summaryrefslogtreecommitdiffstats
path: root/drivers/block/rnbd
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/block/rnbd
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/block/rnbd')
-rw-r--r--drivers/block/rnbd/Kconfig29
-rw-r--r--drivers/block/rnbd/Makefile17
-rw-r--r--drivers/block/rnbd/README93
-rw-r--r--drivers/block/rnbd/rnbd-clt-sysfs.c683
-rw-r--r--drivers/block/rnbd/rnbd-clt.c1848
-rw-r--r--drivers/block/rnbd/rnbd-clt.h151
-rw-r--r--drivers/block/rnbd/rnbd-common.c23
-rw-r--r--drivers/block/rnbd/rnbd-log.h41
-rw-r--r--drivers/block/rnbd/rnbd-proto.h305
-rw-r--r--drivers/block/rnbd/rnbd-srv-sysfs.c250
-rw-r--r--drivers/block/rnbd/rnbd-srv-trace.c17
-rw-r--r--drivers/block/rnbd/rnbd-srv-trace.h207
-rw-r--r--drivers/block/rnbd/rnbd-srv.c848
-rw-r--r--drivers/block/rnbd/rnbd-srv.h75
14 files changed, 4587 insertions, 0 deletions
diff --git a/drivers/block/rnbd/Kconfig b/drivers/block/rnbd/Kconfig
new file mode 100644
index 000000000..2ff05a0d2
--- /dev/null
+++ b/drivers/block/rnbd/Kconfig
@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+config BLK_DEV_RNBD
+ bool
+
+config BLK_DEV_RNBD_CLIENT
+ tristate "RDMA Network Block Device driver client"
+ depends on INFINIBAND_RTRS_CLIENT
+ select BLK_DEV_RNBD
+ select SG_POOL
+ help
+ RNBD client is a network block device driver using rdma transport.
+
+ RNBD client allows for mapping of a remote block devices over
+ RTRS protocol from a target system where RNBD server is running.
+
+ If unsure, say N.
+
+config BLK_DEV_RNBD_SERVER
+ tristate "RDMA Network Block Device driver server"
+ depends on INFINIBAND_RTRS_SERVER
+ select BLK_DEV_RNBD
+ help
+ RNBD server is the server side of RNBD using rdma transport.
+
+ RNBD server allows for exporting local block devices to a remote client
+ over RTRS protocol.
+
+ If unsure, say N.
diff --git a/drivers/block/rnbd/Makefile b/drivers/block/rnbd/Makefile
new file mode 100644
index 000000000..40b316308
--- /dev/null
+++ b/drivers/block/rnbd/Makefile
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+ccflags-y := -I$(srctree)/drivers/infiniband/ulp/rtrs
+
+rnbd-client-y := rnbd-clt.o \
+ rnbd-clt-sysfs.o \
+ rnbd-common.o
+
+CFLAGS_rnbd-srv-trace.o = -I$(src)
+
+rnbd-server-y := rnbd-common.o \
+ rnbd-srv.o \
+ rnbd-srv-sysfs.o \
+ rnbd-srv-trace.o
+
+obj-$(CONFIG_BLK_DEV_RNBD_CLIENT) += rnbd-client.o
+obj-$(CONFIG_BLK_DEV_RNBD_SERVER) += rnbd-server.o
diff --git a/drivers/block/rnbd/README b/drivers/block/rnbd/README
new file mode 100644
index 000000000..080f58a54
--- /dev/null
+++ b/drivers/block/rnbd/README
@@ -0,0 +1,93 @@
+********************************
+RDMA Network Block Device (RNBD)
+********************************
+
+Introduction
+------------
+
+RNBD (RDMA Network Block Device) is a pair of kernel modules
+(client and server) that allow for remote access of a block device on
+the server over RTRS protocol using the RDMA (InfiniBand, RoCE, iWARP)
+transport. After being mapped, the remote block devices can be accessed
+on the client side as local block devices.
+
+I/O is transferred between client and server by the RTRS transport
+modules. The administration of RNBD and RTRS modules is done via
+sysfs entries.
+
+Requirements
+------------
+
+ RTRS kernel modules
+
+Quick Start
+-----------
+
+Server side:
+ # modprobe rnbd_server
+
+Client side:
+ # modprobe rnbd_client
+ # echo "sessname=blya path=ip:10.50.100.66 device_path=/dev/ram0" > \
+ /sys/devices/virtual/rnbd-client/ctl/map_device
+
+ Where "sessname=" is a session name, a string to identify the session
+ on client and on server sides; "path=" is a destination IP address or
+ a pair of a source and a destination IPs, separated by comma. Multiple
+ "path=" options can be specified in order to use multipath (see RTRS
+ description for details); "device_path=" is the block device to be
+ mapped from the server side. After the session to the server machine is
+ established, the mapped device will appear on the client side under
+ /dev/rnbd<N>.
+
+
+RNBD-Server Module Parameters
+=============================
+
+dev_search_path
+---------------
+
+When a device is mapped from the client, the server generates the path
+to the block device on the server side by concatenating dev_search_path
+and the "device_path" that was specified in the map_device operation.
+
+The default dev_search_path is: "/".
+
+dev_search_path option can also contain %SESSNAME% in order to provide
+different device namespaces for different sessions. See "device_path"
+option for details.
+
+============================
+Protocol (rnbd/rnbd-proto.h)
+============================
+
+1. Before mapping first device from a given server, client sends an
+RNBD_MSG_SESS_INFO to the server. Server responds with
+RNBD_MSG_SESS_INFO_RSP. Currently the messages only contain the protocol
+version for backward compatibility.
+
+2. Client requests to open a device by sending RNBD_MSG_OPEN message. This
+contains the path to the device and access mode (read-only or writable).
+Server responds to the message with RNBD_MSG_OPEN_RSP. This contains
+a 32 bit device id to be used for IOs and device "geometry" related
+information: side, max_hw_sectors, etc.
+
+3. Client attaches RNBD_MSG_IO to each IO message send to a device. This
+message contains device id, provided by server in his rnbd_msg_open_rsp,
+sector to be accessed, read-write flags and bi_size.
+
+4. Client closes a device by sending RNBD_MSG_CLOSE which contains only the
+device id provided by the server.
+
+=========================================
+Contributors List(in alphabetical order)
+=========================================
+Danil Kipnis <danil.kipnis@profitbricks.com>
+Fabian Holler <mail@fholler.de>
+Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
+Jack Wang <jinpu.wang@profitbricks.com>
+Kleber Souza <kleber.souza@profitbricks.com>
+Lutz Pogrell <lutz.pogrell@cloud.ionos.com>
+Milind Dumbare <Milind.dumbare@gmail.com>
+Roman Penyaev <roman.penyaev@profitbricks.com>
+Swapnil Ingle <ingleswapnil@gmail.com>
diff --git a/drivers/block/rnbd/rnbd-clt-sysfs.c b/drivers/block/rnbd/rnbd-clt-sysfs.c
new file mode 100644
index 000000000..e7c7d9a68
--- /dev/null
+++ b/drivers/block/rnbd/rnbd-clt-sysfs.c
@@ -0,0 +1,683 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RDMA Network Block Driver
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+
+#undef pr_fmt
+#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
+
+#include <linux/types.h>
+#include <linux/ctype.h>
+#include <linux/parser.h>
+#include <linux/module.h>
+#include <linux/in6.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/device.h>
+#include <rdma/ib.h>
+#include <rdma/rdma_cm.h>
+
+#include "rnbd-clt.h"
+
+static struct device *rnbd_dev;
+static struct class *rnbd_dev_class;
+static struct kobject *rnbd_devs_kobj;
+
+enum {
+ RNBD_OPT_ERR = 0,
+ RNBD_OPT_DEST_PORT = 1 << 0,
+ RNBD_OPT_PATH = 1 << 1,
+ RNBD_OPT_DEV_PATH = 1 << 2,
+ RNBD_OPT_ACCESS_MODE = 1 << 3,
+ RNBD_OPT_SESSNAME = 1 << 6,
+ RNBD_OPT_NR_POLL_QUEUES = 1 << 7,
+};
+
+static const unsigned int rnbd_opt_mandatory[] = {
+ RNBD_OPT_DEV_PATH,
+ RNBD_OPT_SESSNAME,
+};
+
+static const match_table_t rnbd_opt_tokens = {
+ {RNBD_OPT_PATH, "path=%s" },
+ {RNBD_OPT_DEV_PATH, "device_path=%s" },
+ {RNBD_OPT_DEST_PORT, "dest_port=%d" },
+ {RNBD_OPT_ACCESS_MODE, "access_mode=%s" },
+ {RNBD_OPT_SESSNAME, "sessname=%s" },
+ {RNBD_OPT_NR_POLL_QUEUES, "nr_poll_queues=%d" },
+ {RNBD_OPT_ERR, NULL },
+};
+
+struct rnbd_map_options {
+ char *sessname;
+ struct rtrs_addr *paths;
+ size_t *path_cnt;
+ char *pathname;
+ u16 *dest_port;
+ enum rnbd_access_mode *access_mode;
+ u32 *nr_poll_queues;
+};
+
+static int rnbd_clt_parse_map_options(const char *buf, size_t max_path_cnt,
+ struct rnbd_map_options *opt)
+{
+ char *options, *sep_opt;
+ char *p;
+ substring_t args[MAX_OPT_ARGS];
+ int opt_mask = 0;
+ int token;
+ int ret = -EINVAL;
+ int nr_poll_queues = 0;
+ int dest_port = 0;
+ int p_cnt = 0;
+ int i;
+
+ options = kstrdup(buf, GFP_KERNEL);
+ if (!options)
+ return -ENOMEM;
+
+ sep_opt = strstrip(options);
+ while ((p = strsep(&sep_opt, " ")) != NULL) {
+ if (!*p)
+ continue;
+
+ token = match_token(p, rnbd_opt_tokens, args);
+ opt_mask |= token;
+
+ switch (token) {
+ case RNBD_OPT_SESSNAME:
+ p = match_strdup(args);
+ if (!p) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ if (strlen(p) > NAME_MAX) {
+ pr_err("map_device: sessname too long\n");
+ ret = -EINVAL;
+ kfree(p);
+ goto out;
+ }
+ strscpy(opt->sessname, p, NAME_MAX);
+ kfree(p);
+ break;
+
+ case RNBD_OPT_PATH:
+ if (p_cnt >= max_path_cnt) {
+ pr_err("map_device: too many (> %zu) paths provided\n",
+ max_path_cnt);
+ ret = -ENOMEM;
+ goto out;
+ }
+ p = match_strdup(args);
+ if (!p) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = rtrs_addr_to_sockaddr(p, strlen(p),
+ *opt->dest_port,
+ &opt->paths[p_cnt]);
+ if (ret) {
+ pr_err("Can't parse path %s: %d\n", p, ret);
+ kfree(p);
+ goto out;
+ }
+
+ p_cnt++;
+
+ kfree(p);
+ break;
+
+ case RNBD_OPT_DEV_PATH:
+ p = match_strdup(args);
+ if (!p) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ if (strlen(p) > NAME_MAX) {
+ pr_err("map_device: Device path too long\n");
+ ret = -EINVAL;
+ kfree(p);
+ goto out;
+ }
+ strscpy(opt->pathname, p, NAME_MAX);
+ kfree(p);
+ break;
+
+ case RNBD_OPT_DEST_PORT:
+ if (match_int(args, &dest_port) || dest_port < 0 ||
+ dest_port > 65535) {
+ pr_err("bad destination port number parameter '%d'\n",
+ dest_port);
+ ret = -EINVAL;
+ goto out;
+ }
+ *opt->dest_port = dest_port;
+ break;
+
+ case RNBD_OPT_ACCESS_MODE:
+ p = match_strdup(args);
+ if (!p) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (!strcmp(p, "ro")) {
+ *opt->access_mode = RNBD_ACCESS_RO;
+ } else if (!strcmp(p, "rw")) {
+ *opt->access_mode = RNBD_ACCESS_RW;
+ } else if (!strcmp(p, "migration")) {
+ *opt->access_mode = RNBD_ACCESS_MIGRATION;
+ } else {
+ pr_err("map_device: Invalid access_mode: '%s'\n",
+ p);
+ ret = -EINVAL;
+ kfree(p);
+ goto out;
+ }
+
+ kfree(p);
+ break;
+
+ case RNBD_OPT_NR_POLL_QUEUES:
+ if (match_int(args, &nr_poll_queues) || nr_poll_queues < -1 ||
+ nr_poll_queues > (int)nr_cpu_ids) {
+ pr_err("bad nr_poll_queues parameter '%d'\n",
+ nr_poll_queues);
+ ret = -EINVAL;
+ goto out;
+ }
+ if (nr_poll_queues == -1)
+ nr_poll_queues = nr_cpu_ids;
+ *opt->nr_poll_queues = nr_poll_queues;
+ break;
+
+ default:
+ pr_err("map_device: Unknown parameter or missing value '%s'\n",
+ p);
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+ for (i = 0; i < ARRAY_SIZE(rnbd_opt_mandatory); i++) {
+ if ((opt_mask & rnbd_opt_mandatory[i])) {
+ ret = 0;
+ } else {
+ pr_err("map_device: Parameters missing\n");
+ ret = -EINVAL;
+ break;
+ }
+ }
+
+out:
+ *opt->path_cnt = p_cnt;
+ kfree(options);
+ return ret;
+}
+
+static ssize_t state_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *page)
+{
+ struct rnbd_clt_dev *dev;
+
+ dev = container_of(kobj, struct rnbd_clt_dev, kobj);
+
+ switch (dev->dev_state) {
+ case DEV_STATE_INIT:
+ return sysfs_emit(page, "init\n");
+ case DEV_STATE_MAPPED:
+ /* TODO fix cli tool before changing to proper state */
+ return sysfs_emit(page, "open\n");
+ case DEV_STATE_MAPPED_DISCONNECTED:
+ /* TODO fix cli tool before changing to proper state */
+ return sysfs_emit(page, "closed\n");
+ case DEV_STATE_UNMAPPED:
+ return sysfs_emit(page, "unmapped\n");
+ default:
+ return sysfs_emit(page, "unknown\n");
+ }
+}
+
+static struct kobj_attribute rnbd_clt_state_attr = __ATTR_RO(state);
+
+static ssize_t nr_poll_queues_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *page)
+{
+ struct rnbd_clt_dev *dev;
+
+ dev = container_of(kobj, struct rnbd_clt_dev, kobj);
+
+ return sysfs_emit(page, "%d\n", dev->nr_poll_queues);
+}
+
+static struct kobj_attribute rnbd_clt_nr_poll_queues =
+ __ATTR_RO(nr_poll_queues);
+
+static ssize_t mapping_path_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *page)
+{
+ struct rnbd_clt_dev *dev;
+
+ dev = container_of(kobj, struct rnbd_clt_dev, kobj);
+
+ return sysfs_emit(page, "%s\n", dev->pathname);
+}
+
+static struct kobj_attribute rnbd_clt_mapping_path_attr =
+ __ATTR_RO(mapping_path);
+
+static ssize_t access_mode_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *page)
+{
+ struct rnbd_clt_dev *dev;
+
+ dev = container_of(kobj, struct rnbd_clt_dev, kobj);
+
+ return sysfs_emit(page, "%s\n", rnbd_access_mode_str(dev->access_mode));
+}
+
+static struct kobj_attribute rnbd_clt_access_mode =
+ __ATTR_RO(access_mode);
+
+static ssize_t rnbd_clt_unmap_dev_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *page)
+{
+ return sysfs_emit(page, "Usage: echo <normal|force> > %s\n",
+ attr->attr.name);
+}
+
+static ssize_t rnbd_clt_unmap_dev_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct rnbd_clt_dev *dev;
+ char *opt, *options;
+ bool force;
+ int err;
+
+ opt = kstrdup(buf, GFP_KERNEL);
+ if (!opt)
+ return -ENOMEM;
+
+ options = strstrip(opt);
+ dev = container_of(kobj, struct rnbd_clt_dev, kobj);
+ if (sysfs_streq(options, "normal")) {
+ force = false;
+ } else if (sysfs_streq(options, "force")) {
+ force = true;
+ } else {
+ rnbd_clt_err(dev,
+ "unmap_device: Invalid value: %s\n",
+ options);
+ err = -EINVAL;
+ goto out;
+ }
+
+ rnbd_clt_info(dev, "Unmapping device, option: %s.\n",
+ force ? "force" : "normal");
+
+ /*
+ * We take explicit module reference only for one reason: do not
+ * race with lockless rnbd_destroy_sessions().
+ */
+ if (!try_module_get(THIS_MODULE)) {
+ err = -ENODEV;
+ goto out;
+ }
+ err = rnbd_clt_unmap_device(dev, force, &attr->attr);
+ if (err) {
+ if (err != -EALREADY)
+ rnbd_clt_err(dev, "unmap_device: %d\n", err);
+ goto module_put;
+ }
+
+ /*
+ * Here device can be vanished!
+ */
+
+ err = count;
+
+module_put:
+ module_put(THIS_MODULE);
+out:
+ kfree(opt);
+
+ return err;
+}
+
+static struct kobj_attribute rnbd_clt_unmap_device_attr =
+ __ATTR(unmap_device, 0644, rnbd_clt_unmap_dev_show,
+ rnbd_clt_unmap_dev_store);
+
+static ssize_t rnbd_clt_resize_dev_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *page)
+{
+ return sysfs_emit(page, "Usage: echo <new size in sectors> > %s\n",
+ attr->attr.name);
+}
+
+static ssize_t rnbd_clt_resize_dev_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret;
+ unsigned long sectors;
+ struct rnbd_clt_dev *dev;
+
+ dev = container_of(kobj, struct rnbd_clt_dev, kobj);
+
+ ret = kstrtoul(buf, 0, &sectors);
+ if (ret)
+ return ret;
+
+ ret = rnbd_clt_resize_disk(dev, sectors);
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+static struct kobj_attribute rnbd_clt_resize_dev_attr =
+ __ATTR(resize, 0644, rnbd_clt_resize_dev_show,
+ rnbd_clt_resize_dev_store);
+
+static ssize_t rnbd_clt_remap_dev_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *page)
+{
+ return sysfs_emit(page, "Usage: echo <1> > %s\n", attr->attr.name);
+}
+
+static ssize_t rnbd_clt_remap_dev_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct rnbd_clt_dev *dev;
+ char *opt, *options;
+ int err;
+
+ opt = kstrdup(buf, GFP_KERNEL);
+ if (!opt)
+ return -ENOMEM;
+
+ options = strstrip(opt);
+ dev = container_of(kobj, struct rnbd_clt_dev, kobj);
+ if (!sysfs_streq(options, "1")) {
+ rnbd_clt_err(dev,
+ "remap_device: Invalid value: %s\n",
+ options);
+ err = -EINVAL;
+ goto out;
+ }
+ err = rnbd_clt_remap_device(dev);
+ if (likely(!err))
+ err = count;
+
+out:
+ kfree(opt);
+
+ return err;
+}
+
+static struct kobj_attribute rnbd_clt_remap_device_attr =
+ __ATTR(remap_device, 0644, rnbd_clt_remap_dev_show,
+ rnbd_clt_remap_dev_store);
+
+static ssize_t session_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *page)
+{
+ struct rnbd_clt_dev *dev;
+
+ dev = container_of(kobj, struct rnbd_clt_dev, kobj);
+
+ return sysfs_emit(page, "%s\n", dev->sess->sessname);
+}
+
+static struct kobj_attribute rnbd_clt_session_attr =
+ __ATTR_RO(session);
+
+static struct attribute *rnbd_dev_attrs[] = {
+ &rnbd_clt_unmap_device_attr.attr,
+ &rnbd_clt_resize_dev_attr.attr,
+ &rnbd_clt_remap_device_attr.attr,
+ &rnbd_clt_mapping_path_attr.attr,
+ &rnbd_clt_state_attr.attr,
+ &rnbd_clt_session_attr.attr,
+ &rnbd_clt_access_mode.attr,
+ &rnbd_clt_nr_poll_queues.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(rnbd_dev);
+
+void rnbd_clt_remove_dev_symlink(struct rnbd_clt_dev *dev)
+{
+ /*
+ * The module unload rnbd_client_exit path is racing with unmapping of
+ * the last single device from the sysfs manually
+ * i.e. rnbd_clt_unmap_dev_store() leading to a sysfs warning because
+ * of sysfs link already was removed already.
