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Date: Sun, 18 Dec 2005 16:08:16 +0100
From: Steven Scholz <steven.scholz@imc-berlin.de>
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Cc: linux-mtd@lists.infradead.org
Subject: Re: Do I have to umount JFFS2?
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Peter,

>> Didnt get this comment of ur's :
>> 1. Single files can be still corrupted, when you write them and press
>> reset.
>>
> When you press reset, when a file is written, you get a partly written
> block. So you get a file, which is not written completely. This
> corruption is detected by jffs2 and issues warnings. The filesystem as
> whole stays intact, but the file as such doesn't have the contents you
> might expect.

Since you're talking about "pressing reset" I have to ask again.

When we do a firmware update of our devices we do something like

 cp /tmp/large_file /opt/imc/application
 reboot

where /tmp is a ramdisk and / a jffs2 rw rootfs.

So we're not pressing reset but doing a reboot. And I wanted to know if
linux does only reboot _after_ all data is correctly written to flash?

Would it make sense to do

 cp /tmp/large_file /opt/imc/application
 sync
 reboot

???

What's the point of having a line

::shutdown:/bin/umount -a -r

in /etc/inittab?

I have

/dev/mtdblock0 on / type jffs2 (rw,noatime)
/proc on /proc type proc (rw,nodiratime)
devpts on /dev/pts type devpts (rw)
sysfs on /sys type sysfs (rw)
/dev/shm on /var type tmpfs (rw)
/sys/kernel/debug on /var/tmp/debug type debugfs (rw)

So the only real fs is jffs2. Does it help to unmount it before reboot?

--
Steven