Re: Bug?: unlink cause btrfs error but other fs don't

[Josef Bacik]

On Wed, Sep 04, 2019 at 04:02:24PM +0800, Hongzhi, Song wrote:
> Hi ,
> 
> 
> *Kernel:*
> 
>     After v5.2-rc1, qemux86-64
> 
>     make -j40 ARCH=x86_64 CROSS_COMPILE=x86-64-gcc
>     use qemu to bootup kernel
> 
> 
> *Reproduce:*
> 
>     There is a test case failed on btrfs but success on other fs(ext4,ext3),
> see attachment.
> 
> 
>     Download attachments:
> 
>         gcc test.c -o myout -Wall -lpthread
> 
>         copy myout and run.sh to your qemu same directory.
> 
>         on qemu:
> 
>             ./run.sh
> 
> 
>     I found the block device size with btrfs set 512M will cause the error.
>     256M and 1G all success.
> 
> 
> *Error info:*
> 
>     "BTRFS warning (device loop0): could not allocate space for a delete;
> will truncate on mount"
> 
> 
> *Related patch:*
> 
>     I use git bisect to find the following patch introduces the issue.
> 
>     commit c8eaeac7b734347c3afba7008b7af62f37b9c140
>     Author: Josef Bacik <josef@xxxxxxxxxxxxxx>
>     Date:   Wed Apr 10 15:56:10 2019 -0400
> 
>         btrfs: reserve delalloc metadata differently
>         ...
> 
> 

I meant to reply to this but couldn't find the original thread.  The patches I
wrote for this merge window were to address this issue.  Thanks,

Josef