X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fust-app.c;h=ddc7c2336bfac5cfa7029308eaec23b67f14d844;hb=06671f3490837e28032f3c5bc9375e32bd67f42e;hp=59d8a8fc49a96edf8327e85ea033879555e87487;hpb=88e3c2f5610b9ac89b0923d448fee34140fc46fb;p=lttng-tools.git diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c index 59d8a8fc4..ddc7c2336 100644 --- a/src/bin/lttng-sessiond/ust-app.c +++ b/src/bin/lttng-sessiond/ust-app.c @@ -1,19 +1,9 @@ /* - * Copyright (C) 2011 - David Goulet - * Copyright (C) 2016 - Jérémie Galarneau + * Copyright (C) 2011 David Goulet + * Copyright (C) 2016 Jérémie Galarneau * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License, version 2 only, - * as published by the Free Software Foundation. + * SPDX-License-Identifier: GPL-2.0-only * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License along - * with this program; if not, write to the Free Software Foundation, Inc., - * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #define _LGPL_SOURCE @@ -27,7 +17,6 @@ #include #include #include -#include #include #include @@ -38,13 +27,18 @@ #include "health-sessiond.h" #include "ust-app.h" #include "ust-consumer.h" -#include "ust-ctl.h" +#include "lttng-ust-ctl.h" +#include "lttng-ust-error.h" #include "utils.h" #include "session.h" #include "lttng-sessiond.h" #include "notification-thread-commands.h" #include "rotate.h" +struct lttng_ht *ust_app_ht; +struct lttng_ht *ust_app_ht_by_sock; +struct lttng_ht *ust_app_ht_by_notify_sock; + static int ust_app_flush_app_session(struct ust_app *app, struct ust_app_session *ua_sess); @@ -250,7 +244,8 @@ static struct ust_registry_session *get_session_registry( case LTTNG_BUFFER_PER_UID: { struct buffer_reg_uid *reg_uid = buffer_reg_uid_find( - ua_sess->tracing_id, ua_sess->bits_per_long, ua_sess->uid); + ua_sess->tracing_id, ua_sess->bits_per_long, + ua_sess->real_credentials.uid); if (!reg_uid) { goto error; } @@ -281,9 +276,18 @@ void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx, pthread_mutex_lock(&app->sock_lock); ret = ustctl_release_object(sock, ua_ctx->obj); pthread_mutex_unlock(&app->sock_lock); - if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app sock %d release ctx obj handle %d failed with ret %d", - sock, ua_ctx->obj->handle, ret); + if (ret < 0) { + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app release ctx failed. Application is dead: pid = %d, sock = %d", + app->pid, app->sock); + } else if (ret == -EAGAIN) { + WARN("UST app release ctx failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); + } else { + ERR("UST app release ctx obj handle %d failed with ret %d: pid = %d, sock = %d", + ua_ctx->obj->handle, ret, + app->pid, app->sock); + } } free(ua_ctx->obj); } @@ -309,9 +313,17 @@ void delete_ust_app_event(int sock, struct ust_app_event *ua_event, pthread_mutex_lock(&app->sock_lock); ret = ustctl_release_object(sock, ua_event->obj); pthread_mutex_unlock(&app->sock_lock); - if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app sock %d release event obj failed with ret %d", - sock, ret); + if (ret < 0) { + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app release event failed. Application is dead: pid = %d, sock = %d", + app->pid, app->sock); + } else if (ret == -EAGAIN) { + WARN("UST app release event failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); + } else { + ERR("UST app release event obj failed with ret %d: pid = %d, sock = %d", + ret, app->pid, app->sock); + } } free(ua_event->obj); } @@ -334,9 +346,17 @@ static int release_ust_app_stream(int sock, struct ust_app_stream *stream, pthread_mutex_lock(&app->sock_lock); ret = ustctl_release_object(sock, stream->obj); pthread_mutex_unlock(&app->sock_lock); - if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app sock %d release stream obj failed with ret %d", - sock, ret); + if (ret < 0) { + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app release stream failed. Application is dead: pid = %d, sock = %d", + app->pid, app->sock); + } else if (ret == -EAGAIN) { + WARN("UST app release stream failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); + } else { + ERR("UST app release stream obj failed with ret %d: pid = %d, sock = %d", + ret, app->pid, app->sock); + } } lttng_fd_put(LTTNG_FD_APPS, 2); free(stream->obj); @@ -510,9 +530,20 @@ void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan, pthread_mutex_lock(&app->sock_lock); ret = ustctl_release_object(sock, ua_chan->obj); pthread_mutex_unlock(&app->sock_lock); - if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app sock %d release channel obj failed with ret %d", - sock, ret); + if (ret < 0) { + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app channel %s release failed. Application is dead: pid = %d, sock = %d", + ua_chan->name, app->pid, + app->sock); + } else if (ret == -EAGAIN) { + WARN("UST app channel %s release failed. Communication time out: pid = %d, sock = %d", + ua_chan->name, app->pid, + app->sock); + } else { + ERR("UST app channel %s release failed with ret %d: pid = %d, sock = %d", + ua_chan->name, ret, app->pid, + app->sock); + } } lttng_fd_put(LTTNG_FD_APPS, 1); free(ua_chan->obj); @@ -740,6 +771,10 @@ error: * nullified. The session lock MUST be held unless the application is * in the destroy path. * + * Do not hold the registry lock while communicating with the consumerd, because + * doing so causes inter-process deadlocks between consumerd and sessiond with + * the metadata request notification. + * * Return 0 on success else a negative value. */ static int close_metadata(struct ust_registry_session *registry, @@ -747,6 +782,8 @@ static int close_metadata(struct ust_registry_session *registry, { int ret; struct consumer_socket *socket; + uint64_t metadata_key; + bool registry_was_already_closed; assert(registry); assert(consumer); @@ -754,8 +791,19 @@ static int close_metadata(struct ust_registry_session *registry, rcu_read_lock(); pthread_mutex_lock(®istry->lock); + metadata_key = registry->metadata_key; + registry_was_already_closed = registry->metadata_closed; + if (metadata_key != 0) { + /* + * Metadata closed. Even on error this means that the consumer + * is not responding or not found so either way a second close + * should NOT be emit for this registry. + */ + registry->metadata_closed = 1; + } + pthread_mutex_unlock(®istry->lock); - if (!registry->metadata_key || registry->metadata_closed) { + if (metadata_key == 0 || registry_was_already_closed) { ret = 0; goto end; } @@ -765,23 +813,15 @@ static int close_metadata(struct ust_registry_session *registry, consumer); if (!socket) { ret = -1; - goto error; + goto end; } - ret = consumer_close_metadata(socket, registry->metadata_key); + ret = consumer_close_metadata(socket, metadata_key); if (ret < 0) { - goto error; + goto end; } -error: - /* - * Metadata closed. Even on error this means that the consumer is not - * responding or not found so either way a second close should NOT be emit - * for this registry. - */ - registry->metadata_closed = 1; end: - pthread_mutex_unlock(®istry->lock); rcu_read_unlock(); return ret; } @@ -866,10 +906,19 @@ void delete_ust_app_session(int sock, struct ust_app_session *ua_sess, pthread_mutex_lock(&app->sock_lock); ret = ustctl_release_handle(sock, ua_sess->handle); pthread_mutex_unlock(&app->sock_lock); - if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app sock %d release session handle failed with ret %d", - sock, ret); + if (ret < 0) { + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app release session handle failed. Application is dead: pid = %d, sock = %d", + app->pid, app->sock); + } else if (ret == -EAGAIN) { + WARN("UST app release session handle failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); + } else { + ERR("UST app release session handle failed with ret %d: pid = %d, sock = %d", + ret, app->pid, app->sock); + } } + /* Remove session from application UST object descriptor. */ iter.iter.node = &ua_sess->ust_objd_node.node; ret = lttng_ht_del(app->ust_sessions_objd, &iter); @@ -1015,7 +1064,7 @@ error_free: * Alloc new UST app channel. */ static -struct ust_app_channel *alloc_ust_app_channel(char *name, +struct ust_app_channel *alloc_ust_app_channel(const char *name, struct ust_app_session *ua_sess, struct lttng_ust_channel_attr *attr) { @@ -1099,7 +1148,7 @@ struct ust_app_event *alloc_ust_app_event(char *name, /* Init most of the default value by allocating and zeroing */ ua_event = zmalloc(sizeof(struct ust_app_event)); if (ua_event == NULL) { - PERROR("malloc"); + PERROR("Failed to allocate ust_app_event structure"); goto error; } @@ -1311,17 +1360,17 @@ int create_ust_channel_context(struct ust_app_channel *ua_chan, ua_chan->obj, &ua_ctx->obj); pthread_mutex_unlock(&app->sock_lock); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app create channel context failed for app (pid: %d) " - "with ret %d", app->pid, ret); - } else { - /* - * This is normal behavior, an application can die during the - * creation process. Don't report an error so the execution can - * continue normally. - */ + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + ret = 0; + DBG3("UST app create channel context failed. Application is dead: pid = %d, sock = %d", + app->pid, app->sock); + } else if (ret == -EAGAIN) { ret = 0; - DBG3("UST app add context failed. Application is dead."); + WARN("UST app create channel context failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); + } else { + ERR("UST app create channel context failed with ret %d: pid = %d, sock = %d", + ret, app->pid, app->sock); } goto error; } @@ -1363,17 +1412,18 @@ int set_ust_event_filter(struct ust_app_event *ua_event, ua_event->obj); pthread_mutex_unlock(&app->sock_lock); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app event %s filter failed for app (pid: %d) " - "with ret %d", ua_event->attr.name, app->pid, ret); - } else { - /* - * This is normal behavior, an application can die during the - * creation process. Don't report an error so the execution can - * continue normally. - */ + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + ret = 0; + DBG3("UST app set filter failed. Application is dead: pid = %d, sock = %d", + app->pid, app->sock); + } else if (ret == -EAGAIN) { ret = 0; - DBG3("UST app filter event failed. Application is dead."); + DBG3("UST app set filter failed. Communication timeout: pid = %d, sock = %d", + app->pid, app->sock); + } else { + ERR("UST app event set filter failed with ret %d: pid = %d, sock = %d", + ret, app->pid, + app->sock); } goto error; } @@ -1434,17 +1484,17 @@ int set_ust_event_exclusion(struct ust_app_event *ua_event, ret = ustctl_set_exclusion(app->sock, ust_exclusion, ua_event->obj); pthread_mutex_unlock(&app->sock_lock); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app event %s exclusions failed for app (pid: %d) " - "with ret %d", ua_event->attr.name, app->pid, ret); - } else { - /* - * This is normal behavior, an application can die during the - * creation process. Don't report an error so the execution can - * continue normally. - */ + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + ret = 0; + DBG3("UST app event exclusion failed. Application is dead: pid = %d, sock = %d", + app->pid, app->sock); + } else if (ret == -EAGAIN) { ret = 0; - DBG3("UST app event exclusion failed. Application is dead."); + WARN("UST app event exclusion failed. Communication time out(pid: %d, sock = %d", + app->pid, app->sock); + } else { + ERR("UST app event exclusions failed with ret %d: pid = %d, sock = %d, event = %s", + ret, app->pid, app->sock, ua_event->name); } goto error; } @@ -1471,18 +1521,17 @@ static int disable_ust_event(struct ust_app *app, ret = ustctl_disable(app->sock, ua_event->obj); pthread_mutex_unlock(&app->sock_lock); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app event %s disable failed for app (pid: %d) " - "and session handle %d with ret %d", - ua_event->attr.name, app->pid, ua_sess->handle, ret); - } else { - /* - * This is normal behavior, an application can die during the - * creation process. Don't report an error so the execution can - * continue normally. - */ + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + ret = 0; + DBG3("UST app disable event failed. Application is dead: pid = %d, sock = %d", + app->pid, app->sock); + } else if (ret == -EAGAIN) { ret = 0; - DBG3("UST app disable event failed. Application is dead."); + WARN("UST app disable event failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); + } else { + ERR("UST app disable event failed with ret %d: pid = %d, sock = %d , name = %s", + ret, app->pid, app->sock, ua_event->attr.name); } goto error; } @@ -1509,23 +1558,23 @@ static int disable_ust_channel(struct ust_app *app, ret = ustctl_disable(app->sock, ua_chan->obj); pthread_mutex_unlock(&app->sock_lock); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app channel %s disable failed for app (pid: %d) " - "and session handle %d with ret %d", - ua_chan->name, app->pid, ua_sess->handle, ret); - } else { - /* - * This is normal behavior, an application can die during the - * creation process. Don't report an error so the execution can - * continue normally. - */ + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + ret = 0; + DBG3("UST app disable channel failed. Application is dead: pid = %d, sock = %d", + app->pid, app->sock); + } else if (ret == -EAGAIN) { ret = 0; - DBG3("UST app disable channel failed. Application is dead."); + WARN("UST app disable channel failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); + } else { + ERR("UST app channel %s disable failed, session handle %d, with ret %d: pid = %d, sock = %d", + ua_chan->name, ua_sess->handle, ret, + app->pid, app->sock); } goto error; } - DBG2("UST app channel %s disabled successfully for app (pid: %d)", + DBG2("UST app channel %s disabled successfully for app: pid = %d", ua_chan->name, app->pid); error: @@ -1547,25 +1596,25 @@ static int enable_ust_channel(struct ust_app *app, ret = ustctl_enable(app->sock, ua_chan->obj); pthread_mutex_unlock(&app->sock_lock); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app channel %s enable failed for app (pid: %d) " - "and session handle %d with ret %d", - ua_chan->name, app->pid, ua_sess->handle, ret); - } else { - /* - * This is normal behavior, an application can die during the - * creation process. Don't report an error so the execution can - * continue normally. - */ + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + ret = 0; + DBG3("UST app channel %s enable failed. Application is dead: pid = %d, sock = %d", + ua_chan->name, app->pid, app->sock); + } else if (ret == -EAGAIN) { ret = 0; - DBG3("UST app enable channel failed. Application is dead."); + WARN("UST app channel %s enable failed. Communication time out: pid = %d, sock = %d", + ua_chan->name, app->pid, app->sock); + } else { + ERR("UST app channel %s enable failed, session handle %d, with ret %d: pid = %d, sock = %d", + ua_chan->name, ua_sess->handle, ret, + app->pid, app->sock); } goto error; } ua_chan->enabled = 1; - DBG2("UST app channel %s enabled successfully for app (pid: %d)", + DBG2("UST app channel %s enabled successfully for app: pid = %d", ua_chan->name, app->pid); error: @@ -1587,18 +1636,17 @@ static int enable_ust_event(struct ust_app *app, ret = ustctl_enable(app->sock, ua_event->obj); pthread_mutex_unlock(&app->sock_lock); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app event %s enable failed for app (pid: %d) " - "and session handle %d with ret %d", - ua_event->attr.name, app->pid, ua_sess->handle, ret); - } else { - /* - * This is normal behavior, an application can die during the - * creation process. Don't report an error so the execution can - * continue normally. - */ + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + ret = 0; + DBG3("UST app enable event failed. Application is dead: pid = %d, sock = %d", + app->pid, app->sock); + } else if (ret == -EAGAIN) { ret = 0; - DBG3("UST app enable event failed. Application is dead."); + WARN("UST app enable event failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); + } else { + ERR("UST app enable event failed with ret %d: pid = %d, sock = %d, event = %s", + ret, app->pid, app->sock, ua_event->attr.name); } goto error; } @@ -1636,6 +1684,13 @@ static int send_channel_pid_to_ust(struct