Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 6 Nov 2020 23:04:09 +0200
From:      Andriy Gapon <avg@FreeBSD.org>
To:        Mateusz Guzik <mjguzik@gmail.com>
Cc:        freebsd-current@freebsd.org, freebsd-fs@freebsd.org
Subject:   Re: panic: VERIFY(ZFS_TEARDOWN_READ_HELD(zfsvfs)) failed
Message-ID:  <bbeabc54-7b1d-e617-65be-9fc842b53824@FreeBSD.org>
In-Reply-To: <CAGudoHHmBW64HsKq8h8y4_8e9WMqpFgzx2XikpcRCz9=EmRwEQ@mail.gmail.com>
References:  <98c87b4f-4327-8a19-cf51-f3a14e42edf4@FreeBSD.org> <CAGudoHHmBW64HsKq8h8y4_8e9WMqpFgzx2XikpcRCz9=EmRwEQ@mail.gmail.com>

next in thread | previous in thread | raw e-mail | index | archive | help
On 06/11/2020 22:58, Mateusz Guzik wrote:
> Note the underlying primitive was recently replaced.
> 
> One immediate thing to check would be exact state of the lock.
> READ_HELD checks for reading only, fails if you have this
> write-locked, which is a plausible explanation if you are coming in
> from less likely codepath.
> 
> iow what's the backtrace and can you print both rms->readers and
> rms->owner (+ curthread)

Unfortunately, I do not have a vmcore, only a picture of the screen.

ZFS code looks correct, the lock should be held in read mode, so indeed I
suspect that the problem is with rms.

It looks like rms_rlock() does not change rmslock::readers, but rms_rowned()
checks it?

That's just from a first, super-quick look at the code.


> On 11/6/20, Andriy Gapon <avg@freebsd.org> wrote:
>>
>> The subject panic happens for me with r367410 when mounting root
>> filesystem.
>> The panic is in zfs_freebsd_cached_lookup -> zfs_lookup -> zfs_dirlook.
>> I have a picture of the screen with a little bit more details, I'll share it
>> later.

-- 
Andriy Gapon



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bbeabc54-7b1d-e617-65be-9fc842b53824>