From: "Erich E. Hoover" <ehoover@mymail.mines.edu>
Subject: [PATCH 3/7] ntdll: Add support for deleting junction points.
Message-Id: <CAEU2+vpktfvZF31aA3uv7sQ98MdjBmNJNfC_fKe84Dv6OaRhqQ@mail.gmail.com>
Date: Wed, 20 Jun 2012 17:28:36 -0600

This patch adds support for the FSCTL_DELETE_REPARSE_POINT ioctl for
the reparse tag IO_REPARSE_TAG_MOUNT_POINT (junction points).
Allowing for the deletion of junction points created from the feature
in part 1.

From 89095b3ca55ee963a0e5f3b78c6c33f4fccf2ca6 Mon Sep 17 00:00:00 2001
From: Erich Hoover <ehoover@mines.edu>
Date: Wed, 20 Jun 2012 17:18:36 -0600
Subject: ntdll: Add support for deleting junction points.

---
 dlls/ntdll/file.c       |   51 +++++++++++++++++++++++++++++++++++++++++++++++
 dlls/ntdll/tests/file.c |    8 +++++++
 include/ntifs.h         |   11 ++++++++++
 3 files changed, 70 insertions(+), 0 deletions(-)

diff --git a/dlls/ntdll/file.c b/dlls/ntdll/file.c
index efa94cd..593785b 100644
--- a/dlls/ntdll/file.c
+++ b/dlls/ntdll/file.c
@@ -1473,6 +1473,41 @@ cleanup:
 }
 
 
+/*
+ * Retrieve the unix name corresponding to a file handle, remove that symlink, and then recreate
+ * a directory at the location of the old filename.
+ */
+NTSTATUS FILE_RemoveSymlink(HANDLE handle, REPARSE_GUID_DATA_BUFFER *buffer)
+{
+    int dest_fd, needs_close;
+    ANSI_STRING unix_name;
+    NTSTATUS status;
+
+    if ((status = server_get_unix_fd( handle, FILE_READ_DATA, &dest_fd, &needs_close, NULL, NULL )))
+        return status;
+
+    if ((status = server_get_unix_name( handle, &unix_name )))
+        goto cleanup;
+
+    TRACE("Deleting symlink %s\n", unix_name.Buffer);
+    if (unlink( unix_name.Buffer ) < 0)
+    {
+        status = FILE_GetNtStatus();
+        goto cleanup;
+    }
+    if (mkdir( unix_name.Buffer, 0775 ) < 0)
+    {
+        status = FILE_GetNtStatus();
+        goto cleanup;
+    }
+    status = STATUS_SUCCESS;
+
+cleanup:
+    if (needs_close) close( dest_fd );
+    return status;
+}
+
+
 /**************************************************************************
  *              NtFsControlFile                 [NTDLL.@]
  *              ZwFsControlFile                 [NTDLL.@]
@@ -1620,6 +1655,22 @@ NTSTATUS WINAPI NtFsControlFile(HANDLE handle, HANDLE event, PIO_APC_ROUTINE apc
         break;
     }
 
+    case FSCTL_DELETE_REPARSE_POINT:
+    {
+        REPARSE_GUID_DATA_BUFFER *buffer = (REPARSE_GUID_DATA_BUFFER *)in_buffer;
+
+        switch(buffer->ReparseTag)
+        {
+        case IO_REPARSE_TAG_MOUNT_POINT:
+            status = FILE_RemoveSymlink( handle, buffer );
+            break;
+        default:
+            FIXME("stub: FSCTL_DELETE_REPARSE_POINT(%x)\n", buffer->ReparseTag);
+            status = STATUS_NOT_IMPLEMENTED;
+            break;
+        }
+        break;
+    }
     case FSCTL_GET_REPARSE_POINT:
     {
         REPARSE_DATA_BUFFER *buffer = (REPARSE_DATA_BUFFER *)out_buffer;
diff --git a/dlls/ntdll/tests/file.c b/dlls/ntdll/tests/file.c
index 62eb1a3..b626e44 100644
--- a/dlls/ntdll/tests/file.c
+++ b/dlls/ntdll/tests/file.c
@@ -1747,6 +1747,7 @@ static void test_junction_points(void)
     static const WCHAR targetW[] = {'\\','t','a','r','g','e','t',0};
     static const WCHAR fooW[] = {'f','o','o',0};
     static WCHAR volW[] = {'c',':','\\',0};
+    REPARSE_GUID_DATA_BUFFER guid_buffer;
     static const WCHAR dotW[] = {'.',0};
     REPARSE_DATA_BUFFER *buffer = NULL;
     DWORD dwret, dwLen, dwFlags;
@@ -1812,6 +1813,13 @@ static void test_junction_points(void)
     ok(bret, "Failed to read junction point!\n");
     ok((memcmp(dest, nameW.Buffer, string_len) == 0), "Junction point destination does not match ('%s' != '%s')!\n",
                                                       wine_dbgstr_w(dest), wine_dbgstr_w(nameW.Buffer));
+
+    /* Delete the junction point */
+    memset(&guid_buffer, 0x00, sizeof(guid_buffer));
+    guid_buffer.ReparseTag = IO_REPARSE_TAG_MOUNT_POINT;
+    bret = DeviceIoControl(hJunction, FSCTL_DELETE_REPARSE_POINT, (LPVOID)&guid_buffer,
+                           REPARSE_GUID_DATA_BUFFER_HEADER_SIZE, NULL, 0, &dwret, 0);
+    ok(bret, "Failed to delete junction point! (0x%x)\n", GetLastError());
     CloseHandle(hJunction);
 
 cleanup:
diff --git a/include/ntifs.h b/include/ntifs.h
index db07c28..cb8638b 100644
--- a/include/ntifs.h
+++ b/include/ntifs.h
@@ -47,6 +47,17 @@ typedef struct _REPARSE_DATA_BUFFER {
     };
 } REPARSE_DATA_BUFFER, *PREPARSE_DATA_BUFFER;
 
+typedef struct _REPARSE_GUID_DATA_BUFFER {
+    DWORD ReparseTag;
+    WORD  ReparseDataLength;
+    WORD  Reserved;
+    GUID  ReparseGuid;
+    struct {
+        BYTE DataBuffer[1];
+    } GenericReparseBuffer;
+} REPARSE_GUID_DATA_BUFFER, *PREPARSE_GUID_DATA_BUFFER;
+
 #define IO_REPARSE_TAG_MOUNT_POINT           0xa0000003
+#define REPARSE_GUID_DATA_BUFFER_HEADER_SIZE FIELD_OFFSET(REPARSE_GUID_DATA_BUFFER, GenericReparseBuffer)
 
 #endif /* __WINE_NTIFS_H */
-- 
1.7.5.4