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: 1e73973 ("block: optionally merge discontiguous discard bios into a single request") Reviewed-by: Christoph Hellwig <[email protected]> Signed-off-by: Mike Snitzer <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
josf · Jul 24, 2018 · 42c9cdf · 42c9cdf
1 parent c55183c
commit 42c9cdf
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/block/blk-settings.c b/block/blk-settings.c
@@ -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;