages) {
+		rc = get_user_pages_fast(
+		    (unsigned long)data + ((unsigned long)got * PAGE_SIZE),
+		    num_pages - got, write_page, pages + got);
+		if (rc < 0)
+			break;
+		BUG_ON(rc == 0);
+		got += rc;
+	}
+	if (rc < 0)
+		goto fail;
+	return pages;
+
+fail:
+	ceph_put_page_vector(pages, got, false);
+	return ERR_PTR(rc);
+}
+EXPORT_SYMBOL(ceph_get_direct_page_vector);
+
+void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty)
+{
+	int i;
+
+	for (i = 0; i < num_pages; i++) {
+		if (dirty)
+			set_page_dirty_lock(pages[i]);
+		put_page(pages[i]);
+	}
+	kvfree(pages);
+}
+EXPORT_SYMBOL(ceph_put_page_vector);
+
+void ceph_release_page_vector(struct page **pages, int num_pages)
+{
+	int i;
+
+	for (i = 0; i < num_pages; i++)
+		__free_pages(pages[i], 0);
+	kfree(pages);
+}
+EXPORT_SYMBOL(ceph_release_page_vector);
+
+/*
+ * allocate a vector new pages
+ */
+struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
+{
+	struct page **pages;
+	int i;
+
+	pages = kmalloc_array(num_pages, sizeof(*pages), flags);
+	if (!pages)
+		return ERR_PTR(-ENOMEM);
+	for (i = 0; i < num_pages; i++) {
+		pages[i] = __page_cache_alloc(flags);
+		if (pages[i] == NULL) {
+			ceph_release_page_vector(pages, i);
+			return ERR_PTR(-ENOMEM);
+		}
+	}
+	return pages;
+}
+EXPORT_SYMBOL(ceph_alloc_page_vector);
+
+/*
+ * copy user data into a page vector
+ */
+int ceph_copy_user_to_page_vector(struct page **pages,
+					 const void __user *data,
+					 loff_t off, size_t len)
+{
+	int i = 0;
+	int po = off & ~PAGE_MASK;
+	int left = len;
+	int l, bad;
+
+	while (left > 0) {
+		l = min_t(int, PAGE_SIZE-po, left);
+		bad = copy_from_user(page_address(pages[i]) + po, data, l);
+		if (bad == l)
+			return -EFAULT;
+		data += l - bad;
+		left -= l - bad;
+		po += l - bad;
+		if (po == PAGE_SIZE) {
+			po = 0;
+			i++;
+		}
+	}
+	return len;
+}
+EXPORT_SYMBOL(ceph_copy_user_to_page_vector);
+
+void ceph_copy_to_page_vector(struct page **pages,
+				    const void *data,
+				    loff_t off, size_t len)
+{
+	int i = 0;
+	size_t po = off & ~PAGE_MASK;
+	size_t left = len;
+
+	while (left > 0) {
+		size_t l = min_t(size_t, PAGE_SIZE-po, left);
+
+		memcpy(page_address(pages[i]) + po, data, l);
+		data += l;
+		left -= l;
+		po += l;
+		if (po == PAGE_SIZE) {
+			po = 0;
+			i++;
+		}
+	}
+}
+EXPORT_SYMBOL(ceph_copy_to_page_vector);
+
+void ceph_copy_from_page_vector(struct page **pages,
+				    void *data,
+				    loff_t off, size_t len)
+{
+	int i = 0;
+	size_t po = off & ~PAGE_MASK;
+	size_t left = len;
+
+	while (left > 0) {
+		size_t l = min_t(size_t, PAGE_SIZE-po, left);
+
+		memcpy(data, page_address(pages[i]) + po, l);
+		data += l;
+		left -= l;
+		po += l;
+		if (po == PAGE_SIZE) {
+			po = 0;
+			i++;
+		}
+	}
+}
+EXPORT_SYMBOL(ceph_copy_from_page_vector);
+
+/*
+ * Zero an extent within a page vector.  Offset is relative to the
+ * start of the first page.
