Merge branch 'refs/heads/t/kill-w'
[dss.git] / dss.c
1 /*
2 * Copyright (C) 2008-2011 Andre Noll <maan@tuebingen.mpg.de>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6 #include <string.h>
7 #include <stdlib.h>
8 #include <stdio.h>
9 #include <stdarg.h>
10 #include <assert.h>
11 #include <errno.h>
12 #include <sys/types.h>
13 #include <signal.h>
14 #include <ctype.h>
15 #include <stdbool.h>
16 #include <sys/stat.h>
17 #include <unistd.h>
18 #include <inttypes.h>
19 #include <sys/time.h>
20 #include <time.h>
21 #include <sys/wait.h>
22 #include <fnmatch.h>
23 #include <limits.h>
24 #include <fcntl.h>
25 #include <lopsub.h>
26 #include <sys/mman.h>
27
28 #include "gcc-compat.h"
29 #include "log.h"
30 #include "str.h"
31 #include "err.h"
32 #include "file.h"
33 #include "exec.h"
34 #include "daemon.h"
35 #include "sig.h"
36 #include "df.h"
37 #include "tv.h"
38 #include "snap.h"
39 #include "ipc.h"
40 #include "dss.lsg.h"
41
42 #define CMD_PTR(_cname) lls_cmd(LSG_DSS_CMD_ ## _cname, dss_suite)
43 #define OPT_RESULT(_cname, _oname) (lls_opt_result(\
44 LSG_DSS_ ## _cname ## _OPT_ ## _oname, (CMD_PTR(_cname) == CMD_PTR(DSS))? lpr : sublpr))
45 #define OPT_GIVEN(_cname, _oname) (lls_opt_given(OPT_RESULT(_cname, _oname)))
46 #define OPT_STRING_VAL(_cname, _oname) (lls_string_val(0, \
47 OPT_RESULT(_cname, _oname)))
48 #define OPT_UINT32_VAL(_cname, _oname) (lls_uint32_val(0, \
49 OPT_RESULT(_cname, _oname)))
50
51 struct dss_user_data {int (*handler)(void);};
52 #define EXPORT_CMD_HANDLER(_cmd) const struct dss_user_data \
53 lsg_dss_com_ ## _cmd ## _user_data = { \
54 .handler = com_ ## _cmd \
55 };
56
57 /*
58 * Command line and active options. We need to keep a copy of the parsed
59 * command line options for the SIGHUP case where we merge the command line
60 * options and the new config file options.
61 */
62 static struct lls_parse_result *cmdline_lpr, *lpr;
63
64 /** Parsed subcommand options. */
65 static struct lls_parse_result *cmdline_sublpr, *sublpr;
66 /* The executing subcommand (NULL at startup). */
67 static const struct lls_command *subcmd;
68 /** Wether daemon_init() was called. */
69 static bool daemonized;
70 /** Non-NULL if we log to a file. */
71 static FILE *logfile;
72 /** The read end of the signal pipe */
73 static int signal_pipe;
74 /** Process id of current pre-create-hook/rsync/post-create-hook process. */
75 static pid_t create_pid;
76 /** Whether the pre-create-hook/rsync/post-create-hook is currently stopped. */
77 static int create_process_stopped;
78 /** How many times in a row the rsync command failed. */
79 static int num_consecutive_rsync_errors;
80 /** Process id of current pre-remove/rm/post-remove process. */
81 static pid_t remove_pid;
82 /** When the next snapshot is due. */
83 static int64_t next_snapshot_time;
84 /** When to try to remove something. */
85 static struct timeval next_removal_check;
86 /** Creation time of the snapshot currently being created. */
87 static int64_t current_snapshot_creation_time;
88 /** The snapshot currently being removed. */
89 struct snapshot *snapshot_currently_being_removed;
90 /** Needed by the post-create hook. */
91 static char *path_to_last_complete_snapshot;
92 static char *name_of_reference_snapshot;
93 /** \sa \ref snap.h for details. */
94 enum hook_status snapshot_creation_status;
95 /** \sa \ref snap.h for details. */
96 enum hook_status snapshot_removal_status;
97
98
99 DEFINE_DSS_ERRLIST;
100 static const char *hook_status_description[] = {HOOK_STATUS_ARRAY};
101
102 /* may be called with ds == NULL. */
103 static int disk_space_low(struct disk_space *ds)
104 {
105 struct disk_space ds_struct;
106 uint32_t val;
107
108 if (!ds) {
109 int ret = get_disk_space(".", &ds_struct);
110 if (ret < 0)
111 return ret;
112 ds = &ds_struct;
113 }
114 val = OPT_UINT32_VAL(DSS, MIN_FREE_MB);
115 if (val != 0)
116 if (ds->free_mb < val)
117 return 1;
118 val = OPT_UINT32_VAL(DSS, MIN_FREE_PERCENT);
119 if (val != 0)
120 if (ds->percent_free < val)
121 return 1;
122 val = OPT_UINT32_VAL(DSS, MIN_FREE_PERCENT_INODES);
123 if (val != 0)
124 if (ds->percent_free_inodes < val)
125 return 1;
126 return 0;
127 }
128
129 static void dump_dss_config(const char *msg)
130 {
131 const char dash[] = "-----------------------------";
132 char *lopsub_dump;
133 int ret;
134 FILE *log = logfile? logfile : stderr;
135 struct disk_space ds;
136 int64_t now = get_current_time();
137
138 if (OPT_UINT32_VAL(DSS, LOGLEVEL) > INFO)
139 return;
140
141 fprintf(log, "%s <%s config> %s\n", dash, msg, dash);
142 fprintf(log, "\n*** disk space ***\n\n");
143 ret = get_disk_space(".", &ds);
144 if (ret >= 0) {
145 DSS_INFO_LOG(("disk space low: %s\n", disk_space_low(&ds)?
146 "yes" : "no"));
147 log_disk_space(&ds);
148 } else
149 DSS_ERROR_LOG(("can not get free disk space: %s\n",
150 dss_strerror(-ret)));
151
152 /* we continue on errors from get_disk_space */
153
154 fprintf(log, "\n*** non-default options ***\n\n");
155 lopsub_dump = lls_dump_parse_result(lpr, CMD_PTR(DSS), true);
156 fprintf(log, "%s", lopsub_dump);
157 free(lopsub_dump);
158 fprintf(log, "\n*** non-default options for \"run\" ***\n\n");
159 lopsub_dump = lls_dump_parse_result(lpr, CMD_PTR(RUN), true);
160 fprintf(log, "%s", lopsub_dump);
161 free(lopsub_dump);
162 fprintf(log, "\n*** internal state ***\n\n");
163 fprintf(log,
164 "pid: %d\n"
165 "logile: %s\n"
166 "snapshot_currently_being_removed: %s\n"
167 "path_to_last_complete_snapshot: %s\n"
168 "reference_snapshot: %s\n"
169 "snapshot_creation_status: %s\n"
170 "snapshot_removal_status: %s\n"
171 "num_consecutive_rsync_errors: %d\n"
172 ,
173 (int) getpid(),
174 logfile? OPT_STRING_VAL(RUN, LOGFILE) : "stderr",
175 snapshot_currently_being_removed?
176 snapshot_currently_being_removed->name : "(none)",
177 path_to_last_complete_snapshot?
178 path_to_last_complete_snapshot : "(none)",
179 name_of_reference_snapshot?
180 name_of_reference_snapshot : "(none)",
181 hook_status_description[snapshot_creation_status],
182 hook_status_description[snapshot_removal_status],
183 num_consecutive_rsync_errors
184 );
185 if (create_pid != 0)
186 fprintf(log,
187 "create_pid: %" PRId32 "\n"
188 "create process is %sstopped\n"
189 ,
190 create_pid,
191 create_process_stopped? "" : "not "
192 );
193 if (remove_pid != 0)
194 fprintf(log, "remove_pid: %" PRId32 "\n", remove_pid);
195 if (next_snapshot_time != 0)
196 fprintf(log, "next snapshot due in %" PRId64 " seconds\n",
197 next_snapshot_time - now);
198 if (current_snapshot_creation_time != 0)
199 fprintf(log, "current_snapshot_creation_time: %"
200 PRId64 " (%" PRId64 " seconds ago)\n",
201 current_snapshot_creation_time,
202 now - current_snapshot_creation_time
203 );
204 if (next_removal_check.tv_sec != 0) {
205 fprintf(log, "next removal check: %llu (%llu seconds ago)\n",
206 (long long unsigned)next_removal_check.tv_sec,
207 now - (long long unsigned)next_removal_check.tv_sec
208 );
209
210 }
211 fprintf(log, "%s </%s config> %s\n", dash, msg, dash);
212 }
213
214 static int loglevel = -1;
215 static const char *location_file = NULL;
216 static int location_line = -1;
217 static const char *location_func = NULL;
218
219 void dss_log_set_params(int ll, const char *file, int line, const char *func)
220 {
221 loglevel = ll;
222 location_file = file;
223 location_line = line;
224 location_func = func;
225 }
226
227 /**
228 * The log function of dss.
