logical decoding/replication: new functions pg_ls_logicaldir and pg_ls_replslotdir

From 428681ee0a66b98136445d607bd51026b8a204b4 Mon Sep 17 00:00:00 2001
From: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Date: Sat, 30 Oct 2021 09:27:36 +0000
Subject: [PATCH v1] Add pg_ls_logicalsnapdir, pg_ls_logicalmapdir and
 pg_ls_replslotdir functions

These functions lists the contents of the respective directories,
and are intended to be used by monitoring tools.  Unlike pg_ls_dir(),
access to it can be granted to non-superusers so that those monitoring
tools can observe the principle of least privilege.  Access is also
given by default to members of pg_monitor.
---
 doc/src/sgml/func.sgml                   | 72 ++++++++++++++++++++++++
 src/backend/catalog/system_functions.sql | 12 ++++
 src/backend/utils/adt/genfile.c          | 34 +++++++++++
 src/include/catalog/catversion.h         |  2 +-
 src/include/catalog/pg_proc.dat          | 15 +++++
 5 files changed, 134 insertions(+), 1 deletion(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 4b49dff2ff..51825edb01 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -27407,6 +27407,78 @@ SELECT convert_from(pg_read_binary_file('file_in_utf8.txt'), 'UTF8');
         can be granted EXECUTE to run the function.
        </para></entry>
       </row>
+
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_ls_logicalsnapdir</primary>
+        </indexterm>
+        <function>pg_ls_logicalsnapdir</function> ()
+        <returnvalue>setof record</returnvalue>
+        ( <parameter>name</parameter> <type>text</type>,
+        <parameter>size</parameter> <type>bigint</type>,
+        <parameter>modification</parameter> <type>timestamp with time zone</type> )
+       </para>
+       <para>
+        Returns the name, size, and last modification time (mtime) of each
+        ordinary file in the server's pg_logical/snapshots directory.
+        Filenames beginning with a dot, directories, and other special files
+        are excluded.
+       </para>
+       <para>
+        This function is restricted to superusers and members of
+        the <literal>pg_monitor</literal> role by default, but other users can
+        be granted EXECUTE to run the function.
+       </para></entry>
+      </row>
+
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_ls_logicalmapdir</primary>
+        </indexterm>
+        <function>pg_ls_logicalmapdir</function> ()
+        <returnvalue>setof record</returnvalue>
+        ( <parameter>name</parameter> <type>text</type>,
+        <parameter>size</parameter> <type>bigint</type>,
+        <parameter>modification</parameter> <type>timestamp with time zone</type> )
+       </para>
+       <para>
+        Returns the name, size, and last modification time (mtime) of each
+        ordinary file in the server's pg_logical/mappings directory.
+        Filenames beginning with a dot, directories, and other special files
+        are excluded.
+       </para>
+       <para>
+        This function is restricted to superusers and members of
+        the <literal>pg_monitor</literal> role by default, but other users can
+        be granted EXECUTE to run the function.
+       </para></entry>
+      </row>
+
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_ls_replslotdir</primary>
+        </indexterm>
+        <function>pg_ls_replslotdir</function> ( <parameter>slot_name</parameter> <type>text</type> )
+        <returnvalue>setof record</returnvalue>
+        ( <parameter>name</parameter> <type>text</type>,
+        <parameter>size</parameter> <type>bigint</type>,
+        <parameter>modification</parameter> <type>timestamp with time zone</type> )
+       </para>
+       <para>
+        Returns the name, size, and last modification time (mtime) of each
+        ordinary file in the server's pg_replslot/<parameter>slot_name</parameter> directory.
+        Filenames beginning with a dot, directories, and other special files
+        are excluded.
+       </para>
+       <para>
+        This function is restricted to superusers and members of
+        the <literal>pg_monitor</literal> role by default, but other users can
+        be granted EXECUTE to run the function.
+       </para></entry>
+      </row>
      </tbody>
     </tgroup>
    </table>
diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql
index 54c93b16c4..f6789025a5 100644
--- a/src/backend/catalog/system_functions.sql
+++ b/src/backend/catalog/system_functions.sql
@@ -701,6 +701,12 @@ REVOKE EXECUTE ON FUNCTION pg_ls_dir(text,boolean,boolean) FROM public;
 
