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Add simple sanity checks on newly-read pages to GiST, too.
1 parent 766dc45 commit 6236991

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5 files changed

+119
-46
lines changed

5 files changed

+119
-46
lines changed

‎src/backend/access/gist/gist.c

Lines changed: 18 additions & 12 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/access/gist/gist.c,v 1.127 2005/10/18 01:06:22 tgl Exp $
11+
* $PostgreSQL: pgsql/src/backend/access/gist/gist.c,v 1.128 2005/11/06 22:39:20 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -529,12 +529,12 @@ gistfindleaf(GISTInsertState *state, GISTSTATE *giststate)
529529
* ready to recheck path in a bad case... We remember, that page->lsn
530530
* should never be invalid.
531531
*/
532-
while (true)
532+
for (;;)
533533
{
534-
535534
if (XLogRecPtrIsInvalid(state->stack->lsn))
536535
state->stack->buffer = ReadBuffer(state->r, state->stack->blkno);
537536
LockBuffer(state->stack->buffer, GIST_SHARE);
537+
gistcheckpage(state->r, state->stack->buffer);
538538

539539
state->stack->page = (Page) BufferGetPage(state->stack->buffer);
540540
opaque = GistPageGetOpaque(state->stack->page);
@@ -555,7 +555,6 @@ gistfindleaf(GISTInsertState *state, GISTSTATE *giststate)
555555
continue;
556556
}
557557

558-
559558
if (!GistPageIsLeaf(state->stack->page))
560559
{
561560
/*
@@ -649,14 +648,18 @@ gistReadAndLockBuffer(Relation r, BlockNumber blkno)
649648
}
650649

651650
/*
652-
* Traverse the tree to find path from root page,
653-
* to prevent deadlocks, it should lock only one page simultaneously.
654-
* Function uses in recovery and usial mode, so should work with different
655-
* read functions (gistReadAndLockBuffer and XLogReadBuffer)
651+
* Traverse the tree to find path from root page.
652+
*
656653
* returns from the begining of closest parent;
654+
*
655+
* Function is used in both regular and recovery mode, so must work with
656+
* different read functions (gistReadAndLockBuffer and XLogReadBuffer)
657+
*
658+
* To prevent deadlocks, this should lock only one page simultaneously.
657659
*/
658660
GISTInsertStack *
659-
gistFindPath(Relation r, BlockNumber child, Buffer (*myReadBuffer) (Relation, BlockNumber))
661+
gistFindPath(Relation r, BlockNumber child,
662+
Buffer (*myReadBuffer) (Relation, BlockNumber))
660663
{
661664
Page page;
662665
Buffer buffer;
@@ -674,7 +677,8 @@ gistFindPath(Relation r, BlockNumber child, Buffer (*myReadBuffer) (Relation, Bl
674677

675678
while (top && top->blkno != child)
676679
{
677-
buffer = myReadBuffer(r, top->blkno); /* buffer locked */
680+
buffer = myReadBuffer(r, top->blkno); /* locks buffer */
681+
gistcheckpage(r, buffer);
678682
page = (Page) BufferGetPage(buffer);
679683

680684
if (GistPageIsLeaf(page))
@@ -771,9 +775,9 @@ gistFindCorrectParent(Relation r, GISTInsertStack *child)
771775
GISTInsertStack *parent = child->parent;
772776

773777
LockBuffer(parent->buffer, GIST_EXCLUSIVE);
778+
gistcheckpage(r, parent->buffer);
774779
parent->page = (Page) BufferGetPage(parent->buffer);
775780

776-
777781
/* here we don't need to distinguish between split and page update */
778782
if (parent->childoffnum == InvalidOffsetNumber || !XLByteEQ(parent->lsn, PageGetLSN(parent->page)))
779783
{
@@ -811,6 +815,7 @@ gistFindCorrectParent(Relation r, GISTInsertStack *child)
811815
break;
812816
parent->buffer = ReadBuffer(r, parent->blkno);
813817
LockBuffer(parent->buffer, GIST_EXCLUSIVE);
818+
gistcheckpage(r, parent->buffer);
814819
parent->page = (Page) BufferGetPage(parent->buffer);
815820
}
816821

