1 /*
2 ** 2004 May 22
3 **
4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
6 **
7 ** May you do good and not evil.
8 ** May you find forgiveness for yourself and forgive others.
9 ** May you share freely, never taking more than you give.
10 **
11 ******************************************************************************
12 **
13 ** This file contains code that modified the OS layer in order to simulate
14 ** the effect on the database file of an OS crash or power failure. This
15 ** is used to test the ability of SQLite to recover from those situations.
16 */
17 #if SQLITE_TEST /* This file is used for testing only */
18 #include "sqliteInt.h"
19 #include "tcl.h"
20
21 #ifndef SQLITE_OMIT_DISKIO /* This file is a no-op if disk I/O is disabled */
22
23 /* #define TRACE_CRASHTEST */
24
25 typedef struct CrashFile CrashFile;
26 typedef struct CrashGlobal CrashGlobal;
27 typedef struct WriteBuffer WriteBuffer;
28
29 /*
30 ** Method:
31 **
32 ** This layer is implemented as a wrapper around the "real"
33 ** sqlite3_file object for the host system. Each time data is
34 ** written to the file object, instead of being written to the
35 ** underlying file, the write operation is stored in an in-memory
36 ** structure (type WriteBuffer). This structure is placed at the
37 ** end of a global ordered list (the write-list).
38 **
39 ** When data is read from a file object, the requested region is
40 ** first retrieved from the real file. The write-list is then
41 ** traversed and data copied from any overlapping WriteBuffer
42 ** structures to the output buffer. i.e. a read() operation following
43 ** one or more write() operations works as expected, even if no
44 ** data has actually been written out to the real file.
45 **
46 ** When a fsync() operation is performed, an operating system crash
47 ** may be simulated, in which case exit(-1) is called (the call to
48 ** xSync() never returns). Whether or not a crash is simulated,
49 ** the data associated with a subset of the WriteBuffer structures
50 ** stored in the write-list is written to the real underlying files
51 ** and the entries removed from the write-list. If a crash is simulated,
52 ** a subset of the buffers may be corrupted before the data is written.
53 **
54 ** The exact subset of the write-list written and/or corrupted is
55 ** determined by the simulated device characteristics and sector-size.
56 **
57 ** "Normal" mode:
58 **
59 ** Normal mode is used when the simulated device has none of the
60 ** SQLITE_IOCAP_XXX flags set.
61 **
62 ** In normal mode, if the fsync() is not a simulated crash, the
63 ** write-list is traversed from beginning to end. Each WriteBuffer
64 ** structure associated with the file handle used to call xSync()
65 ** is written to the real file and removed from the write-list.
66 **
67 ** If a crash is simulated, one of the following takes place for
68 ** each WriteBuffer in the write-list, regardless of which
69 ** file-handle it is associated with:
70 **
71 ** 1. The buffer is correctly written to the file, just as if
72 ** a crash were not being simulated.
73 **
74 ** 2. Nothing is done.
75 **
76 ** 3. Garbage data is written to all sectors of the file that
77 ** overlap the region specified by the WriteBuffer. Or garbage
78 ** data is written to some contiguous section within the
79 ** overlapped sectors.
80 **
81 ** Device Characteristic flag handling:
82 **
83 ** If the IOCAP_ATOMIC flag is set, then option (3) above is
84 ** never selected.
85 **
86 ** If the IOCAP_ATOMIC512 flag is set, and the WriteBuffer represents
87 ** an aligned write() of an integer number of 512 byte regions, then
88 ** option (3) above is never selected. Instead, each 512 byte region
89 ** is either correctly written or left completely untouched. Similar
90 ** logic governs the behaviour if any of the other ATOMICXXX flags
91 ** is set.
92 **
93 ** If either the IOCAP_SAFEAPPEND or IOCAP_SEQUENTIAL flags are set
94 ** and a crash is being simulated, then an entry of the write-list is
95 ** selected at random. Everything in the list after the selected entry
96 ** is discarded before processing begins.
97 **
98 ** If IOCAP_SEQUENTIAL is set and a crash is being simulated, option
99 ** (1) is selected for all write-list entries except the last. If a
100 ** crash is not being simulated, then all entries in the write-list
101 ** that occur before at least one write() on the file-handle specified
102 ** as part of the xSync() are written to their associated real files.
103 **
104 ** If IOCAP_SAFEAPPEND is set and the first byte written by the write()
105 ** operation is one byte past the current end of the file, then option
106 ** (1) is always selected.
107 */
108
109 /*
110 ** Each write operation in the write-list is represented by an instance
111 ** of the following structure.
112 **
113 ** If zBuf is 0, then this structure represents a call to xTruncate(),
114 ** not xWrite(). In that case, iOffset is the size that the file is
115 ** truncated to.
116 */
117 struct WriteBuffer {
118 i64 iOffset; /* Byte offset of the start of this write() */
119 int nBuf; /* Number of bytes written */
120 u8 *zBuf; /* Pointer to copy of written data */
121 CrashFile *pFile; /* File this write() applies to */
122
123 WriteBuffer *pNext; /* Next in CrashGlobal.pWriteList */
124 };
125
126 struct CrashFile {
127 const sqlite3_io_methods *pMethod; /* Must be first */
128 sqlite3_file *pRealFile; /* Underlying "real" file handle */
129 char *zName;
130 int flags; /* Flags the file was opened with */
131
132 /* Cache of the entire file. This is used to speed up OsRead() and
133 ** OsFileSize() calls. Although both could be done by traversing the
134 ** write-list, in practice this is impractically slow.
