Changeset 77231 in vbox for trunk/src/VBox/Runtime/r3/win

Timestamp:

Feb 8, 2019 11:18:13 PM (6 years ago)

Author:

vboxsync

Message:

IPRT: Return VERR_FILE_TOO_BIG if we exceed the FAT file limit while writing or when calling RTFileSetSize. (The previous IsBeyondLimit() code never ever worked AFAIK.)

File:

• trunk/src/VBox/Runtime/r3/win/fileio-win.cpp (modified) (8 diffs)

trunk/src/VBox/Runtime/r3/win/fileio-win.cpp

@@ -96 +96 @@
 
 /**
- * This is a helper to check if an attempt was made to grow a file beyond the
- * limit of the filesystem.
- *
- * @returns true for file size limit exceeded.
- * @param   hFile       Filehandle.
- * @param   offSeek     Offset to seek.
- * @param   uMethod     The seek method.
+ * Helper for checking if a VERR_DISK_FULL isn't a VERR_FILE_TOO_BIG.
+ * @returns VERR_DISK_FULL or VERR_FILE_TOO_BIG.
  */
-DECLINLINE(bool) IsBeyondLimit(RTFILE hFile, uint64_t offSeek, unsigned uMethod)
-{
-    bool fIsBeyondLimit = false;
-
-    /*
-     * Get the current file position and try set the new one.
-     * If it fails with a seek error it's because we hit the file system limit.
-     */
-/** @todo r=bird: I'd be very interested to know on which versions of windows and on which file systems
- * this supposedly works. The fastfat sources in the latest WDK makes no limit checks during
- * file seeking, only at the time of writing (and some other odd ones we cannot make use of). */
-    uint64_t offCurrent;
-    if (MySetFilePointer(hFile, 0, &offCurrent, FILE_CURRENT))
-    {
-        if (!MySetFilePointer(hFile, offSeek, NULL, uMethod))
-            fIsBeyondLimit = GetLastError() == ERROR_SEEK;
-        else /* Restore file pointer on success. */
-            MySetFilePointer(hFile, offCurrent, NULL, FILE_BEGIN);
-    }
-
-    return fIsBeyondLimit;
+static int rtFileWinCheckIfDiskReallyFull(RTFILE hFile, uint64_t cbDesired)
+{
+    /*
+     * Windows doesn't appear to have a way to query the file size limit of a
+     * file system, so we have to deduce the limit from the file system driver name.
+     * This means it will only work for known file systems.
+     */
+    if (cbDesired >= _2G - 1)
+    {
+        uint64_t cbMaxFile = UINT64_MAX;
+        RTFSTYPE enmFsType;
+        int rc = rtNtQueryFsType((HANDLE)RTFileToNative(hFile), &enmFsType);
+        if (RT_SUCCESS(rc))
+            switch (enmFsType)
+            {
+                case RTFSTYPE_NTFS:
+                case RTFSTYPE_EXFAT:
+                case RTFSTYPE_UDF:
+                    cbMaxFile = UINT64_C(0xffffffffffffffff); /* (May be limited by IFS.) */
+                    break;
+
+                case RTFSTYPE_ISO9660:
+                    cbMaxFile = 8 *_1T;
+                    break;
+
+                case RTFSTYPE_FAT:
+                    cbMaxFile = _4G;
+                    break;
+
+                case RTFSTYPE_HPFS:
+                    cbMaxFile = _2G;
+                    break;
+
+                default:
+                    break;
+            }
+        if (cbDesired >= cbMaxFile)
+            return VERR_FILE_TOO_BIG;
+    }
+    return VERR_DISK_FULL;
 }
 
@@ -563 +577 @@
                 {
                     int rc = RTErrConvertFromWin32(GetLastError());
-                    if (   rc == VERR_DISK_FULL
-                        && IsBeyondLimit(hFile, cbToWriteAdj - cbWritten, FILE_CURRENT)
-                       )
-                        rc = VERR_FILE_TOO_BIG;
+                    if (rc == VERR_DISK_FULL)
+                        rc = rtFileWinCheckIfDiskReallyFull(hFile, RTFileTell(hFile) + cbToWriteAdj - cbWritten);
                     return rc;
                 }
@@ -607 +619 @@
                 }
                 int rc = RTErrConvertFromWin32(dwErr);
-                if (   rc == VERR_DISK_FULL
-                    && IsBeyondLimit(hFile, cbToWriteAdj - cbWritten, FILE_CURRENT))
-                    rc = VERR_FILE_TOO_BIG;
+                if (rc == VERR_DISK_FULL)
+                    rc = rtFileWinCheckIfDiskReallyFull(hFile, RTFileTell(hFile) + cbToWrite);
                 return rc;
             }
@@ -628 +639 @@
 
     int rc = RTErrConvertFromWin32(dwErr);
-    if (   rc == VERR_DISK_FULL
-        && IsBeyondLimit(hFile, cbToWriteAdj - cbWritten, FILE_CURRENT))
-        rc = VERR_FILE_TOO_BIG;
+    if (rc == VERR_DISK_FULL)
+        rc = rtFileWinCheckIfDiskReallyFull(hFile, RTFileTell(hFile) + cbToWriteAdj);
     return rc;
 }
@@ -669 +679 @@
                 {
                     int rc = RTErrConvertFromWin32(GetLastError());
-                    if (   rc == VERR_DISK_FULL
-                        && IsBeyondLimit(hFile, cbToWriteAdj - cbWritten, FILE_CURRENT)
-                       )
-                        rc = VERR_FILE_TOO_BIG;
+                    if (rc == VERR_DISK_FULL)
+                        rc = rtFileWinCheckIfDiskReallyFull(hFile, off + cbToWriteAdj);
                     return rc;
                 }
@@ -684 +692 @@
 
     int rc = RTErrConvertFromWin32(GetLastError());
-    if (   rc == VERR_DISK_FULL
-        && IsBeyondLimit(hFile, cbToWriteAdj - cbWritten, FILE_CURRENT))
-        rc = VERR_FILE_TOO_BIG;
+    if (rc == VERR_DISK_FULL)
+        rc = rtFileWinCheckIfDiskReallyFull(hFile, off + cbToWriteAdj);
     return rc;
 }
@@ -703 +710 @@
 
 
-RTR3DECL(int)  RTFileSetSize(RTFILE hFile, uint64_t cbSize)
+RTR3DECL(int) RTFileSetSize(RTFILE hFile, uint64_t cbSize)
 {
     /*
@@ -734 +741 @@
             rc = GetLastError();
             MySetFilePointer(hFile, offCurrent, NULL, FILE_BEGIN);
+
+            if (rc == ERROR_DISK_FULL)
+                return rtFileWinCheckIfDiskReallyFull(hFile, cbSize);
         }
         else