4.14-stable review patch. If anyone has any objections, please let me know.
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From: Mike Snitzer snitzer@redhat.com
[ Upstream commit 42c9cdfe1e11e083dceb0f0c4977b758cf7403b9 ]
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: 1e739730c5b9e ("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 Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- block/blk-settings.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -128,7 +128,7 @@ void blk_set_stacking_limits(struct queu
/* 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;