Re: [PATCH v3] Btrfs: fix task hang under heavy compressed write

[Liu Bo <bo.li.liu@oracle.com>]

On Tue, Aug 26, 2014 at 12:20:28PM +0200, Martin Steigerwald wrote:
> Am Montag, 25. August 2014, 10:58:13 schrieb Chris Mason:
> > On 08/15/2014 11:36 AM, Liu Bo wrote:
> > > This has been reported and discussed for a long time, and this hang occurs
> > > in both 3.15 and 3.16.
> > 
> > [ great description ]
> > 
> > I ran this through tests last week, and an overnight test over the
> > weekend.  It's in my for-linus branch now, along with everything else I
> > plan on sending for rc3.
> > 
> > Please double check my merge, I had to undo your rebase onto Miao's patches.
> 
> I would like to test this on 3.17-rc2, what do I need to do to make it apply 
> cleanly? That function in disk-io.c looks quite different from what the patch 
> assumes at the beginning, so I am not sure how to merge this.
> 
> martin@merkaba:~/Computer/Merkaba/Kernel/linux> patch -p1 < "../[PATCH v3] 
> Btrfs_fix task hang under heavy compressed write.mbox"   
> patching file fs/btrfs/async-thread.c
> patching file fs/btrfs/async-thread.h
> patching file fs/btrfs/delayed-inode.c
> patching file fs/btrfs/disk-io.c
> Hunk #2 FAILED at 713.
> Hunk #3 succeeded at 827 (offset -29 lines).
> 1 out of 3 hunks FAILED -- saving rejects to file fs/btrfs/disk-io.c.rej
> patching file fs/btrfs/extent-tree.c
> patching file fs/btrfs/inode.c
> Hunk #1 succeeded at 1096 (offset -15 lines).
> Hunk #2 succeeded at 1883 (offset -43 lines).
> Hunk #3 succeeded at 2825 (offset -47 lines).
> Hunk #4 succeeded at 2835 (offset -47 lines).
> Hunk #5 succeeded at 7166 (offset -345 lines).
> Hunk #6 succeeded at 8504 (offset -371 lines).
> patching file fs/btrfs/ordered-data.c
> patching file fs/btrfs/qgroup.c
> Hunk #1 succeeded at 2720 (offset -2 lines).
> patching file fs/btrfs/raid56.c
> patching file fs/btrfs/reada.c
> patching file fs/btrfs/scrub.c
> Hunk #1 succeeded at 428 (offset 1 line).
> Hunk #2 succeeded at 999 (offset 2 lines).
> Hunk #3 succeeded at 1616 (offset -8 lines).
> Hunk #4 succeeded at 3204 (offset -29 lines).
> patching file fs/btrfs/volumes.c
> Hunk #1 succeeded at 5800 (offset -87 lines).
> 
> Otherwise, I´d wait till rc3, as my current 3.16.2 with v1 of this patch seems 
> to behave stable with trees occupying all space:
> 
> merkaba:~> btrfs fi sh /home
> Label: 'home'  uuid: […]
>         Total devices 2 FS bytes used 127.69GiB
>         devid    1 size 160.00GiB used 160.00GiB path /dev/dm-0
>         devid    2 size 160.00GiB used 160.00GiB path /dev/mapper/sata-home

Hmm, the v3 patch is based on Chris's integration branch, so it's expected not
to apply it cleanly.  But if you're urgent, I can provide a patch based on
3.17-rc2.

(rc3 is coming soon though ;-) )

thanks,
-liubo

> 
> Ciao,
> -- 
> Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
> GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7