LU-16796 lnet: Change struct lnet_ping_buffer to use kref

This patch changes struct lnet_ping_buffer to use
kref instead of atomic_t

Test-Parameters: trivial testlist=sanity-lnet
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: Ic180e576c3b11afec687dcb3b55b857c730598f6
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/56177
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Timothy Day <timday@amazon.com>
Reviewed-by: Chris Horn <chris.horn@hpe.com>
Reviewed-by: Neil Brown <neilb@suse.de>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lnet/include/lnet/lib-lnet.h b/lnet/include/lnet/lib-lnet.h
index eba26b6..519870f 100644 (file)
--- a/lnet/include/lnet/lib-lnet.h
+++ b/lnet/include/lnet/lib-lnet.h
@@ -384,12 +384,6 @@ lnet_peer_decref_locked(struct lnet_peer *lp)
                lnet_destroy_peer_locked(lp);
 }
 
-static inline void
-lnet_peer_ni_addref_locked(struct lnet_peer_ni *lp)
-{
-       kref_get(&lp->lpni_kref);
-}
-
 extern void lnet_destroy_peer_ni_locked(struct kref *ref);
 
 static inline void
@@ -981,23 +975,10 @@ void lnet_swap_pinginfo(struct lnet_ping_buffer *pbuf);
 
 int lnet_ping_info_validate(struct lnet_ping_info *pinfo);
 struct lnet_ping_buffer *lnet_ping_buffer_alloc(int bytes, gfp_t gfp);
-void lnet_ping_buffer_free(struct lnet_ping_buffer *pbuf);
+void lnet_ping_buffer_free(struct kref *kref);
 int lnet_get_link_status(struct net_device *dev);
 __u32 lnet_set_link_fatal_state(struct lnet_ni *ni, unsigned int link_state);
 
-static inline void lnet_ping_buffer_addref(struct lnet_ping_buffer *pbuf)
-{
-       atomic_inc(&pbuf->pb_refcnt);
-}
-
-static inline void lnet_ping_buffer_decref(struct lnet_ping_buffer *pbuf)
-{
-       if (atomic_dec_and_test(&pbuf->pb_refcnt)) {
-               wake_up_var(&pbuf->pb_refcnt);
-               lnet_ping_buffer_free(pbuf);
-       }
-}
-
 struct lnet_ping_iter {
        struct lnet_ping_info   *pinfo;
        void                    *pos, *end;

diff --git a/lnet/include/lnet/lib-types.h b/lnet/include/lnet/lib-types.h
index 8a13cc1..c3c8124 100644 (file)
--- a/lnet/include/lnet/lib-types.h
+++ b/lnet/include/lnet/lib-types.h
@@ -1263,7 +1263,7 @@ struct lnet_ni {
  */
 struct lnet_ping_buffer {
        int                     pb_nbytes;      /* sizeof pb_info */
-       atomic_t                pb_refcnt;
+       struct kref             pb_refcnt;
        bool                    pb_needs_post;
        struct lnet_ping_info   pb_info;
 };

diff --git a/lnet/lnet/api-ni.c b/lnet/lnet/api-ni.c
index aaff0d5..0335632 100644 (file)
--- a/lnet/lnet/api-ni.c
+++ b/lnet/lnet/api-ni.c
@@ -1786,16 +1786,20 @@ lnet_ping_buffer_alloc(int nbytes, gfp_t gfp)
        if (pbuf) {
                pbuf->pb_nbytes = nbytes;       /* sizeof of pb_info */
                pbuf->pb_needs_post = false;
-               atomic_set(&pbuf->pb_refcnt, 1);
+               kref_init(&pbuf->pb_refcnt);
        }
 
        return pbuf;
 }
 
 void
-lnet_ping_buffer_free(struct lnet_ping_buffer *pbuf)
+lnet_ping_buffer_free(struct kref *kerf)
 {
-       LASSERT(atomic_read(&pbuf->pb_refcnt) == 0);
+       struct lnet_ping_buffer *pbuf = container_of(kerf,
+                                                    struct lnet_ping_buffer,
+                                                    pb_refcnt);
+
+       wake_up_var(&pbuf->pb_refcnt);
        LIBCFS_FREE(pbuf, LNET_PING_BUFFER_SIZE(pbuf->pb_nbytes));
 }
 
