]> git.proxmox.com Git - ceph.git/blobdiff - ceph/src/spdk/module/bdev/lvol/vbdev_lvol.c
update source to Ceph Pacific 16.2.2
[ceph.git] / ceph / src / spdk / module / bdev / lvol / vbdev_lvol.c
diff --git a/ceph/src/spdk/module/bdev/lvol/vbdev_lvol.c b/ceph/src/spdk/module/bdev/lvol/vbdev_lvol.c
new file mode 100644 (file)
index 0000000..275d68e
--- /dev/null
@@ -0,0 +1,1354 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright (c) Intel Corporation.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "spdk/blob_bdev.h"
+#include "spdk/rpc.h"
+#include "spdk/bdev_module.h"
+#include "spdk_internal/log.h"
+#include "spdk/string.h"
+#include "spdk/uuid.h"
+
+#include "vbdev_lvol.h"
+
+static TAILQ_HEAD(, lvol_store_bdev) g_spdk_lvol_pairs = TAILQ_HEAD_INITIALIZER(
+                       g_spdk_lvol_pairs);
+
+static int vbdev_lvs_init(void);
+static int vbdev_lvs_get_ctx_size(void);
+static void vbdev_lvs_examine(struct spdk_bdev *bdev);
+
+static struct spdk_bdev_module g_lvol_if = {
+       .name = "lvol",
+       .module_init = vbdev_lvs_init,
+       .examine_disk = vbdev_lvs_examine,
+       .get_ctx_size = vbdev_lvs_get_ctx_size,
+
+};
+
+SPDK_BDEV_MODULE_REGISTER(lvol, &g_lvol_if)
+
+struct lvol_store_bdev *
+vbdev_get_lvs_bdev_by_lvs(struct spdk_lvol_store *lvs_orig)
+{
+       struct spdk_lvol_store *lvs = NULL;
+       struct lvol_store_bdev *lvs_bdev = vbdev_lvol_store_first();
+
+       while (lvs_bdev != NULL) {
+               lvs = lvs_bdev->lvs;
+               if (lvs == lvs_orig) {
+                       if (lvs_bdev->req != NULL) {
+                               /* We do not allow access to lvs that are being destroyed */
+                               return NULL;
+                       } else {
+                               return lvs_bdev;
+                       }
+               }
+               lvs_bdev = vbdev_lvol_store_next(lvs_bdev);
+       }
+
+       return NULL;
+}
+
+static int
+_vbdev_lvol_change_bdev_alias(struct spdk_lvol *lvol, const char *new_lvol_name)
+{
+       struct spdk_bdev_alias *tmp;
+       char *old_alias;
+       char *alias;
+       int rc;
+       int alias_number = 0;
+
+       /* bdev representing lvols have only one alias,
+        * while we changed lvs name earlier, we have to iterate alias list to get one,
+        * and check if there is only one alias */
+
+       TAILQ_FOREACH(tmp, &lvol->bdev->aliases, tailq) {
+               if (++alias_number > 1) {
+                       SPDK_ERRLOG("There is more than 1 alias in bdev %s\n", lvol->bdev->name);
+                       return -EINVAL;
+               }
+
+               old_alias = tmp->alias;
+       }
+
+       if (alias_number == 0) {
+               SPDK_ERRLOG("There are no aliases in bdev %s\n", lvol->bdev->name);
+               return -EINVAL;
+       }
+
+       alias = spdk_sprintf_alloc("%s/%s", lvol->lvol_store->name, new_lvol_name);
+       if (alias == NULL) {
+               SPDK_ERRLOG("Cannot alloc memory for alias\n");
+               return -ENOMEM;
+       }
+
+       rc = spdk_bdev_alias_add(lvol->bdev, alias);
+       if (rc != 0) {
+               SPDK_ERRLOG("cannot add alias '%s'\n", alias);
+               free(alias);
+               return rc;
+       }
+       free(alias);
+
+       rc = spdk_bdev_alias_del(lvol->bdev, old_alias);
+       if (rc != 0) {
+               SPDK_ERRLOG("cannot remove alias '%s'\n", old_alias);
+               return rc;
+       }
+
+       return 0;
+}
+
+static struct lvol_store_bdev *
+vbdev_get_lvs_bdev_by_bdev(struct spdk_bdev *bdev_orig)
+{
+       struct lvol_store_bdev *lvs_bdev = vbdev_lvol_store_first();
+
+       while (lvs_bdev != NULL) {
+               if (lvs_bdev->bdev == bdev_orig) {
+                       if (lvs_bdev->req != NULL) {
+                               /* We do not allow access to lvs that are being destroyed */
+                               return NULL;
+                       } else {
+                               return lvs_bdev;
+                       }
+               }
+               lvs_bdev = vbdev_lvol_store_next(lvs_bdev);
+       }
+
+       return NULL;
+}
+
+static void
+vbdev_lvs_hotremove_cb(void *ctx)
+{
+       struct spdk_bdev *bdev = ctx;
+       struct lvol_store_bdev *lvs_bdev;
+
+       lvs_bdev = vbdev_get_lvs_bdev_by_bdev(bdev);
+       if (lvs_bdev != NULL) {
+               vbdev_lvs_unload(lvs_bdev->lvs, NULL, NULL);
+       }
+}
+
+static void
+_vbdev_lvs_create_cb(void *cb_arg, struct spdk_lvol_store *lvs, int lvserrno)
+{
+       struct spdk_lvs_with_handle_req *req = cb_arg;
+       struct lvol_store_bdev *lvs_bdev;
+       struct spdk_bdev *bdev = req->base_bdev;
+       struct spdk_bs_dev *bs_dev = req->bs_dev;
+
+       if (lvserrno != 0) {
+               assert(lvs == NULL);
+               SPDK_ERRLOG("Cannot create lvol store bdev\n");
+               goto end;
+       }
+
+       lvserrno = spdk_bs_bdev_claim(bs_dev, &g_lvol_if);
+       if (lvserrno != 0) {
+               SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Lvol store base bdev already claimed by another bdev\n");
+               req->bs_dev->destroy(req->bs_dev);
+               goto end;
+       }
+
+       assert(lvs != NULL);
