SUMMARY patch for JFFS2

SUMMARY patch for JFFS2

[Niraj Maheshwari]

Hi,

I am using Intel NOR flash having a 5.5 MB parition specific for
JFFS2. I have enabled the JFFS2 SUMMARY option after applying the
patch from the below
website on latest MTD for JFFS2 only.

http://www.inf.u-szeged.hu/jffs2/mount.php

Flash is completely erased and i am trying to mount this by using 

mount -t jffs2 /dev/mtdblock0 tmp/

It gets mounted..and then i completely full this partition ( 5.5 MB)
with data... then i  remove few of the files from this partition..then
i do a sync.

In the next reboot, i get to see lot of error while mounting this parition.

jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00270020:
0x00b0 instead
jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00270024:
0x00b0 instead
Further such events for this erase block will not be printed 

Am i doing some mistake as i guess SUMMARY patch must have been
completely tested for NOR flash as mentioned in the site.

I am having the same problem when i try to use SUMMARY in JFFS3. 

If you could help me out to resolve this problem then it would be great.

Thanks
Niraj

Re: SUMMARY patch for JFFS2

[Ferenc Havasi]

Hi Niraj,

> It gets mounted..and then i completely full this partition ( 5.5 MB)
> with data... then i  remove few of the files from this partition..then
> i do a sync.
> In the next reboot, i get to see lot of error while mounting this parition.

Can you send some more information about your flash chip? (erase block 
size, ...)

If you also can send us JFFS2 image before it goes wrong and after that 
also would be very big help for us to investigate what the problem is.

Thanks,
Ferenc

Re: SUMMARY patch for JFFS2

[Niraj Maheshwari]

On 5/10/05, Ferenc Havasi <havasi@inf.u-szeged.hu> wrote:
> Hi Niraj,
> 
> > It gets mounted..and then i completely full this partition ( 5.5 MB)
> > with data... then i  remove few of the files from this partition..then
> > i do a sync.
> > In the next reboot, i get to see lot of error while mounting this parition.
> 
> Can you send some more information about your flash chip? (erase block
> size, ...)


Flash chip is Intel W18 NOR Flash and erase block size is 0x10000,
Flash Size=16MB.

 
> If you also can send us JFFS2 image before it goes wrong and after that
> also would be very big help for us to investigate what the problem is.

I didn't understand..what do you mean by JFFS2 image. As i told in the
earlier mail that we are not flashing the JFFS2 image in the Flash.

Process is explained below.

1. Erase the JFFS2 partition ( 5.5 MB ) of the Flash by using some tool. 
2. Now boot the kernel in which JFFS2 Summary support is enabled.
3. After booting mount the JFFS2 parition from the flash in SDRAM.
    mount -t jffs2 /dev/mtdblock0 tmp/
4. Try to copy 6 MB of data in the tmp/ directory. As space available is 5.5MB,
    it will give Disk  Space Full error..and comes out.
5. "df" command shows 100% full on the mounted parition.
6. Remove few files to make it 80% in the mounted partition.
7. Run "sync" command.
8. Unmount the partition.
9. Reboot the system, then again mount it. You will get lot of errors.
   "Magic bitmask 0x1985 not found at 0x4f0018: 0x00b0 instead"
10. It does mount the partition but files/directories which i removed
in step-6, are
    still there.

Pl. note if i just disable the Summary Option in the Kernel,
everything work smoothly. I have thoroughly tested without Summary
Option.

Let me know if you need further information on this. I just want to
repeat again that the same behaviour is seen in latest MTD code as
well for JFFS3 with Summary Option. Without Summary options, JFFS3
also works fine on the same flash.

Thanks
Niraj
  

 
> Thanks,
> Ferenc
>

Re: SUMMARY patch for JFFS2

[Ferenc Havasi]

Hi Niraj,

We've tried to reproducate your problem but we was not succesfull yet.

Can you send us:
- a JFFS2 image before the things go wrong
- a JFFS2 image after went wrong (which cannot be mounted)
- the steps between these (commands you executed)

To make an image do "cat /dev/mtdblock0 >dump.jffs2" or similar.

Maybe it can be too big for mail, if you can put somewhere where we can
download from.

Thanks,
Ferenc