RDS: make m_rdma_op a member of rds_message

This eliminates a separate memory alloc, although
it is now necessary to add an "r_active" flag, since
it is no longer to use the m_rdma_op pointer as an
indicator of if an rdma op is present.

rdma SGs allocated from rm sg pool.

rds_rm_size also gets bigger. It's a little inefficient to
run through CMSGs twice, but it makes later steps a lot smoother.

Signed-off-by: Andy Grover <andy.grover@oracle.com>

6 files changed, 129 insertions, 90 deletions

diff --git a/net/rds/ib_send.c b/net/rds/ib_send.c
index 575fce463c65..f0edfdb2866c 100644
--- a/net/rds/ib_send.c
+++ b/net/rds/ib_send.c
@@ -85,8 +85,8 @@ static void rds_ib_send_unmap_rm(struct rds_ib_connection *ic,
                         rm->data.m_sg, rm->data.m_nents,
                         DMA_TO_DEVICE);
 
-        if (rm->rdma.m_rdma_op) {
-                rds_ib_send_unmap_rdma(ic, rm->rdma.m_rdma_op);
+        if (rm->rdma.m_rdma_op.r_active) {
+                rds_ib_send_unmap_rdma(ic, &rm->rdma.m_rdma_op);
 
                 /* If the user asked for a completion notification on this
                  * message, we can implement three different semantics:
@@ -110,10 +110,10 @@ static void rds_ib_send_unmap_rm(struct rds_ib_connection *ic,
                  */
                 rds_ib_send_rdma_complete(rm, wc_status);
 
-                if (rm->rdma.m_rdma_op->r_write)
-                        rds_stats_add(s_send_rdma_bytes, rm->rdma.m_rdma_op->r_bytes);
+                if (rm->rdma.m_rdma_op.r_write)
+                        rds_stats_add(s_send_rdma_bytes, rm->rdma.m_rdma_op.r_bytes);
                 else
-                        rds_stats_add(s_recv_rdma_bytes, rm->rdma.m_rdma_op->r_bytes);
+                        rds_stats_add(s_recv_rdma_bytes, rm->rdma.m_rdma_op.r_bytes);
         }
 
         /* If anyone waited for this message to get flushed out, wake
@@ -243,8 +243,8 @@ void rds_ib_send_cq_comp_handler(struct ib_cq *cq, void *context)
 
                                 rm = rds_send_get_message(conn, send->s_op);
                                 if (rm) {
-                                        if (rm->rdma.m_rdma_op)
-                                                rds_ib_send_unmap_rdma(ic, rm->rdma.m_rdma_op);
+                                        if (rm->rdma.m_rdma_op.r_active)
+                                                rds_ib_send_unmap_rdma(ic, &rm->rdma.m_rdma_op);
                                         rds_ib_send_rdma_complete(rm, wc.status);
                                         rds_message_put(rm);
                                 }
@@ -560,10 +560,10 @@ int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm,
 
                 /* If it has a RDMA op, tell the peer we did it. This is
                  * used by the peer to release use-once RDMA MRs. */
-                if (rm->rdma.m_rdma_op) {
+                if (rm->rdma.m_rdma_op.r_active) {
                         struct rds_ext_header_rdma ext_hdr;
 
-                        ext_hdr.h_rdma_rkey = cpu_to_be32(rm->rdma.m_rdma_op->r_key);
+                        ext_hdr.h_rdma_rkey = cpu_to_be32(rm->rdma.m_rdma_op.r_key);
                         rds_message_add_extension(&rm->m_inc.i_hdr,
                                         RDS_EXTHDR_RDMA, &ext_hdr, sizeof(ext_hdr));
                 }
@@ -601,7 +601,7 @@ int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm,
          * or when requested by the user. Right now, we let
          * the application choose.
          */
-        if (rm->rdma.m_rdma_op && rm->rdma.m_rdma_op->r_fence)
+        if (rm->rdma.m_rdma_op.r_active && rm->rdma.m_rdma_op.r_fence)
                 send_flags = IB_SEND_FENCE;
 
         /*
diff --git a/net/rds/iw_send.c b/net/rds/iw_send.c
index 62234b804d93..9b79a1b10445 100644
--- a/net/rds/iw_send.c
+++ b/net/rds/iw_send.c
@@ -85,8 +85,8 @@ static void rds_iw_send_unmap_rm(struct rds_iw_connection *ic,
                      rm->data.m_sg, rm->data.m_nents,
                      DMA_TO_DEVICE);
 