229 *
230 * \param ll Loglevel.
231 * \param fml Usual format string.
232 *
233 * All DSS_XXX_LOG() macros use this function.
234 */
235 __printf_1_2 void dss_log(const char* fmt,...)
236 {
237 va_list argp;
238 FILE *outfd;
239 struct tm *tm;
240 time_t t1;
241 char str[255] = "";
242 int lpr_ll = lpr? OPT_UINT32_VAL(DSS, LOGLEVEL) : WARNING;
243
244 if (loglevel < lpr_ll)
245 return;
246 outfd = logfile? logfile : stderr;
247 if (subcmd == CMD_PTR(RUN)) {
248 time(&t1);
249 tm = localtime(&t1);
250 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
251 fprintf(outfd, "%s ", str);
252 if (lpr_ll <= INFO)
253 fprintf(outfd, "%i: ", loglevel);
254 }
255 if (subcmd == CMD_PTR(RUN))
256 #ifdef DSS_NO_FUNC_NAMES
257 fprintf(outfd, "%s:%d: ", location_file, location_line);
258 #else
259 fprintf(outfd, "%s: ", location_func);
260 #endif
261 va_start(argp, fmt);
262 vfprintf(outfd, fmt, argp);
263 va_end(argp);
264 }
265
266 /**
267 * Print a message either to stdout or to the log file.
268 */
269 static __printf_1_2 void dss_msg(const char* fmt,...)
270 {
271 FILE *outfd = logfile? logfile : stdout;
272 va_list argp;
273 va_start(argp, fmt);
274 vfprintf(outfd, fmt, argp);
275 va_end(argp);
276 }
277
278 static char *get_config_file_name(void)
279 {
280 char *home, *config_file;
281
282 if (OPT_GIVEN(DSS, CONFIG_FILE))
283 return dss_strdup(OPT_STRING_VAL(DSS, CONFIG_FILE));
284 home = get_homedir();
285 config_file = make_message("%s/.dssrc", home);
286 free(home);
287 return config_file;
288 }
289
290 static int send_signal(int sig, bool wait)
291 {
292 pid_t pid;
293 char *config_file = get_config_file_name();
294 int ret = get_dss_pid(config_file, &pid);
295 unsigned ms = 32;
296 struct timespec ts;
297
298 free(config_file);
299 if (ret < 0)
300 return ret;
301 if (OPT_GIVEN(DSS, DRY_RUN)) {
302 dss_msg("%d\n", (int)pid);
303 return 0;
304 }
305 DSS_NOTICE_LOG(("sending signal %d to pid %d\n", sig, (int)pid));
306 ret = kill(pid, sig);
307 if (ret < 0)
308 return -ERRNO_TO_DSS_ERROR(errno);
309 if (!wait)
310 return 1;
311 while (ms < 5000) {
312 ts.tv_sec = ms / 1000;
313 ts.tv_nsec = (ms % 1000) * 1000 * 1000;
314 ret = nanosleep(&ts, NULL);
315 if (ret < 0)
316 return -ERRNO_TO_DSS_ERROR(errno);
317 ret = kill(pid, 0);
318 if (ret < 0) {
319 if (errno != ESRCH)
320 return -ERRNO_TO_DSS_ERROR(errno);
321 return 1;
322 }
323 ms *= 2;
324 }
325 return -E_KILL_TIMEOUT;
326 }
327
328 struct signal_info {
329 const char * const name;
330 int num;
331 };
332
333 /*
334 * The table below was taken 2016 from proc/sig.c of procps-3.2.8. Copyright
335 * 1998-2003 by Albert Cahalan, GPLv2.
336 */
337 static const struct signal_info signal_table[] = {
338 {"ABRT", SIGABRT}, /* IOT */
339 {"ALRM", SIGALRM},
340 {"BUS", SIGBUS},
341 {"CHLD", SIGCHLD}, /* CLD */
342 {"CONT", SIGCONT},
343 {"FPE", SIGFPE},
344 {"HUP", SIGHUP},
345 {"ILL", SIGILL},
346 {"INT", SIGINT},
347 {"KILL", SIGKILL},
348 {"PIPE", SIGPIPE},
349 #ifdef SIGPOLL
350 {"POLL", SIGPOLL}, /* IO */
351 #endif
352 {"PROF", SIGPROF},
353 #ifdef SIGPWR
354 {"PWR", SIGPWR},
355 #endif
356 {"QUIT", SIGQUIT},
357 {"SEGV", SIGSEGV},
358 #ifdef SIGSTKFLT
359 {"STKFLT", SIGSTKFLT},
360 #endif
361 {"STOP", SIGSTOP},
362 {"SYS", SIGSYS}, /* UNUSED */
363 {"TERM", SIGTERM},
364 {"TRAP", SIGTRAP},
365 {"TSTP", SIGTSTP},
366 {"TTIN", SIGTTIN},
367 {"TTOU", SIGTTOU},
368 {"URG", SIGURG},
369 {"USR1", SIGUSR1},
370 {"USR2", SIGUSR2},
371 {"VTALRM", SIGVTALRM},
372 {"WINCH", SIGWINCH},
373 {"XCPU", SIGXCPU},
374 {"XFSZ", SIGXFSZ}
375 };
376
377 #define SIGNAL_TABLE_SIZE (sizeof(signal_table) / sizeof(signal_table[0]))
378 #ifndef SIGRTMAX
379 #define SIGRTMAX 64
380 #endif
381
382 static int com_kill(void)
383 {
384 bool w_given = OPT_GIVEN(KILL, WAIT);
385 const char *arg = OPT_STRING_VAL(KILL, SIGNAL);
386 int ret, i;
387
388 if (*arg >= '0' && *arg <= '9') {
389 int64_t val;
390 ret = dss_atoi64(arg, &val);
391 if (ret < 0)
392 return ret;
393 if (val < 0 || val > SIGRTMAX)
394 return -ERRNO_TO_DSS_ERROR(EINVAL);
395 return send_signal(val, w_given);
396 }
397 if (strncasecmp(arg, "sig", 3) == 0)
398 arg += 3;
399 if (strcasecmp(arg, "CLD") == 0)
400 return send_signal(SIGCHLD, w_given);
401 if (strcasecmp(arg, "IOT") == 0)
402 return send_signal(SIGABRT, w_given);
403 for (i = 0; i < SIGNAL_TABLE_SIZE; i++)
404 if (strcasecmp(arg, signal_table[i].name) == 0)
405 return send_signal(signal_table[i].num, w_given);
406 DSS_ERROR_LOG(("invalid sigspec: %s\n", arg));
407 return -ERRNO_TO_DSS_ERROR(EINVAL);
408 }
409 EXPORT_CMD_HANDLER(kill);
410
411 static void dss_get_snapshot_list(struct snapshot_list *sl)
412 {
413 get_snapshot_list(sl, OPT_UINT32_VAL(DSS, UNIT_INTERVAL),
414 OPT_UINT32_VAL(DSS, NUM_INTERVALS));
415 }
416
417 static int64_t compute_next_snapshot_time(void)
418 {
419 int64_t x = 0, now = get_current_time(), unit_interval
420 = 24 * 3600 * OPT_UINT32_VAL(DSS, UNIT_INTERVAL), ret;
421 unsigned wanted = desired_number_of_snapshots(0,
422 OPT_UINT32_VAL(DSS, NUM_INTERVALS)),
423 num_complete = 0;
424 int i;
425 struct snapshot *s = NULL;
426 struct snapshot_list sl;
427
428 dss_get_snapshot_list(&sl);
429 FOR_EACH_SNAPSHOT(s, i, &sl) {
430 if (!(s->flags & SS_COMPLETE))
431 continue;
432 num_complete++;
433 x += s->completion_time - s->creation_time;
434 }
435 assert(x >= 0);
436
437 ret = now;
438 if (num_complete == 0)
439 goto out;
440 x /= num_complete; /* avg time to create one snapshot */
441 if (unit_interval < x * wanted) /* oops, no sleep at all */
442 goto out;
443 ret = s->completion_time + unit_interval / wanted - x;
444 out:
445 free_snapshot_list(&sl);
446 return ret;
447 }
448
449 static inline void invalidate_next_snapshot_time(void)
450 {
451 next_snapshot_time = 0;
452 }
453
454 static inline int next_snapshot_time_is_valid(void)
455 {
456 return next_snapshot_time != 0;
457 }
458
459 static int next_snapshot_is_due(void)
460 {
461 int64_t now = get_current_time();
462
463 if (!next_snapshot_time_is_valid())
464 next_snapshot_time = compute_next_snapshot_time();
465 if (next_snapshot_time <= now) {
466 DSS_DEBUG_LOG(("next snapshot: now\n"));
467 return 1;
468 }
469 DSS_DEBUG_LOG(("next snapshot due in %" PRId64 " seconds\n",
