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From: Thomas Gleixner <tglx@linutronix.de>
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To: Mateusz Guzik <mjguzik@gmail.com>, Bert Karwatzki <spasswolf@web.de>,
 Christian Brauner <brauner@kernel.org>
Cc: linux-kernel@vger.kernel.org, linux-next@vger.kernel.org,
 linux-rt-devel@lists.linux.dev, linux-fsdevel@vger.kernel.org,
 adobriyan@gmail.com, jack@suse.cz, viro@zeniv.linux.org.uk, Sebastian
 Andrzej Siewior <bigeasy@linutronix.de>
Subject: Re: context switch within RCU read-side critical section in
 next-20260518+ with PREEMPT_RT
In-Reply-To: <fnrz73n5jojl2wlbgrsjdtu5zuwykwbcjzznaijbquuovpoand@i6ihdqn7a6zv>
References: <20260520225245.2962-1-spasswolf@web.de>
 <fnrz73n5jojl2wlbgrsjdtu5zuwykwbcjzznaijbquuovpoand@i6ihdqn7a6zv>
Date: Thu, 21 May 2026 12:05:27 +0200
Message-ID: <87bje9w00o.ffs@tglx>
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On Thu, May 21 2026 at 10:53, Mateusz Guzik wrote:
> On Thu, May 21, 2026 at 12:52:44AM +0200, Bert Karwatzki wrote:
>> With these reverts next-20260519 boots 30 times in a row without error, so
>> it appears that commit dc651e25a6d2 ("fs: RCU-ify filesystems list") causing the
>> error.
>> 
>
> I think the patch below will do the trick.
>
> If someone wonders how come the missing unlocks: the original patch had
> them in place, but when I was rebasing on top of the RCU-ifing commit I
> figured I'm going to do guard/scoped_guard in there as well. Later it
> started failing as the compiler did not like goto retry out of a scoped
> guard area and the unlocks did not come back.
>
> tl;dr there is definitely my bug here and it is most likely *the* bug

I was staring at the wrong commit then :)