diff options
Diffstat (limited to 'src/backend/commands/dbcommands.c')
| -rw-r--r-- | src/backend/commands/dbcommands.c | 27 |
1 files changed, 11 insertions, 16 deletions
diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c index b779715fe8e..24eb5b531d3 100644 --- a/src/backend/commands/dbcommands.c +++ b/src/backend/commands/dbcommands.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/commands/dbcommands.c,v 1.39 1999/07/17 20:16:52 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/commands/dbcommands.c,v 1.40 1999/09/18 19:06:40 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -103,6 +103,8 @@ destroydb(char *dbname, CommandDest dest) /* stop the vacuum daemon */ stop_vacuum(dbpath, dbname); + /* XXX what about stopping backends connected to the target database? */ + path = ExpandDatabasePath(dbpath); if (path == NULL) elog(ERROR, "Unable to locate path '%s'" @@ -189,6 +191,7 @@ check_permissions(char *command, utup = SearchSysCacheTuple(USENAME, PointerGetDatum(userName), 0, 0, 0); + Assert(utup); *userIdP = ((Form_pg_shadow) GETSTRUCT(utup))->usesysid; use_super = ((Form_pg_shadow) GETSTRUCT(utup))->usesuper; use_createdb = ((Form_pg_shadow) GETSTRUCT(utup))->usecreatedb; @@ -211,22 +214,13 @@ check_permissions(char *command, /* Check to make sure database is owned by this user */ /* - * need the reldesc to get the database owner out of dbtup and to set - * a write lock on it. + * Acquire exclusive lock on pg_database from the beginning, even though + * we only need read access right here, to avoid potential deadlocks + * from upgrading our lock later. (Is this still necessary? Could we + * use something weaker than exclusive lock?) */ - dbrel = heap_openr(DatabaseRelationName); - - if (!RelationIsValid(dbrel)) - elog(FATAL, "%s: cannot open relation \"%-.*s\"", - command, DatabaseRelationName); + dbrel = heap_openr(DatabaseRelationName, AccessExclusiveLock); - /* - * Acquire a write lock on pg_database from the beginning to avoid - * upgrading a read lock to a write lock. Upgrading causes long - * delays when multiple 'createdb's or 'destroydb's are run simult. - * -mer 7/3/91 - */ - LockRelation(dbrel, AccessExclusiveLock); dbtup = get_pg_dbtup(command, dbname, dbrel); dbfound = HeapTupleIsValid(dbtup); @@ -248,7 +242,8 @@ check_permissions(char *command, else *dbIdP = InvalidOid; - heap_close(dbrel); + /* We will keep the lock on dbrel until end of transaction. */ + heap_close(dbrel, NoLock); /* * Now be sure that the user is allowed to do this. |