Make the world safe for full_page_writes. Allow XLOG records that try to
update no-longer-existing pages to fall through as no-ops, but make a note of each page number referenced by such records. If we don't see a later XLOG entry dropping the table or truncating away the page, complain at the end of XLOG replay. Since this fixes the known failure mode for full_page_writes = off, revert my previous band-aid patch that disabled that GUC variable.
This commit is contained in:
Tom Lane
parent
0fcc3c2f1d
commit
defe93463c
|
|
@ -7,7 +7,7 @@
|
|||
* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.234 2006/04/05 03:34:05 tgl Exp $
|
||||
* $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.235 2006/04/14 20:27:24 tgl Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
|
|
@ -980,7 +980,8 @@ XLogCheckBuffer(XLogRecData *rdata,
|
|||
*/
|
||||
*lsn = page->pd_lsn;
|
||||
|
||||
if (XLByteLE(page->pd_lsn, RedoRecPtr))
|
||||
if (fullPageWrites &&
|
||||
XLByteLE(page->pd_lsn, RedoRecPtr))
|
||||
{
|
||||
/*
|
||||
* The page needs to be backed up, so set up *bkpb
|
||||
|
|
@ -4786,6 +4787,12 @@ StartupXLOG(void)
|
|||
RmgrTable[rmid].rm_cleanup();
|
||||
}
|
||||
|
||||
/*
|
||||
* Check to see if the XLOG sequence contained any unresolved
|
||||
* references to uninitialized pages.
|
||||
*/
|
||||
XLogCheckInvalidPages();
|
||||
|
||||
/*
|
||||
* Reset pgstat data, because it may be invalid after recovery.
|
||||
*/
|
||||
|
|
|
|||
|
|
@ -11,7 +11,7 @@
|
|||
* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* $PostgreSQL: pgsql/src/backend/access/transam/xlogutils.c,v 1.43 2006/03/31 23:32:06 tgl Exp $
|
||||
* $PostgreSQL: pgsql/src/backend/access/transam/xlogutils.c,v 1.44 2006/04/14 20:27:24 tgl Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
|
|
@ -24,6 +24,176 @@
|
|||
#include "utils/hsearch.h"
|
||||
|
||||
|
||||
/*
|
||||
* During XLOG replay, we may see XLOG records for incremental updates of
|
||||
* pages that no longer exist, because their relation was later dropped or
|
||||
* truncated. (Note: this is only possible when full_page_writes = OFF,
|
||||
* since when it's ON, the first reference we see to a page should always
|
||||
* be a full-page rewrite not an incremental update.) Rather than simply
|
||||
* ignoring such records, we make a note of the referenced page, and then
|
||||
* complain if we don't actually see a drop or truncate covering the page
|
||||
* later in replay.
|
||||
*/
|
||||
typedef struct xl_invalid_page_key
|
||||
{
|
||||
RelFileNode node; /* the relation */
|
||||
BlockNumber blkno; /* the page */
|
||||
} xl_invalid_page_key;
|
||||
|
||||
typedef struct xl_invalid_page
|
||||
{
|
||||
xl_invalid_page_key key; /* hash key ... must be first */
|
||||
bool present; /* page existed but contained zeroes */
|
||||
} xl_invalid_page;
|
||||
|
||||
static HTAB *invalid_page_tab = NULL;
|
||||
|
||||
|
||||
/* Log a reference to an invalid page */
|
||||
static void
|
||||
log_invalid_page(RelFileNode node, BlockNumber blkno, bool present)
|
||||
{
|
||||
xl_invalid_page_key key;
|
||||
xl_invalid_page *hentry;
|
||||
bool found;
|
||||
|
||||
/*
|
||||
* Log references to invalid pages at DEBUG1 level. This allows some
|
||||
* tracing of the cause (note the elog context mechanism will tell us
|
||||
* something about the XLOG record that generated the reference).