135 */
136 int iSize; /* Size of file in bytes */
137 int nData; /* Size of buffer allocated at zData */
138 u8 *zData; /* Buffer containing file contents */
139 };
140
141 struct CrashGlobal {
142 WriteBuffer *pWriteList; /* Head of write-list */
143 WriteBuffer *pWriteListEnd; /* End of write-list */
144
145 int iSectorSize; /* Value of simulated sector size */
146 int iDeviceCharacteristics; /* Value of simulated device characteristics */
147
148 int iCrash; /* Crash on the iCrash'th call to xSync() */
149 char zCrashFile[500]; /* Crash during an xSync() on this file */
150 };
151
152 static CrashGlobal g = {0, 0, SQLITE_DEFAULT_SECTOR_SIZE, 0, 0};
153
154 /*
155 ** Set this global variable to 1 to enable crash testing.
156 */
157 static int sqlite3CrashTestEnable = 0;
158
crash_malloc(int nByte)159 static void *crash_malloc(int nByte){
160 return (void *)Tcl_Alloc((size_t)nByte);
161 }
crash_free(void * p)162 static void crash_free(void *p){
163 Tcl_Free(p);
164 }
crash_realloc(void * p,int n)165 static void *crash_realloc(void *p, int n){
166 return (void *)Tcl_Realloc(p, (size_t)n);
167 }
168
169 /*
170 ** Wrapper around the sqlite3OsWrite() function that avoids writing to the
171 ** 512 byte block begining at offset PENDING_BYTE.
172 */
writeDbFile(CrashFile * p,u8 * z,i64 iAmt,i64 iOff)173 static int writeDbFile(CrashFile *p, u8 *z, i64 iAmt, i64 iOff){
174 int rc = SQLITE_OK;
175 int iSkip = 0;
176 if( iOff==PENDING_BYTE && (p->flags&SQLITE_OPEN_MAIN_DB) ){
177 iSkip = 512;
178 }
179 if( (iAmt-iSkip)>0 ){
180 rc = sqlite3OsWrite(p->pRealFile, &z[iSkip], (int)iAmt-iSkip, iOff+iSkip);
181 }
182 return rc;
183 }
184
185 /*
186 ** Flush the write-list as if xSync() had been called on file handle
187 ** pFile. If isCrash is true, simulate a crash.
188 */
writeListSync(CrashFile * pFile,int isCrash)189 static int writeListSync(CrashFile *pFile, int isCrash){
190 int rc = SQLITE_OK;
191 int iDc = g.iDeviceCharacteristics;
192
193 WriteBuffer *pWrite;
194 WriteBuffer **ppPtr;
195
196 /* If this is not a crash simulation, set pFinal to point to the
197 ** last element of the write-list that is associated with file handle
198 ** pFile.
199 **
200 ** If this is a crash simulation, set pFinal to an arbitrarily selected
201 ** element of the write-list.
202 */
203 WriteBuffer *pFinal = 0;
204 if( !isCrash ){
205 for(pWrite=g.pWriteList; pWrite; pWrite=pWrite->pNext){
206 if( pWrite->pFile==pFile ){
207 pFinal = pWrite;
208 }
209 }
210 }else if( iDc&(SQLITE_IOCAP_SEQUENTIAL|SQLITE_IOCAP_SAFE_APPEND) ){
211 int nWrite = 0;
212 int iFinal;
213 for(pWrite=g.pWriteList; pWrite; pWrite=pWrite->pNext) nWrite++;
214 sqlite3_randomness(sizeof(int), &iFinal);
215 iFinal = ((iFinal<0)?-1*iFinal:iFinal)%nWrite;
216 for(pWrite=g.pWriteList; iFinal>0; pWrite=pWrite->pNext) iFinal--;
217 pFinal = pWrite;
218 }
219
220 #ifdef TRACE_CRASHTEST
221 printf("Sync %s (is %s crash)\n", pFile->zName, (isCrash?"a":"not a"));
222 #endif
223
224 ppPtr = &g.pWriteList;
225 for(pWrite=*ppPtr; rc==SQLITE_OK && pWrite; pWrite=*ppPtr){
226 sqlite3_file *pRealFile = pWrite->pFile->pRealFile;
227
228 /* (eAction==1) -> write block out normally,
229 ** (eAction==2) -> do nothing,
230 ** (eAction==3) -> trash sectors.
231 */
232 int eAction = 0;
233 if( !isCrash ){
234 eAction = 2;
235 if( (pWrite->pFile==pFile || iDc&SQLITE_IOCAP_SEQUENTIAL) ){
236 eAction = 1;
237 }
238 }else{
239 char random;
240 sqlite3_randomness(1, &random);
241
242 /* Do not select option 3 (sector trashing) if the IOCAP_ATOMIC flag
243 ** is set or this is an OsTruncate(), not an Oswrite().