 REVOKE EXECUTE ON FUNCTION pg_log_backend_memory_contexts(integer) FROM PUBLIC;
 
+REVOKE EXECUTE ON FUNCTION pg_ls_logicalsnapdir() FROM PUBLIC;
+
+REVOKE EXECUTE ON FUNCTION pg_ls_logicalmapdir() FROM PUBLIC;
+
+REVOKE EXECUTE ON FUNCTION pg_ls_replslotdir(text) FROM PUBLIC;
+
 --
 -- We also set up some things as accessible to standard roles.
 --
@@ -715,6 +721,12 @@ GRANT EXECUTE ON FUNCTION pg_ls_tmpdir() TO pg_monitor;
 
 GRANT EXECUTE ON FUNCTION pg_ls_tmpdir(oid) TO pg_monitor;
 
+GRANT EXECUTE ON FUNCTION pg_ls_logicalsnapdir() TO pg_monitor;
+
+GRANT EXECUTE ON FUNCTION pg_ls_logicalmapdir() TO pg_monitor;
+
+GRANT EXECUTE ON FUNCTION pg_ls_replslotdir(text) TO pg_monitor;
+
 GRANT pg_read_all_settings TO pg_monitor;
 
 GRANT pg_read_all_stats TO pg_monitor;
diff --git a/src/backend/utils/adt/genfile.c b/src/backend/utils/adt/genfile.c
index c436d9318b..a83700c576 100644
--- a/src/backend/utils/adt/genfile.c
+++ b/src/backend/utils/adt/genfile.c
@@ -720,3 +720,37 @@ pg_ls_archive_statusdir(PG_FUNCTION_ARGS)
 {
 	return pg_ls_dir_files(fcinfo, XLOGDIR "/archive_status", true);
 }
+
+/*
+ * Function to return the list of files in the pg_logical/snapshots directory.
+ */
+Datum
+pg_ls_logicalsnapdir(PG_FUNCTION_ARGS)
+{
+	return pg_ls_dir_files(fcinfo, "pg_logical/snapshots", false);
+}
+
+/*
+ * Function to return the list of files in the pg_logical/mappings directory.
+ */
+Datum
+pg_ls_logicalmapdir(PG_FUNCTION_ARGS)
+{
+	return pg_ls_dir_files(fcinfo, "pg_logical/mappings", false);
+}
+
+/*
+ * Function to return the list of files in the pg_replslot/<replication_slot>
+ * directory.
+ */
+Datum
+pg_ls_replslotdir(PG_FUNCTION_ARGS)
+{
+	text	   *filename_t = PG_GETARG_TEXT_PP(0);
+	char		path[MAXPGPATH + 11];
+	char	   *filename;
+
+	filename = text_to_cstring(filename_t);
+	snprintf(path, sizeof(path), "%s/%s", "pg_replslot", filename);
+	return pg_ls_dir_files(fcinfo, path, false);
+}
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 9faf017457..f1c2c4d1e9 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202110272
+#define CATALOG_VERSION_NO	202110300
 
 #endif
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index d068d6532e..ca0d6ca1d1 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11619,6 +11619,21 @@
   proallargtypes => '{oid,text,int8,timestamptz}', proargmodes => '{i,o,o,o}',
   proargnames => '{tablespace,name,size,modification}',
   prosrc => 'pg_ls_tmpdir_1arg' },
+{ oid => '4642', descr => 'list of files in the pg_logical/snapshots directory',
+  proname => 'pg_ls_logicalsnapdir', procost => '10', prorows => '20', proretset => 't',
+  provolatile => 'v', prorettype => 'record', proargtypes => '',
+  proallargtypes => '{text,int8,timestamptz}', proargmodes => '{o,o,o}',
+  proargnames => '{name,size,modification}', prosrc => 'pg_ls_logicalsnapdir' },
+{ oid => '4643', descr => 'list of files in the pg_logical/mappings directory',
+  proname => 'pg_ls_logicalmapdir', procost => '10', prorows => '20', proretset => 't',
+  provolatile => 'v', prorettype => 'record', proargtypes => '',
+  proallargtypes => '{text,int8,timestamptz}', proargmodes => '{o,o,o}',
+  proargnames => '{name,size,modification}', prosrc => 'pg_ls_logicalmapdir' },
+{ oid => '4644', descr => 'list of files in the pg_logical/mappings directory',
+  proname => 'pg_ls_replslotdir', procost => '10', prorows => '20', proretset => 't',
+  provolatile => 'v', prorettype => 'record', proargtypes => 'text',
+  proallargtypes => '{text,text,int8,timestamptz}', proargmodes => '{i,o,o,o}',
+  proargnames => '{slot_name,name,size,modification}', prosrc => 'pg_ls_replslotdir' },
 
