1/*-------------------------------------------------------------------------
2 *
3 * syslogger.c
4 *
5 * The system logger (syslogger) appeared in Postgres 8.0. It catches all
6 * stderr output from the postmaster, backends, and other subprocesses
7 * by redirecting to a pipe, and writes it to a set of logfiles.
8 * It's possible to have size and age limits for the logfile configured
9 * in postgresql.conf. If these limits are reached or passed, the
10 * current logfile is closed and a new one is created (rotated).
11 * The logfiles are stored in a subdirectory (configurable in
12 * postgresql.conf), using a user-selectable naming scheme.
13 *
14 * Author: Andreas Pflug <pgadmin@pse-consulting.de>
15 *
16 * Copyright (c) 2004-2019, PostgreSQL Global Development Group
17 *
18 *
19 * IDENTIFICATION
20 * src/backend/postmaster/syslogger.c
21 *
22 *-------------------------------------------------------------------------
23 */
24#include "postgres.h"
25
26#include <fcntl.h>
27#include <limits.h>
28#include <signal.h>
29#include <time.h>
30#include <unistd.h>
31#include <sys/stat.h>
32#include <sys/time.h>
33
34#include "common/file_perm.h"
35#include "lib/stringinfo.h"
36#include "libpq/pqsignal.h"
37#include "miscadmin.h"
38#include "nodes/pg_list.h"
39#include "pgstat.h"
40#include "pgtime.h"
41#include "postmaster/fork_process.h"
42#include "postmaster/postmaster.h"
43#include "postmaster/syslogger.h"
44#include "storage/dsm.h"
45#include "storage/fd.h"
46#include "storage/ipc.h"
47#include "storage/latch.h"
48#include "storage/pg_shmem.h"
49#include "tcop/tcopprot.h"
50#include "utils/guc.h"
51#include "utils/ps_status.h"
52#include "utils/timestamp.h"
53
54/*
55 * We read() into a temp buffer twice as big as a chunk, so that any fragment
56 * left after processing can be moved down to the front and we'll still have
57 * room to read a full chunk.
58 */
59#define READ_BUF_SIZE (2 * PIPE_CHUNK_SIZE)
60
61/* Log rotation signal file path, relative to $PGDATA */
62#define LOGROTATE_SIGNAL_FILE "logrotate"
63
64
65/*
66 * GUC parameters. Logging_collector cannot be changed after postmaster
67 * start, but the rest can change at SIGHUP.
68 */
69bool Logging_collector = false;
70int Log_RotationAge = HOURS_PER_DAY * MINS_PER_HOUR;
71int Log_RotationSize = 10 * 1024;
72char *Log_directory = NULL;
73char *Log_filename = NULL;
74bool Log_truncate_on_rotation = false;
75int Log_file_mode = S_IRUSR | S_IWUSR;
76
77/*
78 * Globally visible state (used by elog.c)
79 */
80bool am_syslogger = false;
81
82extern bool redirection_done;
83
84/*
85 * Private state
86 */
87static pg_time_t next_rotation_time;
88static bool pipe_eof_seen = false;
89static bool rotation_disabled = false;
90static FILE *syslogFile = NULL;
91static FILE *csvlogFile = NULL;
92NON_EXEC_STATIC pg_time_t first_syslogger_file_time = 0;
93static char *last_file_name = NULL;
94static char *last_csv_file_name = NULL;
95
96/*
97 * Buffers for saving partial messages from different backends.
98 *
99 * Keep NBUFFER_LISTS lists of these, with the entry for a given source pid
100 * being in the list numbered (pid % NBUFFER_LISTS), so as to cut down on
101 * the number of entries we have to examine for any one incoming message.
102 * There must never be more than one entry for the same source pid.
103 *
104 * An inactive buffer is not removed from its list, just held for re-use.
105 * An inactive buffer has pid == 0 and undefined contents of data.
106 */
107typedef struct
108{
109 int32 pid; /* PID of source process */
110 StringInfoData data; /* accumulated data, as a StringInfo */
111} save_buffer;
112
113#define NBUFFER_LISTS 256
114static List *buffer_lists[NBUFFER_LISTS];
115
116/* These must be exported for EXEC_BACKEND case ... annoying */
117#ifndef WIN32
118int syslogPipe[2] = {-1, -1};
119#else
120HANDLE syslogPipe[2] = {0, 0};
121#endif
122
123#ifdef WIN32
124static HANDLE threadHandle = 0;
125static CRITICAL_SECTION sysloggerSection;
126#endif
127
128/*
129 * Flags set by interrupt handlers for later service in the main loop.
130 */
131static volatile sig_atomic_t got_SIGHUP = false;
132static volatile sig_atomic_t rotation_requested = false;
133
134
135/* Local subroutines */
136#ifdef EXEC_BACKEND
137static pid_t syslogger_forkexec(void);
138static void syslogger_parseArgs(int argc, char *argv[]);
139#endif
140NON_EXEC_STATIC void SysLoggerMain(int argc, char *argv[]) pg_attribute_noreturn();
141static void process_pipe_input(char *logbuffer, int *bytes_in_logbuffer);
142static void flush_pipe_input(char *logbuffer, int *bytes_in_logbuffer);
143static FILE *logfile_open(const char *filename, const char *mode,
144 bool allow_errors);
145
146#ifdef WIN32
147static unsigned int __stdcall pipeThread(void *arg);
148#endif
149static void logfile_rotate(bool time_based_rotation, int size_rotation_for);
150static char *logfile_getname(pg_time_t timestamp, const char *suffix);
151static void set_next_rotation_time(void);
152static void sigHupHandler(SIGNAL_ARGS);
153static void sigUsr1Handler(SIGNAL_ARGS);
154static void update_metainfo_datafile(void);
155
156
157/*
158 * Main entry point for syslogger process
159 * argc/argv parameters are valid only in EXEC_BACKEND case.
160 */
161NON_EXEC_STATIC void
162SysLoggerMain(int argc, char *argv[])
163{
164#ifndef WIN32
165 char logbuffer[READ_BUF_SIZE];
166 int bytes_in_logbuffer = 0;
167#endif
168 char *currentLogDir;
169 char *currentLogFilename;
170 int currentLogRotationAge;
171 pg_time_t now;
172 WaitEventSet *wes;
173
174 now = MyStartTime;
175
176#ifdef EXEC_BACKEND
177 syslogger_parseArgs(argc, argv);
178#endif /* EXEC_BACKEND */
179
180 am_syslogger = true;
181
182 init_ps_display("logger", "", "", "");
183
184 /*
185 * If we restarted, our stderr is already redirected into our own input
186 * pipe. This is of course pretty useless, not to mention that it
187 * interferes with detecting pipe EOF. Point stderr to /dev/null. This
188 * assumes that all interesting messages generated in the syslogger will
189 * come through elog.c and will be sent to write_syslogger_file.
