On Fri, May 02, 2008 at 11:28:40AM -0500, Tom Tucker wrote:
> The rdma_read_xdr function did discriminate between no read-list and
^^^
did not?
> an error posting the read-list. This results a leak of a page in the
> context when an asyncrhonous error occurs on the transport.
>
> Signed-off-by: Tom Tucker <tom@xxxxxxxxxxxxxxxxxxxxx>
>
> ---
> net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 17 +++++++++++++----
> 1 files changed, 13 insertions(+), 4 deletions(-)
>
> diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
> index f3a108a..0ac375a 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;
> @@ -536,8 +541,12 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
> * 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)) {
> - svc_xprt_received(xprt);
> + ret = rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt);
> + if (ret) {
> + if (ret > 0)
> + svc_xprt_received(xprt);
> + else
> + svc_rdma_put_context(ctxt, 1);
> return 0;
> }
>
Possibly slightly more straightforward?:
/* Read read-list data. */
ret = rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt);
if (ret < 0) {
svc_rdma_put_context(ctxt, 1);
return 0;
}
if (ret > 0) {
/*
* We need to wait; defer the request. Note that in
* this case, we don't return the RQ credit until after
* the read completes.
*/
svc_xprt_received(xprt);
return 0;
}
...
--b.
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