+ */
+ if (dev->blk_symlink_name) {
+ if (try_module_get(THIS_MODULE)) {
+ sysfs_remove_link(rnbd_devs_kobj, dev->blk_symlink_name);
+ module_put(THIS_MODULE);
+ }
+ /* It should be freed always. */
+ kfree(dev->blk_symlink_name);
+ dev->blk_symlink_name = NULL;
+ }
+}
+
+static struct kobj_type rnbd_dev_ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_groups = rnbd_dev_groups,
+};
+
+static int rnbd_clt_add_dev_kobj(struct rnbd_clt_dev *dev)
+{
+ int ret;
+ struct kobject *gd_kobj = &disk_to_dev(dev->gd)->kobj;
+
+ ret = kobject_init_and_add(&dev->kobj, &rnbd_dev_ktype, gd_kobj, "%s",
+ "rnbd");
+ if (ret) {
+ rnbd_clt_err(dev, "Failed to create device sysfs dir, err: %d\n",
+ ret);
+ kobject_put(&dev->kobj);
+ }
+ kobject_uevent(gd_kobj, KOBJ_ONLINE);
+
+ return ret;
+}
+
+static ssize_t rnbd_clt_map_device_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *page)
+{
+ return sysfs_emit(page,
+ "Usage: echo \"[dest_port=server port number] sessname=<name of the rtrs session> path=<[srcaddr@]dstaddr> [path=<[srcaddr@]dstaddr>] device_path=<full path on remote side> [access_mode=<ro|rw|migration>] [nr_poll_queues=<number of queues>]\" > %s\n\naddr ::= [ ip:<ipv4> | ip:<ipv6> | gid:<gid> ]\n",
+ attr->attr.name);
+}
+
+static int rnbd_clt_get_path_name(struct rnbd_clt_dev *dev, char *buf,
+ size_t len)
+{
+ int ret;
+ char pathname[NAME_MAX], *s;
+
+ strscpy(pathname, dev->pathname, sizeof(pathname));
+ while ((s = strchr(pathname, '/')))
+ s[0] = '!';
+
+ ret = snprintf(buf, len, "%s@%s", pathname, dev->sess->sessname);
+ if (ret >= len)
+ return -ENAMETOOLONG;
+
+ return 0;
+}
+
+static int rnbd_clt_add_dev_symlink(struct rnbd_clt_dev *dev)
+{
+ struct kobject *gd_kobj = &disk_to_dev(dev->gd)->kobj;
+ int ret, len;
+
+ len = strlen(dev->pathname) + strlen(dev->sess->sessname) + 2;
+ dev->blk_symlink_name = kzalloc(len, GFP_KERNEL);
+ if (!dev->blk_symlink_name) {
+ rnbd_clt_err(dev, "Failed to allocate memory for blk_symlink_name\n");
+ return -ENOMEM;
+ }
+
+ ret = rnbd_clt_get_path_name(dev, dev->blk_symlink_name,
+ len);
+ if (ret) {
+ rnbd_clt_err(dev, "Failed to get /sys/block symlink path, err: %d\n",
+ ret);
+ goto out_err;
+ }
+
+ ret = sysfs_create_link(rnbd_devs_kobj, gd_kobj,
+ dev->blk_symlink_name);
+ if (ret) {
+ rnbd_clt_err(dev, "Creating /sys/block symlink failed, err: %d\n",
+ ret);
+ goto out_err;
+ }
+
+ return 0;
+
+out_err:
+ kfree(dev->blk_symlink_name);
+ dev->blk_symlink_name = NULL ;
+ return ret;
+}
+
+static ssize_t rnbd_clt_map_device_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct rnbd_clt_dev *dev;
+ struct rnbd_map_options opt;
+ int ret;
+ char pathname[NAME_MAX];
+ char sessname[NAME_MAX];
+ enum rnbd_access_mode access_mode = RNBD_ACCESS_RW;
+ u16 port_nr = RTRS_PORT;
+ u32 nr_poll_queues = 0;
+
+ struct sockaddr_storage *addrs;
+ struct rtrs_addr paths[6];
+ size_t path_cnt;
+
+ opt.sessname = sessname;
+ opt.paths = paths;
+ opt.path_cnt = &path_cnt;
+ opt.pathname = pathname;
+ opt.dest_port = &port_nr;
+ opt.access_mode = &access_mode;
+ opt.nr_poll_queues = &nr_poll_queues;
+ addrs = kcalloc(ARRAY_SIZE(paths) * 2, sizeof(*addrs), GFP_KERNEL);
+ if (!addrs)
+ return -ENOMEM;
+
+ for (path_cnt = 0; path_cnt < ARRAY_SIZE(paths); path_cnt++) {
+ paths[path_cnt].src = &addrs[path_cnt * 2];
+ paths[path_cnt].dst = &addrs[path_cnt * 2 + 1];
+ }
+
+ ret = rnbd_clt_parse_map_options(buf, ARRAY_SIZE(paths), &opt);
+ if (ret)
+ goto out;
+
+ pr_info("Mapping device %s on session %s, (access_mode: %s, nr_poll_queues: %d)\n",
+ pathname, sessname,
+ rnbd_access_mode_str(access_mode),
+ nr_poll_queues);
+
+ dev = rnbd_clt_map_device(sessname, paths, path_cnt, port_nr, pathname,
+ access_mode, nr_poll_queues);
+ if (IS_ERR(dev)) {
+ ret = PTR_ERR(dev);
+ goto out;
+ }
+
+ ret = rnbd_clt_add_dev_kobj(dev);
+ if (ret)
+ goto unmap_dev;
+
+ ret = rnbd_clt_add_dev_symlink(dev);
+ if (ret)
+ goto unmap_dev;
+
+ kfree(addrs);
+ return count;
+
+unmap_dev:
+ rnbd_clt_unmap_device(dev, true, NULL);
+out:
+ kfree(addrs);
+ return ret;
+}
+
+static struct kobj_attribute rnbd_clt_map_device_attr =
+ __ATTR(map_device, 0644,
+ rnbd_clt_map_device_show, rnbd_clt_map_device_store);
+
+static struct attribute *default_attrs[] = {
+ &rnbd_clt_map_device_attr.attr,
+ NULL,
+};
+
+static struct attribute_group default_attr_group = {
+ .attrs = default_attrs,
+};
+
+static const struct attribute_group *default_attr_groups[] = {
+ &default_attr_group,
+ NULL,
+};
+
+int rnbd_clt_create_sysfs_files(void)
+{
+ int err;
+
+ rnbd_dev_class = class_create(THIS_MODULE, "rnbd-client");
+ if (IS_ERR(rnbd_dev_class))
+ return PTR_ERR(rnbd_dev_class);
+
+ rnbd_dev = device_create_with_groups(rnbd_dev_class, NULL,
+ MKDEV(0, 0), NULL,
+ default_attr_groups, "ctl");
+ if (IS_ERR(rnbd_dev)) {
+ err = PTR_ERR(rnbd_dev);
+ goto cls_destroy;
+ }
+ rnbd_devs_kobj = kobject_create_and_add("devices", &rnbd_dev->kobj);
+ if (!rnbd_devs_kobj) {
+ err = -ENOMEM;
+ goto dev_destroy;
+ }
+
+ return 0;
+
+dev_destroy:
+ device_destroy(rnbd_dev_class, MKDEV(0, 0));
+cls_destroy:
+ class_destroy(rnbd_dev_class);
+
+ return err;
+}
+
+void rnbd_clt_destroy_sysfs_files(void)
+{
+ sysfs_remove_group(&rnbd_dev->kobj, &default_attr_group);
+ kobject_del(rnbd_devs_kobj);
+ kobject_put(rnbd_devs_kobj);
+ device_destroy(rnbd_dev_class, MKDEV(0, 0));
+ class_destroy(rnbd_dev_class);
+}
diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c
new file mode 100644
index 000000000..5eb8c7855
--- /dev/null
+++ b/drivers/block/rnbd/rnbd-clt.c
@@ -0,0 +1,1848 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RDMA Network Block Driver
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+
+#undef pr_fmt
+#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
+
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/hdreg.h>
+#include <linux/scatterlist.h>
+#include <linux/idr.h>
+
+#include "rnbd-clt.h"
+
+MODULE_DESCRIPTION("RDMA Network Block Device Client");
+MODULE_LICENSE("GPL");
+
+static int rnbd_client_major;
+static DEFINE_IDA(index_ida);
+static DEFINE_MUTEX(sess_lock);
+static LIST_HEAD(sess_list);
+static struct workqueue_struct *rnbd_clt_wq;
+
+/*
+ * Maximum number of partitions an instance can have.
+ * 6 bits = 64 minors = 63 partitions (one minor is used for the device itself)
+ */
+#define RNBD_PART_BITS 6
+
+static inline bool rnbd_clt_get_sess(struct rnbd_clt_session *sess)
+{
+ return refcount_inc_not_zero(&sess->refcount);
+}
+
+static void free_sess(struct rnbd_clt_session *sess);
+
+static void rnbd_clt_put_sess(struct rnbd_clt_session *sess)
+{
+ might_sleep();
+
+ if (refcount_dec_and_test(&sess->refcount))
+ free_sess(sess);
+}
+
+static void rnbd_clt_put_dev(struct rnbd_clt_dev *dev)
+{
+ might_sleep();
+
+ if (!refcount_dec_and_test(&dev->refcount))
+ return;
+
+ ida_free(&index_ida, dev->clt_device_id);
+ kfree(dev->hw_queues);
+ kfree(dev->pathname);
+ rnbd_clt_put_sess(dev->sess);
+ mutex_destroy(&dev->lock);
+ kfree(dev);
+}
+
+static inline bool rnbd_clt_get_dev(struct rnbd_clt_dev *dev)
+{
+ return refcount_inc_not_zero(&dev->refcount);
+}
+
+static void rnbd_clt_change_capacity(struct rnbd_clt_dev *dev,
+ sector_t new_nsectors)
+{
+ if (get_capacity(dev->gd) == new_nsectors)
+ return;
+
+ /*
+ * If the size changed, we need to revalidate it
+ */
+ rnbd_clt_info(dev, "Device size changed from %llu to %llu sectors\n",
+ get_capacity(dev->gd), new_nsectors);
+ set_capacity_and_notify(dev->gd, new_nsectors);
+}
+
+static int process_msg_open_rsp(struct rnbd_clt_dev *dev,
+ struct rnbd_msg_open_rsp *rsp)
+{
+ struct kobject *gd_kobj;
+ int err = 0;
+
+ mutex_lock(&dev->lock);
+ if (dev->dev_state == DEV_STATE_UNMAPPED) {
+ rnbd_clt_info(dev,
+ "Ignoring Open-Response message from server for unmapped device\n");
+ err = -ENOENT;
+ goto out;
+ }
+ if (dev->dev_state == DEV_STATE_MAPPED_DISCONNECTED) {
+ u64 nsectors = le64_to_cpu(rsp->nsectors);
+
+ rnbd_clt_change_capacity(dev, nsectors);
+ gd_kobj = &disk_to_dev(dev->gd)->kobj;
+ kobject_uevent(gd_kobj, KOBJ_ONLINE);
+ rnbd_clt_info(dev, "Device online, device remapped successfully\n");
+ }
+ if (!rsp->logical_block_size) {
+ err = -EINVAL;
+ goto out;
+ }
+ dev->device_id = le32_to_cpu(rsp->device_id);
+ dev->dev_state = DEV_STATE_MAPPED;
+
+out:
+ mutex_unlock(&dev->lock);
+
+ return err;
+}
+
+int rnbd_clt_resize_disk(struct rnbd_clt_dev *dev, sector_t newsize)
+{
+ int ret = 0;
+
+ mutex_lock(&dev->lock);
+ if (dev->dev_state != DEV_STATE_MAPPED) {
+ pr_err("Failed to set new size of the device, device is not opened\n");
+ ret = -ENOENT;
+ goto out;
+ }
+ rnbd_clt_change_capacity(dev, newsize);
+
+out:
+ mutex_unlock(&dev->lock);
+
+ return ret;
+}
+
+static inline void rnbd_clt_dev_requeue(struct rnbd_queue *q)
+{
+ if (WARN_ON(!q->hctx))
+ return;
+
+ /* We can come here from interrupt, thus async=true */
+ blk_mq_run_hw_queue(q->hctx, true);
+}
+
+enum {
+ RNBD_DELAY_IFBUSY = -1,
+};
+
+/**
+ * rnbd_get_cpu_qlist() - finds a list with HW queues to be rerun
+ * @sess: Session to find a queue for
+ * @cpu: Cpu to start the search from
+ *
+ * Description:
+ * Each CPU has a list of HW queues, which needs to be rerun. If a list
+ * is not empty - it is marked with a bit. This function finds first
+ * set bit in a bitmap and returns corresponding CPU list.
+ */
+static struct rnbd_cpu_qlist *
+rnbd_get_cpu_qlist(struct rnbd_clt_session *sess, int cpu)
+{
+ int bit;
+
+ /* Search from cpu to nr_cpu_ids */
+ bit = find_next_bit(sess->cpu_queues_bm, nr_cpu_ids, cpu);
+ if (bit < nr_cpu_ids) {
+ return per_cpu_ptr(sess->cpu_queues, bit);
+ } else if (cpu != 0) {
+ /* Search from 0 to cpu */
+ bit = find_first_bit(sess->cpu_queues_bm, cpu);
+ if (bit < cpu)
+ return per_cpu_ptr(sess->cpu_queues, bit);
+ }
+
+ return NULL;
+}
+
+static inline int nxt_cpu(int cpu)
+{
+ return (cpu + 1) % nr_cpu_ids;
+}
+
+/**
+ * rnbd_rerun_if_needed() - rerun next queue marked as stopped
+ * @sess: Session to rerun a queue on
+ *
+ * Description:
+ * Each CPU has it's own list of HW queues, which should be rerun.
+ * Function finds such list with HW queues, takes a list lock, picks up
+ * the first HW queue out of the list and requeues it.
+ *
+ * Return:
+ * True if the queue was requeued, false otherwise.
+ *
+ * Context:
+ * Does not matter.
+ */
+static bool rnbd_rerun_if_needed(struct rnbd_clt_session *sess)
+{
+ struct rnbd_queue *q = NULL;
+ struct rnbd_cpu_qlist *cpu_q;
+ unsigned long flags;
+ int *cpup;
+
+ /*
+ * To keep fairness and not to let other queues starve we always
+ * try to wake up someone else in round-robin manner. That of course
+ * increases latency but queues always have a chance to be executed.
+ */
+ cpup = get_cpu_ptr(sess->cpu_rr);
+ for (cpu_q = rnbd_get_cpu_qlist(sess, nxt_cpu(*cpup)); cpu_q;
+ cpu_q = rnbd_get_cpu_qlist(sess, nxt_cpu(cpu_q->cpu))) {
+ if (!spin_trylock_irqsave(&cpu_q->requeue_lock, flags))
+ continue;
+ if (!test_bit(cpu_q->cpu, sess->cpu_queues_bm))
+ goto unlock;
+ q = list_first_entry_or_null(&cpu_q->requeue_list,
+ typeof(*q), requeue_list);
+ if (WARN_ON(!q))
+ goto clear_bit;
+ list_del_init(&q->requeue_list);
+ clear_bit_unlock(0, &q->in_list);
+
+ if (list_empty(&cpu_q->requeue_list)) {
+ /* Clear bit if nothing is left */
+clear_bit:
+ clear_bit(cpu_q->cpu, sess->cpu_queues_bm);
+ }
+unlock:
+ spin_unlock_irqrestore(&cpu_q->requeue_lock, flags);
+
+ if (q)
+ break;
+ }
+
+ /**
+ * Saves the CPU that is going to be requeued on the per-cpu var. Just
+ * incrementing it doesn't work because rnbd_get_cpu_qlist() will
+ * always return the first CPU with something on the queue list when the
+ * value stored on the var is greater than the last CPU with something
+ * on the list.
+ */
+ if (cpu_q)
+ *cpup = cpu_q->cpu;
+ put_cpu_ptr(sess->cpu_rr);
+
+ if (q)
+ rnbd_clt_dev_requeue(q);
+
+ return q;
+}
+
+/**
+ * rnbd_rerun_all_if_idle() - rerun all queues left in the list if
+ * session is idling (there are no requests
+ * in-flight).
+ * @sess: Session to rerun the queues on
+ *
+ * Description:
+ * This function tries to rerun all stopped queues if there are no
+ * requests in-flight anymore. This function tries to solve an obvious
+ * problem, when number of tags < than number of queues (hctx), which
+ * are stopped and put to sleep. If last permit, which has been just put,
+ * does not wake up all left queues (hctxs), IO requests hang forever.
+ *
+ * That can happen when all number of permits, say N, have been exhausted
+ * from one CPU, and we have many block devices per session, say M.
+ * Each block device has it's own queue (hctx) for each CPU, so eventually
+ * we can put that number of queues (hctxs) to sleep: M x nr_cpu_ids.
+ * If number of permits N < M x nr_cpu_ids finally we will get an IO hang.
+ *
+ * To avoid this hang last caller of rnbd_put_permit() (last caller is the
+ * one who observes sess->busy == 0) must wake up all remaining queues.
+ *
+ * Context:
+ * Does not matter.
+ */
+static void rnbd_rerun_all_if_idle(struct rnbd_clt_session *sess)
+{
+ bool requeued;
+
+ do {
+ requeued = rnbd_rerun_if_needed(sess);
+ } while (atomic_read(&sess->busy) == 0 && requeued);
+}
+
+static struct rtrs_permit *rnbd_get_permit(struct rnbd_clt_session *sess,
+ enum rtrs_clt_con_type con_type,
+ enum wait_type wait)
+{
+ struct rtrs_permit *permit;
+
+ permit = rtrs_clt_get_permit(sess->rtrs, con_type, wait);
+ if (permit)
+ /* We have a subtle rare case here, when all permits can be
+ * consumed before busy counter increased. This is safe,
+ * because loser will get NULL as a permit, observe 0 busy
+ * counter and immediately restart the queue himself.
+ */
+ atomic_inc(&sess->busy);
+
+ return permit;
+}
+
+static void rnbd_put_permit(struct rnbd_clt_session *sess,
+ struct rtrs_permit *permit)
+{
+ rtrs_clt_put_permit(sess->rtrs, permit);
+ atomic_dec(&sess->busy);
+ /* Paired with rnbd_clt_dev_add_to_requeue(). Decrement first
+ * and then check queue bits.
+ */
+ smp_mb__after_atomic();
+ rnbd_rerun_all_if_idle(sess);
+}
+
+static struct rnbd_iu *rnbd_get_iu(struct rnbd_clt_session *sess,
+ enum rtrs_clt_con_type con_type,
+ enum wait_type wait)
+{
+ struct rnbd_iu *iu;
+ struct rtrs_permit *permit;
+
+ iu = kzalloc(sizeof(*iu), GFP_KERNEL);
+ if (!iu)
+ return NULL;
+
+ permit = rnbd_get_permit(sess, con_type, wait);
+ if (!permit) {
+ kfree(iu);
+ return NULL;
+ }
+
+ iu->permit = permit;
+ /*
+ * 1st reference is dropped after finishing sending a "user" message,
+ * 2nd reference is dropped after confirmation with the response is
+ * returned.
+ * 1st and 2nd can happen in any order, so the rnbd_iu should be
+ * released (rtrs_permit returned to rtrs) only after both
+ * are finished.