+
+       lvs_bdev = calloc(1, sizeof(*lvs_bdev));
+       if (!lvs_bdev) {
+               lvserrno = -ENOMEM;
+               goto end;
+       }
+       lvs_bdev->lvs = lvs;
+       lvs_bdev->bdev = bdev;
+       lvs_bdev->req = NULL;
+
+       TAILQ_INSERT_TAIL(&g_spdk_lvol_pairs, lvs_bdev, lvol_stores);
+       SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Lvol store bdev inserted\n");
+
+end:
+       req->cb_fn(req->cb_arg, lvs, lvserrno);
+       free(req);
+
+       return;
+}
+
+int
+vbdev_lvs_create(struct spdk_bdev *base_bdev, const char *name, uint32_t cluster_sz,
+                enum lvs_clear_method clear_method, spdk_lvs_op_with_handle_complete cb_fn, void *cb_arg)
+{
+       struct spdk_bs_dev *bs_dev;
+       struct spdk_lvs_with_handle_req *lvs_req;
+       struct spdk_lvs_opts opts;
+       int rc;
+       int len;
+
+       if (base_bdev == NULL) {
+               SPDK_ERRLOG("Bdev does not exist\n");
+               return -ENODEV;
+       }
+
+       spdk_lvs_opts_init(&opts);
+       if (cluster_sz != 0) {
+               opts.cluster_sz = cluster_sz;
+       }
+
+       if (clear_method != 0) {
+               opts.clear_method = clear_method;
+       }
+
+       if (name == NULL) {
+               SPDK_ERRLOG("missing name param\n");
+               return -EINVAL;
+       }
+
+       len = strnlen(name, SPDK_LVS_NAME_MAX);
+
+       if (len == 0 || len == SPDK_LVS_NAME_MAX) {
+               SPDK_ERRLOG("name must be between 1 and %d characters\n", SPDK_LVS_NAME_MAX - 1);
+               return -EINVAL;
+       }
+       snprintf(opts.name, sizeof(opts.name), "%s", name);
+
+       lvs_req = calloc(1, sizeof(*lvs_req));
+       if (!lvs_req) {
+               SPDK_ERRLOG("Cannot alloc memory for vbdev lvol store request pointer\n");
+               return -ENOMEM;
+       }
+
+       bs_dev = spdk_bdev_create_bs_dev(base_bdev, vbdev_lvs_hotremove_cb, base_bdev);
+       if (!bs_dev) {
+               SPDK_ERRLOG("Cannot create blobstore device\n");
+               free(lvs_req);
+               return -ENODEV;
+       }
+
+       lvs_req->bs_dev = bs_dev;
+       lvs_req->base_bdev = base_bdev;
+       lvs_req->cb_fn = cb_fn;
+       lvs_req->cb_arg = cb_arg;
+
+       rc = spdk_lvs_init(bs_dev, &opts, _vbdev_lvs_create_cb, lvs_req);
+       if (rc < 0) {
+               free(lvs_req);
+               bs_dev->destroy(bs_dev);
+               return rc;
+       }
+
+       return 0;
+}
+
+static void
+_vbdev_lvs_rename_cb(void *cb_arg, int lvserrno)
+{
+       struct spdk_lvs_req *req = cb_arg;
+       struct spdk_lvol *tmp;
+
+       if (lvserrno != 0) {
+               SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Lvol store rename failed\n");
+       } else {
+               TAILQ_FOREACH(tmp, &req->lvol_store->lvols, link) {
+                       /* We have to pass current lvol name, since only lvs name changed */
+                       _vbdev_lvol_change_bdev_alias(tmp, tmp->name);
+               }
+       }
+
+       req->cb_fn(req->cb_arg, lvserrno);
+       free(req);
+}
+
+void
+vbdev_lvs_rename(struct spdk_lvol_store *lvs, const char *new_lvs_name,
+                spdk_lvs_op_complete cb_fn, void *cb_arg)
+{
+       struct lvol_store_bdev *lvs_bdev;
+
+       struct spdk_lvs_req *req;
+
+       lvs_bdev = vbdev_get_lvs_bdev_by_lvs(lvs);
+       if (!lvs_bdev) {
+               SPDK_ERRLOG("No such lvol store found\n");
+               cb_fn(cb_arg, -ENODEV);
+               return;
+       }
+
+       req = calloc(1, sizeof(*req));
+       if (!req) {
+               SPDK_ERRLOG("Cannot alloc memory for vbdev lvol store request pointer\n");
+               cb_fn(cb_arg, -ENOMEM);
+               return;
+       }
+       req->cb_fn = cb_fn;
+       req->cb_arg = cb_arg;
+       req->lvol_store = lvs;
+
+       spdk_lvs_rename(lvs, new_lvs_name, _vbdev_lvs_rename_cb, req);
+}
+
+static void
+_vbdev_lvs_remove_cb(void *cb_arg, int lvserrno)
+{
+       struct lvol_store_bdev *lvs_bdev = cb_arg;
+       struct spdk_lvs_req *req = lvs_bdev->req;
+
+       if (lvserrno != 0) {
+               SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Lvol store removed with error: %d.\n", lvserrno);
+       }
+
+       TAILQ_REMOVE(&g_spdk_lvol_pairs, lvs_bdev, lvol_stores);
+       free(lvs_bdev);
+
+       if (req->cb_fn != NULL) {
+               req->cb_fn(req->cb_arg, lvserrno);
+       }
+       free(req);
+}
+
+static void
+_vbdev_lvs_remove_lvol_cb(void *cb_arg, int lvolerrno)
+{
+       struct lvol_store_bdev *lvs_bdev = cb_arg;
+       struct spdk_lvol_store *lvs = lvs_bdev->lvs;
+       struct spdk_lvol *lvol;
+
+       if (lvolerrno != 0) {
+               SPDK_DEBUGLOG(SPDK_LOG_VBDEV_LVOL, "Lvol removed with errno %d\n", lvolerrno);
+       }
+
+       if (TAILQ_EMPTY(&lvs->lvols)) {
+               spdk_lvs_destroy(lvs, _vbdev_lvs_remove_cb, lvs_bdev);
+               return;
+       }
+
+       lvol = TAILQ_FIRST(&lvs->lvols);
+       while (lvol != NULL) {
+               if (spdk_lvol_deletable(lvol)) {
+                       vbdev_lvol_destroy(lvol, _vbdev_lvs_remove_lvol_cb, lvs_bdev);
+                       return;
+               }
+               lvol = TAILQ_NEXT(lvol, link);
