Re: [PATCH, RFC] properly lock group descriptors before initializing

[Eric Sandeen <sandeen@redhat.com>]

Eric Sandeen wrote:
> I noticed when filling a 1T filesystem with 4 threads using the 
> fs_mark benchmark:
> 
> fs_mark -d /mnt/test -D 256 -n 100000 -t 4 -s 20480 -F -S 0
> 
> that I occasionally got checksum mismatch errors:
> 
> EXT4-fs error (device sdb): ext4_init_inode_bitmap: Checksum bad for group 6935
> 
> etc.  I'd reliably get 4-5 of them during the run.
> 
> It appears that the problem is likely a race to init the bg's
> when the uninit_bg feature is enabled.
> 
> With the patch below I was able to complete 2 runs with no errors
> or warnings.  However, I did hit a hang on one run that I can't yet
> explain, so maybe this bears more inspection or testing.

Crud hit it again, looks like it's my fault.  So hold off on this one :)

-Eric