@@ -1917,7 +1921,7 @@ lnet_ping_target_destroy(void)
                }
        }
 
-       lnet_ping_buffer_decref(the_lnet.ln_ping_target);
+       kref_put(&(the_lnet.ln_ping_target)->pb_refcnt, lnet_ping_buffer_free);
        the_lnet.ln_ping_target = NULL;
 
        lnet_net_unlock(LNET_LOCK_EX);
@@ -1929,7 +1933,7 @@ lnet_ping_target_event_handler(struct lnet_event *event)
        struct lnet_ping_buffer *pbuf = event->md_user_ptr;
 
        if (event->unlinked)
-               lnet_ping_buffer_decref(pbuf);
+               kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
 }
 
 static int
@@ -1980,13 +1984,12 @@ lnet_ping_target_setup(struct lnet_ping_buffer **ppbuf,
                CERROR("Can't attach ping target MD: %d\n", rc);
                goto fail_decref_ping_buffer;
        }
-       lnet_ping_buffer_addref(*ppbuf);
+       kref_get(&(*ppbuf)->pb_refcnt);
 
        return 0;
 
 fail_decref_ping_buffer:
-       LASSERT(atomic_read(&(*ppbuf)->pb_refcnt) == 1);
-       lnet_ping_buffer_decref(*ppbuf);
+       kref_put(&(*ppbuf)->pb_refcnt, lnet_ping_buffer_free);
        *ppbuf = NULL;
 fail_free_eq:
        return rc;
@@ -2001,7 +2004,7 @@ lnet_ping_md_unlink(struct lnet_ping_buffer *pbuf,
 
        /* NB the MD could be busy; this just starts the unlink */
        wait_var_event_warning(&pbuf->pb_refcnt,
-                              atomic_read(&pbuf->pb_refcnt) <= 1,
+                              kref_read(&pbuf->pb_refcnt) == 1,
                               "Still waiting for ping data MD to unlink\n");
 }
 
@@ -2116,7 +2119,7 @@ __must_hold(&the_lnet.ln_api_mutex)
                mutex_unlock(&the_lnet.ln_api_mutex);
                lnet_ping_md_unlink(old_pbuf, &old_ping_md);
                mutex_lock(&the_lnet.ln_api_mutex);
-               lnet_ping_buffer_decref(old_pbuf);
+               kref_put(&old_pbuf->pb_refcnt, lnet_ping_buffer_free);
        }
 
        lnet_push_update_to_peers(0);
@@ -2162,7 +2165,7 @@ again:
        rc = lnet_push_target_post(pbuf, &mdh);
        if (rc) {
                CDEBUG(D_NET, "Failed to post push target: %d\n", rc);
-               lnet_ping_buffer_decref(pbuf);
+               kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
                return rc;
        }
 
@@ -2176,7 +2179,7 @@ again:
        if (old_pbuf) {
                LNetMDUnlink(old_mdh);
                /* Drop ref set by lnet_ping_buffer_alloc() */
-               lnet_ping_buffer_decref(old_pbuf);
+               kref_put(&old_pbuf->pb_refcnt, lnet_ping_buffer_free);
        }
 
        /* Received another push or reply that requires a larger buffer */
@@ -2207,7 +2210,7 @@ int lnet_push_target_post(struct lnet_ping_buffer *pbuf,
        pbuf->pb_needs_post = false;
 
        /* This reference is dropped by lnet_push_target_event_handler() */
-       lnet_ping_buffer_addref(pbuf);
+       kref_get(&pbuf->pb_refcnt);
 
        /* initialize md content */
        md.start     = &pbuf->pb_info;
@@ -2221,7 +2224,7 @@ int lnet_push_target_post(struct lnet_ping_buffer *pbuf,
        rc = LNetMDAttach(me, &md, LNET_UNLINK, mdhp);
        if (rc) {
                CERROR("Can't attach push MD: %d\n", rc);
-               lnet_ping_buffer_decref(pbuf);
+               kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
                pbuf->pb_needs_post = true;
                return rc;
        }
@@ -2243,14 +2246,14 @@ static void lnet_push_target_event_handler(struct lnet_event *ev)
 
        if (ev->type == LNET_EVENT_UNLINK) {
                /* Drop ref added by lnet_push_target_post() */
-               lnet_ping_buffer_decref(pbuf);
+               kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
                return;
        }
 
        lnet_peer_push_event(ev);
        if (ev->unlinked)
                /* Drop ref added by lnet_push_target_post */
-               lnet_ping_buffer_decref(pbuf);
+               kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
 }
 
 /* Initialize the push target. */
@@ -2291,11 +2294,11 @@ static void lnet_push_target_fini(void)
 
