Re: Btrfs-progs release 3.17

[Gui Hecheng <guihc.fnst@cn.fujitsu.com>]

On Thu, 2014-10-23 at 16:13 +0800, Anand Jain wrote:
> 
> Some of the disks on my system were missing and I was able to hit
> this issue.
> 
> 
> ----------------
> Check tree block failed, want=12582912, have=0
> read block failed check_tree_block
> Couldn't read chunk root
> warning devid 2 not found already
> Check tree block failed, want=143360, have=0
> read block failed check_tree_block
> Couldn't read chunk root
> warning, device 4 is missing
> warning, device 3 is missing
> warning, device 2 is missing
> warning, device 1 is missing
> ----------------
> 
> 
> Did a bisect and it leads to this following patch.
> 
> ----------------
> commit 915902c5002485fb13d27c4b699a73fb66cc0f09
> 
>      btrfs-progs: fix device missing of btrfs fi show with seed devices
> ----------------
> 
>   Also this patch stalls ~2sec in the cmd btrfs fi show, on my system
>   with 48 disks.
> 
> Also a simple test case hits some warnings...
> 
> ----------------
>   mkfs.btrfs -draid1 -mraid1 /dev/sdb /dev/sdc
>   mount /dev/sdb /btrfs && fillfs /btrfs 100 && umount /btrfs
>   wipefs -a /dev/sdb
>   modprobe -r btrfs && modprobe btrfs
>   mount -o degraded /dev/sdb /btrfs
>   btrfs fi show
> Label: none  uuid: 9844cd05-1c8c-473e-a84b-bac95aab7bc9
>          Total devices 2 FS bytes used 1.59MiB
>          devid    2 size 967.87MiB used 104.75MiB path /dev/sdc
>          *** Some devices missing
> 
> warning, device 1 is missing
> warning, device 1 is missing
> warning devid 1 not found already
> ----------------
> 

Hi Anand and Petr,

Oh, it seems that there are btrfs with missing devs that are bringing
troubles to the @open_ctree_... function.
This should be a missing case of the patch above which should only take
effects when seeding devices are present.
I will try my best to follow this case, suggestions are welcome, Thanks!

-Gui

> 
> 
> 
> On 10/23/14 14:57, Petr Janecek wrote:
> > Hello,
> >
> >>   You have mentioned two issues when balance and fi show running
> >>   concurrently
> >
> >    my mail was a bit chaotic, but I get the stalls even on idle system.
> > Today I got
> >
> > parent transid verify failed on 1559973888000 wanted 1819 found 1821
> > parent transid verify failed on 1559973888000 wanted 1819 found 1821
> > parent transid verify failed on 1559973888000 wanted 1819 found 1821
> > parent transid verify failed on 1559973888000 wanted 1819 found 1821
> > Ignoring transid failure
> > leaf parent key incorrect 1559973888000
> >
> > from 'btrfs fi sh' while I was just copying something, no balance running.
> >
> > [...]
> >> [PATCH 1/1] btrfs-progs: code optimize cmd_scan_dev() use
> >> btrfs_register_one_device()
> >> [PATCH 1/2] btrfs-progs: introduce btrfs_register_all_device()
> >> [PATCH 2/2] btrfs-progs: optimize btrfs_scan_lblkid() for multiple calls
> >>
> >> If you could, pls..
> >>   Now on 3.17 apply above 3 patches and see if you see any better
> >>   performance for the stalling issue.
> >
> >    no perceptible change: takes ~40 seconds both before and after
> > applying. Old version <1 sec.
> >
> >>   can you do same steps on 3.16 and report what you observe
> >
> >    So many rejects -- do you have older versions of these patches?
> >
> >
> > Thanks,
> >
> > Petr
> > --
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