244 */
245 if( (iDc&SQLITE_IOCAP_ATOMIC) || (pWrite->zBuf==0) ){
246 random &= 0x01;
247 }
248
249 /* If IOCAP_SEQUENTIAL is set and this is not the final entry
250 ** in the truncated write-list, always select option 1 (write
251 ** out correctly).
252 */
253 if( (iDc&SQLITE_IOCAP_SEQUENTIAL && pWrite!=pFinal) ){
254 random = 0;
255 }
256
257 /* If IOCAP_SAFE_APPEND is set and this OsWrite() operation is
258 ** an append (first byte of the written region is 1 byte past the
259 ** current EOF), always select option 1 (write out correctly).
260 */
261 if( iDc&SQLITE_IOCAP_SAFE_APPEND && pWrite->zBuf ){
262 i64 iSize;
263 sqlite3OsFileSize(pRealFile, &iSize);
264 if( iSize==pWrite->iOffset ){
265 random = 0;
266 }
267 }
268
269 if( (random&0x06)==0x06 ){
270 eAction = 3;
271 }else{
272 eAction = ((random&0x01)?2:1);
273 }
274 }
275
276 switch( eAction ){
277 case 1: { /* Write out correctly */
278 if( pWrite->zBuf ){
279 rc = writeDbFile(
280 pWrite->pFile, pWrite->zBuf, pWrite->nBuf, pWrite->iOffset
281 );
282 }else{
283 rc = sqlite3OsTruncate(pRealFile, pWrite->iOffset);
284 }
285 *ppPtr = pWrite->pNext;
286 #ifdef TRACE_CRASHTEST
287 if( isCrash ){
288 printf("Writing %d bytes @ %d (%s)\n",
289 pWrite->nBuf, (int)pWrite->iOffset, pWrite->pFile->zName
290 );
291 }
292 #endif
293 crash_free(pWrite);
294 break;
295 }
296 case 2: { /* Do nothing */
297 ppPtr = &pWrite->pNext;
298 #ifdef TRACE_CRASHTEST
299 if( isCrash ){
300 printf("Omiting %d bytes @ %d (%s)\n",
301 pWrite->nBuf, (int)pWrite->iOffset, pWrite->pFile->zName
302 );
303 }
304 #endif
305 break;
306 }
307 case 3: { /* Trash sectors */
308 u8 *zGarbage;
309 int iFirst = ((int)pWrite->iOffset/g.iSectorSize);
310 int iLast = ((int)pWrite->iOffset+pWrite->nBuf-1)/g.iSectorSize;
311
312 assert(pWrite->zBuf);
313
314 #ifdef TRACE_CRASHTEST
315 printf("Trashing %d sectors @ sector %d (%s)\n",
316 1+iLast-iFirst, iFirst, pWrite->pFile->zName
317 );
318 #endif
319
320 zGarbage = crash_malloc(g.iSectorSize);
321 if( zGarbage ){
322 sqlite3_int64 i;
323 for(i=iFirst; rc==SQLITE_OK && i<=iLast; i++){
324 sqlite3_randomness(g.iSectorSize, zGarbage);
325 rc = writeDbFile(
326 pWrite->pFile, zGarbage, g.iSectorSize, i*g.iSectorSize
327 );
328 }
329 crash_free(zGarbage);
330 }else{
331 rc = SQLITE_NOMEM;
332 }
333
334 ppPtr = &pWrite->pNext;
335 break;
336 }
337
338 default:
339 assert(!"Cannot happen");
340 }
341
342 if( pWrite==pFinal ) break;
343 }
344
345 if( rc==SQLITE_OK && isCrash ){
346 exit(-1);
347 }
348
349 for(pWrite=g.pWriteList; pWrite && pWrite->pNext; pWrite=pWrite->pNext);
350 g.pWriteListEnd = pWrite;
351
352 return rc;
353 }
354
355 /*
356 ** Add an entry to the end of the write-list.
357 */
writeListAppend(sqlite3_file * pFile,sqlite3_int64 iOffset,const u8 * zBuf,int nBuf)358 static int writeListAppend(
359 sqlite3_file *pFile,
360 sqlite3_int64 iOffset,
361 const u8 *zBuf,
362 int nBuf
363 ){
364 WriteBuffer *pNew;
365
366 assert((zBuf && nBuf) || (!nBuf && !zBuf));
367
368 pNew = (WriteBuffer *)crash_malloc(sizeof(WriteBuffer) + nBuf);
369 if( pNew==0 ){
370 fprintf(stderr, "out of memory in the crash simulator\n");
371 }
372 memset(pNew, 0, sizeof(WriteBuffer)+nBuf);
373 pNew->iOffset = iOffset;
374 pNew->nBuf = nBuf;
375 pNew->pFile = (CrashFile *)pFile;
376 if( zBuf ){
377 pNew->zBuf = (u8 *)&pNew[1];
378 memcpy(pNew->zBuf, zBuf, nBuf);
379 }
380
381 if( g.pWriteList ){
382 assert(g.pWriteListEnd);
383 g.pWriteListEnd->pNext = pNew;
384 }else{
385 g.pWriteList = pNew;
386 }
387 g.pWriteListEnd = pNew;
388
389 return SQLITE_OK;
390 }
391
392 /*
393 ** Close a crash-file.
