From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id EFBAE1381F3 for ; Sun, 9 Jun 2013 13:48:36 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 01D65E0853; Sun, 9 Jun 2013 13:48:30 +0000 (UTC) Received: from smtp.gentoo.org (smtp.gentoo.org [140.211.166.183]) (using TLSv1 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 32522E084C for ; Sun, 9 Jun 2013 13:48:30 +0000 (UTC) Received: from hornbill.gentoo.org (hornbill.gentoo.org [94.100.119.163]) (using TLSv1 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.gentoo.org (Postfix) with ESMTPS id 43A2F33E328 for ; Sun, 9 Jun 2013 13:48:29 +0000 (UTC) Received: from localhost.localdomain (localhost [127.0.0.1]) by hornbill.gentoo.org (Postfix) with ESMTP id E4D23E5462 for ; Sun, 9 Jun 2013 13:48:27 +0000 (UTC) From: "Richard Yao" To: gentoo-commits@lists.gentoo.org Content-Transfer-Encoding: 8bit Content-type: text/plain; charset=UTF-8 Reply-To: gentoo-dev@lists.gentoo.org, "Richard Yao" Message-ID: <1370785659.c6cd9c59f8cfb7993f79754cf4dbc1f21040c0f7.ryao@gentoo> Subject: [gentoo-commits] proj/genkernel:master commit in: defaults/ X-VCS-Repository: proj/genkernel X-VCS-Files: defaults/initrd.scripts defaults/linuxrc X-VCS-Directories: defaults/ X-VCS-Committer: ryao X-VCS-Committer-Name: Richard Yao X-VCS-Revision: c6cd9c59f8cfb7993f79754cf4dbc1f21040c0f7 X-VCS-Branch: master Date: Sun, 9 Jun 2013 13:48:27 +0000 (UTC) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-commits@lists.gentoo.org X-Archives-Salt: 77b71786-e802-401f-bd4f-f57e3bd4869c X-Archives-Hash: ade4af8784d339dbb6578c7693e7aa83 commit: c6cd9c59f8cfb7993f79754cf4dbc1f21040c0f7 Author: Richard Yao gentoo org> AuthorDate: Sun Jun 9 13:13:58 2013 +0000 Commit: Richard Yao gentoo org> CommitDate: Sun Jun 9 13:47:39 2013 +0000 URL: http://git.overlays.gentoo.org/gitweb/?p=proj/genkernel.git;a=commit;h=c6cd9c59 Workaround busybox modprobe's inability to load ZFS modules Commit 3a054014e880e5b1ff28e3d87767c45a073da6b5 replaced our modprobe with busybox's modprobe. Unfortunately, busybox's modprobe appears to be unable to properly load modules with more than 1 level of dependencies. The zfs and zpool commands will invoke modprobe if /dev/zvol is missing, which concealed this problem. However, this caused problems because some invocations would fail and under certain circumstances, init would be killed, causing a kernel panic. This issue was made clear by commit 71d35173727dc968d7baa2107accb99ebbc5b188, which ensured that the zpool and zfs commands were not run until the ZFS module was loaded. busybox modprobe's failure to load module dependencies correctly appears to occur because busybox modprobe does not wait until until a module is loaded before loading a module that depends on it, which is a race. It would be best to correct this race by waiting until the module has properly loaded, but it is not clear that the race is the only thing going wrong and developer time is a premium. We implement a workaround by modifying the busy loop added in the previous commit to explicit call `modprobe zfs` on each iteration. While the first few calls fail due to bugs in busybox modprobe, it will eventually work, after which each call is a noop. This lets us keep looping until either the loop exit condition that /dev/zvol exist is reached or the 5 second timeout is reached. Once the busybox modprobe issue is fixed, this workaround should be safe to revert. Signed-off-by: Richard Yao gentoo.org> --- defaults/initrd.scripts | 5 +++-- defaults/linuxrc | 2 -- 2 files changed, 3 insertions(+), 4 deletions(-) diff --git a/defaults/initrd.scripts b/defaults/initrd.scripts index 35e5957..cb0fcb8 100644 --- a/defaults/initrd.scripts +++ b/defaults/initrd.scripts @@ -637,9 +637,10 @@ chooseKeymap() { } # This helper function is to be called using call_func_timeout. -# It enables us to wait a reasonable amount of time until /dev/zfs appears. +# This works around the inability of busybox modprobe to handle complex module dependencies. +# This also enables us to wait a reasonable amount of time until /dev/zfs appears. waitForZFS() { - while [ ! -c /dev/zfs ]; do echo >/dev/null; done; + while [ ! -c /dev/zfs ]; do modprobe zfs 2> /dev/null; done; } startVolumes() { diff --git a/defaults/linuxrc b/defaults/linuxrc index 3784456..d6d0eaa 100644 --- a/defaults/linuxrc +++ b/defaults/linuxrc @@ -307,8 +307,6 @@ then break fi done - - [ "USE_ZFS" = "1" ] && MY_HWOPTS="${MY_HWOPTS} zfs" fi splash 'init'