]> git.baikalelectronics.ru Git - kernel.git/commit
dm thin metadata: fix bug when taking a metadata snapshot
authorJoe Thornber <ejt@redhat.com>
Wed, 9 Dec 2015 16:23:24 +0000 (16:23 +0000)
committerMike Snitzer <snitzer@redhat.com>
Wed, 9 Dec 2015 18:18:12 +0000 (13:18 -0500)
commit14fd064aacf2cb7924f35a9abfc0d914a5992192
treed4bf6148e45a044eaf8cba9c5e827efff06a7f1b
parent1bb5a088fdb2ea8725f01a67f855886c63a2da3c
dm thin metadata: fix bug when taking a metadata snapshot

When you take a metadata snapshot the btree roots for the mapping and
details tree need to have their reference counts incremented so they
persist for the lifetime of the metadata snap.

The roots being incremented were those currently written in the
superblock, which could possibly be out of date if concurrent IO is
triggering new mappings, breaking of sharing, etc.

Fix this by performing a commit with the metadata lock held while taking
a metadata snapshot.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
drivers/md/dm-thin-metadata.c