/* Copyright (c) 2009, 2010, 2011, 2012, 2013 Nicira, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include #include "ovsdb-idl.h" #include #include #include #include #include "bitmap.h" #include "dynamic-string.h" #include "fatal-signal.h" #include "json.h" #include "jsonrpc.h" #include "ovsdb-data.h" #include "ovsdb-error.h" #include "ovsdb-idl-provider.h" #include "poll-loop.h" #include "shash.h" #include "util.h" #include "vlog.h" VLOG_DEFINE_THIS_MODULE(ovsdb_idl); /* An arc from one idl_row to another. When row A contains a UUID that * references row B, this is represented by an arc from A (the source) to B * (the destination). * * Arcs from a row to itself are omitted, that is, src and dst are always * different. * * Arcs are never duplicated, that is, even if there are multiple references * from A to B, there is only a single arc from A to B. * * Arcs are directed: an arc from A to B is the converse of an an arc from B to * A. Both an arc and its converse may both be present, if each row refers * to the other circularly. * * The source and destination row may be in the same table or in different * tables. */ struct ovsdb_idl_arc { struct list src_node; /* In src->src_arcs list. */ struct list dst_node; /* In dst->dst_arcs list. */ struct ovsdb_idl_row *src; /* Source row. */ struct ovsdb_idl_row *dst; /* Destination row. */ }; struct ovsdb_idl { const struct ovsdb_idl_class *class; struct jsonrpc_session *session; struct shash table_by_name; struct ovsdb_idl_table *tables; /* Contains "struct ovsdb_idl_table *"s.*/ struct json *monitor_request_id; unsigned int last_monitor_request_seqno; unsigned int change_seqno; bool verify_write_only; /* Database locking. */ char *lock_name; /* Name of lock we need, NULL if none. */ bool has_lock; /* Has db server told us we have the lock? */ bool is_lock_contended; /* Has db server told us we can't get lock? */ struct json *lock_request_id; /* JSON-RPC ID of in-flight lock request. */ /* Transaction support. */ struct ovsdb_idl_txn *txn; struct hmap outstanding_txns; }; struct ovsdb_idl_txn { struct hmap_node hmap_node; struct json *request_id; struct ovsdb_idl *idl; struct hmap txn_rows; enum ovsdb_idl_txn_status status; char *error; bool dry_run; struct ds comment; /* Increments. */ const char *inc_table; const char *inc_column; struct uuid inc_row; unsigned int inc_index; int64_t inc_new_value; /* Inserted rows. */ struct hmap inserted_rows; /* Contains "struct ovsdb_idl_txn_insert"s. */ }; struct ovsdb_idl_txn_insert { struct hmap_node hmap_node; /* In struct ovsdb_idl_txn's inserted_rows. */ struct uuid dummy; /* Dummy UUID used locally. */ int op_index; /* Index into transaction's operation array. */ struct uuid real; /* Real UUID used by database server. */ }; static struct vlog_rate_limit syntax_rl = VLOG_RATE_LIMIT_INIT(1, 5); static struct vlog_rate_limit semantic_rl = VLOG_RATE_LIMIT_INIT(1, 5); static void ovsdb_idl_clear(struct ovsdb_idl *); static void ovsdb_idl_send_monitor_request(struct ovsdb_idl *); static void ovsdb_idl_parse_update(struct ovsdb_idl *, const struct json *); static struct ovsdb_error *ovsdb_idl_parse_update__(struct ovsdb_idl *, const struct json *); static bool ovsdb_idl_process_update(struct ovsdb_idl_table *, const struct uuid *, const struct json *old, const struct json *new); static void ovsdb_idl_insert_row(struct ovsdb_idl_row *, const struct json *); static void ovsdb_idl_delete_row(struct ovsdb_idl_row *); static bool ovsdb_idl_modify_row(struct ovsdb_idl_row *, const struct json *); static bool ovsdb_idl_row_is_orphan(const struct ovsdb_idl_row *); static struct ovsdb_idl_row *ovsdb_idl_row_create__( const struct ovsdb_idl_table_class *); static struct ovsdb_idl_row *ovsdb_idl_row_create(struct ovsdb_idl_table *, const struct uuid *); static void ovsdb_idl_row_destroy(struct ovsdb_idl_row *); static void ovsdb_idl_row_parse(struct ovsdb_idl_row *); static void ovsdb_idl_row_unparse(struct ovsdb_idl_row *); static void ovsdb_idl_row_clear_old(struct ovsdb_idl_row *); static void ovsdb_idl_row_clear_new(struct ovsdb_idl_row *); static void ovsdb_idl_txn_abort_all(struct ovsdb_idl *); static bool ovsdb_idl_txn_process_reply(struct ovsdb_idl *, const struct jsonrpc_msg *msg); static void ovsdb_idl_send_lock_request(struct ovsdb_idl *); static void ovsdb_idl_send_unlock_request(struct ovsdb_idl *); static void ovsdb_idl_parse_lock_reply(struct ovsdb_idl *, const struct json *); static void ovsdb_idl_parse_lock_notify(struct ovsdb_idl *, const struct json *params, bool new_has_lock); /* Creates and returns a connection to database 'remote', which should be in a * form acceptable to jsonrpc_session_open(). The connection will maintain an * in-memory replica of the remote database whose schema is described by * 'class'. (Ordinarily 'class' is compiled from an OVSDB schema automatically * by ovsdb-idlc.) * * Passes 'retry' to jsonrpc_session_open(). See that function for * documentation. * * If 'monitor_everything_by_default' is true, then everything in the remote * database will be replicated by default. ovsdb_idl_omit() and * ovsdb_idl_omit_alert() may be used to selectively drop some columns from * monitoring. * * If 'monitor_everything_by_default' is false, then no columns or tables will * be replicated by default. ovsdb_idl_add_column() and ovsdb_idl_add_table() * must be used to choose some columns or tables to replicate. */ struct ovsdb_idl * ovsdb_idl_create(const char *remote, const struct ovsdb_idl_class *class, bool monitor_everything_by_default, bool retry) { struct ovsdb_idl *idl; uint8_t default_mode; size_t i; default_mode = (monitor_everything_by_default ? OVSDB_IDL_MONITOR | OVSDB_IDL_ALERT : 0); idl = xzalloc(sizeof *idl); idl->class = class; idl->session = jsonrpc_session_open(remote, retry); shash_init(&idl->table_by_name); idl->tables = xmalloc(class->n_tables * sizeof *idl->tables); for (i = 0; i < class->n_tables; i++) { const struct ovsdb_idl_table_class *tc = &class->tables[i]; struct ovsdb_idl_table *table = &idl->tables[i]; size_t j; shash_add_assert(&idl->table_by_name, tc->name, table); table->class = tc; table->modes = xmalloc(tc->n_columns); memset(table->modes, default_mode, tc->n_columns); table->need_table = false; shash_init(&table->columns); for (j = 0; j < tc->n_columns; j++) { const struct ovsdb_idl_column *column = &tc->columns[j]; shash_add_assert(&table->columns, column->name, column); } hmap_init(&table->rows); table->idl = idl; } idl->last_monitor_request_seqno = UINT_MAX; hmap_init(&idl->outstanding_txns); return idl; } /* Destroys 'idl' and all of the data structures that it manages. */ void ovsdb_idl_destroy(struct ovsdb_idl *idl) { if (idl) { size_t i; ovs_assert(!idl->txn); ovsdb_idl_clear(idl); jsonrpc_session_close(idl->session); for (i = 0; i < idl->class->n_tables; i++) { struct ovsdb_idl_table *table = &idl->tables[i]; shash_destroy(&table->columns); hmap_destroy(&table->rows); free(table->modes); } shash_destroy(&idl->table_by_name); free(idl->tables); json_destroy(idl->monitor_request_id); free(idl->lock_name); json_destroy(idl->lock_request_id); hmap_destroy(&idl->outstanding_txns); free(idl); } } static void ovsdb_idl_clear(struct ovsdb_idl *idl) { bool changed = false; size_t i; for (i = 0; i < idl->class->n_tables; i++) { struct ovsdb_idl_table *table = &idl->tables[i]; struct ovsdb_idl_row *row, *next_row; if (hmap_is_empty(&table->rows)) { continue; } changed = true; HMAP_FOR_EACH_SAFE (row, next_row, hmap_node, &table->rows) { struct ovsdb_idl_arc *arc, *next_arc; if (!ovsdb_idl_row_is_orphan(row)) { ovsdb_idl_row_unparse(row); } LIST_FOR_EACH_SAFE (arc, next_arc, src_node, &row->src_arcs) { free(arc); } /* No need to do anything with dst_arcs: some node has those arcs * as forward arcs and will destroy them itself. */ ovsdb_idl_row_destroy(row); } } if (changed) { idl->change_seqno++; } } /* Processes a batch of messages from the database server on 'idl'. This may * cause the IDL's contents to change. The client may check for that with * ovsdb_idl_get_seqno(). */ void ovsdb_idl_run(struct ovsdb_idl *idl) { int i; ovs_assert(!idl->txn); jsonrpc_session_run(idl->session); for (i = 0; jsonrpc_session_is_connected(idl->session) && i < 50; i++) { struct jsonrpc_msg *msg; unsigned int seqno; seqno = jsonrpc_session_get_seqno(idl->session); if (idl->last_monitor_request_seqno != seqno) { idl->last_monitor_request_seqno = seqno; ovsdb_idl_txn_abort_all(idl); ovsdb_idl_send_monitor_request(idl); if (idl->lock_name) { ovsdb_idl_send_lock_request(idl); } break; } msg = jsonrpc_session_recv(idl->session); if (!msg) { break; } if (msg->type == JSONRPC_NOTIFY && !strcmp(msg->method, "update") && msg->params->type == JSON_ARRAY && msg->params->u.array.n == 2 && msg->params->u.array.elems[0]->type == JSON_NULL) { /* Database contents changed. */ ovsdb_idl_parse_update(idl, msg->params->u.array.elems[1]); } else if (msg->type == JSONRPC_REPLY && idl->monitor_request_id && json_equal(idl->monitor_request_id, msg->id)) { /* Reply to our "monitor" request. */ idl->change_seqno++; json_destroy(idl->monitor_request_id); idl->monitor_request_id = NULL; ovsdb_idl_clear(idl); ovsdb_idl_parse_update(idl, msg->result); } else if (msg->type == JSONRPC_REPLY && idl->lock_request_id && json_equal(idl->lock_request_id, msg->id)) { /* Reply to our "lock" request. */ ovsdb_idl_parse_lock_reply(idl, msg->result); } else if (msg->type == JSONRPC_NOTIFY && !strcmp(msg->method, "locked")) { /* We got our lock. */ ovsdb_idl_parse_lock_notify(idl, msg->params, true); } else if (msg->type == JSONRPC_NOTIFY && !strcmp(msg->method, "stolen")) { /* Someone else stole our lock. */ ovsdb_idl_parse_lock_notify(idl, msg->params, false); } else if ((msg->type == JSONRPC_ERROR || msg->type == JSONRPC_REPLY) && ovsdb_idl_txn_process_reply(idl, msg)) { /* ovsdb_idl_txn_process_reply() did everything needful. */ } else { /* This can happen if ovsdb_idl_txn_destroy() is called to destroy * a transaction before we receive the reply, so keep the log level * low. */ VLOG_DBG("%s: received unexpected %s message", jsonrpc_session_get_name(idl->session), jsonrpc_msg_type_to_string(msg->type)); } jsonrpc_msg_destroy(msg); } } /* Arranges for poll_block() to wake up when ovsdb_idl_run() has something to * do or when activity occurs on a transaction on 'idl'. */ void ovsdb_idl_wait(struct ovsdb_idl *idl) { jsonrpc_session_wait(idl->session); jsonrpc_session_recv_wait(idl->session); } /* Returns a "sequence number" that represents the state of 'idl'. When * ovsdb_idl_run() changes the database, the sequence number changes. The * initial fetch of the entire contents of the remote database is considered to * be one kind of change. Successfully acquiring a lock, if one has been * configured with ovsdb_idl_set_lock(), is also considered to be a change. * * As long as the sequence number does not change, the client may continue to * use any data structures it obtains from 'idl'. But when it changes, the * client must not access any of these data structures again, because they * could have freed or reused for other purposes. * * The sequence number can occasionally change even if the database does not. * This happens if the connection to the database drops and reconnects, which * causes the database contents to be reloaded even if they didn't change. (It * could also happen if the database server sends out a "change" that reflects * what the IDL already thought was in the database. The database server is * not supposed to do that, but bugs could in theory cause it to do so.) */ unsigned int ovsdb_idl_get_seqno(const struct ovsdb_idl *idl) { return idl->change_seqno; } /* Returns true if 'idl' successfully connected to the remote database and * retrieved its contents (even if the connection subsequently dropped and is * in the process of reconnecting). If so, then 'idl' contains an atomic * snapshot of the database's contents (but it might be arbitrarily old if the * connection dropped). * * Returns false if 'idl' has never connected or retrieved the database's * contents. If so, 'idl' is empty. */ bool ovsdb_idl_has_ever_connected(const struct ovsdb_idl *idl) { return ovsdb_idl_get_seqno(idl) != 0; } /* Reconfigures 'idl' so that it would reconnect to the database, if * connection was dropped. */ void ovsdb_idl_enable_reconnect(struct ovsdb_idl *idl) { jsonrpc_session_enable_reconnect(idl->session); } /* Forces 'idl' to drop its connection to the database and reconnect. In the * meantime, the contents of 'idl' will not change. */ void ovsdb_idl_force_reconnect(struct ovsdb_idl *idl) { jsonrpc_session_force_reconnect(idl->session); } /* Some IDL users should only write to write-only columns. Furthermore, * writing to a column which is not write-only can cause serious performance * degradations for these users. This function causes 'idl' to reject writes * to columns which are not marked write only using ovsdb_idl_omit_alert(). */ void ovsdb_idl_verify_write_only(struct ovsdb_idl *idl) { idl->verify_write_only = true; } bool ovsdb_idl_is_alive(const struct ovsdb_idl *idl) { return jsonrpc_session_is_alive(idl->session); } int ovsdb_idl_get_last_error(const struct ovsdb_idl *idl) { return jsonrpc_session_get_last_error(idl->session); } static unsigned char * ovsdb_idl_get_mode(struct ovsdb_idl *idl, const struct ovsdb_idl_column *column) { size_t i; ovs_assert(!idl->change_seqno); for (i = 0; i < idl->class->n_tables; i++) { const struct ovsdb_idl_table *table = &idl->tables[i]; const struct ovsdb_idl_table_class *tc = table->class; if (column >= tc->columns && column < &tc->columns[tc->n_columns]) { return &table->modes[column - tc->columns]; } } OVS_NOT_REACHED(); } static void add_ref_table(struct ovsdb_idl *idl, const struct ovsdb_base_type *base) { if (base->type == OVSDB_TYPE_UUID && base->u.uuid.refTableName) { struct ovsdb_idl_table *table; table = shash_find_data(&idl->table_by_name, base->u.uuid.refTableName); if (table) { table->need_table = true; } else { VLOG_WARN("%s IDL class missing referenced table %s", idl->class->database, base->u.uuid.refTableName); } } } /* Turns on OVSDB_IDL_MONITOR and OVSDB_IDL_ALERT for 'column' in 'idl'. Also * ensures that any tables referenced by 'column' will be replicated, even if * no columns in that table are selected for replication (see * ovsdb_idl_add_table() for more information). * * This function is only useful if 'monitor_everything_by_default' was false in * the call to ovsdb_idl_create(). This function should be called between * ovsdb_idl_create() and the first call to ovsdb_idl_run(). */ void ovsdb_idl_add_column(struct ovsdb_idl *idl, const struct ovsdb_idl_column *column) { *ovsdb_idl_get_mode(idl, column) = OVSDB_IDL_MONITOR | OVSDB_IDL_ALERT; add_ref_table(idl, &column->type.key); add_ref_table(idl, &column->type.value); } /* Ensures that the table with class 'tc' will be replicated on 'idl' even if * no columns are selected for replication. This can be useful because it * allows 'idl' to keep track of what rows in the table actually exist, which * in turn allows columns that reference the table to have accurate contents. * (The IDL presents the database with references to rows that do not exist * removed.) * * This function is only useful if 'monitor_everything_by_default' was false in * the call to ovsdb_idl_create(). This function should be called between * ovsdb_idl_create() and the first call to ovsdb_idl_run(). */ void ovsdb_idl_add_table(struct ovsdb_idl *idl, const struct ovsdb_idl_table_class *tc) { size_t i; for (i = 0; i < idl->class->n_tables; i++) { struct ovsdb_idl_table *table = &idl->tables[i]; if (table->class == tc) { table->need_table = true; return; } } OVS_NOT_REACHED(); } /* Turns off OVSDB_IDL_ALERT for 'column' in 'idl'. * * This function should be called between ovsdb_idl_create() and the first call * to ovsdb_idl_run(). */ void ovsdb_idl_omit_alert(struct ovsdb_idl *idl, const struct ovsdb_idl_column *column) { *ovsdb_idl_get_mode(idl, column) &= ~OVSDB_IDL_ALERT; } /* Sets the mode for 'column' in 'idl' to 0. See the big comment above * OVSDB_IDL_MONITOR for details. * * This function should be called between ovsdb_idl_create() and the first call * to ovsdb_idl_run(). */ void ovsdb_idl_omit(struct ovsdb_idl *idl, const struct ovsdb_idl_column *column) { *ovsdb_idl_get_mode(idl, column) = 0; } static void ovsdb_idl_send_monitor_request(struct ovsdb_idl *idl) { struct json *monitor_requests; struct jsonrpc_msg *msg; size_t i; monitor_requests = json_object_create(); for (i = 0; i < idl->class->n_tables; i++) { const struct ovsdb_idl_table *table = &idl->tables[i]; const struct ovsdb_idl_table_class *tc = table->class; struct json *monitor_request, *columns; size_t j; columns = table->need_table ? json_array_create_empty() : NULL; for (j = 0; j < tc->n_columns; j++) { const struct ovsdb_idl_column *column = &tc->columns[j]; if (table->modes[j] & OVSDB_IDL_MONITOR) { if (!columns) { columns = json_array_create_empty(); } json_array_add(columns, json_string_create(column->name)); } } if (columns) { monitor_request = json_object_create(); json_object_put(monitor_request, "columns", columns); json_object_put(monitor_requests, tc->name, monitor_request); } } json_destroy(idl->monitor_request_id); msg = jsonrpc_create_request( "monitor", json_array_create_3(json_string_create(idl->class->database), json_null_create(), monitor_requests), &idl->monitor_request_id); jsonrpc_session_send(idl->session, msg); } static