190 */
191 if (redirection_done)
192 {
193 int fd = open(DEVNULL, O_WRONLY, 0);
194
195 /*
196 * The closes might look redundant, but they are not: we want to be
197 * darn sure the pipe gets closed even if the open failed. We can
198 * survive running with stderr pointing nowhere, but we can't afford
199 * to have extra pipe input descriptors hanging around.
200 *
201 * As we're just trying to reset these to go to DEVNULL, there's not
202 * much point in checking for failure from the close/dup2 calls here,
203 * if they fail then presumably the file descriptors are closed and
204 * any writes will go into the bitbucket anyway.
205 */
206 close(fileno(stdout));
207 close(fileno(stderr));
208 if (fd != -1)
209 {
210 (void) dup2(fd, fileno(stdout));
211 (void) dup2(fd, fileno(stderr));
212 close(fd);
213 }
214 }
215
216 /*
217 * Syslogger's own stderr can't be the syslogPipe, so set it back to text
218 * mode if we didn't just close it. (It was set to binary in
219 * SubPostmasterMain).
220 */
221#ifdef WIN32
222 else
223 _setmode(_fileno(stderr), _O_TEXT);
224#endif
225
226 /*
227 * Also close our copy of the write end of the pipe. This is needed to
228 * ensure we can detect pipe EOF correctly. (But note that in the restart
229 * case, the postmaster already did this.)
230 */
231#ifndef WIN32
232 if (syslogPipe[1] >= 0)
233 close(syslogPipe[1]);
234 syslogPipe[1] = -1;
235#else
236 if (syslogPipe[1])
237 CloseHandle(syslogPipe[1]);
238 syslogPipe[1] = 0;
239#endif
240
241 /*
242 * Properly accept or ignore signals the postmaster might send us
243 *
244 * Note: we ignore all termination signals, and instead exit only when all
245 * upstream processes are gone, to ensure we don't miss any dying gasps of
246 * broken backends...
247 */
248
249 pqsignal(SIGHUP, sigHupHandler); /* set flag to read config file */
250 pqsignal(SIGINT, SIG_IGN);
251 pqsignal(SIGTERM, SIG_IGN);
252 pqsignal(SIGQUIT, SIG_IGN);
253 pqsignal(SIGALRM, SIG_IGN);
254 pqsignal(SIGPIPE, SIG_IGN);
255 pqsignal(SIGUSR1, sigUsr1Handler); /* request log rotation */
256 pqsignal(SIGUSR2, SIG_IGN);
257
258 /*
259 * Reset some signals that are accepted by postmaster but not here
260 */
261 pqsignal(SIGCHLD, SIG_DFL);
262
263 PG_SETMASK(&UnBlockSig);
264
265#ifdef WIN32
266 /* Fire up separate data transfer thread */
267 InitializeCriticalSection(&sysloggerSection);
268 EnterCriticalSection(&sysloggerSection);
269
270 threadHandle = (HANDLE) _beginthreadex(NULL, 0, pipeThread, NULL, 0, NULL);
271 if (threadHandle == 0)
272 elog(FATAL, "could not create syslogger data transfer thread: %m");
273#endif /* WIN32 */
274
275 /*
276 * Remember active logfiles' name(s). We recompute 'em from the reference
277 * time because passing down just the pg_time_t is a lot cheaper than
278 * passing a whole file path in the EXEC_BACKEND case.
279 */
280 last_file_name = logfile_getname(first_syslogger_file_time, NULL);
281 if (csvlogFile != NULL)
282 last_csv_file_name = logfile_getname(first_syslogger_file_time, ".csv");
283
284 /* remember active logfile parameters */
285 currentLogDir = pstrdup(Log_directory);
286 currentLogFilename = pstrdup(Log_filename);
287 currentLogRotationAge = Log_RotationAge;
288 /* set next planned rotation time */
289 set_next_rotation_time();
290 update_metainfo_datafile();
291
292 /*
293 * Reset whereToSendOutput, as the postmaster will do (but hasn't yet, at
294 * the point where we forked). This prevents duplicate output of messages
295 * from syslogger itself.
296 */
297 whereToSendOutput = DestNone;
298
299 /*
300 * Set up a reusable WaitEventSet object we'll use to wait for our latch,
301 * and (except on Windows) our socket.
302 *
303 * Unlike all other postmaster child processes, we'll ignore postmaster
304 * death because we want to collect final log output from all backends and
305 * then exit last. We'll do that by running until we see EOF on the
306 * syslog pipe, which implies that all other backends have exited
307 * (including the postmaster).
308 */
309 wes = CreateWaitEventSet(CurrentMemoryContext, 2);
310 AddWaitEventToSet(wes, WL_LATCH_SET, PGINVALID_SOCKET, MyLatch, NULL);
311#ifndef WIN32
312 AddWaitEventToSet(wes, WL_SOCKET_READABLE, syslogPipe[0], NULL, NULL);
313#endif
314
315 /* main worker loop */
316 for (;;)
317 {
318 bool time_based_rotation = false;
319 int size_rotation_for = 0;
320 long cur_timeout;
321 WaitEvent event;
322
323#ifndef WIN32
324 int rc;
325#endif
326
327 /* Clear any already-pending wakeups */
328 ResetLatch(MyLatch);
329
330 /*
331 * Process any requests or signals received recently.
332 */
333 if (got_SIGHUP)
334 {
335 got_SIGHUP = false;
336 ProcessConfigFile(PGC_SIGHUP);
337
338 /*
339 * Check if the log directory or filename pattern changed in
340 * postgresql.conf. If so, force rotation to make sure we're
341 * writing the logfiles in the right place.
342 */
343 if (strcmp(Log_directory, currentLogDir) != 0)
344 {
345 pfree(currentLogDir);
346 currentLogDir = pstrdup(Log_directory);
347 rotation_requested = true;
348
349 /*
350 * Also, create new directory if not present; ignore errors
351 */
352 (void) MakePGDirectory(Log_directory);
353 }
354 if (strcmp(Log_filename, currentLogFilename) != 0)
355 {
356 pfree(currentLogFilename);
357 currentLogFilename = pstrdup(Log_filename);
358 rotation_requested = true;
359 }
360
361 /*
362 * Force a rotation if CSVLOG output was just turned on or off and
363 * we need to open or close csvlogFile accordingly.
364 */
365 if (((Log_destination & LOG_DESTINATION_CSVLOG) != 0) !=
366 (csvlogFile != NULL))
367 rotation_requested = true;
368
369 /*
370 * If rotation time parameter changed, reset next rotation time,
371 * but don't immediately force a rotation.
