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Add tests for malloc() failure when the atomic-write optimization is being used. Also fix things so that rollback can occur without a malloc(), even if there is a master journal file. (CVS 4330)

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FossilOrigin-Name: 481fd3a89e50e329596d96565170e3d9977aae29
This commit is contained in:
danielk1977
2007-08-30 08:08:17 +00:00
parent c1a7f94098
commit 65839c6afd
4 changed files with 103 additions and 40 deletions
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72
src/pager.c
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@@ -18,7 +18,7 @@
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.380 2007/08/29 12:31:27 danielk1977 Exp $
** @(#) $Id: pager.c,v 1.381 2007/08/30 08:08:17 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
@@ -872,14 +872,19 @@ static void checkPage(PgHdr *pPg){
/*
** When this is called the journal file for pager pPager must be open.
** The master journal file name is read from the end of the file and
** written into memory obtained from sqlite3_malloc(). *pzMaster is
** set to point at the memory and SQLITE_OK returned. The caller must
** sqlite3_free() *pzMaster.
** written into memory supplied by the caller.
**
** If no master journal file name is present *pzMaster is set to 0 and
** zMaster must point to a buffer of at least nMaster bytes allocated by
** the caller. This should be sqlite3_vfs.mxPathname+1 (to ensure there is
** enough space to write the master journal name). If the master journal
** name in the journal is longer than nMaster bytes (including a
** nul-terminator), then this is handled as if no master journal name
** were present in the journal.
**
** If no master journal file name is present zMaster[0] is set to 0 and
** SQLITE_OK returned.
*/
static int readMasterJournal(sqlite3_file *pJrnl, char **pzMaster){
static int readMasterJournal(sqlite3_file *pJrnl, char *zMaster, int nMaster){
int rc;
u32 len;
i64 szJ;
@@ -887,7 +892,7 @@ static int readMasterJournal(sqlite3_file *pJrnl, char **pzMaster){
int i;
unsigned char aMagic[8]; /* A buffer to hold the magic header */
*pzMaster = 0;
zMaster[0] = '\0';
rc = sqlite3OsFileSize(pJrnl, &szJ);
if( rc!=SQLITE_OK || szJ<16 ) return rc;
@@ -895,37 +900,33 @@ static int readMasterJournal(sqlite3_file *pJrnl, char **pzMaster){
rc = read32bits(pJrnl, szJ-16, &len);
if( rc!=SQLITE_OK ) return rc;
if( len>=nMaster ){
return SQLITE_OK;
}
rc = read32bits(pJrnl, szJ-12, &cksum);
if( rc!=SQLITE_OK ) return rc;
rc = sqlite3OsRead(pJrnl, aMagic, 8, szJ-8);
if( rc!=SQLITE_OK || memcmp(aMagic, aJournalMagic, 8) ) return rc;
*pzMaster = (char *)sqlite3MallocZero(len+1);
if( !*pzMaster ){
return SQLITE_NOMEM;
}
rc = sqlite3OsRead(pJrnl, *pzMaster, len, szJ-16-len);
rc = sqlite3OsRead(pJrnl, zMaster, len, szJ-16-len);
if( rc!=SQLITE_OK ){
sqlite3_free(*pzMaster);
*pzMaster = 0;
return rc;
}
zMaster[len] = '\0';
/* See if the checksum matches the master journal name */
for(i=0; i<len; i++){
cksum -= (*pzMaster)[i];
}
cksum -= zMaster[i];
}
if( cksum ){
/* If the checksum doesn't add up, then one or more of the disk sectors
** containing the master journal filename is corrupted. This means
** definitely roll back, so just return SQLITE_OK and report a (nul)
** master-journal filename.
*/
sqlite3_free(*pzMaster);
*pzMaster = 0;
}else{
(*pzMaster)[len] = '\0';
zMaster[0] = '\0';
}
return SQLITE_OK;
