Make the "unix-excl" VFS work exactly like "unix" if the database

file is read-only.

FossilOrigin-Name: d9846834993079fb2e42d6bd2644b2154ef324d1

manifest

@@ -1,8 +1,8 @@
 -----BEGIN PGP SIGNED MESSAGE-----
 Hash: SHA1
 
-C Fix\san\sout-of-order\svariable\sdeclaration\sin\sshell.c.
+C Make\sthe\s"unix-excl"\sVFS\swork\sexactly\slike\s"unix"\sif\sthe\sdatabase\nfile\sis\sread-only.
-D 2011-03-15T18:35:44.256
+D 2011-03-15T19:08:48.027
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 27701a1653595a1f2187dc61c8117e00a6c1d50f
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -165,7 +165,7 @@ F src/os.c 22ac61d06e72a0dac900400147333b07b13d8e1d
 F src/os.h 9dbed8c2b9c1f2f2ebabc09e49829d4777c26bf9
 F src/os_common.h a8f95b81eca8a1ab8593d23e94f8a35f35d4078f
 F src/os_os2.c 2596fd2d5d0976c6c0c628d0c3c7c4e7a724f4cf
-F src/os_unix.c 1debf5ea6efd0f35335a2a615198a7a1017ffd4b
+F src/os_unix.c 919972244dd7267815f9fc176b662390ff0b2348
 F src/os_win.c 24d72407a90551969744cf9bcbb1b4c72c5fa845
 F src/pager.c 6aa906b60a59664ba58d3f746164bb010d407ce1
 F src/pager.h 3f8c783de1d4706b40b1ac15b64f5f896bcc78d1
@@ -916,14 +916,14 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
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+P 725708465072fc63736e99610cc9cb0ac336145a
-R 2ceb7e2495de2e32fa2e2aca83b58f09
+R c6fd073182d6b083be2e4d503e5f99b8
 U drh
-Z e7ee1c18a6d623c4d19a0ae664dea8d8
+Z 981ae6e8a2633665045ed876d4741a1e
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manifest.uuid

@@ -1 +1 @@
-725708465072fc63736e99610cc9cb0ac336145a
+d9846834993079fb2e42d6bd2644b2154ef324d1

src/os_unix.c

@@ -247,6 +247,7 @@ struct unixFile {
 ** Allowed values for the unixFile.ctrlFlags bitmask:
 */
 #define UNIXFILE_EXCL   0x01     /* Connections from one process only */
+#define UNIXFILE_RDONLY 0x02     /* Connection is read only */
 
 /*
 ** Include code that is common to all os_*.c files
@@ -1192,20 +1193,26 @@ static int unixCheckReservedLock(sqlite3_file *id, int *pResOut){
 ** Attempt to set a system-lock on the file pFile.  The lock is 
 ** described by pLock.
 **
-** If the pFile was opened from unix-excl, then the only lock ever
+** If the pFile was opened read/write from unix-excl, then the only lock
-** obtained is an exclusive lock, and it is obtained exactly once
+** ever obtained is an exclusive lock, and it is obtained exactly once
 ** the first time any lock is attempted.  All subsequent system locking
 ** operations become no-ops.  Locking operations still happen internally,
 ** in order to coordinate access between separate database connections
 ** within this process, but all of that is handled in memory and the
 ** operating system does not participate.
+**
+** This function is a pass-through to fcntl(F_SETLK) if pFile is using
+** any VFS other than "unix-excl" or if pFile is opened on "unix-excl"
+** and is read-only.
 */
 static int unixFileLock(unixFile *pFile, struct flock *pLock){
   int rc;
   unixInodeInfo *pInode = pFile->pInode;
   assert( unixMutexHeld() );
   assert( pInode!=0 );
-  if( (pFile->ctrlFlags & UNIXFILE_EXCL)!=0 || pInode->bProcessLock ){
+  if( ((pFile->ctrlFlags & UNIXFILE_EXCL)!=0 || pInode->bProcessLock)
+   && ((pFile->ctrlFlags & UNIXFILE_RDONLY)==0)
+  ){
     if( pInode->bProcessLock==0 ){
       struct flock lock;
       assert( pInode->nLock==0 );
@@ -4402,7 +4409,8 @@ static int fillInUnixFile(
   sqlite3_file *pId,      /* Write to the unixFile structure here */
   const char *zFilename,  /* Name of the file being opened */
   int noLock,             /* Omit locking if true */
-  int isDelete            /* Delete on close if true */
+  int isDelete,           /* Delete on close if true */
+  int isReadOnly          /* True if the file is opened read-only */
 ){
   const sqlite3_io_methods *pLockingStyle;
   unixFile *pNew = (unixFile *)pId;
@@ -4435,6 +4443,9 @@ static int fillInUnixFile(
   }else{
     pNew->ctrlFlags = 0;
   }
+  if( isReadOnly ){
+    pNew->ctrlFlags |= UNIXFILE_RDONLY;
+  }
 
 #if OS_VXWORKS
   pNew->pId = vxworksFindFileId(zFilename);
@@ -4942,6 +4953,7 @@ static int unixOpen(
       openFlags &= ~(O_RDWR|O_CREAT);
       flags |= SQLITE_OPEN_READONLY;
       openFlags |= O_RDONLY;
+      isReadonly = 1;
       fd = robust_open(zName, openFlags, openMode);
     }
     if( fd<0 ){
@@ -5038,7 +5050,8 @@ static int unixOpen(
       useProxy = !(fsInfo.f_flags&MNT_LOCAL);
     }
     if( useProxy ){
-      rc = fillInUnixFile(pVfs, fd, dirfd, pFile, zPath, noLock, isDelete);
+      rc = fillInUnixFile(pVfs, fd, dirfd, pFile, zPath, noLock,
+                          isDelete, isReadonly);
       if( rc==SQLITE_OK ){
         rc = proxyTransformUnixFile((unixFile*)pFile, ":auto:");
         if( rc!=SQLITE_OK ){
@@ -5055,7 +5068,8 @@ static int unixOpen(
   }
 #endif
   
-  rc = fillInUnixFile(pVfs, fd, dirfd, pFile, zPath, noLock, isDelete);
+  rc = fillInUnixFile(pVfs, fd, dirfd, pFile, zPath, noLock,
+                      isDelete, isReadonly);
 open_finished:
   if( rc!=SQLITE_OK ){
     sqlite3_free(p->pUnused);
@@ -5717,7 +5731,7 @@ static int proxyCreateUnixFile(
   pUnused->flags = openFlags;
   pNew->pUnused = pUnused;
   
-  rc = fillInUnixFile(&dummyVfs, fd, dirfd, (sqlite3_file*)pNew, path, 0, 0);
+  rc = fillInUnixFile(&dummyVfs, fd, dirfd, (sqlite3_file*)pNew, path, 0, 0, 0);
   if( rc==SQLITE_OK ){
     *ppFile = pNew;
     return SQLITE_OK;