Allow the xAccess method in the VFS to return -1 to signal an I/O

error, and in particular an SQLITE_IOERR_NOMEM. (CVS 4925)

FossilOrigin-Name: 3cb704c4c439425781644b1b653b7e50f02fd91e

6 files changed, 61 insertions, 29 deletions

diff --git a/src/fault.c b/src/fault.c
index 7e183ed43..d31dd4387 100644
--- a/src/fault.c
+++ b/src/fault.c
@@ -42,7 +42,7 @@ static struct FaultInjector {
   int nBenign;      /* Number of benign failures seen since last config */
   int nFail;        /* Number of failures seen since last config */
   u8 enable;        /* True if enabled */
-  u8 benign;        /* Ture if next failure will be benign */
+  u8 benign;        /* True if next failure will be benign */
 } aFault[SQLITE_FAULTINJECTOR_COUNT];
 
 /*
@@ -105,8 +105,14 @@ int sqlite3FaultPending(int id){
 ** a hash table resize is a benign fault.  
 */
 void sqlite3FaultBenign(int id, int enable){
-  assert( id>=0 && id<SQLITE_FAULTINJECTOR_COUNT );
-  aFault[id].benign = enable;
+  if( id<0 ){
+    for(id=0; id<SQLITE_FAULTINJECTOR_COUNT; id++){
+      aFault[id].benign = enable;
+    }
+  }else{
+    assert( id>=0 && id<SQLITE_FAULTINJECTOR_COUNT );
+    aFault[id].benign = enable;
+  }
 }
 
 /*
diff --git a/src/os.c b/src/os.c
index 6671d0ae3..10e40a079 100644
--- a/src/os.c
+++ b/src/os.c
@@ -115,7 +115,13 @@ int sqlite3OsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
   return pVfs->xDelete(pVfs, zPath, dirSync);
 }
 int sqlite3OsAccess(sqlite3_vfs *pVfs, const char *zPath, int flags){
-  int rc = pVfs->xAccess(pVfs, zPath, flags);
+  int rc;
+#ifdef SQLITE_TEST
+  void *pTstAlloc = sqlite3_malloc(10);
+  if (!pTstAlloc) return -1;
+  sqlite3_free(pTstAlloc);
+#endif
+  rc = pVfs->xAccess(pVfs, zPath, flags);
   assert( rc==0 || rc==1 );
   return rc;
 }
diff --git a/src/pager.c b/src/pager.c
index 7f76c13d5..d47321a08 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 1.420 2008/03/20 11:04:21 danielk1977 Exp $
+** @(#) $Id: pager.c,v 1.421 2008/03/27 22:42:52 drh Exp $
 */
 #ifndef SQLITE_OMIT_DISKIO
 #include "sqliteInt.h"
@@ -1602,7 +1602,12 @@ static int pager_delmaster(Pager *pPager, const char *zMaster){
 
     zJournal = zMasterJournal;
     while( (zJournal-zMasterJournal)<nMasterJournal ){
-      if( sqlite3OsAccess(pVfs, zJournal, SQLITE_ACCESS_EXISTS) ){
+      rc = sqlite3OsAccess(pVfs, zJournal, SQLITE_ACCESS_EXISTS);
+      if( rc!=0 && rc!=1 ){
+        rc = SQLITE_IOERR_NOMEM;
+        goto delmaster_out;
+      }
+      if( rc==1 ){
         /* One of the journals pointed to by the master journal exists.
         ** Open it and check if it points at the master journal. If
         ** so, return without deleting the master journal file.
@@ -1773,12 +1778,10 @@ static int pager_playback(Pager *pPager, int isHot){
   */
   zMaster = pPager->pTmpSpace;
   rc = readMasterJournal(pPager->jfd, zMaster, pPager->pVfs->mxPathname+1);
-  assert( rc!=SQLITE_DONE );
   if( rc!=SQLITE_OK 
-   || (zMaster[0] && !sqlite3OsAccess(pVfs, zMaster, SQLITE_ACCESS_EXISTS)) 
+   || (zMaster[0] && sqlite3OsAccess(pVfs, zMaster, SQLITE_ACCESS_EXISTS)==0 ) 
   ){
     zMaster = 0;
-    if( rc==SQLITE_DONE ) rc = SQLITE_OK;
     goto end_playback;
   }
   pPager->journalOff = 0;
@@ -3053,19 +3056,23 @@ static PgHdr *pager_get_all_dirty_pages(Pager *pPager){
 }
 