|
||||
*/
|
||||
if (present)
|
||||
elog(DEBUG1, "page %u of relation %u/%u/%u is uninitialized",
|
||||
blkno, node.spcNode, node.dbNode, node.relNode);
|
||||
else
|
||||
elog(DEBUG1, "page %u of relation %u/%u/%u does not exist",
|
||||
blkno, node.spcNode, node.dbNode, node.relNode);
|
||||
|
||||
if (invalid_page_tab == NULL)
|
||||
{
|
||||
/* create hash table when first needed */
|
||||
HASHCTL ctl;
|
||||
|
||||
memset(&ctl, 0, sizeof(ctl));
|
||||
ctl.keysize = sizeof(xl_invalid_page_key);
|
||||
ctl.entrysize = sizeof(xl_invalid_page);
|
||||
ctl.hash = tag_hash;
|
||||
|
||||
invalid_page_tab = hash_create("XLOG invalid-page table",
|
||||
100,
|
||||
&ctl,
|
||||
HASH_ELEM | HASH_FUNCTION);
|
||||
}
|
||||
|
||||
/* we currently assume xl_invalid_page_key contains no padding */
|
||||
key.node = node;
|
||||
key.blkno = blkno;
|
||||
hentry = (xl_invalid_page *)
|
||||
hash_search(invalid_page_tab, (void *) &key, HASH_ENTER, &found);
|
||||
|
||||
if (!found)
|
||||
{
|
||||
/* hash_search already filled in the key */
|
||||
hentry->present = present;
|
||||
}
|
||||
else
|
||||
{
|
||||
/* repeat reference ... leave "present" as it was */
|
||||
}
|
||||
}
|
||||
|
||||
/* Forget any invalid pages >= minblkno, because they've been dropped */
|
||||
static void
|
||||
forget_invalid_pages(RelFileNode node, BlockNumber minblkno)
|
||||
{
|
||||
HASH_SEQ_STATUS status;
|
||||
xl_invalid_page *hentry;
|
||||
|
||||
if (invalid_page_tab == NULL)
|
||||
return; /* nothing to do */
|
||||
|
||||
hash_seq_init(&status, invalid_page_tab);
|
||||
|
||||
while ((hentry = (xl_invalid_page *) hash_seq_search(&status)) != NULL)
|
||||
{
|
||||
if (RelFileNodeEquals(hentry->key.node, node) &&
|
||||
hentry->key.blkno >= minblkno)
|
||||
{
|
||||
elog(DEBUG2, "page %u of relation %u/%u/%u has been dropped",
|
||||
hentry->key.blkno, hentry->key.node.spcNode,
|
||||
hentry->key.node.dbNode, hentry->key.node.relNode);
|
||||
|
||||
if (hash_search(invalid_page_tab,
|
||||
(void *) &hentry->key,
|
||||
HASH_REMOVE, NULL) == NULL)
|
||||
elog(ERROR, "hash table corrupted");
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/* Forget any invalid pages in a whole database */
|
||||
static void
|
||||
forget_invalid_pages_db(Oid dbid)
|
||||
{
|
||||
HASH_SEQ_STATUS status;
|
||||
xl_invalid_page *hentry;
|
||||
|
||||
if (invalid_page_tab == NULL)
|
||||
return; /* nothing to do */
|
||||
|
||||
hash_seq_init(&status, invalid_page_tab);
|
||||
|
||||
while ((hentry = (xl_invalid_page *) hash_seq_search(&status)) != NULL)
|
||||
{
|
||||
if (hentry->key.node.dbNode == dbid)
|
||||
{
|
||||
elog(DEBUG2, "page %u of relation %u/%u/%u has been dropped",
|
||||
hentry->key.blkno, hentry->key.node.spcNode,
|
||||
hentry->key.node.dbNode, hentry->key.node.relNode);
|
||||
|
||||
if (hash_search(invalid_page_tab,
|
||||
(void *) &hentry->key,
|
||||
HASH_REMOVE, NULL) == NULL)
|
||||
elog(ERROR, "hash table corrupted");
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/* Complain about any remaining invalid-page entries */
|
||||
void
|
||||
XLogCheckInvalidPages(void)
|
||||
{
|
||||
HASH_SEQ_STATUS status;
|
||||
xl_invalid_page *hentry;
|
||||
bool foundone = false;
|
||||
|
||||
if (invalid_page_tab == NULL)
|
||||
return; /* nothing to do */
|
||||
|
||||
hash_seq_init(&status, invalid_page_tab);
|
||||
|
||||
/*
|
||||
* Our strategy is to emit WARNING messages for all remaining entries
|
||||
* and only PANIC after we've dumped all the available info.
