Fix compute_next_snapshot_time().
[dss.git] / dss.c
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #include <string.h>
3 #include <stdlib.h>
4 #include <stdio.h>
5 #include <stdarg.h>
6 #include <assert.h>
7 #include <errno.h>
8 #include <sys/types.h>
9 #include <signal.h>
10 #include <ctype.h>
11 #include <stdbool.h>
12 #include <sys/stat.h>
13 #include <unistd.h>
14 #include <inttypes.h>
15 #include <sys/time.h>
16 #include <time.h>
17 #include <sys/wait.h>
18 #include <fnmatch.h>
19 #include <limits.h>
20 #include <fcntl.h>
21 #include <lopsub.h>
22 #include <sys/mman.h>
23
24 #include "gcc-compat.h"
25 #include "log.h"
26 #include "str.h"
27 #include "err.h"
28 #include "file.h"
29 #include "exec.h"
30 #include "daemon.h"
31 #include "sig.h"
32 #include "df.h"
33 #include "tv.h"
34 #include "snap.h"
35 #include "ipc.h"
36 #include "dss.lsg.h"
37
38 #define CMD_PTR(_cname) lls_cmd(LSG_DSS_CMD_ ## _cname, dss_suite)
39 #define OPT_RESULT(_cname, _oname) (lls_opt_result(\
40 LSG_DSS_ ## _cname ## _OPT_ ## _oname, (CMD_PTR(_cname) == CMD_PTR(DSS))? lpr : sublpr))
41 #define OPT_GIVEN(_cname, _oname) (lls_opt_given(OPT_RESULT(_cname, _oname)))
42 #define OPT_STRING_VAL(_cname, _oname) (lls_string_val(0, \
43 OPT_RESULT(_cname, _oname)))
44 #define OPT_UINT32_VAL(_cname, _oname) (lls_uint32_val(0, \
45 OPT_RESULT(_cname, _oname)))
46
47 struct dss_user_data {int (*handler)(void);};
48 #define EXPORT_CMD_HANDLER(_cmd) const struct dss_user_data \
49 lsg_dss_com_ ## _cmd ## _user_data = { \
50 .handler = com_ ## _cmd \
51 };
52
53 /*
54 * Command line and active options. We need to keep a copy of the parsed
55 * command line options for the SIGHUP case where we merge the command line
56 * options and the new config file options.
57 */
58 static struct lls_parse_result *cmdline_lpr, *lpr;
59
60 /** Parsed subcommand options. */
61 static struct lls_parse_result *cmdline_sublpr, *sublpr;
62 /* The executing subcommand (NULL at startup). */
63 static const struct lls_command *subcmd;
64 /** Wether daemon_init() was called. */
65 static bool daemonized;
66 /** Non-NULL if we log to a file. */
67 static FILE *logfile;
68 /** The read end of the signal pipe */
69 static int signal_pipe;
70 /** Process id of current pre-create-hook/rsync/post-create-hook process. */
71 static pid_t create_pid;
72 /** Whether the pre-create-hook/rsync/post-create-hook is currently stopped. */
73 static int create_process_stopped;
74 /** How many times in a row the rsync command failed. */
75 static int num_consecutive_rsync_errors;
76 /** Process id of current pre-remove/rm/post-remove process. */
77 static pid_t remove_pid;
78 /** When the next snapshot is due. */
79 static int64_t next_snapshot_time;
80 /** When to try to remove something. */
81 static struct timeval next_removal_check;
82 /** Creation time of the snapshot currently being created. */
83 static int64_t current_snapshot_creation_time;
84 /** The snapshot currently being removed. */
85 struct snapshot *snapshot_currently_being_removed;
86 /** Needed by the post-create hook. */
87 static char *path_to_last_complete_snapshot;
88 static char *name_of_reference_snapshot;
89 /** \sa \ref snap.h for details. */
90 enum hook_status snapshot_creation_status;
91 /** \sa \ref snap.h for details. */
92 enum hook_status snapshot_removal_status;
93
94
95 DEFINE_DSS_ERRLIST;
96 static const char *hook_status_description[] = {HOOK_STATUS_ARRAY};
97
98 /* may be called with ds == NULL. */
99 static int disk_space_low(struct disk_space *ds)
100 {
101 struct disk_space ds_struct;
102 uint32_t val;
103
104 if (!ds) {
105 int ret = get_disk_space(".", &ds_struct);
106 if (ret < 0)
107 return ret;
108 ds = &ds_struct;
109 }
110 val = OPT_UINT32_VAL(DSS, MIN_FREE_MB);
111 if (val != 0)
112 if (ds->free_mb < val)
113 return 1;
114 val = OPT_UINT32_VAL(DSS, MIN_FREE_PERCENT);
115 if (val != 0)
116 if (ds->percent_free < val)
117 return 1;
118 val = OPT_UINT32_VAL(DSS, MIN_FREE_PERCENT_INODES);
119 if (val != 0)
120 if (ds->percent_free_inodes < val)
121 return 1;
122 return 0;
123 }
124
125 static void dump_dss_config(const char *msg)
126 {
127 const char dash[] = "-----------------------------";
128 char *lopsub_dump;
129 int ret;
130 FILE *log = logfile? logfile : stderr;
131 struct disk_space ds;
132 int64_t now = get_current_time();
133
134 if (OPT_UINT32_VAL(DSS, LOGLEVEL) > INFO)
135 return;
136
137 fprintf(log, "%s <%s config> %s\n", dash, msg, dash);
138 fprintf(log, "\n*** disk space ***\n\n");
139 ret = get_disk_space(".", &ds);
140 if (ret >= 0) {
141 DSS_INFO_LOG(("disk space low: %s\n", disk_space_low(&ds)?
142 "yes" : "no"));
143 log_disk_space(&ds);
144 } else
145 DSS_ERROR_LOG(("can not get free disk space: %s\n",
146 dss_strerror(-ret)));
147
148 /* we continue on errors from get_disk_space */
149
150 fprintf(log, "\n*** non-default options ***\n\n");
151 lopsub_dump = lls_dump_parse_result(lpr, CMD_PTR(DSS), true);
152 fprintf(log, "%s", lopsub_dump);
153 free(lopsub_dump);
154 fprintf(log, "\n*** non-default options for \"run\" ***\n\n");
155 lopsub_dump = lls_dump_parse_result(lpr, CMD_PTR(RUN), true);
156 fprintf(log, "%s", lopsub_dump);
157 free(lopsub_dump);
158 fprintf(log, "\n*** internal state ***\n\n");
159 fprintf(log,
160 "pid: %d\n"
161 "logile: %s\n"
162 "snapshot_currently_being_removed: %s\n"
163 "path_to_last_complete_snapshot: %s\n"
164 "reference_snapshot: %s\n"
165 "snapshot_creation_status: %s\n"
166 "snapshot_removal_status: %s\n"
167 "num_consecutive_rsync_errors: %d\n"
168 ,
169 (int) getpid(),
170 logfile? OPT_STRING_VAL(RUN, LOGFILE) : "stderr",
171 snapshot_currently_being_removed?
172 snapshot_currently_being_removed->name : "(none)",
173 path_to_last_complete_snapshot?
174 path_to_last_complete_snapshot : "(none)",
175 name_of_reference_snapshot?
176 name_of_reference_snapshot : "(none)",
177 hook_status_description[snapshot_creation_status],
178 hook_status_description[snapshot_removal_status],
179 num_consecutive_rsync_errors
180 );
181 if (create_pid != 0)
182 fprintf(log,
183 "create_pid: %" PRId32 "\n"
184 "create process is %sstopped\n"
185 ,
186 create_pid,
187 create_process_stopped? "" : "not "
188 );
189 if (remove_pid != 0)
190 fprintf(log, "remove_pid: %" PRId32 "\n", remove_pid);
191 if (next_snapshot_time != 0)
192 fprintf(log, "next snapshot due in %" PRId64 " seconds\n",
193 next_snapshot_time - now);
194 if (current_snapshot_creation_time != 0)
195 fprintf(log, "current_snapshot_creation_time: %"
196 PRId64 " (%" PRId64 " seconds ago)\n",
197 current_snapshot_creation_time,
198 now - current_snapshot_creation_time
199 );
200 if (next_removal_check.tv_sec != 0) {
201 fprintf(log, "next removal check: %llu (%llu seconds ago)\n",
202 (long long unsigned)next_removal_check.tv_sec,
203 now - (long long unsigned)next_removal_check.tv_sec
204 );
205
206 }
207 fprintf(log, "%s </%s config> %s\n", dash, msg, dash);
208 }
209
210 static int loglevel = -1;
211 static const char *location_file = NULL;
212 static int location_line = -1;
213 static const char *location_func = NULL;
214
215 void dss_log_set_params(int ll, const char *file, int line, const char *func)
216 {
217 loglevel = ll;
218 location_file = file;
219 location_line = line;
220 location_func = func;
221 }
222
223 /**
224 * The log function of dss.
