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Simplify split_args().
[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 /* Set by the pre-rm hook, cleared by handle_remove_exit(). */
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 "logfile: %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 static struct snapshot *find_redundant_snapshot(struct snapshot_list *sl)
578 {
579 int i, interval;
580 struct snapshot *s;
581 unsigned missing = 0;
582 uint32_t N = OPT_UINT32_VAL(DSS, NUM_INTERVALS);
583
584 DSS_DEBUG_LOG(("looking for intervals containing too many snapshots\n"));
585 for (interval = N - 1; interval >= 0; interval--) {
586 unsigned keep = desired_number_of_snapshots(interval, N);
587 unsigned num = sl->interval_count[interval];
588 struct snapshot *victim = NULL, *prev = NULL;
589 int64_t score = LONG_MAX;
590
591 if (keep >= num)
592 missing += keep - num;
593 if (keep + missing >= num)
594 continue;
595 /* redundant snapshot in this interval, pick snapshot with lowest score */
596 FOR_EACH_SNAPSHOT(s, i, sl) {
597 int64_t this_score;
598
599 if (snapshot_is_being_created(s))
600 continue;
601 if (is_reference_snapshot(s))
602 continue;
603 if (s->interval > interval) {
604 prev = s;
605 continue;
606 }
607 if (s->interval < interval)
608 break;
609 if (!victim) {
610 victim = s;
611 prev = s;
612 continue;
613 }
614 assert(prev);
615 /* check if s is a better victim */
616 this_score = s->creation_time - prev->creation_time;
617 assert(this_score >= 0);
618 if (this_score < score) {
619 score = this_score;
620 victim = s;
621 }
622 prev = s;
623 }
624 assert(victim);
625 return victim;
626 }
627 return NULL;
628 }
629
630 static struct snapshot *find_outdated_snapshot(struct snapshot_list *sl)
631 {
632 int i;
633 struct snapshot *s;
634
635 DSS_DEBUG_LOG(("looking for snapshots belonging to intervals >= %d\n",
636 OPT_UINT32_VAL(DSS, NUM_INTERVALS)));
637 FOR_EACH_SNAPSHOT(s, i, sl) {
638 if (snapshot_is_being_created(s))
639 continue;
640 if (is_reference_snapshot(s))
641 continue;
642 if (s->interval < OPT_UINT32_VAL(DSS, NUM_INTERVALS))
643 continue;
644 return s;
645 }
646 return NULL;
647 }
648
649 static struct snapshot *find_oldest_removable_snapshot(struct snapshot_list *sl)
650 {
651 int i, num_complete;
652 struct snapshot *s, *ref = NULL;
653
654 num_complete = num_complete_snapshots(sl);
655 if (num_complete <= OPT_UINT32_VAL(DSS, MIN_COMPLETE))
656 return NULL;
657 FOR_EACH_SNAPSHOT(s, i, sl) {
658 if (snapshot_is_being_created(s))
659 continue;
660 if (is_reference_snapshot(s)) { /* avoid this one */
661 ref = s;
662 continue;
663 }
664 DSS_INFO_LOG(("oldest removable snapshot: %s\n", s->name));
665 return s;
666 }
667 assert(ref);
668 DSS_WARNING_LOG(("removing reference snapshot %s\n", ref->name));
669 return ref;
670 }
671
672 static int rename_incomplete_snapshot(int64_t start)
673 {
674 char *old_name;
675 int ret;
676 int64_t now;
677
678 /*
679 * We don't want the dss_rename() below to fail with EEXIST because the
680 * last complete snapshot was created (and completed) in the same
681 * second as this one.
682 */
683 while ((now = get_current_time()) == start)
684 sleep(1);
685 free(path_to_last_complete_snapshot);
686 ret = complete_name(start, now, &path_to_last_complete_snapshot);
687 if (ret < 0)
688 return ret;
689 old_name = incomplete_name(start);
690 ret = dss_rename(old_name, path_to_last_complete_snapshot);
691 if (ret >= 0)
692 DSS_NOTICE_LOG(("%s -> %s\n", old_name,
693 path_to_last_complete_snapshot));
694 free(old_name);
695 return ret;
696 }
697
698 static int try_to_free_disk_space(void)
699 {
700 int ret;
701 struct snapshot_list sl;
702 struct snapshot *victim;
703 struct timeval now;
704 const char *why;
705 int low_disk_space;
706
707 ret = disk_space_low(NULL);
708 if (ret < 0)
709 return ret;
710 low_disk_space = ret;
711 gettimeofday(&now, NULL);
712 if (tv_diff(&next_removal_check, &now, NULL) > 0)
713 return 0;
714 if (!low_disk_space) {
715 if (OPT_GIVEN(DSS, KEEP_REDUNDANT))
716 return 0;
717 if (snapshot_creation_status != HS_READY)
718 return 0;
719 if (next_snapshot_is_due())
720 return 0;
721 }
722 /*
723 * Idle and --keep_redundant not given, or low disk space. Look at
724 * existing snapshots.
725 */
726 dss_get_snapshot_list(&sl);
727 ret = 0;
728 /*
729 * Don't remove anything if there is free space and we have fewer
730 * snapshots than configured, plus one. This way there is always one
731 * snapshot that can be recycled.
