]> granicus.if.org Git - postgresql/commitdiff
Fix potential assertion failure when reindexing a pg_class index.
authorAndres Freund <andres@anarazel.de>
Tue, 30 Apr 2019 02:42:04 +0000 (19:42 -0700)
committerAndres Freund <andres@anarazel.de>
Tue, 30 Apr 2019 02:42:08 +0000 (19:42 -0700)
When reindexing individual indexes on pg_class it was possible to
either trigger an assertion failure:
TRAP: FailedAssertion("!(!ReindexIsProcessingIndex(((index)->rd_id)))

That's because reindex_index() called SetReindexProcessing() - which
enables an asserts ensuring no index insertions happen into the index
- before calling RelationSetNewRelfilenode(). That not correct for
indexes on pg_class, because RelationSetNewRelfilenode() updates the
relevant pg_class row, which needs to update the indexes.

The are two reasons this wasn't noticed earlier. Firstly the bug
doesn't trigger when reindexing all of pg_class, as reindex_relation
has code "hiding" all yet-to-be-reindexed indexes. Secondly, the bug
only triggers when the the update to pg_class doesn't turn out to be a
HOT update - otherwise there's no index insertion to trigger the
bug. Most of the time there's enough space, making this bug hard to
trigger.

To fix, move RelationSetNewRelfilenode() to before the
SetReindexProcessing() (and, together with some other code, to outside
of the PG_TRY()).

To make sure the error checking intended by SetReindexProcessing() is
more robust, modify CatalogIndexInsert() to check
ReindexIsProcessingIndex() even when the update is a HOT update.

Also add a few regression tests for REINDEXing of system catalogs.

The last two improvements would have prevented some of the issues
fixed in 5c1560606dc4c from being introduced in the first place.

Reported-By: Michael Paquier
Diagnosed-By: Tom Lane and Andres Freund
Author: Andres Freund
Reviewed-By: Tom Lane
Discussion: https://postgr.es/m/20190418011430.GA19133@paquier.xyz
Backpatch: 9.4-, the bug is present in all branches

contrib/test_decoding/expected/rewrite.out
contrib/test_decoding/sql/rewrite.sql
src/backend/catalog/index.c
src/backend/catalog/indexing.c
src/test/regress/expected/create_index.out
src/test/regress/sql/create_index.sql

index 3bf2afa9315f5a1cbc0f7d6f332aa93aeb201c73..28998b86f9e91b8863341d532cb0a97181be987a 100644 (file)
@@ -103,6 +103,10 @@ COMMIT;
  -- repeated rewrites in different transactions
 VACUUM FULL pg_class;
 VACUUM FULL pg_class;
+-- reindexing of important relations / indexes
+REINDEX TABLE pg_class;
+REINDEX INDEX pg_class_oid_index;
+REINDEX INDEX pg_class_tblspc_relfilenode_index;
 INSERT INTO replication_example(somedata, testcolumn1) VALUES (5, 3);
 BEGIN;
 INSERT INTO replication_example(somedata, testcolumn1) VALUES (6, 4);
index 4271b82bead4b290357f4853afd2e85028b8a94b..c9503a0da59b98c20a1632190362d40d33d49ca5 100644 (file)
@@ -74,6 +74,11 @@ COMMIT;
 VACUUM FULL pg_class;
 VACUUM FULL pg_class;
 
+-- reindexing of important relations / indexes
+REINDEX TABLE pg_class;
+REINDEX INDEX pg_class_oid_index;
+REINDEX INDEX pg_class_tblspc_relfilenode_index;
+
 INSERT INTO replication_example(somedata, testcolumn1) VALUES (5, 3);
 
 BEGIN;
index 331f90528cdd3d48c596361346acdd5c86f2e24e..ce024101fc9b960f439d601f5e5467b3e5e8a105 100644 (file)
@@ -3316,28 +3316,34 @@ reindex_index(Oid indexId, bool skip_constraint_checks, char persistence,
         */
        TransferPredicateLocksToHeapRelation(iRel);
 
+       /* Fetch info needed for index_build */
+       indexInfo = BuildIndexInfo(iRel);
+
+       /* If requested, skip checking uniqueness/exclusion constraints */
+       if (skip_constraint_checks)
+       {
+               if (indexInfo->ii_Unique || indexInfo->ii_ExclusionOps != NULL)
+                       skipped_constraint = true;
+               indexInfo->ii_Unique = false;
+               indexInfo->ii_ExclusionOps = NULL;
+               indexInfo->ii_ExclusionProcs = NULL;
+               indexInfo->ii_ExclusionStrats = NULL;
+       }
+
+       /*
+        * Build a new physical relation for the index. Need to do that before
+        * "officially" starting the reindexing with SetReindexProcessing -
+        * otherwise the necessary pg_class changes cannot be made with
+        * encountering assertions.
+        */
+       RelationSetNewRelfilenode(iRel, persistence);
+
+       /* ensure SetReindexProcessing state isn't leaked */
        PG_TRY();
        {
                /* Suppress use of the target index while rebuilding it */
                SetReindexProcessing(heapId, indexId);
 
