block: move integrity information into queue_limits

Move the integrity information into the queue limits so that it can be
set atomically with other queue limits, and that the sysfs changes to
the read_verify and write_generate flags are properly synchronized.
This also allows to provide a more useful helper to stack the integrity
fields, although it still is separate from the main stacking function
as not all stackable devices want to inherit the integrity settings.
Even with that it greatly simplifies the code in md and dm.

Note that the integrity field is moved as-is into the queue limits.
While there are good arguments for removing the separate blk_integrity
structure, this would cause a lot of churn and might better be done at a
later time if desired.  However the integrity field in the queue_limits
structure is now unconditional so that various ifdefs can be avoided or
replaced with IS_ENABLED().  Given that tiny size of it that seems like
a worthwhile trade off.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240613084839.1044015-13-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

3 files changed, 17 insertions, 34 deletions

diff --git a/include/linux/blk-integrity.h b/include/linux/blk-integrity.h
index bafa01d4e7f9..d201140d77a3 100644
--- a/include/linux/blk-integrity.h
+++ b/include/linux/blk-integrity.h
@@ -11,6 +11,7 @@ enum blk_integrity_flags {
 	BLK_INTEGRITY_NOGENERATE	= 1 << 1,
 	BLK_INTEGRITY_DEVICE_CAPABLE	= 1 << 2,
 	BLK_INTEGRITY_REF_TAG		= 1 << 3,
+	BLK_INTEGRITY_STACKED		= 1 << 4,
 };
 
 struct blk_integrity_iter {
@@ -23,11 +24,15 @@ struct blk_integrity_iter {
 };
 
 const char *blk_integrity_profile_name(struct blk_integrity *bi);
+bool queue_limits_stack_integrity(struct queue_limits *t,
+		struct queue_limits *b);
+static inline bool queue_limits_stack_integrity_bdev(struct queue_limits *t,
+		struct block_device *bdev)
+{
+	return queue_limits_stack_integrity(t, &bdev->bd_disk->queue->limits);
+}
 
 #ifdef CONFIG_BLK_DEV_INTEGRITY
-void blk_integrity_register(struct gendisk *, struct blk_integrity *);
-void blk_integrity_unregister(struct gendisk *);
-int blk_integrity_compare(struct gendisk *, struct gendisk *);
 int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
 				   struct scatterlist *);
 int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
@@ -35,14 +40,14 @@ int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
 static inline bool
 blk_integrity_queue_supports_integrity(struct request_queue *q)
 {
-	return q->integrity.tuple_size;
+	return q->limits.integrity.tuple_size;
 }
 
 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
 {
 	if (!blk_integrity_queue_supports_integrity(disk->queue))
 		return NULL;
-	return &disk->queue->integrity;
+	return &disk->queue->limits.integrity;
 }
 
 static inline struct blk_integrity *
@@ -119,17 +124,6 @@ blk_integrity_queue_supports_integrity(struct request_queue *q)
 {
 	return false;
 }
-static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
-{
-	return 0;
-}
-static inline void blk_integrity_register(struct gendisk *d,
-					 struct blk_integrity *b)
-{
-}
-static inline void blk_integrity_unregister(struct gendisk *d)
-{
-}
 static inline unsigned short
 queue_max_integrity_segments(const struct request_queue *q)
 {
@@ -157,4 +151,5 @@ static inline struct bio_vec *rq_integrity_vec(struct request *rq)
 	return NULL;
 }
 #endif /* CONFIG_BLK_DEV_INTEGRITY */
+
 #endif /* _LINUX_BLK_INTEGRITY_H */
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index f9089750919c..0c247a716885 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -334,6 +334,8 @@ struct queue_limits {
 	 * due to possible offsets.
 	 */
 	unsigned int		dma_alignment;
+
+	struct blk_integrity	integrity;
 };
 
 typedef int (*report_zones_cb)(struct blk_zone *zone, unsigned int idx,
@@ -419,10 +421,6 @@ struct request_queue {
 
 	struct queue_limits	limits;
 
-#ifdef  CONFIG_BLK_DEV_INTEGRITY
-	struct blk_integrity integrity;
-#endif	/* CONFIG_BLK_DEV_INTEGRITY */
-
 #ifdef CONFIG_PM
 	struct device		*dev;
 	enum rpm_status		rpm_status;
@@ -1300,11 +1298,9 @@ static inline bool bdev_stable_writes(struct block_device *bdev)
 {
 	struct request_queue *q = bdev_get_queue(bdev);
 
-#ifdef CONFIG_BLK_DEV_INTEGRITY
-	/* BLK_INTEGRITY_CSUM_NONE is not available in blkdev.h */
-	if (q->integrity.csum_type != 0)
+	if (IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY) &&
+	    q->limits.integrity.csum_type != BLK_INTEGRITY_CSUM_NONE)
 		return true;
-#endif
 	return test_bit(QUEUE_FLAG_STABLE_WRITES, &q->queue_flags);
 }
 
diff --git a/include/linux/t10-pi.h b/include/linux/t10-pi.h
index d2bafb76badf..1773610010eb 100644
--- a/include/linux/t10-pi.h
+++ b/include/linux/t10-pi.h
@@ -39,12 +39,8 @@ struct t10_pi_tuple {
 
 static inline u32 t10_pi_ref_tag(struct request *rq)
 {
-	unsigned int shift = ilog2(queue_logical_block_size(rq->q));
+	unsigned int shift = rq->q->limits.integrity.interval_exp;
 
-#ifdef CONFIG_BLK_DEV_INTEGRITY
-	if (rq->q->integrity.interval_exp)
-		shift = rq->q->integrity.interval_exp;
-#endif
 	return blk_rq_pos(rq) >> (shift - SECTOR_SHIFT) & 0xffffffff;
 }
 
@@ -65,12 +61,8 @@ static inline u64 lower_48_bits(u64 n)
 
 static inline u64 ext_pi_ref_tag(struct request *rq)
 {
-	unsigned int shift = ilog2(queue_logical_block_size(rq->q));
+	unsigned int shift = rq->q->limits.integrity.interval_exp;
 
-#ifdef CONFIG_BLK_DEV_INTEGRITY
-	if (rq->q->integrity.interval_exp)
-		shift = rq->q->integrity.interval_exp;
-#endif
 	return lower_48_bits(blk_rq_pos(rq) >> (shift - SECTOR_SHIFT));
 }