RBD devices are currently incorrectly initialised with the block queue discard_alignment set to the underlying RADOS object size. 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 from the RADOS object size to zero (the blk_set_default_limits() default) has no effect on how discard requests are propagated through the block layer - @alignment in __blkdev_issue_discard() remains zero. However, it does fix the UNMAP granularity alignment value advertised to SCSI initiators via the Block Limits VPD. Signed-off-by: David Disseldorp <ddiss@xxxxxxx> --- drivers/block/rbd.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index b640ad8a6d20..016542c75e1f 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -4423,7 +4423,6 @@ static int rbd_init_disk(struct rbd_device *rbd_dev) /* enable the discard support */ queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q); q->limits.discard_granularity = segment_size; - q->limits.discard_alignment = segment_size; blk_queue_max_discard_sectors(q, segment_size / SECTOR_SIZE); blk_queue_max_write_zeroes_sectors(q, segment_size / SECTOR_SIZE); -- 2.13.6 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
