Re: [Bulk] Re: page_mkwrite vs pte dirty race in fb_defio

On 05/25/2010 08:47 PM, Nick Piggin wrote:

quoted

quoted

I hope that should provide a more elegant solution to your problem. I
would really like you to take a look at that, because we already have
filesystem code (NFS) relying on it, and more code we have relying on
this synchronization, the more chance we would find a subtle problem
with it (also it should be just nicer).

So if I undestand it correctly, using the "new" calling convention I should just lock the page on fb_deferred_io_mkwrite() and return VM_FAULT_LOCKED to fix the described race for fb_defio.

As far as I can see from quick reading of the fb_defio code, yes
that should solve it (provided you lock the page inside the mutex,
of course).

Ok, thanks. I'm posting a new version as RFT.

Cheers,
Albert