diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/pager.c | 81 | ||||
| -rw-r--r-- | src/sqliteLimit.h | 9 |
2 files changed, 61 insertions, 29 deletions
diff --git a/src/pager.c b/src/pager.c index db8d0d4e3..baae60ec2 100644 --- a/src/pager.c +++ b/src/pager.c @@ -18,7 +18,7 @@ ** file simultaneously, or one process from reading the database while ** another is writing. ** -** @(#) $Id: pager.c,v 1.544 2009/01/09 17:11:05 danielk1977 Exp $ +** @(#) $Id: pager.c,v 1.545 2009/01/10 16:15:09 danielk1977 Exp $ */ #ifndef SQLITE_OMIT_DISKIO #include "sqliteInt.h" @@ -117,6 +117,14 @@ int sqlite3PagerTrace=1; /* True to enable tracing */ #endif /* +** The maximum allowed sector size. 16MB. If the xSectorsize() method +** returns a value larger than this, then MAX_SECTOR_SIZE is used instead. +** This could conceivably cause corruption following a power failure on +** such a system. This is currently an undocumented limit. +*/ +#define MAX_SECTOR_SIZE 0x0100000 + +/* ** An instance of the following structure is allocated for each active ** savepoint and statement transaction in the system. All such structures ** are stored in the Pager.aSavepoint[] array, which is allocated and @@ -401,7 +409,7 @@ static int jrnlBufferSize(Pager *pPager){ if( fd->pMethods ){ dc = sqlite3OsDeviceCharacteristics(fd); - nSector = sqlite3OsSectorSize(fd); + nSector = pPager->sectorSize; szPage = pPager->pageSize; } @@ -760,7 +768,8 @@ static int readJournalHdr( int rc; unsigned char aMagic[8]; /* A buffer to hold the magic header */ i64 jrnlOff; - int iPageSize; + u32 iPageSize; + u32 iSectorSize; seekJournalHdr(pPager); if( pPager->journalOff+JOURNAL_HDR_SZ(pPager) > journalSize ){ @@ -785,28 +794,41 @@ static int readJournalHdr( rc = read32bits(pPager->jfd, jrnlOff+8, pDbSize); if( rc ) return rc; - rc = read32bits(pPager->jfd, jrnlOff+16, (u32 *)&iPageSize); - if( rc==SQLITE_OK - && iPageSize>=512 - && iPageSize<=SQLITE_MAX_PAGE_SIZE - && ((iPageSize-1)&iPageSize)==0 - ){ - u16 pagesize = (u16)iPageSize; - rc = sqlite3PagerSetPagesize(pPager, &pagesize); - } - if( rc ) return rc; + if( pPager->journalOff==0 ){ + rc = read32bits(pPager->jfd, jrnlOff+16, &iPageSize); + if( rc ) return rc; - /* Update the assumed sector-size to match the value used by - ** the process that created this journal. If this journal was - ** created by a process other than this one, then this routine - ** is being called from within pager_playback(). The local value - ** of Pager.sectorSize is restored at the end of that routine. - */ - rc = read32bits(pPager->jfd, jrnlOff+12, &pPager->sectorSize); - if( rc ) return rc; - if( (pPager->sectorSize & (pPager->sectorSize-1))!=0 - || pPager->sectorSize>0x1000000 ){ - return SQLITE_DONE; + if( iPageSize<512 + || iPageSize>SQLITE_MAX_PAGE_SIZE + || ((iPageSize-1)&iPageSize)!=0 + ){ + /* If the page-size in the journal-header is invalid, then the process + ** that wrote the journal-header must have crashed before the header + ** was synced. In this case stop reading the journal file here. + */ + rc = SQLITE_DONE; + }else{ + u16 pagesize = (u16)iPageSize; + rc = sqlite3PagerSetPagesize(pPager, &pagesize); + assert( rc!=SQLITE_OK || pagesize==(u16)iPageSize ); + } + if( rc ) return rc; + + /* Update the assumed sector-size to match the value used by + ** the process that created this journal. If this journal was + ** created by a process other than this one, then this routine + ** is being called from within pager_playback(). The local value + ** of Pager.sectorSize is restored at the end of that routine. + */ + rc = read32bits(pPager->jfd, jrnlOff+12, &iSectorSize); + if( rc ) return rc; + if( (iSectorSize&(iSectorSize-1)) + || iSectorSize<512 + || iSectorSize>MAX_SECTOR_SIZE + ){ + return SQLITE_DONE; + } + pPager->sectorSize = iSectorSize; } pPager->journalOff += JOURNAL_HDR_SZ(pPager); @@ -1503,7 +1525,7 @@ static int pager_truncate(Pager *pPager, Pgno nPage){ ** Set the sectorSize for the given pager. ** ** The sector size is at least as big as the sector size reported -** by sqlite3OsSectorSize(). The minimum sector size is 512. +** by sqlite3OsSectorSize(). The minimum sector size is 512. */ static void setSectorSize(Pager *pPager){ assert(pPager->fd->pMethods||pPager->tempFile); @@ -1517,6 +1539,9 @@ static void setSectorSize(Pager *pPager){ if( pPager->sectorSize<512 ){ pPager->sectorSize = 512; } + if( pPager->sectorSize>MAX_SECTOR_SIZE ){ + pPager->sectorSize = MAX_SECTOR_SIZE; + } } /* @@ -2022,9 +2047,9 @@ int sqlite3PagerOpen( ** + The largest page size that can be written atomically. */ if( rc==SQLITE_OK && !readOnly ){ - int iSectorSize = sqlite3OsSectorSize(pPager->fd); - if( szPageDflt<iSectorSize ){ - szPageDflt = iSectorSize; + setSectorSize(pPager); + if( szPageDflt<pPager->sectorSize ){ + szPageDflt = pPager->sectorSize; } #ifdef SQLITE_ENABLE_ATOMIC_WRITE { diff --git a/src/sqliteLimit.h b/src/sqliteLimit.h index 8d77d0da2..26375197b 100644 --- a/src/sqliteLimit.h +++ b/src/sqliteLimit.h @@ -12,7 +12,7 @@ ** ** This file defines various limits of what SQLite can process. ** -** @(#) $Id: sqliteLimit.h,v 1.9 2009/01/07 16:15:43 danielk1977 Exp $ +** @(#) $Id: sqliteLimit.h,v 1.10 2009/01/10 16:15:09 danielk1977 Exp $ */ /* @@ -130,6 +130,13 @@ /* Maximum page size. The upper bound on this value is 32768. This a limit ** imposed by the necessity of storing the value in a 2-byte unsigned integer ** and the fact that the page size must be a power of 2. +** +** If this limit is changed, then the compiled library is technically +** incompatible with an SQLite library compiled with a different limit. If +** a process operating on a database with a page-size of 65536 bytes +** crashes, then an instance of SQLite compiled with the default page-size +** limit will not be able to rollback the aborted transaction. This could +** lead to database corruption. */ #ifndef SQLITE_MAX_PAGE_SIZE # define SQLITE_MAX_PAGE_SIZE 32768 |