librbd has the locking API that can be used to implement .bdrv_lockf.
Signed-off-by: Fam Zheng <f...@redhat.com>
---
block/rbd.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/block/rbd.c b/block/rbd.c
index 5bc5b32..a495083 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -810,6 +810,30 @@ static int qemu_rbd_truncate(BlockDriverState *bs, int64_t
offset)
return 0;
}
+static int qemu_rbd_lockf(BlockDriverState *bs, BdrvLockfCmd cmd)
+{
+ int ret;
+ BDRVRBDState *s = bs->opaque;
+
+ /* XXX: RBD locks are not released automatically when program exits, which
+ * means if QEMU dies it cannot open the image next time until manually
+ * unlocked. */
+ switch (cmd) {
+ case BDRV_LOCKF_RWLOCK:
+ ret = rbd_lock_exclusive(s->image, NULL);
+ break;
+ case BDRV_LOCKF_ROLOCK:
+ ret = rbd_lock_shared(s->image, NULL, NULL);
+ break;
+ case BDRV_LOCKF_UNLOCK:
+ ret = rbd_unlock(s->image, NULL);
+ break;
+ default:
+ abort();
+ }
+ return ret;
+}
+
static int qemu_rbd_snap_create(BlockDriverState *bs,
QEMUSnapshotInfo *sn_info)
{
@@ -998,6 +1022,7 @@ static BlockDriver bdrv_rbd = {
.bdrv_aio_discard = qemu_rbd_aio_discard,
#endif
+ .bdrv_lockf = qemu_rbd_lockf,
.bdrv_snapshot_create = qemu_rbd_snap_create,
.bdrv_snapshot_delete = qemu_rbd_snap_remove,
.bdrv_snapshot_list = qemu_rbd_snap_list,
--
2.8.0
