Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935770AbZDCQGA (ORCPT ); Fri, 3 Apr 2009 12:06:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934887AbZDCP4j (ORCPT ); Fri, 3 Apr 2009 11:56:39 -0400 Received: from mx2.redhat.com ([66.187.237.31]:56580 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934718AbZDCP42 (ORCPT ); Fri, 3 Apr 2009 11:56:28 -0400 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 21/41] CacheFiles: Permit the page lock state to be monitored [ver #48] To: linux-kernel@vger.kernel.org Cc: dhowells@redhat.com, nfsv4@linux-nfs.org, linux-fsdevel@vger.kernel.org Date: Fri, 03 Apr 2009 16:56:24 +0100 Message-ID: <20090403155624.28714.87176.stgit@warthog.procyon.org.uk> In-Reply-To: <20090403155436.28714.23368.stgit@warthog.procyon.org.uk> References: <20090403155436.28714.23368.stgit@warthog.procyon.org.uk> User-Agent: StGIT/0.14.3 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 Content-Length: 2392 Lines: 70 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 Acked-by: Steve Dickson Acked-by: Trond Myklebust Acked-by: Rik van Riel Acked-by: Al Viro Tested-by: Daire Byrne --- 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 076a7dc..34da523 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -384,6 +384,11 @@ static inline void wait_on_page_writeback(struct page *page) extern void end_page_writeback(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 cbc5772..fc11974 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -565,6 +565,24 @@ 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 * -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/