X-Git-Url: http://git.tuebingen.mpg.de/?a=blobdiff_plain;ds=sidebyside;f=dss.c;h=04fe30c4bb7798ae8a049b9eb46638b278ea3927;hb=7c487767f42a70358eea15eb9a86ac673856f905;hp=d2afc10d59d266e0db54cdae04c283feca68c306;hpb=409cd61e2e3db02a726f22c759f2725cf1dfa506;p=dss.git diff --git a/dss.c b/dss.c index d2afc10..04fe30c 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; @@ -313,6 +324,13 @@ static struct snapshot *find_orphaned_snapshot(struct snapshot_list *sl) 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 */ @@ -341,6 +359,8 @@ static struct snapshot *find_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; @@ -375,12 +395,14 @@ static struct snapshot *find_outdated_snapshot(struct snapshot_list *sl) 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 (s->interval < conf.num_intervals_arg) continue; return s; } @@ -389,14 +411,17 @@ static struct snapshot *find_outdated_snapshot(struct snapshot_list *sl) struct snapshot *find_oldest_removable_snapshot(struct snapshot_list *sl) { - struct snapshot *s = get_oldest_snapshot(sl); - - if (!s) /* no snapshot found */ - return NULL; - DSS_INFO_LOG("oldest snapshot: %s\n", s->name); - if (snapshot_is_being_created(s)) - return NULL; - return s; + 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) @@ -418,20 +443,34 @@ 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 = 0; + if (!low_disk_space && sl.num_snapshots <= 1) + goto out; why = "outdated"; victim = find_outdated_snapshot(&sl); if (victim) @@ -441,7 +480,6 @@ static int try_to_free_disk_space(int low_disk_space) if (victim) goto remove; /* try harder only if disk space is low */ - ret = 0; if (!low_disk_space) goto out; why = "orphaned"; @@ -452,7 +490,7 @@ static int try_to_free_disk_space(int low_disk_space) victim = find_oldest_removable_snapshot(&sl); if (victim) goto remove; - DSS_CRIT_LOG("uhuhu: not enough disk space for a single snapshot\n"); + DSS_CRIT_LOG("uhuhu: disk space low and nothing to remove\n"); ret = -ERRNO_TO_DSS_ERROR(ENOSPC); goto out; remove: @@ -679,8 +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; } @@ -694,6 +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; @@ -718,8 +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 */ } - gettimeofday(&next_snapshot_time, NULL); - next_snapshot_time.tv_sec += 60; + next_snapshot_time = get_current_time() + 60; snapshot_creation_status = HS_READY; ret = 0; goto out; @@ -868,6 +906,7 @@ static int handle_sighup(void) ret = parse_config_file(1); if (ret < 0) return ret; + invalidate_next_snapshot_time(); return change_to_dest_dir(); } @@ -916,12 +955,13 @@ 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 *)); @@ -930,12 +970,12 @@ 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); @@ -986,7 +1026,6 @@ static int select_loop(void) for (;;) { fd_set rfds; - int low_disk_space; struct timeval *tvp; if (remove_pid) @@ -1021,11 +1060,7 @@ 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) {