diff options
Diffstat (limited to 'src/backend/commands/user.c')
| -rw-r--r-- | src/backend/commands/user.c | 68 |
1 files changed, 31 insertions, 37 deletions
diff --git a/src/backend/commands/user.c b/src/backend/commands/user.c index 5fddd80dfd..61956b2770 100644 --- a/src/backend/commands/user.c +++ b/src/backend/commands/user.c @@ -6,7 +6,7 @@ * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/backend/commands/user.c,v 1.170 2006/03/05 15:58:25 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/commands/user.c,v 1.171 2006/05/04 16:07:29 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -274,10 +274,9 @@ CreateRole(CreateRoleStmt *stmt) /* * Check the pg_authid relation to be certain the role doesn't already - * exist. Note we secure exclusive lock because we need to protect our - * eventual update of the flat auth file. + * exist. */ - pg_authid_rel = heap_open(AuthIdRelationId, ExclusiveLock); + pg_authid_rel = heap_open(AuthIdRelationId, RowExclusiveLock); pg_authid_dsc = RelationGetDescr(pg_authid_rel); tuple = SearchSysCache(AUTHNAME, @@ -377,8 +376,8 @@ CreateRole(CreateRoleStmt *stmt) GetUserId(), false); /* - * Now we can clean up; but keep lock until commit (to avoid possible - * deadlock when commit code tries to acquire lock). + * Close pg_authid, but keep lock till commit (this is important + * to prevent any risk of deadlock failure while updating flat file) */ heap_close(pg_authid_rel, NoLock); @@ -538,10 +537,9 @@ AlterRole(AlterRoleStmt *stmt) validUntil = strVal(dvalidUntil->arg); /* - * Scan the pg_authid relation to be certain the user exists. Note we - * secure exclusive lock to protect our update of the flat auth file. + * Scan the pg_authid relation to be certain the user exists. */ - pg_authid_rel = heap_open(AuthIdRelationId, ExclusiveLock); + pg_authid_rel = heap_open(AuthIdRelationId, RowExclusiveLock); pg_authid_dsc = RelationGetDescr(pg_authid_rel); tuple = SearchSysCache(AUTHNAME, @@ -697,8 +695,8 @@ AlterRole(AlterRoleStmt *stmt) false); /* - * Now we can clean up; but keep lock until commit (to avoid possible - * deadlock when commit code tries to acquire lock). + * Close pg_authid, but keep lock till commit (this is important + * to prevent any risk of deadlock failure while updating flat file) */ heap_close(pg_authid_rel, NoLock); @@ -726,10 +724,6 @@ AlterRoleSet(AlterRoleSetStmt *stmt) valuestr = flatten_set_variable_args(stmt->variable, stmt->value); - /* - * RowExclusiveLock is sufficient, because we don't need to update the - * flat auth file. - */ rel = heap_open(AuthIdRelationId, RowExclusiveLock); oldtuple = SearchSysCache(AUTHNAME, PointerGetDatum(stmt->role), @@ -799,6 +793,7 @@ AlterRoleSet(AlterRoleSetStmt *stmt) CatalogUpdateIndexes(rel, newtuple); ReleaseSysCache(oldtuple); + /* needn't keep lock since we won't be updating the flat file */ heap_close(rel, RowExclusiveLock); } @@ -820,11 +815,9 @@ DropRole(DropRoleStmt *stmt) /* * Scan the pg_authid relation to find the Oid of the role(s) to be - * deleted. Note we secure exclusive lock on pg_authid, because we need - * to protect our update of the flat auth file. A regular writer's lock - * on pg_auth_members is sufficient though. + * deleted. */ - pg_authid_rel = heap_open(AuthIdRelationId, ExclusiveLock); + pg_authid_rel = heap_open(AuthIdRelationId, RowExclusiveLock); pg_auth_members_rel = heap_open(AuthMemRelationId, RowExclusiveLock); foreach(item, stmt->roles) @@ -960,7 +953,7 @@ DropRole(DropRoleStmt *stmt) /* * Now we can clean up; but keep locks until commit (to avoid possible - * deadlock when commit code tries to acquire lock). + * deadlock failure while updating