1 files changed, 644 insertions, 0 deletions

diff --git a/fs/dlm/rcom.c b/fs/dlm/rcom.c
new file mode 100644
index 000000000..70c625999
--- /dev/null
+++ b/fs/dlm/rcom.c
@@ -0,0 +1,644 @@
+/******************************************************************************
+*******************************************************************************
+**
+**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
+**  Copyright (C) 2005-2008 Red Hat, Inc.  All rights reserved.
+**
+**  This copyrighted material is made available to anyone wishing to use,
+**  modify, copy, or redistribute it subject to the terms and conditions
+**  of the GNU General Public License v.2.
+**
+*******************************************************************************
+******************************************************************************/
+
+#include "dlm_internal.h"
+#include "lockspace.h"
+#include "member.h"
+#include "lowcomms.h"
+#include "midcomms.h"
+#include "rcom.h"
+#include "recover.h"
+#include "dir.h"
+#include "config.h"
+#include "memory.h"
+#include "lock.h"
+#include "util.h"
+
+static int rcom_response(struct dlm_ls *ls)
+{
+	return test_bit(LSFL_RCOM_READY, &ls->ls_flags);
+}
+
+static int create_rcom(struct dlm_ls *ls, int to_nodeid, int type, int len,
+		       struct dlm_rcom **rc_ret, struct dlm_mhandle **mh_ret)
+{
+	struct dlm_rcom *rc;
+	struct dlm_mhandle *mh;
+	char *mb;
+	int mb_len = sizeof(struct dlm_rcom) + len;
+
+	mh = dlm_lowcomms_get_buffer(to_nodeid, mb_len, GFP_NOFS, &mb);
+	if (!mh) {
+		log_print("create_rcom to %d type %d len %d ENOBUFS",
+			  to_nodeid, type, len);
+		return -ENOBUFS;
+	}
+	memset(mb, 0, mb_len);
+
+	rc = (struct dlm_rcom *) mb;
+
+	rc->rc_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
+	rc->rc_header.h_lockspace = ls->ls_global_id;
+	rc->rc_header.h_nodeid = dlm_our_nodeid();
+	rc->rc_header.h_length = mb_len;
+	rc->rc_header.h_cmd = DLM_RCOM;
+
+	rc->rc_type = type;
+
+	spin_lock(&ls->ls_recover_lock);
+	rc->rc_seq = ls->ls_recover_seq;
+	spin_unlock(&ls->ls_recover_lock);
+
+	*mh_ret = mh;
+	*rc_ret = rc;
+	return 0;
+}
+
+static void send_rcom(struct dlm_ls *ls, struct dlm_mhandle *mh,
+		      struct dlm_rcom *rc)
+{
+	dlm_rcom_out(rc);
+	dlm_lowcomms_commit_buffer(mh);
+}
+
+static void set_rcom_status(struct dlm_ls *ls, struct rcom_status *rs,
+			    uint32_t flags)
+{
+	rs->rs_flags = cpu_to_le32(flags);
+}
+
+/* When replying to a status request, a node also sends back its
+   configuration values.  The requesting node then checks that the remote
+   node is configured the same way as itself. */
+
+static void set_rcom_config(struct dlm_ls *ls, struct rcom_config *rf,
+			    uint32_t num_slots)
+{
+	rf->rf_lvblen = cpu_to_le32(ls->ls_lvblen);
+	rf->rf_lsflags = cpu_to_le32(ls->ls_exflags);
+
