Re: [PATCH] btrfs: tree-checker: add type and sequence check for inline backrefs

[Josef Bacik <josef@toxicpanda.com>]

On Fri, Nov 03, 2023 at 07:19:41AM +1030, Qu Wenruo wrote:
> 
> 
> On 2023/11/3 07:06, Josef Bacik wrote:
> > On Tue, Oct 24, 2023 at 12:41:11PM +1030, Qu Wenruo wrote:
> > > [BUG]
> > > There is a bug report that ntfs2btrfs had a bug that it can lead to
> > > transaction abort and the filesystem flips to read-only.
> > > 
> > > [CAUSE]
> > > For inline backref items, kernel has a strict requirement for their
> > > ordered, they must follow the following rules:
> > > 
> > > - All btrfs_extent_inline_ref::type should be in an ascending order
> > > 
> > > - Within the same type, the items should follow a descending order by
> > >    their sequence number
> > > 
> > >    For EXTENT_DATA_REF type, the sequence number is result from
> > >    hash_extent_data_ref().
> > >    For other types, their sequence numbers are
> > >    btrfs_extent_inline_ref::offset.
> > > 
> > > Thus if there is any code not following above rules, the resulted
> > > inline backrefs can prevent the kernel to locate the needed inline
> > > backref and lead to transaction abort.
> > > 
> > > [FIX]
> > > Ntrfs2btrfs has already fixed the problem, and btrfs-progs has added the
> > > ability to detect such problems.
> > > 
> > > For kernel, let's be more noisy and be more specific about the order, so
> > > that the next time kernel hits such problem we would reject it in the
> > > first place, without leading to transaction abort.
> > > 
> > > Link: https://github.com/kdave/btrfs-progs/pull/622
> > > Signed-off-by: Qu Wenruo <wqu@suse.com>
> > 
> > This broke squotas and I didn't notice it until I was running the CI for my
> > mount api changes.
> > 
> > Lets try to use the CI for most things, even if you send it at the same time you
> > submit a job, it'll keep this sort of thing from happening.  Thanks,
> 
> My bad, didn't utilize CI at all.
> 
> Any quick guides/docs on the CI system?
> 

I'll put something in the developers docs, but just push your branch to github,
and submit a PR against btrfs/linux, the 'ci' branch, and it'll automatically
kick it off for you.  Thanks,

Josef