Re: panic(s) in ZFS on CURRENT

Hi Gleb,

There are two probably related PRs upstream:
https://github.com/openzfs/zfs/pull/14939
https://github.com/openzfs/zfs/pull/14954

On 09.06.2023 00:57, Gleb Smirnoff wrote:
> On Thu, Jun 08, 2023 at 07:56:07PM -0700, Gleb Smirnoff wrote:
> T> I'm switching to INVARIANTS kernel right now and will see if that panics earlier.
> 
> This is what I got with INVARIANTS:
> 
> panic: VERIFY3(dev->l2ad_hand <= dev->l2ad_evict) failed (225142071296 <= 225142063104)
> 
> cpuid = 17
> time = 1686286015
> KDB: stack backtrace:
> db_trace_self_wrapper() at db_trace_self_wrapper+0x2c/frame 0xfffffe0160dcea90
> kdb_backtrace() at kdb_backtrace+0x46/frame 0xfffffe0160dceb40
> vpanic() at vpanic+0x21f/frame 0xfffffe0160dcebe0
> spl_panic() at spl_panic+0x4d/frame 0xfffffe0160dcec60
> l2arc_write_buffers() at l2arc_write_buffers+0xcda/frame 0xfffffe0160dcedf0
> l2arc_feed_thread() at l2arc_feed_thread+0x547/frame 0xfffffe0160dceec0
> fork_exit() at fork_exit+0x122/frame 0xfffffe0160dcef30
> fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe0160dcef30
> --- trap 0, rip = 0, rsp = 0, rbp = 0 ---
> Uptime: 1m4s
> Dumping 5473 out of 65308 MB:..1%..11%..21%..31%..41%..51%..61%..71%..81%..91%
> 
> (kgdb) frame 4
> #4  0xffffffff804342ea in l2arc_write_buffers (spa=0xfffffe022e942000, dev=0xfffffe023116a000, target_sz=16777216)
>      at /usr/src/FreeBSD/sys/contrib/openzfs/module/zfs/arc.c:9445
> 9445                    ASSERT3U(dev->l2ad_hand, <=, dev->l2ad_evict);
> (kgdb) p dev
> $1 = (l2arc_dev_t *) 0xfffffe023116a000
> (kgdb) p dev->l2ad_hand
> $2 = 225142071296
> (kgdb) p dev->l2ad_evict
> $3 = 225142063104
> (kgdb) p *dev
> value of type `l2arc_dev_t' requires 66136 bytes, which is more than max-value-size
> 
> Never seen kgdb not being able to print a structure that reported to be too big.
> 

-- 
Alexander Motin