From 0ce9aa936d77e7783fd3922bd9aa2ee34bd42422 Mon Sep 17 00:00:00 2001 From: =?utf8?q?J=C3=A9r=C3=A9mie=20Galarneau?= Date: Thu, 10 Jan 2019 13:48:28 -0500 Subject: [PATCH] Fix: only synchronize application configuration on tracing start MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The UST configuration of applications is currently replicated as it is changed from the ltt_ust_{session, channel, event} data structures to their ust_app_* equivalent as they are modified. While this worked correctly for the most part, it caused a problem in per-PID mode since the buffers would get allocated (and files created, in applicable tracing modes) even though tracing was never started during some applications' lifetime. A previous fix attempt, 0498a00cb, adressed this problem but introduced a regression that caused configurations to become mismatched between the sessiond and applications in cases where a tracing session was started, stopped, modified, and started again within the lifetime of a given application. This change introduces an explicit "synchronize" set of operations that ensures that a session's channels and events configurations, as known by the application(s), match those of the session daemon whenever a session is started. Signed-off-by: Jérémie Galarneau --- src/bin/lttng-sessiond/channel.c | 29 +- src/bin/lttng-sessiond/context.c | 17 +- src/bin/lttng-sessiond/dispatch.c | 2 +- src/bin/lttng-sessiond/event.c | 47 ++- src/bin/lttng-sessiond/trace-ust.c | 10 +- src/bin/lttng-sessiond/ust-app.c | 564 ++++++++++++----------------- src/bin/lttng-sessiond/ust-app.h | 11 - 7 files changed, 288 insertions(+), 392 deletions(-) diff --git a/src/bin/lttng-sessiond/channel.c b/src/bin/lttng-sessiond/channel.c index f19dbec37..dc2c91ddc 100644 --- a/src/bin/lttng-sessiond/channel.c +++ b/src/bin/lttng-sessiond/channel.c @@ -311,6 +311,18 @@ int channel_ust_enable(struct ltt_ust_session *usess, DBG3("Channel %s already enabled. Skipping", uchan->name); ret = LTTNG_ERR_UST_CHAN_EXIST; goto end; + } else { + uchan->enabled = 1; + DBG2("Channel %s enabled successfully", uchan->name); + } + + if (!usess->active) { + /* + * The channel will be activated against the apps + * when the session is started as part of the + * application channel "synchronize" operation. + */ + goto end; } DBG2("Channel %s being enabled in UST domain", uchan->name); @@ -325,8 +337,6 @@ int channel_ust_enable(struct ltt_ust_session *usess, */ (void) ust_app_enable_channel_glb(usess, uchan); - uchan->enabled = 1; - DBG2("Channel %s enabled successfully", uchan->name); end: return ret; @@ -465,11 +475,13 @@ int channel_ust_create(struct ltt_ust_session *usess, goto error_free_chan; } - /* Enable channel for global domain */ - ret = ust_app_create_channel_glb(usess, uchan); - if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) { - ret = LTTNG_ERR_UST_CHAN_FAIL; - goto error_free_chan; + if (usess->active) { + /* Enable channel for global domain */ + ret = ust_app_create_channel_glb(usess, uchan); + if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) { + ret = LTTNG_ERR_UST_CHAN_FAIL; + goto error_free_chan; + } } /* Adding the channel to the channel hash table. */ @@ -533,6 +545,9 @@ int channel_ust_disable(struct ltt_ust_session *usess, DBG2("Channel UST %s already disabled", uchan->name); goto end; } + if (!usess->active) { + goto end; + } DBG2("Channel %s being disabled in UST global domain", uchan->name); /* Disable channel for global domain */ diff --git a/src/bin/lttng-sessiond/context.c b/src/bin/lttng-sessiond/context.c index 6cf301dcd..3861d22c1 100644 --- a/src/bin/lttng-sessiond/context.c +++ b/src/bin/lttng-sessiond/context.c @@ -169,18 +169,19 @@ static int add_uctx_to_channel(struct ltt_ust_session *usess, goto error; } - ret = ust_app_add_ctx_channel_glb(usess, uchan, uctx); - if (ret < 0) { - goto error; - } - - rcu_read_lock(); - /* Add ltt UST context node to ltt UST channel */ lttng_ht_add_ulong(uchan->ctx, &uctx->node); - rcu_read_unlock(); cds_list_add_tail(&uctx->list, &uchan->ctx_list); + if (!usess->active) { + goto end; + } + + ret = ust_app_add_ctx_channel_glb(usess, uchan, uctx); + if (ret < 0) { + goto error; + } +end: DBG("Context UST %d added to channel %s", uctx->ctx.ctx, uchan->name); return 