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Diffstat (limited to 'xlators/mgmt/glusterd/src/glusterd-sm.c')
-rw-r--r--xlators/mgmt/glusterd/src/glusterd-sm.c255
1 files changed, 210 insertions, 45 deletions
diff --git a/xlators/mgmt/glusterd/src/glusterd-sm.c b/xlators/mgmt/glusterd/src/glusterd-sm.c
index 9d0c49f04c2..db34ef1ddf8 100644
--- a/xlators/mgmt/glusterd/src/glusterd-sm.c
+++ b/xlators/mgmt/glusterd/src/glusterd-sm.c
@@ -156,14 +156,19 @@ glusterd_broadcast_friend_delete (char *hostname, uuid_t uuid)
if (ret)
goto out;
- cds_list_for_each_entry (peerinfo, &priv->peers, uuid_list) {
+ rcu_read_lock ();
+ cds_list_for_each_entry_rcu (peerinfo, &priv->peers, uuid_list) {
if (!peerinfo->connected || !peerinfo->peer)
continue;
+ /* Setting a direct reference to peerinfo in the dict is okay as
+ * it is only going to be used within this read critical section
+ * (in glusterd_rpc_friend_update)
+ */
ret = dict_set_static_ptr (friends, "peerinfo", peerinfo);
if (ret) {
gf_log ("", GF_LOG_ERROR, "failed to set peerinfo");
- goto out;
+ goto unlock;
}
proc = &peerinfo->peer->proctable[GLUSTERD_FRIEND_UPDATE];
@@ -171,6 +176,8 @@ glusterd_broadcast_friend_delete (char *hostname, uuid_t uuid)
ret = proc->fn (NULL, this, friends);
}
}
+unlock:
+ rcu_read_unlock ();
gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);
@@ -213,7 +220,16 @@ glusterd_ac_reverse_probe_begin (glusterd_friend_sm_event_t *event, void *ctx)
GF_ASSERT (event);
GF_ASSERT (ctx);
- peerinfo = event->peerinfo;
+ rcu_read_lock ();
+
+ peerinfo = glusterd_peerinfo_find (event->peerid, event->peername);
+ if (!peerinfo) {
+ gf_log (THIS->name, GF_LOG_ERROR, "Could not find peer %s(%s)",
+ event->peername, uuid_utoa (event->peerid));
+ ret = -1;
+ goto out;
+ }
+
ret = glusterd_friend_sm_new_event
(GD_FRIEND_EVENT_PROBE, &new_event);
@@ -234,7 +250,8 @@ glusterd_ac_reverse_probe_begin (glusterd_friend_sm_event_t *event, void *ctx)
new_ev_ctx->port = peerinfo->port;
new_ev_ctx->req = NULL;
- new_event->peerinfo = peerinfo;
+ new_event->peername = gf_strdup (peerinfo->hostname);
+ uuid_copy (new_event->peerid, peerinfo->uuid);
new_event->ctx = new_ev_ctx;
ret = glusterd_friend_sm_inject_event (new_event);
@@ -245,7 +262,11 @@ glusterd_ac_reverse_probe_begin (glusterd_friend_sm_event_t *event, void *ctx)
}
out:
+ rcu_read_unlock ();
+
if (ret) {
+ if (new_event)
+ GF_FREE (new_event->peername);
GF_FREE (new_event);
if (new_ev_ctx)
GF_FREE (new_ev_ctx->hostname);
@@ -266,13 +287,21 @@ glusterd_ac_friend_add (glusterd_friend_sm_event_t *event, void *ctx)
xlator_t *this = NULL;
GF_ASSERT (event);
- peerinfo = event->peerinfo;
this = THIS;
conf = this->private;
GF_ASSERT (conf);
+ rcu_read_lock ();
+
+ peerinfo = glusterd_peerinfo_find (event->peerid, event->peername);
+ if (!peerinfo) {
+ gf_log (this->name, GF_LOG_ERROR, "Could not find peer %s(%s)",
+ event->peername, uuid_utoa (event->peerid));
+ goto out;
+ }
+
if (!peerinfo->peer)
goto out;
proc = &peerinfo->peer->proctable[GLUSTERD_FRIEND_ADD];
@@ -286,8 +315,9 @@ glusterd_ac_friend_add (glusterd_friend_sm_event_t *event, void *ctx)
}
out:
- gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);
+ rcu_read_unlock ();
+ gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);
return ret;
}
@@ -315,10 +345,11 @@ glusterd_ac_friend_probe (glusterd_friend_sm_event_t *event, void *ctx)
GF_ASSERT (conf);
+ rcu_read_lock ();
peerinfo = glusterd_peerinfo_find (NULL, probe_ctx->hostname);
if (peerinfo == NULL) {
//We should not reach this state ideally
- GF_ASSERT (0);
+ ret = -1;
goto out;
}
@@ -342,6 +373,10 @@ glusterd_ac_friend_probe (glusterd_friend_sm_event_t *event, void *ctx)
if (ret)
goto out;
+ /* The peerinfo reference being set here is going to be used
+ * only within this critical section, in glusterd_rpc_probe
+ * (ie. proc->fn).
