From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Howells Subject: [PATCH 07/14] CacheFiles: Permit the page lock state to be monitored Date: Tue, 31 Jul 2007 21:25:31 +0100 Message-ID: <20070731202531.6412.25477.stgit@warthog.cambridge.redhat.com> References: <20070731202454.6412.88646.stgit@warthog.cambridge.redhat.com> Reply-To: Linux filesystem caching discussion list Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: linux-fsdevel@vger.kernel.org, linux-cachefs@redhat.com, nfsv4@linux-nfs.org, linux-kernel@vger.kernel.org To: torvalds@osdl.org, akpm@osdl.org, steved@redhat.com, trond.myklebust@fys.uio.no Return-path: In-Reply-To: <20070731202454.6412.88646.stgit@warthog.cambridge.redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-cachefs-bounces@redhat.com Errors-To: linux-cachefs-bounces@redhat.com List-Id: linux-fsdevel.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 | 19 +++++++++++++++++++ 2 files changed, 24 insertions(+), 0 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index d1049b6..452fdcf 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -220,6 +220,11 @@ static inline void wait_on_page_fscache_write(struct page *page) extern void end_page_fscache_write(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 76606db..0c1720c 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -518,6 +518,25 @@ void fastcall 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 *