Re: eCryptfs: Request for review

[Michael Thompson <michael.craig.thompson@gmail.com>]

On 10/19/05, Badari Pulavarty <pbadari@gmail.com> wrote:
> It is telling you that there is already IO in progress on that page.
> Either you ended up in  __block_write_full_page() twice or called
> __block_write_full_page() before finishing up end_page_writeback().

OK, I have narrowed it down to the following: we are in
ecryptfs_writepage, and do the following:
lower_page = grab_cache_page(lower_inode->i_mapping, 0);
where lower_page is the page in the lower filesysetm we want to write to.

We consistantly panic when, after we do the grab_cache_page(), we have
a locked page which is set for PageWriteback....
PageWriteback(lower_page) != 0.

What I would like to know is how I should proceed when I am in this
condition. I am not sure if it is acceptable to simply return from the
function, or if I need to set some flags, or wait on the lock to free
up. Unfortunately, I haven't been digging around the VFS long enough
to know what makes sense in this case.

_Any_ guidance would be extremely helpful.

Cheers,
Mike