On 13.09.23 16:36, Aleksander Alekseev wrote:
All in all the patch looks OK but I have a couple of nitpicks.
```
+ working on a data directory in an unclean shutdown state or with a corrupt
+ control file.
```
```
+ After running this command on a data directory with corrupted WAL or a
+ corrupt control file,
```
I'm not a native English speaker but shouldn't it be "corruptED control file"?
fixed
```
+ Force <command>pg_resetwal</command> to proceed even in situations where
+ it could be dangerous,
```
"where" is probably fine but wouldn't "WHEN it could be dangerous" be better?
Hmm, I think I like "where" better.
Attached is an updated patch set where I have split the changes into
smaller pieces. The last two patches still have some open questions
about what certain constants mean etc. The other patches should be settled.
From 0922727410313e37c1ffaad4f6fbf90f9990923b Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pe...@eisentraut.org>
Date: Tue, 19 Sep 2023 15:54:37 +0200
Subject: [PATCH v2 1/7] pg_resetwal: Update an obsolete comment
---
src/bin/pg_resetwal/pg_resetwal.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/src/bin/pg_resetwal/pg_resetwal.c
b/src/bin/pg_resetwal/pg_resetwal.c
index 25ecdaaa15..b7885e34f3 100644
--- a/src/bin/pg_resetwal/pg_resetwal.c
+++ b/src/bin/pg_resetwal/pg_resetwal.c
@@ -6,8 +6,7 @@
*
* The theory of operation is fairly simple:
* 1. Read the existing pg_control (which will include the last
- * checkpoint record). If it is an old format then update to
- * current format.
+ * checkpoint record).
* 2. If pg_control is corrupt, attempt to intuit reasonable values,
* by scanning the old xlog if necessary.
* 3. Modify pg_control to reflect a "shutdown" state with a checkpoint
base-commit: bf094372d14bf00f1c04f70f6ec5790f8b2c8801
--
2.42.0
From 8fee9806bfa94fc999e730d3fb55946c656e6c64 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pe...@eisentraut.org>
Date: Tue, 19 Sep 2023 15:58:49 +0200
Subject: [PATCH v2 2/7] pg_resetwal: Improve error with wrong/missing data
directory
Run chdir() before permission check to get a less confusing error
message if the specified data directory does not exist.
---
src/bin/pg_resetwal/pg_resetwal.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/src/bin/pg_resetwal/pg_resetwal.c
b/src/bin/pg_resetwal/pg_resetwal.c
index b7885e34f3..e344c9284d 100644
--- a/src/bin/pg_resetwal/pg_resetwal.c
+++ b/src/bin/pg_resetwal/pg_resetwal.c
@@ -345,6 +345,10 @@ main(int argc, char *argv[])
get_restricted_token();
+ if (chdir(DataDir) < 0)
+ pg_fatal("could not change directory to \"%s\": %m",
+ DataDir);
+
/* Set mask based on PGDATA permissions */
if (!GetDataDirectoryCreatePerm(DataDir))
pg_fatal("could not read permissions of directory \"%s\": %m",
@@ -352,10 +356,6 @@ main(int argc, char *argv[])
umask(pg_mode_mask);
- if (chdir(DataDir) < 0)
- pg_fatal("could not change directory to \"%s\": %m",
- DataDir);
-
/* Check that data directory matches our server version */
CheckDataVersion();
--
2.42.0
From 241dc252f314ee32ebf853f236a17029ec477d50 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pe...@eisentraut.org>
Date: Tue, 19 Sep 2023 16:02:35 +0200
Subject: [PATCH v2 3/7] pg_resetwal: Regroup --help output
Put the options to modify the control values into a separate group.
This matches the outline of the man page.
