open-dsi
/
postgres
mirror of https://github.com/postgres/postgres
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Harden xxx_is_visible() functions against concurrent object drops.

Browse Source 
For the same reasons given in commit 403ac226d, adjust these
functions to not assume that checking SearchSysCacheExists can
guarantee success of a later fetch.

This follows the same internal API choices made in the earlier commit:
add a function XXXExt(oid, is_missing) and use that to eliminate
the need for a separate existence check.  The changes are very
straightforward, though tedious.  For the moment I just made the new
functions static in namespace.c, but we could export them if a need
emerges.

Per bug #18014 from Alexander Lakhin.  Given the lack of hard evidence
that there's a bug in non-debug builds, I'm content to fix this only
in HEAD.

Discussion: https://postgr.es/m/18014-28c81cb79d44295d@postgresql.org
pull/145/head
Tom Lane 2 years ago
parent 403ac226dd
commit fcdd6689d0
2 changed files with 343 additions and 46 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 387
      src/backend/catalog/namespace.c
  2. 2
      src/include/catalog/namespace.h

387
src/backend/catalog/namespace.c
Unescape View File

@ -183,6 +183,19 @@ char *namespace_search_path = NULL;
/* Local functions */
static bool RelationIsVisibleExt(Oid relid, bool *is_missing);
static bool TypeIsVisibleExt(Oid typid, bool *is_missing);
static bool FunctionIsVisibleExt(Oid funcid, bool *is_missing);
static bool OperatorIsVisibleExt(Oid oprid, bool *is_missing);
static bool OpclassIsVisibleExt(Oid opcid, bool *is_missing);
static bool OpfamilyIsVisibleExt(Oid opfid, bool *is_missing);
static bool CollationIsVisibleExt(Oid collid, bool *is_missing);
static bool ConversionIsVisibleExt(Oid conid, bool *is_missing);
static bool StatisticsObjIsVisibleExt(Oid stxid, bool *is_missing);
static bool TSParserIsVisibleExt(Oid prsId, bool *is_missing);
static bool TSDictionaryIsVisibleExt(Oid dictId, bool *is_missing);
static bool TSTemplateIsVisibleExt(Oid tmplId, bool *is_missing);
static bool TSConfigIsVisibleExt(Oid cfgid, bool *is_missing);
static void recomputeNamespacePath(void);
static void AccessTempTableNamespace(bool force);
static void InitTempTableNamespace(void);
@ -691,6 +704,18 @@ RelnameGetRelid(const char *relname)
*/
bool
RelationIsVisible(Oid relid)
{
return RelationIsVisibleExt(relid, NULL);
}
/*
* RelationIsVisibleExt
* As above, but if the relation isn't found and is_missing is not NULL,
* then set *is_missing = true and return false instead of throwing
* an error. (Caller must initialize *is_missing = false.)
*/
static bool
RelationIsVisibleExt(Oid relid, bool *is_missing)
{
HeapTuple reltup;
Form_pg_class relform;
@ -699,7 +724,14 @@ RelationIsVisible(Oid relid)
reltup = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(reltup))
{
if (is_missing != NULL)
{
*is_missing = true;
return false;
}
elog(ERROR, "cache lookup failed for relation %u", relid);
}
relform = (Form_pg_class) GETSTRUCT(reltup);
recomputeNamespacePath();
@ -799,6 +831,18 @@ TypenameGetTypidExtended(const char *typname, bool temp_ok)
*/
bool
TypeIsVisible(Oid typid)
{
return TypeIsVisibleExt(typid, NULL);
}
/*
* TypeIsVisibleExt
* As above, but if the type isn't found and is_missing is not NULL,
* then set *is_missing = true and return false instead of throwing
* an error. (Caller must initialize *is_missing = false.)