225 *
226 * \param ll Loglevel.
227 * \param fml Usual format string.
228 *
229 * All DSS_XXX_LOG() macros use this function.
230 */
231 __printf_1_2 void dss_log(const char* fmt,...)
232 {
233 va_list argp;
234 FILE *outfd;
235 struct tm *tm;
236 time_t t1;
237 char str[255] = "";
238 int lpr_ll = lpr? OPT_UINT32_VAL(DSS, LOGLEVEL) : WARNING;
239
240 if (loglevel < lpr_ll)
241 return;
242 outfd = logfile? logfile : stderr;
243 if (subcmd == CMD_PTR(RUN)) {
244 time(&t1);
245 tm = localtime(&t1);
246 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
247 fprintf(outfd, "%s ", str);
248 if (lpr_ll <= INFO)
249 fprintf(outfd, "%i: ", loglevel);
250 }
251 if (subcmd == CMD_PTR(RUN))
252 #ifdef DSS_NO_FUNC_NAMES
253 fprintf(outfd, "%s:%d: ", location_file, location_line);
254 #else
255 fprintf(outfd, "%s: ", location_func);
256 #endif
257 va_start(argp, fmt);
258 vfprintf(outfd, fmt, argp);
259 va_end(argp);
260 }
261
262 /**
263 * Print a message either to stdout or to the log file.
264 */
265 static __printf_1_2 void dss_msg(const char* fmt,...)
266 {
267 FILE *outfd = logfile? logfile : stdout;
268 va_list argp;
269 va_start(argp, fmt);
270 vfprintf(outfd, fmt, argp);
271 va_end(argp);
272 }
273
274 static char *get_config_file_name(void)
275 {
276 char *home, *config_file;
277
278 if (OPT_GIVEN(DSS, CONFIG_FILE))
279 return dss_strdup(OPT_STRING_VAL(DSS, CONFIG_FILE));
280 home = get_homedir();
281 config_file = make_message("%s/.dssrc", home);
282 free(home);
283 return config_file;
284 }
285
286 static int send_signal(int sig, bool wait)
287 {
288 pid_t pid;
289 char *config_file = get_config_file_name();
290 int ret = get_dss_pid(config_file, &pid);
291 unsigned ms = 32;
292 struct timespec ts;
293
294 free(config_file);
295 if (ret < 0)
296 return ret;
297 if (OPT_GIVEN(DSS, DRY_RUN)) {
298 dss_msg("%d\n", (int)pid);
299 return 0;
300 }
301 DSS_NOTICE_LOG(("sending signal %d to pid %d\n", sig, (int)pid));
302 ret = kill(pid, sig);
303 if (ret < 0)
304 return -ERRNO_TO_DSS_ERROR(errno);
305 if (!wait)
306 return 1;
307 while (ms < 5000) {
308 ts.tv_sec = ms / 1000;
309 ts.tv_nsec = (ms % 1000) * 1000 * 1000;
310 ret = nanosleep(&ts, NULL);
311 if (ret < 0)
312 return -ERRNO_TO_DSS_ERROR(errno);
313 ret = kill(pid, 0);
314 if (ret < 0) {
315 if (errno != ESRCH)
316 return -ERRNO_TO_DSS_ERROR(errno);
317 return 1;
318 }
319 ms *= 2;
320 }
321 return -E_KILL_TIMEOUT;
322 }
323
324 struct signal_info {
325 const char * const name;
326 int num;
327 };
328
329 /*
330 * The table below was taken 2016 from proc/sig.c of procps-3.2.8. Copyright
331 * 1998-2003 by Albert Cahalan, GPLv2.
332 */
333 static const struct signal_info signal_table[] = {
334 {"ABRT", SIGABRT}, /* IOT */
335 {"ALRM", SIGALRM},
336 {"BUS", SIGBUS},
337 {"CHLD", SIGCHLD}, /* CLD */
338 {"CONT", SIGCONT},
339 {"FPE", SIGFPE},
340 {"HUP", SIGHUP},
341 {"ILL", SIGILL},
342 {"INT", SIGINT},
343 {"KILL", SIGKILL},
344 {"PIPE", SIGPIPE},
345 #ifdef SIGPOLL
346 {"POLL", SIGPOLL}, /* IO */
347 #endif
348 {"PROF", SIGPROF},
349 #ifdef SIGPWR
350 {"PWR", SIGPWR},
351 #endif
352 {"QUIT", SIGQUIT},
353 {"SEGV", SIGSEGV},
354 #ifdef SIGSTKFLT
355 {"STKFLT", SIGSTKFLT},
356 #endif
357 {"STOP", SIGSTOP},
358 {"SYS", SIGSYS}, /* UNUSED */
359 {"TERM", SIGTERM},
360 {"TRAP", SIGTRAP},
361 {"TSTP", SIGTSTP},
362 {"TTIN", SIGTTIN},
363 {"TTOU", SIGTTOU},
364 {"URG", SIGURG},
365 {"USR1", SIGUSR1},
366 {"USR2", SIGUSR2},
367 {"VTALRM", SIGVTALRM},
368 {"WINCH", SIGWINCH},
369 {"XCPU", SIGXCPU},
370 {"XFSZ", SIGXFSZ}
371 };
372
373 #define SIGNAL_TABLE_SIZE (sizeof(signal_table) / sizeof(signal_table[0]))
374 #ifndef SIGRTMAX
375 #define SIGRTMAX 64
376 #endif
377
378 static int com_kill(void)
379 {
380 bool w_given = OPT_GIVEN(KILL, WAIT);
381 const char *arg = OPT_STRING_VAL(KILL, SIGNAL);
382 int ret, i;
383
384 if (*arg >= '0' && *arg <= '9') {
385 int64_t val;
386 ret = dss_atoi64(arg, &val);
387 if (ret < 0)
388 return ret;
389 if (val < 0 || val > SIGRTMAX)
390 return -ERRNO_TO_DSS_ERROR(EINVAL);
391 return send_signal(val, w_given);
392 }
393 if (strncasecmp(arg, "sig", 3) == 0)
394 arg += 3;
395 if (strcasecmp(arg, "CLD") == 0)
396 return send_signal(SIGCHLD, w_given);
397 if (strcasecmp(arg, "IOT") == 0)
398 return send_signal(SIGABRT, w_given);
399 for (i = 0; i < SIGNAL_TABLE_SIZE; i++)
400 if (strcasecmp(arg, signal_table[i].name) == 0)
401 return send_signal(signal_table[i].num, w_given);
402 DSS_ERROR_LOG(("invalid sigspec: %s\n", arg));
403 return -ERRNO_TO_DSS_ERROR(EINVAL);
404 }
405 EXPORT_CMD_HANDLER(kill);
406
407 static void dss_get_snapshot_list(struct snapshot_list *sl)
408 {
409 get_snapshot_list(sl, OPT_UINT32_VAL(DSS, UNIT_INTERVAL),
410 OPT_UINT32_VAL(DSS, NUM_INTERVALS));
411 }
412
413 static int64_t compute_next_snapshot_time(void)
414 {
415 int64_t x = 0, now = get_current_time(), unit_interval
416 = 24 * 3600 * OPT_UINT32_VAL(DSS, UNIT_INTERVAL), ret,
417 last_completion_time;
418 unsigned wanted = desired_number_of_snapshots(0,
419 OPT_UINT32_VAL(DSS, NUM_INTERVALS)),
420 num_complete = 0;
421 int i;
422 struct snapshot *s = NULL;
423 struct snapshot_list sl;
424
425 dss_get_snapshot_list(&sl);
426 FOR_EACH_SNAPSHOT(s, i, &sl) {
427 if (!(s->flags & SS_COMPLETE))
428 continue;
429 num_complete++;
430 x += s->completion_time - s->creation_time;
431 last_completion_time = s->completion_time;
432 }
433 assert(x >= 0);
434
435 ret = now;
436 if (num_complete == 0)
437 goto out;
438 x /= num_complete; /* avg time to create one snapshot */
439 if (unit_interval < x * wanted) /* oops, no sleep at all */
440 goto out;
441 ret = last_completion_time + unit_interval / wanted - x;
442 out:
443 free_snapshot_list(&sl);
444 return ret;
445 }
446
447 static inline void invalidate_next_snapshot_time(void)
448 {
449 next_snapshot_time = 0;
450 }
451
452 static inline int next_snapshot_time_is_valid(void)
453 {
454 return next_snapshot_time != 0;
455 }
456
457 static int next_snapshot_is_due(void)
458 {
459 int64_t now = get_current_time();
460
461 if (!next_snapshot_time_is_valid())
462 next_snapshot_time = compute_next_snapshot_time();
463 if (next_snapshot_time <= now) {
464 DSS_DEBUG_LOG(("next snapshot: now\n"));
465 return 1;
466 }
