Commit 4a8be425 authored Nov 12, 2009 by TARUISI Hiroaki Committed by Chris Mason Dec 17, 2009

Btrfs: deny sys_link across subvolumes.



I rebased Christian Parpart's patch to deny hard link across
subvolumes. Original patch modifies also btrfs_rename, but
I excluded it because we can move across subvolumes now and
it make no problem.
-----------------

Hard link across subvolumes should not allowed in Btrfs.
btrfs_link checks root of 'to' directory is same as root
of 'from' file. If not same, btrfs_link returns -EPERM.

Signed-off-by: TARUISI Hiroaki <taruishi.hiroak@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

parent a7a3f7ca

fs/btrfs/inode.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -4462,6 +4462,10 @@ static int btrfs_link(struct dentry old_dentry, struct inode dir,
		if (inode->i_nlink == 0)
		return -ENOENT;

		/* do not allow sys_link's with other subvols of the same device */
		if (root->objectid != BTRFS_I(inode)->root->objectid)
		return -EPERM;

		/*
		* 1 item for inode ref
		* 2 items for dir items

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