svn commit: r1682265 - /subversion/trunk/subversion/libsvn_fs_fs/util.c

[stefan2]

Author: stefan2
Date: Thu May 28 15:45:55 2015
New Revision: 1682265

URL: http://svn.apache.org/r1682265
Log:
Correctly fsync() after renames in FSFS on Win32.  We must flush the disk
buffers after the rename, otherwise the metadata may not be persistent.
Moreover, if the rename is degraded to a copy by Win32, we won't even have
the complete file contents on disk without a buffer flush.

* subversion/libsvn_fs_fs/util.c
  (svn_fs_fs__move_into_place): On Win32, always flush after rename.

Modified:
    subversion/trunk/subversion/libsvn_fs_fs/util.c

Modified: subversion/trunk/subversion/libsvn_fs_fs/util.c
URL: 
http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_fs_fs/util.c?rev=1682265&r1=1682264&r2=1682265&view=diff
==============================================================================
--- subversion/trunk/subversion/libsvn_fs_fs/util.c (original)
+++ subversion/trunk/subversion/libsvn_fs_fs/util.c Thu May 28 15:45:55 2015
@@ -637,6 +637,22 @@ svn_fs_fs__move_into_place(const char *o
                            apr_pool_t *pool)
 {
   svn_error_t *err;
+  apr_file_t *file;
+
+#if defined(WIN32) || defined(__OS2__)
+
+  /* APR will *not* error out on Win32 if this requires a copy instead of
+     of a move. */
+  SVN_ERR(svn_io_file_rename(old_filename, new_filename, pool));
+
+  /* Flush the target of the copy to disk. */
+  SVN_ERR(svn_io_file_open(&file, new_filename, APR_WRITE,
+                           APR_OS_DEFAULT, pool));
+  SVN_ERR(svn_io_file_flush_to_disk(file, pool));
+  SVN_ERR(svn_io_file_close(file, pool));
+
+  /* Copying permissions is a no-op on WIN32. */
+#else
 
   SVN_ERR(svn_io_copy_perms(perms_reference, old_filename, pool));
 
@@ -644,8 +660,6 @@ svn_fs_fs__move_into_place(const char *o
   err = svn_io_file_rename(old_filename, new_filename, pool);
   if (err && APR_STATUS_IS_EXDEV(err->apr_err))
     {
-      apr_file_t *file;
-
       /* Can't rename across devices; fall back to copying. */
       svn_error_clear(err);
       err = SVN_NO_ERROR;
@@ -654,11 +668,6 @@ svn_fs_fs__move_into_place(const char *o
       /* Flush the target of the copy to disk. */
       SVN_ERR(svn_io_file_open(&file, new_filename, APR_READ,
                                APR_OS_DEFAULT, pool));
-      /* ### BH: Does this really guarantee a flush of the data written
-         ### via a completely different handle on all operating systems?
-         ###
-         ### Maybe we should perform the copy ourselves instead of making
-         ### apr do that and flush the real handle? */
       SVN_ERR(svn_io_file_flush_to_disk(file, pool));
       SVN_ERR(svn_io_file_close(file, pool));
     }
@@ -672,7 +681,6 @@ svn_fs_fs__move_into_place(const char *o
        On other operating systems, we'd only be asking for trouble
        by trying to open and fsync a directory. */
     const char *dirname;
-    apr_file_t *file;
 
     dirname = svn_dirent_dirname(new_filename, pool);
     SVN_ERR(svn_io_file_open(&file, dirname, APR_READ, APR_OS_DEFAULT,
@@ -682,6 +690,8 @@ svn_fs_fs__move_into_place(const char *o
   }
 #endif
 
+#endif /*  defined(WIN32) || defined(__OS2__) */
+
   return SVN_NO_ERROR;
 }