+ */
+ atomic_set(&iu->refcount, 2);
+ init_waitqueue_head(&iu->comp.wait);
+ iu->comp.errno = INT_MAX;
+
+ if (sg_alloc_table(&iu->sgt, 1, GFP_KERNEL)) {
+ rnbd_put_permit(sess, permit);
+ kfree(iu);
+ return NULL;
+ }
+
+ return iu;
+}
+
+static void rnbd_put_iu(struct rnbd_clt_session *sess, struct rnbd_iu *iu)
+{
+ if (atomic_dec_and_test(&iu->refcount)) {
+ sg_free_table(&iu->sgt);
+ rnbd_put_permit(sess, iu->permit);
+ kfree(iu);
+ }
+}
+
+static void rnbd_softirq_done_fn(struct request *rq)
+{
+ struct rnbd_clt_dev *dev = rq->q->disk->private_data;
+ struct rnbd_clt_session *sess = dev->sess;
+ struct rnbd_iu *iu;
+
+ iu = blk_mq_rq_to_pdu(rq);
+ sg_free_table_chained(&iu->sgt, RNBD_INLINE_SG_CNT);
+ rnbd_put_permit(sess, iu->permit);
+ blk_mq_end_request(rq, errno_to_blk_status(iu->errno));
+}
+
+static void msg_io_conf(void *priv, int errno)
+{
+ struct rnbd_iu *iu = priv;
+ struct rnbd_clt_dev *dev = iu->dev;
+ struct request *rq = iu->rq;
+ int rw = rq_data_dir(rq);
+
+ iu->errno = errno;
+
+ blk_mq_complete_request(rq);
+
+ if (errno)
+ rnbd_clt_info_rl(dev, "%s I/O failed with err: %d\n",
+ rw == READ ? "read" : "write", errno);
+}
+
+static void wake_up_iu_comp(struct rnbd_iu *iu, int errno)
+{
+ iu->comp.errno = errno;
+ wake_up(&iu->comp.wait);
+}
+
+static void msg_conf(void *priv, int errno)
+{
+ struct rnbd_iu *iu = priv;
+
+ iu->errno = errno;
+ schedule_work(&iu->work);
+}
+
+static int send_usr_msg(struct rtrs_clt_sess *rtrs, int dir,
+ struct rnbd_iu *iu, struct kvec *vec,
+ size_t len, struct scatterlist *sg, unsigned int sg_len,
+ void (*conf)(struct work_struct *work),
+ int *errno, int wait)
+{
+ int err;
+ struct rtrs_clt_req_ops req_ops;
+
+ INIT_WORK(&iu->work, conf);
+ req_ops = (struct rtrs_clt_req_ops) {
+ .priv = iu,
+ .conf_fn = msg_conf,
+ };
+ err = rtrs_clt_request(dir, &req_ops, rtrs, iu->permit,
+ vec, 1, len, sg, sg_len);
+ if (!err && wait) {
+ wait_event(iu->comp.wait, iu->comp.errno != INT_MAX);
+ *errno = iu->comp.errno;
+ } else {
+ *errno = 0;
+ }
+
+ return err;
+}
+
+static void msg_close_conf(struct work_struct *work)
+{
+ struct rnbd_iu *iu = container_of(work, struct rnbd_iu, work);
+ struct rnbd_clt_dev *dev = iu->dev;
+
+ wake_up_iu_comp(iu, iu->errno);
+ rnbd_put_iu(dev->sess, iu);
+ rnbd_clt_put_dev(dev);
+}
+
+static int send_msg_close(struct rnbd_clt_dev *dev, u32 device_id,
+ enum wait_type wait)
+{
+ struct rnbd_clt_session *sess = dev->sess;
+ struct rnbd_msg_close msg;
+ struct rnbd_iu *iu;
+ struct kvec vec = {
+ .iov_base = &msg,
+ .iov_len = sizeof(msg)
+ };
+ int err, errno;
+
+ iu = rnbd_get_iu(sess, RTRS_ADMIN_CON, RTRS_PERMIT_WAIT);
+ if (!iu)
+ return -ENOMEM;
+
+ iu->buf = NULL;
+ iu->dev = dev;
+
+ msg.hdr.type = cpu_to_le16(RNBD_MSG_CLOSE);
+ msg.device_id = cpu_to_le32(device_id);
+
+ WARN_ON(!rnbd_clt_get_dev(dev));
+ err = send_usr_msg(sess->rtrs, WRITE, iu, &vec, 0, NULL, 0,
+ msg_close_conf, &errno, wait);
+ if (err) {
+ rnbd_clt_put_dev(dev);
+ rnbd_put_iu(sess, iu);
+ } else {
+ err = errno;
+ }
+
+ rnbd_put_iu(sess, iu);
+ return err;
+}
+
+static void msg_open_conf(struct work_struct *work)
+{
+ struct rnbd_iu *iu = container_of(work, struct rnbd_iu, work);
+ struct rnbd_msg_open_rsp *rsp = iu->buf;
+ struct rnbd_clt_dev *dev = iu->dev;
+ int errno = iu->errno;
+ bool from_map = false;
+
+ /* INIT state is only triggered from rnbd_clt_map_device */
+ if (dev->dev_state == DEV_STATE_INIT)
+ from_map = true;
+
+ if (errno) {
+ rnbd_clt_err(dev,
+ "Opening failed, server responded: %d\n",
+ errno);
+ } else {
+ errno = process_msg_open_rsp(dev, rsp);
+ if (errno) {
+ u32 device_id = le32_to_cpu(rsp->device_id);
+ /*
+ * If server thinks its fine, but we fail to process
+ * then be nice and send a close to server.
+ */
+ send_msg_close(dev, device_id, RTRS_PERMIT_NOWAIT);
+ }
+ }
+ /* We free rsp in rnbd_clt_map_device for map scenario */
+ if (!from_map)
+ kfree(rsp);
+ wake_up_iu_comp(iu, errno);
+ rnbd_put_iu(dev->sess, iu);
+ rnbd_clt_put_dev(dev);
+}
+
+static void msg_sess_info_conf(struct work_struct *work)
+{
+ struct rnbd_iu *iu = container_of(work, struct rnbd_iu, work);
+ struct rnbd_msg_sess_info_rsp *rsp = iu->buf;
+ struct rnbd_clt_session *sess = iu->sess;
+
+ if (!iu->errno)
+ sess->ver = min_t(u8, rsp->ver, RNBD_PROTO_VER_MAJOR);
+
+ kfree(rsp);
+ wake_up_iu_comp(iu, iu->errno);
+ rnbd_put_iu(sess, iu);
+ rnbd_clt_put_sess(sess);
+}
+
+static int send_msg_open(struct rnbd_clt_dev *dev, enum wait_type wait)
+{
+ struct rnbd_clt_session *sess = dev->sess;
+ struct rnbd_msg_open_rsp *rsp;
+ struct rnbd_msg_open msg;
+ struct rnbd_iu *iu;
+ struct kvec vec = {
+ .iov_base = &msg,
+ .iov_len = sizeof(msg)
+ };
+ int err, errno;
+
+ rsp = kzalloc(sizeof(*rsp), GFP_KERNEL);
+ if (!rsp)
+ return -ENOMEM;
+
+ iu = rnbd_get_iu(sess, RTRS_ADMIN_CON, RTRS_PERMIT_WAIT);
+ if (!iu) {
+ kfree(rsp);
+ return -ENOMEM;
+ }
+
+ iu->buf = rsp;
+ iu->dev = dev;
+
+ sg_init_one(iu->sgt.sgl, rsp, sizeof(*rsp));
+
+ msg.hdr.type = cpu_to_le16(RNBD_MSG_OPEN);
+ msg.access_mode = dev->access_mode;
+ strscpy(msg.dev_name, dev->pathname, sizeof(msg.dev_name));
+
+ WARN_ON(!rnbd_clt_get_dev(dev));
+ err = send_usr_msg(sess->rtrs, READ, iu,
+ &vec, sizeof(*rsp), iu->sgt.sgl, 1,
+ msg_open_conf, &errno, wait);
+ if (err) {
+ rnbd_clt_put_dev(dev);
+ rnbd_put_iu(sess, iu);
+ kfree(rsp);
+ } else {
+ err = errno;
+ }
+
+ rnbd_put_iu(sess, iu);
+ return err;
+}
+
+static int send_msg_sess_info(struct rnbd_clt_session *sess, enum wait_type wait)
+{
+ struct rnbd_msg_sess_info_rsp *rsp;
+ struct rnbd_msg_sess_info msg;
+ struct rnbd_iu *iu;
+ struct kvec vec = {
+ .iov_base = &msg,
+ .iov_len = sizeof(msg)
+ };
+ int err, errno;
+
+ rsp = kzalloc(sizeof(*rsp), GFP_KERNEL);
+ if (!rsp)
+ return -ENOMEM;
+
+ iu = rnbd_get_iu(sess, RTRS_ADMIN_CON, RTRS_PERMIT_WAIT);
+ if (!iu) {
+ kfree(rsp);
+ return -ENOMEM;
+ }
+
+ iu->buf = rsp;
+ iu->sess = sess;
+ sg_init_one(iu->sgt.sgl, rsp, sizeof(*rsp));
+
+ msg.hdr.type = cpu_to_le16(RNBD_MSG_SESS_INFO);
+ msg.ver = RNBD_PROTO_VER_MAJOR;
+
+ if (!rnbd_clt_get_sess(sess)) {
+ /*
+ * That can happen only in one case, when RTRS has restablished
+ * the connection and link_ev() is called, but session is almost
+ * dead, last reference on session is put and caller is waiting
+ * for RTRS to close everything.
+ */
+ err = -ENODEV;
+ goto put_iu;
+ }
+ err = send_usr_msg(sess->rtrs, READ, iu,
+ &vec, sizeof(*rsp), iu->sgt.sgl, 1,
+ msg_sess_info_conf, &errno, wait);
+ if (err) {
+ rnbd_clt_put_sess(sess);
+put_iu:
+ rnbd_put_iu(sess, iu);
+ kfree(rsp);
+ } else {
+ err = errno;
+ }
+ rnbd_put_iu(sess, iu);
+ return err;
+}
+
+static void set_dev_states_to_disconnected(struct rnbd_clt_session *sess)
+{
+ struct rnbd_clt_dev *dev;
+ struct kobject *gd_kobj;
+
+ mutex_lock(&sess->lock);
+ list_for_each_entry(dev, &sess->devs_list, list) {
+ rnbd_clt_err(dev, "Device disconnected.\n");
+
+ mutex_lock(&dev->lock);
+ if (dev->dev_state == DEV_STATE_MAPPED) {
+ dev->dev_state = DEV_STATE_MAPPED_DISCONNECTED;
+ gd_kobj = &disk_to_dev(dev->gd)->kobj;
+ kobject_uevent(gd_kobj, KOBJ_OFFLINE);
+ }
+ mutex_unlock(&dev->lock);
+ }
+ mutex_unlock(&sess->lock);
+}
+
+static void remap_devs(struct rnbd_clt_session *sess)
+{
+ struct rnbd_clt_dev *dev;
+ struct rtrs_attrs attrs;
+ int err;
+
+ /*
+ * Careful here: we are called from RTRS link event directly,
+ * thus we can't send any RTRS request and wait for response
+ * or RTRS will not be able to complete request with failure
+ * if something goes wrong (failing of outstanding requests
+ * happens exactly from the context where we are blocking now).
+ *
+ * So to avoid deadlocks each usr message sent from here must
+ * be asynchronous.
+ */
+
+ err = send_msg_sess_info(sess, RTRS_PERMIT_NOWAIT);
+ if (err) {
+ pr_err("send_msg_sess_info(\"%s\"): %d\n", sess->sessname, err);
+ return;
+ }
+
+ err = rtrs_clt_query(sess->rtrs, &attrs);
+ if (err) {
+ pr_err("rtrs_clt_query(\"%s\"): %d\n", sess->sessname, err);
+ return;
+ }
+ mutex_lock(&sess->lock);
+ sess->max_io_size = attrs.max_io_size;
+
+ list_for_each_entry(dev, &sess->devs_list, list) {
+ bool skip;
+
+ mutex_lock(&dev->lock);
+ skip = (dev->dev_state == DEV_STATE_INIT);
+ mutex_unlock(&dev->lock);
+ if (skip)
+ /*
+ * When device is establishing connection for the first
+ * time - do not remap, it will be closed soon.
+ */
+ continue;
+
+ rnbd_clt_info(dev, "session reconnected, remapping device\n");
+ err = send_msg_open(dev, RTRS_PERMIT_NOWAIT);
+ if (err) {
+ rnbd_clt_err(dev, "send_msg_open(): %d\n", err);
+ break;
+ }
+ }
+ mutex_unlock(&sess->lock);
+}
+
+static void rnbd_clt_link_ev(void *priv, enum rtrs_clt_link_ev ev)
+{
+ struct rnbd_clt_session *sess = priv;
+
+ switch (ev) {
+ case RTRS_CLT_LINK_EV_DISCONNECTED:
+ set_dev_states_to_disconnected(sess);
+ break;
+ case RTRS_CLT_LINK_EV_RECONNECTED:
+ remap_devs(sess);
+ break;
+ default:
+ pr_err("Unknown session event received (%d), session: %s\n",
+ ev, sess->sessname);
+ }
+}
+
+static void rnbd_init_cpu_qlists(struct rnbd_cpu_qlist __percpu *cpu_queues)
+{
+ unsigned int cpu;
+ struct rnbd_cpu_qlist *cpu_q;
+
+ for_each_possible_cpu(cpu) {
+ cpu_q = per_cpu_ptr(cpu_queues, cpu);
+
+ cpu_q->cpu = cpu;
+ INIT_LIST_HEAD(&cpu_q->requeue_list);
+ spin_lock_init(&cpu_q->requeue_lock);
+ }
+}
+
+static void destroy_mq_tags(struct rnbd_clt_session *sess)
+{
+ if (sess->tag_set.tags)
+ blk_mq_free_tag_set(&sess->tag_set);
+}
+
+static inline void wake_up_rtrs_waiters(struct rnbd_clt_session *sess)
+{
+ sess->rtrs_ready = true;
+ wake_up_all(&sess->rtrs_waitq);
+}
+
+static void close_rtrs(struct rnbd_clt_session *sess)
+{
+ might_sleep();
+
+ if (!IS_ERR_OR_NULL(sess->rtrs)) {
+ rtrs_clt_close(sess->rtrs);
+ sess->rtrs = NULL;
+ wake_up_rtrs_waiters(sess);
+ }
+}
+
+static void free_sess(struct rnbd_clt_session *sess)
+{
+ WARN_ON(!list_empty(&sess->devs_list));
+
+ might_sleep();
+
+ close_rtrs(sess);
+ destroy_mq_tags(sess);
+ if (!list_empty(&sess->list)) {
+ mutex_lock(&sess_lock);
+ list_del(&sess->list);
+ mutex_unlock(&sess_lock);
+ }
+ free_percpu(sess->cpu_queues);
+ free_percpu(sess->cpu_rr);
+ mutex_destroy(&sess->lock);
+ kfree(sess);
+}
+
+static struct rnbd_clt_session *alloc_sess(const char *sessname)
+{
+ struct rnbd_clt_session *sess;
+ int err, cpu;
+
+ sess = kzalloc_node(sizeof(*sess), GFP_KERNEL, NUMA_NO_NODE);
+ if (!sess)
+ return ERR_PTR(-ENOMEM);
+ strscpy(sess->sessname, sessname, sizeof(sess->sessname));
+ atomic_set(&sess->busy, 0);
+ mutex_init(&sess->lock);
+ INIT_LIST_HEAD(&sess->devs_list);
+ INIT_LIST_HEAD(&sess->list);
+ bitmap_zero(sess->cpu_queues_bm, num_possible_cpus());
+ init_waitqueue_head(&sess->rtrs_waitq);
+ refcount_set(&sess->refcount, 1);
+
+ sess->cpu_queues = alloc_percpu(struct rnbd_cpu_qlist);
+ if (!sess->cpu_queues) {
+ err = -ENOMEM;
+ goto err;
+ }
+ rnbd_init_cpu_qlists(sess->cpu_queues);
+
+ /*
+ * That is simple percpu variable which stores cpu indices, which are
+ * incremented on each access. We need that for the sake of fairness
+ * to wake up queues in a round-robin manner.
+ */
+ sess->cpu_rr = alloc_percpu(int);
+ if (!sess->cpu_rr) {
+ err = -ENOMEM;
+ goto err;
+ }
+ for_each_possible_cpu(cpu)
+ * per_cpu_ptr(sess->cpu_rr, cpu) = cpu;
+
+ return sess;
+
+err:
+ free_sess(sess);
+
+ return ERR_PTR(err);
+}
+
+static int wait_for_rtrs_connection(struct rnbd_clt_session *sess)
+{
+ wait_event(sess->rtrs_waitq, sess->rtrs_ready);
+ if (IS_ERR_OR_NULL(sess->rtrs))
+ return -ECONNRESET;
+
+ return 0;
+}
+
+static void wait_for_rtrs_disconnection(struct rnbd_clt_session *sess)
+ __releases(&sess_lock)
+ __acquires(&sess_lock)
+{
+ DEFINE_WAIT(wait);
+
+ prepare_to_wait(&sess->rtrs_waitq, &wait, TASK_UNINTERRUPTIBLE);
+ if (IS_ERR_OR_NULL(sess->rtrs)) {
+ finish_wait(&sess->rtrs_waitq, &wait);
+ return;
+ }
+ mutex_unlock(&sess_lock);
+ /* loop in caller, see __find_and_get_sess().
+ * You can't leave mutex locked and call schedule(), you will catch a
+ * deadlock with a caller of free_sess(), which has just put the last
+ * reference and is about to take the sess_lock in order to delete
+ * the session from the list.
+ */
+ schedule();
+ mutex_lock(&sess_lock);
+}
+
+static struct rnbd_clt_session *__find_and_get_sess(const char *sessname)
+ __releases(&sess_lock)
+ __acquires(&sess_lock)
+{
+ struct rnbd_clt_session *sess, *sn;
+ int err;
+
+again:
+ list_for_each_entry_safe(sess, sn, &sess_list, list) {
+ if (strcmp(sessname, sess->sessname))
+ continue;
+
+ if (sess->rtrs_ready && IS_ERR_OR_NULL(sess->rtrs))
+ /*
+ * No RTRS connection, session is dying.
+ */
+ continue;
+
+ if (rnbd_clt_get_sess(sess)) {
+ /*
+ * Alive session is found, wait for RTRS connection.
+ */
+ mutex_unlock(&sess_lock);
+ err = wait_for_rtrs_connection(sess);
+ if (err)
+ rnbd_clt_put_sess(sess);
+ mutex_lock(&sess_lock);
+
+ if (err)
+ /* Session is dying, repeat the loop */
+ goto again;
+
+ return sess;
+ }
+ /*
+ * Ref is 0, session is dying, wait for RTRS disconnect
+ * in order to avoid session names clashes.
+ */
+ wait_for_rtrs_disconnection(sess);
+ /*
+ * RTRS is disconnected and soon session will be freed,
+ * so repeat a loop.
+ */
+ goto again;
+ }
+
+ return NULL;
+}
+
+/* caller is responsible for initializing 'first' to false */
+static struct
+rnbd_clt_session *find_or_create_sess(const char *sessname, bool *first)
+{
+ struct rnbd_clt_session *sess = NULL;
+
+ mutex_lock(&sess_lock);
+ sess = __find_and_get_sess(sessname);
+ if (!sess) {
+ sess = alloc_sess(sessname);
+ if (IS_ERR(sess)) {
+ mutex_unlock(&sess_lock);
+ return sess;
+ }
+ list_add(&sess->list, &sess_list);
+ *first = true;
+ }
+ mutex_unlock(&sess_lock);
+
+ return sess;
+}
+
+static int rnbd_client_open(struct block_device *block_device, fmode_t mode)
+{
+ struct rnbd_clt_dev *dev = block_device->bd_disk->private_data;
+
+ if (get_disk_ro(dev->gd) && (mode & FMODE_WRITE))
+ return -EPERM;
+
+ if (dev->dev_state == DEV_STATE_UNMAPPED ||
+ !rnbd_clt_get_dev(dev))
+ return -EIO;
+
+ return 0;
+}
+
+static void rnbd_client_release(struct gendisk *gen, fmode_t mode)
+{
+ struct rnbd_clt_dev *dev = gen->private_data;
+
+ rnbd_clt_put_dev(dev);
+}
+
+static int rnbd_client_getgeo(struct block_device *block_device,
+ struct hd_geometry *geo)
+{
+ u64 size;
+ struct rnbd_clt_dev *dev = block_device->bd_disk->private_data;
+ struct queue_limits *limit = &dev->queue->limits;
+
+ size = dev->size * (limit->logical_block_size / SECTOR_SIZE);
+ geo->cylinders = size >> 6; /* size/64 */
+ geo->heads = 4;
+ geo->sectors = 16;
+ geo->start = 0;
+
+ return 0;
+}
+
+static const struct block_device_operations rnbd_client_ops = {
+ .owner = THIS_MODULE,
+ .open = rnbd_client_open,
+ .release = rnbd_client_release,
+ .getgeo = rnbd_client_getgeo
+};
+
+/* The amount of data that belongs to an I/O and the amount of data that
+ * should be read or written to the disk (bi_size) can differ.
+ *
+ * E.g. When WRITE_SAME is used, only a small amount of data is
+ * transferred that is then written repeatedly over a lot of sectors.
