Subcommand sensitive logging.
[dss.git] / dss.c
1 /*
2 * Copyright (C) 2008-2011 Andre Noll <maan@tuebingen.mpg.de>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6 #include <string.h>
7 #include <stdlib.h>
8 #include <stdio.h>
9 #include <stdarg.h>
10 #include <assert.h>
11 #include <errno.h>
12 #include <sys/types.h>
13 #include <signal.h>
14 #include <ctype.h>
15 #include <stdbool.h>
16 #include <sys/stat.h>
17 #include <unistd.h>
18 #include <inttypes.h>
19 #include <sys/time.h>
20 #include <time.h>
21 #include <sys/wait.h>
22 #include <fnmatch.h>
23 #include <limits.h>
24 #include <fcntl.h>
25 #include <lopsub.h>
26 #include <sys/mman.h>
27
28 #include "gcc-compat.h"
29 #include "log.h"
30 #include "str.h"
31 #include "err.h"
32 #include "file.h"
33 #include "exec.h"
34 #include "daemon.h"
35 #include "sig.h"
36 #include "df.h"
37 #include "tv.h"
38 #include "snap.h"
39 #include "ipc.h"
40 #include "dss.lsg.h"
41
42 #define CMD_PTR(_cname) lls_cmd(LSG_DSS_CMD_ ## _cname, dss_suite)
43 #define OPT_RESULT(_cname, _oname) (lls_opt_result(\
44 LSG_DSS_ ## _cname ## _OPT_ ## _oname, (CMD_PTR(_cname) == CMD_PTR(DSS))? lpr : sublpr))
45 #define OPT_GIVEN(_cname, _oname) (lls_opt_given(OPT_RESULT(_cname, _oname)))
46 #define OPT_STRING_VAL(_cname, _oname) (lls_string_val(0, \
47 OPT_RESULT(_cname, _oname)))
48 #define OPT_UINT32_VAL(_cname, _oname) (lls_uint32_val(0, \
49 OPT_RESULT(_cname, _oname)))
50
51 struct dss_user_data {int (*handler)(void);};
52 #define EXPORT_CMD_HANDLER(_cmd) const struct dss_user_data \
53 lsg_dss_com_ ## _cmd ## _user_data = { \
54 .handler = com_ ## _cmd \
55 };
56
57 /*
58 * Command line and active options. We need to keep a copy of the parsed
59 * command line options for the SIGHUP case where we merge the command line
60 * options and the new config file options.
61 */
62 static struct lls_parse_result *cmdline_lpr, *lpr;
63
64 /** Parsed subcommand options. */
65 static struct lls_parse_result *cmdline_sublpr, *sublpr;
66 /* The executing subcommand (NULL at startup). */
67 static const struct lls_command *subcmd;
68 /** Wether daemon_init() was called. */
69 static bool daemonized;
70 /** Non-NULL if we log to a file. */
71 static FILE *logfile;
72 /** The read end of the signal pipe */
73 static int signal_pipe;
74 /** Process id of current pre-create-hook/rsync/post-create-hook process. */
75 static pid_t create_pid;
76 /** Whether the pre-create-hook/rsync/post-create-hook is currently stopped. */
77 static int create_process_stopped;
78 /** How many times in a row the rsync command failed. */
79 static int num_consecutive_rsync_errors;
80 /** Process id of current pre-remove/rm/post-remove process. */
81 static pid_t remove_pid;
82 /** When the next snapshot is due. */
83 static int64_t next_snapshot_time;
84 /** When to try to remove something. */
85 static struct timeval next_removal_check;
86 /** Creation time of the snapshot currently being created. */
87 static int64_t current_snapshot_creation_time;
88 /** The snapshot currently being removed. */
89 struct snapshot *snapshot_currently_being_removed;
90 /** Needed by the post-create hook. */
91 static char *path_to_last_complete_snapshot;
92 static char *name_of_reference_snapshot;
93 /** \sa \ref snap.h for details. */
94 enum hook_status snapshot_creation_status;
95 /** \sa \ref snap.h for details. */
96 enum hook_status snapshot_removal_status;
97
98
99 DEFINE_DSS_ERRLIST;
100 static const char *hook_status_description[] = {HOOK_STATUS_ARRAY};
101
102 /* may be called with ds == NULL. */
103 static int disk_space_low(struct disk_space *ds)
104 {
105 struct disk_space ds_struct;
106 uint32_t val;
107
108 if (!ds) {
109 int ret = get_disk_space(".", &ds_struct);
110 if (ret < 0)
111 return ret;
112 ds = &ds_struct;
113 }
114 val = OPT_UINT32_VAL(DSS, MIN_FREE_MB);
115 if (val != 0)
116 if (ds->free_mb < val)
117 return 1;
118 val = OPT_UINT32_VAL(DSS, MIN_FREE_PERCENT);
119 if (val != 0)
120 if (ds->percent_free < val)
121 return 1;
122 val = OPT_UINT32_VAL(DSS, MIN_FREE_PERCENT_INODES);
123 if (val != 0)
124 if (ds->percent_free_inodes < val)
125 return 1;
126 return 0;
127 }
128
129 static void dump_dss_config(const char *msg)
130 {
131 const char dash[] = "-----------------------------";
132 char *lopsub_dump;
133 int ret;
134 FILE *log = logfile? logfile : stderr;
135 struct disk_space ds;
136 int64_t now = get_current_time();
137
138 if (OPT_UINT32_VAL(DSS, LOGLEVEL) > INFO)
139 return;
140
141 fprintf(log, "%s <%s config> %s\n", dash, msg, dash);
142 fprintf(log, "\n*** disk space ***\n\n");
143 ret = get_disk_space(".", &ds);
144 if (ret >= 0) {
145 DSS_INFO_LOG(("disk space low: %s\n", disk_space_low(&ds)?
146 "yes" : "no"));
147 log_disk_space(&ds);
148 } else
149 DSS_ERROR_LOG(("can not get free disk space: %s\n",
150 dss_strerror(-ret)));
151
152 /* we continue on errors from get_disk_space */
153
154 fprintf(log, "\n*** non-default options ***\n\n");
155 lopsub_dump = lls_dump_parse_result(lpr, CMD_PTR(DSS), true);
156 fprintf(log, "%s", lopsub_dump);
157 free(lopsub_dump);
158 fprintf(log, "\n*** non-default options for \"run\" ***\n\n");
159 lopsub_dump = lls_dump_parse_result(lpr, CMD_PTR(RUN), true);
160 fprintf(log, "%s", lopsub_dump);
161 free(lopsub_dump);
162 fprintf(log, "\n*** internal state ***\n\n");
163 fprintf(log,
164 "pid: %d\n"
165 "logile: %s\n"
166 "snapshot_currently_being_removed: %s\n"
167 "path_to_last_complete_snapshot: %s\n"
168 "reference_snapshot: %s\n"
169 "snapshot_creation_status: %s\n"
170 "snapshot_removal_status: %s\n"
171 "num_consecutive_rsync_errors: %d\n"
172 ,
173 (int) getpid(),
174 logfile? OPT_STRING_VAL(RUN, LOGFILE) : "stderr",
175 snapshot_currently_being_removed?
176 snapshot_currently_being_removed->name : "(none)",
177 path_to_last_complete_snapshot?
178 path_to_last_complete_snapshot : "(none)",
179 name_of_reference_snapshot?