372 */
373 if (currentLogRotationAge != Log_RotationAge)
374 {
375 currentLogRotationAge = Log_RotationAge;
376 set_next_rotation_time();
377 }
378
379 /*
380 * If we had a rotation-disabling failure, re-enable rotation
381 * attempts after SIGHUP, and force one immediately.
382 */
383 if (rotation_disabled)
384 {
385 rotation_disabled = false;
386 rotation_requested = true;
387 }
388
389 /*
390 * Force rewriting last log filename when reloading configuration.
391 * Even if rotation_requested is false, log_destination may have
392 * been changed and we don't want to wait the next file rotation.
393 */
394 update_metainfo_datafile();
395 }
396
397 if (Log_RotationAge > 0 && !rotation_disabled)
398 {
399 /* Do a logfile rotation if it's time */
400 now = (pg_time_t) time(NULL);
401 if (now >= next_rotation_time)
402 rotation_requested = time_based_rotation = true;
403 }
404
405 if (!rotation_requested && Log_RotationSize > 0 && !rotation_disabled)
406 {
407 /* Do a rotation if file is too big */
408 if (ftell(syslogFile) >= Log_RotationSize * 1024L)
409 {
410 rotation_requested = true;
411 size_rotation_for |= LOG_DESTINATION_STDERR;
412 }
413 if (csvlogFile != NULL &&
414 ftell(csvlogFile) >= Log_RotationSize * 1024L)
415 {
416 rotation_requested = true;
417 size_rotation_for |= LOG_DESTINATION_CSVLOG;
418 }
419 }
420
421 if (rotation_requested)
422 {
423 /*
424 * Force rotation when both values are zero. It means the request
425 * was sent by pg_rotate_logfile() or "pg_ctl logrotate".
426 */
427 if (!time_based_rotation && size_rotation_for == 0)
428 size_rotation_for = LOG_DESTINATION_STDERR | LOG_DESTINATION_CSVLOG;
429 logfile_rotate(time_based_rotation, size_rotation_for);
430 }
431
432 /*
433 * Calculate time till next time-based rotation, so that we don't
434 * sleep longer than that. We assume the value of "now" obtained
435 * above is still close enough. Note we can't make this calculation
436 * until after calling logfile_rotate(), since it will advance
437 * next_rotation_time.
438 *
439 * Also note that we need to beware of overflow in calculation of the
440 * timeout: with large settings of Log_RotationAge, next_rotation_time
441 * could be more than INT_MAX msec in the future. In that case we'll
442 * wait no more than INT_MAX msec, and try again.
443 */
444 if (Log_RotationAge > 0 && !rotation_disabled)
445 {
446 pg_time_t delay;
447
448 delay = next_rotation_time - now;
449 if (delay > 0)
450 {
451 if (delay > INT_MAX / 1000)
452 delay = INT_MAX / 1000;
453 cur_timeout = delay * 1000L; /* msec */
454 }
455 else
456 cur_timeout = 0;
457 }
458 else
459 cur_timeout = -1L;
460
461 /*
462 * Sleep until there's something to do
463 */
464#ifndef WIN32
465 rc = WaitEventSetWait(wes, cur_timeout, &event, 1,
466 WAIT_EVENT_SYSLOGGER_MAIN);
467
468 if (rc == 1 && event.events == WL_SOCKET_READABLE)
469 {
470 int bytesRead;
471
472 bytesRead = read(syslogPipe[0],
473 logbuffer + bytes_in_logbuffer,
474 sizeof(logbuffer) - bytes_in_logbuffer);
475 if (bytesRead < 0)
476 {
477 if (errno != EINTR)
478 ereport(LOG,
479 (errcode_for_socket_access(),
480 errmsg("could not read from logger pipe: %m")));
481 }
482 else if (bytesRead > 0)
483 {
484 bytes_in_logbuffer += bytesRead;
485 process_pipe_input(logbuffer, &bytes_in_logbuffer);
486 continue;
487 }
488 else
489 {
490 /*
491 * Zero bytes read when select() is saying read-ready means
492 * EOF on the pipe: that is, there are no longer any processes
493 * with the pipe write end open. Therefore, the postmaster
494 * and all backends are shut down, and we are done.
495 */
496 pipe_eof_seen = true;
497
498 /* if there's any data left then force it out now */
499 flush_pipe_input(logbuffer, &bytes_in_logbuffer);
500 }
501 }
502#else /* WIN32 */
503
504 /*
505 * On Windows we leave it to a separate thread to transfer data and
506 * detect pipe EOF. The main thread just wakes up to handle SIGHUP
507 * and rotation conditions.
508 *
509 * Server code isn't generally thread-safe, so we ensure that only one
510 * of the threads is active at a time by entering the critical section
511 * whenever we're not sleeping.
512 */
513 LeaveCriticalSection(&sysloggerSection);
514
515 (void) WaitEventSetWait(wes, cur_timeout, &event, 1,
516 WAIT_EVENT_SYSLOGGER_MAIN);
517
518 EnterCriticalSection(&sysloggerSection);
519#endif /* WIN32 */
520
521 if (pipe_eof_seen)
522 {
523 /*
524 * seeing this message on the real stderr is annoying - so we make
525 * it DEBUG1 to suppress in normal use.
526 */
527 ereport(DEBUG1,
528 (errmsg("logger shutting down")));
529
530 /*
531 * Normal exit from the syslogger is here. Note that we
532 * deliberately do not close syslogFile before exiting; this is to
533 * allow for the possibility of elog messages being generated
534 * inside proc_exit. Regular exit() will take care of flushing
535 * and closing stdio channels.
536 */
537 proc_exit(0);
538 }
539 }
540}
541
542/*
543 * Postmaster subroutine to start a syslogger subprocess.
544 */
545int
546SysLogger_Start(void)
547{
548 pid_t sysloggerPid;
549 char *filename;
550
551 if (!Logging_collector)
552 return 0;
553
554 /*
555 * If first time through, create the pipe which will receive stderr
556 * output.
557 *
558 * If the syslogger crashes and needs to be restarted, we continue to use
559 * the same pipe (indeed must do so, since extant backends will be writing
560 * into that pipe).
561 *
562 * This means the postmaster must continue to hold the read end of the
563 * pipe open, so we can pass it down to the reincarnated syslogger. This
564 * is a bit klugy but we have little choice.