ust_app *app, if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { ret = -ENOTCONN; /* Caused by app exiting. */ goto error; + } else if (ret == -EAGAIN) { + /* Caused by timeout. */ + WARN("Communication with application %d timed out on send_channel for channel \"%s\" of session \"%" PRIu64 "\".", + app->pid, ua_chan->name, ua_sess->tracing_id); + /* Treat this the same way as an application that is exiting. */ + ret = -ENOTCONN; + goto error; } else if (ret < 0) { goto error; } @@ -1646,8 +1701,18 @@ static int send_channel_pid_to_ust(struct ust_app *app, cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) { ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream); if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { - ret = -ENOTCONN; /* Caused by app exiting. */ + ret = -ENOTCONN; /* Caused by app exiting. */ goto error; + } else if (ret == -EAGAIN) { + /* Caused by timeout. */ + WARN("Communication with application %d timed out on send_stream for stream \"%s\" of channel \"%s\" of session \"%" PRIu64 "\".", + app->pid, stream->name, ua_chan->name, + ua_sess->tracing_id); + /* + * Treat this the same way as an application that is + * exiting. + */ + ret = -ENOTCONN; } else if (ret < 0) { goto error; } @@ -1682,18 +1747,18 @@ int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess, &ua_event->obj); 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 { - /* - * This is normal behavior, an application can die during the - * creation process. Don't report an error so the execution can - * continue normally. - */ + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { ret = 0; - DBG3("UST app create event failed. Application is dead."); + DBG3("UST app create event failed. Application is dead: pid = %d, sock = %d", + app->pid, app->sock); + } else if (ret == -EAGAIN) { + ret = 0; + WARN("UST app create event failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); + } else { + ERR("UST app create event '%s' failed with ret %d: pid = %d, sock = %d", + ua_event->attr.name, ret, app->pid, + app->sock); } goto error; } @@ -1831,25 +1896,22 @@ 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) { - time_t rawtime; struct tm *timeinfo; char datetime[16]; int ret; char tmp_shm_path[PATH_MAX]; - /* Get date and time for unique app path */ - time(&rawtime); - timeinfo = localtime(&rawtime); + timeinfo = localtime(&app->registration_time); strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo); DBG2("Shadow copy of session handle %d", ua_sess->handle); ua_sess->tracing_id = usess->id; ua_sess->id = get_next_session_id(); - ua_sess->uid = app->uid; - ua_sess->gid = app->gid; - ua_sess->euid = usess->uid; - ua_sess->egid = usess->gid; + ua_sess->real_credentials.uid = app->uid; + ua_sess->real_credentials.gid = app->gid; + ua_sess->effective_credentials.uid = usess->uid; + ua_sess->effective_credentials.gid = usess->gid; ua_sess->buffer_type = usess->buffer_type; ua_sess->bits_per_long = app->bits_per_long; @@ -1870,7 +1932,9 @@ static void shadow_copy_session(struct ust_app_session *ua_sess, break; case LTTNG_BUFFER_PER_UID: ret = snprintf(ua_sess->path, sizeof(ua_sess->path), - DEFAULT_UST_TRACE_UID_PATH, ua_sess->uid, app->bits_per_long); + DEFAULT_UST_TRACE_UID_PATH, + ua_sess->real_credentials.uid, + app->bits_per_long); break; default: assert(0); @@ -1892,12 +1956,12 @@ static void shadow_copy_session(struct ust_app_session *ua_sess, switch (ua_sess->buffer_type) { case LTTNG_BUFFER_PER_PID: ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path), - DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", + "/" DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid, datetime); break; case LTTNG_BUFFER_PER_UID: ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path), - DEFAULT_UST_TRACE_UID_PATH, + "/" DEFAULT_UST_TRACE_UID_PATH, app->uid, app->bits_per_long); break; default: @@ -1923,7 +1987,7 @@ error: * Lookup sesison wrapper. */ static -void __lookup_session_by_app(struct ltt_ust_session *usess, +void __lookup_session_by_app(const struct ltt_ust_session *usess, struct ust_app *app, struct lttng_ht_iter *iter) { /* Get right UST app session from app */ @@ -1935,7 +1999,7 @@ void __lookup_session_by_app(struct ltt_ust_session *usess, * id. */ static struct ust_app_session *lookup_session_by_app( - struct ltt_ust_session *usess, struct ust_app *app) + const struct ltt_ust_session *usess, struct ust_app *app) { struct lttng_ht_iter iter; struct lttng_ht_node_u64 *node; @@ -1990,10 +2054,11 @@ static int setup_buffer_reg_pid(struct ust_app_session *ua_sess, app->bits_per_long, app->uint8_t_alignment, app->uint16_t_alignment, app->uint32_t_alignment, app->uint64_t_alignment, app->long_alignment, - app->byte_order, app->version.major, - app->version.minor, reg_pid->root_shm_path, - reg_pid->shm_path, - ua_sess->euid, ua_sess->egid); + app->byte_order, app->version.major, app->version.minor, + reg_pid->root_shm_path, reg_pid->shm_path, + ua_sess->effective_credentials.uid, + ua_sess->effective_credentials.gid, ua_sess->tracing_id, + app->uid); if (ret < 0) { /* * reg_pid->registry->reg.ust is NULL upon error, so we need to @@ -2060,7 +2125,8 @@ static int setup_buffer_reg_uid(struct ltt_ust_session *usess, app->uint64_t_alignment, app->long_alignment, app->byte_order, app->version.major, app->version.minor, reg_uid->root_shm_path, - reg_uid->shm_path, usess->uid, usess->gid); + reg_uid->shm_path, usess->uid, usess->gid, + ua_sess->tracing_id, app->uid); if (ret < 0) { /* * reg_uid->registry->reg.ust is NULL upon error, so we need to @@ -2154,18 +2220,17 @@ static int find_or_create_ust_app_session(struct ltt_ust_session *usess, ret = ustctl_create_session(app->sock); pthread_mutex_unlock(&app->sock_lock); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("Creating session for app pid %d with ret %d", - app->pid, ret); - } else { - DBG("UST app creating session failed. Application is dead"); - /* - * This is normal behavior, an application can die during the - * creation process. Don't report an error so the execution can - * continue normally. This will get flagged ENOTCONN and the - * caller will handle it. - */ + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG("UST app creating session failed. Application is dead: pid = %d, sock = %d", + app->pid, app->sock); ret = 0; + } else if (ret == -EAGAIN) { + DBG("UST app creating session failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); + ret = 0; + } else { + ERR("UST app creating session failed with ret %d: pid = %d, sock =%d", + ret, app->pid, app->sock); } delete_ust_app_session(-1, ua_sess, app); if (ret != -ENOMEM) { @@ -2462,7 +2527,7 @@ static int do_consumer_create_channel(struct ltt_ust_session *usess, * stream we have to expect. */ ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket, - registry, trace_archive_id); + registry, usess->current_trace_chunk); if (ret < 0) { goto error_ask; } @@ -2483,7 +2548,7 @@ static int do_consumer_create_channel(struct ltt_ust_session *usess, health_code_update(); /* - * Now get the channel from the consumer. This call wil populate the stream + * Now get the channel from the consumer. This call will populate the stream * list of that channel and set the ust objects. */ if (usess->consumer->enabled) { @@ -2747,6 +2812,13 @@ static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan, if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { ret = -ENOTCONN; /* Caused by app exiting. */ goto error; + } else if (ret == -EAGAIN) { + /* Caused by timeout. */ + WARN("Communication with application %d timed out on send_channel for channel \"%s\" of session \"%" PRIu64 "\".", + app->pid, ua_chan->name, ua_sess->tracing_id); + /* Treat this the same way as an application that is exiting. */ + ret = -ENOTCONN; + goto error; } else if (ret < 0) { goto error; } @@ -2765,10 +2837,21 @@ static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan, ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream); if (ret < 0) { - (void) release_ust_app_stream(-1, &stream, app); if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { ret = -ENOTCONN; /* Caused by app exiting. */ + } else if (ret == -EAGAIN) { + /* + * Caused by timeout. + * Treat this the same way as an application + * that is exiting. + */ + WARN("Communication with application %d timed out on send_stream for stream \"%s\" of channel \"%s\" of session \"%" PRIu64 "\".", + app->pid, stream.name, + ua_chan->name, + ua_sess->tracing_id); + ret = -ENOTCONN; } + (void) release_ust_app_stream(-1, &stream, app); goto error_stream_unlock; } @@ -2845,7 +2928,7 @@ static int create_channel_per_uid(struct ust_app *app, */ ret = do_consumer_create_channel(usess, ua_sess, ua_chan, app->bits_per_long, reg_uid->registry->reg.ust, - session->current_archive_id); + session->most_recent_chunk_id.value); if (ret < 0) { ERR("Error creating UST channel \"%s\" on the consumer daemon", ua_chan->name); @@ -2882,10 +2965,9 @@ static int create_channel_per_uid(struct ust_app *app, notification_ret = notification_thread_command_add_channel( notification_thread_handle, session->name, - ua_sess->euid, ua_sess->egid, - ua_chan->name, - ua_chan->key, - LTTNG_DOMAIN_UST, + ua_sess->effective_credentials.uid, + ua_sess->effective_credentials.gid, ua_chan->name, + ua_chan->key, LTTNG_DOMAIN_UST, ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf); if (notification_ret != LTTNG_OK) { ret = - (int) notification_ret; @@ -2959,7 +3041,7 @@ static int create_channel_per_pid(struct ust_app *app, /* Create and get channel on the consumer side. */ ret = do_consumer_create_channel(usess, ua_sess, ua_chan, app->bits_per_long, registry, - session->current_archive_id); + session->most_recent_chunk_id.value); if (ret < 0) { ERR("Error creating UST channel \"%s\" on the consumer daemon", ua_chan->name); @@ -2983,10 +3065,9 @@ static int create_channel_per_pid(struct ust_app *app, cmd_ret = notification_thread_command_add_channel( notification_thread_handle, session->name, - ua_sess->euid, ua_sess->egid, - ua_chan->name, - ua_chan->key, - LTTNG_DOMAIN_UST, + ua_sess->effective_credentials.uid, + ua_sess->effective_credentials.gid, ua_chan->name, + ua_chan->key, LTTNG_DOMAIN_UST, ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf); if (cmd_ret != LTTNG_OK) { ret = - (int) cmd_ret; @@ -3133,7 +3214,7 @@ int create_ust_app_event(struct ust_app_session *ua_sess, ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr); if (ua_event == NULL) { - /* Only malloc can failed so something is really wrong */ + /* Only failure mode of alloc_ust_app_event(). */ ret = -ENOMEM; goto end; } @@ -3142,8 +3223,19 @@ int create_ust_app_event(struct ust_app_session *ua_sess, /* Create it on the tracer side */ ret = create_ust_event(app, ua_sess, ua_chan, ua_event); if (ret < 0) { - /* Not found previously means that it does not exist on the tracer */ - assert(ret != -LTTNG_UST_ERR_EXIST); + /* + * Not found previously means that it does not exist on the + * tracer. If the application reports that the event existed, + * it means there is a bug in the sessiond or lttng-ust + * (or corruption, etc.) + */ + if (ret == -LTTNG_UST_ERR_EXIST) { + ERR("Tracer for application reported that an event being created already existed: " + "event_name = \"%s\", pid = %d, ppid = %d, uid = %d, gid = %d", + uevent->attr.name, + app->pid, app->ppid, app->uid, + app->gid); + } goto error; } @@ -3236,7 +3328,7 @@ static int create_ust_app_metadata(struct ust_app_session *ua_sess, * consumer. */ ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket, - registry, session->current_archive_id); + registry, session->current_trace_chunk); if (ret < 0) { /* Nullify the metadata key so we don't try to close it later on. */ registry->metadata_key = 0; @@ -3376,6 +3468,8 @@ void ust_app_add(struct ust_app *app) assert(app); assert(app->notify_sock >= 0); + app->registration_time = time(NULL); + rcu_read_lock(); /* @@ -3395,8 +3489,8 @@ void ust_app_add(struct ust_app *app) lttng_ht_node_init_ulong(&app->notify_sock_n, app->notify_sock); lttng_ht_add_unique_ulong(ust_app_ht_by_notify_sock, &app->notify_sock_n); - DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s " - "notify_sock:%d (version %d.%d)", app->pid, app->ppid, app->uid, + DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock =%d name:%s " + "notify_sock =%d (version %d.%d)", app->pid, app->ppid, app->uid, app->gid, app->sock, app->name, app->notify_sock, app->v_major, app->v_minor); @@ -3419,10 +3513,15 @@ int ust_app_version(struct ust_app *app) ret = ustctl_tracer_version(app->sock, &app->version); pthread_mutex_unlock(&app->sock_lock); if (ret < 0) { - if (ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) { - ERR("UST app %d version failed with ret %d", app->sock, ret); + if (ret == -LTTNG_UST_ERR_EXITING || ret == -EPIPE) { + DBG3("UST app version failed. Application is dead: pid = %d, sock = %d", + app->pid, app->sock); + } else if (ret == -EAGAIN) { + WARN("UST app version failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); } else { - DBG3("UST app %d version failed. Application is dead", app->sock); + ERR("UST app version failed with ret %d: pid = %d, sock = %d", + ret, app->pid, app->sock); } } @@ -3604,11 +3703,6 @@ int ust_app_list_events(struct lttng_event **events) app->sock, ret); } else { DBG3("UST app tp list get failed. Application is dead"); - /* - * This is normal behavior, an application can die during the - * creation process. Don't report an error so the execution can - * continue normally. Continue normal execution. - */ break; } free(tmp_event); @@ -3663,8 +3757,17 @@ int ust_app_list_events(struct lttng_event **events) } ret = ustctl_release_handle(app->sock, handle); pthread_mutex_unlock(&app->sock_lock); - if (ret < 0 && ret != -LTTNG_UST_ERR_EXITING && ret != -EPIPE) { - ERR("Error releasing app handle for app %d with ret %d", app->sock, ret); + if (ret < 0) { + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("Error releasing app handle. Application died: pid = %d, sock = %d", + app->pid, app->sock); + } else if (ret == -EAGAIN) { + WARN("Error releasing app handle. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); + } else { + ERR("Error releasing app handle with ret %d: pid = %d, sock = %d", + ret, app->pid, app->sock); + } } } @@ -3735,11 +3838,6 @@ int ust_app_list_event_fields(struct lttng_event_field **fields) app->sock, ret); } else { DBG3("UST app tp list field failed. Application is dead"); - /* - * This is normal behavior, an application can die during the - * creation process. Don't report an error so the execution can - * continue normally. Reset list and count for next app. - */ break; } free(tmp_event); @@ -4096,11 +4194,14 @@ int ust_app_channel_create(struct ltt_ust_session *usess, 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; + if (ret < 0) { + goto error; + } + + ret = ust_app_channel_send(app, usess, + ua_sess, ua_chan); + if (ret) { + goto error; } /* Add contexts. */ @@ -4108,10 +4209,12 @@ int ust_app_channel_create(struct ltt_ust_session *usess, ret = create_ust_app_channel_context(ua_chan, &uctx->ctx, app); if (ret) { - goto end; + goto error; } } } + +error: if (ret < 0) { switch (ret) { case -ENOTCONN: @@ -4127,7 +4230,7 @@ int ust_app_channel_create(struct ltt_ust_session *usess, break; } } -end: + if (ret == 0 && _ua_chan) { /* * Only return the application's channel on success. Note @@ -4139,75 +4242,6 @@ end: return ret; } -/* - * For a specific UST session, create the channel for all registered apps. - */ -int ust_app_create_channel_glb(struct ltt_ust_session *usess, - struct ltt_ust_channel *uchan) -{ - int ret = 0; - struct cds_lfht_iter iter; - struct ust_app *app; - - assert(usess); - assert(usess->active); - assert(uchan); - - DBG2("UST app adding channel %s to UST domain for session id %" PRIu64, - uchan->name, usess->id); - - rcu_read_lock(); - /* For every registered applications */ - 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; - } - - /* - * Create session on the tracer side and add it to app session HT. Note - * 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, - &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; it is not an error. - */ - ret = 0; - goto error_rcu_unlock; - case -ENOMEM: - default: - goto error_rcu_unlock; - } - } - - if (ua_sess->deleted) { - continue; - } - ret = ust_app_channel_create(usess, ua_sess, uchan, app, NULL); - if (ret) { - if (session_was_created) { - destroy_app_session(app, ua_sess); - } - goto error_rcu_unlock; - } - } - -error_rcu_unlock: - rcu_read_unlock(); - return ret; -} - /* * Enable event for a specific session and channel on the tracer. */ @@ -4394,83 +4428,45 @@ int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app) goto end; } + if (ua_sess->enabled) { + pthread_mutex_unlock(&ua_sess->lock); + goto end; + } + /* Upon restart, we skip the setup, already done */ if (ua_sess->started) { goto skip_setup; } - /* Create directories if consumer is LOCAL and has a path defined. */ - if (usess->consumer->type == CONSUMER_DST_LOCAL && - usess->consumer->dst.session_root_path[0] != '\0') { - char *tmp_path; - - tmp_path = zmalloc(LTTNG_PATH_MAX); - if (!tmp_path) { - ERR("Alloc tmp_path"); - goto error_unlock; - } - ret = snprintf(tmp_path, LTTNG_PATH_MAX, "%s%s%s", - usess->consumer->dst.session_root_path, - usess->consumer->chunk_path, - usess->consumer->subdir); - if (ret >= LTTNG_PATH_MAX) { - ERR("Local destination path exceeds the maximal allowed length of %i bytes (needs %i bytes) with path = \"%s%s%s\"", - LTTNG_PATH_MAX, ret, - usess->consumer->dst.session_root_path, - usess->consumer->chunk_path, - usess->consumer->subdir); - free(tmp_path); - goto error_unlock; - } - - DBG("Creating directory path for local tracing: \"%s\"", - tmp_path); - ret = run_as_mkdir_recursive(tmp_path, S_IRWXU | S_IRWXG, - ua_sess->euid, ua_sess->egid); - free(tmp_path); - if (ret < 0) { - if (errno != EEXIST) { - ERR("Trace directory creation error"); - goto error_unlock; - } - } - } - - /* - * Create the metadata for the application. This returns gracefully if a - * metadata was already set for the session. - */ - ret = create_ust_app_metadata(ua_sess, app, usess->consumer); - if (ret < 0) { - goto error_unlock; - } - health_code_update(); skip_setup: - /* This start the UST tracing */ + /* This starts the UST tracing */ pthread_mutex_lock(&app->sock_lock); ret = ustctl_start_session(app->sock, ua_sess->handle); pthread_mutex_unlock(&app->sock_lock); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("Error starting tracing for app pid: %d (ret: %d)", - app->pid, ret); - } else { - DBG("UST app start session failed. Application is dead."); - /* - * This is normal behavior, an application can die during the - * creation process. Don't report an error so the execution can - * continue normally. - */ + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app start session failed. Application is dead: pid = %d, sock = %d", + app->pid, app->sock); + pthread_mutex_unlock(&ua_sess->lock); + goto end; + } else if (ret == -EAGAIN) { + WARN("UST app start session failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); pthread_mutex_unlock(&ua_sess->lock); goto end; + + } else { + ERR("UST app start session failed with ret %d: pid = %d, sock = %d", + ret, app->pid, app->sock); } goto error_unlock; } /* Indicate that the session has been started once */ ua_sess->started = 1; + ua_sess->enabled = 1; pthread_mutex_unlock(&ua_sess->lock); @@ -4480,9 +4476,17 @@ skip_setup: pthread_mutex_lock(&app->sock_lock); ret = ustctl_wait_quiescent(app->sock); pthread_mutex_unlock(&app->sock_lock); - if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app wait quiescent failed for app pid %d ret %d", - app->pid, ret); + if (ret < 0) { + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app wait quiescent failed. Application is dead: pid = %d, sock = %d", + app->pid, app->sock); + } else if (ret == -EAGAIN) { + WARN("UST app wait quiescent failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); + } else { + ERR("UST app wait quiescent failed with ret %d: pid %d, sock = %d", + ret, app->pid, app->sock); + } } end: @@ -4544,30 +4548,40 @@ int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app) ret = ustctl_stop_session(app->sock, ua_sess->handle); pthread_mutex_unlock(&app->sock_lock); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("Error stopping tracing for app pid: %d (ret: %d)", - app->pid, ret); - } else { - DBG("UST app stop session failed. Application is dead."); - /* - * This is normal behavior, an application can die during the - * creation process. Don't report an error so the execution can - * continue normally. - */ + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app stop session failed. Application is dead: pid = %d, sock = %d", + app->pid, app->sock); + goto end_unlock; + } else if (ret == -EAGAIN) { + WARN("UST app stop session failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); goto end_unlock; + + } else { + ERR("UST app stop session failed with ret %d: pid = %d, sock = %d", + ret, app->pid, app->sock); } goto error_rcu_unlock; } health_code_update(); + ua_sess->enabled = 0; /* Quiescent wait after stopping trace */ pthread_mutex_lock(&app->sock_lock); ret = ustctl_wait_quiescent(app->sock); pthread_mutex_unlock(&app->sock_lock); - if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app wait quiescent failed for app pid %d ret %d", - app->pid, ret); + if (ret < 0) { + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app wait quiescent failed. Application is dead: pid= %d, sock = %d)", + app->pid, app->sock); + } else if (ret == -EAGAIN) { + WARN("UST app wait quiescent failed. Communication time out: pid= %d, sock = %d)", + app->pid, app->sock); + } else { + ERR("UST app wait quiescent failed with ret %d: pid= %d, sock = %d)", + ret, app->pid, app->sock); + } } health_code_update(); @@ -4915,9 +4929,17 @@ static int destroy_trace(struct ltt_ust_session *usess, struct ust_app *app) pthread_mutex_lock(&app->sock_lock); ret = ustctl_wait_quiescent(app->sock); pthread_mutex_unlock(&app->sock_lock); - if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app wait quiescent failed for app pid %d ret %d", - app->pid, ret); + if (ret < 0) { + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app wait quiescent failed. Application is dead: pid= %d, sock = %d)", + app->pid, app->sock); + } else if (ret == -EAGAIN) { + WARN("UST app wait quiescent failed. Communication time out: pid= %d, sock = %d)", + app->pid, app->sock); + } else { + ERR("UST app wait quiescent failed with ret %d: pid= %d, sock = %d)", + ret, app->pid, app->sock); + } } end: rcu_read_unlock(); @@ -5079,7 +5101,7 @@ end: /* * The caller must ensure that the application is compatible and is tracked - * by the PID tracker. + * by the process attribute trackers. */ static void ust_app_synchronize(struct ltt_ust_session *usess, @@ -5110,6 +5132,7 @@ void ust_app_synchronize(struct ltt_ust_session *usess, } rcu_read_lock(); + cds_lfht_for_each_entry(usess->domain_global.channels->ht, &uchan_iter, uchan, node.node) { struct ust_app_channel *ua_chan; @@ -5153,6 +5176,21 @@ void ust_app_synchronize(struct ltt_ust_session *usess, } } } + + /* + * Create the metadata for the application. This returns gracefully if a + * metadata was already set for the session. + * + * The metadata channel must be created after the data channels as the + * consumer daemon assumes this ordering. When interacting with a relay + * daemon, the consumer will use this assumption to send the + * "STREAMS_SENT" message to the relay daemon. + */ + ret = create_ust_app_metadata(ua_sess, app, usess->consumer); + if (ret < 0) { + goto error_unlock; + } + rcu_read_unlock(); end: @@ -5199,7 +5237,14 @@ void ust_app_global_update(struct ltt_ust_session *usess, struct ust_app *app) if (!app->compatible) { return; } - if (trace_ust_pid_tracker_lookup(usess, app->pid)) { + if (trace_ust_id_tracker_lookup(LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID, + usess, app->pid) && + trace_ust_id_tracker_lookup( + LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID, + usess, app->uid) && + trace_ust_id_tracker_lookup( + LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID, + usess, app->gid)) { /* * Synchronize the application's internal tracing configuration * and start tracing. @@ -5413,7 +5458,7 @@ static int reply_ust_register_channel(int sock, int cobjd, if (!app) { DBG("Application socket %d is being torn down. Abort event notify", sock); - ret = 0; + ret = -1; goto error_rcu_unlock; } @@ -5477,15 +5522,20 @@ static int reply_ust_register_channel(int sock, int cobjd, reply: DBG3("UST app replying to register channel key %" PRIu64 - " with id %u, type: %d, ret: %d", chan_reg_key, chan_id, type, + " with id %u, type = %d, ret = %d", chan_reg_key, chan_id, type, ret_code); ret = ustctl_reply_register_channel(sock, chan_id, type, ret_code); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app reply channel failed with ret %d", ret); + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app reply channel failed. Application died: pid = %d, sock = %d", + app->pid, app->sock); + } else if (ret == -EAGAIN) { + WARN("UST app reply channel failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); } else { - DBG3("UST app reply channel failed. Application died"); + ERR("UST app reply channel failed with ret %d: pid = %d, sock = %d", + ret, app->pid, app->sock); } goto error; } @@ -5529,7 +5579,7 @@ static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name, if (!app) { DBG("Application socket %d is being torn down. Abort event notify", sock); - ret = 0; + ret = -1; goto error_rcu_unlock; } @@ -5579,10 +5629,15 @@ static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name, */ ret = ustctl_reply_register_event(sock, event_id, ret_code); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app reply event failed with ret %d", ret); + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app reply event failed. Application died: pid = %d, sock = %d.", + app->pid, app->sock); + } else if (ret == -EAGAIN) { + WARN("UST app reply event failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); } else { - DBG3("UST app reply event failed. Application died"); + ERR("UST app reply event failed with ret %d: pid = %d, sock = %d", + ret, app->pid, app->sock); } /* * No need to wipe the create event since the application socket will @@ -5630,6 +5685,7 @@ static int add_enum_ust_registry(int sock, int sobjd, char *name, DBG("Application socket %d is being torn down. Aborting enum registration", sock); free(entries); + ret = -1; goto error_rcu_unlock; } @@ -5637,14 +5693,14 @@ static int add_enum_ust_registry(int sock, int sobjd, char *name, ua_sess = find_session_by_objd(app, sobjd); if (!ua_sess) { /* Return an error since this is not an error */ - DBG("Application session is being torn down (session not found). Aborting enum registration."); + DBG("Application session is being torn down (session not found Aborting enum registration."); free(entries); goto error_rcu_unlock; } registry = get_session_registry(ua_sess); if (!registry) { - DBG("Application session is being torn down (registry not found). Aborting enum registration."); + DBG("Application session is being torn down (registry not found Aborting enum registration."); free(entries); goto error_rcu_unlock; } @@ -5667,10 +5723,15 @@ static int add_enum_ust_registry(int sock, int sobjd, char *name, */ ret = ustctl_reply_register_enum(sock, enum_id, ret_code); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app reply enum failed with ret %d", ret); + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app reply enum failed. Application died: pid = %d, sock = %d", + app->pid, app->sock); + } else if (ret == -EAGAIN) { + WARN("UST app reply enum failed. Communication time out: pid = %d, sock = %d", + app->pid, app->sock); } else { - DBG3("UST app reply enum failed. Application died"); + ERR("UST app reply enum failed with ret %d: pid = %d, sock = %d", + ret, app->pid, app->sock); } /* * No need to wipe the create enum since the application socket will @@ -5702,10 +5763,15 @@ int ust_app_recv_notify(int sock) ret = ustctl_recv_notify(sock, &cmd); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app recv notify failed with ret %d", ret); + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app recv notify failed. Application died: sock = %d", + sock); + } else if (ret == -EAGAIN) { + WARN("UST app recv notify failed. Communication time out: sock = %d", + sock); } else { - DBG3("UST app recv notify failed. Application died"); + ERR("UST app recv notify failed with ret %d: sock = %d", + ret, sock); } goto error; } @@ -5724,10 +5790,15 @@ int ust_app_recv_notify(int sock) &loglevel_value, &sig, &nr_fields, &fields, &model_emf_uri); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app recv event failed with ret %d", ret); + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app recv event failed. Application died: sock = %d", + sock); + } else if (ret == -EAGAIN) { + WARN("UST app recv event failed. Communication time out: sock = %d", + sock); } else { - DBG3("UST app recv event failed. Application died"); + ERR("UST app recv event failed with ret %d: sock = %d", + ret, sock); } goto error; } @@ -5757,10 +5828,15 @@ int ust_app_recv_notify(int sock) ret = ustctl_recv_register_channel(sock, &sobjd, &cobjd, &nr_fields, &fields); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app recv channel failed with ret %d", ret); + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app recv channel failed. Application died: sock = %d", + sock); + } else if (ret == -EAGAIN) { + WARN("UST app recv channel failed. Communication time out: sock = %d", + sock); } else { - DBG3("UST app recv channel failed. Application died"); + ERR("UST app recv channel failed with ret %d: sock = %d)", + ret, sock); } goto error; } @@ -5790,10 +5866,15 @@ int ust_app_recv_notify(int sock) ret = ustctl_recv_register_enum(sock, &sobjd, name, &entries, &nr_entries); if (ret < 0) { - if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) { - ERR("UST app recv enum failed with ret %d", ret); + if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) { + DBG3("UST app recv enum failed. Application died: sock = %d", + sock); + } else if (ret == -EAGAIN) { + WARN("UST app recv enum failed. Communication time out: sock = %d", + sock); } else { - DBG3("UST app recv enum failed. Application died"); + ERR("UST app recv enum failed with ret %d: sock = %d", + ret, sock); } goto error; } @@ -5911,29 +5992,22 @@ void ust_app_destroy(struct ust_app *app) * * Returns LTTNG_OK on success or a LTTNG_ERR error code. */ -enum lttng_error_code ust_app_snapshot_record(struct ltt_ust_session *usess, - struct snapshot_output *output, int wait, +enum lttng_error_code ust_app_snapshot_record( + const struct ltt_ust_session *usess, + const struct consumer_output *output, int wait, uint64_t nb_packets_per_stream) { int ret = 0; enum lttng_error_code status = LTTNG_OK; struct lttng_ht_iter iter; struct ust_app *app; - char pathname[PATH_MAX]; - struct ltt_session *session = NULL; - uint64_t trace_archive_id; + char *trace_path = NULL; assert(usess); assert(output); rcu_read_lock(); - session = session_find_by_id(usess->id); - assert(session); - assert(pthread_mutex_trylock(&session->lock)); - assert(session_trylock_list()); - trace_archive_id = session->current_archive_id; - switch (usess->buffer_type) { case LTTNG_BUFFER_PER_UID: { @@ -5942,6 +6016,8 @@ enum lttng_error_code ust_app_snapshot_record(struct ltt_ust_session *usess, cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) { struct buffer_reg_channel *reg_chan; struct consumer_socket *socket; + char pathname[PATH_MAX]; + size_t consumer_path_offset = 0; if (!reg->registry->reg.ust->metadata_key) { /* Skip since no metadata is present */ @@ -5958,31 +6034,37 @@ enum lttng_error_code ust_app_snapshot_record(struct ltt_ust_session *usess, memset(pathname, 0, sizeof(pathname)); ret = snprintf(pathname, sizeof(pathname), - DEFAULT_UST_TRACE_DIR "/" DEFAULT_UST_TRACE_UID_PATH, + DEFAULT_UST_TRACE_UID_PATH, reg->uid, reg->bits_per_long); if (ret < 0) { PERROR("snprintf snapshot path"); status = LTTNG_ERR_INVALID; goto error; } - - /* Add the UST default trace dir to path. */ + /* Free path allowed on previous iteration. */ + free(trace_path); + trace_path = setup_channel_trace_path(usess->consumer, pathname, + &consumer_path_offset); + if (!trace_path) { + status = LTTNG_ERR_INVALID; + goto error; + } + /* Add the UST