-               /* Fetch info needed for index_build */
-               indexInfo = BuildIndexInfo(iRel);
-
-               /* If requested, skip checking uniqueness/exclusion constraints */
-               if (skip_constraint_checks)
-               {
-                       if (indexInfo->ii_Unique || indexInfo->ii_ExclusionOps != NULL)
-                               skipped_constraint = true;
-                       indexInfo->ii_Unique = false;
-                       indexInfo->ii_ExclusionOps = NULL;
-                       indexInfo->ii_ExclusionProcs = NULL;
-                       indexInfo->ii_ExclusionStrats = NULL;
-               }
-
-               /* We'll build a new physical relation for the index */
-               RelationSetNewRelfilenode(iRel, persistence);
-
                /* Initialize the index and rebuild */
                /* Note: we do not need to re-establish pkey setting */
                index_build(heapRelation, iRel, indexInfo, true, true);
index 0c994122d858bcf4f82b4c15828cf70b060c81ba..507879ecaf06387af7722251e91148bb6a599cdf 100644 (file)
@@ -82,9 +82,15 @@ CatalogIndexInsert(CatalogIndexState indstate, HeapTuple heapTuple)
        Datum           values[INDEX_MAX_KEYS];
        bool            isnull[INDEX_MAX_KEYS];
 
-       /* HOT update does not require index inserts */
+       /*
+        * HOT update does not require index inserts. But with asserts enabled we
+        * want to check that it'd be legal to currently insert into the
+        * table/index.
+        */
+#ifndef USE_ASSERT_CHECKING
        if (HeapTupleIsHeapOnly(heapTuple))
                return;
+#endif
 
        /*
         * Get information from the state structure.  Fall out if nothing to do.
@@ -107,8 +113,10 @@ CatalogIndexInsert(CatalogIndexState indstate, HeapTuple heapTuple)
        for (i = 0; i < numIndexes; i++)
        {
                IndexInfo  *indexInfo;
+               Relation        index;
 
                indexInfo = indexInfoArray[i];
+               index = relationDescs[i];
 
                /* If the index is marked as read-only, ignore it */
                if (!indexInfo->ii_ReadyForInserts)
@@ -121,9 +129,18 @@ CatalogIndexInsert(CatalogIndexState indstate, HeapTuple heapTuple)
                Assert(indexInfo->ii_Expressions == NIL);
                Assert(indexInfo->ii_Predicate == NIL);
                Assert(indexInfo->ii_ExclusionOps == NULL);
-               Assert(relationDescs[i]->rd_index->indimmediate);
+               Assert(index->rd_index->indimmediate);
                Assert(indexInfo->ii_NumIndexKeyAttrs != 0);
 
+               /* see earlier check above */
+#ifdef USE_ASSERT_CHECKING
+               if (HeapTupleIsHeapOnly(heapTuple))
+               {
+                       Assert(!ReindexIsProcessingIndex(RelationGetRelid(index)));
+                       continue;
+               }
+#endif /* USE_ASSERT_CHECKING */
+
                /*
                 * FormIndexDatum fills in its values and isnull parameters with the
                 * appropriate values for the column(s) of the index.
index 326dc4417768a10cd963ce0f1e9febfcab06dc88..ef8c8cd654d125d56a6ecf60652082a5ebcaecdd 100644 (file)
@@ -1939,6 +1939,24 @@ INFO:  index "reindex_verbose_pkey" was reindexed
 \set VERBOSITY default
 DROP TABLE reindex_verbose;
 --
+-- check that system tables can be reindexed
+--
+-- whole tables
+REINDEX TABLE pg_class; -- mapped, non-shared, critical
+REINDEX TABLE pg_index; -- non-mapped, non-shared, critical
+REINDEX TABLE pg_operator; -- non-mapped, non-shared, critical
+REINDEX TABLE pg_database; -- mapped, shared, critical
+REINDEX TABLE pg_shdescription; -- mapped, shared non-critical
+-- Check that individual system indexes can be reindexed. That's a bit
+-- different from the entire-table case because reindex_relation
+-- treats e.g. pg_class special.
+REINDEX INDEX pg_class_oid_index; -- mapped, non-shared, critical
+REINDEX INDEX pg_class_relname_nsp_index; -- mapped, non-shared, non-critical
+REINDEX INDEX pg_index_indexrelid_index; -- non-mapped, non-shared, critical
+REINDEX INDEX pg_index_indrelid_index; -- non-mapped, non-shared, non-critical
+REINDEX INDEX pg_database_oid_index; -- mapped, shared, critical
+REINDEX INDEX pg_shdescription_o_c_index; -- mapped, shared, non-critical
+--
 -- REINDEX CONCURRENTLY
 --
 CREATE TABLE concur_reindex_tab (c1 int);
index f29b8ca826fae03acc153ec97f1232a903b516e9..f6f2d7c14bb14e51866a8e6c7a57732ef013a057 100644 (file)
@@ -747,6 +747,27 @@ REINDEX (VERBOSE) TABLE reindex_verbose;
 \set VERBOSITY default
 DROP TABLE reindex_verbose;
 
+--
+-- check that system tables can be reindexed
+--
+
+-- whole tables
+REINDEX TABLE pg_class; -- mapped, non-shared, critical
+REINDEX TABLE pg_index; -- non-mapped, non-shared, critical
+REINDEX TABLE pg_operator; -- non-mapped, non-shared, critical
+REINDEX TABLE pg_database; -- mapped, shared, critical
+REINDEX TABLE pg_shdescription; -- mapped, shared non-critical
+
+-- Check that individual system indexes can be reindexed. That's a bit
+-- different from the entire-table case because reindex_relation
+-- treats e.g. pg_class special.
+REINDEX INDEX pg_class_oid_index; -- mapped, non-shared, critical
+REINDEX INDEX pg_class_relname_nsp_index; -- mapped, non-shared, non-critical
+REINDEX INDEX pg_index_indexrelid_index; -- non-mapped, non-shared, critical
+REINDEX INDEX pg_index_indrelid_index; -- non-mapped, non-shared, non-critical
+REINDEX INDEX pg_database_oid_index; -- mapped, shared, critical
+REINDEX INDEX pg_shdescription_o_c_index; -- mapped, shared, non-critical
+
 --
 -- REINDEX CONCURRENTLY
 --