LU-13004 lnet: always pass struct lnet_md by reference.

Both LNetMDAttach and LNetMDBind expected a struct lnet_md to be
passed by value.  This requires copying the data structure onto the
stack, which is a waste of stack space and brings no value.

So change them to expect a reference, and declare it 'const' to be
sure it doesn't get changed.

Signed-off-by: Mr NeilBrown <neilb@suse.de>
Change-Id: I343797d1e70cc85fde92d544e56536e982e02973
Reviewed-on: https://review.whamcloud.com/37853
Reviewed-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Chris Horn <chris.horn@hpe.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lnet/include/lnet/api.h b/lnet/include/lnet/api.h
index bc6e9d9..f552349 100644 (file)
--- a/lnet/include/lnet/api.h
+++ b/lnet/include/lnet/api.h
@@ -119,11 +119,11 @@ void LNetMEUnlink(struct lnet_me *current_in);
  * associated with a MD: LNetMDUnlink().
  * @{ */
 int LNetMDAttach(struct lnet_me *current_in,
-                struct lnet_md md_in,
+                const struct lnet_md *md_in,
                 enum lnet_unlink unlink_in,
                 struct lnet_handle_md *md_handle_out);
 
-int LNetMDBind(struct lnet_md   md_in,
+int LNetMDBind(const struct lnet_md *md_in,
               enum lnet_unlink unlink_in,
               struct lnet_handle_md *md_handle_out);
 

diff --git a/lnet/lnet/api-ni.c b/lnet/lnet/api-ni.c
index 05c0cb3..0d5e45b 100644 (file)
--- a/lnet/lnet/api-ni.c
+++ b/lnet/lnet/api-ni.c
@@ -1724,7 +1724,7 @@ lnet_ping_target_setup(struct lnet_ping_buffer **ppbuf,
        md.handler   = the_lnet.ln_ping_target_handler;
        md.user_ptr  = *ppbuf;
 
-       rc = LNetMDAttach(me, md, LNET_RETAIN, ping_mdh);
+       rc = LNetMDAttach(me, &md, LNET_RETAIN, ping_mdh);
        if (rc != 0) {
                CERROR("Can't attach ping target MD: %d\n", rc);
                goto fail_unlink_ping_me;
@@ -1933,7 +1933,7 @@ int lnet_push_target_post(struct lnet_ping_buffer *pbuf,
        md.user_ptr  = pbuf;
        md.handler   = the_lnet.ln_push_target_handler;
 
-       rc = LNetMDAttach(me, md, LNET_UNLINK, mdhp);
+       rc = LNetMDAttach(me, &md, LNET_UNLINK, mdhp);
        if (rc) {
                CERROR("Can't attach push MD: %d\n", rc);
                LNetMEUnlink(me);
@@ -4160,7 +4160,7 @@ static int lnet_ping(struct lnet_process_id id, signed long timeout,
 
        init_completion(&pd.completion);
 
-       rc = LNetMDBind(md, LNET_UNLINK, &pd.mdh);
+       rc = LNetMDBind(&md, LNET_UNLINK, &pd.mdh);
        if (rc != 0) {
                CERROR("Can't bind MD: %d\n", rc);
                goto fail_ping_buffer_decref;

diff --git a/lnet/lnet/lib-md.c b/lnet/lnet/lib-md.c
index 0ab9060..268e856 100644 (file)
--- a/lnet/lnet/lib-md.c
+++ b/lnet/lnet/lib-md.c
@@ -142,7 +142,7 @@ out:
 }
 
 static struct lnet_libmd *
-lnet_md_build(struct lnet_md *umd, int unlink)
+lnet_md_build(const struct lnet_md *umd, int unlink)
 {
        int i;
        unsigned int niov;
@@ -299,7 +299,7 @@ lnet_md_deconstruct(struct lnet_libmd *lmd, struct lnet_event *ev)
 }
 
 static int
-lnet_md_validate(struct lnet_md *umd)
+lnet_md_validate(const struct lnet_md *umd)
 {
        if (umd->start == NULL && umd->length != 0) {
                CERROR("MD start pointer can not be NULL with length %u\n",
@@ -343,7 +343,7 @@ lnet_md_validate(struct lnet_md *umd)
  * a MD.
  */
 int
-LNetMDAttach(struct lnet_me *me, struct lnet_md umd,
+LNetMDAttach(struct lnet_me *me, const struct lnet_md *umd,
             enum lnet_unlink unlink, struct lnet_handle_md *handle)
 {
        LIST_HEAD(matches);
@@ -354,15 +354,15 @@ LNetMDAttach(struct lnet_me *me, struct lnet_md umd,
 
