9P/RDMA: Improve error handling in rdma_request

Most importantly:
- do not free the recv context (rpl_context) after a successful post_recv()
- but do free the send context (c) after a failed send.

Signed-off-by: Simon Derr <simon.derr@bull.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

diff --git a/net/9p/trans_rdma.c b/net/9p/trans_rdma.c
index 1bd4c71..926e72d 100644 (file)
--- a/net/9p/trans_rdma.c
+++ b/net/9p/trans_rdma.c
@@ -430,7 +430,7 @@ static int rdma_request(struct p9_client *client, struct p9_req_t *req)
        rpl_context = kmalloc(sizeof *rpl_context, GFP_NOFS);
        if (!rpl_context) {
                err = -ENOMEM;
-               goto err_close;
+               goto recv_error;
        }
        rpl_context->rc = req->rc;
 
@@ -441,13 +441,15 @@ static int rdma_request(struct p9_client *client, struct p9_req_t *req)
         * outstanding request, so we must keep a count to avoid
         * overflowing the RQ.
         */
-       if (down_interruptible(&rdma->rq_sem))
-               goto error; /* FIXME : -EINTR instead */
+       if (down_interruptible(&rdma->rq_sem)) {
+               err = -EINTR;
+               goto recv_error;
+       }
 
        err = post_recv(client, rpl_context);
        if (err) {
                p9_debug(P9_DEBUG_FCALL, "POST RECV failed\n");
-               goto err_free;
+               goto recv_error;
        }
 
        /* remove posted receive buffer from request structure */
@@ -457,15 +459,17 @@ static int rdma_request(struct p9_client *client, struct p9_req_t *req)
        c = kmalloc(sizeof *c, GFP_NOFS);
        if (!c) {
                err = -ENOMEM;
-               goto err_free;
+               goto send_error;
        }
        c->req = req;
 
        c->busa = ib_dma_map_single(rdma->cm_id->device,
                                    c->req->tc->sdata, c->req->tc->size,
                                    DMA_TO_DEVICE);
-       if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
-               goto error;
+       if (ib_dma_mapping_error(rdma->cm_id->device, c->busa)) {
+               err = -EIO;
+               goto send_error;
+       }
 
        sge.addr = c->busa;
        sge.length = c->req->tc->size;
@@ -479,19 +483,27 @@ static int rdma_request(struct p9_client *client, struct p9_req_t *req)
        wr.sg_list = &sge;
        wr.num_sge = 1;
 
-       if (down_interruptible(&rdma->sq_sem))
-               goto error;
+       if (down_interruptible(&rdma->sq_sem)) {
+               err = -EINTR;
+               goto send_error;
+       }
 
-       return ib_post_send(rdma->qp, &wr, &bad_wr);
+       err = ib_post_send(rdma->qp, &wr, &bad_wr);
+       if (err)
+               goto send_error;
 
- error:
+       /* Success */
+       return 0;
+
+ /* Handle errors that happened during or while preparing the send: */
+ send_error:
        kfree(c);
+       p9_debug(P9_DEBUG_ERROR, "Error %d in rdma_request()\n", err);
+       return err;
+
+ /* Handle errors that happened during or while preparing post_recv(): */
+ recv_error:
        kfree(rpl_context);
-       p9_debug(P9_DEBUG_ERROR, "EIO\n");
-       return -EIO;
- err_free:
-       kfree(rpl_context);
- err_close:
        spin_lock_irqsave(&rdma->req_lock, flags);
        if (rdma->state < P9_RDMA_CLOSING) {
                rdma->state = P9_RDMA_CLOSING;