Resguardo inicial

linux-7.2.3/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.

linux-7.2.3/drivers/block/rnbd/Makefile

@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+ccflags-y := -I$(srctree)/drivers/infiniband/ulp/rtrs
+
+rnbd-client-y := rnbd-clt.o \
+		  rnbd-clt-sysfs.o
+
+CFLAGS_rnbd-srv-trace.o = -I$(src)
+
+rnbd-server-y := 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

linux-7.2.3/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>

linux-7.2.3/drivers/block/rnbd/rnbd-clt-sysfs.c

@@ -0,0 +1,693 @@
+// 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 const struct class rnbd_dev_class = {
+	.name = "rnbd-client",
+};
+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_modes[dev->access_mode].str);
+}
+
+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 void rnbd_dev_release(struct kobject *kobj)
+{
+	struct rnbd_clt_dev *dev = container_of(kobj, struct rnbd_clt_dev, kobj);
+
+	kfree(dev);
+}
+
+static const struct kobj_type rnbd_dev_ktype = {
+	.sysfs_ops      = &kobj_sysfs_ops,
+	.default_groups = rnbd_dev_groups,
+	.release	= rnbd_dev_release,
+};
+
+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 = kzalloc_objs(*addrs, ARRAY_SIZE(paths) * 2);
+	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_modes[access_mode].str,
+		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;
+
+	err = class_register(&rnbd_dev_class);
+	if (err)
+		return err;
+
+	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_unregister(&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_unregister(&rnbd_dev_class);
+}

linux-7.2.3/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. */
+	int			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 */

linux-7.2.3/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 */

linux-7.2.3/drivers/block/rnbd/rnbd-proto.h

@@ -0,0 +1,321 @@
+/* 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 2
+
+/* The default port number the RTRS server is listening on. */
+#define RTRS_PORT 1234
+
+/**
+ * enum rnbd_msg_type - 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;
+	/* private: */
+	__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,
+};
+
+static const __maybe_unused struct {
+	enum rnbd_access_mode mode;
+	const char *str;
+} rnbd_access_modes[] = {
+	[RNBD_ACCESS_RO] = {RNBD_ACCESS_RO, "ro"},
+	[RNBD_ACCESS_RW] = {RNBD_ACCESS_RW, "rw"},
+	[RNBD_ACCESS_MIGRATION] = {RNBD_ACCESS_MIGRATION, "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;
+	/* private: */
+	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;
+	/* private: */
+	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
+ * @dev_name:		device path on remote side
+ */
+struct rnbd_msg_open {
+	struct rnbd_msg_hdr hdr;
+	u8		access_mode;
+	/* private: */
+	u8		resv1;
+	/* public: */
+	s8		dev_name[NAME_MAX];
+	/* private: */
+	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_zeroes_sectors: max sectors for WRITE ZEROES 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_zeroes_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;
+	/* private: */
+	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_ZEROES:   write zeroes sectors
+ *
+ * @RNBD_F_SYNC:	     request is sync (sync write or read)
+ * @RNBD_F_FUA:             forced unit access
+ * @RNBD_F_PREFLUSH:	    request for cache flush
+ * @RNBD_F_NOUNMAP:	    do not free blocks when zeroing
+ */
+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_ZEROES	= 5,
+
+	/* Flags */
+	RNBD_F_SYNC  = 1<<(RNBD_OP_BITS + 0),
+	RNBD_F_FUA   = 1<<(RNBD_OP_BITS + 1),
+	RNBD_F_PREFLUSH = 1<<(RNBD_OP_BITS + 2),
+	RNBD_F_NOUNMAP = 1<<(RNBD_OP_BITS + 3)
+};
+
+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 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;
+	case RNBD_OP_WRITE_ZEROES:
+		bio_opf = REQ_OP_WRITE_ZEROES;
+
+		if (rnbd_opf & RNBD_F_NOUNMAP)
+			bio_opf |= REQ_NOUNMAP;
+		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;
+
+	if (rnbd_opf & RNBD_F_PREFLUSH)
+		bio_opf |= REQ_PREFLUSH;
+
+	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_WRITE_ZEROES:
+		rnbd_opf = RNBD_OP_WRITE_ZEROES;
+
+		if (rq->cmd_flags & REQ_NOUNMAP)
+			rnbd_opf |= RNBD_F_NOUNMAP;
+		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;
+
+	if (rq->cmd_flags & REQ_PREFLUSH)
+		rnbd_opf |= RNBD_F_PREFLUSH;
+
+	return rnbd_opf;
+}
+
+const char *rnbd_access_mode_str(enum rnbd_access_mode mode);
+
+#endif /* RNBD_PROTO_H */

