Unverified Commit 4021e685 authored by Gao Xiang's avatar Gao Xiang Committed by Christian Brauner
Browse files

fs/super.c: introduce get_tree_bdev_flags() 

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@mail.gmail.com
[2] https://lore.kernel.org/r/ZwUkJEtwIpUA4qMz@infradead.org



Suggested-by: default avatarChristoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20241009033151.2334888-1-hsiangkao@linux.alibaba.com


Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 42f7652d

fs/super.c

+20 −6
Original line number Diff line number Diff line
@@ -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) {

		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)

include/linux/fs_context.h

+6 −0
Original line number Diff line number Diff line
@@ -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));