Merge branch 'from-tomtucker' into for-2.6.26

5 files changed, 223 insertions, 215 deletions

diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
index c11bbcc081f9..05eb4664d0dd 100644
--- a/include/linux/sunrpc/svc_rdma.h
+++ b/include/linux/sunrpc/svc_rdma.h
@@ -71,7 +71,8 @@ extern atomic_t rdma_stat_sq_prod;
  * completes.
  */
 struct svc_rdma_op_ctxt {
-        struct svc_rdma_op_ctxt *next;
+        struct svc_rdma_op_ctxt *read_hdr;
+        struct list_head free_list;
         struct xdr_buf arg;
         struct list_head dto_q;
         enum ib_wr_opcode wr_op;
@@ -85,7 +86,6 @@ struct svc_rdma_op_ctxt {
         struct page *pages[RPCSVC_MAXPAGES];
 };
 
-#define RDMACTXT_F_READ_DONE    1
 #define RDMACTXT_F_LAST_CTXT    2
 
 struct svcxprt_rdma {
@@ -104,7 +104,8 @@ struct svcxprt_rdma {
 
         struct ib_pd         *sc_pd;
 
-        struct svc_rdma_op_ctxt  *sc_ctxt_head;
+        atomic_t             sc_ctxt_used;
+        struct list_head     sc_ctxt_free;
         int                  sc_ctxt_cnt;
         int                  sc_ctxt_bump;
         int                  sc_ctxt_max;
@@ -123,6 +124,7 @@ struct svcxprt_rdma {
         struct list_head     sc_dto_q;          /* DTO tasklet I/O pending Q */
         struct list_head     sc_read_complete_q;
         spinlock_t           sc_read_complete_lock;
+        struct work_struct   sc_work;
 };
 /* sc_flags */
 #define RDMAXPRT_RQ_PENDING     1
@@ -164,8 +166,8 @@ extern int svc_rdma_sendto(struct svc_rqst *);
 
 /* svc_rdma_transport.c */
 extern int svc_rdma_send(struct svcxprt_rdma *, struct ib_send_wr *);
-extern int svc_rdma_send_error(struct svcxprt_rdma *, struct rpcrdma_msg *,
-                               enum rpcrdma_errcode);
+extern void svc_rdma_send_error(struct svcxprt_rdma *, struct rpcrdma_msg *,
+                                enum rpcrdma_errcode);
 struct page *svc_rdma_get_page(void);
 extern int svc_rdma_post_recv(struct svcxprt_rdma *);
 extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *);
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index d8e8d79a8451..e46c825f4954 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -6,30 +6,9 @@
 
 #include <linux/sched.h>
 #include <linux/errno.h>
-#include <linux/fcntl.h>
-#include <linux/net.h>
-#include <linux/in.h>
-#include <linux/inet.h>
-#include <linux/udp.h>
-#include <linux/tcp.h>
-#include <linux/unistd.h>
-#include <linux/slab.h>
-#include <linux/netdevice.h>
-#include <linux/skbuff.h>
-#include <linux/file.h>
 #include <linux/freezer.h>
 #include <linux/kthread.h>
 #include <net/sock.h>
-#include <net/checksum.h>
-#include <net/ip.h>
-#include <net/ipv6.h>
-#include <net/tcp_states.h>
-#include <linux/uaccess.h>
-#include <asm/ioctls.h>
-
-#include <linux/sunrpc/types.h>
-#include <linux/sunrpc/clnt.h>
-#include <linux/sunrpc/xdr.h>
 #include <linux/sunrpc/stats.h>
 #include <linux/sunrpc/svc_xprt.h>
 
@@ -296,8 +275,6 @@ void svc_xprt_enqueue(struct svc_xprt *xprt)
         if (!(xprt->xpt_flags &
               ((1<<XPT_CONN)|(1<<XPT_DATA)|(1<<XPT_CLOSE)|(1<<XPT_DEFERRED))))
                 return;
-        if (test_bit(XPT_DEAD, &xprt->xpt_flags))
-                return;
 
         cpu = get_cpu();
         pool = svc_pool_for_cpu(xprt->xpt_server, cpu);
diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index c22d6b6f2db4..06ab4841537b 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!
@@ -284,7 +289,6 @@ static int rdma_read_xdr(struct svcxprt_rdma *xprt,
         u64 sgl_offset;
         struct rpcrdma_read_chunk *ch;
         struct svc_rdma_op_ctxt *ctxt = NULL;
-        struct svc_rdma_op_ctxt *head;
         struct svc_rdma_op_ctxt *tmp_sge_ctxt;
         struct svc_rdma_op_ctxt *tmp_ch_ctxt;
         struct chunk_sge *ch_sge_ary;
@@ -302,25 +306,19 @@ static int rdma_read_xdr(struct svcxprt_rdma *xprt,
         ch_sge_ary = (struct chunk_sge *)tmp_ch_ctxt->sge;
 
