[lustre-devel] [PATCH 03/34] lnet: Change lpni_refcount to atomic_t

[NeilBrown]

This is part of
    Commit: 58091af960fe ("LU-7734 lnet: Multi-Rail peer split")
from upstream lustre, where it is marked:
    Signed-off-by: Amir Shehata <amir.shehata at intel.com>
    WC-bug-id: https://jira.whamcloud.com/browse/LU-7734
    Reviewed-on: http://review.whamcloud.com/18293
    Reviewed-by: Olaf Weber <olaf at sgi.com>
    Reviewed-by: Doug Oucharek <doug.s.oucharek at intel.com>

Signed-off-by: NeilBrown <neilb at suse.com>
---
 .../staging/lustre/include/linux/lnet/lib-lnet.h   |   10 +++++-----
 .../staging/lustre/include/linux/lnet/lib-types.h  |    2 +-
 drivers/staging/lustre/lnet/lnet/peer.c            |    8 ++++----
 drivers/staging/lustre/lnet/lnet/router.c          |    4 ++--
 drivers/staging/lustre/lnet/lnet/router_proc.c     |    4 ++--
 5 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/staging/lustre/include/linux/lnet/lib-lnet.h b/drivers/staging/lustre/include/linux/lnet/lib-lnet.h
index ef53638e20f6..88e010aa3f68 100644
--- a/drivers/staging/lustre/include/linux/lnet/lib-lnet.h
+++ b/drivers/staging/lustre/include/linux/lnet/lib-lnet.h
@@ -313,8 +313,8 @@ lnet_handle2me(struct lnet_handle_me *handle)
 static inline void
 lnet_peer_addref_locked(struct lnet_peer_ni *lp)
 {
-	LASSERT(lp->lpni_refcount > 0);
-	lp->lpni_refcount++;
+	LASSERT(atomic_read(&lp->lpni_refcount) > 0);
+	atomic_inc(&lp->lpni_refcount);
 }
 
 void lnet_destroy_peer_locked(struct lnet_peer_ni *lp);
@@ -322,9 +322,9 @@ void lnet_destroy_peer_locked(struct lnet_peer_ni *lp);
 static inline void
 lnet_peer_decref_locked(struct lnet_peer_ni *lp)
 {
-	LASSERT(lp->lpni_refcount > 0);
-	lp->lpni_refcount--;
-	if (!lp->lpni_refcount)
+	LASSERT(atomic_read(&lp->lpni_refcount) > 0);
+	atomic_dec(&lp->lpni_refcount);
+	if (atomic_read(&lp->lpni_refcount) == 0)
 		lnet_destroy_peer_locked(lp);
 }
 
diff --git a/drivers/staging/lustre/include/linux/lnet/lib-types.h b/drivers/staging/lustre/include/linux/lnet/lib-types.h
index 4b26801d7d29..9a2cf319dba9 100644
--- a/drivers/staging/lustre/include/linux/lnet/lib-types.h
+++ b/drivers/staging/lustre/include/linux/lnet/lib-types.h
@@ -429,7 +429,7 @@ struct lnet_peer_ni {
 	/* peer's NID */
 	lnet_nid_t		 lpni_nid;
 	/* # refs */
-	int			 lpni_refcount;
+	atomic_t		 lpni_refcount;
 	/* CPT this peer attached on */
 	int			 lpni_cpt;
 	/* # refs from lnet_route::lr_gateway */
diff --git a/drivers/staging/lustre/lnet/lnet/peer.c b/drivers/staging/lustre/lnet/lnet/peer.c
index 67614309f242..7475678ea184 100644
--- a/drivers/staging/lustre/lnet/lnet/peer.c
+++ b/drivers/staging/lustre/lnet/lnet/peer.c
@@ -221,7 +221,7 @@ lnet_destroy_peer_locked(struct lnet_peer_ni *lp)
 {
 	struct lnet_peer_table *ptable;
 
