Re: ext4_ext_check_inode: bad header/extent in inode

[Eric Sandeen <sandeen@redhat.com>]

Christian Kujau wrote:
> On Fri, 24 Apr 2009, Eric Sandeen wrote:
>> Christian, is there anything in dmesg along with it this time?
> 
> Yes, as soon as the input/output errors occur, I get:
> 
> [34989.160273] EXT4-fs error (device md0): ext4_ext_check_inode: bad header/extent in inode #12042: invalid magic - magic 800, entries 8192, max 5696(0), depth 6144(6144)
> [34989.162491] EXT4-fs error (device md0): ext4_ext_check_inode: bad header/extent in inode #12207: invalid magic - magic 42fc, entries 17104, max 62268(0), depth 1283(1283)
> [34989.166784] EXT4-fs error (device md0): ext4_ext_check_inode: bad header/extent in inode #12249: invalid magic - magic 42fc, entries 17104, max 62268(0), depth 1283(1283)

Oh, duh, of course.  Now that I'm thinking about it right ...

So these are funny inodes:

# file mnt/lost+found/*
mnt/lost+found/#12042: setuid setgid character special
mnt/lost+found/#12207: setgid socket
mnt/lost+found/#12249: setgid socket

by virtue of the corruption.

They don't actually have any blocks,

debugfs:  stat <12042>
Inode: 12042   Type: character special    Mode:  0012   Flags: 0xe0406
Generation: 1123828476    Version: 0x21204098
User: -62782456   Group: -62766025   Size: 0
File ACL: 0    Directory ACL: 0
Links: 1   Blockcount: 0
Fragment:  Address: 0    Number: 0    Size: 0
ctime: 0x00063400 -- Mon Jan  5 10:55:28 1970
atime: 0x01380030 -- Tue Aug 25 10:48:00 1970
mtime: 0x00103001 -- Tue Jan 13 00:41:05 1970
Size of extra inode fields: 4
Device major/minor number: 08:00 (hex 08:00)

so we shouldn't be checking the extent header, I think.

        if (ei->i_flags & EXT4_EXTENTS_FL) {
                /* Validate extent which is part of inode */
                ret = ext4_ext_check_inode(inode);
        } else if ...

Or maybe fsck should be clearing the extents flag on inodes like this?

-Eric