From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Venkateswararao Jujjuri (JV)" Subject: [PATCH 7/7] [net/9p] Handle TREAD/RERROR case in !dotl case. Date: Sun, 13 Feb 2011 18:21:33 -0800 Message-ID: <1297650093-10508-8-git-send-email-jvrao@linux.vnet.ibm.com> References: <1297650093-10508-1-git-send-email-jvrao@linux.vnet.ibm.com> Cc: linux-fsdevel@vger.kernel.org, "Venkateswararao Jujjuri (JV)" To: v9fs-developer@lists.sourceforge.net Return-path: Received: from e37.co.us.ibm.com ([32.97.110.158]:36677 "EHLO e37.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755437Ab1BNBnR (ORCPT ); Sun, 13 Feb 2011 20:43:17 -0500 Received: from d03relay05.boulder.ibm.com (d03relay05.boulder.ibm.com [9.17.195.107]) by e37.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id p1E1efiH023529 for ; Sun, 13 Feb 2011 18:40:41 -0700 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay05.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p1E1hDRQ101384 for ; Sun, 13 Feb 2011 18:43:13 -0700 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p1E1hCmT017114 for ; Sun, 13 Feb 2011 18:43:13 -0700 In-Reply-To: <1297650093-10508-1-git-send-email-jvrao@linux.vnet.ibm.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: This is a rather sticky issue to deal with in non-9P2000.L protocols. In 9P2000.L, the error is a fixed size (errno) hence not an issue. But for other protocols it is a string of size (ERRMAX). To take care of TREAD/RERROR scenario in !dotl this change makes sure that the read buffer is big enough to accommodate ERRMAX string. It also means that there is a chance of scribbling on the payload/user buffer in the error case for those non-POSIX complaint protocols. Signed-off-by: Venkateswararao Jujjuri --- net/9p/client.c | 64 +++++++++++++++++++++++++++++++++++------------------- 1 files changed, 41 insertions(+), 23 deletions(-) diff --git a/net/9p/client.c b/net/9p/client.c index 412c52e..f00ca1f 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -443,6 +443,7 @@ static int p9_check_errors(struct p9_client *c, struct p9_req_t *req) { int8_t type; int err; + int ecode; err = p9_parse_header(req->rc, NULL, &type, NULL, 0); if (err) { @@ -450,36 +451,53 @@ static int p9_check_errors(struct p9_client *c, struct p9_req_t *req) return err; } - if (type == P9_RERROR || type == P9_RLERROR) { - int ecode; - - if (!p9_is_proto_dotl(c)) { - char *ename; + if (type != P9_RERROR && type != P9_RLERROR) + return 0; - err = p9pdu_readf(req->rc, c->proto_version, "s?d", - &ename, &ecode); - if (err) - goto out_err; + if (!p9_is_proto_dotl(c)) { + char *ename; + + if (req->tc->pbuf_size) { + /* Handle user buffers */ + size_t len = req->rc->size - req->rc->offset; + if (req->tc->pubuf) { + /* User Buffer */ + err = copy_from_user( + &req->rc->sdata[req->rc->offset], + req->tc->pubuf, len); + if (err) { + err = -EFAULT; + goto out_err; + } + } else { + /* Kernel Buffer */ + memmove(&req->rc->sdata[req->rc->offset], + req->tc->pkbuf, len); + } + } + err = p9pdu_readf(req->rc, c->proto_version, "s?d", + &ename, &ecode); + if (err) + goto out_err; - if (p9_is_proto_dotu(c)) - err = -ecode; + if (p9_is_proto_dotu(c)) + err = -ecode; - if (!err || !IS_ERR_VALUE(err)) { - err = p9_errstr2errno(ename, strlen(ename)); + if (!err || !IS_ERR_VALUE(err)) { + err = p9_errstr2errno(ename, strlen(ename)); - P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename); + P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, + ename); - kfree(ename); - } - } else { - err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode); - err = -ecode; - - P9_DPRINTK(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode); + kfree(ename); } + } else { + err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode); + err = -ecode; + + P9_DPRINTK(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode); + } - } else - err = 0; return err; -- 1.6.5.2