180 name_of_reference_snapshot : "(none)",
181 hook_status_description[snapshot_creation_status],
182 hook_status_description[snapshot_removal_status],
183 num_consecutive_rsync_errors
184 );
185 if (create_pid != 0)
186 fprintf(log,
187 "create_pid: %" PRId32 "\n"
188 "create process is %sstopped\n"
189 ,
190 create_pid,
191 create_process_stopped? "" : "not "
192 );
193 if (remove_pid != 0)
194 fprintf(log, "remove_pid: %" PRId32 "\n", remove_pid);
195 if (next_snapshot_time != 0)
196 fprintf(log, "next snapshot due in %" PRId64 " seconds\n",
197 next_snapshot_time - now);
198 if (current_snapshot_creation_time != 0)
199 fprintf(log, "current_snapshot_creation_time: %"
200 PRId64 " (%" PRId64 " seconds ago)\n",
201 current_snapshot_creation_time,
202 now - current_snapshot_creation_time
203 );
204 if (next_removal_check.tv_sec != 0) {
205 fprintf(log, "next removal check: %llu (%llu seconds ago)\n",
206 (long long unsigned)next_removal_check.tv_sec,
207 now - (long long unsigned)next_removal_check.tv_sec
208 );
209
210 }
211 fprintf(log, "%s </%s config> %s\n", dash, msg, dash);
212 }
213
214 static int loglevel = -1;
215 static const char *location_file = NULL;
216 static int location_line = -1;
217 static const char *location_func = NULL;
218
219 void dss_log_set_params(int ll, const char *file, int line, const char *func)
220 {
221 loglevel = ll;
222 location_file = file;
223 location_line = line;
224 location_func = func;
225 }
226
227 /**
228 * The log function of dss.
229 *
230 * \param ll Loglevel.
231 * \param fml Usual format string.
232 *
233 * All DSS_XXX_LOG() macros use this function.
234 */
235 __printf_1_2 void dss_log(const char* fmt,...)
236 {
237 va_list argp;
238 FILE *outfd;
239 struct tm *tm;
240 time_t t1;
241 char str[255] = "";
242 int lpr_ll = lpr? OPT_UINT32_VAL(DSS, LOGLEVEL) : WARNING;
243
244 if (loglevel < lpr_ll)
245 return;
246 outfd = logfile? logfile : stderr;
247 if (subcmd == CMD_PTR(RUN)) {
248 time(&t1);
249 tm = localtime(&t1);
250 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
251 fprintf(outfd, "%s ", str);
252 if (lpr_ll <= INFO)
253 fprintf(outfd, "%i: ", loglevel);
254 }
255 if (subcmd == CMD_PTR(RUN))
256 #ifdef DSS_NO_FUNC_NAMES
257 fprintf(outfd, "%s:%d: ", location_file, location_line);
258 #else
259 fprintf(outfd, "%s: ", location_func);
260 #endif
261 va_start(argp, fmt);
262 vfprintf(outfd, fmt, argp);
263 va_end(argp);
264 }
265
266 /**
267 * Print a message either to stdout or to the log file.
268 */
269 static __printf_1_2 void dss_msg(const char* fmt,...)
270 {
271 FILE *outfd = logfile? logfile : stdout;
272 va_list argp;
273 va_start(argp, fmt);
274 vfprintf(outfd, fmt, argp);
275 va_end(argp);
276 }
277
278 static char *get_config_file_name(void)
279 {
280 char *home, *config_file;
281
282 if (OPT_GIVEN(DSS, CONFIG_FILE))
283 return dss_strdup(OPT_STRING_VAL(DSS, CONFIG_FILE));
284 home = get_homedir();
285 config_file = make_message("%s/.dssrc", home);
286 free(home);
287 return config_file;
288 }
289
290 static int send_signal(int sig)
291 {
292 pid_t pid;
293 char *config_file = get_config_file_name();
294 int ret = get_dss_pid(config_file, &pid);
295
296 free(config_file);
297 if (ret < 0)
298 return ret;
299 if (OPT_GIVEN(DSS, DRY_RUN)) {
300 dss_msg("%d\n", (int)pid);
301 return 0;
302 }
303 ret = kill(pid, sig);
304 if (ret < 0)
305 return -ERRNO_TO_DSS_ERROR(errno);
306 return 1;
307 }
308
309 struct signal_info {
310 const char * const name;
311 int num;
312 };
313
314 /*
315 * The table below was taken 2016 from proc/sig.c of procps-3.2.8. Copyright
316 * 1998-2003 by Albert Cahalan, GPLv2.
317 */
318 static const struct signal_info signal_table[] = {
319 {"ABRT", SIGABRT}, /* IOT */
320 {"ALRM", SIGALRM},
321 {"BUS", SIGBUS},
322 {"CHLD", SIGCHLD}, /* CLD */
323 {"CONT", SIGCONT},
324 {"FPE", SIGFPE},
325 {"HUP", SIGHUP},
326 {"ILL", SIGILL},
327 {"INT", SIGINT},
328 {"KILL", SIGKILL},
329 {"PIPE", SIGPIPE},
330 #ifdef SIGPOLL
331 {"POLL", SIGPOLL}, /* IO */
332 #endif
333 {"PROF", SIGPROF},
334 #ifdef SIGPWR
335 {"PWR", SIGPWR},
336 #endif
337 {"QUIT", SIGQUIT},
338 {"SEGV", SIGSEGV},
339 #ifdef SIGSTKFLT
340 {"STKFLT", SIGSTKFLT},
341 #endif
342 {"STOP", SIGSTOP},
343 {"SYS", SIGSYS}, /* UNUSED */
344 {"TERM", SIGTERM},
345 {"TRAP", SIGTRAP},
346 {"TSTP", SIGTSTP},
347 {"TTIN", SIGTTIN},
348 {"TTOU", SIGTTOU},
349 {"URG", SIGURG},
350 {"USR1", SIGUSR1},
351 {"USR2", SIGUSR2},
352 {"VTALRM", SIGVTALRM},
353 {"WINCH", SIGWINCH},
354 {"XCPU", SIGXCPU},
355 {"XFSZ", SIGXFSZ}
356 };
357
358 #define SIGNAL_TABLE_SIZE (sizeof(signal_table) / sizeof(signal_table[0]))
359 #ifndef SIGRTMAX
360 #define SIGRTMAX 64
361 #endif
362
363 static int com_kill(void)
364 {
365 const char *arg = OPT_STRING_VAL(KILL, SIGNAL);
366 int ret, i;
367
368 if (*arg >= '0' && *arg <= '9') {
369 int64_t val;
370 ret = dss_atoi64(arg, &val);
371 if (ret < 0)
372 return ret;
373 if (val < 0 || val > SIGRTMAX)
374 return -ERRNO_TO_DSS_ERROR(EINVAL);
375 return send_signal(val);
376 }
377 if (strncasecmp(arg, "sig", 3) == 0)
378 arg += 3;
379 if (strcasecmp(arg, "CLD") == 0)
380 return send_signal(SIGCHLD);
381 if (strcasecmp(arg, "IOT") == 0)
382 return send_signal(SIGABRT);
383 for (i = 0; i < SIGNAL_TABLE_SIZE; i++)
384 if (strcasecmp(arg, signal_table[i].name) == 0)
385 return send_signal(signal_table[i].num);
386 DSS_ERROR_LOG(("invalid sigspec: %s\n", arg));
387 return -ERRNO_TO_DSS_ERROR(EINVAL);
388 }
389 EXPORT_CMD_HANDLER(kill);
390
391 static void dss_get_snapshot_list(struct snapshot_list *sl)
392 {
393 get_snapshot_list(sl, OPT_UINT32_VAL(DSS, UNIT_INTERVAL),
394 OPT_UINT32_VAL(DSS, NUM_INTERVALS));
395 }
396
397 static int64_t compute_next_snapshot_time(void)
398 {
399 int64_t x = 0, now = get_current_time(), unit_interval
400 = 24 * 3600 * OPT_UINT32_VAL(DSS, UNIT_INTERVAL), ret;
401 unsigned wanted = desired_number_of_snapshots(0,
402 OPT_UINT32_VAL(DSS, NUM_INTERVALS)),
403 num_complete = 0;
404 int i;
405 struct snapshot *s = NULL;
406 struct snapshot_list sl;
407
408 dss_get_snapshot_list(&sl);
409 FOR_EACH_SNAPSHOT(s, i, &sl) {
410 if (!(s->flags & SS_COMPLETE))
411 continue;
412 num_complete++;
413 x += s->completion_time - s->creation_time;
414 }
415 assert(x >= 0);
416
417 ret = now;
418 if (num_complete == 0)
419 goto out;
420 x /= num_complete; /* avg time to create one snapshot */
421 if (unit_interval < x * wanted) /* oops, no sleep at all */
422 goto out;
423 ret = s->completion_time + unit_interval / wanted - x;
424 out:
425 free_snapshot_list(&sl);
426 return ret;
427 }
428
429 static inline void invalidate_next_snapshot_time(void)
430 {