0; diff --git a/src/bin/lttng-sessiond/dispatch.c b/src/bin/lttng-sessiond/dispatch.c index 8ef3c38cf..04b3954c0 100644 --- a/src/bin/lttng-sessiond/dispatch.c +++ b/src/bin/lttng-sessiond/dispatch.c @@ -61,7 +61,7 @@ static void update_ust_app(int app_sock) continue; } session_lock(sess); - if (!sess->ust_session) { + if (!sess->active || !sess->ust_session) { goto unlock_session; } diff --git a/src/bin/lttng-sessiond/event.c b/src/bin/lttng-sessiond/event.c index 0a46ffb4b..f97148db1 100644 --- a/src/bin/lttng-sessiond/event.c +++ b/src/bin/lttng-sessiond/event.c @@ -162,7 +162,7 @@ int event_ust_enable_tracepoint(struct ltt_ust_session *usess, struct lttng_event_exclusion *exclusion, bool internal_event) { - int ret, to_create = 0; + int ret = LTTNG_OK, to_create = 0; struct ltt_ust_event *uevent; assert(usess); @@ -195,6 +195,14 @@ int event_ust_enable_tracepoint(struct ltt_ust_session *usess, } uevent->enabled = 1; + if (to_create) { + /* Add ltt ust event to channel */ + add_unique_ust_event(uchan->events, uevent); + } + + if (!usess->active) { + goto end; + } if (to_create) { /* Create event on all UST registered apps for session */ @@ -214,11 +222,6 @@ int event_ust_enable_tracepoint(struct ltt_ust_session *usess, } } - if (to_create) { - /* Add ltt ust event to channel */ - add_unique_ust_event(uchan->events, uevent); - } - DBG("Event UST %s %s in channel %s", uevent->attr.name, to_create ? "created" : "enabled", uchan->name); @@ -291,17 +294,18 @@ int event_ust_disable_tracepoint(struct ltt_ust_session *usess, /* It's already disabled so everything is OK */ goto next; } + uevent->enabled = 0; + DBG2("Event UST %s disabled in channel %s", uevent->attr.name, + uchan->name); + if (!usess->active) { + goto next; + } ret = ust_app_disable_event_glb(usess, uchan, uevent); if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) { ret = LTTNG_ERR_UST_DISABLE_FAIL; goto error; } - uevent->enabled = 0; - - DBG2("Event UST %s disabled in channel %s", uevent->attr.name, - uchan->name); - next: /* Get next duplicate event by name. */ cds_lfht_next_duplicate(ht->ht, trace_ust_ht_match_event_by_name, @@ -506,11 +510,6 @@ int event_agent_enable(struct ltt_ust_session *usess, created = 1; } - /* Already enabled? */ - if (aevent->enabled) { - goto end; - } - if (created && filter) { ret = add_filter_app_ctx(filter, filter_expression, agt); if (ret != LTTNG_OK) { @@ -518,6 +517,12 @@ int event_agent_enable(struct ltt_ust_session *usess, } } + /* Already enabled? */ + if (aevent->enabled) { + ret = LTTNG_OK; + goto end; + } + ret = agent_enable_event(aevent, agt->domain); if (ret != LTTNG_OK) { goto error; @@ -629,10 +634,12 @@ static int event_agent_disable_one(struct ltt_ust_session *usess, /* If the agent event exists, it must be available on the UST side. */ assert(uevent); - ret = ust_app_disable_event_glb(usess, uchan, uevent); - if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) { - ret = LTTNG_ERR_UST_DISABLE_FAIL; - goto error; + if (usess->active) { + ret = ust_app_disable_event_glb(usess, uchan, uevent); + if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) { + ret = LTTNG_ERR_UST_DISABLE_FAIL; + goto error; + } } /* diff --git a/src/bin/lttng-sessiond/trace-ust.c b/src/bin/lttng-sessiond/trace-ust.c index 45dbec74e..8d63e2525 100644 --- a/src/bin/lttng-sessiond/trace-ust.c +++ b/src/bin/lttng-sessiond/trace-ust.c @@ -827,13 +827,14 @@ int trace_ust_pid_tracker_lookup(struct ltt_ust_session *session, int pid) int trace_ust_track_pid(struct ltt_ust_session *session, int pid) { int retval = LTTNG_OK; + bool should_update_apps = false; if (pid == -1) { /* Track all pids: destroy tracker if exists. */ if (session->pid_tracker.ht) { fini_pid_tracker(&session->pid_tracker); /* Ensure all apps have session. */ - ust_app_global_update_all(session); + should_update_apps = true; } } else { int ret; @@ -852,7 +853,7 @@ int trace_ust_track_pid(struct ltt_ust_session *session, int pid) goto end; } /* Remove all apps from session except pid. */ - ust_app_global_update_all(session); + should_update_apps = true; } else { struct ust_app *app; @@ -864,10 +865,13 @@ int trace_ust_track_pid(struct ltt_ust_session *session, int pid) /* Add session to application */ app = ust_app_find_by_pid(pid); if (app) { - ust_app_global_update(session, app); + should_update_apps = true; } } } + if (should_update_apps && session->active) { + ust_app_global_update_all(session); + } end: return retval; } diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c index 0b0a62532..59d8a8fc4 100644 --- a/src/bin/lttng-sessiond/ust-app.c +++ b/src/bin/lttng-sessiond/ust-app.c @@ -1260,7 +1260,7 @@ error: * Return an ust_app_event object or NULL on error. */ static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht, - char *name, struct lttng_filter_bytecode *filter, + const char *name, const struct lttng_filter_bytecode *filter, int loglevel_value, const struct lttng_event_exclusion *exclusion) { @@ -1321,7 +1321,7 @@ int create_ust_channel_context(struct ust_app_channel *ua_chan, * continue normally. */ ret = 0; - DBG3("UST app disable event failed. Application is dead."); + DBG3("UST app add context failed. Application is dead."); } goto error; } @@ -1683,6 +1683,7 @@ int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess, pthread_mutex_unlock(&app->sock_lock); if (ret < 0) { if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { + abort(); ERR("Error ustctl create event %s for app pid: %d with ret %d", ua_event->attr.name, app->pid, ret); } else { @@ -1795,11 +1796,6 @@ static void shadow_copy_event(struct ust_app_event *ua_event, static void shadow_copy_channel(struct ust_app_channel *ua_chan, struct ltt_ust_channel *uchan) { - struct lttng_ht_iter iter; - struct ltt_ust_event *uevent; - struct ltt_ust_context *uctx; - struct ust_app_event *ua_event; - DBG2("UST app shadow copy of channel %s started", ua_chan->name); strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name)); @@ -1826,34 +1822,6 @@ static void shadow_copy_channel(struct ust_app_channel *ua_chan, ua_chan->enabled = uchan->enabled; ua_chan->tracing_channel_id = uchan->id; - cds_list_for_each_entry(uctx, &uchan->ctx_list, list) { - struct ust_app_ctx *ua_ctx = alloc_ust_app_ctx(&uctx->ctx); - - if (ua_ctx == NULL) { - continue; - } - lttng_ht_node_init_ulong(&ua_ctx->node, - (unsigned long) ua_ctx->ctx.ctx); - lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node); - cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list); - } - - /* Copy all events from ltt ust channel to ust app channel */ - cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) { - ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name, - uevent->filter, uevent->attr.loglevel, uevent->exclusion); - if (ua_event == NULL) { - DBG2("UST event %s not found on shadow copy channel", - uevent->attr.name); - ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr); - if (ua_event == NULL) { - continue; - } - shadow_copy_event(ua_event, uevent); - add_unique_ust_app_event(ua_chan, ua_event); - } - } - DBG3("UST app shadow copy of channel %s done", ua_chan->name); } @@ -1863,10 +1831,6 @@ static void shadow_copy_channel(struct ust_app_channel *ua_chan, static void shadow_copy_session(struct ust_app_session *ua_sess, struct ltt_ust_session *usess, struct ust_app *app) { - struct lttng_ht_node_str *ua_chan_node; - struct lttng_ht_iter iter; - struct ltt_ust_channel *uchan; - struct ust_app_channel *ua_chan; time_t rawtime; struct tm *timeinfo; char datetime[16]; @@ -1949,37 +1913,6 @@ static void shadow_copy_session(struct ust_app_session *ua_sess, sizeof(ua_sess->shm_path) - strlen(ua_sess->shm_path) - 1); ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0'; } - - /* Iterate over all channels in global domain. */ - cds_lfht_for_each_entry(usess->domain_global.channels->ht, &iter.iter, - uchan, node.node) { - struct lttng_ht_iter uiter; - - lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter); - ua_chan_node = lttng_ht_iter_get_node_str(&uiter); - if (ua_chan_node != NULL) { - /* Session exist. Contiuing. */ - continue; - } - - DBG2("Channel %s not found on shadow session copy, creating it", - uchan->name); - ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, - &uchan->attr); - if (ua_chan == NULL) { - /* malloc failed FIXME: Might want to do handle ENOMEM .. */ - continue; - } - shadow_copy_channel(ua_chan, uchan); - /* - * The concept of metadata channel does not exist on the tracing - * registry