database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-08-07 02:42:48 +03:00
Code Activity

Better detection and handling of corrupt database files. (CVS 1922)

Browse Source 
FossilOrigin-Name: 8f5b199e845fa7ae3444ef69bd840716d305cf73
This commit is contained in:
drh
2004-08-30 16:52:17 +00:00
parent 57ee3cc2ce
commit ee696e2218
7 changed files with 187 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

68
src/btree.c
View File

@@ -9,7 +9,7 @@
** May you share freely, never taking more than you give.
**
*************************************************************************
** $Id: btree.c,v 1.182 2004/08/14 19:20:10 drh Exp $
** $Id: btree.c,v 1.183 2004/08/30 16:52:18 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
@@ -822,8 +822,10 @@ static int initPage(
assert( pParent==0 || pParent->pBt==pPage->pBt );
assert( pPage->pgno==sqlite3pager_pagenumber(pPage->aData) );
assert( pPage->aData == &((unsigned char*)pPage)[-pPage->pBt->pageSize] );
assert( pPage->pParent==0 || pPage->pParent==pParent );
assert( pPage->pParent==pParent || !pPage->isInit );
if( pPage->pParent!=pParent && (pPage->pParent!=0 || pPage->isInit) ){
/* The parent page should never change unless the file is corrupt */
return SQLITE_CORRUPT; /* bkpt-CORRUPT */
}
if( pPage->isInit ) return SQLITE_OK;
if( pPage->pParent==0 && pParent!=0 ){
pPage->pParent = pParent;
@@ -838,6 +840,14 @@ static int initPage(
pPage->cellOffset = cellOffset = hdr + 12 - 4*pPage->leaf;
top = get2byte(&data[hdr+5]);
pPage->nCell = get2byte(&data[hdr+3]);
if( pPage->nCell>MX_CELL ){
/* To many cells for a single page. The page must be corrupt */
return SQLITE_CORRUPT; /* bkpt-CORRUPT */
}
if( pPage->nCell==0 && pParent!=0 && pParent->pgno!=1 ){
/* All pages must have at least one cell, except for root pages */
return SQLITE_CORRUPT; /* bkpt-CORRUPT */
}
/* Compute the total free space on the page */
pc = get2byte(&data[hdr+1]);
@@ -845,16 +855,28 @@ static int initPage(
i = 0;
while( pc>0 ){
int next, size;
if( pc>=usableSize ) return SQLITE_CORRUPT;
if( i++>SQLITE_MAX_PAGE_SIZE ) return SQLITE_CORRUPT;
if( pc>usableSize-4 ){
/* Free block is off the page */
return SQLITE_CORRUPT; /* bkpt-CORRUPT */
}
if( i++>SQLITE_MAX_PAGE_SIZE/4 ){
/* The free block list forms an infinite loop */
return SQLITE_CORRUPT; /* bkpt-CORRUPT */
}
next = get2byte(&data[pc]);
size = get2byte(&data[pc+2]);
if( next>0 && next<=pc+size+3 ) return SQLITE_CORRUPT;
if( next>0 && next<=pc+size+3 ){
/* Free blocks must be in accending order */
return SQLITE_CORRUPT; /* bkpt-CORRUPT */
}
nFree += size;
pc = next;
}
pPage->nFree = nFree;
if( nFree>=usableSize ) return SQLITE_CORRUPT;
if( nFree>=usableSize ){
/* Free space cannot exceed total page size */
return SQLITE_CORRUPT; /* bkpt-CORRUPT */
}
pPage->isInit = 1;
pageIntegrity(pPage);
@@ -922,6 +944,9 @@ static int getAndInitPage(
MemPage *pParent /* Parent of the page */
){
int rc;
if( pgno==0 ){
return SQLITE_CORRUPT; /* bkpt-CORRUPT */
}
rc = getPage(pBt, pgno, ppPage);
if( rc==SQLITE_OK && (*ppPage)->isInit==0 ){
rc = initPage(*ppPage, pParent);
@@ -1790,7 +1815,7 @@ static int getPayload(
}
if( amt>0 ){
return SQLITE_CORRUPT;
return SQLITE_CORRUPT; /* bkpt-CORRUPT */
}
return SQLITE_OK;
}
@@ -1931,7 +1956,7 @@ static int moveToChild(BtCursor *pCur, u32 newPgno){
pCur->idx = 0;
pCur->info.nSize = 0;
if( pNewPage->nCell<1 ){
return SQLITE_CORRUPT;
return SQLITE_CORRUPT; /* bkpt-CORRUPT */
}
return SQLITE_OK;
}
@@ -2386,6 +2411,9 @@ static int allocatePage(Btree *pBt, MemPage **ppPage, Pgno *pPgno, Pgno nearby){
memcpy(&pPage1->aData[32], &pTrunk->aData[0], 4);
*ppPage = pTrunk;
TRACE(("ALLOCATE: %d trunk - %d free pages left\n", *pPgno, n-1));
}else if( k>pBt->usableSize/4 - 8 ){
/* Value of k is out of range. Database corruption */
return SQLITE_CORRUPT; /* bkpt-CORRUPT */
}else{
/* Extract a leaf from the trunk */
int closest;
@@ -2404,6 +2432,10 @@ static int allocatePage(Btree *pBt, MemPage **ppPage, Pgno *pPgno, Pgno nearby){
closest = 0;
}
*pPgno = get4byte(&aData[8+closest*4]);
if( *pPgno>sqlite3pager_pagecount(pBt->pPager) ){
/* Free page off the end of the file */
return SQLITE_CORRUPT; /* bkpt-CORRUPT */
}
TRACE(("ALLOCATE: %d was leaf %d of %d on trunk %d: %d more free pages\n",
*pPgno, closest+1, k, pTrunk->pgno, n-1));
if( closest<k-1 ){
@@ -2465,7 +2497,7 @@ static int freePage(MemPage *pPage){
rc = getPage(pBt, get4byte(&pPage1->aData[32]), &pTrunk);
if( rc ) return rc;
k = get4byte(&pTrunk->aData[4]);
if( k==pBt->usableSize/4 - 8 ){
if( k>=pBt->usableSize/4 - 8 ){
/* The trunk is full. Turn the page being freed into a new
** trunk page with no leaves. */
rc = sqlite3pager_write(pPage->aData);
@@ -3565,7 +3597,9 @@ int sqlite3BtreeDelete(BtCursor *pCur){
getTempCursor(pCur, &leafCur);
rc = sqlite3BtreeNext(&leafCur, &notUsed);
if( rc!=SQLITE_OK ){
if( rc!=SQLITE_NOMEM ) rc = SQLITE_CORRUPT;
if( rc!=SQLITE_NOMEM ){
rc = SQLITE_CORRUPT; /* bkpt-CORRUPT */
}
return rc;
}
rc = sqlite3pager_write(leafCur.pPage->aData);
@@ -4041,10 +4075,16 @@ static void checkList(
}
if( isFreeList ){
int n = get4byte(&pOvfl[4]);
for(i=0; i<n; i++){
checkRef(pCheck, get4byte(&pOvfl[8+i*4]), zContext);
if( n>=pCheck->pBt->usableSize/4-8 ){
sprintf(zMsg, "freelist leaf count too big on page %d", iPage);
checkAppendMsg(pCheck, zContext, zMsg);
N--;
}else{
for(i=0; i<n; i++){
checkRef(pCheck, get4byte(&pOvfl[8+i*4]), zContext);
}
N -= n;
}
N -= n;
}
iPage = get4byte(pOvfl);
sqlite3pager_unref(pOvfl);