Re: panic: System call lstat returning with 1 locks held

From: Yar Tikhiy <yar_at_FreeBSD.org>
Date: Thu, 24 Jan 2008 12:28:08 +0000
On Tue, Jan 15, 2008 at 04:39:24PM +0200, Kostik Belousov wrote:
>
> I think this could be related to the recent vn_lock()/VOP_LOCK() KPI changes.
> Please, add DEBUG_VFS_LOCKS to the kernel config, and do the
> 	show lockedvnods
> from the ddb prompt when the panic occurs. The witness does not track
> the lockmgr locks.

I think I'm seeing the same panic on UFS.  It's rather nasty: I
cannot rebuild CURRENT natively due to it so I have to build it
under 6-STABLE.  My favourite way to trigger the panic reliably is
running `make install' in a simple port directory, e.g., portmaster,
but my system also panics during daily scripts run and, as already
said, if trying to build world.

Now my kernel config is:

	include GENERIC
	ident	"_LOCKTEST"
	options DEBUG_VFS_LOCKS

Attached is the debug output after the panic.  Alas, no locked
vnodes are shown.  How can I help to investigate this issue
further?

Yar

panic: System call lstat returning with 1 locks held
cpuid = 0
KDB: enter: panic
[thread pid 2024 tid 100102 ]
Stopped at      kdb_enter+0x3a: movl    $0,kdb_why
db> show lockedvnods
Locked vnodes
db> where
Tracing pid 2024 tid 100102 td 0xc3720000
kdb_enter(c0b0bdc0,c0b0bdc0,c0b3c319,d6218c8c,0,...) at kdb_enter+0x3a
panic(c0b3c319,c0b11902,1,c0b11902,c0bbf390,...) at panic+0x12c
syscall(d6218d38) at syscall+0x46e
Xint0x80_syscall() at Xint0x80_syscall+0x20
--- syscall (0, FreeBSD ELF32, nosys), eip = 0x2815da8b, esp = 0xbfbfe86c, ebp = 0xbfbfe8f8 ---
Received on Thu Jan 24 2008 - 11:28:08 UTC

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