Commit 9f5710bb authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

fs: allow cross-vfsmount reflink/dedupe 



Currently we disallow reflink and dedupe if the two files aren't on the
same vfsmount.  However we really only need to disallow it if they're
not on the same super block.  It is very common for btrfs to have a main
subvolume that is mounted and then different subvolumes mounted at
different locations.  It's allowed to reflink between these volumes, but
the vfsmount check disallows this.  Instead fix dedupe to check for the
same superblock, and simply remove the vfsmount check for reflink as it
already does the superblock check.

Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarNikolay Borisov <nborisov@suse.com>
Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent ae460f05

fs/ioctl.c

+0 −4
Original line number Diff line number Diff line
@@ -236,9 +236,6 @@ static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd, 


	if (!src_file.file)

		return -EBADF;

	ret = -EXDEV;

	if (src_file.file->f_path.mnt != dst_file->f_path.mnt)

		goto fdput;

	cloned = vfs_clone_file_range(src_file.file, off, dst_file, destoff,

				      olen, 0);

	if (cloned < 0)
@@ -247,7 +244,6 @@ static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd, 
		ret = -EINVAL;

	else

		ret = 0;

fdput:

	fdput(src_file);

	return ret;

}

fs/remap_range.c

+1 −6
Original line number Diff line number Diff line
@@ -362,11 +362,6 @@ loff_t do_clone_file_range(struct file *file_in, loff_t pos_in, 


	WARN_ON_ONCE(remap_flags & REMAP_FILE_DEDUP);



	/*

	 * FICLONE/FICLONERANGE ioctls enforce that src and dest files are on

	 * the same mount. Practically, they only need to be on the same file

	 * system.

	 */

	if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)

		return -EXDEV;
@@ -458,7 +453,7 @@ loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos, 
		goto out_drop_write;



	ret = -EXDEV;

	if (src_file->f_path.mnt != dst_file->f_path.mnt)

	if (file_inode(src_file)->i_sb != file_inode(dst_file)->i_sb)

		goto out_drop_write;



	ret = -EISDIR;