 # hash partitioning constraint function
 { oid => '5028', descr => 'hash partition CHECK constraint',
-- 
2.25.1

From b8ecfbf1a1987b57d4735a2fea6b8f4f8dfd5b5d Mon Sep 17 00:00:00 2001
From: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Date: Thu, 18 Nov 2021 07:35:51 +0000
Subject: [PATCH v2] Add pg_ls_logicalsnapdir, pg_ls_logicalmapdir,
 pg_ls_replslotdir functions

These functions lists the contents of the respective directories,
and are intended to be used by monitoring tools.  Unlike pg_ls_dir(),
access to it can be granted to non-superusers so that those monitoring
tools can observe the principle of least privilege.  Access is also
given by default to members of pg_monitor.

Note: Haven't changed the CATALOG_VERSION_NO as it is creating the
conflicts with the committed code, so the committer can take care
of it while committing this patch.
---
 doc/src/sgml/func.sgml                   | 72 ++++++++++++++++++++++++
 src/backend/catalog/system_functions.sql | 12 ++++
 src/backend/utils/adt/genfile.c          | 47 ++++++++++++++++
 src/include/catalog/pg_proc.dat          | 15 +++++
 4 files changed, 146 insertions(+)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24447c0017..5e7eb76023 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -27417,6 +27417,78 @@ SELECT convert_from(pg_read_binary_file('file_in_utf8.txt'), 'UTF8');
         can be granted EXECUTE to run the function.
        </para></entry>
       </row>
+
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_ls_logicalsnapdir</primary>
+        </indexterm>
+        <function>pg_ls_logicalsnapdir</function> ()
+        <returnvalue>setof record</returnvalue>
+        ( <parameter>name</parameter> <type>text</type>,
+        <parameter>size</parameter> <type>bigint</type>,
+        <parameter>modification</parameter> <type>timestamp with time zone</type> )
+       </para>
+       <para>
+        Returns the name, size, and last modification time (mtime) of each
+        ordinary file in the server's pg_logical/snapshots directory.
+        Filenames beginning with a dot, directories, and other special files
+        are excluded.
+       </para>
+       <para>
+        This function is restricted to superusers and members of
+        the <literal>pg_monitor</literal> role by default, but other users can
+        be granted EXECUTE to run the function.
+       </para></entry>
+      </row>
+
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_ls_logicalmapdir</primary>
+        </indexterm>
+        <function>pg_ls_logicalmapdir</function> ()
+        <returnvalue>setof record</returnvalue>
+        ( <parameter>name</parameter> <type>text</type>,
+        <parameter>size</parameter> <type>bigint</type>,
+        <parameter>modification</parameter> <type>timestamp with time zone</type> )
+       </para>
+       <para>
+        Returns the name, size, and last modification time (mtime) of each
+        ordinary file in the server's pg_logical/mappings directory.
+        Filenames beginning with a dot, directories, and other special files
+        are excluded.
+       </para>
+       <para>
+        This function is restricted to superusers and members of
+        the <literal>pg_monitor</literal> role by default, but other users can
+        be granted EXECUTE to run the function.
+       </para></entry>
+      </row>
+
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_ls_replslotdir</primary>
+        </indexterm>
+        <function>pg_ls_replslotdir</function> ( <parameter>slot_name</parameter> <type>text</type> )
+        <returnvalue>setof record</returnvalue>
+        ( <parameter>name</parameter> <type>text</type>,
+        <parameter>size</parameter> <type>bigint</type>,
+        <parameter>modification</parameter> <type>timestamp with time zone</type> )
+       </para>
+       <para>
+        Returns the name, size, and last modification time (mtime) of each
+        ordinary file in the server's pg_replslot/<parameter>slot_name</parameter> directory.
+        Filenames beginning with a dot, directories, and other special files
+        are excluded.
+       </para>
+       <para>
+        This function is restricted to superusers and members of
+        the <literal>pg_monitor</literal> role by default, but other users can
+        be granted EXECUTE to run the function.
+       </para></entry>
+      </row>
      </tbody>
     </tgroup>
    </table>
diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql
index 54c93b16c4..f6789025a5 100644
--- a/src/backend/catalog/system_functions.sql
+++ b/src/backend/catalog/system_functions.sql
@@ -701,6 +701,12 @@ REVOKE EXECUTE ON FUNCTION pg_ls_dir(text,boolean,boolean) FROM public;
 
