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>

1 files changed, 17 insertions, 55 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index aff9118ff697..67ece2cd725f 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2410,36 +2410,10 @@ static LIST_HEAD(pending_raid_disks);
  */
 int md_integrity_register(struct mddev *mddev)
 {
-	struct md_rdev *rdev, *reference = NULL;
-
 	if (list_empty(&mddev->disks))
 		return 0; /* nothing to do */
-	if (mddev_is_dm(mddev) || blk_get_integrity(mddev->gendisk))
-		return 0; /* shouldn't register, or already is */
-	rdev_for_each(rdev, mddev) {
-		/* skip spares and non-functional disks */
-		if (test_bit(Faulty, &rdev->flags))
-			continue;
-		if (rdev->raid_disk < 0)
-			continue;
-		if (!reference) {
-			/* Use the first rdev as the reference */
-			reference = rdev;
-			continue;
-		}
-		/* does this rdev's profile match the reference profile? */
-		if (blk_integrity_compare(reference->bdev->bd_disk,
-				rdev->bdev->bd_disk) < 0)
-			return -EINVAL;
-	}
-	if (!reference || !bdev_get_integrity(reference->bdev))
-		return 0;
-	/*
-	 * All component devices are integrity capable and have matching
-	 * profiles, register the common profile for the md device.
-	 */
-	blk_integrity_register(mddev->gendisk,
-			       bdev_get_integrity(reference->bdev));
+	if (mddev_is_dm(mddev) || !blk_get_integrity(mddev->gendisk))
+		return 0; /* shouldn't register */
 
 	pr_debug("md: data integrity enabled on %s\n", mdname(mddev));
 	if (bioset_integrity_create(&mddev->bio_set, BIO_POOL_SIZE) ||
@@ -2459,32 +2433,6 @@ int md_integrity_register(struct mddev *mddev)
 }
 EXPORT_SYMBOL(md_integrity_register);
 
-/*
- * Attempt to add an rdev, but only if it is consistent with the current
- * integrity profile
- */
-int md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev)
-{
-	struct blk_integrity *bi_mddev;
-
-	if (mddev_is_dm(mddev))
-		return 0;
-
-	bi_mddev = blk_get_integrity(mddev->gendisk);
-
-	if (!bi_mddev) /* nothing to do */
-		return 0;
-
-	if (blk_integrity_compare(mddev->gendisk, rdev->bdev->bd_disk) != 0) {
-		pr_err("%s: incompatible integrity profile for %pg\n",
-		       mdname(mddev), rdev->bdev);
-		return -ENXIO;
-	}
-
-	return 0;
-}
-EXPORT_SYMBOL(md_integrity_add_rdev);
-
 static bool rdev_read_only(struct md_rdev *rdev)
 {
 	return bdev_read_only(rdev->bdev) ||
@@ -5755,14 +5703,20 @@ static const struct kobj_type md_ktype = {
 int mdp_major = 0;
 
 /* stack the limit for all rdevs into lim */
-void mddev_stack_rdev_limits(struct mddev *mddev, struct queue_limits *lim)
+int mddev_stack_rdev_limits(struct mddev *mddev, struct queue_limits *lim,
+		unsigned int flags)
 {
 	struct md_rdev *rdev;
 
 	rdev_for_each(rdev, mddev) {
 		queue_limits_stack_bdev(lim, rdev->bdev, rdev->data_offset,
 					mddev->gendisk->disk_name);
+		if ((flags & MDDEV_STACK_INTEGRITY) &&
+		    !queue_limits_stack_integrity_bdev(lim, rdev->bdev))
+			return -EINVAL;
 	}
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(mddev_stack_rdev_limits);
 
@@ -5777,6 +5731,14 @@ int mddev_stack_new_rdev(struct mddev *mddev, struct md_rdev *rdev)
 	lim = queue_limits_start_update(mddev->gendisk->queue);
 	queue_limits_stack_bdev(&lim, rdev->bdev, rdev->data_offset,
 				mddev->gendisk->disk_name);
+
+	if (!queue_limits_stack_integrity_bdev(&lim, rdev->bdev)) {
+		pr_err("%s: incompatible integrity profile for %pg\n",
+		       mdname(mddev), rdev->bdev);
+		queue_limits_cancel_update(mddev->gendisk->queue);
+		return -ENXIO;
+	}
+
 	return queue_limits_commit_update(mddev->gendisk->queue, &lim);
 }
 EXPORT_SYMBOL_GPL(mddev_stack_new_rdev);