BlockBackend name is empty if it is added with '-blockdev' and '-device'
options or hotplugged with QMP but callers still expect backend to be
accesible by name for operations like commit or statistics access.
Intoduce blk_lookup function to search both by name and BDS-root node_name.
Signed-off-by: Anton Kuchin <antonkuc...@yandex-team.ru>
---
block/block-backend.c | 29 +++++++++++++++++++++++++++++
include/sysemu/block-backend.h | 7 +++++++
2 files changed, 36 insertions(+)
diff --git a/block/block-backend.c b/block/block-backend.c
index 60d37a0c3d..86a492853c 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -684,6 +684,35 @@ static BlockBackend *bdrv_first_blk(BlockDriverState *bs)
return NULL;
}
+/*
+ * Return the BlockBackend that has attached BDS-tree root with
+ * node_name @node_name if it exists, else null.
+ * @node_name must not be null.
+ */
+static BlockBackend *blk_by_root_name(const char *node_name)
+{
+ BlockBackend *blk = NULL;
+
+ assert(node_name);
+ while ((blk = blk_all_next(blk)) != NULL) {
+ BlockDriverState *bs = blk_bs(blk);
+ if (bs && !strcmp(node_name, bs->node_name)) {
+ return blk;
+ }
+ }
+ return NULL;
+}
+
+BlockBackend *blk_lookup(const char *name)
+{
+ assert(name);
+ BlockBackend *blk = blk_by_name(name);
+ if (!blk) {
+ blk = blk_by_root_name(name);
+ }
+ return blk;
+}
+
/*
* Returns true if @bs has an associated BlockBackend.
*/
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index c96bcdee14..290b8f8fc9 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -85,6 +85,13 @@ void blk_unref(BlockBackend *blk);
void blk_remove_all_bs(void);
const char *blk_name(const BlockBackend *blk);
BlockBackend *blk_by_name(const char *name);
+
+/*
+ * Search BlockBackend by name or root BlockDriverSate node_name.
+ * Hotplug BlockBackends have no name so need to also check BDS-tree roots
+ * @name must not be null.
+ */
+BlockBackend *blk_lookup(const char *name);
BlockBackend *blk_next(BlockBackend *blk);
BlockBackend *blk_all_next(BlockBackend *blk);
bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp);
--
2.19.1
