Permission problem on mtd block device

Permission problem on mtd block device

[Nikunj A. Dadhania]

Hi,

I have compiled kernel 2.4.2 and patched it for arm.
I am using an Assabet board.

I have statically compiled the mtd and loaded jffs as modules.

The kernel booted and I got the entry in /proc too.

The outputs of various commands are as follows:

*************************************************************************
/ # ls /dev/mt* -l
crw-r--r--   1 0        0         90,   0 Jan  1 00:00 /dev/mtd0
brw-r--r--   1 0        0         31,   0 Jan  1 00:01 /dev/mtdblock0
crw-r--r--   1 0        0         90,   1 Jan  1 00:00 /dev/mtdr0

/ # ls -al
drwxr-xr-x  12 0        0            1024 Jul  2  2001 .
drwxr-xr-x  12 0        0            1024 Jul  2  2001 ..
drwxr-sr-x   2 0        1000         1024 Jul  2  2001 bin
drwxr-xr-x   3 0        0            1024 Jan  1 00:01 dev
drwxr-xr-x   4 0        0            1024 Jun 30  2001 etc
drwxr-xr-x   3 0        0            1024 Jul  1  2001 lib

/***************The mount point I used**************/
dr-xr-xr-x   1 0        0               0 Jan  1 00:03 mnt
/***************************************************/

dr-xr-xr-x  20 0        0               0 Jan  1 00:00 proc
drwxr-sr-x   2 0        1000         1024 Jul  2  2001 sbin
drwxr-xr-x   2 0        0            1024 Jun 30  2001 tmp
drwxr-sr-x   5 0        0            1024 Jul  2  2001 usr
drwxr-xr-x   5 0        0            1024 Jun 30  2001 var

/ # cat /proc/mtd 
dev:    size   erasesize  name
mtd0: 00040000 00040000 "bootloader"
mtd1: 00040000 00040000 "bootloader params"
mtd2: 01f80000 00040000 "jffs"
***************************************************************************

Then it I mounted the device using
(i tried mount -t jffs option but it didnt work)
I am using Busybox.

mount /dev/mtdblock0 /mnt 

this command works. it gives some directory listing such as..

/ # ls -al /mnt
dr-xr-xr-x   1 0        0               0 Jan  1 00:03 .
drwxr-xr-x  12 0        0            1024 Jul  2  2001 ..
dr-xr-xr-x   1 0        0               0 Jan  1 00:03 001
-r--r--r--   1 0        0               0 Jan  1 00:03 devices
-r--r--r--   1 0        0               0 Jan  1 00:03 drivers


but I cannot write to it nor can i delete any file from it ..
what could the problem possibly be??

I would be extremely grateful if i could get an early reply.

thanks in advance

nikunj

PS: I am not subscribed to this list. So please mail me at my 
personal address 

Re: Permission problem on mtd block device

[David Woodhouse]

nikunj@bindaas.org said:
> mount /dev/mtdblock0 /mnt 
>
> this command works. it gives some directory listing such as..
>
> / # ls -al /mnt
> dr-xr-xr-x   1 0        0               0 Jan  1 00:03 .
> drwxr-xr-x  12 0        0            1024 Jul  2  2001 ..
> dr-xr-xr-x   1 0        0               0 Jan  1 00:03 001
> -r--r--r--   1 0        0               0 Jan  1 00:03 devices
> -r--r--r--   1 0        0               0 Jan  1 00:03 drivers

That looks like usbdevfs.

cat /proc/mounts /proc/filesystems

--
dwmw2

Re: Permission problem on mtd block device

[Nikunj A. Dadhania]

David Woodhouse <dwmw2@infradead.org> writes:

> nikunj@bindaas.org said:
> > mount /dev/mtdblock0 /mnt 
> >
> > this command works. it gives some directory listing such as..
> >
> > / # ls -al /mnt
> > dr-xr-xr-x   1 0        0               0 Jan  1 00:03 .
> > drwxr-xr-x  12 0        0            1024 Jul  2  2001 ..
> > dr-xr-xr-x   1 0        0               0 Jan  1 00:03 001
> > -r--r--r--   1 0        0               0 Jan  1 00:03 devices
> > -r--r--r--   1 0        0               0 Jan  1 00:03 drivers
> 
> That looks like usbdevfs.
Ooppps ... you are right...  

