* NEWS: Document that mkdir -p and install -d now fork on occasion.

* bootstrap.conf (gnulib_modules): Add savewd.
* src/install.c: Include savewd.h.
(process_dir): New function.
(main, install_file_in_file_parents): Use it, along with the new
savewd module, to avoid some race conditions.
* src/mkdir.c: Include savewd.h.
(struct mkdir_options): New members make_ancestor_function, mode,
mode_bits.
(make_ancestor): Return 1 if the resulting directory is not readable.
(process_dir): New function.
(main): Use it, along with new savewd module, to avoid some
race conditions.  Fill in new slots of struct mkdir_options, so
that callees get the values.
* tests/install/basic-1: Test for coreutils 5.97 bug that was
fixed in coreutils 6.0, and which should still be fixed with
this change.
* tests/mkdir/p-3: Likewise.

2 files changed, 90 insertions, 38 deletions

diff --git a/src/install.c b/src/install.c
index 78fa28e0b..9c5150fbc 100644
--- a/src/install.c
+++ b/src/install.c
@@ -35,6 +35,7 @@
 #include "mkdir-p.h"
 #include "modechange.h"
 #include "quote.h"
+#include "savewd.h"
 #include "stat-time.h"
 #include "utimens.h"
 #include "xstrtol.h"
@@ -193,11 +194,23 @@ target_directory_operand (char const *file)
   return is_a_dir;
 }
 
+/* Process a command-line file name, for the -d option.  */
+static int
+process_dir (char *dir, struct savewd *wd, void *options)
+{
+  return (make_dir_parents (dir, wd,
+			    make_ancestor, options,
+			    dir_mode, announce_mkdir,
+			    dir_mode_bits, owner_id, group_id, false)
+	  ? EXIT_SUCCESS
+	  : EXIT_FAILURE);
+}
+
 int
 main (int argc, char **argv)
 {
   int optc;
-  bool ok = true;
+  int exit_status = EXIT_SUCCESS;
   const char *specified_mode = NULL;
   bool make_backups = false;
   char *backup_suffix_string;
@@ -361,13 +374,7 @@ main (int argc, char **argv)
   get_ids ();
 
   if (dir_arg)
-    {
-      int i;
-      for (i = 0; i < n_files; i++)
-	ok &= make_dir_parents (file[i], make_ancestor, &x,
-				dir_mode, announce_mkdir,
-				dir_mode_bits, owner_id, group_id, false);
-    }
+    exit_status = savewd_process_files (n_files, file, process_dir, &x);
   else
     {
       /* FIXME: it's a little gross that this initialization is
@@ -376,23 +383,22 @@ main (int argc, char **argv)
 
       if (!target_directory)
         {
-          if (mkdir_and_install)
-	    ok = install_file_in_file_parents (file[0], file[1], &x);
-	  else
-	    ok = install_file_in_file (file[0], file[1], &x);
+          if (! (mkdir_and_install
+		 ? install_file_in_file_parents (file[0], file[1], &x)
+		 : install_file_in_file (file[0], file[1], &x)))
+	    exit_status = EXIT_FAILURE;
 	}
       else
 	{
 	  int i;
 	  dest_info_init (&x);
 	  for (i = 0; i < n_files; i++)
-	    {
-	      ok &= install_file_in_dir (file[i], target_directory, &x);
-	    }
+	    if (! install_file_in_dir (file[i], target_directory, &x))
+	      exit_status = EXIT_FAILURE;
 	}
     }
 
-  exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
+  exit (exit_status);
 }
 
 /* Copy file FROM onto file TO, creating any missing parent directories of TO.
@@ -402,13 +408,36 @@ static bool
 install_file_in_file_parents (char const *from, char *to,
 			      struct cp_options *x)
 {
-  if (mkancesdirs (to, make_ancestor, x) != 0)
+  bool save_working_directory =
+    ! (IS_ABSOLUTE_FILE_NAME (from) && IS_ABSOLUTE_FILE_NAME (to));
+  int status = EXIT_SUCCESS;
+
+  struct savewd wd;
+  savewd_init (&wd);
+  if (! save_working_directory)
+    savewd_finish (&wd);
+
+  if (mkancesdirs (to, &wd, make_ancestor, x) == -1)
     {
       error (0, errno, _("cannot create directory %s"), to);
-      return false;
+      status = EXIT_FAILURE;
+    }
+
+  if (save_working_directory)
+    {
+      int restore_result = savewd_restore (&wd, status);
+      int restore_errno = errno;
+      savewd_finish (&wd);
+      if (EXIT_SUCCESS < restore_result)
+	return false;
+      if (restore_result < 0 && status == EXIT_SUCCESS)
+	{
+	  error (0, restore_errno, _("cannot create directory %s"), to);
+	  return false;
+	}
     }
 
