From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764655AbYB2A57 (ORCPT ); Thu, 28 Feb 2008 19:57:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932716AbYB2ArF (ORCPT ); Thu, 28 Feb 2008 19:47:05 -0500 Received: from mx1.redhat.com ([66.187.233.31]:58785 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932668AbYB2Aq5 (ORCPT ); Thu, 28 Feb 2008 19:46:57 -0500 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells Subject: [PATCH 18/37] CacheFiles: Permit the page lock state to be monitored [ver #34] To: Trond.Myklebust@netapp.com, chuck.lever@oracle.com, casey@schaufler-ca.com Cc: nfsv4@linux-nfs.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, selinux@tycho.nsa.gov, linux-security-module@vger.kernel.org, dhowells@redhat.com Date: Fri, 29 Feb 2008 00:45:10 +0000 Message-ID: <20080229004509.4142.77190.stgit@warthog.procyon.org.uk> In-Reply-To: <20080229004332.4142.51771.stgit@warthog.procyon.org.uk> References: <20080229004332.4142.51771.stgit@warthog.procyon.org.uk> User-Agent: StGIT/0.14.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a function to install a monitor on the page lock waitqueue for a particular page, thus allowing the page being unlocked to be detected. 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. Signed-off-by: David Howells --- include/linux/pagemap.h | 5 +++++ mm/filemap.c | 18 ++++++++++++++++++ 2 files changed, 23 insertions(+), 0 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index c8bd762..76b5307 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -242,6 +242,11 @@ static inline void wait_on_page_owner_priv_2(struct page *page) extern void end_page_owner_priv_2(struct page *page); /* + * Add an arbitrary waiter to a page's wait queue + */ +extern void add_page_wait_queue(struct page *page, wait_queue_t *waiter); + +/* * Fault a userspace page into pagetables. Return non-zero on a fault. * * This assumes that two userspace pages are always sufficient. That's diff --git a/mm/filemap.c b/mm/filemap.c index a583f44..561e6c7 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -548,6 +548,24 @@ void wait_on_page_bit(struct page *page, int bit_nr) EXPORT_SYMBOL(wait_on_page_bit); /** + * add_page_wait_queue - Add an arbitrary waiter to a page's wait queue + * @page - Page defining the wait queue of interest + * @waiter - Waiter to add to the queue + * + * Add an arbitrary @waiter to the wait queue for the nominated @page. + */ +void add_page_wait_queue(struct page *page, wait_queue_t *waiter) +{ + wait_queue_head_t *q = page_waitqueue(page); + unsigned long flags; + + spin_lock_irqsave(&q->lock, flags); + __add_wait_queue(q, waiter); + spin_unlock_irqrestore(&q->lock, flags); +} +EXPORT_SYMBOL_GPL(add_page_wait_queue); + +/** * unlock_page - unlock a locked page * @page: the page *