         svc_rdma_rcl_chunk_counts(ch, &ch_count, &byte_count);
+        if (ch_count > RPCSVC_MAXPAGES)
+                return -EINVAL;
         sge_count = rdma_rcl_to_sge(xprt, rqstp, hdr_ctxt, rmsgp,
                                     sge, ch_sge_ary,
                                     ch_count, byte_count);
-        head = svc_rdma_get_context(xprt);
         sgl_offset = 0;
         ch_no = 0;
 
         for (ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
              ch->rc_discrim != 0; ch++, ch_no++) {
 next_sge:
-                if (!ctxt)
-                        ctxt = head;
-                else {
-                        ctxt->next = svc_rdma_get_context(xprt);
-                        ctxt = ctxt->next;
-                }
-                ctxt->next = NULL;
+                ctxt = svc_rdma_get_context(xprt);
                 ctxt->direction = DMA_FROM_DEVICE;
-                clear_bit(RDMACTXT_F_READ_DONE, &ctxt->flags);
                 clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
 
                 /* Prepare READ WR */
@@ -347,20 +345,15 @@ next_sge:
                          * the client and the RPC needs to be enqueued.
                          */
                         set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
-                        ctxt->next = hdr_ctxt;
-                        hdr_ctxt->next = head;
+                        ctxt->read_hdr = hdr_ctxt;
                 }
                 /* Post the read */
                 err = svc_rdma_send(xprt, &read_wr);
                 if (err) {
-                        printk(KERN_ERR "svcrdma: Error posting send = %d\n",
+                        printk(KERN_ERR "svcrdma: Error %d posting RDMA_READ\n",
                                err);
-                        /*
-                         * Break the circular list so free knows when
-                         * to stop if the error happened to occur on
-                         * the last read
-                         */
-                        ctxt->next = NULL;
+                        set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
+                        svc_rdma_put_context(ctxt, 0);
                         goto out;
                 }
                 atomic_inc(&rdma_stat_read);
@@ -371,7 +364,7 @@ next_sge:
                         goto next_sge;
                 }
                 sgl_offset = 0;
-                err = 0;
+                err = 1;
         }
 
  out:
@@ -389,25 +382,12 @@ next_sge:
         while (rqstp->rq_resused)
                 rqstp->rq_respages[--rqstp->rq_resused] = NULL;
 
-        if (err) {
-                printk(KERN_ERR "svcrdma : RDMA_READ error = %d\n", err);
-                set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
-                /* Free the linked list of read contexts */
-                while (head != NULL) {
-                        ctxt = head->next;
-                        svc_rdma_put_context(head, 1);
-                        head = ctxt;
-                }
-                return 0;
-        }
-
-        return 1;
+        return err;
 }
 
 static int rdma_read_complete(struct svc_rqst *rqstp,
-                              struct svc_rdma_op_ctxt *data)
+                              struct svc_rdma_op_ctxt *head)
 {
-        struct svc_rdma_op_ctxt *head = data->next;
         int page_no;
         int ret;
 
@@ -433,21 +413,12 @@ static int rdma_read_complete(struct svc_rqst *rqstp,
         rqstp->rq_arg.len = head->arg.len;
         rqstp->rq_arg.buflen = head->arg.buflen;
 
+        /* Free the context */
+        svc_rdma_put_context(head, 0);
+
         /* XXX: What should this be? */
         rqstp->rq_prot = IPPROTO_MAX;
-
-        /*
-         * Free the contexts we used to build the RDMA_READ. We have
-         * to be careful here because the context list uses the same
-         * next pointer used to chain the contexts associated with the
-         * RDMA_READ
-         */
-        data->next = NULL;      /* terminate circular list */
-        do {
-                data = head->next;
-                svc_rdma_put_context(head, 0);
-                head = data;
-        } while (head != NULL);
+        svc_xprt_copy_addrs(rqstp, rqstp->rq_xprt);
 
         ret = rqstp->rq_arg.head[0].iov_len
                 + rqstp->rq_arg.page_len
@@ -457,8 +428,6 @@ static int rdma_read_complete(struct svc_rqst *rqstp,
                 ret, rqstp->rq_arg.len, rqstp->rq_arg.head[0].iov_base,
                 rqstp->rq_arg.head[0].iov_len);
 
-        /* Indicate that we've consumed an RQ credit */
-        rqstp->rq_xprt_ctxt = rqstp->rq_xprt;
         svc_xprt_received(rqstp->rq_xprt);
         return ret;
 }
@@ -480,13 +449,6 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
 
         dprintk("svcrdma: rqstp=%p\n", rqstp);
 
