Re: Spare area access information from JFFS2

[Thomas Gleixner <tglx@linutronix.de>]

On Sat, 2007-05-05 at 21:48 +0530, Sudeep K N wrote:
>        1. During Mount: scans the block, [erases], and writes "0x20031985"
>                into the spare area on start of every block followed by another
>                18 bytes which spans across multiple pages because free bytes in
>                spare area is only 4

JFFS2 writes only 4 bytes, when you set the ecclayout information
correct. Even if you set it to something else, it writes max. 12 bytes.
So your 4 + 18 bytes observation is rather strange.

>        2. Later during main page program operation our nand controller
>                updates spare area ECC bytes, during this sequence we are not
>                clear whether JFFS2 perform any spare operation to updates it
>                meta data.

JFFS2 does not use the spare area for metadata information other than
the cleanmarker.

>        3. Also, we want know, later the above sequence, does JFFS2 performs
>                any spare only program operations.
> 

No. The only exception is the block_mark_bad operation.

	tglx