394 */
cfClose(sqlite3_file * pFile)395 static int cfClose(sqlite3_file *pFile){
396 CrashFile *pCrash = (CrashFile *)pFile;
397 writeListSync(pCrash, 0);
398 sqlite3OsClose(pCrash->pRealFile);
399 return SQLITE_OK;
400 }
401
402 /*
403 ** Read data from a crash-file.
404 */
cfRead(sqlite3_file * pFile,void * zBuf,int iAmt,sqlite_int64 iOfst)405 static int cfRead(
406 sqlite3_file *pFile,
407 void *zBuf,
408 int iAmt,
409 sqlite_int64 iOfst
410 ){
411 CrashFile *pCrash = (CrashFile *)pFile;
412
413 /* Check the file-size to see if this is a short-read */
414 if( pCrash->iSize<(iOfst+iAmt) ){
415 return SQLITE_IOERR_SHORT_READ;
416 }
417
418 memcpy(zBuf, &pCrash->zData[iOfst], iAmt);
419 return SQLITE_OK;
420 }
421
422 /*
423 ** Write data to a crash-file.
424 */
cfWrite(sqlite3_file * pFile,const void * zBuf,int iAmt,sqlite_int64 iOfst)425 static int cfWrite(
426 sqlite3_file *pFile,
427 const void *zBuf,
428 int iAmt,
429 sqlite_int64 iOfst
430 ){
431 CrashFile *pCrash = (CrashFile *)pFile;
432 if( iAmt+iOfst>pCrash->iSize ){
433 pCrash->iSize = iAmt+(int)iOfst;
434 }
435 while( pCrash->iSize>pCrash->nData ){
436 u8 *zNew;
437 int nNew = (pCrash->nData*2) + 4096;
438 zNew = crash_realloc(pCrash->zData, nNew);
439 if( !zNew ){
440 return SQLITE_NOMEM;
441 }
442 memset(&zNew[pCrash->nData], 0, nNew-pCrash->nData);
443 pCrash->nData = nNew;
444 pCrash->zData = zNew;
445 }
446 memcpy(&pCrash->zData[iOfst], zBuf, iAmt);
447 return writeListAppend(pFile, iOfst, zBuf, iAmt);
448 }
449
450 /*
451 ** Truncate a crash-file.
452 */
cfTruncate(sqlite3_file * pFile,sqlite_int64 size)453 static int cfTruncate(sqlite3_file *pFile, sqlite_int64 size){
454 CrashFile *pCrash = (CrashFile *)pFile;
455 assert(size>=0);
456 if( pCrash->iSize>size ){
457 pCrash->iSize = (int)size;
458 }
459 return writeListAppend(pFile, size, 0, 0);
460 }
461
462 /*
463 ** Sync a crash-file.
464 */
cfSync(sqlite3_file * pFile,int flags)465 static int cfSync(sqlite3_file *pFile, int flags){
466 CrashFile *pCrash = (CrashFile *)pFile;
467 int isCrash = 0;
468
469 const char *zName = pCrash->zName;
470 const char *zCrashFile = g.zCrashFile;
471 int nName = strlen(zName);
472 int nCrashFile = strlen(zCrashFile);
473
474 if( nCrashFile>0 && zCrashFile[nCrashFile-1]=='*' ){
475 nCrashFile--;
476 if( nName>nCrashFile ) nName = nCrashFile;
477 }
478
479 if( nName==nCrashFile && 0==memcmp(zName, zCrashFile, nName) ){
480 if( (--g.iCrash)==0 ) isCrash = 1;
481 }
482
483 return writeListSync(pCrash, isCrash);
484 }
485
486 /*
487 ** Return the current file-size of the crash-file.
488 */
cfFileSize(sqlite3_file * pFile,sqlite_int64 * pSize)489 static int cfFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
490 CrashFile *pCrash = (CrashFile *)pFile;
491 *pSize = (i64)pCrash->iSize;
492 return SQLITE_OK;
493 }
494
495 /*
496 ** Calls related to file-locks are passed on to the real file handle.
497 */
cfLock(sqlite3_file * pFile,int eLock)498 static int cfLock(sqlite3_file *pFile, int eLock){
499 return sqlite3OsLock(((CrashFile *)pFile)->pRealFile, eLock);
500 }
cfUnlock(sqlite3_file * pFile,int eLock)501 static int cfUnlock(sqlite3_file *pFile, int eLock){
502 return sqlite3OsUnlock(((CrashFile *)pFile)->pRealFile, eLock);
503 }
cfCheckReservedLock(sqlite3_file * pFile,int * pResOut)504 static int cfCheckReservedLock(sqlite3_file *pFile, int *pResOut){
505 return sqlite3OsCheckReservedLock(((CrashFile *)pFile)->pRealFile, pResOut);
506 }
cfFileControl(sqlite3_file * pFile,int op,void * pArg)507 static int cfFileControl(sqlite3_file *pFile, int op, void *pArg){
508 return sqlite3OsFileControl(((CrashFile *)pFile)->pRealFile, op, pArg);
509 }
510
511 /*
512 ** The xSectorSize() and xDeviceCharacteristics() functions return
513 ** the global values configured by the [sqlite_crashparams] tcl
514 * interface.