-        if (rm->rdma.m_rdma_op) {
-                rds_iw_send_unmap_rdma(ic, rm->rdma.m_rdma_op);
+        if (rm->rdma.m_rdma_op.r_active) {
+                rds_iw_send_unmap_rdma(ic, &rm->rdma.m_rdma_op);
 
                 /* If the user asked for a completion notification on this
                  * message, we can implement three different semantics:
@@ -110,10 +110,10 @@ static void rds_iw_send_unmap_rm(struct rds_iw_connection *ic,
                  */
                 rds_iw_send_rdma_complete(rm, wc_status);
 
-                if (rm->rdma.m_rdma_op->r_write)
-                        rds_stats_add(s_send_rdma_bytes, rm->rdma.m_rdma_op->r_bytes);
+                if (rm->rdma.m_rdma_op.r_write)
+                        rds_stats_add(s_send_rdma_bytes, rm->rdma.m_rdma_op.r_bytes);
                 else
-                        rds_stats_add(s_recv_rdma_bytes, rm->rdma.m_rdma_op->r_bytes);
+                        rds_stats_add(s_recv_rdma_bytes, rm->rdma.m_rdma_op.r_bytes);
         }
 
         /* If anyone waited for this message to get flushed out, wake
@@ -591,10 +591,10 @@ int rds_iw_xmit(struct rds_connection *conn, struct rds_message *rm,
 
                 /* If it has a RDMA op, tell the peer we did it. This is
                  * used by the peer to release use-once RDMA MRs. */
-                if (rm->rdma.m_rdma_op) {
+                if (rm->rdma.m_rdma_op.r_active) {
                         struct rds_ext_header_rdma ext_hdr;
 
-                        ext_hdr.h_rdma_rkey = cpu_to_be32(rm->rdma.m_rdma_op->r_key);
+                        ext_hdr.h_rdma_rkey = cpu_to_be32(rm->rdma.m_rdma_op.r_key);
                         rds_message_add_extension(&rm->m_inc.i_hdr,
                                         RDS_EXTHDR_RDMA, &ext_hdr, sizeof(ext_hdr));
                 }
@@ -632,7 +632,7 @@ int rds_iw_xmit(struct rds_connection *conn, struct rds_message *rm,
          * or when requested by the user. Right now, we let
          * the application choose.
          */
-        if (rm->rdma.m_rdma_op && rm->rdma.m_rdma_op->r_fence)
+        if (rm->rdma.m_rdma_op.r_active && rm->rdma.m_rdma_op.r_fence)
                 send_flags = IB_SEND_FENCE;
 
         /*
diff --git a/net/rds/message.c b/net/rds/message.c
index fb382fbb5b6f..4352ce79b376 100644
--- a/net/rds/message.c
+++ b/net/rds/message.c
@@ -69,8 +69,8 @@ static void rds_message_purge(struct rds_message *rm)
         }
         rm->data.m_nents = 0;
 
-        if (rm->rdma.m_rdma_op)
-                rds_rdma_free_op(rm->rdma.m_rdma_op);
+        if (rm->rdma.m_rdma_op.r_active)
+                rds_rdma_free_op(&rm->rdma.m_rdma_op);
         if (rm->rdma.m_rdma_mr)
                 rds_mr_put(rm->rdma.m_rdma_mr);
 }
@@ -259,14 +259,17 @@ struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned in
 {
         struct rds_message *rm;
         unsigned int i;
+        int num_sgs = ceil(total_len, PAGE_SIZE);
+        int extra_bytes = num_sgs * sizeof(struct scatterlist);
 
-        rm = rds_message_alloc(ceil(total_len, PAGE_SIZE), GFP_KERNEL);
+        rm = rds_message_alloc(extra_bytes, GFP_KERNEL);
         if (!rm)
                 return ERR_PTR(-ENOMEM);
 
         set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
         rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
         rm->data.m_nents = ceil(total_len, PAGE_SIZE);
+        rm->data.m_sg = rds_message_alloc_sgs(rm, num_sgs);
 
         for (i = 0; i < rm->data.m_nents; ++i) {
                 sg_set_page(&rm->data.m_sg[i],
diff --git a/net/rds/rdma.c b/net/rds/rdma.c
index a21edad33950..7ff3379bab14 100644
--- a/net/rds/rdma.c
+++ b/net/rds/rdma.c
@@ -458,26 +458,60 @@ void rds_rdma_free_op(struct rds_rdma_op *ro)
         }
 