default trace dir to path. */ cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter, reg_chan, node.node) { status = consumer_snapshot_channel(socket, reg_chan->consumer_key, output, 0, usess->uid, - usess->gid, pathname, wait, - nb_packets_per_stream, - trace_archive_id); + usess->gid, &trace_path[consumer_path_offset], wait, + nb_packets_per_stream); if (status != LTTNG_OK) { goto error; } } status = consumer_snapshot_channel(socket, reg->registry->reg.ust->metadata_key, output, 1, - usess->uid, usess->gid, pathname, wait, 0, - trace_archive_id); + usess->uid, usess->gid, &trace_path[consumer_path_offset], + wait, 0); if (status != LTTNG_OK) { goto error; } @@ -5997,6 +6079,8 @@ enum lttng_error_code ust_app_snapshot_record(struct ltt_ust_session *usess, struct ust_app_channel *ua_chan; struct ust_app_session *ua_sess; struct ust_registry_session *registry; + char pathname[PATH_MAX]; + size_t consumer_path_offset = 0; ua_sess = lookup_session_by_app(usess, app); if (!ua_sess) { @@ -6006,7 +6090,7 @@ enum lttng_error_code ust_app_snapshot_record(struct ltt_ust_session *usess, /* Get the right consumer socket for the application. */ socket = consumer_find_socket_by_bitness(app->bits_per_long, - output->consumer); + output); if (!socket) { status = LTTNG_ERR_INVALID; goto error; @@ -6014,22 +6098,31 @@ enum lttng_error_code ust_app_snapshot_record(struct ltt_ust_session *usess, /* Add the UST default trace dir to path. */ memset(pathname, 0, sizeof(pathname)); - ret = snprintf(pathname, sizeof(pathname), DEFAULT_UST_TRACE_DIR "/%s", + ret = snprintf(pathname, sizeof(pathname), "%s", ua_sess->path); if (ret < 0) { status = LTTNG_ERR_INVALID; PERROR("snprintf snapshot path"); goto error; } - - cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter, + /* Free path allowed on previous iteration. */ + free(trace_path); + trace_path = setup_channel_trace_path(usess->consumer, pathname, + &consumer_path_offset); + if (!trace_path) { + status = LTTNG_ERR_INVALID; + goto error; + } + cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter, ua_chan, node.node) { status = consumer_snapshot_channel(socket, - ua_chan->key, output, - 0, ua_sess->euid, ua_sess->egid, - pathname, wait, - nb_packets_per_stream, - trace_archive_id); + ua_chan->key, output, 0, + ua_sess->effective_credentials + .uid, + ua_sess->effective_credentials + .gid, + &trace_path[consumer_path_offset], wait, + nb_packets_per_stream); switch (status) { case LTTNG_OK: break; @@ -6046,10 +6139,10 @@ enum lttng_error_code ust_app_snapshot_record(struct ltt_ust_session *usess, continue; } status = consumer_snapshot_channel(socket, - registry->metadata_key, output, - 1, ua_sess->euid, ua_sess->egid, - pathname, wait, 0, - trace_archive_id); + registry->metadata_key, output, 1, + ua_sess->effective_credentials.uid, + ua_sess->effective_credentials.gid, + &trace_path[consumer_path_offset], wait, 0); switch (status) { case LTTNG_OK: break; @@ -6067,18 +6160,16 @@ enum lttng_error_code ust_app_snapshot_record(struct ltt_ust_session *usess, } error: + free(trace_path); rcu_read_unlock(); - if (session) { - session_put(session); - } return status; } /* * Return the size taken by one more packet per stream. */ -uint64_t ust_app_get_size_one_more_packet_per_stream(struct ltt_ust_session *usess, - uint64_t cur_nr_packets) +uint64_t ust_app_get_size_one_more_packet_per_stream( + const struct ltt_ust_session *usess, uint64_t cur_nr_packets) { uint64_t tot_size = 0; struct ust_app *app; @@ -6317,7 +6408,6 @@ enum lttng_error_code ust_app_rotate_session(struct ltt_session *session) struct lttng_ht_iter iter; struct ust_app *app; struct ltt_ust_session *usess = session->ust_session; - char pathname[LTTNG_PATH_MAX]; assert(usess); @@ -6340,38 +6430,40 @@ enum lttng_error_code ust_app_rotate_session(struct ltt_session *session) goto error; } - ret = snprintf(pathname, sizeof(pathname), - DEFAULT_UST_TRACE_DIR "/" DEFAULT_UST_TRACE_UID_PATH, - reg->uid, reg->bits_per_long); - if (ret < 0 || ret == sizeof(pathname)) { - PERROR("Failed to format rotation path"); - cmd_ret = LTTNG_ERR_INVALID; - goto error; - } - /* Rotate the data channels. */ cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter, reg_chan, node.node) { ret = consumer_rotate_channel(socket, reg_chan->consumer_key, usess->uid, usess->gid, - usess->consumer, pathname, - /* is_metadata_channel */ false, - session->current_archive_id); + usess->consumer, + /* is_metadata_channel */ false); if (ret < 0) { cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER; goto error; } } + /* + * The metadata channel might not be present. + * + * Consumer stream allocation can be done + * asynchronously and can fail on intermediary + * operations (i.e add context) and lead to data + * channels created with no metadata channel. + */ + if (!reg->registry->reg.ust->metadata_key) { + /* Skip since no metadata is present. */ + continue; + } + (void) push_metadata(reg->registry->reg.ust, usess->consumer); ret = consumer_rotate_channel(socket, reg->registry->reg.ust->metadata_key, usess->uid, usess->gid, - usess->consumer, pathname, - /* is_metadata_channel */ true, - session->current_archive_id); + usess->consumer, + /* is_metadata_channel */ true); if (ret < 0) { cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER; goto error; @@ -6393,14 +6485,6 @@ enum lttng_error_code ust_app_rotate_session(struct ltt_session *session) /* Session not associated with this app. */ continue; } - ret = snprintf(pathname, sizeof(pathname), - DEFAULT_UST_TRACE_DIR "/%s", - ua_sess->path); - if (ret < 0 || ret == sizeof(pathname)) { - PERROR("Failed to format rotation path"); - cmd_ret = LTTNG_ERR_INVALID; - goto error; - } /* Get the right consumer socket for the application. */ socket = consumer_find_socket_by_bitness(app->bits_per_long, @@ -6416,15 +6500,17 @@ enum lttng_error_code ust_app_rotate_session(struct ltt_session *session) continue; } - /* Rotate the data channels. */ cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter, ua_chan, node.node) { - ret = consumer_rotate_channel(socket, ua_chan->key, - ua_sess->euid, ua_sess->egid, - ua_sess->consumer, pathname, - /* is_metadata_channel */ false, - session->current_archive_id); + ret = consumer_rotate_channel(socket, + ua_chan->key, + ua_sess->effective_credentials + .uid, + ua_sess->effective_credentials + .gid, + ua_sess->consumer, + /* is_metadata_channel */ false); if (ret < 0) { /* Per-PID buffer and application going away. */ if (ret == -LTTNG_ERR_CHAN_NOT_FOUND) @@ -6436,11 +6522,12 @@ enum lttng_error_code ust_app_rotate_session(struct ltt_session *session) /* Rotate the metadata channel. */ (void) push_metadata(registry, usess->consumer); - ret = consumer_rotate_channel(socket, registry->metadata_key, - ua_sess->euid, ua_sess->egid, - ua_sess->consumer, pathname, - /* is_metadata_channel */ true, - session->current_archive_id); + ret = consumer_rotate_channel(socket, + registry->metadata_key, + ua_sess->effective_credentials.uid, + ua_sess->effective_credentials.gid, + ua_sess->consumer, + /* is_metadata_channel */ true); if (ret < 0) { /* Per-PID buffer and application going away. */ if (ret == -LTTNG_ERR_CHAN_NOT_FOUND) @@ -6462,3 +6549,381 @@ error: rcu_read_unlock(); return cmd_ret; } + +enum lttng_error_code ust_app_create_channel_subdirectories( + const struct ltt_ust_session *usess) +{ + enum lttng_error_code ret = LTTNG_OK; + struct lttng_ht_iter iter; + enum lttng_trace_chunk_status chunk_status; + char *pathname_index; + int fmt_ret; + + assert(usess->current_trace_chunk); + rcu_read_lock(); + + switch (usess->buffer_type) { + case LTTNG_BUFFER_PER_UID: + { + struct buffer_reg_uid *reg; + + cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) { + fmt_ret = asprintf(&pathname_index, + DEFAULT_UST_TRACE_DIR "/" DEFAULT_UST_TRACE_UID_PATH "/" DEFAULT_INDEX_DIR, + reg->uid, reg->bits_per_long); + if (fmt_ret < 0) { + ERR("Failed to format channel index directory"); + ret = LTTNG_ERR_CREATE_DIR_FAIL; + goto error; + } + + /* + * Create the index subdirectory which will take care + * of implicitly creating the channel's path. + */ + chunk_status = lttng_trace_chunk_create_subdirectory( + usess->current_trace_chunk, + pathname_index); + free(pathname_index); + if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) { + ret = LTTNG_ERR_CREATE_DIR_FAIL; + goto error; + } + } + break; + } + case LTTNG_BUFFER_PER_PID: + { + struct ust_app *app; + + /* + * Create the toplevel ust/ directory in case no apps are running. + */ + chunk_status = lttng_trace_chunk_create_subdirectory( + usess->current_trace_chunk, + DEFAULT_UST_TRACE_DIR); + if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) { + ret = LTTNG_ERR_CREATE_DIR_FAIL; + goto error; + } + + cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, + pid_n.node) { + struct ust_app_session *ua_sess; + struct ust_registry_session *registry; + + ua_sess = lookup_session_by_app(usess, app); + if (!ua_sess) { + /* Session not associated with this app. */ + continue; + } + + registry = get_session_registry(ua_sess); + if (!registry) { + DBG("Application session is being torn down. Skip application."); + continue; + } + + fmt_ret = asprintf(&pathname_index, + DEFAULT_UST_TRACE_DIR "/%s/" DEFAULT_INDEX_DIR, + ua_sess->path); + if (fmt_ret < 0) { + ERR("Failed to format channel index directory"); + ret = LTTNG_ERR_CREATE_DIR_FAIL; + goto error; + } + /* + * Create the index subdirectory which will take care + * of implicitly creating the channel's path. + */ + chunk_status = lttng_trace_chunk_create_subdirectory( + usess->current_trace_chunk, + pathname_index); + free(pathname_index); + if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) { + ret = LTTNG_ERR_CREATE_DIR_FAIL; + goto error; + } + } + break; + } + default: + abort(); + } + + ret = LTTNG_OK; +error: + rcu_read_unlock(); + return ret; +} + +/* + * Clear all the channels of a session. + * + * Return LTTNG_OK on success or else an LTTng error code. + */ +enum lttng_error_code ust_app_clear_session(struct ltt_session *session) +{ + int ret; + enum lttng_error_code cmd_ret = LTTNG_OK; + struct lttng_ht_iter iter; + struct ust_app *app; + struct ltt_ust_session *usess = session->ust_session; + + assert(usess); + + rcu_read_lock(); + + if (usess->active) { + ERR("Expecting inactive session %s (%" PRIu64 ")", session->name, session->id); + cmd_ret = LTTNG_ERR_FATAL; + goto end; + } + + switch (usess->buffer_type) { + case LTTNG_BUFFER_PER_UID: + { + struct buffer_reg_uid *reg; + + cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) { + struct buffer_reg_channel *reg_chan; + struct consumer_socket *socket; + + /* Get consumer socket to use to push the metadata.*/ + socket = consumer_find_socket_by_bitness(reg->bits_per_long, + usess->consumer); + if (!socket) { + cmd_ret = LTTNG_ERR_INVALID; + goto error_socket; + } + + /* Clear the data channels. */ + cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter, + reg_chan, node.node) { + ret = consumer_clear_channel(socket, + reg_chan->consumer_key); + if (ret < 0) { + goto error; + } + } + + (void) push_metadata(reg->registry->reg.ust, usess->consumer); + + /* + * Clear the metadata channel. + * Metadata channel is not cleared per se but we still need to + * perform a rotation operation on it behind the scene. + */ + ret = consumer_clear_channel(socket, + reg->registry->reg.ust->metadata_key); + if (ret < 0) { + goto error; + } + } + break; + } + case LTTNG_BUFFER_PER_PID: + { + cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) { + struct consumer_socket *socket; + struct lttng_ht_iter chan_iter; + struct ust_app_channel *ua_chan; + struct ust_app_session *ua_sess; + struct ust_registry_session *registry; + + ua_sess = lookup_session_by_app(usess, app); + if (!ua_sess) { + /* Session not associated with this app. */ + continue; + } + + /* Get the right consumer socket for the application. */ + socket = consumer_find_socket_by_bitness(app->bits_per_long, + usess->consumer); + if (!socket) { + cmd_ret = LTTNG_ERR_INVALID; + goto error_socket; + } + + registry = get_session_registry(ua_sess); + if (!registry) { + DBG("Application session is being torn down. Skip application."); + continue; + } + + /* Clear the data channels. */ + cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter, + ua_chan, node.node) { + ret = consumer_clear_channel(socket, ua_chan->key); + if (ret < 0) { + /* Per-PID buffer and application going away. */ + if (ret == -LTTNG_ERR_CHAN_NOT_FOUND) { + continue; + } + goto error; + } + } + + (void) push_metadata(registry, usess->consumer); + + /* + * Clear the metadata channel. + * Metadata channel is not cleared per se but we still need to + * perform rotation operation on it behind the scene. + */ + ret = consumer_clear_channel(socket, registry->metadata_key); + if (ret < 0) { + /* Per-PID buffer and application going away. */ + if (ret == -LTTNG_ERR_CHAN_NOT_FOUND) { + continue; + } + goto error; + } + } + break; + } + default: + assert(0); + break; + } + + cmd_ret = LTTNG_OK; + goto end; + +error: + switch (-ret) { + case LTTCOMM_CONSUMERD_RELAYD_CLEAR_DISALLOWED: + cmd_ret = LTTNG_ERR_CLEAR_RELAY_DISALLOWED; + break; + default: + cmd_ret = LTTNG_ERR_CLEAR_FAIL_CONSUMER; + } + +error_socket: +end: + rcu_read_unlock(); + return cmd_ret; +} + +/* + * This function skips the metadata channel as the begin/end timestamps of a + * metadata packet are useless. + * + * Moreover, opening a packet after a "clear" will cause problems for live + * sessions as it will introduce padding that was not part of the first trace + * chunk. The relay daemon expects the content of the metadata stream of + * successive metadata trace chunks to be strict supersets of one another. + * + * For example, flushing a packet at the beginning of the metadata stream of + * a trace chunk resulting from a "clear" session command will cause the + * size of the metadata stream of the new trace chunk to not match the size of + * the metadata stream of the original chunk. This will confuse the relay + * daemon as the same "offset" in a metadata stream will no longer point + * to the same content. + */ +enum lttng_error_code ust_app_open_packets(struct ltt_session *session) +{ + enum lttng_error_code ret = LTTNG_OK; + struct lttng_ht_iter iter; + struct ltt_ust_session *usess = session->ust_session; + + assert(usess); + + rcu_read_lock(); + + switch (usess->buffer_type) { + case LTTNG_BUFFER_PER_UID: + { + struct buffer_reg_uid *reg; + + cds_list_for_each_entry ( + reg, &usess->buffer_reg_uid_list, lnode) { + struct buffer_reg_channel *reg_chan; + struct consumer_socket *socket; + + socket = consumer_find_socket_by_bitness( + reg->bits_per_long, usess->consumer); + if (!socket) { + ret = LTTNG_ERR_FATAL; + goto error; + } + + cds_lfht_for_each_entry(reg->registry->channels->ht, + &iter.iter, reg_chan, node.node) { + const int open_ret = + consumer_open_channel_packets( + socket, + reg_chan->consumer_key); + + if (open_ret < 0) { + ret = LTTNG_ERR_UNK; + goto error; + } + } + } + break; + } + case LTTNG_BUFFER_PER_PID: + { + struct ust_app *app; + + cds_lfht_for_each_entry ( + ust_app_ht->ht, &iter.iter, app, pid_n.node) { + struct consumer_socket *socket; + struct lttng_ht_iter chan_iter; + struct ust_app_channel *ua_chan; + struct ust_app_session *ua_sess; + struct ust_registry_session *registry; + + ua_sess = lookup_session_by_app(usess, app); + if (!ua_sess) { + /* Session not associated with this app. */ + continue; + } + + /* Get the right consumer socket for the application. */ + socket = consumer_find_socket_by_bitness( + app->bits_per_long, usess->consumer); + if (!socket) { + ret = LTTNG_ERR_FATAL; + goto error; + } + + registry = get_session_registry(ua_sess); + if (!registry) { + DBG("Application session is being torn down. Skip application."); + continue; + } + + cds_lfht_for_each_entry(ua_sess->channels->ht, + &chan_iter.iter, ua_chan, node.node) { + const int open_ret = + consumer_open_channel_packets( + socket, + ua_chan->key); + + if (open_ret < 0) { + /* + * Per-PID buffer and application going + * away. + */ + if (open_ret == -LTTNG_ERR_CHAN_NOT_FOUND) { + continue; + } + + ret = LTTNG_ERR_UNK; + goto error; + } + } + } + break; + } + default: + abort(); + break; + } + +error: + rcu_read_unlock(); + return ret; +}