+	rf->rf_our_slot = cpu_to_le16(ls->ls_slot);
+	rf->rf_num_slots = cpu_to_le16(num_slots);
+	rf->rf_generation =  cpu_to_le32(ls->ls_generation);
+}
+
+static int check_rcom_config(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid)
+{
+	struct rcom_config *rf = (struct rcom_config *) rc->rc_buf;
+
+	if ((rc->rc_header.h_version & 0xFFFF0000) != DLM_HEADER_MAJOR) {
+		log_error(ls, "version mismatch: %x nodeid %d: %x",
+			  DLM_HEADER_MAJOR | DLM_HEADER_MINOR, nodeid,
+			  rc->rc_header.h_version);
+		return -EPROTO;
+	}
+
+	if (le32_to_cpu(rf->rf_lvblen) != ls->ls_lvblen ||
+	    le32_to_cpu(rf->rf_lsflags) != ls->ls_exflags) {
+		log_error(ls, "config mismatch: %d,%x nodeid %d: %d,%x",
+			  ls->ls_lvblen, ls->ls_exflags, nodeid,
+			  le32_to_cpu(rf->rf_lvblen),
+			  le32_to_cpu(rf->rf_lsflags));
+		return -EPROTO;
+	}
+	return 0;
+}
+
+static void allow_sync_reply(struct dlm_ls *ls, uint64_t *new_seq)
+{
+	spin_lock(&ls->ls_rcom_spin);
+	*new_seq = ++ls->ls_rcom_seq;
+	set_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
+	spin_unlock(&ls->ls_rcom_spin);
+}
+
+static void disallow_sync_reply(struct dlm_ls *ls)
+{
+	spin_lock(&ls->ls_rcom_spin);
+	clear_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
+	clear_bit(LSFL_RCOM_READY, &ls->ls_flags);
+	spin_unlock(&ls->ls_rcom_spin);
+}
+
+/*
+ * low nodeid gathers one slot value at a time from each node.
+ * it sets need_slots=0, and saves rf_our_slot returned from each
+ * rcom_config.
+ *
+ * other nodes gather all slot values at once from the low nodeid.
+ * they set need_slots=1, and ignore the rf_our_slot returned from each
+ * rcom_config.  they use the rf_num_slots returned from the low
+ * node's rcom_config.
+ */
+
+int dlm_rcom_status(struct dlm_ls *ls, int nodeid, uint32_t status_flags)
+{
+	struct dlm_rcom *rc;
+	struct dlm_mhandle *mh;
+	int error = 0;
+
+	ls->ls_recover_nodeid = nodeid;
+
+	if (nodeid == dlm_our_nodeid()) {
+		rc = ls->ls_recover_buf;
+		rc->rc_result = dlm_recover_status(ls);
+		goto out;
+	}
+
+retry:
+	error = create_rcom(ls, nodeid, DLM_RCOM_STATUS,
+			    sizeof(struct rcom_status), &rc, &mh);
+	if (error)
+		goto out;
+
+	set_rcom_status(ls, (struct rcom_status *)rc->rc_buf, status_flags);
+
+	allow_sync_reply(ls, &rc->rc_id);
+	memset(ls->ls_recover_buf, 0, dlm_config.ci_buffer_size);
+
+	send_rcom(ls, mh, rc);
+
+	error = dlm_wait_function(ls, &rcom_response);
+	disallow_sync_reply(ls);
+	if (error == -ETIMEDOUT)
+		goto retry;
+	if (error)
+		goto out;
+
+	rc = ls->ls_recover_buf;
+
+	if (rc->rc_result == -ESRCH) {
+		/* we pretend the remote lockspace exists with 0 status */
+		log_debug(ls, "remote node %d not ready", nodeid);
+		rc->rc_result = 0;
+		error = 0;
+	} else {
+		error = check_rcom_config(ls, rc, nodeid);
+	}
+
+	/* the caller looks at rc_result for the remote recovery status */