+ */
+void ceph_zero_page_vector_range(int off, int len, struct page **pages)
+{
+	int i = off >> PAGE_SHIFT;
+
+	off &= ~PAGE_MASK;
+
+	dout("zero_page_vector_page %u~%u\n", off, len);
+
+	/* leading partial page? */
+	if (off) {
+		int end = min((int)PAGE_SIZE, off + len);
+		dout("zeroing %d %p head from %d\n", i, pages[i],
+		     (int)off);
+		zero_user_segment(pages[i], off, end);
+		len -= (end - off);
+		i++;
+	}
+	while (len >= PAGE_SIZE) {
+		dout("zeroing %d %p len=%d\n", i, pages[i], len);
+		zero_user_segment(pages[i], 0, PAGE_SIZE);
+		len -= PAGE_SIZE;
+		i++;
+	}
+	/* trailing partial page? */
+	if (len) {
+		dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
+		zero_user_segment(pages[i], 0, len);
+	}
+}
+EXPORT_SYMBOL(ceph_zero_page_vector_range);
diff --git a/net/ceph/snapshot.c b/net/ceph/snapshot.c
new file mode 100644
index 000000000..e14a5d038
--- /dev/null
+++ b/net/ceph/snapshot.c
@@ -0,0 +1,76 @@
+/*
+ * snapshot.c    Ceph snapshot context utility routines (part of libceph)
+ *
+ * Copyright (C) 2013 Inktank Storage, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <linux/types.h>
+#include <linux/export.h>
+#include <linux/ceph/libceph.h>
+
+/*
+ * Ceph snapshot contexts are reference counted objects, and the
+ * returned structure holds a single reference.  Acquire additional
+ * references with ceph_get_snap_context(), and release them with
+ * ceph_put_snap_context().  When the reference count reaches zero
+ * the entire structure is freed.
+ */
+
+/*
+ * Create a new ceph snapshot context large enough to hold the
+ * indicated number of snapshot ids (which can be 0).  Caller has
+ * to fill in snapc->seq and snapc->snaps[0..snap_count-1].
+ *
+ * Returns a null pointer if an error occurs.
+ */
+struct ceph_snap_context *ceph_create_snap_context(u32 snap_count,
+						gfp_t gfp_flags)
+{
+	struct ceph_snap_context *snapc;
+	size_t size;
+
+	size = sizeof (struct ceph_snap_context);
+	size += snap_count * sizeof (snapc->snaps[0]);
+	snapc = kzalloc(size, gfp_flags);
+	if (!snapc)
+		return NULL;
+
+	refcount_set(&snapc->nref, 1);
+	snapc->num_snaps = snap_count;
+
+	return snapc;
+}
+EXPORT_SYMBOL(ceph_create_snap_context);
+
+struct ceph_snap_context *ceph_get_snap_context(struct ceph_snap_context *sc)
+{
+	if (sc)
+		refcount_inc(&sc->nref);
+	return sc;
+}
+EXPORT_SYMBOL(ceph_get_snap_context);
+
+void ceph_put_snap_context(struct ceph_snap_context *sc)
+{
+	if (!sc)
+		return;
+	if (refcount_dec_and_test(&sc->nref)) {
+		/*printk(" deleting snap_context %p\n", sc);*/
+		kfree(sc);
+	}
+}
+EXPORT_SYMBOL(ceph_put_snap_context);
diff --git a/net/ceph/string_table.c b/net/ceph/string_table.c
new file mode 100644
index 000000000..3191d9d16
--- /dev/null
+++ b/net/ceph/string_table.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/slab.h>
