Attachment 42126 Details for Bug 8284 – Make _dbus_directory_get_next_file use readdir, not readdir_r

[patch] Make _dbus_directory_get_next_file use readdir, not readdir_r

0001-Make-_dbus_directory_get_next_file-use-readdir-not-r.patch (text/plain), 4.16 KB, created by Simon McVittie on 2011-01-17 11:47:50 UTC

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Creator: Simon McVittie

Created: 2011-01-17 11:47:50 UTC

Size: 4.16 KB

patch

obsolete

>From b30bbd8e35ef5932bfe38ae3a1cc75697c32b576 Mon Sep 17 00:00:00 2001
>From: Simon McVittie <simon.mcvittie@collabora.co.uk>
>Date: Mon, 17 Jan 2011 18:40:15 +0000
>Subject: [PATCH] Make _dbus_directory_get_next_file use readdir, not readdir_r
>
>This isn't thread-safe or reentrant, but it turns out we don't need
>either of those properties, and readdir_r is a real pain to use correctly,
>particularly in the presence of FUSE filesystems that might implement
>statfs() wrong.
>
>Bug: https://bugs.freedesktop.org/show_bug.cgi?id=8284
>Bug: https://bugs.freedesktop.org/show_bug.cgi?id=15922
>---
> dbus/dbus-sysdeps-util-unix.c |   75 +++++-----------------------------------
> 1 files changed, 10 insertions(+), 65 deletions(-)
>
>diff --git a/dbus/dbus-sysdeps-util-unix.c b/dbus/dbus-sysdeps-util-unix.c
>index 00705b3..6e09245 100644
>--- a/dbus/dbus-sysdeps-util-unix.c
>+++ b/dbus/dbus-sysdeps-util-unix.c
>@@ -608,54 +608,14 @@ _dbus_directory_open (const DBusString *filename,
>   return iter;
> }
> 
>-/* Calculate the required buffer size (in bytes) for directory
>- * entries read from the given directory handle.  Return -1 if this
>- * this cannot be done. 
>- *
>- * If you use autoconf, include fpathconf and dirfd in your
>- * AC_CHECK_FUNCS list.  Otherwise use some other method to detect
>- * and use them where available.
>- */
>-static dbus_bool_t
>-dirent_buf_size(DIR * dirp, size_t *size)
>-{
>- long name_max;
>-#   if defined(HAVE_FPATHCONF) && defined(_PC_NAME_MAX)
>-#      if defined(HAVE_DIRFD)
>-          name_max = fpathconf(dirfd(dirp), _PC_NAME_MAX);
>-#      elif defined(HAVE_DDFD)
>-          name_max = fpathconf(dirp->dd_fd, _PC_NAME_MAX);
>-#      else
>-          name_max = fpathconf(dirp->__dd_fd, _PC_NAME_MAX);
>-#      endif /* HAVE_DIRFD */
>-     if (name_max == -1)
>-#           if defined(NAME_MAX)
>-	     name_max = NAME_MAX;
>-#           else
>-	     return FALSE;
>-#           endif
>-#   elif defined(MAXNAMELEN)
>-     name_max = MAXNAMELEN;
>-#   else
>-#       if defined(NAME_MAX)
>-	 name_max = NAME_MAX;
>-#       else
>-#           error "buffer size for readdir_r cannot be determined"
>-#       endif
>-#   endif
>-  if (size)
>-    *size = (size_t)offsetof(struct dirent, d_name) + name_max + 1;
>-  else
>-    return FALSE;
>-
>-  return TRUE;
>-}
>-
> /**
>  * Get next file in the directory. Will not return "." or ".."  on
>  * UNIX. If an error occurs, the contents of "filename" are
>  * undefined. The error is never set if the function succeeds.
>  *
>+ * This function is not re-entrant, and not necessarily thread-safe.
>+ * Only use it for test code or single-threaded utilities.
>+ *
>  * @param iter the iterator
>  * @param filename string to be set to the next file in the dir
>  * @param error return location for error
>@@ -666,37 +626,24 @@ _dbus_directory_get_next_file (DBusDirIter      *iter,
>                                DBusString       *filename,
>                                DBusError        *error)
> {
>-  struct dirent *d, *ent;
>-  size_t buf_size;
>+  struct dirent *ent;
>   int err;
> 
>   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
>- 
>-  if (!dirent_buf_size (iter->d, &buf_size))
>-    {
>-      dbus_set_error (error, DBUS_ERROR_FAILED,
>-                      "Can't calculate buffer size when reading directory");
>-      return FALSE;
>-    }
>-
>-  d = (struct dirent *)dbus_malloc (buf_size);
>-  if (!d)
>-    {
>-      dbus_set_error (error, DBUS_ERROR_NO_MEMORY,
>-                      "No memory to read directory entry");
>-      return FALSE;
>-    }
> 
>  again:
>-  err = readdir_r (iter->d, d, &ent);
>-  if (err || !ent)
>+  errno = 0;
>+  ent = readdir (iter->d);
>+
>+  if (!ent)
>     {
>+      err = errno;
>+
>       if (err != 0)
>         dbus_set_error (error,
>                         _dbus_error_from_errno (err),
>                         "%s", _dbus_strerror (err));
> 
>-      dbus_free (d);
>       return FALSE;
>     }
>   else if (ent->d_name[0] == '.' &&
>@@ -710,12 +657,10 @@ _dbus_directory_get_next_file (DBusDirIter      *iter,
>         {
>           dbus_set_error (error, DBUS_ERROR_NO_MEMORY,
>                           "No memory to read directory entry");
>-          dbus_free (d);
>           return FALSE;
>         }
>       else
>         {
>-          dbus_free (d);
>           return TRUE;
>         }
>     }
>-- 
>1.7.2.3
>

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