@@ -831,7 +836,8 @@ gistFindCorrectParent(Relation r, GISTInsertStack *child)
831836
ptr = parent = gistFindPath(r, child->blkno, gistReadAndLockBuffer);
832837
Assert(ptr != NULL);
833838

834-
/* read all buffers as supposed in caller */
839+
/* read all buffers as expected by caller */
840+
/* note we don't lock them or gistcheckpage them here! */
835841
while (ptr)
836842
{
837843
ptr->buffer = ReadBuffer(r, ptr->blkno);

‎src/backend/access/gist/gistget.c

Lines changed: 7 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/access/gist/gistget.c,v 1.52 2005/10/06 02:29:07 tgl Exp $
11+
* $PostgreSQL: pgsql/src/backend/access/gist/gistget.c,v 1.53 2005/11/06 22:39:20 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -40,6 +40,7 @@ killtuple(Relation r, GISTScanOpaque so, ItemPointer iptr)
4040
maxoff;
4141

4242
LockBuffer(buffer, GIST_SHARE);
43+
gistcheckpage(r, buffer);
4344
p = (Page) BufferGetPage(buffer);
4445

4546
if (buffer == so->curbuf && XLByteEQ(so->stack->lsn, PageGetLSN(p)))
@@ -176,6 +177,7 @@ gistnext(IndexScanDesc scan, ScanDirection dir, ItemPointer tids, int maxtids, b
176177
/* First of all, we need lock buffer */
177178
Assert(so->curbuf != InvalidBuffer);
178179
LockBuffer(so->curbuf, GIST_SHARE);
180+
gistcheckpage(scan->indexRelation, so->curbuf);
179181
p = BufferGetPage(so->curbuf);
180182
opaque = GistPageGetOpaque(p);
181183
resetoffset = false;
@@ -224,7 +226,8 @@ gistnext(IndexScanDesc scan, ScanDirection dir, ItemPointer tids, int maxtids, b
224226
continue;
225227
}
226228

227-
if (!GistPageIsLeaf(p) || resetoffset || ItemPointerIsValid(&scan->currentItemData) == false)
229+
if (!GistPageIsLeaf(p) || resetoffset ||
230+
!ItemPointerIsValid(&scan->currentItemData))
228231
{
229232
if (ScanDirectionIsBackward(dir))
230233
n = PageGetMaxOffsetNumber(p);
@@ -268,7 +271,8 @@ gistnext(IndexScanDesc scan, ScanDirection dir, ItemPointer tids, int maxtids, b
268271
return ntids;
269272
}
270273

271-
so->curbuf = ReleaseAndReadBuffer(so->curbuf, scan->indexRelation,
274+
so->curbuf = ReleaseAndReadBuffer(so->curbuf,
275+
scan->indexRelation,
272276
stk->block);
273277
/* XXX go up */
274278
break;

‎src/backend/access/gist/gistutil.c

Lines changed: 82 additions & 27 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/access/gist/gistutil.c,v 1.7 2005/09/22 20:44:36 momjian Exp $
11+
* $PostgreSQL: pgsql/src/backend/access/gist/gistutil.c,v 1.8 2005/11/06 22:39:20 tgl Exp $
1212
*-------------------------------------------------------------------------
1313
*/
1414
#include "postgres.h"
@@ -798,23 +798,6 @@ gistpenalty(GISTSTATE *giststate, int attno,
798798
PointerGetDatum(penalty));
799799
}
800800

