Re: [PATCH v3 0/4] bcachefs: fiemap delalloc support and cleanup

Kent Overstreet
2024-04-09T03:33:11Z

On Mon, Apr 08, 2024 at 10:48:42AM -0400, Brian Foster wrote:
> Hi all,
>
> Here's v3 of the fiemap delalloc support patches for bcachefs. The main
> difference from v2 is that the pagecache seek calls are now using
> nonblocking mode to avoid deadlocks between fiemap and the write path.
> The write path locks in folio -> extent btree order while fiemap walks
> the extent btree and scans for folios in transaction context. Therefore,
> the latter must restart the iterating transaction in the event of folio
> trylock failure and restart the scan from where it left off.
>
> The series is pushed to CI via my test branch, as usual:
>
> https://evilpiepirate.org/~testdashboard/ci?branch=bfoster

So our testing is currently busted because of a bug in 9pfs - I need you
to rebase onto my 9p-revert branch so we can get test results we can
look at:
https://evilpiepirate.org/git/bcachefs.git/log/?h=9p-revert

Eric, is this getting fixed? If it's not, and _soon_, we need to send
this revert to Linus - then put it through more testing, more asserts,
whatever you need and send it again next cycle, _after_ you've figured
out what wwent wrong.

Patch series looks good, though - if there's nothing you think needs
special attention I'll go ahead and merge it.

I wonder if at some point we could clean up the indirect extent lookup,
that's common between this code and the read paths, but that's low
priority.