-        /*
-         * The rq_xprt_ctxt indicates if we've consumed an RQ credit
-         * or not. It is used in the rdma xpo_release_rqst function to
-         * determine whether or not to return an RQ WQE to the RQ.
-         */
-        rqstp->rq_xprt_ctxt = NULL;
-
         spin_lock_bh(&rdma_xprt->sc_read_complete_lock);
         if (!list_empty(&rdma_xprt->sc_read_complete_q)) {
                 ctxt = list_entry(rdma_xprt->sc_read_complete_q.next,
@@ -537,21 +499,22 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
         /* If the request is invalid, reply with an error */
         if (len < 0) {
                 if (len == -ENOSYS)
-                        (void)svc_rdma_send_error(rdma_xprt, rmsgp, ERR_VERS);
+                        svc_rdma_send_error(rdma_xprt, rmsgp, ERR_VERS);
                 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;
         }
-
-        /* Indicate we've consumed an RQ credit */
-        rqstp->rq_xprt_ctxt = rqstp->rq_xprt;
+        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
@@ -569,11 +532,8 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
         return ret;
 
  close_out:
-        if (ctxt) {
+        if (ctxt)
                 svc_rdma_put_context(ctxt, 1);
-                /* Indicate we've consumed an RQ credit */
-                rqstp->rq_xprt_ctxt = rqstp->rq_xprt;
-        }
         dprintk("svcrdma: transport %p is closing\n", xprt);
         /*
          * Set the close bit and enqueue it. svc_recv will see the
diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
index 981f190c1b39..fb82b1b683f8 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -389,6 +389,17 @@ static int send_reply(struct svcxprt_rdma *rdma,
         int page_no;
         int ret;
 
+        /* Post a recv buffer to handle another request. */
+        ret = svc_rdma_post_recv(rdma);
+        if (ret) {
+                printk(KERN_INFO
+                       "svcrdma: could not post a receive buffer, err=%d."
+                       "Closing transport %p.\n", ret, rdma);
+                set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags);
+                svc_rdma_put_context(ctxt, 0);
+                return -ENOTCONN;
+        }
+
         /* Prepare the context */
         ctxt->pages[0] = page;
         ctxt->count = 1;
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index af408fc12634..e132509d1db0 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -103,8 +103,8 @@ static int rdma_bump_context_cache(struct svcxprt_rdma *xprt)
                 spin_lock_bh(&xprt->sc_ctxt_lock);
                 if (ctxt) {
                         at_least_one = 1;
-                        ctxt->next = xprt->sc_ctxt_head;
-                        xprt->sc_ctxt_head = ctxt;
+                        INIT_LIST_HEAD(&ctxt->free_list);
+                        list_add(&ctxt->free_list, &xprt->sc_ctxt_free);
                 } else {
                         /* kmalloc failed...give up for now */
                         xprt->sc_ctxt_cnt--;
@@ -123,7 +123,7 @@ struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt)
 
         while (1) {
                 spin_lock_bh(&xprt->sc_ctxt_lock);
-                if (unlikely(xprt->sc_ctxt_head == NULL)) {
+                if (unlikely(list_empty(&xprt->sc_ctxt_free))) {
                         /* Try to bump my cache. */
                         spin_unlock_bh(&xprt->sc_ctxt_lock);
 
@@ -136,12 +136,15 @@ struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt)
                         schedule_timeout_uninterruptible(msecs_to_jiffies(500));
                         continue;
                 }
-                ctxt = xprt->sc_ctxt_head;
-                xprt->sc_ctxt_head = ctxt->next;
+                ctxt = list_entry(xprt->sc_ctxt_free.next,
+                                  struct svc_rdma_op_ctxt,
+                                  free_list);
+                list_del_init(&ctxt->free_list);
                 spin_unlock_bh(&xprt->sc_ctxt_lock);
                 ctxt->xprt = xprt;
                 INIT_LIST_HEAD(&ctxt->dto_q);
                 ctxt->count = 0;
+                atomic_inc(&xprt->sc_ctxt_used);
                 break;
         }
         return ctxt;
@@ -159,14 +162,15 @@ void svc_rdma_put_context(struct svc_rdma_op_ctxt *ctxt, int free_pages)
                         put_page(ctxt->pages[i]);
 
         for (i = 0; i < ctxt->count; i++)
-                dma_unmap_single(xprt->sc_cm_id->device->dma_device,
-                                 ctxt->sge[i].addr,
-                                 ctxt->sge[i].length,
-                                 ctxt->direction);
+                ib_dma_unmap_single(xprt->sc_cm_id->device,
+                                    ctxt->sge[i].addr,
+                                    ctxt->sge[i].length,
+                                    ctxt->direction);
+
         spin_lock_bh(&xprt->sc_ctxt_lock);
-        ctxt->next = xprt->sc_ctxt_head;
-        xprt->sc_ctxt_head = ctxt;
+        list_add(&ctxt->free_list, &xprt->sc_ctxt_free);
         spin_unlock_bh(&xprt->sc_ctxt_lock);
+        atomic_dec(&xprt->sc_ctxt_used);
 }
 