side of the session daemon so this can only be a per CPU - * channel and not metadata. - */ - ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU; - - lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node); - } return; error: @@ -3075,7 +3008,7 @@ error: /* * From an already allocated ust app channel, create the channel buffers if - * need and send it to the application. This MUST be called with a RCU read + * needed and send them to the application. This MUST be called with a RCU read * side lock acquired. * * Called with UST app session lock held. @@ -3083,7 +3016,7 @@ error: * Return 0 on success or else a negative value. Returns -ENOTCONN if * the application exited concurrently. */ -static int do_create_channel(struct ust_app *app, +static int ust_app_channel_send(struct ust_app *app, struct ltt_ust_session *usess, struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan) { @@ -3091,6 +3024,7 @@ static int do_create_channel(struct ust_app *app, assert(app); assert(usess); + assert(usess->active); assert(ua_sess); assert(ua_chan); @@ -3135,16 +3069,14 @@ error: } /* - * Create UST app channel and create it on the tracer. Set ua_chanp of the - * newly created channel if not NULL. + * Create UST app channel and return it through ua_chanp if not NULL. * * Called with UST app session lock and RCU read-side lock held. * - * Return 0 on success or else a negative value. Returns -ENOTCONN if - * the application exited concurrently. + * Return 0 on success or else a negative value. */ -static int create_ust_app_channel(struct ust_app_session *ua_sess, - struct ltt_ust_channel *uchan, struct ust_app *app, +static int ust_app_channel_allocate(struct ust_app_session *ua_sess, + struct ltt_ust_channel *uchan, enum lttng_ust_chan_type type, struct ltt_ust_session *usess, struct ust_app_channel **ua_chanp) { @@ -3165,21 +3097,13 @@ static int create_ust_app_channel(struct ust_app_session *ua_sess, if (ua_chan == NULL) { /* Only malloc can fail here */ ret = -ENOMEM; - goto error_alloc; + goto error; } shadow_copy_channel(ua_chan, uchan); /* Set channel type. */ ua_chan->attr.type = type; - ret = do_create_channel(app, usess, ua_sess, ua_chan); - if (ret < 0) { - goto error; - } - - DBG2("UST app create channel %s for PID %d completed", ua_chan->name, - app->pid); - /* Only add the channel if successful on the tracer side. */ lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node); end: @@ -3191,8 +3115,6 @@ end: return 0; error: - delete_ust_app_channel(ua_chan->is_sent ? app->sock : -1, ua_chan, app); -error_alloc: return ret; } @@ -3209,15 +3131,6 @@ int create_ust_app_event(struct ust_app_session *ua_sess, int ret = 0; struct ust_app_event *ua_event; - /* Get event node */ - ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name, - uevent->filter, uevent->attr.loglevel, uevent->exclusion); - if (ua_event != NULL) { - ret = -EEXIST; - goto end; - } - - /* Does not exist so create one */ ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr); if (ua_event == NULL) { /* Only malloc can failed so something is really wrong */ @@ -4003,19 +3916,10 @@ int ust_app_disable_channel_glb(struct ltt_ust_session *usess, struct ust_app_session *ua_sess; struct ust_app_channel *ua_chan; - if (usess == NULL || uchan == NULL) { - ERR("Disabling UST global channel with NULL values"); - ret = -1; - goto error; - } - + assert(usess->active); DBG2("UST app disabling channel %s from global domain for session id %" PRIu64, uchan->name, usess->id); - if (!usess->active) { - goto end; - } - rcu_read_lock(); /* For every registered applications */ @@ -4052,9 +3956,6 @@ int ust_app_disable_channel_glb(struct ltt_ust_session *usess, } rcu_read_unlock(); - -error: -end: return ret; } @@ -4069,19 +3970,10 @@ int ust_app_enable_channel_glb(struct ltt_ust_session *usess, struct ust_app *app; struct ust_app_session *ua_sess; - if (usess == NULL || uchan == NULL) { - ERR("Adding UST global channel to NULL values"); - ret = -1; - goto error; - } - + assert(usess->active); DBG2("UST app enabling channel %s to global domain for session id %" PRIu64, uchan->name, usess->id); - if (!usess->active) { - goto end; - } - rcu_read_lock(); /* For every registered applications */ @@ -4107,9 +3999,6 @@ int