1 files changed, 452 insertions, 0 deletions

diff --git a/src/bin/pg_upgrade/exec.c b/src/bin/pg_upgrade/exec.c
new file mode 100644
index 0000000..19cc06e
--- /dev/null
+++ b/src/bin/pg_upgrade/exec.c
@@ -0,0 +1,452 @@
+/*
+ *	exec.c
+ *
+ *	execution functions
+ *
+ *	Copyright (c) 2010-2021, PostgreSQL Global Development Group
+ *	src/bin/pg_upgrade/exec.c
+ */
+
+#include "postgres_fe.h"
+
+#include <fcntl.h>
+
+#include "common/string.h"
+#include "pg_upgrade.h"
+
+static void check_data_dir(ClusterInfo *cluster);
+static void check_bin_dir(ClusterInfo *cluster, bool check_versions);
+static void get_bin_version(ClusterInfo *cluster);
+static void check_exec(const char *dir, const char *program, bool check_version);
+
+#ifdef WIN32
+static int	win32_check_directory_write_permissions(void);
+#endif
+
+
+/*
+ * get_bin_version
+ *
+ *	Fetch major version of binaries for cluster.
+ */
+static void
+get_bin_version(ClusterInfo *cluster)
+{
+	char		cmd[MAXPGPATH],
+				cmd_output[MAX_STRING];
+	FILE	   *output;
+	int			v1 = 0,
+				v2 = 0;
+
+	snprintf(cmd, sizeof(cmd), "\"%s/pg_ctl\" --version", cluster->bindir);
+
+	if ((output = popen(cmd, "r")) == NULL ||
+		fgets(cmd_output, sizeof(cmd_output), output) == NULL)
+		pg_fatal("could not get pg_ctl version data using %s: %s\n",
+				 cmd, strerror(errno));
+
+	pclose(output);
+
+	if (sscanf(cmd_output, "%*s %*s %d.%d", &v1, &v2) < 1)
+		pg_fatal("could not get pg_ctl version output from %s\n", cmd);
+
+	if (v1 < 10)
+	{
+		/* old style, e.g. 9.6.1 */
+		cluster->bin_version = v1 * 10000 + v2 * 100;
+	}
+	else
+	{
+		/* new style, e.g. 10.1 */
+		cluster->bin_version = v1 * 10000;
+	}
+}
+
+
+/*
+ * exec_prog()
+ *		Execute an external program with stdout/stderr redirected, and report
+ *		errors
+ *
+ * Formats a command from the given argument list, logs it to the log file,
+ * and attempts to execute that command.  If the command executes
+ * successfully, exec_prog() returns true.
+ *
+ * If the command fails, an error message is optionally written to the specified
+ * log_file, and the program optionally exits.
+ *
+ * The code requires it be called first from the primary thread on Windows.
+ */
+bool
+exec_prog(const char *log_file, const char *opt_log_file,
+		  bool report_error, bool exit_on_error, const char *fmt,...)
+{
+	int			result = 0;
+	int			written;
+
+#define MAXCMDLEN (2 * MAXPGPATH)
+	char		cmd[MAXCMDLEN];
+	FILE	   *log;
+	va_list		ap;
+
+#ifdef WIN32
+	static DWORD mainThreadId = 0;
+
+	/* We assume we are called from the primary thread first */
+	if (mainThreadId == 0)
+		mainThreadId = GetCurrentThreadId();
+#endif
+
+	written = 0;
+	va_start(ap, fmt);
+	written += vsnprintf(cmd + written, MAXCMDLEN - written, fmt, ap);
+	va_end(ap);
+	if (written >= MAXCMDLEN)
+		pg_fatal("command too long\n");
+	written += snprintf(cmd + written, MAXCMDLEN - written,
+						" >> \"%s\" 2>&1", log_file);
+	if (written >= MAXCMDLEN)
+		pg_fatal("command too long\n");
+
+	pg_log(PG_VERBOSE, "%s\n", cmd);
+
+#ifdef WIN32
+
+	/*
+	 * For some reason, Windows issues a file-in-use error if we write data to
+	 * the log file from a non-primary thread just before we create a
+	 * subprocess that also writes to the same log file.  One fix is to sleep
+	 * for 100ms.  A cleaner fix is to write to the log file _after_ the
+	 * subprocess has completed, so we do this only when writing from a
+	 * non-primary thread.  fflush(), running system() twice, and pre-creating
+	 * the file do not see to help.
