From 52948169bcddf443b76d6ff1806259b153a2ac04 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Thu, 13 Jan 2011 19:01:28 -0500
Subject: [PATCH] Code review for postmaster.pid contents changes.
Fix broken test for pre-existing postmaster, caused by wrong code for
appending lines to the lockfile; don't write a failed listen_address
setting into the lockfile; don't arbitrarily change the location of the
data directory in the lockfile compared to previous releases; provide more
consistent and useful definitions of the socket path and listen_address
entries; avoid assuming that pg_ctl has the same DEFAULT_PGSOCKET_DIR as
the postmaster; assorted code style improvements.
---
doc/src/sgml/storage.sgml | 11 +-
src/backend/port/ipc_test.c | 4 +-
src/backend/port/sysv_shmem.c | 13 +-
src/backend/postmaster/postmaster.c | 35 +++---
src/backend/utils/init/miscinit.c | 77 ++++++------
src/bin/pg_ctl/pg_ctl.c | 185 ++++++++++++++--------------
src/include/miscadmin.h | 28 ++++-
7 files changed, 194 insertions(+), 159 deletions(-)
diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index 746a48219fd..ad9fba2d0f3 100644
--- a/doc/src/sgml/storage.sgml
+++ b/doc/src/sgml/storage.sgml
@@ -117,9 +117,14 @@ last started with</entry>
<row>
<entry><filename>postmaster.pid</></entry>
<entry>A lock file recording the current postmaster process id (PID),
- postmaster start time, cluster data directory, port number, user-specified
- Unix domain socket directory, first valid listen_address host, and
- shared memory segment ID</entry>
+ cluster data directory path,
+ postmaster start timestamp,
+ port number,
+ Unix-domain socket directory path (empty on Windows),
+ first valid listen_address (IP address or <literal>*</>, or empty if
+ not listening on TCP),
+ and shared memory segment ID
+ (this file is not present after server shutdown)</entry>
</row>
</tbody>
diff --git a/src/backend/port/ipc_test.c b/src/backend/port/ipc_test.c
index 2518007c4b6..b4bcf40a7ab 100644
--- a/src/backend/port/ipc_test.c
+++ b/src/backend/port/ipc_test.c
@@ -104,7 +104,7 @@ on_exit_reset(void)
}
void
-AddToLockFile(int target_line, const char *str)
+AddToDataDirLockFile(int target_line, const char *str)
{
}
@@ -135,7 +135,7 @@ errcode_for_file_access(void)
bool
errstart(int elevel, const char *filename, int lineno,
- const char *funcname)
+ const char *funcname, const char *domain)
{
return (elevel >= ERROR);
}
diff --git a/src/backend/port/sysv_shmem.c b/src/backend/port/sysv_shmem.c
index 474c6142ebe..aece026ec64 100644
--- a/src/backend/port/sysv_shmem.c
+++ b/src/backend/port/sysv_shmem.c
@@ -199,15 +199,16 @@ InternalIpcMemoryCreate(IpcMemoryKey memKey, Size size)
on_shmem_exit(IpcMemoryDetach, PointerGetDatum(memAddress));
/*
- * Append record key and ID in lockfile for data directory. Format
- * to try to keep it the same length.
+ * Store shmem key and ID in data directory lockfile. Format to try to
+ * keep it the same length always (trailing junk in the lockfile won't
+ * hurt, but might confuse humans).