470 next_snapshot_time - now));
471 return 0;
472 }
473
474 static void pre_create_hook(void)
475 {
476 assert(snapshot_creation_status == HS_READY);
477 /* make sure that the next snapshot time will be recomputed */
478 invalidate_next_snapshot_time();
479 DSS_DEBUG_LOG(("executing %s\n", OPT_STRING_VAL(DSS, PRE_CREATE_HOOK)));
480 dss_exec_cmdline_pid(&create_pid, OPT_STRING_VAL(DSS, PRE_CREATE_HOOK));
481 snapshot_creation_status = HS_PRE_RUNNING;
482 }
483
484 static void pre_remove_hook(struct snapshot *s, const char *why)
485 {
486 char *cmd;
487
488 if (!s)
489 return;
490 DSS_DEBUG_LOG(("%s snapshot %s\n", why, s->name));
491 assert(snapshot_removal_status == HS_READY);
492 assert(remove_pid == 0);
493 assert(!snapshot_currently_being_removed);
494
495 snapshot_currently_being_removed = dss_malloc(sizeof(struct snapshot));
496 *snapshot_currently_being_removed = *s;
497 snapshot_currently_being_removed->name = dss_strdup(s->name);
498
499 cmd = make_message("%s %s/%s", OPT_STRING_VAL(DSS, PRE_REMOVE_HOOK),
500 OPT_STRING_VAL(DSS, DEST_DIR), s->name);
501 DSS_DEBUG_LOG(("executing %s\n", cmd));
502 dss_exec_cmdline_pid(&remove_pid, cmd);
503 free(cmd);
504 snapshot_removal_status = HS_PRE_RUNNING;
505 }
506
507 static int exec_rm(void)
508 {
509 struct snapshot *s = snapshot_currently_being_removed;
510 char *new_name = being_deleted_name(s);
511 char *argv[4];
512 int ret;
513
514 argv[0] = "rm";
515 argv[1] = "-rf";
516 argv[2] = new_name;
517 argv[3] = NULL;
518
519 assert(snapshot_removal_status == HS_PRE_SUCCESS);
520 assert(remove_pid == 0);
521
522 DSS_NOTICE_LOG(("removing %s (interval = %i)\n", s->name, s->interval));
523 ret = dss_rename(s->name, new_name);
524 if (ret < 0)
525 goto out;
526 dss_exec(&remove_pid, argv[0], argv);
527 snapshot_removal_status = HS_RUNNING;
528 out:
529 free(new_name);
530 return ret;
531 }
532
533 static int snapshot_is_being_created(struct snapshot *s)
534 {
535 return s->creation_time == current_snapshot_creation_time;
536 }
537
538 static struct snapshot *find_orphaned_snapshot(struct snapshot_list *sl)
539 {
540 struct snapshot *s;
541 int i;
542
543 DSS_DEBUG_LOG(("looking for old incomplete snapshots\n"));
544 FOR_EACH_SNAPSHOT(s, i, sl) {
545 if (snapshot_is_being_created(s))
546 continue;
547 /*
548 * We know that no rm is currently running, so if s is marked
549 * as being deleted, a previously started rm must have failed.
550 */
551 if (s->flags & SS_BEING_DELETED)
552 return s;
553
554 if (s->flags & SS_COMPLETE) /* good snapshot */
555 continue;
556 /*
557 * This snapshot is incomplete and it is not the snapshot
558 * currently being created. However, we must not remove it if
559 * rsync is about to be restarted. As only the newest snapshot
560 * can be restarted, this snapshot is orphaned if it is not the
561 * newest snapshot or if we are not about to restart rsync.
562 */
563 if (get_newest_snapshot(sl) != s)
564 return s;
565 if (snapshot_creation_status != HS_NEEDS_RESTART)
566 return s;
567 }
568 /* no orphaned snapshots */
569 return NULL;
570 }
571
572 static int is_reference_snapshot(struct snapshot *s)
573 {
574 if (!name_of_reference_snapshot)
575 return 0;
576 return strcmp(s->name, name_of_reference_snapshot)? 0 : 1;
577 }
578
579 /*
580 * return: 0: no redundant snapshots, 1: rm process started, negative: error
581 */
582 static struct snapshot *find_redundant_snapshot(struct snapshot_list *sl)
583 {
584 int i, interval;
585 struct snapshot *s;
586 unsigned missing = 0;
587 uint32_t N = OPT_UINT32_VAL(DSS, NUM_INTERVALS);
588
589 DSS_DEBUG_LOG(("looking for intervals containing too many snapshots\n"));
590 for (interval = N - 1; interval >= 0; interval--) {
591 unsigned keep = desired_number_of_snapshots(interval, N);
592 unsigned num = sl->interval_count[interval];
593 struct snapshot *victim = NULL, *prev = NULL;
594 int64_t score = LONG_MAX;
595
596 if (keep >= num)
597 missing += keep - num;
598 if (keep + missing >= num)
599 continue;
600 /* redundant snapshot in this interval, pick snapshot with lowest score */
601 FOR_EACH_SNAPSHOT(s, i, sl) {
602 int64_t this_score;
603
604 if (snapshot_is_being_created(s))
605 continue;
606 if (is_reference_snapshot(s))
607 continue;
608 if (s->interval > interval) {
609 prev = s;
610 continue;
611 }
612 if (s->interval < interval)
613 break;
614 if (!victim) {
615 victim = s;
616 prev = s;
617 continue;
618 }
619 assert(prev);
620 /* check if s is a better victim */
621 this_score = s->creation_time - prev->creation_time;
622 assert(this_score >= 0);
623 if (this_score < score) {
624 score = this_score;
625 victim = s;
626 }
627 prev = s;
628 }
629 assert(victim);
630 return victim;
631 }
632 return NULL;
633 }
634
635 static struct snapshot *find_outdated_snapshot(struct snapshot_list *sl)
636 {
637 int i;
638 struct snapshot *s;
639
640 DSS_DEBUG_LOG(("looking for snapshots belonging to intervals >= %d\n",
641 OPT_UINT32_VAL(DSS, NUM_INTERVALS)));
642 FOR_EACH_SNAPSHOT(s, i, sl) {
643 if (snapshot_is_being_created(s))
644 continue;
645 if (is_reference_snapshot(s))
646 continue;
647 if (s->interval < OPT_UINT32_VAL(DSS, NUM_INTERVALS))
648 continue;
649 return s;
650 }
651 return NULL;
652 }
653
654 static struct snapshot *find_oldest_removable_snapshot(struct snapshot_list *sl)
655 {
656 int i, num_complete;
657 struct snapshot *s, *ref = NULL;
658
659 num_complete = num_complete_snapshots(sl);
660 if (num_complete <= OPT_UINT32_VAL(DSS, MIN_COMPLETE))
661 return NULL;
662 FOR_EACH_SNAPSHOT(s, i, sl) {
663 if (snapshot_is_being_created(s))
664 continue;
665 if (is_reference_snapshot(s)) { /* avoid this one */
666 ref = s;
667 continue;
668 }
669 DSS_INFO_LOG(("oldest removable snapshot: %s\n", s->name));
670 return s;
671 }
672 assert(ref);
673 DSS_WARNING_LOG(("removing reference snapshot %s\n", ref->name));
674 return ref;
675 }
676
677 static int rename_incomplete_snapshot(int64_t start)
678 {
679 char *old_name;
680 int ret;
681 int64_t now;
682
683 /*
684 * We don't want the dss_rename() below to fail with EEXIST because the
685 * last complete snapshot was created (and completed) in the same
686 * second as this one.