+#include <linux/gfp.h>
+#include <linux/string.h>
+#include <linux/spinlock.h>
+#include <linux/ceph/string_table.h>
+
+static DEFINE_SPINLOCK(string_tree_lock);
+static struct rb_root string_tree = RB_ROOT;
+
+struct ceph_string *ceph_find_or_create_string(const char* str, size_t len)
+{
+	struct ceph_string *cs, *exist;
+	struct rb_node **p, *parent;
+	int ret;
+
+	exist = NULL;
+	spin_lock(&string_tree_lock);
+	p = &string_tree.rb_node;
+	while (*p) {
+		exist = rb_entry(*p, struct ceph_string, node);
+		ret = ceph_compare_string(exist, str, len);
+		if (ret > 0)
+			p = &(*p)->rb_left;
+		else if (ret < 0)
+			p = &(*p)->rb_right;
+		else
+			break;
+		exist = NULL;
+	}
+	if (exist && !kref_get_unless_zero(&exist->kref)) {
+		rb_erase(&exist->node, &string_tree);
+		RB_CLEAR_NODE(&exist->node);
+		exist = NULL;
+	}
+	spin_unlock(&string_tree_lock);
+	if (exist)
+		return exist;
+
+	cs = kmalloc(sizeof(*cs) + len + 1, GFP_NOFS);
+	if (!cs)
+		return NULL;
+
+	kref_init(&cs->kref);
+	cs->len = len;
+	memcpy(cs->str, str, len);
+	cs->str[len] = 0;
+
+retry:
+	exist = NULL;
+	parent = NULL;
+	p = &string_tree.rb_node;
+	spin_lock(&string_tree_lock);
+	while (*p) {
+		parent = *p;
+		exist = rb_entry(*p, struct ceph_string, node);
+		ret = ceph_compare_string(exist, str, len);
+		if (ret > 0)
+			p = &(*p)->rb_left;
+		else if (ret < 0)
+			p = &(*p)->rb_right;
+		else
+			break;
+		exist = NULL;
+	}
+	ret = 0;
+	if (!exist) {
+		rb_link_node(&cs->node, parent, p);
+		rb_insert_color(&cs->node, &string_tree);
+	} else if (!kref_get_unless_zero(&exist->kref)) {
+		rb_erase(&exist->node, &string_tree);
+		RB_CLEAR_NODE(&exist->node);
+		ret = -EAGAIN;
+	}
+	spin_unlock(&string_tree_lock);
+	if (ret == -EAGAIN)
+		goto retry;
+
+	if (exist) {
+		kfree(cs);
+		cs = exist;
+	}
+
+	return cs;
+}
+EXPORT_SYMBOL(ceph_find_or_create_string);
+
+void ceph_release_string(struct kref *ref)
+{
+	struct ceph_string *cs = container_of(ref, struct ceph_string, kref);
+
+	spin_lock(&string_tree_lock);
+	if (!RB_EMPTY_NODE(&cs->node)) {
+		rb_erase(&cs->node, &string_tree);
+		RB_CLEAR_NODE(&cs->node);
+	}
+	spin_unlock(&string_tree_lock);
+
+	kfree_rcu(cs, rcu);
+}
+EXPORT_SYMBOL(ceph_release_string);
+
+bool ceph_strings_empty(void)
+{
+	return RB_EMPTY_ROOT(&string_tree);
+}
diff --git a/net/ceph/striper.c b/net/ceph/striper.c
new file mode 100644
index 000000000..c36462dc8
--- /dev/null
+++ b/net/ceph/striper.c
@@ -0,0 +1,261 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/math64.h>
+#include <linux/slab.h>
+
+#include <linux/ceph/striper.h>
+#include <linux/ceph/types.h>
+
+/*
+ * Map a file extent to a stripe unit within an object.
+ * Fill in objno, offset into object, and object extent length (i.e. the
+ * number of bytes mapped, less than or equal to @l->stripe_unit).