+ */
ret = dict_set_static_ptr (dict, "peerinfo", peerinfo);
if (ret) {
gf_log ("", GF_LOG_ERROR, "failed to set peerinfo");
@@ -354,8 +389,9 @@ glusterd_ac_friend_probe (glusterd_friend_sm_event_t *event, void *ctx)
}
-
out:
+ rcu_read_unlock ();
+
if (dict)
dict_unref (dict);
gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);
@@ -378,13 +414,20 @@ glusterd_ac_send_friend_remove_req (glusterd_friend_sm_event_t *event,
glusterd_friend_sm_event_t *new_event = NULL;
GF_ASSERT (event);
- peerinfo = event->peerinfo;
this = THIS;
conf = this->private;
GF_ASSERT (conf);
+ rcu_read_lock ();
+
+ peerinfo = glusterd_peerinfo_find (event->peerid, event->peername);
+ if (!peerinfo) {
+ gf_log (this->name, GF_LOG_ERROR, "Could not find peer %s(%s)",
+ event->peername, uuid_utoa (event->peerid));
+ goto out;
+ }
ctx = event->ctx;
if (!peerinfo->connected) {
@@ -393,22 +436,19 @@ glusterd_ac_send_friend_remove_req (glusterd_friend_sm_event_t *event,
ret = glusterd_friend_sm_new_event (event_type, &new_event);
if (!ret) {
- new_event->peerinfo = peerinfo;
+ new_event->peername = peerinfo->hostname;
+ uuid_copy (new_event->peerid, peerinfo->uuid);
ret = glusterd_friend_sm_inject_event (new_event);
} else {
gf_log ("glusterd", GF_LOG_ERROR,
"Unable to get event");
}
- if (ctx)
+ if (ctx) {
ret = glusterd_xfer_cli_deprobe_resp (ctx->req, ret, 0,
NULL,
ctx->hostname,
ctx->dict);
- glusterd_friend_sm ();
- glusterd_op_sm ();
-
- if (ctx) {
glusterd_broadcast_friend_delete (ctx->hostname, NULL);
glusterd_destroy_probe_ctx (ctx);
}
@@ -428,6 +468,8 @@ glusterd_ac_send_friend_remove_req (glusterd_friend_sm_event_t *event,
}
out:
+ rcu_read_unlock ();
+
gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);
return ret;
@@ -461,13 +503,22 @@ glusterd_ac_send_friend_update (glusterd_friend_sm_event_t *event, void *ctx)
int32_t count = 0;
GF_ASSERT (event);
- cur_peerinfo = event->peerinfo;
this = THIS;
priv = this->private;
GF_ASSERT (priv);
+ rcu_read_lock ();
+
+ cur_peerinfo = glusterd_peerinfo_find (event->peerid, event->peername);
+ if (!cur_peerinfo) {
+ gf_log (this->name, GF_LOG_ERROR, "Could not find peer %s(%s)",
+ event->peername, uuid_utoa (event->peerid));
+ ret = -1;
+ goto out;
+ }
+
ev_ctx.op = GD_FRIEND_UPDATE_ADD;
friends = dict_new ();
@@ -479,7 +530,7 @@ glusterd_ac_send_friend_update (glusterd_friend_sm_event_t *event, void *ctx)
if (ret)
goto out;
- cds_list_for_each_entry (peerinfo, &priv->peers, uuid_list) {
+ cds_list_for_each_entry_rcu (peerinfo, &priv->peers, uuid_list) {
if (!glusterd_should_update_peer (peerinfo, cur_peerinfo))
continue;
@@ -496,7 +547,7 @@ glusterd_ac_send_friend_update (glusterd_friend_sm_event_t *event, void *ctx)
if (ret)
goto out;
- cds_list_for_each_entry (peerinfo, &priv->peers, uuid_list) {
+ cds_list_for_each_entry_rcu (peerinfo, &priv->peers, uuid_list) {
if (!peerinfo->connected || !peerinfo->peer)