565 */
566#ifndef WIN32
567 if (syslogPipe[0] < 0)
568 {
569 if (pipe(syslogPipe) < 0)
570 ereport(FATAL,
571 (errcode_for_socket_access(),
572 (errmsg("could not create pipe for syslog: %m"))));
573 }
574#else
575 if (!syslogPipe[0])
576 {
577 SECURITY_ATTRIBUTES sa;
578
579 memset(&sa, 0, sizeof(SECURITY_ATTRIBUTES));
580 sa.nLength = sizeof(SECURITY_ATTRIBUTES);
581 sa.bInheritHandle = TRUE;
582
583 if (!CreatePipe(&syslogPipe[0], &syslogPipe[1], &sa, 32768))
584 ereport(FATAL,
585 (errcode_for_file_access(),
586 (errmsg("could not create pipe for syslog: %m"))));
587 }
588#endif
589
590 /*
591 * Create log directory if not present; ignore errors
592 */
593 (void) MakePGDirectory(Log_directory);
594
595 /*
596 * The initial logfile is created right in the postmaster, to verify that
597 * the Log_directory is writable. We save the reference time so that the
598 * syslogger child process can recompute this file name.
599 *
600 * It might look a bit strange to re-do this during a syslogger restart,
601 * but we must do so since the postmaster closed syslogFile after the
602 * previous fork (and remembering that old file wouldn't be right anyway).
603 * Note we always append here, we won't overwrite any existing file. This
604 * is consistent with the normal rules, because by definition this is not
605 * a time-based rotation.
606 */
607 first_syslogger_file_time = time(NULL);
608
609 filename = logfile_getname(first_syslogger_file_time, NULL);
610
611 syslogFile = logfile_open(filename, "a", false);
612
613 pfree(filename);
614
615 /*
616 * Likewise for the initial CSV log file, if that's enabled. (Note that
617 * we open syslogFile even when only CSV output is nominally enabled,
618 * since some code paths will write to syslogFile anyway.)
619 */
620 if (Log_destination & LOG_DESTINATION_CSVLOG)
621 {
622 filename = logfile_getname(first_syslogger_file_time, ".csv");
623
624 csvlogFile = logfile_open(filename, "a", false);
625
626 pfree(filename);
627 }
628
629#ifdef EXEC_BACKEND
630 switch ((sysloggerPid = syslogger_forkexec()))
631#else
632 switch ((sysloggerPid = fork_process()))
633#endif
634 {
635 case -1:
636 ereport(LOG,
637 (errmsg("could not fork system logger: %m")));
638 return 0;
639
640#ifndef EXEC_BACKEND
641 case 0:
642 /* in postmaster child ... */
643 InitPostmasterChild();
644
645 /* Close the postmaster's sockets */
646 ClosePostmasterPorts(true);
647
648 /* Drop our connection to postmaster's shared memory, as well */
649 dsm_detach_all();
650 PGSharedMemoryDetach();
651
652 /* do the work */
653 SysLoggerMain(0, NULL);
654 break;
655#endif
656
657 default:
658 /* success, in postmaster */
659
660 /* now we redirect stderr, if not done already */
661 if (!redirection_done)
662 {
663#ifdef WIN32
664 int fd;
665#endif
666
667 /*
668 * Leave a breadcrumb trail when redirecting, in case the user
669 * forgets that redirection is active and looks only at the
670 * original stderr target file.
671 */
672 ereport(LOG,
673 (errmsg("redirecting log output to logging collector process"),
674 errhint("Future log output will appear in directory \"%s\".",
675 Log_directory)));
676
677#ifndef WIN32
678 fflush(stdout);
679 if (dup2(syslogPipe[1], fileno(stdout)) < 0)
680 ereport(FATAL,
681 (errcode_for_file_access(),
682 errmsg("could not redirect stdout: %m")));
683 fflush(stderr);
684 if (dup2(syslogPipe[1], fileno(stderr)) < 0)
685 ereport(FATAL,
686 (errcode_for_file_access(),
687 errmsg("could not redirect stderr: %m")));
688 /* Now we are done with the write end of the pipe. */
689 close(syslogPipe[1]);
690 syslogPipe[1] = -1;
691#else
692
693 /*
694 * open the pipe in binary mode and make sure stderr is binary
695 * after it's been dup'ed into, to avoid disturbing the pipe
696 * chunking protocol.
697 */
698 fflush(stderr);
699 fd = _open_osfhandle((intptr_t) syslogPipe[1],
700 _O_APPEND | _O_BINARY);
701 if (dup2(fd, _fileno(stderr)) < 0)
702 ereport(FATAL,
703 (errcode_for_file_access(),
704 errmsg("could not redirect stderr: %m")));
705 close(fd);
706 _setmode(_fileno(stderr), _O_BINARY);
707
708 /*
709 * Now we are done with the write end of the pipe.
710 * CloseHandle() must not be called because the preceding
711 * close() closes the underlying handle.
712 */
713 syslogPipe[1] = 0;
714#endif
715 redirection_done = true;
716 }
717
718 /* postmaster will never write the file(s); close 'em */
719 fclose(syslogFile);
720 syslogFile = NULL;
721 if (csvlogFile != NULL)
722 {
723 fclose(csvlogFile);
724 csvlogFile = NULL;
725 }
726 return (int) sysloggerPid;
727 }
728
729 /* we should never reach here */
730 return 0;
731}
732
733
734#ifdef EXEC_BACKEND
735
736/*
737 * syslogger_forkexec() -
738 *
739 * Format up the arglist for, then fork and exec, a syslogger process
740 */
741static pid_t
742syslogger_forkexec(void)
743{
744 char *av[10];
745 int ac = 0;
746 char filenobuf[32];
747 char csvfilenobuf[32];
748
749 av[ac++] = "postgres";
750 av[ac++] = "--forklog";
751 av[ac++] = NULL; /* filled in by postmaster_forkexec */
752
753 /* static variables (those not passed by write_backend_variables) */
754#ifndef WIN32
755 if (syslogFile != NULL)
756 snprintf(filenobuf, sizeof(filenobuf), "%d",
757 fileno(syslogFile));
758 else
759 strcpy(filenobuf, "-1");
760#else /* WIN32 */
761 if (syslogFile != NULL)
762 snprintf(filenobuf, sizeof(filenobuf), "%ld",
763 (long) _get_osfhandle(_fileno(syslogFile)));
764 else
765 strcpy(filenobuf, "0");
766#endif /* WIN32 */
767 av[ac++] = filenobuf;
768
769#ifndef WIN32
770 if (csvlogFile != NULL)
771 snprintf(csvfilenobuf, sizeof(csvfilenobuf), "%d",
772 fileno(csvlogFile));
773 else
774 strcpy(csvfilenobuf, "-1");
775#else /* WIN32 */
776 if (csvlogFile != NULL)
777 snprintf(csvfilenobuf, sizeof(csvfilenobuf), "%ld",
778 (long) _get_osfhandle(_fileno(csvlogFile)));
779 else
780 strcpy(csvfilenobuf, "0");
781#endif /* WIN32 */
782 av[ac++] = csvfilenobuf;
783
784 av[ac] = NULL;
785 Assert(ac < lengthof(av));
786
787 return postmaster_forkexec(ac, av);
788}
789
790/*
791 * syslogger_parseArgs() -
792 *
793 * Extract data from the arglist for exec'ed syslogger process
794 */
795static void
796syslogger_parseArgs(int argc, char *argv[])
797{
798 int fd;
799
800 Assert(argc == 5);
801 argv += 3;
802
803 /*
804 * Re-open the error output files that were opened by SysLogger_Start().
