[PATCH 02/17] btrfs: always open the device read-only in btrfs_scan_one_device
From: Christoph Hellwig <hch@lst.de>
Date: 2023-08-11 10:09:24
Also in:
linux-btrfs, linux-fsdevel, linux-s390
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
btrfs_scan_one_device opens the block device only to read the super block. Instead of passing a blk_mode_t argument to sometimes open it for writing, just hard code BLK_OPEN_READ as it will never write to the device or hand the block_device out to someone else. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/btrfs/super.c | 15 +++++++-------- fs/btrfs/volumes.c | 4 ++-- fs/btrfs/volumes.h | 2 +- 3 files changed, 10 insertions(+), 11 deletions(-)
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index f1dd172d8d5bd7..b318bddefd5236 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c@@ -849,7 +849,7 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options, * All other options will be parsed on much later in the mount process and * only when we need to allocate a new super block. */ -static int btrfs_parse_device_options(const char *options, blk_mode_t flags) +static int btrfs_parse_device_options(const char *options) { substring_t args[MAX_OPT_ARGS]; char *device_name, *opts, *orig, *p;
@@ -883,7 +883,7 @@ static int btrfs_parse_device_options(const char *options, blk_mode_t flags) error = -ENOMEM; goto out; } - device = btrfs_scan_one_device(device_name, flags); + device = btrfs_scan_one_device(device_name); kfree(device_name); if (IS_ERR(device)) { error = PTR_ERR(device);
@@ -1440,7 +1440,6 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type, struct btrfs_fs_devices *fs_devices = NULL; struct btrfs_fs_info *fs_info = NULL; void *new_sec_opts = NULL; - blk_mode_t mode = sb_open_mode(flags); int error = 0; if (data) {
@@ -1472,13 +1471,13 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type, } mutex_lock(&uuid_mutex); - error = btrfs_parse_device_options(data, mode); + error = btrfs_parse_device_options(data); if (error) { mutex_unlock(&uuid_mutex); goto error_fs_info; } - device = btrfs_scan_one_device(device_name, mode); + device = btrfs_scan_one_device(device_name); if (IS_ERR(device)) { mutex_unlock(&uuid_mutex); error = PTR_ERR(device);
@@ -1488,7 +1487,7 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type, fs_devices = device->fs_devices; fs_info->fs_devices = fs_devices; - error = btrfs_open_devices(fs_devices, mode, fs_type); + error = btrfs_open_devices(fs_devices, sb_open_mode(flags), fs_type); mutex_unlock(&uuid_mutex); if (error) goto error_fs_info;
@@ -2190,7 +2189,7 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd, switch (cmd) { case BTRFS_IOC_SCAN_DEV: mutex_lock(&uuid_mutex); - device = btrfs_scan_one_device(vol->name, BLK_OPEN_READ); + device = btrfs_scan_one_device(vol->name); ret = PTR_ERR_OR_ZERO(device); mutex_unlock(&uuid_mutex); break;
@@ -2204,7 +2203,7 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd, break; case BTRFS_IOC_DEVICES_READY: mutex_lock(&uuid_mutex); - device = btrfs_scan_one_device(vol->name, BLK_OPEN_READ); + device = btrfs_scan_one_device(vol->name); if (IS_ERR(device)) { mutex_unlock(&uuid_mutex); ret = PTR_ERR(device);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 73f9ea7672dbda..8246578c70f55b 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c@@ -1356,7 +1356,7 @@ int btrfs_forget_devices(dev_t devt) * and we are not allowed to call set_blocksize during the scan. The superblock * is read via pagecache */ -struct btrfs_device *btrfs_scan_one_device(const char *path, blk_mode_t flags) +struct btrfs_device *btrfs_scan_one_device(const char *path) { struct btrfs_super_block *disk_super; bool new_device_added = false;
@@ -1384,7 +1384,7 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, blk_mode_t flags) * values temporarily, as the device paths of the fsid are the only * required information for assembling the volume. */ - bdev = blkdev_get_by_path(path, flags, NULL, NULL); + bdev = blkdev_get_by_path(path, BLK_OPEN_READ, NULL, NULL); if (IS_ERR(bdev)) return ERR_CAST(bdev);
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index b8c51f16ba867f..824161c6dd063e 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h@@ -611,7 +611,7 @@ struct btrfs_block_group *btrfs_create_chunk(struct btrfs_trans_handle *trans, void btrfs_mapping_tree_free(struct extent_map_tree *tree); int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, blk_mode_t flags, void *holder); -struct btrfs_device *btrfs_scan_one_device(const char *path, blk_mode_t flags); +struct btrfs_device *btrfs_scan_one_device(const char *path); int btrfs_forget_devices(dev_t devt); void btrfs_close_devices(struct btrfs_fs_devices *fs_devices); void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices);
--
2.39.2