linux-kernel September 2007 archive
Main Archive Page > Month Archives  > linux-kernel archives
linux-kernel: Re: [PATCH 11/22] CacheFiles: Permit the page lock

Re: [PATCH 11/22] CacheFiles: Permit the page lock state to be monitored

From: David Howells <dhowells_at_nospam>
Date: Fri Sep 21 2007 - 23:14:41 GMT
To: Trond Myklebust <Trond.Myklebust@netapp.com>

Trond Myklebust <Trond.Myklebust@netapp.com> wrote:

> > This is used by CacheFiles to detect read completion on a page in the
> > backing filesystem so that it can then copy the data to the waiting netfs
> > page.
>
> Won't it in any case want to lock the page too?

No. Why would it? All it wants to do is to read the page (copying it to the netfs's page), assuming it becomes PG_uptodate.

> That would be the only way to ensure that the page is still mapped into the
> address space when you're writing it out...

I don't understand what you're getting at. Write the page out where? We've just read it in from the cache, so why would we be writing it back out?

David
-
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html