linux-7.2.3/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 <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 const struct class rnbd_dev_class = {
+	.name = "rnbd-server",
+};
+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 const 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->readonly);
+}
+
+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_modes[sess_dev->access_mode].str);
+}
+
+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 const 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;
+
+	err = class_register(&rnbd_dev_class);
+	if (err)
+		return err;
+
+	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_unregister(&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_unregister(&rnbd_dev_class);
+}

linux-7.2.3/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"

linux-7.2.3/drivers/block/rnbd/rnbd-srv-trace.h

@@ -0,0 +1,189 @@
+/* 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);
+	),
+
+	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_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);
+		__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: %u, 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,
+		   __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);
+	),
+
+	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);
+		__assign_str(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);
+	),
+
+	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>
+

linux-7.2.3/drivers/block/rnbd/rnbd-srv.c

@@ -0,0 +1,862 @@
+// 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 (!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_obj(*priv);
+	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: %pe\n",
+				   srv_sess->sessname, dev_id, sess_dev);
+		err = -ENOTCONN;
+		goto err;
+	}
+
+	priv->sess_dev = sess_dev;
+	priv->id = id;
+
+	bio = bio_alloc(file_bdev(sess_dev->bdev_file), !!datalen,
+			rnbd_to_bio_flags(le32_to_cpu(msg->rw)), GFP_KERNEL);
+	if (unlikely(!bio)) {
+		err = -ENOMEM;
+		goto put_sess_dev;
+	}
+
+	if (!datalen) {
+		/*
+		 * For special requests like DISCARD and WRITE_ZEROES, the datalen is zero.
+		 */
+		bio->bi_iter.bi_size = le32_to_cpu(msg->bi_size);
+	} else {
+		bio_add_virt_nofail(bio, data, datalen);
+		bio->bi_opf = rnbd_to_bio_flags(le32_to_cpu(msg->rw));
+		if (bio->bi_iter.bi_size != le32_to_cpu(msg->bi_size)) {
+			rnbd_srv_err_rl(sess_dev,
+					"Datalen mismatch:  bio bi_size (%u), bi_size (%u)\n",
+					bio->bi_iter.bi_size, msg->bi_size);
+			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);
+	prio = srv_sess->ver < RNBD_PROTO_VER_MAJOR ||
+	       usrlen < sizeof(*msg) ? 0 : le16_to_cpu(msg->prio);
+	bio->bi_ioprio = prio;
+
+	submit_bio(bio);
+
+	return 0;
+
+bio_put:
+	bio_put(bio);
+put_sess_dev:
+	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->name);
+
+	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 */
+
+	fput(sess_dev->bdev_file);
+	mutex_lock(&sess_dev->dev->lock);
+	list_del(&sess_dev->dev_list);
+	if (!sess_dev->readonly)
+		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_obj(*srv_sess);
+	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 void 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:
+		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_obj(*sess_dev);
+	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_obj(*dev);
+	if (!dev)
+		return ERR_PTR(-ENOMEM);
+
+	snprintf(dev->name, sizeof(dev->name), "%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->name, new_dev->name, sizeof(dev->name))) {
+			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 = 0;
+
+	mutex_lock(&srv_dev->lock);
+
+	switch (access_mode) {
+	case RNBD_ACCESS_RO:
+		break;
+	case RNBD_ACCESS_RW:
+		if (srv_dev->open_write_cnt == 0)  {
+			srv_dev->open_write_cnt++;
+		} 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->name, srv_sess->sessname,
+			       srv_dev->open_write_cnt,
+			       rnbd_access_modes[access_mode].str);