+ *
+ * Example for stripe_count = 3, stripes_per_object = 4:
+ *
+ * blockno   |  0  3  6  9 |  1  4  7 10 |  2  5  8 11 | 12 15 18 21 | 13 16 19
+ * stripeno  |  0  1  2  3 |  0  1  2  3 |  0  1  2  3 |  4  5  6  7 |  4  5  6
+ * stripepos |      0      |      1      |      2      |      0      |      1
+ * objno     |      0      |      1      |      2      |      3      |      4
+ * objsetno  |                    0                    |                    1
+ */
+void ceph_calc_file_object_mapping(struct ceph_file_layout *l,
+				   u64 off, u64 len,
+				   u64 *objno, u64 *objoff, u32 *xlen)
+{
+	u32 stripes_per_object = l->object_size / l->stripe_unit;
+	u64 blockno;	/* which su in the file (i.e. globally) */
+	u32 blockoff;	/* offset into su */
+	u64 stripeno;	/* which stripe */
+	u32 stripepos;	/* which su in the stripe,
+			   which object in the object set */
+	u64 objsetno;	/* which object set */
+	u32 objsetpos;	/* which stripe in the object set */
+
+	blockno = div_u64_rem(off, l->stripe_unit, &blockoff);
+	stripeno = div_u64_rem(blockno, l->stripe_count, &stripepos);
+	objsetno = div_u64_rem(stripeno, stripes_per_object, &objsetpos);
+
+	*objno = objsetno * l->stripe_count + stripepos;
+	*objoff = objsetpos * l->stripe_unit + blockoff;
+	*xlen = min_t(u64, len, l->stripe_unit - blockoff);
+}
+EXPORT_SYMBOL(ceph_calc_file_object_mapping);
+
+/*
+ * Return the last extent with given objno (@object_extents is sorted
+ * by objno).  If not found, return NULL and set @add_pos so that the
+ * new extent can be added with list_add(add_pos, new_ex).
+ */
+static struct ceph_object_extent *
+lookup_last(struct list_head *object_extents, u64 objno,
+	    struct list_head **add_pos)
+{
+	struct list_head *pos;
+
+	list_for_each_prev(pos, object_extents) {
+		struct ceph_object_extent *ex =
+		    list_entry(pos, typeof(*ex), oe_item);
+
+		if (ex->oe_objno == objno)
+			return ex;
+
+		if (ex->oe_objno < objno)
+			break;
+	}
+
+	*add_pos = pos;
+	return NULL;
+}
+
+static struct ceph_object_extent *
+lookup_containing(struct list_head *object_extents, u64 objno,
+		  u64 objoff, u32 xlen)
+{
+	struct ceph_object_extent *ex;
+
+	list_for_each_entry(ex, object_extents, oe_item) {
+		if (ex->oe_objno == objno &&
+		    ex->oe_off <= objoff &&
+		    ex->oe_off + ex->oe_len >= objoff + xlen) /* paranoia */
+			return ex;
+
+		if (ex->oe_objno > objno)
+			break;
+	}
+
+	return NULL;
+}
+
+/*
+ * Map a file extent to a sorted list of object extents.
+ *
+ * We want only one (or as few as possible) object extents per object.
+ * Adjacent object extents will be merged together, each returned object
+ * extent may reverse map to multiple different file extents.
+ *
+ * Call @alloc_fn for each new object extent and @action_fn for each
+ * mapped stripe unit, whether it was merged into an already allocated
+ * object extent or started a new object extent.
+ *
+ * Newly allocated object extents are added to @object_extents.
+ * To keep @object_extents sorted, successive calls to this function
+ * must map successive file extents (i.e. the list of file extents that
+ * are mapped using the same @object_extents must be sorted).
+ *
+ * The caller is responsible for @object_extents.
+ */
+int ceph_file_to_extents(struct ceph_file_layout *l, u64 off, u64 len,
+			 struct list_head *object_extents,
+			 struct ceph_object_extent *alloc_fn(void *arg),
+			 void *alloc_arg,
+			 ceph_object_extent_fn_t action_fn,
+			 void *action_arg)
+{
+	struct ceph_object_extent *last_ex, *ex;
+
+	while (len) {
+		struct list_head *add_pos = NULL;
+		u64 objno, objoff;
+		u32 xlen;
+
+		ceph_calc_file_object_mapping(l, off, len, &objno, &objoff,
+					      &xlen);
+
+		last_ex = lookup_last(object_extents, objno, &add_pos);
+		if (!last_ex || last_ex->oe_off + last_ex->oe_len != objoff) {
+			ex = alloc_fn(alloc_arg);
+			if (!ex)
+				return -ENOMEM;
+
+			ex->oe_objno = objno;
+			ex->oe_off = objoff;
+			ex->oe_len = xlen;
+			if (action_fn)
+				action_fn(ex, xlen, action_arg);
+
+			if (!last_ex)
+				list_add(&ex->oe_item, add_pos);
+			else
+				list_add(&ex->oe_item, &last_ex->oe_item);
+		} else {
+			last_ex->oe_len += xlen;
+			if (action_fn)
+				action_fn(last_ex, xlen, action_arg);
+		}
+
+		off += xlen;
+		len -= xlen;
+	}
+
+	for (last_ex = list_first_entry(object_extents, typeof(*ex), oe_item),
+	     ex = list_next_entry(last_ex, oe_item);
+	     &ex->oe_item != object_extents;
+	     last_ex = ex, ex = list_next_entry(ex, oe_item)) {
+		if (last_ex->oe_objno > ex->oe_objno ||
+		    (last_ex->oe_objno == ex->oe_objno &&
+		     last_ex->oe_off + last_ex->oe_len >= ex->oe_off)) {
+			WARN(1, "%s: object_extents list not sorted!\n",
+			     __func__);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(ceph_file_to_extents);
+
+/*
+ * A stripped down, non-allocating version of ceph_file_to_extents(),
+ * for when @object_extents is already populated.