805 *
806 * We expect this will always succeed, which is too optimistic, but if it
807 * fails there's not a lot we can do to report the problem anyway. As
808 * coded, we'll just crash on a null pointer dereference after failure...
809 */
810#ifndef WIN32
811 fd = atoi(*argv++);
812 if (fd != -1)
813 {
814 syslogFile = fdopen(fd, "a");
815 setvbuf(syslogFile, NULL, PG_IOLBF, 0);
816 }
817 fd = atoi(*argv++);
818 if (fd != -1)
819 {
820 csvlogFile = fdopen(fd, "a");
821 setvbuf(csvlogFile, NULL, PG_IOLBF, 0);
822 }
823#else /* WIN32 */
824 fd = atoi(*argv++);
825 if (fd != 0)
826 {
827 fd = _open_osfhandle(fd, _O_APPEND | _O_TEXT);
828 if (fd > 0)
829 {
830 syslogFile = fdopen(fd, "a");
831 setvbuf(syslogFile, NULL, PG_IOLBF, 0);
832 }
833 }
834 fd = atoi(*argv++);
835 if (fd != 0)
836 {
837 fd = _open_osfhandle(fd, _O_APPEND | _O_TEXT);
838 if (fd > 0)
839 {
840 csvlogFile = fdopen(fd, "a");
841 setvbuf(csvlogFile, NULL, PG_IOLBF, 0);
842 }
843 }
844#endif /* WIN32 */
845}
846#endif /* EXEC_BACKEND */
847
848
849/* --------------------------------
850 * pipe protocol handling
851 * --------------------------------
852 */
853
854/*
855 * Process data received through the syslogger pipe.
856 *
857 * This routine interprets the log pipe protocol which sends log messages as
858 * (hopefully atomic) chunks - such chunks are detected and reassembled here.
859 *
860 * The protocol has a header that starts with two nul bytes, then has a 16 bit
861 * length, the pid of the sending process, and a flag to indicate if it is
862 * the last chunk in a message. Incomplete chunks are saved until we read some
863 * more, and non-final chunks are accumulated until we get the final chunk.
864 *
865 * All of this is to avoid 2 problems:
866 * . partial messages being written to logfiles (messes rotation), and
867 * . messages from different backends being interleaved (messages garbled).
868 *
869 * Any non-protocol messages are written out directly. These should only come
870 * from non-PostgreSQL sources, however (e.g. third party libraries writing to
871 * stderr).
872 *
873 * logbuffer is the data input buffer, and *bytes_in_logbuffer is the number
874 * of bytes present. On exit, any not-yet-eaten data is left-justified in
875 * logbuffer, and *bytes_in_logbuffer is updated.
876 */
877static void
878process_pipe_input(char *logbuffer, int *bytes_in_logbuffer)
879{
880 char *cursor = logbuffer;
881 int count = *bytes_in_logbuffer;
882 int dest = LOG_DESTINATION_STDERR;
883
884 /* While we have enough for a header, process data... */
885 while (count >= (int) (offsetof(PipeProtoHeader, data) + 1))
886 {
887 PipeProtoHeader p;
888 int chunklen;
889
890 /* Do we have a valid header? */
891 memcpy(&p, cursor, offsetof(PipeProtoHeader, data));
892 if (p.nuls[0] == '\0' && p.nuls[1] == '\0' &&
893 p.len > 0 && p.len <= PIPE_MAX_PAYLOAD &&
894 p.pid != 0 &&
895 (p.is_last == 't' || p.is_last == 'f' ||
896 p.is_last == 'T' || p.is_last == 'F'))
897 {
898 List *buffer_list;
899 ListCell *cell;
900 save_buffer *existing_slot = NULL,
901 *free_slot = NULL;
902 StringInfo str;
903
904 chunklen = PIPE_HEADER_SIZE + p.len;
905
906 /* Fall out of loop if we don't have the whole chunk yet */
907 if (count < chunklen)
908 break;
909
910 dest = (p.is_last == 'T' || p.is_last == 'F') ?
911 LOG_DESTINATION_CSVLOG : LOG_DESTINATION_STDERR;
912
913 /* Locate any existing buffer for this source pid */
914 buffer_list = buffer_lists[p.pid % NBUFFER_LISTS];
915 foreach(cell, buffer_list)
916 {
917 save_buffer *buf = (save_buffer *) lfirst(cell);
918
919 if (buf->pid == p.pid)
920 {
921 existing_slot = buf;
922 break;
923 }
924 if (buf->pid == 0 && free_slot == NULL)
925 free_slot = buf;
926 }
927
928 if (p.is_last == 'f' || p.is_last == 'F')
929 {
930 /*
931 * Save a complete non-final chunk in a per-pid buffer
932 */
933 if (existing_slot != NULL)
934 {
935 /* Add chunk to data from preceding chunks */
936 str = &(existing_slot->data);
937 appendBinaryStringInfo(str,
938 cursor + PIPE_HEADER_SIZE,
939 p.len);
940 }
941 else
942 {
943 /* First chunk of message, save in a new buffer */
944 if (free_slot == NULL)
945 {
946 /*
947 * Need a free slot, but there isn't one in the list,
948 * so create a new one and extend the list with it.
949 */
950 free_slot = palloc(sizeof(save_buffer));
951 buffer_list = lappend(buffer_list, free_slot);
952 buffer_lists[p.pid % NBUFFER_LISTS] = buffer_list;
953 }
954 free_slot->pid = p.pid;
955 str = &(free_slot->data);
956 initStringInfo(str);
957 appendBinaryStringInfo(str,
958 cursor + PIPE_HEADER_SIZE,
959 p.len);
960 }
961 }
962 else
963 {
964 /*
965 * Final chunk --- add it to anything saved for that pid, and
966 * either way write the whole thing out.
967 */
968 if (existing_slot != NULL)
969 {
970 str = &(existing_slot->data);
971 appendBinaryStringInfo(str,
972 cursor + PIPE_HEADER_SIZE,
973 p.len);
974 write_syslogger_file(str->data, str->len, dest);
975 /* Mark the buffer unused, and reclaim string storage */
976 existing_slot->pid = 0;
977 pfree(str->data);
978 }
979 else
980 {
981 /* The whole message was one chunk, evidently. */
982 write_syslogger_file(cursor + PIPE_HEADER_SIZE, p.len,
983 dest);
984 }
985 }
986
987 /* Finished processing this chunk */
988 cursor += chunklen;
989 count -= chunklen;
990 }
991 else
992 {
993 /* Process non-protocol data */
994
995 /*
996 * Look for the start of a protocol header. If found, dump data
997 * up to there and repeat the loop. Otherwise, dump it all and
998 * fall out of the loop. (Note: we want to dump it all if at all
999 * possible, so as to avoid dividing non-protocol messages across
1000 * logfiles. We expect that in many scenarios, a non-protocol
1001 * message will arrive all in one read(), and we want to respect
1002 * the read() boundary if possible.)