687 */
688 while ((now = get_current_time()) == start)
689 sleep(1);
690 free(path_to_last_complete_snapshot);
691 ret = complete_name(start, now, &path_to_last_complete_snapshot);
692 if (ret < 0)
693 return ret;
694 old_name = incomplete_name(start);
695 ret = dss_rename(old_name, path_to_last_complete_snapshot);
696 if (ret >= 0)
697 DSS_NOTICE_LOG(("%s -> %s\n", old_name,
698 path_to_last_complete_snapshot));
699 free(old_name);
700 return ret;
701 }
702
703 static int try_to_free_disk_space(void)
704 {
705 int ret;
706 struct snapshot_list sl;
707 struct snapshot *victim;
708 struct timeval now;
709 const char *why;
710 int low_disk_space;
711
712 ret = disk_space_low(NULL);
713 if (ret < 0)
714 return ret;
715 low_disk_space = ret;
716 gettimeofday(&now, NULL);
717 if (tv_diff(&next_removal_check, &now, NULL) > 0)
718 return 0;
719 if (!low_disk_space) {
720 if (OPT_GIVEN(DSS, KEEP_REDUNDANT))
721 return 0;
722 if (snapshot_creation_status != HS_READY)
723 return 0;
724 if (next_snapshot_is_due())
725 return 0;
726 }
727 /*
728 * Idle and --keep_redundant not given, or low disk space. Look at
729 * existing snapshots.
730 */
731 dss_get_snapshot_list(&sl);
732 ret = 0;
733 /*
734 * Don't remove anything if there is free space and we have fewer
735 * snapshots than configured, plus one. This way there is always one
736 * snapshot that can be recycled.
737 */
738 if (!low_disk_space && sl.num_snapshots <=
739 1 << OPT_UINT32_VAL(DSS, NUM_INTERVALS))
740 goto out;
741 why = "outdated";
742 victim = find_outdated_snapshot(&sl);
743 if (victim)
744 goto remove;
745 why = "redundant";
746 victim = find_redundant_snapshot(&sl);
747 if (victim)
748 goto remove;
749 why = "orphaned";
750 victim = find_orphaned_snapshot(&sl);
751 if (victim)
752 goto remove;
753 /* try harder only if disk space is low */
754 if (!low_disk_space)
755 goto out;
756 DSS_WARNING_LOG(("disk space low and nothing obvious to remove\n"));
757 why = "oldest";
758 victim = find_oldest_removable_snapshot(&sl);
759 if (victim)
760 goto remove;
761 DSS_CRIT_LOG(("uhuhu: disk space low and nothing to remove\n"));
762 ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
763 goto out;
764 remove:
765 pre_remove_hook(victim, why);
766 out:
767 free_snapshot_list(&sl);
768 return ret;
769 }
770
771 static void post_create_hook(void)
772 {
773 char *cmd = make_message("%s %s/%s",
774 OPT_STRING_VAL(DSS, POST_CREATE_HOOK),
775 OPT_STRING_VAL(DSS, DEST_DIR), path_to_last_complete_snapshot);
776 DSS_NOTICE_LOG(("executing %s\n", cmd));
777 dss_exec_cmdline_pid(&create_pid, cmd);
778 free(cmd);
779 snapshot_creation_status = HS_POST_RUNNING;
780 }
781
782 static void post_remove_hook(void)
783 {
784 char *cmd;
785 struct snapshot *s = snapshot_currently_being_removed;
786
787 assert(s);
788
789 cmd = make_message("%s %s/%s", OPT_STRING_VAL(DSS, POST_REMOVE_HOOK),
790 OPT_STRING_VAL(DSS, DEST_DIR), s->name);
791 DSS_NOTICE_LOG(("executing %s\n", cmd));
792 dss_exec_cmdline_pid(&remove_pid, cmd);
793 free(cmd);
794 snapshot_removal_status = HS_POST_RUNNING;
795 }
796
797 static void dss_kill(pid_t pid, int sig, const char *msg)
798 {
799 const char *signame, *process_name;
800
801 if (pid == 0)
802 return;
803 switch (sig) {
804 case SIGTERM: signame = "TERM"; break;
805 case SIGSTOP: signame = "STOP"; break;
806 case SIGCONT: signame = "CONT"; break;
807 default: signame = "????";
808 }
809
810 if (pid == create_pid)
811 process_name = "create";
812 else if (pid == remove_pid)
813 process_name = "remove";
814 else process_name = "??????";
815
816 if (msg)
817 DSS_INFO_LOG(("%s\n", msg));
818 DSS_DEBUG_LOG(("sending signal %d (%s) to pid %d (%s process)\n",
819 sig, signame, (int)pid, process_name));
820 if (kill(pid, sig) >= 0)
821 return;
822 DSS_INFO_LOG(("failed to send signal %d (%s) to pid %d (%s process)\n",
823 sig, signame, (int)pid, process_name));
824 }
825
826 static void stop_create_process(void)
827 {
828 if (create_process_stopped)
829 return;
830 dss_kill(create_pid, SIGSTOP, "suspending create process");
831 create_process_stopped = 1;
832 }
833
834 static void restart_create_process(void)
835 {
836 if (!create_process_stopped)
837 return;
838 dss_kill(create_pid, SIGCONT, "resuming create process");
839 create_process_stopped = 0;
840 }
841
842 /**
843 * Print a log message about the exit status of a child.
844 */
845 static void log_termination_msg(pid_t pid, int status)
846 {
847 if (WIFEXITED(status))
848 DSS_INFO_LOG(("child %i exited. Exit status: %i\n", (int)pid,
849 WEXITSTATUS(status)));
850 else if (WIFSIGNALED(status))
851 DSS_NOTICE_LOG(("child %i was killed by signal %i\n", (int)pid,
852 WTERMSIG(status)));
853 else
854 DSS_WARNING_LOG(("child %i terminated abormally\n", (int)pid));
855 }
856
857 static int wait_for_process(pid_t pid, int *status)
858 {
859 int ret;
860
861 DSS_DEBUG_LOG(("Waiting for process %d to terminate\n", (int)pid));
862 for (;;) {
863 fd_set rfds;
864
865 FD_ZERO(&rfds);
866 FD_SET(signal_pipe, &rfds);
867 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
868 if (ret < 0)
869 break;
870 ret = next_signal();
871 if (!ret)
872 continue;
873 if (ret == SIGCHLD) {
874 ret = waitpid(pid, status, 0);
875 if (ret >= 0)
876 break;
877 if (errno != EINTR) { /* error */
878 ret = -ERRNO_TO_DSS_ERROR(errno);
879 break;
880 }
881 }
882 /* SIGINT or SIGTERM */
883 dss_kill(pid, SIGTERM, "killing child process");
884 }
885 if (ret < 0)
886 DSS_ERROR_LOG(("failed to wait for process %d\n", (int)pid));
887 else
888 log_termination_msg(pid, *status);
889 return ret;
890 }
891
892 static void handle_pre_remove_exit(int status)
893 {
894 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
895 snapshot_removal_status = HS_READY;
896 gettimeofday(&next_removal_check, NULL);
897 next_removal_check.tv_sec += 60;
898 return;
899 }
900 snapshot_removal_status = HS_PRE_SUCCESS;
901 }
902
903 static int handle_rm_exit(int status)
904 {
905 if (!WIFEXITED(status)) {
906 snapshot_removal_status = HS_READY;
907 return -E_INVOLUNTARY_EXIT;
908 }
909 if (WEXITSTATUS(status)) {
910 snapshot_removal_status = HS_READY;
911 return -E_BAD_EXIT_CODE;
