[PATCH] ext4: ignore ext3/ext2 only mount options

[Tom Gundersen <teg@jklm.no>]

There is a regression when using the ext4 module to mount
ext2 or ext3 filesystems: When mountoptions are used that are
supported by ext2 or ext3, but not by ext4 the mount fails.

This patch changes the failure into a warning. The case when
the ext4 module is not used for ext2/3 support is unchanged.

Report: https://bbs.archlinux.org/profile.php?id=33804
Signed-off-by: Tom Gundersen <teg@jklm.no>
Cc: Thomas Baechler <thomas@archlinux.org>
Cc: Tobias Powalowski <tobias.powalowski@googlemail.com>
Cc: Dave Reisner <d@falconindy.com>
---
 fs/ext4/super.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 502c61f..30de9cd 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1333,6 +1333,7 @@ enum {
 	Opt_inode_readahead_blks, Opt_journal_ioprio,
 	Opt_dioread_nolock, Opt_dioread_lock,
 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
+	Opt_nocheck, Opt_reservation, Opt_noreservation, Opt_journal_inum,
 };
 
 static const match_table_t tokens = {
@@ -1408,6 +1409,10 @@ static const match_table_t tokens = {
 	{Opt_init_itable, "init_itable=%u"},
 	{Opt_init_itable, "init_itable"},
 	{Opt_noinit_itable, "noinit_itable"},
+	{Opt_nocheck, "nocheck"},
+	{Opt_reservation, "reservation"},
+	{Opt_noreservation, "noreservation"},
+	{Opt_journal_inum, "journal=%u"},
 	{Opt_err, NULL},
 };
 
@@ -1904,6 +1909,16 @@ set_qf_format:
 		case Opt_noinit_itable:
 			clear_opt(sb, INIT_INODE_TABLE);
 			break;
+#ifdef CONFIG_EXT4_USE_FOR_EXT23
+		case Opt_nocheck:
+		case Opt_reservation:
+		case Opt_noreservation:
+		case Opt_journal_inum:
+			ext4_msg(sb, KERN_WARNING,
+			       "ext3 mount option \"%s\" ignored "
+			       "by ext4 module", p);
+			break;
+#endif
 		default:
 			ext4_msg(sb, KERN_ERR,
 			       "Unrecognized mount option \"%s\" "
-- 
1.7.9.2