515 */
cfSectorSize(sqlite3_file * pFile)516 static int cfSectorSize(sqlite3_file *pFile){
517 return g.iSectorSize;
518 }
cfDeviceCharacteristics(sqlite3_file * pFile)519 static int cfDeviceCharacteristics(sqlite3_file *pFile){
520 return g.iDeviceCharacteristics;
521 }
522
523 /*
524 ** Pass-throughs for WAL support.
525 */
cfShmLock(sqlite3_file * pFile,int ofst,int n,int flags)526 static int cfShmLock(sqlite3_file *pFile, int ofst, int n, int flags){
527 return sqlite3OsShmLock(((CrashFile*)pFile)->pRealFile, ofst, n, flags);
528 }
cfShmBarrier(sqlite3_file * pFile)529 static void cfShmBarrier(sqlite3_file *pFile){
530 sqlite3OsShmBarrier(((CrashFile*)pFile)->pRealFile);
531 }
cfShmUnmap(sqlite3_file * pFile,int delFlag)532 static int cfShmUnmap(sqlite3_file *pFile, int delFlag){
533 return sqlite3OsShmUnmap(((CrashFile*)pFile)->pRealFile, delFlag);
534 }
cfShmMap(sqlite3_file * pFile,int iRegion,int sz,int w,void volatile ** pp)535 static int cfShmMap(
536 sqlite3_file *pFile, /* Handle open on database file */
537 int iRegion, /* Region to retrieve */
538 int sz, /* Size of regions */
539 int w, /* True to extend file if necessary */
540 void volatile **pp /* OUT: Mapped memory */
541 ){
542 return sqlite3OsShmMap(((CrashFile*)pFile)->pRealFile, iRegion, sz, w, pp);
543 }
544
545 static const sqlite3_io_methods CrashFileVtab = {
546 2, /* iVersion */
547 cfClose, /* xClose */
548 cfRead, /* xRead */
549 cfWrite, /* xWrite */
550 cfTruncate, /* xTruncate */
551 cfSync, /* xSync */
552 cfFileSize, /* xFileSize */
553 cfLock, /* xLock */
554 cfUnlock, /* xUnlock */
555 cfCheckReservedLock, /* xCheckReservedLock */
556 cfFileControl, /* xFileControl */
557 cfSectorSize, /* xSectorSize */
558 cfDeviceCharacteristics, /* xDeviceCharacteristics */
559 cfShmMap, /* xShmMap */
560 cfShmLock, /* xShmLock */
561 cfShmBarrier, /* xShmBarrier */
562 cfShmUnmap /* xShmUnmap */
563 };
564
565 /*
566 ** Application data for the crash VFS
567 */
568 struct crashAppData {
569 sqlite3_vfs *pOrig; /* Wrapped vfs structure */
570 };
571
572 /*
573 ** Open a crash-file file handle.
574 **
575 ** The caller will have allocated pVfs->szOsFile bytes of space
576 ** at pFile. This file uses this space for the CrashFile structure
577 ** and allocates space for the "real" file structure using
578 ** sqlite3_malloc(). The assumption here is (pVfs->szOsFile) is
579 ** equal or greater than sizeof(CrashFile).
580 */
cfOpen(sqlite3_vfs * pCfVfs,const char * zName,sqlite3_file * pFile,int flags,int * pOutFlags)581 static int cfOpen(
582 sqlite3_vfs *pCfVfs,
583 const char *zName,
584 sqlite3_file *pFile,
585 int flags,
586 int *pOutFlags
587 ){
588 sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
589 int rc;
590 CrashFile *pWrapper = (CrashFile *)pFile;
591 sqlite3_file *pReal = (sqlite3_file*)&pWrapper[1];
592
593 memset(pWrapper, 0, sizeof(CrashFile));
594 rc = sqlite3OsOpen(pVfs, zName, pReal, flags, pOutFlags);
595
596 if( rc==SQLITE_OK ){
597 i64 iSize;
598 pWrapper->pMethod = &CrashFileVtab;
599 pWrapper->zName = (char *)zName;
600 pWrapper->pRealFile = pReal;
601 rc = sqlite3OsFileSize(pReal, &iSize);
602 pWrapper->iSize = (int)iSize;
603 pWrapper->flags = flags;
604 }
605 if( rc==SQLITE_OK ){
606 pWrapper->nData = (4096 + pWrapper->iSize);
607 pWrapper->zData = crash_malloc(pWrapper->nData);
608 if( pWrapper->zData ){
609 /* os_unix.c contains an assert() that fails if the caller attempts
610 ** to read data from the 512-byte locking region of a file opened
611 ** with the SQLITE_OPEN_MAIN_DB flag. This region of a database file
612 ** never contains valid data anyhow. So avoid doing such a read here.
