From: Chuck Lever Subject: [PATCH 1/4] NFS: Introduce iovec I/O helpers to fs/nfs/direct.c Date: Mon, 12 Nov 2007 12:16:47 -0500 Message-ID: <20071112171647.3053.70179.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: nfs@lists.sourceforge.net To: trond.myklebust@fys.uio.no Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1Ircun-0006t2-Qx for nfs@lists.sourceforge.net; Mon, 12 Nov 2007 09:17:38 -0800 Received: from flpi185.sbcis.sbc.com ([207.115.20.187] helo=flpi185.prodigy.net) by mail.sourceforge.net with esmtp (Exim 4.44) id 1Ircut-0001Iw-6g for nfs@lists.sourceforge.net; Mon, 12 Nov 2007 09:17:43 -0800 List-Id: "Discussion of NFS under Linux development, interoperability, and testing." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfs-bounces@lists.sourceforge.net Errors-To: nfs-bounces@lists.sourceforge.net Add helpers that iterate over multi-segment iovecs. These will be used to support multi-segment scatter/gather direct I/O in a later patch. Signed-off-by: Chuck Lever Signed-off-by: Chuck Lever --- fs/nfs/direct.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 71 insertions(+), 0 deletions(-) diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index afcab00..e30d928 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -355,6 +355,41 @@ static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned lo return result < 0 ? (ssize_t) result : -EFAULT; } +static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, + const struct iovec *iov, + unsigned long nr_segs, + loff_t pos) +{ + ssize_t result = -EINVAL; + size_t requested_bytes = 0; + unsigned long seg; + + get_dreq(dreq); + + for (seg = 0; seg < nr_segs; seg++) { + const struct iovec *vec = &iov[seg]; + result = nfs_direct_read_schedule(dreq, + (unsigned long)vec->iov_base, + vec->iov_len, pos); + if (result < 0) + break; + requested_bytes += result; + if ((size_t)result < vec->iov_len) + break; + pos += vec->iov_len; + } + + if (put_dreq(dreq)) + nfs_direct_complete(dreq); + + if (requested_bytes != 0) + return 0; + + if (result < 0) + return result; + return -EIO; +} + static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos) { ssize_t result = 0; @@ -697,6 +732,42 @@ static ssize_t nfs_direct_write_schedule(struct nfs_direct_req *dreq, unsigned l return result < 0 ? (ssize_t) result : -EFAULT; } +static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, + const struct iovec *iov, + unsigned long nr_segs, + loff_t pos, int sync) +{ + ssize_t result = 0; + size_t requested_bytes = 0; + unsigned long seg; + + get_dreq(dreq); + + for (seg = 0; seg < nr_segs; seg++) { + const struct iovec *vec = &iov[seg]; + result = nfs_direct_write_schedule(dreq, + (unsigned long)vec->iov_base, + vec->iov_len, + pos, sync); + if (result < 0) + break; + requested_bytes += result; + if ((size_t)result < vec->iov_len) + break; + pos += vec->iov_len; + } + + if (put_dreq(dreq)) + nfs_direct_write_complete(dreq, dreq->inode); + + if (requested_bytes != 0) + return 0; + + if (result < 0) + return result; + return -EIO; +} + static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos) { ssize_t result = 0; ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs