summaryrefslogtreecommitdiff
path: root/drivers/block
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/rbd.c30
1 files changed, 28 insertions, 2 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 8b6091b6d5cb..9717e20f3477 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1929,6 +1929,11 @@ static void rbd_dev_parent_put(struct rbd_device *rbd_dev)
* If an image has a non-zero parent overlap, get a reference to its
* parent.
*
+ * We must get the reference before checking for the overlap to
+ * coordinate properly with zeroing the parent overlap in
+ * rbd_dev_v2_parent_info() when an image gets flattened. We
+ * drop it again if there is no overlap.
+ *
* Returns true if the rbd device has a parent with a non-zero
* overlap and a reference for it was successfully taken, or
* false otherwise.
@@ -3782,8 +3787,26 @@ static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
end = reply_buf + ret;
ret = -ERANGE;
ceph_decode_64_safe(&p, end, pool_id, out_err);
- if (pool_id == CEPH_NOPOOL)
+ if (pool_id == CEPH_NOPOOL) {
+ /*
+ * Either the parent never existed, or we have
+ * record of it but the image got flattened so it no
+ * longer has a parent. When the parent of a
+ * layered image disappears we immediately set the
+ * overlap to 0. The effect of this is that all new
+ * requests will be treated as if the image had no
+ * parent.
+ */
+ if (rbd_dev->parent_overlap) {
+ rbd_dev->parent_overlap = 0;
+ smp_mb();
+ rbd_dev_parent_put(rbd_dev);
+ pr_info("%s: clone image has been flattened\n",
+ rbd_dev->disk->disk_name);
+ }
+
goto out; /* No parent? No problem. */
+ }
/* The ceph file layout needs to fit pool id in 32 bits */
@@ -4633,7 +4656,10 @@ static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
{
struct rbd_image_header *header;
- rbd_dev_parent_put(rbd_dev);
+ /* Drop parent reference unless it's already been done (or none) */
+
+ if (rbd_dev->parent_overlap)
+ rbd_dev_parent_put(rbd_dev);
/* Free dynamic fields from the header, then zero it out */