+	 */
+	if (mainThreadId != GetCurrentThreadId())
+		result = system(cmd);
+#endif
+
+	log = fopen(log_file, "a");
+
+#ifdef WIN32
+	{
+		/*
+		 * "pg_ctl -w stop" might have reported that the server has stopped
+		 * because the postmaster.pid file has been removed, but "pg_ctl -w
+		 * start" might still be in the process of closing and might still be
+		 * holding its stdout and -l log file descriptors open.  Therefore,
+		 * try to open the log file a few more times.
+		 */
+		int			iter;
+
+		for (iter = 0; iter < 4 && log == NULL; iter++)
+		{
+			pg_usleep(1000000); /* 1 sec */
+			log = fopen(log_file, "a");
+		}
+	}
+#endif
+
+	if (log == NULL)
+		pg_fatal("could not open log file \"%s\": %m\n", log_file);
+
+#ifdef WIN32
+	/* Are we printing "command:" before its output? */
+	if (mainThreadId == GetCurrentThreadId())
+		fprintf(log, "\n\n");
+#endif
+	fprintf(log, "command: %s\n", cmd);
+#ifdef WIN32
+	/* Are we printing "command:" after its output? */
+	if (mainThreadId != GetCurrentThreadId())
+		fprintf(log, "\n\n");
+#endif
+
+	/*
+	 * In Windows, we must close the log file at this point so the file is not
+	 * open while the command is running, or we get a share violation.
+	 */
+	fclose(log);
+
+#ifdef WIN32
+	/* see comment above */
+	if (mainThreadId == GetCurrentThreadId())
+#endif
+		result = system(cmd);
+
+	if (result != 0 && report_error)
+	{
+		/* we might be in on a progress status line, so go to the next line */
+		report_status(PG_REPORT, "\n*failure*");
+		fflush(stdout);
+
+		pg_log(PG_VERBOSE, "There were problems executing \"%s\"\n", cmd);
+		if (opt_log_file)
+			pg_log(exit_on_error ? PG_FATAL : PG_REPORT,
+				   "Consult the last few lines of \"%s\" or \"%s\" for\n"
+				   "the probable cause of the failure.\n",
+				   log_file, opt_log_file);
+		else
+			pg_log(exit_on_error ? PG_FATAL : PG_REPORT,
+				   "Consult the last few lines of \"%s\" for\n"
+				   "the probable cause of the failure.\n",
+				   log_file);
+	}
+
+#ifndef WIN32
+
+	/*
+	 * We can't do this on Windows because it will keep the "pg_ctl start"
+	 * output filename open until the server stops, so we do the \n\n above on
+	 * that platform.  We use a unique filename for "pg_ctl start" that is
+	 * never reused while the server is running, so it works fine.  We could
+	 * log these commands to a third file, but that just adds complexity.
+	 */
+	if ((log = fopen(log_file, "a")) == NULL)
+		pg_fatal("could not write to log file \"%s\": %m\n", log_file);
+	fprintf(log, "\n\n");
+	fclose(log);
+#endif
+
+	return result == 0;
+}
+
+
+/*
+ * pid_lock_file_exists()
+ *
+ * Checks whether the postmaster.pid file exists.
+ */
+bool
+pid_lock_file_exists(const char *datadir)
+{
+	char		path[MAXPGPATH];
+	int			fd;
+
+	snprintf(path, sizeof(path), "%s/postmaster.pid", datadir);
+
+	if ((fd = open(path, O_RDONLY, 0)) < 0)
+	{
+		/* ENOTDIR means we will throw a more useful error later */
+		if (errno != ENOENT && errno != ENOTDIR)
+			pg_fatal("could not open file \"%s\" for reading: %s\n",
+					 path, strerror(errno));
+
+		return false;
+	}
+
+	close(fd);
+	return true;
+}
+
+
+/*
+ * verify_directories()
+ *
+ * does all the hectic work of verifying directories and executables
+ * of old and new server.
+ *
+ * NOTE: May update the values of all parameters
+ */
+void
+verify_directories(void)
+{
+#ifndef WIN32
+	if (access(".", R_OK | W_OK | X_OK) != 0)
+#else
+	if (win32_check_directory_write_permissions() != 0)
+#endif
+		pg_fatal("You must have read and write access in the current directory.\n");
+
+	check_bin_dir(&old_cluster, false);
+	check_data_dir(&old_cluster);
+	check_bin_dir(&new_cluster, true);
+	check_data_dir(&new_cluster);
+}
+
+
+#ifdef WIN32
+/*
+ * win32_check_directory_write_permissions()
+ *
+ *	access() on WIN32 can't check directory permissions, so we have to
+ *	optionally create, then delete a file to check.
+ *		http://msdn.microsoft.com/en-us/library/1w06ktdy%28v=vs.80%29.aspx
+ */
+static int
+win32_check_directory_write_permissions(void)
+{
+	int			fd;
+
+	/*
+	 * We open a file we would normally create anyway.  We do this even in
+	 * 'check' mode, which isn't ideal, but this is the best we can do.
+	 */
+	if ((fd = open(GLOBALS_DUMP_FILE, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR)) < 0)
+		return -1;
+	close(fd);
+
+	return unlink(GLOBALS_DUMP_FILE);
+}
+#endif
+
+
+/*
+ * check_single_dir()
+ *
+ *	Check for the presence of a single directory in PGDATA, and fail if
+ * is it missing or not accessible.
+ */
+static void
+check_single_dir(const char *pg_data, const char *subdir)
+{
+	struct stat statBuf;
+	char		subDirName[MAXPGPATH];
+
+	snprintf(subDirName, sizeof(subDirName), "%s%s%s", pg_data,
+	/* Win32 can't stat() a directory with a trailing slash. */
+			 *subdir ? "/" : "",
+			 subdir);
+
+	if (stat(subDirName, &statBuf) != 0)
+		report_status(PG_FATAL, "check for \"%s\" failed: %s\n",
+					  subDirName, strerror(errno));
+	else if (!S_ISDIR(statBuf.st_mode))
+		report_status(PG_FATAL, "\"%s\" is not a directory\n",
+					  subDirName);
+}
+
+
+/*
+ * check_data_dir()
+ *
+ *	This function validates the given cluster directory - we search for a
+ *	small set of subdirectories that we expect to find in a valid $PGDATA
+ *	directory.  If any of the subdirectories are missing (or secured against
+ *	us) we display an error message and exit()
+ *
+ */
+static void
+check_data_dir(ClusterInfo *cluster)
+{
+	const char *pg_data = cluster->pgdata;
+
+	/* get the cluster version */
+	cluster->major_version = get_major_server_version(cluster);
+
+	check_single_dir(pg_data, "");
+	check_single_dir(pg_data, "base");
+	check_single_dir(pg_data, "global");
+	check_single_dir(pg_data, "pg_multixact");
+	check_single_dir(pg_data, "pg_subtrans");
+	check_single_dir(pg_data, "pg_tblspc");
+	check_single_dir(pg_data, "pg_twophase");
+
+	/* pg_xlog has been renamed to pg_wal in v10 */
+	if (GET_MAJOR_VERSION(cluster->major_version) <= 906)
+		check_single_dir(pg_data, "pg_xlog");
+	else
+		check_single_dir(pg_data, "pg_wal");
+
+	/* pg_clog has been renamed to pg_xact in v10 */
+	if (GET_MAJOR_VERSION(cluster->major_version) <= 906)
+		check_single_dir(pg_data, "pg_clog");
+	else
+		check_single_dir(pg_data, "pg_xact");
+}
+
+
+/*
+ * check_bin_dir()
+ *
+ *	This function searches for the executables that we expect to find
+ *	in the binaries directory.  If we find that a required executable
+ *	is missing (or secured against us), we display an error message and
+ *	exit().
