block: remove the discard_alignment flag

queue_limits.discard_alignment is never read except in the places
where it is stacked into another limit.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240619154623.450048-6-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-settings.c

@@ -578,16 +578,6 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 	if (b->discard_granularity) {
 		alignment = queue_limit_discard_alignment(b, start);
 
-		if (t->discard_granularity != 0 &&
-		    t->discard_alignment != alignment) {
-			top = t->discard_granularity + t->discard_alignment;
-			bottom = b->discard_granularity + alignment;
-
-			/* Verify that top and bottom intervals line up */
-			if ((max(top, bottom) % min(top, bottom)) != 0)
-				t->discard_misaligned = 1;
-		}
-
 		t->max_discard_sectors = min_not_zero(t->max_discard_sectors,
 						      b->max_discard_sectors);
 		t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors,

drivers/md/dm-cache-target.c

@@ -3403,7 +3403,6 @@ static void set_discard_limits(struct cache *cache, struct queue_limits *limits)
 	limits->max_hw_discard_sectors = origin_limits->max_hw_discard_sectors;
 	limits->discard_granularity = origin_limits->discard_granularity;
 	limits->discard_alignment = origin_limits->discard_alignment;
-	limits->discard_misaligned = origin_limits->discard_misaligned;
 }
 
 static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits)

drivers/md/dm-clone-target.c

@@ -2059,7 +2059,6 @@ static void set_discard_limits(struct clone *clone, struct queue_limits *limits)
 	limits->max_hw_discard_sectors = dest_limits->max_hw_discard_sectors;
 	limits->discard_granularity = dest_limits->discard_granularity;
 	limits->discard_alignment = dest_limits->discard_alignment;
-	limits->discard_misaligned = dest_limits->discard_misaligned;
 	limits->max_discard_segments = dest_limits->max_discard_segments;
 }
 

drivers/md/dm-table.c

@@ -1808,7 +1808,6 @@ int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 		limits->max_hw_discard_sectors = 0;
 		limits->discard_granularity = 0;
 		limits->discard_alignment = 0;
-		limits->discard_misaligned = 0;
 	}
 
 	if (!dm_table_supports_write_zeroes(t))

include/linux/blkdev.h

@@ -377,7 +377,6 @@ struct queue_limits {
 	unsigned short		max_integrity_segments;
 	unsigned short		max_discard_segments;
 
-	unsigned char		discard_misaligned;
 	unsigned char		raid_partial_stripes_expensive;
 	unsigned int		max_open_zones;
 	unsigned int		max_active_zones;