 /* ib_cq event handler */
@@ -228,23 +232,8 @@ static void dto_tasklet_func(unsigned long data)
                 list_del_init(&xprt->sc_dto_q);
                 spin_unlock_irqrestore(&dto_lock, flags);
 
-                if (test_and_clear_bit(RDMAXPRT_RQ_PENDING, &xprt->sc_flags)) {
-                        ib_req_notify_cq(xprt->sc_rq_cq, IB_CQ_NEXT_COMP);
-                        rq_cq_reap(xprt);
-                        set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags);
-                        /*
-                         * If data arrived before established event,
-                         * don't enqueue. This defers RPC I/O until the
-                         * RDMA connection is complete.
-                         */
-                        if (!test_bit(RDMAXPRT_CONN_PENDING, &xprt->sc_flags))
-                                svc_xprt_enqueue(&xprt->sc_xprt);
-                }
-
-                if (test_and_clear_bit(RDMAXPRT_SQ_PENDING, &xprt->sc_flags)) {
-                        ib_req_notify_cq(xprt->sc_sq_cq, IB_CQ_NEXT_COMP);
-                        sq_cq_reap(xprt);
-                }
+                rq_cq_reap(xprt);
+                sq_cq_reap(xprt);
 
                 svc_xprt_put(&xprt->sc_xprt);
                 spin_lock_irqsave(&dto_lock, flags);
@@ -263,11 +252,15 @@ static void rq_comp_handler(struct ib_cq *cq, void *cq_context)
         struct svcxprt_rdma *xprt = cq_context;
         unsigned long flags;
 
+        /* Guard against unconditional flush call for destroyed QP */
+        if (atomic_read(&xprt->sc_xprt.xpt_ref.refcount)==0)
+                return;
+
         /*
          * Set the bit regardless of whether or not it's on the list
          * because it may be on the list already due to an SQ
          * completion.
-        */
+         */
         set_bit(RDMAXPRT_RQ_PENDING, &xprt->sc_flags);
 
         /*
@@ -290,6 +283,8 @@ static void rq_comp_handler(struct ib_cq *cq, void *cq_context)
  *
  * Take all completing WC off the CQE and enqueue the associated DTO
  * context on the dto_q for the transport.
+ *
+ * Note that caller must hold a transport reference.
  */
 static void rq_cq_reap(struct svcxprt_rdma *xprt)
 {
@@ -297,29 +292,47 @@ static void rq_cq_reap(struct svcxprt_rdma *xprt)
         struct ib_wc wc;
         struct svc_rdma_op_ctxt *ctxt = NULL;
 
+        if (!test_and_clear_bit(RDMAXPRT_RQ_PENDING, &xprt->sc_flags))
+                return;
+
+        ib_req_notify_cq(xprt->sc_rq_cq, IB_CQ_NEXT_COMP);
         atomic_inc(&rdma_stat_rq_poll);
 
-        spin_lock_bh(&xprt->sc_rq_dto_lock);
         while ((ret = ib_poll_cq(xprt->sc_rq_cq, 1, &wc)) > 0) {
                 ctxt = (struct svc_rdma_op_ctxt *)(unsigned long)wc.wr_id;
                 ctxt->wc_status = wc.status;
                 ctxt->byte_len = wc.byte_len;
                 if (wc.status != IB_WC_SUCCESS) {
                         /* Close the transport */
+                        dprintk("svcrdma: transport closing putting ctxt %p\n", ctxt);
                         set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
                         svc_rdma_put_context(ctxt, 1);
+                        svc_xprt_put(&xprt->sc_xprt);
                         continue;
                 }
+                spin_lock_bh(&xprt->sc_rq_dto_lock);
                 list_add_tail(&ctxt->dto_q, &xprt->sc_rq_dto_q);
+                spin_unlock_bh(&xprt->sc_rq_dto_lock);
+                svc_xprt_put(&xprt->sc_xprt);
         }
-        spin_unlock_bh(&xprt->sc_rq_dto_lock);
 
         if (ctxt)
                 atomic_inc(&rdma_stat_rq_prod);
+
+        set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags);
+        /*
+         * If data arrived before established event,
+         * don't enqueue. This defers RPC I/O until the
+         * RDMA connection is complete.
+         */
+        if (!test_bit(RDMAXPRT_CONN_PENDING, &xprt->sc_flags))
+                svc_xprt_enqueue(&xprt->sc_xprt);
 }
 
 /*
  * Send Queue Completion Handler - potentially called on interrupt context.
+ *
+ * Note that caller must hold a transport reference.
  */
 static void sq_cq_reap(struct svcxprt_rdma *xprt)
 {
@@ -328,6 +341,11 @@ static void sq_cq_reap(struct svcxprt_rdma *xprt)
         struct ib_cq *cq = xprt->sc_sq_cq;
         int ret;
 
