mmap on jffs2(2.4.19)

[leeyang]

I need mmap a "writable" file,
and it fails.My code is as below:

 fd = open("/usr/dat/sot.dat",O_RDWR,FILEMODE);
 
 ptr1=mmap(NULL,filesize,PROT_READ|PROT_WRITE,MAP_SHARED,fd,0);

fd returns 3,but ptr1 returns -1 and 
mmap errno says invalid agrument.
These codes runs well on ext2.

Then I checked the old maillist and source code.
It seems jffs2 currently not support mmap writable.
Am I right?

In
http://lists.infradead.org/pipermail/linux-mtd/2002-July/005436.html
dw said "some kind of mtd_remap()",
Has it been implemented now? 


BTW:
My last msg was blocked by 
"Message has a suspicious header"

I'm not sure the reason,I guess 
the smtp server I used is broken,
and I change to another one,
hope this one works.

leeyang