*/
{
- char line[32];
+ char line[64];
- sprintf(line, "%9lu %9lu\n", (unsigned long) memKey,
- (unsigned long) shmid);
- AddToLockFile(LOCK_FILE_LINES, line);
+ sprintf(line, "%9lu %9lu",
+ (unsigned long) memKey, (unsigned long) shmid);
+ AddToDataDirLockFile(LOCK_FILE_LINE_SHMEM_KEY, line);
}
return memAddress;
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index d158ded390b..179048f32d1 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -482,9 +482,9 @@ PostmasterMain(int argc, char *argv[])
int opt;
int status;
char *userDoption = NULL;
+ bool listen_addr_saved = false;
int i;
- bool connection_line_output = false;
-
+
MyProcPid = PostmasterPid = getpid();
MyStartTime = time(NULL);
@@ -861,24 +861,21 @@ PostmasterMain(int argc, char *argv[])
UnixSocketDir,
ListenSocket, MAXLISTEN);
else
- {
status = StreamServerPort(AF_UNSPEC, curhost,
(unsigned short) PostPortNumber,
UnixSocketDir,
ListenSocket, MAXLISTEN);
- /* must supply a valid listen_address for PQping() */
- if (!connection_line_output)
- {
- char line[MAXPGPATH + 2];
- sprintf(line, "%s\n", curhost);
- AddToLockFile(LOCK_FILE_LINES - 1, line);
- connection_line_output = true;
- }
- }
-
if (status == STATUS_OK)
+ {
success++;
+ /* record the first successful host addr in lockfile */
+ if (!listen_addr_saved)
+ {
+ AddToDataDirLockFile(LOCK_FILE_LINE_LISTEN_ADDR, curhost);
+ listen_addr_saved = true;
+ }
+ }
else
ereport(WARNING,
(errmsg("could not create listen socket for \"%s\"",
@@ -893,10 +890,6 @@ PostmasterMain(int argc, char *argv[])
pfree(rawstring);
}
- /* Supply an empty listen_address line for PQping() */
- if (!connection_line_output)
- AddToLockFile(LOCK_FILE_LINES - 1, "\n");
-
#ifdef USE_BONJOUR
/* Register for Bonjour only if we opened TCP socket(s) */
if (enable_bonjour && ListenSocket[0] != PGINVALID_SOCKET)
@@ -952,6 +945,14 @@ PostmasterMain(int argc, char *argv[])
ereport(FATAL,
(errmsg("no socket created for listening")));
+ /*
+ * If no valid TCP ports, write an empty line for listen address,
+ * indicating the Unix socket must be used. Note that this line is not
+ * added to the lock file until there is a socket backing it.
+ */
+ if (!listen_addr_saved)
+ AddToDataDirLockFile(LOCK_FILE_LINE_LISTEN_ADDR, "");
+
/*
* Set up shared memory and semaphores.
*/
diff --git a/src/backend/utils/init/miscinit.c b/src/backend/utils/init/miscinit.c
index 4f708352daa..ef6422e75c3 100644
--- a/src/backend/utils/init/miscinit.c
+++ b/src/backend/utils/init/miscinit.c
@@ -46,20 +46,7 @@
#define DIRECTORY_LOCK_FILE "postmaster.pid"
-/*
- * The lock file contents are:
- *
- * line #
- * 1 pid
- * 2 postmaster start time
- * 3 data directory
- * 4 port #
- * 5 user-specified socket directory
- * (the lines below are added later)
- * 6 first valid listen_address
- * 7 shared memory key
- */
-
+
ProcessingMode Mode = InitProcessing;
/* Note: we rely on this to initialize as zeroes */
@@ -244,7 +231,6 @@ static int SecurityRestrictionContext = 0;
static bool SetRoleIsActive = false;
-
/*
* GetUserId - get the current effective user ID.
*
@@ -691,7 +677,7 @@ CreateLockFile(const char *filename, bool amPostmaster,
bool isDDLock, const char *refName)
{
int fd;
- char buffer[MAXPGPATH * 3 + 256];
+ char buffer[MAXPGPATH * 2 + 256];
int ntries;
int len;
int encoded_pid;
@@ -852,26 +838,26 @@ CreateLockFile(const char *filename, bool amPostmaster,
* looking to see if there is an associated shmem segment that is
* still in use.
*
- * Note: because postmaster.pid is written in two steps, we might not
- * find the shmem ID values in it; we can't treat that as an error.
+ * Note: because postmaster.pid is written in multiple steps, we might
+ * not find the shmem ID values in it; we can't treat that as an
+ * error.