467 DSS_DEBUG_LOG(("next snapshot due in %" PRId64 " seconds\n",
468 next_snapshot_time - now));
469 return 0;
470 }
471
472 static void pre_create_hook(void)
473 {
474 assert(snapshot_creation_status == HS_READY);
475 /* make sure that the next snapshot time will be recomputed */
476 invalidate_next_snapshot_time();
477 DSS_DEBUG_LOG(("executing %s\n", OPT_STRING_VAL(DSS, PRE_CREATE_HOOK)));
478 dss_exec_cmdline_pid(&create_pid, OPT_STRING_VAL(DSS, PRE_CREATE_HOOK));
479 snapshot_creation_status = HS_PRE_RUNNING;
480 }
481
482 static void pre_remove_hook(struct snapshot *s, const char *why)
483 {
484 char *cmd;
485
486 if (!s)
487 return;
488 DSS_DEBUG_LOG(("%s snapshot %s\n", why, s->name));
489 assert(snapshot_removal_status == HS_READY);
490 assert(remove_pid == 0);
491 assert(!snapshot_currently_being_removed);
492
493 snapshot_currently_being_removed = dss_malloc(sizeof(struct snapshot));
494 *snapshot_currently_being_removed = *s;
495 snapshot_currently_being_removed->name = dss_strdup(s->name);
496
497 cmd = make_message("%s %s/%s", OPT_STRING_VAL(DSS, PRE_REMOVE_HOOK),
498 OPT_STRING_VAL(DSS, DEST_DIR), s->name);
499 DSS_DEBUG_LOG(("executing %s\n", cmd));
500 dss_exec_cmdline_pid(&remove_pid, cmd);
501 free(cmd);
502 snapshot_removal_status = HS_PRE_RUNNING;
503 }
504
505 static int exec_rm(void)
506 {
507 struct snapshot *s = snapshot_currently_being_removed;
508 char *new_name = being_deleted_name(s);
509 char *argv[4];
510 int ret;
511
512 argv[0] = "rm";
513 argv[1] = "-rf";
514 argv[2] = new_name;
515 argv[3] = NULL;
516
517 assert(snapshot_removal_status == HS_PRE_SUCCESS);
518 assert(remove_pid == 0);
519
520 DSS_NOTICE_LOG(("removing %s (interval = %i)\n", s->name, s->interval));
521 ret = dss_rename(s->name, new_name);
522 if (ret < 0)
523 goto out;
524 dss_exec(&remove_pid, argv[0], argv);
525 snapshot_removal_status = HS_RUNNING;
526 out:
527 free(new_name);
528 return ret;
529 }
530
531 static int snapshot_is_being_created(struct snapshot *s)
532 {
533 return s->creation_time == current_snapshot_creation_time;
534 }
535
536 static struct snapshot *find_orphaned_snapshot(struct snapshot_list *sl)
537 {
538 struct snapshot *s;
539 int i;
540
541 DSS_DEBUG_LOG(("looking for old incomplete snapshots\n"));
542 FOR_EACH_SNAPSHOT(s, i, sl) {
543 if (snapshot_is_being_created(s))
544 continue;
545 /*
546 * We know that no rm is currently running, so if s is marked
547 * as being deleted, a previously started rm must have failed.
548 */
549 if (s->flags & SS_BEING_DELETED)
550 return s;
551
552 if (s->flags & SS_COMPLETE) /* good snapshot */
553 continue;
554 /*
555 * This snapshot is incomplete and it is not the snapshot
556 * currently being created. However, we must not remove it if
557 * rsync is about to be restarted. As only the newest snapshot
558 * can be restarted, this snapshot is orphaned if it is not the
559 * newest snapshot or if we are not about to restart rsync.
560 */
561 if (get_newest_snapshot(sl) != s)
562 return s;
563 if (snapshot_creation_status != HS_NEEDS_RESTART)
564 return s;
565 }
566 /* no orphaned snapshots */
567 return NULL;
568 }
569
570 static int is_reference_snapshot(struct snapshot *s)
571 {
572 if (!name_of_reference_snapshot)
573 return 0;
574 return strcmp(s->name, name_of_reference_snapshot)? 0 : 1;
575 }
576
577 /*
578 * return: 0: no redundant snapshots, 1: rm process started, negative: error
579 */
580 static struct snapshot *find_redundant_snapshot(struct snapshot_list *sl)
581 {
582 int i, interval;
583 struct snapshot *s;
584 unsigned missing = 0;
585 uint32_t N = OPT_UINT32_VAL(DSS, NUM_INTERVALS);
586
587 DSS_DEBUG_LOG(("looking for intervals containing too many snapshots\n"));
588 for (interval = N - 1; interval >= 0; interval--) {
589 unsigned keep = desired_number_of_snapshots(interval, N);
590 unsigned num = sl->interval_count[interval];
591 struct snapshot *victim = NULL, *prev = NULL;
592 int64_t score = LONG_MAX;
593
594 if (keep >= num)
595 missing += keep - num;
596 if (keep + missing >= num)
597 continue;
598 /* redundant snapshot in this interval, pick snapshot with lowest score */
599 FOR_EACH_SNAPSHOT(s, i, sl) {
600 int64_t this_score;
601
602 if (snapshot_is_being_created(s))
603 continue;
604 if (is_reference_snapshot(s))
605 continue;
606 if (s->interval > interval) {
607 prev = s;
608 continue;
609 }
610 if (s->interval < interval)
611 break;
612 if (!victim) {
613 victim = s;
614 prev = s;
615 continue;
616 }
617 assert(prev);
618 /* check if s is a better victim */
619 this_score = s->creation_time - prev->creation_time;
620 assert(this_score >= 0);
621 if (this_score < score) {
622 score = this_score;
623 victim = s;
624 }
625 prev = s;
626 }
627 assert(victim);
628 return victim;
629 }
630 return NULL;
631 }
632
633 static struct snapshot *find_outdated_snapshot(struct snapshot_list *sl)
634 {
635 int i;
636 struct snapshot *s;
637
638 DSS_DEBUG_LOG(("looking for snapshots belonging to intervals >= %d\n",
639 OPT_UINT32_VAL(DSS, NUM_INTERVALS)));
640 FOR_EACH_SNAPSHOT(s, i, sl) {
641 if (snapshot_is_being_created(s))
642 continue;
643 if (is_reference_snapshot(s))
644 continue;
645 if (s->interval < OPT_UINT32_VAL(DSS, NUM_INTERVALS))
646 continue;
647 return s;
648 }
649 return NULL;
650 }
651
652 static struct snapshot *find_oldest_removable_snapshot(struct snapshot_list *sl)
653 {
654 int i, num_complete;
655 struct snapshot *s, *ref = NULL;
656
657 num_complete = num_complete_snapshots(sl);
658 if (num_complete <= OPT_UINT32_VAL(DSS, MIN_COMPLETE))
659 return NULL;
660 FOR_EACH_SNAPSHOT(s, i, sl) {
661 if (snapshot_is_being_created(s))
662 continue;
663 if (is_reference_snapshot(s)) { /* avoid this one */
664 ref = s;
665 continue;
666 }
667 DSS_INFO_LOG(("oldest removable snapshot: %s\n", s->name));
668 return s;
669 }
670 assert(ref);
671 DSS_WARNING_LOG(("removing reference snapshot %s\n", ref->name));
672 return ref;
673 }
674
675 static int rename_incomplete_snapshot(int64_t start)
676 {
677 char *old_name;
678 int ret;
679 int64_t now;
680
681 /*
682 * We don't want the dss_rename() below to fail with EEXIST because the
683 * last complete snapshot was created (and completed) in the same
684 * second as this one.