613 */
614 const int isDb = (flags&SQLITE_OPEN_MAIN_DB);
615 int iChunk = pWrapper->iSize;
616 if( iChunk>PENDING_BYTE && isDb ){
617 iChunk = PENDING_BYTE;
618 }
619 memset(pWrapper->zData, 0, pWrapper->nData);
620 rc = sqlite3OsRead(pReal, pWrapper->zData, iChunk, 0);
621 if( SQLITE_OK==rc && pWrapper->iSize>(PENDING_BYTE+512) && isDb ){
622 i64 iOff = PENDING_BYTE+512;
623 iChunk = pWrapper->iSize - (int)iOff;
624 rc = sqlite3OsRead(pReal, &pWrapper->zData[iOff], iChunk, iOff);
625 }
626 }else{
627 rc = SQLITE_NOMEM;
628 }
629 }
630 if( rc!=SQLITE_OK && pWrapper->pMethod ){
631 sqlite3OsClose(pFile);
632 }
633 return rc;
634 }
635
cfDelete(sqlite3_vfs * pCfVfs,const char * zPath,int dirSync)636 static int cfDelete(sqlite3_vfs *pCfVfs, const char *zPath, int dirSync){
637 sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
638 return pVfs->xDelete(pVfs, zPath, dirSync);
639 }
cfAccess(sqlite3_vfs * pCfVfs,const char * zPath,int flags,int * pResOut)640 static int cfAccess(
641 sqlite3_vfs *pCfVfs,
642 const char *zPath,
643 int flags,
644 int *pResOut
645 ){
646 sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
647 return pVfs->xAccess(pVfs, zPath, flags, pResOut);
648 }
cfFullPathname(sqlite3_vfs * pCfVfs,const char * zPath,int nPathOut,char * zPathOut)649 static int cfFullPathname(
650 sqlite3_vfs *pCfVfs,
651 const char *zPath,
652 int nPathOut,
653 char *zPathOut
654 ){
655 sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
656 return pVfs->xFullPathname(pVfs, zPath, nPathOut, zPathOut);
657 }
cfDlOpen(sqlite3_vfs * pCfVfs,const char * zPath)658 static void *cfDlOpen(sqlite3_vfs *pCfVfs, const char *zPath){
659 sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
660 return pVfs->xDlOpen(pVfs, zPath);
661 }
cfDlError(sqlite3_vfs * pCfVfs,int nByte,char * zErrMsg)662 static void cfDlError(sqlite3_vfs *pCfVfs, int nByte, char *zErrMsg){
663 sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
664 pVfs->xDlError(pVfs, nByte, zErrMsg);
665 }
cfDlSym(sqlite3_vfs * pCfVfs,void * pH,const char * zSym)666 static void (*cfDlSym(sqlite3_vfs *pCfVfs, void *pH, const char *zSym))(void){
667 sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
668 return pVfs->xDlSym(pVfs, pH, zSym);
669 }
cfDlClose(sqlite3_vfs * pCfVfs,void * pHandle)670 static void cfDlClose(sqlite3_vfs *pCfVfs, void *pHandle){
671 sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
672 pVfs->xDlClose(pVfs, pHandle);
673 }
cfRandomness(sqlite3_vfs * pCfVfs,int nByte,char * zBufOut)674 static int cfRandomness(sqlite3_vfs *pCfVfs, int nByte, char *zBufOut){
675 sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
676 return pVfs->xRandomness(pVfs, nByte, zBufOut);
677 }
cfSleep(sqlite3_vfs * pCfVfs,int nMicro)678 static int cfSleep(sqlite3_vfs *pCfVfs, int nMicro){
679 sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
680 return pVfs->xSleep(pVfs, nMicro);
681 }
cfCurrentTime(sqlite3_vfs * pCfVfs,double * pTimeOut)682 static int cfCurrentTime(sqlite3_vfs *pCfVfs, double *pTimeOut){
683 sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
684 return pVfs->xCurrentTime(pVfs, pTimeOut);
685 }
686
processDevSymArgs(Tcl_Interp * interp,int objc,Tcl_Obj * CONST objv[],int * piDeviceChar,int * piSectorSize)687 static int processDevSymArgs(
688 Tcl_Interp *interp,
689 int objc,
690 Tcl_Obj *CONST objv[],
691 int *piDeviceChar,
692 int *piSectorSize
693 ){
694 struct DeviceFlag {
695 char *zName;
696 int iValue;
697 } aFlag[] = {
698 { "atomic", SQLITE_IOCAP_ATOMIC },
699 { "atomic512", SQLITE_IOCAP_ATOMIC512 },
700 { "atomic1k", SQLITE_IOCAP_ATOMIC1K },
701 { "atomic2k", SQLITE_IOCAP_ATOMIC2K },
702 { "atomic4k", SQLITE_IOCAP_ATOMIC4K },
703 { "atomic8k", SQLITE_IOCAP_ATOMIC8K },
704 { "atomic16k", SQLITE_IOCAP_ATOMIC16K },
705 { "atomic32k", SQLITE_IOCAP_ATOMIC32K },
706 { "atomic64k", SQLITE_IOCAP_ATOMIC64K },
707 { "sequential", SQLITE_IOCAP_SEQUENTIAL },
708 { "safe_append", SQLITE_IOCAP_SAFE_APPEND },
