Re: [RFC PATCH] ovl: keep merged and impure readdir caches separate
Amir Goldstein <[email protected]> Thu, 14 May 2026 23:16:30 +0200
| Newsgroups | org.kernel.vger.linux-unionfs,org.kernel.vger.linux-fsdevel,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <CAOQ4uxjSUufiFpU1JuTNEq7vHejCRVZL1huBPQ5ZqbtZAjKS0Q@mail.gmail.com> |
On Thu, May 14, 2026 at 5:16 PM Amir Goldstein <[email protected]> wrote: > > On Thu, May 14, 2026 at 4:55 PM Nirmoy Das <[email protected]> wrote: > > On 14.05.26 16:09, Amir Goldstein wrote: > ... > >> Patch looks great - real root cause, gave you minor comments. > >> > >> IIUC, as far as you know, the repro never triggered the theoretic > >> OVL_WHITEOUTS race? > >> > >> It was always just this ERR_PTR(PTR_ERR()) black magic? > > > > > > Yes, with this particular syzkaller reproducer, it was always this black magic. I tried with and without your suggested changes and saw no difference in the crash behavior. > > > > But I think we should also have the fix for OVL_WHITEOUTS race as well. > > > > Yeh maybe. > I don't like making fixes to theoretical races without reproducers. > I'll think about it. > Maybe I'll try to reproduce synthetically. > Or maybe I'll just do a fortify patch. FYI pushed readdir cache fortify patch to ovl-fixes in github. It is based on the idea of your first patch, but implementation is different. Feel free to review. I will post it later after testing and deciding what to do about the "race fix" patch. Thanks, Amir.