From e78fd9084587cd485fdec3eb3eaeef567e1707d5 Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Thu, 4 Aug 2022 20:02:02 +0200 Subject: [PATCH] Fix ENABLE/DISABLE TRIGGER to handle recursion correctly Using ATSimpleRecursion() in ATPrepCmd() to do so as bbb927b4db9b did is not correct, because ATPrepCmd() can't distinguish between triggers that may be cloned and those that may not, so would wrongly try to recurse for the latter category of triggers. So this commit restores the code in EnableDisableTrigger() that 86f575948c77 had added to do the recursion, which would do it only for triggers that may be cloned, that is, row-level triggers. This also changes tablecmds.c such that ATExecCmd() is able to pass the value of ONLY flag down to EnableDisableTrigger() using its new 'recurse' parameter. This also fixes what seems like an oversight of 86f575948c77 that the recursion to partition triggers would only occur if EnableDisableTrigger() had actually changed the trigger. It is more apt to recurse to inspect partition triggers even if the parent's trigger didn't need to be changed: only then can we be certain that all descendants share the same state afterwards. Backpatch all the way back to 11, like bbb927b4db9b. Care is taken not to break ABI compatibility (and that no catversion bump is needed.) Co-authored-by: Amit Langote Reviewed-by: Dmitry Koval Discussion: https://postgr.es/m/CA+HiwqG-cZT3XzGAnEgZQLoQbyfJApVwOTQaCaas1mhpf+4V5A@mail.gmail.com --- src/backend/commands/tablecmds.c | 64 ++++++++++++++++++-------- src/backend/commands/trigger.c | 47 ++++++++++++++++++- src/backend/nodes/copyfuncs.c | 1 + src/backend/nodes/equalfuncs.c | 1 + src/include/commands/trigger.h | 3 ++ src/include/nodes/parsenodes.h | 1 + src/test/regress/expected/triggers.out | 40 +++++++++++----- src/test/regress/sql/triggers.sql | 11 ++++- 8 files changed, 134 insertions(+), 34 deletions(-) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index a555371d939..cfbe2fa2d97 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -580,7 +580,8 @@ static void ATExecSetRelOptions(Relation rel, List *defList, AlterTableType operation, LOCKMODE lockmode); static void ATExecEnableDisableTrigger(Relation rel, const char *trigname, - char fires_when, bool skip_system, LOCKMODE lockmode); + char fires_when, bool skip_system, bool recurse, + LOCKMODE lockmode); static void ATExecEnableDisableRule(Relation rel, const char *rulename, char fires_when, LOCKMODE lockmode); static void ATPrepAddInherit(Relation child_rel); @@ -4053,9 +4054,7 @@ AlterTableLookupRelation(AlterTableStmt *stmt, LOCKMODE lockmode) * be done in this phase. Generally, this phase acquires table locks, * checks permissions and relkind, and recurses to find child tables. * - * ATRewriteCatalogs performs phase 2 for each affected table. (Note that - * phases 2 and 3 normally do no explicit recursion, since phase 1 already - * did it --- although some subcommands have to recurse in phase 2 instead.) + * ATRewriteCatalogs performs phase 2 for each affected table. * Certain subcommands need to be performed before others to avoid * unnecessary conflicts; for example, DROP COLUMN should come before * ADD COLUMN. Therefore phase 1 divides the subcommands into multiple @@ -4063,6 +4062,12 @@ AlterTableLookupRelation(AlterTableStmt *stmt, LOCKMODE lockmode) * * ATRewriteTables performs phase 3 for those tables that need it. * + * For most subcommand types, phases 2 and 3 do no explicit recursion, + * since phase 1 already does it. However, for certain subcommand types + * it is only possible to determine how to recurse at phase 2 time; for + * those cases, phase 1 sets the cmd->recurse flag (or, in some older coding, + * changes the command subtype of a "Recurse" variant XXX to be cleaned