         kfree(ro->r_notifier);
-        kfree(ro);
+        ro->r_notifier = NULL;
+        ro->r_active = 0;
+}
+
+/*
+ * Count the number of pages needed to describe an incoming iovec.
+ */
+static int rds_rdma_pages(struct rds_rdma_args *args)
+{
+        struct rds_iovec vec;
+        struct rds_iovec __user *local_vec;
+        unsigned int tot_pages = 0;
+        unsigned int nr_pages;
+        unsigned int i;
+
+        local_vec = (struct rds_iovec __user *)(unsigned long) args->local_vec_addr;
+
+        /* figure out the number of pages in the vector */
+        for (i = 0; i < args->nr_local; i++) {
+                if (copy_from_user(&vec, &local_vec[i],
+                                   sizeof(struct rds_iovec)))
+                        return -EFAULT;
+
+                nr_pages = rds_pages_in_vec(&vec);
+                if (nr_pages == 0)
+                        return -EINVAL;
+
+                tot_pages += nr_pages;
+        }
+
+        return tot_pages;
+}
+
+int rds_rdma_extra_size(struct rds_rdma_args *args)
+{
+        return rds_rdma_pages(args) * sizeof(struct scatterlist);
 }
 
 /*
  * args is a pointer to an in-kernel copy in the sendmsg cmsg.
  */
-static struct rds_rdma_op *rds_rdma_prepare(struct rds_sock *rs,
-                                            struct rds_rdma_args *args)
+static int rds_rdma_prepare(struct rds_message *rm,
+                            struct rds_sock *rs,
+                            struct rds_rdma_args *args)
 {
         struct rds_iovec vec;
-        struct rds_rdma_op *op = NULL;
+        struct rds_rdma_op *op = &rm->rdma.m_rdma_op;
         unsigned int nr_pages;
-        unsigned int max_pages;
         unsigned int nr_bytes;
         struct page **pages = NULL;
         struct rds_iovec __user *local_vec;
-        struct scatterlist *sg;
         unsigned int nr;
         unsigned int i, j;
-        int ret;
+        int ret = 0;
 
 
         if (rs->rs_bound_addr == 0) {
@@ -490,44 +524,21 @@ static struct rds_rdma_op *rds_rdma_prepare(struct rds_sock *rs,
                 goto out;
         }
 
-        nr_pages = 0;
-        max_pages = 0;
-
-        local_vec = (struct rds_iovec __user *)(unsigned long) args->local_vec_addr;
-
-        /* figure out the number of pages in the vector */
-        for (i = 0; i < args->nr_local; i++) {
-                if (copy_from_user(&vec, &local_vec[i],
-                                   sizeof(struct rds_iovec))) {
-                        ret = -EFAULT;
-                        goto out;
-                }
-
-                nr = rds_pages_in_vec(&vec);
-                if (nr == 0) {
-                        ret = -EINVAL;
-                        goto out;
-                }
-
-                max_pages = max(nr, max_pages);
-                nr_pages += nr;
-        }
-
-        pages = kcalloc(max_pages, sizeof(struct page *), GFP_KERNEL);
-        if (!pages) {
-                ret = -ENOMEM;
+        nr_pages = rds_rdma_pages(args);
+        if (nr_pages < 0)
                 goto out;
-        }
 
-        op = kzalloc(offsetof(struct rds_rdma_op, r_sg[nr_pages]), GFP_KERNEL);
-        if (!op) {
+        pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
+        if (!pages) {
                 ret = -ENOMEM;
                 goto out;
         }
 
+        op->r_sg = rds_message_alloc_sgs(rm, nr_pages);
         op->r_write = !!(args->flags & RDS_RDMA_READWRITE);
         op->r_fence = !!(args->flags & RDS_RDMA_FENCE);
         op->r_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME);
+        op->r_active = 1;
         op->r_recverr = rs->rs_recverr;
         WARN_ON(!nr_pages);
         sg_init_table(op->r_sg, nr_pages);
@@ -564,6 +575,8 @@ static struct rds_rdma_op *rds_rdma_prepare(struct rds_sock *rs,
                (unsigned long long)args->remote_vec.addr,
                op->r_key);
 
