From ecbe6bc0003bfd5bf8581cb679cae0eb944432cb Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 16 Jul 2020 16:33:09 +0200 Subject: [PATCH] block: use bd_prepare_to_claim directly in the loop driver 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 Acked-by: Tejun Heo Signed-off-by: Jens Axboe --- 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 a943207..d181601 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 b7b2ee4b..ee80bd8 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 @@ retry: 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 71173a1..06995b9 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); -- 2.7.4