732 */
733 if (!low_disk_space && sl.num_snapshots <=
734 1 << OPT_UINT32_VAL(DSS, NUM_INTERVALS))
735 goto out;
736 why = "outdated";
737 victim = find_outdated_snapshot(&sl);
738 if (victim)
739 goto remove;
740 why = "redundant";
741 victim = find_redundant_snapshot(&sl);
742 if (victim)
743 goto remove;
744 why = "orphaned";
745 victim = find_orphaned_snapshot(&sl);
746 if (victim)
747 goto remove;
748 /* try harder only if disk space is low */
749 if (!low_disk_space)
750 goto out;
751 DSS_WARNING_LOG(("disk space low and nothing obvious to remove\n"));
752 why = "oldest";
753 victim = find_oldest_removable_snapshot(&sl);
754 if (victim)
755 goto remove;
756 DSS_CRIT_LOG(("uhuhu: disk space low and nothing to remove\n"));
757 ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
758 goto out;
759 remove:
760 pre_remove_hook(victim, why);
761 out:
762 free_snapshot_list(&sl);
763 return ret;
764 }
765
766 static void post_create_hook(void)
767 {
768 char *cmd = make_message("%s %s/%s",
769 OPT_STRING_VAL(DSS, POST_CREATE_HOOK),
770 OPT_STRING_VAL(DSS, DEST_DIR), path_to_last_complete_snapshot);
771 DSS_NOTICE_LOG(("executing %s\n", cmd));
772 dss_exec_cmdline_pid(&create_pid, cmd);
773 free(cmd);
774 snapshot_creation_status = HS_POST_RUNNING;
775 }
776
777 static void post_remove_hook(void)
778 {
779 char *cmd;
780 struct snapshot *s = snapshot_currently_being_removed;
781
782 assert(s);
783
784 cmd = make_message("%s %s/%s", OPT_STRING_VAL(DSS, POST_REMOVE_HOOK),
785 OPT_STRING_VAL(DSS, DEST_DIR), s->name);
786 DSS_NOTICE_LOG(("executing %s\n", cmd));
787 dss_exec_cmdline_pid(&remove_pid, cmd);
788 free(cmd);
789 snapshot_removal_status = HS_POST_RUNNING;
790 }
791
792 static void dss_kill(pid_t pid, int sig, const char *msg)
793 {
794 const char *signame, *process_name;
795
796 if (pid == 0)
797 return;
798 switch (sig) {
799 case SIGTERM: signame = "TERM"; break;
800 case SIGSTOP: signame = "STOP"; break;
801 case SIGCONT: signame = "CONT"; break;
802 default: signame = "????";
803 }
804
805 if (pid == create_pid)
806 process_name = "create";
807 else if (pid == remove_pid)
808 process_name = "remove";
809 else process_name = "??????";
810
811 if (msg)
812 DSS_INFO_LOG(("%s\n", msg));
813 DSS_DEBUG_LOG(("sending signal %d (%s) to pid %d (%s process)\n",
814 sig, signame, (int)pid, process_name));
815 if (kill(pid, sig) >= 0)
816 return;
817 DSS_INFO_LOG(("failed to send signal %d (%s) to pid %d (%s process)\n",
818 sig, signame, (int)pid, process_name));
819 }
820
821 static void stop_create_process(void)
822 {
823 if (create_process_stopped)
824 return;
825 dss_kill(create_pid, SIGSTOP, "suspending create process");
826 create_process_stopped = 1;
827 }
828
829 static void restart_create_process(void)
830 {
831 if (!create_process_stopped)
832 return;
833 dss_kill(create_pid, SIGCONT, "resuming create process");
834 create_process_stopped = 0;
835 }
836
837 /**
838 * Print a log message about the exit status of a child.
839 */
840 static void log_termination_msg(pid_t pid, int status)
841 {
842 if (WIFEXITED(status))
843 DSS_INFO_LOG(("child %i exited. Exit status: %i\n", (int)pid,
844 WEXITSTATUS(status)));
845 else if (WIFSIGNALED(status))
846 DSS_NOTICE_LOG(("child %i was killed by signal %i\n", (int)pid,
847 WTERMSIG(status)));
848 else
849 DSS_WARNING_LOG(("child %i terminated abormally\n", (int)pid));
850 }
851
852 static int wait_for_process(pid_t pid, int *status)
853 {
854 int ret;
855
856 DSS_DEBUG_LOG(("Waiting for process %d to terminate\n", (int)pid));
857 for (;;) {
858 fd_set rfds;
859
860 FD_ZERO(&rfds);
861 FD_SET(signal_pipe, &rfds);
862 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
863 if (ret < 0)
864 break;
865 ret = next_signal();
866 if (!ret)
867 continue;
868 if (ret == SIGCHLD) {
869 ret = waitpid(pid, status, 0);
870 if (ret >= 0)
871 break;
872 if (errno != EINTR) { /* error */
873 ret = -ERRNO_TO_DSS_ERROR(errno);
874 break;
875 }
876 }
877 /* SIGINT or SIGTERM */
878 dss_kill(pid, SIGTERM, "killing child process");
879 }
880 if (ret < 0)
881 DSS_ERROR_LOG(("failed to wait for process %d\n", (int)pid));
882 else
883 log_termination_msg(pid, *status);
884 return ret;
885 }
886
887 static void handle_pre_remove_exit(int status)
888 {
889 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
890 snapshot_removal_status = HS_READY;
891 gettimeofday(&next_removal_check, NULL);
892 next_removal_check.tv_sec += 60;
893 return;
894 }
895 snapshot_removal_status = HS_PRE_SUCCESS;
896 }
897
898 static int handle_rm_exit(int status)
899 {
900 if (!WIFEXITED(status)) {
