From: Christoph Hellwig <hch@lst.de>
Date: Tue, 14 Apr 2020 09:28:54 +0200
Subject: [PATCH] block: pass a hd_struct to delete_partition
Git-commit: cddae808aeb77e5c29d22a8e0dfbdaed413f9e04
Patch-Mainline: v5.8-rc1
References: bsc#1175995,jsc#SLE-15608

All callers have the hd_struct at hand, so pass it instead of performing
another lookup.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 block/blk.h             |  2 +-
 block/genhd.c           |  2 +-
 block/partitions/core.c | 22 ++++++++--------------
 3 files changed, 10 insertions(+), 16 deletions(-)

diff --git a/block/blk.h b/block/blk.h
index 305e0ac22bf7..0cbf64108922 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -390,7 +390,7 @@ char *disk_name(struct gendisk *hd, int partno, char *buf);
 #define ADDPART_FLAG_RAID	1
 #define ADDPART_FLAG_WHOLEDISK	2
 void __delete_partition(struct percpu_ref *ref);
-void delete_partition(struct gendisk *disk, int partno);
+void delete_partition(struct gendisk *disk, struct hd_struct *part);
 int bdev_add_partition(struct block_device *bdev, int partno,
 		sector_t start, sector_t length);
 int bdev_del_partition(struct block_device *bdev, int partno);
diff --git a/block/genhd.c b/block/genhd.c
index 06b642b23a07..1cc50ad5b191 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -897,7 +897,7 @@ void del_gendisk(struct gendisk *disk)
 	while ((part = disk_part_iter_next(&piter))) {
 		invalidate_partition(disk, part->partno);
 		bdev_unhash_inode(part_devt(part));
-		delete_partition(disk, part->partno);
+		delete_partition(disk, part);
 	}
 	disk_part_iter_exit(&piter);
 
diff --git a/block/partitions/core.c b/block/partitions/core.c
index 7e2f40875166..6dc534b502a9 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -296,20 +296,12 @@ void __delete_partition(struct percpu_ref *ref)
  * Must be called either with bd_mutex held, before a disk can be opened or
  * after all disk users are gone.
  */
-void delete_partition(struct gendisk *disk, int partno)
+void delete_partition(struct gendisk *disk, struct hd_struct *part)
 {
 	struct disk_part_tbl *ptbl =
 		rcu_dereference_protected(disk->part_tbl, 1);
-	struct hd_struct *part;
-
-	if (partno >= ptbl->len)
-		return;
 
-	part = rcu_dereference_protected(ptbl->part[partno], 1);
-	if (!part)
-		return;
-
-	rcu_assign_pointer(ptbl->part[partno], NULL);
+	rcu_assign_pointer(ptbl->part[part->partno], NULL);
 	rcu_assign_pointer(ptbl->last_lookup, NULL);
 	kobject_put(part->holder_dir);
 	device_del(part_to_dev(part));
@@ -520,10 +512,10 @@ int bdev_del_partition(struct block_device *bdev, int partno)
 	if (!part)
 		return -ENXIO;
 
+	ret = -ENOMEM;
 	bdevp = bdget(part_devt(part));
-	disk_put_part(part);
 	if (!bdevp)
-		return -ENOMEM;
+		goto out_put_part;
 
 	mutex_lock(&bdevp->bd_mutex);
 
@@ -535,13 +527,15 @@ int bdev_del_partition(struct block_device *bdev, int partno)
 	invalidate_bdev(bdevp);
 
 	mutex_lock_nested(&bdev->bd_mutex, 1);
-	delete_partition(bdev->bd_disk, partno);
+	delete_partition(bdev->bd_disk, part);
 	mutex_unlock(&bdev->bd_mutex);
 
 	ret = 0;
 out_unlock:
 	mutex_unlock(&bdevp->bd_mutex);
 	bdput(bdevp);
+out_put_part:
+	disk_put_part(part);
 	return ret;
 }
 
@@ -617,7 +611,7 @@ int blk_drop_partitions(struct gendisk *disk, struct block_device *bdev)
 
 	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
 	while ((part = disk_part_iter_next(&piter)))
-		delete_partition(disk, part->partno);
+		delete_partition(disk, part);
 	disk_part_iter_exit(&piter);
 
 	return 0;
-- 
2.16.4