+
+        if (!test_and_clear_bit(RDMAXPRT_SQ_PENDING, &xprt->sc_flags))
+                return;
+
+        ib_req_notify_cq(xprt->sc_sq_cq, IB_CQ_NEXT_COMP);
         atomic_inc(&rdma_stat_sq_poll);
         while ((ret = ib_poll_cq(cq, 1, &wc)) > 0) {
                 ctxt = (struct svc_rdma_op_ctxt *)(unsigned long)wc.wr_id;
@@ -349,14 +367,16 @@ static void sq_cq_reap(struct svcxprt_rdma *xprt)
 
                 case IB_WR_RDMA_READ:
                         if (test_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags)) {
+                                struct svc_rdma_op_ctxt *read_hdr = ctxt->read_hdr;
+                                BUG_ON(!read_hdr);
                                 set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags);
-                                set_bit(RDMACTXT_F_READ_DONE, &ctxt->flags);
                                 spin_lock_bh(&xprt->sc_read_complete_lock);
-                                list_add_tail(&ctxt->dto_q,
+                                list_add_tail(&read_hdr->dto_q,
                                               &xprt->sc_read_complete_q);
                                 spin_unlock_bh(&xprt->sc_read_complete_lock);
                                 svc_xprt_enqueue(&xprt->sc_xprt);
                         }
+                        svc_rdma_put_context(ctxt, 0);
                         break;
 
                 default:
@@ -365,6 +385,7 @@ static void sq_cq_reap(struct svcxprt_rdma *xprt)
                                wc.opcode, wc.status);
                         break;
                 }
+                svc_xprt_put(&xprt->sc_xprt);
         }
 
         if (ctxt)
@@ -376,11 +397,15 @@ static void sq_comp_handler(struct ib_cq *cq, void *cq_context)
         struct svcxprt_rdma *xprt = cq_context;
         unsigned long flags;
 
+        /* Guard against unconditional flush call for destroyed QP */
+        if (atomic_read(&xprt->sc_xprt.xpt_ref.refcount)==0)
+                return;
+
         /*
          * Set the bit regardless of whether or not it's on the list
          * because it may be on the list already due to an RQ
          * completion.
-        */
+         */
         set_bit(RDMAXPRT_SQ_PENDING, &xprt->sc_flags);
 
         /*
@@ -407,28 +432,29 @@ static void create_context_cache(struct svcxprt_rdma *xprt,
         xprt->sc_ctxt_max = ctxt_max;
         xprt->sc_ctxt_bump = ctxt_bump;
         xprt->sc_ctxt_cnt = 0;
-        xprt->sc_ctxt_head = NULL;
+        atomic_set(&xprt->sc_ctxt_used, 0);
+
+        INIT_LIST_HEAD(&xprt->sc_ctxt_free);
         for (i = 0; i < ctxt_count; i++) {
                 ctxt = kmalloc(sizeof(*ctxt), GFP_KERNEL);
                 if (ctxt) {
-                        ctxt->next = xprt->sc_ctxt_head;
-                        xprt->sc_ctxt_head = ctxt;
+                        INIT_LIST_HEAD(&ctxt->free_list);
+                        list_add(&ctxt->free_list, &xprt->sc_ctxt_free);
                         xprt->sc_ctxt_cnt++;
                 }
         }
 }
 
-static void destroy_context_cache(struct svc_rdma_op_ctxt *ctxt)
+static void destroy_context_cache(struct svcxprt_rdma *xprt)
 {
-        struct svc_rdma_op_ctxt *next;
-        if (!ctxt)
-                return;
-
-        do {
-                next = ctxt->next;
+        while (!list_empty(&xprt->sc_ctxt_free)) {
+                struct svc_rdma_op_ctxt *ctxt;
+                ctxt = list_entry(xprt->sc_ctxt_free.next,
+                                  struct svc_rdma_op_ctxt,
+                                  free_list);
+                list_del_init(&ctxt->free_list);
                 kfree(ctxt);
-                ctxt = next;
-        } while (next);
+        }
 }
 
 static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv,
@@ -465,7 +491,7 @@ static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv,
                                      reqs +
                                      cma_xprt->sc_sq_depth +
                                      RPCRDMA_MAX_THREADS + 1); /* max */
-                if (!cma_xprt->sc_ctxt_head) {
+                if (list_empty(&cma_xprt->sc_ctxt_free)) {
                         kfree(cma_xprt);
                         return NULL;
                 }
@@ -520,7 +546,12 @@ int svc_rdma_post_recv(struct svcxprt_rdma *xprt)
         recv_wr.num_sge = ctxt->count;
         recv_wr.wr_id = (u64)(unsigned long)ctxt;
 
+        svc_xprt_get(&xprt->sc_xprt);
         ret = ib_post_recv(xprt->sc_qp, &recv_wr, &bad_recv_wr);
+        if (ret) {
+                svc_xprt_put(&xprt->sc_xprt);
+                svc_rdma_put_context(ctxt, 1);
+        }
         return ret;
 }
 