+        local_vec = (struct rds_iovec __user *)(unsigned long) args->local_vec_addr;
+
         for (i = 0; i < args->nr_local; i++) {
                 if (copy_from_user(&vec, &local_vec[i],
                                    sizeof(struct rds_iovec))) {
@@ -580,11 +593,6 @@ static struct rds_rdma_op *rds_rdma_prepare(struct rds_sock *rs,
                 rs->rs_user_addr = vec.addr;
                 rs->rs_user_bytes = vec.bytes;
 
-                /* did the user change the vec under us? */
-                if (nr > max_pages || op->r_nents + nr > nr_pages) {
-                        ret = -EINVAL;
-                        goto out;
-                }
                 /* If it's a WRITE operation, we want to pin the pages for reading.
                  * If it's a READ operation, we need to pin the pages for writing.
                  */
@@ -599,6 +607,7 @@ static struct rds_rdma_op *rds_rdma_prepare(struct rds_sock *rs,
 
                 for (j = 0; j < nr; j++) {
                         unsigned int offset = vec.addr & ~PAGE_MASK;
+                        struct scatterlist *sg;
 
                         sg = &op->r_sg[op->r_nents + j];
                         sg_set_page(sg, pages[j],
@@ -628,12 +637,10 @@ static struct rds_rdma_op *rds_rdma_prepare(struct rds_sock *rs,
         ret = 0;
 out:
         kfree(pages);
-        if (ret) {
-                if (op)
-                        rds_rdma_free_op(op);
-                op = ERR_PTR(ret);
-        }
-        return op;
+        if (ret)
+                rds_rdma_free_op(op);
+
+        return ret;
 }
 
 /*
@@ -643,17 +650,17 @@ out:
 int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
                           struct cmsghdr *cmsg)
 {
-        struct rds_rdma_op *op;
+        int ret;
 
         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_rdma_args)) ||
-            rm->rdma.m_rdma_op)
+            rm->rdma.m_rdma_op.r_active)
                 return -EINVAL;
 
-        op = rds_rdma_prepare(rs, CMSG_DATA(cmsg));
-        if (IS_ERR(op))
-                return PTR_ERR(op);
+        ret = rds_rdma_prepare(rm, rs, CMSG_DATA(cmsg));
+        if (ret)
+                return ret;
+
         rds_stats_inc(s_send_rdma);
-        rm->rdma.m_rdma_op = op;
         return 0;
 }
 
diff --git a/net/rds/rds.h b/net/rds/rds.h
index 7c4adbe8c284..0bb4957e0cfc 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -316,7 +316,7 @@ struct rds_message {
         rds_rdma_cookie_t       m_rdma_cookie;
         struct {
                 struct {
-                        struct rds_rdma_op      *m_rdma_op;
+                        struct rds_rdma_op      m_rdma_op;
                         struct rds_mr           *m_rdma_mr;
                 } rdma;
                 struct {
diff --git a/net/rds/send.c b/net/rds/send.c
index 89e26ffdc812..72dbe7fc4f54 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -235,7 +235,7 @@ int rds_send_xmit(struct rds_connection *conn)
                          * connection.
                          * Therefore, we never retransmit messages with RDMA ops.
                          */
-                        if (rm->rdma.m_rdma_op &&
+                        if (rm->rdma.m_rdma_op.r_active &&
                             test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags)) {
                                 spin_lock_irqsave(&conn->c_lock, flags);
                                 if (test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags))
@@ -267,8 +267,8 @@ int rds_send_xmit(struct rds_connection *conn)
                  * keep this simple and require that the transport either
                  * send the whole rdma or none of it.
                  */
-                if (rm->rdma.m_rdma_op && !conn->c_xmit_rdma_sent) {
-                        ret = conn->c_trans->xmit_rdma(conn, rm->rdma.m_rdma_op);
+                if (rm->rdma.m_rdma_op.r_active && !conn->c_xmit_rdma_sent) {
+                        ret = conn->c_trans->xmit_rdma(conn, &rm->rdma.m_rdma_op);
                         if (ret)
                                 break;
                         conn->c_xmit_rdma_sent = 1;
@@ -418,9 +418,9 @@ void rds_rdma_send_complete(struct rds_message *rm, int status)
 
         spin_lock_irqsave(&rm->m_rs_lock, flags);
 
-        ro = rm->rdma.m_rdma_op;
+        ro = &rm->rdma.m_rdma_op;
         if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags) &&
-            ro && ro->r_notify && ro->r_notifier) {
+            ro->r_active && ro->r_notify && ro->r_notifier) {
                 notifier = ro->r_notifier;
                 rs = rm->m_rs;
                 sock_hold(rds_rs_to_sk(rs));
@@ -452,8 +452,8 @@ __rds_rdma_send_complete(struct rds_sock *rs, struct rds_message *rm, int status
 {
         struct rds_rdma_op *ro;
 
