[PATCH] Fix ftw

[PATCH] Fix ftw

[Jakub Jelinek]

Hi!

If dir->streamfd != -1 and
FXSTATAT (_STAT_VER, dir->streamfd, name, &st, 0);
fails with EACCESS or ENOENT, then ftw is supposed to
find out if that is because of a dead symlink or for some
other reason.  If d_type is DT_LNK, then no further
work is needed, however otherwise we were calling LXSTAT.
But name in this case is relative to dir->streamfd, not absolute
or relative to current working directory, so it tells us something
different from what we are looking for.
The following patch fixes it (tested on s390x where ftwtest failed
because of this).

2006-03-02  Jakub Jelinek  <jakub@redhat.com>

	* io/ftw.c (process_entry): If dir->streamfd != -1,
	use FXSTATAT rather than LXSTAT to find if unstatable
	file is a dead symlink.

--- libc/io/ftw.c.jj	2006-02-12 16:40:36.000000000 -0500
+++ libc/io/ftw.c	2006-03-02 10:37:41.000000000 -0500
@@ -419,13 +419,22 @@ process_entry (struct ftw_data *data, st
     {
       if (errno != EACCES && errno != ENOENT)
 	result = -1;
-      else if (!(data->flags & FTW_PHYS)
-	       && (d_type == DT_LNK
-		   || (LXSTAT (_STAT_VER, name, &st) == 0
-		       && S_ISLNK (st.st_mode))))
+      else if (data->flags & FTW_PHYS)
+	flag = FTW_NS;
+      else if (d_type == DT_LNK)
 	flag = FTW_SLN;
       else
-	flag = FTW_NS;
+	{
+	  if (dir->streamfd != -1)
+	    statres = FXSTATAT (_STAT_VER, dir->streamfd, name, &st,
+				AT_SYMLINK_NOFOLLOW);
+	  else
+	    statres = LXSTAT (_STAT_VER, name, &st);
+	  if (statres == 0 && S_ISLNK (st.st_mode))
+	    flag = FTW_SLN;
+	  else
+	    flag = FTW_NS;
+	}
     }
   else
     {

	Jakub

Re: [PATCH] Fix ftw

[Ulrich Drepper]

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Applied.

-- 
➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖


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[PATCH] Fix ftw

[Jakub Jelinek]

Hi!

The following testcase shows ftw leaking filedescriptors (one per call)
and the attached patch seems to fix it.

2003-11-04  Jakub Jelinek  <jakub@redhat.com>

	* io/ftw.c (ftw_dir): Close dir if callback with FTW_D type returns
	non-zero.
	* io/Makefile (tests): Add bug-ftw4.
	* io/bug-ftw4.c: New test.

--- libc/io/Makefile.jj	2003-10-29 00:18:42.000000000 +0100
+++ libc/io/Makefile	2003-11-04 19:40:10.000000000 +0100
@@ -57,7 +57,7 @@ static-only-routines = stat fstat lstat 
 others		:= pwd
 test-srcs	:= ftwtest
 tests		:= test-utime test-stat test-stat2 test-lfs tst-getcwd \
-		   tst-fcntl bug-ftw1 bug-ftw2 bug-ftw3 tst-statvfs
+		   tst-fcntl bug-ftw1 bug-ftw2 bug-ftw3 bug-ftw4 tst-statvfs
 
 distribute	:= ftwtest-sh
 
--- libc/io/ftw.c.jj	2003-06-11 23:48:58.000000000 +0200
+++ libc/io/ftw.c	2003-11-04 19:57:42.000000000 +0100
@@ -476,23 +476,27 @@ ftw_dir (struct ftw_data *data, struct S
     {
       result = (*data->func) (data->dirbuf, st, FTW_D, &data->ftw);
       if (result != 0)
-	return result;
-    }
-
-  /* If necessary, change to this directory.  */
-  if (data->flags & FTW_CHDIR)
-    {
-      if (__fchdir (dirfd (dir.stream)) < 0)
 	{
-	  int save_err = errno;
+	  int save_err;
+fail:
+	  save_err = errno;
 	  __closedir (dir.stream);
 	  __set_errno (save_err);
 
 	  if (data->actdir-- == 0)
 	    data->actdir = data->maxdir - 1;
 	  data->dirstreams[data->actdir] = NULL;
+	  return result;
+	}
+    }
 
-	  return -1;
+  /* If necessary, change to this directory.  */
+  if (data->flags & FTW_CHDIR)
+    {
+      if (__fchdir (dirfd (dir.stream)) < 0)
+	{
+	  result = -1;
+	  goto fail;
 	}
     }
 
--- libc/io/bug-ftw4.c.jj	2003-11-04 19:39:53.000000000 +0100
+++ libc/io/bug-ftw4.c	2003-11-04 19:43:57.000000000 +0100
@@ -0,0 +1,124 @@
+/* Test if ftw function doesn't leak fds.
+   Copyright (C) 2003 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jakub Jelinek <jakub@redhat.com>, 2003.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <fcntl.h>
+#include <ftw.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+static int cb_called;
+
+static int
+cb (const char *name, const struct stat64 *st, int type)
+{
+  return cb_called++ & 1;
+}
+
+int
+main (void)
+{
+  char name[32] = "/tmp/ftwXXXXXX", *p;
+  int ret, i, result = 0, fd, fd1, fd2;
+
+  if (mkdtemp (name) == NULL)
+    {
+      printf ("Couldn't make temporary directory: %m\n");
+      exit (EXIT_FAILURE);
+    }
+  p = strchr (name, '\0');
+  strcpy (p, "/1");
+  if (mkdir (name, 0755) < 0)
+    {
+      printf ("Couldn't make temporary subdirectory: %m\n");
+      exit (EXIT_FAILURE);
+    }
+  *p = '\0';
+
+  ret = ftw64 (name, cb, 20);
+  if (ret != 1)
+    {
+      printf ("ftw64 returned %d instead of 1", ret);
+      result = 1;
+    }
+
+  fd = open (name, O_RDONLY);
+  if (fd < 0)
+    {
+      printf ("open failed: %m\n");
+      result = 1;
+    }
+  fd1 = open (name, O_RDONLY);
+  if (fd1 < 0)
+    {
+      printf ("open failed: %m\n");
+      result = 1;
+    }
+  else
+    close (fd1);
+  if (fd >= 0)
+    close (fd);
+
+  for (i = 0; i < 128; ++i)
+    {
+      ret = ftw64 (name, cb, 20);
+      if (ret != 1)
+	{
+	  printf ("ftw64 returned %d instead of 1", ret);
+	  result = 1;
+	}
+    }
+
+  fd = open (name, O_RDONLY);
+  if (fd < 0)
+    {
+      printf ("open failed: %m\n");
+      result = 1;
+    }
+  fd2 = open (name, O_RDONLY);
+  if (fd2 < 0)
+    {
+      printf ("open failed: %m\n");
+      result = 1;
+    }
+  else
+    close (fd2);
+  if (fd >= 0)
+    close (fd);
+
+  if (fd2 >= fd1 + 128)
+    {
+      printf ("ftw64 leaking fds: %d -> %d\n", fd1, fd2);
+      result = 1;
+    }
+
+  if (cb_called != 129 * 2)
+    {
+      printf ("callback called %d times\n", cb_called);
+      result = 1;
+    }
+
+  strcpy (p, "/1");
+  rmdir (name);
+  *p = '\0';
+  rmdir (name);
+  return result;
+}

	Jakub