431 next_snapshot_time = 0;
432 }
433
434 static inline int next_snapshot_time_is_valid(void)
435 {
436 return next_snapshot_time != 0;
437 }
438
439 static int next_snapshot_is_due(void)
440 {
441 int64_t now = get_current_time();
442
443 if (!next_snapshot_time_is_valid())
444 next_snapshot_time = compute_next_snapshot_time();
445 if (next_snapshot_time <= now) {
446 DSS_DEBUG_LOG(("next snapshot: now\n"));
447 return 1;
448 }
449 DSS_DEBUG_LOG(("next snapshot due in %" PRId64 " seconds\n",
450 next_snapshot_time - now));
451 return 0;
452 }
453
454 static void pre_create_hook(void)
455 {
456 assert(snapshot_creation_status == HS_READY);
457 /* make sure that the next snapshot time will be recomputed */
458 invalidate_next_snapshot_time();
459 DSS_DEBUG_LOG(("executing %s\n", OPT_STRING_VAL(DSS, PRE_CREATE_HOOK)));
460 dss_exec_cmdline_pid(&create_pid, OPT_STRING_VAL(DSS, PRE_CREATE_HOOK));
461 snapshot_creation_status = HS_PRE_RUNNING;
462 }
463
464 static void pre_remove_hook(struct snapshot *s, const char *why)
465 {
466 char *cmd;
467
468 if (!s)
469 return;
470 DSS_DEBUG_LOG(("%s snapshot %s\n", why, s->name));
471 assert(snapshot_removal_status == HS_READY);
472 assert(remove_pid == 0);
473 assert(!snapshot_currently_being_removed);
474
475 snapshot_currently_being_removed = dss_malloc(sizeof(struct snapshot));
476 *snapshot_currently_being_removed = *s;
477 snapshot_currently_being_removed->name = dss_strdup(s->name);
478
479 cmd = make_message("%s %s/%s", OPT_STRING_VAL(DSS, PRE_REMOVE_HOOK),
480 OPT_STRING_VAL(DSS, DEST_DIR), s->name);
481 DSS_DEBUG_LOG(("executing %s\n", cmd));
482 dss_exec_cmdline_pid(&remove_pid, cmd);
483 free(cmd);
484 snapshot_removal_status = HS_PRE_RUNNING;
485 }
486
487 static int exec_rm(void)
488 {
489 struct snapshot *s = snapshot_currently_being_removed;
490 char *new_name = being_deleted_name(s);
491 char *argv[4];
492 int ret;
493
494 argv[0] = "rm";
495 argv[1] = "-rf";
496 argv[2] = new_name;
497 argv[3] = NULL;
498
499 assert(snapshot_removal_status == HS_PRE_SUCCESS);
500 assert(remove_pid == 0);
501
502 DSS_NOTICE_LOG(("removing %s (interval = %i)\n", s->name, s->interval));
503 ret = dss_rename(s->name, new_name);
504 if (ret < 0)
505 goto out;
506 dss_exec(&remove_pid, argv[0], argv);
507 snapshot_removal_status = HS_RUNNING;
508 out:
509 free(new_name);
510 return ret;
511 }
512
513 static int snapshot_is_being_created(struct snapshot *s)
514 {
515 return s->creation_time == current_snapshot_creation_time;
516 }
517
518 static struct snapshot *find_orphaned_snapshot(struct snapshot_list *sl)
519 {
520 struct snapshot *s;
521 int i;
522
523 DSS_DEBUG_LOG(("looking for orphaned snapshots\n"));
524 FOR_EACH_SNAPSHOT(s, i, sl) {
525 if (snapshot_is_being_created(s))
526 continue;
527 /*
528 * We know that no rm is currently running, so if s is marked
529 * as being deleted, a previously started rm must have failed.
530 */
531 if (s->flags & SS_BEING_DELETED)
532 return s;
533
534 if (s->flags & SS_COMPLETE) /* good snapshot */
535 continue;
536 /*
537 * This snapshot is incomplete and it is not the snapshot
538 * currently being created. However, we must not remove it if
539 * rsync is about to be restarted. As only the newest snapshot
540 * can be restarted, this snapshot is orphaned if it is not the
541 * newest snapshot or if we are not about to restart rsync.
542 */
543 if (get_newest_snapshot(sl) != s)
544 return s;
545 if (snapshot_creation_status != HS_NEEDS_RESTART)
546 return s;
547 }
548 /* no orphaned snapshots */
549 return NULL;
550 }
551
552 static int is_reference_snapshot(struct snapshot *s)
553 {
554 if (!name_of_reference_snapshot)
555 return 0;
556 return strcmp(s->name, name_of_reference_snapshot)? 0 : 1;
557 }
558
559 /*
560 * return: 0: no redundant snapshots, 1: rm process started, negative: error
561 */
562 static struct snapshot *find_redundant_snapshot(struct snapshot_list *sl)
563 {
564 int i, interval;
565 struct snapshot *s;
566 unsigned missing = 0;
567 uint32_t N = OPT_UINT32_VAL(DSS, NUM_INTERVALS);
568
569 DSS_DEBUG_LOG(("looking for intervals containing too many snapshots\n"));
570 for (interval = N - 1; interval >= 0; interval--) {
571 unsigned keep = desired_number_of_snapshots(interval, N);
572 unsigned num = sl->interval_count[interval];
573 struct snapshot *victim = NULL, *prev = NULL;
574 int64_t score = LONG_MAX;
575
576 if (keep >= num)
577 missing += keep - num;
578 if (keep + missing >= num)
579 continue;
580 /* redundant snapshot in this interval, pick snapshot with lowest score */
581 FOR_EACH_SNAPSHOT(s, i, sl) {
582 int64_t this_score;
583
584 if (snapshot_is_being_created(s))
585 continue;
586 if (is_reference_snapshot(s))
587 continue;
588 if (s->interval > interval) {
589 prev = s;
590 continue;
591 }
592 if (s->interval < interval)
593 break;
594 if (!victim) {
595 victim = s;
596 prev = s;
597 continue;
598 }
599 assert(prev);
600 /* check if s is a better victim */
601 this_score = s->creation_time - prev->creation_time;
602 assert(this_score >= 0);
603 if (this_score < score) {
604 score = this_score;
605 victim = s;
606 }
607 prev = s;
608 }
609 assert(victim);
610 return victim;
611 }
612 return NULL;
613 }
614
615 static struct snapshot *find_outdated_snapshot(struct snapshot_list *sl)
616 {
617 int i;
618 struct snapshot *s;
619
620 DSS_DEBUG_LOG(("looking for snapshots belonging to intervals >= %d\n",
621 OPT_UINT32_VAL(DSS, NUM_INTERVALS)));
622 FOR_EACH_SNAPSHOT(s, i, sl) {
623 if (snapshot_is_being_created(s))
624 continue;
625 if (is_reference_snapshot(s))
626 continue;
627 if (s->interval < OPT_UINT32_VAL(DSS, NUM_INTERVALS))
628 continue;
629 return s;
630 }
631 return NULL;
632 }
633
634 static struct snapshot *find_oldest_removable_snapshot(struct snapshot_list *sl)
635 {
636 int i, num_complete;
637 struct snapshot *s, *ref = NULL;
638
639 num_complete = num_complete_snapshots(sl);
640 if (num_complete <= OPT_UINT32_VAL(DSS, MIN_COMPLETE))
641 return NULL;
642 FOR_EACH_SNAPSHOT(s, i, sl) {
643 if (snapshot_is_being_created(s))
644 continue;
645 if (is_reference_snapshot(s)) { /* avoid this one */
646 ref = s;
647 continue;
648 }
649 DSS_INFO_LOG(("oldest removable snapshot: %s\n", s->name));
650 return s;
651 }
652 assert(ref);
653 DSS_WARNING_LOG(("removing reference snapshot %s\n", ref->name));
654 return ref;
655 }
656
657 static int rename_incomplete_snapshot(int64_t start)
658 {
659 char *old_name;
660 int ret;
661 int64_t now;
662
663 /*
664 * We don't want the dss_rename() below to fail with EEXIST because the
665 * last complete snapshot was created (and completed) in the same
666 * second as this one.