+       }
+
+       /* If no lvol is deletable, that means there is circular dependency. */
+       SPDK_ERRLOG("Lvols left in lvs, but unable to delete.\n");
+       assert(false);
+}
+
+static void
+_vbdev_lvs_remove_bdev_unregistered_cb(void *cb_arg, int bdeverrno)
+{
+       struct lvol_store_bdev *lvs_bdev = cb_arg;
+       struct spdk_lvol_store *lvs = lvs_bdev->lvs;
+       struct spdk_lvol *lvol, *tmp;
+
+       if (bdeverrno != 0) {
+               SPDK_DEBUGLOG(SPDK_LOG_VBDEV_LVOL, "Lvol unregistered with errno %d\n", bdeverrno);
+       }
+
+       TAILQ_FOREACH_SAFE(lvol, &lvs->lvols, link, tmp) {
+               if (lvol->ref_count != 0) {
+                       /* An lvol is still open, don't unload whole lvol store. */
+                       return;
+               }
+       }
+       spdk_lvs_unload(lvs, _vbdev_lvs_remove_cb, lvs_bdev);
+}
+
+static void
+_vbdev_lvs_remove(struct spdk_lvol_store *lvs, spdk_lvs_op_complete cb_fn, void *cb_arg,
+                 bool destroy)
+{
+       struct spdk_lvs_req *req;
+       struct lvol_store_bdev *lvs_bdev;
+       struct spdk_lvol *lvol, *tmp;
+       bool all_lvols_closed = true;
+
+       lvs_bdev = vbdev_get_lvs_bdev_by_lvs(lvs);
+       if (!lvs_bdev) {
+               SPDK_ERRLOG("No such lvol store found\n");
+               if (cb_fn != NULL) {
+                       cb_fn(cb_arg, -ENODEV);
+               }
+               return;
+       }
+
+       req = calloc(1, sizeof(*req));
+       if (!req) {
+               SPDK_ERRLOG("Cannot alloc memory for vbdev lvol store request pointer\n");
+               if (cb_fn != NULL) {
+                       cb_fn(cb_arg, -ENOMEM);
+               }
+               return;
+       }
+
+       req->cb_fn = cb_fn;
+       req->cb_arg = cb_arg;
+       lvs_bdev->req = req;
+
+       TAILQ_FOREACH_SAFE(lvol, &lvs->lvols, link, tmp) {
+               if (lvol->ref_count != 0) {
+                       all_lvols_closed = false;
+               }
+       }
+
+       if (all_lvols_closed == true) {
+               if (destroy) {
+                       spdk_lvs_destroy(lvs, _vbdev_lvs_remove_cb, lvs_bdev);
+               } else {
+                       spdk_lvs_unload(lvs, _vbdev_lvs_remove_cb, lvs_bdev);
+               }
+       } else {
+               lvs->destruct = destroy;
+               if (destroy) {
+                       _vbdev_lvs_remove_lvol_cb(lvs_bdev, 0);
+               } else {
+                       TAILQ_FOREACH_SAFE(lvol, &lvs->lvols, link, tmp) {
+                               spdk_bdev_unregister(lvol->bdev, _vbdev_lvs_remove_bdev_unregistered_cb, lvs_bdev);
+                       }
+               }
+       }
+}
+
+void
+vbdev_lvs_unload(struct spdk_lvol_store *lvs, spdk_lvs_op_complete cb_fn, void *cb_arg)
+{
+       _vbdev_lvs_remove(lvs, cb_fn, cb_arg, false);
+}
+
+void
+vbdev_lvs_destruct(struct spdk_lvol_store *lvs, spdk_lvs_op_complete cb_fn, void *cb_arg)
+{
+       _vbdev_lvs_remove(lvs, cb_fn, cb_arg, true);
+}
+
+struct lvol_store_bdev *
+vbdev_lvol_store_first(void)
+{
+       struct lvol_store_bdev *lvs_bdev;
+
+       lvs_bdev = TAILQ_FIRST(&g_spdk_lvol_pairs);
+       if (lvs_bdev) {
+               SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Starting lvolstore iteration at %p\n", lvs_bdev->lvs);
+       }
+
+       return lvs_bdev;
+}
+
+struct lvol_store_bdev *
+vbdev_lvol_store_next(struct lvol_store_bdev *prev)
+{
+       struct lvol_store_bdev *lvs_bdev;
+
+       if (prev == NULL) {
+               SPDK_ERRLOG("prev argument cannot be NULL\n");
+               return NULL;
+       }
+
+       lvs_bdev = TAILQ_NEXT(prev, lvol_stores);
+       if (lvs_bdev) {
+               SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Continuing lvolstore iteration at %p\n", lvs_bdev->lvs);
+       }
+
+       return lvs_bdev;
+}
+
+static struct spdk_lvol_store *
+_vbdev_get_lvol_store_by_uuid(const struct spdk_uuid *uuid)
+{
+       struct spdk_lvol_store *lvs = NULL;
+       struct lvol_store_bdev *lvs_bdev = vbdev_lvol_store_first();
+
+       while (lvs_bdev != NULL) {
+               lvs = lvs_bdev->lvs;
+               if (spdk_uuid_compare(&lvs->uuid, uuid) == 0) {
+                       return lvs;
+               }
+               lvs_bdev = vbdev_lvol_store_next(lvs_bdev);
+       }
+       return NULL;
+}
+
+struct spdk_lvol_store *
+vbdev_get_lvol_store_by_uuid(const char *uuid_str)
+{
+       struct spdk_uuid uuid;
+
+       if (spdk_uuid_parse(&uuid, uuid_str)) {
+               return NULL;
+       }
+
+       return _vbdev_get_lvol_store_by_uuid(&uuid);
+}
+
+struct spdk_lvol_store *
+vbdev_get_lvol_store_by_name(const char *name)
+{
+       struct spdk_lvol_store *lvs = NULL;
+       struct lvol_store_bdev *lvs_bdev = vbdev_lvol_store_first();
+
+       while (lvs_bdev != NULL) {
+               lvs = lvs_bdev->lvs;
+               if (strncmp(lvs->name, name, sizeof(lvs->name)) == 0) {
+                       return lvs;
+               }
+               lvs_bdev = vbdev_lvol_store_next(lvs_bdev);
+       }
+       return NULL;
+}
+
+struct vbdev_lvol_destroy_ctx {
+       struct spdk_lvol *lvol;
+       spdk_lvol_op_complete cb_fn;
+       void *cb_arg;
+};
+
+static void