flat file) */ heap_close(pg_auth_members_rel, NoLock); heap_close(pg_authid_rel, NoLock); @@ -989,8 +982,7 @@ RenameRole(const char *oldname, const char *newname) int i; Oid roleid; - /* ExclusiveLock because we need to update the flat auth file */ - rel = heap_open(AuthIdRelationId, ExclusiveLock); + rel = heap_open(AuthIdRelationId, RowExclusiveLock); dsc = RelationGetDescr(rel); oldtuple = SearchSysCache(AUTHNAME, @@ -1080,6 +1072,11 @@ RenameRole(const char *oldname, const char *newname) CatalogUpdateIndexes(rel, newtuple); ReleaseSysCache(oldtuple); + + /* + * Close pg_authid, but keep lock till commit (this is important + * to prevent any risk of deadlock failure while updating flat file) + */ heap_close(rel, NoLock); /* @@ -1108,11 +1105,8 @@ GrantRole(GrantRoleStmt *stmt) grantee_ids = roleNamesToIds(stmt->grantee_roles); - /* - * Even though this operation doesn't change pg_authid, we must secure - * exclusive lock on it to protect our update of the flat auth file. - */ - pg_authid_rel = heap_open(AuthIdRelationId, ExclusiveLock); + /* AccessShareLock is enough since we aren't modifying pg_authid */ + pg_authid_rel = heap_open(AuthIdRelationId, AccessShareLock); /* * Step through all of the granted roles and add/remove entries for the @@ -1136,6 +1130,10 @@ GrantRole(GrantRoleStmt *stmt) stmt->admin_opt); } + /* + * Close pg_authid, but keep lock till commit (this is important + * to prevent any risk of deadlock failure while updating flat file) + */ heap_close(pg_authid_rel, NoLock); /* @@ -1237,8 +1235,7 @@ roleNamesToIds(List *memberNames) * grantorId: who is granting the membership * admin_opt: granting admin option? * - * Note: caller is responsible for holding ExclusiveLock on pg_authid, - * and for calling auth_file_update_needed(). + * Note: caller is responsible for calling auth_file_update_needed(). */ static void AddRoleMems(const char *rolename, Oid roleid, @@ -1283,7 +1280,6 @@ AddRoleMems(const char *rolename, Oid roleid, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("must be superuser to set grantor"))); - /* We need only regular writer's lock on pg_auth_members */ pg_authmem_rel = heap_open(AuthMemRelationId, RowExclusiveLock); pg_authmem_dsc = RelationGetDescr(pg_authmem_rel); @@ -1363,8 +1359,8 @@ AddRoleMems(const char *rolename, Oid roleid, } /* - * Now we can clean up; but keep lock until commit (to avoid possible - * deadlock when commit code tries to acquire lock). + * Close pg_authmem, but keep lock till commit (this is important + * to prevent any risk of deadlock failure while updating flat file) */ heap_close(pg_authmem_rel, NoLock); } @@ -1378,8 +1374,7 @@ AddRoleMems(const char *rolename, Oid roleid, * memberIds: OIDs of roles to del * admin_opt: remove admin option only? * - * Note: caller is responsible for holding ExclusiveLock on pg_authid, - * and for calling auth_file_update_needed(). + * Note: caller is responsible for calling auth_file_update_needed(). */ static void DelRoleMems(const char *rolename, Oid roleid, @@ -1418,7 +1413,6 @@ DelRoleMems(const char *rolename, Oid roleid, rolename))); } - /* We need only regular writer's lock on pg_auth_members */ pg_authmem_rel = heap_open(AuthMemRelationId, RowExclusiveLock); pg_authmem_dsc = RelationGetDescr(pg_authmem_rel); @@ -1478,8 +1472,8 @@ DelRoleMems(const char *rolename, Oid roleid, } /* - * Now we can clean up; but keep lock until commit (to avoid possible - * deadlock when commit code tries to acquire lock). + * Close pg_authmem, but keep lock till commit (this is important + * to prevent any risk of deadlock failure while updating flat file) */ heap_close(pg_authmem_rel, NoLock); } |