912 }
913 snapshot_removal_status = HS_SUCCESS;
914 return 1;
915 }
916
917 static void handle_post_remove_exit(void)
918 {
919 snapshot_removal_status = HS_READY;
920 }
921
922 static int handle_remove_exit(int status)
923 {
924 int ret;
925 struct snapshot *s = snapshot_currently_being_removed;
926
927 assert(s);
928 switch (snapshot_removal_status) {
929 case HS_PRE_RUNNING:
930 handle_pre_remove_exit(status);
931 ret = 1;
932 break;
933 case HS_RUNNING:
934 ret = handle_rm_exit(status);
935 break;
936 case HS_POST_RUNNING:
937 handle_post_remove_exit();
938 ret = 1;
939 break;
940 default:
941 ret = -E_BUG;
942 }
943 if (snapshot_removal_status == HS_READY) {
944 free(s->name);
945 free(s);
946 snapshot_currently_being_removed = NULL;
947 }
948 remove_pid = 0;
949 return ret;
950 }
951
952 static int wait_for_remove_process(void)
953 {
954 int status, ret;
955
956 assert(remove_pid);
957 assert(
958 snapshot_removal_status == HS_PRE_RUNNING ||
959 snapshot_removal_status == HS_RUNNING ||
960 snapshot_removal_status == HS_POST_RUNNING
961 );
962 ret = wait_for_process(remove_pid, &status);
963 if (ret < 0)
964 return ret;
965 return handle_remove_exit(status);
966 }
967
968 static int handle_rsync_exit(int status)
969 {
970 int es, ret;
971
972 if (!WIFEXITED(status)) {
973 DSS_ERROR_LOG(("rsync process %d died involuntary\n", (int)create_pid));
974 ret = -E_INVOLUNTARY_EXIT;
975 snapshot_creation_status = HS_READY;
976 goto out;
977 }
978 es = WEXITSTATUS(status);
979 /*
980 * Restart rsync on non-fatal errors:
981 * 24: Partial transfer due to vanished source files
982 */
983 if (es != 0 && es != 24) {
984 DSS_WARNING_LOG(("rsync exit code %d, error count %d\n",
985 es, ++num_consecutive_rsync_errors));
986 if (!logfile) { /* called by com_run() */
987 ret = -E_BAD_EXIT_CODE;
988 goto out;
989 }
990 if (num_consecutive_rsync_errors >
991 OPT_UINT32_VAL(RUN, MAX_RSYNC_ERRORS)) {
992 ret = -E_TOO_MANY_RSYNC_ERRORS;
993 snapshot_creation_status = HS_READY;
994 goto out;
995 }
996 DSS_WARNING_LOG(("restarting rsync process\n"));
997 snapshot_creation_status = HS_NEEDS_RESTART;
998 next_snapshot_time = get_current_time() + 60;
999 ret = 1;
1000 goto out;
1001 }
1002 num_consecutive_rsync_errors = 0;
1003 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
1004 if (ret < 0)
1005 goto out;
1006 snapshot_creation_status = HS_SUCCESS;
1007 free(name_of_reference_snapshot);
1008 name_of_reference_snapshot = NULL;
1009 out:
1010 create_process_stopped = 0;
1011 return ret;
1012 }
1013
1014 static int handle_pre_create_hook_exit(int status)
1015 {
1016 int es, ret;
1017 static int warn_count;
1018
1019 if (!WIFEXITED(status)) {
1020 snapshot_creation_status = HS_READY;
1021 ret = -E_INVOLUNTARY_EXIT;
1022 goto out;
1023 }
1024 es = WEXITSTATUS(status);
1025 if (es) {
1026 if (!warn_count--) {
1027 DSS_NOTICE_LOG(("pre_create_hook %s returned %d\n",
1028 OPT_STRING_VAL(DSS, PRE_CREATE_HOOK), es));
1029 DSS_NOTICE_LOG(("deferring snapshot creation...\n"));
1030 warn_count = 60; /* warn only once per hour */
1031 }
1032 next_snapshot_time = get_current_time() + 60;
1033 snapshot_creation_status = HS_READY;
1034 ret = 0;
1035 goto out;
1036 }
1037 warn_count = 0;
1038 snapshot_creation_status = HS_PRE_SUCCESS;
1039 ret = 1;
1040 out:
1041 return ret;
1042 }
1043
1044 static int handle_sigchld(void)
1045 {
1046 pid_t pid;
1047 int status, ret = reap_child(&pid, &status);
1048
1049 if (ret <= 0)
1050 return ret;
1051
1052 if (pid == create_pid) {
1053 switch (snapshot_creation_status) {
1054 case HS_PRE_RUNNING:
1055 ret = handle_pre_create_hook_exit(status);
1056 break;
1057 case HS_RUNNING:
1058 ret = handle_rsync_exit(status);
1059 break;
1060 case HS_POST_RUNNING:
1061 snapshot_creation_status = HS_READY;
1062 ret = 1;
1063 break;
1064 default:
1065 DSS_EMERG_LOG(("BUG: create can't die in status %d\n",
1066 snapshot_creation_status));
1067 return -E_BUG;
1068 }
1069 create_pid = 0;
1070 return ret;
1071 }
1072 if (pid == remove_pid) {
1073 ret = handle_remove_exit(status);
1074 if (ret < 0)
1075 return ret;
1076 return ret;
1077 }
1078 DSS_EMERG_LOG(("BUG: unknown process %d died\n", (int)pid));
1079 return -E_BUG;
1080 }
1081
1082 /* also checks if . is a mountpoint, if --mountpoint was given */
1083 static int change_to_dest_dir(void)
1084 {
1085 int ret;
1086 const char *dd = OPT_STRING_VAL(DSS, DEST_DIR);
1087 struct stat dot, dotdot;
1088
1089 DSS_INFO_LOG(("changing cwd to %s\n", dd));
1090 if (chdir(dd) < 0) {
1091 ret = -ERRNO_TO_DSS_ERROR(errno);
1092 DSS_ERROR_LOG(("could not change cwd to %s\n", dd));
1093 return ret;
1094 }
1095 if (!OPT_GIVEN(DSS, MOUNTPOINT))
1096 return 0;
1097 if (stat(".", &dot) < 0) {
1098 ret = -ERRNO_TO_DSS_ERROR(errno);
1099 DSS_ERROR_LOG(("could not stat .\n"));
1100 return ret;
1101 }
1102 if (stat("..", &dotdot) < 0) {
1103 ret = -ERRNO_TO_DSS_ERROR(errno);
1104 DSS_ERROR_LOG(("could not stat ..\n"));
1105 return ret;
1106 }
1107 if (dot.st_dev == dotdot.st_dev && dot.st_ino != dotdot.st_ino) {
1108 DSS_ERROR_LOG(("mountpoint check failed for %s\n", dd));
1109 return -E_MOUNTPOINT;
1110 }
1111 return 1;
1112 }
1113
1114 static int check_config(void)
1115 {
1116 int ret;
1117 uint32_t unit_interval = OPT_UINT32_VAL(DSS, UNIT_INTERVAL);
1118 uint32_t num_intervals = OPT_UINT32_VAL(DSS, NUM_INTERVALS);
1119
1120 if (unit_interval == 0) {
1121 DSS_ERROR_LOG(("bad unit interval: %i\n", unit_interval));
1122 return -E_INVALID_NUMBER;
1123 }
1124 DSS_DEBUG_LOG(("unit interval: %i day(s)\n", unit_interval));
1125
1126 if (num_intervals == 0 || num_intervals > 30) {
1127 DSS_ERROR_LOG(("bad number of intervals: %i\n", num_intervals));
1128 return -E_INVALID_NUMBER;
1129 }
1130 if (subcmd == CMD_PTR(RUN) || subcmd == CMD_PTR(CREATE))
1131 if (!OPT_GIVEN(DSS, SOURCE_DIR)) {
1132 DSS_ERROR_LOG(("--source-dir required\n"));
1133 return -E_SYNTAX;
1134 }
1135 if (subcmd == CMD_PTR(RUN) || subcmd == CMD_PTR(CREATE)
1136 || subcmd == CMD_PTR(LS) || subcmd == CMD_PTR(PRUNE)) {
1137 if (!OPT_GIVEN(DSS, DEST_DIR)) {
1138 DSS_ERROR_LOG(("--dest-dir required\n"));
1139 return -E_SYNTAX;
1140 }
