Remove unnecessary RCU read lock

[lttng-tools.git] / src / bin / lttng-sessiond / agent.c

diff --git a/src/bin/lttng-sessiond/agent.c b/src/bin/lttng-sessiond/agent.c
index c321ae41f0987c42a308ba3311b381eb4237ceff..0821630865106182365cd404fecaf0cd9bcb64cc 100644 (file)
--- a/src/bin/lttng-sessiond/agent.c
+++ b/src/bin/lttng-sessiond/agent.c
@@ -28,6 +28,44 @@
 #include "agent.h"
 #include "ust-app.h"
 #include "utils.h"
+#include "error.h"
+
+#define AGENT_RET_CODE_INDEX(code) (code - AGENT_RET_CODE_SUCCESS)
+
+/*
+ * Human readable agent return code.
+ */
+static const char *error_string_array[] = {
+       [ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_SUCCESS) ] = "Success",
+       [ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_INVALID) ] = "Invalid command",
+       [ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_UNKNOWN_NAME) ] = "Unknown logger name",
+
+       /* Last element */
+       [ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_NR) ] = "Unknown code",
+};
+
+static
+void log_reply_code(uint32_t in_reply_ret_code)
+{
+       int level = PRINT_DBG3;
+       /*
+        * reply_ret_code and in_reply_ret_code are kept separate to have a
+        * sanitized value (used to retrieve the human readable string) and the
+        * original value which is logged as-is.
+        */
+       uint32_t reply_ret_code = in_reply_ret_code;
+
+       if (reply_ret_code < AGENT_RET_CODE_SUCCESS ||
+                       reply_ret_code >= AGENT_RET_CODE_NR) {
+               reply_ret_code = AGENT_RET_CODE_NR;
+               level = PRINT_ERR;
+       }
+
+       LOG(level, "Agent replied with retcode: %s (%"PRIu32")",
+                       error_string_array[AGENT_RET_CODE_INDEX(
+                       reply_ret_code)],
+                       in_reply_ret_code);
+}
 
 /*
  * Match function for the events hash table lookup by name.
@@ -235,6 +273,7 @@ static ssize_t list_events(struct agent_app *app, struct lttng_event **events)
        int ret, i, len = 0, offset = 0;
        uint32_t nb_event;
        size_t data_size;
+       uint32_t reply_ret_code;
        struct lttng_event *tmp_events = NULL;
        struct lttcomm_agent_list_reply *reply = NULL;
        struct lttcomm_agent_list_reply_hdr reply_hdr;
@@ -257,14 +296,14 @@ static ssize_t list_events(struct agent_app *app, struct lttng_event **events)
                goto error_io;
        }
 
-       switch (be32toh(reply_hdr.ret_code)) {
+       reply_ret_code = be32toh(reply_hdr.ret_code);
+       log_reply_code(reply_ret_code);
+       switch (reply_ret_code) {
        case AGENT_RET_CODE_SUCCESS:
                data_size = be32toh(reply_hdr.data_size) + sizeof(*reply);
                break;
        default:
-               ERR("Agent returned an unknown code: %" PRIu32,
-                               be32toh(reply_hdr.ret_code));
-               ret = LTTNG_ERR_FATAL;
+               ret = LTTNG_ERR_UNK;
                goto error;
        }
 
@@ -320,6 +359,7 @@ static int enable_event(struct agent_app *app, struct agent_event *event)
 {
        int ret;
        uint64_t data_size;
+       uint32_t reply_ret_code;
        struct lttcomm_agent_enable msg;
        struct lttcomm_agent_generic_reply reply;
 
@@ -351,16 +391,16 @@ static int enable_event(struct agent_app *app, struct agent_event *event)
                goto error_io;
        }
 
-       switch (be32toh(reply.ret_code)) {
+       reply_ret_code = be32toh(reply.ret_code);
+       log_reply_code(reply_ret_code);
+       switch (reply_ret_code) {
        case AGENT_RET_CODE_SUCCESS:
                break;
        case AGENT_RET_CODE_UNKNOWN_NAME:
                ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
                goto error;
        default:
-               ERR("Agent returned an unknown code: %" PRIu32,
-                               be32toh(reply.ret_code));
-               ret = LTTNG_ERR_FATAL;
+               ret = LTTNG_ERR_UNK;
                goto error;
        }
 
@@ -382,6 +422,7 @@ static int disable_event(struct agent_app *app, struct agent_event *event)
 {
        int ret;
        uint64_t data_size;
+       uint32_t reply_ret_code;
        struct lttcomm_agent_disable msg;
        struct lttcomm_agent_generic_reply reply;
 
@@ -411,16 +452,16 @@ static int disable_event(struct agent_app *app, struct agent_event *event)
                goto error_io;
        }
 
-       switch (be32toh(reply.ret_code)) {
+       reply_ret_code = be32toh(reply.ret_code);
+       log_reply_code(reply_ret_code);
+       switch (reply_ret_code) {
        case AGENT_RET_CODE_SUCCESS:
                break;
        case AGENT_RET_CODE_UNKNOWN_NAME:
                ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
                goto error;
        default:
-               ERR("Agent returned an unknown code: %" PRIu32,
-                               be32toh(reply.ret_code));
-               ret = LTTNG_ERR_FATAL;
+               ret = LTTNG_ERR_UNK;
                goto error;
        }
 
@@ -675,10 +716,7 @@ void agent_add_app(struct agent_app *app)
        assert(app);
 
        DBG3("Agent adding app sock: %d and pid: %d to ht", app->sock->fd, app->pid);
-
-       rcu_read_lock();
        lttng_ht_add_unique_ulong(agent_apps_ht_by_sock, &app->node);
-       rcu_read_unlock();
 }
 
 /*
@@ -751,9 +789,7 @@ void agent_add(struct agent *agt, struct lttng_ht *ht)
 
        DBG3("Agent adding from domain %d", agt->domain);
 
-       rcu_read_lock();
        lttng_ht_add_unique_u64(ht, &agt->node);
-       rcu_read_unlock();
 }
 
 /*
@@ -766,7 +802,7 @@ struct agent *agent_create(enum lttng_domain_type domain)
        int ret;
        struct agent *agt;
 
-       agt = zmalloc(sizeof(*agt));
+       agt = zmalloc(sizeof(struct agent));
        if (!agt) {
                goto error;
        }
@@ -825,10 +861,7 @@ void agent_add_event(struct agent_event *event, struct agent *agt)
        assert(agt->events);
 
        DBG3("Agent adding event %s", event->name);
-
-       rcu_read_lock();
        add_unique_agent_event(agt->events, event);
-       rcu_read_unlock();
        agt->being_used = 1;
 }
 
@@ -917,6 +950,7 @@ void agent_destroy_event(struct agent_event *event)
        assert(event);
 
        free(event->filter);
+       free(event->filter_expression);
        free(event);
 }