+ out:
+	return error;
+}
+
+static void receive_rcom_status(struct dlm_ls *ls, struct dlm_rcom *rc_in)
+{
+	struct dlm_rcom *rc;
+	struct dlm_mhandle *mh;
+	struct rcom_status *rs;
+	uint32_t status;
+	int nodeid = rc_in->rc_header.h_nodeid;
+	int len = sizeof(struct rcom_config);
+	int num_slots = 0;
+	int error;
+
+	if (!dlm_slots_version(&rc_in->rc_header)) {
+		status = dlm_recover_status(ls);
+		goto do_create;
+	}
+
+	rs = (struct rcom_status *)rc_in->rc_buf;
+
+	if (!(le32_to_cpu(rs->rs_flags) & DLM_RSF_NEED_SLOTS)) {
+		status = dlm_recover_status(ls);
+		goto do_create;
+	}
+
+	spin_lock(&ls->ls_recover_lock);
+	status = ls->ls_recover_status;
+	num_slots = ls->ls_num_slots;
+	spin_unlock(&ls->ls_recover_lock);
+	len += num_slots * sizeof(struct rcom_slot);
+
+ do_create:
+	error = create_rcom(ls, nodeid, DLM_RCOM_STATUS_REPLY,
+			    len, &rc, &mh);
+	if (error)
+		return;
+
+	rc->rc_id = rc_in->rc_id;
+	rc->rc_seq_reply = rc_in->rc_seq;
+	rc->rc_result = status;
+
+	set_rcom_config(ls, (struct rcom_config *)rc->rc_buf, num_slots);
+
+	if (!num_slots)
+		goto do_send;
+
+	spin_lock(&ls->ls_recover_lock);
+	if (ls->ls_num_slots != num_slots) {
+		spin_unlock(&ls->ls_recover_lock);
+		log_debug(ls, "receive_rcom_status num_slots %d to %d",
+			  num_slots, ls->ls_num_slots);
+		rc->rc_result = 0;
+		set_rcom_config(ls, (struct rcom_config *)rc->rc_buf, 0);
+		goto do_send;
+	}
+
+	dlm_slots_copy_out(ls, rc);
+	spin_unlock(&ls->ls_recover_lock);
+
+ do_send:
+	send_rcom(ls, mh, rc);
+}
+
+static void receive_sync_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
+{
+	spin_lock(&ls->ls_rcom_spin);
+	if (!test_bit(LSFL_RCOM_WAIT, &ls->ls_flags) ||
+	    rc_in->rc_id != ls->ls_rcom_seq) {
+		log_debug(ls, "reject reply %d from %d seq %llx expect %llx",
+			  rc_in->rc_type, rc_in->rc_header.h_nodeid,
+			  (unsigned long long)rc_in->rc_id,
+			  (unsigned long long)ls->ls_rcom_seq);
+		goto out;
+	}
+	memcpy(ls->ls_recover_buf, rc_in, rc_in->rc_header.h_length);
+	set_bit(LSFL_RCOM_READY, &ls->ls_flags);
+	clear_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
+	wake_up(&ls->ls_wait_general);
+ out:
+	spin_unlock(&ls->ls_rcom_spin);
+}
+
+int dlm_rcom_names(struct dlm_ls *ls, int nodeid, char *last_name, int last_len)
+{
+	struct dlm_rcom *rc;
+	struct dlm_mhandle *mh;
+	int error = 0;
+
+	ls->ls_recover_nodeid = nodeid;
+
+retry:
+	error = create_rcom(ls, nodeid, DLM_RCOM_NAMES, last_len, &rc, &mh);
+	if (error)
+		goto out;
+	memcpy(rc->rc_buf, last_name, last_len);
+
+	allow_sync_reply(ls, &rc->rc_id);
+	memset(ls->ls_recover_buf, 0, dlm_config.ci_buffer_size);
+
+	send_rcom(ls, mh, rc);
+
+	error = dlm_wait_function(ls, &rcom_response);
+	disallow_sync_reply(ls);
+	if (error == -ETIMEDOUT)
+		goto retry;
+ out:
+	return error;
+}
+