901 snapshot_removal_status = HS_READY;
902 return -E_INVOLUNTARY_EXIT;
903 }
904 if (WEXITSTATUS(status)) {
905 snapshot_removal_status = HS_READY;
906 return -E_BAD_EXIT_CODE;
907 }
908 snapshot_removal_status = HS_SUCCESS;
909 return 1;
910 }
911
912 static void handle_post_remove_exit(void)
913 {
914 snapshot_removal_status = HS_READY;
915 }
916
917 static int handle_remove_exit(int status)
918 {
919 int ret;
920 struct snapshot *s = snapshot_currently_being_removed;
921
922 assert(s);
923 switch (snapshot_removal_status) {
924 case HS_PRE_RUNNING:
925 handle_pre_remove_exit(status);
926 ret = 1;
927 break;
928 case HS_RUNNING:
929 ret = handle_rm_exit(status);
930 break;
931 case HS_POST_RUNNING:
932 handle_post_remove_exit();
933 ret = 1;
934 break;
935 default:
936 ret = -E_BUG;
937 }
938 if (snapshot_removal_status == HS_READY) {
939 free(s->name);
940 free(s);
941 snapshot_currently_being_removed = NULL;
942 }
943 remove_pid = 0;
944 return ret;
945 }
946
947 static int wait_for_remove_process(void)
948 {
949 int status, ret;
950
951 assert(remove_pid);
952 assert(
953 snapshot_removal_status == HS_PRE_RUNNING ||
954 snapshot_removal_status == HS_RUNNING ||
955 snapshot_removal_status == HS_POST_RUNNING
956 );
957 ret = wait_for_process(remove_pid, &status);
958 if (ret < 0)
959 return ret;
960 return handle_remove_exit(status);
961 }
962
963 static int handle_rsync_exit(int status)
964 {
965 int es, ret;
966
967 if (!WIFEXITED(status)) {
968 DSS_ERROR_LOG(("rsync process %d died involuntary\n", (int)create_pid));
969 ret = -E_INVOLUNTARY_EXIT;
970 snapshot_creation_status = HS_READY;
971 goto out;
972 }
973 es = WEXITSTATUS(status);
974 /*
975 * Restart rsync on non-fatal errors:
976 * 24: Partial transfer due to vanished source files
977 */
978 if (es != 0 && es != 24) {
979 DSS_WARNING_LOG(("rsync exit code %d, error count %d\n",
980 es, ++num_consecutive_rsync_errors));
981 if (!logfile) { /* called by com_run() */
982 ret = -E_BAD_EXIT_CODE;
983 goto out;
984 }
985 if (num_consecutive_rsync_errors >
986 OPT_UINT32_VAL(RUN, MAX_RSYNC_ERRORS)) {
987 ret = -E_TOO_MANY_RSYNC_ERRORS;
988 snapshot_creation_status = HS_READY;
989 goto out;
990 }
991 DSS_WARNING_LOG(("restarting rsync process\n"));
992 snapshot_creation_status = HS_NEEDS_RESTART;
993 next_snapshot_time = get_current_time() + 60;
994 ret = 1;
995 goto out;
996 }
997 num_consecutive_rsync_errors = 0;
998 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
999 if (ret < 0)
1000 goto out;
1001 snapshot_creation_status = HS_SUCCESS;
1002 free(name_of_reference_snapshot);
1003 name_of_reference_snapshot = NULL;
1004 out:
1005 create_process_stopped = 0;
1006 return ret;
1007 }
1008
1009 static int handle_pre_create_hook_exit(int status)
1010 {
1011 int es, ret;
1012 static int warn_count;
1013
1014 if (!WIFEXITED(status)) {
1015 snapshot_creation_status = HS_READY;
1016 ret = -E_INVOLUNTARY_EXIT;
1017 goto out;
1018 }
1019 es = WEXITSTATUS(status);
1020 if (es) {
1021 if (!warn_count--) {
1022 DSS_NOTICE_LOG(("pre_create_hook %s returned %d\n",
1023 OPT_STRING_VAL(DSS, PRE_CREATE_HOOK), es));
1024 DSS_NOTICE_LOG(("deferring snapshot creation...\n"));
1025 warn_count = 60; /* warn only once per hour */
1026 }
1027 next_snapshot_time = get_current_time() + 60;
1028 snapshot_creation_status = HS_READY;
1029 ret = 0;
1030 goto out;
1031 }
1032 warn_count = 0;
1033 snapshot_creation_status = HS_PRE_SUCCESS;
1034 ret = 1;
1035 out:
1036 return ret;
1037 }
1038
1039 static int handle_sigchld(void)
1040 {
1041 pid_t pid;
1042 int status, ret = reap_child(&pid, &status);
1043
1044 if (ret <= 0)
1045 return ret;
1046
1047 if (pid == create_pid) {
1048 switch (snapshot_creation_status) {
1049 case HS_PRE_RUNNING:
1050 ret = handle_pre_create_hook_exit(status);
1051 break;
1052 case HS_RUNNING:
1053 ret = handle_rsync_exit(status);
1054 break;
1055 case HS_POST_RUNNING:
1056 snapshot_creation_status = HS_READY;
1057 ret = 1;
1058 break;
1059 default:
1060 DSS_EMERG_LOG(("BUG: create can't die in status %d\n",
1061 snapshot_creation_status));
1062 return -E_BUG;
1063 }
1064 create_pid = 0;
1065 return ret;
1066 }
1067 if (pid == remove_pid) {
1068 ret = handle_remove_exit(status);
1069 if (ret < 0)
1070 return ret;
1071 return ret;
1072 }
1073 DSS_EMERG_LOG(("BUG: unknown process %d died\n", (int)pid));
1074 return -E_BUG;
1075 }
1076
1077 /* also checks if . is a mountpoint, if --mountpoint was given */
1078 static int change_to_dest_dir(void)
1079 {
1080 int ret;
1081 const char *dd = OPT_STRING_VAL(DSS, DEST_DIR);
