From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: linux-next: Tree for Jan 20 -- Kernel panic - Unable to mount root fs Date: Tue, 20 Jan 2015 20:01:26 -0800 Message-ID: <54BF2496.4000807@roeck-us.net> References: <20150120165655.GA10904@kria> <20150120232726.GA16913@kria> <1517211.UYLV49hvpg@sifl> <1528536.jyty2pu4Mz@sifl> <20150121004117.GM29656@ZenIV.linux.org.uk> <54BF1292.2080902@roeck-us.net> <20150121033600.GN29656@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: Paul Moore , Sabrina Dubroca , Stephen Rothwell , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-audit@redhat.com, Richard Guy Briggs To: Al Viro Return-path: In-Reply-To: <20150121033600.GN29656@ZenIV.linux.org.uk> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On 01/20/2015 07:36 PM, Al Viro wrote: > On Tue, Jan 20, 2015 at 06:44:34PM -0800, Guenter Roeck wrote: >>> The shit hits the fan earlier - when we end up missing /dev. There are >>> two places where it could've been created (depending on CONFIG_BLK_DEV_INITRD); >>> sys_mkdir(collected, mode); >>> in init/initramfs.c (line 353 in linux-next) and >>> err = sys_mkdir((const char __user __force *) "/dev", 0755); >>> in init/noinitramfs.c (line 32). The latter would've screamed on failure; >>> could you printk of collected (%s), mode (%o) and return value (%d) in the >>> former and see what happens? >>> >> >> sys_mkdir .:40775 returned -17 >> sys_mkdir usr:40775 returned 0 >> sys_mkdir usr/lib:40775 returned -2 >> sys_mkdir usr/share:40755 returned -2 >> sys_mkdir usr/share/udhcpc:40755 returned -2 >> sys_mkdir usr/bin:40775 returned -2 >> sys_mkdir usr/sbin:40775 returned -2 >> sys_mkdir mnt:40775 returned 0 >> sys_mkdir proc:40775 returned 0 >> sys_mkdir root:40775 returned 0 >> sys_mkdir lib:40775 returned 0 >> sys_mkdir lib/modules:40775 returned -2 >> sys_mkdir lib/modules/3.9.2:40775 returned -2 >> sys_mkdir lib/modules/3.9.2/kernel:40775 returned -2 >> >> with >> int err = sys_mkdir(collected, mode); >> pr_info("sys_mkdir %s:%o returned %d\n", collected, mode, err); >> added in init/initramfs.c. > > Just what is lib/modules/3.9.2 doing there? In any case, I think I have at Artifact from when I created the root file system (which apparently was with 3.9.2). It is irrelevant for my testing, at least so far, so I never bothered fixing it. > least a plausible direction for digging. Look: > > diff --git a/fs/namei.c b/fs/namei.c > index 323957f..c7d107c 100644 > --- a/fs/namei.c > +++ b/fs/namei.c With this patch: sys_mkdir .:40775 returned -17 sys_mkdir usr:40775 returned 0 sys_mkdir usr/lib:40775 returned 0 sys_mkdir usr/share:40755 returned 0 sys_mkdir usr/share/udhcpc:40755 returned 0 sys_mkdir usr/bin:40775 returned 0 sys_mkdir usr/sbin:40775 returned 0 sys_mkdir mnt:40775 returned 0 sys_mkdir proc:40775 returned 0 sys_mkdir root:40775 returned 0 sys_mkdir lib:40775 returned 0 sys_mkdir lib/modules:40775 returned 0 ... and the problem is fixed. Guenter