        /* Wait for the unlink to complete. */
        wait_var_event_warning(&the_lnet.ln_push_target->pb_refcnt,
-                              atomic_read(&the_lnet.ln_push_target->pb_refcnt) <= 1,
+                              kref_read(&the_lnet.ln_push_target->pb_refcnt) == 1,
                               "Still waiting for ping data MD to unlink\n");
 
        /* Drop ref set by lnet_ping_buffer_alloc() */
-       lnet_ping_buffer_decref(the_lnet.ln_push_target);
+       kref_put(&(the_lnet.ln_push_target)->pb_refcnt, lnet_ping_buffer_free);
        the_lnet.ln_push_target = NULL;
        the_lnet.ln_push_target_nbytes = 0;
 
@@ -3660,7 +3663,7 @@ static int lnet_add_net_common(struct lnet_net *net,
 
 failed:
        lnet_ping_md_unlink(pbuf, &ping_mdh);
-       lnet_ping_buffer_decref(pbuf);
+       kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
        return rc;
 }
 
@@ -10141,7 +10144,7 @@ static int lnet_ping(struct lnet_processid *id, struct lnet_nid *src_nid,
        }
        rc = i;
 fail_ping_buffer_decref:
-       lnet_ping_buffer_decref(pbuf);
+       kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
        return rc;
 }
 

diff --git a/lnet/lnet/lib-move.c b/lnet/lnet/lib-move.c
index add5a27..2b33310 100644 (file)
--- a/lnet/lnet/lib-move.c
+++ b/lnet/lnet/lib-move.c
@@ -1842,11 +1842,10 @@ lnet_handle_send(struct lnet_send_data *sd)
        struct lnet_peer_ni *best_lpni = sd->sd_best_lpni;
        struct lnet_peer_ni *final_dst_lpni = sd->sd_final_dst_lpni;
        struct lnet_msg *msg = sd->sd_msg;
-       int cpt2;
        __u32 send_case = sd->sd_send_case;
-       int rc;
        __u32 routing = send_case & REMOTE_DST;
        struct lnet_rsp_tracker *rspt;
+       int cpt2, rc;
 
        /* Increment sequence number of the selected peer, peer net,
         * local ni and local net so that we pick the next ones
@@ -1870,14 +1869,12 @@ lnet_handle_send(struct lnet_send_data *sd)
               best_lpni->lpni_txcredits,
               best_lpni->lpni_sel_priority);
 
-       /*
-        * grab a reference on the peer_ni so it sticks around even if
+       /* grab a reference on the peer_ni so it sticks around even if
         * we need to drop and relock the lnet_net_lock below.
         */
-       lnet_peer_ni_addref_locked(best_lpni);
+       kref_get(&best_lpni->lpni_kref);
 
-       /*
-        * Use lnet_cpt_of_nid() to determine the CPT used to commit the
+       /* Use lnet_cpt_of_nid() to determine the CPT used to commit the
         * message. This ensures that we get a CPT that is correct for
         * the NI when the NI has been restricted to a subset of all CPTs.
         * If the selected CPT differs from the one currently locked, we
@@ -2097,11 +2094,11 @@ static int
 lnet_initiate_peer_discovery(struct lnet_peer_ni *lpni, struct lnet_msg *msg,
                             int cpt)
 {
-       struct lnet_peer *peer;
        struct lnet_peer_ni *new_lpni;
+       struct lnet_peer *peer;
        int rc;
 
-       lnet_peer_ni_addref_locked(lpni);
+       kref_get(&lpni->lpni_kref);
 
        peer = lpni->lpni_peer_net->lpn_peer;
 
@@ -4129,7 +4126,7 @@ lnet_send_ping(struct lnet_nid *dest_nid,
 
        rc = LNetMDBind(&md, LNET_UNLINK, mdh);
        if (rc) {
-               lnet_ping_buffer_decref(pbuf);
+               kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
                CERROR("Can't bind MD: %d\n", rc);
                rc = -rc; /* change the rc to positive */
                goto fail_error;
@@ -4253,7 +4250,7 @@ lnet_mt_event_handler(struct lnet_event *event)
        if (event->unlinked) {
                LIBCFS_FREE(ev_info, sizeof(*ev_info));
                pbuf = LNET_PING_INFO_TO_BUFFER(event->md_start);
-               lnet_ping_buffer_decref(pbuf);
+               kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
        }
 }
 