1082 struct stat dot, dotdot;
1083
1084 DSS_INFO_LOG(("changing cwd to %s\n", dd));
1085 if (chdir(dd) < 0) {
1086 ret = -ERRNO_TO_DSS_ERROR(errno);
1087 DSS_ERROR_LOG(("could not change cwd to %s\n", dd));
1088 return ret;
1089 }
1090 if (!OPT_GIVEN(DSS, MOUNTPOINT))
1091 return 0;
1092 if (stat(".", &dot) < 0) {
1093 ret = -ERRNO_TO_DSS_ERROR(errno);
1094 DSS_ERROR_LOG(("could not stat .\n"));
1095 return ret;
1096 }
1097 if (stat("..", &dotdot) < 0) {
1098 ret = -ERRNO_TO_DSS_ERROR(errno);
1099 DSS_ERROR_LOG(("could not stat ..\n"));
1100 return ret;
1101 }
1102 if (dot.st_dev == dotdot.st_dev && dot.st_ino != dotdot.st_ino) {
1103 DSS_ERROR_LOG(("mountpoint check failed for %s\n", dd));
1104 return -E_MOUNTPOINT;
1105 }
1106 return 1;
1107 }
1108
1109 static int check_config(void)
1110 {
1111 int ret;
1112 uint32_t unit_interval = OPT_UINT32_VAL(DSS, UNIT_INTERVAL);
1113 uint32_t num_intervals = OPT_UINT32_VAL(DSS, NUM_INTERVALS);
1114
1115 if (unit_interval == 0) {
1116 DSS_ERROR_LOG(("bad unit interval: %i\n", unit_interval));
1117 return -E_INVALID_NUMBER;
1118 }
1119 DSS_DEBUG_LOG(("unit interval: %i day(s)\n", unit_interval));
1120
1121 if (num_intervals == 0 || num_intervals > 30) {
1122 DSS_ERROR_LOG(("bad number of intervals: %i\n", num_intervals));
1123 return -E_INVALID_NUMBER;
1124 }
1125 if (subcmd == CMD_PTR(RUN) || subcmd == CMD_PTR(CREATE))
1126 if (!OPT_GIVEN(DSS, SOURCE_DIR)) {
1127 DSS_ERROR_LOG(("--source-dir required\n"));
1128 return -E_SYNTAX;
1129 }
1130 if (subcmd == CMD_PTR(RUN) || subcmd == CMD_PTR(CREATE)
1131 || subcmd == CMD_PTR(LS) || subcmd == CMD_PTR(PRUNE)) {
1132 if (!OPT_GIVEN(DSS, DEST_DIR)) {
1133 DSS_ERROR_LOG(("--dest-dir required\n"));
1134 return -E_SYNTAX;
1135 }
1136 ret = change_to_dest_dir();
1137 if (ret < 0)
1138 return ret;
1139 }
1140 DSS_DEBUG_LOG(("number of intervals: %i\n", num_intervals));
1141 return 1;
1142 }
1143
1144 static int lopsub_error(int lopsub_ret, char **errctx)
1145 {
1146 const char *msg = lls_strerror(-lopsub_ret);
1147 if (*errctx)
1148 DSS_ERROR_LOG(("%s: %s\n", *errctx, msg));
1149 else
1150 DSS_ERROR_LOG(("%s\n", msg));
1151 free(*errctx);
1152 *errctx = NULL;
1153 return -E_LOPSUB;
1154 }
1155
1156 static int parse_config_file(bool sighup, const struct lls_command *cmd)
1157 {
1158 int ret, fd = -1;
1159 char *config_file = get_config_file_name();
1160 struct stat statbuf;
1161 void *map;
1162 size_t sz;
1163 int cf_argc;
1164 char **cf_argv, *errctx = NULL;
1165 struct lls_parse_result *cf_lpr, *merged_lpr, *clpr;
1166 const char *subcmd_name;
1167
1168 ret = open(config_file, O_RDONLY);
1169 if (ret < 0) {
1170 if (errno != ENOENT || OPT_GIVEN(DSS, CONFIG_FILE)) {
1171 ret = -ERRNO_TO_DSS_ERROR(errno);
1172 DSS_ERROR_LOG(("config file %s can not be opened\n",
1173 config_file));
1174 goto out;
1175 }
1176 /* no config file -- nothing to do */
1177 ret = 0;
1178 goto success;
1179 }
1180 fd = ret;
1181 ret = fstat(fd, &statbuf);
1182 if (ret < 0) {
1183 ret = -ERRNO_TO_DSS_ERROR(errno);
1184 DSS_ERROR_LOG(("failed to stat config file %s\n", config_file));
1185 goto close_fd;
1186 }
1187 sz = statbuf.st_size;
1188 if (sz == 0) { /* config file is empty -- nothing to do */
1189 ret = 0;
1190 goto success;
1191 }
1192 map = mmap(NULL, sz, PROT_READ, MAP_PRIVATE, fd, 0);
1193 if (map == MAP_FAILED) {
1194 ret = -ERRNO_TO_DSS_ERROR(errno);
1195 DSS_ERROR_LOG(("failed to mmap config file %s\n",
1196 config_file));
1197 goto close_fd;
1198 }
1199 if (cmd == CMD_PTR(DSS))
1200 subcmd_name = NULL;
1201 else
1202 subcmd_name = lls_command_name(cmd);
1203 ret = lls_convert_config(map, sz, subcmd_name, &cf_argv, &errctx);
1204 munmap(map, sz);
1205 if (ret < 0) {
1206 DSS_ERROR_LOG(("failed to convert config file %s\n",
1207 config_file));
1208 ret = lopsub_error(ret, &errctx);
1209 goto close_fd;
1210 }
1211 cf_argc = ret;
1212 ret = lls_parse(cf_argc, cf_argv, cmd, &cf_lpr, &errctx);
1213 lls_free_argv(cf_argv);
1214 if (ret < 0) {
1215 ret = lopsub_error(ret, &errctx);
1216 goto close_fd;
1217 }
1218 clpr = cmd == CMD_PTR(DSS)? cmdline_lpr : cmdline_sublpr;
1219 if (sighup) /* config file overrides command line */
1220 ret = lls_merge(cf_lpr, clpr, cmd, &merged_lpr, &errctx);
1221 else /* command line options overrride config file options */
1222 ret = lls_merge(clpr, cf_lpr, cmd, &merged_lpr, &errctx);
1223 lls_free_parse_result(cf_lpr, cmd);
1224 if (ret < 0) {
1225 ret = lopsub_error(ret, &errctx);
1226 goto close_fd;
1227 }
1228 ret = 1;
1229 success:
1230 assert(ret >= 0);
1231 DSS_DEBUG_LOG(("loglevel: %d\n", OPT_UINT32_VAL(DSS, LOGLEVEL)));