---
src/bin/pg_resetwal/pg_resetwal.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)
diff --git a/src/bin/pg_resetwal/pg_resetwal.c
b/src/bin/pg_resetwal/pg_resetwal.c
index e344c9284d..12e0869251 100644
--- a/src/bin/pg_resetwal/pg_resetwal.c
+++ b/src/bin/pg_resetwal/pg_resetwal.c
@@ -1128,24 +1128,29 @@ static void
usage(void)
{
printf(_("%s resets the PostgreSQL write-ahead log.\n\n"), progname);
- printf(_("Usage:\n %s [OPTION]... DATADIR\n\n"), progname);
- printf(_("Options:\n"));
+ printf(_("Usage:\n"));
+ printf(_(" %s [OPTION]... DATADIR\n"), progname);
+
+ printf(_("\nOptions:\n"));
+ printf(_(" [-D, --pgdata=]DATADIR data directory\n"));
+ printf(_(" -f, --force force update to be done\n"));
+ printf(_(" -n, --dry-run no update, just show what would be
done\n"));
+ printf(_(" -V, --version output version information, then
exit\n"));
+ printf(_(" -?, --help show this help, then exit\n"));
+
+ printf(_("\nOptions to override control file values:\n"));
printf(_(" -c, --commit-timestamp-ids=XID,XID\n"
" set oldest and
newest transactions bearing\n"
" commit timestamp
(zero means no change)\n"));
- printf(_(" [-D, --pgdata=]DATADIR data directory\n"));
printf(_(" -e, --epoch=XIDEPOCH set next transaction ID
epoch\n"));
- printf(_(" -f, --force force update to be
done\n"));
printf(_(" -l, --next-wal-file=WALFILE set minimum starting
location for new WAL\n"));
printf(_(" -m, --multixact-ids=MXID,MXID set next and oldest
multitransaction ID\n"));
- printf(_(" -n, --dry-run no update, just show what
would be done\n"));
printf(_(" -o, --next-oid=OID set next OID\n"));
printf(_(" -O, --multixact-offset=OFFSET set next multitransaction
offset\n"));
printf(_(" -u, --oldest-transaction-id=XID set oldest transaction
ID\n"));
- printf(_(" -V, --version output version
information, then exit\n"));
printf(_(" -x, --next-transaction-id=XID set next transaction
ID\n"));
printf(_(" --wal-segsize=SIZE size of WAL segments, in
megabytes\n"));
- printf(_(" -?, --help show this help, then
exit\n"));
+
printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
}
--
2.42.0
From ff81acdd646c64efcae8b6cf083daff0494f6f82 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pe...@eisentraut.org>
Date: Tue, 19 Sep 2023 16:06:22 +0200
Subject: [PATCH v2 4/7] pg_resetwal: Use frontend logging API
This now causes error messages related to the lack of the -f option to
appear on standard error rather than standard output.
---
src/bin/pg_resetwal/pg_resetwal.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)
diff --git a/src/bin/pg_resetwal/pg_resetwal.c
b/src/bin/pg_resetwal/pg_resetwal.c
index 12e0869251..35876e1c95 100644
--- a/src/bin/pg_resetwal/pg_resetwal.c
+++ b/src/bin/pg_resetwal/pg_resetwal.c
@@ -458,20 +458,22 @@ main(int argc, char *argv[])
if (minXlogSegNo > newXlogSegNo)
newXlogSegNo = minXlogSegNo;
+ if (noupdate)
+ {
+ PrintNewControlValues();
+ exit(0);
+ }
+
/*
* If we had to guess anything, and -f was not given, just print the
- * guessed values and exit. Also print if -n is given.
+ * guessed values and exit.
*/
- if ((guessed && !force) || noupdate)
+ if (guessed && !force)
{
PrintNewControlValues();
- if (!noupdate)
- {
- printf(_("\nIf these values seem acceptable, use -f to
force reset.\n"));
- exit(1);
- }
- else
- exit(0);
+ pg_log_error("not proceeding because control file values were
guessed");
+ pg_log_error_hint("If these values seem acceptable, use -f to
force reset.");
+ exit(1);
}
/*
@@ -479,9 +481,9 @@ main(int argc, char *argv[])
*/
if (ControlFile.state != DB_SHUTDOWNED && !force)
{
- printf(_("The database server was not shut down cleanly.\n"
- "Resetting the write-ahead log might cause
data to be lost.\n"
- "If you want to proceed anyway, use -f to
force reset.\n"));
+ pg_log_error("database server was not shut down cleanly");
+ pg_log_error_detail("Resetting the write-ahead log might cause
data to be lost.");
+ pg_log_error_hint("If you want to proceed anyway, use -f to
force reset.");
exit(1);
}
--
2.42.0
From fda162ae9864b121c386e07fabed520de089a3f5 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pe...@eisentraut.org>
Date: Tue, 19 Sep 2023 16:09:32 +0200
Subject: [PATCH v2 5/7] doc: Improve documentation about pg_resetwal -f option
---
doc/src/sgml/ref/pg_resetwal.sgml | 62 +++++++++++++++++++++++++------
src/bin/pg_resetwal/pg_resetwal.c | 3 +-
2 files changed, 53 insertions(+), 12 deletions(-)
diff --git a/doc/src/sgml/ref/pg_resetwal.sgml
b/doc/src/sgml/ref/pg_resetwal.sgml
index fd539f5604..1f9c4b69dd 100644
--- a/doc/src/sgml/ref/pg_resetwal.sgml
+++ b/doc/src/sgml/ref/pg_resetwal.sgml
@@ -52,21 +52,33 @@ <title>Description</title>
</para>
<para>
- After running this command, it should be possible to start the server,
+ Some options, such as <option>--wal-segsize</option> (see below), can also
+ be used to modify certain global settings of a database cluster without the
+ need to rerun <command>initdb</command>. This can be done safely on an
+ otherwise sound database cluster, if none of the dangerous modes mentioned
+ below are used.