+			ret = -EPERM;
+		}
+		break;
+	case RNBD_ACCESS_MIGRATION:
+		if (srv_dev->open_write_cnt < 2) {
+			srv_dev->open_write_cnt++;
+		} 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->name, srv_sess->sessname,
+			       srv_dev->open_write_cnt,
+			       rnbd_access_modes[access_mode].str);
+			ret = -EPERM;
+		}
+		break;
+	default:
+		pr_err("Received mapping request for device '%s' on session %s with invalid access mode: %d\n",
+		       srv_dev->name, 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 = file_bdev(sess_dev->bdev_file);
+
+	memset(rsp, 0, sizeof(*rsp));
+
+	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_zeroes_sectors =
+		cpu_to_le32(bdev_write_zeroes_sectors(bdev));
+	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 file *bdev_file, bool readonly,
+			      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_file		= bdev_file;
+	sdev->sess		= srv_sess;
+	sdev->dev		= srv_dev;
+	sdev->readonly		= readonly;
+	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;
+	int len;
+
+	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) {
+		len = a - dev_search_path;
+
+		len = snprintf(full_path, PATH_MAX, "%.*s/%s/%s", len,
+			       dev_search_path, srv_sess->sessname, dev_name);
+	} else {
+		len = snprintf(full_path, PATH_MAX, "%s/%s",
+			       dev_search_path, 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);
+	}
+
+	/* 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 void 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);
+
+	memset(rsp, 0, sizeof(*rsp));
+	rsp->hdr.type = cpu_to_le16(RNBD_MSG_SESS_INFO_RSP);
+	rsp->ver = srv_sess->ver;
+}
+
+/**
+ * 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 file *bdev_file;
+	blk_mode_t open_flags = BLK_OPEN_READ;
+	char *full_path;
+	struct rnbd_msg_open_rsp *rsp = data;
+
+	trace_process_msg_open(srv_sess, open_msg);
+
+	if (open_msg->access_mode != RNBD_ACCESS_RO)
+		open_flags |= BLK_OPEN_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: %pe\n",
+		       open_msg->dev_name, srv_sess->sessname, full_path);
+		goto reject;
+	}
+
+	bdev_file = bdev_file_open_by_path(full_path, open_flags, NULL, NULL);
+	if (IS_ERR(bdev_file)) {
+		ret = PTR_ERR(bdev_file);
+		pr_err("Opening device '%s' on session %s failed, failed to open the block device, err: %pe\n",
+		       full_path, srv_sess->sessname, bdev_file);
+		goto free_path;
+	}
+
+	srv_dev = rnbd_srv_get_or_create_srv_dev(file_bdev(bdev_file), 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: %pe\n",
+		       full_path, srv_sess->sessname, srv_dev);
+		ret = PTR_ERR(srv_dev);
+		goto blkdev_put;
+	}
+
+	srv_sess_dev = rnbd_srv_create_set_sess_dev(srv_sess, open_msg,
+				bdev_file,
+				open_msg->access_mode == RNBD_ACCESS_RO,
+				srv_dev);
+	if (IS_ERR(srv_sess_dev)) {
+		pr_err("Opening device '%s' on session %s failed, creating sess_dev failed, err: %pe\n",
+		       full_path, srv_sess->sessname, 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, file_bdev(bdev_file));
+		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->name);
+
+	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:
+	fput(bdev_file);
+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 = 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);
+	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)) {
+		pr_err("rtrs_srv_open(), err: %pe\n", rtrs_ctx);
+		return PTR_ERR(rtrs_ctx);
+	}
+
+	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;
+}
+
+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);

linux-7.2.3/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				name[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 file			*bdev_file;
+	struct rnbd_srv_session		*sess;
+	struct rnbd_srv_dev		*dev;
+	struct kobject                  kobj;
+	u32                             device_id;
+	bool				keep_id;
+	bool				readonly;
+	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 */