@@ -1493,6 +1494,10 @@ static int pager_playback_one_page(
** This routine checks if it is possible to delete the master journal file,
** and does so if it is.
**
** Argument zMaster may point to Pager.pTmpSpace. So that buffer is not
** available for use within this function.
**
**
** The master journal file contains the names of all child journals.
** To tell if a master journal can be deleted, check to each of the
** children. If all children are either missing or do not refer to
@@ -1527,15 +1532,17 @@ static int pager_delmaster(Pager *pPager, const char *zMaster){
if( nMasterJournal>0 ){
char *zJournal;
char *zMasterPtr = 0;
int nMasterPtr = pPager->pVfs->mxPathname+1;
/* Load the entire master journal file into space obtained from
** sqlite3_malloc() and pointed to by zMasterJournal.
*/
zMasterJournal = (char *)sqlite3_malloc(nMasterJournal);
zMasterJournal = (char *)sqlite3_malloc(nMasterJournal + nMasterPtr);
if( !zMasterJournal ){
rc = SQLITE_NOMEM;
goto delmaster_out;
}
zMasterPtr = &zMasterJournal[nMasterJournal];
rc = sqlite3OsRead(pMaster, zMasterJournal, nMasterJournal, 0);
if( rc!=SQLITE_OK ) goto delmaster_out;
@@ -1553,14 +1560,13 @@ static int pager_delmaster(Pager *pPager, const char *zMaster){
goto delmaster_out;
}
rc = readMasterJournal(pJournal, &zMasterPtr);
rc = readMasterJournal(pJournal, zMasterPtr, nMasterPtr);
sqlite3OsClose(pJournal);
if( rc!=SQLITE_OK ){
goto delmaster_out;
}
c = zMasterPtr!=0 && strcmp(zMasterPtr, zMaster)==0;
sqlite3_free(zMasterPtr);
c = zMasterPtr[0]!=0 && strcmp(zMasterPtr, zMaster)==0;
if( c ){
/* We have a match. Do not delete the master journal file. */
goto delmaster_out;
@@ -1698,17 +1704,18 @@ static int pager_playback(Pager *pPager, int isHot){
** present on disk, then the journal is not hot and does not need to be
** played back.
*/
rc = readMasterJournal(pPager->jfd, &zMaster);
zMaster = pPager->pTmpSpace;
rc = readMasterJournal(pPager->jfd, zMaster, pPager->pVfs->mxPathname+1);
assert( rc!=SQLITE_DONE );
if( rc!=SQLITE_OK
|| (zMaster && !sqlite3OsAccess(pVfs, zMaster, SQLITE_ACCESS_EXISTS))
|| (zMaster[0] && !sqlite3OsAccess(pVfs, zMaster, SQLITE_ACCESS_EXISTS))
){
sqlite3_free(zMaster);
zMaster = 0;
if( rc==SQLITE_DONE ) rc = SQLITE_OK;
goto end_playback;
}
pPager->journalOff = 0;
zMaster = 0;
/* This loop terminates either when the readJournalHdr() call returns
** SQLITE_DONE or an IO error occurs. */
@@ -1779,17 +1786,18 @@ static int pager_playback(Pager *pPager, int isHot){
assert( 0 );
end_playback:
if( rc==SQLITE_OK ){
zMaster = pPager->pTmpSpace;
rc = readMasterJournal(pPager->jfd, zMaster, pPager->pVfs->mxPathname+1);
}
if( rc==SQLITE_OK ){
rc = pager_end_transaction(pPager);
}
if( zMaster ){
if( rc==SQLITE_OK && zMaster[0] ){
/* If there was a master journal and this routine will return success,
** see if it is possible to delete the master journal.
*/
if( rc==SQLITE_OK ){
rc = pager_delmaster(pPager, zMaster);
}
sqlite3_free(zMaster);
rc = pager_delmaster(pPager, zMaster);
}
/* The Pager.sectorSize variable may have been updated while rolling