+ </para>
+
+ <para>
+ If <command>pg_resetwal</command> is used on a data directory where the
+ server has been cleanly shut down and the control file is sound, then it
+ will have no effect on the contents of the database system, except that no
+ longer used WAL files are cleared away. Any other use is potentially
+ dangerous and must be done with great care. <command>pg_resetwal</command>
+ will require the <option>-f</option> (force) option to be specified before
+ working on a data directory in an unclean shutdown state or with a
+ corrupted control file.
+ </para>
+
+ <para>
+ After running this command on a data directory with corrupted WAL or a
+ corrupted control file, it should be possible to start the server,
but bear in mind that the database might contain inconsistent data due to
partially-committed transactions. You should immediately dump your data,
run <command>initdb</command>, and restore. After restore, check for
inconsistencies and repair as needed.
</para>
- <para>
- This utility can only be run by the user who installed the server, because
- it requires read/write access to the data directory.
- For safety reasons, you must specify the data directory on the command line.
- <command>pg_resetwal</command> does not use the environment variable
- <envar>PGDATA</envar>.
- </para>
-
<para>
If <command>pg_resetwal</command> complains that it cannot determine
valid data for <filename>pg_control</filename>, you can force it to proceed
anyway
@@ -82,19 +94,41 @@ <title>Description</title>
execute any data-modifying operations in the database before you dump,
as any such action is likely to make the corruption worse.
</para>
+
+ <para>
+ This utility can only be run by the user who installed the server, because
+ it requires read/write access to the data directory.
+ </para>
</refsect1>
<refsect1>
<title>Options</title>
<variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">datadir</replaceable></term>
+ <term><option>-D <replaceable
class="parameter">datadir</replaceable></option></term>
+ <term><option>--pgdata=<replaceable
class="parameter">datadir</replaceable></option></term>
+ <listitem>
+ <para>
+ Specifies the location of the database directory.
+ For safety reasons, you must specify the data directory on the command
+ line. <command>pg_resetwal</command> does not use the environment
+ variable <envar>PGDATA</envar>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>-f</option></term>
<term><option>--force</option></term>
<listitem>
<para>
- Force <command>pg_resetwal</command> to proceed even if it cannot
determine
- valid data for <filename>pg_control</filename>, as explained above.
+ Force <command>pg_resetwal</command> to proceed even in situations where
+ it could be dangerous, as explained above. Specifically, this option is
+ required to proceed if the server had not been cleanly shut down, or if
+ <command>pg_resetwal</command> cannot determine valid data for
+ <filename>pg_control</filename>.
</para>
</listitem>
</varlistentry>
@@ -284,6 +318,12 @@ <title>Options</title>
linkend="app-initdb"/> for more information.
</para>
+ <para>
+ This option can also be used to change the WAL segment size of an
+ existing database cluster, avoiding the need to
+ re-<command>initdb</command>.
