[PATCH] ext3: wrong error behavior

From: Vasily Averin
Date: Sat Sep 02 2006 - 07:40:06 EST


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@xxxxxxxxxxxxxx
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@xxxxx>
Ack-by: Kirill Korotaev <dev@xxxxx>

Thank you,
Vasily Averin

SWsoft Virtuozzo/OpenVZ Linux kernel team
--- linux-2.6.18-rc5/fs/ext3/super.c.orig 2006-09-02 12:54:01.000000000 +0400
+++ linux-2.6.18-rc5/fs/ext3/super.c 2006-09-02 13:10:02.000000000 +0400
@@ -159,20 +159,21 @@ static void ext3_handle_error(struct sup
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,