 REVOKE EXECUTE ON FUNCTION pg_log_backend_memory_contexts(integer) FROM PUBLIC;
 
+REVOKE EXECUTE ON FUNCTION pg_ls_logicalsnapdir() FROM PUBLIC;
+
+REVOKE EXECUTE ON FUNCTION pg_ls_logicalmapdir() FROM PUBLIC;
+
+REVOKE EXECUTE ON FUNCTION pg_ls_replslotdir(text) FROM PUBLIC;
+
 --
 -- We also set up some things as accessible to standard roles.
 --
@@ -715,6 +721,12 @@ GRANT EXECUTE ON FUNCTION pg_ls_tmpdir() TO pg_monitor;
 
 GRANT EXECUTE ON FUNCTION pg_ls_tmpdir(oid) TO pg_monitor;
 
+GRANT EXECUTE ON FUNCTION pg_ls_logicalsnapdir() TO pg_monitor;
+
+GRANT EXECUTE ON FUNCTION pg_ls_logicalmapdir() TO pg_monitor;
+
+GRANT EXECUTE ON FUNCTION pg_ls_replslotdir(text) TO pg_monitor;
+
 GRANT pg_read_all_settings TO pg_monitor;
 
 GRANT pg_read_all_stats TO pg_monitor;
diff --git a/src/backend/utils/adt/genfile.c b/src/backend/utils/adt/genfile.c
index c436d9318b..04666589d3 100644
--- a/src/backend/utils/adt/genfile.c
+++ b/src/backend/utils/adt/genfile.c
@@ -29,6 +29,7 @@
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
 #include "postmaster/syslogger.h"
+#include "replication/slot.h"
 #include "storage/fd.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
@@ -720,3 +721,49 @@ pg_ls_archive_statusdir(PG_FUNCTION_ARGS)
 {
 	return pg_ls_dir_files(fcinfo, XLOGDIR "/archive_status", true);
 }
+
+/*
+ * Function to return the list of files in the pg_logical/snapshots directory.
+ */
+Datum
+pg_ls_logicalsnapdir(PG_FUNCTION_ARGS)
+{
+	return pg_ls_dir_files(fcinfo, "pg_logical/snapshots", false);
+}
+
+/*
+ * Function to return the list of files in the pg_logical/mappings directory.
+ */
+Datum
+pg_ls_logicalmapdir(PG_FUNCTION_ARGS)
+{
+	return pg_ls_dir_files(fcinfo, "pg_logical/mappings", false);
+}
+
+/*
+ * Function to return the list of files in the pg_replslot/<replication_slot>
+ * directory.
+ */
+Datum
+pg_ls_replslotdir(PG_FUNCTION_ARGS)
+{
+	text	   *slotname_t;
+	char		path[MAXPGPATH];
+	char	   *slotname;
+	ReplicationSlot *slot;
+
+	slotname_t = PG_GETARG_TEXT_PP(0);
+
+	slotname = text_to_cstring(slotname_t);
+
+	slot = SearchNamedReplicationSlot(slotname, true);
+
+	if (!slot)
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("replication slot \"%s\" does not exist",
+						slotname)));
+
+	snprintf(path, sizeof(path), "%s/%s", "pg_replslot", slotname);
