Re: Jffs2 and big file = very slow jffs2_garbage_collect_pass

Matthieu CASTET
2008-01-22T08:58:48Z

Jörn Engel wrote:
> On Mon, 21 January 2008 16:16:12 -0600, Josh Boyer wrote:
>> Wait... you're writing a flash filesystem that doesn't really deal with
>> bad blocks?
>
> I never said that. Like any other new piece of code, logfs has bugs.
> Plain and simple. And having blocks rot underneith you is something I
> don't have automated tests for, so don't be surprised to find bugs in
> this area.
On mtd->read I have see no checking for EBADMSG or EUCLEAN.
There no call to mtd->block_markbad or mtd->block_isbad (it is only
called in mtd_find_sb).

So I don't see how this can work on NAND flash.

Good test could be to add bad block simulation to nandsim.
There is some patch for this
(http://lists.infradead.org/pipermail/linux-mtd/2006-December/017107.html).
Note they don't simulate bit-flip on read.

Matthieu