Re: [PATCH 0/9] xfs: metadata CRCs, kernel, first batch

Ben Myers
2013-02-22T23:50:32Z

Hi Dave,

On Sat, Feb 23, 2013 at 10:12:17AM +1100, Dave Chinner wrote:
> On Fri, Feb 22, 2013 at 09:19:31AM -0600, Ben Myers wrote:
> > Dave,
> >
> > Dunno if you've seen this one:
> >
> > BUG: unable to handle kernel NULL pointer dereference at 00000000000000d0
> > [601393.932814] IP: [<ffffffffa06e5dcc>] xfs_dquot_buf_verify+0x1c/0xb0 [xfs]
> .....
> > [601393.932814] Call Trace:
> > [601393.932814] [<ffffffffa06e7b89>] xfs_dquot_buf_write_verify+0x29/0x90 [xfs]
> > [601393.932814] [<ffffffff811db523>] ? blk_finish_plug+0x13/0x50
> > [601393.932814] [<ffffffffa0676058>] _xfs_buf_ioapply+0x68/0x360 [xfs]
> > [601393.932814] [<ffffffff810696b0>] ? try_to_wake_up+0x2b0/0x2b0
> > [601393.932814] [<ffffffffa0677b23>] xfs_buf_iorequest+0x53/0x70 [xfs]
> > [601393.932814] [<ffffffffa0677e25>] xfs_bdstrat_cb+0x35/0x60 [xfs]
> > [601393.932814] [<ffffffffa0677f98>] __xfs_buf_delwri_submit+0x148/0x1c0 [xfs]
> > [601393.932814] [<ffffffffa067803b>] xfs_buf_delwri_submit+0x2b/0x90 [xfs]
> > [601393.932814] [<ffffffffa06d1de1>] xlog_recover_commit_trans+0x111/0x120 [xfs]
> > [601393.932814] [<ffffffffa06d1ff1>] xlog_recover_process_data+0x201/0x2b0 [xfs]
> > [601393.932814] [<ffffffffa06d257c>] xlog_do_recovery_pass+0x4dc/0x760 [xfs]
> > [601393.932814] [<ffffffff8103e3b5>] ? console_unlock+0x265/0x3a0
> > [601393.932814] [<ffffffffa06d289c>] xlog_do_log_recovery+0x9c/0x110 [xfs]
> > [601393.932814] [<ffffffffa06d2933>] xlog_do_recover+0x23/0x1e0 [xfs]
>
> This is mentioned in the patch zero description:
>
> "This series makes is through to 001-092 in xfstests - there is a
> problem in the dquot verifier that causes log recovery of dquot
> buffers to follow a NULL pointer."
>
> Basically, mp->m_quotainfo is not initialised until after log
> recovery occurs, so this has to be detected in the verify/crc
> routines otherwise it goes splat like above. My current patch series
> has this fixed.

Cool. Sorry for the extra noise.

-Ben