+ *
+ * Get the size of data to be transferred via RTRS by summing up the size
+ * of the scather-gather list entries.
+ */
+static size_t rnbd_clt_get_sg_size(struct scatterlist *sglist, u32 len)
+{
+ struct scatterlist *sg;
+ size_t tsize = 0;
+ int i;
+
+ for_each_sg(sglist, sg, len, i)
+ tsize += sg->length;
+ return tsize;
+}
+
+static int rnbd_client_xfer_request(struct rnbd_clt_dev *dev,
+ struct request *rq,
+ struct rnbd_iu *iu)
+{
+ struct rtrs_clt_sess *rtrs = dev->sess->rtrs;
+ struct rtrs_permit *permit = iu->permit;
+ struct rnbd_msg_io msg;
+ struct rtrs_clt_req_ops req_ops;
+ unsigned int sg_cnt = 0;
+ struct kvec vec;
+ size_t size;
+ int err;
+
+ iu->rq = rq;
+ iu->dev = dev;
+ msg.sector = cpu_to_le64(blk_rq_pos(rq));
+ msg.bi_size = cpu_to_le32(blk_rq_bytes(rq));
+ msg.rw = cpu_to_le32(rq_to_rnbd_flags(rq));
+ msg.prio = cpu_to_le16(req_get_ioprio(rq));
+
+ /*
+ * We only support discards with single segment for now.
+ * See queue limits.
+ */
+ if (req_op(rq) != REQ_OP_DISCARD)
+ sg_cnt = blk_rq_map_sg(dev->queue, rq, iu->sgt.sgl);
+
+ if (sg_cnt == 0)
+ sg_mark_end(&iu->sgt.sgl[0]);
+
+ msg.hdr.type = cpu_to_le16(RNBD_MSG_IO);
+ msg.device_id = cpu_to_le32(dev->device_id);
+
+ vec = (struct kvec) {
+ .iov_base = &msg,
+ .iov_len = sizeof(msg)
+ };
+ size = rnbd_clt_get_sg_size(iu->sgt.sgl, sg_cnt);
+ req_ops = (struct rtrs_clt_req_ops) {
+ .priv = iu,
+ .conf_fn = msg_io_conf,
+ };
+ err = rtrs_clt_request(rq_data_dir(rq), &req_ops, rtrs, permit,
+ &vec, 1, size, iu->sgt.sgl, sg_cnt);
+ if (err) {
+ rnbd_clt_err_rl(dev, "RTRS failed to transfer IO, err: %d\n",
+ err);
+ return err;
+ }
+
+ return 0;
+}
+
+/**
+ * rnbd_clt_dev_add_to_requeue() - add device to requeue if session is busy
+ * @dev: Device to be checked
+ * @q: Queue to be added to the requeue list if required
+ *
+ * Description:
+ * If session is busy, that means someone will requeue us when resources
+ * are freed. If session is not doing anything - device is not added to
+ * the list and @false is returned.
+ */
+static bool rnbd_clt_dev_add_to_requeue(struct rnbd_clt_dev *dev,
+ struct rnbd_queue *q)
+{
+ struct rnbd_clt_session *sess = dev->sess;
+ struct rnbd_cpu_qlist *cpu_q;
+ unsigned long flags;
+ bool added = true;
+ bool need_set;
+
+ cpu_q = get_cpu_ptr(sess->cpu_queues);
+ spin_lock_irqsave(&cpu_q->requeue_lock, flags);
+
+ if (!test_and_set_bit_lock(0, &q->in_list)) {
+ if (WARN_ON(!list_empty(&q->requeue_list)))
+ goto unlock;
+
+ need_set = !test_bit(cpu_q->cpu, sess->cpu_queues_bm);
+ if (need_set) {
+ set_bit(cpu_q->cpu, sess->cpu_queues_bm);
+ /* Paired with rnbd_put_permit(). Set a bit first
+ * and then observe the busy counter.
+ */
+ smp_mb__before_atomic();
+ }
+ if (atomic_read(&sess->busy)) {
+ list_add_tail(&q->requeue_list, &cpu_q->requeue_list);
+ } else {
+ /* Very unlikely, but possible: busy counter was
+ * observed as zero. Drop all bits and return
+ * false to restart the queue by ourselves.
+ */
+ if (need_set)
+ clear_bit(cpu_q->cpu, sess->cpu_queues_bm);
+ clear_bit_unlock(0, &q->in_list);
+ added = false;
+ }
+ }
+unlock:
+ spin_unlock_irqrestore(&cpu_q->requeue_lock, flags);
+ put_cpu_ptr(sess->cpu_queues);
+
+ return added;
+}
+
+static void rnbd_clt_dev_kick_mq_queue(struct rnbd_clt_dev *dev,
+ struct blk_mq_hw_ctx *hctx,
+ int delay)
+{
+ struct rnbd_queue *q = hctx->driver_data;
+
+ if (delay != RNBD_DELAY_IFBUSY)
+ blk_mq_delay_run_hw_queue(hctx, delay);
+ else if (!rnbd_clt_dev_add_to_requeue(dev, q))
+ /*
+ * If session is not busy we have to restart
+ * the queue ourselves.
+ */
+ blk_mq_delay_run_hw_queue(hctx, 10/*ms*/);
+}
+
+static blk_status_t rnbd_queue_rq(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *bd)
+{
+ struct request *rq = bd->rq;
+ struct rnbd_clt_dev *dev = rq->q->disk->private_data;
+ struct rnbd_iu *iu = blk_mq_rq_to_pdu(rq);
+ int err;
+ blk_status_t ret = BLK_STS_IOERR;
+
+ if (dev->dev_state != DEV_STATE_MAPPED)
+ return BLK_STS_IOERR;
+
+ iu->permit = rnbd_get_permit(dev->sess, RTRS_IO_CON,
+ RTRS_PERMIT_NOWAIT);
+ if (!iu->permit) {
+ rnbd_clt_dev_kick_mq_queue(dev, hctx, RNBD_DELAY_IFBUSY);
+ return BLK_STS_RESOURCE;
+ }
+
+ iu->sgt.sgl = iu->first_sgl;
+ err = sg_alloc_table_chained(&iu->sgt,
+ /* Even-if the request has no segment,
+ * sglist must have one entry at least.
+ */
+ blk_rq_nr_phys_segments(rq) ? : 1,
+ iu->sgt.sgl,
+ RNBD_INLINE_SG_CNT);
+ if (err) {
+ rnbd_clt_err_rl(dev, "sg_alloc_table_chained ret=%d\n", err);
+ rnbd_clt_dev_kick_mq_queue(dev, hctx, 10/*ms*/);
+ rnbd_put_permit(dev->sess, iu->permit);
+ return BLK_STS_RESOURCE;
+ }
+
+ blk_mq_start_request(rq);
+ err = rnbd_client_xfer_request(dev, rq, iu);
+ if (err == 0)
+ return BLK_STS_OK;
+ if (err == -EAGAIN || err == -ENOMEM) {
+ rnbd_clt_dev_kick_mq_queue(dev, hctx, 10/*ms*/);
+ ret = BLK_STS_RESOURCE;
+ }
+ sg_free_table_chained(&iu->sgt, RNBD_INLINE_SG_CNT);
+ rnbd_put_permit(dev->sess, iu->permit);
+ return ret;
+}
+
+static int rnbd_rdma_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob)
+{
+ struct rnbd_queue *q = hctx->driver_data;
+ struct rnbd_clt_dev *dev = q->dev;
+
+ return rtrs_clt_rdma_cq_direct(dev->sess->rtrs, hctx->queue_num);
+}
+
+static void rnbd_rdma_map_queues(struct blk_mq_tag_set *set)
+{
+ struct rnbd_clt_session *sess = set->driver_data;
+
+ /* shared read/write queues */
+ set->map[HCTX_TYPE_DEFAULT].nr_queues = num_online_cpus();
+ set->map[HCTX_TYPE_DEFAULT].queue_offset = 0;
+ set->map[HCTX_TYPE_READ].nr_queues = num_online_cpus();
+ set->map[HCTX_TYPE_READ].queue_offset = 0;
+ blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]);
+ blk_mq_map_queues(&set->map[HCTX_TYPE_READ]);
+
+ if (sess->nr_poll_queues) {
+ /* dedicated queue for poll */
+ set->map[HCTX_TYPE_POLL].nr_queues = sess->nr_poll_queues;
+ set->map[HCTX_TYPE_POLL].queue_offset = set->map[HCTX_TYPE_READ].queue_offset +
+ set->map[HCTX_TYPE_READ].nr_queues;
+ blk_mq_map_queues(&set->map[HCTX_TYPE_POLL]);
+ pr_info("[session=%s] mapped %d/%d/%d default/read/poll queues.\n",
+ sess->sessname,
+ set->map[HCTX_TYPE_DEFAULT].nr_queues,
+ set->map[HCTX_TYPE_READ].nr_queues,
+ set->map[HCTX_TYPE_POLL].nr_queues);
+ } else {
+ pr_info("[session=%s] mapped %d/%d default/read queues.\n",
+ sess->sessname,
+ set->map[HCTX_TYPE_DEFAULT].nr_queues,
+ set->map[HCTX_TYPE_READ].nr_queues);
+ }
+}
+
+static struct blk_mq_ops rnbd_mq_ops = {
+ .queue_rq = rnbd_queue_rq,
+ .complete = rnbd_softirq_done_fn,
+ .map_queues = rnbd_rdma_map_queues,
+ .poll = rnbd_rdma_poll,
+};
+
+static int setup_mq_tags(struct rnbd_clt_session *sess)
+{
+ struct blk_mq_tag_set *tag_set = &sess->tag_set;
+
+ memset(tag_set, 0, sizeof(*tag_set));
+ tag_set->ops = &rnbd_mq_ops;
+ tag_set->queue_depth = sess->queue_depth;
+ tag_set->numa_node = NUMA_NO_NODE;
+ tag_set->flags = BLK_MQ_F_SHOULD_MERGE |
+ BLK_MQ_F_TAG_QUEUE_SHARED;
+ tag_set->cmd_size = sizeof(struct rnbd_iu) + RNBD_RDMA_SGL_SIZE;
+
+ /* for HCTX_TYPE_DEFAULT, HCTX_TYPE_READ, HCTX_TYPE_POLL */
+ tag_set->nr_maps = sess->nr_poll_queues ? HCTX_MAX_TYPES : 2;
+ /*
+ * HCTX_TYPE_DEFAULT and HCTX_TYPE_READ share one set of queues
+ * others are for HCTX_TYPE_POLL
+ */
+ tag_set->nr_hw_queues = num_online_cpus() + sess->nr_poll_queues;
+ tag_set->driver_data = sess;
+
+ return blk_mq_alloc_tag_set(tag_set);
+}
+
+static struct rnbd_clt_session *
+find_and_get_or_create_sess(const char *sessname,
+ const struct rtrs_addr *paths,
+ size_t path_cnt, u16 port_nr, u32 nr_poll_queues)
+{
+ struct rnbd_clt_session *sess;
+ struct rtrs_attrs attrs;
+ int err;
+ bool first = false;
+ struct rtrs_clt_ops rtrs_ops;
+
+ sess = find_or_create_sess(sessname, &first);
+ if (sess == ERR_PTR(-ENOMEM)) {
+ return ERR_PTR(-ENOMEM);
+ } else if ((nr_poll_queues && !first) || (!nr_poll_queues && sess->nr_poll_queues)) {
+ /*
+ * A device MUST have its own session to use the polling-mode.
+ * It must fail to map new device with the same session.
+ */
+ err = -EINVAL;
+ goto put_sess;
+ }
+
+ if (!first)
+ return sess;
+
+ if (!path_cnt) {
+ pr_err("Session %s not found, and path parameter not given", sessname);
+ err = -ENXIO;
+ goto put_sess;
+ }
+
+ rtrs_ops = (struct rtrs_clt_ops) {
+ .priv = sess,
+ .link_ev = rnbd_clt_link_ev,
+ };
+ /*
+ * Nothing was found, establish rtrs connection and proceed further.
+ */
+ sess->rtrs = rtrs_clt_open(&rtrs_ops, sessname,
+ paths, path_cnt, port_nr,
+ 0, /* Do not use pdu of rtrs */
+ RECONNECT_DELAY,
+ MAX_RECONNECTS, nr_poll_queues);
+ if (IS_ERR(sess->rtrs)) {
+ err = PTR_ERR(sess->rtrs);
+ goto wake_up_and_put;
+ }
+
+ err = rtrs_clt_query(sess->rtrs, &attrs);
+ if (err)
+ goto close_rtrs;
+
+ sess->max_io_size = attrs.max_io_size;
+ sess->queue_depth = attrs.queue_depth;
+ sess->nr_poll_queues = nr_poll_queues;
+ sess->max_segments = attrs.max_segments;
+
+ err = setup_mq_tags(sess);
+ if (err)
+ goto close_rtrs;
+
+ err = send_msg_sess_info(sess, RTRS_PERMIT_WAIT);
+ if (err)
+ goto close_rtrs;
+
+ wake_up_rtrs_waiters(sess);
+
+ return sess;
+
+close_rtrs:
+ close_rtrs(sess);
+put_sess:
+ rnbd_clt_put_sess(sess);
+
+ return ERR_PTR(err);
+
+wake_up_and_put:
+ wake_up_rtrs_waiters(sess);
+ goto put_sess;
+}
+
+static inline void rnbd_init_hw_queue(struct rnbd_clt_dev *dev,
+ struct rnbd_queue *q,
+ struct blk_mq_hw_ctx *hctx)
+{
+ INIT_LIST_HEAD(&q->requeue_list);
+ q->dev = dev;
+ q->hctx = hctx;
+}
+
+static void rnbd_init_mq_hw_queues(struct rnbd_clt_dev *dev)
+{
+ unsigned long i;
+ struct blk_mq_hw_ctx *hctx;
+ struct rnbd_queue *q;
+
+ queue_for_each_hw_ctx(dev->queue, hctx, i) {
+ q = &dev->hw_queues[i];
+ rnbd_init_hw_queue(dev, q, hctx);
+ hctx->driver_data = q;
+ }
+}
+
+static void setup_request_queue(struct rnbd_clt_dev *dev,
+ struct rnbd_msg_open_rsp *rsp)
+{
+ blk_queue_logical_block_size(dev->queue,
+ le16_to_cpu(rsp->logical_block_size));
+ blk_queue_physical_block_size(dev->queue,
+ le16_to_cpu(rsp->physical_block_size));
+ blk_queue_max_hw_sectors(dev->queue,
+ dev->sess->max_io_size / SECTOR_SIZE);
+
+ /*
+ * we don't support discards to "discontiguous" segments
+ * in on request
+ */
+ blk_queue_max_discard_segments(dev->queue, 1);
+
+ blk_queue_max_discard_sectors(dev->queue,
+ le32_to_cpu(rsp->max_discard_sectors));
+ dev->queue->limits.discard_granularity =
+ le32_to_cpu(rsp->discard_granularity);
+ dev->queue->limits.discard_alignment =
+ le32_to_cpu(rsp->discard_alignment);
+ if (le16_to_cpu(rsp->secure_discard))
+ blk_queue_max_secure_erase_sectors(dev->queue,
+ le32_to_cpu(rsp->max_discard_sectors));
+ blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, dev->queue);
+ blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, dev->queue);
+ blk_queue_max_segments(dev->queue, dev->sess->max_segments);
+ blk_queue_io_opt(dev->queue, dev->sess->max_io_size);
+ blk_queue_virt_boundary(dev->queue, SZ_4K - 1);
+ blk_queue_write_cache(dev->queue,
+ !!(rsp->cache_policy & RNBD_WRITEBACK),
+ !!(rsp->cache_policy & RNBD_FUA));
+}
+
+static int rnbd_clt_setup_gen_disk(struct rnbd_clt_dev *dev,
+ struct rnbd_msg_open_rsp *rsp, int idx)
+{
+ int err;
+
+ dev->gd->major = rnbd_client_major;
+ dev->gd->first_minor = idx << RNBD_PART_BITS;
+ dev->gd->minors = 1 << RNBD_PART_BITS;
+ dev->gd->fops = &rnbd_client_ops;
+ dev->gd->queue = dev->queue;
+ dev->gd->private_data = dev;
+ snprintf(dev->gd->disk_name, sizeof(dev->gd->disk_name), "rnbd%d",
+ idx);
+ pr_debug("disk_name=%s, capacity=%llu\n",
+ dev->gd->disk_name,
+ le64_to_cpu(rsp->nsectors) *
+ (le16_to_cpu(rsp->logical_block_size) / SECTOR_SIZE));
+
+ set_capacity(dev->gd, le64_to_cpu(rsp->nsectors));
+
+ if (dev->access_mode == RNBD_ACCESS_RO)
+ set_disk_ro(dev->gd, true);
+
+ /*
+ * Network device does not need rotational
+ */
+ blk_queue_flag_set(QUEUE_FLAG_NONROT, dev->queue);
+ err = add_disk(dev->gd);
+ if (err)
+ put_disk(dev->gd);
+
+ return err;
+}
+
+static int rnbd_client_setup_device(struct rnbd_clt_dev *dev,
+ struct rnbd_msg_open_rsp *rsp)
+{
+ int idx = dev->clt_device_id;
+
+ dev->size = le64_to_cpu(rsp->nsectors) *
+ le16_to_cpu(rsp->logical_block_size);
+
+ dev->gd = blk_mq_alloc_disk(&dev->sess->tag_set, dev);
+ if (IS_ERR(dev->gd))
+ return PTR_ERR(dev->gd);
+ dev->queue = dev->gd->queue;
+ rnbd_init_mq_hw_queues(dev);
+
+ setup_request_queue(dev, rsp);
+ return rnbd_clt_setup_gen_disk(dev, rsp, idx);
+}
+
+static struct rnbd_clt_dev *init_dev(struct rnbd_clt_session *sess,
+ enum rnbd_access_mode access_mode,
+ const char *pathname,
+ u32 nr_poll_queues)
+{
+ struct rnbd_clt_dev *dev;
+ int ret;
+
+ dev = kzalloc_node(sizeof(*dev), GFP_KERNEL, NUMA_NO_NODE);
+ if (!dev)
+ return ERR_PTR(-ENOMEM);
+
+ /*
+ * nr_cpu_ids: the number of softirq queues
+ * nr_poll_queues: the number of polling queues
+ */
+ dev->hw_queues = kcalloc(nr_cpu_ids + nr_poll_queues,
+ sizeof(*dev->hw_queues),
+ GFP_KERNEL);
+ if (!dev->hw_queues) {
+ ret = -ENOMEM;
+ goto out_alloc;
+ }
+
+ ret = ida_alloc_max(&index_ida, (1 << (MINORBITS - RNBD_PART_BITS)) - 1,
+ GFP_KERNEL);
+ if (ret < 0) {
+ pr_err("Failed to initialize device '%s' from session %s, allocating idr failed, err: %d\n",
+ pathname, sess->sessname, ret);
+ goto out_queues;
+ }
+
+ dev->pathname = kstrdup(pathname, GFP_KERNEL);
+ if (!dev->pathname) {
+ ret = -ENOMEM;
+ goto out_queues;
+ }
+
+ dev->clt_device_id = ret;
+ dev->sess = sess;
+ dev->access_mode = access_mode;
+ dev->nr_poll_queues = nr_poll_queues;
+ mutex_init(&dev->lock);
+ refcount_set(&dev->refcount, 1);
+ dev->dev_state = DEV_STATE_INIT;
+
+ /*
+ * Here we called from sysfs entry, thus clt-sysfs is
+ * responsible that session will not disappear.