1141 ret = change_to_dest_dir();
1142 if (ret < 0)
1143 return ret;
1144 }
1145 DSS_DEBUG_LOG(("number of intervals: %i\n", num_intervals));
1146 return 1;
1147 }
1148
1149 static int lopsub_error(int lopsub_ret, char **errctx)
1150 {
1151 const char *msg = lls_strerror(-lopsub_ret);
1152 if (*errctx)
1153 DSS_ERROR_LOG(("%s: %s\n", *errctx, msg));
1154 else
1155 DSS_ERROR_LOG(("%s\n", msg));
1156 free(*errctx);
1157 *errctx = NULL;
1158 return -E_LOPSUB;
1159 }
1160
1161 static int parse_config_file(bool sighup, const struct lls_command *cmd)
1162 {
1163 int ret, fd = -1;
1164 char *config_file = get_config_file_name();
1165 struct stat statbuf;
1166 void *map;
1167 size_t sz;
1168 int cf_argc;
1169 char **cf_argv, *errctx = NULL;
1170 struct lls_parse_result *cf_lpr, *merged_lpr, *clpr;
1171 const char *subcmd_name;
1172
1173 ret = open(config_file, O_RDONLY);
1174 if (ret < 0) {
1175 if (errno != ENOENT || OPT_GIVEN(DSS, CONFIG_FILE)) {
1176 ret = -ERRNO_TO_DSS_ERROR(errno);
1177 DSS_ERROR_LOG(("config file %s can not be opened\n",
1178 config_file));
1179 goto out;
1180 }
1181 /* no config file -- nothing to do */
1182 ret = 0;
1183 goto success;
1184 }
1185 fd = ret;
1186 ret = fstat(fd, &statbuf);
1187 if (ret < 0) {
1188 ret = -ERRNO_TO_DSS_ERROR(errno);
1189 DSS_ERROR_LOG(("failed to stat config file %s\n", config_file));
1190 goto close_fd;
1191 }
1192 sz = statbuf.st_size;
1193 if (sz == 0) { /* config file is empty -- nothing to do */
1194 ret = 0;
1195 goto success;
1196 }
1197 map = mmap(NULL, sz, PROT_READ, MAP_PRIVATE, fd, 0);
1198 if (map == MAP_FAILED) {
1199 ret = -ERRNO_TO_DSS_ERROR(errno);
1200 DSS_ERROR_LOG(("failed to mmap config file %s\n",
1201 config_file));
1202 goto close_fd;
1203 }
1204 if (cmd == CMD_PTR(DSS))
1205 subcmd_name = NULL;
1206 else
1207 subcmd_name = lls_command_name(cmd);
1208 ret = lls_convert_config(map, sz, subcmd_name, &cf_argv, &errctx);
1209 munmap(map, sz);
1210 if (ret < 0) {
1211 DSS_ERROR_LOG(("failed to convert config file %s\n",
1212 config_file));
1213 ret = lopsub_error(ret, &errctx);
1214 goto close_fd;
1215 }
1216 cf_argc = ret;
1217 ret = lls_parse(cf_argc, cf_argv, cmd, &cf_lpr, &errctx);
1218 lls_free_argv(cf_argv);
1219 if (ret < 0) {
1220 ret = lopsub_error(ret, &errctx);
1221 goto close_fd;
1222 }
1223 clpr = cmd == CMD_PTR(DSS)? cmdline_lpr : cmdline_sublpr;
1224 if (sighup) /* config file overrides command line */
1225 ret = lls_merge(cf_lpr, clpr, cmd, &merged_lpr, &errctx);
1226 else /* command line options overrride config file options */
1227 ret = lls_merge(clpr, cf_lpr, cmd, &merged_lpr, &errctx);
1228 lls_free_parse_result(cf_lpr, cmd);
1229 if (ret < 0) {
1230 ret = lopsub_error(ret, &errctx);
1231 goto close_fd;
1232 }
1233 ret = 1;
1234 success:
1235 assert(ret >= 0);
1236 DSS_DEBUG_LOG(("loglevel: %d\n", OPT_UINT32_VAL(DSS, LOGLEVEL)));
1237 if (cmd != CMD_PTR(DSS)) {
1238 if (ret > 0) {
1239 if (sublpr != cmdline_sublpr)
1240 lls_free_parse_result(sublpr, cmd);
1241 sublpr = merged_lpr;
1242 } else
1243 sublpr = cmdline_sublpr;
1244 } else {
1245 if (ret > 0) {
1246 if (lpr != cmdline_lpr)
1247 lls_free_parse_result(lpr, cmd);
1248 lpr = merged_lpr;
1249 } else
1250 lpr = cmdline_lpr;
1251 }
1252 close_fd:
1253 if (fd >= 0)
1254 close(fd);
1255 out:
1256 free(config_file);
1257 if (ret < 0)
1258 DSS_EMERG_LOG(("%s\n", dss_strerror(-ret)));
1259 return ret;
1260 }
1261
1262 static int handle_sighup(void)
1263 {
1264 int ret;
1265
1266 DSS_NOTICE_LOG(("SIGHUP, re-reading config\n"));
1267 dump_dss_config("old");
1268 ret = parse_config_file(true /* SIGHUP */, CMD_PTR(DSS));
1269 if (ret < 0)
1270 return ret;
1271 ret = parse_config_file(true /* SIGHUP */, CMD_PTR(RUN));
1272 if (ret < 0)
1273 return ret;
1274 ret = check_config();
1275 if (ret < 0)
1276 return ret;
1277 close_log(logfile);
1278 logfile = NULL;
1279 if (OPT_GIVEN(RUN, DAEMON) || daemonized) {
1280 logfile = open_log(OPT_STRING_VAL(RUN, LOGFILE));
1281 log_welcome(OPT_UINT32_VAL(DSS, LOGLEVEL));
1282 daemonized = true;
1283 }
1284 dump_dss_config("reloaded");
1285 invalidate_next_snapshot_time();
1286 return 1;
1287 }
1288
1289 static void kill_children(void)
1290 {
1291 restart_create_process();
1292 dss_kill(create_pid, SIGTERM, NULL);
1293 dss_kill(remove_pid, SIGTERM, NULL);
1294 }
1295
1296 static int handle_signal(void)
1297 {
1298 int sig, ret = next_signal();
1299
1300 if (ret <= 0)
1301 goto out;
1302 sig = ret;
1303 switch (sig) {
1304 case SIGINT:
1305 case SIGTERM:
1306 kill_children();
1307 ret = -E_SIGNAL;
1308 break;
1309 case SIGHUP:
1310 ret = handle_sighup();
1311 break;
1312 case SIGCHLD:
1313 ret = handle_sigchld();
1314 break;
1315 }
1316 out:
1317 if (ret < 0)
1318 DSS_ERROR_LOG(("%s\n", dss_strerror(-ret)));
1319 return ret;
1320 }
1321
1322 /*
1323 * We can not use rsync locally if the local user is different from the remote
1324 * user or if the src dir is not on the local host (or both).
1325 */
1326 static int use_rsync_locally(char *logname)
1327 {
1328 const char *h = OPT_STRING_VAL(DSS, REMOTE_HOST);
1329
1330 if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
1331 return 0;
1332 if (OPT_GIVEN(DSS, REMOTE_USER) &&
1333 strcmp(OPT_STRING_VAL(DSS, REMOTE_USER), logname))
1334 return 0;
1335 return 1;
1336 }
1337
1338 static int rename_resume_snap(int64_t creation_time)
1339 {
1340 struct snapshot_list sl;
1341 struct snapshot *s = NULL;
1342 char *new_name = incomplete_name(creation_time);
1343 int ret;
1344 const char *why;
1345
1346 sl.num_snapshots = 0;
1347
1348 ret = 0;
1349 dss_get_snapshot_list(&sl);
1350 /*
1351 * Snapshot recycling: We first look at the newest snapshot. If this
1352 * snapshot happens to be incomplete, the last rsync process was
1353 * aborted and we reuse this one. Otherwise we look at snapshots which
1354 * could be removed (outdated and redundant snapshots) as candidates
1355 * for recycling. If no outdated/redundant snapshot exists, we check if
1356 * there is an orphaned snapshot, which likely is useless anyway.
1357 *
1358 * Only if no existing snapshot is suitable for recycling, we bite the
1359 * bullet and create a new one.
