On 11/10/2018 16:50, Peter Eisentraut wrote:
> On 10/10/2018 21:50, Bruce Momjian wrote:
>>> I see. Peter is proposing to have a fourth mode, essentially
>>> --transfer-mode=clone-or-copy.
>>
>> Uh, if you use --link, and the two data directories are on different
>> file systems, it fails. No one has ever asked for link-or-copy, so why
>> are we considering clone-or-copy? Are we going to need
>> link-or-clone-or-copy too? I do realize that clone and copy have
>> non-destructive behavior on the old cluster once started, so it does
>> make some sense to merge them, unlike link.
>
> I'm OK to get rid of the clone-or-copy mode. I can see the confusion.
New patch that removes all the various reflink modes and adds a new
option --clone that works similar to --link. I think it's much cleaner now.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
From 8b7285e61e425fad4d07a011efe2ccd7fd280d54 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pete...@gmx.net>
Date: Thu, 18 Oct 2018 23:09:59 +0200
Subject: [PATCH v6] pg_upgrade: Allow use of file cloning
Add another transfer mode --clone to pg_upgrade (besides the existing
--link and the default copy), using special file cloning calls. This
makes the file transfer faster and more space efficient, achieving
speed similar to --link mode without the associated drawbacks.
On Linux, file cloning is supported on Btrfs and XFS (if formatted with
reflink support). On macOS, file cloning is supported on APFS.
---
configure | 2 +-
configure.in | 1 +
doc/src/sgml/ref/pgupgrade.sgml | 37 ++++++++++---
src/bin/pg_upgrade/check.c | 13 ++++-
src/bin/pg_upgrade/file.c | 90 ++++++++++++++++++++++++++++++++
src/bin/pg_upgrade/option.c | 8 +++
src/bin/pg_upgrade/pg_upgrade.h | 6 ++-
src/bin/pg_upgrade/relfilenode.c | 44 ++++++++++------
src/include/pg_config.h.in | 3 ++
9 files changed, 179 insertions(+), 25 deletions(-)
diff --git a/configure b/configure
index 43ae8c869d..5a7aa02b27 100755
--- a/configure
+++ b/configure
@@ -15130,7 +15130,7 @@ fi
LIBS_including_readline="$LIBS"
LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
-for ac_func in cbrt clock_gettime fdatasync getifaddrs getpeerucred getrlimit
mbstowcs_l memmove poll posix_fallocate ppoll pstat pthread_is_threaded_np
readlink setproctitle setproctitle_fast setsid shm_open strchrnul symlink
sync_file_range utime utimes wcstombs_l
+for ac_func in cbrt clock_gettime copyfile fdatasync getifaddrs getpeerucred
getrlimit mbstowcs_l memmove poll posix_fallocate ppoll pstat
pthread_is_threaded_np readlink setproctitle setproctitle_fast setsid shm_open
strchrnul symlink sync_file_range utime utimes wcstombs_l
do :
as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
diff --git a/configure.in b/configure.in
index 519ecd5e1e..7f22bcee75 100644
--- a/configure.in
+++ b/configure.in
@@ -1602,6 +1602,7 @@ LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e
's/-lreadline//g'`
AC_CHECK_FUNCS(m4_normalize([
cbrt
clock_gettime
+ copyfile
fdatasync
getifaddrs
getpeerucred
diff --git a/doc/src/sgml/ref/pgupgrade.sgml b/doc/src/sgml/ref/pgupgrade.sgml
index d51146d641..e616ea9dbc 100644
--- a/doc/src/sgml/ref/pgupgrade.sgml
+++ b/doc/src/sgml/ref/pgupgrade.sgml
@@ -182,6 +182,25 @@ <title>Options</title>
<listitem><para>display version information, then exit</para></listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>--clone</option></term>
+ <listitem>
+ <para>
+ Use efficient file cloning (also known as <quote>reflinks</quote>)
+ instead of copying files to the new cluster. This can result in
+ near-instantaneous copying of the data files, giving the speed
+ advantages of <option>-k</option>/<option>--link</option> while
+ leaving the old cluster untouched.
+ </para>
+
+ <para>
+ At present, reflinks are supported on Linux (kernel 4.5 or later) with
+ Btrfs and XFS (on file systems created with reflink support, which is
+ not the default for XFS at this writing), and on macOS with APFS.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>-?</option></term>
<term><option>--help</option></term>
@@ -340,7 +359,7 @@ <title>Run <application>pg_upgrade</application></title>
Always run the <application>pg_upgrade</application> binary of the new
server, not the old one.
