quota: ext4: make ext4 handle quotaon on remount

Update ext4 to handle quotaon on remount RW.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ext4/super.c

@@ -813,7 +813,8 @@ static int ext4_acquire_dquot(struct dquot *dquot);
 static int ext4_release_dquot(struct dquot *dquot);
 static int ext4_mark_dquot_dirty(struct dquot *dquot);
 static int ext4_write_info(struct super_block *sb, int type);
-static int ext4_quota_on(struct super_block *sb, int type, int format_id, char *path);
+static int ext4_quota_on(struct super_block *sb, int type, int format_id,
+				char *path, int remount);
 static int ext4_quota_on_mount(struct super_block *sb, int type);
 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 			       size_t len, loff_t off);
@@ -1632,7 +1633,7 @@ static void ext4_orphan_cleanup (struct super_block * sb,
 	/* Turn quotas off */
 	for (i = 0; i < MAXQUOTAS; i++) {
 		if (sb_dqopt(sb)->files[i])
-			vfs_quota_off(sb, i);
+			vfs_quota_off(sb, i, 0);
 	}
 #endif
 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
@@ -3143,7 +3144,7 @@ static int ext4_quota_on_mount(struct super_block *sb, int type)
  * Standard function to be called on quota_on
  */
 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
-			 char *path)
+			 char *path, int remount)
 {
 	int err;
 	struct nameidata nd;
@@ -3151,9 +3152,9 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 	if (!test_opt(sb, QUOTA))
 		return -EINVAL;
 	/* Not journalling quota? */
-	if (!EXT4_SB(sb)->s_qf_names[USRQUOTA] &&
-	    !EXT4_SB(sb)->s_qf_names[GRPQUOTA])
-		return vfs_quota_on(sb, type, format_id, path);
+	if ((!EXT4_SB(sb)->s_qf_names[USRQUOTA] &&
+	    !EXT4_SB(sb)->s_qf_names[GRPQUOTA]) || remount)
+		return vfs_quota_on(sb, type, format_id, path, remount);
 	err = path_lookup(path, LOOKUP_FOLLOW, &nd);
 	if (err)
 		return err;
@@ -3168,7 +3169,7 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 			"EXT4-fs: Quota file not on filesystem root. "
 			"Journalled quota will not work.\n");
 	path_put(&nd.path);
-	return vfs_quota_on(sb, type, format_id, path);
+	return vfs_quota_on(sb, type, format_id, path, remount);
 }
 
 /* Read data from quotafile - avoid pagecache and such because we cannot afford