block: Mark bdrv_co_create() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_create() need to hold a reader lock for the graph.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-17-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/block/create.c b/block/create.c
index 4df43f1..bf67b99 100644
--- a/block/create.c
+++ b/block/create.c
@@ -43,6 +43,7 @@ static int coroutine_fn blockdev_create_run(Job *job, Error **errp)
     int ret;
 
     GLOBAL_STATE_CODE();
+    GRAPH_RDLOCK_GUARD();
 
     job_progress_set_remaining(&s->common, 1);
     ret = s->drv->bdrv_co_create(s->opts, errp);
@@ -59,6 +60,12 @@ static const JobDriver blockdev_create_job_driver = {
     .run           = blockdev_create_run,
 };
 
+/* Checking whether the function is present doesn't require the graph lock */
+static inline bool TSA_NO_TSA has_bdrv_co_create(BlockDriver *drv)
+{
+    return drv->bdrv_co_create;
+}
+
 void qmp_blockdev_create(const char *job_id, BlockdevCreateOptions *options,
                          Error **errp)
 {
@@ -79,7 +86,7 @@ void qmp_blockdev_create(const char *job_id, BlockdevCreateOptions *options,
     }
 
     /* Error out if the driver doesn't support .bdrv_co_create */
-    if (!drv->bdrv_co_create) {
+    if (!has_bdrv_co_create(drv)) {
         error_setg(errp, "Driver does not support blockdev-create");
         return;
     }