From: Jan Kara jack@suse.cz
[ Upstream commit e719b4d156749f02eafed31a3c515f2aa9dcc72a ]
Create struct bdev_handle that contains all parameters that need to be passed to blkdev_put() and provide bdev_open_* functions that return this structure instead of plain bdev pointer. This will eventually allow us to pass one more argument to blkdev_put() (renamed to bdev_release()) without too much hassle.
Acked-by: Christoph Hellwig hch@lst.de Reviewed-by: Christian Brauner brauner@kernel.org Signed-off-by: Jan Kara jack@suse.cz Link: https://lore.kernel.org/r/20230927093442.25915-1-jack@suse.cz Signed-off-by: Christian Brauner brauner@kernel.org Stable-dep-of: 0f28be64d132 ("erofs: fix lockdep false positives on initializing erofs_pseudo_mnt") Signed-off-by: Sasha Levin sashal@kernel.org --- block/bdev.c | 48 ++++++++++++++++++++++++++++++++++++++++++ include/linux/blkdev.h | 10 +++++++++ 2 files changed, 58 insertions(+)
diff --git a/block/bdev.c b/block/bdev.c index 04dba25b0019e..5a54977518eea 100644 --- a/block/bdev.c +++ b/block/bdev.c @@ -831,6 +831,25 @@ struct block_device *blkdev_get_by_dev(dev_t dev, blk_mode_t mode, void *holder, } EXPORT_SYMBOL(blkdev_get_by_dev);
+struct bdev_handle *bdev_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, + const struct blk_holder_ops *hops) +{ + struct bdev_handle *handle = kmalloc(sizeof(*handle), GFP_KERNEL); + struct block_device *bdev; + + if (!handle) + return ERR_PTR(-ENOMEM); + bdev = blkdev_get_by_dev(dev, mode, holder, hops); + if (IS_ERR(bdev)) { + kfree(handle); + return ERR_CAST(bdev); + } + handle->bdev = bdev; + handle->holder = holder; + return handle; +} +EXPORT_SYMBOL(bdev_open_by_dev); + /** * blkdev_get_by_path - open a block device by name * @path: path to the block device to open @@ -869,6 +888,28 @@ struct block_device *blkdev_get_by_path(const char *path, blk_mode_t mode, } EXPORT_SYMBOL(blkdev_get_by_path);
+struct bdev_handle *bdev_open_by_path(const char *path, blk_mode_t mode, + void *holder, const struct blk_holder_ops *hops) +{ + struct bdev_handle *handle; + dev_t dev; + int error; + + error = lookup_bdev(path, &dev); + if (error) + return ERR_PTR(error); + + handle = bdev_open_by_dev(dev, mode, holder, hops); + if (!IS_ERR(handle) && (mode & BLK_OPEN_WRITE) && + bdev_read_only(handle->bdev)) { + bdev_release(handle); + return ERR_PTR(-EACCES); + } + + return handle; +} +EXPORT_SYMBOL(bdev_open_by_path); + void blkdev_put(struct block_device *bdev, void *holder) { struct gendisk *disk = bdev->bd_disk; @@ -905,6 +946,13 @@ void blkdev_put(struct block_device *bdev, void *holder) } EXPORT_SYMBOL(blkdev_put);
+void bdev_release(struct bdev_handle *handle) +{ + blkdev_put(handle->bdev, handle->holder); + kfree(handle); +} +EXPORT_SYMBOL(bdev_release); + /** * lookup_bdev() - Look up a struct block_device by name. * @pathname: Name of the block device in the filesystem. diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index f59fcd5b499a5..5b6e86b2c37a5 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1479,14 +1479,24 @@ extern const struct blk_holder_ops fs_holder_ops; #define sb_open_mode(flags) \ (BLK_OPEN_READ | (((flags) & SB_RDONLY) ? 0 : BLK_OPEN_WRITE))
+struct bdev_handle { + struct block_device *bdev; + void *holder; +}; + struct block_device *blkdev_get_by_dev(dev_t dev, blk_mode_t mode, void *holder, const struct blk_holder_ops *hops); struct block_device *blkdev_get_by_path(const char *path, blk_mode_t mode, void *holder, const struct blk_holder_ops *hops); +struct bdev_handle *bdev_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, + const struct blk_holder_ops *hops); +struct bdev_handle *bdev_open_by_path(const char *path, blk_mode_t mode, + void *holder, const struct blk_holder_ops *hops); int bd_prepare_to_claim(struct block_device *bdev, void *holder, const struct blk_holder_ops *hops); void bd_abort_claiming(struct block_device *bdev, void *holder); void blkdev_put(struct block_device *bdev, void *holder); +void bdev_release(struct bdev_handle *handle);
/* just for blk-cgroup, don't use elsewhere */ struct block_device *blkdev_get_no_open(dev_t dev);