667 */
668 while ((now = get_current_time()) == start)
669 sleep(1);
670 free(path_to_last_complete_snapshot);
671 ret = complete_name(start, now, &path_to_last_complete_snapshot);
672 if (ret < 0)
673 return ret;
674 old_name = incomplete_name(start);
675 ret = dss_rename(old_name, path_to_last_complete_snapshot);
676 if (ret >= 0)
677 DSS_NOTICE_LOG(("%s -> %s\n", old_name,
678 path_to_last_complete_snapshot));
679 free(old_name);
680 return ret;
681 }
682
683 static int try_to_free_disk_space(void)
684 {
685 int ret;
686 struct snapshot_list sl;
687 struct snapshot *victim;
688 struct timeval now;
689 const char *why;
690 int low_disk_space;
691
692 ret = disk_space_low(NULL);
693 if (ret < 0)
694 return ret;
695 low_disk_space = ret;
696 gettimeofday(&now, NULL);
697 if (tv_diff(&next_removal_check, &now, NULL) > 0)
698 return 0;
699 if (!low_disk_space) {
700 if (OPT_GIVEN(DSS, KEEP_REDUNDANT))
701 return 0;
702 if (snapshot_creation_status != HS_READY)
703 return 0;
704 if (next_snapshot_is_due())
705 return 0;
706 }
707 /*
708 * Idle and --keep_redundant not given, or low disk space. Look at
709 * existing snapshots.
710 */
711 dss_get_snapshot_list(&sl);
712 ret = 0;
713 /*
714 * Don't remove anything if there is free space and we have fewer
715 * snapshots than configured, plus one. This way there is always one
716 * snapshot that can be recycled.
717 */
718 if (!low_disk_space && sl.num_snapshots <=
719 1 << OPT_UINT32_VAL(DSS, NUM_INTERVALS))
720 goto out;
721 why = "outdated";
722 victim = find_outdated_snapshot(&sl);
723 if (victim)
724 goto remove;
725 why = "redundant";
726 victim = find_redundant_snapshot(&sl);
727 if (victim)
728 goto remove;
729 why = "orphaned";
730 victim = find_orphaned_snapshot(&sl);
731 if (victim)
732 goto remove;
733 /* try harder only if disk space is low */
734 if (!low_disk_space)
735 goto out;
736 DSS_WARNING_LOG(("disk space low and nothing obvious to remove\n"));
737 victim = find_oldest_removable_snapshot(&sl);
738 if (victim)
739 goto remove;
740 DSS_CRIT_LOG(("uhuhu: disk space low and nothing to remove\n"));
741 ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
742 goto out;
743 remove:
744 pre_remove_hook(victim, why);
745 out:
746 free_snapshot_list(&sl);
747 return ret;
748 }
749
750 static void post_create_hook(void)
751 {
752 char *cmd = make_message("%s %s/%s",
753 OPT_STRING_VAL(DSS, POST_CREATE_HOOK),
754 OPT_STRING_VAL(DSS, DEST_DIR), path_to_last_complete_snapshot);
755 DSS_NOTICE_LOG(("executing %s\n", cmd));
756 dss_exec_cmdline_pid(&create_pid, cmd);
757 free(cmd);
758 snapshot_creation_status = HS_POST_RUNNING;
759 }
760
761 static void post_remove_hook(void)
762 {
763 char *cmd;
764 struct snapshot *s = snapshot_currently_being_removed;
765
766 assert(s);
767
768 cmd = make_message("%s %s/%s", OPT_STRING_VAL(DSS, POST_REMOVE_HOOK),
769 OPT_STRING_VAL(DSS, DEST_DIR), s->name);
770 DSS_NOTICE_LOG(("executing %s\n", cmd));
771 dss_exec_cmdline_pid(&remove_pid, cmd);
772 free(cmd);
773 snapshot_removal_status = HS_POST_RUNNING;
774 }
775
776 static void dss_kill(pid_t pid, int sig, const char *msg)
777 {
778 const char *signame, *process_name;
779
780 if (pid == 0)
781 return;
782 switch (sig) {
783 case SIGTERM: signame = "TERM"; break;
784 case SIGSTOP: signame = "STOP"; break;
785 case SIGCONT: signame = "CONT"; break;
786 default: signame = "????";
787 }
788
789 if (pid == create_pid)
790 process_name = "create";
791 else if (pid == remove_pid)
792 process_name = "remove";
793 else process_name = "??????";
794
795 if (msg)
796 DSS_INFO_LOG(("%s\n", msg));
797 DSS_DEBUG_LOG(("sending signal %d (%s) to pid %d (%s process)\n",
798 sig, signame, (int)pid, process_name));
799 if (kill(pid, sig) >= 0)
800 return;
801 DSS_INFO_LOG(("failed to send signal %d (%s) to pid %d (%s process)\n",
802 sig, signame, (int)pid, process_name));
803 }
804
805 static void stop_create_process(void)
806 {
807 if (create_process_stopped)
808 return;
809 dss_kill(create_pid, SIGSTOP, "suspending create process");
810 create_process_stopped = 1;
811 }
812
813 static void restart_create_process(void)
814 {
815 if (!create_process_stopped)
816 return;
817 dss_kill(create_pid, SIGCONT, "resuming create process");
818 create_process_stopped = 0;
819 }
820
821 /**
822 * Print a log message about the exit status of a child.
823 */
824 static void log_termination_msg(pid_t pid, int status)
825 {
826 if (WIFEXITED(status))
827 DSS_INFO_LOG(("child %i exited. Exit status: %i\n", (int)pid,
828 WEXITSTATUS(status)));
829 else if (WIFSIGNALED(status))
830 DSS_NOTICE_LOG(("child %i was killed by signal %i\n", (int)pid,
831 WTERMSIG(status)));
832 else
833 DSS_WARNING_LOG(("child %i terminated abormally\n", (int)pid));
834 }
835
836 static int wait_for_process(pid_t pid, int *status)
837 {
838 int ret;
839
840 DSS_DEBUG_LOG(("Waiting for process %d to terminate\n", (int)pid));
841 for (;;) {
842 fd_set rfds;
843
844 FD_ZERO(&rfds);
845 FD_SET(signal_pipe, &rfds);
846 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
847 if (ret < 0)
848 break;
849 ret = next_signal();
850 if (!ret)
851 continue;
852 if (ret == SIGCHLD) {
853 ret = waitpid(pid, status, 0);
854 if (ret >= 0)
855 break;
856 if (errno != EINTR) { /* error */
857 ret = -ERRNO_TO_DSS_ERROR(errno);
858 break;
859 }
860 }
861 /* SIGINT or SIGTERM */
862 dss_kill(pid, SIGTERM, "killing child process");
863 }
864 if (ret < 0)
865 DSS_ERROR_LOG(("failed to wait for process %d\n", (int)pid));
866 else
867 log_termination_msg(pid, *status);
868 return ret;
869 }
870
871 static void handle_pre_remove_exit(int status)
872 {
873 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
874 snapshot_removal_status = HS_READY;
875 gettimeofday(&next_removal_check, NULL);
876 next_removal_check.tv_sec += 60;
877 return;
878 }
879 snapshot_removal_status = HS_PRE_SUCCESS;
880 }
881
882 static int handle_rm_exit(int status)
883 {