+_vbdev_lvol_unregister_cb(void *ctx, int lvolerrno)
+{
+       struct spdk_bdev *bdev = ctx;
+
+       spdk_bdev_destruct_done(bdev, lvolerrno);
+       free(bdev);
+}
+
+static int
+vbdev_lvol_unregister(void *ctx)
+{
+       struct spdk_lvol *lvol = ctx;
+
+       assert(lvol != NULL);
+
+       spdk_bdev_alias_del_all(lvol->bdev);
+       spdk_lvol_close(lvol, _vbdev_lvol_unregister_cb, lvol->bdev);
+
+       /* return 1 to indicate we have an operation that must finish asynchronously before the
+        *  lvol is closed
+        */
+       return 1;
+}
+
+static void
+_vbdev_lvol_destroy_cb(void *cb_arg, int bdeverrno)
+{
+       struct vbdev_lvol_destroy_ctx *ctx = cb_arg;
+       struct spdk_lvol *lvol = ctx->lvol;
+
+       if (bdeverrno < 0) {
+               SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Could not unregister bdev during lvol (%s) destroy\n",
+                            lvol->unique_id);
+               ctx->cb_fn(ctx->cb_arg, bdeverrno);
+               free(ctx);
+               return;
+       }
+
+       spdk_lvol_destroy(lvol, ctx->cb_fn, ctx->cb_arg);
+       free(ctx);
+}
+
+void
+vbdev_lvol_destroy(struct spdk_lvol *lvol, spdk_lvol_op_complete cb_fn, void *cb_arg)
+{
+       struct vbdev_lvol_destroy_ctx *ctx;
+       size_t count;
+
+       assert(lvol != NULL);
+       assert(cb_fn != NULL);
+
+       /* Check if it is possible to delete lvol */
+       spdk_blob_get_clones(lvol->lvol_store->blobstore, lvol->blob_id, NULL, &count);
+       if (count > 1) {
+               /* throw an error */
+               SPDK_ERRLOG("Cannot delete lvol\n");
+               cb_fn(cb_arg, -EPERM);
+               return;
+       }
+
+       ctx = calloc(1, sizeof(*ctx));
+       if (!ctx) {
+               cb_fn(cb_arg, -ENOMEM);
+               return;
+       }
+
+       ctx->lvol = lvol;
+       ctx->cb_fn = cb_fn;
+       ctx->cb_arg = cb_arg;
+
+       spdk_bdev_unregister(lvol->bdev, _vbdev_lvol_destroy_cb, ctx);
+}
+
+static char *
+vbdev_lvol_find_name(struct spdk_lvol *lvol, spdk_blob_id blob_id)
+{
+       struct spdk_lvol_store *lvs;
+       struct spdk_lvol *_lvol;
+
+       assert(lvol != NULL);
+
+       lvs = lvol->lvol_store;
+
+       assert(lvs);
+
+       TAILQ_FOREACH(_lvol, &lvs->lvols, link) {
+               if (_lvol->blob_id == blob_id) {
+                       return _lvol->name;
+               }
+       }
+
+       return NULL;
+}
+
+static int
+vbdev_lvol_dump_info_json(void *ctx, struct spdk_json_write_ctx *w)
+{
+       struct spdk_lvol *lvol = ctx;
+       struct lvol_store_bdev *lvs_bdev;
+       struct spdk_bdev *bdev;
+       struct spdk_blob *blob;
+       char lvol_store_uuid[SPDK_UUID_STRING_LEN];
+       spdk_blob_id *ids = NULL;
+       size_t count, i;
+       char *name;
+       int rc = 0;
+
+       spdk_json_write_named_object_begin(w, "lvol");
+
+       lvs_bdev = vbdev_get_lvs_bdev_by_lvs(lvol->lvol_store);
+       if (!lvs_bdev) {
+               SPDK_ERRLOG("No such lvol store found\n");
+               rc = -ENODEV;
+               goto end;
+       }
+
+       bdev = lvs_bdev->bdev;
+
+       spdk_uuid_fmt_lower(lvol_store_uuid, sizeof(lvol_store_uuid), &lvol->lvol_store->uuid);
+       spdk_json_write_named_string(w, "lvol_store_uuid", lvol_store_uuid);
+
+       spdk_json_write_named_string(w, "base_bdev", spdk_bdev_get_name(bdev));
+
+       blob = lvol->blob;
+
+       spdk_json_write_named_bool(w, "thin_provision", spdk_blob_is_thin_provisioned(blob));
+
+       spdk_json_write_named_bool(w, "snapshot", spdk_blob_is_snapshot(blob));
+
+       spdk_json_write_named_bool(w, "clone", spdk_blob_is_clone(blob));
+
+       if (spdk_blob_is_clone(blob)) {
+               spdk_blob_id snapshotid = spdk_blob_get_parent_snapshot(lvol->lvol_store->blobstore, lvol->blob_id);
+               if (snapshotid != SPDK_BLOBID_INVALID) {
+                       name = vbdev_lvol_find_name(lvol, snapshotid);
+                       if (name != NULL) {
+                               spdk_json_write_named_string(w, "base_snapshot", name);
+                       } else {
+                               SPDK_ERRLOG("Cannot obtain snapshots name\n");
+                       }
+               }
+       }
+
+       if (spdk_blob_is_snapshot(blob)) {
+               /* Take a number of clones */
+               rc = spdk_blob_get_clones(lvol->lvol_store->blobstore, lvol->blob_id, NULL, &count);
+               if (rc == -ENOMEM && count > 0) {
+                       ids = malloc(sizeof(spdk_blob_id) * count);
+                       if (ids == NULL) {
+                               SPDK_ERRLOG("Cannot allocate memory\n");
+                               rc = -ENOMEM;
+                               goto end;
+                       }
+
+                       rc = spdk_blob_get_clones(lvol->lvol_store->blobstore, lvol->blob_id, ids, &count);
+                       if (rc == 0) {
+                               spdk_json_write_named_array_begin(w, "clones");
+                               for (i = 0; i < count; i++) {
+                                       name = vbdev_lvol_find_name(lvol, ids[i]);
+                                       if (name != NULL) {