+static void receive_rcom_names(struct dlm_ls *ls, struct dlm_rcom *rc_in)
+{
+	struct dlm_rcom *rc;
+	struct dlm_mhandle *mh;
+	int error, inlen, outlen, nodeid;
+
+	nodeid = rc_in->rc_header.h_nodeid;
+	inlen = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
+	outlen = dlm_config.ci_buffer_size - sizeof(struct dlm_rcom);
+
+	error = create_rcom(ls, nodeid, DLM_RCOM_NAMES_REPLY, outlen, &rc, &mh);
+	if (error)
+		return;
+	rc->rc_id = rc_in->rc_id;
+	rc->rc_seq_reply = rc_in->rc_seq;
+
+	dlm_copy_master_names(ls, rc_in->rc_buf, inlen, rc->rc_buf, outlen,
+			      nodeid);
+	send_rcom(ls, mh, rc);
+}
+
+int dlm_send_rcom_lookup(struct dlm_rsb *r, int dir_nodeid)
+{
+	struct dlm_rcom *rc;
+	struct dlm_mhandle *mh;
+	struct dlm_ls *ls = r->res_ls;
+	int error;
+
+	error = create_rcom(ls, dir_nodeid, DLM_RCOM_LOOKUP, r->res_length,
+			    &rc, &mh);
+	if (error)
+		goto out;
+	memcpy(rc->rc_buf, r->res_name, r->res_length);
+	rc->rc_id = (unsigned long) r->res_id;
+
+	send_rcom(ls, mh, rc);
+ out:
+	return error;
+}
+
+static void receive_rcom_lookup(struct dlm_ls *ls, struct dlm_rcom *rc_in)
+{
+	struct dlm_rcom *rc;
+	struct dlm_mhandle *mh;
+	int error, ret_nodeid, nodeid = rc_in->rc_header.h_nodeid;
+	int len = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
+
+	error = create_rcom(ls, nodeid, DLM_RCOM_LOOKUP_REPLY, 0, &rc, &mh);
+	if (error)
+		return;
+
+	/* Old code would send this special id to trigger a debug dump. */
+	if (rc_in->rc_id == 0xFFFFFFFF) {
+		log_error(ls, "receive_rcom_lookup dump from %d", nodeid);
+		dlm_dump_rsb_name(ls, rc_in->rc_buf, len);
+		return;
+	}
+
+	error = dlm_master_lookup(ls, nodeid, rc_in->rc_buf, len,
+				  DLM_LU_RECOVER_MASTER, &ret_nodeid, NULL);
+	if (error)
+		ret_nodeid = error;
+	rc->rc_result = ret_nodeid;
+	rc->rc_id = rc_in->rc_id;
+	rc->rc_seq_reply = rc_in->rc_seq;
+
+	send_rcom(ls, mh, rc);
+}
+
+static void receive_rcom_lookup_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
+{
+	dlm_recover_master_reply(ls, rc_in);
+}
+
+static void pack_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb,
+			   struct rcom_lock *rl)
+{
+	memset(rl, 0, sizeof(*rl));
+
+	rl->rl_ownpid = cpu_to_le32(lkb->lkb_ownpid);
+	rl->rl_lkid = cpu_to_le32(lkb->lkb_id);
+	rl->rl_exflags = cpu_to_le32(lkb->lkb_exflags);
+	rl->rl_flags = cpu_to_le32(lkb->lkb_flags);
+	rl->rl_lvbseq = cpu_to_le32(lkb->lkb_lvbseq);
+	rl->rl_rqmode = lkb->lkb_rqmode;
+	rl->rl_grmode = lkb->lkb_grmode;
+	rl->rl_status = lkb->lkb_status;
+	rl->rl_wait_type = cpu_to_le16(lkb->lkb_wait_type);
+
+	if (lkb->lkb_bastfn)
+		rl->rl_asts |= DLM_CB_BAST;
+	if (lkb->lkb_astfn)
+		rl->rl_asts |= DLM_CB_CAST;
+
+	rl->rl_namelen = cpu_to_le16(r->res_length);
+	memcpy(rl->rl_name, r->res_name, r->res_length);
+
+	/* FIXME: might we have an lvb without DLM_LKF_VALBLK set ?
