From d16d40093a95f2b31007d7a7abefc50e6b27e236 Mon Sep 17 00:00:00 2001 From: Tom Tucker Date: Tue, 6 May 2008 10:04:50 -0500 Subject: [PATCH] svcrdma: Return error from rdma_read_xdr so caller knows to free context The rdma_read_xdr function did not discriminate between no read-list and an error posting the read-list. This results in a leak of a page if there is an error posting the read-list. Signed-off-by: Tom Tucker --- net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c index f3a108a864a..5e03d95b25e 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c @@ -260,11 +260,16 @@ static int rdma_read_max_sge(struct svcxprt_rdma *xprt, int sge_count) * On our side, we need to read into a pagelist. The first page immediately * follows the RPC header. * - * This function returns 1 to indicate success. The data is not yet in + * This function returns: + * 0 - No error and no read-list found. + * + * 1 - Successful read-list processing. The data is not yet in * the pagelist and therefore the RPC request must be deferred. The * I/O completion will enqueue the transport again and * svc_rdma_recvfrom will complete the request. * + * <0 - Error processing/posting read-list. + * * NOTE: The ctxt must not be touched after the last WR has been posted * because the I/O completion processing may occur on another * processor and free / modify the context. Ne touche pas! @@ -398,7 +403,7 @@ next_sge: svc_rdma_put_context(head, 1); head = ctxt; } - return 0; + return err; } return 1; @@ -532,14 +537,18 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp) goto close_out; } - /* Read read-list data. If we would need to wait, defer - * it. Not that in this case, we don't return the RQ credit - * until after the read completes. - */ - if (rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt)) { + /* Read read-list data. */ + ret = rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt); + if (ret > 0) { + /* read-list posted, defer until data received from client. */ svc_xprt_received(xprt); return 0; } + if (ret < 0) { + /* Post of read-list failed, free context. */ + svc_rdma_put_context(ctxt, 1); + return 0; + } ret = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len -- 2.20.1