+                                               spdk_json_write_string(w, name);
+                                       } else {
+                                               SPDK_ERRLOG("Cannot obtain clone name\n");
+                                       }
+
+                               }
+                               spdk_json_write_array_end(w);
+                       }
+                       free(ids);
+               }
+
+       }
+
+end:
+       spdk_json_write_object_end(w);
+
+       return rc;
+}
+
+static void
+vbdev_lvol_write_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w)
+{
+       /* Nothing to dump as lvol configuration is saved on physical device. */
+}
+
+static struct spdk_io_channel *
+vbdev_lvol_get_io_channel(void *ctx)
+{
+       struct spdk_lvol *lvol = ctx;
+
+       return spdk_lvol_get_io_channel(lvol);
+}
+
+static bool
+vbdev_lvol_io_type_supported(void *ctx, enum spdk_bdev_io_type io_type)
+{
+       struct spdk_lvol *lvol = ctx;
+
+       switch (io_type) {
+       case SPDK_BDEV_IO_TYPE_WRITE:
+       case SPDK_BDEV_IO_TYPE_UNMAP:
+       case SPDK_BDEV_IO_TYPE_WRITE_ZEROES:
+               return !spdk_blob_is_read_only(lvol->blob);
+       case SPDK_BDEV_IO_TYPE_RESET:
+       case SPDK_BDEV_IO_TYPE_READ:
+               return true;
+       default:
+               return false;
+       }
+}
+
+static void
+lvol_op_comp(void *cb_arg, int bserrno)
+{
+       struct spdk_bdev_io *bdev_io = cb_arg;
+       enum spdk_bdev_io_status status = SPDK_BDEV_IO_STATUS_SUCCESS;
+
+       if (bserrno != 0) {
+               if (bserrno == -ENOMEM) {
+                       status = SPDK_BDEV_IO_STATUS_NOMEM;
+               } else {
+                       status = SPDK_BDEV_IO_STATUS_FAILED;
+               }
+       }
+
+       SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Vbdev processing callback on device %s with type %d\n",
+                    bdev_io->bdev->name, bdev_io->type);
+       spdk_bdev_io_complete(bdev_io, status);
+}
+
+static void
+lvol_unmap(struct spdk_lvol *lvol, struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
+{
+       uint64_t start_page, num_pages;
+       struct spdk_blob *blob = lvol->blob;
+
+       start_page = bdev_io->u.bdev.offset_blocks;
+       num_pages = bdev_io->u.bdev.num_blocks;
+
+       SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL,
+                    "Vbdev doing unmap at offset %" PRIu64 " using %" PRIu64 " pages on device %s\n", start_page,
+                    num_pages, bdev_io->bdev->name);
+       spdk_blob_io_unmap(blob, ch, start_page, num_pages, lvol_op_comp, bdev_io);
+}
+
+static void
+lvol_write_zeroes(struct spdk_lvol *lvol, struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
+{
+       uint64_t start_page, num_pages;
+       struct spdk_blob *blob = lvol->blob;
+
+       start_page = bdev_io->u.bdev.offset_blocks;
+       num_pages = bdev_io->u.bdev.num_blocks;
+
+       SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL,
+                    "Vbdev doing write zeros at offset %" PRIu64 " using %" PRIu64 " pages on device %s\n", start_page,
+                    num_pages, bdev_io->bdev->name);
+       spdk_blob_io_write_zeroes(blob, ch, start_page, num_pages, lvol_op_comp, bdev_io);
+}
+
+static void
+lvol_read(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
+{
+       uint64_t start_page, num_pages;
+       struct spdk_lvol *lvol = bdev_io->bdev->ctxt;
+       struct spdk_blob *blob = lvol->blob;
+
+       start_page = bdev_io->u.bdev.offset_blocks;
+       num_pages = bdev_io->u.bdev.num_blocks;
+
+       SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL,
+                    "Vbdev doing read at offset %" PRIu64 " using %" PRIu64 " pages on device %s\n", start_page,
+                    num_pages, bdev_io->bdev->name);
+       spdk_blob_io_readv(blob, ch, bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt, start_page,
+                          num_pages, lvol_op_comp, bdev_io);
+}
+
+static void
+lvol_write(struct spdk_lvol *lvol, struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
+{
+       uint64_t start_page, num_pages;
+       struct spdk_blob *blob = lvol->blob;
+
+       start_page = bdev_io->u.bdev.offset_blocks;
+       num_pages = bdev_io->u.bdev.num_blocks;
+
+       SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL,
+                    "Vbdev doing write at offset %" PRIu64 " using %" PRIu64 " pages on device %s\n", start_page,
+                    num_pages, bdev_io->bdev->name);
+       spdk_blob_io_writev(blob, ch, bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt, start_page,
+                           num_pages, lvol_op_comp, bdev_io);
+}
+
+static int
+lvol_reset(struct spdk_bdev_io *bdev_io)
+{
+       spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
+
+       return 0;
+}
+
+static void
+lvol_get_buf_cb(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io, bool success)
+{
+       if (!success) {
+               spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
+               return;
+       }
+
+       lvol_read(ch, bdev_io);
+}
+
+static void
+vbdev_lvol_submit_request(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
+{
+       struct spdk_lvol *lvol = bdev_io->bdev->ctxt;