+ */
+int ceph_iterate_extents(struct ceph_file_layout *l, u64 off, u64 len,
+			 struct list_head *object_extents,
+			 ceph_object_extent_fn_t action_fn,
+			 void *action_arg)
+{
+	while (len) {
+		struct ceph_object_extent *ex;
+		u64 objno, objoff;
+		u32 xlen;
+
+		ceph_calc_file_object_mapping(l, off, len, &objno, &objoff,
+					      &xlen);
+
+		ex = lookup_containing(object_extents, objno, objoff, xlen);
+		if (!ex) {
+			WARN(1, "%s: objno %llu %llu~%u not found!\n",
+			     __func__, objno, objoff, xlen);
+			return -EINVAL;
+		}
+
+		action_fn(ex, xlen, action_arg);
+
+		off += xlen;
+		len -= xlen;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(ceph_iterate_extents);
+
+/*
+ * Reverse map an object extent to a sorted list of file extents.
+ *
+ * On success, the caller is responsible for:
+ *
+ *     kfree(file_extents)
+ */
+int ceph_extent_to_file(struct ceph_file_layout *l,
+			u64 objno, u64 objoff, u64 objlen,
+			struct ceph_file_extent **file_extents,
+			u32 *num_file_extents)
+{
+	u32 stripes_per_object = l->object_size / l->stripe_unit;
+	u64 blockno;	/* which su */
+	u32 blockoff;	/* offset into su */
+	u64 stripeno;	/* which stripe */
+	u32 stripepos;	/* which su in the stripe,
+			   which object in the object set */
+	u64 objsetno;	/* which object set */
+	u32 i = 0;
+
+	if (!objlen) {
+		*file_extents = NULL;
+		*num_file_extents = 0;
+		return 0;
+	}
+
+	*num_file_extents = DIV_ROUND_UP_ULL(objoff + objlen, l->stripe_unit) -
+				     DIV_ROUND_DOWN_ULL(objoff, l->stripe_unit);
+	*file_extents = kmalloc_array(*num_file_extents, sizeof(**file_extents),
+				      GFP_NOIO);
+	if (!*file_extents)
+		return -ENOMEM;
+
+	div_u64_rem(objoff, l->stripe_unit, &blockoff);
+	while (objlen) {
+		u64 off, len;
+
+		objsetno = div_u64_rem(objno, l->stripe_count, &stripepos);
+		stripeno = div_u64(objoff, l->stripe_unit) +
+						objsetno * stripes_per_object;
+		blockno = stripeno * l->stripe_count + stripepos;
+		off = blockno * l->stripe_unit + blockoff;
+		len = min_t(u64, objlen, l->stripe_unit - blockoff);
+
+		(*file_extents)[i].fe_off = off;
+		(*file_extents)[i].fe_len = len;
+
+		blockoff = 0;
+		objoff += len;
+		objlen -= len;
+		i++;
+	}
+
+	BUG_ON(i != *num_file_extents);
+	return 0;
+}
+EXPORT_SYMBOL(ceph_extent_to_file);