+ */
+ WARN_ON(!rnbd_clt_get_sess(sess));
+
+ return dev;
+
+out_queues:
+ kfree(dev->hw_queues);
+out_alloc:
+ kfree(dev);
+ return ERR_PTR(ret);
+}
+
+static bool __exists_dev(const char *pathname, const char *sessname)
+{
+ struct rnbd_clt_session *sess;
+ struct rnbd_clt_dev *dev;
+ bool found = false;
+
+ list_for_each_entry(sess, &sess_list, list) {
+ if (sessname && strncmp(sess->sessname, sessname,
+ sizeof(sess->sessname)))
+ continue;
+ mutex_lock(&sess->lock);
+ list_for_each_entry(dev, &sess->devs_list, list) {
+ if (strlen(dev->pathname) == strlen(pathname) &&
+ !strcmp(dev->pathname, pathname)) {
+ found = true;
+ break;
+ }
+ }
+ mutex_unlock(&sess->lock);
+ if (found)
+ break;
+ }
+
+ return found;
+}
+
+static bool exists_devpath(const char *pathname, const char *sessname)
+{
+ bool found;
+
+ mutex_lock(&sess_lock);
+ found = __exists_dev(pathname, sessname);
+ mutex_unlock(&sess_lock);
+
+ return found;
+}
+
+static bool insert_dev_if_not_exists_devpath(struct rnbd_clt_dev *dev)
+{
+ bool found;
+ struct rnbd_clt_session *sess = dev->sess;
+
+ mutex_lock(&sess_lock);
+ found = __exists_dev(dev->pathname, sess->sessname);
+ if (!found) {
+ mutex_lock(&sess->lock);
+ list_add_tail(&dev->list, &sess->devs_list);
+ mutex_unlock(&sess->lock);
+ }
+ mutex_unlock(&sess_lock);
+
+ return found;
+}
+
+static void delete_dev(struct rnbd_clt_dev *dev)
+{
+ struct rnbd_clt_session *sess = dev->sess;
+
+ mutex_lock(&sess->lock);
+ list_del(&dev->list);
+ mutex_unlock(&sess->lock);
+}
+
+struct rnbd_clt_dev *rnbd_clt_map_device(const char *sessname,
+ struct rtrs_addr *paths,
+ size_t path_cnt, u16 port_nr,
+ const char *pathname,
+ enum rnbd_access_mode access_mode,
+ u32 nr_poll_queues)
+{
+ struct rnbd_clt_session *sess;
+ struct rnbd_clt_dev *dev;
+ int ret, errno;
+ struct rnbd_msg_open_rsp *rsp;
+ struct rnbd_msg_open msg;
+ struct rnbd_iu *iu;
+ struct kvec vec = {
+ .iov_base = &msg,
+ .iov_len = sizeof(msg)
+ };
+
+ if (exists_devpath(pathname, sessname))
+ return ERR_PTR(-EEXIST);
+
+ sess = find_and_get_or_create_sess(sessname, paths, path_cnt, port_nr, nr_poll_queues);
+ if (IS_ERR(sess))
+ return ERR_CAST(sess);
+
+ dev = init_dev(sess, access_mode, pathname, nr_poll_queues);
+ if (IS_ERR(dev)) {
+ pr_err("map_device: failed to map device '%s' from session %s, can't initialize device, err: %ld\n",
+ pathname, sess->sessname, PTR_ERR(dev));
+ ret = PTR_ERR(dev);
+ goto put_sess;
+ }
+ if (insert_dev_if_not_exists_devpath(dev)) {
+ ret = -EEXIST;
+ goto put_dev;
+ }
+
+ rsp = kzalloc(sizeof(*rsp), GFP_KERNEL);
+ if (!rsp) {
+ ret = -ENOMEM;
+ goto del_dev;
+ }
+
+ iu = rnbd_get_iu(sess, RTRS_ADMIN_CON, RTRS_PERMIT_WAIT);
+ if (!iu) {
+ ret = -ENOMEM;
+ kfree(rsp);
+ goto del_dev;
+ }
+ iu->buf = rsp;
+ iu->dev = dev;
+ sg_init_one(iu->sgt.sgl, rsp, sizeof(*rsp));
+
+ msg.hdr.type = cpu_to_le16(RNBD_MSG_OPEN);
+ msg.access_mode = dev->access_mode;
+ strscpy(msg.dev_name, dev->pathname, sizeof(msg.dev_name));
+
+ WARN_ON(!rnbd_clt_get_dev(dev));
+ ret = send_usr_msg(sess->rtrs, READ, iu,
+ &vec, sizeof(*rsp), iu->sgt.sgl, 1,
+ msg_open_conf, &errno, RTRS_PERMIT_WAIT);
+ if (ret) {
+ rnbd_clt_put_dev(dev);
+ rnbd_put_iu(sess, iu);
+ } else {
+ ret = errno;
+ }
+ if (ret) {
+ rnbd_clt_err(dev,
+ "map_device: failed, can't open remote device, err: %d\n",
+ ret);
+ goto put_iu;
+ }
+ mutex_lock(&dev->lock);
+ pr_debug("Opened remote device: session=%s, path='%s'\n",
+ sess->sessname, pathname);
+ ret = rnbd_client_setup_device(dev, rsp);
+ if (ret) {
+ rnbd_clt_err(dev,
+ "map_device: Failed to configure device, err: %d\n",
+ ret);
+ mutex_unlock(&dev->lock);
+ goto send_close;
+ }
+
+ rnbd_clt_info(dev,
+ "map_device: Device mapped as %s (nsectors: %llu, logical_block_size: %d, physical_block_size: %d, max_discard_sectors: %d, discard_granularity: %d, discard_alignment: %d, secure_discard: %d, max_segments: %d, max_hw_sectors: %d, wc: %d, fua: %d)\n",
+ dev->gd->disk_name, le64_to_cpu(rsp->nsectors),
+ le16_to_cpu(rsp->logical_block_size),
+ le16_to_cpu(rsp->physical_block_size),
+ le32_to_cpu(rsp->max_discard_sectors),
+ le32_to_cpu(rsp->discard_granularity),
+ le32_to_cpu(rsp->discard_alignment),
+ le16_to_cpu(rsp->secure_discard),
+ sess->max_segments, sess->max_io_size / SECTOR_SIZE,
+ !!(rsp->cache_policy & RNBD_WRITEBACK),
+ !!(rsp->cache_policy & RNBD_FUA));
+
+ mutex_unlock(&dev->lock);
+ kfree(rsp);
+ rnbd_put_iu(sess, iu);
+ rnbd_clt_put_sess(sess);
+
+ return dev;
+
+send_close:
+ send_msg_close(dev, dev->device_id, RTRS_PERMIT_WAIT);
+put_iu:
+ kfree(rsp);
+ rnbd_put_iu(sess, iu);
+del_dev:
+ delete_dev(dev);
+put_dev:
+ rnbd_clt_put_dev(dev);
+put_sess:
+ rnbd_clt_put_sess(sess);
+
+ return ERR_PTR(ret);
+}
+
+static void destroy_gen_disk(struct rnbd_clt_dev *dev)
+{
+ del_gendisk(dev->gd);
+ put_disk(dev->gd);
+}
+
+static void destroy_sysfs(struct rnbd_clt_dev *dev,
+ const struct attribute *sysfs_self)
+{
+ rnbd_clt_remove_dev_symlink(dev);
+ if (dev->kobj.state_initialized) {
+ if (sysfs_self)
+ /* To avoid deadlock firstly remove itself */
+ sysfs_remove_file_self(&dev->kobj, sysfs_self);
+ kobject_del(&dev->kobj);
+ kobject_put(&dev->kobj);
+ }
+}
+
+int rnbd_clt_unmap_device(struct rnbd_clt_dev *dev, bool force,
+ const struct attribute *sysfs_self)
+{
+ struct rnbd_clt_session *sess = dev->sess;
+ int refcount, ret = 0;
+ bool was_mapped;
+
+ mutex_lock(&dev->lock);
+ if (dev->dev_state == DEV_STATE_UNMAPPED) {
+ rnbd_clt_info(dev, "Device is already being unmapped\n");
+ ret = -EALREADY;
+ goto err;
+ }
+ refcount = refcount_read(&dev->refcount);
+ if (!force && refcount > 1) {
+ rnbd_clt_err(dev,
+ "Closing device failed, device is in use, (%d device users)\n",
+ refcount - 1);
+ ret = -EBUSY;
+ goto err;
+ }
+ was_mapped = (dev->dev_state == DEV_STATE_MAPPED);
+ dev->dev_state = DEV_STATE_UNMAPPED;
+ mutex_unlock(&dev->lock);
+
+ delete_dev(dev);
+ destroy_sysfs(dev, sysfs_self);
+ destroy_gen_disk(dev);
+ if (was_mapped && sess->rtrs)
+ send_msg_close(dev, dev->device_id, RTRS_PERMIT_WAIT);
+
+ rnbd_clt_info(dev, "Device is unmapped\n");
+
+ /* Likely last reference put */
+ rnbd_clt_put_dev(dev);
+
+ /*
+ * Here device and session can be vanished!
+ */
+
+ return 0;
+err:
+ mutex_unlock(&dev->lock);
+
+ return ret;
+}
+
+int rnbd_clt_remap_device(struct rnbd_clt_dev *dev)
+{
+ int err;
+
+ mutex_lock(&dev->lock);
+ if (dev->dev_state == DEV_STATE_MAPPED_DISCONNECTED)
+ err = 0;
+ else if (dev->dev_state == DEV_STATE_UNMAPPED)
+ err = -ENODEV;
+ else if (dev->dev_state == DEV_STATE_MAPPED)
+ err = -EALREADY;
+ else
+ err = -EBUSY;
+ mutex_unlock(&dev->lock);
+ if (!err) {
+ rnbd_clt_info(dev, "Remapping device.\n");
+ err = send_msg_open(dev, RTRS_PERMIT_WAIT);
+ if (err)
+ rnbd_clt_err(dev, "remap_device: %d\n", err);
+ }
+
+ return err;
+}
+
+static void unmap_device_work(struct work_struct *work)
+{
+ struct rnbd_clt_dev *dev;
+
+ dev = container_of(work, typeof(*dev), unmap_on_rmmod_work);
+ rnbd_clt_unmap_device(dev, true, NULL);
+}
+
+static void rnbd_destroy_sessions(void)
+{
+ struct rnbd_clt_session *sess, *sn;
+ struct rnbd_clt_dev *dev, *tn;
+
+ /* Firstly forbid access through sysfs interface */
+ rnbd_clt_destroy_sysfs_files();
+
+ /*
+ * Here at this point there is no any concurrent access to sessions
+ * list and devices list:
+ * 1. New session or device can't be created - session sysfs files
+ * are removed.
+ * 2. Device or session can't be removed - module reference is taken
+ * into account in unmap device sysfs callback.
+ * 3. No IO requests inflight - each file open of block_dev increases
+ * module reference in get_disk().
+ *
+ * But still there can be user requests inflights, which are sent by
+ * asynchronous send_msg_*() functions, thus before unmapping devices
+ * RTRS session must be explicitly closed.
+ */
+
+ list_for_each_entry_safe(sess, sn, &sess_list, list) {
+ if (!rnbd_clt_get_sess(sess))
+ continue;
+ close_rtrs(sess);
+ list_for_each_entry_safe(dev, tn, &sess->devs_list, list) {
+ /*
+ * Here unmap happens in parallel for only one reason:
+ * del_gendisk() takes around half a second, so
+ * on huge amount of devices the whole module unload
+ * procedure takes minutes.
+ */
+ INIT_WORK(&dev->unmap_on_rmmod_work, unmap_device_work);
+ queue_work(rnbd_clt_wq, &dev->unmap_on_rmmod_work);
+ }
+ rnbd_clt_put_sess(sess);
+ }
+ /* Wait for all scheduled unmap works */
+ flush_workqueue(rnbd_clt_wq);
+ WARN_ON(!list_empty(&sess_list));
+}
+
+static int __init rnbd_client_init(void)
+{
+ int err = 0;
+
+ BUILD_BUG_ON(sizeof(struct rnbd_msg_hdr) != 4);
+ BUILD_BUG_ON(sizeof(struct rnbd_msg_sess_info) != 36);
+ BUILD_BUG_ON(sizeof(struct rnbd_msg_sess_info_rsp) != 36);
+ BUILD_BUG_ON(sizeof(struct rnbd_msg_open) != 264);
+ BUILD_BUG_ON(sizeof(struct rnbd_msg_close) != 8);
+ BUILD_BUG_ON(sizeof(struct rnbd_msg_open_rsp) != 56);
+ rnbd_client_major = register_blkdev(rnbd_client_major, "rnbd");
+ if (rnbd_client_major <= 0) {
+ pr_err("Failed to load module, block device registration failed\n");
+ return -EBUSY;
+ }
+
+ err = rnbd_clt_create_sysfs_files();
+ if (err) {
+ pr_err("Failed to load module, creating sysfs device files failed, err: %d\n",
+ err);
+ unregister_blkdev(rnbd_client_major, "rnbd");
+ return err;
+ }
+ rnbd_clt_wq = alloc_workqueue("rnbd_clt_wq", 0, 0);
+ if (!rnbd_clt_wq) {
+ pr_err("Failed to load module, alloc_workqueue failed.\n");
+ rnbd_clt_destroy_sysfs_files();
+ unregister_blkdev(rnbd_client_major, "rnbd");
+ err = -ENOMEM;
+ }
+
+ return err;
+}
+
+static void __exit rnbd_client_exit(void)
+{
+ rnbd_destroy_sessions();
+ unregister_blkdev(rnbd_client_major, "rnbd");
+ ida_destroy(&index_ida);
+ destroy_workqueue(rnbd_clt_wq);
+}
+
+module_init(rnbd_client_init);
+module_exit(rnbd_client_exit);
diff --git a/drivers/block/rnbd/rnbd-clt.h b/drivers/block/rnbd/rnbd-clt.h
new file mode 100644
index 000000000..a48e040ab
--- /dev/null
+++ b/drivers/block/rnbd/rnbd-clt.h
@@ -0,0 +1,151 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * RDMA Network Block Driver
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+
+#ifndef RNBD_CLT_H
+#define RNBD_CLT_H
+
+#include <linux/wait.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/blk-mq.h>
+#include <linux/refcount.h>
+
+#include <rtrs.h>
+#include "rnbd-proto.h"
+#include "rnbd-log.h"
+
+/* time in seconds between reconnect tries, default to 30 s */
+#define RECONNECT_DELAY 30
+/*
+ * Number of times to reconnect on error before giving up, 0 for * disabled,
+ * -1 for forever
+ */
+#define MAX_RECONNECTS -1
+
+enum rnbd_clt_dev_state {
+ DEV_STATE_INIT,
+ DEV_STATE_MAPPED,
+ DEV_STATE_MAPPED_DISCONNECTED,
+ DEV_STATE_UNMAPPED,
+};
+
+struct rnbd_iu_comp {
+ wait_queue_head_t wait;
+ int errno;
+};
+
+#ifdef CONFIG_ARCH_NO_SG_CHAIN
+#define RNBD_INLINE_SG_CNT 0
+#else
+#define RNBD_INLINE_SG_CNT 2
+#endif
+#define RNBD_RDMA_SGL_SIZE (sizeof(struct scatterlist) * RNBD_INLINE_SG_CNT)
+
+struct rnbd_iu {
+ union {
+ struct request *rq; /* for block io */
+ void *buf; /* for user messages */
+ };
+ struct rtrs_permit *permit;
+ union {
+ /* use to send msg associated with a dev */
+ struct rnbd_clt_dev *dev;
+ /* use to send msg associated with a sess */
+ struct rnbd_clt_session *sess;
+ };
+ struct sg_table sgt;
+ struct work_struct work;
+ int errno;
+ struct rnbd_iu_comp comp;
+ atomic_t refcount;
+ struct scatterlist first_sgl[]; /* must be the last one */
+};
+
+struct rnbd_cpu_qlist {
+ struct list_head requeue_list;
+ spinlock_t requeue_lock;
+ unsigned int cpu;
+};
+
+struct rnbd_clt_session {
+ struct list_head list;
+ struct rtrs_clt_sess *rtrs;
+ wait_queue_head_t rtrs_waitq;
+ bool rtrs_ready;
+ struct rnbd_cpu_qlist __percpu
+ *cpu_queues;
+ DECLARE_BITMAP(cpu_queues_bm, NR_CPUS);
+ int __percpu *cpu_rr; /* per-cpu var for CPU round-robin */
+ atomic_t busy;
+ size_t queue_depth;
+ u32 max_io_size;
+ u32 max_segments;
+ struct blk_mq_tag_set tag_set;
+ u32 nr_poll_queues;
+ struct mutex lock; /* protects state and devs_list */
+ struct list_head devs_list; /* list of struct rnbd_clt_dev */
+ refcount_t refcount;
+ char sessname[NAME_MAX];
+ u8 ver; /* protocol version */
+};
+
+/**
+ * Submission queues.
+ */
+struct rnbd_queue {
+ struct list_head requeue_list;
+ unsigned long in_list;
+ struct rnbd_clt_dev *dev;
+ struct blk_mq_hw_ctx *hctx;
+};
+
+struct rnbd_clt_dev {
+ struct kobject kobj;
+ struct rnbd_clt_session *sess;
+ struct request_queue *queue;
+ struct rnbd_queue *hw_queues;
+ u32 device_id;
+ /* local Idr index - used to track minor number allocations. */
+ u32 clt_device_id;
+ struct mutex lock;
+ enum rnbd_clt_dev_state dev_state;
+ refcount_t refcount;
+ char *pathname;
+ enum rnbd_access_mode access_mode;
+ u32 nr_poll_queues;
+ u64 size; /* device size in bytes */
+ struct list_head list;
+ struct gendisk *gd;
+ char *blk_symlink_name;
+ struct work_struct unmap_on_rmmod_work;
+};
+
+/* rnbd-clt.c */
+
+struct rnbd_clt_dev *rnbd_clt_map_device(const char *sessname,
+ struct rtrs_addr *paths,
+ size_t path_cnt, u16 port_nr,
+ const char *pathname,
+ enum rnbd_access_mode access_mode,
+ u32 nr_poll_queues);
+int rnbd_clt_unmap_device(struct rnbd_clt_dev *dev, bool force,
+ const struct attribute *sysfs_self);
+
+int rnbd_clt_remap_device(struct rnbd_clt_dev *dev);
+int rnbd_clt_resize_disk(struct rnbd_clt_dev *dev, sector_t newsize);
+
+/* rnbd-clt-sysfs.c */
+
+int rnbd_clt_create_sysfs_files(void);
+
+void rnbd_clt_destroy_sysfs_files(void);
+
+void rnbd_clt_remove_dev_symlink(struct rnbd_clt_dev *dev);
+
+#endif /* RNBD_CLT_H */
diff --git a/drivers/block/rnbd/rnbd-common.c b/drivers/block/rnbd/rnbd-common.c
new file mode 100644
index 000000000..596c3f732
--- /dev/null
+++ b/drivers/block/rnbd/rnbd-common.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RDMA Network Block Driver
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+#include "rnbd-proto.h"
+
+const char *rnbd_access_mode_str(enum rnbd_access_mode mode)
+{
+ switch (mode) {
+ case RNBD_ACCESS_RO:
+ return "ro";
+ case RNBD_ACCESS_RW:
+ return "rw";
+ case RNBD_ACCESS_MIGRATION:
+ return "migration";
+ default:
+ return "unknown";
+ }
+}
diff --git a/drivers/block/rnbd/rnbd-log.h b/drivers/block/rnbd/rnbd-log.h
new file mode 100644
index 000000000..136e7d6c3
--- /dev/null
+++ b/drivers/block/rnbd/rnbd-log.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * RDMA Network Block Driver
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+#ifndef RNBD_LOG_H
+#define RNBD_LOG_H
+
+#include "rnbd-clt.h"
+#include "rnbd-srv.h"
+
+#define rnbd_clt_log(fn, dev, fmt, ...) ( \
+ fn("<%s@%s> " fmt, (dev)->pathname, \
+ (dev)->sess->sessname, \
+ ##__VA_ARGS__))
+#define rnbd_srv_log(fn, dev, fmt, ...) ( \
+ fn("<%s@%s>: " fmt, (dev)->pathname, \
+ (dev)->sess->sessname, ##__VA_ARGS__))
+
+#define rnbd_clt_err(dev, fmt, ...) \
+ rnbd_clt_log(pr_err, dev, fmt, ##__VA_ARGS__)
+#define rnbd_clt_err_rl(dev, fmt, ...) \
+ rnbd_clt_log(pr_err_ratelimited, dev, fmt, ##__VA_ARGS__)
+#define rnbd_clt_info(dev, fmt, ...) \
+ rnbd_clt_log(pr_info, dev, fmt, ##__VA_ARGS__)
+#define rnbd_clt_info_rl(dev, fmt, ...) \
+ rnbd_clt_log(pr_info_ratelimited, dev, fmt, ##__VA_ARGS__)
+
+#define rnbd_srv_err(dev, fmt, ...) \
+ rnbd_srv_log(pr_err, dev, fmt, ##__VA_ARGS__)
+#define rnbd_srv_err_rl(dev, fmt, ...) \
+ rnbd_srv_log(pr_err_ratelimited, dev, fmt, ##__VA_ARGS__)
+#define rnbd_srv_info(dev, fmt, ...) \
+ rnbd_srv_log(pr_info, dev, fmt, ##__VA_ARGS__)
+#define rnbd_srv_info_rl(dev, fmt, ...) \
+ rnbd_srv_log(pr_info_ratelimited, dev, fmt, ##__VA_ARGS__)
+
+#endif /* RNBD_LOG_H */
diff --git a/drivers/block/rnbd/rnbd-proto.h b/drivers/block/rnbd/rnbd-proto.h
new file mode 100644
index 000000000..da1d0542d
--- /dev/null
+++ b/drivers/block/rnbd/rnbd-proto.h
@@ -0,0 +1,305 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * RDMA Network Block Driver
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+#ifndef RNBD_PROTO_H
+#define RNBD_PROTO_H
+
+#include <linux/types.h>
+#include <linux/blk-mq.h>
+#include <linux/limits.h>
+#include <linux/inet.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <rdma/ib.h>
+
+#define RNBD_PROTO_VER_MAJOR 2
+#define RNBD_PROTO_VER_MINOR 0
+
+/* The default port number the RTRS server is listening on. */
+#define RTRS_PORT 1234
+
+/**
+ * enum rnbd_msg_types - RNBD message types
+ * @RNBD_MSG_SESS_INFO: initial session info from client to server
+ * @RNBD_MSG_SESS_INFO_RSP: initial session info from server to client
+ * @RNBD_MSG_OPEN: open (map) device request
+ * @RNBD_MSG_OPEN_RSP: response to an @RNBD_MSG_OPEN
+ * @RNBD_MSG_IO: block IO request operation
+ * @RNBD_MSG_CLOSE: close (unmap) device request
+ */
+enum rnbd_msg_type {
+ RNBD_MSG_SESS_INFO,
+ RNBD_MSG_SESS_INFO_RSP,
+ RNBD_MSG_OPEN,
+ RNBD_MSG_OPEN_RSP,
+ RNBD_MSG_IO,
+ RNBD_MSG_CLOSE,
+};
+
+/**
+ * struct rnbd_msg_hdr - header of RNBD messages
+ * @type: Message type, valid values see: enum rnbd_msg_types
+ */
+struct rnbd_msg_hdr {
+ __le16 type;
+ __le16 __padding;
+};
+
+/**
+ * We allow to map RO many times and RW only once. We allow to map yet another
+ * time RW, if MIGRATION is provided (second RW export can be required for
+ * example for VM migration)
+ */
+enum rnbd_access_mode {
+ RNBD_ACCESS_RO,
+ RNBD_ACCESS_RW,
+ RNBD_ACCESS_MIGRATION,
+};
+
+/**
+ * struct rnbd_msg_sess_info - initial session info from client to server
+ * @hdr: message header
+ * @ver: RNBD protocol version
+ */
+struct rnbd_msg_sess_info {
+ struct rnbd_msg_hdr hdr;
+ u8 ver;
+ u8 reserved[31];
+};
+
+/**
+ * struct rnbd_msg_sess_info_rsp - initial session info from server to client
+ * @hdr: message header
+ * @ver: RNBD protocol version
+ */
+struct rnbd_msg_sess_info_rsp {
+ struct rnbd_msg_hdr hdr;
+ u8 ver;
+ u8 reserved[31];
+};
+
+/**
+ * struct rnbd_msg_open - request to open a remote device.