1003 */
1004 for (chunklen = 1; chunklen < count; chunklen++)
1005 {
1006 if (cursor[chunklen] == '\0')
1007 break;
1008 }
1009 /* fall back on the stderr log as the destination */
1010 write_syslogger_file(cursor, chunklen, LOG_DESTINATION_STDERR);
1011 cursor += chunklen;
1012 count -= chunklen;
1013 }
1014 }
1015
1016 /* We don't have a full chunk, so left-align what remains in the buffer */
1017 if (count > 0 && cursor != logbuffer)
1018 memmove(logbuffer, cursor, count);
1019 *bytes_in_logbuffer = count;
1020}
1021
1022/*
1023 * Force out any buffered data
1024 *
1025 * This is currently used only at syslogger shutdown, but could perhaps be
1026 * useful at other times, so it is careful to leave things in a clean state.
1027 */
1028static void
1029flush_pipe_input(char *logbuffer, int *bytes_in_logbuffer)
1030{
1031 int i;
1032
1033 /* Dump any incomplete protocol messages */
1034 for (i = 0; i < NBUFFER_LISTS; i++)
1035 {
1036 List *list = buffer_lists[i];
1037 ListCell *cell;
1038
1039 foreach(cell, list)
1040 {
1041 save_buffer *buf = (save_buffer *) lfirst(cell);
1042
1043 if (buf->pid != 0)
1044 {
1045 StringInfo str = &(buf->data);
1046
1047 write_syslogger_file(str->data, str->len,
1048 LOG_DESTINATION_STDERR);
1049 /* Mark the buffer unused, and reclaim string storage */
1050 buf->pid = 0;
1051 pfree(str->data);
1052 }
1053 }
1054 }
1055
1056 /*
1057 * Force out any remaining pipe data as-is; we don't bother trying to
1058 * remove any protocol headers that may exist in it.
1059 */
1060 if (*bytes_in_logbuffer > 0)
1061 write_syslogger_file(logbuffer, *bytes_in_logbuffer,
1062 LOG_DESTINATION_STDERR);
1063 *bytes_in_logbuffer = 0;
1064}
1065
1066
1067/* --------------------------------
1068 * logfile routines
1069 * --------------------------------
1070 */
1071
1072/*
1073 * Write text to the currently open logfile
1074 *
1075 * This is exported so that elog.c can call it when am_syslogger is true.
1076 * This allows the syslogger process to record elog messages of its own,
1077 * even though its stderr does not point at the syslog pipe.
1078 */
1079void
1080write_syslogger_file(const char *buffer, int count, int destination)
1081{
1082 int rc;
1083 FILE *logfile;
1084
1085 /*
1086 * If we're told to write to csvlogFile, but it's not open, dump the data
1087 * to syslogFile (which is always open) instead. This can happen if CSV
1088 * output is enabled after postmaster start and we've been unable to open
1089 * csvlogFile. There are also race conditions during a parameter change
1090 * whereby backends might send us CSV output before we open csvlogFile or
1091 * after we close it. Writing CSV-formatted output to the regular log
1092 * file isn't great, but it beats dropping log output on the floor.
1093 *
1094 * Think not to improve this by trying to open csvlogFile on-the-fly. Any
1095 * failure in that would lead to recursion.
1096 */
1097 logfile = (destination == LOG_DESTINATION_CSVLOG &&
1098 csvlogFile != NULL) ? csvlogFile : syslogFile;
1099
1100 rc = fwrite(buffer, 1, count, logfile);
1101
1102 /*
1103 * Try to report any failure. We mustn't use ereport because it would
1104 * just recurse right back here, but write_stderr is OK: it will write
1105 * either to the postmaster's original stderr, or to /dev/null, but never
1106 * to our input pipe which would result in a different sort of looping.
1107 */
1108 if (rc != count)
1109 write_stderr("could not write to log file: %s\n", strerror(errno));
1110}
1111
1112#ifdef WIN32
1113
1114/*
1115 * Worker thread to transfer data from the pipe to the current logfile.
1116 *
1117 * We need this because on Windows, WaitforMultipleObjects does not work on
1118 * unnamed pipes: it always reports "signaled", so the blocking ReadFile won't
1119 * allow for SIGHUP; and select is for sockets only.
1120 */
1121static unsigned int __stdcall
1122pipeThread(void *arg)
1123{
1124 char logbuffer[READ_BUF_SIZE];
1125 int bytes_in_logbuffer = 0;
1126
1127 for (;;)
1128 {
1129 DWORD bytesRead;
1130 BOOL result;
1131
1132 result = ReadFile(syslogPipe[0],
1133 logbuffer + bytes_in_logbuffer,
1134 sizeof(logbuffer) - bytes_in_logbuffer,
1135 &bytesRead, 0);
1136
1137 /*
1138 * Enter critical section before doing anything that might touch
1139 * global state shared by the main thread. Anything that uses
1140 * palloc()/pfree() in particular are not safe outside the critical
1141 * section.
1142 */
1143 EnterCriticalSection(&sysloggerSection);
1144 if (!result)
1145 {
1146 DWORD error = GetLastError();
1147
1148 if (error == ERROR_HANDLE_EOF ||
1149 error == ERROR_BROKEN_PIPE)
1150 break;
1151 _dosmaperr(error);
1152 ereport(LOG,
1153 (errcode_for_file_access(),
1154 errmsg("could not read from logger pipe: %m")));
1155 }
1156 else if (bytesRead > 0)
1157 {
1158 bytes_in_logbuffer += bytesRead;
1159 process_pipe_input(logbuffer, &bytes_in_logbuffer);
1160 }
1161
1162 /*
1163 * If we've filled the current logfile, nudge the main thread to do a
1164 * log rotation.
1165 */
1166 if (Log_RotationSize > 0)
1167 {
1168 if (ftell(syslogFile) >= Log_RotationSize * 1024L ||
1169 (csvlogFile != NULL && ftell(csvlogFile) >= Log_RotationSize * 1024L))
1170 SetLatch(MyLatch);
1171 }
1172 LeaveCriticalSection(&sysloggerSection);
1173 }
1174
1175 /* We exit the above loop only upon detecting pipe EOF */
1176 pipe_eof_seen = true;
1177
1178 /* if there's any data left then force it out now */
1179 flush_pipe_input(logbuffer, &bytes_in_logbuffer);
1180
1181 /* set the latch to waken the main thread, which will quit */
1182 SetLatch(MyLatch);
1183
1184 LeaveCriticalSection(&sysloggerSection);
1185 _endthread();
1186 return 0;
1187}
1188#endif /* WIN32 */
1189
1190/*
1191 * Open a new logfile with proper permissions and buffering options.