@@ -539,6 +570,7 @@ static void handle_connect_req(struct rdma_cm_id *new_cma_id)
 {
         struct svcxprt_rdma *listen_xprt = new_cma_id->context;
         struct svcxprt_rdma *newxprt;
+        struct sockaddr *sa;
 
         /* Create a new transport */
         newxprt = rdma_create_xprt(listen_xprt->sc_xprt.xpt_server, 0);
@@ -551,6 +583,12 @@ static void handle_connect_req(struct rdma_cm_id *new_cma_id)
         dprintk("svcrdma: Creating newxprt=%p, cm_id=%p, listenxprt=%p\n",
                 newxprt, newxprt->sc_cm_id, listen_xprt);
 
+        /* Set the local and remote addresses in the transport */
+        sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.dst_addr;
+        svc_xprt_set_remote(&newxprt->sc_xprt, sa, svc_addr_len(sa));
+        sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.src_addr;
+        svc_xprt_set_local(&newxprt->sc_xprt, sa, svc_addr_len(sa));
+
         /*
          * Enqueue the new transport on the accept queue of the listening
          * transport
@@ -627,6 +665,7 @@ static int rdma_cma_handler(struct rdma_cm_id *cma_id,
                 if (xprt) {
                         set_bit(XPT_CLOSE, &xprt->xpt_flags);
                         svc_xprt_enqueue(xprt);
+                        svc_xprt_put(xprt);
                 }
                 break;
         case RDMA_CM_EVENT_DEVICE_REMOVAL:
@@ -661,31 +700,27 @@ static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
 
         cma_xprt = rdma_create_xprt(serv, 1);
         if (!cma_xprt)
-                return ERR_PTR(ENOMEM);
+                return ERR_PTR(-ENOMEM);
         xprt = &cma_xprt->sc_xprt;
 
         listen_id = rdma_create_id(rdma_listen_handler, cma_xprt, RDMA_PS_TCP);
         if (IS_ERR(listen_id)) {
-                svc_xprt_put(&cma_xprt->sc_xprt);
-                dprintk("svcrdma: rdma_create_id failed = %ld\n",
-                        PTR_ERR(listen_id));
-                return (void *)listen_id;
+                ret = PTR_ERR(listen_id);
+                dprintk("svcrdma: rdma_create_id failed = %d\n", ret);
+                goto err0;
         }
+
         ret = rdma_bind_addr(listen_id, sa);
         if (ret) {
-                rdma_destroy_id(listen_id);
-                svc_xprt_put(&cma_xprt->sc_xprt);
                 dprintk("svcrdma: rdma_bind_addr failed = %d\n", ret);
-                return ERR_PTR(ret);
+                goto err1;
         }
         cma_xprt->sc_cm_id = listen_id;
 
         ret = rdma_listen(listen_id, RPCRDMA_LISTEN_BACKLOG);
         if (ret) {
-                rdma_destroy_id(listen_id);
-                svc_xprt_put(&cma_xprt->sc_xprt);
                 dprintk("svcrdma: rdma_listen failed = %d\n", ret);
-                return ERR_PTR(ret);
+                goto err1;
         }
 
         /*
@@ -696,6 +731,12 @@ static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
         svc_xprt_set_local(&cma_xprt->sc_xprt, sa, salen);
 
         return &cma_xprt->sc_xprt;
+
+ err1:
+        rdma_destroy_id(listen_id);
+ err0:
+        kfree(cma_xprt);
+        return ERR_PTR(ret);
 }
 
 /*
@@ -716,7 +757,6 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
         struct rdma_conn_param conn_param;
         struct ib_qp_init_attr qp_attr;
         struct ib_device_attr devattr;
-        struct sockaddr *sa;
         int ret;
         int i;
 
@@ -826,7 +866,6 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
                 newxprt->sc_sq_depth = qp_attr.cap.max_send_wr;
                 newxprt->sc_max_requests = qp_attr.cap.max_recv_wr;
         }
-        svc_xprt_get(&newxprt->sc_xprt);
         newxprt->sc_qp = newxprt->sc_cm_id->qp;
 
         /* Register all of physical memory */
@@ -850,6 +889,13 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
         /* Swap out the handler */
         newxprt->sc_cm_id->event_handler = rdma_cma_handler;
 
+        /*
+         * Arm the CQs for the SQ and RQ before accepting so we can't
+         * miss the first message
+         */
+        ib_req_notify_cq(newxprt->sc_sq_cq, IB_CQ_NEXT_COMP);
+        ib_req_notify_cq(newxprt->sc_rq_cq, IB_CQ_NEXT_COMP);
+
         /* Accept Connection */
         set_bit(RDMAXPRT_CONN_PENDING, &newxprt->sc_flags);
         memset(&conn_param, 0, sizeof conn_param);
@@ -886,58 +932,26 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
                 newxprt->sc_max_requests,
                 newxprt->sc_ord);
 
