As Allison reported [1], currently get_tree_bdev() will store "Can't lookup blockdev" error message. Although it makes sense for pure bdev-based fses, this message may mislead users who try to use EROFS file-backed mounts since get_tree_nodev() is used as a fallback then. Add get_tree_bdev_flags() to specify extensible flags [2] and GET_TREE_BDEV_QUIET_LOOKUP to silence "Can't lookup blockdev" message since it's misleading to EROFS file-backed mounts now. [1] https://lore.kernel.org/r/CAOYeF9VQ8jKVmpy5Zy9DNhO6xmWSKMB-DO8yvBB0XvBE7=3Ugg@xxxxxxxxxxxxxx [2] https://lore.kernel.org/r/ZwUkJEtwIpUA4qMz@xxxxxxxxxxxxx Suggested-by: Christoph Hellwig <hch@xxxxxxxxxxxxx> Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx> --- v1: https://lore.kernel.org/r/20241008095606.990466-1-hsiangkao@xxxxxxxxxxxxxxxxx change since v1: - add get_tree_bdev_flags() suggested by Christoph. fs/super.c | 26 ++++++++++++++++++++------ include/linux/fs_context.h | 6 ++++++ 2 files changed, 26 insertions(+), 6 deletions(-) diff --git a/fs/super.c b/fs/super.c index 1db230432960..c9c7223bc2a2 100644 --- a/fs/super.c +++ b/fs/super.c @@ -1596,13 +1596,14 @@ int setup_bdev_super(struct super_block *sb, int sb_flags, EXPORT_SYMBOL_GPL(setup_bdev_super); /** - * get_tree_bdev - Get a superblock based on a single block device + * get_tree_bdev_flags - Get a superblock based on a single block device * @fc: The filesystem context holding the parameters * @fill_super: Helper to initialise a new superblock + * @flags: GET_TREE_BDEV_* flags */ -int get_tree_bdev(struct fs_context *fc, - int (*fill_super)(struct super_block *, - struct fs_context *)) +int get_tree_bdev_flags(struct fs_context *fc, + int (*fill_super)(struct super_block *sb, + struct fs_context *fc), unsigned int flags) { struct super_block *s; int error = 0; @@ -1613,10 +1614,10 @@ int get_tree_bdev(struct fs_context *fc, error = lookup_bdev(fc->source, &dev); if (error) { - errorf(fc, "%s: Can't lookup blockdev", fc->source); + if (!(flags & GET_TREE_BDEV_QUIET_LOOKUP)) + errorf(fc, "%s: Can't lookup blockdev", fc->source); return error; } - fc->sb_flags |= SB_NOSEC; s = sget_dev(fc, dev); if (IS_ERR(s)) @@ -1644,6 +1645,19 @@ int get_tree_bdev(struct fs_context *fc, fc->root = dget(s->s_root); return 0; } +EXPORT_SYMBOL_GPL(get_tree_bdev_flags); + +/** + * get_tree_bdev - Get a superblock based on a single block device + * @fc: The filesystem context holding the parameters + * @fill_super: Helper to initialise a new superblock + */ +int get_tree_bdev(struct fs_context *fc, + int (*fill_super)(struct super_block *, + struct fs_context *)) +{ + return get_tree_bdev_flags(fc, fill_super, 0); +} EXPORT_SYMBOL(get_tree_bdev); static int test_bdev_super(struct super_block *s, void *data) diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h index c13e99cbbf81..4b4bfef6f053 100644 --- a/include/linux/fs_context.h +++ b/include/linux/fs_context.h @@ -160,6 +160,12 @@ extern int get_tree_keyed(struct fs_context *fc, int setup_bdev_super(struct super_block *sb, int sb_flags, struct fs_context *fc); + +#define GET_TREE_BDEV_QUIET_LOOKUP 0x0001 +int get_tree_bdev_flags(struct fs_context *fc, + int (*fill_super)(struct super_block *sb, + struct fs_context *fc), unsigned int flags); + extern int get_tree_bdev(struct fs_context *fc, int (*fill_super)(struct super_block *sb, struct fs_context *fc)); -- 2.43.5
