* [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
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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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