*/
static bool
TypeIsVisibleExt(Oid typid, bool *is_missing)
{
HeapTuple typtup;
Form_pg_type typform;
@ -807,7 +851,14 @@ TypeIsVisible(Oid typid)
typtup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(typid));
if (!HeapTupleIsValid(typtup))
{
if (is_missing != NULL)
{
*is_missing = true;
return false;
}
elog(ERROR, "cache lookup failed for type %u", typid);
}
typform = (Form_pg_type) GETSTRUCT(typtup);
recomputeNamespacePath();
@ -1436,6 +1487,18 @@ MatchNamedCall(HeapTuple proctup, int nargs, List *argnames,
*/
bool
FunctionIsVisible(Oid funcid)
{
return FunctionIsVisibleExt(funcid, NULL);
}
/*
* FunctionIsVisibleExt
* As above, but if the function isn't found and is_missing is not NULL,
* then set *is_missing = true and return false instead of throwing
* an error. (Caller must initialize *is_missing = false.)
*/
static bool
FunctionIsVisibleExt(Oid funcid, bool *is_missing)
{
HeapTuple proctup;
Form_pg_proc procform;
@ -1444,7 +1507,14 @@ FunctionIsVisible(Oid funcid)
proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
if (!HeapTupleIsValid(proctup))
{
if (is_missing != NULL)
{
*is_missing = true;
return false;
}
elog(ERROR, "cache lookup failed for function %u", funcid);
}
procform = (Form_pg_proc) GETSTRUCT(proctup);
recomputeNamespacePath();
@ -1770,6 +1840,18 @@ OpernameGetCandidates(List *names, char oprkind, bool missing_schema_ok)
*/
bool
OperatorIsVisible(Oid oprid)
{
return OperatorIsVisibleExt(oprid, NULL);
}
/*
* OperatorIsVisibleExt
* As above, but if the operator isn't found and is_missing is not NULL,
* then set *is_missing = true and return false instead of throwing
* an error. (Caller must initialize *is_missing = false.)
*/
static bool
OperatorIsVisibleExt(Oid oprid, bool *is_missing)
{
HeapTuple oprtup;
Form_pg_operator oprform;
@ -1778,7 +1860,14 @@ OperatorIsVisible(Oid oprid)
oprtup = SearchSysCache1(OPEROID, ObjectIdGetDatum(oprid));
if (!HeapTupleIsValid(oprtup))
{
if (is_missing != NULL)
{
*is_missing = true;
return false;
}
elog(ERROR, "cache lookup failed for operator %u", oprid);
}
oprform = (Form_pg_operator) GETSTRUCT(oprtup);
recomputeNamespacePath();
@ -1856,6 +1945,18 @@ OpclassnameGetOpcid(Oid amid, const char *opcname)
*/
bool
OpclassIsVisible(Oid opcid)
{
return OpclassIsVisibleExt(opcid, NULL);
}
/*
* OpclassIsVisibleExt
* As above, but if the opclass isn't found and is_missing is not NULL,
* then set *is_missing = true and return false instead of throwing
* an error. (Caller must initialize *is_missing = false.)
*/
static bool
OpclassIsVisibleExt(Oid opcid, bool *is_missing)
{
HeapTuple opctup;
Form_pg_opclass opcform;
@ -1864,7 +1965,14 @@ OpclassIsVisible(Oid opcid)
opctup = SearchSysCache1(CLAOID, ObjectIdGetDatum(opcid));
if (!HeapTupleIsValid(opctup))
{
if (is_missing != NULL)
{
*is_missing = true;
return false;
}
elog(ERROR, "cache lookup failed for opclass %u", opcid);
}
opcform = (Form_pg_opclass) GETSTRUCT(opctup);
recomputeNamespacePath();
@ -1939,6 +2047,18 @@ OpfamilynameGetOpfid(Oid amid, const char *opfname)
*/
bool
OpfamilyIsVisible(Oid opfid)
{
return OpfamilyIsVisibleExt(opfid, NULL);
}
/*
* OpfamilyIsVisibleExt
* As above, but if the opfamily isn't found and is_missing is not NULL,
* then set *is_missing = true and return false instead of throwing
* an error. (Caller must initialize *is_missing = false.)
