lib/blobstore: fix real clones check

include/spdk/blob.h

@@ -727,25 +727,42 @@ int spdk_blob_get_clones(struct spdk_blob_store *bs, spdk_blob_id blobid, spdk_b
 			 size_t *count);
 
 /**
- * Provide table with blob id's of clones are dependent on specified snapshot.
+ * Get a count of all snapshot clones.
  * If the clone_attr exists in the blob xattr, then it's a clone.
  *
- * Ids array should be allocated and the count parameter set to the number of
- * id's it can store, before calling this function.
+ * \param bs blobstore.
+ * \param clone_attr Name of the attribute which denotes a clone.
+ * \param snap_uuid Uuid of the snapshot.
  *
- * If ids is NULL or count parameter is not sufficient to handle ids of all
- * clones, -ENOMEM error is returned and count parameter is updated to the
- * total number of clones.
+ * \return count of all clones from snapshots.
+ */
+size_t
+spdk_blob_count_real_clones(struct spdk_blob_store *bs, const char *clone_attr,
+			    const char *snap_uuid);
+
+/**
+ * Callback definition for spdk_bs_blob_clone_iter_cb.
  *
- * \param bs blobstore.
- * \param blobid Snapshots blob id.
- * \param ids Array of the clone ids or NULL to get required size in count.
- * \param count Size of ids. After call it is updated to the number of clones.
+ * \param lvol An iterated lvol.
+ * \param cb_arg Opaque context passed to spdk_bs_blob_clone_iter_cb().
+ * \param blob_id The blob id of the clone.
+ */
+typedef void (*spdk_bs_blob_clone_iter_cb)(void *cb_arg, spdk_blob_id blob_id);
+
+/**
+ * Iterate all snapshot clones.
+ * If the clone_attr exists in the blob xattr, then it's a clone.
  *
- * \return -ENOMEM if count is not sufficient to store all clones.
+ * \param bs blobstore.
+ * \param clone_attr Name of the attribute which denotes a clone.
+ * \param snap_uuid Uuid of the snapshot.
+ * \param cb_fn Callback for each clone.
+ * \param cb_arg Context for each callback.
  */
-int spdk_blob_get_real_clones(struct spdk_blob_store *bs, spdk_blob_id blobid, spdk_blob_id *ids,
-			      size_t *count, const char *clone_attr);
+void
+spdk_blob_get_real_clones(struct spdk_blob_store *bs, const char *clone_attr,
+			  const char *snap_uuid,
+			  spdk_bs_blob_clone_iter_cb cb_fn, void *cb_arg);
 
 /**
  * Get the blob id for the parent snapshot of this blob.

include/spdk/lvol.h

@@ -387,6 +387,16 @@ void spdk_lvol_close(struct spdk_lvol *lvol, spdk_lvol_op_complete cb_fn, void *
  */
 int spdk_lvol_iter_immediate_clones(struct spdk_lvol *lvol, spdk_lvol_iter_cb cb_fn, void *cb_arg);
 
+/**
+ * Get the lvol that has a particular blob id, from the specified lvolstore.
+ *
+ * \param lvs The lvol's lvolstore.
+ * \param uuid The lvol's blobstore blob id.
+ * \return A pointer to the requested lvol on success, else NULL.
+ */
+struct spdk_lvol *
+lvs_get_lvol_by_blob_id(struct spdk_lvol_store *lvs, spdk_blob_id blob_id);
+
 /**
  * Get the lvol that has a particular UUID.
  *

lib/blob/blobstore.c

@@ -9804,7 +9804,8 @@ blob_get_xattr_value(struct spdk_blob *blob, const char *name,
 }
 
 static bool
-blob_xattr_exists(struct spdk_blob *blob, const char *name, bool internal)
+blob_xattr_matches(struct spdk_blob *blob, const char *name, const char *value, int len,
+		   bool internal)
 {
 	struct spdk_xattr	*xattr;
 	struct spdk_xattr_tailq *xattrs;
@@ -9813,7 +9814,11 @@ blob_xattr_exists(struct spdk_blob *blob, const char *name, bool internal)
 