-        ro = rm->rdma.m_rdma_op;
-        if (ro && ro->r_notify && ro->r_notifier) {
+        ro = &rm->rdma.m_rdma_op;
+        if (ro->r_active && ro->r_notify && ro->r_notifier) {
                 ro->r_notifier->n_status = status;
                 list_add_tail(&ro->r_notifier->n_list, &rs->rs_notify_queue);
                 ro->r_notifier = NULL;
@@ -476,7 +476,7 @@ struct rds_message *rds_send_get_message(struct rds_connection *conn,
         spin_lock_irqsave(&conn->c_lock, flags);
 
         list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
-                if (rm->rdma.m_rdma_op == op) {
+                if (&rm->rdma.m_rdma_op == op) {
                         atomic_inc(&rm->m_refcount);
                         found = rm;
                         goto out;
@@ -484,7 +484,7 @@ struct rds_message *rds_send_get_message(struct rds_connection *conn,
         }
 
         list_for_each_entry_safe(rm, tmp, &conn->c_send_queue, m_conn_item) {
-                if (rm->rdma.m_rdma_op == op) {
+                if (&rm->rdma.m_rdma_op == op) {
                         atomic_inc(&rm->m_refcount);
                         found = rm;
                         break;
@@ -544,19 +544,20 @@ void rds_send_remove_from_sock(struct list_head *messages, int status)
                 spin_lock(&rs->rs_lock);
 
                 if (test_and_clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags)) {
-                        struct rds_rdma_op *ro = rm->rdma.m_rdma_op;
+                        struct rds_rdma_op *ro = &rm->rdma.m_rdma_op;
                         struct rds_notifier *notifier;
 
                         list_del_init(&rm->m_sock_item);
                         rds_send_sndbuf_remove(rs, rm);
 
-                        if (ro && ro->r_notifier && (status || ro->r_notify)) {
+                        if (ro->r_active && ro->r_notifier &&
+                            (status || ro->r_notify)) {
                                 notifier = ro->r_notifier;
                                 list_add_tail(&notifier->n_list,
                                                 &rs->rs_notify_queue);
                                 if (!notifier->n_status)
                                         notifier->n_status = status;
-                                rm->rdma.m_rdma_op->r_notifier = NULL;
+                                rm->rdma.m_rdma_op.r_notifier = NULL;
                         }
                         was_on_sock = 1;
                         rm->m_rs = NULL;
@@ -763,9 +764,37 @@ out:
  */
 static int rds_rm_size(struct msghdr *msg, int data_len)
 {
+        struct cmsghdr *cmsg;
         int size = 0;
+        int retval;
+
+        for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
+                if (!CMSG_OK(msg, cmsg))
+                        return -EINVAL;
+
+                if (cmsg->cmsg_level != SOL_RDS)
+                        continue;
+
+                switch (cmsg->cmsg_type) {
+                case RDS_CMSG_RDMA_ARGS:
+                        retval = rds_rdma_extra_size(CMSG_DATA(cmsg));
+                        if (retval < 0)
+                                return retval;
+                        size += retval;
+                        break;
+
+                case RDS_CMSG_RDMA_DEST:
+                case RDS_CMSG_RDMA_MAP:
+                        /* these are valid but do no add any size */
+                        break;
+
+                default:
+                        return -EINVAL;
+                }
+
+        }
 
-        size += ceil(data_len, PAGE_SIZE) * sizeof(struct scatterlist);
+        size += ceil(data_len, PAGE_SIZE) * sizeof(struct scatterlist);
 
         return size;
 }
@@ -896,11 +925,11 @@ int rds_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
         if (ret)
                 goto out;
 
-        if ((rm->m_rdma_cookie || rm->rdma.m_rdma_op) &&
+        if ((rm->m_rdma_cookie || rm->rdma.m_rdma_op.r_active) &&
             !conn->c_trans->xmit_rdma) {
                 if (printk_ratelimit())
                         printk(KERN_NOTICE "rdma_op %p conn xmit_rdma %p\n",
-                                rm->rdma.m_rdma_op, conn->c_trans->xmit_rdma);
+                                &rm->rdma.m_rdma_op, conn->c_trans->xmit_rdma);
                 ret = -EOPNOTSUPP;
                 goto out;
         }