|
||||
*/
|
||||
while ((hentry = (xl_invalid_page *) hash_seq_search(&status)) != NULL)
|
||||
{
|
||||
if (hentry->present)
|
||||
elog(WARNING, "page %u of relation %u/%u/%u was uninitialized",
|
||||
hentry->key.blkno, hentry->key.node.spcNode,
|
||||
hentry->key.node.dbNode, hentry->key.node.relNode);
|
||||
else
|
||||
elog(WARNING, "page %u of relation %u/%u/%u did not exist",
|
||||
hentry->key.blkno, hentry->key.node.spcNode,
|
||||
hentry->key.node.dbNode, hentry->key.node.relNode);
|
||||
foundone = true;
|
||||
}
|
||||
|
||||
if (foundone)
|
||||
elog(PANIC, "WAL contains references to invalid pages");
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* XLogReadBuffer
|
||||
* Read a page during XLOG replay
|
||||
|
|
@ -40,12 +210,11 @@
|
|||
* the page being "new" (all zeroes).
|
||||
*
|
||||
* If "init" is false then the caller needs the page to be valid already.
|
||||
* If the page doesn't exist or contains zeroes, we report failure.
|
||||
*
|
||||
* If the return value is InvalidBuffer (only possible when init = false),
|
||||
* the caller should silently skip the update on this page. This currently
|
||||
* never happens, but we retain it as part of the API spec for possible future
|
||||
* use.
|
||||
* If the page doesn't exist or contains zeroes, we return InvalidBuffer.
|
||||
* In this case the caller should silently skip the update on this page.
|
||||
* (In this situation, we expect that the page was later dropped or truncated.
|
||||
* If we don't see evidence of that later in the WAL sequence, we'll complain
|
||||
* at the end of WAL replay.)
|
||||
*/
|
||||
Buffer
|
||||
XLogReadBuffer(Relation reln, BlockNumber blkno, bool init)
|
||||
|
|
@ -64,9 +233,10 @@ XLogReadBuffer(Relation reln, BlockNumber blkno, bool init)
|
|||
{
|
||||
/* hm, page doesn't exist in file */
|
||||
if (!init)
|
||||
elog(PANIC, "block %u of relation %u/%u/%u does not exist",
|
||||
blkno, reln->rd_node.spcNode,
|
||||
reln->rd_node.dbNode, reln->rd_node.relNode);
|
||||
{
|
||||
log_invalid_page(reln->rd_node, blkno, false);
|
||||
return InvalidBuffer;
|
||||
}
|
||||
/* OK to extend the file */
|
||||
/* we do this in recovery only - no rel-extension lock needed */
|
||||
Assert(InRecovery);
|
||||
|
|
@ -89,9 +259,11 @@ XLogReadBuffer(Relation reln, BlockNumber blkno, bool init)
|
|||
Page page = (Page) BufferGetPage(buffer);
|
||||
|
||||
if (PageIsNew((PageHeader) page))
|
||||
elog(PANIC, "block %u of relation %u/%u/%u is uninitialized",
|
||||
blkno, reln->rd_node.spcNode,
|
||||
reln->rd_node.dbNode, reln->rd_node.relNode);
|
||||
{
|
||||
UnlockReleaseBuffer(buffer);
|
||||
log_invalid_page(reln->rd_node, blkno, true);
|
||||
return InvalidBuffer;
|
||||
}
|
||||
}
|
||||
|
||||
return buffer;
|
||||
|
|
@ -195,6 +367,7 @@ void
|
|||
XLogInitRelationCache(void)
|
||||
{
|
||||
_xl_init_rel_cache();
|
||||
invalid_page_tab = NULL;
|
||||
}
|
||||
|
||||
void
|
||||
|
|
@ -300,22 +473,26 @@ XLogOpenRelation(RelFileNode rnode)
|
|||
*
|
||||
* Currently, we don't bother to physically remove the relation from the
|
||||
* cache, we just let it age out normally.
|
||||
*
|
||||
* This also takes care of removing any open "invalid-page" records for
|
||||
* the relation.
