tree 9f9a631324126407916055efc58b878900993637
parent fcf38cdf332a81b20a59e3ebaea81f6b316bbe0c
author David Disseldorp <ddiss@suse.de> 1511537453 +0100
committer Christoph Hellwig <hch@lst.de> 1513347212 +0100

nvme: set discard_alignment to zero

Similar to 7c084289795b ("rbd: set discard_alignment to zero"), NVMe
devices are currently incorrectly initialised with the block queue
discard_alignment set to the NVMe stream alignment.

As per Documentation/ABI/testing/sysfs-block:
  The discard_alignment parameter indicates how many bytes the beginning
  of the device is offset from the internal allocation unit's natural
  alignment.

Correcting the discard_alignment parameter to zero has no effect on how
discard requests are propagated through the block layer - @alignment in
__blkdev_issue_discard() remains zero. However, it does fix other
consumers, such as LIO's Block Limits VPD response.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>