up.) + * * Thanks to the magic of MVCC, an error anywhere along the way rolls back * the whole operation; we don't have to do anything special to clean up. * @@ -4483,10 +4488,10 @@ ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd, errhint("Use ALTER TABLE ... DETACH PARTITION ... FINALIZE to complete the pending detach operation.")); /* - * Copy the original subcommand for each table. This avoids conflicts - * when different child tables need to make different parse - * transformations (for example, the same column may have different column - * numbers in different children). + * Copy the original subcommand for each table, so we can scribble on it. + * This avoids conflicts when different child tables need to make + * different parse transformations (for example, the same column may have + * different column numbers in different children). */ cmd = copyObject(cmd); @@ -4773,8 +4778,9 @@ ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd, case AT_DisableTrigAll: case AT_DisableTrigUser: ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_FOREIGN_TABLE); - if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) - ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode, context); + /* Set up recursion for phase 2; no other prep needed */ + if (recurse) + cmd->recurse = true; pass = AT_PASS_MISC; break; case AT_EnableRule: /* ENABLE/DISABLE RULE variants */ @@ -5115,35 +5121,51 @@ ATExecCmd(List **wqueue, AlteredTableInfo *tab, break; case AT_EnableTrig: /* ENABLE TRIGGER name */ ATExecEnableDisableTrigger(rel, cmd->name, - TRIGGER_FIRES_ON_ORIGIN, false, lockmode); + TRIGGER_FIRES_ON_ORIGIN, false, + cmd->recurse, + lockmode); break; case AT_EnableAlwaysTrig: /* ENABLE ALWAYS TRIGGER name */ ATExecEnableDisableTrigger(rel, cmd->name, - TRIGGER_FIRES_ALWAYS, false, lockmode); + TRIGGER_FIRES_ALWAYS, false, + cmd->recurse, + lockmode); break; case AT_EnableReplicaTrig: /* ENABLE REPLICA TRIGGER name */ ATExecEnableDisableTrigger(rel, cmd->name, - TRIGGER_FIRES_ON_REPLICA, false, lockmode); + TRIGGER_FIRES_ON_REPLICA, false, + cmd->recurse, + lockmode); break; case AT_DisableTrig: /* DISABLE TRIGGER name */ ATExecEnableDisableTrigger(rel, cmd->name, - TRIGGER_DISABLED, false, lockmode); + TRIGGER_DISABLED, false, + cmd->recurse, + lockmode); break; case AT_EnableTrigAll: /* ENABLE TRIGGER ALL */ ATExecEnableDisableTrigger(rel, NULL, - TRIGGER_FIRES_ON_ORIGIN, false, lockmode); + TRIGGER_FIRES_ON_ORIGIN, false, + cmd->recurse, + lockmode); break; case AT_DisableTrigAll: /* DISABLE TRIGGER ALL */ ATExecEnableDisableTrigger(rel, NULL, - TRIGGER_DISABLED, false, lockmode); + TRIGGER_DISABLED, false, + cmd->recurse, + lockmode); break; case AT_EnableTrigUser: /* ENABLE TRIGGER USER */ ATExecEnableDisableTrigger(rel, NULL, - TRIGGER_FIRES_ON_ORIGIN, true, lockmode); + TRIGGER_FIRES_ON_ORIGIN, true, + cmd->recurse, + lockmode); break; case AT_DisableTrigUser: /* DISABLE TRIGGER USER */ ATExecEnableDisableTrigger(rel, NULL, - TRIGGER_DISABLED, true, lockmode); + TRIGGER_DISABLED, true, + cmd->recurse, + lockmode); break; case AT_EnableRule: /* ENABLE RULE name */ @@ -14699,9 +14721,11 @@ index_copy_data(Relation rel, RelFileNode newrnode) */ static void ATExecEnableDisableTrigger(Relation rel, const char *trigname, - char fires_when, bool skip_system, LOCKMODE lockmode) + char fires_when, bool skip_system, bool recurse, + LOCKMODE lockmode) { - EnableDisableTrigger(rel, trigname, fires_when, skip_system, lockmode); + EnableDisableTriggerNew(rel, trigname, fires_when, skip_system, recurse, + lockmode); } /* diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c index 13cb516752b..464e22517f0 100644 --- a/src/backend/commands/trigger.c +++ b/src/backend/commands/trigger.c @@ -1759,14 +1759,16 @@ renametrig_partition(Relation tgrel, Oid partitionId, Oid parentTriggerOid, * enablement/disablement, this also defines when the trigger * should be fired in session replication roles. * skip_system: if true, skip "system" triggers (constraint triggers) + * recurse: if true, recurse to partitions * * Caller should have checked permissions for the table; here we also * enforce that superuser privilege is required to alter the state of * system triggers */ void -EnableDisableTrigger(Relation rel, const char *tgname, - char fires_when, bool skip_system, LOCKMODE lockmode) +EnableDisableTriggerNew(Relation rel, const char *tgname, + char fires_when, bool skip_system, bool recurse, + LOCKMODE lockmode) { Relation tgrel; int nkeys; @@ -1832,6 +1834,34 @@ EnableDisableTrigger(Relation rel, const char *tgname, changed = true; } + /* + * When altering FOR EACH ROW triggers on a partitioned table, do the + * same on the partitions as well, unless ONLY is specified. + * + * Note that we recurse even if we didn't change the trigger above, + * because the partitions' copy of the trigger may have a different + * value of tgenabled than the parent's trigger and thus might need to + * be changed. + */ + if (recurse && + rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE && + (TRIGGER_FOR_ROW(oldtrig->tgtype))) + { + PartitionDesc partdesc = RelationGetPartitionDesc(rel, true); + int i; + + for (i = 0; i < partdesc->nparts; i++) + { + Relation part; + + part = relation_open(partdesc->oids[i], lockmode); + EnableDisableTriggerNew(part, NameStr(oldtrig->tgname), + fires_when, skip_system, recurse, + lockmode); + table_close(part, NoLock); /* keep lock till commit */ + } + } + InvokeObjectPostAlterHook(TriggerRelationId, oldtrig->oid, 0); } @@ -1855,6 +1885,19 @@ EnableDisableTrigger(Relation rel, const char *tgname, CacheInvalidateRelcache(rel); } +/* + * ABI-compatible wrapper for the above. To keep as close possible to the old + * behavior, this never recurses. Do not call this function in new code. + */ +void +EnableDisableTrigger(Relation rel, const char *tgname, + char fires_when, bool skip_system, + LOCKMODE lockmode) +{ + EnableDisableTriggerNew(rel, tgname, fires_when, skip_system, + true, lockmode); +} + /* * Build trigger data to attach to the given relcache entry. diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c index 706d283a925..b7ef477e9d7 100644 --- a/src/backend/nodes/copyfuncs.c +++ b/src/backend/nodes/copyfuncs.c @@ -3893,6 +3893,7 @@ _copyAlterTableCmd(const AlterTableCmd *from) COPY_NODE_FIELD(def); COPY_SCALAR_FIELD(behavior); COPY_SCALAR_FIELD(missing_ok); + COPY_SCALAR_FIELD(recurse); return newnode; } diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c index fccc0b4a18d..a547b570571 100644 --- a/src/backend/nodes/equalfuncs.c +++ b/src/backend/nodes/equalfuncs.c @@ -1521,6 +1521,7 @@ _equalAlterTableCmd(const AlterTableCmd *a, const AlterTableCmd *b) COMPARE_NODE_FIELD(def); COMPARE_SCALAR_FIELD(behavior); COMPARE_SCALAR_FIELD(missing_ok); + COMPARE_SCALAR_FIELD(recurse); return true; } diff --git a/src/include/commands/trigger.h b/src/include/commands/trigger.h index 194e8d5bc13..0377438861c 100644 --- a/src/include/commands/trigger.h +++ b/src/include/commands/trigger.h @@ -170,6 +170,9 @@ extern Oid get_trigger_oid(Oid relid, const char *name, bool missing_ok); extern ObjectAddress renametrig(RenameStmt *stmt); +extern void EnableDisableTriggerNew(Relation rel, const char *tgname, + char fires_when, bool skip_system, bool recurse, + LOCKMODE lockmode); extern void EnableDisableTrigger(Relation rel, const char *tgname, char fires_when, bool skip_system, LOCKMODE lockmode); diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index 73f635b4553..64b5169f993 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -2317,6 +2317,7 @@ typedef struct AlterTableCmd /* one subcommand of an ALTER TABLE */ * constraint, or parent table */ DropBehavior behavior; /* RESTRICT or CASCADE for DROP cases */ bool missing_ok; /* skip error if missing? */ + bool recurse; /* exec-time recursion */ } AlterTableCmd; diff --git a/src/test/regress/expected/triggers.out b/src/test/regress/expected/triggers.out index 89a34ffbb2d..f131405bc7a 100644 --- a/src/test/regress/expected/triggers.out +++ b/src/test/regress/expected/triggers.out @@ -2681,24 +2681,42 @@ create table parent (a int) partition by list (a); create table child1 partition of parent for values in (1); create trigger tg after insert on parent for each row execute procedure trig_nothing(); +create trigger tg_stmt after insert on parent + for statement execute procedure trig_nothing(); select tgrelid::regclass, tgname, tgenabled from pg_trigger where tgrelid in ('parent'::regclass, 'child1'::regclass) order by tgrelid::regclass::text; - tgrelid | tgname | tgenabled ----------+--------+----------- - child1 | tg | O - parent | tg | O -(2 rows) + tgrelid | tgname | tgenabled +---------+---------+----------- + child1 | tg | O + parent | tg | O + parent | tg_stmt | O +(3 rows) -alter table only parent enable always trigger tg; +alter table only parent enable always trigger tg; -- no recursion because ONLY +alter table parent enable always trigger tg_stmt; -- no recursion because statement trigger select tgrelid::regclass, tgname, tgenabled from pg_trigger where tgrelid in ('parent'::regclass, 'child1'::regclass) order by tgrelid::regclass::text; - tgrelid | tgname | tgenabled ----------+--------+----------- - child1 | tg | O - parent | tg | A -(2 rows) + tgrelid | tgname | tgenabled +---------+---------+----------- + child1 | tg | O + parent | tg | A + parent | tg_stmt | A +(3 rows) + +-- The following is a no-op for the parent trigger but not so +-- for the child trigger, so recursion should be applied. +alter table parent enable always trigger tg; +select tgrelid::regclass, tgname, tgenabled from pg_trigger + where tgrelid in ('parent'::regclass, 'child1'::regclass) + order by tgrelid::regclass::text; + tgrelid | tgname | tgenabled +---------+---------+----------- + child1 | tg | A + parent | tg | A + parent | tg_stmt | A +(3 rows) drop table parent, child1; -- Verify that firing state propagates correctly on creation, too diff --git a/src/test/regress/sql/triggers.sql b/src/test/regress/sql/triggers.sql index 83cd00f54f0..cb6fc4a90ee 100644 --- a/src/test/regress/sql/triggers.sql +++ b/src/test/regress/sql/triggers.sql @@ -1865,10 +1865,19 @@ create table parent (a int) partition by list (a); create table child1 partition of parent for values in (1); create trigger tg after insert on parent for each row execute procedure trig_nothing(); +create trigger tg_stmt after insert on parent + for statement execute procedure trig_nothing(); select tgrelid::regclass, tgname, tgenabled from pg_trigger where tgrelid in ('parent'::regclass, 'child1'::regclass) order by tgrelid::regclass::text; -alter table only parent enable always trigger tg; +alter table only parent enable always trigger tg; -- no recursion because ONLY +alter table parent enable always trigger tg_stmt; -- no recursion because statement trigger +select tgrelid::regclass, tgname, tgenabled from pg_trigger + where tgrelid in ('parent'::regclass, 'child1'::regclass) + order by tgrelid::regclass::text; +-- The following is a no-op for the parent trigger but not so +-- for the child trigger, so recursion should be applied. +alter table parent enable always trigger tg; select tgrelid::regclass, tgname, tgenabled from pg_trigger where tgrelid in ('parent'::regclass, 'child1'::regclass) order by tgrelid::regclass::text;