block: Fix incorrect alignment offset reporting and update documentation
authorMartin K. Petersen <martin.petersen@oracle.com>
Tue, 29 Dec 2009 07:35:35 +0000 (08:35 +0100)
committerJens Axboe <jens.axboe@oracle.com>
Tue, 29 Dec 2009 07:35:35 +0000 (08:35 +0100)
commit81744ee44ab2845c16ffd7d6f762f7b4a49a4750
treec3d0cca0e71080ecd8423cef8af1c632fc444764
parent2f7a2d89a8b5915d89ad9ebeb0065db7d5831cea
block: Fix incorrect alignment offset reporting and update documentation

queue_sector_alignment_offset returned the wrong value which caused
partitions to report an incorrect alignment_offset.  Since offset
alignment calculation is needed several places it has been split into a
separate helper function.  The topology stacking function has been
updated accordingly.

Furthermore, comments have been added to clarify how the stacking
function works.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Tested-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
block/blk-settings.c
include/linux/blkdev.h