+	   If so, receive_rcom_lock_args() won't take this copy. */
+
+	if (lkb->lkb_lvbptr)
+		memcpy(rl->rl_lvb, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
+}
+
+int dlm_send_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+	struct dlm_ls *ls = r->res_ls;
+	struct dlm_rcom *rc;
+	struct dlm_mhandle *mh;
+	struct rcom_lock *rl;
+	int error, len = sizeof(struct rcom_lock);
+
+	if (lkb->lkb_lvbptr)
+		len += ls->ls_lvblen;
+
+	error = create_rcom(ls, r->res_nodeid, DLM_RCOM_LOCK, len, &rc, &mh);
+	if (error)
+		goto out;
+
+	rl = (struct rcom_lock *) rc->rc_buf;
+	pack_rcom_lock(r, lkb, rl);
+	rc->rc_id = (unsigned long) r;
+
+	send_rcom(ls, mh, rc);
+ out:
+	return error;
+}
+
+/* needs at least dlm_rcom + rcom_lock */
+static void receive_rcom_lock(struct dlm_ls *ls, struct dlm_rcom *rc_in)
+{
+	struct dlm_rcom *rc;
+	struct dlm_mhandle *mh;
+	int error, nodeid = rc_in->rc_header.h_nodeid;
+
+	dlm_recover_master_copy(ls, rc_in);
+
+	error = create_rcom(ls, nodeid, DLM_RCOM_LOCK_REPLY,
+			    sizeof(struct rcom_lock), &rc, &mh);
+	if (error)
+		return;
+
+	/* We send back the same rcom_lock struct we received, but
+	   dlm_recover_master_copy() has filled in rl_remid and rl_result */
+
+	memcpy(rc->rc_buf, rc_in->rc_buf, sizeof(struct rcom_lock));
+	rc->rc_id = rc_in->rc_id;
+	rc->rc_seq_reply = rc_in->rc_seq;
+
+	send_rcom(ls, mh, rc);
+}
+
+/* If the lockspace doesn't exist then still send a status message
+   back; it's possible that it just doesn't have its global_id yet. */
+
+int dlm_send_ls_not_ready(int nodeid, struct dlm_rcom *rc_in)
+{
+	struct dlm_rcom *rc;
+	struct rcom_config *rf;
+	struct dlm_mhandle *mh;
+	char *mb;
+	int mb_len = sizeof(struct dlm_rcom) + sizeof(struct rcom_config);
+
+	mh = dlm_lowcomms_get_buffer(nodeid, mb_len, GFP_NOFS, &mb);
+	if (!mh)
+		return -ENOBUFS;
+	memset(mb, 0, mb_len);
+
+	rc = (struct dlm_rcom *) mb;
+
+	rc->rc_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
+	rc->rc_header.h_lockspace = rc_in->rc_header.h_lockspace;
+	rc->rc_header.h_nodeid = dlm_our_nodeid();
+	rc->rc_header.h_length = mb_len;
+	rc->rc_header.h_cmd = DLM_RCOM;
+
+	rc->rc_type = DLM_RCOM_STATUS_REPLY;
+	rc->rc_id = rc_in->rc_id;
+	rc->rc_seq_reply = rc_in->rc_seq;
+	rc->rc_result = -ESRCH;
+
+	rf = (struct rcom_config *) rc->rc_buf;
+	rf->rf_lvblen = cpu_to_le32(~0U);
+
+	dlm_rcom_out(rc);
+	dlm_lowcomms_commit_buffer(mh);
+
+	return 0;
+}
+
+/*
+ * Ignore messages for stage Y before we set
+ * recover_status bit for stage X:
+ *
+ * recover_status = 0
+ *
+ * dlm_recover_members()
+ * - send nothing
+ * - recv nothing
+ * - ignore NAMES, NAMES_REPLY
+ * - ignore LOOKUP, LOOKUP_REPLY
+ * - ignore LOCK, LOCK_REPLY
+ *
+ * recover_status |= NODES
+ *
+ * dlm_recover_members_wait()
+ *
+ * dlm_recover_directory()
+ * - send NAMES
+ * - recv NAMES_REPLY
