Re: [PATCH] xfs: Fix possible truncation of log data in xlog_bread_noalign()

Ben Myers
2013-02-22T19:14:30Z

Hi Tony,

On Fri, Feb 22, 2013 at 08:12:52AM +0000, Tony Lu wrote:
> I encountered the following panic when using xfs partitions as rootfs, which
> is due to the truncated log data read by xlog_bread_noalign(). We should
> extend the buffer by one extra log sector to ensure there's enough space to
> accommodate requested log data, which we indeed did in xlog_get_bp(), but we
> forgot to do in xlog_bread_noalign().
>
> XFS mounting filesystem sda2
> Starting XFS recovery on filesystem: sda2 (logdev: internal)
> XFS: xlog_recover_process_data: bad clientid
> XFS: log mount/recovery failed: error 5
> XFS: log mount failedVFS: Cannot open root device "sda2" or unknown-block(8,)
> Please append a correct "root=" boot option; here are the available partitio:
> 0800 156290904 sda driver: sd
> 0801 31463271 sda1 00000000-0000-0000-0000-000000000000
> 0802 31463302 sda2 00000000-0000-0000-0000-000000000000
> 0803 31463302 sda3 00000000-0000-0000-0000-000000000000
> 0804 1 sda4 00000000-0000-0000-0000-000000000000
> 0805 10490413 sda5 00000000-0000-0000-0000-000000000000
> 0806 51407968 sda6 00000000-0000-0000-0000-000000000000
> Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(8,)
>
> Starting stack dump of tid 1, pid 1 (swapper) on cpu 35 at cycle 42273138234
> frame 0: 0xfffffff70016e5a0 dump_stack+0x0/0x20 (sp 0xfffffe03fbedfe88)
> frame 1: 0xfffffff7004af470 panic+0x150/0x3a0 (sp 0xfffffe03fbedfe88)
> frame 2: 0xfffffff700881e88 mount_block_root+0x2c0/0x4c8 (sp 0xfffffe03fbe)
> frame 3: 0xfffffff700882390 prepare_namespace+0x250/0x358 (sp 0xfffffe03fb)
> frame 4: 0xfffffff700880778 kernel_init+0x4c8/0x520 (sp 0xfffffe03fbedffb0)
> frame 5: 0xfffffff70011ecb8 start_kernel_thread+0x18/0x20 (sp 0xfffffe03fb)
> Stack dump complete
>
> Signed-off-by: Zhigang Lu <zlu@tilera.com>
> Reviewed-by: Chris Metcalf <cmetcalf@tilera.com>

Looks fine to me. I'll pull it in after some testing.

Do you happen to have a metadump of this filesystem?

Reviewed-by: Ben Myers <bpm@sgi.com>

Thanks!
-Ben