 	TAILQ_FOREACH(xattr, xattrs, link) {
 		if (!strcmp(name, xattr->name)) {
-			return true;
+			if (xattr->value_len != len) {
+				SPDK_ERRLOG("Invalid xattr->value_len for %s\n", name);
+			} else if (!strncmp(value, xattr->value, len)) {
+				return true;
+			}
 		}
 	}
 	return false;
@@ -9986,43 +9991,41 @@ spdk_blob_get_parent_snapshot(struct spdk_blob_store *bs, spdk_blob_id blob_id)
 	return SPDK_BLOBID_INVALID;
 }
 
-int
-spdk_blob_get_real_clones(struct spdk_blob_store *bs, spdk_blob_id blobid, spdk_blob_id *ids,
-			  size_t *count, const char *clone_attr)
+void
+spdk_blob_get_real_clones(struct spdk_blob_store *bs, const char *clone_attr, const char *snap_uuid,
+			  spdk_bs_blob_clone_iter_cb cb_fn, void *cb_arg)
 {
-	struct spdk_blob_list *snapshot_entry, *clone_entry;
-	size_t n;
 	struct spdk_blob *blob;
+	int uuid_len = SPDK_UUID_STRING_LEN - 1;
 
-	snapshot_entry = bs_get_snapshot_entry(bs, blobid);
-	if (snapshot_entry == NULL) {
-		*count = 0;
-		return 0;
-	}
-
-	if (ids == NULL || *count < snapshot_entry->clone_count) {
-		n = 0;
-		TAILQ_FOREACH(clone_entry, &snapshot_entry->clones, link) {
-			blob = blob_lookup(bs, clone_entry->id);
-			if (blob && blob_xattr_exists(blob, clone_attr, false)) {
-				n++;
-			}
+	RB_FOREACH(blob, spdk_blob_tree, &bs->open_blobs) {
+		if (!spdk_blob_is_clone(blob)) {
+			continue;
+		}
+		if (blob_xattr_matches(blob, clone_attr, snap_uuid, uuid_len, false)) {
+			cb_fn(cb_arg, blob->id);
 		}
-		*count = n;
-
-		return -ENOMEM;
 	}
-	*count = snapshot_entry->clone_count;
+}
 
-	n = 0;
-	TAILQ_FOREACH(clone_entry, &snapshot_entry->clones, link) {
-		blob = blob_lookup(bs, clone_entry->id);
-		if (blob && blob_xattr_exists(blob, clone_attr, false)) {
-			ids[n++] = clone_entry->id;
+size_t
+spdk_blob_count_real_clones(struct spdk_blob_store *bs, const char *clone_attr,
+			    const char *snap_uuid)
+{
+	size_t count = 0;
+	struct spdk_blob *blob;
+	int uuid_len = SPDK_UUID_STRING_LEN - 1;
+
+	RB_FOREACH(blob, spdk_blob_tree, &bs->open_blobs) {
+		if (!spdk_blob_is_clone(blob)) {
+			continue;
+		}
+		if (blob_xattr_matches(blob, clone_attr, snap_uuid, uuid_len, false)) {
+			count++;
 		}
 	}
 
-	return 0;
+	return count;
 }
 
 int

lib/lvol/lvol.c

@@ -41,7 +41,6 @@ static inline int lvs_opts_copy(const struct spdk_lvs_opts *src, struct spdk_lvs
 static int lvs_esnap_bs_dev_create(void *bs_ctx, void *blob_ctx, struct spdk_blob *blob,
 				   const void *esnap_id, uint32_t id_len,
 				   struct spdk_bs_dev **_bs_dev);
-static struct spdk_lvol *lvs_get_lvol_by_blob_id(struct spdk_lvol_store *lvs, spdk_blob_id blob_id);
 static void lvs_degraded_lvol_set_add(struct spdk_lvs_degraded_lvol_set *degraded_set,
 				      struct spdk_lvol *lvol);
 static void lvs_degraded_lvol_set_remove(struct spdk_lvs_degraded_lvol_set *degraded_set,
@@ -2102,7 +2101,7 @@ spdk_lvs_grow(struct spdk_bs_dev *bs_dev, spdk_lvs_op_with_handle_complete cb_fn
 	spdk_bs_grow(bs_dev, &opts, lvs_load_cb, req);
 }
 
-static struct spdk_lvol *
+struct spdk_lvol *
 lvs_get_lvol_by_blob_id(struct spdk_lvol_store *lvs, spdk_blob_id blob_id)
 {
 	struct spdk_lvol *lvol;