* [3.4-rc1] attempt to access beyond end of device and livelock
[not found] <CAMVG2ss5WzwhgPunD5greRii1HFuEYt1TMQwxgUNitrpHtguVA@mail.gmail.com>
@ 2012-04-06 11:36 ` Daniel J Blueman
2012-04-08 8:49 ` Liu Bo
0 siblings, 1 reply; 3+ messages in thread
From: Daniel J Blueman @ 2012-04-06 11:36 UTC (permalink / raw)
To: Josef Bacik, Chris Mason; +Cc: Linux BTRFS, Linux Kernel
Hi Josef, Chris,
When testing BTRFS with RAID 0 metadata on linux-3.4-rc1, we see
discard ranges exceeding the end of the block device [1], potentially
causing dataloss; when this occurs, filesystem writeback becomes
catatonic due to continual resubmission.
Simply mounting with discard a raid0 metadata filesystem and copying
some data in [2] provokes the issue.
Thanks,
Daniel
--- [1]
attempt to access beyond end of device
ram0: rw=129, want=8452072, limit=4096000
...
--- [2]
modprobe brd rd_size=2048000 (or boot with ramdisk_size=2048000)
mkfs.btrfs -m raid0 /dev/ram0 /dev/ram1
mount /dev/ram0 /mnt -o discard
cd /mnt && tar -xvzf linux.tar.gz
<access beyond end of device and livelock>
--
Daniel J Blueman
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [3.4-rc1] attempt to access beyond end of device and livelock
2012-04-06 11:36 ` [3.4-rc1] attempt to access beyond end of device and livelock Daniel J Blueman
@ 2012-04-08 8:49 ` Liu Bo
2012-04-09 14:44 ` Daniel J Blueman
0 siblings, 1 reply; 3+ messages in thread
From: Liu Bo @ 2012-04-08 8:49 UTC (permalink / raw)
To: Daniel J Blueman; +Cc: Josef Bacik, Chris Mason, Linux BTRFS, Linux Kernel
On 04/06/2012 07:36 PM, Daniel J Blueman wrote:
> Hi Josef, Chris,
>
> When testing BTRFS with RAID 0 metadata on linux-3.4-rc1, we see
> discard ranges exceeding the end of the block device [1], potentially
> causing dataloss; when this occurs, filesystem writeback becomes
> catatonic due to continual resubmission.
>
> Simply mounting with discard a raid0 metadata filesystem and copying
> some data in [2] provokes the issue.
>
> Thanks,
> Daniel
>
> --- [1]
>
> attempt to access beyond end of device
> ram0: rw=129, want=8452072, limit=4096000
> ...
>
> --- [2]
>
> modprobe brd rd_size=2048000 (or boot with ramdisk_size=2048000)
> mkfs.btrfs -m raid0 /dev/ram0 /dev/ram1
> mount /dev/ram0 /mnt -o discard
> cd /mnt && tar -xvzf linux.tar.gz
> <access beyond end of device and livelock>
Thanks for the report, this bug shows we've miscalculated the length of discard extents.
I'll send a patch for this soon.
thanks,
--
liubo
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [3.4-rc1] attempt to access beyond end of device and livelock
2012-04-08 8:49 ` Liu Bo
@ 2012-04-09 14:44 ` Daniel J Blueman
0 siblings, 0 replies; 3+ messages in thread
From: Daniel J Blueman @ 2012-04-09 14:44 UTC (permalink / raw)
To: Liu Bo; +Cc: Josef Bacik, Chris Mason, Linux BTRFS, Linux Kernel
On 8 April 2012 16:49, Liu Bo <liubo2009@cn.fujitsu.com> wrote:
> On 04/06/2012 07:36 PM, Daniel J Blueman wrote:
>> Hi Josef, Chris,
>>
>> When testing BTRFS with RAID 0 metadata on linux-3.4-rc1, we see
>> discard ranges exceeding the end of the block device [1], potentially
>> causing dataloss; when this occurs, filesystem writeback becomes
>> catatonic due to continual resubmission.
[]
> Thanks for the report, this bug shows we've miscalculated the length of discard extents.
>
> I'll send a patch for this soon.
The patch test out well here on 3.4-rc2. Thanks Bo!
Daniel
--
Daniel J Blueman
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-04-09 14:44 UTC | newest]
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[not found] <CAMVG2ss5WzwhgPunD5greRii1HFuEYt1TMQwxgUNitrpHtguVA@mail.gmail.com>
2012-04-06 11:36 ` [3.4-rc1] attempt to access beyond end of device and livelock Daniel J Blueman
2012-04-08 8:49 ` Liu Bo
2012-04-09 14:44 ` Daniel J Blueman
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