[lustre-devel] [PATCH 22/34] lnet: don't take reference in lnet_XX2ni_locked()
Doug Oucharek
doucharek at cray.com
Tue Sep 11 21:18:21 PDT 2018
Reviewed-by: Doug Oucharek <dougso at me.com>
Doug
On 9/6/18, 5:54 PM, "NeilBrown" <neilb at suse.com> wrote:
lnet_net2ni_locked() and lnet_nid2ni_locked() no longer take
a reference - as the lock is held, a ref isn't always needed.
Instead, introduce lnet_nid2ni_addref() which does take the reference
(but doesn't need the lock).
Various places which called lnet_net2ni_locked() or
lnet_nid2ni_locked() no longer need to drop the ref afterwards.
This is part of
8cbb8cd3e771e7f7e0f99cafc19fad32770dc015
LU-7734 lnet: Multi-Rail local NI split
Signed-off-by: NeilBrown <neilb at suse.com>
---
.../staging/lustre/include/linux/lnet/lib-lnet.h | 1 +
.../staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c | 2 +
drivers/staging/lustre/lnet/lnet/acceptor.c | 2 +
drivers/staging/lustre/lnet/lnet/api-ni.c | 27 +++++++++++++-------
drivers/staging/lustre/lnet/lnet/lib-move.c | 17 +------------
5 files changed, 21 insertions(+), 28 deletions(-)
diff --git a/drivers/staging/lustre/include/linux/lnet/lib-lnet.h b/drivers/staging/lustre/include/linux/lnet/lib-lnet.h
index 54a93235834c..6401d9a37b23 100644
--- a/drivers/staging/lustre/include/linux/lnet/lib-lnet.h
+++ b/drivers/staging/lustre/include/linux/lnet/lib-lnet.h
@@ -398,6 +398,7 @@ extern int avoid_asym_router_failure;
int lnet_cpt_of_nid_locked(lnet_nid_t nid, struct lnet_ni *ni);
int lnet_cpt_of_nid(lnet_nid_t nid, struct lnet_ni *ni);
struct lnet_ni *lnet_nid2ni_locked(lnet_nid_t nid, int cpt);
+struct lnet_ni *lnet_nid2ni_addref(lnet_nid_t nid);
struct lnet_ni *lnet_net2ni_locked(__u32 net, int cpt);
struct lnet_ni *lnet_net2ni(__u32 net);
bool lnet_is_ni_healthy_locked(struct lnet_ni *ni);
diff --git a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c
index e64c14914924..af8f863b6a68 100644
--- a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c
+++ b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c
@@ -2294,7 +2294,7 @@ kiblnd_passive_connect(struct rdma_cm_id *cmid, void *priv, int priv_nob)
}
nid = reqmsg->ibm_srcnid;
- ni = lnet_net2ni(LNET_NIDNET(reqmsg->ibm_dstnid));
+ ni = lnet_nid2ni_addref(reqmsg->ibm_dstnid);
if (ni) {
net = (struct kib_net *)ni->ni_data;
diff --git a/drivers/staging/lustre/lnet/lnet/acceptor.c b/drivers/staging/lustre/lnet/lnet/acceptor.c
index 88b90c1fdbaf..25205f686801 100644
--- a/drivers/staging/lustre/lnet/lnet/acceptor.c
+++ b/drivers/staging/lustre/lnet/lnet/acceptor.c
@@ -296,7 +296,7 @@ lnet_accept(struct socket *sock, __u32 magic)
if (flip)
__swab64s(&cr.acr_nid);
- ni = lnet_net2ni(LNET_NIDNET(cr.acr_nid));
+ ni = lnet_nid2ni_addref(cr.acr_nid);
if (!ni || /* no matching net */
ni->ni_nid != cr.acr_nid) { /* right NET, wrong NID! */
if (ni)
diff --git a/drivers/staging/lustre/lnet/lnet/api-ni.c b/drivers/staging/lustre/lnet/lnet/api-ni.c
index ce3dd0f32e12..42e775e2a669 100644
--- a/drivers/staging/lustre/lnet/lnet/api-ni.c
+++ b/drivers/staging/lustre/lnet/lnet/api-ni.c
@@ -655,7 +655,6 @@ lnet_net2ni_locked(__u32 net_id, int cpt)
if (net->net_id == net_id) {
ni = list_entry(net->net_ni_list.next, struct lnet_ni,
ni_netlist);
- lnet_ni_addref_locked(ni, cpt);
return ni;
}
}
@@ -794,16 +793,29 @@ lnet_nid2ni_locked(lnet_nid_t nid, int cpt)
