librbd: take ImageCtx->snap_lock for write in add_snap()

add_snap() updates the ImageCtx snapshot metadata in memory, as well as reading the flags as part of the object map snapshot. Both of these require holding snap_lock. Signed-off-by: Josh Durgin <[email protected]>
aledbf · Feb 25, 2015 · 04d360a · 04d360a
1 parent 40c2abb
commit 04d360a
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/src/librbd/internal.cc b/src/librbd/internal.cc
@@ -1783,6 +1783,7 @@ namespace librbd {
       return r;
     }
 
+    RWLock::WLocker l(ictx->snap_lock);
     if (!ictx->old_format) {
       if (ictx->object_map != NULL) {
 	ictx->object_map->snapshot(snap_id);