*/
if (isDDLock)
{
char *ptr = buffer;
- unsigned long id1, id2;
- int lineno;
+ unsigned long id1,
+ id2;
+ int lineno;
- for (lineno = 1; lineno <= LOCK_FILE_LINES - 1; lineno++)
+ for (lineno = 1; lineno < LOCK_FILE_LINE_SHMEM_KEY; lineno++)
{
if ((ptr = strchr(ptr, '\n')) == NULL)
- {
- elog(LOG, "bogus data in \"%s\"", DIRECTORY_LOCK_FILE);
break;
- }
ptr++;
}
- if (ptr && sscanf(ptr, "%lu %lu", &id1, &id2) == 2)
+ if (ptr != NULL &&
+ sscanf(ptr, "%lu %lu", &id1, &id2) == 2)
{
if (PGSharedMemoryIsInUse(id1, id2))
ereport(FATAL,
@@ -903,12 +889,23 @@ CreateLockFile(const char *filename, bool amPostmaster,
}
/*
- * Successfully created the file, now fill it.
+ * Successfully created the file, now fill it. See comment in miscadmin.h
+ * about the contents. Note that we write the same info into both datadir
+ * and socket lockfiles; although more stuff may get added to the datadir
+ * lockfile later.
*/
- snprintf(buffer, sizeof(buffer), "%d\n%ld\n%s\n%d\n%s\n",
+ snprintf(buffer, sizeof(buffer), "%d\n%s\n%ld\n%d\n%s\n",
amPostmaster ? (int) my_pid : -((int) my_pid),
- (long) MyStartTime, DataDir, PostPortNumber,
- UnixSocketDir);
+ DataDir,
+ (long) MyStartTime,
+ PostPortNumber,
+#ifdef HAVE_UNIX_SOCKETS
+ (*UnixSocketDir != '\0') ? UnixSocketDir : DEFAULT_PGSOCKET_DIR
+#else
+ ""
+#endif
+ );
+
errno = 0;
if (write(fd, buffer, strlen(buffer)) != strlen(buffer))
{
@@ -1019,17 +1016,20 @@ TouchSocketLockFile(void)
/*
- * Add lines to the data directory lock file. This erases all following
- * lines, but that is OK because lines are added in order.
+ * Add (or replace) a line in the data directory lock file.
+ * The given string should not include a trailing newline.
+ *
+ * Caution: this erases all following lines. In current usage that is OK
+ * because lines are added in order. We could improve it if needed.
*/
void
-AddToLockFile(int target_line, const char *str)
+AddToDataDirLockFile(int target_line, const char *str)
{
int fd;
int len;
int lineno;
char *ptr;
- char buffer[MAXPGPATH * 3 + 256];
+ char buffer[BLCKSZ];
fd = open(DIRECTORY_LOCK_FILE, O_RDWR | PG_BINARY, 0);
if (fd < 0)
@@ -1040,7 +1040,7 @@ AddToLockFile(int target_line, const char *str)
DIRECTORY_LOCK_FILE)));
return;
}
- len = read(fd, buffer, sizeof(buffer) - 100);
+ len = read(fd, buffer, sizeof(buffer) - 1);
if (len < 0)
{
ereport(LOG,
@@ -1053,7 +1053,7 @@ AddToLockFile(int target_line, const char *str)
buffer[len] = '\0';
/*
- * Skip over first four lines (PID, pgdata, portnum, socketdir).
+ * Skip over lines we are not supposed to rewrite.
*/
ptr = buffer;
for (lineno = 1; lineno < target_line; lineno++)
@@ -1066,8 +1066,11 @@ AddToLockFile(int target_line, const char *str)
}
ptr++;
}
-
- strlcat(buffer, str, sizeof(buffer));
+
+ /*
+ * Write or rewrite the target line.
