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