[PATCH] ext3: wrong error behavior

SWsoft Virtuozzo/OpenVZ Linux kernel team has discovered that ext3 error
behavior was broken in linux kernels since 2.5.x versions by the following
patch:

2002/10/31 02:15:26-05:00 tytso@snap.thunk.org
Default mount options from superblock for ext2/3 filesystems
http://linux.bkbits.net:8080/linux-2.6/gnupatch@3dc0d88eKbV9ivV4ptRNM8fBuA3JBQ

In case ext3 file system is mounted with errors=continue
(EXT3_ERRORS_CONTINUE) errors should be ignored when possible.  However at
present in case of any error kernel aborts journal and remounts filesystem
to read-only.  Such behavior was hit number of times and noted to differ
from that of 2.4.x kernels.

This patch fixes this:
- do nothing in case of EXT3_ERRORS_CONTINUE,
- set EXT3_MOUNT_ABORT and call journal_abort() in all other cases
- panic() should be called after ext3_commit_super() to save
 sb marked as EXT3_ERROR_FS

Signed-off-by: Vasily Averin <vvs@sw.ru>
Acked-by: Kirill Korotaev <dev@sw.ru>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: "Stephen C. Tweedie" <sct@redhat.com>
Cc: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/ext3/super.c

@@ -159,20 +159,21 @@ static void ext3_handle_error(struct super_block *sb)
 	if (sb->s_flags & MS_RDONLY)
 		return;
 
-	if (test_opt (sb, ERRORS_RO)) {
-		printk (KERN_CRIT "Remounting filesystem read-only\n");
-		sb->s_flags |= MS_RDONLY;
-	} else {
+	if (!test_opt (sb, ERRORS_CONT)) {
 		journal_t *journal = EXT3_SB(sb)->s_journal;
 
 		EXT3_SB(sb)->s_mount_opt |= EXT3_MOUNT_ABORT;
 		if (journal)
 			journal_abort(journal, -EIO);
 	}
+	if (test_opt (sb, ERRORS_RO)) {
+		printk (KERN_CRIT "Remounting filesystem read-only\n");
+		sb->s_flags |= MS_RDONLY;
+	}
+	ext3_commit_super(sb, es, 1);
 	if (test_opt(sb, ERRORS_PANIC))
 		panic("EXT3-fs (device %s): panic forced after error\n",
 			sb->s_id);
-	ext3_commit_super(sb, es, 1);
 }
 
 void ext3_error (struct super_block * sb, const char * function,