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-rw-r--r--net/sunrpc/xprtrdma/ib_client.c24
-rw-r--r--net/sunrpc/xprtrdma/svc_rdma_transport.c28
2 files changed, 44 insertions, 8 deletions
diff --git a/net/sunrpc/xprtrdma/ib_client.c b/net/sunrpc/xprtrdma/ib_client.c
index de49ad02053d..69166d5d9987 100644
--- a/net/sunrpc/xprtrdma/ib_client.c
+++ b/net/sunrpc/xprtrdma/ib_client.c
@@ -51,7 +51,11 @@ static struct rpcrdma_device *rpcrdma_get_client_data(struct ib_device *device)
* to be invoked when the device is removed, unless this notification
* is unregistered first.
*
- * On failure, a negative errno is returned.
+ * On failure, a negative errno is returned. rn->rn_done is left
+ * NULL on every failure path (it is assigned only after xa_alloc
+ * and kref_get have both succeeded), so the @rn may safely be
+ * passed to rpcrdma_rn_unregister() without a separate
+ * registered/unregistered flag in the caller.
*/
int rpcrdma_rn_register(struct ib_device *device,
struct rpcrdma_notification *rn,
@@ -83,6 +87,10 @@ static void rpcrdma_rn_release(struct kref *kref)
* rpcrdma_rn_unregister - stop device removal notifications
* @device: monitored device
* @rn: notification object that no longer wishes to be notified
+ *
+ * It is safe to call this on an @rn whose registration never
+ * completed or failed; rn_done == NULL is treated as
+ * never-registered and the call is a no-op.
*/
void rpcrdma_rn_unregister(struct ib_device *device,
struct rpcrdma_notification *rn)
@@ -92,6 +100,20 @@ void rpcrdma_rn_unregister(struct ib_device *device,
if (!rd)
return;
+ /*
+ * rn_done is the registration sentinel: rpcrdma_rn_register
+ * assigns it last, after xa_alloc and kref_get have both
+ * succeeded. A NULL rn_done means this notification was
+ * never registered (or its registration failed) or has
+ * already been unregistered, and the call is a no-op.
+ * Without this guard, rn_index == 0 from a kzalloc'd
+ * parent would erase another caller's slot 0 and underflow
+ * rd_kref.
+ */
+ if (!rn->rn_done)
+ return;
+ rn->rn_done = NULL;
+
trace_rpcrdma_client_unregister(device, rn);
xa_erase(&rd->rd_xa, rn->rn_index);
kref_put(&rd->rd_kref, rpcrdma_rn_release);
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index 7ca71741106b..9268b6105a74 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -43,6 +43,7 @@
*/
#include <linux/interrupt.h>
+#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
@@ -598,13 +599,26 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
return &newxprt->sc_xprt;
errout:
- /* Take a reference in case the DTO handler runs */
- svc_xprt_get(&newxprt->sc_xprt);
- if (newxprt->sc_qp && !IS_ERR(newxprt->sc_qp))
- ib_destroy_qp(newxprt->sc_qp);
- rdma_destroy_id(newxprt->sc_cm_id);
- rpcrdma_rn_unregister(dev, &newxprt->sc_rn);
- /* This call to put will destroy the transport */
+ /*
+ * Drop the kref_init birth reference. svc_xprt_free will
+ * dispatch xpo_free = svc_rdma_free, which tears down sc_qp,
+ * sc_sq_cq, sc_rq_cq, and sc_pd under existing IS_ERR/NULL
+ * guards, and sc_rn under the rn_done sentinel guard inside
+ * rpcrdma_rn_unregister.
+ *
+ * sc_cm_id is destroyed unconditionally by svc_rdma_free; that
+ * is safe here because sc_cm_id is non-NULL by caller invariant
+ * on every path that reaches this errout: handle_connect_req
+ * installs newxprt->sc_cm_id before queueing the new xprt for
+ * accept, and svc_rdma_accept has already dereferenced it above
+ * the first goto errout.
+ *
+ * svc_handle_xprt() drops its pre-acquired module reference when
+ * ->xpo_accept() returns NULL. Take a replacement reference before
+ * freeing @newxprt, because svc_xprt_free() drops the module
+ * reference associated with @newxprt.
+ */
+ __module_get(newxprt->sc_xprt.xpt_class->xcl_owner);
svc_xprt_put(&newxprt->sc_xprt);
return NULL;
}