dm snapshot: lock snapshot while supplying status
authorMikulas Patocka <mpatocka@redhat.com>
Fri, 16 Oct 2009 22:18:16 +0000 (23:18 +0100)
committerAlasdair G Kergon <agk@redhat.com>
Fri, 16 Oct 2009 22:18:16 +0000 (23:18 +0100)
commit4c6fff445d7aa753957856278d4d93bcad6e2c14
tree56ac3d262699fe5a42f76fe9f992277a6a7a2934
parent0e8c4e4e3ebb15756ddc4170a88149a2cd323cfe
dm snapshot: lock snapshot while supplying status

This patch locks the snapshot when returning status.  It fixes a race
when it could return an invalid number of free chunks if someone
was simultaneously modifying it.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
drivers/md/dm-snap.c