Re: linux-next: Tree for Jan 20 -- Kernel panic - Unable to mount root fs

Sabrina Dubroca
2015-01-20T21:39:05Z

2015-01-20, 21:02:03 +0000, Al Viro wrote:
> On Tue, Jan 20, 2015 at 09:45:04PM +0100, Sabrina Dubroca wrote:
>
> > printk(KERN_ERR "fn_lookup %s %d\n", name, retval);
> >
> > and I get:
> >
> > [ 1.618558] fn_lookup bsg/0:0:0:0 -2
> > [ 1.619437] fn_lookup bsg 0
> > [ 1.620236] fn_lookup bsg/0:0:0:0 -2
> > [ 1.625996] fn_lookup sda 0
> > [ 1.626609] fn_lookup sda 0
> > [ 1.639007] fn_lookup sda1 0
> > [ 1.639691] fn_lookup sda1 0
> > [ 1.643656] fn_lookup bsg/1:0:0:0 -2
> > [ 1.644974] fn_lookup bsg 0
> > [ 1.645928] fn_lookup bsg/1:0:0:0 -2
> > [ 1.649483] fn_lookup /dev/ram -2
> > [ 1.650424] fn_lookup /dev/root -2
> > [ 1.651234] VFS: Cannot open root device "sda1" or unknown-block(8,1): error -2
>
> That -2 is -ENOENT... Wait a sec, what's in filename, filename->name and
> what do you get from your printk on kernel with that commit reverted?

filename->name matches name. with
printk(KERN_ERR "fn_lookup %s %d, %p %s\n", name, retval, filename, filename->name);

[ 1.538646] fn_lookup bsg/0:0:0:0 -2, ffff88001f718000 bsg/0:0:0:0
[ 1.539704] fn_lookup bsg 0, ffff88001f718000 bsg
[ 1.540559] fn_lookup bsg/0:0:0:0 -2, ffff88001f718000 bsg/0:0:0:0
[ 1.552611] fn_lookup bsg/1:0:0:0 -2, ffff88001f718000 bsg/1:0:0:0
[ 1.553689] fn_lookup bsg 0, ffff88001f718000 bsg
[ 1.554505] fn_lookup bsg/1:0:0:0 -2, ffff88001f718000 bsg/1:0:0:0
[ 1.557554] fn_lookup sda 0, ffff88001f718000 sda
[ 1.558368] fn_lookup sda 0, ffff88001f718000 sda
[ 1.564190] fn_lookup sda1 0, ffff88001f718000 sda1
[ 1.565008] fn_lookup sda1 0, ffff88001f718000 sda1
[ 1.570751] fn_lookup /dev/ram -2, ffff88001f71a300 /dev/ram
[ 1.571786] fn_lookup /dev/root -2, ffff88001f71b480 /dev/root

and with
printk(KERN_ERR "fn_lookup %s %d, %s\n", name, retval, filename.name);
in the original do_path_lookup:

[ 1.426101] fn_lookup bsg/0:0:0:0 -2, bsg/0:0:0:0
[ 1.426893] fn_lookup bsg 0, bsg
[ 1.427406] fn_lookup bsg/0:0:0:0 0, bsg/0:0:0:0
[ 1.431530] fn_lookup sda 0, sda
[ 1.438346] fn_lookup bsg/1:0:0:0 0, bsg/1:0:0:0
[ 1.443658] fn_lookup sda1 0, sda1
[ 1.448344] fn_lookup /dev/ram 0, /dev/ram
[ 1.449148] fn_lookup /dev/root 0, /dev/root
[ 1.449835] fn_lookup /dev/root 0, /dev/root
[ 1.451586] EXT4-fs (sda1): couldn't mount as ext3 due to feature incompatibilities
[ 1.452954] fn_lookup /dev/root 0, /dev/root
[ 1.454292] EXT4-fs (sda1): couldn't mount as ext2 due to feature incompatibilities
[ 1.456331] fn_lookup /dev/root 0, /dev/root
[ 1.480208] EXT4-fs (sda1): mounted filesystem with ordered data mode. Opts: (null)
[ 1.481323] VFS: Mounted root (ext4 filesystem) readonly on device 8:1.

--
Sabrina