jffs2 mounting problem

[Robert Kaiser]

Hi,

Am Donnerstag, 4. April 2002 18:07 schrieben Sie:
> I am using two AMD flash of 4MB each. Then I am relocating them such that
> they are continuous.
> Then I create  three partitions, first one for bootloader, second for JFFS2
> root partition and the last is free to be used latter.
>
> Then probing of the flash also shows the following information -
> physmap flash device: 800000 at bf800000
> Number of erase regions: 2
> Primary Vendor Command Set: 0002 (AMD/Fujitsu Standard)
>
> Now when I boot the system from 2nd jffs2 root partition I see the
> following info -
>
> #cat /proc/mtd
> dev:    size   erasesize  name
> mtd0: 000a0000 00010000 "bootstrap and kernel"
> mtd1: 00360000 00010000 "jffs2 filesystem"
> mtd2: 00400000 00010000 "jffs2 2nd filesystem"
>
> Also I have following devices created -
> #ls -l
> crwxr--r--   1 root     root      90,   0 Mar 27  2002 mtd0
> crwxr--r--   1 root     root      90,   1 Mar 27  2002 mtd1
> crwxr--r--   1 root     root      90,   2 Mar 27  2002 mtd2
> crw-r--r--   1 root     root      90,   4 Jan  1 00:03 mtd4
> brwxr--r--   1 root     root      31,   0 Mar 27  2002 mtdblock0
> brwxr--r--   1 root     root      31,   1 Mar 27  2002 mtdblock1
> brw-r--r--   1 root     root      31,   2 Jan  1 00:02 mtdblock2
>

Have a look at the MAKEDEV script in directory "util" of the MTD directory. 
The minor numbers you chose for /dev/mtd? are, umm, unusual. I doubt you 
really want them. The MAKEDEV script would have assigned these numbers:

   mtd0: 0
   mtd1: 2
   mtd2: 4
   mtd4: 8

>
>
> Now I want the last partition to be mounted to /mnt directory.
> For that first I use /dev/mtd4 for erasing the partition and

Due to the (presumably wrong) minor numbers, /dev/mtd4 in your case 
corresponds to device mtd2 (i.e. "jffs2 2nd filesystem"), so that is
what got erased.

> then I use the following command to mount the last partition -
>
> #mount -t jffs2 /dev/mtdblock2 /mnt

The minor number for mtdblock2 is correct (i.e. it also corresponds to the 
"jffs2 2nd filesystem" partition), so this should actually work. My only 
guess is that you may have used "erase /dev/mtd4" to do the erase ? Note that 
the "erase" command by default erases only one block, "eraseall" erases an 
entire device.

>
> When the mounting is completed I use the command "df" and I see the
> used space in the partition increases rapidly to 100%.

This is normal AFAIK. After increasing to 100% as you observed, it should go 
back to some 5% or so (depends on the erase block size).

Hope this helps

Rob


----------------------------------------------------------------
Robert Kaiser                         email: rkaiser at sysgo.de
SYSGO RTS GmbH
Am Pfaffenstein 14                    phone: (49) 6136 9948-762
D-55270 Klein-Winternheim / Germany   fax:   (49) 6136 9948-10