X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fsession.c;h=2d95aa2687cf2be475faf953a93172c54c7a81ed;hp=88bbe1309c4a1270cbbf418a97af3d5aeee57fb5;hb=ddd915a3dd0eeb1667286051cc1e17017436fe5e;hpb=a7ceb342d473cc37e00d74c45b04b5378965e055 diff --git a/src/bin/lttng-sessiond/session.c b/src/bin/lttng-sessiond/session.c index 88bbe1309..2d95aa268 100644 --- a/src/bin/lttng-sessiond/session.c +++ b/src/bin/lttng-sessiond/session.c @@ -1,18 +1,8 @@ /* - * Copyright (C) 2011 - David Goulet + * Copyright (C) 2011 David Goulet * - * 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 @@ -55,7 +45,7 @@ struct ltt_session_clear_notifier_element { * NOTES: * * No ltt_session.lock is taken here because those data structure are widely - * spread across the lttng-tools code base so before caling functions below + * spread across the lttng-tools code base so before calling functions below * that can read/write a session, the caller MUST acquire the session lock * using session_lock() and session_unlock(). */ @@ -77,6 +67,8 @@ static const char *forbidden_name_chars = "/"; /* Global hash table to keep the sessions, indexed by id. */ static struct lttng_ht *ltt_sessions_ht_by_id = NULL; +/* Global hash table to keep the sessions, indexed by name. */ +static struct lttng_ht *ltt_sessions_ht_by_name = NULL; /* * Validate the session name for forbidden characters. @@ -303,7 +295,7 @@ end: } /* - * Allocate the ltt_sessions_ht_by_id HT. + * Allocate the ltt_sessions_ht_by_id and ltt_sessions_ht_by_name HT. * * The session list lock must be held. */ @@ -318,6 +310,15 @@ static int ltt_sessions_ht_alloc(void) ERR("Failed to allocate ltt_sessions_ht_by_id"); goto end; } + + DBG("Allocating ltt_sessions_ht_by_name"); + ltt_sessions_ht_by_name = lttng_ht_new(0, LTTNG_HT_TYPE_STRING); + if (!ltt_sessions_ht_by_name) { + ret = -1; + ERR("Failed to allocate ltt_sessions_ht_by_name"); + goto end; + } + end: return ret; } @@ -329,17 +330,23 @@ end: */ static void ltt_sessions_ht_destroy(void) { - if (!ltt_sessions_ht_by_id) { - return; + if (ltt_sessions_ht_by_id) { + ht_cleanup_push(ltt_sessions_ht_by_id); + ltt_sessions_ht_by_id = NULL; + } + + if (ltt_sessions_ht_by_name) { + ht_cleanup_push(ltt_sessions_ht_by_name); + ltt_sessions_ht_by_name = NULL; } - ht_cleanup_push(ltt_sessions_ht_by_id); - ltt_sessions_ht_by_id = NULL; + + return; } /* - * Add a ltt_session to the ltt_sessions_ht_by_id. - * If unallocated, the ltt_sessions_ht_by_id HT is allocated. - * The session list lock must be held. + * Add a ltt_session to the ltt_sessions_ht_by_id and ltt_sessions_ht_by_name. + * If unallocated, the ltt_sessions_ht_by_id and ltt_sessions_ht_by_name. HTs + * are allocated. The session list lock must be held. */ static void add_session_ht(struct ltt_session *ls) { @@ -354,35 +361,45 @@ static void add_session_ht(struct ltt_session *ls) goto end; } } + + /* Should always be present with ltt_sessions_ht_by_id. */ + assert(ltt_sessions_ht_by_name); + lttng_ht_node_init_u64(&ls->node, ls->id); lttng_ht_add_unique_u64(ltt_sessions_ht_by_id, &ls->node); + lttng_ht_node_init_str(&ls->node_by_name, ls->name); + lttng_ht_add_unique_str(ltt_sessions_ht_by_name, &ls->node_by_name); + end: return; } /* - * Test if ltt_sessions_ht_by_id is empty. + * Test if ltt_sessions_ht_by_id/name are empty. * Return 1 if empty, 0 if not empty. * The session list lock must be held. */ static int ltt_sessions_ht_empty(void) { - int ret; + unsigned long count; if (!ltt_sessions_ht_by_id) { - ret = 1; + count = 0; goto end; } - ret = lttng_ht_get_count(ltt_sessions_ht_by_id) ? 