tree a0369a9de402cd8b9a123129c5e8ba7c69ba1a95
parent 969429b504ae866d3f8b1cafd68a2c099e305093
author Alasdair G Kergon <agk@redhat.com> 1143451070 -0800
committer Linus Torvalds <torvalds@g5.osdl.org> 1143477899 -0800

[PATCH] dm snapshot: fix kcopyd destructor

Before removing a snapshot, wait for the completion of any kcopyd jobs using
it.

Do this by maintaining a count (nr_jobs) of how many outstanding jobs each
kcopyd_client has.

The snapshot destructor first unregisters the snapshot so that no new kcopyd
jobs (created by writes to the origin) will reference that particular
snapshot.  kcopyd_client_destroy() is now run next to wait for the completion
of any outstanding jobs before the snapshot exception structures (that those
jobs reference) are freed.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>