diff --git a/lnet/lnet/peer.c b/lnet/lnet/peer.c
index 05633d3..da51655 100644 (file)
--- a/lnet/lnet/peer.c
+++ b/lnet/lnet/peer.c
@@ -177,7 +177,7 @@ lnet_peer_ni_alloc(struct lnet_nid *nid)
                 * list so it can be easily found and revisited.
                 */
                /* FIXME: per-net implementation instead? */
-               lnet_peer_ni_addref_locked(lpni);
+               kref_get(&lpni->lpni_kref);
                list_add_tail(&lpni->lpni_on_remote_peer_ni_list,
                              &the_lnet.ln_remote_peer_ni_list);
        }
@@ -285,7 +285,7 @@ lnet_destroy_peer_locked(struct lnet_peer *lp)
        LASSERT(list_empty(&lp->lp_dc_list));
 
        if (lp->lp_data)
-               lnet_ping_buffer_decref(lp->lp_data);
+               kref_put(&lp->lp_data->pb_refcnt, lnet_ping_buffer_free);
 
        /*
         * if there are messages still on the pending queue, then make
@@ -687,7 +687,7 @@ lnet_get_peer_ni_locked(struct lnet_peer_table *ptable, struct lnet_nid *nid)
        peers = &ptable->pt_hash[lnet_nid2peerhash(nid)];
        list_for_each_entry(lp, peers, lpni_hashlist) {
                if (nid_same(&lp->lpni_nid, nid)) {
-                       lnet_peer_ni_addref_locked(lp);
+                       kref_get(&lp->lpni_kref);
                        return lp;
                }
        }
@@ -1583,7 +1583,7 @@ lnet_peer_attach_peer_ni(struct lnet_peer *lp,
                ptable = the_lnet.ln_peer_tables[lpni->lpni_cpt];
                list_add_tail(&lpni->lpni_hashlist, &ptable->pt_hash[hash]);
                ptable->pt_version++;
-               lnet_peer_ni_addref_locked(lpni);
+               kref_get(&lpni->lpni_kref);
        }
 
        /* Detach the peer_ni from an existing peer, if necessary. */
@@ -2006,7 +2006,7 @@ __must_hold(&the_lnet.ln_api_mutex)
        /* lnet_peer_attach_peer_ni() always returns 0 */
        rc = lnet_peer_attach_peer_ni(lp, lpn, lpni, flags);
 
-       lnet_peer_ni_addref_locked(lpni);
+       kref_get(&lpni->lpni_kref);
 
 out_err:
        if (rc) {
@@ -3011,10 +3011,10 @@ lnet_discovery_event_reply(struct lnet_peer *lp, struct lnet_event *ev)
               libcfs_nidstr(&lp->lp_primary_nid), lp->lp_peer_seqno,
               lp->lp_state);
        if (lp->lp_state & LNET_PEER_DATA_PRESENT)
-               lnet_ping_buffer_decref(lp->lp_data);
+               kref_put(&lp->lp_data->pb_refcnt, lnet_ping_buffer_free);
        else
                lp->lp_state |= LNET_PEER_DATA_PRESENT;
-       lnet_ping_buffer_addref(pbuf);
+       kref_get(&pbuf->pb_refcnt);
        lp->lp_data = pbuf;
 out:
        lp->lp_state &= ~LNET_PEER_PING_SENT;
@@ -3130,7 +3130,7 @@ static void lnet_discovery_event_handler(struct lnet_event *event)
        }
        if (event->unlinked) {
                pbuf = LNET_PING_INFO_TO_BUFFER(event->md_start);
-               lnet_ping_buffer_decref(pbuf);
+               kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
                lnet_peer_decref_locked(lp);
        }
        lnet_net_unlock(LNET_LOCK_EX);
@@ -3430,7 +3430,7 @@ out:
        CFS_FREE_PTR_ARRAY(curnis, nnis);
        CFS_FREE_PTR_ARRAY(addnis, nnis);
        CFS_FREE_PTR_ARRAY(delnis, nnis);
-       lnet_ping_buffer_decref(pbuf);
+       kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
        CDEBUG(D_NET, "peer %s (%p): %d\n",
               libcfs_nidstr(&lp->lp_primary_nid), lp, rc);
 