+ */
+ snprintf(ptr, buffer + sizeof(buffer) - ptr, "%s\n", str);
/*
* And rewrite the data. Since we write in a single kernel call, this
diff --git a/src/bin/pg_ctl/pg_ctl.c b/src/bin/pg_ctl/pg_ctl.c
index 03a932970d1..6c87f158f3f 100644
--- a/src/bin/pg_ctl/pg_ctl.c
+++ b/src/bin/pg_ctl/pg_ctl.c
@@ -22,7 +22,6 @@
#include <locale.h>
#include <signal.h>
-#include <stdlib.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
@@ -91,6 +90,24 @@ static char *register_username = NULL;
static char *register_password = NULL;
static char *argv0 = NULL;
static bool allow_core_files = false;
+static time_t start_time;
+
+static char postopts_file[MAXPGPATH];
+static char pid_file[MAXPGPATH];
+static char backup_file[MAXPGPATH];
+static char recovery_file[MAXPGPATH];
+
+#if defined(WIN32) || defined(__CYGWIN__)
+static DWORD pgctl_start_type = SERVICE_AUTO_START;
+static SERVICE_STATUS status;
+static SERVICE_STATUS_HANDLE hStatus = (SERVICE_STATUS_HANDLE) 0;
+static HANDLE shutdownHandles[2];
+static pid_t postmasterPID = -1;
+
+#define shutdownEvent shutdownHandles[0]
+#define postmasterProcess shutdownHandles[1]
+#endif
+
static void
write_stderr(const char *fmt,...)
@@ -122,15 +139,6 @@ static void WINAPI pgwin32_ServiceHandler(DWORD);
static void WINAPI pgwin32_ServiceMain(DWORD, LPTSTR *);
static void pgwin32_doRunAsService(void);
static int CreateRestrictedProcess(char *cmd, PROCESS_INFORMATION *processInfo, bool as_service);
-
-static DWORD pgctl_start_type = SERVICE_AUTO_START;
-static SERVICE_STATUS status;
-static SERVICE_STATUS_HANDLE hStatus = (SERVICE_STATUS_HANDLE) 0;
-static HANDLE shutdownHandles[2];
-static pid_t postmasterPID = -1;
-
-#define shutdownEvent shutdownHandles[0]
-#define postmasterProcess shutdownHandles[1]
#endif
static pgpid_t get_pgpid(void);
@@ -140,12 +148,6 @@ static void read_post_opts(void);
static PGPing test_postmaster_connection(bool);
static bool postmaster_is_alive(pid_t pid);
-static time_t start_time;
-
-static char postopts_file[MAXPGPATH];
-static char pid_file[MAXPGPATH];
-static char backup_file[MAXPGPATH];
-static char recovery_file[MAXPGPATH];
#if defined(HAVE_GETRLIMIT) && defined(RLIMIT_CORE)
static void unlimit_core_size(void);
@@ -406,14 +408,10 @@ start_postmaster(void)
static PGPing
test_postmaster_connection(bool do_checkpoint)
{
- int portnum = 0;
- char host_str[MAXPGPATH];
- char connstr[MAXPGPATH + 256];
PGPing ret = PQPING_OK; /* assume success for wait == zero */
- char **optlines;
+ char connstr[MAXPGPATH * 2 + 256];
int i;
- host_str[0] = '\0';
connstr[0] = '\0';
for (i = 0; i < wait_seconds; i++)
@@ -421,108 +419,111 @@ test_postmaster_connection(bool do_checkpoint)
/* Do we need a connection string? */
if (connstr[0] == '\0')
{
- /*
- * The number of lines in postmaster.pid tells us several things:
+ /*----------
+ * The number of lines in postmaster.pid tells us several things:
*
- * # of lines
+ * # of lines
* 0 lock file created but status not written
* 2 pre-9.1 server, shared memory not created
* 3 pre-9.1 server, shared memory created
- * 5 9.1+ server, listen host not created
+ * 5 9.1+ server, ports not opened
* 6 9.1+ server, shared memory not created
* 7 9.1+ server, shared memory created
*
- * For pre-9.1 Unix servers, we grab the port number from the
- * shmem key (first value on line 3). Pre-9.1 Win32 has no
- * written shmem key, so we fail. 9.1+ writes connection
- * information in the file for us to use.