+ *
+ *	If check_versions is true, then the versions of the binaries are checked
+ *	against the version of this pg_upgrade.  This is for checking the target
+ *	bindir.
+ */
+static void
+check_bin_dir(ClusterInfo *cluster, bool check_versions)
+{
+	struct stat statBuf;
+
+	/* check bindir */
+	if (stat(cluster->bindir, &statBuf) != 0)
+		report_status(PG_FATAL, "check for \"%s\" failed: %s\n",
+					  cluster->bindir, strerror(errno));
+	else if (!S_ISDIR(statBuf.st_mode))
+		report_status(PG_FATAL, "\"%s\" is not a directory\n",
+					  cluster->bindir);
+
+	check_exec(cluster->bindir, "postgres", check_versions);
+	check_exec(cluster->bindir, "pg_controldata", check_versions);
+	check_exec(cluster->bindir, "pg_ctl", check_versions);
+
+	/*
+	 * Fetch the binary version after checking for the existence of pg_ctl.
+	 * This way we report a useful error if the pg_ctl binary used for version
+	 * fetching is missing/broken.
+	 */
+	get_bin_version(cluster);
+
+	/* pg_resetxlog has been renamed to pg_resetwal in version 10 */
+	if (GET_MAJOR_VERSION(cluster->bin_version) <= 906)
+		check_exec(cluster->bindir, "pg_resetxlog", check_versions);
+	else
+		check_exec(cluster->bindir, "pg_resetwal", check_versions);
+
+	if (cluster == &new_cluster)
+	{
+		/*
+		 * These binaries are only needed for the target version. pg_dump and
+		 * pg_dumpall are used to dump the old cluster, but must be of the
+		 * target version.
+		 */
+		check_exec(cluster->bindir, "initdb", check_versions);
+		check_exec(cluster->bindir, "pg_dump", check_versions);
+		check_exec(cluster->bindir, "pg_dumpall", check_versions);
+		check_exec(cluster->bindir, "pg_restore", check_versions);
+		check_exec(cluster->bindir, "psql", check_versions);
+		check_exec(cluster->bindir, "vacuumdb", check_versions);
+	}
+}
+
+static void
+check_exec(const char *dir, const char *program, bool check_version)
+{
+	char		path[MAXPGPATH];
+	char		line[MAXPGPATH];
+	char		cmd[MAXPGPATH];
+	char		versionstr[128];
+	int			ret;
+
+	snprintf(path, sizeof(path), "%s/%s", dir, program);
+
+	ret = validate_exec(path);
+
+	if (ret == -1)
+		pg_fatal("check for \"%s\" failed: not a regular file\n",
+				 path);
+	else if (ret == -2)
+		pg_fatal("check for \"%s\" failed: cannot execute (permission denied)\n",
+				 path);
+
+	snprintf(cmd, sizeof(cmd), "\"%s\" -V", path);
+
+	if (!pipe_read_line(cmd, line, sizeof(line)))
+		pg_fatal("check for \"%s\" failed: cannot execute\n",
+				 path);
+
+	if (check_version)
+	{
+		pg_strip_crlf(line);
+
+		snprintf(versionstr, sizeof(versionstr), "%s (PostgreSQL) " PG_VERSION, program);
+
+		if (strcmp(line, versionstr) != 0)
+			pg_fatal("check for \"%s\" failed: incorrect version: found \"%s\", expected \"%s\"\n",
+					 path, line, versionstr);
+	}
+}