685 */
686 while ((now = get_current_time()) == start)
687 sleep(1);
688 free(path_to_last_complete_snapshot);
689 ret = complete_name(start, now, &path_to_last_complete_snapshot);
690 if (ret < 0)
691 return ret;
692 old_name = incomplete_name(start);
693 ret = dss_rename(old_name, path_to_last_complete_snapshot);
694 if (ret >= 0)
695 DSS_NOTICE_LOG(("%s -> %s\n", old_name,
696 path_to_last_complete_snapshot));
697 free(old_name);
698 return ret;
699 }
700
701 static int try_to_free_disk_space(void)
702 {
703 int ret;
704 struct snapshot_list sl;
705 struct snapshot *victim;
706 struct timeval now;
707 const char *why;
708 int low_disk_space;
709
710 ret = disk_space_low(NULL);
711 if (ret < 0)
712 return ret;
713 low_disk_space = ret;
714 gettimeofday(&now, NULL);
715 if (tv_diff(&next_removal_check, &now, NULL) > 0)
716 return 0;
717 if (!low_disk_space) {
718 if (OPT_GIVEN(DSS, KEEP_REDUNDANT))
719 return 0;
720 if (snapshot_creation_status != HS_READY)
721 return 0;
722 if (next_snapshot_is_due())
723 return 0;
724 }
725 /*
726 * Idle and --keep_redundant not given, or low disk space. Look at
727 * existing snapshots.
728 */
729 dss_get_snapshot_list(&sl);
730 ret = 0;
731 /*
732 * Don't remove anything if there is free space and we have fewer
733 * snapshots than configured, plus one. This way there is always one
734 * snapshot that can be recycled.
735 */
736 if (!low_disk_space && sl.num_snapshots <=
737 1 << OPT_UINT32_VAL(DSS, NUM_INTERVALS))
738 goto out;
739 why = "outdated";
740 victim = find_outdated_snapshot(&sl);
741 if (victim)
742 goto remove;
743 why = "redundant";
744 victim = find_redundant_snapshot(&sl);
745 if (victim)
746 goto remove;
747 why = "orphaned";
748 victim = find_orphaned_snapshot(&sl);
749 if (victim)
750 goto remove;
751 /* try harder only if disk space is low */
752 if (!low_disk_space)
753 goto out;
754 DSS_WARNING_LOG(("disk space low and nothing obvious to remove\n"));
755 why = "oldest";
756 victim = find_oldest_removable_snapshot(&sl);
757 if (victim)
758 goto remove;
759 DSS_CRIT_LOG(("uhuhu: disk space low and nothing to remove\n"));
760 ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
761 goto out;
762 remove:
763 pre_remove_hook(victim, why);
764 out:
765 free_snapshot_list(&sl);
766 return ret;
767 }
768
769 static void post_create_hook(void)
770 {
771 char *cmd = make_message("%s %s/%s",
772 OPT_STRING_VAL(DSS, POST_CREATE_HOOK),
773 OPT_STRING_VAL(DSS, DEST_DIR), path_to_last_complete_snapshot);
774 DSS_NOTICE_LOG(("executing %s\n", cmd));
775 dss_exec_cmdline_pid(&create_pid, cmd);
776 free(cmd);
777 snapshot_creation_status = HS_POST_RUNNING;
778 }
779
780 static void post_remove_hook(void)
781 {
782 char *cmd;
783 struct snapshot *s = snapshot_currently_being_removed;
784
785 assert(s);
786
787 cmd = make_message("%s %s/%s", OPT_STRING_VAL(DSS, POST_REMOVE_HOOK),
788 OPT_STRING_VAL(DSS, DEST_DIR), s->name);
789 DSS_NOTICE_LOG(("executing %s\n", cmd));
790 dss_exec_cmdline_pid(&remove_pid, cmd);
791 free(cmd);
792 snapshot_removal_status = HS_POST_RUNNING;
793 }
794
795 static void dss_kill(pid_t pid, int sig, const char *msg)
796 {
797 const char *signame, *process_name;
798
799 if (pid == 0)
800 return;
801 switch (sig) {
802 case SIGTERM: signame = "TERM"; break;
803 case SIGSTOP: signame = "STOP"; break;
804 case SIGCONT: signame = "CONT"; break;
805 default: signame = "????";
806 }
807
808 if (pid == create_pid)
809 process_name = "create";
810 else if (pid == remove_pid)
811 process_name = "remove";
812 else process_name = "??????";
813
814 if (msg)
815 DSS_INFO_LOG(("%s\n", msg));
816 DSS_DEBUG_LOG(("sending signal %d (%s) to pid %d (%s process)\n",
817 sig, signame, (int)pid, process_name));
818 if (kill(pid, sig) >= 0)
819 return;
820 DSS_INFO_LOG(("failed to send signal %d (%s) to pid %d (%s process)\n",
821 sig, signame, (int)pid, process_name));
822 }
823
824 static void stop_create_process(void)
825 {
826 if (create_process_stopped)
827 return;
828 dss_kill(create_pid, SIGSTOP, "suspending create process");
829 create_process_stopped = 1;
830 }
831
832 static void restart_create_process(void)
833 {
834 if (!create_process_stopped)
835 return;
836 dss_kill(create_pid, SIGCONT, "resuming create process");
837 create_process_stopped = 0;
838 }
839
840 /**
841 * Print a log message about the exit status of a child.
842 */
843 static void log_termination_msg(pid_t pid, int status)
844 {
845 if (WIFEXITED(status))
846 DSS_INFO_LOG(("child %i exited. Exit status: %i\n", (int)pid,
847 WEXITSTATUS(status)));
848 else if (WIFSIGNALED(status))
849 DSS_NOTICE_LOG(("child %i was killed by signal %i\n", (int)pid,
850 WTERMSIG(status)));
851 else
852 DSS_WARNING_LOG(("child %i terminated abormally\n", (int)pid));
853 }
854
855 static int wait_for_process(pid_t pid, int *status)
856 {
857 int ret;
858
859 DSS_DEBUG_LOG(("Waiting for process %d to terminate\n", (int)pid));
860 for (;;) {
861 fd_set rfds;
862
863 FD_ZERO(&rfds);
864 FD_SET(signal_pipe, &rfds);
865 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
866 if (ret < 0)
867 break;
868 ret = next_signal();
869 if (!ret)
870 continue;
871 if (ret == SIGCHLD) {
872 ret = waitpid(pid, status, 0);
873 if (ret >= 0)
874 break;
875 if (errno != EINTR) { /* error */
876 ret = -ERRNO_TO_DSS_ERROR(errno);
877 break;
878 }
879 }
880 /* SIGINT or SIGTERM */
881 dss_kill(pid, SIGTERM, "killing child process");
882 }
883 if (ret < 0)
884 DSS_ERROR_LOG(("failed to wait for process %d\n", (int)pid));
885 else
886 log_termination_msg(pid, *status);
887 return ret;
888 }
889
890 static void handle_pre_remove_exit(int status)
891 {
892 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
893 snapshot_removal_status = HS_READY;
894 gettimeofday(&next_removal_check, NULL);
895 next_removal_check.tv_sec += 60;
896 return;
897 }
898 snapshot_removal_status = HS_PRE_SUCCESS;
899 }
900
901 static int handle_rm_exit(int status)
902 {
903 if (!WIFEXITED(status)) {
904 snapshot_removal_status = HS_READY;
905 return -E_INVOLUNTARY_EXIT;
906 }
907 if (WEXITSTATUS(status)) {
908 snapshot_removal_status = HS_READY;
909 return -E_BAD_EXIT_CODE;