- * (PG_VERSION could also have told us the major version.)
+ * This code does not support pre-9.1 servers. On Unix machines
+ * we could consider extracting the port number from the shmem
+ * key, but that (a) is not robust, and (b) doesn't help with
+ * finding out the socket directory. And it wouldn't work anyway
+ * on Windows.
+ *
+ * If we see less than 6 lines in postmaster.pid, just keep
+ * waiting.
+ *----------
*/
-
- /* Try to read a completed postmaster.pid file */
+ char **optlines;
+
+ /* Try to read the postmaster.pid file */
if ((optlines = readfile(pid_file)) != NULL &&
optlines[0] != NULL &&
optlines[1] != NULL &&
- optlines[2] != NULL &&
- /* pre-9.1 server or listen_address line is present? */
- (optlines[3] == NULL ||
- optlines[5] != NULL))
- {
- /* A 3-line file? */
+ optlines[2] != NULL)
+ {
if (optlines[3] == NULL)
{
- /*
- * Pre-9.1: on Unix, we get the port number by
- * deriving it from the shmem key (the first number on
- * on the line); see
- * miscinit.c::RecordSharedMemoryInLockFile().
- */
- portnum = atoi(optlines[2]) / 1000;
- /* Win32 does not give us a shmem key, so we fail. */
- if (portnum == 0)
- {
- write_stderr(_("%s: -w option is not supported on this platform\nwhen connecting to a pre-9.1 server\n"),
- progname);
- return PQPING_NO_ATTEMPT;
- }
+ /* File is exactly three lines, must be pre-9.1 */
+ write_stderr(_("%s: -w option is not supported when starting a pre-9.1 server\n"),
+ progname);
+ return PQPING_NO_ATTEMPT;
}
- else
+ else if (optlines[4] != NULL &&
+ optlines[5] != NULL)
{
+ /* File is complete enough for us, parse it */
+ time_t pmstart;
+ int portnum;
+ char *sockdir;
+ char *hostaddr;
+ char host_str[MAXPGPATH];
+
/*
- * Easy check to see if we are looking at the right
- * data directory: Is the postmaster older than this
- * execution of pg_ctl? Subtract 2 seconds to account
- * for possible clock skew between pg_ctl and the
- * postmaster.
+ * Easy cross-check that we are looking at the right data
+ * directory: is the postmaster older than this execution
+ * of pg_ctl? Subtract 2 seconds to allow for possible
+ * clock skew between pg_ctl and the postmaster.
*/
- if (atol(optlines[1]) < start_time - 2)
+ pmstart = atol(optlines[LOCK_FILE_LINE_START_TIME - 1]);
+ if (pmstart < start_time - 2)
{
- write_stderr(_("%s: this data directory is running an older postmaster\n"),
+ write_stderr(_("%s: this data directory is running a pre-existing postmaster\n"),
progname);
return PQPING_NO_ATTEMPT;
}
-
- portnum = atoi(optlines[3]);
/*
- * Determine the proper host string to use.
- */
-#ifdef HAVE_UNIX_SOCKETS
- /*
- * Use socket directory, if specified. We assume if we
- * have unix sockets, the server does too because we
- * just started the postmaster.
+ * OK, extract port number and host string to use.
+ * Prefer using Unix socket if available.
*/
+ portnum = atoi(optlines[LOCK_FILE_LINE_PORT - 1]);
+
+ sockdir = optlines[LOCK_FILE_LINE_SOCKET_DIR - 1];
+ hostaddr = optlines[LOCK_FILE_LINE_LISTEN_ADDR - 1];
+
/*
- * While unix_socket_directory can accept relative
- * directories, libpq's host must have a leading slash
- * to indicate a socket directory.
+ * While unix_socket_directory can accept relative
+ * directories, libpq's host parameter must have a leading
+ * slash to indicate a socket directory. So, ignore
+ * sockdir if it's relative, and try to use TCP instead.