<application>pg_upgrade</application> requires the specification of the
old and new cluster's
data and executable (<filename>bin</filename>) directories. You can also
specify
- user and port values, and whether you want the data files linked
+ user and port values, and whether you want the data files linked or cloned
instead of the default copy behavior.
</para>
@@ -351,8 +370,12 @@ <title>Run <application>pg_upgrade</application></title>
once you start the new cluster after the upgrade. Link mode also
requires that the old and new cluster data directories be in the
same file system. (Tablespaces and <filename>pg_wal</filename> can be on
- different file systems.) See <literal>pg_upgrade --help</literal> for a
full
- list of options.
+ different file systems.)
+ The clone mode provides the same speed and disk space advantages but will
+ not leave the old cluster unusable after the upgrade. The clone mode
+ also requires that the old and new data directories be in the same file
+ system. The clone mode is only available on certain operating systems
+ and file systems.
</para>
<para>
@@ -388,8 +411,9 @@ <title>Run <application>pg_upgrade</application></title>
to perform only the checks, even if the old server is still
running. <command>pg_upgrade --check</command> will also outline any
manual adjustments you will need to make after the upgrade. If you
- are going to be using link mode, you should use the
<option>--link</option>
- option with <option>--check</option> to enable link-mode-specific checks.
+ are going to be using link or clone mode, you should use the option
+ <option>--link</option> or <option>--clone</option> with
+ <option>--check</option> to enable mode-specific checks.
<command>pg_upgrade</command> requires write permission in the current
directory.
</para>
@@ -722,7 +746,8 @@ <title>Notes</title>
<para>
If you want to use link mode and you do not want your old cluster
- to be modified when the new cluster is started, make a copy of the
+ to be modified when the new cluster is started, consider using the clone
mode.
+ If that is not available, make a copy of the
old cluster and upgrade that in link mode. To make a valid copy
of the old cluster, use <command>rsync</command> to create a dirty
copy of the old cluster while the server is running, then shut down
diff --git a/src/bin/pg_upgrade/check.c b/src/bin/pg_upgrade/check.c
index 5a78d603dc..555e5dcbba 100644
--- a/src/bin/pg_upgrade/check.c
+++ b/src/bin/pg_upgrade/check.c
@@ -149,8 +149,17 @@ check_new_cluster(void)
check_loadable_libraries();
- if (user_opts.transfer_mode == TRANSFER_MODE_LINK)
- check_hard_link();
+ switch (user_opts.transfer_mode)
+ {
+ case TRANSFER_MODE_CLONE:
+ check_file_clone();
+ break;
+ case TRANSFER_MODE_COPY:
+ break;
+ case TRANSFER_MODE_LINK:
+ check_hard_link();
+ break;
+ }
check_is_install_user(&new_cluster);
diff --git a/src/bin/pg_upgrade/file.c b/src/bin/pg_upgrade/file.c
index c27cc93dc2..244dd4d88b 100644
--- a/src/bin/pg_upgrade/file.c
+++ b/src/bin/pg_upgrade/file.c
@@ -18,6 +18,13 @@
#include <sys/stat.h>
#include <fcntl.h>
+#ifdef HAVE_COPYFILE
+#include <copyfile.h>
+#endif
+#ifdef __linux__
+#include <sys/ioctl.h>
+#include <linux/fs.h>
+#endif
#ifdef WIN32
@@ -25,6 +32,47 @@ static int win32_pghardlink(const char *src, const char
*dst);
#endif
+/*
+ * cloneFile()
+ *
+ * Clones/reflinks a relation file from src to dst.
+ *
+ * schemaName/relName are relation's SQL name (used for error messages only).
