Messages in this thread | | | From | Schspa Shi <> | Subject | Re: [PATCH] p9: trans_fd: Fix deadlock when connection cancel | Date | Thu, 01 Sep 2022 10:55:36 +0800 |
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asmadeus@codewreck.org writes:
> Schspa Shi wrote on Thu, Sep 01, 2022 at 02:09:50AM +0800: >> To fix it, we can add extra reference counter to avoid deadlock, and >> decrease it after we unlock the client->lock. > > Thanks for the patch! > > Unfortunately I already sent a slightly different version to the list, > hidden in another syzbot thread, here: > https://lkml.kernel.org/r/YvyD053bdbGE9xoo@codewreck.org > > (yes, sorry, not exactly somewhere I'd expect someone to find it... 9p > hasn't had many contributors recently) > > > Basically instead of taking an extra lock I just released the client > lock before calling p9_client_cb, so it shouldn't hang anymore. > > We don't need the lock to call the cb as in p9_conn_cancel we already > won't accept any new request and by this point the requests are in a > local list that isn't shared anywhere. >
Ok, thank you for pointing that out.
> If you have a test setup, would you mind testing my patch? > That's the main reason I was delaying pushing it. >
I have test it with my enviroment, it not hang anymore.
> Since you went out of your way to make this patch if you agree with my > approach I don't mind adding your sign off or another mark of having > worked on it. > > Thank you,
-- BRs Schspa Shi
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