Keep track of FD used for UST applications (v2)

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

diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c
index 79526fceb61f5d712174baaad97562d6cdae889e..7dbea5c182ca4c6e1a54a89c74a3f0f2c737fe23 100644 (file)
--- a/src/bin/lttng-sessiond/ust-app.c
+++ b/src/bin/lttng-sessiond/ust-app.c
@@ -31,6 +31,7 @@
 #include "ust-app.h"
 #include "ust-consumer.h"
 #include "ust-ctl.h"
+#include "fd-limit.h"
 
 /*
  * Delete ust context safely. RCU read lock must be held before calling
@@ -82,6 +83,7 @@ void delete_ust_app_stream(int sock, struct ltt_ust_stream *stream)
 {
        if (stream->obj) {
                ustctl_release_object(sock, stream->obj);
+               lttng_fd_put(LTTNG_FD_APPS, 2);
                free(stream->obj);
        }
        free(stream);
@@ -125,6 +127,7 @@ void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan)
 
        if (ua_chan->obj != NULL) {
                ustctl_release_object(sock, ua_chan->obj);
+               lttng_fd_put(LTTNG_FD_APPS, 2);
                free(ua_chan->obj);
        }
        free(ua_chan);
@@ -144,10 +147,12 @@ void delete_ust_app_session(int sock, struct ust_app_session *ua_sess)
        if (ua_sess->metadata) {
                if (ua_sess->metadata->stream_obj) {
                        ustctl_release_object(sock, ua_sess->metadata->stream_obj);
+                       lttng_fd_put(LTTNG_FD_APPS, 2);
                        free(ua_sess->metadata->stream_obj);
                }
                if (ua_sess->metadata->obj) {
                        ustctl_release_object(sock, ua_sess->metadata->obj);
+                       lttng_fd_put(LTTNG_FD_APPS, 2);
                        free(ua_sess->metadata->obj);
                }
                trace_ust_destroy_metadata(ua_sess->metadata);
@@ -210,6 +215,7 @@ void delete_ust_app(struct ust_app *app)
        if (ret) {
                PERROR("close");
        }
+       lttng_fd_put(LTTNG_FD_APPS, 1);
 
        DBG2("UST app pid %d deleted", app->pid);
        free(app);
@@ -536,6 +542,12 @@ static int open_ust_metadata(struct ust_app *app,
                ua_sess->metadata->attr.read_timer_interval;
        uattr.output = ua_sess->metadata->attr.output;
 
+       /* We are going to receive 2 fds, we need to reserve them. */
+       ret = lttng_fd_get(LTTNG_FD_APPS, 2);
+       if (ret < 0) {
+               ERR("Exhausted number of available FD upon metadata open");
+               goto error;
+       }
        /* UST tracer metadata creation */
        ret = ustctl_open_metadata(app->sock, ua_sess->handle, &uattr,
                        &ua_sess->metadata->obj);
@@ -559,6 +571,12 @@ static int create_ust_stream(struct ust_app *app,
 {
        int ret;
 
+       /* We are going to receive 2 fds, we need to reserve them. */
+       ret = lttng_fd_get(LTTNG_FD_APPS, 2);
+       if (ret < 0) {
+               ERR("Exhausted number of available FD upon metadata stream create");
+               goto error;
+       }
        ret = ustctl_create_stream(app->sock, ua_sess->metadata->obj,
                        &ua_sess->metadata->stream_obj);
        if (ret < 0) {
@@ -579,6 +597,13 @@ static int create_ust_channel(struct ust_app *app,
        int ret;
 
        /* TODO: remove cast and use lttng-ust-abi.h */
+
+       /* We are going to receive 2 fds, we need to reserve them. */
+       ret = lttng_fd_get(LTTNG_FD_APPS, 2);
+       if (ret < 0) {
+               ERR("Exhausted number of available FD upon create channel");
+               goto error;
+       }
        ret = ustctl_create_channel(app->sock, ua_sess->handle,
                        (struct lttng_ust_channel_attr *)&ua_chan->attr, &ua_chan->obj);
        if (ret < 0) {
@@ -586,6 +611,7 @@ static int create_ust_channel(struct ust_app *app,
                                "and session handle %d with ret %d",
                                ua_chan->name, app->pid, app->sock,
                                ua_sess->handle, ret);
+               lttng_fd_put(LTTNG_FD_APPS, 2);
                goto error;
        }
 
@@ -1281,6 +1307,7 @@ int ust_app_register(struct ust_register_msg *msg, int sock)
                if (ret) {
                        PERROR("close");
                }
+               lttng_fd_put(LTTNG_FD_APPS, 1);
                return -EINVAL;
        }
        if (msg->major != LTTNG_UST_COMM_MAJOR) {
@@ -1291,6 +1318,7 @@ int ust_app_register(struct ust_register_msg *msg, int sock)
                if (ret) {
                        PERROR("close");
                }
+               lttng_fd_put(LTTNG_FD_APPS, 1);
                return -EINVAL;
        }
        lta = zmalloc(sizeof(struct ust_app));
@@ -1977,10 +2005,18 @@ int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
                                goto error_rcu_unlock;
                        }
 
+                       /* We are going to receive 2 fds, we need to reserve them. */
+                       ret = lttng_fd_get(LTTNG_FD_APPS, 2);
+                       if (ret < 0) {
+                               ERR("Exhausted number of available FD upon stream create");
+                               free(ustream);
+                               goto error_rcu_unlock;
+                       }
                        ret = ustctl_create_stream(app->sock, ua_chan->obj,
                                        &ustream->obj);
                        if (ret < 0) {
                                /* Got all streams */
+                               lttng_fd_put(LTTNG_FD_APPS, 2);
                                free(ustream);
                                break;
                        }