From f3a608827d1f8de0dd12813e8d9c6803fe64e119 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Thu, 8 Feb 2024 18:47:35 +0100 Subject: bdev: open block device as files Add two new helpers to allow opening block devices as files. This is not the final infrastructure. This still opens the block device before opening a struct a file. Until we have removed all references to struct bdev_handle we can't switch the order: * Introduce blk_to_file_flags() to translate from block specific to flags usable to pen a new file. * Introduce bdev_file_open_by_{dev,path}(). * Introduce temporary sb_bdev_handle() helper to retrieve a struct bdev_handle from a block device file and update places that directly reference struct bdev_handle to rely on it. * Don't count block device openes against the number of open files. A bdev_file_open_by_{dev,path}() file is never installed into any file descriptor table. One idea that came to mind was to use kernel_tmpfile_open() which would require us to pass a path and it would then call do_dentry_open() going through the regular fops->open::blkdev_open() path. But then we're back to the problem of routing block specific flags such as BLK_OPEN_RESTRICT_WRITES through the open path and would have to waste FMODE_* flags every time we add a new one. With this we can avoid using a flag bit and we have more leeway in how we open block devices from bdev_open_by_{dev,path}(). Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-1-adbd023e19cc@kernel.org Signed-off-by: Christian Brauner --- include/linux/blkdev.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 99e4f5e72213..76706aa47316 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -24,6 +24,7 @@ #include #include #include +#include struct module; struct request_queue; @@ -1474,6 +1475,7 @@ extern const struct blk_holder_ops fs_holder_ops; (BLK_OPEN_READ | BLK_OPEN_RESTRICT_WRITES | \ (((flags) & SB_RDONLY) ? 0 : BLK_OPEN_WRITE)) +/* @bdev_handle will be removed soon. */ struct bdev_handle { struct block_device *bdev; void *holder; @@ -1484,6 +1486,10 @@ 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); +struct file *bdev_file_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, + const struct blk_holder_ops *hops); +struct file *bdev_file_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); @@ -1494,6 +1500,7 @@ struct block_device *blkdev_get_no_open(dev_t dev); void blkdev_put_no_open(struct block_device *bdev); struct block_device *I_BDEV(struct inode *inode); +struct block_device *file_bdev(struct file *bdev_file); #ifdef CONFIG_BLOCK void invalidate_bdev(struct block_device *bdev); -- cgit v1.2.3 From e97d06a46526d9392cbdbd7eda193091e1af2723 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Tue, 23 Jan 2024 14:26:44 +0100 Subject: bdev: remove bdev_open_by_path() Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-27-adbd023e19cc@kernel.org Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/blkdev.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 76706aa47316..5880d5abfebe 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1484,8 +1484,6 @@ struct bdev_handle { 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); struct file *bdev_file_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, const struct blk_holder_ops *hops); struct file *bdev_file_open_by_path(const char *path, blk_mode_t mode, -- cgit v1.2.3 From b1211a25c4fe3443cfef4ed7c39251502a663776 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Tue, 23 Jan 2024 14:26:45 +0100 Subject: bdev: make bdev_{release, open_by_dev}() private to block layer Move both of them to the private block header. There's no caller in the tree anymore that uses them directly. Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-28-adbd023e19cc@kernel.org Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/blkdev.h | 3 --- 1 file changed, 3 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 5880d5abfebe..495f55587207 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1482,8 +1482,6 @@ struct bdev_handle { blk_mode_t mode; }; -struct bdev_handle *bdev_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, - const struct blk_holder_ops *hops); struct file *bdev_file_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, const struct blk_holder_ops *hops); struct file *bdev_file_open_by_path(const char *path, blk_mode_t mode, @@ -1491,7 +1489,6 @@ struct file *bdev_file_open_by_path(const char *path, blk_mode_t mode, 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 bdev_release(struct bdev_handle *handle); /* just for blk-cgroup, don't use elsewhere */ struct block_device *blkdev_get_no_open(dev_t dev); -- cgit v1.2.3 From a56aefca8d386181415a1fb7cfec2f72b0404797 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Tue, 23 Jan 2024 14:26:46 +0100 Subject: bdev: make struct bdev_handle private to the block layer Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-29-adbd023e19cc@kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner --- include/linux/blkdev.h | 7 ------- 1 file changed, 7 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 495f55587207..2f5dbde23094 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1475,13 +1475,6 @@ extern const struct blk_holder_ops fs_holder_ops; (BLK_OPEN_READ | BLK_OPEN_RESTRICT_WRITES | \ (((flags) & SB_RDONLY) ? 0 : BLK_OPEN_WRITE)) -/* @bdev_handle will be removed soon. */ -struct bdev_handle { - struct block_device *bdev; - void *holder; - blk_mode_t mode; -}; - struct file *bdev_file_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, const struct blk_holder_ops *hops); struct file *bdev_file_open_by_path(const char *path, blk_mode_t mode, -- cgit v1.2.3