+ </para>
+
<note>
<para>
While <command>pg_resetwal</command> will set the WAL starting address
diff --git a/src/bin/pg_resetwal/pg_resetwal.c
b/src/bin/pg_resetwal/pg_resetwal.c
index 35876e1c95..47e05bd2c9 100644
--- a/src/bin/pg_resetwal/pg_resetwal.c
+++ b/src/bin/pg_resetwal/pg_resetwal.c
@@ -1135,7 +1135,8 @@ usage(void)
printf(_("\nOptions:\n"));
printf(_(" [-D, --pgdata=]DATADIR data directory\n"));
- printf(_(" -f, --force force update to be done\n"));
+ printf(_(" -f, --force force update to be done even after
unclean shutdown or\n"
+ " if pg_control values had to
be guessed\n"));
printf(_(" -n, --dry-run no update, just show what would be
done\n"));
printf(_(" -V, --version output version information, then
exit\n"));
printf(_(" -?, --help show this help, then exit\n"));
--
2.42.0
From bc62da6173e029e1fd25d13bbbe648f008be6b68 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pe...@eisentraut.org>
Date: Tue, 19 Sep 2023 16:11:38 +0200
Subject: [PATCH v2 6/7] doc: pg_resetwal: Add comments how the multipliers are
derived
---
doc/src/sgml/ref/pg_resetwal.sgml | 8 +++++++-
src/bin/pg_resetwal/pg_resetwal.c | 1 +
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/doc/src/sgml/ref/pg_resetwal.sgml
b/doc/src/sgml/ref/pg_resetwal.sgml
index 1f9c4b69dd..8380f97c04 100644
--- a/doc/src/sgml/ref/pg_resetwal.sgml
+++ b/doc/src/sgml/ref/pg_resetwal.sgml
@@ -166,7 +166,8 @@ <title>Options</title>
<command>pg_resetwal</command> is unable to determine appropriate values
by reading <filename>pg_control</filename>. Safe values can be determined
as
described below. For values that take numeric arguments, hexadecimal
- values can be specified by using the prefix <literal>0x</literal>.
+ values can be specified by using the prefix <literal>0x</literal>. Note
+ that these instructions only apply with the standard block size of 8 kB.
</para>
<variablelist>
@@ -189,6 +190,7 @@ <title>Options</title>
greatest file name in the same directory. The file names are in
hexadecimal.
</para>
+ <!-- FIXME: multiplier? -->
</listitem>
</varlistentry>
@@ -272,6 +274,7 @@ <title>Options</title>
names are in hexadecimal, so the easiest way to do this is to specify
the option value in hexadecimal and append four zeroes.
</para>
+ <!-- 65536 = SLRU_PAGES_PER_SEGMENT * BLCKSZ / sizeof(MultiXactOffset) -->
</listitem>
</varlistentry>
@@ -306,6 +309,7 @@ <title>Options</title>
The file names are in hexadecimal. There is no simple recipe such as
the ones for other options of appending zeroes.
</para>
+ <!-- 52352 = SLRU_PAGES_PER_SEGMENT * floor(BLCKSZ/20) * 4; see
multixact.c -->
</listitem>
</varlistentry>
@@ -354,6 +358,7 @@ <title>Options</title>
in <filename>pg_xact</filename>, <literal>-u 0x700000</literal> will
work (five
trailing zeroes provide the proper multiplier).
</para>
+ <!-- 1048576 = SLRU_PAGES_PER_SEGMENT * BLCKSZ * CLOG_XACTS_PER_BYTE -->
</listitem>
</varlistentry>
@@ -375,6 +380,7 @@ <title>Options</title>
in <filename>pg_xact</filename>, <literal>-x 0x1200000</literal> will
work (five
trailing zeroes provide the proper multiplier).
</para>
+ <!-- 1048576 = SLRU_PAGES_PER_SEGMENT * BLCKSZ * CLOG_XACTS_PER_BYTE -->
</listitem>
</varlistentry>
</variablelist>
diff --git a/src/bin/pg_resetwal/pg_resetwal.c
b/src/bin/pg_resetwal/pg_resetwal.c
index 47e05bd2c9..89b35c2748 100644
--- a/src/bin/pg_resetwal/pg_resetwal.c
+++ b/src/bin/pg_resetwal/pg_resetwal.c
@@ -211,6 +211,7 @@ main(int argc, char *argv[])
exit(1);
}
+ // FIXME: why 2?