+ * @hdr: message header
+ * @access_mode: the mode to open remote device, valid values see:
+ * enum rnbd_access_mode
+ * @device_name: device path on remote side
+ */
+struct rnbd_msg_open {
+ struct rnbd_msg_hdr hdr;
+ u8 access_mode;
+ u8 resv1;
+ s8 dev_name[NAME_MAX];
+ u8 reserved[3];
+};
+
+/**
+ * struct rnbd_msg_close - request to close a remote device.
+ * @hdr: message header
+ * @device_id: device_id on server side to identify the device
+ */
+struct rnbd_msg_close {
+ struct rnbd_msg_hdr hdr;
+ __le32 device_id;
+};
+
+enum rnbd_cache_policy {
+ RNBD_FUA = 1 << 0,
+ RNBD_WRITEBACK = 1 << 1,
+};
+
+/**
+ * struct rnbd_msg_open_rsp - response message to RNBD_MSG_OPEN
+ * @hdr: message header
+ * @device_id: device_id on server side to identify the device
+ * @nsectors: number of sectors in the usual 512b unit
+ * @max_hw_sectors: max hardware sectors in the usual 512b unit
+ * @max_write_same_sectors: max sectors for WRITE SAME in the 512b unit
+ * @max_discard_sectors: max. sectors that can be discarded at once in 512b
+ * unit.
+ * @discard_granularity: size of the internal discard allocation unit in bytes
+ * @discard_alignment: offset from internal allocation assignment in bytes
+ * @physical_block_size: physical block size device supports in bytes
+ * @logical_block_size: logical block size device supports in bytes
+ * @max_segments: max segments hardware support in one transfer
+ * @secure_discard: supports secure discard
+ * @obsolete_rotational: obsolete, not in used.
+ * @cache_policy: support write-back caching or FUA?
+ */
+struct rnbd_msg_open_rsp {
+ struct rnbd_msg_hdr hdr;
+ __le32 device_id;
+ __le64 nsectors;
+ __le32 max_hw_sectors;
+ __le32 max_write_same_sectors;
+ __le32 max_discard_sectors;
+ __le32 discard_granularity;
+ __le32 discard_alignment;
+ __le16 physical_block_size;
+ __le16 logical_block_size;
+ __le16 max_segments;
+ __le16 secure_discard;
+ u8 obsolete_rotational;
+ u8 cache_policy;
+ u8 reserved[10];
+};
+
+/**
+ * struct rnbd_msg_io - message for I/O read/write
+ * @hdr: message header
+ * @device_id: device_id on server side to find the right device
+ * @sector: bi_sector attribute from struct bio
+ * @rw: valid values are defined in enum rnbd_io_flags
+ * @bi_size: number of bytes for I/O read/write
+ * @prio: priority
+ */
+struct rnbd_msg_io {
+ struct rnbd_msg_hdr hdr;
+ __le32 device_id;
+ __le64 sector;
+ __le32 rw;
+ __le32 bi_size;
+ __le16 prio;
+};
+
+#define RNBD_OP_BITS 8
+#define RNBD_OP_MASK ((1 << RNBD_OP_BITS) - 1)
+
+/**
+ * enum rnbd_io_flags - RNBD request types from rq_flag_bits
+ * @RNBD_OP_READ: read sectors from the device
+ * @RNBD_OP_WRITE: write sectors to the device
+ * @RNBD_OP_FLUSH: flush the volatile write cache
+ * @RNBD_OP_DISCARD: discard sectors
+ * @RNBD_OP_SECURE_ERASE: securely erase sectors
+ * @RNBD_OP_WRITE_SAME: write the same sectors many times
+
+ * @RNBD_F_SYNC: request is sync (sync write or read)
+ * @RNBD_F_FUA: forced unit access
+ */
+enum rnbd_io_flags {
+
+ /* Operations */
+
+ RNBD_OP_READ = 0,
+ RNBD_OP_WRITE = 1,
+ RNBD_OP_FLUSH = 2,
+ RNBD_OP_DISCARD = 3,
+ RNBD_OP_SECURE_ERASE = 4,
+ RNBD_OP_WRITE_SAME = 5,
+
+ RNBD_OP_LAST,
+
+ /* Flags */
+
+ RNBD_F_SYNC = 1<<(RNBD_OP_BITS + 0),
+ RNBD_F_FUA = 1<<(RNBD_OP_BITS + 1),
+
+ RNBD_F_ALL = (RNBD_F_SYNC | RNBD_F_FUA)
+
+};
+
+static inline u32 rnbd_op(u32 flags)
+{
+ return flags & RNBD_OP_MASK;
+}
+
+static inline u32 rnbd_flags(u32 flags)
+{
+ return flags & ~RNBD_OP_MASK;
+}
+
+static inline bool rnbd_flags_supported(u32 flags)
+{
+ u32 op;
+
+ op = rnbd_op(flags);
+ flags = rnbd_flags(flags);
+
+ if (op >= RNBD_OP_LAST)
+ return false;
+ if (flags & ~RNBD_F_ALL)
+ return false;
+
+ return true;
+}
+
+static inline blk_opf_t rnbd_to_bio_flags(u32 rnbd_opf)
+{
+ blk_opf_t bio_opf;
+
+ switch (rnbd_op(rnbd_opf)) {
+ case RNBD_OP_READ:
+ bio_opf = REQ_OP_READ;
+ break;
+ case RNBD_OP_WRITE:
+ bio_opf = REQ_OP_WRITE;
+ break;
+ case RNBD_OP_FLUSH:
+ bio_opf = REQ_OP_WRITE | REQ_PREFLUSH;
+ break;
+ case RNBD_OP_DISCARD:
+ bio_opf = REQ_OP_DISCARD;
+ break;
+ case RNBD_OP_SECURE_ERASE:
+ bio_opf = REQ_OP_SECURE_ERASE;
+ break;
+ default:
+ WARN(1, "Unknown RNBD type: %d (flags %d)\n",
+ rnbd_op(rnbd_opf), rnbd_opf);
+ bio_opf = 0;
+ }
+
+ if (rnbd_opf & RNBD_F_SYNC)
+ bio_opf |= REQ_SYNC;
+
+ if (rnbd_opf & RNBD_F_FUA)
+ bio_opf |= REQ_FUA;
+
+ return bio_opf;
+}
+
+static inline u32 rq_to_rnbd_flags(struct request *rq)
+{
+ u32 rnbd_opf;
+
+ switch (req_op(rq)) {
+ case REQ_OP_READ:
+ rnbd_opf = RNBD_OP_READ;
+ break;
+ case REQ_OP_WRITE:
+ rnbd_opf = RNBD_OP_WRITE;
+ break;
+ case REQ_OP_DISCARD:
+ rnbd_opf = RNBD_OP_DISCARD;
+ break;
+ case REQ_OP_SECURE_ERASE:
+ rnbd_opf = RNBD_OP_SECURE_ERASE;
+ break;
+ case REQ_OP_FLUSH:
+ rnbd_opf = RNBD_OP_FLUSH;
+ break;
+ default:
+ WARN(1, "Unknown request type %d (flags %llu)\n",
+ (__force u32)req_op(rq),
+ (__force unsigned long long)rq->cmd_flags);
+ rnbd_opf = 0;
+ }
+
+ if (op_is_sync(rq->cmd_flags))
+ rnbd_opf |= RNBD_F_SYNC;
+
+ if (op_is_flush(rq->cmd_flags))
+ rnbd_opf |= RNBD_F_FUA;
+
+ return rnbd_opf;
+}
+
+const char *rnbd_access_mode_str(enum rnbd_access_mode mode);
+
+#endif /* RNBD_PROTO_H */
diff --git a/drivers/block/rnbd/rnbd-srv-sysfs.c b/drivers/block/rnbd/rnbd-srv-sysfs.c
new file mode 100644
index 000000000..297a6924f
--- /dev/null
+++ b/drivers/block/rnbd/rnbd-srv-sysfs.c
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RDMA Network Block Driver
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+#undef pr_fmt
+#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
+
+#include <uapi/linux/limits.h>
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+#include <linux/stat.h>
+#include <linux/list.h>
+#include <linux/moduleparam.h>
+#include <linux/device.h>
+
+#include "rnbd-srv.h"
+
+static struct device *rnbd_dev;
+static struct class *rnbd_dev_class;
+static struct kobject *rnbd_devs_kobj;
+
+static void rnbd_srv_dev_release(struct kobject *kobj)
+{
+ struct rnbd_srv_dev *dev;
+
+ dev = container_of(kobj, struct rnbd_srv_dev, dev_kobj);
+
+ kfree(dev);
+}
+
+static struct kobj_type dev_ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+ .release = rnbd_srv_dev_release
+};
+
+int rnbd_srv_create_dev_sysfs(struct rnbd_srv_dev *dev,
+ struct block_device *bdev)
+{
+ struct kobject *bdev_kobj;
+ int ret;
+
+ ret = kobject_init_and_add(&dev->dev_kobj, &dev_ktype,
+ rnbd_devs_kobj, "%pg", bdev);
+ if (ret) {
+ kobject_put(&dev->dev_kobj);
+ return ret;
+ }
+
+ dev->dev_sessions_kobj = kobject_create_and_add("sessions",
+ &dev->dev_kobj);
+ if (!dev->dev_sessions_kobj) {
+ ret = -ENOMEM;
+ goto free_dev_kobj;
+ }
+
+ bdev_kobj = &disk_to_dev(bdev->bd_disk)->kobj;
+ ret = sysfs_create_link(&dev->dev_kobj, bdev_kobj, "block_dev");
+ if (ret)
+ goto put_sess_kobj;
+
+ return 0;
+
+put_sess_kobj:
+ kobject_put(dev->dev_sessions_kobj);
+free_dev_kobj:
+ kobject_del(&dev->dev_kobj);
+ kobject_put(&dev->dev_kobj);
+ return ret;
+}
+
+void rnbd_srv_destroy_dev_sysfs(struct rnbd_srv_dev *dev)
+{
+ sysfs_remove_link(&dev->dev_kobj, "block_dev");
+ kobject_del(dev->dev_sessions_kobj);
+ kobject_put(dev->dev_sessions_kobj);
+ kobject_del(&dev->dev_kobj);
+ kobject_put(&dev->dev_kobj);
+}
+
+static ssize_t read_only_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *page)
+{
+ struct rnbd_srv_sess_dev *sess_dev;
+
+ sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
+
+ return sysfs_emit(page, "%d\n",
+ !(sess_dev->open_flags & FMODE_WRITE));
+}
+
+static struct kobj_attribute rnbd_srv_dev_session_ro_attr =
+ __ATTR_RO(read_only);
+
+static ssize_t access_mode_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *page)
+{
+ struct rnbd_srv_sess_dev *sess_dev;
+
+ sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
+
+ return sysfs_emit(page, "%s\n",
+ rnbd_access_mode_str(sess_dev->access_mode));
+}
+
+static struct kobj_attribute rnbd_srv_dev_session_access_mode_attr =
+ __ATTR_RO(access_mode);
+
+static ssize_t mapping_path_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *page)
+{
+ struct rnbd_srv_sess_dev *sess_dev;
+
+ sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
+
+ return sysfs_emit(page, "%s\n", sess_dev->pathname);
+}
+
+static struct kobj_attribute rnbd_srv_dev_session_mapping_path_attr =
+ __ATTR_RO(mapping_path);
+
+static ssize_t rnbd_srv_dev_session_force_close_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *page)
+{
+ return sysfs_emit(page, "Usage: echo 1 > %s\n",
+ attr->attr.name);
+}
+
+static ssize_t rnbd_srv_dev_session_force_close_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct rnbd_srv_sess_dev *sess_dev;
+
+ sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
+
+ if (!sysfs_streq(buf, "1")) {
+ rnbd_srv_err(sess_dev, "%s: invalid value: '%s'\n",
+ attr->attr.name, buf);
+ return -EINVAL;
+ }
+
+ rnbd_srv_info(sess_dev, "force close requested\n");
+ rnbd_srv_sess_dev_force_close(sess_dev, attr);
+
+ return count;
+}
+
+static struct kobj_attribute rnbd_srv_dev_session_force_close_attr =
+ __ATTR(force_close, 0644,
+ rnbd_srv_dev_session_force_close_show,
+ rnbd_srv_dev_session_force_close_store);
+
+static struct attribute *rnbd_srv_default_dev_sessions_attrs[] = {
+ &rnbd_srv_dev_session_access_mode_attr.attr,
+ &rnbd_srv_dev_session_ro_attr.attr,
+ &rnbd_srv_dev_session_mapping_path_attr.attr,
+ &rnbd_srv_dev_session_force_close_attr.attr,
+ NULL,
+};
+
+static struct attribute_group rnbd_srv_default_dev_session_attr_group = {
+ .attrs = rnbd_srv_default_dev_sessions_attrs,
+};
+
+void rnbd_srv_destroy_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev)
+{
+ sysfs_remove_group(&sess_dev->kobj,
+ &rnbd_srv_default_dev_session_attr_group);
+
+ kobject_del(&sess_dev->kobj);
+ kobject_put(&sess_dev->kobj);
+}
+
+static void rnbd_srv_sess_dev_release(struct kobject *kobj)
+{
+ struct rnbd_srv_sess_dev *sess_dev;
+
+ sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
+ rnbd_destroy_sess_dev(sess_dev, sess_dev->keep_id);
+}
+
+static struct kobj_type rnbd_srv_sess_dev_ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+ .release = rnbd_srv_sess_dev_release,
+};
+
+int rnbd_srv_create_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev)
+{
+ int ret;
+
+ ret = kobject_init_and_add(&sess_dev->kobj, &rnbd_srv_sess_dev_ktype,
+ sess_dev->dev->dev_sessions_kobj, "%s",
+ sess_dev->sess->sessname);
+ if (ret) {
+ kobject_put(&sess_dev->kobj);
+ return ret;
+ }
+
+ ret = sysfs_create_group(&sess_dev->kobj,
+ &rnbd_srv_default_dev_session_attr_group);
+ if (ret) {
+ kobject_del(&sess_dev->kobj);
+ kobject_put(&sess_dev->kobj);
+ }
+
+ return ret;
+}
+
+int rnbd_srv_create_sysfs_files(void)
+{
+ int err;
+
+ rnbd_dev_class = class_create(THIS_MODULE, "rnbd-server");
+ if (IS_ERR(rnbd_dev_class))
+ return PTR_ERR(rnbd_dev_class);
+
+ rnbd_dev = device_create(rnbd_dev_class, NULL,
+ MKDEV(0, 0), NULL, "ctl");
+ if (IS_ERR(rnbd_dev)) {
+ err = PTR_ERR(rnbd_dev);
+ goto cls_destroy;
+ }
+ rnbd_devs_kobj = kobject_create_and_add("devices", &rnbd_dev->kobj);
+ if (!rnbd_devs_kobj) {
+ err = -ENOMEM;
+ goto dev_destroy;
+ }
+
+ return 0;
+
+dev_destroy:
+ device_destroy(rnbd_dev_class, MKDEV(0, 0));
+cls_destroy:
+ class_destroy(rnbd_dev_class);
+
+ return err;
+}
+
+void rnbd_srv_destroy_sysfs_files(void)
+{
+ kobject_del(rnbd_devs_kobj);
+ kobject_put(rnbd_devs_kobj);
+ device_destroy(rnbd_dev_class, MKDEV(0, 0));
+ class_destroy(rnbd_dev_class);
+}
diff --git a/drivers/block/rnbd/rnbd-srv-trace.c b/drivers/block/rnbd/rnbd-srv-trace.c
new file mode 100644
index 000000000..30f0895c1
--- /dev/null
+++ b/drivers/block/rnbd/rnbd-srv-trace.c
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * RDMA Network Block Driver
+ *
+ * Copyright (c) 2022 1&1 IONOS SE. All rights reserved.
+ */
+#include "rtrs.h"
+#include "rtrs-srv.h"
+#include "rnbd-srv.h"
+#include "rnbd-proto.h"
+
+/*
+ * We include this last to have the helpers above available for the trace
+ * event implementations.
+ */
+#define CREATE_TRACE_POINTS
+#include "rnbd-srv-trace.h"
diff --git a/drivers/block/rnbd/rnbd-srv-trace.h b/drivers/block/rnbd/rnbd-srv-trace.h
new file mode 100644
index 000000000..8dedf73bd
--- /dev/null
+++ b/drivers/block/rnbd/rnbd-srv-trace.h
@@ -0,0 +1,207 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * RDMA Network Block Driver
+ *
+ * Copyright (c) 2022 1&1 IONOS SE. All rights reserved.
