lkml.org 
[lkml]   [2012]   [Mar]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Oops in ext3_block_to_path.isra.40+0x26/0x11b
On Fri, 16 Mar 2012, Jan Kara wrote:

> > CPU is a Core i3 530, on a Gigabyte motherbord, 4 GB RAM. No ECC,
> > unfortunately, so I can't rule out hardware bit rot. Distribution is
> > a fairly stock Debian/unstable.
> Hmm, is any mounting & unmounting happening during your backup? Because
> the oops happened because sb->s_fs_info was NULL. Dissassembly shows:
> 16: 48 8b 47 18 mov 0x18(%rdi),%rax
> store sb->s_blocksize into RAX
> 1a: 48 8b 8f b0 02 00 00 mov 0x2b0(%rdi),%rcx
> store sb->s_fs_info into RCX
> 21: 48 c1 e8 02 shr $0x2,%rax
> This is division from EXT3_ADDR_PER_BLOCK() - RAX carries 1024 after
> division so that looks correct.
>
> 25: 48 85 db test %rbx,%rbx
> Now check passed i_block argument.
>
> 28: 41 89 c4 mov %eax,%r12d
> 2b:* 8b b1 94 00 00 00 mov 0x94(%rcx),%esi <-- trapping ins
> Try to get RCX->s_addr_per_block_bits...
>
> sb->s_fs_info is set when a superblock is mounted and cleared when
> superblock gets unmounted and otherwise it is never changed. So most likely
> it was some memory corruption clearing that pointer (I wouldn't really
> suspect HW here).
>
> It somewhat looks like the issue described here:
> http://lkml.indiana.edu/hypermail/linux/kernel/1202.3/00132.html
>
> Although there we had f_path.dentry (completely different structure) being
> NULL. But similarity here is that something stomped NULL over our existing
> structure.
>
> Linus, Jiri, that bug didn't get resolved, did it?

I am not aware of anything, but I have a question -- George, did the
machine get suspended/resumed before this happened?

--
Jiri Kosina
SUSE Labs


\
 
 \ /
  Last update: 2012-03-16 10:33    [from the cache]
©2003-2011 Jasper Spaans