884 if (!WIFEXITED(status)) {
885 snapshot_removal_status = HS_READY;
886 return -E_INVOLUNTARY_EXIT;
887 }
888 if (WEXITSTATUS(status)) {
889 snapshot_removal_status = HS_READY;
890 return -E_BAD_EXIT_CODE;
891 }
892 snapshot_removal_status = HS_SUCCESS;
893 return 1;
894 }
895
896 static void handle_post_remove_exit(void)
897 {
898 snapshot_removal_status = HS_READY;
899 }
900
901 static int handle_remove_exit(int status)
902 {
903 int ret;
904 struct snapshot *s = snapshot_currently_being_removed;
905
906 assert(s);
907 switch (snapshot_removal_status) {
908 case HS_PRE_RUNNING:
909 handle_pre_remove_exit(status);
910 ret = 1;
911 break;
912 case HS_RUNNING:
913 ret = handle_rm_exit(status);
914 break;
915 case HS_POST_RUNNING:
916 handle_post_remove_exit();
917 ret = 1;
918 break;
919 default:
920 ret = -E_BUG;
921 }
922 if (snapshot_removal_status == HS_READY) {
923 free(s->name);
924 free(s);
925 snapshot_currently_being_removed = NULL;
926 }
927 remove_pid = 0;
928 return ret;
929 }
930
931 static int wait_for_remove_process(void)
932 {
933 int status, ret;
934
935 assert(remove_pid);
936 assert(
937 snapshot_removal_status == HS_PRE_RUNNING ||
938 snapshot_removal_status == HS_RUNNING ||
939 snapshot_removal_status == HS_POST_RUNNING
940 );
941 ret = wait_for_process(remove_pid, &status);
942 if (ret < 0)
943 return ret;
944 return handle_remove_exit(status);
945 }
946
947 static int handle_rsync_exit(int status)
948 {
949 int es, ret;
950
951 if (!WIFEXITED(status)) {
952 DSS_ERROR_LOG(("rsync process %d died involuntary\n", (int)create_pid));
953 ret = -E_INVOLUNTARY_EXIT;
954 snapshot_creation_status = HS_READY;
955 goto out;
956 }
957 es = WEXITSTATUS(status);
958 /*
959 * Restart rsync on non-fatal errors:
960 * 24: Partial transfer due to vanished source files
961 */
962 if (es != 0 && es != 24) {
963 DSS_WARNING_LOG(("rsync exit code %d, error count %d\n",
964 es, ++num_consecutive_rsync_errors));
965 if (!logfile) { /* called by com_run() */
966 ret = -E_BAD_EXIT_CODE;
967 goto out;
968 }
969 if (num_consecutive_rsync_errors >
970 OPT_UINT32_VAL(RUN, MAX_RSYNC_ERRORS)) {
971 ret = -E_TOO_MANY_RSYNC_ERRORS;
972 snapshot_creation_status = HS_READY;
973 goto out;
974 }
975 DSS_WARNING_LOG(("restarting rsync process\n"));
976 snapshot_creation_status = HS_NEEDS_RESTART;
977 next_snapshot_time = get_current_time() + 60;
978 ret = 1;
979 goto out;
980 }
981 num_consecutive_rsync_errors = 0;
982 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
983 if (ret < 0)
984 goto out;
985 snapshot_creation_status = HS_SUCCESS;
986 free(name_of_reference_snapshot);
987 name_of_reference_snapshot = NULL;
988 out:
989 create_process_stopped = 0;
990 return ret;
991 }
992
993 static int handle_pre_create_hook_exit(int status)
994 {
995 int es, ret;
996 static int warn_count;
997
998 if (!WIFEXITED(status)) {
999 snapshot_creation_status = HS_READY;
1000 ret = -E_INVOLUNTARY_EXIT;
1001 goto out;
1002 }
1003 es = WEXITSTATUS(status);
1004 if (es) {
1005 if (!warn_count--) {
1006 DSS_NOTICE_LOG(("pre_create_hook %s returned %d\n",
1007 OPT_STRING_VAL(DSS, PRE_CREATE_HOOK), es));
1008 DSS_NOTICE_LOG(("deferring snapshot creation...\n"));
1009 warn_count = 60; /* warn only once per hour */
1010 }
1011 next_snapshot_time = get_current_time() + 60;
1012 snapshot_creation_status = HS_READY;
1013 ret = 0;
1014 goto out;
1015 }
1016 warn_count = 0;
1017 snapshot_creation_status = HS_PRE_SUCCESS;
1018 ret = 1;
1019 out:
1020 return ret;
1021 }
1022
1023 static int handle_sigchld(void)
1024 {
1025 pid_t pid;
1026 int status, ret = reap_child(&pid, &status);
1027
1028 if (ret <= 0)
1029 return ret;
1030
1031 if (pid == create_pid) {
1032 switch (snapshot_creation_status) {
1033 case HS_PRE_RUNNING:
1034 ret = handle_pre_create_hook_exit(status);
1035 break;
1036 case HS_RUNNING:
1037 ret = handle_rsync_exit(status);
1038 break;
1039 case HS_POST_RUNNING:
1040 snapshot_creation_status = HS_READY;
1041 ret = 1;
1042 break;
1043 default:
1044 DSS_EMERG_LOG(("BUG: create can't die in status %d\n",
1045 snapshot_creation_status));
1046 return -E_BUG;
1047 }
1048 create_pid = 0;
1049 return ret;
1050 }
1051 if (pid == remove_pid) {
1052 ret = handle_remove_exit(status);
1053 if (ret < 0)
1054 return ret;
1055 return ret;
1056 }
1057 DSS_EMERG_LOG(("BUG: unknown process %d died\n", (int)pid));
1058 return -E_BUG;
1059 }
1060
1061 static int change_to_dest_dir(void)
1062 {
1063 int ret;
1064 const char *dd = OPT_STRING_VAL(DSS, DEST_DIR);
1065
1066 DSS_INFO_LOG(("changing cwd to %s\n", dd));
1067 if (chdir(dd) >= 0)
1068 return 1;
1069 ret = -ERRNO_TO_DSS_ERROR(errno);
1070 DSS_ERROR_LOG(("could not change cwd to %s\n", dd));
1071 return ret;
1072 }
1073
1074 static int check_config(void)
1075 {
1076 int ret;
1077 uint32_t unit_interval = OPT_UINT32_VAL(DSS, UNIT_INTERVAL);
1078 uint32_t num_intervals = OPT_UINT32_VAL(DSS, NUM_INTERVALS);
1079
1080 if (unit_interval == 0) {
1081 DSS_ERROR_LOG(("bad unit interval: %i\n", unit_interval));
1082 return -E_INVALID_NUMBER;
1083 }
1084 DSS_DEBUG_LOG(("unit interval: %i day(s)\n", unit_interval));
1085
1086 if (num_intervals == 0 || num_intervals > 30) {
1087 DSS_ERROR_LOG(("bad number of intervals: %i\n", num_intervals));
1088 return -E_INVALID_NUMBER;
1089 }
1090 if (subcmd == CMD_PTR(RUN) || subcmd == CMD_PTR(CREATE))
1091 if (!OPT_GIVEN(DSS, SOURCE_DIR)) {
1092 DSS_ERROR_LOG(("--source-dir required\n"));
1093 return -E_SYNTAX;
1094 }
1095 if (subcmd == CMD_PTR(RUN) || subcmd == CMD_PTR(CREATE)
1096 || subcmd == CMD_PTR(LS) || subcmd == CMD_PTR(PRUNE)) {
1097 if (!OPT_GIVEN(DSS, DEST_DIR)) {
1098 DSS_ERROR_LOG(("--dest-dir required\n"));
1099 return -E_SYNTAX;
1100 }
1101 ret = change_to_dest_dir();
1102 if (ret < 0)
1103 return ret;
1104 }
1105 DSS_DEBUG_LOG(("number of intervals: %i\n", num_intervals));
1106 return 1;
1107 }
1108
1109 static int lopsub_error(int lopsub_ret, char **errctx)