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM rnbd_srv
+
+#if !defined(_TRACE_RNBD_SRV_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_RNBD_SRV_H
+
+#include <linux/tracepoint.h>
+
+struct rnbd_srv_session;
+struct rtrs_srv_op;
+
+DECLARE_EVENT_CLASS(rnbd_srv_link_class,
+ TP_PROTO(struct rnbd_srv_session *srv),
+
+ TP_ARGS(srv),
+
+ TP_STRUCT__entry(
+ __field(int, qdepth)
+ __string(sessname, srv->sessname)
+ ),
+
+ TP_fast_assign(
+ __entry->qdepth = srv->queue_depth;
+ __assign_str(sessname, srv->sessname);
+ ),
+
+ TP_printk("sessname: %s qdepth: %d",
+ __get_str(sessname),
+ __entry->qdepth
+ )
+);
+
+#define DEFINE_LINK_EVENT(name) \
+DEFINE_EVENT(rnbd_srv_link_class, name, \
+ TP_PROTO(struct rnbd_srv_session *srv), \
+ TP_ARGS(srv))
+
+DEFINE_LINK_EVENT(create_sess);
+DEFINE_LINK_EVENT(destroy_sess);
+
+TRACE_DEFINE_ENUM(RNBD_OP_READ);
+TRACE_DEFINE_ENUM(RNBD_OP_WRITE);
+TRACE_DEFINE_ENUM(RNBD_OP_FLUSH);
+TRACE_DEFINE_ENUM(RNBD_OP_DISCARD);
+TRACE_DEFINE_ENUM(RNBD_OP_SECURE_ERASE);
+TRACE_DEFINE_ENUM(RNBD_F_SYNC);
+TRACE_DEFINE_ENUM(RNBD_F_FUA);
+
+#define show_rnbd_rw_flags(x) \
+ __print_flags(x, "|", \
+ { RNBD_OP_READ, "READ" }, \
+ { RNBD_OP_WRITE, "WRITE" }, \
+ { RNBD_OP_FLUSH, "FLUSH" }, \
+ { RNBD_OP_DISCARD, "DISCARD" }, \
+ { RNBD_OP_SECURE_ERASE, "SECURE_ERASE" }, \
+ { RNBD_F_SYNC, "SYNC" }, \
+ { RNBD_F_FUA, "FUA" })
+
+TRACE_EVENT(process_rdma,
+ TP_PROTO(struct rnbd_srv_session *srv,
+ const struct rnbd_msg_io *msg,
+ struct rtrs_srv_op *id,
+ u32 datalen,
+ size_t usrlen),
+
+ TP_ARGS(srv, msg, id, datalen, usrlen),
+
+ TP_STRUCT__entry(
+ __string(sessname, srv->sessname)
+ __field(u8, dir)
+ __field(u8, ver)
+ __field(u32, device_id)
+ __field(u64, sector)
+ __field(u32, flags)
+ __field(u32, bi_size)
+ __field(u16, ioprio)
+ __field(u32, datalen)
+ __field(size_t, usrlen)
+ ),
+
+ TP_fast_assign(
+ __assign_str(sessname, srv->sessname);
+ __entry->dir = id->dir;
+ __entry->ver = srv->ver;
+ __entry->device_id = le32_to_cpu(msg->device_id);
+ __entry->sector = le64_to_cpu(msg->sector);
+ __entry->bi_size = le32_to_cpu(msg->bi_size);
+ __entry->flags = le32_to_cpu(msg->rw);
+ __entry->ioprio = le16_to_cpu(msg->prio);
+ __entry->datalen = datalen;
+ __entry->usrlen = usrlen;
+ ),
+
+ TP_printk("I/O req: sess: %s, type: %s, ver: %d, devid: %u, sector: %llu, bsize: %u, flags: %s, ioprio: %d, datalen: %u, usrlen: %zu",
+ __get_str(sessname),
+ __print_symbolic(__entry->dir,
+ { READ, "READ" },
+ { WRITE, "WRITE" }),
+ __entry->ver,
+ __entry->device_id,
+ __entry->sector,
+ __entry->bi_size,
+ show_rnbd_rw_flags(__entry->flags),
+ __entry->ioprio,
+ __entry->datalen,
+ __entry->usrlen
+ )
+);
+
+TRACE_EVENT(process_msg_sess_info,
+ TP_PROTO(struct rnbd_srv_session *srv,
+ const struct rnbd_msg_sess_info *msg),
+
+ TP_ARGS(srv, msg),
+
+ TP_STRUCT__entry(
+ __field(u8, proto_ver)
+ __field(u8, clt_ver)
+ __field(u8, srv_ver)
+ __string(sessname, srv->sessname)
+ ),
+
+ TP_fast_assign(
+ __entry->proto_ver = srv->ver;
+ __entry->clt_ver = msg->ver;
+ __entry->srv_ver = RNBD_PROTO_VER_MAJOR;
+ __assign_str(sessname, srv->sessname);
+ ),
+
+ TP_printk("Session %s using proto-ver %d (clt-ver: %d, srv-ver: %d)",
+ __get_str(sessname),
+ __entry->proto_ver,
+ __entry->clt_ver,
+ __entry->srv_ver
+ )
+);
+
+TRACE_DEFINE_ENUM(RNBD_ACCESS_RO);
+TRACE_DEFINE_ENUM(RNBD_ACCESS_RW);
+TRACE_DEFINE_ENUM(RNBD_ACCESS_MIGRATION);
+
+#define show_rnbd_access_mode(x) \
+ __print_symbolic(x, \
+ { RNBD_ACCESS_RO, "RO" }, \
+ { RNBD_ACCESS_RW, "RW" }, \
+ { RNBD_ACCESS_MIGRATION, "MIGRATION" })
+
+TRACE_EVENT(process_msg_open,
+ TP_PROTO(struct rnbd_srv_session *srv,
+ const struct rnbd_msg_open *msg),
+
+ TP_ARGS(srv, msg),
+
+ TP_STRUCT__entry(
+ __field(u8, access_mode)
+ __string(sessname, srv->sessname)
+ __string(dev_name, msg->dev_name)
+ ),
+
+ TP_fast_assign(
+ __entry->access_mode = msg->access_mode;
+ __assign_str(sessname, srv->sessname);
+ __assign_str(dev_name, msg->dev_name);
+ ),
+
+ TP_printk("Open message received: session='%s' path='%s' access_mode=%s",
+ __get_str(sessname),
+ __get_str(dev_name),
+ show_rnbd_access_mode(__entry->access_mode)
+ )
+);
+
+TRACE_EVENT(process_msg_close,
+ TP_PROTO(struct rnbd_srv_session *srv,
+ const struct rnbd_msg_close *msg),
+
+ TP_ARGS(srv, msg),
+
+ TP_STRUCT__entry(
+ __field(u32, device_id)
+ __string(sessname, srv->sessname)
+ ),
+
+ TP_fast_assign(
+ __entry->device_id = le32_to_cpu(msg->device_id);
+ __assign_str(sessname, srv->sessname);
+ ),
+
+ TP_printk("Close message received: session='%s' device id='%d'",
+ __get_str(sessname),
+ __entry->device_id
+ )
+);
+
+#endif /* _TRACE_RNBD_SRV_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE rnbd-srv-trace
+#include <trace/define_trace.h>
+
diff --git a/drivers/block/rnbd/rnbd-srv.c b/drivers/block/rnbd/rnbd-srv.c
new file mode 100644
index 000000000..2cfed2e58
--- /dev/null
+++ b/drivers/block/rnbd/rnbd-srv.c
@@ -0,0 +1,848 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RDMA Network Block Driver
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+#undef pr_fmt
+#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
+
+#include <linux/module.h>
+#include <linux/blkdev.h>
+
+#include "rnbd-srv.h"
+#include "rnbd-srv-trace.h"
+
+MODULE_DESCRIPTION("RDMA Network Block Device Server");
+MODULE_LICENSE("GPL");
+
+static u16 port_nr = RTRS_PORT;
+
+module_param_named(port_nr, port_nr, ushort, 0444);
+MODULE_PARM_DESC(port_nr,
+ "The port number the server is listening on (default: "
+ __stringify(RTRS_PORT)")");
+
+#define DEFAULT_DEV_SEARCH_PATH "/"
+
+static char dev_search_path[PATH_MAX] = DEFAULT_DEV_SEARCH_PATH;
+
+static int dev_search_path_set(const char *val, const struct kernel_param *kp)
+{
+ const char *p = strrchr(val, '\n') ? : val + strlen(val);
+
+ if (strlen(val) >= sizeof(dev_search_path))
+ return -EINVAL;
+
+ snprintf(dev_search_path, sizeof(dev_search_path), "%.*s",
+ (int)(p - val), val);
+
+ pr_info("dev_search_path changed to '%s'\n", dev_search_path);
+
+ return 0;
+}
+
+static struct kparam_string dev_search_path_kparam_str = {
+ .maxlen = sizeof(dev_search_path),
+ .string = dev_search_path
+};
+
+static const struct kernel_param_ops dev_search_path_ops = {
+ .set = dev_search_path_set,
+ .get = param_get_string,
+};
+
+module_param_cb(dev_search_path, &dev_search_path_ops,
+ &dev_search_path_kparam_str, 0444);
+MODULE_PARM_DESC(dev_search_path,
+ "Sets the dev_search_path. When a device is mapped this path is prepended to the device path from the map device operation. If %SESSNAME% is specified in a path, then device will be searched in a session namespace. (default: "
+ DEFAULT_DEV_SEARCH_PATH ")");
+
+static DEFINE_MUTEX(sess_lock);
+static DEFINE_SPINLOCK(dev_lock);
+
+static LIST_HEAD(sess_list);
+static LIST_HEAD(dev_list);
+
+struct rnbd_io_private {
+ struct rtrs_srv_op *id;
+ struct rnbd_srv_sess_dev *sess_dev;
+};
+
+static void rnbd_sess_dev_release(struct kref *kref)
+{
+ struct rnbd_srv_sess_dev *sess_dev;
+
+ sess_dev = container_of(kref, struct rnbd_srv_sess_dev, kref);
+ complete(sess_dev->destroy_comp);
+}
+
+static inline void rnbd_put_sess_dev(struct rnbd_srv_sess_dev *sess_dev)
+{
+ kref_put(&sess_dev->kref, rnbd_sess_dev_release);
+}
+
+static struct rnbd_srv_sess_dev *
+rnbd_get_sess_dev(int dev_id, struct rnbd_srv_session *srv_sess)
+{
+ struct rnbd_srv_sess_dev *sess_dev;
+ int ret = 0;
+
+ rcu_read_lock();
+ sess_dev = xa_load(&srv_sess->index_idr, dev_id);
+ if (sess_dev)
+ ret = kref_get_unless_zero(&sess_dev->kref);
+ rcu_read_unlock();
+
+ if (!sess_dev || !ret)
+ return ERR_PTR(-ENXIO);
+
+ return sess_dev;
+}
+
+static void rnbd_dev_bi_end_io(struct bio *bio)
+{
+ struct rnbd_io_private *rnbd_priv = bio->bi_private;
+ struct rnbd_srv_sess_dev *sess_dev = rnbd_priv->sess_dev;
+
+ rnbd_put_sess_dev(sess_dev);
+ rtrs_srv_resp_rdma(rnbd_priv->id, blk_status_to_errno(bio->bi_status));
+
+ kfree(rnbd_priv);
+ bio_put(bio);
+}
+
+static int process_rdma(struct rnbd_srv_session *srv_sess,
+ struct rtrs_srv_op *id, void *data, u32 datalen,
+ const void *usr, size_t usrlen)
+{
+ const struct rnbd_msg_io *msg = usr;
+ struct rnbd_io_private *priv;
+ struct rnbd_srv_sess_dev *sess_dev;
+ u32 dev_id;
+ int err;
+ struct bio *bio;
+ short prio;
+
+ trace_process_rdma(srv_sess, msg, id, datalen, usrlen);
+
+ priv = kmalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ dev_id = le32_to_cpu(msg->device_id);
+
+ sess_dev = rnbd_get_sess_dev(dev_id, srv_sess);
+ if (IS_ERR(sess_dev)) {
+ pr_err_ratelimited("Got I/O request on session %s for unknown device id %d\n",
+ srv_sess->sessname, dev_id);
+ err = -ENOTCONN;
+ goto err;
+ }
+
+ priv->sess_dev = sess_dev;
+ priv->id = id;
+
+ bio = bio_alloc(sess_dev->bdev, 1,
+ rnbd_to_bio_flags(le32_to_cpu(msg->rw)), GFP_KERNEL);
+ if (bio_add_page(bio, virt_to_page(data), datalen,
+ offset_in_page(data)) != datalen) {
+ rnbd_srv_err(sess_dev, "Failed to map data to bio\n");
+ err = -EINVAL;
+ goto bio_put;
+ }
+
+ bio->bi_end_io = rnbd_dev_bi_end_io;
+ bio->bi_private = priv;
+ bio->bi_iter.bi_sector = le64_to_cpu(msg->sector);
+ bio->bi_iter.bi_size = le32_to_cpu(msg->bi_size);
+ prio = srv_sess->ver < RNBD_PROTO_VER_MAJOR ||
+ usrlen < sizeof(*msg) ? 0 : le16_to_cpu(msg->prio);
+ bio_set_prio(bio, prio);
+
+ submit_bio(bio);
+
+ return 0;
+
+bio_put:
+ bio_put(bio);
+ rnbd_put_sess_dev(sess_dev);
+err:
+ kfree(priv);
+ return err;
+}
+
+static void destroy_device(struct kref *kref)
+{
+ struct rnbd_srv_dev *dev = container_of(kref, struct rnbd_srv_dev, kref);
+
+ WARN_ONCE(!list_empty(&dev->sess_dev_list),
+ "Device %s is being destroyed but still in use!\n",
+ dev->id);
+
+ spin_lock(&dev_lock);
+ list_del(&dev->list);
+ spin_unlock(&dev_lock);
+
+ mutex_destroy(&dev->lock);
+ if (dev->dev_kobj.state_in_sysfs)
+ /*
+ * Destroy kobj only if it was really created.
+ */
+ rnbd_srv_destroy_dev_sysfs(dev);
+ else
+ kfree(dev);
+}
+
+static void rnbd_put_srv_dev(struct rnbd_srv_dev *dev)
+{
+ kref_put(&dev->kref, destroy_device);
+}
+
+void rnbd_destroy_sess_dev(struct rnbd_srv_sess_dev *sess_dev, bool keep_id)
+{
+ DECLARE_COMPLETION_ONSTACK(dc);
+
+ if (keep_id)
+ /* free the resources for the id but don't */
+ /* allow to re-use the id itself because it */
+ /* is still used by the client */
+ xa_cmpxchg(&sess_dev->sess->index_idr, sess_dev->device_id,
+ sess_dev, NULL, 0);
+ else
+ xa_erase(&sess_dev->sess->index_idr, sess_dev->device_id);
+ synchronize_rcu();
+
+ sess_dev->destroy_comp = &dc;
+ rnbd_put_sess_dev(sess_dev);
+ wait_for_completion(&dc); /* wait for inflights to drop to zero */
+
+ blkdev_put(sess_dev->bdev, sess_dev->open_flags);
+ mutex_lock(&sess_dev->dev->lock);
+ list_del(&sess_dev->dev_list);
+ if (sess_dev->open_flags & FMODE_WRITE)
+ sess_dev->dev->open_write_cnt--;
+ mutex_unlock(&sess_dev->dev->lock);
+
+ rnbd_put_srv_dev(sess_dev->dev);
+
+ rnbd_srv_info(sess_dev, "Device closed\n");
+ kfree(sess_dev);
+}
+
+static void destroy_sess(struct rnbd_srv_session *srv_sess)
+{
+ struct rnbd_srv_sess_dev *sess_dev;
+ unsigned long index;
+
+ if (xa_empty(&srv_sess->index_idr))
+ goto out;
+
+ trace_destroy_sess(srv_sess);
+
+ mutex_lock(&srv_sess->lock);
+ xa_for_each(&srv_sess->index_idr, index, sess_dev)
+ rnbd_srv_destroy_dev_session_sysfs(sess_dev);
+ mutex_unlock(&srv_sess->lock);
+
+out:
+ xa_destroy(&srv_sess->index_idr);
+
+ pr_info("RTRS Session %s disconnected\n", srv_sess->sessname);
+
+ mutex_lock(&sess_lock);
+ list_del(&srv_sess->list);
+ mutex_unlock(&sess_lock);
+
+ mutex_destroy(&srv_sess->lock);
+ kfree(srv_sess);
+}
+
+static int create_sess(struct rtrs_srv_sess *rtrs)
+{
+ struct rnbd_srv_session *srv_sess;
+ char pathname[NAME_MAX];
+ int err;
+
+ err = rtrs_srv_get_path_name(rtrs, pathname, sizeof(pathname));
+ if (err) {
+ pr_err("rtrs_srv_get_path_name(%s): %d\n", pathname, err);
+
+ return err;
+ }
+ srv_sess = kzalloc(sizeof(*srv_sess), GFP_KERNEL);
+ if (!srv_sess)
+ return -ENOMEM;
+
+ srv_sess->queue_depth = rtrs_srv_get_queue_depth(rtrs);
+ xa_init_flags(&srv_sess->index_idr, XA_FLAGS_ALLOC);
+ mutex_init(&srv_sess->lock);
+ mutex_lock(&sess_lock);
+ list_add(&srv_sess->list, &sess_list);
+ mutex_unlock(&sess_lock);
+
+ srv_sess->rtrs = rtrs;
+ strscpy(srv_sess->sessname, pathname, sizeof(srv_sess->sessname));
+
+ rtrs_srv_set_sess_priv(rtrs, srv_sess);
+
+ trace_create_sess(srv_sess);
+
+ return 0;
+}
+
+static int rnbd_srv_link_ev(struct rtrs_srv_sess *rtrs,
+ enum rtrs_srv_link_ev ev, void *priv)
+{
+ struct rnbd_srv_session *srv_sess = priv;
+
+ switch (ev) {
+ case RTRS_SRV_LINK_EV_CONNECTED:
+ return create_sess(rtrs);
+
+ case RTRS_SRV_LINK_EV_DISCONNECTED:
+ if (WARN_ON_ONCE(!srv_sess))
+ return -EINVAL;
+
+ destroy_sess(srv_sess);
+ return 0;
+
+ default:
+ pr_warn("Received unknown RTRS session event %d from session %s\n",
+ ev, srv_sess->sessname);
+ return -EINVAL;
+ }
+}
+
+void rnbd_srv_sess_dev_force_close(struct rnbd_srv_sess_dev *sess_dev,
+ struct kobj_attribute *attr)
+{
+ struct rnbd_srv_session *sess = sess_dev->sess;
+
+ /* It is already started to close by client's close message. */
+ if (!mutex_trylock(&sess->lock))
+ return;
+
+ sess_dev->keep_id = true;
+ /* first remove sysfs itself to avoid deadlock */
+ sysfs_remove_file_self(&sess_dev->kobj, &attr->attr);
+ rnbd_srv_destroy_dev_session_sysfs(sess_dev);
+ mutex_unlock(&sess->lock);
+}
+
+static void process_msg_close(struct rnbd_srv_session *srv_sess,
+ void *data, size_t datalen, const void *usr,
+ size_t usrlen)
+{
+ const struct rnbd_msg_close *close_msg = usr;
+ struct rnbd_srv_sess_dev *sess_dev;
+
+ trace_process_msg_close(srv_sess, close_msg);
+
+ sess_dev = rnbd_get_sess_dev(le32_to_cpu(close_msg->device_id),
+ srv_sess);
+ if (IS_ERR(sess_dev))
+ return;
+
+ rnbd_put_sess_dev(sess_dev);
+ mutex_lock(&srv_sess->lock);
+ rnbd_srv_destroy_dev_session_sysfs(sess_dev);
+ mutex_unlock(&srv_sess->lock);
+}
+
+static int process_msg_open(struct rnbd_srv_session *srv_sess,
+ const void *msg, size_t len,
+ void *data, size_t datalen);
+
+static int process_msg_sess_info(struct rnbd_srv_session *srv_sess,
+ const void *msg, size_t len,
+ void *data, size_t datalen);
+
+static int rnbd_srv_rdma_ev(void *priv, struct rtrs_srv_op *id,
+ void *data, size_t datalen,
+ const void *usr, size_t usrlen)
+{
+ struct rnbd_srv_session *srv_sess = priv;
+ const struct rnbd_msg_hdr *hdr = usr;
+ int ret = 0;
+ u16 type;
+
+ if (WARN_ON_ONCE(!srv_sess))
+ return -ENODEV;
+
+ type = le16_to_cpu(hdr->type);
+
+ switch (type) {
+ case RNBD_MSG_IO:
+ return process_rdma(srv_sess, id, data, datalen, usr, usrlen);
+ case RNBD_MSG_CLOSE:
+ process_msg_close(srv_sess, data, datalen, usr, usrlen);
+ break;
+ case RNBD_MSG_OPEN:
+ ret = process_msg_open(srv_sess, usr, usrlen, data, datalen);
+ break;
+ case RNBD_MSG_SESS_INFO:
+ ret = process_msg_sess_info(srv_sess, usr, usrlen, data,
+ datalen);
+ break;
+ default:
+ pr_warn("Received unexpected message type %d from session %s\n",
+ type, srv_sess->sessname);
+ return -EINVAL;
+ }
+
+ /*
+ * Since ret is passed to rtrs to handle the failure case, we
+ * just return 0 at the end otherwise callers in rtrs would call
+ * send_io_resp_imm again to print redundant err message.
