Re: Btrfs-progs release 3.17

[Anand Jain <Anand.Jain@oracle.com>]

On 28/10/2014 12:03, Gui Hecheng wrote:
> On Thu, 2014-10-23 at 21:36 +0800, Anand Jain wrote:
>>
>>    there is no point in re-creating so many btrfs kernel's logic in user
>>    space. its just unnecessary, when kernel is already doing it. use
>>    some interface to get info from kernel after device is registered,
>>    (not necessarily mounted). so progs can be as sleek as possible.
>>    to me it started as just one more bug now we have fixed so many many.
>>    It all needs one good interface for kernel which provides anything
>>    anything from the kernel.
>>
>
> Oh, the interface for kernel you described is really interesting.
> But how to store the seed/sprout relationships so that we can fetch them
> correctly for umounted btrfs?

  remember -  btrfs-control ioctl READY does not work yet when seed is
  present. Some how we need to fix that in kernel right. ? for which
  we need the seed/sprout relation when devices are unmounted. you may
  get that working/accepted in the kernel first, a simple user space
  interface (such as nacked /proc/fs/btrfs/devlist interface or
  discussing sysfs interface (bit risky though)) is all that is needed
  to get this working.



> -Gui
>
>>
>> On 10/23/14 16:52, Gui Hecheng wrote:
>>> 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
>>>>> --
>>>>> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
>>>>> the body of a message to majordomo@vger.kernel.org
>>>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>>>>
>>>
>>>
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>