continue;
@@ -518,6 +569,8 @@ glusterd_ac_send_friend_update (glusterd_friend_sm_event_t *event, void *ctx)
gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);
out:
+ rcu_read_unlock ();
+
if (friends)
dict_unref (friends);
@@ -574,8 +627,6 @@ glusterd_ac_handle_friend_remove_req (glusterd_friend_sm_event_t *event,
GF_ASSERT (ctx);
ev_ctx = ctx;
- peerinfo = event->peerinfo;
- GF_ASSERT (peerinfo);
priv = THIS->private;
GF_ASSERT (priv);
@@ -583,19 +634,29 @@ glusterd_ac_handle_friend_remove_req (glusterd_friend_sm_event_t *event,
ret = glusterd_xfer_friend_remove_resp (ev_ctx->req, ev_ctx->hostname,
ev_ctx->port);
- cds_list_for_each_entry (peerinfo, &priv->peers, uuid_list) {
+ rcu_read_lock ();
+ cds_list_for_each_entry_rcu (peerinfo, &priv->peers, uuid_list) {
ret = glusterd_friend_sm_new_event (GD_FRIEND_EVENT_REMOVE_FRIEND,
&new_event);
- if (ret)
+ if (ret) {
+ rcu_read_unlock ();
goto out;
+ }
- new_event->peerinfo = peerinfo;
+ new_event->peername = gf_strdup (peerinfo->hostname);
+ uuid_copy (new_event->peerid, peerinfo->uuid);
ret = glusterd_friend_sm_inject_event (new_event);
- if (ret)
+ if (ret) {
+ rcu_read_unlock ();
goto out;
+ }
+
+ new_event = NULL;
}
+ rcu_read_unlock ();
+
ret = glusterd_peer_detach_cleanup (priv);
if (ret) {
gf_log (THIS->name, GF_LOG_WARNING,
@@ -603,26 +664,46 @@ glusterd_ac_handle_friend_remove_req (glusterd_friend_sm_event_t *event,
ret = 0;
}
out:
- gf_log (THIS->name, GF_LOG_DEBUG, "Returning with %d", ret);
+ if (new_event)
+ GF_FREE (new_event->peername);
+ GF_FREE (new_event);
+ gf_log (THIS->name, GF_LOG_DEBUG, "Returning with %d", ret);
return ret;
}
static int
glusterd_ac_friend_remove (glusterd_friend_sm_event_t *event, void *ctx)
{
- int ret = -1;
+ int ret = -1;
+ glusterd_peerinfo_t *peerinfo = NULL;
+
+ GF_ASSERT (event);
+
+ rcu_read_lock ();
- ret = glusterd_friend_remove_cleanup_vols (event->peerinfo->uuid);
+ peerinfo = glusterd_peerinfo_find (event->peerid, event->peername);
+ if (!peerinfo) {
+ gf_log (THIS->name, GF_LOG_ERROR, "Could not find peer %s(%s)",
+ event->peername, uuid_utoa (event->peerid));
+ rcu_read_unlock ();
+ goto out;
+ }
+ ret = glusterd_friend_remove_cleanup_vols (peerinfo->uuid);
if (ret)
gf_msg (THIS->name, GF_LOG_WARNING, 0, GD_MSG_VOL_CLEANUP_FAIL,
"Volumes cleanup failed");
- ret = glusterd_peerinfo_cleanup (event->peerinfo);
+ rcu_read_unlock ();
+ /* Exiting read critical section as glusterd_peerinfo_cleanup calls
+ * synchronize_rcu before freeing the peerinfo
+ */
+
+ ret = glusterd_peerinfo_cleanup (peerinfo);
if (ret) {
gf_log (THIS->name, GF_LOG_ERROR, "Cleanup returned: %d", ret);
}
-
+out:
return 0;
}
@@ -654,19 +735,41 @@ glusterd_ac_handle_friend_add_req (glusterd_friend_sm_event_t *event, void *ctx)
this = THIS;
GF_ASSERT (this);
+
GF_ASSERT (ctx);
ev_ctx = ctx;
uuid_copy (uuid, ev_ctx->uuid);
- peerinfo = event->peerinfo;
- GF_ASSERT (peerinfo);
