From owner-freebsd-fs@FreeBSD.ORG Sat Oct 25 16:02:38 2014 Return-Path: Delivered-To: freebsd-fs@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id CCCC4397; Sat, 25 Oct 2014 16:02:38 +0000 (UTC) Received: from mail.madpilot.net (grunt.madpilot.net [78.47.145.38]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 57E868F8; Sat, 25 Oct 2014 16:02:38 +0000 (UTC) Received: from mail (mail [192.168.254.3]) by mail.madpilot.net (Postfix) with ESMTP id 3jQ6X23q2czb3G; Sat, 25 Oct 2014 18:02:26 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=madpilot.net; h= content-transfer-encoding:content-type:content-type:in-reply-to :references:subject:subject:mime-version:user-agent:from:from :date:date:message-id:received:received; s=mail; t=1414252944; x=1416067345; bh=+i1X43VeKO7bXtQEVE9+Ku3mMcwriLVb+P2MoHp/1no=; b= CYzE/rcEydjxWcDIACQpcjFglrIRxIwoyLMYAAVl6pCvPTw9A3covUNc6UXMIKaG SKJQ9HKW4mh6MOadMsrhc/U7Df7dc2o07XbuoZMb1a8u/z6FG+o6wK1/BoIUogw5 ow8T6W77IsR93vpbO2shLGDfd41hXkFdVns0tfheoaI= Received: from mail.madpilot.net ([192.168.254.3]) by mail (mail.madpilot.net [192.168.254.3]) (amavisd-new, port 10024) with ESMTP id GritJvivHpbs; Sat, 25 Oct 2014 18:02:24 +0200 (CEST) Received: from tommy.madpilot.net (micro.madpilot.net [88.149.173.206]) by mail.madpilot.net (Postfix) with ESMTPSA; Sat, 25 Oct 2014 18:02:24 +0200 (CEST) Message-ID: <544BC990.4030700@madpilot.net> Date: Sat, 25 Oct 2014 18:02:24 +0200 From: Guido Falsi User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: FreeBSD FS Subject: Re: panic: detach with active requests on 10.1-RC3 References: <544A538F.6060202@FreeBSD.org> <544BBB85.2020909@madpilot.net> In-Reply-To: <544BBB85.2020909@madpilot.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: Glen Barber , freebsd-stable@FreeBSD.org X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 25 Oct 2014 16:02:38 -0000 On 10/25/14 17:02, Guido Falsi wrote: > On 10/24/14 15:26, Guido Falsi wrote: >> Hi, >> >> I'm making some experiments with 10.1-RC3 on alix boards as hardware >> using NanoBSD. >> >> By mounting and umounting UFS filesystems I have seen umount constantly >> hanging hard in a deadlock. I have tested on two boards with two >> distinct compactflash disks with same results. This was not happening >> with 10.0-RELEASE. >> >> I have build a 10.1-RC3 kernel with full debugging and caused the >> problem to happen, I got this: >> >> root@qtest:~ [0]# umount /cfg >> panic: detach with active requests >> KDB: stack backtrace: >> db_trace_self_wrapper(c0968053,c08ea7f0,c2d48800,c23d6bc8,c0536a16,...) >> at db_trace_self_wrapper+0x2d/frame 0xc23d6b98 >> kdb_backtrace(c09639e1,c09fa7e8,c095761d,c23d6c54,c095761d,...) at >> kdb_backtrace+0x30/frame 0xc23d6c00 >> vpanic(c09fa682,100,c095761d,c23d6c54,c23d6c54,...) at vpanic+0x80/frame >> 0xc23d6c24 >> kassert_panic(c095761d,c09575b3,c2d7acc0,4c7,c2d7acc0,...) at >> kassert_panic+0xe9/frame 0xc23d6c48 >> g_detach(c2d7acc0,4,c095725c,1c2,c09c8d5c,...) at g_detach+0x1d3/frame >> 0xc23d6c64 >> g_wither_washer(c09f7df4,0,c0956544,124,0,...) at >> g_wither_washer+0x109/frame 0xc23d6c90 >> g_run_events(0,c23d6d08,c095d42a,3dc,0,...) at g_run_events+0x40/frame >> 0xc23d6ccc >> fork_exit(c05c4e60,0,c23d6d08) at fork_exit+0x7f/frame 0xc23d6cf4 >> fork_trampoline() at fork_trampoline+0x8/frame 0xc23d6cf4 >> --- trap 0, eip = 0, esp = 0xc23d6d40, ebp = 0 --- >> KDB: enter: panic >> [ thread pid 12 tid 100006 ] >> Stopped at kdb_enter+0x3d: movl $0,kdb_why >> db> >> > > I tried to investigate some more by myself. Maybe what I found is > obvious to anyone with decent VFS knowledge, anyway: > > After some fumbling around I did: > > db> show geom 0xc2e98b40 > consumer: 0xc2e98b40 > class: VFS (0xc09c8d5c) > geom: ffs.ada0s3 (0xc3293600) > provider: ada0s3 (0xc2e7e200) > access: r0w0e0 > flags: 0x0030 > nstart: 19 > nend: 18 > > Which shows nstart != nend, while g_detach asserts them to be the same. > > Going up the chain of providers I find also it's providers have nstart - > nend == 1: > > db> show geom 0xc2e9b7c0 > consumer: 0xc2e9b7c0 > class: PART (0xc09c96b0) > geom: ada0 (0xc2e7e780) > provider: ada0 (0xc2e7e500) > access: r2w0e0 > flags: 0x0030 > nstart: 1430 > nend: 1429 > db> show geom 0xc2e7e500 > provider: ada0 (0xc2e7e500) > class: DISK (0xc09c8890) > geom: ada0 (0xc2e7e580) > mediasize: 4017807360 > sectorsize: 512 > stripesize: 0 > stripeoffset: 0 > access: r2w0e0 > flags: (0x0030) > error: 0 > nstart: 2085 > nend: 2084 > consumer: 0xc2e9a700 (ada0), access=r0w0e0, flags=0x0030 > consumer: 0xc2e9b480 (ada0), access=r0w0e0, flags=0x0030 > consumer: 0xc2e9b7c0 (ada0), access=r2w0e0, flags=0x0030 > > Looking at the code these values are touched only in g_io_request() and > g_io_deliver() respectively. > > So this one now looks like a geom problem. > > In fact the only commit which touched those functions between 10.0 and > 10.1 branches is r260385, which merged quite a few things. > > I've tried reverting it to test without that, but "svn merge -c -260385 > ." generated a few conflicts I'm unable to resolve. So I need some > guidance even to perform this simple test. > I finally succeeded in merging it good enough to compile and boot, and got the same panic, so Even this commit looks unrelated. I must admit I am out of ideas. -- Guido Falsi