vfs: allow vfs_clone_file_range() across mount points (913b86e9) · Commits · 戴 / test

FICLONE/FICLONERANGE ioctls return -EXDEV if src and dest files are not on the same mount point. Practically, clone only requires that src and dest files are on the same file system. Move the check for same mount point to ioctl handler and keep only the check for same super block in the vfs helper. A following patch is going to use the vfs_clone_file_range() helper in overlayfs to copy up between lower and upper mount points on the same file system. Signed-off-by:

Amir Goldstein <amir73il@gmail.com> Signed-off-by:

Miklos Szeredi <mszeredi@redhat.com>

fs/ioctl.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -223,7 +223,11 @@ 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;
		ret = vfs_clone_file_range(src_file.file, off, dst_file, destoff, olen);
		fdput:
		fdput(src_file);
		return ret;
		}

fs/read_write.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -1655,8 +1655,12 @@ int vfs_clone_file_range(struct file *file_in, loff_t pos_in,
		struct inode *inode_out = file_inode(file_out);
		int ret;

		if (inode_in->i_sb != inode_out->i_sb \|\|
		file_in->f_path.mnt != file_out->f_path.mnt)
		/*
		* 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 (inode_in->i_sb != inode_out->i_sb)
		return -EXDEV;

		if (S_ISDIR(inode_in->i_mode) \|\| S_ISDIR(inode_out->i_mode))

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