        LASSERT(the_lnet.ln_refcount > 0);
 
-       if (lnet_md_validate(&umd) != 0)
+       if (lnet_md_validate(umd) != 0)
                return -EINVAL;
 
-       if ((umd.options & (LNET_MD_OP_GET | LNET_MD_OP_PUT)) == 0) {
+       if ((umd->options & (LNET_MD_OP_GET | LNET_MD_OP_PUT)) == 0) {
                CERROR("Invalid option: no MD_OP set\n");
                return -EINVAL;
        }
 
-       md = lnet_md_build(&umd, unlink);
+       md = lnet_md_build(umd, unlink);
        if (IS_ERR(md))
                return PTR_ERR(md);
 
@@ -373,7 +373,7 @@ LNetMDAttach(struct lnet_me *me, struct lnet_md umd,
        if (me->me_md)
                rc = -EBUSY;
        else
-               rc = lnet_md_link(md, umd.handler, cpt);
+               rc = lnet_md_link(md, umd->handler, cpt);
 
        if (rc != 0)
                goto out_unlock;
@@ -415,7 +415,7 @@ EXPORT_SYMBOL(LNetMDAttach);
  * LNetInvalidateHandle() on it.
  */
 int
-LNetMDBind(struct lnet_md umd, enum lnet_unlink unlink,
+LNetMDBind(const struct lnet_md *umd, enum lnet_unlink unlink,
           struct lnet_handle_md *handle)
 {
        struct lnet_libmd       *md;
@@ -424,15 +424,15 @@ LNetMDBind(struct lnet_md umd, enum lnet_unlink unlink,
 
        LASSERT(the_lnet.ln_refcount > 0);
 
-       if (lnet_md_validate(&umd) != 0)
+       if (lnet_md_validate(umd) != 0)
                return -EINVAL;
 
-       if ((umd.options & (LNET_MD_OP_GET | LNET_MD_OP_PUT)) != 0) {
+       if ((umd->options & (LNET_MD_OP_GET | LNET_MD_OP_PUT)) != 0) {
                CERROR("Invalid option: GET|PUT illegal on active MDs\n");
                return -EINVAL;
        }
 
-       md = lnet_md_build(&umd, unlink);
+       md = lnet_md_build(umd, unlink);
        if (IS_ERR(md))
                return PTR_ERR(md);
 
@@ -445,7 +445,7 @@ LNetMDBind(struct lnet_md umd, enum lnet_unlink unlink,
 
        cpt = lnet_res_lock_current();
 
-       rc = lnet_md_link(md, umd.handler, cpt);
+       rc = lnet_md_link(md, umd->handler, cpt);
        if (rc != 0)
                goto out_unlock;
 

diff --git a/lnet/lnet/lib-move.c b/lnet/lnet/lib-move.c
index 30f0d71..9cf30c2 100644 (file)
--- a/lnet/lnet/lib-move.c
+++ b/lnet/lnet/lib-move.c
@@ -3573,7 +3573,7 @@ lnet_send_ping(lnet_nid_t dest_nid,
        md.user_ptr  = user_data;
        md.handler   = handler;
 
-       rc = LNetMDBind(md, LNET_UNLINK, mdh);
+       rc = LNetMDBind(&md, LNET_UNLINK, mdh);
        if (rc) {
                lnet_ping_buffer_decref(pbuf);
                CERROR("Can't bind MD: %d\n", rc);

diff --git a/lnet/lnet/peer.c b/lnet/lnet/peer.c
index 3719a74..b745eb3 100644 (file)
--- a/lnet/lnet/peer.c
+++ b/lnet/lnet/peer.c
@@ -3094,7 +3094,7 @@ __must_hold(&lp->lp_lock)
        md.handler   = the_lnet.ln_dc_handler;
        md.user_ptr  = lp;
 
-       rc = LNetMDBind(md, LNET_UNLINK, &lp->lp_push_mdh);
+       rc = LNetMDBind(&md, LNET_UNLINK, &lp->lp_push_mdh);
        if (rc) {
                lnet_ping_buffer_decref(pbuf);
                CERROR("Can't bind push source MD: %d\n", rc);

diff --git a/lnet/selftest/rpc.c b/lnet/selftest/rpc.c
index 99e3774..db6c704 100644 (file)
--- a/lnet/selftest/rpc.c
+++ b/lnet/selftest/rpc.c
@@ -375,7 +375,7 @@ srpc_post_passive_rdma(int portal, int local, __u64 matchbits, void *buf,
        md.options   = options;
        md.handler   = srpc_data.rpc_lnet_handler;
 