1360 */
1361 s = get_newest_snapshot(&sl);
1362 if (!s) /* no snapshots at all */
1363 goto out;
1364 /* re-use last snapshot if it is incomplete */
1365 why = "aborted";
1366 if ((s->flags & SS_COMPLETE) == 0)
1367 goto out;
1368 why = "outdated";
1369 s = find_outdated_snapshot(&sl);
1370 if (s)
1371 goto out;
1372 why = "redundant";
1373 s = find_redundant_snapshot(&sl);
1374 if (s)
1375 goto out;
1376 why = "orphaned";
1377 s = find_orphaned_snapshot(&sl);
1378 out:
1379 if (s) {
1380 DSS_NOTICE_LOG(("recycling %s snapshot %s\n", why, s->name));
1381 ret = dss_rename(s->name, new_name);
1382 }
1383 if (ret >= 0)
1384 DSS_NOTICE_LOG(("creating %s\n", new_name));
1385 free(new_name);
1386 free_snapshot_list(&sl);
1387 return ret;
1388 }
1389
1390 static void create_rsync_argv(char ***argv, int64_t *num)
1391 {
1392 char *logname;
1393 int i = 0, j, N = OPT_GIVEN(DSS, RSYNC_OPTION);
1394 struct snapshot_list sl;
1395 static bool seeded;
1396
1397 dss_get_snapshot_list(&sl);
1398 assert(!name_of_reference_snapshot);
1399 name_of_reference_snapshot = name_of_newest_complete_snapshot(&sl);
1400 free_snapshot_list(&sl);
1401
1402 *argv = dss_malloc((15 + N) * sizeof(char *));
1403 (*argv)[i++] = dss_strdup("rsync");
1404 (*argv)[i++] = dss_strdup("-a");
1405 (*argv)[i++] = dss_strdup("--delete");
1406 if (!seeded) {
1407 srandom((unsigned)time(NULL)); /* no need to be fancy here */
1408 seeded = true;
1409 }
1410 if (1000 * (random() / (RAND_MAX + 1.0)) < OPT_UINT32_VAL(DSS, CHECKSUM)) {
1411 DSS_NOTICE_LOG(("adding --checksum to rsync options\n"));
1412 (*argv)[i++] = dss_strdup("--checksum");
1413 }
1414 for (j = 0; j < N; j++)
1415 (*argv)[i++] = dss_strdup(lls_string_val(j,
1416 OPT_RESULT(DSS, RSYNC_OPTION)));
1417 if (name_of_reference_snapshot) {
1418 DSS_INFO_LOG(("using %s as reference\n", name_of_reference_snapshot));
1419 (*argv)[i++] = make_message("--link-dest=../%s",
1420 name_of_reference_snapshot);
1421 } else
1422 DSS_INFO_LOG(("no suitable reference snapshot found\n"));
1423 logname = dss_logname();
1424 if (use_rsync_locally(logname))
1425 (*argv)[i++] = dss_strdup(OPT_STRING_VAL(DSS, SOURCE_DIR));
1426 else
1427 (*argv)[i++] = make_message("%s@%s:%s/",
1428 OPT_GIVEN(DSS, REMOTE_USER)?
1429 OPT_STRING_VAL(DSS, REMOTE_USER) : logname,
1430 OPT_STRING_VAL(DSS, REMOTE_HOST),
1431 OPT_STRING_VAL(DSS, SOURCE_DIR));
1432 free(logname);
1433 *num = get_current_time();
1434 (*argv)[i++] = incomplete_name(*num);
1435 (*argv)[i++] = NULL;
1436 for (j = 0; j < i; j++)
1437 DSS_DEBUG_LOG(("argv[%d] = %s\n", j, (*argv)[j]));
1438 }
1439
1440 static void free_rsync_argv(char **argv)
1441 {
1442 int i;
1443
1444 if (!argv)
1445 return;
1446 for (i = 0; argv[i]; i++)
1447 free(argv[i]);
1448 free(argv);
1449 }
1450
1451 static int create_snapshot(char **argv)
1452 {
1453 int ret;
1454
1455 ret = rename_resume_snap(current_snapshot_creation_time);
1456 if (ret < 0)
1457 return ret;
1458 dss_exec(&create_pid, argv[0], argv);
1459 snapshot_creation_status = HS_RUNNING;
1460 return ret;
1461 }
1462
1463 static int select_loop(void)
1464 {
1465 int ret;
1466 /* check every 60 seconds for free disk space */
1467 struct timeval tv;
1468 char **rsync_argv = NULL;
1469
1470 for (;;) {
1471 fd_set rfds;
1472 struct timeval *tvp;
1473
1474 if (remove_pid)
1475 tvp = NULL; /* sleep until rm hook/process dies */
1476 else { /* sleep one minute */
1477 tv.tv_sec = 60;
1478 tv.tv_usec = 0;
1479 tvp = &tv;
1480 }
1481 FD_ZERO(&rfds);
1482 FD_SET(signal_pipe, &rfds);
1483 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
1484 if (ret < 0)
1485 goto out;
1486 if (FD_ISSET(signal_pipe, &rfds)) {
1487 ret = handle_signal();
1488 if (ret < 0)
1489 goto out;
1490 }
1491 if (remove_pid)
1492 continue;
1493 if (snapshot_removal_status == HS_PRE_SUCCESS) {
1494 ret = exec_rm();
1495 if (ret < 0)
1496 goto out;
1497 continue;
1498 }
1499 if (snapshot_removal_status == HS_SUCCESS) {
1500 post_remove_hook();
1501 continue;
1502 }
1503 ret = try_to_free_disk_space();
1504 if (ret < 0)
1505 goto out;
1506 if (snapshot_removal_status != HS_READY) {
1507 stop_create_process();
1508 continue;
1509 }
1510 restart_create_process();
1511 switch (snapshot_creation_status) {
1512 case HS_READY:
1513 if (!next_snapshot_is_due())
1514 continue;
1515 pre_create_hook();
1516 continue;
1517 case HS_PRE_RUNNING:
1518 case HS_RUNNING:
1519 case HS_POST_RUNNING:
1520 continue;
1521 case HS_PRE_SUCCESS:
1522 if (!name_of_reference_snapshot) {
1523 free_rsync_argv(rsync_argv);
1524 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1525 }
1526 ret = create_snapshot(rsync_argv);
1527 if (ret < 0)
1528 goto out;
1529 continue;
1530 case HS_NEEDS_RESTART:
1531 if (!next_snapshot_is_due())
1532 continue;
1533 ret = create_snapshot(rsync_argv);
1534 if (ret < 0)
1535 goto out;
1536 continue;
1537 case HS_SUCCESS:
1538 post_create_hook();
1539 continue;
1540 }
1541 }
1542 out:
1543 return ret;
1544 }
1545
1546 static void exit_hook(int exit_code)
1547 {
1548 pid_t pid;
1549 char **argv, *tmp = dss_strdup(OPT_STRING_VAL(DSS, EXIT_HOOK));
1550 unsigned n = split_args(tmp, &argv, " \t");
1551
1552 n++;
1553 argv = dss_realloc(argv, (n + 1) * sizeof(char *));
1554 argv[n - 1] = dss_strdup(dss_strerror(-exit_code));
1555 argv[n] = NULL;
1556 dss_exec(&pid, argv[0], argv);
1557 free(argv[n - 1]);
1558 free(argv);
1559 free(tmp);
1560 }
1561
1562 static void lock_dss_or_die(void)
1563 {
1564 char *config_file = get_config_file_name();
1565 int ret = lock_dss(config_file);
1566
1567 free(config_file);
1568 if (ret < 0) {
1569 DSS_EMERG_LOG(("failed to lock: %s\n", dss_strerror(-ret)));
1570 exit(EXIT_FAILURE);
1571 }
1572 }
1573
1574 static int com_run(void)
1575 {
1576 int ret, fd = -1;
1577 char *config_file;
1578 pid_t pid;
1579
1580 if (OPT_GIVEN(DSS, DRY_RUN)) {
1581 DSS_ERROR_LOG(("dry run not supported by this command\n"));
1582 return -E_SYNTAX;
1583 }
1584 config_file = get_config_file_name();
1585 ret = get_dss_pid(config_file, &pid);
1586 free(config_file);
1587 if (ret >= 0) {
1588 DSS_ERROR_LOG(("pid %d\n", (int)pid));
1589 return -E_ALREADY_RUNNING;
1590 }
1591 if (OPT_GIVEN(RUN, DAEMON)) {
1592 fd = daemon_init();
1593 daemonized = true;
1594 logfile = open_log(OPT_STRING_VAL(RUN, LOGFILE));
1595 }
1596 lock_dss_or_die();
1597 dump_dss_config("startup");
1598 ret = install_sighandler(SIGHUP);
1599 if (ret < 0)
1600 return ret;
1601 if (fd >= 0) {
1602 ret = write(fd, "\0", 1);
1603 if (ret != 1) {
1604 DSS_ERROR_LOG(("write to daemon pipe returned %d\n",
1605 ret));
1606 if (ret < 0)
1607 return -ERRNO_TO_DSS_ERROR(errno);