1192 *
1193 * If allow_errors is true, we just log any open failure and return NULL
1194 * (with errno still correct for the fopen failure).
1195 * Otherwise, errors are treated as fatal.
1196 */
1197static FILE *
1198logfile_open(const char *filename, const char *mode, bool allow_errors)
1199{
1200 FILE *fh;
1201 mode_t oumask;
1202
1203 /*
1204 * Note we do not let Log_file_mode disable IWUSR, since we certainly want
1205 * to be able to write the files ourselves.
1206 */
1207 oumask = umask((mode_t) ((~(Log_file_mode | S_IWUSR)) & (S_IRWXU | S_IRWXG | S_IRWXO)));
1208 fh = fopen(filename, mode);
1209 umask(oumask);
1210
1211 if (fh)
1212 {
1213 setvbuf(fh, NULL, PG_IOLBF, 0);
1214
1215#ifdef WIN32
1216 /* use CRLF line endings on Windows */
1217 _setmode(_fileno(fh), _O_TEXT);
1218#endif
1219 }
1220 else
1221 {
1222 int save_errno = errno;
1223
1224 ereport(allow_errors ? LOG : FATAL,
1225 (errcode_for_file_access(),
1226 errmsg("could not open log file \"%s\": %m",
1227 filename)));
1228 errno = save_errno;
1229 }
1230
1231 return fh;
1232}
1233
1234/*
1235 * perform logfile rotation
1236 */
1237static void
1238logfile_rotate(bool time_based_rotation, int size_rotation_for)
1239{
1240 char *filename;
1241 char *csvfilename = NULL;
1242 pg_time_t fntime;
1243 FILE *fh;
1244
1245 rotation_requested = false;
1246
1247 /*
1248 * When doing a time-based rotation, invent the new logfile name based on
1249 * the planned rotation time, not current time, to avoid "slippage" in the
1250 * file name when we don't do the rotation immediately.
1251 */
1252 if (time_based_rotation)
1253 fntime = next_rotation_time;
1254 else
1255 fntime = time(NULL);
1256 filename = logfile_getname(fntime, NULL);
1257 if (Log_destination & LOG_DESTINATION_CSVLOG)
1258 csvfilename = logfile_getname(fntime, ".csv");
1259
1260 /*
1261 * Decide whether to overwrite or append. We can overwrite if (a)
1262 * Log_truncate_on_rotation is set, (b) the rotation was triggered by
1263 * elapsed time and not something else, and (c) the computed file name is
1264 * different from what we were previously logging into.
1265 *
1266 * Note: last_file_name should never be NULL here, but if it is, append.
1267 */
1268 if (time_based_rotation || (size_rotation_for & LOG_DESTINATION_STDERR))
1269 {
1270 if (Log_truncate_on_rotation && time_based_rotation &&
1271 last_file_name != NULL &&
1272 strcmp(filename, last_file_name) != 0)
1273 fh = logfile_open(filename, "w", true);
1274 else
1275 fh = logfile_open(filename, "a", true);
1276
1277 if (!fh)
1278 {
1279 /*
1280 * ENFILE/EMFILE are not too surprising on a busy system; just
1281 * keep using the old file till we manage to get a new one.
1282 * Otherwise, assume something's wrong with Log_directory and stop
1283 * trying to create files.
1284 */
1285 if (errno != ENFILE && errno != EMFILE)
1286 {
1287 ereport(LOG,
1288 (errmsg("disabling automatic rotation (use SIGHUP to re-enable)")));
1289 rotation_disabled = true;
1290 }
1291
1292 if (filename)
1293 pfree(filename);
1294 if (csvfilename)
1295 pfree(csvfilename);
1296 return;
1297 }
1298
1299 fclose(syslogFile);
1300 syslogFile = fh;
1301
1302 /* instead of pfree'ing filename, remember it for next time */
1303 if (last_file_name != NULL)
1304 pfree(last_file_name);
1305 last_file_name = filename;
1306 filename = NULL;
1307 }
1308
1309 /*
1310 * Same as above, but for csv file. Note that if LOG_DESTINATION_CSVLOG
1311 * was just turned on, we might have to open csvlogFile here though it was
1312 * not open before. In such a case we'll append not overwrite (since
1313 * last_csv_file_name will be NULL); that is consistent with the normal
1314 * rules since it's not a time-based rotation.
1315 */
1316 if ((Log_destination & LOG_DESTINATION_CSVLOG) &&
1317 (csvlogFile == NULL ||
1318 time_based_rotation || (size_rotation_for & LOG_DESTINATION_CSVLOG)))
1319 {
1320 if (Log_truncate_on_rotation && time_based_rotation &&
1321 last_csv_file_name != NULL &&
1322 strcmp(csvfilename, last_csv_file_name) != 0)
1323 fh = logfile_open(csvfilename, "w", true);
1324 else
1325 fh = logfile_open(csvfilename, "a", true);
1326
1327 if (!fh)
1328 {
1329 /*
1330 * ENFILE/EMFILE are not too surprising on a busy system; just
1331 * keep using the old file till we manage to get a new one.
1332 * Otherwise, assume something's wrong with Log_directory and stop
1333 * trying to create files.
1334 */
1335 if (errno != ENFILE && errno != EMFILE)
1336 {
1337 ereport(LOG,
1338 (errmsg("disabling automatic rotation (use SIGHUP to re-enable)")));
1339 rotation_disabled = true;
1340 }
1341
1342 if (filename)
1343 pfree(filename);
1344 if (csvfilename)
1345 pfree(csvfilename);
1346 return;
1347 }
1348
1349 if (csvlogFile != NULL)
1350 fclose(csvlogFile);
1351 csvlogFile = fh;
1352
1353 /* instead of pfree'ing filename, remember it for next time */
1354 if (last_csv_file_name != NULL)
1355 pfree(last_csv_file_name);
1356 last_csv_file_name = csvfilename;
1357 csvfilename = NULL;
1358 }
1359 else if (!(Log_destination & LOG_DESTINATION_CSVLOG) &&
1360 csvlogFile != NULL)
1361 {
1362 /* CSVLOG was just turned off, so close the old file */
1363 fclose(csvlogFile);
1364 csvlogFile = NULL;
1365 if (last_csv_file_name != NULL)
1366 pfree(last_csv_file_name);
1367 last_csv_file_name = NULL;
1368 }
1369
1370 if (filename)
1371 pfree(filename);
1372 if (csvfilename)
1373 pfree(csvfilename);
1374
1375 update_metainfo_datafile();
1376
1377 set_next_rotation_time();
1378}
1379
1380
1381/*
1382 * construct logfile name using timestamp information
1383 *
1384 * If suffix isn't NULL, append it to the name, replacing any ".log"
1385 * that may be in the pattern.
