Re: EXT4 ENOSPC Bug

[Theodore Tso <tytso@mit.edu>]

On Wed, Feb 18, 2009 at 10:18:57PM +0100, Andres Freund wrote:
> On one of the machines I got several thousand of:
>
> [10379.575904] ext4: find_group_flex failed, fallback succeeded dir 416319
> [10379.576002] ext4: find_group_flex failed, fallback succeeded dir 416319
> [10379.579981] ext4: find_group_flex failed, fallback succeeded dir 416319
> [10379.580097] ext4: find_group_flex failed, fallback succeeded dir 416319
> (with different directories)

Ok, that's good.  Good to know the workaround works.  

Can you send me a dumpe2fs of the filesystem in question?  I'm curious
what was going on...

> No userspace visible behaviour.
>
> So it seems you were right. It seems sensible to put that patch without  
> printk in the kernel until the issue is fully solved...

Thanks for the report.  I'll push the workaround patch to Linus for
2.6.29 to avoid this problem for now.  I recently sent to linux-ext4
for comment a patch to revamp the Orlov allocator for flex_bg and to
use that instead of find_group_flex(), but no way that's going into
2.6.29 at this point....

							- Ted