*/
static bool
OpfamilyIsVisibleExt(Oid opfid, bool *is_missing)
{
HeapTuple opftup;
Form_pg_opfamily opfform;
@ -1947,7 +2067,14 @@ OpfamilyIsVisible(Oid opfid)
opftup = SearchSysCache1(OPFAMILYOID, ObjectIdGetDatum(opfid));
if (!HeapTupleIsValid(opftup))
{
if (is_missing != NULL)
{
*is_missing = true;
return false;
}
elog(ERROR, "cache lookup failed for opfamily %u", opfid);
}
opfform = (Form_pg_opfamily) GETSTRUCT(opftup);
recomputeNamespacePath();
@ -2071,6 +2198,18 @@ CollationGetCollid(const char *collname)
*/
bool
CollationIsVisible(Oid collid)
{
return CollationIsVisibleExt(collid, NULL);
}
/*
* CollationIsVisibleExt
* As above, but if the collation isn't found and is_missing is not NULL,
* then set *is_missing = true and return false instead of throwing
* an error. (Caller must initialize *is_missing = false.)
*/
static bool
CollationIsVisibleExt(Oid collid, bool *is_missing)
{
HeapTuple colltup;
Form_pg_collation collform;
@ -2079,7 +2218,14 @@ CollationIsVisible(Oid collid)
colltup = SearchSysCache1(COLLOID, ObjectIdGetDatum(collid));
if (!HeapTupleIsValid(colltup))
{
if (is_missing != NULL)
{
*is_missing = true;
return false;
}
elog(ERROR, "cache lookup failed for collation %u", collid);
}
collform = (Form_pg_collation) GETSTRUCT(colltup);
recomputeNamespacePath();
@ -2154,6 +2300,18 @@ ConversionGetConid(const char *conname)
*/
bool
ConversionIsVisible(Oid conid)
{
return ConversionIsVisibleExt(conid, NULL);
}
/*
* ConversionIsVisibleExt
* As above, but if the conversion isn't found and is_missing is not NULL,
* then set *is_missing = true and return false instead of throwing
* an error. (Caller must initialize *is_missing = false.)
*/
static bool
ConversionIsVisibleExt(Oid conid, bool *is_missing)
{
HeapTuple contup;
Form_pg_conversion conform;
@ -2162,7 +2320,14 @@ ConversionIsVisible(Oid conid)
contup = SearchSysCache1(CONVOID, ObjectIdGetDatum(conid));
if (!HeapTupleIsValid(contup))
{
if (is_missing != NULL)
{
*is_missing = true;
return false;
}
elog(ERROR, "cache lookup failed for conversion %u", conid);
}
conform = (Form_pg_conversion) GETSTRUCT(contup);
recomputeNamespacePath();
@ -2257,16 +2422,35 @@ get_statistics_object_oid(List *names, bool missing_ok)
* for the unqualified statistics object name".
*/
bool
StatisticsObjIsVisible(Oid relid)
StatisticsObjIsVisible(Oid stxid)
{
return StatisticsObjIsVisibleExt(stxid, NULL);
}
/*
* StatisticsObjIsVisibleExt
* As above, but if the statistics object isn't found and is_missing is
* not NULL, then set *is_missing = true and return false instead of
* throwing an error. (Caller must initialize *is_missing = false.)
*/
static bool
StatisticsObjIsVisibleExt(Oid stxid, bool *is_missing)
{
HeapTuple stxtup;
Form_pg_statistic_ext stxform;
Oid stxnamespace;
bool visible;
stxtup = SearchSysCache1(STATEXTOID, ObjectIdGetDatum(relid));
stxtup = SearchSysCache1(STATEXTOID, ObjectIdGetDatum(stxid));
if (!HeapTupleIsValid(stxtup))
elog(ERROR, "cache lookup failed for statistics object %u", relid);
{
if (is_missing != NULL)
{
*is_missing = true;
return false;
}
elog(ERROR, "cache lookup failed for statistics object %u", stxid);
}
stxform = (Form_pg_statistic_ext) GETSTRUCT(stxtup);
recomputeNamespacePath();
@ -2381,6 +2565,18 @@ get_ts_parser_oid(List *names, bool missing_ok)
*/
bool
TSParserIsVisible(Oid prsId)
{
return TSParserIsVisibleExt(prsId, NULL);
}
/*
* TSParserIsVisibleExt
* As above, but if the parser isn't found and is_missing is not NULL,
* then set *is_missing = true and return false instead of throwing
* an error. (Caller must initialize *is_missing = false.)