-       rc = LNetMDAttach(me, md, LNET_UNLINK, mdh);
+       rc = LNetMDAttach(me, &md, LNET_UNLINK, mdh);
        if (rc != 0) {
                CERROR("LNetMDAttach failed: %d\n", rc);
                LASSERT(rc == -ENOMEM);
@@ -406,7 +406,7 @@ srpc_post_active_rdma(int portal, __u64 matchbits, void *buf, int len,
        md.threshold = ((options & LNET_MD_OP_GET) != 0) ? 2 : 1;
        md.options   = options & ~(LNET_MD_OP_PUT | LNET_MD_OP_GET);
 
-       rc = LNetMDBind(md, LNET_UNLINK, mdh);
+       rc = LNetMDBind(&md, LNET_UNLINK, mdh);
        if (rc != 0) {
                CERROR("LNetMDBind failed: %d\n", rc);
                LASSERT(rc == -ENOMEM);

diff --git a/lustre/ptlrpc/niobuf.c b/lustre/ptlrpc/niobuf.c
index a89b526..43b9db0 100644 (file)
--- a/lustre/ptlrpc/niobuf.c
+++ b/lustre/ptlrpc/niobuf.c
@@ -76,7 +76,7 @@ static int ptl_send_buf(struct lnet_handle_md *mdh, void *base, int len,
                ack = LNET_NOACK_REQ;
        }
 
-       rc = LNetMDBind (md, LNET_UNLINK, mdh);
+       rc = LNetMDBind(&md, LNET_UNLINK, mdh);
        if (unlikely(rc != 0)) {
                CERROR ("LNetMDBind failed: %d\n", rc);
                LASSERT (rc == -ENOMEM);
@@ -208,7 +208,7 @@ int ptlrpc_start_bulk_transfer(struct ptlrpc_bulk_desc *desc)
                 * page-aligned. Otherwise we'd have to send client bulk
                 * sizes over and split server buffer accordingly */
                ptlrpc_fill_bulk_md(&md, desc, posted_md);
-               rc = LNetMDBind(md, LNET_UNLINK, &desc->bd_mds[posted_md]);
+               rc = LNetMDBind(&md, LNET_UNLINK, &desc->bd_mds[posted_md]);
                if (rc != 0) {
                        CERROR("%s: LNetMDBind failed for MD %u: rc = %d\n",
                               exp->exp_obd->obd_name, posted_md, rc);
@@ -393,7 +393,7 @@ int ptlrpc_register_bulk(struct ptlrpc_request *req)
                percpu_ref_get(&ptlrpc_pending);
 
                /* About to let the network at it... */
-               rc = LNetMDAttach(me, md, LNET_UNLINK,
+               rc = LNetMDAttach(me, &md, LNET_UNLINK,
                                  &desc->bd_mds[posted_md]);
                if (rc != 0) {
                        CERROR("%s: LNetMDAttach failed x%llu/%d: rc = %d\n",
@@ -867,7 +867,7 @@ int ptl_send_rpc(struct ptlrpc_request *request, int noreply)
 
                /* We must see the unlink callback to set rq_reply_unlinked,
                 * so we can't auto-unlink */
-               rc = LNetMDAttach(reply_me, reply_md, LNET_RETAIN,
+               rc = LNetMDAttach(reply_me, &reply_md, LNET_RETAIN,
                                  &request->rq_reply_md_h);
                if (rc != 0) {
                        CERROR("LNetMDAttach failed: %d\n", rc);
@@ -991,7 +991,7 @@ int ptlrpc_register_rqbd(struct ptlrpc_request_buffer_desc *rqbd)
        md.user_ptr  = &rqbd->rqbd_cbid;
        md.handler   = ptlrpc_handler;
 
-       rc = LNetMDAttach(me, md, LNET_UNLINK, &rqbd->rqbd_md_h);
+       rc = LNetMDAttach(me, &md, LNET_UNLINK, &rqbd->rqbd_md_h);
        if (rc == 0) {
                percpu_ref_get(&ptlrpc_pending);
                return 0;