1232 if (cmd != CMD_PTR(DSS)) {
1233 if (ret > 0) {
1234 if (sublpr != cmdline_sublpr)
1235 lls_free_parse_result(sublpr, cmd);
1236 sublpr = merged_lpr;
1237 } else
1238 sublpr = cmdline_sublpr;
1239 } else {
1240 if (ret > 0) {
1241 if (lpr != cmdline_lpr)
1242 lls_free_parse_result(lpr, cmd);
1243 lpr = merged_lpr;
1244 } else
1245 lpr = cmdline_lpr;
1246 }
1247 close_fd:
1248 if (fd >= 0)
1249 close(fd);
1250 out:
1251 free(config_file);
1252 if (ret < 0)
1253 DSS_EMERG_LOG(("%s\n", dss_strerror(-ret)));
1254 return ret;
1255 }
1256
1257 static int handle_sighup(void)
1258 {
1259 int ret;
1260
1261 DSS_NOTICE_LOG(("SIGHUP, re-reading config\n"));
1262 dump_dss_config("old");
1263 ret = parse_config_file(true /* SIGHUP */, CMD_PTR(DSS));
1264 if (ret < 0)
1265 return ret;
1266 ret = parse_config_file(true /* SIGHUP */, CMD_PTR(RUN));
1267 if (ret < 0)
1268 return ret;
1269 ret = check_config();
1270 if (ret < 0)
1271 return ret;
1272 close_log(logfile);
1273 logfile = NULL;
1274 if (OPT_GIVEN(RUN, DAEMON) || daemonized) {
1275 logfile = open_log(OPT_STRING_VAL(RUN, LOGFILE));
1276 log_welcome(OPT_UINT32_VAL(DSS, LOGLEVEL));
1277 daemonized = true;
1278 }
1279 dump_dss_config("reloaded");
1280 invalidate_next_snapshot_time();
1281 return 1;
1282 }
1283
1284 static void kill_children(void)
1285 {
1286 restart_create_process();
1287 dss_kill(create_pid, SIGTERM, NULL);
1288 dss_kill(remove_pid, SIGTERM, NULL);
1289 }
1290
1291 static int handle_signal(void)
1292 {
1293 int sig, ret = next_signal();
1294
1295 if (ret <= 0)
1296 goto out;
1297 sig = ret;
1298 switch (sig) {
1299 case SIGINT:
1300 case SIGTERM:
1301 return -E_SIGNAL;
1302 case SIGHUP:
1303 ret = handle_sighup();
1304 break;
1305 case SIGCHLD:
1306 ret = handle_sigchld();
1307 break;
1308 }
1309 out:
1310 if (ret < 0)
1311 DSS_ERROR_LOG(("%s\n", dss_strerror(-ret)));
1312 return ret;
1313 }
1314
1315 /*
1316 * We can not use rsync locally if the local user is different from the remote
1317 * user or if the src dir is not on the local host (or both).
1318 */
1319 static int use_rsync_locally(char *logname)
1320 {
1321 const char *h = OPT_STRING_VAL(DSS, REMOTE_HOST);
1322
1323 if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
1324 return 0;
1325 if (OPT_GIVEN(DSS, REMOTE_USER) &&
1326 strcmp(OPT_STRING_VAL(DSS, REMOTE_USER), logname))
1327 return 0;
1328 return 1;
1329 }
1330
1331 static int rename_resume_snap(int64_t creation_time)
1332 {
1333 struct snapshot_list sl;
1334 struct snapshot *s = NULL;
1335 char *new_name = incomplete_name(creation_time);
1336 int ret;
1337 const char *why;
1338
1339 sl.num_snapshots = 0;
1340
1341 ret = 0;
1342 dss_get_snapshot_list(&sl);
1343 /*
1344 * Snapshot recycling: We first look at the newest snapshot. If this
1345 * snapshot happens to be incomplete, the last rsync process was
1346 * aborted and we reuse this one. Otherwise we look at snapshots which
1347 * could be removed (outdated and redundant snapshots) as candidates
1348 * for recycling. If no outdated/redundant snapshot exists, we check if
1349 * there is an orphaned snapshot, which likely is useless anyway.
1350 *
1351 * Only if no existing snapshot is suitable for recycling, we bite the
1352 * bullet and create a new one.
1353 */
1354 s = get_newest_snapshot(&sl);
1355 if (!s) /* no snapshots at all */
1356 goto out;
1357 /* re-use last snapshot if it is incomplete */
1358 why = "aborted";
1359 if ((s->flags & SS_COMPLETE) == 0)
1360 goto out;
1361 why = "outdated";
1362 s = find_outdated_snapshot(&sl);
1363 if (s)
1364 goto out;
1365 why = "redundant";
1366 s = find_redundant_snapshot(&sl);
1367 if (s)
1368 goto out;
1369 why = "orphaned";
1370 s = find_orphaned_snapshot(&sl);
1371 out:
1372 if (s) {
1373 DSS_NOTICE_LOG(("recycling %s snapshot %s\n", why, s->name));
1374 ret = dss_rename(s->name, new_name);
1375 }
1376 if (ret >= 0)
1377 DSS_NOTICE_LOG(("creating %s\n", new_name));
1378 free(new_name);
1379 free_snapshot_list(&sl);
1380 return ret;
1381 }
1382
1383 static void create_rsync_argv(char ***argv, int64_t *num)
1384 {
1385 char *logname;
1386 int i = 0, j, N;
1387 struct snapshot_list sl;
1388 static bool seeded;
1389
1390 dss_get_snapshot_list(&sl);
1391 assert(!name_of_reference_snapshot);
1392 name_of_reference_snapshot = name_of_newest_complete_snapshot(&sl);
1393 free_snapshot_list(&sl);
1394
1395 /*
1396 * We specify up to 6 arguments, one argument per given rsync option
1397 * and one argument per given source dir. We also need space for the
1398 * terminating NULL pointer.
