dm snapshot: support barriers in snapshot merge target
authorMike Snitzer <snitzer@redhat.com>
Thu, 10 Dec 2009 23:52:31 +0000 (23:52 +0000)
committerAlasdair G Kergon <agk@redhat.com>
Thu, 10 Dec 2009 23:52:31 +0000 (23:52 +0000)
commit10b8106a70433e14153469ebbdd189776500e238
tree5d46ee65e40d165494ef1d4342e03f2fcfaa0492
parent3452c2a1eb5b93c1b9fb0d22bd5b07c0cee4dc29
dm snapshot: support barriers in snapshot merge target

Sets num_flush_requests=2 to support flushing both the origin and cow
devices used by the snapshot-merge target.

Also, snapshot_ctr() now gets the origin device using FMODE_WRITE if the
target is snapshot-merge (which writes to the origin device).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
drivers/md/dm-snap.c