From patchwork Mon Jul 30 15:59:30 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sage Weil X-Patchwork-Id: 1255191 Return-Path: X-Original-To: patchwork-ceph-devel@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 2665BDFE76 for ; Mon, 30 Jul 2012 15:59:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754164Ab2G3P7s (ORCPT ); Mon, 30 Jul 2012 11:59:48 -0400 Received: from cobra.newdream.net ([66.33.216.30]:45772 "EHLO cobra.newdream.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753952Ab2G3P7o (ORCPT ); Mon, 30 Jul 2012 11:59:44 -0400 Received: from nine.aon.corp.newdream.net (unknown [38.122.20.226]) by cobra.newdream.net (Postfix) with ESMTPA id 8C5BE8004F; Mon, 30 Jul 2012 08:59:43 -0700 (PDT) From: Sage Weil To: ceph-devel@vger.kernel.org Cc: Sage Weil Subject: [PATCH 7/8] libceph: change ceph_con_in_msg_alloc convention to be less weird Date: Mon, 30 Jul 2012 08:59:30 -0700 Message-Id: <1343663971-3221-8-git-send-email-sage@inktank.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1343663971-3221-1-git-send-email-sage@inktank.com> References: <1343663971-3221-1-git-send-email-sage@inktank.com> Sender: ceph-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org This function's calling convention is very limiting. In particular, we can't return any error other than ENOMEM (and only implicitly), which is a problem (see next patch). Instead, return an normal 0 or error code, and make the skip a pointer output parameter. Drop the useless in_hdr argument (we have the con pointer). Signed-off-by: Sage Weil Reviewed-by: Alex Elder --- net/ceph/messenger.c | 56 ++++++++++++++++++++++++++++---------------------- 1 file changed, 31 insertions(+), 25 deletions(-) diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index c3b628c..5177af0 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -1733,9 +1733,7 @@ static int read_partial_message_section(struct ceph_connection *con, return 1; } -static bool ceph_con_in_msg_alloc(struct ceph_connection *con, - struct ceph_msg_header *hdr); - +static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip); static int read_partial_message_pages(struct ceph_connection *con, struct page **pages, @@ -1864,9 +1862,14 @@ static int read_partial_message(struct ceph_connection *con) /* allocate message? */ if (!con->in_msg) { + int skip = 0; + dout("got hdr type %d front %d data %d\n", con->in_hdr.type, con->in_hdr.front_len, con->in_hdr.data_len); - if (ceph_con_in_msg_alloc(con, &con->in_hdr)) { + ret = ceph_con_in_msg_alloc(con, &skip); + if (ret < 0) + return ret; + if (skip) { /* skip this message */ dout("alloc_msg said skip message\n"); BUG_ON(con->in_msg); @@ -1876,12 +1879,8 @@ static int read_partial_message(struct ceph_connection *con) con->in_seq++; return 0; } - if (!con->in_msg) { - con->error_msg = - "error allocating memory for incoming message"; - return -ENOMEM; - } + BUG_ON(!con->in_msg); BUG_ON(con->in_msg->con != con); m = con->in_msg; m->front.iov_len = 0; /* haven't read it yet */ @@ -2715,43 +2714,50 @@ static int ceph_alloc_middle(struct ceph_connection *con, struct ceph_msg *msg) * connection, and save the result in con->in_msg. Uses the * connection's private alloc_msg op if available. * - * Returns true if the message should be skipped, false otherwise. - * If true is returned (skip message), con->in_msg will be NULL. - * If false is returned, con->in_msg will contain a pointer to the - * newly-allocated message, or NULL in case of memory exhaustion. + * Returns 0 on success, or a negative error code. + * + * On success, *skip may be set to 1: + * - the next message should be skipped and ignored. + * - con->in_msg == NULL. + * or *skip may be 0: + * - con->in_msg is non-zero. + * On error (ENOMEM, EAGAIN, ...), + * - con->in_msg == NULL */ -static bool ceph_con_in_msg_alloc(struct ceph_connection *con, - struct ceph_msg_header *hdr) +static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip) { + struct ceph_msg_header *hdr = &con->in_hdr; int type = le16_to_cpu(hdr->type); int front_len = le32_to_cpu(hdr->front_len); int middle_len = le32_to_cpu(hdr->middle_len); - int ret; + int ret = 0; BUG_ON(con->in_msg != NULL); if (con->ops->alloc_msg) { - int skip = 0; - mutex_unlock(&con->mutex); - con->in_msg = con->ops->alloc_msg(con, hdr, &skip); + con->in_msg = con->ops->alloc_msg(con, hdr, skip); mutex_lock(&con->mutex); if (con->in_msg) { con->in_msg->con = con->ops->get(con); BUG_ON(con->in_msg->con == NULL); } - if (skip) + if (*skip) { con->in_msg = NULL; - - if (!con->in_msg) - return skip != 0; + return 0; + } + if (!con->in_msg) { + con->error_msg = + "error allocating memory for incoming message"; + return -ENOMEM; + } } if (!con->in_msg) { con->in_msg = ceph_msg_new(type, front_len, GFP_NOFS, false); if (!con->in_msg) { pr_err("unable to allocate msg type %d len %d\n", type, front_len); - return false; + return -ENOMEM; } con->in_msg->con = con->ops->get(con); BUG_ON(con->in_msg->con == NULL); @@ -2767,7 +2773,7 @@ static bool ceph_con_in_msg_alloc(struct ceph_connection *con, } } - return false; + return ret; }