0 : 1; + assert(ltt_sessions_ht_by_name); + + count = lttng_ht_get_count(ltt_sessions_ht_by_id); + assert(count == lttng_ht_get_count(ltt_sessions_ht_by_name)); end: - return ret; + return count ? 0 : 1; } /* - * Remove a ltt_session from the ltt_sessions_ht_by_id. - * If empty, the ltt_sessions_ht_by_id HT is freed. + * Remove a ltt_session from the ltt_sessions_ht_by_id/name. + * If empty, the ltt_sessions_ht_by_id/name HTs are freed. * The session list lock must be held. */ static void del_session_ht(struct ltt_session *ls) @@ -392,13 +409,18 @@ static void del_session_ht(struct ltt_session *ls) assert(ls); assert(ltt_sessions_ht_by_id); + assert(ltt_sessions_ht_by_name); iter.iter.node = &ls->node.node; ret = lttng_ht_del(ltt_sessions_ht_by_id, &iter); assert(!ret); + iter.iter.node = &ls->node_by_name.node; + ret = lttng_ht_del(ltt_sessions_ht_by_name, &iter); + assert(!ret); + if (ltt_sessions_ht_empty()) { - DBG("Empty ltt_sessions_ht_by_id, destroying it"); + DBG("Empty ltt_sessions_ht_by_id/name, destroying hast tables"); ltt_sessions_ht_destroy(); } } @@ -481,7 +503,7 @@ int _session_set_trace_chunk_no_lock_check(struct ltt_session *session, CONSUMER_DST_LOCAL; session->ust_session->current_trace_chunk = new_trace_chunk; - if (is_local_trace) { + if (is_local_trace) { enum lttng_error_code ret_error_code; ret_error_code = ust_app_create_channel_subdirectories( @@ -489,7 +511,7 @@ int _session_set_trace_chunk_no_lock_check(struct ltt_session *session, if (ret_error_code != LTTNG_OK) { goto error; } - } + } cds_lfht_for_each_entry( session->ust_session->consumer->socks->ht, &iter, socket, node.node) { @@ -499,11 +521,11 @@ int _session_set_trace_chunk_no_lock_check(struct ltt_session *session, session->id, new_trace_chunk, DEFAULT_UST_TRACE_DIR); pthread_mutex_unlock(socket->lock); - if (ret) { + if (ret) { goto error; - } - } - } + } + } + } if (session->kernel_session) { const uint64_t relayd_id = session->kernel_session->consumer->net_seq_index; @@ -520,7 +542,7 @@ int _session_set_trace_chunk_no_lock_check(struct ltt_session *session, if (ret_error_code != LTTNG_OK) { goto error; } - } + } cds_lfht_for_each_entry( session->kernel_session->consumer->socks->ht, &iter, socket, node.node) { @@ -530,11 +552,11 @@ int _session_set_trace_chunk_no_lock_check(struct ltt_session *session, session->id, new_trace_chunk, DEFAULT_KERNEL_TRACE_DIR); pthread_mutex_unlock(socket->lock); - if (ret) { + if (ret) { goto error; - } - } - } + } + } + } /* * Update local current trace chunk state last, only if all remote @@ -558,7 +580,7 @@ error: if (session->kernel_session) { session->kernel_session->current_trace_chunk = NULL; } - /* + /* * Release references taken in the case where all references could not * be acquired. */ @@ -584,8 +606,8 @@ struct lttng_trace_chunk *session_create_new_trace_chunk( const char *base_path; struct lttng_directory_handle *session_output_directory = NULL; const struct lttng_credentials session_credentials = { - .uid = session->uid, - .gid = session->gid, + .uid = LTTNG_OPTIONAL_INIT_VALUE(session->uid), + .gid = LTTNG_OPTIONAL_INIT_VALUE(session->gid), }; uint64_t next_chunk_id; const struct consumer_output *output; @@ -802,6 +824,83 @@ end: return 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. + */ +static +enum lttng_error_code session_kernel_open_packets(struct ltt_session *session) +{ + enum lttng_error_code ret = LTTNG_OK; + struct consumer_socket *socket; + struct lttng_ht_iter iter; + struct cds_lfht_node *node; + struct ltt_kernel_channel *chan; + + rcu_read_lock(); + + cds_lfht_first(session->kernel_session->consumer->socks->ht, &iter.iter); + node = cds_lfht_iter_get_node(&iter.iter); + socket = container_of(node, typeof(*socket), node.node); + + cds_list_for_each_entry(chan, + &session->kernel_session->channel_list.head, list) { + int open_ret; + + DBG("Open packet of kernel channel: channel key = %" PRIu64 + ", session name = %s, session_id = %" PRIu64, + chan->key, session->name, session->id); + + open_ret = consumer_open_channel_packets(socket, chan->key); + if (open_ret < 0) { + /* General error (no known error expected). */ + ret = LTTNG_ERR_UNK; + goto end; + } + } + +end: + rcu_read_unlock(); + return ret; +} + +enum lttng_error_code session_open_packets(struct ltt_session *session) +{ + enum lttng_error_code ret = LTTNG_OK; + + DBG("Opening packets of session channels: session name = %s, session id = %" PRIu64, + session->name, session->id); + + if (session->ust_session) { + ret = ust_app_open_packets(session); + if (ret != LTTNG_OK) { + goto end; + } + } + + if (session->kernel_session) { + ret = session_kernel_open_packets(session); + if (ret != LTTNG_OK) { + goto end; + } + } + +end: + return ret; +} + /* * Set a session's current trace chunk. * @@ -865,7 +964,7 @@ void session_release(struct urcu_ref *ref) usess = session->ust_session; ksess = session->kernel_session; - /* Clean kernel session teardown, keeping data for destroy notifier. */ + /* Clean kernel session teardown, keeping data for destroy notifier. */ kernel_destroy_session(ksess); /* UST session teardown, keeping data for destroy notifier. */ @@ -887,7 +986,7 @@ void session_release(struct urcu_ref *ref) * Must notify the kernel thread here to update it's poll set in order to * remove the channel(s)' fd just destroyed. */ - ret = notify_thread_pipe(kernel_poll_pipe[1]); + ret = notify_thread_pipe(the_kernel_poll_pipe[1]); if (ret < 0) { PERROR("write kernel poll pipe"); } @@ -922,6 +1021,7 @@ void session_release(struct urcu_ref *ref) * Broadcast after free-ing to ensure the memory is * reclaimed before the main thread exits. */ + ASSERT_LOCKED(ltt_session_list.lock); pthread_cond_broadcast(<t_session_list.removal_cond); } } @@ -1229,18 +1329,13 @@ error: } /* - * Check if the UID or GID match the session. Root user has access to all + * Check if the UID matches the session. Root user has access to all * sessions. */ -int session_access_ok(struct ltt_session *session, uid_t uid, gid_t gid) +bool session_access_ok(struct ltt_session *session, uid_t uid) { assert(session); - - if (uid != session->uid && gid != session->gid && uid != 0) { - return 0; - } else { - return 1; - } + return (uid == session->uid) || uid == 0; } /* @@ -1290,3 +1385,43 @@ int session_reset_rotation_state(struct ltt_session *session, } return ret; } + +/* + * Sample the id of a session looked up via its name. + * Here the term "sampling" hint the caller that this return the id at a given + * point in time with no guarantee that the session for which the id was + * sampled still exist at that point. + * + * Return 0 when the session is not found, + * Return 1 when the session is found and set `id`. + */ +bool sample_session_id_by_name(const char *name, uint64_t *id) +{ + bool found = false; + struct lttng_ht_node_str *node; + struct lttng_ht_iter iter; + struct ltt_session *ls; + + rcu_read_lock(); + + if (!ltt_sessions_ht_by_name) { + found = false; + goto end; + } + + lttng_ht_lookup(ltt_sessions_ht_by_name, name, &iter); + node = lttng_ht_iter_get_node_str(&iter); + if (node == NULL) { + found = false; + goto end; + } + + ls = caa_container_of(node, struct ltt_session, node_by_name); + *id = ls->id; + found = true; + + DBG3("Session id `%" PRIu64 "` sampled for session `%s", *id, name); +end: + rcu_read_unlock(); + return found; +}