709 { 0, 0 }
710 };
711
712 int i;
713 int iDc = 0;
714 int iSectorSize = 0;
715 int setSectorsize = 0;
716 int setDeviceChar = 0;
717
718 for(i=0; i<objc; i+=2){
719 int nOpt;
720 char *zOpt = Tcl_GetStringFromObj(objv[i], &nOpt);
721
722 if( (nOpt>11 || nOpt<2 || strncmp("-sectorsize", zOpt, nOpt))
723 && (nOpt>16 || nOpt<2 || strncmp("-characteristics", zOpt, nOpt))
724 ){
725 Tcl_AppendResult(interp,
726 "Bad option: \"", zOpt,
727 "\" - must be \"-characteristics\" or \"-sectorsize\"", 0
728 );
729 return TCL_ERROR;
730 }
731 if( i==objc-1 ){
732 Tcl_AppendResult(interp, "Option requires an argument: \"", zOpt, "\"",0);
733 return TCL_ERROR;
734 }
735
736 if( zOpt[1]=='s' ){
737 if( Tcl_GetIntFromObj(interp, objv[i+1], &iSectorSize) ){
738 return TCL_ERROR;
739 }
740 setSectorsize = 1;
741 }else{
742 int j;
743 Tcl_Obj **apObj;
744 int nObj;
745 if( Tcl_ListObjGetElements(interp, objv[i+1], &nObj, &apObj) ){
746 return TCL_ERROR;
747 }
748 for(j=0; j<nObj; j++){
749 int rc;
750 int iChoice;
751 Tcl_Obj *pFlag = Tcl_DuplicateObj(apObj[j]);
752 Tcl_IncrRefCount(pFlag);
753 Tcl_UtfToLower(Tcl_GetString(pFlag));
754
755 rc = Tcl_GetIndexFromObjStruct(
756 interp, pFlag, aFlag, sizeof(aFlag[0]), "no such flag", 0, &iChoice
757 );
758 Tcl_DecrRefCount(pFlag);
759 if( rc ){
760 return TCL_ERROR;
761 }
762
763 iDc |= aFlag[iChoice].iValue;
764 }
765 setDeviceChar = 1;
766 }
767 }
768
769 if( setDeviceChar ){
770 *piDeviceChar = iDc;
771 }
772 if( setSectorsize ){
773 *piSectorSize = iSectorSize;
774 }
775
776 return TCL_OK;
777 }
778
779 /*
780 ** tclcmd: sqlite_crash_enable ENABLE
781 **
782 ** Parameter ENABLE must be a boolean value. If true, then the "crash"
783 ** vfs is added to the system. If false, it is removed.
784 */
crashEnableCmd(void * clientData,Tcl_Interp * interp,int objc,Tcl_Obj * CONST objv[])785 static int crashEnableCmd(
786 void * clientData,
787 Tcl_Interp *interp,
788 int objc,
789 Tcl_Obj *CONST objv[]
790 ){
791 int isEnable;
792 static sqlite3_vfs crashVfs = {
793 2, /* iVersion */
794 0, /* szOsFile */
795 0, /* mxPathname */
796 0, /* pNext */
797 "crash", /* zName */
798 0, /* pAppData */
799
800 cfOpen, /* xOpen */
801 cfDelete, /* xDelete */
802 cfAccess, /* xAccess */
803 cfFullPathname, /* xFullPathname */
804 cfDlOpen, /* xDlOpen */
805 cfDlError, /* xDlError */
806 cfDlSym, /* xDlSym */
807 cfDlClose, /* xDlClose */
808 cfRandomness, /* xRandomness */
809 cfSleep, /* xSleep */
810 cfCurrentTime, /* xCurrentTime */
811 0, /* xGetlastError */
812 0, /* xCurrentTimeInt64 */
813 };
814
815 if( objc!=2 ){
816 Tcl_WrongNumArgs(interp, 1, objv, "ENABLE");
817 return TCL_ERROR;
818 }
819
820 if( Tcl_GetBooleanFromObj(interp, objv[1], &isEnable) ){
821 return TCL_ERROR;
822 }
823
824 if( (isEnable && crashVfs.pAppData) || (!isEnable && !crashVfs.pAppData) ){
825 return TCL_OK;
826 }
827
828 if( crashVfs.pAppData==0 ){
829 sqlite3_vfs *pOriginalVfs = sqlite3_vfs_find(0);
830 crashVfs.mxPathname = pOriginalVfs->mxPathname;
831 crashVfs.pAppData = (void *)pOriginalVfs;
832 crashVfs.szOsFile = sizeof(CrashFile) + pOriginalVfs->szOsFile;
833 sqlite3_vfs_register(&crashVfs, 0);
834 }else{
835 crashVfs.pAppData = 0;
836 sqlite3_vfs_unregister(&crashVfs);
837 }
838
839 return TCL_OK;
840 }
841
842 /*
843 ** tclcmd: sqlite_crashparams ?OPTIONS? DELAY CRASHFILE
844 **
845 ** This procedure implements a TCL command that enables crash testing
846 ** in testfixture. Once enabled, crash testing cannot be disabled.
847 **
848 ** Available options are "-characteristics" and "-sectorsize". Both require
849 ** an argument. For -sectorsize, this is the simulated sector size in
850 ** bytes. For -characteristics, the argument must be a list of io-capability
851 ** flags to simulate. Valid flags are "atomic", "atomic512", "atomic1K",
852 ** "atomic2K", "atomic4K", "atomic8K", "atomic16K", "atomic32K",
853 ** "atomic64K", "sequential" and "safe_append".