1110 {
1111 const char *msg = lls_strerror(-lopsub_ret);
1112 if (*errctx)
1113 DSS_ERROR_LOG(("%s: %s\n", *errctx, msg));
1114 else
1115 DSS_ERROR_LOG(("%s\n", msg));
1116 free(*errctx);
1117 *errctx = NULL;
1118 return -E_LOPSUB;
1119 }
1120
1121 static int parse_config_file(bool sighup, const struct lls_command *cmd)
1122 {
1123 int ret, fd = -1;
1124 char *config_file = get_config_file_name();
1125 struct stat statbuf;
1126 void *map;
1127 size_t sz;
1128 int cf_argc;
1129 char **cf_argv, *errctx = NULL;
1130 struct lls_parse_result *cf_lpr, *merged_lpr, *clpr;
1131 const char *subcmd_name;
1132
1133 ret = open(config_file, O_RDONLY);
1134 if (ret < 0) {
1135 if (errno != ENOENT || OPT_GIVEN(DSS, CONFIG_FILE)) {
1136 ret = -ERRNO_TO_DSS_ERROR(errno);
1137 DSS_ERROR_LOG(("config file %s can not be opened\n",
1138 config_file));
1139 goto out;
1140 }
1141 /* no config file -- nothing to do */
1142 ret = 0;
1143 goto success;
1144 }
1145 fd = ret;
1146 ret = fstat(fd, &statbuf);
1147 if (ret < 0) {
1148 ret = -ERRNO_TO_DSS_ERROR(errno);
1149 DSS_ERROR_LOG(("failed to stat config file %s\n", config_file));
1150 goto close_fd;
1151 }
1152 sz = statbuf.st_size;
1153 if (sz == 0) { /* config file is empty -- nothing to do */
1154 ret = 0;
1155 goto success;
1156 }
1157 map = mmap(NULL, sz, PROT_READ, MAP_PRIVATE, fd, 0);
1158 if (map == MAP_FAILED) {
1159 ret = -ERRNO_TO_DSS_ERROR(errno);
1160 DSS_ERROR_LOG(("failed to mmap config file %s\n",
1161 config_file));
1162 goto close_fd;
1163 }
1164 if (cmd == CMD_PTR(DSS))
1165 subcmd_name = NULL;
1166 else
1167 subcmd_name = lls_command_name(cmd);
1168 ret = lls_convert_config(map, sz, subcmd_name, &cf_argv, &errctx);
1169 munmap(map, sz);
1170 if (ret < 0) {
1171 DSS_ERROR_LOG(("failed to convert config file %s\n",
1172 config_file));
1173 ret = lopsub_error(ret, &errctx);
1174 goto close_fd;
1175 }
1176 cf_argc = ret;
1177 ret = lls_parse(cf_argc, cf_argv, cmd, &cf_lpr, &errctx);
1178 lls_free_argv(cf_argv);
1179 if (ret < 0) {
1180 ret = lopsub_error(ret, &errctx);
1181 goto close_fd;
1182 }
1183 clpr = cmd == CMD_PTR(DSS)? cmdline_lpr : cmdline_sublpr;
1184 if (sighup) /* config file overrides command line */
1185 ret = lls_merge(cf_lpr, clpr, cmd, &merged_lpr, &errctx);
1186 else /* command line options overrride config file options */
1187 ret = lls_merge(clpr, cf_lpr, cmd, &merged_lpr, &errctx);
1188 lls_free_parse_result(cf_lpr, cmd);
1189 if (ret < 0) {
1190 ret = lopsub_error(ret, &errctx);
1191 goto close_fd;
1192 }
1193 ret = 1;
1194 success:
1195 assert(ret >= 0);
1196 DSS_DEBUG_LOG(("loglevel: %d\n", OPT_UINT32_VAL(DSS, LOGLEVEL)));
1197 if (cmd != CMD_PTR(DSS)) {
1198 if (ret > 0) {
1199 if (sublpr != cmdline_sublpr)
1200 lls_free_parse_result(sublpr, cmd);
1201 sublpr = merged_lpr;
1202 } else
1203 sublpr = cmdline_sublpr;
1204 } else {
1205 if (ret > 0) {
1206 if (lpr != cmdline_lpr)
1207 lls_free_parse_result(lpr, cmd);
1208 lpr = merged_lpr;
1209 } else
1210 lpr = cmdline_lpr;
1211 }
1212 close_fd:
1213 if (fd >= 0)
1214 close(fd);
1215 out:
1216 free(config_file);
1217 if (ret < 0)
1218 DSS_EMERG_LOG(("%s\n", dss_strerror(-ret)));
1219 return ret;
1220 }
1221
1222 static int handle_sighup(void)
1223 {
1224 int ret;
1225
1226 DSS_NOTICE_LOG(("SIGHUP, re-reading config\n"));
1227 dump_dss_config("old");
1228 ret = parse_config_file(true /* SIGHUP */, CMD_PTR(DSS));
1229 if (ret < 0)
1230 return ret;
1231 ret = parse_config_file(true /* SIGHUP */, CMD_PTR(RUN));
1232 if (ret < 0)
1233 return ret;
1234 ret = check_config();
1235 if (ret < 0)
1236 return ret;
1237 close_log(logfile);
1238 logfile = NULL;
1239 if (OPT_GIVEN(RUN, DAEMON) || daemonized) {
1240 logfile = open_log(OPT_STRING_VAL(RUN, LOGFILE));
1241 log_welcome(OPT_UINT32_VAL(DSS, LOGLEVEL));
1242 daemonized = true;
1243 }
1244 dump_dss_config("reloaded");
1245 invalidate_next_snapshot_time();
1246 return 1;
1247 }
1248
1249 static void kill_children(void)
1250 {
1251 restart_create_process();
1252 dss_kill(create_pid, SIGTERM, NULL);
1253 dss_kill(remove_pid, SIGTERM, NULL);
1254 }
1255
1256 static int handle_signal(void)
1257 {
1258 int sig, ret = next_signal();
1259
1260 if (ret <= 0)
1261 goto out;
1262 sig = ret;
1263 switch (sig) {
1264 case SIGINT:
1265 case SIGTERM:
1266 kill_children();
1267 ret = -E_SIGNAL;
1268 break;
1269 case SIGHUP:
1270 ret = handle_sighup();
1271 break;
1272 case SIGCHLD:
1273 ret = handle_sigchld();
1274 break;
1275 }
1276 out:
1277 if (ret < 0)
1278 DSS_ERROR_LOG(("%s\n", dss_strerror(-ret)));
1279 return ret;
1280 }
1281
1282 /*
1283 * We can not use rsync locally if the local user is different from the remote
1284 * user or if the src dir is not on the local host (or both).
1285 */
1286 static int use_rsync_locally(char *logname)
1287 {
1288 const char *h = OPT_STRING_VAL(DSS, REMOTE_HOST);
1289
1290 if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
1291 return 0;
1292 if (OPT_GIVEN(DSS, REMOTE_USER) &&
1293 strcmp(OPT_STRING_VAL(DSS, REMOTE_USER), logname))
1294 return 0;
1295 return 1;
1296 }
1297
1298 static int rename_resume_snap(int64_t creation_time)
1299 {
1300 struct snapshot_list sl;
1301 struct snapshot *s = NULL;
1302 char *new_name = incomplete_name(creation_time);
1303 int ret;
1304 const char *why;
1305
1306 sl.num_snapshots = 0;
1307
1308 ret = 0;
1309 dss_get_snapshot_list(&sl);
1310 /*
1311 * Snapshot recycling: We first look at the newest snapshot. If this
1312 * snapshot happens to be incomplete, the last rsync process was
1313 * aborted and we reuse this one. Otherwise we look at snapshots which
1314 * could be removed (outdated and redundant snapshots) as candidates
1315 * for recycling. If no outdated/redundant snapshot exists, we check if
1316 * there is an orphaned snapshot, which likely is useless anyway.
1317 *
1318 * Only if no existing snapshot is suitable for recycling, we bite the
1319 * bullet and create a new one.
