X-Git-Url: http://git.tuebingen.mpg.de/?p=dss.git;a=blobdiff_plain;f=dss.c;h=a233c11f7060c0321502c35e555df78ef0b3931b;hp=3bcf60d4ba39d083f27bd26cb85998bb7a6eff69;hb=1e77c93a4da4dae8b75fcd305552e56ccae89b90;hpb=9967e30b97ef5fb90f31ceb06ac34b974e1788a8 diff --git a/dss.c b/dss.c index 3bcf60d..a233c11 100644 --- a/dss.c +++ b/dss.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2008 Andre Noll + * Copyright (C) 2008-2009 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ @@ -47,15 +47,16 @@ static int create_process_stopped; /** Process id of current pre-remove/rm/post-remove process. */ static pid_t remove_pid; /** When the next snapshot is due. */ -static struct timeval next_snapshot_time; +static int64_t next_snapshot_time; /** When to try to remove something. */ static struct timeval next_removal_check; /** Creation time of the snapshot currently being created. */ static int64_t current_snapshot_creation_time; -/* The snapshot currently being removed. */ +/** The snapshot currently being removed. */ struct snapshot *snapshot_currently_being_removed; /** Needed by the post-create hook. */ static char *path_to_last_complete_snapshot; +static char *name_of_reference_snapshot; /** \sa \ref snap.h for details. */ enum hook_status snapshot_creation_status; /** \sa \ref snap.h for details. */ @@ -150,21 +151,16 @@ static void dss_get_snapshot_list(struct snapshot_list *sl) get_snapshot_list(sl, conf.unit_interval_arg, conf.num_intervals_arg); } -static int next_snapshot_is_due(void) +static int64_t compute_next_snapshot_time(void) { - struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg}, - tmp, diff; - int64_t x = 0; + int64_t x = 0, now = get_current_time(), unit_interval + = 24 * 3600 * conf.unit_interval_arg, ret; unsigned wanted = desired_number_of_snapshots(0, conf.num_intervals_arg), num_complete_snapshots = 0; - int i, ret; + int i; struct snapshot *s = NULL; struct snapshot_list sl; - gettimeofday(&now, NULL); - if (tv_diff(&next_snapshot_time, &now, NULL) > 0) - return 0; - assert(snapshot_creation_status == HS_READY); current_snapshot_creation_time = 0; dss_get_snapshot_list(&sl); FOR_EACH_SNAPSHOT(s, i, &sl) { @@ -174,37 +170,52 @@ static int next_snapshot_is_due(void) x += s->completion_time - s->creation_time; } assert(x >= 0); - if (num_complete_snapshots) - x /= num_complete_snapshots; /* avg time to create one snapshot */ - x *= wanted; /* time to create all snapshots in interval 0 */ - tmp.tv_sec = x; - tmp.tv_usec = 0; - ret = tv_diff(&unit_interval, &tmp, &diff); /* total sleep time per unit interval */ - if (ret < 0 || !s) { /* unit_interval < tmp or no snapshot */ - ret = 1; - goto out; - } - tv_divide(wanted, &diff, &tmp); /* sleep time between two snapshots */ - diff.tv_sec = s->completion_time; /* completion time of the latest snapshot */ - diff.tv_usec = 0; - tv_add(&diff, &tmp, &next_snapshot_time); - ret = (tv_diff(&now, &next_snapshot_time, &diff) < 0)? 0 : 1; + ret = now; + if (num_complete_snapshots == 0) + goto out; + x /= num_complete_snapshots; /* avg time to create one snapshot */ + if (unit_interval < x * wanted) /* oops, no sleep at all */ + goto out; + ret = s->completion_time + unit_interval / wanted - x; out: free_snapshot_list(&sl); - if (ret == 0) - DSS_DEBUG_LOG("next snapshot due in %lu seconds\n", - tv2ms(&diff) / 1000); - else - DSS_DEBUG_LOG("next snapshot: now\n"); return ret; } +static inline void invalidate_next_snapshot_time(void) +{ + next_snapshot_time = 0; +} + +static inline int next_snapshot_time_is_valid(void) +{ + return next_snapshot_time != 0; +} + +static int next_snapshot_is_due(void) +{ + int64_t now = get_current_time(); + + assert(snapshot_creation_status == HS_READY); + if (!next_snapshot_time_is_valid()) + next_snapshot_time = compute_next_snapshot_time(); + if (next_snapshot_time <= now) { + DSS_DEBUG_LOG("next snapshot: now\n"); + return 