What is wrong?

[Brian Norris]

+ Richard, Andrew

(Meant to CC earlier)

On Wed, Feb 26, 2014 at 05:11:48PM -0800, Brian Norris wrote:
> On Wed, Feb 26, 2014 at 04:07:21PM +0200, Leon Pollak wrote:
> > I use JFFS2 version 2.2.(NAND)(SUMMARY)(C) 2001-2006 Red Hat, Inc. 
> > (comes with MontaVistaPro 5.0). Kernel 2.6.18.
> > I prepare JFFS2 partition with mkfs.jffs2 and sumtool and burn it with 
> > flash_eraseall and 'nandwrite -p'.
> > Everything works fine.
> > 
> > The NAND is write protected by HW and the partition is mounted as RO. 
> > At some moment I need to update a small file. 
> > So I do: 
> > - HW write protect off, 
> > - remount RW, 
> > - update file, 
> > - sync, 
> > - remount RO, 
> > - write protect on.
> > 
> > Looking at linux console I see a lot of messages like:
> > Erase at 0x00400000 failed immediately: errno -5
> > Erase at 0x003e0000 failed immediately: errno -5
> > ......
> > Erase at 0x00340000 failed immediately: errno -5
> > jffs2_flush_wbuf(): Write failed with -5
> > Write of 2016 bytes at 0x002578a0 failed. returned -5, retlen 0
> > Not marking the space at 0x002578a0 as dirty because the flash driver 
> > returned retlen zero.
> > 
> > 
> > This is repeated for a long time, but everything seems work OK.
> > The sequential starts and even file updates are also OK, without error 
> > messages.
> > 
> > What do I do wrong? Thanks a lot.
> 
> It's possible you're seeing symptoms of this:
> 
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=807612db2f9940b9fa6deaef054eb16d51bd3e00
> 
> It seems like maybe JFFS2 is still doing some GC and/or write flushing
> after the remount.
> 
> Could try this?
> 
>  - HW write protect off, 
>  - remount RW, 
>  - update file, 
>  - sync, 
>  - remount RO, 
>  - sync, <---------- add this, to see if you're experiencing any
>                      writeback after remount
>  - write protect on.