if (set_oldest_commit_ts_xid < 2 &&
set_oldest_commit_ts_xid != 0)
pg_fatal("transaction ID (-c) must be
either 0 or greater than or equal to 2");
--
2.42.0
From e3874416d63113668ac67cffd92765531a5df697 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pe...@eisentraut.org>
Date: Tue, 19 Sep 2023 16:12:52 +0200
Subject: [PATCH v2 7/7] pg_resetwal: Add more tests and test coverage
---
src/bin/pg_resetwal/t/001_basic.pl | 114 +++++++++++++++++++++++++
src/bin/pg_resetwal/t/002_corrupted.pl | 4 +
2 files changed, 118 insertions(+)
diff --git a/src/bin/pg_resetwal/t/001_basic.pl
b/src/bin/pg_resetwal/t/001_basic.pl
index 7e5efbf56b..001bb455ef 100644
--- a/src/bin/pg_resetwal/t/001_basic.pl
+++ b/src/bin/pg_resetwal/t/001_basic.pl
@@ -14,6 +14,7 @@
my $node = PostgreSQL::Test::Cluster->new('main');
$node->init;
+$node->append_conf('postgresql.conf', 'track_commit_timestamp = on');
command_like([ 'pg_resetwal', '-n', $node->data_dir ],
qr/checkpoint/, 'pg_resetwal -n produces output');
@@ -29,4 +30,117 @@
'check PGDATA permissions');
}
+command_ok([ 'pg_resetwal', '-D', $node->data_dir ], 'pg_resetwal runs');
+$node->start;
+is($node->safe_psql("postgres", "SELECT 1;"), 1, 'server running and working
after reset');
+
+command_fails_like([ 'pg_resetwal', $node->data_dir ], qr/lock file .*
exists/, 'fails if server running');
+
+$node->stop('immediate');
+command_fails_like([ 'pg_resetwal', $node->data_dir ], qr/database server was
not shut down cleanly/, 'does not run after immediate shutdown');
+command_ok([ 'pg_resetwal', '-f', $node->data_dir ], 'runs after immediate
shutdown with force');
+$node->start;
+is($node->safe_psql("postgres", "SELECT 1;"), 1, 'server running and working
after forced reset');
+
+$node->stop;
+
+# check various command-line handling
+
+command_fails_like([ 'pg_resetwal', 'foo' ], qr/error: could not change
directory/, 'fails with nonexistent data directory');
+command_fails_like([ 'pg_resetwal', 'foo', 'bar'], qr/too many command-line
arguments/, 'fails with too many command-line arguments');
+
+$ENV{PGDATA} = $node->data_dir; # not used
+command_fails_like([ 'pg_resetwal' ], qr/no data directory specified/, 'fails
with too few command-line arguments');
+
+# error cases
+# -c
+command_fails_like([ 'pg_resetwal', '-c', 'foo', $node->data_dir], qr/error:
invalid argument for option -c/, 'fails with incorrect -c option');
+command_fails_like([ 'pg_resetwal', '-c', '10,bar', $node->data_dir],
qr/error: invalid argument for option -c/, 'fails with incorrect -c option part
2');
+command_fails_like([ 'pg_resetwal', '-c', '1,10', $node->data_dir], qr/greater
than/, 'fails with -c value 1 part 1');
+command_fails_like([ 'pg_resetwal', '-c', '10,1', $node->data_dir], qr/greater
than/, 'fails with -c value 1 part 2');
+# -e
+command_fails_like([ 'pg_resetwal', '-e', 'foo', $node->data_dir], qr/error:
invalid argument for option -e/, 'fails with incorrect -e option');
+command_fails_like([ 'pg_resetwal', '-e', '-1', $node->data_dir], qr/must not
be -1/, 'fails with -e value -1');
+# -l
+command_fails_like([ 'pg_resetwal', '-l', 'foo', $node->data_dir], qr/error:
invalid argument for option -l/, 'fails with incorrect -l option');
+# -m
+command_fails_like([ 'pg_resetwal', '-m', 'foo', $node->data_dir], qr/error:
invalid argument for option -m/, 'fails with incorrect -m option');
+command_fails_like([ 'pg_resetwal', '-m', '10,bar', $node->data_dir],
qr/error: invalid argument for option -m/, 'fails with incorrect -m option part
2');
+command_fails_like([ 'pg_resetwal', '-m', '0,10', $node->data_dir], qr/must
not be 0/, 'fails with -m value 0 part 1');
+command_fails_like([ 'pg_resetwal', '-m', '10,0', $node->data_dir], qr/must
not be 0/, 'fails with -m value 0 part 2');
+# -o