+
+       SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Vbdev request type %d submitted\n", bdev_io->type);
+
+       switch (bdev_io->type) {
+       case SPDK_BDEV_IO_TYPE_READ:
+               spdk_bdev_io_get_buf(bdev_io, lvol_get_buf_cb,
+                                    bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen);
+               break;
+       case SPDK_BDEV_IO_TYPE_WRITE:
+               lvol_write(lvol, ch, bdev_io);
+               break;
+       case SPDK_BDEV_IO_TYPE_RESET:
+               lvol_reset(bdev_io);
+               break;
+       case SPDK_BDEV_IO_TYPE_UNMAP:
+               lvol_unmap(lvol, ch, bdev_io);
+               break;
+       case SPDK_BDEV_IO_TYPE_WRITE_ZEROES:
+               lvol_write_zeroes(lvol, ch, bdev_io);
+               break;
+       default:
+               SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "lvol: unsupported I/O type %d\n", bdev_io->type);
+               spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
+               return;
+       }
+       return;
+}
+
+static struct spdk_bdev_fn_table vbdev_lvol_fn_table = {
+       .destruct               = vbdev_lvol_unregister,
+       .io_type_supported      = vbdev_lvol_io_type_supported,
+       .submit_request         = vbdev_lvol_submit_request,
+       .get_io_channel         = vbdev_lvol_get_io_channel,
+       .dump_info_json         = vbdev_lvol_dump_info_json,
+       .write_config_json      = vbdev_lvol_write_config_json,
+};
+
+static void
+lvol_destroy_cb(void *cb_arg, int bdeverrno)
+{
+}
+
+static void
+_create_lvol_disk_destroy_cb(void *cb_arg, int bdeverrno)
+{
+       struct spdk_lvol *lvol = cb_arg;
+
+       if (bdeverrno < 0) {
+               SPDK_ERRLOG("Could not unregister bdev for lvol %s\n",
+                           lvol->unique_id);
+               return;
+       }
+
+       spdk_lvol_destroy(lvol, lvol_destroy_cb, NULL);
+}
+
+static void
+_create_lvol_disk_unload_cb(void *cb_arg, int bdeverrno)
+{
+       struct spdk_lvol *lvol = cb_arg;
+
+       if (bdeverrno < 0) {
+               SPDK_ERRLOG("Could not unregister bdev for lvol %s\n",
+                           lvol->unique_id);
+               return;
+       }
+
+       TAILQ_REMOVE(&lvol->lvol_store->lvols, lvol, link);
+       free(lvol);
+}
+
+static int
+_create_lvol_disk(struct spdk_lvol *lvol, bool destroy)
+{
+       struct spdk_bdev *bdev;
+       struct lvol_store_bdev *lvs_bdev;
+       uint64_t total_size;
+       unsigned char *alias;
+       int rc;
+
+       lvs_bdev = vbdev_get_lvs_bdev_by_lvs(lvol->lvol_store);
+       if (lvs_bdev == NULL) {
+               SPDK_ERRLOG("No spdk lvs-bdev pair found for lvol %s\n", lvol->unique_id);
+               return -ENODEV;
+       }
+
+       bdev = calloc(1, sizeof(struct spdk_bdev));
+       if (!bdev) {
+               SPDK_ERRLOG("Cannot alloc memory for lvol bdev\n");
+               return -ENOMEM;
+       }
+
+       bdev->name = lvol->unique_id;
+       bdev->product_name = "Logical Volume";
+       bdev->blocklen = spdk_bs_get_io_unit_size(lvol->lvol_store->blobstore);
+       total_size = spdk_blob_get_num_clusters(lvol->blob) *
+                    spdk_bs_get_cluster_size(lvol->lvol_store->blobstore);
+       assert((total_size % bdev->blocklen) == 0);
+       bdev->blockcnt = total_size / bdev->blocklen;
+       bdev->uuid = lvol->uuid;
+       bdev->required_alignment = lvs_bdev->bdev->required_alignment;
+       bdev->split_on_optimal_io_boundary = true;
+       bdev->optimal_io_boundary = spdk_bs_get_cluster_size(lvol->lvol_store->blobstore) / bdev->blocklen;
+
+       bdev->ctxt = lvol;
+       bdev->fn_table = &vbdev_lvol_fn_table;
+       bdev->module = &g_lvol_if;
+
+       rc = spdk_bdev_register(bdev);
+       if (rc) {
+               free(bdev);
+               return rc;
+       }
+       lvol->bdev = bdev;
+
+       alias = spdk_sprintf_alloc("%s/%s", lvs_bdev->lvs->name, lvol->name);
+       if (alias == NULL) {
+               SPDK_ERRLOG("Cannot alloc memory for alias\n");
+               spdk_bdev_unregister(lvol->bdev, (destroy ? _create_lvol_disk_destroy_cb :
+                                                 _create_lvol_disk_unload_cb), lvol);
+               return -ENOMEM;
+       }
+
+       rc = spdk_bdev_alias_add(bdev, alias);
+       if (rc != 0) {
+               SPDK_ERRLOG("Cannot add alias to lvol bdev\n");
+               spdk_bdev_unregister(lvol->bdev, (destroy ? _create_lvol_disk_destroy_cb :
+                                                 _create_lvol_disk_unload_cb), lvol);
+       }
+       free(alias);
+
+       return rc;
+}
+
+static void
+_vbdev_lvol_create_cb(void *cb_arg, struct spdk_lvol *lvol, int lvolerrno)
+{
+       struct spdk_lvol_with_handle_req *req = cb_arg;
+
+       if (lvolerrno < 0) {
+               goto end;
+       }
+
+       lvolerrno = _create_lvol_disk(lvol, true);
+
+end:
+       req->cb_fn(req->cb_arg, lvol, lvolerrno);
+       free(req);
+}
+
+int
+vbdev_lvol_create(struct spdk_lvol_store *lvs, const char *name, uint64_t sz,
+                 bool thin_provision, enum lvol_clear_method clear_method, spdk_lvol_op_with_handle_complete cb_fn,
+                 void *cb_arg)
+{