+
+ rcu_read_lock ();
+ peerinfo = glusterd_peerinfo_find (event->peerid, event->peername);
+ if (!peerinfo) {
+ gf_log (this->name, GF_LOG_ERROR, "Could not find peer %s(%s)",
+ event->peername, uuid_utoa (event->peerid));
+ ret = -1;
+ rcu_read_unlock ();
+ goto out;
+ }
+
+ /* TODO: How do you do an atomic copy of uuid_t */
+ /* TODO: Updating within a read-critical section is also invalid
+ * Update properly with updater synchronization
+ */
uuid_copy (peerinfo->uuid, ev_ctx->uuid);
+ rcu_read_unlock ();
+
conf = this->private;
GF_ASSERT (conf);
+ /* Passing the peername from the event. glusterd_compare_friend_data
+ * updates volumes and will use synchronize_rcu. If we were to pass
+ * peerinfo->hostname, we would have to do it under a read critical
+ * section which would lead to a deadlock
+ */
+
//Build comparison logic here.
ret = glusterd_compare_friend_data (ev_ctx->vols, &status,
- peerinfo->hostname);
+ event->peername);
if (ret)
goto out;
@@ -693,8 +796,15 @@ glusterd_ac_handle_friend_add_req (glusterd_friend_sm_event_t *event, void *ctx)
op_ret = -1;
}
+ /* glusterd_compare_friend_snapshots and functions only require
+ * a peers hostname and uuid. It also does updates, which
+ * require use of synchronize_rcu. So we pass the hostname and
+ * id from the event instead of the peerinfo object to prevent
+ * deadlocks as above.
+ */
ret = glusterd_compare_friend_snapshots (ev_ctx->vols,
- peerinfo);
+ event->peername,
+ event->peerid);
if (ret) {
gf_log (this->name, GF_LOG_ERROR,
"Conflict in comparing peer's snapshots");
@@ -710,7 +820,8 @@ glusterd_ac_handle_friend_add_req (glusterd_friend_sm_event_t *event, void *ctx)
gf_log ("", GF_LOG_ERROR, "Out of Memory");
}
- new_event->peerinfo = peerinfo;
+ new_event->peername = gf_strdup (event->peername);
+ uuid_copy (new_event->peerid, event->peerid);
new_ev_ctx = GF_CALLOC (1, sizeof (*new_ev_ctx),
gf_gld_mt_friend_update_ctx_t);
@@ -726,33 +837,49 @@ glusterd_ac_handle_friend_add_req (glusterd_friend_sm_event_t *event, void *ctx)
new_event->ctx = new_ev_ctx;
glusterd_friend_sm_inject_event (new_event);
+ new_event = NULL;
ret = glusterd_xfer_friend_add_resp (ev_ctx->req, ev_ctx->hostname,
- peerinfo->hostname, ev_ctx->port,
+ event->peername, ev_ctx->port,
op_ret, op_errno);
out:
- gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);
+ if (new_event)
+ GF_FREE (new_event->peername);
+ GF_FREE (new_event);
+ gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);
return ret;
}
static int
-glusterd_friend_sm_transition_state (glusterd_peerinfo_t *peerinfo,
+glusterd_friend_sm_transition_state (uuid_t peerid, char *peername,
glusterd_sm_t *state,
glusterd_friend_sm_event_type_t event_type)
{
+ int ret = -1;
+ glusterd_peerinfo_t *peerinfo = NULL;
GF_ASSERT (state);
- GF_ASSERT (peerinfo);
+ GF_ASSERT (peername);
+
+ rcu_read_lock ();
+ peerinfo = glusterd_peerinfo_find (peerid, peername);
