Backport: Fix: tracker: ensure consistency of tracker states

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

diff --git a/src/bin/lttng-sessiond/trace-ust.c b/src/bin/lttng-sessiond/trace-ust.c
index 10af67e371406feda5ed6e14e0dc15af286b3b57..29263e7c8a3195e539b04e21d95bf1fa99a35671 100644 (file)
--- a/src/bin/lttng-sessiond/trace-ust.c
+++ b/src/bin/lttng-sessiond/trace-ust.c
@@ -874,6 +874,8 @@ int trace_ust_track_id(enum lttng_tracker_type tracker_type,
        struct ust_id_tracker *id_tracker;
        struct lttng_tracker_list *tracker_list;
        int value;
+       struct lttng_tracker_id *saved_ids;
+       ssize_t saved_ids_count, i;
 
        if (tracker_type == LTTNG_TRACKER_PID) {
                DBG("Backward compatible behavior: translate PID tracker to VPID tracker for UST domain.");
@@ -885,15 +887,19 @@ int trace_ust_track_id(enum lttng_tracker_type tracker_type,
        if (retval != LTTNG_OK) {
                return retval;
        }
-
-       /* Add to list. */
        tracker_list = get_id_tracker_list(session, tracker_type);
        if (!tracker_list) {
                return LTTNG_ERR_INVALID;
        }
+       /* Save list for restore on error. */
+       saved_ids_count = lttng_tracker_id_get_list(tracker_list, &saved_ids);
+       if (saved_ids_count < 0) {
+               return LTTNG_ERR_INVALID;
+       }
+       /* Add to list. */
        retval = lttng_tracker_list_add(tracker_list, id);
        if (retval != LTTNG_OK) {
-               return retval;
+               goto end;
        }
 
        id_tracker = get_id_tracker(session, tracker_type);
@@ -913,12 +919,12 @@ int trace_ust_track_id(enum lttng_tracker_type tracker_type,
                        retval = init_id_tracker(id_tracker);
                        if (retval != LTTNG_OK) {
                                ERR("Error initializing ID tracker");
-                               goto end;
+                               goto end_restore;
                        }
                        retval = id_tracker_add_id(id_tracker, value);
                        if (retval != LTTNG_OK) {
                                fini_id_tracker(id_tracker);
-                               goto end;
+                               goto end_restore;
                        }
                        /* Keep only apps matching ID. */
                        ust_app_global_update_all(session);
@@ -927,7 +933,7 @@ int trace_ust_track_id(enum lttng_tracker_type tracker_type,
 
                        retval = id_tracker_add_id(id_tracker, value);
                        if (retval != LTTNG_OK) {
-                               goto end;
+                               goto end_restore;
                        }
                        /* Add session to application */
                        switch (tracker_type) {
@@ -943,7 +949,17 @@ int trace_ust_track_id(enum lttng_tracker_type tracker_type,
                        }
                }
        }
+       goto end;
+
+end_restore:
+       if (lttng_tracker_id_set_list(tracker_list, saved_ids, saved_ids_count) != LTTNG_OK) {
+               ERR("Error on tracker add error handling.\n");
+       }
 end:
+       for (i = 0; i < saved_ids_count; i++) {
+               free(saved_ids[i].string);
+       }
+       free(saved_ids);
        return retval;
 }
 
@@ -957,6 +973,8 @@ int trace_ust_untrack_id(enum lttng_tracker_type tracker_type,
        struct ust_id_tracker *id_tracker;
        struct lttng_tracker_list *tracker_list;
        int value;
+       struct lttng_tracker_id *saved_ids;
+       ssize_t saved_ids_count, i;
 
        if (tracker_type == LTTNG_TRACKER_PID) {
                DBG("Backward compatible behavior: translate PID tracker to VPID tracker for UST domain.");
@@ -969,14 +987,19 @@ int trace_ust_untrack_id(enum lttng_tracker_type tracker_type,
                return retval;
        }
 
-       /* Remove from list. */
        tracker_list = get_id_tracker_list(session, tracker_type);
        if (!tracker_list) {
                return LTTNG_ERR_INVALID;
        }
+       /* Save list for restore on error. */
+       saved_ids_count = lttng_tracker_id_get_list(tracker_list, &saved_ids);
+       if (saved_ids_count < 0) {
+               return LTTNG_ERR_INVALID;
+       }
+       /* Remove from list. */
        retval = lttng_tracker_list_remove(tracker_list, id);
        if (retval != LTTNG_OK) {
-               return retval;
+               goto end;
        }
 
        id_tracker = get_id_tracker(session, tracker_type);
@@ -994,7 +1017,7 @@ int trace_ust_untrack_id(enum lttng_tracker_type tracker_type,
                        ERR("Error initializing ID tracker");
                        /* Rollback operation. */
                        *id_tracker = tmp_tracker;
-                       goto end;
+                       goto end_restore;
                }
                fini_id_tracker(&tmp_tracker);
 
@@ -1006,12 +1029,12 @@ int trace_ust_untrack_id(enum lttng_tracker_type tracker_type,
                if (!id_tracker->ht) {
                        /* No ID being tracked. */
                        retval = LTTNG_ERR_ID_NOT_TRACKED;
-                       goto end;
+                       goto end_restore;
                }
                /* Remove ID from tracker */
                retval = id_tracker_del_id(id_tracker, value);
                if (retval != LTTNG_OK) {
-                       goto end;
+                       goto end_restore;
                }
                switch (tracker_type) {
                case LTTNG_TRACKER_VPID:
@@ -1026,7 +1049,17 @@ int trace_ust_untrack_id(enum lttng_tracker_type tracker_type,
                        ust_app_global_update_all(session);
                }
        }
+       goto end;
+
+end_restore:
+       if (lttng_tracker_id_set_list(tracker_list, saved_ids, saved_ids_count) != LTTNG_OK) {
+               ERR("Error on tracker remove error handling.\n");
+       }
 end:
+       for (i = 0; i < saved_ids_count; i++) {
+               free(saved_ids[i].string);
+       }
+       free(saved_ids);
        return retval;
 }