-	LASSERT(!lp->lpni_refcount);
+	LASSERT(atomic_read(&lp->lpni_refcount) == 0);
 	LASSERT(!lp->lpni_rtr_refcount);
 	LASSERT(list_empty(&lp->lpni_txq));
 	LASSERT(list_empty(&lp->lpni_hashlist));
@@ -320,7 +320,7 @@ lnet_nid2peer_locked(struct lnet_peer_ni **lpp, lnet_nid_t nid, int cpt)
 	lp->lpni_ping_feats = LNET_PING_FEAT_INVAL;
 	lp->lpni_nid = nid;
 	lp->lpni_cpt = cpt2;
-	lp->lpni_refcount = 2;	/* 1 for caller; 1 for hash */
+	atomic_set(&lp->lpni_refcount, 2);	/* 1 for caller; 1 for hash */
 	lp->lpni_rtr_refcount = 0;
 
 	lnet_net_lock(cpt);
@@ -378,7 +378,7 @@ lnet_debug_peer(lnet_nid_t nid)
 		aliveness = lp->lpni_alive ? "up" : "down";
 
 	CDEBUG(D_WARNING, "%-24s %4d %5s %5d %5d %5d %5d %5d %ld\n",
-	       libcfs_nid2str(lp->lpni_nid), lp->lpni_refcount,
+	       libcfs_nid2str(lp->lpni_nid), atomic_read(&lp->lpni_refcount),
 	       aliveness, lp->lpni_net->net_tunables.lct_peer_tx_credits,
 	       lp->lpni_rtrcredits, lp->lpni_minrtrcredits,
 	       lp->lpni_txcredits, lp->lpni_mintxcredits, lp->lpni_txqnob);
@@ -433,7 +433,7 @@ lnet_get_peer_info(__u32 peer_index, __u64 *nid,
 					 lp->lpni_alive ? "up" : "down");
 
 			*nid = lp->lpni_nid;
-			*refcount = lp->lpni_refcount;
+			*refcount = atomic_read(&lp->lpni_refcount);
 			*ni_peer_tx_credits =
 				lp->lpni_net->net_tunables.lct_peer_tx_credits;
 			*peer_tx_credits = lp->lpni_txcredits;
diff --git a/drivers/staging/lustre/lnet/lnet/router.c b/drivers/staging/lustre/lnet/lnet/router.c
index 31685406dcc3..bfd4b22cc28a 100644
--- a/drivers/staging/lustre/lnet/lnet/router.c
+++ b/drivers/staging/lustre/lnet/lnet/router.c
@@ -172,7 +172,7 @@ lnet_ni_notify_locked(struct lnet_ni *ni, struct lnet_peer_ni *lp)
 static void
 lnet_rtr_addref_locked(struct lnet_peer_ni *lp)
 {
-	LASSERT(lp->lpni_refcount > 0);
+	LASSERT(atomic_read(&lp->lpni_refcount) > 0);
 	LASSERT(lp->lpni_rtr_refcount >= 0);
 
 	/* lnet_net_lock must be exclusively locked */
@@ -200,7 +200,7 @@ lnet_rtr_addref_locked(struct lnet_peer_ni *lp)
 static void
 lnet_rtr_decref_locked(struct lnet_peer_ni *lp)
 {
-	LASSERT(lp->lpni_refcount > 0);
+	LASSERT(atomic_read(&lp->lpni_refcount) > 0);
 	LASSERT(lp->lpni_rtr_refcount > 0);
 
 	/* lnet_net_lock must be exclusively locked */
diff --git a/drivers/staging/lustre/lnet/lnet/router_proc.c b/drivers/staging/lustre/lnet/lnet/router_proc.c
index d0340707feaa..12a4b1708d3c 100644
--- a/drivers/staging/lustre/lnet/lnet/router_proc.c
+++ b/drivers/staging/lustre/lnet/lnet/router_proc.c
@@ -320,7 +320,7 @@ static int proc_lnet_routers(struct ctl_table *table, int write,
 			lnet_nid_t nid = peer->lpni_nid;
 			time64_t now = ktime_get_seconds();
 			time64_t deadline = peer->lpni_ping_deadline;
-			int nrefs = peer->lpni_refcount;
+			int nrefs = atomic_read(&peer->lpni_refcount);
 			int nrtrrefs = peer->lpni_rtr_refcount;
 			int alive_cnt = peer->lpni_alive_count;
 			int alive = peer->lpni_alive;
@@ -486,7 +486,7 @@ static int proc_lnet_peers(struct ctl_table *table, int write,
 
 		if (peer) {
 			lnet_nid_t nid = peer->lpni_nid;
-			int nrefs = peer->lpni_refcount;
+			int nrefs = atomic_read(&peer->lpni_refcount);
 			time64_t lastalive = -1;
 			char *aliveness = "NA";
 			int maxcr = peer->lpni_net->net_tunables.lct_peer_tx_credits;