On win32, loop when opening files if sharing- och lock-violation errors

occur. Hopefully, this will make it possible to recover from broken
antivirus and/or backup software that locks our files.

diff --git a/src/port/open.c b/src/port/open.c
index 526897d16815f9fa699f13f4fe8c91a0375da9bc..ef097416273b82b05077de20cd6cee4bd3b85e82 100644 (file)
--- a/src/port/open.c
+++ b/src/port/open.c
@@ -6,14 +6,18 @@
  *
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/port/open.c,v 1.22 2007/11/30 11:16:43 mha Exp $
+ * $PostgreSQL: pgsql/src/port/open.c,v 1.23 2007/12/20 20:27:53 mha Exp $
  *
  *-------------------------------------------------------------------------
  */
 
 #ifdef WIN32
 
-#include "c.h"
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
 
 #include <windows.h>
 #include <fcntl.h>
@@ -58,8 +62,9 @@ int
 pgwin32_open(const char *fileName, int fileFlags,...)
 {
    int         fd;
-   HANDLE      h;
+   HANDLE      h = INVALID_HANDLE_VALUE;
    SECURITY_ATTRIBUTES sa;
+   int         loops = 0;
 
    /* Check that we can handle the request */
    assert((fileFlags & ((O_RDONLY | O_WRONLY | O_RDWR) | O_APPEND |
@@ -71,7 +76,7 @@ pgwin32_open(const char *fileName, int fileFlags,...)
    sa.bInheritHandle = TRUE;
    sa.lpSecurityDescriptor = NULL;
 
-   if ((h = CreateFile(fileName,
+   while ((h = CreateFile(fileName,
    /* cannot use O_RDONLY, as it == 0 */
                      (fileFlags & O_RDWR) ? (GENERIC_WRITE | GENERIC_READ) :
                     ((fileFlags & O_WRONLY) ? GENERIC_WRITE : GENERIC_READ),
@@ -88,7 +93,32 @@ pgwin32_open(const char *fileName, int fileFlags,...)
                        ((fileFlags & O_DSYNC) ? FILE_FLAG_WRITE_THROUGH : 0),
                        NULL)) == INVALID_HANDLE_VALUE)
    {
-       _dosmaperr(GetLastError());
+       /*
+        * Sharing violation or locking error can indicate antivirus, backup
+        * or similar software that's locking the file. Try again for 30 seconds
+        * before giving up.
+        */
+       DWORD err = GetLastError();
+       if (err == ERROR_SHARING_VIOLATION || 
+           err == ERROR_LOCK_VIOLATION)
+       {
+           pg_usleep(100000);
+           loops++;
+
+#ifndef FRONTEND
+           if (loops == 50)
+               ereport(LOG,
+                   (errmsg("could not open file \"%s\": %s", fileName, 
+                     (err == ERROR_SHARING_VIOLATION)?_("sharing violation"):_("lock violation")),
+                    errdetail("Continuing to retry for 30 seconds."),
+                    errhint("You may have antivirus, backup or similar software interfering with the database.")));
+#endif
+
+           if (loops < 300)
+               continue;
+       }
+
+       _dosmaperr(err);
        return -1;
    }