+	return pg_ls_dir_files(fcinfo, path, false);
+}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 6412f369f1..509b9824fd 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11623,6 +11623,21 @@
   proallargtypes => '{oid,text,int8,timestamptz}', proargmodes => '{i,o,o,o}',
   proargnames => '{tablespace,name,size,modification}',
   prosrc => 'pg_ls_tmpdir_1arg' },
+{ oid => '4642', descr => 'list of files in the pg_logical/snapshots directory',
+  proname => 'pg_ls_logicalsnapdir', procost => '10', prorows => '20', proretset => 't',
+  provolatile => 'v', prorettype => 'record', proargtypes => '',
+  proallargtypes => '{text,int8,timestamptz}', proargmodes => '{o,o,o}',
+  proargnames => '{name,size,modification}', prosrc => 'pg_ls_logicalsnapdir' },
+{ oid => '4643', descr => 'list of files in the pg_logical/mappings directory',
+  proname => 'pg_ls_logicalmapdir', procost => '10', prorows => '20', proretset => 't',
+  provolatile => 'v', prorettype => 'record', proargtypes => '',
+  proallargtypes => '{text,int8,timestamptz}', proargmodes => '{o,o,o}',
+  proargnames => '{name,size,modification}', prosrc => 'pg_ls_logicalmapdir' },
+{ oid => '4644', descr => 'list of files in the pg_logical/mappings directory',
+  proname => 'pg_ls_replslotdir', procost => '10', prorows => '20', proretset => 't',
+  provolatile => 'v', prorettype => 'record', proargtypes => 'text',
+  proallargtypes => '{text,text,int8,timestamptz}', proargmodes => '{i,o,o,o}',
+  proargnames => '{slot_name,name,size,modification}', prosrc => 'pg_ls_replslotdir' },
 
 # hash partitioning constraint function
 { oid => '5028', descr => 'hash partition CHECK constraint',
-- 
2.25.1

From 73f756b9b961588c4dbd732cc4fc0493e8e0f2a3 Mon Sep 17 00:00:00 2001
From: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Date: Sun, 21 Nov 2021 03:13:18 +0000
Subject: [PATCH v3] Add pg_ls_logicalsnapdir, pg_ls_logicalmapdir,
 pg_ls_replslotdir functions

These functions lists the contents of the respective directories,
and are intended to be used by monitoring tools.  Unlike pg_ls_dir(),
access to it can be granted to non-superusers so that those monitoring
tools can observe the principle of least privilege.  Access is also
given by default to members of pg_monitor.

