block: simplify disk_set_independent_access_ranges

Lift setting disk->ia_ranges from disk_register_independent_access_ranges
into disk_set_independent_access_ranges, and make the behavior the same
for the registered vs non-registered queue cases.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Link: https://lore.kernel.org/r/20220629062013.1331068-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-ia-ranges.c

@@ -102,31 +102,18 @@ static struct kobj_type blk_ia_ranges_ktype = {
  * disk_register_independent_access_ranges - register with sysfs a set of
  *		independent access ranges
  * @disk:	Target disk
- * @new_iars:	New set of independent access ranges
  *
  * Register with sysfs a set of independent access ranges for @disk.
- * If @new_iars is not NULL, this set of ranges is registered and the old set
- * specified by disk->ia_ranges is unregistered. Otherwise, disk->ia_ranges is
- * registered if it is not already.
  */
-int disk_register_independent_access_ranges(struct gendisk *disk,
-				struct blk_independent_access_ranges *new_iars)
+int disk_register_independent_access_ranges(struct gendisk *disk)
 {
+	struct blk_independent_access_ranges *iars = disk->ia_ranges;
 	struct request_queue *q = disk->queue;
-	struct blk_independent_access_ranges *iars;
 	int i, ret;
 
 	lockdep_assert_held(&q->sysfs_dir_lock);
 	lockdep_assert_held(&q->sysfs_lock);
 
-	/* If a new range set is specified, unregister the old one */
-	if (new_iars) {
-		if (disk->ia_ranges)
-			disk_unregister_independent_access_ranges(disk);
-		disk->ia_ranges = new_iars;
-	}
-
-	iars = disk->ia_ranges;
 	if (!iars)
 		return 0;
 
@@ -210,6 +197,9 @@ static bool disk_check_ia_ranges(struct gendisk *disk,
 	sector_t sector = 0;
 	int i;
 
+	if (WARN_ON_ONCE(!iars->nr_ia_ranges))
+		return false;
+
 	/*
 	 * While sorting the ranges in increasing LBA order, check that the
 	 * ranges do not overlap, that there are no sector holes and that all
@@ -298,25 +288,15 @@ void disk_set_independent_access_ranges(struct gendisk *disk,
 {
 	struct request_queue *q = disk->queue;
 
-	if (WARN_ON_ONCE(iars && !iars->nr_ia_ranges)) {
+	mutex_lock(&q->sysfs_dir_lock);
+	mutex_lock(&q->sysfs_lock);
+	if (iars && !disk_check_ia_ranges(disk, iars)) {
 		kfree(iars);
 		iars = NULL;
 	}
-
-	mutex_lock(&q->sysfs_dir_lock);
-	mutex_lock(&q->sysfs_lock);
-
-	if (iars) {
-		if (!disk_check_ia_ranges(disk, iars)) {
-			kfree(iars);
-			iars = NULL;
-			goto reg;
-		}
-
-		if (!disk_ia_ranges_changed(disk, iars)) {
-			kfree(iars);
-			goto unlock;
-		}
+	if (iars && !disk_ia_ranges_changed(disk, iars)) {
+		kfree(iars);
+		goto unlock;
 	}
 
 	/*
@@ -324,17 +304,12 @@ void disk_set_independent_access_ranges(struct gendisk *disk,
 	 * revalidation. If that is the case, we need to unregister the old
 	 * set of independent access ranges and register the new set. If the
 	 * queue is not registered, registration of the device request queue
-	 * will register the independent access ranges, so only swap in the
-	 * new set and free the old one.
+	 * will register the independent access ranges.
 	 */
-reg:
-	if (blk_queue_registered(q)) {
-		disk_register_independent_access_ranges(disk, iars);
-	} else {
-		swap(disk->ia_ranges, iars);
-		kfree(iars);
-	}
-
+	disk_unregister_independent_access_ranges(disk);
+	disk->ia_ranges = iars;
+	if (blk_queue_registered(q))
+		disk_register_independent_access_ranges(disk);
 unlock:
 	mutex_unlock(&q->sysfs_lock);
 	mutex_unlock(&q->sysfs_dir_lock);

block/blk-sysfs.c

@@ -832,7 +832,7 @@ int blk_register_queue(struct gendisk *disk)
 		blk_mq_debugfs_register(q);
 	mutex_unlock(&q->debugfs_mutex);
 
-	ret = disk_register_independent_access_ranges(disk, NULL);
+	ret = disk_register_independent_access_ranges(disk);
 	if (ret)
 		goto put_dev;
 

block/blk.h

@@ -459,8 +459,7 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
 
 extern const struct address_space_operations def_blk_aops;
 
-int disk_register_independent_access_ranges(struct gendisk *disk,
-				struct blk_independent_access_ranges *new_iars);
+int disk_register_independent_access_ranges(struct gendisk *disk);
 void disk_unregister_independent_access_ranges(struct gendisk *disk);
 
 #ifdef CONFIG_FAIL_MAKE_REQUEST