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Add simple sanity checks on newly-read pages to GiST, too.

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This commit is contained in:
Tom Lane
2005-11-06 22:39:21 +00:00
parent 766dc45d9f
commit 6236991143
5 changed files with 119 additions and 46 deletions
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109
src/backend/access/gist/gistutil.c
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@ -8,7 +8,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/gist/gistutil.c,v 1.7 2005/09/22 20:44:36 momjian Exp $
* $PostgreSQL: pgsql/src/backend/access/gist/gistutil.c,v 1.8 2005/11/06 22:39:20 tgl Exp $
*-------------------------------------------------------------------------
*/
#include "postgres.h"
@ -798,23 +798,6 @@ gistpenalty(GISTSTATE *giststate, int attno,
PointerGetDatum(penalty));
}
void
GISTInitBuffer(Buffer b, uint32 f)
{
GISTPageOpaque opaque;
Page page;
Size pageSize;
pageSize = BufferGetPageSize(b);
page = BufferGetPage(b);
PageInit(page, pageSize, sizeof(GISTPageOpaqueData));
opaque = GistPageGetOpaque(page);
opaque->flags = f;
opaque->rightlink = InvalidBlockNumber;
memset(&(opaque->nsn), 0, sizeof(GistNSN));
}
void
gistUserPicksplit(Relation r, GistEntryVector *entryvec, GIST_SPLITVEC *v,
IndexTuple *itup, int len, GISTSTATE *giststate)
@ -864,36 +847,108 @@ gistUserPicksplit(Relation r, GistEntryVector *entryvec, GIST_SPLITVEC *v,
}
}
/*
* Initialize a new index page
*/
void
GISTInitBuffer(Buffer b, uint32 f)
{
GISTPageOpaque opaque;
Page page;
Size pageSize;
pageSize = BufferGetPageSize(b);
page = BufferGetPage(b);
PageInit(page, pageSize, sizeof(GISTPageOpaqueData));
opaque = GistPageGetOpaque(page);
opaque->flags = f;
opaque->rightlink = InvalidBlockNumber;
/* page was already zeroed by PageInit, so this is not needed: */
/* memset(&(opaque->nsn), 0, sizeof(GistNSN)); */
}
/*
* Verify that a freshly-read page looks sane.
*/
void
gistcheckpage(Relation rel, Buffer buf)
{
Page page = BufferGetPage(buf);
/*
* ReadBuffer verifies that every newly-read page passes PageHeaderIsValid,
* which means it either contains a reasonably sane page header or is
* all-zero. We have to defend against the all-zero case, however.
*/
if (PageIsNew(page))
ereport(ERROR,
(errcode(ERRCODE_INDEX_CORRUPTED),
errmsg("index \"%s\" contains unexpected zero page at block %u",
RelationGetRelationName(rel),
BufferGetBlockNumber(buf)),
errhint("Please REINDEX it.")));
/*
* Additionally check that the special area looks sane.
*/
if (((PageHeader) (page))->pd_special !=
(BLCKSZ - MAXALIGN(sizeof(GISTPageOpaqueData))))
ereport(ERROR,
(errcode(ERRCODE_INDEX_CORRUPTED),
errmsg("index \"%s\" contains corrupted page at block %u",
RelationGetRelationName(rel),
BufferGetBlockNumber(buf)),
errhint("Please REINDEX it.")));
}
/*
* Allocate a new page (either by recycling, or by extending the index file)
*
* The returned buffer is already pinned and exclusive-locked
*
* Caller is responsible for initializing the page by calling GISTInitBuffer
*/
Buffer
gistNewBuffer(Relation r)
{
Buffer buffer = InvalidBuffer;
Buffer buffer;
bool needLock;
while (true)
/* First, try to get a page from FSM */
for (;;)
{
BlockNumber blkno = GetFreeIndexPage(&r->rd_node);
if (blkno == InvalidBlockNumber)
break;
break; /* nothing left in FSM */
buffer = ReadBuffer(r, blkno);
/*
* We have to guard against the possibility that someone else already
* recycled this page; the buffer may be locked if so.
*/
if (ConditionalLockBuffer(buffer))
{
Page page = BufferGetPage(buffer);
if (PageIsNew(page))
return buffer; /* OK to use, if never initialized */
gistcheckpage(r, buffer);
if (GistPageIsDeleted(page))
{
GistPageSetNonDeleted(page);
return buffer;
}
else
LockBuffer(buffer, GIST_UNLOCK);
return buffer; /* OK to use */
LockBuffer(buffer, GIST_UNLOCK);
}
/* Can't use it, so release buffer and try again */
ReleaseBuffer(buffer);
}
/* Must extend the file */
needLock = !RELATION_IS_LOCAL(r);
if (needLock)