From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751748Ab1AHKJF (ORCPT ); Sat, 8 Jan 2011 05:09:05 -0500 Received: from mail-pw0-f46.google.com ([209.85.160.46]:51428 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751399Ab1AHKJD (ORCPT ); Sat, 8 Jan 2011 05:09:03 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:subject:message-id:mime-version:content-type :content-disposition:user-agent; b=pMVnpJ4oUUBlAEXgU2OesYhDr2fRLGIQnYmqpjhliyYMqAfA3/yy0s6s8+m1P33Mqe 1whSRplQw2EWa656q5SaOqZJN/dF54UtOT+LyyP+/XOQnQM2+3ujmJa1KsRCYXMdj3Ct HQPXCzaNIuvMW0IPP6rh5B6b/s6d8kwJS1JvU= Date: Sat, 8 Jan 2011 18:09:13 +0800 From: Dave Young To: Chris Mason , linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH retry] btrfs: mount failure return value fix Message-ID: <20110108100913.GA2659@darkstar> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I happened to pass swap partition as root partition in cmdline, then kernel panic and tell me about "Cannot open root device". It is not correct, in fact it is a fs type mismatch instead of 'no device'. Eventually I found btrfs mounting failed with -EIO, it should be -EINVAL. The logic in init/do_mounts.c: for (p = fs_names; *p; p += strlen(p)+1) { int err = do_mount_root(name, p, flags, root_mount_data); switch (err) { case 0: goto out; case -EACCES: flags |= MS_RDONLY; goto retry; case -EINVAL: continue; } print "Cannot open root device" panic } SO fs type after btrfs will have no chance to mount Here fix the return value as -EINVAL Signed-off-by: Dave Young --- fs/btrfs/disk-io.c | 4 +++- fs/btrfs/volumes.c | 8 +++++--- 2 files changed, 8 insertions(+), 4 deletions(-) --- linux-2.6.orig/fs/btrfs/disk-io.c 2010-12-29 21:53:17.473333338 +0800 +++ linux-2.6/fs/btrfs/disk-io.c 2010-12-29 21:57:37.916666672 +0800 @@ -1713,8 +1713,10 @@ struct btrfs_root *open_ctree(struct sup fs_info, BTRFS_ROOT_TREE_OBJECTID); bh = btrfs_read_dev_super(fs_devices->latest_bdev); - if (!bh) + if (!bh) { + err = -EINVAL; goto fail_iput; + } memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy)); memcpy(&fs_info->super_for_commit, &fs_info->super_copy, --- linux-2.6.orig/fs/btrfs/volumes.c 2010-12-29 21:53:17.503333338 +0800 +++ linux-2.6/fs/btrfs/volumes.c 2010-12-29 21:57:37.920000005 +0800 @@ -598,8 +598,10 @@ static int __btrfs_open_devices(struct b set_blocksize(bdev, 4096); bh = btrfs_read_dev_super(bdev); - if (!bh) + if (!bh) { + ret = -EINVAL; goto error_close; + } disk_super = (struct btrfs_super_block *)bh->b_data; devid = btrfs_stack_device_id(&disk_super->dev_item); @@ -700,7 +702,7 @@ int btrfs_scan_one_device(const char *pa goto error_close; bh = btrfs_read_dev_super(bdev); if (!bh) { - ret = -EIO; + ret = -EINVAL; goto error_close; } disk_super = (struct btrfs_super_block *)bh->b_data; @@ -1193,7 +1195,7 @@ int btrfs_rm_device(struct btrfs_root *r set_blocksize(bdev, 4096); bh = btrfs_read_dev_super(bdev); if (!bh) { - ret = -EIO; + ret = -EINVAL; goto error_close; } disk_super = (struct btrfs_super_block *)bh->b_data;