1320 */
1321 s = get_newest_snapshot(&sl);
1322 if (!s) /* no snapshots at all */
1323 goto out;
1324 /* re-use last snapshot if it is incomplete */
1325 why = "aborted";
1326 if ((s->flags & SS_COMPLETE) == 0)
1327 goto out;
1328 why = "outdated";
1329 s = find_outdated_snapshot(&sl);
1330 if (s)
1331 goto out;
1332 why = "redundant";
1333 s = find_redundant_snapshot(&sl);
1334 if (s)
1335 goto out;
1336 why = "orphaned";
1337 s = find_orphaned_snapshot(&sl);
1338 out:
1339 if (s) {
1340 DSS_NOTICE_LOG(("recycling %s snapshot %s\n", why, s->name));
1341 ret = dss_rename(s->name, new_name);
1342 }
1343 if (ret >= 0)
1344 DSS_NOTICE_LOG(("creating %s\n", new_name));
1345 free(new_name);
1346 free_snapshot_list(&sl);
1347 return ret;
1348 }
1349
1350 static void create_rsync_argv(char ***argv, int64_t *num)
1351 {
1352 char *logname;
1353 int i = 0, j, N = OPT_GIVEN(DSS, RSYNC_OPTION);
1354 struct snapshot_list sl;
1355 static bool seeded;
1356
1357 dss_get_snapshot_list(&sl);
1358 assert(!name_of_reference_snapshot);
1359 name_of_reference_snapshot = name_of_newest_complete_snapshot(&sl);
1360 free_snapshot_list(&sl);
1361
1362 *argv = dss_malloc((15 + N) * sizeof(char *));
1363 (*argv)[i++] = dss_strdup("rsync");
1364 (*argv)[i++] = dss_strdup("-a");
1365 (*argv)[i++] = dss_strdup("--delete");
1366 if (!seeded) {
1367 srandom((unsigned)time(NULL)); /* no need to be fancy here */
1368 seeded = true;
1369 }
1370 if (1000 * (random() / (RAND_MAX + 1.0)) < OPT_UINT32_VAL(DSS, CHECKSUM)) {
1371 DSS_NOTICE_LOG(("adding --checksum to rsync options\n"));
1372 (*argv)[i++] = dss_strdup("--checksum");
1373 }
1374 for (j = 0; j < N; j++)
1375 (*argv)[i++] = dss_strdup(lls_string_val(j,
1376 OPT_RESULT(DSS, RSYNC_OPTION)));
1377 if (name_of_reference_snapshot) {
1378 DSS_INFO_LOG(("using %s as reference\n", name_of_reference_snapshot));
1379 (*argv)[i++] = make_message("--link-dest=../%s",
1380 name_of_reference_snapshot);
1381 } else
1382 DSS_INFO_LOG(("no suitable reference snapshot found\n"));
1383 logname = dss_logname();
1384 if (use_rsync_locally(logname))
1385 (*argv)[i++] = dss_strdup(OPT_STRING_VAL(DSS, SOURCE_DIR));
1386 else
1387 (*argv)[i++] = make_message("%s@%s:%s/",
1388 OPT_GIVEN(DSS, REMOTE_USER)?
1389 OPT_STRING_VAL(DSS, REMOTE_USER) : logname,
1390 OPT_STRING_VAL(DSS, REMOTE_HOST),
1391 OPT_STRING_VAL(DSS, SOURCE_DIR));
1392 free(logname);
1393 *num = get_current_time();
1394 (*argv)[i++] = incomplete_name(*num);
1395 (*argv)[i++] = NULL;
1396 for (j = 0; j < i; j++)
1397 DSS_DEBUG_LOG(("argv[%d] = %s\n", j, (*argv)[j]));
1398 }
1399
1400 static void free_rsync_argv(char **argv)
1401 {
1402 int i;
1403
1404 if (!argv)
1405 return;
1406 for (i = 0; argv[i]; i++)
1407 free(argv[i]);
1408 free(argv);
1409 }
1410
1411 static int create_snapshot(char **argv)
1412 {
1413 int ret;
1414
1415 ret = rename_resume_snap(current_snapshot_creation_time);
1416 if (ret < 0)
1417 return ret;
1418 dss_exec(&create_pid, argv[0], argv);
1419 snapshot_creation_status = HS_RUNNING;
1420 return ret;
1421 }
1422
1423 static int select_loop(void)
1424 {
1425 int ret;
1426 /* check every 60 seconds for free disk space */
1427 struct timeval tv;
1428 char **rsync_argv = NULL;
1429
1430 for (;;) {
1431 fd_set rfds;
1432 struct timeval *tvp;
1433
1434 if (remove_pid)
1435 tvp = NULL; /* sleep until rm hook/process dies */
1436 else { /* sleep one minute */
1437 tv.tv_sec = 60;
1438 tv.tv_usec = 0;
1439 tvp = &tv;
1440 }
1441 FD_ZERO(&rfds);
1442 FD_SET(signal_pipe, &rfds);
1443 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
1444 if (ret < 0)
1445 goto out;
1446 if (FD_ISSET(signal_pipe, &rfds)) {
1447 ret = handle_signal();
1448 if (ret < 0)
1449 goto out;
1450 }
1451 if (remove_pid)
1452 continue;
1453 if (snapshot_removal_status == HS_PRE_SUCCESS) {
1454 ret = exec_rm();
1455 if (ret < 0)
1456 goto out;
1457 continue;
1458 }
1459 if (snapshot_removal_status == HS_SUCCESS) {
1460 post_remove_hook();
1461 continue;
1462 }
1463 ret = try_to_free_disk_space();
1464 if (ret < 0)
1465 goto out;
1466 if (snapshot_removal_status != HS_READY) {
1467 stop_create_process();
1468 continue;
1469 }
1470 restart_create_process();
1471 switch (snapshot_creation_status) {
1472 case HS_READY:
1473 if (!next_snapshot_is_due())
1474 continue;
1475 pre_create_hook();
1476 continue;
1477 case HS_PRE_RUNNING:
1478 case HS_RUNNING:
1479 case HS_POST_RUNNING:
1480 continue;
1481 case HS_PRE_SUCCESS:
1482 if (!name_of_reference_snapshot) {
1483 free_rsync_argv(rsync_argv);
1484 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1485 }
1486 ret = create_snapshot(rsync_argv);
1487 if (ret < 0)
1488 goto out;
1489 continue;
1490 case HS_NEEDS_RESTART:
1491 if (!next_snapshot_is_due())
1492 continue;
1493 ret = create_snapshot(rsync_argv);
1494 if (ret < 0)
1495 goto out;
1496 continue;
1497 case HS_SUCCESS:
1498 post_create_hook();
1499 continue;
1500 }
1501 }
1502 out:
1503 return ret;
1504 }
1505
1506 static void exit_hook(int exit_code)
1507 {
1508 const char *argv[3];
1509 pid_t pid;
1510
1511 argv[0] = OPT_STRING_VAL(DSS, EXIT_HOOK);
1512 argv[1] = dss_strerror(-exit_code);
1513 argv[2] = NULL;
1514
1515 DSS_NOTICE_LOG(("executing %s %s\n", argv[0], argv[1]));
1516 dss_exec(&pid, argv[0], (char **)argv);
1517 }
1518
1519 static void lock_dss_or_die(void)
1520 {
1521 char *config_file = get_config_file_name();
1522 int ret = lock_dss(config_file);
1523
1524 free(config_file);
1525 if (ret < 0) {
1526 DSS_EMERG_LOG(("failed to lock: %s\n", dss_strerror(-ret)));
1527 exit(EXIT_FAILURE);
1528 }
1529 }
1530
1531 static int com_run(void)
1532 {
1533 int ret, fd = -1;
1534 char *config_file;
1535 pid_t pid;
1536
1537 if (OPT_GIVEN(DSS, DRY_RUN)) {
1538 DSS_ERROR_LOG(("dry run not supported by this command\n"));
1539 return -E_SYNTAX;
1540 }
1541 config_file = get_config_file_name();
1542 ret = get_dss_pid(config_file, &pid);
1543 free(config_file);
1544 if (ret >= 0) {
1545 DSS_ERROR_LOG(("pid %d\n", (int)pid));
1546 return -E_ALREADY_RUNNING;
1547 }
1548 if (OPT_GIVEN(RUN, DAEMON)) {
1549 fd = daemon_init();
1550 daemonized = true;
1551 logfile = open_log(OPT_STRING_VAL(RUN, LOGFILE));
1552 }
1553 lock_dss_or_die();
1554 dump_dss_config("startup");
1555 ret = install_sighandler(SIGHUP);
1556 if (ret < 0)
1557 return ret;
1558 if (fd >= 0) {
1559 ret = write(fd, "\0", 1);
1560 if (ret != 1) {
