Commit c964d62f authored by Keith Busch's avatar Keith Busch Committed by Jens Axboe
Browse files

block: make dma_alignment a stacking queue_limit 



Device mappers had always been getting the default 511 dma mask, but
the underlying device might have a larger alignment requirement. Since
this value is used to determine alloweable direct-io alignment, this
needs to be a stackable limit.

Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221110184501.2451620-2-kbusch@meta.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a7a15981

block/blk-core.c

+0 −1
Original line number Diff line number Diff line
@@ -425,7 +425,6 @@ struct request_queue *blk_alloc_queue(int node_id, bool alloc_srcu) 
				PERCPU_REF_INIT_ATOMIC, GFP_KERNEL))

		goto fail_stats;



	blk_queue_dma_alignment(q, 511);

	blk_set_default_limits(&q->limits);

	q->nr_requests = BLKDEV_DEFAULT_RQ;

block/blk-settings.c

+5 −3
Original line number Diff line number Diff line
@@ -57,6 +57,7 @@ void blk_set_default_limits(struct queue_limits *lim) 
	lim->misaligned = 0;

	lim->zoned = BLK_ZONED_NONE;

	lim->zone_write_granularity = 0;

	lim->dma_alignment = 511;

}

EXPORT_SYMBOL(blk_set_default_limits);
@@ -600,6 +601,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 


	t->io_min = max(t->io_min, b->io_min);

	t->io_opt = lcm_not_zero(t->io_opt, b->io_opt);

	t->dma_alignment = max(t->dma_alignment, b->dma_alignment);



	/* Set non-power-of-2 compatible chunk_sectors boundary */

	if (b->chunk_sectors)
@@ -773,7 +775,7 @@ EXPORT_SYMBOL(blk_queue_virt_boundary); 
 **/

void blk_queue_dma_alignment(struct request_queue *q, int mask)

{

	q->dma_alignment = mask;

	q->limits.dma_alignment = mask;

}

EXPORT_SYMBOL(blk_queue_dma_alignment);
@@ -795,8 +797,8 @@ void blk_queue_update_dma_alignment(struct request_queue *q, int mask) 
{

	BUG_ON(mask > PAGE_SIZE);



	if (mask > q->dma_alignment)

		q->dma_alignment = mask;

	if (mask > q->limits.dma_alignment)

		q->limits.dma_alignment = mask;

}

EXPORT_SYMBOL(blk_queue_update_dma_alignment);

include/linux/blkdev.h

+8 −7
Original line number Diff line number Diff line
@@ -311,6 +311,13 @@ struct queue_limits { 
	unsigned char		discard_misaligned;

	unsigned char		raid_partial_stripes_expensive;

	enum blk_zoned_model	zoned;



	/*

	 * Drivers that set dma_alignment to less than 511 must be prepared to

	 * handle individual bvec's that are not a multiple of a SECTOR_SIZE

	 * due to possible offsets.

	 */

	unsigned int		dma_alignment;

};



typedef int (*report_zones_cb)(struct blk_zone *zone, unsigned int idx,
@@ -456,12 +463,6 @@ struct request_queue { 
	unsigned long		nr_requests;	/* Max # of requests */



	unsigned int		dma_pad_mask;

	/*

	 * Drivers that set dma_alignment to less than 511 must be prepared to

	 * handle individual bvec's that are not a multiple of a SECTOR_SIZE

	 * due to possible offsets.

	 */

	unsigned int		dma_alignment;



#ifdef CONFIG_BLK_INLINE_ENCRYPTION

	struct blk_crypto_profile *crypto_profile;
@@ -1324,7 +1325,7 @@ static inline sector_t bdev_zone_sectors(struct block_device *bdev) 


static inline int queue_dma_alignment(const struct request_queue *q)

{

	return q ? q->dma_alignment : 511;

	return q ? q->limits.dma_alignment : 511;

}



static inline unsigned int bdev_dma_alignment(struct block_device *bdev)