ust_app_enable_channel_glb(struct ltt_ust_session *usess, } rcu_read_unlock(); - -error: -end: return ret; } @@ -4127,14 +4016,11 @@ int ust_app_disable_event_glb(struct ltt_ust_session *usess, struct ust_app_channel *ua_chan; struct ust_app_event *ua_event; + assert(usess->active); DBG("UST app disabling event %s for all apps in channel " "%s for session id %" PRIu64, uevent->attr.name, uchan->name, usess->id); - if (!usess->active) { - goto end; - } - rcu_read_lock(); /* For all registered applications */ @@ -4179,7 +4065,77 @@ int ust_app_disable_event_glb(struct ltt_ust_session *usess, } rcu_read_unlock(); + return ret; +} + +/* The ua_sess lock must be held by the caller. */ +static +int ust_app_channel_create(struct ltt_ust_session *usess, + struct ust_app_session *ua_sess, + struct ltt_ust_channel *uchan, struct ust_app *app, + struct ust_app_channel **_ua_chan) +{ + int ret = 0; + struct ust_app_channel *ua_chan = NULL; + + assert(ua_sess); + ASSERT_LOCKED(ua_sess->lock); + + if (!strncmp(uchan->name, DEFAULT_METADATA_NAME, + sizeof(uchan->name))) { + copy_channel_attr_to_ustctl(&ua_sess->metadata_attr, + &uchan->attr); + ret = 0; + } else { + struct ltt_ust_context *uctx = NULL; + + /* + * Create channel onto application and synchronize its + * configuration. + */ + ret = ust_app_channel_allocate(ua_sess, uchan, + LTTNG_UST_CHAN_PER_CPU, usess, + &ua_chan); + if (ret == 0) { + ret = ust_app_channel_send(app, usess, + ua_sess, ua_chan); + } else { + goto end; + } + + /* Add contexts. */ + cds_list_for_each_entry(uctx, &uchan->ctx_list, list) { + ret = create_ust_app_channel_context(ua_chan, + &uctx->ctx, app); + if (ret) { + goto end; + } + } + } + if (ret < 0) { + switch (ret) { + case -ENOTCONN: + /* + * The application's socket is not valid. Either a bad socket + * or a timeout on it. We can't inform the caller that for a + * specific app, the session failed so lets continue here. + */ + ret = 0; /* Not an error. */ + break; + case -ENOMEM: + default: + break; + } + } end: + if (ret == 0 && _ua_chan) { + /* + * Only return the application's channel on success. Note + * that the channel can still be part of the application's + * channel hashtable on error. + */ + *_ua_chan = ua_chan; + } return ret; } @@ -4189,36 +4145,26 @@ end: int ust_app_create_channel_glb(struct ltt_ust_session *usess, struct ltt_ust_channel *uchan) { - int ret = 0, created; - struct lttng_ht_iter iter; + int ret = 0; + struct cds_lfht_iter iter; struct ust_app *app; - struct ust_app_session *ua_sess = NULL; - /* Very wrong code flow */ assert(usess); + assert(usess->active); assert(uchan); DBG2("UST app adding channel %s to UST domain for session id %" PRIu64, uchan->name, usess->id); - if (!usess->active) { - goto end; - } - rcu_read_lock(); - /* For every registered applications */ - cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) { - if (!app->compatible) { - /* - * TODO: In time, we should notice the caller of this error by - * telling him that this is a version error. - */ - continue; - } - if (!trace_ust_pid_tracker_lookup(usess, app->pid)) { - /* Skip. */ - continue; + cds_lfht_for_each_entry(ust_app_ht->ht, &iter, app, pid_n.node) { + struct ust_app_session *ua_sess; + int session_was_created = 0; + + if (!app->compatible || + !trace_ust_pid_tracker_lookup(usess, app->pid)) { + goto error_rcu_unlock; } /* @@ -4226,65 +4172,39 @@ int ust_app_create_channel_glb(struct ltt_ust_session *usess, * that if session exist, it will simply return a pointer to the ust * app session. */ - ret = find_or_create_ust_app_session(usess, app, &ua_sess, &created); + ret = find_or_create_ust_app_session(usess, app, &ua_sess, + &session_was_created); if (ret < 0) { switch (ret) { case -ENOTCONN: /* - * The application's socket is not valid. Either a bad socket - * or a timeout on it. We can't inform the caller that for a - * specific app, the session failed so lets continue here. + * The application's socket is not valid. Either a bad + * socket or a timeout on it. We can't inform the caller + * that for a specific app, the session failed so lets + * continue here; it is not an error. */ - ret = 0; /* Not an error. */ - continue; + ret = 0; + goto error_rcu_unlock; case -ENOMEM: default: goto