rbd: store snapshot id instead of index
authorJosh Durgin <josh.durgin@dreamhost.com>
Mon, 21 Nov 2011 21:04:42 +0000 (13:04 -0800)
committerAlex Elder <elder@dreamhost.com>
Mon, 14 May 2012 17:12:52 +0000 (12:12 -0500)
commit77dfe99fe3cb0b2b0545e19e2d57b7a9134ee3c0
treead80a6b7d9a9be1880c44e3a91f6d42f674c2fd6
parent403f24d3d51760a8b9368d595fa5f48c309f1a0f
rbd: store snapshot id instead of index

When a device was open at a snapshot, and snapshots were deleted or
added, data from the wrong snapshot could be read. Instead of
assuming the snap context is constant, store the actual snap id when
the device is initialized, and rely on the OSDs to signal an error
if we try reading from a snapshot that was deleted.

Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
drivers/block/rbd.c