1; + } + DSS_DEBUG_LOG("next snapshot due in %" PRId64 " seconds\n", + next_snapshot_time - now); + return 0; +} + static int pre_create_hook(void) { int ret, fds[3] = {0, 0, 0}; assert(snapshot_creation_status == HS_READY); + /* make sure that the next snapshot time will be recomputed */ + invalidate_next_snapshot_time(); if (!conf.pre_create_hook_given) { snapshot_creation_status = HS_PRE_SUCCESS; return 0; @@ -218,11 +229,13 @@ static int pre_create_hook(void) return ret; } -static int pre_remove_hook(struct snapshot *s, char *why) +static int pre_remove_hook(struct snapshot *s, const char *why) { int ret, fds[3] = {0, 0, 0}; char *cmd; + if (!s) + return 0; DSS_DEBUG_LOG("%s snapshot %s\n", why, s->name); assert(snapshot_removal_status == HS_READY); assert(remove_pid == 0); @@ -277,12 +290,53 @@ static int snapshot_is_being_created(struct snapshot *s) return s->creation_time == current_snapshot_creation_time; } +static struct snapshot *find_orphaned_snapshot(struct snapshot_list *sl) +{ + struct snapshot *s; + int i; + + DSS_DEBUG_LOG("looking for orphaned snapshots\n"); + FOR_EACH_SNAPSHOT(s, i, sl) { + if (snapshot_is_being_created(s)) + continue; + /* + * We know that no rm is currently running, so if s is marked + * as being deleted, a previously started rm must have failed. + */ + if (s->flags & SS_BEING_DELETED) + return s; + + if (s->flags & SS_COMPLETE) /* good snapshot */ + continue; + /* + * This snapshot is incomplete and it is not the snapshot + * currently being created. However, we must not remove it if + * rsync is about to be restarted. As only the newest snapshot + * can be restarted, this snapshot is orphaned if it is not the + * newest snapshot or if we are not about to restart rsync. + */ + if (get_newest_snapshot(sl) != s) + return s; + if (snapshot_creation_status != HS_NEEDS_RESTART) + return s; + } + /* no orphaned snapshots */ + return NULL; +} + +static int is_reference_snapshot(struct snapshot *s) +{ + if (!name_of_reference_snapshot) + return 0; + return strcmp(s->name, name_of_reference_snapshot)? 0 : 1; +} + /* * return: 0: no redundant snapshots, 1: rm process started, negative: error */ -static int remove_redundant_snapshot(struct snapshot_list *sl) +static struct snapshot *find_redundant_snapshot(struct snapshot_list *sl) { - int ret, i, interval; + int i, interval; struct snapshot *s; unsigned missing = 0; @@ -305,6 +359,8 @@ static int remove_redundant_snapshot(struct snapshot_list *sl) if (snapshot_is_being_created(s)) continue; + if (is_reference_snapshot(s)) + continue; //DSS_DEBUG_LOG("checking %s\n", s->name); if (s->interval > interval) { prev = s; @@ -329,56 +385,43 @@ static int remove_redundant_snapshot(struct snapshot_list *sl) prev = s; } assert(victim); - if (conf.dry_run_given) { - dss_msg("%s would be removed (interval = %i)\n", - victim->name, victim->interval); - continue; - } - ret = pre_remove_hook(victim, "redundant"); - return ret < 0? ret : 1; + return victim; } - return 0; + return NULL; } -static int remove_outdated_snapshot(struct snapshot_list *sl) +static struct snapshot *find_outdated_snapshot(struct snapshot_list *sl) { - int i, ret; + int i; struct snapshot *s; - DSS_DEBUG_LOG("looking for snapshots belonging to intervals greater than %d\n", + DSS_DEBUG_LOG("looking for snapshots belonging to intervals >= %d\n", conf.num_intervals_arg); FOR_EACH_SNAPSHOT(s, i, sl) { if (snapshot_is_being_created(s)) continue; - if (s->interval <= conf.num_intervals_arg) + if (is_reference_snapshot(s)) continue; - if (conf.dry_run_given) { - dss_msg("%s would be removed (interval = %i)\n", - s->name, s->interval); + if (s->interval < conf.num_intervals_arg) continue; - } - ret = pre_remove_hook(s, "outdated"); - if (ret < 0) - return ret; - return 1; + return s; } - return 0; + return NULL; } -static int remove_oldest_snapshot(struct snapshot_list *sl) +struct snapshot *find_oldest_removable_snapshot(struct snapshot_list *sl) { - int ret; - struct snapshot *s = get_oldest_snapshot(sl); - - if (!s) /* no snapshot found */ - return 0; - DSS_INFO_LOG("oldest snapshot: %s\n", s->name); - if (snapshot_is_being_created(s)) - return 0; - ret = pre_remove_hook(s, "oldest"); - if (ret < 0) - return ret; - return 1; + int i; + struct snapshot *s; + FOR_EACH_SNAPSHOT(s, i, sl) { + if (snapshot_is_being_created(s)) + continue; + if (is_reference_snapshot(s)) + continue; + DSS_INFO_LOG("oldest removable snapshot: %s\n", s->name); + return s; + } + return NULL; } static int rename_incomplete_snapshot(int64_t start) @@ -400,34 +443,58 @@ static int rename_incomplete_snapshot(int64_t start) return ret; } -static int try_to_free_disk_space(int low_disk_space) +static int try_to_free_disk_space(void) { int ret; struct snapshot_list sl; + struct snapshot *victim; struct timeval now; + const char *why; + int low_disk_space; + ret = disk_space_low(); + if (ret < 0) + return ret; + low_disk_space = ret; gettimeofday(&now, NULL); if (tv_diff(&next_removal_check, &now, NULL) > 0) return 0; - if (!low_disk_space && conf.keep_redundant_given) - return 0; + if (!low_disk_space) { + if (conf.keep_redundant_given) + return 0; + if (snapshot_creation_status != HS_READY) + return 0; + if (next_snapshot_is_due()) + return 0; + } dss_get_snapshot_list(&sl); - ret = remove_outdated_snapshot(&sl); - if (ret) /* error, or we are removing something */ - goto out; - /* no outdated snapshot */ - ret = remove_redundant_snapshot(&sl); - if (ret) - goto out; ret = 0; + if (!low_disk_space && sl.num_snapshots <= 1) + goto out; + why = "outdated"; + victim = find_outdated_snapshot(&sl); + if (victim) + goto remove; + why = "redundant"; + victim = find_redundant_snapshot(&sl); + if (victim) + goto remove; + /* try harder only if disk space is low */ if (!low_disk_space) goto out; + why = "orphaned"; + victim = find_orphaned_snapshot(&sl); + if (victim) + goto remove; DSS_WARNING_LOG("disk space low and nothing obvious to remove\n"); - ret = remove_oldest_snapshot(&sl); - if (ret) - goto out; - DSS_CRIT_LOG("uhuhu: not enough disk space for a single snapshot\n"); + victim = find_oldest_removable_snapshot(&sl); + if (victim) + goto remove; + DSS_CRIT_LOG("uhuhu: disk space low and nothing to remove\n"); ret = -ERRNO_TO_DSS_ERROR(ENOSPC); + goto out; +remove: + ret = pre_remove_hook(victim, why); out: free_snapshot_list(&sl); return ret; @@ -650,8 +717,7 @@ static int handle_rsync_exit(int status) DSS_WARNING_LOG("rsync process %d returned %d -- restarting\n", (int)create_pid, es); snapshot_creation_status = HS_NEEDS_RESTART; - gettimeofday(&next_snapshot_time, NULL); - next_snapshot_time.tv_sec += 60; + next_snapshot_time = get_current_time() + 60; ret = 1; goto out; } @@ -665,6 +731,8 @@ static int handle_rsync_exit(int status) if (ret < 0) goto out; snapshot_creation_status = HS_SUCCESS; + free(name_of_reference_snapshot); + name_of_reference_snapshot = NULL; out: create_pid = 0; create_process_stopped = 0; @@ -689,6 +757,7 @@ static int handle_pre_create_hook_exit(int status) DSS_NOTICE_LOG("deferring snapshot creation...\n"); warn_count = 60; /* warn only once per hour */ } + next_snapshot_time = get_current_time() + 60; snapshot_creation_status = HS_READY; ret = 0; goto out; @@ -749,9 +818,13 @@ static int check_config(void) return 1; } +/* + * Returns < 0 on errors, 0 if no config file is given and > 0 if the config + * file was read successfully. + */ static int parse_config_file(int override) { - int ret; + int ret, config_file_exists; char *config_file; struct stat statbuf; char *old_logfile_arg = NULL; @@ -770,13 +843,13 @@ static int parse_config_file(int override) old_daemon_given = conf.daemon_given; } - ret = stat(config_file, &statbuf); - if (ret && conf.config_file_given) { + config_file_exists = !stat(config_file, &statbuf); + if (!config_file_exists && conf.config_file_given) { ret = -ERRNO_TO_DSS_ERROR(errno); DSS_ERROR_LOG("failed to stat config file %s\n", config_file); goto out; } - if (!ret) { + if (config_file_exists) { struct cmdline_parser_params params = { .override = override, .initialize = 0, @@ -816,6 +889,7 @@ static int parse_config_file(int override) } DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg); // cmdline_parser_dump(logfile? logfile : stdout, &conf); + ret = config_file_exists; out: free(config_file); if (ret < 0) @@ -837,6 +911,7 @@ static int handle_sighup(void) ret = parse_config_file(1); if (ret < 0) return ret; + invalidate_next_snapshot_time(); return change_to_dest_dir(); } @@ -885,12 +960,13 @@ static int use_rsync_locally(char *logname) static void create_rsync_argv(char ***argv, int64_t *num) { - char *logname, *newest; + char *logname; int i = 0, j; struct snapshot_list sl; dss_get_snapshot_list(&sl); - newest = name_of_newest_complete_snapshot(&sl); + assert(!name_of_reference_snapshot); + name_of_reference_snapshot = name_of_newest_complete_snapshot(&sl); free_snapshot_list(&sl); *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *)); @@ -899,12 +975,12 @@ static void create_rsync_argv(char ***argv, int64_t *num) (*argv)[i++] = dss_strdup("--delete"); for (j = 0; j < conf.rsync_option_given; j++) (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]); - if (newest) { - DSS_INFO_LOG("using %s as reference snapshot\n", newest); - (*argv)[i++] = make_message("--link-dest=../%s", newest); - free(newest); + if (name_of_reference_snapshot) { + DSS_INFO_LOG("using %s as reference\n", name_of_reference_snapshot); + (*argv)[i++] = make_message("--link-dest=../%s", + name_of_reference_snapshot); } else - DSS_INFO_LOG("no previous snapshot found\n"); + DSS_INFO_LOG("no suitable reference snapshot found\n"); logname = dss_logname(); if (use_rsync_locally(logname)) (*argv)[i++] = dss_strdup(conf.source_dir_arg); @@ -955,7 +1031,6 @@ static int select_loop(void) for (;;) { fd_set rfds; - int low_disk_space; struct timeval *tvp; if (remove_pid) @@ -990,11 +1065,7 @@ static int select_loop(void) goto out; continue; } - ret = disk_space_low(); - if (ret < 0) - goto out; - low_disk_space = ret; - ret = try_to_free_disk_space(low_disk_space); + ret = try_to_free_disk_space(); if (ret < 0) goto out; if (snapshot_removal_status != HS_READY) { @@ -1068,26 +1139,35 @@ static int com_prune(void) { int ret; struct snapshot_list sl; + struct snapshot *victim; struct disk_space ds; + const char *why; ret = get_disk_space(".", &ds); if (ret < 0) return ret; log_disk_space(&ds); dss_get_snapshot_list(&sl); - ret = remove_outdated_snapshot(&sl); - if (ret < 0) - goto out; - if (ret > 0) + why = "outdated"; + victim = find_outdated_snapshot(&sl); + if (victim) goto rm; - ret = remove_redundant_snapshot(&sl); - if (ret < 0) - goto out; - if (ret > 0) + why = "redundant"; + victim = find_redundant_snapshot(&sl); + if (victim) goto rm; ret = 0; goto out; rm: + if (conf.dry_run_given) { + dss_msg("%s snapshot %s (interval = %i)\n", + why, victim->name, victim->interval); + ret = 0; + goto out; + } + ret = pre_remove_hook(victim, why); + if (ret < 0) + goto out; if (snapshot_removal_status == HS_PRE_RUNNING) { ret = wait_for_remove_process(); if (ret < 0) @@ -1219,6 +1299,20 @@ int main(int argc, char **argv) ret = parse_config_file(0); if (ret < 0) goto out; + if (ret == 0) { /* no config file given */ + /* + * Parse the command line options again, but this time check + * that all required options are given. + */ + params = (struct cmdline_parser_params) { + .override = 1, + .initialize = 1, + .check_required = 1, + .check_ambiguity = 1, + .print_errors = 1 + }; + cmdline_parser_ext(argc, argv, &conf, ¶ms); /* aborts on errors */ + } if (conf.daemon_given) daemon_init(); ret = change_to_dest_dir();