1386 *
1387 * Result is palloc'd.
1388 */
1389static char *
1390logfile_getname(pg_time_t timestamp, const char *suffix)
1391{
1392 char *filename;
1393 int len;
1394
1395 filename = palloc(MAXPGPATH);
1396
1397 snprintf(filename, MAXPGPATH, "%s/", Log_directory);
1398
1399 len = strlen(filename);
1400
1401 /* treat Log_filename as a strftime pattern */
1402 pg_strftime(filename + len, MAXPGPATH - len, Log_filename,
1403 pg_localtime(&timestamp, log_timezone));
1404
1405 if (suffix != NULL)
1406 {
1407 len = strlen(filename);
1408 if (len > 4 && (strcmp(filename + (len - 4), ".log") == 0))
1409 len -= 4;
1410 strlcpy(filename + len, suffix, MAXPGPATH - len);
1411 }
1412
1413 return filename;
1414}
1415
1416/*
1417 * Determine the next planned rotation time, and store in next_rotation_time.
1418 */
1419static void
1420set_next_rotation_time(void)
1421{
1422 pg_time_t now;
1423 struct pg_tm *tm;
1424 int rotinterval;
1425
1426 /* nothing to do if time-based rotation is disabled */
1427 if (Log_RotationAge <= 0)
1428 return;
1429
1430 /*
1431 * The requirements here are to choose the next time > now that is a
1432 * "multiple" of the log rotation interval. "Multiple" can be interpreted
1433 * fairly loosely. In this version we align to log_timezone rather than
1434 * GMT.
1435 */
1436 rotinterval = Log_RotationAge * SECS_PER_MINUTE; /* convert to seconds */
1437 now = (pg_time_t) time(NULL);
1438 tm = pg_localtime(&now, log_timezone);
1439 now += tm->tm_gmtoff;
1440 now -= now % rotinterval;
1441 now += rotinterval;
1442 now -= tm->tm_gmtoff;
1443 next_rotation_time = now;
1444}
1445
1446/*
1447 * Store the name of the file(s) where the log collector, when enabled, writes
1448 * log messages. Useful for finding the name(s) of the current log file(s)
1449 * when there is time-based logfile rotation. Filenames are stored in a
1450 * temporary file and which is renamed into the final destination for
1451 * atomicity. The file is opened with the same permissions as what gets
1452 * created in the data directory and has proper buffering options.
1453 */
1454static void
1455update_metainfo_datafile(void)
1456{
1457 FILE *fh;
1458 mode_t oumask;
1459
1460 if (!(Log_destination & LOG_DESTINATION_STDERR) &&
1461 !(Log_destination & LOG_DESTINATION_CSVLOG))
1462 {
1463 if (unlink(LOG_METAINFO_DATAFILE) < 0 && errno != ENOENT)
1464 ereport(LOG,
1465 (errcode_for_file_access(),
1466 errmsg("could not remove file \"%s\": %m",
1467 LOG_METAINFO_DATAFILE)));
1468 return;
1469 }
1470
1471 /* use the same permissions as the data directory for the new file */
1472 oumask = umask(pg_mode_mask);
1473 fh = fopen(LOG_METAINFO_DATAFILE_TMP, "w");
1474 umask(oumask);
1475
1476 if (fh)
1477 {
1478 setvbuf(fh, NULL, PG_IOLBF, 0);
1479
1480#ifdef WIN32
1481 /* use CRLF line endings on Windows */
1482 _setmode(_fileno(fh), _O_TEXT);
1483#endif
1484 }
1485 else
1486 {
1487 ereport(LOG,
1488 (errcode_for_file_access(),
1489 errmsg("could not open file \"%s\": %m",
1490 LOG_METAINFO_DATAFILE_TMP)));
1491 return;
1492 }
1493
1494 if (last_file_name && (Log_destination & LOG_DESTINATION_STDERR))
1495 {
1496 if (fprintf(fh, "stderr %s\n", last_file_name) < 0)
1497 {
1498 ereport(LOG,
1499 (errcode_for_file_access(),
1500 errmsg("could not write file \"%s\": %m",
1501 LOG_METAINFO_DATAFILE_TMP)));
1502 fclose(fh);
1503 return;
1504 }
1505 }
1506
1507 if (last_csv_file_name && (Log_destination & LOG_DESTINATION_CSVLOG))
1508 {
1509 if (fprintf(fh, "csvlog %s\n", last_csv_file_name) < 0)
1510 {
1511 ereport(LOG,
1512 (errcode_for_file_access(),
1513 errmsg("could not write file \"%s\": %m",
1514 LOG_METAINFO_DATAFILE_TMP)));
1515 fclose(fh);
1516 return;
1517 }
1518 }
1519 fclose(fh);
1520
1521 if (rename(LOG_METAINFO_DATAFILE_TMP, LOG_METAINFO_DATAFILE) != 0)
1522 ereport(LOG,
1523 (errcode_for_file_access(),
1524 errmsg("could not rename file \"%s\" to \"%s\": %m",
1525 LOG_METAINFO_DATAFILE_TMP, LOG_METAINFO_DATAFILE)));
1526}
1527
1528/* --------------------------------
1529 * signal handler routines
1530 * --------------------------------
1531 */
1532
1533/*
1534 * Check to see if a log rotation request has arrived. Should be
1535 * called by postmaster after receiving SIGUSR1.
1536 */
1537bool
1538CheckLogrotateSignal(void)
1539{
1540 struct stat stat_buf;
1541
1542 if (stat(LOGROTATE_SIGNAL_FILE, &stat_buf) == 0)
1543 return true;
1544
1545 return false;
1546}
1547
1548/*
1549 * Remove the file signaling a log rotation request.
1550 */
1551void
1552RemoveLogrotateSignalFiles(void)
1553{
1554 unlink(LOGROTATE_SIGNAL_FILE);
1555}
1556
1557/* SIGHUP: set flag to reload config file */
1558static void
1559sigHupHandler(SIGNAL_ARGS)
1560{
1561 int save_errno = errno;
1562
1563 got_SIGHUP = true;
1564 SetLatch(MyLatch);
1565
1566 errno = save_errno;
1567}
1568
1569/* SIGUSR1: set flag to rotate logfile */
1570static void
1571sigUsr1Handler(SIGNAL_ARGS)
1572{
1573 int save_errno = errno;
1574
1575 rotation_requested = true;
1576 SetLatch(MyLatch);
1577
1578 errno = save_errno;
1579}
1580