801-
void
802-
GISTInitBuffer(Buffer b, uint32 f)
803-
{
804-
GISTPageOpaque opaque;
805-
Page page;
806-
Size pageSize;
807-
808-
pageSize = BufferGetPageSize(b);
809-
page = BufferGetPage(b);
810-
PageInit(page, pageSize, sizeof(GISTPageOpaqueData));
811-
812-
opaque = GistPageGetOpaque(page);
813-
opaque->flags = f;
814-
opaque->rightlink = InvalidBlockNumber;
815-
memset(&(opaque->nsn), 0, sizeof(GistNSN));
816-
}
817-
818801
void
819802
gistUserPicksplit(Relation r, GistEntryVector *entryvec, GIST_SPLITVEC *v,
820803
IndexTuple *itup, int len, GISTSTATE *giststate)
@@ -864,36 +847,108 @@ gistUserPicksplit(Relation r, GistEntryVector *entryvec, GIST_SPLITVEC *v,
864847
}
865848
}
866849

850+
/*
851+
* Initialize a new index page
852+
*/
853+
void
854+
GISTInitBuffer(Buffer b, uint32 f)
855+
{
856+
GISTPageOpaque opaque;
857+
Page page;
858+
Size pageSize;
859+
860+
pageSize = BufferGetPageSize(b);
861+
page = BufferGetPage(b);
862+
PageInit(page, pageSize, sizeof(GISTPageOpaqueData));
863+
864+
opaque = GistPageGetOpaque(page);
865+
opaque->flags = f;
866+
opaque->rightlink = InvalidBlockNumber;
867+
/* page was already zeroed by PageInit, so this is not needed: */
868+
/* memset(&(opaque->nsn), 0, sizeof(GistNSN)); */
869+
}
870+
871+
/*
872+
* Verify that a freshly-read page looks sane.
873+
*/
874+
void
875+
gistcheckpage(Relation rel, Buffer buf)
876+
{
877+
Page page = BufferGetPage(buf);
878+
879+
/*
880+
* ReadBuffer verifies that every newly-read page passes PageHeaderIsValid,
881+
* which means it either contains a reasonably sane page header or is
882+
* all-zero. We have to defend against the all-zero case, however.
883+
*/
884+
if (PageIsNew(page))
885+
ereport(ERROR,
886+
(errcode(ERRCODE_INDEX_CORRUPTED),
887+
errmsg("index \"%s\" contains unexpected zero page at block %u",
888+
RelationGetRelationName(rel),
889+
BufferGetBlockNumber(buf)),
890+
errhint("Please REINDEX it.")));
891+
892+
/*
893+
* Additionally check that the special area looks sane.
894+
*/
895+
if (((PageHeader) (page))->pd_special !=
896+
(BLCKSZ - MAXALIGN(sizeof(GISTPageOpaqueData))))
897+
ereport(ERROR,
898+
(errcode(ERRCODE_INDEX_CORRUPTED),
899+
errmsg("index \"%s\" contains corrupted page at block %u",
900+
RelationGetRelationName(rel),
901+
BufferGetBlockNumber(buf)),
902+
errhint("Please REINDEX it.")));
903+
}
904+
905+
906+
/*
907+
* Allocate a new page (either by recycling, or by extending the index file)
908+
*
909+
* The returned buffer is already pinned and exclusive-locked
910+
*
911+
* Caller is responsible for initializing the page by calling GISTInitBuffer
912+
*/
867913
Buffer
868914
gistNewBuffer(Relation r)
869915
{
870-
Buffer buffer = InvalidBuffer;
916+
Buffer buffer;
871917
bool needLock;
872918

873-
while (true)
919+
/* First, try to get a page from FSM */
920+
for (;;)
874921
{
875922
BlockNumber blkno = GetFreeIndexPage(&r->rd_node);
876923

877924
if (blkno == InvalidBlockNumber)
878-
break;
925+
break; /* nothing left in FSM */
879926