-  return install_file_in_file (from, to, x);
+  return (status == EXIT_SUCCESS && install_file_in_file (from, to, x));
 }
 
 /* Copy file FROM onto file TO and give TO the appropriate
diff --git a/src/mkdir.c b/src/mkdir.c
index 852bc3e15..b28a02ac0 100644
--- a/src/mkdir.c
+++ b/src/mkdir.c
@@ -28,6 +28,7 @@
 #include "mkdir-p.h"
 #include "modechange.h"
 #include "quote.h"
+#include "savewd.h"
 
 /* The official name of this program (e.g., no `g' prefix).  */
 #define PROGRAM_NAME "mkdir"
@@ -75,12 +76,22 @@ Mandatory arguments to long options are mandatory for short options too.\n\
   exit (status);
 }
 
-/* Options for announce_mkdir and make_ancestor.  */
+/* Options passed to subsidiary functions.  */
 struct mkdir_options
 {
+  /* Function to make an ancestor, or NULL if ancestors should not be
+     made.  */
+  int (*make_ancestor_function) (char const *, void *);
+
   /* Mode for ancestor directory.  */
   mode_t ancestor_mode;
 
+  /* Mode for directory itself.  */
+  mode_t mode;
+
+  /* File mode bits affected by MODE.  */
+  mode_t mode_bits;
+
   /* If not null, format to use when reporting newly made directories.  */
   char const *created_directory_format;
 };
@@ -94,27 +105,44 @@ announce_mkdir (char const *dir, void *options)
     error (0, 0, o->created_directory_format, quote (dir));
 }
 
-/* Make ancestor directory DIR, with options OPTIONS.  */
+/* Make ancestor directory DIR, with options OPTIONS.  Return 0 if
+   successful and the resulting directory is readable, 1 if successful
+   but the resulting directory is not readable, -1 (setting errno)
+   otherwise.  */
 static int
 make_ancestor (char const *dir, void *options)
 {
   struct mkdir_options const *o = options;
   int r = mkdir (dir, o->ancestor_mode);
   if (r == 0)
-    announce_mkdir (dir, options);
+    {
+      r = ! (o->ancestor_mode & S_IRUSR);
+      announce_mkdir (dir, options);
+    }
   return r;
 }
 
+/* Process a command-line file name.  */
+static int
+process_dir (char *dir, struct savewd *wd, void *options)
+{
+  struct mkdir_options const *o = options;
+  return (make_dir_parents (dir, wd, o->make_ancestor_function, options,
+			    o->mode, announce_mkdir,
+			    o->mode_bits, (uid_t) -1, (gid_t) -1, true)
+	  ? EXIT_SUCCESS
+	  : EXIT_FAILURE);
+}
+
 int
 main (int argc, char **argv)
 {
-  mode_t mode = S_IRWXUGO;
-  mode_t mode_bits = 0;
-  int (*make_ancestor_function) (char const *, void *) = NULL;
   const char *specified_mode = NULL;
-  int exit_status = EXIT_SUCCESS;
   int optc;
   struct mkdir_options options;
+  options.make_ancestor_function = NULL;
+  options.mode = S_IRWXUGO;
+  options.mode_bits = 0;
   options.created_directory_format = NULL;
 
   initialize_main (&argc, &argv);
@@ -130,7 +158,7 @@ main (int argc, char **argv)
       switch (optc)
 	{
 	case 'p':
-	  make_ancestor_function = make_ancestor;
+	  options.make_ancestor_function = make_ancestor;
 	  break;
 	case 'm':
 	  specified_mode = optarg;
@@ -151,7 +179,7 @@ main (int argc, char **argv)
       usage (EXIT_FAILURE);
     }
 
-  if (make_ancestor_function || specified_mode)
+  if (options.make_ancestor_function || specified_mode)
     {
       mode_t umask_value = umask (0);
 
@@ -163,19 +191,14 @@ main (int argc, char **argv)
 	  if (!change)
 	    error (EXIT_FAILURE, 0, _("invalid mode %s"),
 		   quote (specified_mode));
-	  mode = mode_adjust (S_IRWXUGO, true, umask_value, change,
-			      &mode_bits);
+	  options.mode = mode_adjust (S_IRWXUGO, true, umask_value, change,
+				      &options.mode_bits);
 	  free (change);
 	}
       else
-	mode &= ~umask_value;
+	options.mode = S_IRWXUGO & ~umask_value;
     }
 
-  for (; optind < argc; ++optind)
-    if (! make_dir_parents (argv[optind], make_ancestor_function, &options,
-			    mode, announce_mkdir,
-			    mode_bits, (uid_t) -1, (gid_t) -1, true))
-      exit_status = EXIT_FAILURE;
-
-  exit (exit_status);
+  exit (savewd_process_files (argc - optind, argv + optind,
+			      process_dir, &options));
 }