ecryptfs: add missing lock around notify_change

Callers of notify_change() need to hold i_mutex.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ecryptfs/inode.c

@@ -908,7 +908,9 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
 	if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
 		ia->ia_valid &= ~ATTR_MODE;
 
+	mutex_lock(&lower_dentry->d_inode->i_mutex);
 	rc = notify_change(lower_dentry, ia);
+	mutex_unlock(&lower_dentry->d_inode->i_mutex);
 out:
 	fsstack_copy_attr_all(inode, lower_inode, NULL);
 	return rc;