* fhandler_disk_file.cc (fhandler_disk_file::opendir): Try to open

	directory with stat()-friendly access mask first.  Explain why.

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 70e5d6a..9d3743d 100644 (file)
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,5 +1,10 @@
 2010-02-19  Corinna Vinschen  <corinna@vinschen.de>
 
+       * fhandler_disk_file.cc (fhandler_disk_file::opendir): Try to open
+       directory with stat()-friendly access mask first.  Explain why.
+
+2010-02-19  Corinna Vinschen  <corinna@vinschen.de>
+
        * fhandler_disk_file.cc (fhandler_base::fstat_helper):  Set st_rdev
        to same value as st_dev.  Avoid useless debug output in executable
        check.  Add filename to debug output.

diff --git a/winsup/cygwin/fhandler_disk_file.cc b/winsup/cygwin/fhandler_disk_file.cc
index 2d0dad2..04eceaf 100644 (file)
--- a/winsup/cygwin/fhandler_disk_file.cc
+++ b/winsup/cygwin/fhandler_disk_file.cc
@@ -1660,19 +1660,41 @@ fhandler_disk_file::opendir (int fd)
              OBJECT_ATTRIBUTES attr;
              NTSTATUS status;
              IO_STATUS_BLOCK io;
-
-             status = NtOpenFile (&get_handle (),
-                                  SYNCHRONIZE | FILE_LIST_DIRECTORY,
-                                  pc.get_object_attr (attr, sec_none_nih),
-                                  &io, FILE_SHARE_VALID_FLAGS,
-                                  FILE_SYNCHRONOUS_IO_NONALERT
-                                  | FILE_OPEN_FOR_BACKUP_INTENT
-                                  | FILE_DIRECTORY_FILE);
-             if (!NT_SUCCESS (status))
+             /* Tools like ls(1) call dirfd() to fetch the directory
+                descriptor for calls to facl or fstat.  The tight access mask
+                used so far is not sufficient to reuse the handle for these
+                calls, instead the facl/fstat calls find the handle to be
+                unusable and have to re-open the file for reading attributes
+                and control data.  So, what we do here is to try to open the
+                directory with more relaxed access mask which enables to use
+                the handle for the aforementioned purpose.  This should work
+                in almost all cases.  Only if it doesn't work due to
+                permission problems, we drop the additional access bits and
+                try again. */
+             ACCESS_MASK fstat_mask = READ_CONTROL | FILE_READ_ATTRIBUTES;
+
+             do
                {
-                 __seterrno_from_nt_status (status);
-                 goto free_mounts;
+                 status = NtOpenFile (&get_handle (),
+                                      SYNCHRONIZE | FILE_LIST_DIRECTORY
+                                      | fstat_mask,
+                                      pc.get_object_attr (attr, sec_none_nih),
+                                      &io, FILE_SHARE_VALID_FLAGS,
+                                      FILE_SYNCHRONOUS_IO_NONALERT
+                                      | FILE_OPEN_FOR_BACKUP_INTENT
+                                      | FILE_DIRECTORY_FILE);
+                 if (!NT_SUCCESS (status))
+                   {
+                     if (status == STATUS_ACCESS_DENIED && fstat_mask)
+                       fstat_mask = 0;
+                     else
+                       {
+                         __seterrno_from_nt_status (status);
+                         goto free_mounts;
+                       }
+                   }
                }
+             while (!NT_SUCCESS (status));
            }
 
          /* FileIdBothDirectoryInformation is apparently unsupported on