From: "Aneesh Kumar K.V" Subject: [PATCH 1/4] Add buffer head related helper functions Date: Thu, 15 Nov 2007 17:40:43 +0530 Message-ID: <1195128646-15143-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1195128646-15143-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Cc: cmm@us.ibm.com, torvalds@linux-foundation.org, a.p.zijlstra@chello.nl, akpm@linux-foundation.org, adilger@clusterfs.com, "Aneesh Kumar K.V" To: linux-ext4@vger.kernel.org Return-path: Received: from E23SMTP06.au.ibm.com ([202.81.18.175]:39060 "EHLO e23smtp06.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756842AbXKOMLc (ORCPT ); Thu, 15 Nov 2007 07:11:32 -0500 Received: from d23relay03.au.ibm.com (d23relay03.au.ibm.com [202.81.18.234]) by e23smtp06.au.ibm.com (8.13.1/8.13.1) with ESMTP id lAFCBSub010318 for ; Thu, 15 Nov 2007 23:11:28 +1100 Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v8.6) with ESMTP id lAFCBUxN2498696 for ; Thu, 15 Nov 2007 23:11:30 +1100 Received: from d23av01.au.ibm.com (loopback [127.0.0.1]) by d23av01.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id lAFBAZfa004930 for ; Thu, 15 Nov 2007 22:10:36 +1100 In-Reply-To: <1195128646-15143-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Add buffer head related helper function bh_uptodate_or_lock and bh_submit_read which can be used by file system Signed-off-by: Aneesh Kumar K.V --- include/linux/buffer_head.h | 29 +++++++++++++++++++++++++++++ 1 files changed, 29 insertions(+), 0 deletions(-) diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index da0d83f..82cc9ef 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -327,6 +327,35 @@ static inline void lock_buffer(struct buffer_head *bh) extern int __set_page_dirty_buffers(struct page *page); +/* Return true if the buffer is up-to-date. + * Return false, with the buffer locked, if not. + */ +static inline int bh_uptodate_or_lock(struct buffer_head *bh) +{ + if (!buffer_uptodate(bh)) { + lock_buffer(bh); + if (!buffer_uptodate(bh)) + return 0; + unlock_buffer(bh); + } + return 1; +} +/* + * Submit a locked buffer for reading, + * return a negative error and release + * the buffer if failed. + */ +static inline int bh_submit_read(struct buffer_head *bh) +{ + get_bh(bh); + bh->b_end_io = end_buffer_read_sync; + submit_bh(READ, bh); + wait_on_buffer(bh); + if (buffer_uptodate(bh)) + return 0; + brelse(bh); + return -EIO; +} #else /* CONFIG_BLOCK */ static inline void buffer_init(void) {} -- 1.5.3.5.652.gf192c-dirty