dm: disable WRITE SAME
authorMike Snitzer <snitzer@redhat.com>
Fri, 21 Dec 2012 20:23:30 +0000 (20:23 +0000)
committerAlasdair G Kergon <agk@redhat.com>
Fri, 21 Dec 2012 20:23:30 +0000 (20:23 +0000)
commitc1a94672a830e01d58c7c7e8de530c3f136d6ff2
tree00f9fa087a3bbae3fe55bda80f6b222512eea51a
parente910d7ebecd1aac43125944a8641b6cb1a0dfabe
dm: disable WRITE SAME

WRITE SAME bios are not yet handled correctly by device-mapper so
disable their use on device-mapper devices by setting
max_write_same_sectors to zero.

As an example, a ciphertext device is incompatible because the data
gets changed according to the location at which it written and so the
dm crypt target cannot support it.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Cc: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
drivers/md/dm-table.c