Re: btrfs BUG on creating huge sparse file

Chris Mason
2009-04-29T11:40:22Z

On Wed, 2009-04-29 at 16:21 +0800, Wu Fengguang wrote:
> On Wed, Apr 29, 2009 at 04:16:16PM +0800, Wu Fengguang wrote:
> > On Thu, Apr 09, 2009 at 10:37:39AM -0400, Chris Mason wrote:
> [snip]
> > > PagePrivate is very common. try_to_releasepage failing on a clean page
> > > without the writeback bit set and without dirty/locked buffers will be
> > > pretty rare.
> >
> > Yup. btrfs seems to tag most(if not all) dirty pages with PG_private.
> > While ext4 won't.
>
> Chris, I run into a btrfs BUG() when doing
>
> dd if=/dev/zero of=/b/sparse bs=1k count=1 seek=104857512345
>
> The half created sparse file is
>
> -rw-r--r-- 1 root root 98T 2009-04-29 14:54 /b/sparse
> Or
> -rw-r--r-- 1 root root 107374092641280 2009-04-29 14:54 /b/sparse
>
> Below is the kernel messages. I can test patches you throw at me :-)
>

How big was the FS you were testing this on? It works for me...

-chris