Re: [PATCH 3/3] reiser4: in our own sync writes, mark pages dirty before marking them writeback.

[Edward Shishkin <edward.shishkin@gmail.com>]

On 10/10/2015 06:51 PM, Oleg Drokin wrote:
> On Oct 10, 2015, at 11:03 AM, Edward Shishkin wrote:
>>>> For formatted nodes we can continue to narrow down the problem
>>>> (see the attached patch).
>>> Having applied the patch, I saw loads and loads of warnings (in ~10
>>> distinct stacktraces), but no panics or oopses in the initial location.
>>> The false positives are possible, right?
>> Yes, a lot of ones and nothing interesting.
>> The same for Dushan's logs. Sorry for bad idea..
> Actually the idea might not be as bad as you think.
>
> This is because not every page that you forgot to call page_dirty on
> will cause a crash.
> Only the pages that had never ever had been set dirty.
> So in a lot of cases the crash does not happen because the page got
> dirtied by a normal path somewhere else and then cleared by normal
> means, but i_wb remains with that page forever until it's fully torn down
> from the pagecache.

I wanted something more efficient than simply code review..
However, in all paths found by Ivan I see that pages are not
obliged to become dirty in write-locking sessions..

Edward.