+ */
+ rtrs_srv_resp_rdma(id, ret);
+ return 0;
+}
+
+static struct rnbd_srv_sess_dev
+*rnbd_sess_dev_alloc(struct rnbd_srv_session *srv_sess)
+{
+ struct rnbd_srv_sess_dev *sess_dev;
+ int error;
+
+ sess_dev = kzalloc(sizeof(*sess_dev), GFP_KERNEL);
+ if (!sess_dev)
+ return ERR_PTR(-ENOMEM);
+
+ error = xa_alloc(&srv_sess->index_idr, &sess_dev->device_id, sess_dev,
+ xa_limit_32b, GFP_NOWAIT);
+ if (error < 0) {
+ pr_warn("Allocating idr failed, err: %d\n", error);
+ kfree(sess_dev);
+ return ERR_PTR(error);
+ }
+
+ return sess_dev;
+}
+
+static struct rnbd_srv_dev *rnbd_srv_init_srv_dev(struct block_device *bdev)
+{
+ struct rnbd_srv_dev *dev;
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return ERR_PTR(-ENOMEM);
+
+ snprintf(dev->id, sizeof(dev->id), "%pg", bdev);
+ kref_init(&dev->kref);
+ INIT_LIST_HEAD(&dev->sess_dev_list);
+ mutex_init(&dev->lock);
+
+ return dev;
+}
+
+static struct rnbd_srv_dev *
+rnbd_srv_find_or_add_srv_dev(struct rnbd_srv_dev *new_dev)
+{
+ struct rnbd_srv_dev *dev;
+
+ spin_lock(&dev_lock);
+ list_for_each_entry(dev, &dev_list, list) {
+ if (!strncmp(dev->id, new_dev->id, sizeof(dev->id))) {
+ if (!kref_get_unless_zero(&dev->kref))
+ /*
+ * We lost the race, device is almost dead.
+ * Continue traversing to find a valid one.
+ */
+ continue;
+ spin_unlock(&dev_lock);
+ return dev;
+ }
+ }
+ list_add(&new_dev->list, &dev_list);
+ spin_unlock(&dev_lock);
+
+ return new_dev;
+}
+
+static int rnbd_srv_check_update_open_perm(struct rnbd_srv_dev *srv_dev,
+ struct rnbd_srv_session *srv_sess,
+ enum rnbd_access_mode access_mode)
+{
+ int ret = -EPERM;
+
+ mutex_lock(&srv_dev->lock);
+
+ switch (access_mode) {
+ case RNBD_ACCESS_RO:
+ ret = 0;
+ break;
+ case RNBD_ACCESS_RW:
+ if (srv_dev->open_write_cnt == 0) {
+ srv_dev->open_write_cnt++;
+ ret = 0;
+ } else {
+ pr_err("Mapping device '%s' for session %s with RW permissions failed. Device already opened as 'RW' by %d client(s), access mode %s.\n",
+ srv_dev->id, srv_sess->sessname,
+ srv_dev->open_write_cnt,
+ rnbd_access_mode_str(access_mode));
+ }
+ break;
+ case RNBD_ACCESS_MIGRATION:
+ if (srv_dev->open_write_cnt < 2) {
+ srv_dev->open_write_cnt++;
+ ret = 0;
+ } else {
+ pr_err("Mapping device '%s' for session %s with migration permissions failed. Device already opened as 'RW' by %d client(s), access mode %s.\n",
+ srv_dev->id, srv_sess->sessname,
+ srv_dev->open_write_cnt,
+ rnbd_access_mode_str(access_mode));
+ }
+ break;
+ default:
+ pr_err("Received mapping request for device '%s' on session %s with invalid access mode: %d\n",
+ srv_dev->id, srv_sess->sessname, access_mode);
+ ret = -EINVAL;
+ }
+
+ mutex_unlock(&srv_dev->lock);
+
+ return ret;
+}
+
+static struct rnbd_srv_dev *
+rnbd_srv_get_or_create_srv_dev(struct block_device *bdev,
+ struct rnbd_srv_session *srv_sess,
+ enum rnbd_access_mode access_mode)
+{
+ int ret;
+ struct rnbd_srv_dev *new_dev, *dev;
+
+ new_dev = rnbd_srv_init_srv_dev(bdev);
+ if (IS_ERR(new_dev))
+ return new_dev;
+
+ dev = rnbd_srv_find_or_add_srv_dev(new_dev);
+ if (dev != new_dev)
+ kfree(new_dev);
+
+ ret = rnbd_srv_check_update_open_perm(dev, srv_sess, access_mode);
+ if (ret) {
+ rnbd_put_srv_dev(dev);
+ return ERR_PTR(ret);
+ }
+
+ return dev;
+}
+
+static void rnbd_srv_fill_msg_open_rsp(struct rnbd_msg_open_rsp *rsp,
+ struct rnbd_srv_sess_dev *sess_dev)
+{
+ struct block_device *bdev = sess_dev->bdev;
+
+ rsp->hdr.type = cpu_to_le16(RNBD_MSG_OPEN_RSP);
+ rsp->device_id = cpu_to_le32(sess_dev->device_id);
+ rsp->nsectors = cpu_to_le64(bdev_nr_sectors(bdev));
+ rsp->logical_block_size = cpu_to_le16(bdev_logical_block_size(bdev));
+ rsp->physical_block_size = cpu_to_le16(bdev_physical_block_size(bdev));
+ rsp->max_segments = cpu_to_le16(bdev_max_segments(bdev));
+ rsp->max_hw_sectors =
+ cpu_to_le32(queue_max_hw_sectors(bdev_get_queue(bdev)));
+ rsp->max_write_same_sectors = 0;
+ rsp->max_discard_sectors = cpu_to_le32(bdev_max_discard_sectors(bdev));
+ rsp->discard_granularity = cpu_to_le32(bdev_discard_granularity(bdev));
+ rsp->discard_alignment = cpu_to_le32(bdev_discard_alignment(bdev));
+ rsp->secure_discard = cpu_to_le16(bdev_max_secure_erase_sectors(bdev));
+ rsp->cache_policy = 0;
+ if (bdev_write_cache(bdev))
+ rsp->cache_policy |= RNBD_WRITEBACK;
+ if (bdev_fua(bdev))
+ rsp->cache_policy |= RNBD_FUA;
+}
+
+static struct rnbd_srv_sess_dev *
+rnbd_srv_create_set_sess_dev(struct rnbd_srv_session *srv_sess,
+ const struct rnbd_msg_open *open_msg,
+ struct block_device *bdev, fmode_t open_flags,
+ struct rnbd_srv_dev *srv_dev)
+{
+ struct rnbd_srv_sess_dev *sdev = rnbd_sess_dev_alloc(srv_sess);
+
+ if (IS_ERR(sdev))
+ return sdev;
+
+ kref_init(&sdev->kref);
+
+ strscpy(sdev->pathname, open_msg->dev_name, sizeof(sdev->pathname));
+
+ sdev->bdev = bdev;
+ sdev->sess = srv_sess;
+ sdev->dev = srv_dev;
+ sdev->open_flags = open_flags;
+ sdev->access_mode = open_msg->access_mode;
+
+ return sdev;
+}
+
+static char *rnbd_srv_get_full_path(struct rnbd_srv_session *srv_sess,
+ const char *dev_name)
+{
+ char *full_path;
+ char *a, *b;
+
+ full_path = kmalloc(PATH_MAX, GFP_KERNEL);
+ if (!full_path)
+ return ERR_PTR(-ENOMEM);
+
+ /*
+ * Replace %SESSNAME% with a real session name in order to
+ * create device namespace.
+ */
+ a = strnstr(dev_search_path, "%SESSNAME%", sizeof(dev_search_path));
+ if (a) {
+ int len = a - dev_search_path;
+
+ len = snprintf(full_path, PATH_MAX, "%.*s/%s/%s", len,
+ dev_search_path, srv_sess->sessname, dev_name);
+ if (len >= PATH_MAX) {
+ pr_err("Too long path: %s, %s, %s\n",
+ dev_search_path, srv_sess->sessname, dev_name);
+ kfree(full_path);
+ return ERR_PTR(-EINVAL);
+ }
+ } else {
+ snprintf(full_path, PATH_MAX, "%s/%s",
+ dev_search_path, dev_name);
+ }
+
+ /* eliminitate duplicated slashes */
+ a = strchr(full_path, '/');
+ b = a;
+ while (*b != '\0') {
+ if (*b == '/' && *a == '/') {
+ b++;
+ } else {
+ a++;
+ *a = *b;
+ b++;
+ }
+ }
+ a++;
+ *a = '\0';
+
+ return full_path;
+}
+
+static int process_msg_sess_info(struct rnbd_srv_session *srv_sess,
+ const void *msg, size_t len,
+ void *data, size_t datalen)
+{
+ const struct rnbd_msg_sess_info *sess_info_msg = msg;
+ struct rnbd_msg_sess_info_rsp *rsp = data;
+
+ srv_sess->ver = min_t(u8, sess_info_msg->ver, RNBD_PROTO_VER_MAJOR);
+
+ trace_process_msg_sess_info(srv_sess, sess_info_msg);
+
+ rsp->hdr.type = cpu_to_le16(RNBD_MSG_SESS_INFO_RSP);
+ rsp->ver = srv_sess->ver;
+
+ return 0;
+}
+
+/**
+ * find_srv_sess_dev() - a dev is already opened by this name
+ * @srv_sess: the session to search.
+ * @dev_name: string containing the name of the device.
+ *
+ * Return struct rnbd_srv_sess_dev if srv_sess already opened the dev_name
+ * NULL if the session didn't open the device yet.
+ */
+static struct rnbd_srv_sess_dev *
+find_srv_sess_dev(struct rnbd_srv_session *srv_sess, const char *dev_name)
+{
+ struct rnbd_srv_sess_dev *sess_dev;
+ unsigned long index;
+
+ if (xa_empty(&srv_sess->index_idr))
+ return NULL;
+
+ xa_for_each(&srv_sess->index_idr, index, sess_dev)
+ if (!strcmp(sess_dev->pathname, dev_name))
+ return sess_dev;
+
+ return NULL;
+}
+
+static int process_msg_open(struct rnbd_srv_session *srv_sess,
+ const void *msg, size_t len,
+ void *data, size_t datalen)
+{
+ int ret;
+ struct rnbd_srv_dev *srv_dev;
+ struct rnbd_srv_sess_dev *srv_sess_dev;
+ const struct rnbd_msg_open *open_msg = msg;
+ struct block_device *bdev;
+ fmode_t open_flags;
+ char *full_path;
+ struct rnbd_msg_open_rsp *rsp = data;
+
+ trace_process_msg_open(srv_sess, open_msg);
+
+ open_flags = FMODE_READ;
+ if (open_msg->access_mode != RNBD_ACCESS_RO)
+ open_flags |= FMODE_WRITE;
+
+ mutex_lock(&srv_sess->lock);
+
+ srv_sess_dev = find_srv_sess_dev(srv_sess, open_msg->dev_name);
+ if (srv_sess_dev)
+ goto fill_response;
+
+ if ((strlen(dev_search_path) + strlen(open_msg->dev_name))
+ >= PATH_MAX) {
+ pr_err("Opening device for session %s failed, device path too long. '%s/%s' is longer than PATH_MAX (%d)\n",
+ srv_sess->sessname, dev_search_path, open_msg->dev_name,
+ PATH_MAX);
+ ret = -EINVAL;
+ goto reject;
+ }
+ if (strstr(open_msg->dev_name, "..")) {
+ pr_err("Opening device for session %s failed, device path %s contains relative path ..\n",
+ srv_sess->sessname, open_msg->dev_name);
+ ret = -EINVAL;
+ goto reject;
+ }
+ full_path = rnbd_srv_get_full_path(srv_sess, open_msg->dev_name);
+ if (IS_ERR(full_path)) {
+ ret = PTR_ERR(full_path);
+ pr_err("Opening device '%s' for client %s failed, failed to get device full path, err: %d\n",
+ open_msg->dev_name, srv_sess->sessname, ret);
+ goto reject;
+ }
+
+ bdev = blkdev_get_by_path(full_path, open_flags, THIS_MODULE);
+ if (IS_ERR(bdev)) {
+ ret = PTR_ERR(bdev);
+ pr_err("Opening device '%s' on session %s failed, failed to open the block device, err: %d\n",
+ full_path, srv_sess->sessname, ret);
+ goto free_path;
+ }
+
+ srv_dev = rnbd_srv_get_or_create_srv_dev(bdev, srv_sess,
+ open_msg->access_mode);
+ if (IS_ERR(srv_dev)) {
+ pr_err("Opening device '%s' on session %s failed, creating srv_dev failed, err: %ld\n",
+ full_path, srv_sess->sessname, PTR_ERR(srv_dev));
+ ret = PTR_ERR(srv_dev);
+ goto blkdev_put;
+ }
+
+ srv_sess_dev = rnbd_srv_create_set_sess_dev(srv_sess, open_msg,
+ bdev, open_flags,
+ srv_dev);
+ if (IS_ERR(srv_sess_dev)) {
+ pr_err("Opening device '%s' on session %s failed, creating sess_dev failed, err: %ld\n",
+ full_path, srv_sess->sessname, PTR_ERR(srv_sess_dev));
+ ret = PTR_ERR(srv_sess_dev);
+ goto srv_dev_put;
+ }
+
+ /* Create the srv_dev sysfs files if they haven't been created yet. The
+ * reason to delay the creation is not to create the sysfs files before
+ * we are sure the device can be opened.
+ */
+ mutex_lock(&srv_dev->lock);
+ if (!srv_dev->dev_kobj.state_in_sysfs) {
+ ret = rnbd_srv_create_dev_sysfs(srv_dev, bdev);
+ if (ret) {
+ mutex_unlock(&srv_dev->lock);
+ rnbd_srv_err(srv_sess_dev,
+ "Opening device failed, failed to create device sysfs files, err: %d\n",
+ ret);
+ goto free_srv_sess_dev;
+ }
+ }
+
+ ret = rnbd_srv_create_dev_session_sysfs(srv_sess_dev);
+ if (ret) {
+ mutex_unlock(&srv_dev->lock);
+ rnbd_srv_err(srv_sess_dev,
+ "Opening device failed, failed to create dev client sysfs files, err: %d\n",
+ ret);
+ goto free_srv_sess_dev;
+ }
+
+ list_add(&srv_sess_dev->dev_list, &srv_dev->sess_dev_list);
+ mutex_unlock(&srv_dev->lock);
+
+ rnbd_srv_info(srv_sess_dev, "Opened device '%s'\n", srv_dev->id);
+
+ kfree(full_path);
+
+fill_response:
+ rnbd_srv_fill_msg_open_rsp(rsp, srv_sess_dev);
+ mutex_unlock(&srv_sess->lock);
+ return 0;
+
+free_srv_sess_dev:
+ xa_erase(&srv_sess->index_idr, srv_sess_dev->device_id);
+ synchronize_rcu();
+ kfree(srv_sess_dev);
+srv_dev_put:
+ if (open_msg->access_mode != RNBD_ACCESS_RO) {
+ mutex_lock(&srv_dev->lock);
+ srv_dev->open_write_cnt--;
+ mutex_unlock(&srv_dev->lock);
+ }
+ rnbd_put_srv_dev(srv_dev);
+blkdev_put:
+ blkdev_put(bdev, open_flags);
+free_path:
+ kfree(full_path);
+reject:
+ mutex_unlock(&srv_sess->lock);
+ return ret;
+}
+
+static struct rtrs_srv_ctx *rtrs_ctx;
+
+static struct rtrs_srv_ops rtrs_ops;
+static int __init rnbd_srv_init_module(void)
+{
+ int err;
+
+ BUILD_BUG_ON(sizeof(struct rnbd_msg_hdr) != 4);
+ BUILD_BUG_ON(sizeof(struct rnbd_msg_sess_info) != 36);
+ BUILD_BUG_ON(sizeof(struct rnbd_msg_sess_info_rsp) != 36);
+ BUILD_BUG_ON(sizeof(struct rnbd_msg_open) != 264);
+ BUILD_BUG_ON(sizeof(struct rnbd_msg_close) != 8);
+ BUILD_BUG_ON(sizeof(struct rnbd_msg_open_rsp) != 56);
+ rtrs_ops = (struct rtrs_srv_ops) {
+ .rdma_ev = rnbd_srv_rdma_ev,
+ .link_ev = rnbd_srv_link_ev,
+ };
+ rtrs_ctx = rtrs_srv_open(&rtrs_ops, port_nr);
+ if (IS_ERR(rtrs_ctx)) {
+ err = PTR_ERR(rtrs_ctx);
+ pr_err("rtrs_srv_open(), err: %d\n", err);
+ return err;
+ }
+
+ err = rnbd_srv_create_sysfs_files();
+ if (err) {
+ pr_err("rnbd_srv_create_sysfs_files(), err: %d\n", err);
+ rtrs_srv_close(rtrs_ctx);
+ return err;
+ }
+
+ return 0;
+}
+
+static void __exit rnbd_srv_cleanup_module(void)
+{
+ rtrs_srv_close(rtrs_ctx);
+ WARN_ON(!list_empty(&sess_list));
+ rnbd_srv_destroy_sysfs_files();
+}
+
+module_init(rnbd_srv_init_module);
+module_exit(rnbd_srv_cleanup_module);
diff --git a/drivers/block/rnbd/rnbd-srv.h b/drivers/block/rnbd/rnbd-srv.h
new file mode 100644
index 000000000..f5962fd31
--- /dev/null
+++ b/drivers/block/rnbd/rnbd-srv.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * RDMA Network Block Driver
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+#ifndef RNBD_SRV_H
+#define RNBD_SRV_H
+
+#include <linux/types.h>
+#include <linux/idr.h>
+#include <linux/kref.h>
+
+#include <rtrs.h>
+#include "rnbd-proto.h"
+#include "rnbd-log.h"
+
+struct rnbd_srv_session {
+ /* Entry inside global sess_list */
+ struct list_head list;
+ struct rtrs_srv_sess *rtrs;
+ char sessname[NAME_MAX];
+ int queue_depth;
+
+ struct xarray index_idr;
+ struct mutex lock;
+ u8 ver;
+};
+
+struct rnbd_srv_dev {
+ /* Entry inside global dev_list */
+ struct list_head list;
+ struct kobject dev_kobj;
+ struct kobject *dev_sessions_kobj;
+ struct kref kref;
+ char id[NAME_MAX];
+ /* List of rnbd_srv_sess_dev structs */
+ struct list_head sess_dev_list;
+ struct mutex lock;
+ int open_write_cnt;
+};
+
+/* Structure which binds N devices and N sessions */
+struct rnbd_srv_sess_dev {
+ /* Entry inside rnbd_srv_dev struct */
+ struct list_head dev_list;
+ struct block_device *bdev;
+ struct rnbd_srv_session *sess;
+ struct rnbd_srv_dev *dev;
+ struct kobject kobj;
+ u32 device_id;
+ bool keep_id;
+ fmode_t open_flags;
+ struct kref kref;
+ struct completion *destroy_comp;
+ char pathname[NAME_MAX];
+ enum rnbd_access_mode access_mode;
+};
+
+void rnbd_srv_sess_dev_force_close(struct rnbd_srv_sess_dev *sess_dev,
+ struct kobj_attribute *attr);
+/* rnbd-srv-sysfs.c */
+
+int rnbd_srv_create_dev_sysfs(struct rnbd_srv_dev *dev,
+ struct block_device *bdev);
+void rnbd_srv_destroy_dev_sysfs(struct rnbd_srv_dev *dev);
+int rnbd_srv_create_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev);
+void rnbd_srv_destroy_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev);
+int rnbd_srv_create_sysfs_files(void);
+void rnbd_srv_destroy_sysfs_files(void);
+void rnbd_destroy_sess_dev(struct rnbd_srv_sess_dev *sess_dev, bool keep_id);
+
+#endif /* RNBD_SRV_H */