*/
static bool
TSParserIsVisibleExt(Oid prsId, bool *is_missing)
{
HeapTuple tup;
Form_pg_ts_parser form;
@ -2389,7 +2585,14 @@ TSParserIsVisible(Oid prsId)
tup = SearchSysCache1(TSPARSEROID, ObjectIdGetDatum(prsId));
if (!HeapTupleIsValid(tup))
{
if (is_missing != NULL)
{
*is_missing = true;
return false;
}
elog(ERROR, "cache lookup failed for text search parser %u", prsId);
}
form = (Form_pg_ts_parser) GETSTRUCT(tup);
recomputeNamespacePath();
@ -2507,6 +2710,18 @@ get_ts_dict_oid(List *names, bool missing_ok)
*/
bool
TSDictionaryIsVisible(Oid dictId)
{
return TSDictionaryIsVisibleExt(dictId, NULL);
}
/*
* TSDictionaryIsVisibleExt
* As above, but if the dictionary isn't found and is_missing is not NULL,
* then set *is_missing = true and return false instead of throwing
* an error. (Caller must initialize *is_missing = false.)
*/
static bool
TSDictionaryIsVisibleExt(Oid dictId, bool *is_missing)
{
HeapTuple tup;
Form_pg_ts_dict form;
@ -2515,8 +2730,15 @@ TSDictionaryIsVisible(Oid dictId)
tup = SearchSysCache1(TSDICTOID, ObjectIdGetDatum(dictId));
if (!HeapTupleIsValid(tup))
{
if (is_missing != NULL)
{
*is_missing = true;
return false;
}
elog(ERROR, "cache lookup failed for text search dictionary %u",
dictId);
}
form = (Form_pg_ts_dict) GETSTRUCT(tup);
recomputeNamespacePath();
@ -2634,6 +2856,18 @@ get_ts_template_oid(List *names, bool missing_ok)
*/
bool
TSTemplateIsVisible(Oid tmplId)
{
return TSTemplateIsVisibleExt(tmplId, NULL);
}
/*
* TSTemplateIsVisibleExt
* As above, but if the template isn't found and is_missing is not NULL,
* then set *is_missing = true and return false instead of throwing
* an error. (Caller must initialize *is_missing = false.)
*/
static bool
TSTemplateIsVisibleExt(Oid tmplId, bool *is_missing)
{
HeapTuple tup;
Form_pg_ts_template form;
@ -2642,7 +2876,14 @@ TSTemplateIsVisible(Oid tmplId)
tup = SearchSysCache1(TSTEMPLATEOID, ObjectIdGetDatum(tmplId));
if (!HeapTupleIsValid(tup))
{
if (is_missing != NULL)
{
*is_missing = true;
return false;
}
elog(ERROR, "cache lookup failed for text search template %u", tmplId);
}
form = (Form_pg_ts_template) GETSTRUCT(tup);
recomputeNamespacePath();
@ -2760,6 +3001,18 @@ get_ts_config_oid(List *names, bool missing_ok)
*/
bool
TSConfigIsVisible(Oid cfgid)
{
return TSConfigIsVisibleExt(cfgid, NULL);
}
/*
* TSConfigIsVisibleExt
* As above, but if the configuration isn't found and is_missing is not
* NULL, then set *is_missing = true and return false instead of throwing
* an error. (Caller must initialize *is_missing = false.)
