Merge branch 'for-6.11/block-limits' into for-6.11/block

Merge in queue limits cleanups.

* for-6.11/block-limits:
  block: move the raid_partial_stripes_expensive flag into the features field
  block: remove the discard_alignment flag
  block: move the misaligned flag into the features field
  block: renumber and rename the cache disabled flag
  block: fix spelling and grammar for in writeback_cache_control.rst
  block: remove the unused blk_bounce enum

Author: axboe

Documentation/block/writeback_cache_control.rst

@@ -70,8 +70,8 @@ flag in the features field of the queue_limits structure.
 Implementation details for bio based block drivers
 --------------------------------------------------
 
-For bio based drivers the REQ_PREFLUSH and REQ_FUA bit are simplify passed on
-to the driver if the drivers sets the BLK_FEAT_WRITE_CACHE flag and the drivers
+For bio based drivers the REQ_PREFLUSH and REQ_FUA bit are simply passed on to
+the driver if the driver sets the BLK_FEAT_WRITE_CACHE flag and the driver
 needs to handle them.
 
 *NOTE*: The REQ_FUA bit also gets passed on when the BLK_FEAT_FUA flags is
@@ -89,7 +89,7 @@ When the BLK_FEAT_WRITE_CACHE flag is set, REQ_OP_WRITE | REQ_PREFLUSH requests
 with a payload are automatically turned into a sequence of a REQ_OP_FLUSH
 request followed by the actual write by the block layer.
 
-When the BLK_FEAT_FUA flags is set, the REQ_FUA bit simplify passed on for the
+When the BLK_FEAT_FUA flags is set, the REQ_FUA bit is simply passed on for the
 REQ_OP_WRITE request, else a REQ_OP_FLUSH request is sent by the block layer
 after the completion of the write request for bio submissions with the REQ_FUA
 bit set.

block/blk-settings.c

@@ -266,7 +266,7 @@ static int blk_validate_limits(struct queue_limits *lim)
 
 	if (lim->alignment_offset) {
 		lim->alignment_offset &= (lim->physical_block_size - 1);
-		lim->misaligned = 0;
+		lim->features &= ~BLK_FEAT_MISALIGNED;
 	}
 
 	if (!(lim->features & BLK_FEAT_WRITE_CACHE))
@@ -477,6 +477,8 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 	if (!(b->features & BLK_FEAT_POLL))
 		t->features &= ~BLK_FEAT_POLL;
 
+	t->flags |= (b->flags & BLK_FEAT_MISALIGNED);
+
 	t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
 	t->max_user_sectors = min_not_zero(t->max_user_sectors,
 			b->max_user_sectors);
@@ -501,8 +503,6 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 	t->max_segment_size = min_not_zero(t->max_segment_size,
 					   b->max_segment_size);
 
-	t->misaligned |= b->misaligned;
-
 	alignment = queue_limit_alignment_offset(b, start);
 
 	/* Bottom device has different alignment.  Check that it is
@@ -516,7 +516,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 
 		/* Verify that top and bottom intervals line up */
 		if (max(top, bottom) % min(top, bottom)) {
-			t->misaligned = 1;
+			t->flags |= BLK_FEAT_MISALIGNED;
 			ret = -1;
 		}
 	}
@@ -538,42 +538,38 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 	/* Physical block size a multiple of the logical block size? */
 	if (t->physical_block_size & (t->logical_block_size - 1)) {
 		t->physical_block_size = t->logical_block_size;
-		t->misaligned = 1;
+		t->flags |= BLK_FEAT_MISALIGNED;
 		ret = -1;
 	}
 
 	/* Minimum I/O a multiple of the physical block size? */
 	if (t->io_min & (t->physical_block_size - 1)) {
 		t->io_min = t->physical_block_size;
-		t->misaligned = 1;
+		t->flags |= BLK_FEAT_MISALIGNED;
 		ret = -1;
 	}
 
 	/* Optimal I/O a multiple of the physical block size? */
 	if (t->io_opt & (t->physical_block_size - 1)) {
 		t->io_opt = 0;
-		t->misaligned = 1;
+		t->flags |= BLK_FEAT_MISALIGNED;
 		ret = -1;
 	}
 
 	/* chunk_sectors a multiple of the physical block size? */
 	if ((t->chunk_sectors << 9) & (t->physical_block_size - 1)) {
 		t->chunk_sectors = 0;
-		t->misaligned = 1;
+		t->flags |= BLK_FEAT_MISALIGNED;
 		ret = -1;
 	}
 
-	t->raid_partial_stripes_expensive =
-		max(t->raid_partial_stripes_expensive,
-		    b->raid_partial_stripes_expensive);
-
 	/* Find lowest common alignment_offset */
 	t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment)
 		% max(t->physical_block_size, t->io_min);
 
 	/* Verify that new alignment_offset is on a logical block boundary */
 	if (t->alignment_offset & (t->logical_block_size - 1)) {
-		t->misaligned = 1;
+		t->flags |= BLK_FEAT_MISALIGNED;
 		ret = -1;
 	}
 
@@ -585,16 +581,6 @@ 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,
@@ -736,7 +722,7 @@ int bdev_alignment_offset(struct block_device *bdev)
 {
 	struct request_queue *q = bdev_get_queue(bdev);
 