|
||||
*/
|
||||
void
|
||||
XLogDropRelation(RelFileNode rnode)
|
||||
{
|
||||
XLogRelDesc *rdesc;
|
||||
XLogRelCacheEntry *hentry;
|
||||
|
||||
hentry = (XLogRelCacheEntry *)
|
||||
hash_search(_xlrelcache, (void *) &rnode, HASH_FIND, NULL);
|
||||
|
||||
if (!hentry)
|
||||
return; /* not in cache so no work */
|
||||
if (hentry)
|
||||
{
|
||||
XLogRelDesc *rdesc = hentry->rdesc;
|
||||
|
||||
rdesc = hentry->rdesc;
|
||||
RelationCloseSmgr(&(rdesc->reldata));
|
||||
}
|
||||
|
||||
RelationCloseSmgr(&(rdesc->reldata));
|
||||
forget_invalid_pages(rnode, 0);
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
@ -338,4 +515,18 @@ XLogDropDatabase(Oid dbid)
|
|||
if (hentry->rnode.dbNode == dbid)
|
||||
RelationCloseSmgr(&(rdesc->reldata));
|
||||
}
|
||||
|
||||
forget_invalid_pages_db(dbid);
|
||||
}
|
||||
|
||||
/*
|
||||
* Truncate a relation during XLOG replay
|
||||
*
|
||||
* We don't need to do anything to the fake relcache, but we do need to
|
||||
* clean up any open "invalid-page" records for the dropped pages.
|
||||
*/
|
||||
void
|
||||
XLogTruncateRelation(RelFileNode rnode, BlockNumber nblocks)
|
||||
{
|
||||
forget_invalid_pages(rnode, nblocks);
|
||||
}
|
||||
|
|
|
|||
|
|
@ -11,13 +11,14 @@
|
|||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $PostgreSQL: pgsql/src/backend/storage/smgr/smgr.c,v 1.98 2006/03/30 22:11:55 tgl Exp $
|
||||
* $PostgreSQL: pgsql/src/backend/storage/smgr/smgr.c,v 1.99 2006/04/14 20:27:24 tgl Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
#include "postgres.h"
|
||||
|
||||
#include "access/xact.h"
|
||||
#include "access/xlogutils.h"
|
||||
#include "commands/tablespace.h"
|
||||
#include "pgstat.h"
|
||||
#include "storage/bufmgr.h"
|
||||
|
|
@ -942,6 +943,9 @@ smgr_redo(XLogRecPtr lsn, XLogRecord *record)
|
|||
reln->smgr_rnode.dbNode,
|
||||
reln->smgr_rnode.relNode,
|
||||
xlrec->blkno)));
|
||||
|
||||
/* Also tell xlogutils.c about it */
|
||||
XLogTruncateRelation(xlrec->rnode, xlrec->blkno);
|
||||
}
|
||||
else
|
||||
elog(PANIC, "smgr_redo: unknown op code %u", info);
|
||||
|
|
|
|||
|
|
@ -6,7 +6,7 @@
|
|||
* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* $PostgreSQL: pgsql/src/include/access/xlogutils.h,v 1.20 2006/03/29 21:17:39 tgl Exp $
|
||||
* $PostgreSQL: pgsql/src/include/access/xlogutils.h,v 1.21 2006/04/14 20:27:24 tgl Exp $
|
||||
*/
|
||||
#ifndef XLOG_UTILS_H
|
||||
#define XLOG_UTILS_H
|
||||
|
|
@ -16,11 +16,13 @@
|
|||
|
||||
|
||||
extern void XLogInitRelationCache(void);
|
||||
extern void XLogCheckInvalidPages(void);
|
||||
extern void XLogCloseRelationCache(void);
|
||||
|
||||
extern Relation XLogOpenRelation(RelFileNode rnode);
|
||||
extern void XLogDropRelation(RelFileNode rnode);
|
||||
extern void XLogDropDatabase(Oid dbid);
|
||||
extern void XLogTruncateRelation(RelFileNode rnode, BlockNumber nblocks);
|
||||
|
||||
extern Buffer XLogReadBuffer(Relation reln, BlockNumber blkno, bool init);
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue