diff options
| -rw-r--r-- | drivers/block/rbd.c | 30 |
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 */ |