1561 DSS_ERROR_LOG(("write to daemon pipe returned %d\n",
1562 ret));
1563 if (ret < 0)
1564 return -ERRNO_TO_DSS_ERROR(errno);
1565 return -E_BUG;
1566 }
1567 }
1568 ret = select_loop();
1569 if (ret >= 0) /* impossible */
1570 ret = -E_BUG;
1571 kill_children();
1572 exit_hook(ret);
1573 return ret;
1574 }
1575 EXPORT_CMD_HANDLER(run);
1576
1577 static int com_prune(void)
1578 {
1579 int ret;
1580 struct snapshot_list sl;
1581 struct snapshot *victim;
1582 struct disk_space ds;
1583 const char *why;
1584
1585 lock_dss_or_die();
1586 ret = get_disk_space(".", &ds);
1587 if (ret < 0)
1588 return ret;
1589 log_disk_space(&ds);
1590 dss_get_snapshot_list(&sl);
1591 why = "outdated";
1592 victim = find_outdated_snapshot(&sl);
1593 if (victim)
1594 goto rm;
1595 why = "redundant";
1596 victim = find_redundant_snapshot(&sl);
1597 if (victim)
1598 goto rm;
1599 ret = 0;
1600 goto out;
1601 rm:
1602 if (OPT_GIVEN(DSS, DRY_RUN)) {
1603 dss_msg("%s snapshot %s (interval = %i)\n",
1604 why, victim->name, victim->interval);
1605 ret = 0;
1606 goto out;
1607 }
1608 pre_remove_hook(victim, why);
1609 if (snapshot_removal_status == HS_PRE_RUNNING) {
1610 ret = wait_for_remove_process();
1611 if (ret < 0)
1612 goto out;
1613 if (snapshot_removal_status != HS_PRE_SUCCESS)
1614 goto out;
1615 }
1616 ret = exec_rm();
1617 if (ret < 0)
1618 goto out;
1619 ret = wait_for_remove_process();
1620 if (ret < 0)
1621 goto out;
1622 if (snapshot_removal_status != HS_SUCCESS)
1623 goto out;
1624 post_remove_hook();
1625 if (snapshot_removal_status != HS_POST_RUNNING)
1626 goto out;
1627 ret = wait_for_remove_process();
1628 if (ret < 0)
1629 goto out;
1630 ret = 1;
1631 out:
1632 free_snapshot_list(&sl);
1633 return ret;
1634 }
1635 EXPORT_CMD_HANDLER(prune);
1636
1637 static int com_create(void)
1638 {
1639 int ret, status;
1640 char **rsync_argv;
1641
1642 lock_dss_or_die();
1643 if (OPT_GIVEN(DSS, DRY_RUN)) {
1644 int i;
1645 char *msg = NULL;
1646 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1647 for (i = 0; rsync_argv[i]; i++) {
1648 char *tmp = msg;
1649 msg = make_message("%s%s%s", tmp? tmp : "",
1650 tmp? " " : "", rsync_argv[i]);
1651 free(tmp);
1652 }
1653 free_rsync_argv(rsync_argv);
1654 dss_msg("%s\n", msg);
1655 free(msg);
1656 return 1;
1657 }
1658 pre_create_hook();
1659 if (create_pid) {
1660 ret = wait_for_process(create_pid, &status);
1661 if (ret < 0)
1662 return ret;
1663 ret = handle_pre_create_hook_exit(status);
1664 if (ret <= 0) /* error, or pre-create failed */
1665 return ret;
1666 }
1667 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1668 ret = create_snapshot(rsync_argv);
1669 if (ret < 0)
1670 goto out;
1671 ret = wait_for_process(create_pid, &status);
1672 if (ret < 0)
1673 goto out;
1674 ret = handle_rsync_exit(status);
1675 if (ret < 0)
1676 goto out;
1677 post_create_hook();
1678 if (create_pid)
1679 ret = wait_for_process(create_pid, &status);
1680 out:
1681 free_rsync_argv(rsync_argv);
1682 return ret;
1683 }
1684 EXPORT_CMD_HANDLER(create);
1685
1686 static int com_ls(void)
1687 {
1688 int i;
1689 struct snapshot_list sl;
1690 struct snapshot *s;
1691
1692 dss_get_snapshot_list(&sl);
1693 FOR_EACH_SNAPSHOT(s, i, &sl) {
1694 int64_t d = 0;
1695 if (s->flags & SS_COMPLETE)
1696 d = (s->completion_time - s->creation_time) / 60;
1697 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval, s->name, d/60, d%60);
1698 }
1699 free_snapshot_list(&sl);
1700 return 1;
1701 }
1702 EXPORT_CMD_HANDLER(ls);
1703
1704 static int setup_signal_handling(void)
1705 {
1706 int ret;
1707
1708 DSS_INFO_LOG(("setting up signal handlers\n"));
1709 signal_pipe = signal_init(); /* always successful */
1710 ret = install_sighandler(SIGINT);
1711 if (ret < 0)
1712 return ret;
1713 ret = install_sighandler(SIGTERM);
1714 if (ret < 0)
1715 return ret;
1716 return install_sighandler(SIGCHLD);
1717 }
1718
1719 static void handle_version_and_help(void)
1720 {
1721 char *txt;
1722
1723 if (OPT_GIVEN(DSS, DETAILED_HELP))
1724 txt = lls_long_help(CMD_PTR(DSS));
1725 else if (OPT_GIVEN(DSS, HELP))
1726 txt = lls_short_help(CMD_PTR(DSS));
1727 else if (OPT_GIVEN(DSS, VERSION))
1728 txt = dss_strdup(VERSION_STRING);
1729 else
1730 return;
1731 printf("%s", txt);
1732 free(txt);
1733 exit(EXIT_SUCCESS);
1734 }
1735
1736 static void show_subcommand_summary(void)
1737 {
1738 const struct lls_command *cmd;
1739 int i;
1740
1741 printf("Available subcommands:\n");
1742 for (i = 1; (cmd = lls_cmd(i, dss_suite)); i++) {
1743 const char *name = lls_command_name(cmd);
1744 const char *purpose = lls_purpose(cmd);
1745 printf("%-10s%s\n", name, purpose);
1746 }
1747 exit(EXIT_SUCCESS);
1748 }
1749
1750 int main(int argc, char **argv)
1751 {
1752 int ret;
1753 char *errctx = NULL;
1754 unsigned num_inputs;
1755 const struct dss_user_data *ud;
1756
1757 ret = lls_parse(argc, argv, CMD_PTR(DSS), &cmdline_lpr, &errctx);
1758 if (ret < 0) {
1759 ret = lopsub_error(ret, &errctx);
1760 goto out;
1761 }
1762 lpr = cmdline_lpr;
1763 ret = parse_config_file(false /* no SIGHUP */, CMD_PTR(DSS));
1764 if (ret < 0)
1765 goto out;
1766 handle_version_and_help();
1767 num_inputs = lls_num_inputs(lpr);
1768 if (num_inputs == 0)
1769 show_subcommand_summary();
1770 ret = lls_lookup_subcmd(argv[argc - num_inputs], dss_suite, &errctx);
1771 if (ret < 0) {
1772 ret = lopsub_error(ret, &errctx);
1773 goto out;
1774 }
1775 subcmd = lls_cmd(ret, dss_suite);
1776 ret = lls_parse(num_inputs, argv + argc - num_inputs, subcmd,
1777 &cmdline_sublpr, &errctx);
1778 if (ret < 0) {
1779 ret = lopsub_error(ret, &errctx);
1780 goto out;
1781 }
1782 sublpr = cmdline_sublpr;
1783 ret = parse_config_file(false /* no SIGHUP */, subcmd);
1784 if (ret < 0)
1785 goto out;
1786 ret = check_config();
1787 if (ret < 0)
1788 goto out;
1789 ret = setup_signal_handling();
1790 if (ret < 0)
1791 goto out;
1792 ud = lls_user_data(subcmd);
1793 ret = ud->handler();
1794 signal_shutdown();
1795 out:
1796 if (ret < 0) {
1797 if (errctx)
1798 DSS_ERROR_LOG(("%s\n", errctx));
1799 DSS_EMERG_LOG(("%s\n", dss_strerror(-ret)));
1800 }
1801 free(errctx);
1802 lls_free_parse_result(lpr, CMD_PTR(DSS));
1803 if (lpr != cmdline_lpr)
1804 lls_free_parse_result(cmdline_lpr, CMD_PTR(DSS));
1805 lls_free_parse_result(sublpr, subcmd);
1806 if (sublpr != cmdline_sublpr)
1807 lls_free_parse_result(cmdline_sublpr, subcmd);
1808 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1809 }