Fix pg_rewind with in-place tablespaces when source is remote

libpq_source.c would consider any result returned by
pg_tablespace_location() as a symlink, resulting in run-time errors like
that:
pg_rewind: error: file "pg_tblspc/NN" is of different type in source and target

In-place tablespaces are directories located in pg_tblspc/, returned as
relative paths instead of absolute paths, so rely on that to make the
difference with a normal tablespace and an in-place one.  If the path is
relative, the tablespace is handled as a directory.  If the path is
absolute, consider it as a symlink.

In-place tablespaces are only intended for development purposes, so like
363e8f9 no backpatch is done.  A test is added in pg_rewind with an
in-place tablespace and some data in it.

Author: Rui Zhao, Michael Paquier
Discussion: https://postgr.es/m/2b79d2a8-b2d5-4bd7-a15b-31e485100980.xiyuan.zr@alibaba-inc.com

1 files changed, 20 insertions, 0 deletions

diff --git a/src/bin/pg_rewind/t/001_basic.pl b/src/bin/pg_rewind/t/001_basic.pl
index 031594e14e6..c7b48255a71 100644
--- a/src/bin/pg_rewind/t/001_basic.pl
+++ b/src/bin/pg_rewind/t/001_basic.pl
@@ -18,6 +18,12 @@ sub run_test
 	RewindTest::setup_cluster($test_mode);
 	RewindTest::start_primary();
 
+	# Create an in-place tablespace with some data on it.
+	primary_psql("CREATE TABLESPACE space_test LOCATION ''");
+	primary_psql("CREATE TABLE space_tbl (d text) TABLESPACE space_test");
+	primary_psql(
+		"INSERT INTO space_tbl VALUES ('in primary, before promotion')");
+
 	# Create a test table and insert a row in primary.
 	primary_psql("CREATE TABLE tbl1 (d text)");
 	primary_psql("INSERT INTO tbl1 VALUES ('in primary')");
@@ -78,6 +84,13 @@ sub run_test
 		"insert into drop_tbl values ('in primary, after promotion')");
 	primary_psql("DROP TABLE drop_tbl");
 
+	# Insert some data in the in-place tablespace for the old primary and
+	# the standby.
+	primary_psql(
+		"INSERT INTO space_tbl VALUES ('in primary, after promotion')");
+	standby_psql(
+		"INSERT INTO space_tbl VALUES ('in standby, after promotion')");
+
 	# Before running pg_rewind, do a couple of extra tests with several
 	# option combinations.  As the code paths taken by those tests
 	# do not change for the "local" and "remote" modes, just run them
@@ -146,6 +159,13 @@ sub run_test
 	RewindTest::run_pg_rewind($test_mode);
 
 	check_query(
+		'SELECT * FROM space_tbl ORDER BY d',
+		qq(in primary, before promotion
+in standby, after promotion
+),
+		'table content');
+
+	check_query(
 		'SELECT * FROM tbl1',
 		qq(in primary
 in primary, before promotion