910 }
911 snapshot_removal_status = HS_SUCCESS;
912 return 1;
913 }
914
915 static void handle_post_remove_exit(void)
916 {
917 snapshot_removal_status = HS_READY;
918 }
919
920 static int handle_remove_exit(int status)
921 {
922 int ret;
923 struct snapshot *s = snapshot_currently_being_removed;
924
925 assert(s);
926 switch (snapshot_removal_status) {
927 case HS_PRE_RUNNING:
928 handle_pre_remove_exit(status);
929 ret = 1;
930 break;
931 case HS_RUNNING:
932 ret = handle_rm_exit(status);
933 break;
934 case HS_POST_RUNNING:
935 handle_post_remove_exit();
936 ret = 1;
937 break;
938 default:
939 ret = -E_BUG;
940 }
941 if (snapshot_removal_status == HS_READY) {
942 free(s->name);
943 free(s);
944 snapshot_currently_being_removed = NULL;
945 }
946 remove_pid = 0;
947 return ret;
948 }
949
950 static int wait_for_remove_process(void)
951 {
952 int status, ret;
953
954 assert(remove_pid);
955 assert(
956 snapshot_removal_status == HS_PRE_RUNNING ||
957 snapshot_removal_status == HS_RUNNING ||
958 snapshot_removal_status == HS_POST_RUNNING
959 );
960 ret = wait_for_process(remove_pid, &status);
961 if (ret < 0)
962 return ret;
963 return handle_remove_exit(status);
964 }
965
966 static int handle_rsync_exit(int status)
967 {
968 int es, ret;
969
970 if (!WIFEXITED(status)) {
971 DSS_ERROR_LOG(("rsync process %d died involuntary\n", (int)create_pid));
972 ret = -E_INVOLUNTARY_EXIT;
973 snapshot_creation_status = HS_READY;
974 goto out;
975 }
976 es = WEXITSTATUS(status);
977 /*
978 * Restart rsync on non-fatal errors:
979 * 24: Partial transfer due to vanished source files
980 */
981 if (es != 0 && es != 24) {
982 DSS_WARNING_LOG(("rsync exit code %d, error count %d\n",
983 es, ++num_consecutive_rsync_errors));
984 if (!logfile) { /* called by com_run() */
985 ret = -E_BAD_EXIT_CODE;
986 goto out;
987 }
988 if (num_consecutive_rsync_errors >
989 OPT_UINT32_VAL(RUN, MAX_RSYNC_ERRORS)) {
990 ret = -E_TOO_MANY_RSYNC_ERRORS;
991 snapshot_creation_status = HS_READY;
992 goto out;
993 }
994 DSS_WARNING_LOG(("restarting rsync process\n"));
995 snapshot_creation_status = HS_NEEDS_RESTART;
996 next_snapshot_time = get_current_time() + 60;
997 ret = 1;
998 goto out;
999 }
1000 num_consecutive_rsync_errors = 0;
1001 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
1002 if (ret < 0)
1003 goto out;
1004 snapshot_creation_status = HS_SUCCESS;
1005 free(name_of_reference_snapshot);
1006 name_of_reference_snapshot = NULL;
1007 out:
1008 create_process_stopped = 0;
1009 return ret;
1010 }
1011
1012 static int handle_pre_create_hook_exit(int status)
1013 {
1014 int es, ret;
1015 static int warn_count;
1016
1017 if (!WIFEXITED(status)) {
1018 snapshot_creation_status = HS_READY;
1019 ret = -E_INVOLUNTARY_EXIT;
1020 goto out;
1021 }
1022 es = WEXITSTATUS(status);
1023 if (es) {
1024 if (!warn_count--) {
1025 DSS_NOTICE_LOG(("pre_create_hook %s returned %d\n",
1026 OPT_STRING_VAL(DSS, PRE_CREATE_HOOK), es));
1027 DSS_NOTICE_LOG(("deferring snapshot creation...\n"));
1028 warn_count = 60; /* warn only once per hour */
1029 }
1030 next_snapshot_time = get_current_time() + 60;
1031 snapshot_creation_status = HS_READY;
1032 ret = 0;
1033 goto out;
1034 }
1035 warn_count = 0;
1036 snapshot_creation_status = HS_PRE_SUCCESS;
1037 ret = 1;
1038 out:
1039 return ret;
1040 }
1041
1042 static int handle_sigchld(void)
1043 {
1044 pid_t pid;
1045 int status, ret = reap_child(&pid, &status);
1046
1047 if (ret <= 0)
1048 return ret;
1049
1050 if (pid == create_pid) {
1051 switch (snapshot_creation_status) {
1052 case HS_PRE_RUNNING:
1053 ret = handle_pre_create_hook_exit(status);
1054 break;
1055 case HS_RUNNING:
1056 ret = handle_rsync_exit(status);
1057 break;
1058 case HS_POST_RUNNING:
1059 snapshot_creation_status = HS_READY;
1060 ret = 1;
1061 break;
1062 default:
1063 DSS_EMERG_LOG(("BUG: create can't die in status %d\n",
1064 snapshot_creation_status));
1065 return -E_BUG;
1066 }
1067 create_pid = 0;
1068 return ret;
1069 }
1070 if (pid == remove_pid) {
1071 ret = handle_remove_exit(status);
1072 if (ret < 0)
1073 return ret;
1074 return ret;
1075 }
1076 DSS_EMERG_LOG(("BUG: unknown process %d died\n", (int)pid));
1077 return -E_BUG;
1078 }
1079
1080 /* also checks if . is a mountpoint, if --mountpoint was given */
1081 static int change_to_dest_dir(void)
1082 {
1083 int ret;
1084 const char *dd = OPT_STRING_VAL(DSS, DEST_DIR);
1085 struct stat dot, dotdot;
1086
1087 DSS_INFO_LOG(("changing cwd to %s\n", dd));
1088 if (chdir(dd) < 0) {
1089 ret = -ERRNO_TO_DSS_ERROR(errno);
1090 DSS_ERROR_LOG(("could not change cwd to %s\n", dd));
1091 return ret;
1092 }
1093 if (!OPT_GIVEN(DSS, MOUNTPOINT))
1094 return 0;
1095 if (stat(".", &dot) < 0) {
1096 ret = -ERRNO_TO_DSS_ERROR(errno);
1097 DSS_ERROR_LOG(("could not stat .\n"));
1098 return ret;
1099 }
1100 if (stat("..", &dotdot) < 0) {
1101 ret = -ERRNO_TO_DSS_ERROR(errno);
1102 DSS_ERROR_LOG(("could not stat ..\n"));
1103 return ret;
1104 }
1105 if (dot.st_dev == dotdot.st_dev && dot.st_ino != dotdot.st_ino) {
1106 DSS_ERROR_LOG(("mountpoint check failed for %s\n", dd));
1107 return -E_MOUNTPOINT;
1108 }
1109 return 1;
1110 }
1111
1112 static int check_config(void)
1113 {
1114 int ret;
1115 uint32_t unit_interval = OPT_UINT32_VAL(DSS, UNIT_INTERVAL);
1116 uint32_t num_intervals = OPT_UINT32_VAL(DSS, NUM_INTERVALS);
1117
1118 if (unit_interval == 0) {
1119 DSS_ERROR_LOG(("bad unit interval: %i\n", unit_interval));
1120 return -E_INVALID_NUMBER;
1121 }
1122 DSS_DEBUG_LOG(("unit interval: %i day(s)\n", unit_interval));
1123
1124 if (num_intervals == 0 || num_intervals > 30) {
1125 DSS_ERROR_LOG(("bad number of intervals: %i\n", num_intervals));
1126 return -E_INVALID_NUMBER;
1127 }
1128 if (subcmd == CMD_PTR(RUN) || subcmd == CMD_PTR(CREATE))
1129 if (!OPT_GIVEN(DSS, SOURCE_DIR)) {
1130 DSS_ERROR_LOG(("--source-dir required\n"));
1131 return -E_SYNTAX;
1132 }
1133 if (subcmd == CMD_PTR(RUN) || subcmd == CMD_PTR(CREATE)
1134 || subcmd == CMD_PTR(LS) || subcmd == CMD_PTR(PRUNE)) {
1135 if (!OPT_GIVEN(DSS, DEST_DIR)) {
1136 DSS_ERROR_LOG(("--dest-dir required\n"));
1137 return -E_SYNTAX;
1138 }