+ */
+void
+cloneFile(const char *src, const char *dst,
+ const char *schemaName, const char *relName)
+{
+#if defined(HAVE_COPYFILE) && defined(COPYFILE_CLONE_FORCE)
+ if (copyfile(src, dst, NULL, COPYFILE_CLONE_FORCE) < 0)
+ pg_fatal("error while cloning relation \"%s.%s\" (\"%s\" to
\"%s\"): %s\n",
+ schemaName, relName, src, dst,
strerror(errno));
+#elif defined(__linux__) && defined(FICLONE)
+ int src_fd;
+ int dest_fd;
+
+ if ((src_fd = open(src, O_RDONLY | PG_BINARY, 0)) < 0)
+ pg_fatal("error while cloning relation \"%s.%s\": could not
open file \"%s\": %s\n",
+ schemaName, relName, src, strerror(errno));
+
+ if ((dest_fd = open(dst, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
+ pg_file_create_mode)) < 0)
+ pg_fatal("error while cloning relation \"%s.%s\": could not
create file \"%s\": %s\n",
+ schemaName, relName, dst, strerror(errno));
+
+ if (ioctl(dest_fd, FICLONE, src_fd) < 0)
+ {
+ unlink(dst);
+ pg_fatal("error while cloning relation \"%s.%s\" (\"%s\" to
\"%s\"): %s\n",
+ schemaName, relName, src, dst,
strerror(errno));
+ }
+
+ close(src_fd);
+ close(dest_fd);
+#endif
+}
+
+
/*
* copyFile()
*
@@ -270,6 +318,48 @@ rewriteVisibilityMap(const char *fromfile, const char
*tofile,
close(src_fd);
}
+void
+check_file_clone(void)
+{
+ char existing_file[MAXPGPATH];
+ char new_link_file[MAXPGPATH];
+
+ snprintf(existing_file, sizeof(existing_file), "%s/PG_VERSION",
old_cluster.pgdata);
+ snprintf(new_link_file, sizeof(new_link_file),
"%s/PG_VERSION.clonetest", new_cluster.pgdata);
+ unlink(new_link_file); /* might fail */
+
+#if defined(HAVE_COPYFILE) && defined(COPYFILE_CLONE_FORCE)
+ if (copyfile(existing_file, new_link_file, NULL, COPYFILE_CLONE_FORCE)
< 0)
+ pg_fatal("could not clone file between old and new data
directories: %s\n",
+ strerror(errno));
+#elif defined(__linux__) && defined(FICLONE)
+ {
+ int src_fd;
+ int dest_fd;
+
+ if ((src_fd = open(existing_file, O_RDONLY | PG_BINARY, 0)) < 0)
+ pg_fatal("could not open file \"%s\": %s\n",
+ existing_file, strerror(errno));
+
+ if ((dest_fd = open(new_link_file, O_RDWR | O_CREAT | O_EXCL |
PG_BINARY,
+ pg_file_create_mode)) <
0)
+ pg_fatal("could not create file \"%s\": %s\n",
+ new_link_file, strerror(errno));
+
+ if (ioctl(dest_fd, FICLONE, src_fd) < 0)
+ pg_fatal("could not clone file between old and new data
directories: %s\n",
+ strerror(errno));
+
+ close(src_fd);
+ close(dest_fd);
+ }
+#else
+ pg_fatal("file cloning not supported on this platform\n");
+#endif
+
+ unlink(new_link_file);
+}
+
void
check_hard_link(void)
{
diff --git a/src/bin/pg_upgrade/option.c b/src/bin/pg_upgrade/option.c
index 9dbc9225a6..eb3b9f603d 100644
--- a/src/bin/pg_upgrade/option.c
+++ b/src/bin/pg_upgrade/option.c
@@ -53,6 +53,9 @@ parseCommandLine(int argc, char *argv[])
{"retain", no_argument, NULL, 'r'},
{"jobs", required_argument, NULL, 'j'},
{"verbose", no_argument, NULL, 'v'},
+
+ {"clone", no_argument, NULL, 1},
+
{NULL, 0, NULL, 0}
};
int option; /* Command line option
*/
@@ -203,6 +206,10 @@ parseCommandLine(int argc, char *argv[])
log_opts.verbose = true;
break;
+ case 1:
+ user_opts.transfer_mode = TRANSFER_MODE_CLONE;
+ break;
+
default:
pg_fatal("Try \"%s --help\" for more
information.\n",
os_info.progname);
@@ -293,6 +300,7 @@ usage(void)
printf(_(" -U, --username=NAME cluster superuser (default
\"%s\")\n"), os_info.user);
printf(_(" -v, --verbose enable verbose internal
logging\n"));
printf(_(" -V, --version display version information,
then exit\n"));
+ printf(_(" --clone clone instead of copying
files to new cluster\n"));
