Re: Corrupted XFS log replay oops. (was Re: Warning and BUG with btrfs and corrupted image)

[Nick Piggin <nickpiggin@yahoo.com.au>]

On Wednesday 21 January 2009 14:57:03 Dave Chinner wrote:
> [drop btrfs list from this thread]
>
> On Tue, Jan 20, 2009 at 06:34:55PM +0100, Eric Sesterhenn wrote:

> > [  235.250167] ------------[ cut here ]------------
> > [  235.250354] kernel BUG at mm/vmalloc.c:164!
> > [  235.250478] invalid opcode: 0000 [#1] PREEMPT DEBUG_PAGEALLOC
> > [  235.250869] last sysfs file: /sys/block/ram9/range
> > [  235.250998] Modules linked in:
> > [  235.251037]
> > [  235.251037] Pid: 5352, comm: mount Not tainted
> > (2.6.29-rc2-00021-gd84d31c #216) System Name
> > [  235.251037] EIP: 0060:[<c0182af1>] EFLAGS: 00010246 CPU: 0
> > [  235.251037] EIP is at vmap_page_range+0x19/0x112
> > [  235.251037] EAX: d1000000 EBX: d1000000 ECX: 00000163 EDX: d1000000
> > [  235.251037] ESI: 00000003 EDI: d1000000 EBP: cbbd2c08 ESP: cbbd2be8
> > [  235.251037]  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
> > [  235.251037] Process mount (pid: 5352, ti=cbbd2000 task=cbb85b00
> > task.ti=cbbd2000)
> > [  235.251037] Stack:
> > [  235.251037]  00000246 cbb85b00 00000163 c01414cf cbbd2c0c d1000000
> > 00000003 cba0f810
> > [  235.251037]  cbbd2c40 c018367c c848e280 00100000 00000000 c848e280
> > 00000000 00000014
> > [  235.251037]  d1000000 cba0f944 00000000 c848e160 00000000 c848e160
> > cbbd2c54 c03b2e1e
> > [  235.251037] Call Trace:
> > [  235.251037]  [<c01414cf>] ? trace_hardirqs_on+0xb/0xd
> > [  235.251037]  [<c018367c>] ? vm_map_ram+0x36e/0x38a
> > [  235.251037]  [<c03b2e1e>] ? _xfs_buf_map_pages+0x42/0x6d
> > [  235.251037]  [<c03b3773>] ? xfs_buf_get_noaddr+0xbc/0x11f
> > [  235.251037]  [<c03a2406>] ? xlog_get_bp+0x5a/0x5d
> > [  235.251037]  [<c03a28fa>] ? xlog_find_verify_log_record+0x26/0x208
> > [  235.251037]  [<c03a3521>] ? xlog_find_zeroed+0x1d6/0x214
> > [  235.251037]  [<c03a3584>] ? xlog_find_head+0x25/0x358
>
> .....
>
> Ok, that's crashing in the new vmap code. It might take a couple
> of days before I get a chance to look at this, but I've cc'd Nick Piggin
> in case he has a chance to look at it before that. It's probably
> an XFS bug, anyway.

Hmm, it is crashing in BUG_ON(addr >= end); where this could happen
if XFS asks to map a really huge (or -ve) number of pages and wraps
the range, or if vmap subsystem returns an address right near the
end of the address range and addr+size wraps (which would be a bug
in vmap of course, but I think maybe less likely).

Printing out the values for addr and end might be instructive (XFS
might be asking to map -ERRNO pages or something).