1139 ret = change_to_dest_dir();
1140 if (ret < 0)
1141 return ret;
1142 }
1143 DSS_DEBUG_LOG(("number of intervals: %i\n", num_intervals));
1144 return 1;
1145 }
1146
1147 static int lopsub_error(int lopsub_ret, char **errctx)
1148 {
1149 const char *msg = lls_strerror(-lopsub_ret);
1150 if (*errctx)
1151 DSS_ERROR_LOG(("%s: %s\n", *errctx, msg));
1152 else
1153 DSS_ERROR_LOG(("%s\n", msg));
1154 free(*errctx);
1155 *errctx = NULL;
1156 return -E_LOPSUB;
1157 }
1158
1159 static int parse_config_file(bool sighup, const struct lls_command *cmd)
1160 {
1161 int ret, fd = -1;
1162 char *config_file = get_config_file_name();
1163 struct stat statbuf;
1164 void *map;
1165 size_t sz;
1166 int cf_argc;
1167 char **cf_argv, *errctx = NULL;
1168 struct lls_parse_result *cf_lpr, *merged_lpr, *clpr;
1169 const char *subcmd_name;
1170
1171 ret = open(config_file, O_RDONLY);
1172 if (ret < 0) {
1173 if (errno != ENOENT || OPT_GIVEN(DSS, CONFIG_FILE)) {
1174 ret = -ERRNO_TO_DSS_ERROR(errno);
1175 DSS_ERROR_LOG(("config file %s can not be opened\n",
1176 config_file));
1177 goto out;
1178 }
1179 /* no config file -- nothing to do */
1180 ret = 0;
1181 goto success;
1182 }
1183 fd = ret;
1184 ret = fstat(fd, &statbuf);
1185 if (ret < 0) {
1186 ret = -ERRNO_TO_DSS_ERROR(errno);
1187 DSS_ERROR_LOG(("failed to stat config file %s\n", config_file));
1188 goto close_fd;
1189 }
1190 sz = statbuf.st_size;
1191 if (sz == 0) { /* config file is empty -- nothing to do */
1192 ret = 0;
1193 goto success;
1194 }
1195 map = mmap(NULL, sz, PROT_READ, MAP_PRIVATE, fd, 0);
1196 if (map == MAP_FAILED) {
1197 ret = -ERRNO_TO_DSS_ERROR(errno);
1198 DSS_ERROR_LOG(("failed to mmap config file %s\n",
1199 config_file));
1200 goto close_fd;
1201 }
1202 if (cmd == CMD_PTR(DSS))
1203 subcmd_name = NULL;
1204 else
1205 subcmd_name = lls_command_name(cmd);
1206 ret = lls_convert_config(map, sz, subcmd_name, &cf_argv, &errctx);
1207 munmap(map, sz);
1208 if (ret < 0) {
1209 DSS_ERROR_LOG(("failed to convert config file %s\n",
1210 config_file));
1211 ret = lopsub_error(ret, &errctx);
1212 goto close_fd;
1213 }
1214 cf_argc = ret;
1215 ret = lls_parse(cf_argc, cf_argv, cmd, &cf_lpr, &errctx);
1216 lls_free_argv(cf_argv);
1217 if (ret < 0) {
1218 ret = lopsub_error(ret, &errctx);
1219 goto close_fd;
1220 }
1221 clpr = cmd == CMD_PTR(DSS)? cmdline_lpr : cmdline_sublpr;
1222 if (sighup) /* config file overrides command line */
1223 ret = lls_merge(cf_lpr, clpr, cmd, &merged_lpr, &errctx);
1224 else /* command line options overrride config file options */
1225 ret = lls_merge(clpr, cf_lpr, cmd, &merged_lpr, &errctx);
1226 lls_free_parse_result(cf_lpr, cmd);
1227 if (ret < 0) {
1228 ret = lopsub_error(ret, &errctx);
1229 goto close_fd;
1230 }
1231 ret = 1;
1232 success:
1233 assert(ret >= 0);
1234 DSS_DEBUG_LOG(("loglevel: %d\n", OPT_UINT32_VAL(DSS, LOGLEVEL)));
1235 if (cmd != CMD_PTR(DSS)) {
1236 if (ret > 0) {
1237 if (sublpr != cmdline_sublpr)
1238 lls_free_parse_result(sublpr, cmd);
1239 sublpr = merged_lpr;
1240 } else
1241 sublpr = cmdline_sublpr;
1242 } else {
1243 if (ret > 0) {
1244 if (lpr != cmdline_lpr)
1245 lls_free_parse_result(lpr, cmd);
1246 lpr = merged_lpr;
1247 } else
1248 lpr = cmdline_lpr;
1249 }
1250 close_fd:
1251 if (fd >= 0)
1252 close(fd);
1253 out:
1254 free(config_file);
1255 if (ret < 0)
1256 DSS_EMERG_LOG(("%s\n", dss_strerror(-ret)));
1257 return ret;
1258 }
1259
1260 static int handle_sighup(void)
1261 {
1262 int ret;
1263
1264 DSS_NOTICE_LOG(("SIGHUP, re-reading config\n"));
1265 dump_dss_config("old");
1266 ret = parse_config_file(true /* SIGHUP */, CMD_PTR(DSS));
1267 if (ret < 0)
1268 return ret;
1269 ret = parse_config_file(true /* SIGHUP */, CMD_PTR(RUN));
1270 if (ret < 0)
1271 return ret;
1272 ret = check_config();
1273 if (ret < 0)
1274 return ret;
1275 close_log(logfile);
1276 logfile = NULL;
1277 if (OPT_GIVEN(RUN, DAEMON) || daemonized) {
1278 logfile = open_log(OPT_STRING_VAL(RUN, LOGFILE));
1279 log_welcome(OPT_UINT32_VAL(DSS, LOGLEVEL));
1280 daemonized = true;
1281 }
1282 dump_dss_config("reloaded");
1283 invalidate_next_snapshot_time();
1284 return 1;
1285 }
1286
1287 static void kill_children(void)
1288 {
1289 restart_create_process();
1290 dss_kill(create_pid, SIGTERM, NULL);
1291 dss_kill(remove_pid, SIGTERM, NULL);
1292 }
1293
1294 static int handle_signal(void)
1295 {
1296 int sig, ret = next_signal();
1297
1298 if (ret <= 0)
1299 goto out;
1300 sig = ret;
1301 switch (sig) {
1302 case SIGINT:
1303 case SIGTERM:
1304 kill_children();
1305 ret = -E_SIGNAL;
1306 break;
1307 case SIGHUP:
1308 ret = handle_sighup();
1309 break;
1310 case SIGCHLD:
1311 ret = handle_sigchld();
1312 break;
1313 }
1314 out:
1315 if (ret < 0)
1316 DSS_ERROR_LOG(("%s\n", dss_strerror(-ret)));
1317 return ret;
1318 }
1319
1320 /*
1321 * We can not use rsync locally if the local user is different from the remote
1322 * user or if the src dir is not on the local host (or both).
1323 */
1324 static int use_rsync_locally(char *logname)
1325 {
1326 const char *h = OPT_STRING_VAL(DSS, REMOTE_HOST);
1327
1328 if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
1329 return 0;
1330 if (OPT_GIVEN(DSS, REMOTE_USER) &&
1331 strcmp(OPT_STRING_VAL(DSS, REMOTE_USER), logname))
1332 return 0;
1333 return 1;
1334 }
1335
1336 static int rename_resume_snap(int64_t creation_time)
1337 {
1338 struct snapshot_list sl;
1339 struct snapshot *s = NULL;
1340 char *new_name = incomplete_name(creation_time);
1341 int ret;
1342 const char *why;
1343
1344 sl.num_snapshots = 0;
1345
1346 ret = 0;
1347 dss_get_snapshot_list(&sl);
1348 /*
1349 * Snapshot recycling: We first look at the newest snapshot. If this
1350 * snapshot happens to be incomplete, the last rsync process was
1351 * aborted and we reuse this one. Otherwise we look at snapshots which
1352 * could be removed (outdated and redundant snapshots) as candidates
1353 * for recycling. If no outdated/redundant snapshot exists, we check if
1354 * there is an orphaned snapshot, which likely is useless anyway.
1355 *
1356 * Only if no existing snapshot is suitable for recycling, we bite the
1357 * bullet and create a new one.