-	if (q->limits.misaligned)
+	if (q->limits.flags & BLK_FEAT_MISALIGNED)
 		return -1;
 	if (bdev_is_partition(bdev))
 		return queue_limit_alignment_offset(&q->limits,

block/blk-sysfs.c

@@ -429,7 +429,7 @@ static ssize_t queue_io_timeout_store(struct request_queue *q, const char *page,
 
 static ssize_t queue_wc_show(struct request_queue *q, char *page)
 {
-	if (q->limits.features & BLK_FLAGS_WRITE_CACHE_DISABLED)
+	if (q->limits.features & BLK_FLAG_WRITE_CACHE_DISABLED)
 		return sprintf(page, "write through\n");
 	return sprintf(page, "write back\n");
 }
@@ -452,9 +452,9 @@ static ssize_t queue_wc_store(struct request_queue *q, const char *page,
 
 	lim = queue_limits_start_update(q);
 	if (disable)
-		lim.flags |= BLK_FLAGS_WRITE_CACHE_DISABLED;
+		lim.flags |= BLK_FLAG_WRITE_CACHE_DISABLED;
 	else
-		lim.flags &= ~BLK_FLAGS_WRITE_CACHE_DISABLED;
+		lim.flags &= ~BLK_FLAG_WRITE_CACHE_DISABLED;
 	err = queue_limits_commit_update(q, &lim);
 	if (err)
 		return err;

drivers/md/bcache/super.c

@@ -1416,8 +1416,8 @@ static int cached_dev_init(struct cached_dev *dc, unsigned int block_size)
 	}
 
 	if (bdev_io_opt(dc->bdev))
-		dc->partial_stripes_expensive =
-			q->limits.raid_partial_stripes_expensive;
+		dc->partial_stripes_expensive = q->limits.features &
+			BLK_FEAT_RAID_PARTIAL_STRIPES_EXPENSIVE;
 
 	ret = bcache_device_init(&dc->disk, block_size,
 			 bdev_nr_sectors(dc->bdev) - dc->sb.data_offset,

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))

drivers/md/raid5.c

@@ -7711,7 +7711,7 @@ static int raid5_set_limits(struct mddev *mddev)
 	blk_set_stacking_limits(&lim);
 	lim.io_min = mddev->chunk_sectors << 9;
 	lim.io_opt = lim.io_min * (conf->raid_disks - conf->max_degraded);
-	lim.raid_partial_stripes_expensive = 1;
+	lim.features |= BLK_FEAT_RAID_PARTIAL_STRIPES_EXPENSIVE;
 	lim.discard_granularity = stripe;
 	lim.max_write_zeroes_sectors = 0;
 	mddev_stack_rdev_limits(mddev, &lim, 0);

include/linux/blkdev.h

@@ -328,28 +328,26 @@ enum {
 
 	/* bounce all highmem pages */
 	BLK_FEAT_BOUNCE_HIGH			= (1u << 14),
+
+	/* undocumented magic for bcache */
+	BLK_FEAT_RAID_PARTIAL_STRIPES_EXPENSIVE	= (1u << 15),
 };
 
 /*
  * Flags automatically inherited when stacking limits.
  */
 #define BLK_FEAT_INHERIT_MASK \
 	(BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA | BLK_FEAT_ROTATIONAL | \
-	 BLK_FEAT_STABLE_WRITES | BLK_FEAT_ZONED | BLK_FEAT_BOUNCE_HIGH)
+	 BLK_FEAT_STABLE_WRITES | BLK_FEAT_ZONED | BLK_FEAT_BOUNCE_HIGH | \
+	 BLK_FEAT_RAID_PARTIAL_STRIPES_EXPENSIVE)
 
 /* internal flags in queue_limits.flags */
 enum {
-	/* do not send FLUSH or FUA command despite advertised write cache */
-	BLK_FLAGS_WRITE_CACHE_DISABLED		= (1u << 31),
-};
+	/* do not send FLUSH/FUA commands despite advertising a write cache */
+	BLK_FLAG_WRITE_CACHE_DISABLED		= (1u << 0),
 
-/*
- * BLK_BOUNCE_NONE:	never bounce (default)
- * BLK_BOUNCE_HIGH:	bounce all highmem pages
- */
-enum blk_bounce {
-	BLK_BOUNCE_NONE,
-	BLK_BOUNCE_HIGH,
+	/* I/O topology is misaligned */
+	BLK_FEAT_MISALIGNED			= (1u << 1),
 };
 
 struct queue_limits {
@@ -383,9 +381,6 @@ struct queue_limits {
 	unsigned short		max_integrity_segments;
 	unsigned short		max_discard_segments;
 
-	unsigned char		misaligned;
-	unsigned char		discard_misaligned;
-	unsigned char		raid_partial_stripes_expensive;
 	unsigned int		max_open_zones;
 	unsigned int		max_active_zones;
 
@@ -1347,7 +1342,7 @@ static inline bool bdev_stable_writes(struct block_device *bdev)
 static inline bool blk_queue_write_cache(struct request_queue *q)
 {
 	return (q->limits.features & BLK_FEAT_WRITE_CACHE) &&
-		!(q->limits.flags & BLK_FLAGS_WRITE_CACHE_DISABLED);
+		!(q->limits.flags & BLK_FLAG_WRITE_CACHE_DISABLED);
 }
 
 static inline bool bdev_write_cache(struct block_device *bdev)