diff options
Diffstat (limited to 'src/backend/optimizer/prep/prepsecurity.c')
| -rw-r--r-- | src/backend/optimizer/prep/prepsecurity.c | 35 |
1 files changed, 28 insertions, 7 deletions
diff --git a/src/backend/optimizer/prep/prepsecurity.c b/src/backend/optimizer/prep/prepsecurity.c index af3ee61bef1..08309538ffa 100644 --- a/src/backend/optimizer/prep/prepsecurity.c +++ b/src/backend/optimizer/prep/prepsecurity.c @@ -37,7 +37,7 @@ typedef struct } security_barrier_replace_vars_context; static void expand_security_qual(PlannerInfo *root, List *tlist, int rt_index, - RangeTblEntry *rte, Node *qual); + RangeTblEntry *rte, Node *qual, bool targetRelation); static void security_barrier_replace_vars(Node *node, security_barrier_replace_vars_context *context); @@ -63,6 +63,7 @@ expand_security_quals(PlannerInfo *root, List *tlist) Query *parse = root->parse; int rt_index; ListCell *cell; + bool targetRelation = false; /* * Process each RTE in the rtable list. @@ -98,6 +99,15 @@ expand_security_quals(PlannerInfo *root, List *tlist) { RangeTblEntry *newrte = copyObject(rte); + /* + * We need to let expand_security_qual know if this is the target + * relation, as it has additional work to do in that case. + * + * Capture that information here as we're about to replace + * parse->resultRelation. + */ + targetRelation = true; + parse->rtable = lappend(parse->rtable, newrte); parse->resultRelation = list_length(parse->rtable); @@ -147,7 +157,8 @@ expand_security_quals(PlannerInfo *root, List *tlist) rte->securityQuals = list_delete_first(rte->securityQuals); ChangeVarNodes(qual, rt_index, 1, 0); - expand_security_qual(root, tlist, rt_index, rte, qual); + expand_security_qual(root, tlist, rt_index, rte, qual, + targetRelation); } } } @@ -160,7 +171,7 @@ expand_security_quals(PlannerInfo *root, List *tlist) */ static void expand_security_qual(PlannerInfo *root, List *tlist, int rt_index, - RangeTblEntry *rte, Node *qual) + RangeTblEntry *rte, Node *qual, bool targetRelation) { Query *parse = root->parse; Oid relid = rte->relid; @@ -219,10 +230,11 @@ expand_security_qual(PlannerInfo *root, List *tlist, int rt_index, * Now deal with any PlanRowMark on this RTE by requesting a lock * of the same strength on the RTE copied down to the subquery. * - * Note that we can't push the user-defined quals down since they - * may included untrusted functions and that means that we will - * end up locking all rows which pass the securityQuals, even if - * those rows don't pass the user-defined quals. This is + * Note that we can only push down user-defined quals if they are + * only using leakproof (and therefore trusted) functions and + * operators. As a result, we may end up locking more rows than + * strictly necessary (and, in the worst case, we could end up + * locking all rows which pass the securityQuals). This is * currently documented behavior, but it'd be nice to come up with * a better solution some day. */ @@ -256,6 +268,15 @@ expand_security_qual(PlannerInfo *root, List *tlist, int rt_index, } /* + * When we are replacing the target relation with a subquery, we + * need to make sure to add a locking clause explicitly to the + * generated subquery since there won't be any row marks against + * the target relation itself. + */ + if (targetRelation) + applyLockingClause(subquery, 1, LCS_FORUPDATE, + LockWaitBlock, false); + /* * Replace any variables in the outer query that refer to the * original relation RTE with references to columns that we will * expose in the new subquery, building the subquery's targetlist |