list_for_each_entry(net, &the_lnet.ln_nets, net_list) {
list_for_each_entry(ni, &net->net_ni_list, ni_netlist) {
- if (ni->ni_nid == nid) {
- lnet_ni_addref_locked(ni, cpt);
+ if (ni->ni_nid == nid)
return ni;
- }
}
}
return NULL;
}
+struct lnet_ni *
+lnet_nid2ni_addref(lnet_nid_t nid)
+{
+ struct lnet_ni *ni;
+
+ lnet_net_lock(0);
+ ni = lnet_nid2ni_locked(nid, 0);
+ if (ni)
+ lnet_ni_addref_locked(ni, 0);
+ lnet_net_unlock(0);
+
+ return ni;
+}
+EXPORT_SYMBOL(lnet_nid2ni_addref);
+
int
lnet_islocalnid(lnet_nid_t nid)
{
@@ -812,8 +824,6 @@ lnet_islocalnid(lnet_nid_t nid)
cpt = lnet_net_lock_current();
ni = lnet_nid2ni_locked(nid, cpt);
- if (ni)
- lnet_ni_decref_locked(ni, cpt);
lnet_net_unlock(cpt);
return !!ni;
@@ -1412,6 +1422,7 @@ lnet_startup_lndnet(struct lnet_net *net, struct lnet_lnd_tunables *tun)
if (rc < 0)
goto failed1;
+ lnet_ni_addref(ni);
list_add_tail(&ni->ni_netlist, &local_ni_list);
ni_count++;
@@ -2032,9 +2043,6 @@ lnet_dyn_del_ni(__u32 net)
goto failed;
}
- /* decrement the reference counter taken by lnet_net2ni() */
- lnet_ni_decref_locked(ni, 0);
-
lnet_shutdown_lndni(ni);
if (!lnet_count_acceptor_nets())
@@ -2264,7 +2272,6 @@ LNetCtl(unsigned int cmd, void *arg)
else
rc = ni->ni_net->net_lnd->lnd_ctl(ni, cmd, arg);
- lnet_ni_decref(ni);
return rc;
}
/* not reached */
diff --git a/drivers/staging/lustre/lnet/lnet/lib-move.c b/drivers/staging/lustre/lnet/lnet/lib-move.c
index 00a89221c9b3..60f34c4b85d3 100644
--- a/drivers/staging/lustre/lnet/lnet/lib-move.c
+++ b/drivers/staging/lustre/lnet/lnet/lib-move.c
@@ -1127,11 +1127,7 @@ lnet_send(lnet_nid_t src_nid, struct lnet_msg *msg, lnet_nid_t rtr_nid)
if (!src_ni) {
src_ni = local_ni;
src_nid = src_ni->ni_nid;
- } else if (src_ni == local_ni) {
- lnet_ni_decref_locked(local_ni, cpt);
- } else {
- lnet_ni_decref_locked(local_ni, cpt);
- lnet_ni_decref_locked(src_ni, cpt);
+ } else if (src_ni != local_ni) {
lnet_net_unlock(cpt);
LCONSOLE_WARN("No route to %s via from %s\n",
libcfs_nid2str(dst_nid),
@@ -1149,16 +1145,10 @@ lnet_send(lnet_nid_t src_nid, struct lnet_msg *msg, lnet_nid_t rtr_nid)
/* No send credit hassles with LOLND */
lnet_net_unlock(cpt);
lnet_ni_send(src_ni, msg);
-
- lnet_net_lock(cpt);
- lnet_ni_decref_locked(src_ni, cpt);
- lnet_net_unlock(cpt);
return 0;
}
rc = lnet_nid2peer_locked(&lp, dst_nid, cpt);
- /* lp has ref on src_ni; lose mine */
- lnet_ni_decref_locked(src_ni, cpt);
if (rc) {
lnet_net_unlock(cpt);
LCONSOLE_WARN("Error %d finding peer %s\n", rc,
@@ -1173,8 +1163,6 @@ lnet_send(lnet_nid_t src_nid, struct lnet_msg *msg, lnet_nid_t rtr_nid)
src_ni->ni_net : NULL,
dst_nid, rtr_nid);
if (!lp) {
- if (src_ni)
- lnet_ni_decref_locked(src_ni, cpt);
lnet_net_unlock(cpt);
LCONSOLE_WARN("No route to %s via %s (all routers down)\n",
@@ -1192,8 +1180,6 @@ lnet_send(lnet_nid_t src_nid, struct lnet_msg *msg, lnet_nid_t rtr_nid)
if (rtr_nid != lp->lp_nid) {
cpt2 = lp->lp_cpt;
if (cpt2 != cpt) {
- if (src_ni)
- lnet_ni_decref_locked(src_ni, cpt);
lnet_net_unlock(cpt);
rtr_nid = lp->lp_nid;
@@ -1212,7 +1198,6 @@ lnet_send(lnet_nid_t src_nid, struct lnet_msg *msg, lnet_nid_t rtr_nid)
src_nid = src_ni->ni_nid;
} else {
LASSERT(src_ni->ni_net == lp->lp_net);
- lnet_ni_decref_locked(src_ni, cpt);
}
lnet_peer_addref_locked(lp);
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