Note: Bump the CATALOG_VERSION_NO
---
 doc/src/sgml/func.sgml                       | 73 ++++++++++++++++++++
 src/backend/catalog/system_functions.sql     | 12 ++++
 src/backend/utils/adt/genfile.c              | 47 +++++++++++++
 src/include/catalog/pg_proc.dat              | 15 ++++
 src/test/regress/expected/misc_functions.out | 65 +++++++++++++++++
 src/test/regress/sql/misc_functions.sql      | 31 +++++++++
 6 files changed, 243 insertions(+)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24447c0017..5e2a7753a5 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -27417,6 +27417,79 @@ SELECT convert_from(pg_read_binary_file('file_in_utf8.txt'), 'UTF8');
         can be granted EXECUTE to run the function.
        </para></entry>
       </row>
+
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_ls_logicalsnapdir</primary>
+        </indexterm>
+        <function>pg_ls_logicalsnapdir</function> ()
+        <returnvalue>setof record</returnvalue>
+        ( <parameter>name</parameter> <type>text</type>,
+        <parameter>size</parameter> <type>bigint</type>,
+        <parameter>modification</parameter> <type>timestamp with time zone</type> )
+       </para>
+       <para>
+        Returns the name, size, and last modification time (mtime) of each
+        ordinary file in the server's <filename>pg_logical/snapshots</filename>
+        directory. Filenames beginning with a dot, directories, and other
+        special files are excluded.
+       </para>
+       <para>
+        This function is restricted to superusers and members of
+        the <literal>pg_monitor</literal> role by default, but other users can
+        be granted EXECUTE to run the function.
+       </para></entry>
+      </row>
+
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_ls_logicalmapdir</primary>
+        </indexterm>
+        <function>pg_ls_logicalmapdir</function> ()
+        <returnvalue>setof record</returnvalue>
+        ( <parameter>name</parameter> <type>text</type>,
+        <parameter>size</parameter> <type>bigint</type>,
+        <parameter>modification</parameter> <type>timestamp with time zone</type> )
+       </para>
+       <para>
+        Returns the name, size, and last modification time (mtime) of each
+        ordinary file in the server's <filename>pg_logical/mappings</filename>
+        directory. Filenames beginning with a dot, directories, and other
+        special files are excluded.
+       </para>
+       <para>
+        This function is restricted to superusers and members of
+        the <literal>pg_monitor</literal> role by default, but other users can
+        be granted EXECUTE to run the function.
+       </para></entry>
+      </row>
+
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_ls_replslotdir</primary>
+        </indexterm>
+        <function>pg_ls_replslotdir</function> ( <parameter>slot_name</parameter> <type>text</type> )
+        <returnvalue>setof record</returnvalue>
+        ( <parameter>name</parameter> <type>text</type>,
+        <parameter>size</parameter> <type>bigint</type>,
+        <parameter>modification</parameter> <type>timestamp with time zone</type> )
+       </para>
+       <para>
+        Returns the name, size, and last modification time (mtime) of each
+        ordinary file in the server's <filename>pg_replslot/slot_name</filename>
+        (where <parameter>slot_name</parameter> is name of the replication slot
+        provided as an input to the function) directory. Filenames beginning
+        with a dot, directories, and other special files are excluded.
+       </para>
+       <para>
+        This function is restricted to superusers and members of
+        the <literal>pg_monitor</literal> role by default, but other users can
+        be granted EXECUTE to run the function.
+       </para></entry>
+      </row>
      </tbody>
     </tgroup>
    </table>
diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql
index 54c93b16c4..f6789025a5 100644
--- a/src/backend/catalog/system_functions.sql
+++ b/src/backend/catalog/system_functions.sql
@@ -701,6 +701,12 @@ REVOKE EXECUTE ON FUNCTION pg_ls_dir(text,boolean,boolean) FROM public;
 
 REVOKE EXECUTE ON FUNCTION pg_log_backend_memory_contexts(integer) FROM PUBLIC;
 
+REVOKE EXECUTE ON FUNCTION pg_ls_logicalsnapdir() FROM PUBLIC;
+
+REVOKE EXECUTE ON FUNCTION pg_ls_logicalmapdir() FROM PUBLIC;
+
+REVOKE EXECUTE ON FUNCTION pg_ls_replslotdir(text) FROM PUBLIC;
+
 --
 -- We also set up some things as accessible to standard roles.
 --
@@ -715,6 +721,12 @@ GRANT EXECUTE ON FUNCTION pg_ls_tmpdir() TO pg_monitor;
 
 GRANT EXECUTE ON FUNCTION pg_ls_tmpdir(oid) TO pg_monitor;
 
+GRANT EXECUTE ON FUNCTION pg_ls_logicalsnapdir() TO pg_monitor;
+
+GRANT EXECUTE ON FUNCTION pg_ls_logicalmapdir() TO pg_monitor;
+
+GRANT EXECUTE ON FUNCTION pg_ls_replslotdir(text) TO pg_monitor;
+
 GRANT pg_read_all_settings TO pg_monitor;
 