+       struct spdk_lvol_with_handle_req *req;
+       int rc;
+
+       req = calloc(1, sizeof(*req));
+       if (req == NULL) {
+               return -ENOMEM;
+       }
+       req->cb_fn = cb_fn;
+       req->cb_arg = cb_arg;
+
+       rc = spdk_lvol_create(lvs, name, sz, thin_provision, clear_method,
+                             _vbdev_lvol_create_cb, req);
+       if (rc != 0) {
+               free(req);
+       }
+
+       return rc;
+}
+
+void
+vbdev_lvol_create_snapshot(struct spdk_lvol *lvol, const char *snapshot_name,
+                          spdk_lvol_op_with_handle_complete cb_fn, void *cb_arg)
+{
+       struct spdk_lvol_with_handle_req *req;
+
+       req = calloc(1, sizeof(*req));
+       if (req == NULL) {
+               cb_fn(cb_arg, NULL, -ENOMEM);
+               return;
+       }
+
+       req->cb_fn = cb_fn;
+       req->cb_arg = cb_arg;
+
+       spdk_lvol_create_snapshot(lvol, snapshot_name, _vbdev_lvol_create_cb, req);
+}
+
+void
+vbdev_lvol_create_clone(struct spdk_lvol *lvol, const char *clone_name,
+                       spdk_lvol_op_with_handle_complete cb_fn, void *cb_arg)
+{
+       struct spdk_lvol_with_handle_req *req;
+
+       req = calloc(1, sizeof(*req));
+       if (req == NULL) {
+               cb_fn(cb_arg, NULL, -ENOMEM);
+               return;
+       }
+
+       req->cb_fn = cb_fn;
+       req->cb_arg = cb_arg;
+
+       spdk_lvol_create_clone(lvol, clone_name, _vbdev_lvol_create_cb, req);
+}
+
+static void
+_vbdev_lvol_rename_cb(void *cb_arg, int lvolerrno)
+{
+       struct spdk_lvol_req *req = cb_arg;
+
+       if (lvolerrno != 0) {
+               SPDK_ERRLOG("Renaming lvol failed\n");
+       }
+
+       req->cb_fn(req->cb_arg, lvolerrno);
+       free(req);
+}
+
+void
+vbdev_lvol_rename(struct spdk_lvol *lvol, const char *new_lvol_name,
+                 spdk_lvol_op_complete cb_fn, void *cb_arg)
+{
+       struct spdk_lvol_req *req;
+       int rc;
+
+       rc = _vbdev_lvol_change_bdev_alias(lvol, new_lvol_name);
+       if (rc != 0) {
+               SPDK_ERRLOG("renaming lvol to '%s' does not succeed\n", new_lvol_name);
+               cb_fn(cb_arg, rc);
+               return;
+       }
+
+       req = calloc(1, sizeof(*req));
+       if (req == NULL) {
+               cb_fn(cb_arg, -ENOMEM);
+               return;
+       }
+       req->cb_fn = cb_fn;
+       req->cb_arg = cb_arg;
+
+       spdk_lvol_rename(lvol, new_lvol_name, _vbdev_lvol_rename_cb, req);
+}
+
+static void
+_vbdev_lvol_resize_cb(void *cb_arg, int lvolerrno)
+{
+       struct spdk_lvol_req *req = cb_arg;
+       struct spdk_lvol *lvol = req->lvol;
+       uint64_t total_size;
+
+       /* change bdev size */
+       if (lvolerrno != 0) {
+               SPDK_ERRLOG("CB function for bdev lvol %s receive error no: %d.\n", lvol->name, lvolerrno);
+               goto finish;
+       }
+
+       total_size = spdk_blob_get_num_clusters(lvol->blob) *
+                    spdk_bs_get_cluster_size(lvol->lvol_store->blobstore);
+       assert((total_size % lvol->bdev->blocklen) == 0);
+
+       lvolerrno = spdk_bdev_notify_blockcnt_change(lvol->bdev, total_size / lvol->bdev->blocklen);
+       if (lvolerrno != 0) {
+               SPDK_ERRLOG("Could not change num blocks for bdev lvol %s with error no: %d.\n",
+                           lvol->name, lvolerrno);
+       }
+
+finish:
+       req->cb_fn(req->cb_arg, lvolerrno);
+       free(req);
+}
+
+void
+vbdev_lvol_resize(struct spdk_lvol *lvol, uint64_t sz, spdk_lvol_op_complete cb_fn, void *cb_arg)
+{
+       struct spdk_lvol_req *req;
+
+       if (lvol == NULL) {
+               SPDK_ERRLOG("lvol does not exist\n");
+               cb_fn(cb_arg, -EINVAL);
+               return;
+       }
+
+       assert(lvol->bdev != NULL);
+
+       req = calloc(1, sizeof(*req));
+       if (req == NULL) {
+               cb_fn(cb_arg, -ENOMEM);
+               return;
+       }
+
+       req->cb_fn = cb_fn;
+       req->cb_arg = cb_arg;
+       req->sz = sz;
+       req->lvol = lvol;
+
+       spdk_lvol_resize(req->lvol, req->sz, _vbdev_lvol_resize_cb, req);
+}
+
+static void
+_vbdev_lvol_set_read_only_cb(void *cb_arg, int lvolerrno)
+{
+       struct spdk_lvol_req *req = cb_arg;
+       struct spdk_lvol *lvol = req->lvol;
+
+       if (lvolerrno != 0) {
+               SPDK_ERRLOG("Could not set bdev lvol %s as read only due to error: %d.\n", lvol->name, lvolerrno);
+       }
+
+       req->cb_fn(req->cb_arg, lvolerrno);
+       free(req);
+}
+
+void
+vbdev_lvol_set_read_only(struct spdk_lvol *lvol, spdk_lvol_op_complete cb_fn, void *cb_arg)
+{
+       struct spdk_lvol_req *req;
+
+       if (lvol == NULL) {
+               SPDK_ERRLOG("lvol does not exist\n");
+               cb_fn(cb_arg, -EINVAL);
+               return;
+       }
+
+       assert(lvol->bdev != NULL);
+
+       req = calloc(1, sizeof(*req));
+       if (req == NULL) {
+               cb_fn(cb_arg, -ENOMEM);
+               return;
+       }
+
+       req->cb_fn = cb_fn;
+       req->cb_arg = cb_arg;
+       req->lvol = lvol;
+
+       spdk_lvol_set_read_only(lvol, _vbdev_lvol_set_read_only_cb, req);
+}
+
+static int
+vbdev_lvs_init(void)
+{
+       return 0;
+}
+
+static int
+vbdev_lvs_get_ctx_size(void)
+{
+       return 0;
