RDMA/cxgb3: Release dependent resources only when endpoint memory is freed.

The cxgb3 l2t entry, hwtid, and dst entry were being released before
all the iwch_ep references were released.  This can cause a crash in
t3_l2t_send_slow() and other places where the l2t entry is used.

The fix is to defer releasing these resources until all endpoint
references are gone.

Details:

- move flags field to the iwch_ep_common struct.
- add a flag indicating resources are to be released.
- release resources at endpoint free time instead of close/abort time.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

diff --git a/drivers/infiniband/hw/cxgb3/iwch_cm.c b/drivers/infiniband/hw/cxgb3/iwch_cm.c
index 59e1c5f..fef3f1a 100644 (file)
--- a/drivers/infiniband/hw/cxgb3/iwch_cm.c
+++ b/drivers/infiniband/hw/cxgb3/iwch_cm.c
@@ -282,18 +282,22 @@ static void *alloc_ep(int size, gfp_t gfp)
 
 void __free_ep(struct kref *kref)
 {
-       struct iwch_ep_common *epc;
-       epc = container_of(kref, struct iwch_ep_common, kref);
-       PDBG("%s ep %p state %s\n", __func__, epc, states[state_read(epc)]);
-       kfree(epc);
+       struct iwch_ep *ep;
+       ep = container_of(container_of(kref, struct iwch_ep_common, kref),
+                         struct iwch_ep, com);
+       PDBG("%s ep %p state %s\n", __func__, ep, states[state_read(&ep->com)]);
+       if (ep->com.flags & RELEASE_RESOURCES) {
+               cxgb3_remove_tid(ep->com.tdev, (void *)ep, ep->hwtid);
+               dst_release(ep->dst);
+               l2t_release(L2DATA(ep->com.tdev), ep->l2t);
+       }
+       kfree(ep);
 }
 
 static void release_ep_resources(struct iwch_ep *ep)
 {
        PDBG("%s ep %p tid %d\n", __func__, ep, ep->hwtid);
-       cxgb3_remove_tid(ep->com.tdev, (void *)ep, ep->hwtid);
-       dst_release(ep->dst);
-       l2t_release(L2DATA(ep->com.tdev), ep->l2t);
+       ep->com.flags |= RELEASE_RESOURCES;
        put_ep(&ep->com);
 }
 
@@ -1152,8 +1156,8 @@ static int abort_rpl(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
         * We get 2 abort replies from the HW.  The first one must
         * be ignored except for scribbling that we need one more.
         */
-       if (!(ep->flags & ABORT_REQ_IN_PROGRESS)) {
-               ep->flags |= ABORT_REQ_IN_PROGRESS;
+       if (!(ep->com.flags & ABORT_REQ_IN_PROGRESS)) {
+               ep->com.flags |= ABORT_REQ_IN_PROGRESS;
                return CPL_RET_BUF_DONE;
        }
 
@@ -1557,8 +1561,8 @@ static int peer_abort(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
         * We get 2 peer aborts from the HW.  The first one must
         * be ignored except for scribbling that we need one more.
         */
-       if (!(ep->flags & PEER_ABORT_IN_PROGRESS)) {
-               ep->flags |= PEER_ABORT_IN_PROGRESS;
+       if (!(ep->com.flags & PEER_ABORT_IN_PROGRESS)) {
+               ep->com.flags |= PEER_ABORT_IN_PROGRESS;
                return CPL_RET_BUF_DONE;
        }
 

diff --git a/drivers/infiniband/hw/cxgb3/iwch_cm.h b/drivers/infiniband/hw/cxgb3/iwch_cm.h
index d7c7e09..43c0aea 100644 (file)
--- a/drivers/infiniband/hw/cxgb3/iwch_cm.h
+++ b/drivers/infiniband/hw/cxgb3/iwch_cm.h
@@ -147,6 +147,7 @@ enum iwch_ep_state {
 enum iwch_ep_flags {
        PEER_ABORT_IN_PROGRESS  = (1 << 0),
        ABORT_REQ_IN_PROGRESS   = (1 << 1),
+       RELEASE_RESOURCES       = (1 << 2),
 };
 
 struct iwch_ep_common {
@@ -161,6 +162,7 @@ struct iwch_ep_common {
        wait_queue_head_t waitq;
        int rpl_done;
        int rpl_err;
+       u32 flags;
 };
 
 struct iwch_listen_ep {
@@ -188,7 +190,6 @@ struct iwch_ep {
        u16 plen;
        u32 ird;
        u32 ord;
-       u32 flags;
 };
 
 static inline struct iwch_ep *to_ep(struct iw_cm_id *cm_id)