1358 */
1359 s = get_newest_snapshot(&sl);
1360 if (!s) /* no snapshots at all */
1361 goto out;
1362 /* re-use last snapshot if it is incomplete */
1363 why = "aborted";
1364 if ((s->flags & SS_COMPLETE) == 0)
1365 goto out;
1366 why = "outdated";
1367 s = find_outdated_snapshot(&sl);
1368 if (s)
1369 goto out;
1370 why = "redundant";
1371 s = find_redundant_snapshot(&sl);
1372 if (s)
1373 goto out;
1374 why = "orphaned";
1375 s = find_orphaned_snapshot(&sl);
1376 out:
1377 if (s) {
1378 DSS_NOTICE_LOG(("recycling %s snapshot %s\n", why, s->name));
1379 ret = dss_rename(s->name, new_name);
1380 }
1381 if (ret >= 0)
1382 DSS_NOTICE_LOG(("creating %s\n", new_name));
1383 free(new_name);
1384 free_snapshot_list(&sl);
1385 return ret;
1386 }
1387
1388 static void create_rsync_argv(char ***argv, int64_t *num)
1389 {
1390 char *logname;
1391 int i = 0, j, N = OPT_GIVEN(DSS, RSYNC_OPTION);
1392 struct snapshot_list sl;
1393 static bool seeded;
1394
1395 dss_get_snapshot_list(&sl);
1396 assert(!name_of_reference_snapshot);
1397 name_of_reference_snapshot = name_of_newest_complete_snapshot(&sl);
1398 free_snapshot_list(&sl);
1399
1400 *argv = dss_malloc((15 + N) * sizeof(char *));
1401 (*argv)[i++] = dss_strdup("rsync");
1402 (*argv)[i++] = dss_strdup("-a");
1403 (*argv)[i++] = dss_strdup("--delete");
1404 if (!seeded) {
1405 srandom((unsigned)time(NULL)); /* no need to be fancy here */
1406 seeded = true;
1407 }
1408 if (1000 * (random() / (RAND_MAX + 1.0)) < OPT_UINT32_VAL(DSS, CHECKSUM)) {
1409 DSS_NOTICE_LOG(("adding --checksum to rsync options\n"));
1410 (*argv)[i++] = dss_strdup("--checksum");
1411 }
1412 for (j = 0; j < N; j++)
1413 (*argv)[i++] = dss_strdup(lls_string_val(j,
1414 OPT_RESULT(DSS, RSYNC_OPTION)));
1415 if (name_of_reference_snapshot) {
1416 DSS_INFO_LOG(("using %s as reference\n", name_of_reference_snapshot));
1417 (*argv)[i++] = make_message("--link-dest=../%s",
1418 name_of_reference_snapshot);
1419 } else
1420 DSS_INFO_LOG(("no suitable reference snapshot found\n"));
1421 logname = dss_logname();
1422 if (use_rsync_locally(logname))
1423 (*argv)[i++] = dss_strdup(OPT_STRING_VAL(DSS, SOURCE_DIR));
1424 else
1425 (*argv)[i++] = make_message("%s@%s:%s/",
1426 OPT_GIVEN(DSS, REMOTE_USER)?
1427 OPT_STRING_VAL(DSS, REMOTE_USER) : logname,
1428 OPT_STRING_VAL(DSS, REMOTE_HOST),
1429 OPT_STRING_VAL(DSS, SOURCE_DIR));
1430 free(logname);
1431 *num = get_current_time();
1432 (*argv)[i++] = incomplete_name(*num);
1433 (*argv)[i++] = NULL;
1434 for (j = 0; j < i; j++)
1435 DSS_DEBUG_LOG(("argv[%d] = %s\n", j, (*argv)[j]));
1436 }
1437
1438 static void free_rsync_argv(char **argv)
1439 {
1440 int i;
1441
1442 if (!argv)
1443 return;
1444 for (i = 0; argv[i]; i++)
1445 free(argv[i]);
1446 free(argv);
1447 }
1448
1449 static int create_snapshot(char **argv)
1450 {
1451 int ret;
1452
1453 assert(argv);
1454 ret = rename_resume_snap(current_snapshot_creation_time);
1455 if (ret < 0)
1456 return ret;
1457 dss_exec(&create_pid, argv[0], argv);
1458 snapshot_creation_status = HS_RUNNING;
1459 return ret;
1460 }
1461
1462 static int select_loop(void)
1463 {
1464 int ret;
1465 /* check every 60 seconds for free disk space */
1466 struct timeval tv;
1467 char **rsync_argv = NULL;
1468
1469 for (;;) {
1470 fd_set rfds;
1471 struct timeval *tvp;
1472
1473 if (remove_pid)
1474 tvp = NULL; /* sleep until rm hook/process dies */
1475 else { /* sleep one minute */
1476 tv.tv_sec = 60;
1477 tv.tv_usec = 0;
1478 tvp = &tv;
1479 }
1480 FD_ZERO(&rfds);
1481 FD_SET(signal_pipe, &rfds);
1482 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
1483 if (ret < 0)
1484 goto out;
1485 if (FD_ISSET(signal_pipe, &rfds)) {
1486 ret = handle_signal();
1487 if (ret < 0)
1488 goto out;
1489 }
1490 if (remove_pid)
1491 continue;
1492 if (snapshot_removal_status == HS_PRE_SUCCESS) {
1493 ret = exec_rm();
1494 if (ret < 0)
1495 goto out;
1496 continue;
1497 }
1498 if (snapshot_removal_status == HS_SUCCESS) {
1499 post_remove_hook();
1500 continue;
1501 }
1502 ret = try_to_free_disk_space();
1503 if (ret < 0)
1504 goto out;
1505 if (snapshot_removal_status != HS_READY) {
1506 stop_create_process();
1507 continue;
1508 }
1509 restart_create_process();
1510 switch (snapshot_creation_status) {
1511 case HS_READY:
1512 if (!next_snapshot_is_due())
1513 continue;
1514 pre_create_hook();
1515 continue;
1516 case HS_PRE_RUNNING:
1517 case HS_RUNNING:
1518 case HS_POST_RUNNING:
1519 continue;
1520 case HS_PRE_SUCCESS:
1521 if (!name_of_reference_snapshot) {
1522 free_rsync_argv(rsync_argv);
1523 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1524 }
1525 ret = create_snapshot(rsync_argv);
1526 if (ret < 0)
1527 goto out;
1528 continue;
1529 case HS_NEEDS_RESTART:
1530 if (!next_snapshot_is_due())
1531 continue;
1532 ret = create_snapshot(rsync_argv);
1533 if (ret < 0)
1534 goto out;
1535 continue;
1536 case HS_SUCCESS:
1537 post_create_hook();
1538 continue;
1539 }
1540 }
1541 out:
1542 return ret;
1543 }
1544
1545 static void exit_hook(int exit_code)
1546 {
1547 pid_t pid;
1548 char **argv, *tmp = dss_strdup(OPT_STRING_VAL(DSS, EXIT_HOOK));
1549 unsigned n = split_args(tmp, &argv, " \t");
1550
1551 n++;
1552 argv = dss_realloc(argv, (n + 1) * sizeof(char *));
1553 argv[n - 1] = dss_strdup(dss_strerror(-exit_code));
1554 argv[n] = NULL;
1555 dss_exec(&pid, argv[0], argv);
1556 free(argv[n - 1]);
1557 free(argv);
1558 free(tmp);
1559 }
1560
1561 static void lock_dss_or_die(void)
1562 {
1563 char *config_file = get_config_file_name();
1564 int ret = lock_dss(config_file);
1565
1566 free(config_file);
1567 if (ret < 0) {
1568 DSS_EMERG_LOG(("failed to lock: %s\n", dss_strerror(-ret)));
1569 exit(EXIT_FAILURE);
1570 }
1571 }
1572
1573 static int com_run(void)
1574 {
1575 int ret, fd = -1;
1576 char *config_file;
1577 pid_t pid;
1578
1579 if (OPT_GIVEN(DSS, DRY_RUN)) {
1580 DSS_ERROR_LOG(("dry run not supported by this command\n"));
1581 return -E_SYNTAX;
1582 }
1583 config_file = get_config_file_name();
1584 ret = get_dss_pid(config_file, &pid);
1585 free(config_file);
1586 if (ret >= 0) {
1587 DSS_ERROR_LOG(("pid %d\n", (int)pid));
1588 return -E_ALREADY_RUNNING;
1589 }
1590 if (OPT_GIVEN(RUN, DAEMON)) {
1591 fd = daemon_init();
1592 daemonized = true;
1593 logfile = open_log(OPT_STRING_VAL(RUN, LOGFILE));
1594 }
1595 lock_dss_or_die();
1596 dump_dss_config("startup");
1597 ret = install_sighandler(SIGHUP);
1598 if (ret < 0)
1599 return ret;
1600 if (fd >= 0) {
1601 ret = write(fd, "\0", 1);
1602 if (ret != 1) {
1603 DSS_ERROR_LOG(("write to daemon pipe returned %d\n",
1604 ret));
1605 if (ret < 0)
1606 return -ERRNO_TO_DSS_ERROR(errno);