@@ -3474,13 +3474,13 @@ lnet_peer_set_primary_data(struct lnet_peer *lp, struct lnet_ping_buffer *pbuf)
                        lp->lp_peer_seqno = LNET_PING_BUFFER_SEQNO(pbuf);
                } else if (lp->lp_state & LNET_PEER_DATA_PRESENT) {
                        lp->lp_state &= ~LNET_PEER_DATA_PRESENT;
-                       lnet_ping_buffer_decref(pbuf);
+                       kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
                        pbuf = lp->lp_data;
                        lp->lp_data = NULL;
                }
        }
        if (lp->lp_state & LNET_PEER_DATA_PRESENT) {
-               lnet_ping_buffer_decref(lp->lp_data);
+               kref_put(&lp->lp_data->pb_refcnt, lnet_ping_buffer_free);
                lp->lp_data = NULL;
                lp->lp_state &= ~LNET_PEER_DATA_PRESENT;
        }
@@ -3624,7 +3624,7 @@ __must_hold(&lp->lp_lock)
         */
        mutex_lock(&the_lnet.ln_api_mutex);
        if (the_lnet.ln_state != LNET_STATE_RUNNING) {
-               lnet_ping_buffer_decref(pbuf);
+               kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
                rc = -ESHUTDOWN;
                goto out;
        }
@@ -3635,7 +3635,7 @@ __must_hold(&lp->lp_lock)
         * alive. Don't do any work on it.
         */
        if (list_empty(&lp->lp_peer_list)) {
-               lnet_ping_buffer_decref(pbuf);
+               kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
                goto out;
        }
 
@@ -3657,7 +3657,7 @@ __must_hold(&lp->lp_lock)
         * can show up with only the loopback NID in the ping buffer.
         */
        if (!find_primary(&nid, pbuf)) {
-               lnet_ping_buffer_decref(pbuf);
+               kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
                goto out;
        }
        /* If lp_merge_primary_nid is set, assign it as primary,
@@ -3673,7 +3673,7 @@ __must_hold(&lp->lp_lock)
        if (nid_is_lo0(&lp->lp_primary_nid)) {
                rc = lnet_peer_set_primary_nid(lp, &nid, flags);
                if (rc)
-                       lnet_ping_buffer_decref(pbuf);
+                       kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
                else
                        rc = lnet_peer_merge_data(lp, pbuf);
        /*
@@ -3696,7 +3696,8 @@ __must_hold(&lp->lp_lock)
                                CERROR("Primary NID error %s versus %s: %d\n",
                                       libcfs_nidstr(&lp->lp_primary_nid),
                                       libcfs_nidstr(&nid), rc);
-                               lnet_ping_buffer_decref(pbuf);
+                               kref_put(&pbuf->pb_refcnt,
+                                        lnet_ping_buffer_free);
                        } else {
                                rc = lnet_peer_merge_data(lp, pbuf);
                        }
@@ -3900,7 +3901,7 @@ __must_hold(&lp->lp_lock)
 
        cpt = lnet_net_lock_current();
        pbuf = the_lnet.ln_ping_target;
-       lnet_ping_buffer_addref(pbuf);
+       kref_get(&pbuf->pb_refcnt);
        lnet_net_unlock(cpt);
 
        /* Push source MD */
@@ -3914,7 +3915,7 @@ __must_hold(&lp->lp_lock)
 
        rc = LNetMDBind(&md, LNET_UNLINK, &lp->lp_push_mdh);
        if (rc) {
-               lnet_ping_buffer_decref(pbuf);
+               kref_put(&pbuf->pb_refcnt, lnet_ping_buffer_free);
                CERROR("Can't bind push source MD: %d\n", rc);
                goto fail_error;
        }
@@ -4541,7 +4542,8 @@ lnet_peer_ni_add_to_recoveryq_locked(struct lnet_peer_ni *lpni,
        }
 
        /* This peer NI is going on the recovery queue, so take a ref on it */
-       lnet_peer_ni_addref_locked(lpni);
+       kref_get(&lpni->lpni_kref);
+
 
        lnet_peer_ni_set_next_ping(lpni, now);
 

diff --git a/lnet/lnet/router.c b/lnet/lnet/router.c
index 7bcb1be..1db22a2 100644 (file)
--- a/lnet/lnet/router.c
+++ b/lnet/lnet/router.c
@@ -1168,7 +1168,7 @@ rescan:
                               libcfs_nidstr(&rtr->lp_primary_nid));
                        continue;
                }
-               lnet_peer_ni_addref_locked(lpni);
+               kref_get(&lpni->lpni_kref);
 
                /* specify the net to use */
                rtr->lp_disc_net_id = lpn->lpn_net_id;