block: properly stack underlying max_segment_size to DM device

commit d82ae52e68892338068e7559a0c0657193341ce4 upstream.

Without this patch all DM devices will default to BLK_MAX_SEGMENT_SIZE
(65536) even if the underlying device(s) have a larger value -- this is
due to blk_stack_limits() using min_not_zero() when stacking the
max_segment_size limit.

1073741824

before patch:
65536

after patch:
1073741824

Reported-by: Lukasz Flis <l.flis@cyfronet.pl>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mike Snitzer 2013-10-18 09:44:49 -06:00 committed by Greg Kroah-Hartman
parent 12e6e9c2a5
commit 0deb6f9cb8
1 changed files with 1 additions and 0 deletions

View File

@ -144,6 +144,7 @@ void blk_set_stacking_limits(struct queue_limits *lim)
lim->discard_zeroes_data = 1;
lim->max_segments = USHRT_MAX;
lim->max_hw_sectors = UINT_MAX;
lim->max_segment_size = UINT_MAX;
lim->max_sectors = UINT_MAX;
lim->max_write_same_sectors = UINT_MAX;
}