1608 return -E_BUG;
1609 }
1610 }
1611 ret = select_loop();
1612 if (ret >= 0) /* impossible */
1613 ret = -E_BUG;
1614 kill_children();
1615 exit_hook(ret);
1616 while (wait(NULL) >= 0 || errno != ECHILD)
1617 ; /* still have children to wait for */
1618 return ret;
1619 }
1620 EXPORT_CMD_HANDLER(run);
1621
1622 static int com_prune(void)
1623 {
1624 int ret;
1625 struct snapshot_list sl;
1626 struct snapshot *victim;
1627 struct disk_space ds;
1628 const char *why;
1629
1630 lock_dss_or_die();
1631 ret = get_disk_space(".", &ds);
1632 if (ret < 0)
1633 return ret;
1634 log_disk_space(&ds);
1635 dss_get_snapshot_list(&sl);
1636 why = "outdated";
1637 victim = find_outdated_snapshot(&sl);
1638 if (victim)
1639 goto rm;
1640 why = "redundant";
1641 victim = find_redundant_snapshot(&sl);
1642 if (victim)
1643 goto rm;
1644 ret = 0;
1645 goto out;
1646 rm:
1647 if (OPT_GIVEN(DSS, DRY_RUN)) {
1648 dss_msg("%s snapshot %s (interval = %i)\n",
1649 why, victim->name, victim->interval);
1650 ret = 0;
1651 goto out;
1652 }
1653 pre_remove_hook(victim, why);
1654 if (snapshot_removal_status == HS_PRE_RUNNING) {
1655 ret = wait_for_remove_process();
1656 if (ret < 0)
1657 goto out;
1658 if (snapshot_removal_status != HS_PRE_SUCCESS)
1659 goto out;
1660 }
1661 ret = exec_rm();
1662 if (ret < 0)
1663 goto out;
1664 ret = wait_for_remove_process();
1665 if (ret < 0)
1666 goto out;
1667 if (snapshot_removal_status != HS_SUCCESS)
1668 goto out;
1669 post_remove_hook();
1670 if (snapshot_removal_status != HS_POST_RUNNING)
1671 goto out;
1672 ret = wait_for_remove_process();
1673 if (ret < 0)
1674 goto out;
1675 ret = 1;
1676 out:
1677 free_snapshot_list(&sl);
1678 return ret;
1679 }
1680 EXPORT_CMD_HANDLER(prune);
1681
1682 static int com_create(void)
1683 {
1684 int ret, status;
1685 char **rsync_argv;
1686
1687 lock_dss_or_die();
1688 if (OPT_GIVEN(DSS, DRY_RUN)) {
1689 int i;
1690 char *msg = NULL;
1691 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1692 for (i = 0; rsync_argv[i]; i++) {
1693 char *tmp = msg;
1694 msg = make_message("%s%s%s", tmp? tmp : "",
1695 tmp? " " : "", rsync_argv[i]);
1696 free(tmp);
1697 }
1698 free_rsync_argv(rsync_argv);
1699 dss_msg("%s\n", msg);
1700 free(msg);
1701 return 1;
1702 }
1703 pre_create_hook();
1704 if (create_pid) {
1705 ret = wait_for_process(create_pid, &status);
1706 if (ret < 0)
1707 return ret;
1708 ret = handle_pre_create_hook_exit(status);
1709 if (ret <= 0) /* error, or pre-create failed */
1710 return ret;
1711 }
1712 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1713 ret = create_snapshot(rsync_argv);
1714 if (ret < 0)
1715 goto out;
1716 ret = wait_for_process(create_pid, &status);
1717 if (ret < 0)
1718 goto out;
1719 ret = handle_rsync_exit(status);
1720 if (ret < 0)
1721 goto out;
1722 post_create_hook();
1723 if (create_pid)
1724 ret = wait_for_process(create_pid, &status);
1725 out:
1726 free_rsync_argv(rsync_argv);
1727 return ret;
1728 }
1729 EXPORT_CMD_HANDLER(create);
1730
1731 static int com_ls(void)
1732 {
1733 int i;
1734 struct snapshot_list sl;
1735 struct snapshot *s;
1736 int64_t now = get_current_time();
1737
1738 dss_get_snapshot_list(&sl);
1739 FOR_EACH_SNAPSHOT(s, i, &sl) {
1740 int64_t d;
1741 if (s->flags & SS_COMPLETE)
1742 d = (s->completion_time - s->creation_time) / 60;
1743 else
1744 d = (now - s->creation_time) / 60;
1745 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval,
1746 s->name, d / 60, d % 60);
1747 }
1748 free_snapshot_list(&sl);
1749 return 1;
1750 }
1751 EXPORT_CMD_HANDLER(ls);
1752
1753 static int com_configtest(void)
1754 {
1755 printf("Syntax Ok\n");
1756 return 0;
1757 }
1758 EXPORT_CMD_HANDLER(configtest);
1759
1760 static int setup_signal_handling(void)
1761 {
1762 int ret;
1763
1764 DSS_INFO_LOG(("setting up signal handlers\n"));
1765 signal_pipe = signal_init(); /* always successful */
1766 ret = install_sighandler(SIGINT);
1767 if (ret < 0)
1768 return ret;
1769 ret = install_sighandler(SIGTERM);
1770 if (ret < 0)
1771 return ret;
1772 return install_sighandler(SIGCHLD);
1773 }
1774
1775 static void handle_version_and_help(void)
1776 {
1777 char *txt;
1778
1779 if (OPT_GIVEN(DSS, DETAILED_HELP))
1780 txt = lls_long_help(CMD_PTR(DSS));
1781 else if (OPT_GIVEN(DSS, HELP))
1782 txt = lls_short_help(CMD_PTR(DSS));
1783 else if (OPT_GIVEN(DSS, VERSION))
1784 txt = dss_strdup(VERSION_STRING);
1785 else
1786 return;
1787 printf("%s", txt);
1788 free(txt);
1789 exit(EXIT_SUCCESS);
1790 }
1791
1792 static void show_subcommand_summary(void)
1793 {
1794 const struct lls_command *cmd;
1795 int i;
1796
1797 printf("Available subcommands:\n");
1798 for (i = 1; (cmd = lls_cmd(i, dss_suite)); i++) {
1799 const char *name = lls_command_name(cmd);
1800 const char *purpose = lls_purpose(cmd);
1801 printf("%-11s%s\n", name, purpose);
1802 }
1803 exit(EXIT_SUCCESS);
1804 }
1805
1806 int main(int argc, char **argv)
1807 {
1808 int ret;
1809 char *errctx = NULL;
1810 unsigned num_inputs;
1811 const struct dss_user_data *ud;
1812
1813 ret = lls_parse(argc, argv, CMD_PTR(DSS), &cmdline_lpr, &errctx);
1814 if (ret < 0) {
1815 ret = lopsub_error(ret, &errctx);
1816 goto out;
1817 }
1818 lpr = cmdline_lpr;
1819 ret = parse_config_file(false /* no SIGHUP */, CMD_PTR(DSS));
1820 if (ret < 0)
1821 goto out;
1822 handle_version_and_help();
1823 num_inputs = lls_num_inputs(lpr);
1824 if (num_inputs == 0)
1825 show_subcommand_summary();
1826 ret = lls_lookup_subcmd(argv[argc - num_inputs], dss_suite, &errctx);
1827 if (ret < 0) {
1828 ret = lopsub_error(ret, &errctx);
1829 goto out;
1830 }
1831 subcmd = lls_cmd(ret, dss_suite);
1832 ret = lls_parse(num_inputs, argv + argc - num_inputs, subcmd,
1833 &cmdline_sublpr, &errctx);
1834 if (ret < 0) {
1835 ret = lopsub_error(ret, &errctx);
1836 goto out;
1837 }
1838 sublpr = cmdline_sublpr;
1839 ret = parse_config_file(false /* no SIGHUP */, subcmd);
1840 if (ret < 0)
1841 goto out;
1842 ret = check_config();
1843 if (ret < 0)
1844 goto out;
1845 ret = setup_signal_handling();
1846 if (ret < 0)
1847 goto out;
1848 ud = lls_user_data(subcmd);
1849 ret = ud->handler();
1850 signal_shutdown();
1851 out:
1852 if (ret < 0) {
1853 if (errctx)
1854 DSS_ERROR_LOG(("%s\n", errctx));
1855 DSS_EMERG_LOG(("%s\n", dss_strerror(-ret)));
1856 }
1857 free(errctx);
1858 lls_free_parse_result(lpr, CMD_PTR(DSS));
1859 if (lpr != cmdline_lpr)
1860 lls_free_parse_result(cmdline_lpr, CMD_PTR(DSS));
1861 lls_free_parse_result(sublpr, subcmd);
1862 if (sublpr != cmdline_sublpr)
1863 lls_free_parse_result(cmdline_sublpr, subcmd);
1864 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1865 }