-        /* Set the local and remote addresses in the transport */
-        sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.dst_addr;
-        svc_xprt_set_remote(&newxprt->sc_xprt, sa, svc_addr_len(sa));
-        sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.src_addr;
-        svc_xprt_set_local(&newxprt->sc_xprt, sa, svc_addr_len(sa));
-
-        ib_req_notify_cq(newxprt->sc_sq_cq, IB_CQ_NEXT_COMP);
-        ib_req_notify_cq(newxprt->sc_rq_cq, IB_CQ_NEXT_COMP);
         return &newxprt->sc_xprt;
 
  errout:
         dprintk("svcrdma: failure accepting new connection rc=%d.\n", ret);
         /* Take a reference in case the DTO handler runs */
         svc_xprt_get(&newxprt->sc_xprt);
-        if (newxprt->sc_qp && !IS_ERR(newxprt->sc_qp)) {
+        if (newxprt->sc_qp && !IS_ERR(newxprt->sc_qp))
                 ib_destroy_qp(newxprt->sc_qp);
-                svc_xprt_put(&newxprt->sc_xprt);
-        }
         rdma_destroy_id(newxprt->sc_cm_id);
         /* This call to put will destroy the transport */
         svc_xprt_put(&newxprt->sc_xprt);
         return NULL;
 }
 
-/*
- * Post an RQ WQE to the RQ when the rqst is being released. This
- * effectively returns an RQ credit to the client. The rq_xprt_ctxt
- * will be null if the request is deferred due to an RDMA_READ or the
- * transport had no data ready (EAGAIN). Note that an RPC deferred in
- * svc_process will still return the credit, this is because the data
- * is copied and no longer consume a WQE/WC.
- */
 static void svc_rdma_release_rqst(struct svc_rqst *rqstp)
 {
-        int err;
-        struct svcxprt_rdma *rdma =
-                container_of(rqstp->rq_xprt, struct svcxprt_rdma, sc_xprt);
-        if (rqstp->rq_xprt_ctxt) {
-                BUG_ON(rqstp->rq_xprt_ctxt != rdma);
-                err = svc_rdma_post_recv(rdma);
-                if (err)
-                        dprintk("svcrdma: failed to post an RQ WQE error=%d\n",
-                                err);
-        }
-        rqstp->rq_xprt_ctxt = NULL;
 }
 
 /*
- * When connected, an svc_xprt has at least three references:
- *
- * - A reference held by the QP. We still hold that here because this
- *   code deletes the QP and puts the reference.
+ * When connected, an svc_xprt has at least two references:
  *
  * - A reference held by the cm_id between the ESTABLISHED and
  *   DISCONNECTED events. If the remote peer disconnected first, this
@@ -946,7 +960,7 @@ static void svc_rdma_release_rqst(struct svc_rqst *rqstp)
  * - A reference held by the svc_recv code that called this function
  *   as part of close processing.
  *
- * At a minimum two references should still be held.
+ * At a minimum one references should still be held.
  */
 static void svc_rdma_detach(struct svc_xprt *xprt)
 {
@@ -956,23 +970,53 @@ static void svc_rdma_detach(struct svc_xprt *xprt)
 
         /* Disconnect and flush posted WQE */
         rdma_disconnect(rdma->sc_cm_id);
-
-        /* Destroy the QP if present (not a listener) */
-        if (rdma->sc_qp && !IS_ERR(rdma->sc_qp)) {
-                ib_destroy_qp(rdma->sc_qp);
-                svc_xprt_put(xprt);
-        }
-
-        /* Destroy the CM ID */
-        rdma_destroy_id(rdma->sc_cm_id);
 }
 