printf(_(" -?, --help show this help, then
exit\n"));
printf(_("\n"
"Before running pg_upgrade you must:\n"
diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h
index f83a3eeb67..51bd211d46 100644
--- a/src/bin/pg_upgrade/pg_upgrade.h
+++ b/src/bin/pg_upgrade/pg_upgrade.h
@@ -230,10 +230,11 @@ typedef struct
} ControlData;
/*
- * Enumeration to denote link modes
+ * Enumeration to denote transfer modes
*/
typedef enum
{
+ TRANSFER_MODE_CLONE,
TRANSFER_MODE_COPY,
TRANSFER_MODE_LINK
} transferMode;
@@ -372,12 +373,15 @@ bool pid_lock_file_exists(const char
*datadir);
/* file.c */
+void cloneFile(const char *src, const char *dst,
+ const char *schemaName, const char *relName);
void copyFile(const char *src, const char *dst,
const char *schemaName, const char *relName);
void linkFile(const char *src, const char *dst,
const char *schemaName, const char *relName);
void rewriteVisibilityMap(const char *fromfile, const char *tofile,
const char *schemaName, const char
*relName);
+void check_file_clone(void);
void check_hard_link(void);
/* fopen_priv() is no longer different from fopen() */
diff --git a/src/bin/pg_upgrade/relfilenode.c b/src/bin/pg_upgrade/relfilenode.c
index ed604f26ca..3b16c92a02 100644
--- a/src/bin/pg_upgrade/relfilenode.c
+++ b/src/bin/pg_upgrade/relfilenode.c
@@ -30,10 +30,18 @@ void
transfer_all_new_tablespaces(DbInfoArr *old_db_arr, DbInfoArr *new_db_arr,
char *old_pgdata, char
*new_pgdata)
{
- if (user_opts.transfer_mode == TRANSFER_MODE_LINK)
- pg_log(PG_REPORT, "Linking user relation files\n");
- else
- pg_log(PG_REPORT, "Copying user relation files\n");
+ switch (user_opts.transfer_mode)
+ {
+ case TRANSFER_MODE_CLONE:
+ pg_log(PG_REPORT, "Cloning user relation files\n");
+ break;
+ case TRANSFER_MODE_COPY:
+ pg_log(PG_REPORT, "Copying user relation files\n");
+ break;
+ case TRANSFER_MODE_LINK:
+ pg_log(PG_REPORT, "Linking user relation files\n");
+ break;
+ }
/*
* Transferring files by tablespace is tricky because a single database
@@ -250,17 +258,23 @@ transfer_relfile(FileNameMap *map, const char
*type_suffix, bool vm_must_add_fro
old_file, new_file);
rewriteVisibilityMap(old_file, new_file, map->nspname,
map->relname);
}
- else if (user_opts.transfer_mode == TRANSFER_MODE_COPY)
- {
- pg_log(PG_VERBOSE, "copying \"%s\" to \"%s\"\n",
- old_file, new_file);
- copyFile(old_file, new_file, map->nspname,
map->relname);
- }
else
- {
- pg_log(PG_VERBOSE, "linking \"%s\" to \"%s\"\n",
- old_file, new_file);
- linkFile(old_file, new_file, map->nspname,
map->relname);
- }
+ switch (user_opts.transfer_mode)
+ {
+ case TRANSFER_MODE_CLONE:
+ pg_log(PG_VERBOSE, "cloning \"%s\" to
\"%s\"\n",
+ old_file, new_file);
+ cloneFile(old_file, new_file,
map->nspname, map->relname);
+ break;
+ case TRANSFER_MODE_COPY:
+ pg_log(PG_VERBOSE, "copying \"%s\" to
\"%s\"\n",
+ old_file, new_file);
+ copyFile(old_file, new_file,
map->nspname, map->relname);
+ break;
+ case TRANSFER_MODE_LINK:
+ pg_log(PG_VERBOSE, "linking \"%s\" to
\"%s\"\n",
+ old_file, new_file);
+ linkFile(old_file, new_file,
map->nspname, map->relname);
+ }
}
}
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 9798bd24b4..d2a356a356 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -114,6 +114,9 @@
/* Define to 1 if your compiler handles computed gotos. */
#undef HAVE_COMPUTED_GOTO
+/* Define to 1 if you have the `copyfile' function. */
+#undef HAVE_COPYFILE
+
/* Define to 1 if you have the <crtdefs.h> header file. */
#undef HAVE_CRTDEFS_H
base-commit: e74dd00f53cd6dc1887f76b9672e5f6dcf0fd8a2
--
2.19.1