+command_fails_like([ 'pg_resetwal', '-o', 'foo', $node->data_dir], qr/error:
invalid argument for option -o/, 'fails with incorrect -o option');
+command_fails_like([ 'pg_resetwal', '-o', '0', $node->data_dir], qr/must not
be 0/, 'fails with -o value 0');
+# -O
+command_fails_like([ 'pg_resetwal', '-O', 'foo', $node->data_dir], qr/error:
invalid argument for option -O/, 'fails with incorrect -O option');
+command_fails_like([ 'pg_resetwal', '-O', '-1', $node->data_dir], qr/must not
be -1/, 'fails with -O value -1');
+# --wal-segsize
+command_fails_like([ 'pg_resetwal', '--wal-segsize', 'foo', $node->data_dir],
qr/error: invalid value/, 'fails with incorrect --wal-segsize option');
+command_fails_like([ 'pg_resetwal', '--wal-segsize', '13', $node->data_dir],
qr/must be a power/, 'fails with invalid --wal-segsize value');
+# -u
+command_fails_like([ 'pg_resetwal', '-u', 'foo', $node->data_dir], qr/error:
invalid argument for option -u/, 'fails with incorrect -u option');
+command_fails_like([ 'pg_resetwal', '-u', '1', $node->data_dir], qr/must be
greater than/, 'fails with -u value too small');
+# -x
+command_fails_like([ 'pg_resetwal', '-x', 'foo', $node->data_dir], qr/error:
invalid argument for option -x/, 'fails with incorrect -x option');
+command_fails_like([ 'pg_resetwal', '-x', '1', $node->data_dir], qr/must be
greater than/, 'fails with -x value too small');
+
+# run with control override options
+
+my $out = (run_command([ 'pg_resetwal', '-n', $node->data_dir ]))[0];
+$out =~ /^Database block size: *(\d+)$/m or die;
+my $blcksz = $1;
+
+my @cmd = ('pg_resetwal', '-D', $node->data_dir);
+
+# some not-so-critical hardcoded values
+push @cmd, '-e', 1;
+push @cmd, '-l', '00000001000000320000004B';
+push @cmd, '-o', 100_000;
+push @cmd, '--wal-segsize', 1;
+
+# these use the guidance from the documentation
+
+sub get_slru_files
+{
+ opendir(my $dh, $node->data_dir . '/' . $_[0]) or die $!;
+ my @files = sort grep { /[0-9A-F]+/ } readdir $dh;
+ closedir $dh;
+ return @files;
+}
+
+my (@files, $mult);
+
+@files = get_slru_files('pg_commit_ts');
+$mult = 32 * $blcksz * 4; # FIXME
+# -c argument is "old,new"
+push @cmd,
+ '-c', sprintf("%d,%d",
+ hex($files[0]) == 0 ? 2 : hex($files[0]), hex($files[-1]));
+
+@files = get_slru_files('pg_multixact/offsets');
+$mult = 32 * $blcksz / 4;
+# -m argument is "new,old"
+push @cmd,
+ '-m', sprintf("%d,%d",
+ (hex($files[-1]) + 1) * $mult,
+ hex($files[0]) == 0 ? 1 : hex($files[0] * $mult));
+
+@files = get_slru_files('pg_multixact/members');
+$mult = 32 * int($blcksz/20) * 4;
+push @cmd,
+ '-O', (hex($files[-1]) + 1) * $mult;
+
+@files = get_slru_files('pg_xact');
+$mult = 32 * $blcksz * 4;
+push @cmd,
+ '-u', (hex($files[0]) == 0 ? 3 : hex($files[0]) * $mult),
+ '-x', ((hex($files[-1]) + 1) * $mult);
+
+command_ok([@cmd, '-n'], 'runs with control override options, dry run');
+command_ok(\@cmd, 'runs with control override options');
+command_like([ 'pg_resetwal', '-n', $node->data_dir ], qr/^Latest checkpoint's
NextOID: *100000$/m, 'spot check that control changes were applied');
+
+$node->start;
+ok(1, 'server started after reset');
+
done_testing();
diff --git a/src/bin/pg_resetwal/t/002_corrupted.pl
b/src/bin/pg_resetwal/t/002_corrupted.pl
index 6d19a1efd5..ddbd0556bb 100644
--- a/src/bin/pg_resetwal/t/002_corrupted.pl
+++ b/src/bin/pg_resetwal/t/002_corrupted.pl
@@ -55,4 +55,8 @@
],
'processes zero WAL segment size');
+# now try to run it
+command_fails_like([ 'pg_resetwal', $node->data_dir ], qr/not proceeding
because control file values were guessed/, 'does not run when control file
values were guessed');
+command_ok([ 'pg_resetwal', '-f', $node->data_dir ], 'runs with force when
control file values were guessed');
+
done_testing();
--
2.42.0