 GRANT pg_read_all_stats TO pg_monitor;
diff --git a/src/backend/utils/adt/genfile.c b/src/backend/utils/adt/genfile.c
index c436d9318b..6805a00d2c 100644
--- a/src/backend/utils/adt/genfile.c
+++ b/src/backend/utils/adt/genfile.c
@@ -29,6 +29,7 @@
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
 #include "postmaster/syslogger.h"
+#include "replication/slot.h"
 #include "storage/fd.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
@@ -720,3 +721,49 @@ pg_ls_archive_statusdir(PG_FUNCTION_ARGS)
 {
 	return pg_ls_dir_files(fcinfo, XLOGDIR "/archive_status", true);
 }
+
+/*
+ * Function to return the list of files in the pg_logical/snapshots directory.
+ */
+Datum
+pg_ls_logicalsnapdir(PG_FUNCTION_ARGS)
+{
+	return pg_ls_dir_files(fcinfo, "pg_logical/snapshots", false);
+}
+
+/*
+ * Function to return the list of files in the pg_logical/mappings directory.
+ */
+Datum
+pg_ls_logicalmapdir(PG_FUNCTION_ARGS)
+{
+	return pg_ls_dir_files(fcinfo, "pg_logical/mappings", false);
+}
+
+/*
+ * Function to return the list of files in the pg_replslot/<replication_slot>
+ * directory.
+ */
+Datum
+pg_ls_replslotdir(PG_FUNCTION_ARGS)
+{
+	text	   *slotname_t;
+	char		path[MAXPGPATH];
+	char	   *slotname;
+	ReplicationSlot *slot;
+
+	slotname_t = PG_GETARG_TEXT_PP(0);
+
+	slotname = text_to_cstring(slotname_t);
+
+	slot = SearchNamedReplicationSlot(slotname, true);
+
+	if (!slot)
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("replication slot \"%s\" does not exist",
+						slotname)));
+
+	snprintf(path, sizeof(path), "pg_replslot/%s", slotname);
+	return pg_ls_dir_files(fcinfo, path, false);
+}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 6412f369f1..509b9824fd 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11623,6 +11623,21 @@
   proallargtypes => '{oid,text,int8,timestamptz}', proargmodes => '{i,o,o,o}',
   proargnames => '{tablespace,name,size,modification}',
   prosrc => 'pg_ls_tmpdir_1arg' },
+{ oid => '4642', descr => 'list of files in the pg_logical/snapshots directory',
+  proname => 'pg_ls_logicalsnapdir', procost => '10', prorows => '20', proretset => 't',
+  provolatile => 'v', prorettype => 'record', proargtypes => '',
+  proallargtypes => '{text,int8,timestamptz}', proargmodes => '{o,o,o}',
+  proargnames => '{name,size,modification}', prosrc => 'pg_ls_logicalsnapdir' },
+{ oid => '4643', descr => 'list of files in the pg_logical/mappings directory',
+  proname => 'pg_ls_logicalmapdir', procost => '10', prorows => '20', proretset => 't',
+  provolatile => 'v', prorettype => 'record', proargtypes => '',
+  proallargtypes => '{text,int8,timestamptz}', proargmodes => '{o,o,o}',
+  proargnames => '{name,size,modification}', prosrc => 'pg_ls_logicalmapdir' },
+{ oid => '4644', descr => 'list of files in the pg_logical/mappings directory',
+  proname => 'pg_ls_replslotdir', procost => '10', prorows => '20', proretset => 't',
+  provolatile => 'v', prorettype => 'record', proargtypes => 'text',
+  proallargtypes => '{text,text,int8,timestamptz}', proargmodes => '{i,o,o,o}',
+  proargnames => '{slot_name,name,size,modification}', prosrc => 'pg_ls_replslotdir' },
 
 # hash partitioning constraint function
 { oid => '5028', descr => 'hash partition CHECK constraint',
diff --git a/src/test/regress/expected/misc_functions.out b/src/test/regress/expected/misc_functions.out
index 71d316cad3..dbe9e57ddb 100644
--- a/src/test/regress/expected/misc_functions.out
+++ b/src/test/regress/expected/misc_functions.out
@@ -243,6 +243,71 @@ select count(*) > 0 from
  t
 (1 row)
 
