diff options
Diffstat (limited to 'block/bdev.c')
| -rw-r--r-- | block/bdev.c | 41 |
1 files changed, 29 insertions, 12 deletions
diff --git a/block/bdev.c b/block/bdev.c index f5ffcac762e0..5c46ff107706 100644 --- a/block/bdev.c +++ b/block/bdev.c @@ -102,7 +102,7 @@ int truncate_bdev_range(struct block_device *bdev, fmode_t mode, * under live filesystem. */ if (!(mode & FMODE_EXCL)) { - int err = bd_prepare_to_claim(bdev, truncate_bdev_range); + int err = bd_prepare_to_claim(bdev, truncate_bdev_range, NULL); if (err) goto invalidate; } @@ -415,6 +415,7 @@ struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) bdev = I_BDEV(inode); mutex_init(&bdev->bd_fsfreeze_mutex); spin_lock_init(&bdev->bd_size_lock); + mutex_init(&bdev->bd_holder_lock); bdev->bd_partno = partno; bdev->bd_inode = inode; bdev->bd_queue = disk->queue; @@ -464,13 +465,15 @@ long nr_blockdev_pages(void) * bd_may_claim - test whether a block device can be claimed * @bdev: block device of interest * @holder: holder trying to claim @bdev + * @hops: holder ops * * Test whether @bdev can be claimed by @holder. * * RETURNS: * %true if @bdev can be claimed, %false otherwise. */ -static bool bd_may_claim(struct block_device *bdev, void *holder) +static bool bd_may_claim(struct block_device *bdev, void *holder, + const struct blk_holder_ops *hops) { struct block_device *whole = bdev_whole(bdev); @@ -480,8 +483,11 @@ static bool bd_may_claim(struct block_device *bdev, void *holder) /* * The same holder can always re-claim. */ - if (bdev->bd_holder == holder) + if (bdev->bd_holder == holder) { + if (WARN_ON_ONCE(bdev->bd_holder_ops != hops)) + return false; return true; + } return false; } @@ -499,6 +505,7 @@ static bool bd_may_claim(struct block_device *bdev, void *holder) * bd_prepare_to_claim - claim a block device * @bdev: block device of interest * @holder: holder trying to claim @bdev + * @hops: holder ops. * * Claim @bdev. This function fails if @bdev is already claimed by another * holder and waits if another claiming is in progress. return, the caller @@ -507,7 +514,8 @@ static bool bd_may_claim(struct block_device *bdev, void *holder) * RETURNS: * 0 if @bdev can be claimed, -EBUSY otherwise. */ -int bd_prepare_to_claim(struct block_device *bdev, void *holder) +int bd_prepare_to_claim(struct block_device *bdev, void *holder, + const struct blk_holder_ops *hops) { struct block_device *whole = bdev_whole(bdev); @@ -516,7 +524,7 @@ int bd_prepare_to_claim(struct block_device *bdev, void *holder) retry: mutex_lock(&bdev_lock); /* if someone else claimed, fail */ - if (!bd_may_claim(bdev, holder)) { + if (!bd_may_claim(bdev, holder, hops)) { mutex_unlock(&bdev_lock); return -EBUSY; } @@ -557,12 +565,13 @@ static void bd_clear_claiming(struct block_device *whole, void *holder) * Finish exclusive open of a block device. Mark the device as exlusively * open by the holder and wake up all waiters for exclusive open to finish. */ -static void bd_finish_claiming(struct block_device *bdev, void *holder) +static void bd_finish_claiming(struct block_device *bdev, void *holder, + const struct blk_holder_ops *hops) { struct block_device *whole = bdev_whole(bdev); mutex_lock(&bdev_lock); - BUG_ON(!bd_may_claim(bdev, holder)); + BUG_ON(!bd_may_claim(bdev, holder, hops)); /* * Note that for a whole device bd_holders will be incremented twice, * and bd_holder will be set to bd_may_claim before being set to holder @@ -570,7 +579,10 @@ static void bd_finish_claiming(struct block_device *bdev, void *holder) whole->bd_holders++; whole->bd_holder = bd_may_claim; bdev->bd_holders++; + mutex_lock(&bdev->bd_holder_lock); bdev->bd_holder = holder; + bdev->bd_holder_ops = hops; + mutex_unlock(&bdev->bd_holder_lock); bd_clear_claiming(whole, holder); mutex_unlock(&bdev_lock); } @@ -605,7 +617,10 @@ static void bd_end_claim(struct block_device *bdev) WARN_ON_ONCE(--bdev->bd_holders < 0); WARN_ON_ONCE(--whole->bd_holders < 0); if (!bdev->bd_holders) { + mutex_lock(&bdev->bd_holder_lock); bdev->bd_holder = NULL; + bdev->bd_holder_ops = NULL; + mutex_unlock(&bdev->bd_holder_lock); if (bdev->bd_write_holder) unblock = true; } @@ -735,6 +750,7 @@ void blkdev_put_no_open(struct block_device *bdev) * @dev: device number of block device to open * @mode: FMODE_* mask * @holder: exclusive holder identifier + * @hops: holder operations * * Open the block device described by device number @dev. If @mode includes * %FMODE_EXCL, the block device is opened with exclusive access. Specifying @@ -751,7 +767,8 @@ void blkdev_put_no_open(struct block_device *bdev) * RETURNS: * Reference to the block_device on success, ERR_PTR(-errno) on failure. */ -struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) +struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder, + const struct blk_holder_ops *hops) { bool unblock_events = true; struct block_device *bdev; @@ -771,7 +788,7 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) disk = bdev->bd_disk; if (mode & FMODE_EXCL) { - ret = bd_prepare_to_claim(bdev, holder); + ret = bd_prepare_to_claim(bdev, holder, hops); if (ret) goto put_blkdev; } @@ -791,7 +808,7 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) if (ret) goto put_module; if (mode & FMODE_EXCL) { - bd_finish_claiming(bdev, holder); + bd_finish_claiming(bdev, holder, hops); /* * Block event polling for write claims if requested. Any write @@ -842,7 +859,7 @@ EXPORT_SYMBOL(blkdev_get_by_dev); * Reference to the block_device on success, ERR_PTR(-errno) on failure. */ struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, - void *holder) + void *holder, const struct blk_holder_ops *hops) { struct block_device *bdev; dev_t dev; @@ -852,7 +869,7 @@ struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, if (error) return ERR_PTR(error); - bdev = blkdev_get_by_dev(dev, mode, holder); + bdev = blkdev_get_by_dev(dev, mode, holder, hops); if (!IS_ERR(bdev) && (mode & FMODE_WRITE) && bdev_read_only(bdev)) { blkdev_put(bdev, mode); return ERR_PTR(-EACCES); |