880927
buffer = ReadBuffer(r, blkno);
928+
/*
929+
* We have to guard against the possibility that someone else already
930+
* recycled this page; the buffer may be locked if so.
931+
*/
881932
if (ConditionalLockBuffer(buffer))
882933
{
883934
Page page = BufferGetPage(buffer);
884935

936+
if (PageIsNew(page))
937+
return buffer; /* OK to use, if never initialized */
938+
939+
gistcheckpage(r, buffer);
940+
885941
if (GistPageIsDeleted(page))
886-
{
887-
GistPageSetNonDeleted(page);
888-
return buffer;
889-
}
890-
else
891-
LockBuffer(buffer, GIST_UNLOCK);
942+
return buffer; /* OK to use */
943+
944+
LockBuffer(buffer, GIST_UNLOCK);
892945
}
893946

947+
/* Can't use it, so release buffer and try again */
894948
ReleaseBuffer(buffer);
895949
}
896950

951+
/* Must extend the file */
897952
needLock = !RELATION_IS_LOCAL(r);
898953

899954
if (needLock)

‎src/backend/access/gist/gistvacuum.c

Lines changed: 10 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/access/gist/gistvacuum.c,v 1.9 2005/09/22 20:44:36 momjian Exp $
11+
* $PostgreSQL: pgsql/src/backend/access/gist/gistvacuum.c,v 1.10 2005/11/06 22:39:20 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -65,6 +65,11 @@ gistVacuumUpdate(GistVacuum *gv, BlockNumber blkno, bool needunion)
6565
lencompleted = 16;
6666

6767
buffer = ReadBuffer(gv->index, blkno);
68+
/*
69+
* This is only used during VACUUM FULL, so we need not bother to lock
70+
* individual index pages
71+
*/
72+
gistcheckpage(gv->index, buffer);
6873
page = (Page) BufferGetPage(buffer);
6974
maxoff = PageGetMaxOffsetNumber(page);
7075

@@ -378,9 +383,10 @@ gistvacuumcleanup(PG_FUNCTION_ARGS)
378383

379384
needFullVacuum = false;
380385

381-
needLock = !RELATION_IS_LOCAL(rel);
382386
if (info->vacuum_full)
383387
needLock = false; /* relation locked with AccessExclusiveLock */
388+
else
389+
needLock = !RELATION_IS_LOCAL(rel);
384390

385391
/* try to find deleted pages */
386392
if (needLock)
@@ -403,7 +409,7 @@ gistvacuumcleanup(PG_FUNCTION_ARGS)
403409
LockBuffer(buffer, GIST_SHARE);
404410
page = (Page) BufferGetPage(buffer);
405411

406-
if (GistPageIsDeleted(page))
412+
if (PageIsNew(page) || GistPageIsDeleted(page))
407413
{
408414
if (nFreePages < maxFreePages)
409415
{
@@ -513,6 +519,7 @@ gistbulkdelete(PG_FUNCTION_ARGS)
513519
ItemId iid;
514520

515521
LockBuffer(buffer, GIST_SHARE);
522+
gistcheckpage(rel, buffer);
516523
page = (Page) BufferGetPage(buffer);
517524

518525
if (GistPageIsLeaf(page))

‎src/include/access/gist_private.h

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $PostgreSQL: pgsql/src/include/access/gist_private.h,v 1.8 2005/10/15 02:49:42 momjian Exp $
10+
* $PostgreSQL: pgsql/src/include/access/gist_private.h,v 1.9 2005/11/06 22:39:21 tgl Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -263,6 +263,7 @@ extern Datum gistgettuple(PG_FUNCTION_ARGS);
263263
extern Datum gistgetmulti(PG_FUNCTION_ARGS);
264264

265265
/* gistutil.c */
266+
extern void gistcheckpage(Relation rel, Buffer buf);
266267
extern Buffer gistNewBuffer(Relation r);
267268
extern OffsetNumber gistfillbuffer(Relation r, Page page, IndexTuple *itup,
268269
int len, OffsetNumber off);

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