1607 return -E_BUG;
1608 }
1609 }
1610 ret = select_loop();
1611 if (ret >= 0) /* impossible */
1612 ret = -E_BUG;
1613 kill_children();
1614 exit_hook(ret);
1615 while (wait(NULL) >= 0 || errno != ECHILD)
1616 ; /* still have children to wait for */
1617 return ret;
1618 }
1619 EXPORT_CMD_HANDLER(run);
1620
1621 static int com_prune(void)
1622 {
1623 int ret;
1624 struct snapshot_list sl;
1625 struct snapshot *victim;
1626 struct disk_space ds;
1627 const char *why;
1628
1629 lock_dss_or_die();
1630 ret = get_disk_space(".", &ds);
1631 if (ret < 0)
1632 return ret;
1633 log_disk_space(&ds);
1634 dss_get_snapshot_list(&sl);
1635 why = "outdated";
1636 victim = find_outdated_snapshot(&sl);
1637 if (victim)
1638 goto rm;
1639 why = "redundant";
1640 victim = find_redundant_snapshot(&sl);
1641 if (victim)
1642 goto rm;
1643 ret = 0;
1644 goto out;
1645 rm:
1646 if (OPT_GIVEN(DSS, DRY_RUN)) {
1647 dss_msg("%s snapshot %s (interval = %i)\n",
1648 why, victim->name, victim->interval);
1649 ret = 0;
1650 goto out;
1651 }
1652 pre_remove_hook(victim, why);
1653 if (snapshot_removal_status == HS_PRE_RUNNING) {
1654 ret = wait_for_remove_process();
1655 if (ret < 0)
1656 goto out;
1657 if (snapshot_removal_status != HS_PRE_SUCCESS)
1658 goto out;
1659 }
1660 ret = exec_rm();
1661 if (ret < 0)
1662 goto out;
1663 ret = wait_for_remove_process();
1664 if (ret < 0)
1665 goto out;
1666 if (snapshot_removal_status != HS_SUCCESS)
1667 goto out;
1668 post_remove_hook();
1669 if (snapshot_removal_status != HS_POST_RUNNING)
1670 goto out;
1671 ret = wait_for_remove_process();
1672 if (ret < 0)
1673 goto out;
1674 ret = 1;
1675 out:
1676 free_snapshot_list(&sl);
1677 return ret;
1678 }
1679 EXPORT_CMD_HANDLER(prune);
1680
1681 static int com_create(void)
1682 {
1683 int ret, status;
1684 char **rsync_argv;
1685
1686 lock_dss_or_die();
1687 if (OPT_GIVEN(DSS, DRY_RUN)) {
1688 int i;
1689 char *msg = NULL;
1690 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1691 for (i = 0; rsync_argv[i]; i++) {
1692 char *tmp = msg;
1693 msg = make_message("%s%s%s", tmp? tmp : "",
1694 tmp? " " : "", rsync_argv[i]);
1695 free(tmp);
1696 }
1697 free_rsync_argv(rsync_argv);
1698 dss_msg("%s\n", msg);
1699 free(msg);
1700 return 1;
1701 }
1702 pre_create_hook();
1703 if (create_pid) {
1704 ret = wait_for_process(create_pid, &status);
1705 if (ret < 0)
1706 return ret;
1707 ret = handle_pre_create_hook_exit(status);
1708 if (ret <= 0) /* error, or pre-create failed */
1709 return ret;
1710 }
1711 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1712 ret = create_snapshot(rsync_argv);
1713 if (ret < 0)
1714 goto out;
1715 ret = wait_for_process(create_pid, &status);
1716 if (ret < 0)
1717 goto out;
1718 ret = handle_rsync_exit(status);
1719 if (ret < 0)
1720 goto out;
1721 post_create_hook();
1722 if (create_pid)
1723 ret = wait_for_process(create_pid, &status);
1724 out:
1725 free_rsync_argv(rsync_argv);
1726 return ret;
1727 }
1728 EXPORT_CMD_HANDLER(create);
1729
1730 static int com_ls(void)
1731 {
1732 int i;
1733 struct snapshot_list sl;
1734 struct snapshot *s;
1735 int64_t now = get_current_time();
1736
1737 dss_get_snapshot_list(&sl);
1738 FOR_EACH_SNAPSHOT(s, i, &sl) {
1739 int64_t d;
1740 if (s->flags & SS_COMPLETE)
1741 d = (s->completion_time - s->creation_time) / 60;
1742 else
1743 d = (now - s->creation_time) / 60;
1744 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval,
1745 s->name, d / 60, d % 60);
1746 }
1747 free_snapshot_list(&sl);
1748 return 1;
1749 }
1750 EXPORT_CMD_HANDLER(ls);
1751
1752 static int com_configtest(void)
1753 {
1754 printf("Syntax Ok\n");
1755 return 0;
1756 }
1757 EXPORT_CMD_HANDLER(configtest);
1758
1759 static int setup_signal_handling(void)
1760 {
1761 int ret;
1762
1763 DSS_INFO_LOG(("setting up signal handlers\n"));
1764 signal_pipe = signal_init(); /* always successful */
1765 ret = install_sighandler(SIGINT);
1766 if (ret < 0)
1767 return ret;
1768 ret = install_sighandler(SIGTERM);
1769 if (ret < 0)
1770 return ret;
1771 return install_sighandler(SIGCHLD);
1772 }
1773
1774 static void handle_version_and_help(void)
1775 {
1776 char *txt;
1777
1778 if (OPT_GIVEN(DSS, DETAILED_HELP))
1779 txt = lls_long_help(CMD_PTR(DSS));
1780 else if (OPT_GIVEN(DSS, HELP))
1781 txt = lls_short_help(CMD_PTR(DSS));
1782 else if (OPT_GIVEN(DSS, VERSION))
1783 txt = dss_strdup(VERSION_STRING);
1784 else
1785 return;
1786 printf("%s", txt);
1787 free(txt);
1788 exit(EXIT_SUCCESS);
1789 }
1790
1791 static void show_subcommand_summary(void)
1792 {
1793 const struct lls_command *cmd;
1794 int i;
1795
1796 printf("Available subcommands:\n");
1797 for (i = 1; (cmd = lls_cmd(i, dss_suite)); i++) {
1798 const char *name = lls_command_name(cmd);
1799 const char *purpose = lls_purpose(cmd);
1800 printf("%-11s%s\n", name, purpose);
1801 }
1802 exit(EXIT_SUCCESS);
1803 }
1804
1805 int main(int argc, char **argv)
1806 {
1807 int ret;
1808 char *errctx = NULL;
1809 unsigned num_inputs;
1810 const struct dss_user_data *ud;
1811
1812 ret = lls_parse(argc, argv, CMD_PTR(DSS), &cmdline_lpr, &errctx);
1813 if (ret < 0) {
1814 ret = lopsub_error(ret, &errctx);
1815 goto out;
1816 }
1817 lpr = cmdline_lpr;
1818 ret = parse_config_file(false /* no SIGHUP */, CMD_PTR(DSS));
1819 if (ret < 0)
1820 goto out;
1821 handle_version_and_help();
1822 num_inputs = lls_num_inputs(lpr);
1823 if (num_inputs == 0)
1824 show_subcommand_summary();
1825 ret = lls_lookup_subcmd(argv[argc - num_inputs], dss_suite, &errctx);
1826 if (ret < 0) {
1827 ret = lopsub_error(ret, &errctx);
1828 goto out;
1829 }
1830 subcmd = lls_cmd(ret, dss_suite);
1831 ret = lls_parse(num_inputs, argv + argc - num_inputs, subcmd,
1832 &cmdline_sublpr, &errctx);
1833 if (ret < 0) {
1834 ret = lopsub_error(ret, &errctx);
1835 goto out;
1836 }
1837 sublpr = cmdline_sublpr;
1838 ret = parse_config_file(false /* no SIGHUP */, subcmd);
1839 if (ret < 0)
1840 goto out;
1841 ret = check_config();
1842 if (ret < 0)
1843 goto out;
1844 ret = setup_signal_handling();
1845 if (ret < 0)
1846 goto out;
1847 ud = lls_user_data(subcmd);
1848 ret = ud->handler();
1849 signal_shutdown();
1850 out:
1851 if (ret < 0) {
1852 if (errctx)
1853 DSS_ERROR_LOG(("%s\n", errctx));
1854 DSS_EMERG_LOG(("%s\n", dss_strerror(-ret)));
1855 }
1856 free(errctx);
1857 lls_free_parse_result(lpr, CMD_PTR(DSS));
1858 if (lpr != cmdline_lpr)
1859 lls_free_parse_result(cmdline_lpr, CMD_PTR(DSS));
1860 lls_free_parse_result(sublpr, subcmd);
1861 if (sublpr != cmdline_sublpr)
1862 lls_free_parse_result(cmdline_sublpr, subcmd);
1863 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1864 }