 /*
-** Return TRUE if there is a hot journal on the given pager.
+** Return 1 if there is a hot journal on the given pager.
 ** A hot journal is one that needs to be played back.
 **
 ** If the current size of the database file is 0 but a journal file
 ** exists, that is probably an old journal left over from a prior
 ** database with the same name.  Just delete the journal.
+**
+** Return negative if unable to determine the status of the journal.
 */
 static int hasHotJournal(Pager *pPager){
   sqlite3_vfs *pVfs = pPager->pVfs;
+  int rc;
   if( !pPager->useJournal ) return 0;
   if( !pPager->fd->pMethods ) return 0;
-  if( !sqlite3OsAccess(pVfs, pPager->zJournal, SQLITE_ACCESS_EXISTS) ){
-    return 0;
+  rc = sqlite3OsAccess(pVfs, pPager->zJournal, SQLITE_ACCESS_EXISTS);
+  if( rc<=0 ){
+    return rc;
   }
   if( sqlite3OsCheckReservedLock(pPager->fd) ){
     return 0;
@@ -3365,7 +3372,11 @@ static int pagerSharedLock(Pager *pPager){
       /* If a journal file exists, and there is no RESERVED lock on the
       ** database file, then it either needs to be played back or deleted.
       */
-      if( hasHotJournal(pPager) || isHot ){
+      rc = hasHotJournal(pPager);
+      if( rc<0 ){
+        return pager_error(pPager, SQLITE_IOERR_NOMEM);
+      }
+      if( rc==1 || isHot ){
         /* Get an EXCLUSIVE lock on the database file. At this point it is
         ** important that a RESERVED lock is not obtained on the way to the
         ** EXCLUSIVE lock. If it were, another process might open the
@@ -3402,7 +3413,7 @@ static int pagerSharedLock(Pager *pPager){
         */
         if( !isHot ){
           rc = SQLITE_BUSY;
-          if( sqlite3OsAccess(pVfs, pPager->zJournal, SQLITE_ACCESS_EXISTS) ){
+          if( sqlite3OsAccess(pVfs, pPager->zJournal,SQLITE_ACCESS_EXISTS)==1 ){
             int fout = 0;
             int f = SQLITE_OPEN_READWRITE|SQLITE_OPEN_MAIN_JOURNAL;
             assert( !pPager->tempFile );
diff --git a/src/pragma.c b/src/pragma.c
index 8c396b3b4..a712bd869 100644
--- a/src/pragma.c
+++ b/src/pragma.c
@@ -11,7 +11,7 @@
 *************************************************************************
 ** This file contains code used to implement the PRAGMA command.
 **
-** $Id: pragma.c,v 1.173 2008/03/25 17:23:33 drh Exp $
+** $Id: pragma.c,v 1.174 2008/03/27 22:42:52 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -571,7 +571,7 @@ void sqlite3Pragma(
       }
     }else{
       if( zRight[0] 
-       && !sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE) 
+       && sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE)==0 
       ){
         sqlite3ErrorMsg(pParse, "not a writable directory");
         goto pragma_out;
diff --git a/src/vdbe.c b/src/vdbe.c
index e41c6eed0..61e99978a 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -43,7 +43,7 @@
 ** in this file for details.  If in doubt, do not deviate from existing
 ** commenting and indentation practices when changing or adding code.
 **
-** $Id: vdbe.c,v 1.719 2008/03/27 17:59:02 danielk1977 Exp $
+** $Id: vdbe.c,v 1.720 2008/03/27 22:42:52 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -578,8 +578,9 @@ int sqlite3VdbeExec(
   CHECK_FOR_INTERRUPT;
   sqlite3VdbeIOTraceSql(p);
 #ifdef SQLITE_DEBUG
+  sqlite3FaultBenign(-1, 1);
   if( p->pc==0 && ((p->db->flags & SQLITE_VdbeListing)!=0
-    || sqlite3OsAccess(db->pVfs, "vdbe_explain", SQLITE_ACCESS_EXISTS))
+    || sqlite3OsAccess(db->pVfs, "vdbe_explain", SQLITE_ACCESS_EXISTS)==1 )
   ){
     int i;
     printf("VDBE Program Listing:\n");
@@ -588,9 +589,10 @@ int sqlite3VdbeExec(
       sqlite3VdbePrintOp(stdout, i, &p->aOp[i]);
     }
   }
-  if( sqlite3OsAccess(db->pVfs, "vdbe_trace", SQLITE_ACCESS_EXISTS) ){
+  if( sqlite3OsAccess(db->pVfs, "vdbe_trace", SQLITE_ACCESS_EXISTS)==1 ){
     p->trace = stdout;
   }
+  sqlite3FaultBenign(-1, 0);
 #endif
   for(pc=p->pc; rc==SQLITE_OK; pc++){
     assert( pc>=0 && pc<p->nOp );
@@ -611,9 +613,12 @@ int sqlite3VdbeExec(
       }
       sqlite3VdbePrintOp(p->trace, pc, pOp);
     }
-    if( p->trace==0 && pc==0 
-     && sqlite3OsAccess(db->pVfs, "vdbe_sqltrace", SQLITE_ACCESS_EXISTS) ){
-      sqlite3VdbePrintSql(p);
+    if( p->trace==0 && pc==0 ){
+      sqlite3FaultBenign(-1, 1);
+      if( sqlite3OsAccess(db->pVfs, "vdbe_sqltrace", SQLITE_ACCESS_EXISTS)==1 ){
+        sqlite3VdbePrintSql(p);
+      }
+      sqlite3FaultBenign(-1, 0);
     }
 #endif
       
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index 369946c4e..ce37808f1 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -1290,13 +1290,17 @@ static int vdbeCommit(sqlite3 *db){
       if( !zMaster ){
         return SQLITE_NOMEM;
       }
-    }while( sqlite3OsAccess(pVfs, zMaster, SQLITE_ACCESS_EXISTS) );
-
-    /* Open the master journal. */
-    rc = sqlite3OsOpenMalloc(pVfs, zMaster, &pMaster, 
-        SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|
-        SQLITE_OPEN_EXCLUSIVE|SQLITE_OPEN_MASTER_JOURNAL, 0
-    );
+      rc = sqlite3OsAccess(pVfs, zMaster, SQLITE_ACCESS_EXISTS);
+    }while( rc==1 );
+    if( rc!=0 ){
+      rc = SQLITE_IOERR_NOMEM;
+    }else{
+      /* Open the master journal. */
+      rc = sqlite3OsOpenMalloc(pVfs, zMaster, &pMaster, 
+          SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|
+          SQLITE_OPEN_EXCLUSIVE|SQLITE_OPEN_MASTER_JOURNAL, 0
+      );
+    }
     if( rc!=SQLITE_OK ){
       sqlite3_free(zMaster);
       return rc;