*/
static bool
TSConfigIsVisibleExt(Oid cfgid, bool *is_missing)
{
HeapTuple tup;
Form_pg_ts_config form;
@ -2768,8 +3021,15 @@ TSConfigIsVisible(Oid cfgid)
tup = SearchSysCache1(TSCONFIGOID, ObjectIdGetDatum(cfgid));
if (!HeapTupleIsValid(tup))
{
if (is_missing != NULL)
{
*is_missing = true;
return false;
}
elog(ERROR, "cache lookup failed for text search configuration %u",
cfgid);
}
form = (Form_pg_ts_config) GETSTRUCT(tup);
recomputeNamespacePath();
@ -4283,152 +4543,189 @@ fetch_search_path_array(Oid *sarray, int sarray_len)
* condition errors when a query that's scanning a catalog using an MVCC
* snapshot uses one of these functions. The underlying IsVisible functions
* always use an up-to-date snapshot and so might see the object as already
* gone when it's still visible to the transaction snapshot. (There is no race
* condition in the current coding because we don't accept sinval messages
* between the SearchSysCacheExists test and the subsequent lookup.)
* gone when it's still visible to the transaction snapshot.
*/
Datum
pg_table_is_visible(PG_FUNCTION_ARGS)
{
Oid oid = PG_GETARG_OID(0);
bool result;
bool is_missing = false;
if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(oid)))
PG_RETURN_NULL();
result = RelationIsVisibleExt(oid, &is_missing);
PG_RETURN_BOOL(RelationIsVisible(oid));
if (is_missing)
PG_RETURN_NULL();
PG_RETURN_BOOL(result);
}
Datum
pg_type_is_visible(PG_FUNCTION_ARGS)
{
Oid oid = PG_GETARG_OID(0);
bool result;
bool is_missing = false;
if (!SearchSysCacheExists1(TYPEOID, ObjectIdGetDatum(oid)))
PG_RETURN_NULL();
result = TypeIsVisibleExt(oid, &is_missing);
PG_RETURN_BOOL(TypeIsVisible(oid));
if (is_missing)
PG_RETURN_NULL();
PG_RETURN_BOOL(result);
}
Datum
pg_function_is_visible(PG_FUNCTION_ARGS)
{
Oid oid = PG_GETARG_OID(0);
bool result;
bool is_missing = false;
if (!SearchSysCacheExists1(PROCOID, ObjectIdGetDatum(oid)))
PG_RETURN_NULL();
result = FunctionIsVisibleExt(oid, &is_missing);
PG_RETURN_BOOL(FunctionIsVisible(oid));
if (is_missing)
PG_RETURN_NULL();
PG_RETURN_BOOL(result);
}
Datum
pg_operator_is_visible(PG_FUNCTION_ARGS)
{
Oid oid = PG_GETARG_OID(0);
bool result;
bool is_missing = false;
if (!SearchSysCacheExists1(OPEROID, ObjectIdGetDatum(oid)))
PG_RETURN_NULL();
result = OperatorIsVisibleExt(oid, &is_missing);
PG_RETURN_BOOL(OperatorIsVisible(oid));
if (is_missing)
PG_RETURN_NULL();
PG_RETURN_BOOL(result);
}
Datum
pg_opclass_is_visible(PG_FUNCTION_ARGS)
{
Oid oid = PG_GETARG_OID(0);
bool result;
bool is_missing = false;
if (!SearchSysCacheExists1(CLAOID, ObjectIdGetDatum(oid)))
PG_RETURN_NULL();
result = OpclassIsVisibleExt(oid, &is_missing);
PG_RETURN_BOOL(OpclassIsVisible(oid));
if (is_missing)
PG_RETURN_NULL();
PG_RETURN_BOOL(result);
}
Datum
pg_opfamily_is_visible(PG_FUNCTION_ARGS)
{
Oid oid = PG_GETARG_OID(0);
bool result;
bool is_missing = false;
if (!SearchSysCacheExists1(OPFAMILYOID, ObjectIdGetDatum(oid)))
PG_RETURN_NULL();
result = OpfamilyIsVisibleExt(oid, &is_missing);
PG_RETURN_BOOL(OpfamilyIsVisible(oid));