error_rcu_unlock; } } - assert(ua_sess); - - pthread_mutex_lock(&ua_sess->lock); if (ua_sess->deleted) { - pthread_mutex_unlock(&ua_sess->lock); continue; } - - if (!strncmp(uchan->name, DEFAULT_METADATA_NAME, - sizeof(uchan->name))) { - copy_channel_attr_to_ustctl(&ua_sess->metadata_attr, &uchan->attr); - ret = 0; - } else { - /* Create channel onto application. We don't need the chan ref. */ - ret = create_ust_app_channel(ua_sess, uchan, app, - LTTNG_UST_CHAN_PER_CPU, usess, NULL); - } - pthread_mutex_unlock(&ua_sess->lock); - if (ret < 0) { - /* Cleanup the created session if it's the case. */ - if (created) { + ret = ust_app_channel_create(usess, ua_sess, uchan, app, NULL); + if (ret) { + if (session_was_created) { destroy_app_session(app, ua_sess); } - switch (ret) { - case -ENOTCONN: - /* - * The application's socket is not valid. Either a bad socket - * or a timeout on it. We can't inform the caller that for a - * specific app, the session failed so lets continue here. - */ - ret = 0; /* Not an error. */ - continue; - case -ENOMEM: - default: - goto error_rcu_unlock; - } + goto error_rcu_unlock; } } error_rcu_unlock: rcu_read_unlock(); -end: return ret; } @@ -4302,13 +4222,10 @@ int ust_app_enable_event_glb(struct ltt_ust_session *usess, struct ust_app_channel *ua_chan; struct ust_app_event *ua_event; + assert(usess->active); DBG("UST app enabling event %s for all apps for session id %" PRIu64, uevent->attr.name, usess->id); - if (!usess->active) { - goto end; - } - /* * NOTE: At this point, this function is called only if the session and * channel passed are already created for all apps. and enabled on the @@ -4374,7 +4291,6 @@ int ust_app_enable_event_glb(struct ltt_ust_session *usess, error: rcu_read_unlock(); -end: return ret; } @@ -4392,13 +4308,10 @@ int ust_app_create_event_glb(struct ltt_ust_session *usess, struct ust_app_session *ua_sess; struct ust_app_channel *ua_chan; + assert(usess->active); DBG("UST app creating event %s for all apps for session id %" PRIu64, uevent->attr.name, usess->id); - if (!usess->active) { - goto end; - } - rcu_read_lock(); /* For all registered applications */ @@ -4445,7 +4358,6 @@ int ust_app_create_event_glb(struct ltt_ust_session *usess, } rcu_read_unlock(); -end: return ret; } @@ -5018,7 +4930,6 @@ end: */ int ust_app_start_trace_all(struct ltt_ust_session *usess) { - int ret = 0; struct lttng_ht_iter iter; struct ust_app *app; @@ -5044,14 +4955,6 @@ int ust_app_start_trace_all(struct ltt_ust_session *usess) ust_app_global_update(usess, app); } - cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) { - ret = ust_app_start_trace(usess, app); - if (ret < 0) { - /* Continue to next apps even on error */ - continue; - } - } - rcu_read_unlock(); return 0; @@ -5118,93 +5021,147 @@ int ust_app_destroy_trace_all(struct ltt_ust_session *usess) return 0; } +/* The ua_sess lock must be held by the caller. */ static -void ust_app_global_create(struct ltt_ust_session *usess, struct ust_app *app) +int find_or_create_ust_app_channel( + struct ltt_ust_session *usess, + struct ust_app_session *ua_sess, + struct ust_app *app, + struct ltt_ust_channel *uchan, + struct ust_app_channel **ua_chan) { int ret = 0; - struct lttng_ht_iter iter, uiter; + struct lttng_ht_iter iter; + struct lttng_ht_node_str *ua_chan_node; + + lttng_ht_lookup(ua_sess->channels, (void *) uchan->name, &iter); + ua_chan_node = lttng_ht_iter_get_node_str(&iter); + if (ua_chan_node) { + *ua_chan = caa_container_of(ua_chan_node, + struct ust_app_channel, node); + goto end; + } + + ret = ust_app_channel_create(usess, ua_sess, uchan, app, ua_chan); + if (ret) { + goto end; + } +end: + return ret; +} + +static +int ust_app_channel_synchronize_event(struct ust_app_channel *ua_chan, + struct ltt_ust_event *uevent, struct ust_app_session *ua_sess, + struct ust_app *app) +{ + int ret = 0; + struct ust_app_event *ua_event = NULL; + + ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name, + uevent->filter, uevent->attr.loglevel, uevent->exclusion); + if (!ua_event) { + ret = create_ust_app_event(ua_sess, ua_chan, uevent, app); + if (ret < 0) { + goto end; + } + } else { + if (ua_event->enabled != uevent->enabled) { + ret = uevent->enabled ? + enable_ust_app_event(ua_sess, ua_event, app) : + disable_ust_app_event(ua_sess, ua_event, app); + } + } + +end: + return ret; +} + +/* + * The caller must ensure that the application is compatible and is tracked + * by the PID tracker. + */ +static +void ust_app_synchronize(struct ltt_ust_session *usess, + struct ust_app *app) +{ + int ret = 0; + struct cds_lfht_iter uchan_iter; + struct ltt_ust_channel *uchan; struct ust_app_session *ua_sess = NULL; - struct ust_app_channel *ua_chan; - struct ust_app_event *ua_event; - struct ust_app_ctx *ua_ctx; - int is_created = 0; - ret = find_or_create_ust_app_session(usess, app, &ua_sess, &is_created); + /* + * The application's configuration should only be synchronized for + * active sessions. + */ + assert(usess->active); + + ret = find_or_create_ust_app_session(usess, app, &ua_sess, NULL); if (ret < 0) { /* Tracer is probably gone or ENOMEM. */ goto error; } - if (!is_created) { - /* App session already created. */ - goto end; - } - if (!usess->active) { - goto end; - } assert(ua_sess); pthread_mutex_lock(&ua_sess->lock); - if (ua_sess->deleted) { pthread_mutex_unlock(&ua_sess->lock); goto end; } - /* - * We can iterate safely here over all UST app session since the create ust - * app session above made a shadow copy of the UST global domain from the - * ltt ust session. - */ - cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan, - node.node) { - ret = do_create_channel(app, usess, ua_sess, ua_chan); - if (ret < 0 && ret != -ENOTCONN) { - /* - * Stop everything. On error, the application - * failed, no more file descriptor are available - * or ENOMEM so stopping here is the only thing - * we can do for now. The only exception is - * -ENOTCONN, which indicates that the application - * has exit. - */ - goto error_unlock; - } + rcu_read_lock(); + cds_lfht_for_each_entry(usess->domain_global.channels->ht, &uchan_iter, + uchan, node.node) { + struct ust_app_channel *ua_chan; + struct cds_lfht_iter uevent_iter; + struct ltt_ust_event *uevent; /* - * Add context using the list so they are enabled in the same order the - * user added them. + * Search for a matching ust_app_channel. If none is found, + * create it. Creating the channel will cause the ua_chan + * structure to be allocated, the channel buffers to be + * allocated (if necessary) and sent to the application, and + * all enabled contexts will be added to the channel. */ - cds_list_for_each_entry(ua_ctx, &ua_chan->ctx_list, list) { - ret = create_ust_channel_context(ua_chan, ua_ctx, app); - if (ret < 0) { - goto error_unlock; - } + ret = find_or_create_ust_app_channel(usess, ua_sess, + app, uchan, &ua_chan); + if (ret) { + /* Tracer is probably gone or ENOMEM. */ + goto error_unlock; } + if (!ua_chan) { + /* ua_chan will be NULL for the metadata channel */ + continue; + } - /* For each events */ - cds_lfht_for_each_entry(ua_chan->events->ht, &uiter.iter, ua_event, + cds_lfht_for_each_entry(uchan->events->ht, &uevent_iter, uevent, node.node) { - ret = create_ust_event(app, ua_sess, ua_chan, ua_event); - if (ret < 0) { + ret = ust_app_channel_synchronize_event(ua_chan, + uevent, ua_sess, app); + if (ret) { goto error_unlock; } } - } - - pthread_mutex_unlock(&ua_sess->lock); - ret = ust_app_start_trace(usess, app); - if (ret < 0) { - goto error; + if (ua_chan->enabled != uchan->enabled) { + ret = uchan->enabled ? + enable_ust_app_channel(ua_sess, uchan, app) : + disable_ust_app_channel(ua_sess, ua_chan, app); + if (ret) { + goto error_unlock; + } + } } + rcu_read_unlock(); - DBG2("UST trace started for app pid %d", app->pid); end: + pthread_mutex_unlock(&ua_sess->lock); /* Everything went well at this point. */ return; error_unlock: + rcu_read_unlock(); pthread_mutex_unlock(&ua_sess->lock); error: if (ua_sess) { @@ -5234,6 +5191,7 @@ void ust_app_global_destroy(struct ltt_ust_session *usess, struct ust_app *app) void ust_app_global_update(struct ltt_ust_session *usess, struct ust_app *app) { assert(usess); + assert(usess->active); DBG2("UST app global update for app sock %d for session id %" PRIu64, app->sock, usess->id); @@ -5241,11 +5199,13 @@ void ust_app_global_update(struct ltt_ust_session *usess, struct ust_app *app) if (!app->compatible) { return; } - if (!usess->active) { - return; - } if (trace_ust_pid_tracker_lookup(usess, app->pid)) { - ust_app_global_create(usess, app); + /* + * Synchronize the application's internal tracing configuration + * and start tracing. + */ + ust_app_synchronize(usess, app); + ust_app_start_trace(usess, app); } else { ust_app_global_destroy(usess, app); } @@ -5259,9 +5219,6 @@ void ust_app_global_update_all(struct ltt_ust_session *usess) struct lttng_ht_iter iter; struct ust_app *app; - if (!usess->active) { - return; - } rcu_read_lock(); cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) { ust_app_global_update(usess, app); @@ -5282,12 +5239,9 @@ int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess, struct ust_app_session *ua_sess; struct ust_app *app; - if (!usess->active) { - goto end; - } + assert(usess->active); rcu_read_lock(); - cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) { if (!app->compatible) { /* @@ -5325,80 +5279,6 @@ int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess, } rcu_read_unlock(); -end: - return ret; -} - -/* - * Enable event for a channel from a UST session for a specific PID. - */ -int ust_app_enable_event_pid(struct ltt_ust_session *usess, - struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent, pid_t pid) -{ - int ret = 0; - struct lttng_ht_iter iter; - struct lttng_ht_node_str *ua_chan_node; - struct ust_app *app; - struct ust_app_session *ua_sess; - struct ust_app_channel *ua_chan; - struct ust_app_event *ua_event; - - DBG("UST app enabling event %s for PID %d", uevent->attr.name, pid); - - rcu_read_lock(); - - app = ust_app_find_by_pid(pid); - if (app == NULL) { - ERR("UST app enable event per PID %d not found", pid); - ret = -1; - goto end; - } - - if (!app->compatible) { - ret = 0; - goto end; - } - - ua_sess = lookup_session_by_app(usess, app); - if (!ua_sess) { - /* The application has problem or is probably dead. */ - ret = 0; - goto end; - } - - pthread_mutex_lock(&ua_sess->lock); - - if (ua_sess->deleted) { - ret = 0; - goto end_unlock; - } - - /* Lookup channel in the ust app session */ - lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter); - ua_chan_node = lttng_ht_iter_get_node_str(&iter); - /* If the channel is not found, there is a code flow error */ - assert(ua_chan_node); - - ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node); - - ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name, - uevent->filter, uevent->attr.loglevel, uevent->exclusion); - if (ua_event == NULL) { - ret = create_ust_app_event(ua_sess, ua_chan, uevent, app); - if (ret < 0) { - goto end_unlock; - } - } else { - ret = enable_ust_app_event(ua_sess, ua_event, app); - if (ret < 0) { - goto end_unlock; - } - } - -end_unlock: - pthread_mutex_unlock(&ua_sess->lock); -end: - rcu_read_unlock(); return ret; } diff --git a/src/bin/lttng-sessiond/ust-app.h b/src/bin/lttng-sessiond/ust-app.h index fbf523399..b90ff4bce 100644 --- a/src/bin/lttng-sessiond/ust-app.h +++ b/src/bin/lttng-sessiond/ust-app.h @@ -315,17 +315,12 @@ int ust_app_create_channel_glb(struct ltt_ust_session *usess, struct ltt_ust_channel *uchan); int ust_app_create_event_glb(struct ltt_ust_session *usess, struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent); -int ust_app_enable_event_pid(struct ltt_ust_session *usess, - struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent, - pid_t pid); int ust_app_disable_channel_glb(struct ltt_ust_session *usess, struct ltt_ust_channel *uchan); int ust_app_enable_channel_glb(struct ltt_ust_session *usess, struct ltt_ust_channel *uchan); int ust_app_enable_event_glb(struct ltt_ust_session *usess, struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent); -int ust_app_enable_all_event_glb(struct ltt_ust_session *usess, - struct ltt_ust_channel *uchan); int ust_app_disable_event_glb(struct ltt_ust_session *usess, struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent); int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess, @@ -468,12 +463,6 @@ int ust_app_create_channel_glb(struct ltt_ust_session *usess, return 0; } static inline -int ust_app_enable_all_event_glb(struct ltt_ust_session *usess, - struct ltt_ust_channel *uchan) -{ - return 0; -} -static inline int ust_app_create_event_glb(struct ltt_ust_session *usess, struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent) { -- 2.34.1