Re: [PATCH] tests/xfs: test for log recovery failure after tail overwrite

[Eryu Guan <eguan@redhat.com>]

Hi Brian,

On Fri, Jun 16, 2017 at 12:46:19PM -0400, Brian Foster wrote:
> XFS is susceptible to log recovery problems if the fs crashes under
> certain circumstances. If the tail has been pinned for long enough
> to the log to fill and the next batch of log buffer submissions
> happen to fail, the filesystem shutsdown having potentially
> overwritten part of the range between the last good tail->head range
> in the log. This causes log recovery to fail with crc mismatch or
> invalid log record errors.
> 
> This problem is not yet fixed and thus known/expected to fail. At
> this time, this test serves as a reminder that the problem exists
> and a reproducer for future verification purposes. Note that this
> problem is currently only reproducible with larger (non-default) log
> buffer sizes (i.e., '-o logbsize=256k') or smaller block sizes (1k).
> 
> Signed-off-by: Brian Foster <bfoster@redhat.com>
> ---
> 
> Hi all,
> 
> This patch uses the XFS debug kernel mechanism recently posted for
> review[1] to reproduce an XFS log recovery problem. Note that this test
> depends on the aforementioned patch and thus should not be merged
> until/unless the corresponding kernel patch is merged.

Any decision made on the kernel side patch? Sorry, I'm a bit lost on the
kernel side discussions.

Thanks,
Eryu