> cat /proc/mounts /proc/filesystems

/mnt # cat /proc/mounts 
/dev/root / ext2 rw 0 0
/proc /proc proc rw 0 0
/dev/mtdblock0 /mnt usbdevfs rw 0 0

/mnt # cat /proc/filesystems 
nodev   sockfs
nodev   shm
nodev   pipefs
nodev   proc
        ext2
nodev   usbdevfs
nodev   devpts
        jffs

but where is the flash ?
Is the major and minor number are correct which I have specified in 
previous mail? (for the reference mtd0 90 0, mtdr 90 1, mtdblock0 31 0)
In the /proc/mtd it shows the mtd0, mtd1 and mtd2 entries.
And when i give the command

mount -t jffs /dev/mtdblock0 /mnt/
mount: Mounting /dev/mtdblock0 on /mnt failed: Permission denied

how do I mount the jffs??

>
> --
> dwmw2

regards
nikunj

Re: Permission problem on mtd block device

[David Woodhouse]

nikunj@bindaas.org said:
> Is the major and minor number are correct which I have specified in
> previous mail? (for the reference mtd0 90 0, mtdr 90 1, mtdblock0 31
> 0)

Yep, they're fine.


>  mount -t jffs /dev/mtdblock0 /mnt/ 
> mount: Mounting /dev/mtdblock0 on /mnt failed: Permission denied 

I don't think that error is coming from JFFS. Can you build it with 
debugging enabled and show the output of 'dmesg'? It'll show us whether 
it's even getting as far as jffs_read_super().



--
dwmw2

Re: Permission problem on mtd block device

[Nikunj A. Dadhania]

nikunj@bindaas.org (Nikunj A. Dadhania) writes:

> David Woodhouse <dwmw2@infradead.org> writes:
> 
> > nikunj@bindaas.org said:
> > > mount /dev/mtdblock0 /mnt 
> > >
> > > this command works. it gives some directory listing such as..
> > >
> > > / # ls -al /mnt
> > > dr-xr-xr-x   1 0        0               0 Jan  1 00:03 .
> > > drwxr-xr-x  12 0        0            1024 Jul  2  2001 ..
> > > dr-xr-xr-x   1 0        0               0 Jan  1 00:03 001
> > > -r--r--r--   1 0        0               0 Jan  1 00:03 devices
> > > -r--r--r--   1 0        0               0 Jan  1 00:03 drivers
> > 
> > That looks like usbdevfs.
> Ooppps ... you are right...  
> 
> > cat /proc/mounts /proc/filesystems
> 
> /mnt # cat /proc/mounts 
> /dev/root / ext2 rw 0 0
> /proc /proc proc rw 0 0
> /dev/mtdblock0 /mnt usbdevfs rw 0 0
> 
> /mnt # cat /proc/filesystems 
> nodev   sockfs
> nodev   shm
> nodev   pipefs
> nodev   proc
>         ext2
> nodev   usbdevfs
> nodev   devpts
>         jffs
> 
> but where is the flash ?
> Is the major and minor number are correct which I have specified in 
> previous mail? (for the reference mtd0 90 0, mtdr 90 1, mtdblock0 31 0)
> In the /proc/mtd it shows the mtd0, mtd1 and mtd2 entries.
> And when i give the command
> 
> mount -t jffs /dev/mtdblock0 /mnt/
> mount: Mounting /dev/mtdblock0 on /mnt failed: Permission denied
> 
> how do I mount the jffs??

sorry to bother u all. Actually i was assigning wrong minor numbers.
I got the mtdblock2 mounted using jffs2. But still jffs is not working :( 

/dev # mount -t jffs /dev/mtdblock2 /mnt
jffs_scan_falsh():Free size accounting screwed
jfffs_scan_flash():free_chunk_size1 == 0x758c0, free_chunk_size2 == 0x0, fmc->free_size == 0x113540
JFFS: Failed to mount device 1f:02.
mount: Mounting /dev/mtdblock2 on /mnt failed: Invalid argument

Is jffs2 stable enough to use in production use or should i stick with jffs?
If i have to use jffs please guide me in this regard.


regards,

nikunj