void ovsdb_idl_parse_update(struct ovsdb_idl *idl, const struct json *table_updates) { struct ovsdb_error *error = ovsdb_idl_parse_update__(idl, table_updates); if (error) { if (!VLOG_DROP_WARN(&syntax_rl)) { char *s = ovsdb_error_to_string(error); VLOG_WARN_RL(&syntax_rl, "%s", s); free(s); } ovsdb_error_destroy(error); } } static struct ovsdb_error * ovsdb_idl_parse_update__(struct ovsdb_idl *idl, const struct json *table_updates) { const struct shash_node *tables_node; if (table_updates->type != JSON_OBJECT) { return ovsdb_syntax_error(table_updates, NULL, " is not an object"); } SHASH_FOR_EACH (tables_node, json_object(table_updates)) { const struct json *table_update = tables_node->data; const struct shash_node *table_node; struct ovsdb_idl_table *table; table = shash_find_data(&idl->table_by_name, tables_node->name); if (!table) { return ovsdb_syntax_error( table_updates, NULL, " includes unknown table \"%s\"", tables_node->name); } if (table_update->type != JSON_OBJECT) { return ovsdb_syntax_error(table_update, NULL, " for table \"%s\" is " "not an object", table->class->name); } SHASH_FOR_EACH (table_node, json_object(table_update)) { const struct json *row_update = table_node->data; const struct json *old_json, *new_json; struct uuid uuid; if (!uuid_from_string(&uuid, table_node->name)) { return ovsdb_syntax_error(table_update, NULL, " for table \"%s\" " "contains bad UUID " "\"%s\" as member name", table->class->name, table_node->name); } if (row_update->type != JSON_OBJECT) { return ovsdb_syntax_error(row_update, NULL, " for table \"%s\" " "contains for %s that " "is not an object", table->class->name, table_node->name); } old_json = shash_find_data(json_object(row_update), "old"); new_json = shash_find_data(json_object(row_update), "new"); if (old_json && old_json->type != JSON_OBJECT) { return ovsdb_syntax_error(old_json, NULL, "\"old\" is not object"); } else if (new_json && new_json->type != JSON_OBJECT) { return ovsdb_syntax_error(new_json, NULL, "\"new\" is not object"); } else if ((old_json != NULL) + (new_json != NULL) != shash_count(json_object(row_update))) { return ovsdb_syntax_error(row_update, NULL, " contains unexpected " "member"); } else if (!old_json && !new_json) { return ovsdb_syntax_error(row_update, NULL, " missing \"old\" " "and \"new\" members"); } if (ovsdb_idl_process_update(table, &uuid, old_json, new_json)) { idl->change_seqno++; } } } return NULL; } static struct ovsdb_idl_row * ovsdb_idl_get_row(struct ovsdb_idl_table *table, const struct uuid *uuid) { struct ovsdb_idl_row *row; HMAP_FOR_EACH_WITH_HASH (row, hmap_node, uuid_hash(uuid), &table->rows) { if (uuid_equals(&row->uuid, uuid)) { return row; } } return NULL; } /* Returns true if a column with mode OVSDB_IDL_MODE_RW changed, false * otherwise. */ static bool ovsdb_idl_process_update(struct ovsdb_idl_table *table, const struct uuid *uuid, const struct json *old, const struct json *new) { struct ovsdb_idl_row *row; row = ovsdb_idl_get_row(table, uuid); if (!new) { /* Delete row. */ if (row && !ovsdb_idl_row_is_orphan(row)) { /* XXX perhaps we should check the 'old' values? */ ovsdb_idl_delete_row(row); } else { VLOG_WARN_RL(&semantic_rl, "cannot delete missing row "UUID_FMT" " "from table %s", UUID_ARGS(uuid), table->class->name); return false; } } else if (!old) { /* Insert row. */ if (!row) { ovsdb_idl_insert_row(ovsdb_idl_row_create(table, uuid), new); } else if (ovsdb_idl_row_is_orphan(row)) { ovsdb_idl_insert_row(row, new); } else { VLOG_WARN_RL(&semantic_rl, "cannot add existing row "UUID_FMT" to " "table %s", UUID_ARGS(uuid), table->class->name); return ovsdb_idl_modify_row(row, new); } } else { /* Modify row. */ if (row) { /* XXX perhaps we should check the 'old' values? */ if (!ovsdb_idl_row_is_orphan(row)) { return ovsdb_idl_modify_row(row, new); } else { VLOG_WARN_RL(&semantic_rl, "cannot modify missing but " "referenced row "UUID_FMT" in table %s", UUID_ARGS(uuid), table->class->name); ovsdb_idl_insert_row(row, new); } } else { VLOG_WARN_RL(&semantic_rl, "cannot modify missing row "UUID_FMT" " "in table %s", UUID_ARGS(uuid), table->class->name); ovsdb_idl_insert_row(ovsdb_idl_row_create(table, uuid), new); } } return true; } /* Returns true if a column with mode OVSDB_IDL_MODE_RW changed, false * otherwise. */ static bool ovsdb_idl_row_update(struct ovsdb_idl_row *row, const struct json *row_json) { struct ovsdb_idl_table *table = row->table; struct shash_node *node; bool changed = false; SHASH_FOR_EACH (node, json_object(row_json)) { const char *column_name = node->name; const struct ovsdb_idl_column *column; struct ovsdb_datum datum; struct ovsdb_error *error; column = shash_find_data(&table->columns, column_name); if (!column) { VLOG_WARN_RL(&syntax_rl, "unknown column %s updating row "UUID_FMT, column_name, UUID_ARGS(&row->uuid)); continue; } error = ovsdb_datum_from_json(&datum, &column->type, node->data, NULL); if (!error) { unsigned int column_idx = column - table->class->columns; struct ovsdb_datum *old = &row->old[column_idx]; if (!ovsdb_datum_equals(old, &datum, &column->type)) { ovsdb_datum_swap(old, &datum); if (table->modes[column_idx] & OVSDB_IDL_ALERT) { changed = true; } } else { /* Didn't really change but the OVSDB monitor protocol always * includes every value in a row. */ } ovsdb_datum_destroy(&datum, &column->type); } else { char *s = ovsdb_error_to_string(error); VLOG_WARN_RL(&syntax_rl, "error parsing column %s in row "UUID_FMT " in table %s: %s", column_name, UUID_ARGS(&row->uuid), table->class->name, s); free(s); ovsdb_error_destroy(error); } } return changed; } /* When a row A refers to row B through a column with a "refTable" constraint, * but row B does not exist, row B is called an "orphan row". Orphan rows * should not persist, because the database enforces referential integrity, but * they can appear transiently as changes from the database are received (the * database doesn't try to topologically sort them and circular references mean * it isn't always possible anyhow). * * This function returns true if 'row' is an orphan row, otherwise false. */ static bool ovsdb_idl_row_is_orphan(const struct ovsdb_idl_row *row) { return !row->old && !row->new; } /* Returns true if 'row' is conceptually part of the database as modified by * the current transaction (if any), false otherwise. * * This function will return true if 'row' is not an orphan (see the comment on * ovsdb_idl_row_is_orphan()) and: * * - 'row' exists in the database and has not been deleted within the * current transaction (if any). * * - 'row' was inserted within the current transaction and has not been * deleted. (In the latter case you should not have passed 'row' in at * all, because ovsdb_idl_txn_delete() freed it.) * * This function will return false if 'row' is an orphan or if 'row' was * deleted within the current transaction. */ static bool ovsdb_idl_row_exists(const struct ovsdb_idl_row *row) { return row->new != NULL; } static void ovsdb_idl_row_parse(struct ovsdb_idl_row *row) { const struct ovsdb_idl_table_class *class = row->table->class; size_t i; for (i = 0; i < class->n_columns; i++) { const struct ovsdb_idl_column *c = &class->columns[i]; (c->parse)(row, &row->old[i]); } } static void ovsdb_idl_row_unparse(struct ovsdb_idl_row *row) { const struct ovsdb_idl_table_class *class = row->table->class; size_t i; for (i = 0; i < class->n_columns; i++) { const struct ovsdb_idl_column *c = &class->columns[i]; (c->unparse)(row); } } static void ovsdb_idl_row_clear_old(struct ovsdb_idl_row *row) { ovs_assert(row->old == row->new); if (!ovsdb_idl_row_is_orphan(row)) { const struct ovsdb_idl_table_class *class = row->table->class; size_t i; for (i = 0; i < class->n_columns; i++) { ovsdb_datum_destroy(&row->old[i], &class->columns[i].type); } free(row->old); row->old = row->new = NULL; } } static void ovsdb_idl_row_clear_new(struct ovsdb_idl_row *row) { if (row->old != row->new) { if (row->new) { const struct ovsdb_idl_table_class *class = row->table->class; size_t i; if (row->written) { BITMAP_FOR_EACH_1 (i, class->n_columns, row->written) { ovsdb_datum_destroy(&row->new[i], &class->columns[i].type); } } free(row->new); free(row->written); row->written = NULL; } row->new = row->old; } } static void ovsdb_idl_row_clear_arcs(struct ovsdb_idl_row *row, bool destroy_dsts) { struct ovsdb_idl_arc *arc, *next; /* Delete all forward arcs. If 'destroy_dsts', destroy any orphaned rows * that this causes to be unreferenced. */ LIST_FOR_EACH_SAFE (arc, next, src_node, &row->src_arcs) { list_remove(&arc->dst_node); if (destroy_dsts && ovsdb_idl_row_is_orphan(arc->dst) && list_is_empty(&arc->dst->dst_arcs)) { ovsdb_idl_row_destroy(arc->dst); } free(arc); } list_init(&row->src_arcs); } /* Force nodes that reference 'row' to reparse. */ static void ovsdb_idl_row_reparse_backrefs(struct ovsdb_idl_row *row) { struct ovsdb_idl_arc *arc, *next; /* This is trickier than it looks. ovsdb_idl_row_clear_arcs() will destroy * 'arc', so we need to use the "safe" variant of list traversal. However, * calling an ovsdb_idl_column's 'parse' function will add an arc * equivalent to 'arc' to row->arcs. That could be a problem for * traversal, but it adds it at the beginning of the list to prevent us * from stumbling upon it again. * * (If duplicate arcs were possible then we would need to make sure that * 'next' didn't also point into 'arc''s destination, but we forbid * duplicate arcs.) */ LIST_FOR_EACH_SAFE (arc, next, dst_node, &row->dst_arcs) { struct ovsdb_idl_row *ref = arc->src; ovsdb_idl_row_unparse(ref); ovsdb_idl_row_clear_arcs(ref, false); ovsdb_idl_row_parse(ref); } } static struct ovsdb_idl_row * ovsdb_idl_row_create__(const struct ovsdb_idl_table_class *class) { struct ovsdb_idl_row *row = xzalloc(class->allocation_size); class->row_init(row); list_init(&row->src_arcs); list_init(&row->dst_arcs); hmap_node_nullify(&row->txn_node); return row; } static struct ovsdb_idl_row * ovsdb_idl_row_create(struct ovsdb_idl_table *table, const struct uuid *uuid) { struct ovsdb_idl_row *row = ovsdb_idl_row_create__(table->class); hmap_insert(&table->rows, &row->hmap_node, uuid_hash(uuid)); row->uuid = *uuid; row->table = table; return row; } static void ovsdb_idl_row_destroy(struct ovsdb_idl_row *row) { if (row) { ovsdb_idl_row_clear_old(row); hmap_remove(&row->table->rows, &row->hmap_node); free(row); } } static void ovsdb_idl_insert_row(struct ovsdb_idl_row *row, const struct json *row_json) { const struct ovsdb_idl_table_class *class = row->table->class; size_t i; ovs_assert(!row->old && !row->new); row->old = row->new = xmalloc(class->n_columns * sizeof *row->old); for (i = 0; i < class->n_columns; i++) { ovsdb_datum_init_default(&row->old[i], &class->columns[i].type); } ovsdb_idl_row_update(row, row_json); ovsdb_idl_row_parse(row); ovsdb_idl_row_reparse_backrefs(row); } static void ovsdb_idl_delete_row(struct ovsdb_idl_row *row) { ovsdb_idl_row_unparse(row); ovsdb_idl_row_clear_arcs(row, true); ovsdb_idl_row_clear_old(row); if (list_is_empty(&row->dst_arcs)) { ovsdb_idl_row_destroy(row); } else { ovsdb_idl_row_reparse_backrefs(row); } } /* Returns true if a column with mode OVSDB_IDL_MODE_RW changed, false * otherwise. */ static bool ovsdb_idl_modify_row(struct ovsdb_idl_row *row, const struct json *row_json) { bool changed; ovsdb_idl_row_unparse(row); ovsdb_idl_row_clear_arcs(row, true); changed = ovsdb_idl_row_update(row, row_json); ovsdb_idl_row_parse(row); return changed; } static bool may_add_arc(const struct ovsdb_idl_row *src, const struct ovsdb_idl_row *dst) { const struct ovsdb_idl_arc *arc; /* No self-arcs. */ if (src == dst) { return false; } /* No duplicate arcs. * * We only need to test whether the first arc in dst->dst_arcs originates * at 'src', since we add all of the arcs from a given source in a clump * (in a single call to ovsdb_idl_row_parse()) and new arcs are always * added at the front of the dst_arcs list. */ if (list_is_empty(&dst->dst_arcs)) { return true; } arc = CONTAINER_OF(dst->dst_arcs.next, struct ovsdb_idl_arc, dst_node); return arc->src != src; } static struct ovsdb_idl_table * ovsdb_idl_table_from_class(const struct ovsdb_idl *idl, const struct ovsdb_idl_table_class *table_class) { return &idl->tables[table_class - idl->class->tables]; } /* Called by ovsdb-idlc generated code. */ struct ovsdb_idl_row * ovsdb_idl_get_row_arc(struct ovsdb_idl_row *src, struct ovsdb_idl_table_class *dst_table_class, const struct uuid *dst_uuid) { struct ovsdb_idl *idl = src->table->idl; struct ovsdb_idl_table *dst_table; struct ovsdb_idl_arc *arc; struct ovsdb_idl_row *dst; dst_table = ovsdb_idl_table_from_class(idl, dst_table_class); dst = ovsdb_idl_get_row(dst_table, dst_uuid); if (idl->txn) { /* We're being called from ovsdb_idl_txn_write(). We must not update * any arcs, because the transaction will be backed out at commit or * abort time and we don't want our graph screwed up. * * Just return the destination row, if there is one and it has not been * deleted. */ if (dst && (hmap_node_is_null(&dst->txn_node) || dst->new)) { return dst; } return NULL; } else { /* We're being called from some other context. Update the graph. */ if (!dst) { dst = ovsdb_idl_row_create(dst_table, dst_uuid); } /* Add a new arc, if it wouldn't be a self-arc or a duplicate arc. */ if (may_add_arc(src, dst)) { /* The arc *must* be added at the front of the dst_arcs list. See * ovsdb_idl_row_reparse_backrefs() for details. */ arc = xmalloc(sizeof *arc); list_push_front(&src->src_arcs, &arc->src_node); list_push_front(&dst->dst_arcs, &arc->dst_node); arc->src = src; arc->dst = dst; } return !ovsdb_idl_row_is_orphan(dst) ? dst : NULL; } } /* Searches 'tc''s table in 'idl' for a row with UUID 'uuid'. Returns a * pointer to the row if there is one, otherwise a null pointer. */ const struct ovsdb_idl_row * ovsdb_idl_get_row_for_uuid(const struct ovsdb_idl *idl, const struct ovsdb_idl_table_class *tc, const struct uuid *uuid) { return ovsdb_idl_get_row(ovsdb_idl_table_from_class(idl, tc), uuid); } static struct ovsdb_idl_row * next_real_row(struct ovsdb_idl_table *table, struct hmap_node *node) { for (; node; node = hmap_next(&table->rows, node)) { struct ovsdb_idl_row *row; row = CONTAINER_OF(node, struct ovsdb_idl_row, hmap_node); if (ovsdb_idl_row_exists(row)) { return row; } } return NULL; } /* Returns a row in 'table_class''s table in 'idl', or a null pointer if that * table is empty. * * Database tables are internally maintained as hash tables, so adding or * removing rows while traversing the same table can cause some rows to be * visited twice or not at apply. */ const struct ovsdb_idl_row * ovsdb_idl_first_row(const struct ovsdb_idl *idl, const struct ovsdb_idl_table_class *table_class) { struct ovsdb_idl_table *table = ovsdb_idl_table_from_class(idl, table_class); return next_real_row(table, hmap_first(&table->rows)); } /* Returns a row following 'row' within its table, or a null pointer if 'row' * is the last row in its table. */ const struct ovsdb_idl_row * ovsdb_idl_next_row(const struct ovsdb_idl_row *row) { struct ovsdb_idl_table *table = row->table; return next_real_row(table, hmap_next(&table->rows, &row->hmap_node)); } /* Reads and returns the value of 'column' within 'row'. If an ongoing * transaction has changed 'column''s value, the modified value is returned. * * The caller must not modify or free the returned value. * * Various kinds of changes can invalidate the returned value: writing to the * same 'column' in 'row' (e.g. with ovsdb_idl_txn_write()), deleting 'row' * (e.g. with ovsdb_idl_txn_delete()), or completing an ongoing transaction * (e.g. with ovsdb_idl_txn_commit() or ovsdb_idl_txn_abort()). If the * returned value is needed for a long time, it is best to make a copy of it * with ovsdb_datum_clone(). */ const struct ovsdb_datum * ovsdb_idl_read(const struct ovsdb_idl_row *row, const struct ovsdb_idl_column *column) { const struct ovsdb_idl_table_class *class; size_t column_idx; ovs_assert(!ovsdb_idl_row_is_synthetic(row)); class = row->table->class; column_idx = column - class->columns; ovs_assert(row->new != NULL); ovs_assert(column_idx < class->n_columns); if (row->written && bitmap_is_set(row->written, column_idx)) { return &row->new[column_idx]; } else if (row->old) { return &row->old[column_idx]; } else { return ovsdb_datum_default(&column->type); } } /* Same as ovsdb_idl_read(), except that it also asserts that 'column' has key * type 'key_type' and value type 'value_type'. (Scalar and set types will * have a value type of OVSDB_TYPE_VOID.) * * This is useful in code that "knows" that a particular column has a given * type, so that it will abort if someone changes the column's type without * updating the code that uses it. */ const struct ovsdb_datum * ovsdb_idl_get(const struct ovsdb_idl_row *row, const struct ovsdb_idl_column *column, enum ovsdb_atomic_type key_type OVS_UNUSED, enum ovsdb_atomic_type value_type OVS_UNUSED) { ovs_assert(column->type.key.type == key_type); ovs_assert(column->type.value.type == value_type); return ovsdb_idl_read(row, column); } /* Returns false if 'row' was obtained from the IDL, true if it was initialized * to all-zero-bits by some other entity. If 'row' was set up some other way * then the return value is indeterminate. */ bool ovsdb_idl_row_is_synthetic(const struct ovsdb_idl_row *row) { return row->table == NULL; } /* Transactions. */ static void ovsdb_idl_txn_complete(struct ovsdb_idl_txn *txn, enum ovsdb_idl_txn_status); /* Returns a string representation of 'status'. The caller must not modify or * free the returned string. * * The return value is probably useful only for debug log messages and unit * tests. */ const char * ovsdb_idl_txn_status_to_string(enum ovsdb_idl_txn_status status) { switch (status) { case TXN_UNCOMMITTED: return "uncommitted"; case TXN_UNCHANGED: return "unchanged"; case TXN_INCOMPLETE: return "incomplete"; case TXN_ABORTED: return "aborted"; case TXN_SUCCESS: return "success"; case TXN_TRY_AGAIN: return "try again"; case TXN_NOT_LOCKED: return "not locked"; case TXN_ERROR: return "error"; } return ""; } /* Starts a new transaction on 'idl'. A given ovsdb_idl may only have a single * active transaction at a time. See the large comment in ovsdb-idl.h for * general information on transactions. */ struct ovsdb_idl_txn * ovsdb_idl_txn_create(struct ovsdb_idl *idl) { struct ovsdb_idl_txn *txn; ovs_assert(!idl->txn); idl->txn = txn = xmalloc(sizeof *txn); txn->request_id = NULL; txn->idl = idl; hmap_init(&txn->txn_rows); txn->status = TXN_UNCOMMITTED; txn->error = NULL; txn->dry_run = false; ds_init(&txn->comment); txn->inc_table = NULL; txn->inc_column = NULL; hmap_init(&txn->inserted_rows); return txn; } /* Appends 's', which is treated as a printf()-type format string, to the * comments that will be passed to the OVSDB server when 'txn' is committed. * (The comment will be committed to the OVSDB log, which "ovsdb-tool * show-log" can print in a relatively human-readable form.) */ void ovsdb_idl_txn_add_comment(struct ovsdb_idl_txn *txn, const char *s, ...) { va_list args; if (txn->comment.length) { ds_put_char(&txn->comment, '\n'); } va_start(args, s); ds_put_format_valist(&txn->comment, s, args); va_end(args); } /* Marks 'txn' as a transaction that will not actually modify the database. In * almost every way, the transaction is treated like other transactions. It * must be committed or aborted like other transactions, it will be sent to the * database server like other transactions, and so on. The only difference is * that the operations sent to the database server will include, as the last * step, an "abort" operation, so that any changes made by the transaction will * not actually take effect. */ void ovsdb_idl_txn_set_dry_run(struct ovsdb_idl_txn *txn) { txn->dry_run = true; } /* Causes 'txn', when committed, to increment the value of 'column' within * 'row' by 1. 'column' must have an integer type. After 'txn' commits * successfully, the client may retrieve the final (incremented) value of * 'column' with ovsdb_idl_txn_get_increment_new_value(). * * The client could accomplish something similar with ovsdb_idl_read(), * ovsdb_idl_txn_verify() and ovsdb_idl_txn_write(), or with ovsdb-idlc * generated wrappers for these functions. However, ovsdb_idl_txn_increment() * will never (by itself) fail because of a verify error. * * The intended use is for incrementing the "next_cfg" column in the * Open_vSwitch table. */ void ovsdb_idl_txn_increment(struct ovsdb_idl_txn *txn, const struct ovsdb_idl_row *row, const struct ovsdb_idl_column *column) { ovs_assert(!txn->inc_table); ovs_assert(column->type.key.type == OVSDB_TYPE_INTEGER); ovs_assert(column->type.value.type == OVSDB_TYPE_VOID); txn->inc_table = row->table->class->name; txn->inc_column = column->name; txn->inc_row = row->uuid; } /* Destroys 'txn' and frees all associated memory. If ovsdb_idl_txn_commit() * has been called for 'txn' but the commit is still incomplete (that is, the * last call returned TXN_INCOMPLETE) then the transaction may or may not still * end up committing at the database server, but the client will not be able to * get any further status information back. */ void ovsdb_idl_txn_destroy(struct ovsdb_idl_txn *txn) { struct ovsdb_idl_txn_insert *insert, *next; json_destroy(txn->request_id); if (txn->status == TXN_INCOMPLETE) { hmap_remove(&txn->idl->outstanding_txns, &txn->hmap_node); } ovsdb_idl_txn_abort(txn); ds_destroy(&txn->comment); free(txn->error); HMAP_FOR_EACH_SAFE (insert, next, hmap_node, &txn->inserted_rows) { free(insert); } hmap_destroy(&txn->inserted_rows); free(txn); } /* Causes poll_block() to wake up if 'txn' has completed committing. */ void ovsdb_idl_txn_wait(const struct ovsdb_idl_txn *txn) { if (txn->status != TXN_UNCOMMITTED && txn->status != TXN_INCOMPLETE) { poll_immediate_wake(); } } static struct json * where_uuid_equals(const struct uuid *uuid) { return json_array_create_1( json_array_create_3( json_string_create("_uuid"), json_string_create("=="), json_array_create_2( json_string_create("uuid"), json_string_create_nocopy( xasprintf(UUID_FMT, UUID_ARGS(uuid)))))); } static char * uuid_name_from_uuid(const struct uuid *uuid) { char *name; char *p; name = xasprintf("row"UUID_FMT, UUID_ARGS(uuid)); for (p = name; *p != '\0'; p++) { if (*p == '-') { *p = '_'; } } return name; } static const struct ovsdb_idl_row * ovsdb_idl_txn_get_row(const struct ovsdb_idl_txn *txn, const struct uuid *uuid) { const struct ovsdb_idl_row *row; HMAP_FOR_EACH_WITH_HASH (row, txn_node, uuid_hash(uuid), &txn->txn_rows) { if (uuid_equals(&row->uuid, uuid)) { return row; } } return NULL; } /* XXX there must be a cleaner way to do this */ static struct json * substitute_uuids(struct json *json, const struct ovsdb_idl_txn *txn) { if (json->type == JSON_ARRAY) { struct uuid uuid; size_t i; if (json->u.array.n == 2 && json->u.array.elems[0]->type == JSON_STRING && json->u.array.elems[1]->type == JSON_STRING && !strcmp(json->u.array.elems[0]->u.string, "uuid") && uuid_from_string(&uuid, json->u.array.elems[1]->u.string)) { const struct ovsdb_idl_row *row; row = ovsdb_idl_txn_get_row(txn, &uuid); if (row && !row->old && row->new) { json_destroy(json); return json_array_create_2( json_string_create("named-uuid"), json_string_create_nocopy(uuid_name_from_uuid(&uuid))); } } for (i = 0; i < json->u.array.n; i++) { json->u.array.elems[i] = substitute_uuids(json->u.array.elems[i], txn); } } else if (json->type == JSON_OBJECT) { struct shash_node *node; SHASH_FOR_EACH (node, json_object(json)) { node->data = substitute_uuids(node->data, txn); } } return json; } static void ovsdb_idl_txn_disassemble(struct ovsdb_idl_txn *txn) { struct ovsdb_idl_row *row, *next; /* This must happen early. Otherwise, ovsdb_idl_row_parse() will call an * ovsdb_idl_column's 'parse' function, which will call * ovsdb_idl_get_row_arc(), which will seen that the IDL is in a * transaction and fail to update the graph. */ txn->idl->txn = NULL; HMAP_FOR_EACH_SAFE (row, next, txn_node, &txn->txn_rows) { if (row->old) { if (row->written) { ovsdb_idl_row_unparse(row); ovsdb_idl_row_clear_arcs(row, false); ovsdb_idl_row_parse(row); } } else { ovsdb_idl_row_unparse(row); } ovsdb_idl_row_clear_new(row); free(row->prereqs); row->prereqs = NULL; free(row->written); row->written = NULL; hmap_remove(&txn->txn_rows, &row->txn_node); hmap_node_nullify(&row->txn_node); if (!row->old) { hmap_remove(&row->table->rows, &row->hmap_node); free(row); } } hmap_destroy(&txn->txn_rows); hmap_init(&txn->txn_rows); } /* Attempts to commit 'txn'. Returns the status of the commit operation, one * of the following TXN_* constants: * * TXN_INCOMPLETE: * * The transaction is in progress, but not yet complete. The caller * should call again later, after calling ovsdb_idl_run() to let the IDL * do OVSDB protocol processing. * * TXN_UNCHANGED: * * The transaction is complete. (It didn't actually change the database, * so the IDL didn't send any request to the database server.) * * TXN_ABORTED: * * The caller previously called ovsdb_idl_txn_abort(). * * TXN_SUCCESS: * * The transaction was successful. The update made by the transaction * (and possibly other changes made by other database clients) should * already be visible in the IDL. * * TXN_TRY_AGAIN: * * The transaction failed for some transient reason, e.g. because a * "verify" operation reported an inconsistency or due to a network * problem. The caller should wait for a change to the database, then * compose a new transaction, and commit the new transaction. * * Use the return value of ovsdb_idl_get_seqno() to wait for a change in * the database. It is important to use its return value *before* the * initial call to ovsdb_idl_txn_commit() as the baseline for this * purpose, because the change that one should wait for can happen after * the initial call but before the call that returns TXN_TRY_AGAIN, and * using some other baseline value in that situation could cause an * indefinite wait if the database rarely changes. * * TXN_NOT_LOCKED: * * The transaction failed because the IDL has been configured to require * a database lock (with ovsdb_idl_set_lock()) but didn't get it yet or * has already lost it. * * Committing a transaction rolls back all of the changes that it made to the * IDL's copy of the database. If the transaction commits successfully, then * the database server will send an update and, thus, the IDL will be updated * with the committed changes. */ enum ovsdb_idl_txn_status ovsdb_idl_txn_commit(struct ovsdb_idl_txn *txn) { struct ovsdb_idl_row *row; struct json *operations; bool any_updates; if (txn != txn->idl->txn) { return txn->status; } /* If we need a lock but don't have it, give up quickly. */ if (txn->idl->lock_name && !ovsdb_idl_has_lock(txn->idl)) { txn->status = TXN_NOT_LOCKED; ovsdb_idl_txn_disassemble(txn); return txn->status; } operations = json_array_create_1( json_string_create(txn->idl->class->database)); /* Assert that we have the required lock (avoiding a race). */ if (txn->idl->lock_name) { struct json *op = json_object_create(); json_array_add(operations, op); json_object_put_string(op, "op", "assert"); json_object_put_string(op, "lock", txn->idl->lock_name); } /* Add prerequisites and declarations of new rows. */ HMAP_FOR_EACH (row, txn_node, &txn->txn_rows) { /* XXX check that deleted rows exist even if no prereqs? */ if (row->prereqs) { const struct ovsdb_idl_table_class *class = row->table->class; size_t n_columns = class->n_columns; struct json *op, *columns, *row_json; size_t idx; op = json_object_create(); json_array_add(operations, op); json_object_put_string(op, "op", "wait"); json_object_put_string(op, "table", class->name); json_object_put(op, "timeout", json_integer_create(0)); json_object_put(op, "where", where_uuid_equals(&row->uuid)); json_object_put_string(op, "until", "=="); columns = json_array_create_empty(); json_object_put(op, "columns", columns); row_json = json_object_create(); json_object_put(op, "rows", json_array_create_1(row_json)); BITMAP_FOR_EACH_1 (idx, n_columns, row->prereqs) { const struct ovsdb_idl_column *column = &class->columns[idx]; json_array_add(columns, json_string_create(column->name)); json_object_put(row_json, column->name, ovsdb_datum_to_json(&row->old[idx], &column->type)); } } } /* Add updates. */ any_updates = false; HMAP_FOR_EACH (row, txn_node, &txn->txn_rows) { const struct ovsdb_idl_table_class *class = row->table->class; if (!row->new) { if (class->is_root) { struct json *op = json_object_create(); json_object_put_string(op, "op", "delete"); json_object_put_string(op, "table", class->name); json_object_put(op, "where", where_uuid_equals(&row->uuid)); json_array_add(operations, op); any_updates = true; } else { /* Let ovsdb-server decide whether to really delete it. */ } } else if (row->old != row->new) { struct json *row_json; struct json *op; size_t idx; op = json_object_create(); json_object_put_string(op, "op", row->old ? "update" : "insert"); json_object_put_string(op, "table", class->name); if (row->old) { json_object_put(op, "where", where_uuid_equals(&row->uuid)); } else { struct ovsdb_idl_txn_insert *insert; any_updates = true; json_object_put(op, "uuid-name", json_string_create_nocopy( uuid_name_from_uuid(&row->uuid))); insert = xmalloc(sizeof *insert); insert->dummy = row->uuid; insert->op_index = operations->u.array.n - 1; uuid_zero(&insert->real); hmap_insert(&txn->inserted_rows, &insert->hmap_node, uuid_hash(&insert->dummy)); } row_json = json_object_create(); json_object_put(op, "row", row_json); if (row->written) { BITMAP_FOR_EACH_1 (idx, class->n_columns, row->written) { const struct ovsdb_idl_column *column = &class->columns[idx]; if (row->old || !ovsdb_datum_is_default(&row->new[idx], &column->type)) { json_object_put(row_json, column->name, substitute_uuids( ovsdb_datum_to_json(&row->new[idx], &column->type), txn)); /* If anything really changed, consider it an update. * We can't suppress not-really-changed values earlier * or transactions would become nonatomic (see the big * comment inside ovsdb_idl_txn_write()). */ if (!any_updates && row->old && !ovsdb_datum_equals(&row->old[idx], &row->new[idx], &column->type)) { any_updates = true; } } } } if (!row->old || !shash_is_empty(json_object(row_json))) { json_array_add(operations, op); } else { json_destroy(op); } } } /* Add increment. */ if (txn->inc_table && any_updates) { struct json *op; txn->inc_index = operations->u.array.n - 1; op = json_object_create(); json_object_put_string(op, "op", "mutate"); json_object_put_string(op, "table", txn->inc_table); json_object_put(op, "where", substitute_uuids(where_uuid_equals(&txn->inc_row), txn)); json_object_put(op, "mutations", json_array_create_1( json_array_create_3( json_string_create(txn->inc_column), json_string_create("+="), json_integer_create(1)))); json_array_add(operations, op); op = json_object_create(); json_object_put_string(op, "op", "select"); json_object_put_string(op, "table", txn->inc_table); json_object_put(op, "where", substitute_uuids(where_uuid_equals(&txn->inc_row), txn)); json_object_put(op, "columns", json_array_create_1(json_string_create( txn->inc_column))); json_array_add(operations, op); } if (txn->comment.length) { struct json *op = json_object_create(); json_object_put_string(op, "op", "comment"); json_object_put_string(op, "comment", ds_cstr(&txn->comment)); json_array_add(operations, op); } if (txn->dry_run) { struct json *op = json_object_create(); json_object_put_string(op, "op", "abort"); json_array_add(operations, op); } if (!any_updates) { txn->status = TXN_UNCHANGED; json_destroy(operations); } else if (!jsonrpc_session_send( txn->idl->session, jsonrpc_create_request( "transact", operations, &txn->request_id))) { hmap_insert(&txn->idl->outstanding_txns, &txn->hmap_node, json_hash(txn->request_id, 0)); txn->status = TXN_INCOMPLETE; } else { txn->status = TXN_TRY_AGAIN; } ovsdb_idl_txn_disassemble(txn); return txn->status; } /* Attempts to commit 'txn', blocking until the commit either succeeds or * fails. Returns the final commit status, which may be any TXN_* value other * than TXN_INCOMPLETE. * * This function calls ovsdb_idl_run() on 'txn''s IDL, so it may cause the * return value of ovsdb_idl_get_seqno() to change. */ enum ovsdb_idl_txn_status ovsdb_idl_txn_commit_block(struct ovsdb_idl_txn *txn) { enum ovsdb_idl_txn_status status; fatal_signal_run(); while ((status = ovsdb_idl_txn_commit(txn)) == TXN_INCOMPLETE) { ovsdb_idl_run(txn->idl); ovsdb_idl_wait(txn->idl); ovsdb_idl_txn_wait(txn); poll_block(); } return status; } /* Returns the final (incremented) value of the column in 'txn' that was set to * be incremented by ovsdb_idl_txn_increment(). 'txn' must have committed * successfully. */ int64_t ovsdb_idl_txn_get_increment_new_value(const struct ovsdb_idl_txn *txn) { ovs_assert(txn->status == TXN_SUCCESS); return txn->inc_new_value; } /* Aborts 'txn' without sending it to the database server. This is effective * only if ovsdb_idl_txn_commit() has not yet been called for 'txn'. * Otherwise, it has no effect. * * Aborting a transaction doesn't free its memory. Use * ovsdb_idl_txn_destroy() to do that. */ void ovsdb_idl_txn_abort(struct ovsdb_idl_txn *txn) { ovsdb_idl_txn_disassemble(txn); if (txn->status == TXN_UNCOMMITTED || txn->status == TXN_INCOMPLETE) { txn->status = TXN_ABORTED; } } /* Returns a string that reports the error status for 'txn'. The caller must * not modify or free the returned string. A call to ovsdb_idl_txn_destroy() * for 'txn' may free the returned string. * * The return value is ordinarily one of the strings that * ovsdb_idl_txn_status_to_string() would return, but if the transaction failed * due to an error reported by the database server, the return value is that * error. */ const char * ovsdb_idl_txn_get_error(const struct ovsdb_idl_txn *txn) { if (txn->status != TXN_ERROR) { return ovsdb_idl_txn_status_to_string(txn->status); } else if (txn->error) { return txn->error; } else { return "no error details available"; } } static void ovsdb_idl_txn_set_error_json(struct ovsdb_idl_txn *txn, const struct json *json) { if (txn->error == NULL) { txn->error = json_to_string(json, JSSF_SORT); } } /* For transaction 'txn' that completed successfully, finds and returns the * permanent UUID that the database assigned to a newly inserted row, given the * 'uuid' that ovsdb_idl_txn_insert() assigned locally to that row. * * Returns NULL if 'uuid' is not a UUID assigned by ovsdb_idl_txn_insert() or * if it was assigned by that function and then deleted by * ovsdb_idl_txn_delete() within the same transaction. (Rows that are inserted * and then deleted within a single transaction are never sent to the database * server, so it never assigns them a permanent UUID.) */ const struct uuid * ovsdb_idl_txn_get_insert_uuid(const struct ovsdb_idl_txn *txn, const struct uuid *uuid) { const struct ovsdb_idl_txn_insert *insert; ovs_assert(txn->status == TXN_SUCCESS || txn->status == TXN_UNCHANGED); HMAP_FOR_EACH_IN_BUCKET (insert, hmap_node, uuid_hash(uuid), &txn->inserted_rows) { if (uuid_equals(uuid, &insert->dummy)) { return &insert->real; } } return NULL; } static void ovsdb_idl_txn_complete(struct ovsdb_idl_txn *txn, enum ovsdb_idl_txn_status status) { txn->status = status; hmap_remove(&txn->idl->outstanding_txns, &txn->hmap_node); } /* Writes 'datum' to the specified 'column' in 'row_'. Updates both 'row_' * itself and the structs derived from it (e.g. the "struct ovsrec_*", for * ovs-vswitchd). * * 'datum' must have the correct type for its column. The IDL does not check * that it meets schema constraints, but ovsdb-server will do so at commit time * so it had better be correct. * * A transaction must be in progress. Replication of 'column' must not have * been disabled (by calling ovsdb_idl_omit()). * * Usually this function is used indirectly through one of the "set" functions * generated by ovsdb-idlc. * * Takes ownership of what 'datum' points to (and in some cases destroys that * data before returning) but makes a copy of 'datum' itself. (Commonly * 'datum' is on the caller's stack.) */ static void ovsdb_idl_txn_write__(const struct ovsdb_idl_row *row_, const struct ovsdb_idl_column *column, struct ovsdb_datum *datum, bool owns_datum) { struct ovsdb_idl_row *row = CONST_CAST(struct ovsdb_idl_row *, row_); const struct ovsdb_idl_table_class *class; size_t column_idx; bool write_only; if (ovsdb_idl_row_is_synthetic(row)) { goto discard_datum; } class = row->table->class; column_idx = column - class->columns; write_only = row->table->modes[column_idx] == OVSDB_IDL_MONITOR; ovs_assert(row->new != NULL); ovs_assert(column_idx < class->n_columns); ovs_assert(row->old == NULL || row->table->modes[column_idx] & OVSDB_IDL_MONITOR); if (row->table->idl->verify_write_only && !write_only) { VLOG_ERR("Bug: Attempt to write to a read/write column (%s:%s) when" " explicitly configured not to.", class->name, column->name); goto discard_datum; } /* If this is a write-only column and the datum being written is the same * as the one already there, just skip the update entirely. This is worth * optimizing because we have a lot of columns that get periodically * refreshed into the database but don't actually change that often. * * We don't do this for read/write columns because that would break * atomicity of transactions--some other client might have written a * different value in that column since we read it. (But if a whole * transaction only does writes of existing values, without making any real * changes, we will drop the whole transaction later in * ovsdb_idl_txn_commit().) */ if (write_only && ovsdb_datum_equals(ovsdb_idl_read(row, column), datum, &column->type)) { goto discard_datum; } if (hmap_node_is_null(&row->txn_node)) { hmap_insert(&row->table->idl->txn->txn_rows, &row->txn_node, uuid_hash(&row->uuid)); } if (row->old == row->new) { row->new = xmalloc(class->n_columns * sizeof *row->new); } if (!row->written) { row->written = bitmap_allocate(class->n_columns); } if (bitmap_is_set(row->written, column_idx)) { ovsdb_datum_destroy(&row->new[column_idx], &column->type); } else { bitmap_set1(row->written, column_idx); } if (owns_datum) { row->new[column_idx] = *datum; } else { ovsdb_datum_clone(&row->new[column_idx], datum, &column->type); } (column->unparse)(row); (column->parse)(row, &row->new[column_idx]); return; discard_datum: if (owns_datum) { ovsdb_datum_destroy(datum, &column->type); } } void ovsdb_idl_txn_write(const struct ovsdb_idl_row *row, const struct ovsdb_idl_column *column, struct ovsdb_datum *datum) { ovsdb_idl_txn_write__(row, column, datum, true); } void ovsdb_idl_txn_write_clone(const struct ovsdb_idl_row *row, const struct ovsdb_idl_column *column, const struct ovsdb_datum *datum) { ovsdb_idl_txn_write__(row, column, CONST_CAST(struct ovsdb_datum *, datum), false); } /* Causes the original contents of 'column' in 'row_' to be verified as a * prerequisite to completing the transaction. That is, if 'column' in 'row_' * changed (or if 'row_' was deleted) between the time that the IDL originally * read its contents and the time that the transaction commits, then the * transaction aborts and ovsdb_idl_txn_commit() returns TXN_AGAIN_WAIT or * TXN_AGAIN_NOW (depending on whether the database change has already been * received). * * The intention is that, to ensure that no transaction commits based on dirty * reads, an application should call ovsdb_idl_txn_verify() on each data item * read as part of a read-modify-write operation. * * In some cases ovsdb_idl_txn_verify() reduces to a no-op, because the current * value of 'column' is already known: * * - If 'row_' is a row created by the current transaction (returned by * ovsdb_idl_txn_insert()). * * - If 'column' has already been modified (with ovsdb_idl_txn_write()) * within the current transaction. * * Because of the latter property, always call ovsdb_idl_txn_verify() *before* * ovsdb_idl_txn_write() for a given read-modify-write. * * A transaction must be in progress. * * Usually this function is used indirectly through one of the "verify" * functions generated by ovsdb-idlc. */ void ovsdb_idl_txn_verify(const struct ovsdb_idl_row *row_, const struct ovsdb_idl_column *column) { struct ovsdb_idl_row *row = CONST_CAST(struct ovsdb_idl_row *, row_); const struct ovsdb_idl_table_class *class; size_t column_idx; if (ovsdb_idl_row_is_synthetic(row)) { return; } class = row->table->class; column_idx = column - class->columns; ovs_assert(row->new != NULL); ovs_assert(row->old == NULL || row->table->modes[column_idx] & OVSDB_IDL_MONITOR); if (!row->old || (row->written && bitmap_is_set(row->written, column_idx))) { return; } if (hmap_node_is_null(&row->txn_node)) { hmap_insert(&row->table->idl->txn->txn_rows, &row->txn_node, uuid_hash(&row->uuid)); } if (!row->prereqs) { row->prereqs = bitmap_allocate(class->n_columns); } bitmap_set1(row->prereqs, column_idx); } /* Deletes 'row_' from its table. May free 'row_', so it must not be * accessed afterward. * * A transaction must be in progress. * * Usually this function is used indirectly through one of the "delete" * functions generated by ovsdb-idlc. */ void ovsdb_idl_txn_delete(const struct ovsdb_idl_row *row_) { struct ovsdb_idl_row *row = CONST_CAST(struct ovsdb_idl_row *, row_); if (ovsdb_idl_row_is_synthetic(row)) { return; } ovs_assert(row->new != NULL); if (!row->old) { ovsdb_idl_row_unparse(row); ovsdb_idl_row_clear_new(row); ovs_assert(!row->prereqs); hmap_remove(&row->table->rows, &row->hmap_node); hmap_remove(&row->table->idl->txn->txn_rows, &row->txn_node); free(row); return; } if (hmap_node_is_null(&row->txn_node)) { hmap_insert(&row->table->idl->txn->txn_rows, &row->txn_node, uuid_hash(&row->uuid)); } ovsdb_idl_row_clear_new(row); row->new = NULL; } /* Inserts and returns a new row in the table with the specified 'class' in the * database with open transaction 'txn'. * * The new row is assigned a provisional UUID. If 'uuid' is null then one is * randomly generated; otherwise 'uuid' should specify a randomly generated * UUID not otherwise in use. ovsdb-server will assign a different UUID when * 'txn' is committed, but the IDL will replace any uses of the provisional * UUID in the data to be to be committed by the UUID assigned by * ovsdb-server. * * Usually this function is used indirectly through one of the "insert" * functions generated by ovsdb-idlc. */ const struct ovsdb_idl_row * ovsdb_idl_txn_insert(struct ovsdb_idl_txn *txn, const struct ovsdb_idl_table_class *class, const struct uuid *uuid) { struct ovsdb_idl_row *row = ovsdb_idl_row_create__(class); if (uuid) { ovs_assert(!ovsdb_idl_txn_get_row(txn, uuid)); row->uuid = *uuid; } else { uuid_generate(&row->uuid); } row->table = ovsdb_idl_table_from_class(txn->idl, class); row->new = xmalloc(class->n_columns * sizeof *row->new); hmap_insert(&row->table->rows, &row->hmap_node, uuid_hash(&row->uuid)); hmap_insert(&txn->txn_rows, &row->txn_node, uuid_hash(&row->uuid)); return row; } static void ovsdb_idl_txn_abort_all(struct ovsdb_idl *idl) { struct ovsdb_idl_txn *txn; HMAP_FOR_EACH (txn, hmap_node, &idl->outstanding_txns) { ovsdb_idl_txn_complete(txn, TXN_TRY_AGAIN); } } static struct ovsdb_idl_txn * ovsdb_idl_txn_find(struct ovsdb_idl *idl, const struct json *id) { struct ovsdb_idl_txn *txn; HMAP_FOR_EACH_WITH_HASH (txn, hmap_node, json_hash(id, 0), &idl->outstanding_txns) { if (json_equal(id, txn->request_id)) { return