kern/160790: [fusefs] [panic] VPUTX: negative ref count with FUSE

[Allen Landsidel]

The following reply was made to PR kern/160790; it has been noted by GNATS.

From: Allen Landsidel <landsidel.allen at gmail.com>
To: bug-followup at FreeBSD.org
Cc:  
Subject: Re: kern/160790: [fusefs] [panic] VPUTX: negative ref count with
 FUSE
Date: Thu, 31 May 2012 15:30:47 -0400

 This bug continues to occur on a new system, different 'hardware'.  The 
 system is running MooseFS and was migrated some time ago to an VMWare 
 ESX 5 VM, 64bit.
 
 OS version is: 8.2-STABLE FreeBSD 8.2-STABLE #0: Fri Oct 14 00:11:10 UTC 
 2011     
 root at freebsd-82-64.master.concord.internal:/usr/obj/usr/src/sys/GENERIC  
 amd64
 
 My initial suspicion is there is some kind of race involved, as the 
 error only seems to occur during times of heavy write load.
 
 The virtualized system does reboot on the panic however, though the 
 physical machine the initial bug report regards did not.
 
 Panic:
 panic: vputx: negative ref cnt
 cpuid = 1
 KDB: stack backtrace:
 #0 0xffffffff80607050 at kdb_backtrace+0x60
 #1 0xffffffff805d4e74 at panic+0x1b4
 #2 0xffffffff80666e31 at vputx+0x101
 #3 0xffffffff8066702e at vput+0xe
 #4 0xffffffff8067206c at vn_open_cred+0x56c
 #5 0xffffffff8067210c at vn_open+0x1c
 #6 0xffffffff8066fc03 at kern_openat+0x163
 #7 0xffffffff8066ff89 at kern_open+0x19
 #8 0xffffffff8066ffa8 at open+0x18
 #9 0xffffffff808c6301 at amd64_syscall+0x301
 #10 0xffffffff808aee0c at Xfast_syscall+0xfc
 panic: bufwrite: buffer is not busy???