854 **
855 ** Example:
856 **
857 ** sqlite_crashparams -sect 1024 -char {atomic sequential} ./test.db 1
858 **
859 */
crashParamsObjCmd(void * clientData,Tcl_Interp * interp,int objc,Tcl_Obj * CONST objv[])860 static int crashParamsObjCmd(
861 void * clientData,
862 Tcl_Interp *interp,
863 int objc,
864 Tcl_Obj *CONST objv[]
865 ){
866 int iDelay;
867 const char *zCrashFile;
868 int nCrashFile, iDc, iSectorSize;
869
870 iDc = -1;
871 iSectorSize = -1;
872
873 if( objc<3 ){
874 Tcl_WrongNumArgs(interp, 1, objv, "?OPTIONS? DELAY CRASHFILE");
875 goto error;
876 }
877
878 zCrashFile = Tcl_GetStringFromObj(objv[objc-1], &nCrashFile);
879 if( nCrashFile>=sizeof(g.zCrashFile) ){
880 Tcl_AppendResult(interp, "Filename is too long: \"", zCrashFile, "\"", 0);
881 goto error;
882 }
883 if( Tcl_GetIntFromObj(interp, objv[objc-2], &iDelay) ){
884 goto error;
885 }
886
887 if( processDevSymArgs(interp, objc-3, &objv[1], &iDc, &iSectorSize) ){
888 return TCL_ERROR;
889 }
890
891 if( iDc>=0 ){
892 g.iDeviceCharacteristics = iDc;
893 }
894 if( iSectorSize>=0 ){
895 g.iSectorSize = iSectorSize;
896 }
897
898 g.iCrash = iDelay;
899 memcpy(g.zCrashFile, zCrashFile, nCrashFile+1);
900 sqlite3CrashTestEnable = 1;
901 return TCL_OK;
902
903 error:
904 return TCL_ERROR;
905 }
906
devSymObjCmd(void * clientData,Tcl_Interp * interp,int objc,Tcl_Obj * CONST objv[])907 static int devSymObjCmd(
908 void * clientData,
909 Tcl_Interp *interp,
910 int objc,
911 Tcl_Obj *CONST objv[]
912 ){
913 void devsym_register(int iDeviceChar, int iSectorSize);
914
915 int iDc = -1;
916 int iSectorSize = -1;
917
918 if( processDevSymArgs(interp, objc-1, &objv[1], &iDc, &iSectorSize) ){
919 return TCL_ERROR;
920 }
921 devsym_register(iDc, iSectorSize);
922
923 return TCL_OK;
924 }
925
926 /*
927 ** tclcmd: register_jt_vfs ?-default? PARENT-VFS
928 */
jtObjCmd(void * clientData,Tcl_Interp * interp,int objc,Tcl_Obj * CONST objv[])929 static int jtObjCmd(
930 void * clientData,
931 Tcl_Interp *interp,
932 int objc,
933 Tcl_Obj *CONST objv[]
934 ){
935 int jt_register(char *, int);
936 char *zParent = 0;
937
938 if( objc!=2 && objc!=3 ){
939 Tcl_WrongNumArgs(interp, 1, objv, "?-default? PARENT-VFS");
940 return TCL_ERROR;
941 }
942 zParent = Tcl_GetString(objv[1]);
943 if( objc==3 ){
944 if( strcmp(zParent, "-default") ){
945 Tcl_AppendResult(interp,
946 "bad option \"", zParent, "\": must be -default", 0
947 );
948 return TCL_ERROR;
949 }
950 zParent = Tcl_GetString(objv[2]);
951 }
952
953 if( !(*zParent) ){
954 zParent = 0;
955 }
956 if( jt_register(zParent, objc==3) ){
957 Tcl_AppendResult(interp, "Error in jt_register", 0);
958 return TCL_ERROR;
959 }
960
961 return TCL_OK;
962 }
963
964 /*
965 ** tclcmd: unregister_jt_vfs
966 */
jtUnregisterObjCmd(void * clientData,Tcl_Interp * interp,int objc,Tcl_Obj * CONST objv[])967 static int jtUnregisterObjCmd(
968 void * clientData,
969 Tcl_Interp *interp,
970 int objc,
971 Tcl_Obj *CONST objv[]
972 ){
973 void jt_unregister(void);
974
975 if( objc!=1 ){
976 Tcl_WrongNumArgs(interp, 1, objv, "");
977 return TCL_ERROR;
978 }
979
980 jt_unregister();
981 return TCL_OK;
982 }
983
984 #endif /* SQLITE_OMIT_DISKIO */
985
986 /*
987 ** This procedure registers the TCL procedures defined in this file.
988 */
Sqlitetest6_Init(Tcl_Interp * interp)989 int Sqlitetest6_Init(Tcl_Interp *interp){
990 #ifndef SQLITE_OMIT_DISKIO
991 Tcl_CreateObjCommand(interp, "sqlite3_crash_enable", crashEnableCmd, 0, 0);
992 Tcl_CreateObjCommand(interp, "sqlite3_crashparams", crashParamsObjCmd, 0, 0);
993 Tcl_CreateObjCommand(interp, "sqlite3_simulate_device", devSymObjCmd, 0, 0);
994 Tcl_CreateObjCommand(interp, "register_jt_vfs", jtObjCmd, 0, 0);
995 Tcl_CreateObjCommand(interp, "unregister_jt_vfs", jtUnregisterObjCmd, 0, 0);
996 #endif
997 return TCL_OK;
998 }
999
1000 #endif /* SQLITE_TEST */
1001