+ if (!peerinfo) {
+ goto out;
+ }
(void) glusterd_sm_tr_log_transition_add (&peerinfo->sm_log,
peerinfo->state.state,
state[event_type].next_state,
event_type);
- peerinfo->state.state = state[event_type].next_state;
- return 0;
+ uatomic_set (&peerinfo->state.state, state[event_type].next_state);
+
+ ret = 0;
+out:
+ rcu_read_unlock ();
+ return ret;
}
@@ -1049,13 +1176,18 @@ glusterd_friend_sm ()
cds_list_del_init (&event->list);
event_type = event->event;
- peerinfo = event->peerinfo;
+
+ rcu_read_lock ();
+
+ peerinfo = glusterd_peerinfo_find (event->peerid,
+ event->peername);
if (!peerinfo) {
gf_log ("glusterd", GF_LOG_CRITICAL, "Received"
" event %s with empty peer info",
glusterd_friend_sm_event_name_get (event_type));
GF_FREE (event);
+ rcu_read_unlock ();
continue;
}
gf_log ("", GF_LOG_DEBUG, "Dequeued event of type: '%s'",
@@ -1063,7 +1195,17 @@ glusterd_friend_sm ()
old_state = peerinfo->state.state;
- state = glusterd_friend_state_table[peerinfo->state.state];
+
+ rcu_read_unlock ();
+ /* Giving up read-critical section here as we only need
+ * the current state to call the handler.
+ *
+ * We cannot continue into the handler in a read
+ * critical section as there are handlers who do
+ * updates, and could cause deadlocks.
+ */
+
+ state = glusterd_friend_state_table[old_state];
GF_ASSERT (state);
@@ -1091,18 +1233,40 @@ glusterd_friend_sm ()
continue;
}
- ret = glusterd_friend_sm_transition_state (peerinfo,
- state, event_type);
+ ret = glusterd_friend_sm_transition_state
+ (event->peerid, event->peername, state,
+ event_type);
if (ret) {
gf_log ("glusterd", GF_LOG_ERROR, "Unable to transition"
" state from '%s' to '%s' for event '%s'",
- glusterd_friend_sm_state_name_get(peerinfo->state.state),
+ glusterd_friend_sm_state_name_get(old_state),
glusterd_friend_sm_state_name_get(state[event_type].next_state),
glusterd_friend_sm_event_name_get(event_type));
goto out;
}
+ peerinfo = NULL;
+ /* We need to obtain peerinfo reference once again as we
+ * had exited the read critical section above.
+ */
+ rcu_read_lock ();
+ peerinfo = glusterd_peerinfo_find (event->peerid,
+ event->peername);
+ if (!peerinfo) {
+ rcu_read_unlock ();
+ /* A peer can only be deleted as a effect of
+ * this state machine, and two such state
+ * machines can never run at the same time.
+ * So if we cannot find the peerinfo here,
+ * something has gone terribly wrong.
+ */
+ ret = -1;
+ gf_log ("glusterd", GF_LOG_ERROR,
+ "Cannot find peer %s(%s)",
+ event->peername, uuid_utoa (event->peerid));
+ goto out;
+ }
if (gd_does_peer_affect_quorum (old_state, event_type,
peerinfo)) {
peerinfo->quorum_contrib = QUORUM_UP;
@@ -1113,6 +1277,7 @@ glusterd_friend_sm ()
}
ret = glusterd_store_peerinfo (peerinfo);
+ rcu_read_unlock ();
glusterd_destroy_friend_event_context (event);
GF_FREE (event);
generated by cgit (git 2.34.1) at 2024-05-12 19:24:17 +0000