From: David Disseldorp <ddiss@suse.de>
Date: Fri, 24 Nov 2017 16:30:53 +0100
Subject: nvme: set discard_alignment to zero
Patch-mainline: v4.15-rc5
Git-commit: b224f6134d72e3493a023b5bea917f9a6beea0c8
References: FATE#323952, FATE#322506
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>
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
---
drivers/nvme/host/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1287,7 +1287,7 @@ static void nvme_config_discard(struct n
BUILD_BUG_ON(PAGE_SIZE / sizeof(struct nvme_dsm_range) <
NVME_DSM_MAX_RANGES);
- queue->limits.discard_alignment = size;
+ queue->limits.discard_alignment = 0;
queue->limits.discard_granularity = size;
blk_queue_max_discard_sectors(queue, UINT_MAX);