xfs: fix timestamp handling in xfs_setattr

commit d6d59bada372bcf8bd36c3bbc71c485c29dd2a4b upstream

We currently have some rather odd code in xfs_setattr for
updating the a/c/mtime timestamps:

 - first we do a non-transaction update if all three are updated
   together
 - second we implicitly update the ctime for various changes
   instead of relying on the ATTR_CTIME flag
 - third we set the timestamps to the current time instead of the
   arguments in the iattr structure in many cases.

This patch makes sure we update it in a consistent way:

 - always transactional
 - ctime is only updated if ATTR_CTIME is set or we do a size
   update, which is a special case
 - always to the times passed in from the caller instead of the
   current time

The only non-size caller of xfs_setattr that doesn't come from
the VFS is updated to set ATTR_CTIME and pass in a valid ctime
value.

Reported-by: Eric Blake <ebb9@byu.net>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/xfs/linux-2.6/xfs_acl.c b/fs/xfs/linux-2.6/xfs_acl.c
index b23a54506446..4c7b14503716 100644
--- a/fs/xfs/linux-2.6/xfs_acl.c
+++ b/fs/xfs/linux-2.6/xfs_acl.c
@@ -250,8 +250,9 @@ xfs_set_mode(struct inode *inode, mode_t mode)
 	if (mode != inode->i_mode) {
 		struct iattr iattr;
 
-		iattr.ia_valid = ATTR_MODE;
+		iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
 		iattr.ia_mode = mode;
+		iattr.ia_ctime = current_fs_time(inode->i_sb);
 
 		error = -xfs_setattr(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
 	}