+}
+
+static void
+_vbdev_lvs_examine_failed(void *cb_arg, int lvserrno)
+{
+       spdk_bdev_module_examine_done(&g_lvol_if);
+}
+
+static void
+_vbdev_lvol_examine_close_cb(struct spdk_lvol_store *lvs)
+{
+       if (lvs->lvols_opened >= lvs->lvol_count) {
+               SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Opening lvols finished\n");
+               spdk_bdev_module_examine_done(&g_lvol_if);
+       }
+}
+
+static void
+_vbdev_lvs_examine_finish(void *cb_arg, struct spdk_lvol *lvol, int lvolerrno)
+{
+       struct spdk_lvol_store *lvs = cb_arg;
+
+       if (lvolerrno != 0) {
+               SPDK_ERRLOG("Error opening lvol %s\n", lvol->unique_id);
+               TAILQ_REMOVE(&lvs->lvols, lvol, link);
+               lvs->lvol_count--;
+               free(lvol);
+               goto end;
+       }
+
+       if (_create_lvol_disk(lvol, false)) {
+               SPDK_ERRLOG("Cannot create bdev for lvol %s\n", lvol->unique_id);
+               lvs->lvol_count--;
+               _vbdev_lvol_examine_close_cb(lvs);
+               SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Opening lvol %s failed\n", lvol->unique_id);
+               return;
+       }
+
+       lvs->lvols_opened++;
+       SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Opening lvol %s succeeded\n", lvol->unique_id);
+
+end:
+
+       if (lvs->lvols_opened >= lvs->lvol_count) {
+               SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Opening lvols finished\n");
+               spdk_bdev_module_examine_done(&g_lvol_if);
+       }
+}
+
+static void
+_vbdev_lvs_examine_cb(void *arg, struct spdk_lvol_store *lvol_store, int lvserrno)
+{
+       struct lvol_store_bdev *lvs_bdev;
+       struct spdk_lvs_with_handle_req *req = (struct spdk_lvs_with_handle_req *)arg;
+       struct spdk_lvol *lvol, *tmp;
+
+       if (lvserrno == -EEXIST) {
+               SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL,
+                            "Name for lvolstore on device %s conflicts with name for already loaded lvs\n",
+                            req->base_bdev->name);
+               /* On error blobstore destroys bs_dev itself */
+               spdk_bdev_module_examine_done(&g_lvol_if);
+               goto end;
+       } else if (lvserrno != 0) {
+               SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Lvol store not found on %s\n", req->base_bdev->name);
+               /* On error blobstore destroys bs_dev itself */
+               spdk_bdev_module_examine_done(&g_lvol_if);
+               goto end;
+       }
+
+       lvserrno = spdk_bs_bdev_claim(lvol_store->bs_dev, &g_lvol_if);
+       if (lvserrno != 0) {
+               SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Lvol store base bdev already claimed by another bdev\n");
+               spdk_lvs_unload(lvol_store, _vbdev_lvs_examine_failed, NULL);
+               goto end;
+       }
+
+       lvs_bdev = calloc(1, sizeof(*lvs_bdev));
+       if (!lvs_bdev) {
+               SPDK_ERRLOG("Cannot alloc memory for lvs_bdev\n");
+               spdk_lvs_unload(lvol_store, _vbdev_lvs_examine_failed, NULL);
+               goto end;
+       }
+
+       lvs_bdev->lvs = lvol_store;
+       lvs_bdev->bdev = req->base_bdev;
+
+       TAILQ_INSERT_TAIL(&g_spdk_lvol_pairs, lvs_bdev, lvol_stores);
+
+       SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Lvol store found on %s - begin parsing\n",
+                    req->base_bdev->name);
+
+       lvol_store->lvols_opened = 0;
+
+       if (TAILQ_EMPTY(&lvol_store->lvols)) {
+               SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Lvol store examination done\n");
+               spdk_bdev_module_examine_done(&g_lvol_if);
+       } else {
+               /* Open all lvols */
+               TAILQ_FOREACH_SAFE(lvol, &lvol_store->lvols, link, tmp) {
+                       spdk_lvol_open(lvol, _vbdev_lvs_examine_finish, lvol_store);
+               }
+       }
+
+end:
+       free(req);
+}
+
+static void
+vbdev_lvs_examine(struct spdk_bdev *bdev)
+{
+       struct spdk_bs_dev *bs_dev;
+       struct spdk_lvs_with_handle_req *req;
+
+       req = calloc(1, sizeof(*req));
+       if (req == NULL) {
+               spdk_bdev_module_examine_done(&g_lvol_if);
+               SPDK_ERRLOG("Cannot alloc memory for vbdev lvol store request pointer\n");
+               return;
+       }
+
+       bs_dev = spdk_bdev_create_bs_dev(bdev, vbdev_lvs_hotremove_cb, bdev);
+       if (!bs_dev) {
+               SPDK_INFOLOG(SPDK_LOG_VBDEV_LVOL, "Cannot create bs dev on %s\n", bdev->name);
+               spdk_bdev_module_examine_done(&g_lvol_if);
+               free(req);
+               return;
+       }
+
+       req->base_bdev = bdev;
+
+       spdk_lvs_load(bs_dev, _vbdev_lvs_examine_cb, req);
+}
+
+struct spdk_lvol *
+vbdev_lvol_get_from_bdev(struct spdk_bdev *bdev)
+{
+       if (!bdev || bdev->module != &g_lvol_if) {
+               return NULL;
+       }
+
+       if (bdev->ctxt == NULL) {
+               SPDK_ERRLOG("No lvol ctx assigned to bdev %s\n", bdev->name);
+               return NULL;
+       }
+
+       return (struct spdk_lvol *)bdev->ctxt;
+}
+
+SPDK_LOG_REGISTER_COMPONENT("vbdev_lvol", SPDK_LOG_VBDEV_LVOL);