Refactor dir/file permissions

Consolidate directory and file create permissions for tools which work
with the PG data directory by adding a new module (common/file_perm.c)
that contains variables (pg_file_create_mode, pg_dir_create_mode) and
constants to initialize them (0600 for files and 0700 for directories).

Convert mkdir() calls in the backend to MakePGDirectory() if the
original call used default permissions (always the case for regular PG
directories).

Add tests to make sure permissions in PGDATA are set correctly by the
tools which modify the PG data directory.

Authors: David Steele <david@pgmasters.net>,
         Adam Brightwell <adam.brightwell@crunchydata.com>
Reviewed-By: Michael Paquier, with discussion amongst many others.
Discussion: https://postgr.es/m/ad346fe6-b23e-59f1-ecb7-0e08390ad629%40pgmasters.net

1 files changed, 73 insertions, 0 deletions

diff --git a/src/test/perl/TestLib.pm b/src/test/perl/TestLib.pm
index b6862688d4f..93610e4bc40 100644
--- a/src/test/perl/TestLib.pm
+++ b/src/test/perl/TestLib.pm
@@ -13,8 +13,11 @@ use warnings;
 use Config;
 use Cwd;
 use Exporter 'import';
+use Fcntl qw(:mode);
 use File::Basename;
+use File::Find;
 use File::Spec;
+use File::stat qw(stat);
 use File::Temp ();
 use IPC::Run;
 use SimpleTee;
@@ -27,6 +30,7 @@ our @EXPORT = qw(
   slurp_dir
   slurp_file
   append_to_file
+  check_mode_recursive
   check_pg_config
   system_or_bail
   system_log
@@ -240,6 +244,75 @@ sub append_to_file
 	close $fh;
 }
 
+# Check that all file/dir modes in a directory match the expected values,
+# ignoring the mode of any specified files.
+sub check_mode_recursive
+{
+	my ($dir, $expected_dir_mode, $expected_file_mode, $ignore_list) = @_;
+
+	# Result defaults to true
+	my $result = 1;
+
+	find
+	(
+		{follow_fast => 1,
+		wanted =>
+			sub
+			{
+				my $file_stat = stat($File::Find::name);
+
+				# Is file in the ignore list?
+				foreach my $ignore ($ignore_list ? @{$ignore_list} : [])
+				{
+					if ("$dir/$ignore" eq $File::Find::name)
+					{
+						return;
+					}
+				}
+
+				defined($file_stat)
+					or die("unable to stat $File::Find::name");
+
+				my $file_mode = S_IMODE($file_stat->mode);
+
+				# Is this a file?
+				if (S_ISREG($file_stat->mode))
+				{
+					if ($file_mode != $expected_file_mode)
+					{
+						print(*STDERR,
+							sprintf("$File::Find::name mode must be %04o\n",
+							$expected_file_mode));
+
+						$result = 0;
+						return;
+					}
+				}
+				# Else a directory?
+				elsif (S_ISDIR($file_stat->mode))
+				{
+					if ($file_mode != $expected_dir_mode)
+					{
+						print(*STDERR,
+							sprintf("$File::Find::name mode must be %04o\n",
+							$expected_dir_mode));
+
+						$result = 0;
+						return;
+					}
+				}
+				# Else something we can't handle
+				else
+				{
+					die "unknown file type for $File::Find::name";
+				}
+			}},
+		$dir
+	);
+
+	return $result;
+}
+
 # Check presence of a given regexp within pg_config.h for the installation
 # where tests are running, returning a match status result depending on
 # that.