From owner-freebsd-hackers Fri Feb 27 17:47:38 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id RAA19067 for freebsd-hackers-outgoing; Fri, 27 Feb 1998 17:47:38 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from dingo.cdrom.com (dingo.cdrom.com [204.216.28.145]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id RAA19057 for ; Fri, 27 Feb 1998 17:47:34 -0800 (PST) (envelope-from mike@dingo.cdrom.com) Received: from dingo.cdrom.com (localhost [127.0.0.1]) by dingo.cdrom.com (8.8.8/8.8.5) with ESMTP id RAA29930; Fri, 27 Feb 1998 17:45:41 -0800 (PST) Message-Id: <199802280145.RAA29930@dingo.cdrom.com> X-Mailer: exmh version 2.0zeta 7/24/97 To: Greg Lehey cc: FreeBSD Hackers Subject: Re: Kernel debugging: what's going on here? In-reply-to: Your message of "Sat, 28 Feb 1998 11:43:49 +1030." <19980228114349.01329@freebie.lemis.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 27 Feb 1998 17:45:39 -0800 From: Mike Smith Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > Can anybody explain this to me? I'm writing a disk block, and am > currently at bwrite: > > (kgdb) bt > #0 bwrite (bp=0xf051ec00) at ../../kern/vfs_bio.c:364 > #1 0xf0138d6a in vop_stdbwrite (ap=0xf2a76c74) at ../../kern/vfs_default.c:283 > #2 0xf0138bb1 in vop_defaultop (ap=0xf2a76c74) at ../../kern/vfs_default.c:130 > #3 0xf0146639 in spec_vnoperate (ap=0xf2a76c74) at ../../miscfs/specfs/spec_vnops.c:127 > #4 0xf01c5679 in ufs_vnoperatespec (ap=0xf2a76c74) at ../../ufs/ufs/ufs_vnops.c:2242 > #5 0xf2aab097 in VOP_BWRITE (bp=0xf051ec00) at vnode_if.h:1117 > #6 0xf2aa95c4 in vinumstart (vol=0xf0563000, bp=0xf10f1bb0) at request.c:228 > #7 0xf2aa9189 in vinumstrategy (bp=0xf10f1bb0) at request.c:71 > #8 0xf2aa7b63 in vinum_writedisklabel (vol=0xf0563000, lp=0xf0563110) at io.c:830 > > I've handed a buffer header up from frame 6 (not the bp in the > parameter list). When it gets to bwrite, it has a different content. > gdb tells me different contents depending on the frame it's in: My guess would be that the bp has been translated to reflect the block device that it will be operating on at bwrite level rather than the logical device that you were operating on when you called VOP_BWRITE. This would involve a change in vnode, as well as (maybe) offset etc. -- \\ Sometimes you're ahead, \\ Mike Smith \\ sometimes you're behind. \\ mike@smith.net.au \\ The race is long, and in the \\ msmith@freebsd.org \\ end it's only with yourself. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message