if (is_missing)
PG_RETURN_NULL();
PG_RETURN_BOOL(result);
}
Datum
pg_collation_is_visible(PG_FUNCTION_ARGS)
{
Oid oid = PG_GETARG_OID(0);
bool result;
bool is_missing = false;
if (!SearchSysCacheExists1(COLLOID, ObjectIdGetDatum(oid)))
PG_RETURN_NULL();
result = CollationIsVisibleExt(oid, &is_missing);
PG_RETURN_BOOL(CollationIsVisible(oid));
if (is_missing)
PG_RETURN_NULL();
PG_RETURN_BOOL(result);
}
Datum
pg_conversion_is_visible(PG_FUNCTION_ARGS)
{
Oid oid = PG_GETARG_OID(0);
bool result;
bool is_missing = false;
if (!SearchSysCacheExists1(CONVOID, ObjectIdGetDatum(oid)))
PG_RETURN_NULL();
result = ConversionIsVisibleExt(oid, &is_missing);
PG_RETURN_BOOL(ConversionIsVisible(oid));
if (is_missing)
PG_RETURN_NULL();
PG_RETURN_BOOL(result);
}
Datum
pg_statistics_obj_is_visible(PG_FUNCTION_ARGS)
{
Oid oid = PG_GETARG_OID(0);
bool result;
bool is_missing = false;
if (!SearchSysCacheExists1(STATEXTOID, ObjectIdGetDatum(oid)))
PG_RETURN_NULL();
result = StatisticsObjIsVisibleExt(oid, &is_missing);
PG_RETURN_BOOL(StatisticsObjIsVisible(oid));
if (is_missing)
PG_RETURN_NULL();
PG_RETURN_BOOL(result);
}
Datum
pg_ts_parser_is_visible(PG_FUNCTION_ARGS)
{
Oid oid = PG_GETARG_OID(0);
bool result;
bool is_missing = false;
if (!SearchSysCacheExists1(TSPARSEROID, ObjectIdGetDatum(oid)))
PG_RETURN_NULL();
result = TSParserIsVisibleExt(oid, &is_missing);
PG_RETURN_BOOL(TSParserIsVisible(oid));
if (is_missing)
PG_RETURN_NULL();
PG_RETURN_BOOL(result);
}
Datum
pg_ts_dict_is_visible(PG_FUNCTION_ARGS)
{
Oid oid = PG_GETARG_OID(0);
bool result;
bool is_missing = false;
if (!SearchSysCacheExists1(TSDICTOID, ObjectIdGetDatum(oid)))
PG_RETURN_NULL();
result = TSDictionaryIsVisibleExt(oid, &is_missing);
PG_RETURN_BOOL(TSDictionaryIsVisible(oid));
if (is_missing)
PG_RETURN_NULL();
PG_RETURN_BOOL(result);
}
Datum
pg_ts_template_is_visible(PG_FUNCTION_ARGS)
{
Oid oid = PG_GETARG_OID(0);
bool result;
bool is_missing = false;
if (!SearchSysCacheExists1(TSTEMPLATEOID, ObjectIdGetDatum(oid)))
PG_RETURN_NULL();
result = TSTemplateIsVisibleExt(oid, &is_missing);
PG_RETURN_BOOL(TSTemplateIsVisible(oid));
if (is_missing)
PG_RETURN_NULL();
PG_RETURN_BOOL(result);
}
Datum
pg_ts_config_is_visible(PG_FUNCTION_ARGS)
{
Oid oid = PG_GETARG_OID(0);
bool result;
bool is_missing = false;
if (!SearchSysCacheExists1(TSCONFIGOID, ObjectIdGetDatum(oid)))
PG_RETURN_NULL();
result = TSConfigIsVisibleExt(oid, &is_missing);
PG_RETURN_BOOL(TSConfigIsVisible(oid));
if (is_missing)
PG_RETURN_NULL();
PG_RETURN_BOOL(result);
}
Datum

2
src/include/catalog/namespace.h
Unescape View File

@ -122,7 +122,7 @@ extern Oid ConversionGetConid(const char *conname);
extern bool ConversionIsVisible(Oid conid);
extern Oid get_statistics_object_oid(List *names, bool missing_ok);
extern bool StatisticsObjIsVisible(Oid relid);
extern bool StatisticsObjIsVisible(Oid stxid);
extern Oid get_ts_parser_oid(List *names, bool missing_ok);
extern bool TSParserIsVisible(Oid prsId);

Write Preview
Loading…
Cancel
Save