Re: openzfs panic: VERIFY3U(offset, <, dn->dn_datablksz) failed

From: Alexander Leidinger <Alexander_at_Leidinger.net>
Date: Fri, 01 May 2026 10:41:30 UTC
Am 2026-04-30 20:12, schrieb Jean-Sébastien Pédron:
> On 25/04/2026 10:24, Kristof Provost wrote:
>> On 24 Apr 2026, at 14:18, Alexander Leidinger wrote:
>>     recent current (last commit 2026-04-23-222413).
>> 
>>     short:
>>     #3 0xffffffff805502f7 in vpanic (
>>     fmt=0xffffffff82556d5d "VERIFY3U(offset, <, dn->dn_datablksz) 
>> failed
>>     (%llu < %llu)\n", ap=ap@entry=0xfffffe0228f57c70)
>>     at /space/system/usr_src/sys/kern/kern_shutdown.c:974
>>     buf = "VERIFY3U(offset, <, dn->dn_datablksz) failed
>>     (9223372036854775807 < 24576)\n", '\000' <repeats 180 times>
>>     __pc = 0x0
>>     __pc = 0x0
>>     __pc = 0x0
>>     other_cpus = {__bits = {16777213, 0 <repeats 15 times>}}
>>     td = 0xfffff80741b6e780
>>     bootopt = <unavailable>
>>     newpanic = <optimized out>
>> 
>> I’m seeing the same panic (somewhat regularly, without obvious 
>> trigger), so I’m fairly confident it’s not some obscure corruption in 
>> your pool.
> I get it while working on RabbitMQ as well, 100% reproducible. I shared 
> what I think I understand of the problem on the pull request that added 
> POSIX_FADV_DONTNEED support:
> https://github.com/openzfs/zfs/pull/18399
> 
> However, the patch I drafted, even though it does not cause the panic 
> anymore, is incorrect as I misunderstood that code.

There is now https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=294903

Bye,
Alexander.

-- 
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