diff --git a/fs/quota.c b/fs/quota.c
index 612e04d..d14d872 100644
--- a/fs/quota.c
+++ b/fs/quota.c
@@ -168,7 +168,7 @@
 	sync_blockdev(sb->s_bdev);
 
 	/* Now when everything is written we can discard the pagecache so
-	 * that userspace sees the changes. We need i_sem and so we could
+	 * that userspace sees the changes. We need i_mutex and so we could
 	 * not do it inside dqonoff_sem. Moreover we need to be carefull
 	 * about races with quotaoff() (that is the reason why we have own
 	 * reference to inode). */
@@ -184,9 +184,9 @@
 	up(&sb_dqopt(sb)->dqonoff_sem);
 	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
 		if (discard[cnt]) {
-			down(&discard[cnt]->i_sem);
+			mutex_lock(&discard[cnt]->i_mutex);
 			truncate_inode_pages(&discard[cnt]->i_data, 0);
-			up(&discard[cnt]->i_sem);
+			mutex_unlock(&discard[cnt]->i_mutex);
 			iput(discard[cnt]);
 		}
 	}