+--
+-- Test replication slot directory functions
+--
+-- The outputs of these are variable, so we can't just print their results
+-- directly, but we can at least verify that the code doesn't fail, and that
+-- the permissions are set properly.
+--
+CREATE ROLE regress_slot_dir_funcs;
+SELECT has_function_privilege('regress_slot_dir_funcs',
+  'pg_ls_logicalsnapdir()', 'EXECUTE'); -- no
+ has_function_privilege 
+------------------------
+ f
+(1 row)
+
+SELECT has_function_privilege('regress_slot_dir_funcs',
+  'pg_ls_logicalmapdir()', 'EXECUTE'); -- no
+ has_function_privilege 
+------------------------
+ f
+(1 row)
+
+SELECT has_function_privilege('regress_slot_dir_funcs',
+  'pg_ls_replslotdir(text)', 'EXECUTE'); -- no
+ has_function_privilege 
+------------------------
+ f
+(1 row)
+
+GRANT pg_monitor TO regress_slot_dir_funcs;
+SELECT 'init' FROM pg_create_physical_replication_slot('slot_dir_funcs');
+ ?column? 
+----------
+ init
+(1 row)
+
+SET ROLE regress_slot_dir_funcs;
+SELECT COUNT(*) >= 0 AS OK FROM pg_ls_logicalsnapdir();
+ ok 
+----
+ t
+(1 row)
+
+SELECT COUNT(*) >= 0 AS OK FROM pg_ls_logicalmapdir();
+ ok 
+----
+ t
+(1 row)
+
+SELECT COUNT(*) >= 0 AS OK FROM pg_ls_replslotdir('slot_dir_funcs');
+ ok 
+----
+ t
+(1 row)
+
+SELECT pg_ls_replslotdir('non_existent_slot'); -- ERROR
+ERROR:  replication slot "non_existent_slot" does not exist
+RESET ROLE;
+SELECT pg_drop_replication_slot('slot_dir_funcs');
+ pg_drop_replication_slot 
+--------------------------
+ 
+(1 row)
+
+DROP ROLE regress_slot_dir_funcs;
 --
 -- Test adding a support function to a subject function
 --
diff --git a/src/test/regress/sql/misc_functions.sql b/src/test/regress/sql/misc_functions.sql
index 8c23874b3f..c47d013624 100644
--- a/src/test/regress/sql/misc_functions.sql
+++ b/src/test/regress/sql/misc_functions.sql
@@ -91,6 +91,37 @@ select count(*) > 0 from
    where spcname = 'pg_default') pts
   join pg_database db on pts.pts = db.oid;
 
+--
+-- Test replication slot directory functions
+--
+-- The outputs of these are variable, so we can't just print their results
+-- directly, but we can at least verify that the code doesn't fail, and that
+-- the permissions are set properly.
+--
+
+CREATE ROLE regress_slot_dir_funcs;
+
+SELECT has_function_privilege('regress_slot_dir_funcs',
+  'pg_ls_logicalsnapdir()', 'EXECUTE'); -- no
+SELECT has_function_privilege('regress_slot_dir_funcs',
+  'pg_ls_logicalmapdir()', 'EXECUTE'); -- no
+SELECT has_function_privilege('regress_slot_dir_funcs',
+  'pg_ls_replslotdir(text)', 'EXECUTE'); -- no
+
+GRANT pg_monitor TO regress_slot_dir_funcs;
+
+SELECT 'init' FROM pg_create_physical_replication_slot('slot_dir_funcs');
+
+SET ROLE regress_slot_dir_funcs;
+SELECT COUNT(*) >= 0 AS OK FROM pg_ls_logicalsnapdir();
+SELECT COUNT(*) >= 0 AS OK FROM pg_ls_logicalmapdir();
+SELECT COUNT(*) >= 0 AS OK FROM pg_ls_replslotdir('slot_dir_funcs');
+SELECT pg_ls_replslotdir('non_existent_slot'); -- ERROR
+RESET ROLE;
+
+SELECT pg_drop_replication_slot('slot_dir_funcs');
+DROP ROLE regress_slot_dir_funcs;
+
 --
 -- Test adding a support function to a subject function
 --
-- 
2.25.1