1399 */
1400 N = OPT_GIVEN(DSS, RSYNC_OPTION) + OPT_GIVEN(DSS, SOURCE_DIR);
1401 *argv = dss_malloc((7 + N) * sizeof(char *));
1402 (*argv)[i++] = dss_strdup("rsync");
1403 (*argv)[i++] = dss_strdup("-a");
1404 (*argv)[i++] = dss_strdup("--delete");
1405 if (!seeded) {
1406 srandom((unsigned)time(NULL)); /* no need to be fancy here */
1407 seeded = true;
1408 }
1409 if (1000 * (random() / (RAND_MAX + 1.0)) < OPT_UINT32_VAL(DSS, CHECKSUM)) {
1410 DSS_NOTICE_LOG(("adding --checksum to rsync options\n"));
1411 (*argv)[i++] = dss_strdup("--checksum");
1412 }
1413 for (j = 0; j < OPT_GIVEN(DSS, RSYNC_OPTION); j++)
1414 (*argv)[i++] = dss_strdup(lls_string_val(j,
1415 OPT_RESULT(DSS, RSYNC_OPTION)));
1416 if (name_of_reference_snapshot) {
1417 DSS_INFO_LOG(("using %s as reference\n", name_of_reference_snapshot));
1418 (*argv)[i++] = make_message("--link-dest=../%s",
1419 name_of_reference_snapshot);
1420 } else
1421 DSS_INFO_LOG(("no suitable reference snapshot found\n"));
1422 logname = dss_logname();
1423 if (use_rsync_locally(logname)) {
1424 for (j = 0; j < OPT_GIVEN(DSS, SOURCE_DIR); j++)
1425 (*argv)[i++] = dss_strdup(lls_string_val(j,
1426 OPT_RESULT(DSS, SOURCE_DIR)));
1427 } else {
1428 /*
1429 * dss-1.0 and earlier did not support multiple source
1430 * directories. These versions appended a slash to the end of
1431 * the source directory to make sure that only the contents of
1432 * the single source directory, but not the directory itself,
1433 * are copied to the destination. For multiple source
1434 * directories, however, this is not a good idea because the
1435 * source directories may well contain identical file names,
1436 * which would then be copied to the same location on the
1437 * destination, overwriting each other. Moreover, we want the
1438 * directory on the destination match the source. To preserve
1439 * the old behaviour, we thus have to special-case N=1.
1440 */
1441 for (j = 0; j < OPT_GIVEN(DSS, SOURCE_DIR); j++) {
1442 (*argv)[i++] = make_message("%s@%s:%s%s",
1443 OPT_GIVEN(DSS, REMOTE_USER)?
1444 OPT_STRING_VAL(DSS, REMOTE_USER) : logname,
1445 OPT_STRING_VAL(DSS, REMOTE_HOST),
1446 lls_string_val(j, OPT_RESULT(DSS, SOURCE_DIR)),
1447 N == 1? "/" : ""
1448 );
1449 }
1450 }
1451 free(logname);
1452 *num = get_current_time();
1453 (*argv)[i++] = incomplete_name(*num);
1454 (*argv)[i++] = NULL;
1455 for (j = 0; j < i; j++)
1456 DSS_DEBUG_LOG(("argv[%d] = %s\n", j, (*argv)[j]));
1457 }
1458
1459 static void free_rsync_argv(char **argv)
1460 {
1461 int i;
1462
1463 if (!argv)
1464 return;
1465 for (i = 0; argv[i]; i++)
1466 free(argv[i]);
1467 free(argv);
1468 }
1469
1470 static int create_snapshot(char **argv)
1471 {
1472 int ret;
1473
1474 assert(argv);
1475 ret = rename_resume_snap(current_snapshot_creation_time);
1476 if (ret < 0)
1477 return ret;
1478 dss_exec(&create_pid, argv[0], argv);
1479 snapshot_creation_status = HS_RUNNING;
1480 return ret;
1481 }
1482
1483 static int select_loop(void)
1484 {
1485 int ret;
1486 /* check every 60 seconds for free disk space */
1487 struct timeval tv;
1488 char **rsync_argv = NULL;
1489
1490 for (;;) {
1491 fd_set rfds;
1492 struct timeval *tvp;
1493
1494 if (remove_pid)
1495 tvp = NULL; /* sleep until rm hook/process dies */
1496 else { /* sleep one minute */
1497 tv.tv_sec = 60;
1498 tv.tv_usec = 0;
1499 tvp = &tv;
1500 }
1501 FD_ZERO(&rfds);
1502 FD_SET(signal_pipe, &rfds);
1503 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
1504 if (ret < 0)
1505 goto out;
1506 if (FD_ISSET(signal_pipe, &rfds)) {
1507 ret = handle_signal();
1508 if (ret < 0)
1509 goto out;
1510 }
1511 if (remove_pid)
1512 continue;
1513 if (snapshot_removal_status == HS_PRE_SUCCESS) {
1514 ret = exec_rm();
1515 if (ret < 0)
1516 goto out;
1517 continue;
1518 }
1519 if (snapshot_removal_status == HS_SUCCESS) {
1520 post_remove_hook();
1521 continue;
1522 }
1523 ret = try_to_free_disk_space();
1524 if (ret < 0)
1525 goto out;
1526 if (snapshot_removal_status != HS_READY) {
1527 stop_create_process();
1528 continue;
1529 }
1530 restart_create_process();
1531 switch (snapshot_creation_status) {
1532 case HS_READY:
1533 if (!next_snapshot_is_due())
1534 continue;
1535 pre_create_hook();
1536 continue;
1537 case HS_PRE_RUNNING:
1538 case HS_RUNNING:
1539 case HS_POST_RUNNING:
1540 continue;
1541 case HS_PRE_SUCCESS:
1542 if (!name_of_reference_snapshot) {
