Hello Jens

On Thu, Nov 9, 2017 at 1:51 AM, Jens Rudberg <jens@teenage.engineering>
wrote:

> Hi,
> During development of a new embedded platform I have run into an unwanted
> behaviour by yaffs.
> We use yaffs in direct mode on an micron SLC nand with 2k pages and
> built-in ECC functionality.
> It seems like yaffs sometimes roll back the file system when it is
> mounted, even if there should be no checkpoint available.
> We see this by noticing that sometimes after a sudden reboot / crash files
> are rollbacked to previous versions.
>
> I was under the impression that the checkpoint is invalidated immediately
> when a partition is mounted, but this may not be the case?
>

No it should be invalidated as soon as there is any modification to the
filesystem (modify file/directory, delete file/directory or any garbage
collection). If you don't do any modifications the checkpoint will stay
"forever".


Our current method to avoid this is to call yaffs_sync() after every file
> operation, which doesn’t seems like the right way to do it.
> yaffs_sync() both does a full sync including checkpoint.
> replacing the calls to yaffs_sync() with yaffs_sync_files()
>

What happens if you don't  use any checkpoint. eg. mount with
skip_checkpt_read set to 1.

I will have a look at the log and see if anything stands out.

Regards

Charles