what i do is i have backupmenu installed and fsck all partitions. works very well

okay then try the steps above only instead of reboot, do:

mount -o rw /dev/mmcblk0p1 /home/user/MyDocs

rm -rf /home/user/MyDocs/[thefaultyfile]

and after that pls follow the 4 steps above your post again.

Can you please elaborate more on this ?

Actually i cannot put faulty file as all files in My Docs(File Manager i.e internal memory) are in read only mode.I cannot add , delete or edit files Internal memory.

thats why you have to use root terminal with rm -rf

mount -o rw /dev/mmcblk0p1 /home/user/MyDocs

rm -rf /home/user/MyDocs/[thefaultyfile]

So what do i put in place of [thefaultyfile] ?

You were probably copying something that broke the clean state of your filesystem.

Delete that.

@andy2611
First a quick tip for once you've got this sorted
- install "FileBox". It's much more powerful than the standard file browser and it has a good GUI. Remeber to put things in "MyDocs" that need to be opened by other software though!

If a file is un-openable because an extension got altered, you can open the file with leafpad and do Save As, remebering to add the correct extension.

If a file is un-openable because it is corrupt, well, the instructions in post #3 work but the file will get deleted. My suggestion would be to do the fsck for the whole device rather than just one file - there might be others. Only reboot once you have cycled through enough times to get no errors and then complete the remaining step(s).

This is what you can expect when you have no errors:
NB. I typed root, instead of sudo gainroot but the commands and the output (num files excepted) should be the same.

I did the same as suggested by you

1st step -

Root


2nd step -

Nokia-N900:~# umount /dev/mmcblk0p1

3rd Step

Nokia-N900:~# fsck -a /dev/mmcblk0p1

Output I got :

fsck 1.41.3.maemo0 (12-Oct-2008)
dosfsck 2.11, 12 Mar 2005, FAT32, LFN
/dev/mmcblk0p1: 2786 files, 58184/442377 clusters
Nokia-N900:~#


Then i mounted again:

4th step

Nokia-N900:~# mount /dev/mmcblk0p1


Rebooted

But nothing changed

mount as read write..

as root :

umount /dev/mmcblk0p1
fsck.vfat /dev/mmcblk0p1
mount -t vfat -o rw /dev/mmcblk0p1 /homeuser/MyDocs
that should do it.. , no need to reboot , test copying files to MyDocs before rebooting.

[Edit]

in case the above doesn't do the job for you , try installing backupmenu from extras-devel then reboot your phone with your keyboard open , you will get to a menu , connect your n900 to your pc then press 'w' , all partitions on the emmc will be available as mass storage devices on your pc .

if you are using Windows , you will get a bunch of format partition dialogues , just close them all .
then go to My Computer , right click on the MyDocs partition then click properties then tools , then check disk .

if you are using linux , I recommend using gparted .
when you open it it will search for available devices , select /dev/sdb from the selection menu (thats assuming you have only one hard disk connected to your computer and no other storage devices connected) , if there are , the name might not be /dev/sdb
once you find your n900 , right click on the first partition then select unmount then check .
thats it..

in case the file system check returns errors , copy all files you need from the MyDocs partition then format it .

you can format it from your n900 :

as root :

umount /dev/mmcblk0p1
mkfs.vfat /dev/mmcblk0p1
reboot

on your pc : I guess thats easy enough no need to explain

you will lose every thing stored in MyDocs if you format it .

incase formatting fails : try flashing the emmc .. incase flashing fails , I guess you have a hardware problem and probably you will have to send it to nokia for repairs .