-static void svc_rdma_free(struct svc_xprt *xprt)
+static void __svc_rdma_free(struct work_struct *work)
 {
-        struct svcxprt_rdma *rdma = (struct svcxprt_rdma *)xprt;
+        struct svcxprt_rdma *rdma =
+                container_of(work, struct svcxprt_rdma, sc_work);
         dprintk("svcrdma: svc_rdma_free(%p)\n", rdma);
+
         /* We should only be called from kref_put */
-        BUG_ON(atomic_read(&xprt->xpt_ref.refcount) != 0);
+        BUG_ON(atomic_read(&rdma->sc_xprt.xpt_ref.refcount) != 0);
+
+        /*
+         * Destroy queued, but not processed read completions. Note
+         * that this cleanup has to be done before destroying the
+         * cm_id because the device ptr is needed to unmap the dma in
+         * svc_rdma_put_context.
+         */
+        spin_lock_bh(&rdma->sc_read_complete_lock);
+        while (!list_empty(&rdma->sc_read_complete_q)) {
+                struct svc_rdma_op_ctxt *ctxt;
+                ctxt = list_entry(rdma->sc_read_complete_q.next,
+                                  struct svc_rdma_op_ctxt,
+                                  dto_q);
+                list_del_init(&ctxt->dto_q);
+                svc_rdma_put_context(ctxt, 1);
+        }
+        spin_unlock_bh(&rdma->sc_read_complete_lock);
+
+        /* Destroy queued, but not processed recv completions */
+        spin_lock_bh(&rdma->sc_rq_dto_lock);
+        while (!list_empty(&rdma->sc_rq_dto_q)) {
+                struct svc_rdma_op_ctxt *ctxt;
+                ctxt = list_entry(rdma->sc_rq_dto_q.next,
+                                  struct svc_rdma_op_ctxt,
+                                  dto_q);
+                list_del_init(&ctxt->dto_q);
+                svc_rdma_put_context(ctxt, 1);
+        }
+        spin_unlock_bh(&rdma->sc_rq_dto_lock);
+
+        /* Warn if we leaked a resource or under-referenced */
+        WARN_ON(atomic_read(&rdma->sc_ctxt_used) != 0);
+
+        /* Destroy the QP if present (not a listener) */
+        if (rdma->sc_qp && !IS_ERR(rdma->sc_qp))
+                ib_destroy_qp(rdma->sc_qp);
+
         if (rdma->sc_sq_cq && !IS_ERR(rdma->sc_sq_cq))
                 ib_destroy_cq(rdma->sc_sq_cq);
 
@@ -985,10 +1029,21 @@ static void svc_rdma_free(struct svc_xprt *xprt)
         if (rdma->sc_pd && !IS_ERR(rdma->sc_pd))
                 ib_dealloc_pd(rdma->sc_pd);
 
-        destroy_context_cache(rdma->sc_ctxt_head);
+        /* Destroy the CM ID */
+        rdma_destroy_id(rdma->sc_cm_id);
+
+        destroy_context_cache(rdma);
         kfree(rdma);
 }
 
+static void svc_rdma_free(struct svc_xprt *xprt)
+{
+        struct svcxprt_rdma *rdma =
+                container_of(xprt, struct svcxprt_rdma, sc_xprt);
+        INIT_WORK(&rdma->sc_work, __svc_rdma_free);
+        schedule_work(&rdma->sc_work);
+}
+
 static int svc_rdma_has_wspace(struct svc_xprt *xprt)
 {
         struct svcxprt_rdma *rdma =
@@ -1018,7 +1073,7 @@ int svc_rdma_send(struct svcxprt_rdma *xprt, struct ib_send_wr *wr)
         int ret;
 
         if (test_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags))
-                return 0;
+                return -ENOTCONN;
 
         BUG_ON(wr->send_flags != IB_SEND_SIGNALED);
         BUG_ON(((struct svc_rdma_op_ctxt *)(unsigned long)wr->wr_id)->wr_op !=
@@ -1029,7 +1084,8 @@ int svc_rdma_send(struct svcxprt_rdma *xprt, struct ib_send_wr *wr)
                 if (xprt->sc_sq_depth == atomic_read(&xprt->sc_sq_count)) {
                         spin_unlock_bh(&xprt->sc_lock);
                         atomic_inc(&rdma_stat_sq_starve);
-                        /* See if we can reap some SQ WR */
+
+                        /* See if we can opportunistically reap SQ WR to make room */
                         sq_cq_reap(xprt);
 
                         /* Wait until SQ WR available if SQ still full */
@@ -1041,22 +1097,25 @@ int svc_rdma_send(struct svcxprt_rdma *xprt, struct ib_send_wr *wr)
                         continue;
                 }
                 /* Bumped used SQ WR count and post */
+                svc_xprt_get(&xprt->sc_xprt);
                 ret = ib_post_send(xprt->sc_qp, wr, &bad_wr);
                 if (!ret)
                         atomic_inc(&xprt->sc_sq_count);
-                else
+                else {
+                        svc_xprt_put(&xprt->sc_xprt);
                         dprintk("svcrdma: failed to post SQ WR rc=%d, "
                                "sc_sq_count=%d, sc_sq_depth=%d\n",
                                ret, atomic_read(&xprt->sc_sq_count),
                                xprt->sc_sq_depth);
+                }
                 spin_unlock_bh(&xprt->sc_lock);
                 break;
         }
         return ret;
 }
 
-int svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp,
-                        enum rpcrdma_errcode err)
+void svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp,
+                         enum rpcrdma_errcode err)
 {
         struct ib_send_wr err_wr;
         struct ib_sge sge;
@@ -1094,9 +1153,8 @@ int svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp,
         /* Post It */
         ret = svc_rdma_send(xprt, &err_wr);
         if (ret) {
-                dprintk("svcrdma: Error posting send = %d\n", ret);
+                dprintk("svcrdma: Error %d posting send for protocol error\n",
+                        ret);
                 svc_rdma_put_context(ctxt, 1);
         }
-
-        return ret;
 }