+ * - ignore LOOKUP, LOOKUP_REPLY
+ * - ignore LOCK, LOCK_REPLY
+ *
+ * recover_status |= DIR
+ *
+ * dlm_recover_directory_wait()
+ *
+ * dlm_recover_masters()
+ * - send LOOKUP
+ * - recv LOOKUP_REPLY
+ *
+ * dlm_recover_locks()
+ * - send LOCKS
+ * - recv LOCKS_REPLY
+ *
+ * recover_status |= LOCKS
+ *
+ * dlm_recover_locks_wait()
+ *
+ * recover_status |= DONE
+ */
+
+/* Called by dlm_recv; corresponds to dlm_receive_message() but special
+   recovery-only comms are sent through here. */
+
+void dlm_receive_rcom(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid)
+{
+	int lock_size = sizeof(struct dlm_rcom) + sizeof(struct rcom_lock);
+	int stop, reply = 0, names = 0, lookup = 0, lock = 0;
+	uint32_t status;
+	uint64_t seq;
+
+	switch (rc->rc_type) {
+	case DLM_RCOM_STATUS_REPLY:
+		reply = 1;
+		break;
+	case DLM_RCOM_NAMES:
+		names = 1;
+		break;
+	case DLM_RCOM_NAMES_REPLY:
+		names = 1;
+		reply = 1;
+		break;
+	case DLM_RCOM_LOOKUP:
+		lookup = 1;
+		break;
+	case DLM_RCOM_LOOKUP_REPLY:
+		lookup = 1;
+		reply = 1;
+		break;
+	case DLM_RCOM_LOCK:
+		lock = 1;
+		break;
+	case DLM_RCOM_LOCK_REPLY:
+		lock = 1;
+		reply = 1;
+		break;
+	};
+
+	spin_lock(&ls->ls_recover_lock);
+	status = ls->ls_recover_status;
+	stop = test_bit(LSFL_RECOVER_STOP, &ls->ls_flags);
+	seq = ls->ls_recover_seq;
+	spin_unlock(&ls->ls_recover_lock);
+
+	if (stop && (rc->rc_type != DLM_RCOM_STATUS))
+		goto ignore;
+
+	if (reply && (rc->rc_seq_reply != seq))
+		goto ignore;
+
+	if (!(status & DLM_RS_NODES) && (names || lookup || lock))
+		goto ignore;
+
+	if (!(status & DLM_RS_DIR) && (lookup || lock))
+		goto ignore;
+
+	switch (rc->rc_type) {
+	case DLM_RCOM_STATUS:
+		receive_rcom_status(ls, rc);
+		break;
+
+	case DLM_RCOM_NAMES:
+		receive_rcom_names(ls, rc);
+		break;
+
+	case DLM_RCOM_LOOKUP:
+		receive_rcom_lookup(ls, rc);
+		break;
+
+	case DLM_RCOM_LOCK:
+		if (rc->rc_header.h_length < lock_size)
+			goto Eshort;
+		receive_rcom_lock(ls, rc);
+		break;
+
+	case DLM_RCOM_STATUS_REPLY:
+		receive_sync_reply(ls, rc);
+		break;
+
+	case DLM_RCOM_NAMES_REPLY:
+		receive_sync_reply(ls, rc);
+		break;
+
+	case DLM_RCOM_LOOKUP_REPLY:
+		receive_rcom_lookup_reply(ls, rc);
+		break;
+
+	case DLM_RCOM_LOCK_REPLY:
+		if (rc->rc_header.h_length < lock_size)
+			goto Eshort;
+		dlm_recover_process_copy(ls, rc);
+		break;
+
+	default:
+		log_error(ls, "receive_rcom bad type %d", rc->rc_type);
+	}
+	return;
+
+ignore:
+	log_limit(ls, "dlm_receive_rcom ignore msg %d "
+		  "from %d %llu %llu recover seq %llu sts %x gen %u",
+		   rc->rc_type,
+		   nodeid,
+		   (unsigned long long)rc->rc_seq,
+		   (unsigned long long)rc->rc_seq_reply,
+		   (unsigned long long)seq,
+		   status, ls->ls_generation);
+	return;
+Eshort:
+	log_error(ls, "recovery message %d from %d is too short",
+		  rc->rc_type, nodeid);
+}
+