Commit 42c9cdfe authored Jul 20, 2018 by Mike Snitzer Committed by Jens Axboe Jul 24, 2018

block: allow max_discard_segments to be stacked



Set max_discard_segments to USHRT_MAX in blk_set_stacking_limits() so
that blk_stack_limits() can stack up this limit for stacked devices.

before:

$ cat /sys/block/nvme0n1/queue/max_discard_segments
256
$ cat /sys/block/dm-0/queue/max_discard_segments
1

after:

$ cat /sys/block/nvme0n1/queue/max_discard_segments
256
$ cat /sys/block/dm-0/queue/max_discard_segments
256

Fixes: 1e739730 ("block: optionally merge discontiguous discard bios into a single request")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent c55183c9

block/blk-settings.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -128,7 +128,7 @@ void blk_set_stacking_limits(struct queue_limits *lim)

		/* Inherit limits from component devices */
		lim->max_segments = USHRT_MAX;
		lim->max_discard_segments = 1;
		lim->max_discard_segments = USHRT_MAX;
		lim->max_hw_sectors = UINT_MAX;
		lim->max_segment_size = UINT_MAX;
		lim->max_sectors = UINT_MAX;

Admin message