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 5FBFD1381F3 for ; Sun, 9 Jun 2013 13:21:09 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id E1CADE0801; Sun, 9 Jun 2013 13:21:08 +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 57E98E0801 for ; Sun, 9 Jun 2013 13:21:08 +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 59D2133E140 for ; Sun, 9 Jun 2013 13:21:07 +0000 (UTC) Received: from localhost.localdomain (localhost [127.0.0.1]) by hornbill.gentoo.org (Postfix) with ESMTP id F0858E468F for ; Sun, 9 Jun 2013 13:21:05 +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: <1370783977.1c0131bc6d5acb9a0f7b6d6a7d6c80c0ce2f4cf7.ryao@gentoo> Subject: [gentoo-commits] proj/genkernel:ryao 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: 1c0131bc6d5acb9a0f7b6d6a7d6c80c0ce2f4cf7 X-VCS-Branch: ryao Date: Sun, 9 Jun 2013 13:21:05 +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: b76c8426-3754-45d1-94f4-42a9f1e7a218 X-Archives-Hash: 60a1485ef80dd4f4bace6ca090463300 commit: 1c0131bc6d5acb9a0f7b6d6a7d6c80c0ce2f4cf7 Author: Richard Yao gentoo org> AuthorDate: Sun Jun 9 13:13:58 2013 +0000 Commit: Richard Yao gentoo org> CommitDate: Sun Jun 9 13:19:37 2013 +0000 URL: http://git.overlays.gentoo.org/gitweb/?p=proj/genkernel.git;a=commit;h=1c0131bc 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 because it 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 f598402..73c0f0c 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'