block: properly stack underlying max_segment_size to DM device
authorMike Snitzer <snitzer@redhat.com>
Fri, 18 Oct 2013 15:44:49 +0000 (09:44 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 29 Nov 2013 19:11:51 +0000 (11:11 -0800)
commit0deb6f9cb87494f6646fb014f09b41d3ded76c63
tree59fdafc3554f3f237a3320cfb624341b22117eca
parent12e6e9c2a578d3a2f0474d48d845f796361a90c0
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>
block/blk-settings.c