From owner-freebsd-current@FreeBSD.ORG Fri Aug 21 18:00:53 2009 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 099C2106568C for ; Fri, 21 Aug 2009 18:00:53 +0000 (UTC) (envelope-from rmacklem@uoguelph.ca) Received: from esa-jnhn.mail.uoguelph.ca (esa-jnhn.mail.uoguelph.ca [131.104.91.44]) by mx1.freebsd.org (Postfix) with ESMTP id B41188FC0C for ; Fri, 21 Aug 2009 18:00:52 +0000 (UTC) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ApoEAPZ9jkqDaFvL/2dsb2JhbADXOIQaBYFP X-IronPort-AV: E=Sophos;i="4.44,251,1249272000"; d="scan'208";a="45172921" Received: from nile.cs.uoguelph.ca ([131.104.91.203]) by esa-jnhn-pri.mail.uoguelph.ca with ESMTP; 21 Aug 2009 14:00:50 -0400 Received: from localhost (localhost.localdomain [127.0.0.1]) by nile.cs.uoguelph.ca (Postfix) with ESMTP id 075318D4041; Fri, 21 Aug 2009 14:00:51 -0400 (EDT) X-Virus-Scanned: amavisd-new at nile.cs.uoguelph.ca Received: from nile.cs.uoguelph.ca ([127.0.0.1]) by localhost (nile.cs.uoguelph.ca [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id NhzEVvNqr8b0; Fri, 21 Aug 2009 14:00:49 -0400 (EDT) Received: from muncher.cs.uoguelph.ca (muncher.cs.uoguelph.ca [131.104.91.102]) by nile.cs.uoguelph.ca (Postfix) with ESMTP id C1EB48D4138; Fri, 21 Aug 2009 14:00:49 -0400 (EDT) Received: from localhost (rmacklem@localhost) by muncher.cs.uoguelph.ca (8.11.7p3+Sun/8.11.6) with ESMTP id n7LI5DH15410; Fri, 21 Aug 2009 14:05:13 -0400 (EDT) X-Authentication-Warning: muncher.cs.uoguelph.ca: rmacklem owned process doing -bs Date: Fri, 21 Aug 2009 14:05:13 -0400 (EDT) From: Rick Macklem X-X-Sender: rmacklem@muncher.cs.uoguelph.ca To: "Rick C. Petty" In-Reply-To: <20090819175029.GA90205@keira.kiwi-computer.com> Message-ID: References: <20090819161817.GA89704@keira.kiwi-computer.com> <20090819175029.GA90205@keira.kiwi-computer.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: bzeeb+freebsd+lor@zabbadoz.net, current@freebsd.org Subject: Re: various vfs LORs X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 Aug 2009 18:00:53 -0000 On Wed, 19 Aug 2009, Rick C. Petty wrote: > > This LOR doesn't seem to be reported anywhere: > >> lock order reversal: >> 1st 0xffffff00046de7f8 nfs (nfs) @ /usr/src/sys/kern/vfs_syscalls.c:4097 >> 2nd 0xffffff80a5129968 bufwait (bufwait) @ /usr/src/sys/kern/vfs_bio.c:1835 >> 3rd 0xffffff00046de620 nfs (nfs) @ /usr/src/sys/nfsclient/nfs_node.c:161 >> KDB: stack backtrace: >> db_trace_self_wrapper() at db_trace_self_wrapper+0x2a >> _witness_debugger() at _witness_debugger+0x2e >> witness_checkorder() at witness_checkorder+0x81e >> __lockmgr_args() at __lockmgr_args+0xcf3 >> nfs_nget() at nfs_nget+0x1c9 >> nfs_readdirplusrpc() at nfs_readdirplusrpc+0x7cc >> nfs_doio() at nfs_doio+0x617 >> nfs_bioread() at nfs_bioread+0xa9f >> nfs_readdir() at nfs_readdir+0x85 >> kern_getdirentries() at kern_getdirentries+0x12e >> getdirentries() at getdirentries+0x23 >> syscall() at syscall+0x1af >> Xfast_syscall() at Xfast_syscall+0xe1 >> --- syscall (196, FreeBSD ELF64, getdirentries), rip = 0x8009d11dc, rsp = 0x7fffffffc3a8, rbp = 0x1 --- Since the 3rd one is locking a newly allocated nfs vnode (that isn't yet in the mount point list, etc), I don't think this will cause a problem and I don't see an easy way to avoid it. rick