ext4: enforce online defrag restriction for encrypted files

Online defragging of encrypted files is not currently implemented.
However, the move extent ioctl can still return successfully when
called.  For example, this occurs when xfstest ext4/020 is run on an
encrypted file system, resulting in a corrupted test file and a
corresponding test failure.

Until the proper functionality is implemented, fail the move extent
ioctl if either the original or donor file is encrypted.

Cc: stable@vger.kernel.org
Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index a920c5d29fac0a5b5ef83c9cca18feeb3dcc0fe7..6fc14def0c707231ba6430dfb851307a7a13c3eb 100644 (file)
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -598,6 +598,13 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk,
                return -EOPNOTSUPP;
        }
 
+       if (ext4_encrypted_inode(orig_inode) ||
+           ext4_encrypted_inode(donor_inode)) {
+               ext4_msg(orig_inode->i_sb, KERN_ERR,
+                        "Online defrag not supported for encrypted files");
+               return -EOPNOTSUPP;
+       }
+
        /* Protect orig and donor inodes against a truncate */
        lock_two_nondirectories(orig_inode, donor_inode);