From: Christoph Hellwig <hch@lst.de>
Date: Thu, 16 Jul 2020 16:33:09 +0200
Subject: [PATCH] block: use bd_prepare_to_claim directly in the loop driver
Git-commit: ecbe6bc0003bfd5bf8581cb679cae0eb944432cb
Patch-mainline: v5.9-rc1
References: bsc#1175995,jsc#SLE-15608
The arcane magic in bd_start_claiming is only needed to be able to claim
a block_device that hasn't been fully set up. Switch the loop driver
that claims from the ioctl path with a fully set up struct block_device
to just use the much simpler bd_prepare_to_claim directly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
drivers/block/loop.c | 7 +++----
fs/block_dev.c | 9 +++++----
include/linux/blkdev.h | 3 ++-
3 files changed, 10 insertions(+), 9 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index a943207705dd..d18160146226 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1090,11 +1090,10 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
* here to avoid changing device under exclusive owner.
*/
if (!(mode & FMODE_EXCL)) {
- claimed_bdev = bd_start_claiming(bdev, loop_configure);
- if (IS_ERR(claimed_bdev)) {
- error = PTR_ERR(claimed_bdev);
+ claimed_bdev = bdev->bd_contains;
+ error = bd_prepare_to_claim(bdev, claimed_bdev, loop_configure);
+ if (error)
goto out_putf;
- }
}
error = mutex_lock_killable(&loop_ctl_mutex);
diff --git a/fs/block_dev.c b/fs/block_dev.c
index b7b2ee4b288a..ee80bd81af74 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1027,8 +1027,8 @@ static bool bd_may_claim(struct block_device *bdev, struct block_device *whole,
* RETURNS:
* 0 if @bdev can be claimed, -EBUSY otherwise.
*/
-static int bd_prepare_to_claim(struct block_device *bdev,
- struct block_device *whole, void *holder)
+int bd_prepare_to_claim(struct block_device *bdev, struct block_device *whole,
+ void *holder)
{
retry:
spin_lock(&bdev_lock);
@@ -1055,6 +1055,7 @@ static int bd_prepare_to_claim(struct block_device *bdev,
spin_unlock(&bdev_lock);
return 0;
}
+EXPORT_SYMBOL_GPL(bd_prepare_to_claim); /* only for the loop driver */
static struct gendisk *bdev_get_gendisk(struct block_device *bdev, int *partno)
{
@@ -1100,7 +1101,8 @@ static struct gendisk *bdev_get_gendisk(struct block_device *bdev, int *partno)
* Pointer to the block device containing @bdev on success, ERR_PTR()
* value on failure.
*/
-struct block_device *bd_start_claiming(struct block_device *bdev, void *holder)
+static struct block_device *bd_start_claiming(struct block_device *bdev,
+ void *holder)
{
struct gendisk *disk;
struct block_device *whole;
@@ -1141,7 +1143,6 @@ struct block_device *bd_start_claiming(struct block_device *bdev, void *holder)
return whole;
}
-EXPORT_SYMBOL(bd_start_claiming);
static void bd_clear_claiming(struct block_device *whole, void *holder)
{
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 71173a1ffa8b..06995b96e946 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1919,7 +1919,8 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder);
struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
void *holder);
struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder);
-struct block_device *bd_start_claiming(struct block_device *bdev, void *holder);
+int bd_prepare_to_claim(struct block_device *bdev, struct block_device *whole,
+ void *holder);
void bd_abort_claiming(struct block_device *bdev, struct block_device *whole,
void *holder);
void blkdev_put(struct block_device *bdev, fmode_t mode);
--
2.16.4