Re: Punch hole problem on PAGE_SIZE > blocksize

[Allison Henderson <achender@linux.vnet.ibm.com>]

On 02/12/2012 03:31 AM, Lukas Czerner wrote:
> On Sun, 12 Feb 2012, Allison Henderson wrote:
>
>> On 02/10/2012 12:10 PM, Lukas Czerner wrote:
>>> Hi Allison,
>>>
>>> I found quite disturbing problem when testing loop discard support on
>>> file systems where PAGE_SIZE>   blocksize. The result is that the file
>>> system image is completely destroyed, but the underlying file system
>>> seems ok. I have seen this messages in the logs:
>>>
>>> EXT4-fs error (device sdb): ext4_ext_search_left:1221: inode #12: comm
>>> flush-8:16: ix (2248761) != EXT_FIRST_INDEX (0) (depth 1)!
>>> EXT4-fs (sdb): delayed block allocation failed for inode 12 at logical
>>> offset 2258177 with max blocks 64 with error -5
>>> EXT4-fs (sdb): This should not happen!! Data will be lost
>>>
>>> and
>>>
>>> EXT4-fs error (device sdd2): ext4_ext_get_blocks: inode #12: (comm
>>> loop0) bad extent address iblock: 34479, depth: 3 pblock 0
>>>
>>> Steps to reproduce
>>>
>>> mkfs.ext4 -b1024 /dev/sdb
>>> mount /dev/sdb /mnt/test2
>>> dd if=/dev/zero of=/mnt/test2/file bs=1M count=4096
>>> losetup /dev/loop0 /mnt/test2/file
>>>
>>> cd xfstests
>>>
>>> export TEST_DIR=/mnt/test
>>> export TEST_DEV=/dev/sda
>>> export SCRATCH_DEV=/dev/loop0
>>> export SCRATCH_MNT=/mnt/test1
>>> export MKFS_OPTIONS="-F -b1024"
>>> export MOUNT_OPTIONS="-o discard"
>>> export FSTYP="ext4"
>>>
>>> while ./check 251; do echo "OK"; done
>>>
>>> ..and just wait and watch the logs.
>>>
>>> Do you have any idea what might be the problem ?
>>>
>>> Thanks!
>>> -Lukas
>>>
>>
>> Hi Lukas,
>>
>> Im having some trouble getting the bug to reproduce for me.  I have the
>> dm-crypt module, but when I get to the test loop, i get "mount: unknown
>> filesystem type 'crypto_LUKS'". Is there something else I need to do or
>> install? With out being able to dig into it, I cant think of why it would do
>> that, I have not seen it produce that error before.  :(   Thx!
>>
>> Allison Henderson
>
> Hi Allison,
>
> I do not understand it either, there is no dm-crypt involved in this
> scenario. One think that comes to my mind is that TEST_DEV (in my case
> /dev/sda) needs to contain valid file system, but that is just how
> xfstests works. Please, let me know if you still have problems
> reproducing it.
>
> Thanks!
> -Lukas
>
Ok, I got it, it was my fault I had forgotten that I had used the 
scratch partition for an encryption test a while back.  Sorry!  I am 
getting a "[not run] FSTRIM is not supported" though, I think I need a 
device that supports discard.  I will poke around Monday and see if I 
can borrow one from somebody.

Allison Henderson