1543 free_rsync_argv(rsync_argv);
1544 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1545 }
1546 ret = create_snapshot(rsync_argv);
1547 if (ret < 0)
1548 goto out;
1549 continue;
1550 case HS_NEEDS_RESTART:
1551 if (!next_snapshot_is_due())
1552 continue;
1553 ret = create_snapshot(rsync_argv);
1554 if (ret < 0)
1555 goto out;
1556 continue;
1557 case HS_SUCCESS:
1558 post_create_hook();
1559 continue;
1560 }
1561 }
1562 out:
1563 return ret;
1564 }
1565
1566 static void exit_hook(int exit_code)
1567 {
1568 pid_t pid;
1569 char **argv, *tmp = dss_strdup(OPT_STRING_VAL(DSS, EXIT_HOOK));
1570 unsigned n = split_args(tmp, &argv);
1571
1572 n++;
1573 argv = dss_realloc(argv, (n + 1) * sizeof(char *));
1574 argv[n - 1] = dss_strdup(dss_strerror(-exit_code));
1575 argv[n] = NULL;
1576 dss_exec(&pid, argv[0], argv);
1577 free(argv[n - 1]);
1578 free(argv);
1579 free(tmp);
1580 }
1581
1582 static void lock_dss_or_die(void)
1583 {
1584 char *config_file = get_config_file_name();
1585 int ret = lock_dss(config_file);
1586
1587 free(config_file);
1588 if (ret < 0) {
1589 DSS_EMERG_LOG(("failed to lock: %s\n", dss_strerror(-ret)));
1590 exit(EXIT_FAILURE);
1591 }
1592 }
1593
1594 static int com_run(void)
1595 {
1596 int ret, fd = -1;
1597 char *config_file;
1598 pid_t pid;
1599
1600 if (OPT_GIVEN(DSS, DRY_RUN)) {
1601 DSS_ERROR_LOG(("dry run not supported by this command\n"));
1602 return -E_SYNTAX;
1603 }
1604 config_file = get_config_file_name();
1605 ret = get_dss_pid(config_file, &pid);
1606 free(config_file);
1607 if (ret >= 0) {
1608 DSS_ERROR_LOG(("pid %d\n", (int)pid));
1609 return -E_ALREADY_RUNNING;
1610 }
1611 if (OPT_GIVEN(RUN, DAEMON)) {
1612 fd = daemon_init();
1613 daemonized = true;
1614 logfile = open_log(OPT_STRING_VAL(RUN, LOGFILE));
1615 }
1616 lock_dss_or_die();
1617 dump_dss_config("startup");
1618 ret = install_sighandler(SIGHUP);
1619 if (ret < 0)
1620 return ret;
1621 if (fd >= 0) {
1622 ret = write(fd, "\0", 1);
1623 if (ret != 1) {
1624 DSS_ERROR_LOG(("write to daemon pipe returned %d\n",
1625 ret));
1626 if (ret < 0)
1627 return -ERRNO_TO_DSS_ERROR(errno);
1628 return -E_BUG;
1629 }
1630 }
1631 ret = select_loop();
1632 if (ret >= 0) /* impossible */
1633 ret = -E_BUG;
1634 kill_children();
1635 exit_hook(ret);
1636 while (wait(NULL) >= 0 || errno != ECHILD)
1637 ; /* still have children to wait for */
1638 return ret;
1639 }
1640 EXPORT_CMD_HANDLER(run);
1641
1642 static int com_prune(void)
1643 {
1644 int ret;
1645 struct snapshot_list sl;
1646 struct snapshot *victim;
1647 struct disk_space ds;
1648 const char *why;
1649
1650 lock_dss_or_die();
1651 ret = get_disk_space(".", &ds);
1652 if (ret < 0)
1653 return ret;
1654 log_disk_space(&ds);
1655 dss_get_snapshot_list(&sl);
1656 why = "outdated";
1657 victim = find_outdated_snapshot(&sl);
1658 if (victim)
1659 goto rm;
1660 why = "redundant";
1661 victim = find_redundant_snapshot(&sl);
1662 if (victim)
1663 goto rm;
1664 ret = 0;
1665 goto out;
1666 rm:
1667 if (OPT_GIVEN(DSS, DRY_RUN)) {
1668 dss_msg("%s snapshot %s (interval = %i)\n",
1669 why, victim->name, victim->interval);
1670 ret = 0;
1671 goto out;
1672 }
1673 pre_remove_hook(victim, why);
1674 if (snapshot_removal_status == HS_PRE_RUNNING) {
1675 ret = wait_for_remove_process();
1676 if (ret < 0)
1677 goto out;
1678 if (snapshot_removal_status != HS_PRE_SUCCESS)
1679 goto out;
1680 }
1681 ret = exec_rm();
1682 if (ret < 0)
1683 goto out;
1684 ret = wait_for_remove_process();
1685 if (ret < 0)
1686 goto out;
1687 if (snapshot_removal_status != HS_SUCCESS)
1688 goto out;
1689 post_remove_hook();
1690 if (snapshot_removal_status != HS_POST_RUNNING)
1691 goto out;
1692 ret = wait_for_remove_process();
1693 if (ret < 0)
1694 goto out;
1695 ret = 1;
1696 out:
1697 free_snapshot_list(&sl);
1698 return ret;
1699 }
1700 EXPORT_CMD_HANDLER(prune);
1701
1702 static int com_create(void)
1703 {
1704 int ret, status;
1705 char **rsync_argv;
1706
1707 lock_dss_or_die();
1708 if (OPT_GIVEN(DSS, DRY_RUN)) {
1709 int i;
1710 char *msg = NULL;
1711 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1712 for (i = 0; rsync_argv[i]; i++) {
1713 char *tmp = msg;
1714 msg = make_message("%s%s%s", tmp? tmp : "",
1715 tmp? " " : "", rsync_argv[i]);
1716 free(tmp);
1717 }
1718 free_rsync_argv(rsync_argv);
1719 dss_msg("%s\n", msg);
1720 free(msg);
1721 return 1;
1722 }
1723 pre_create_hook();