*/
- if (optlines[4][0] != '\n' && optlines[4][0] != '/')
+ if (sockdir[0] == '/')
+ strlcpy(host_str, sockdir, sizeof(host_str));
+ else
+ strlcpy(host_str, hostaddr, sizeof(host_str));
+
+ /* remove trailing newline */
+ if (strchr(host_str, '\n') != NULL)
+ *strchr(host_str, '\n') = '\0';
+
+ /* Fail if we couldn't get either sockdir or host addr */
+ if (host_str[0] == '\0')
{
write_stderr(_("%s: -w option cannot use a relative socket directory specification\n"),
progname);
return PQPING_NO_ATTEMPT;
}
- strlcpy(host_str, optlines[4], sizeof(host_str));
-#else
- strlcpy(host_str, optlines[5], sizeof(host_str));
-#endif
- /* remove newline */
- if (strchr(host_str, '\n') != NULL)
- *strchr(host_str, '\n') = '\0';
- }
-
- /*
- * We need to set connect_timeout otherwise on Windows the
- * Service Control Manager (SCM) will probably timeout first.
- */
- snprintf(connstr, sizeof(connstr),
- "dbname=postgres port=%d connect_timeout=5", portnum);
- if (host_str[0] != '\0')
- snprintf(connstr + strlen(connstr), sizeof(connstr) - strlen(connstr),
- " host='%s'", host_str);
+ /* If postmaster is listening on "*", use "localhost" */
+ if (strcmp(host_str, "*") == 0)
+ strcpy(host_str, "localhost");
+
+ /*
+ * We need to set connect_timeout otherwise on Windows the
+ * Service Control Manager (SCM) will probably timeout
+ * first.
+ */
+ snprintf(connstr, sizeof(connstr),
+ "dbname=postgres port=%d host='%s' connect_timeout=5",
+ portnum, host_str);
+ }
}
}
@@ -544,7 +545,7 @@ test_postmaster_connection(bool do_checkpoint)
* startup time is changing, otherwise it'll usually send a
* stop signal after 20 seconds, despite incrementing the
* checkpoint counter.
- */
+ */
status.dwWaitHint += 6000;
status.dwCheckPoint++;
SetServiceStatus(hStatus, (LPSERVICE_STATUS) &status);
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index 382a5deced4..aa8cce5ca81 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -348,11 +348,35 @@ extern PGDLLIMPORT bool process_shared_preload_libraries_in_progress;
extern char *shared_preload_libraries_string;
extern char *local_preload_libraries_string;
-#define LOCK_FILE_LINES 7
+/*
+ * As of 9.1, the contents of the data-directory lock file are:
+ *
+ * line #
+ * 1 postmaster PID (or negative of a standalone backend's PID)
+ * 2 data directory path
+ * 3 postmaster start timestamp (time_t representation)
+ * 4 port number
+ * 5 socket directory path (empty on Windows)
+ * 6 first listen_address (IP address or "*"; empty if no TCP port)
+ * 7 shared memory key (not present on Windows)
+ *
+ * Lines 6 and up are added via AddToDataDirLockFile() after initial file
+ * creation; they have to be ordered according to time of addition.
+ *
+ * The socket lock file, if used, has the same contents as lines 1-5.
+ */
+#define LOCK_FILE_LINE_PID 1
+#define LOCK_FILE_LINE_DATA_DIR 2
+#define LOCK_FILE_LINE_START_TIME 3
+#define LOCK_FILE_LINE_PORT 4
+#define LOCK_FILE_LINE_SOCKET_DIR 5
+#define LOCK_FILE_LINE_LISTEN_ADDR 6
+#define LOCK_FILE_LINE_SHMEM_KEY 7
+
extern void CreateDataDirLockFile(bool amPostmaster);
extern void CreateSocketLockFile(const char *socketfile, bool amPostmaster);
extern void TouchSocketLockFile(void);
-extern void AddToLockFile(int target_line, const char *str);
+extern void AddToDataDirLockFile(int target_line, const char *str);
extern void ValidatePgVersion(const char *path);
extern void process_shared_preload_libraries(void);
extern void process_local_preload_libraries(void);
--
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