txn; } } return NULL; } static bool check_json_type(const struct json *json, enum json_type type, const char *name) { if (!json) { VLOG_WARN_RL(&syntax_rl, "%s is missing", name); return false; } else if (json->type != type) { VLOG_WARN_RL(&syntax_rl, "%s is %s instead of %s", name, json_type_to_string(json->type), json_type_to_string(type)); return false; } else { return true; } } static bool ovsdb_idl_txn_process_inc_reply(struct ovsdb_idl_txn *txn, const struct json_array *results) { struct json *count, *rows, *row, *column; struct shash *mutate, *select; if (txn->inc_index + 2 > results->n) { VLOG_WARN_RL(&syntax_rl, "reply does not contain enough operations " "for increment (has %"PRIuSIZE", needs %u)", results->n, txn->inc_index + 2); return false; } /* We know that this is a JSON object because the loop in * ovsdb_idl_txn_process_reply() checked. */ mutate = json_object(results->elems[txn->inc_index]); count = shash_find_data(mutate, "count"); if (!check_json_type(count, JSON_INTEGER, "\"mutate\" reply \"count\"")) { return false; } if (count->u.integer != 1) { VLOG_WARN_RL(&syntax_rl, "\"mutate\" reply \"count\" is %lld instead of 1", count->u.integer); return false; } select = json_object(results->elems[txn->inc_index + 1]); rows = shash_find_data(select, "rows"); if (!check_json_type(rows, JSON_ARRAY, "\"select\" reply \"rows\"")) { return false; } if (rows->u.array.n != 1) { VLOG_WARN_RL(&syntax_rl, "\"select\" reply \"rows\" has %"PRIuSIZE" elements " "instead of 1", rows->u.array.n); return false; } row = rows->u.array.elems[0]; if (!check_json_type(row, JSON_OBJECT, "\"select\" reply row")) { return false; } column = shash_find_data(json_object(row), txn->inc_column); if (!check_json_type(column, JSON_INTEGER, "\"select\" reply inc column")) { return false; } txn->inc_new_value = column->u.integer; return true; } static bool ovsdb_idl_txn_process_insert_reply(struct ovsdb_idl_txn_insert *insert, const struct json_array *results) { static const struct ovsdb_base_type uuid_type = OVSDB_BASE_UUID_INIT; struct ovsdb_error *error; struct json *json_uuid; union ovsdb_atom uuid; struct shash *reply; if (insert->op_index >= results->n) { VLOG_WARN_RL(&syntax_rl, "reply does not contain enough operations " "for insert (has %"PRIuSIZE", needs %u)", results->n, insert->op_index); return false; } /* We know that this is a JSON object because the loop in * ovsdb_idl_txn_process_reply() checked. */ reply = json_object(results->elems[insert->op_index]); json_uuid = shash_find_data(reply, "uuid"); if (!check_json_type(json_uuid, JSON_ARRAY, "\"insert\" reply \"uuid\"")) { return false; } error = ovsdb_atom_from_json(&uuid, &uuid_type, json_uuid, NULL); if (error) { char *s = ovsdb_error_to_string(error); VLOG_WARN_RL(&syntax_rl, "\"insert\" reply \"uuid\" is not a JSON " "UUID: %s", s); free(s); ovsdb_error_destroy(error); return false; } insert->real = uuid.uuid; return true; } static bool ovsdb_idl_txn_process_reply(struct ovsdb_idl *idl, const struct jsonrpc_msg *msg) { struct ovsdb_idl_txn *txn; enum ovsdb_idl_txn_status status; txn = ovsdb_idl_txn_find(idl, msg->id); if (!txn) { return false; } if (msg->type == JSONRPC_ERROR) { status = TXN_ERROR; } else if (msg->result->type != JSON_ARRAY) { VLOG_WARN_RL(&syntax_rl, "reply to \"transact\" is not JSON array"); status = TXN_ERROR; } else { struct json_array *ops = &msg->result->u.array; int hard_errors = 0; int soft_errors = 0; int lock_errors = 0; size_t i; for (i = 0; i < ops->n; i++) { struct json *op = ops->elems[i]; if (op->type == JSON_NULL) { /* This isn't an error in itself but indicates that some prior * operation failed, so make sure that we know about it. */ soft_errors++; } else if (op->type == JSON_OBJECT) { struct json *error; error = shash_find_data(json_object(op), "error"); if (error) { if (error->type == JSON_STRING) { if (!strcmp(error->u.string, "timed out")) { soft_errors++; } else if (!strcmp(error->u.string, "not owner")) { lock_errors++; } else if (strcmp(error->u.string, "aborted")) { hard_errors++; ovsdb_idl_txn_set_error_json(txn, op); } } else { hard_errors++; ovsdb_idl_txn_set_error_json(txn, op); VLOG_WARN_RL(&syntax_rl, "\"error\" in reply is not JSON string"); } } } else { hard_errors++; ovsdb_idl_txn_set_error_json(txn, op); VLOG_WARN_RL(&syntax_rl, "operation reply is not JSON null or object"); } } if (!soft_errors && !hard_errors && !lock_errors) { struct ovsdb_idl_txn_insert *insert; if (txn->inc_table && !ovsdb_idl_txn_process_inc_reply(txn, ops)) { hard_errors++; } HMAP_FOR_EACH (insert, hmap_node, &txn->inserted_rows) { if (!ovsdb_idl_txn_process_insert_reply(insert, ops)) { hard_errors++; } } } status = (hard_errors ? TXN_ERROR : lock_errors ? TXN_NOT_LOCKED : soft_errors ? TXN_TRY_AGAIN : TXN_SUCCESS); } ovsdb_idl_txn_complete(txn, status); return true; } /* Returns the transaction currently active for 'row''s IDL. A transaction * must currently be active. */ struct ovsdb_idl_txn * ovsdb_idl_txn_get(const struct ovsdb_idl_row *row) { struct ovsdb_idl_txn *txn = row->table->idl->txn; ovs_assert(txn != NULL); return txn; } /* Returns the IDL on which 'txn' acts. */ struct ovsdb_idl * ovsdb_idl_txn_get_idl (struct ovsdb_idl_txn *txn) { return txn->idl; } /* If 'lock_name' is nonnull, configures 'idl' to obtain the named lock from * the database server and to avoid modifying the database when the lock cannot * be acquired (that is, when another client has the same lock). * * If 'lock_name' is NULL, drops the locking requirement and releases the * lock. */ void ovsdb_idl_set_lock(struct ovsdb_idl *idl, const char *lock_name) { ovs_assert(!idl->txn); ovs_assert(hmap_is_empty(&idl->outstanding_txns)); if (idl->lock_name && (!lock_name || strcmp(lock_name, idl->lock_name))) { /* Release previous lock. */ ovsdb_idl_send_unlock_request(idl); free(idl->lock_name); idl->lock_name = NULL; idl->is_lock_contended = false; } if (lock_name && !idl->lock_name) { /* Acquire new lock. */ idl->lock_name = xstrdup(lock_name); ovsdb_idl_send_lock_request(idl); } } /* Returns true if 'idl' is configured to obtain a lock and owns that lock. * * Locking and unlocking happens asynchronously from the database client's * point of view, so the information is only useful for optimization (e.g. if * the client doesn't have the lock then there's no point in trying to write to * the database). */ bool ovsdb_idl_has_lock(const struct ovsdb_idl *idl) { return idl->has_lock; } /* Returns true if 'idl' is configured to obtain a lock but the database server * has indicated that some other client already owns the requested lock. */ bool ovsdb_idl_is_lock_contended(const struct ovsdb_idl *idl) { return idl->is_lock_contended; } static void ovsdb_idl_update_has_lock(struct ovsdb_idl *idl, bool new_has_lock) { if (new_has_lock && !idl->has_lock) { if (!idl->monitor_request_id) { idl->change_seqno++; } else { /* We're waiting for a monitor reply, so don't signal that the * database changed. The monitor reply will increment change_seqno * anyhow. */ } idl->is_lock_contended = false; } idl->has_lock = new_has_lock; } static void ovsdb_idl_send_lock_request__(struct ovsdb_idl *idl, const char *method, struct json **idp) { ovsdb_idl_update_has_lock(idl, false); json_destroy(idl->lock_request_id); idl->lock_request_id = NULL; if (jsonrpc_session_is_connected(idl->session)) { struct json *params; params = json_array_create_1(json_string_create(idl->lock_name)); jsonrpc_session_send(idl->session, jsonrpc_create_request(method, params, idp)); } } static void ovsdb_idl_send_lock_request(struct ovsdb_idl *idl) { ovsdb_idl_send_lock_request__(idl, "lock", &idl->lock_request_id); } static void ovsdb_idl_send_unlock_request(struct ovsdb_idl *idl) { ovsdb_idl_send_lock_request__(idl, "unlock", NULL); } static void ovsdb_idl_parse_lock_reply(struct ovsdb_idl *idl, const struct json *result) { bool got_lock; json_destroy(idl->lock_request_id); idl->lock_request_id = NULL; if (result->type == JSON_OBJECT) { const struct json *locked; locked = shash_find_data(json_object(result), "locked"); got_lock = locked && locked->type == JSON_TRUE; } else { got_lock = false; } ovsdb_idl_update_has_lock(idl, got_lock); if (!got_lock) { idl->is_lock_contended = true; } } static void ovsdb_idl_parse_lock_notify(struct ovsdb_idl *idl, const struct json *params, bool new_has_lock) { if (idl->lock_name && params->type == JSON_ARRAY && json_array(params)->n > 0 && json_array(params)->elems[0]->type == JSON_STRING) { const char *lock_name = json_string(json_array(params)->elems[0]); if (!strcmp(idl->lock_name, lock_name)) { ovsdb_idl_update_has_lock(idl, new_has_lock); if (!new_has_lock) { idl->is_lock_contended = true; } } } }