1724 if (create_pid) {
1725 ret = wait_for_process(create_pid, &status);
1726 if (ret < 0)
1727 return ret;
1728 ret = handle_pre_create_hook_exit(status);
1729 if (ret <= 0) /* error, or pre-create failed */
1730 return ret;
1731 }
1732 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1733 ret = create_snapshot(rsync_argv);
1734 if (ret < 0)
1735 goto out;
1736 ret = wait_for_process(create_pid, &status);
1737 if (ret < 0)
1738 goto out;
1739 ret = handle_rsync_exit(status);
1740 if (ret < 0)
1741 goto out;
1742 post_create_hook();
1743 if (create_pid)
1744 ret = wait_for_process(create_pid, &status);
1745 out:
1746 free_rsync_argv(rsync_argv);
1747 return ret;
1748 }
1749 EXPORT_CMD_HANDLER(create);
1750
1751 static int com_ls(void)
1752 {
1753 int i;
1754 struct snapshot_list sl;
1755 struct snapshot *s;
1756 int64_t now = get_current_time();
1757
1758 dss_get_snapshot_list(&sl);
1759 FOR_EACH_SNAPSHOT(s, i, &sl) {
1760 int64_t d;
1761 if (s->flags & SS_COMPLETE)
1762 d = (s->completion_time - s->creation_time) / 60;
1763 else
1764 d = (now - s->creation_time) / 60;
1765 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval,
1766 s->name, d / 60, d % 60);
1767 }
1768 free_snapshot_list(&sl);
1769 return 1;
1770 }
1771 EXPORT_CMD_HANDLER(ls);
1772
1773 static int com_configtest(void)
1774 {
1775 printf("Syntax Ok\n");
1776 return 0;
1777 }
1778 EXPORT_CMD_HANDLER(configtest);
1779
1780 static int setup_signal_handling(void)
1781 {
1782 int ret;
1783
1784 DSS_INFO_LOG(("setting up signal handlers\n"));
1785 signal_pipe = signal_init(); /* always successful */
1786 ret = install_sighandler(SIGINT);
1787 if (ret < 0)
1788 return ret;
1789 ret = install_sighandler(SIGTERM);
1790 if (ret < 0)
1791 return ret;
1792 return install_sighandler(SIGCHLD);
1793 }
1794
1795 static void handle_version_and_help(void)
1796 {
1797 char *txt;
1798
1799 if (OPT_GIVEN(DSS, DETAILED_HELP))
1800 txt = lls_long_help(CMD_PTR(DSS));
1801 else if (OPT_GIVEN(DSS, HELP))
1802 txt = lls_short_help(CMD_PTR(DSS));
1803 else if (OPT_GIVEN(DSS, VERSION))
1804 txt = make_message("%s\n", VERSION_STRING);
1805 else
1806 return;
1807 printf("%s", txt);
1808 free(txt);
1809 exit(EXIT_SUCCESS);
1810 }
1811
1812 static void show_subcommand_summary(void)
1813 {
1814 const struct lls_command *cmd;
1815 int i;
1816
1817 printf("Available subcommands:\n");
1818 for (i = 1; (cmd = lls_cmd(i, dss_suite)); i++) {
1819 const char *name = lls_command_name(cmd);
1820 const char *purpose = lls_purpose(cmd);
1821 printf("%-11s%s\n", name, purpose);
1822 }
1823 exit(EXIT_SUCCESS);
1824 }
1825
1826 int main(int argc, char **argv)
1827 {
1828 int ret;
1829 char *errctx = NULL;
1830 unsigned num_inputs;
1831 const struct dss_user_data *ud;
1832
1833 ret = lls_parse(argc, argv, CMD_PTR(DSS), &cmdline_lpr, &errctx);
1834 if (ret < 0) {
1835 ret = lopsub_error(ret, &errctx);
1836 goto out;
1837 }
1838 lpr = cmdline_lpr;
1839 ret = parse_config_file(false /* no SIGHUP */, CMD_PTR(DSS));
1840 if (ret < 0)
1841 goto out;
1842 handle_version_and_help();
1843 num_inputs = lls_num_inputs(lpr);
1844 if (num_inputs == 0)
1845 show_subcommand_summary();
1846 ret = lls_lookup_subcmd(argv[argc - num_inputs], dss_suite, &errctx);
1847 if (ret < 0) {
1848 ret = lopsub_error(ret, &errctx);
1849 goto out;
1850 }
1851 subcmd = lls_cmd(ret, dss_suite);
1852 ret = lls_parse(num_inputs, argv + argc - num_inputs, subcmd,
1853 &cmdline_sublpr, &errctx);
1854 if (ret < 0) {
1855 ret = lopsub_error(ret, &errctx);
1856 goto out;
1857 }
1858 sublpr = cmdline_sublpr;
1859 ret = parse_config_file(false /* no SIGHUP */, subcmd);
1860 if (ret < 0)
1861 goto out;
1862 ret = check_config();
1863 if (ret < 0)
1864 goto out;
1865 ret = setup_signal_handling();
1866 if (ret < 0)
1867 goto out;
1868 ud = lls_user_data(subcmd);
1869 ret = ud->handler();
1870 signal_shutdown();
1871 out:
1872 if (ret < 0) {
1873 if (errctx)
1874 DSS_ERROR_LOG(("%s\n", errctx));
1875 DSS_EMERG_LOG(("%s\n", dss_strerror(-ret)));
1876 }
1877 free(errctx);
1878 lls_free_parse_result(lpr, CMD_PTR(DSS));
1879 if (lpr != cmdline_lpr)
1880 lls_free_parse_result(cmdline_lpr, CMD_PTR(DSS));
1881 lls_free_parse_result(sublpr, subcmd);
1882 if (sublpr != cmdline_sublpr)
1883 lls_free_parse_result(cmdline_sublpr, subcmd);
1884 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1885 }
DSS - dyadic snapshot scheduler