#include <sys/stat.h>
#include <unistd.h>
#include <inttypes.h>
+#include <sys/time.h>
#include <time.h>
#include <sys/wait.h>
#include <fnmatch.h>
#include "daemon.h"
#include "signal.h"
#include "df.h"
+#include "time.h"
struct gengetopt_args_info conf;
static FILE *logfile;
int signal_pipe;
+/** Process id of current rsync process. */
+static pid_t rsync_pid;
+/** Whether the rsync process is currently stopped */
+static int rsync_stopped;
+/** Process id of current rm process. */
+static pid_t rm_pid;
+/** When the next snapshot is due. */
+struct timeval next_snapshot_time;
+/* Creation time of the snapshot currently being created. */
+int64_t current_snapshot_creation_time;
+
+
DEFINE_DSS_ERRLIST;
unsigned interval;
};
+/*
+ * An edge snapshot is either the oldest one or the newest one.
+ *
+ * We need to find either of them occasionally: The create code
+ * needs to know the newest snapshot because that is the one
+ * used as the link destination dir. The pruning code needs to
+ * find the oldest one in case disk space becomes low.
+ */
+struct edge_snapshot_data {
+ int64_t now;
+ struct snapshot snap;
+};
+
__printf_2_3 void dss_log(int ll, const char* fmt,...)
{
va_list argp;
va_end(argp);
}
+/**
+ * Return the desired number of snapshots of an interval.
+ */
+unsigned num_snapshots(int interval)
+{
+ unsigned n;
+
+ assert(interval >= 0);
+
+ if (interval >= conf.num_intervals_arg)
+ return 0;
+ n = conf.num_intervals_arg - interval - 1;
+ return 1 << n;
+}
+
int is_snapshot(const char *dirname, int64_t now, struct snapshot *s)
{
int i, ret;
compare_snapshots);
}
+void stop_rsync_process(void)
+{
+ if (!rsync_pid || rsync_stopped)
+ return;
+ kill(SIGSTOP, rsync_pid);
+ rsync_stopped = 1;
+}
+
+void restart_rsync_process(void)
+{
+ if (!rsync_pid || !rsync_stopped)
+ return;
+ kill (SIGCONT, rsync_pid);
+ rsync_stopped = 0;
+}
+
void free_snapshot_list(struct snapshot_list *sl)
{
int i;
return ret;
}
-int remove_snapshot(struct snapshot *s, pid_t *pid)
+int remove_snapshot(struct snapshot *s)
{
int fds[3] = {0, 0, 0};
+ assert(!rm_pid);
char *new_name = being_deleted_name(s);
int ret = dss_rename(s->name, new_name);
char *argv[] = {"rm", "-rf", new_name, NULL};
if (ret < 0)
goto out;
DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
- ret = dss_exec(pid, argv[0], argv, fds);
+ stop_rsync_process();
+ ret = dss_exec(&rm_pid, argv[0], argv, fds);
out:
free(new_name);
return ret;
}
-
-int remove_redundant_snapshot(struct snapshot_list *sl, pid_t *pid)
+/*
+ * return: 0: no redundant snapshots, 1: rm process started, negative: error
+ */
+int remove_redundant_snapshot(struct snapshot_list *sl)
{
int ret, i, interval;
struct snapshot *s;
DSS_INFO_LOG("looking for intervals containing too many snapshots\n");
for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
- unsigned keep = 1<<(conf.num_intervals_arg - interval - 1);
+ unsigned keep = num_snapshots(interval);
unsigned num = sl->interval_count[interval];
struct snapshot *victim = NULL, *prev = NULL;
int64_t score = LONG_MAX;
victim->name, victim->interval);
continue;
}
- ret = remove_snapshot(victim, pid);
+ ret = remove_snapshot(victim);
return ret < 0? ret : 1;
}
return 0;
}
-int remove_old_snapshot(struct snapshot_list *sl, pid_t *pid)
+int remove_outdated_snapshot(struct snapshot_list *sl)
{
int i, ret;
struct snapshot *s;
s->name, s->interval);
continue;
}
- ret = remove_snapshot(s, pid);
+ ret = remove_snapshot(s);
if (ret < 0)
return ret;
return 1;
return 0;
}
-int wait_for_rm_process(pid_t pid)
+int handle_rm_exit(int status)
{
- int status, es, ret = wait_for_process(pid, &status);
- if (ret < 0)
- return ret;
+ int es, ret;
+
if (!WIFEXITED(status)) {
- ret = E_INVOLUNTARY_EXIT;
- make_err_msg("rm process %d died involuntary", (int)pid);
- return ret;
+ make_err_msg("rm process %d died involuntary", (int)rm_pid);
+ ret = -E_INVOLUNTARY_EXIT;
+ goto out;
}
es = WEXITSTATUS(status);
if (es) {
+ make_err_msg("rm process %d returned %d", (int)rm_pid, es);
ret = -E_BAD_EXIT_CODE;
- make_err_msg("rm process %d returned %d", (int)pid, es);
+ goto out;
+ }
+ ret = 1;
+ rm_pid = 0;
+out:
+ return ret;
+}
+
+
+int wait_for_rm_process(void)
+{
+ int status, ret = wait_for_process(rm_pid, &status);
+
+ if (ret < 0)
+ return ret;
+ return handle_rm_exit(status);
+}
+
+void kill_process(pid_t pid)
+{
+ if (!pid)
+ return
+ DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
+ kill(pid, SIGTERM);
+}
+
+void handle_sighup()
+{
+ DSS_INFO_LOG("FIXME: no sighup handling yet\n");
+}
+
+int rename_incomplete_snapshot(int64_t start)
+{
+ char *old_name, *new_name;
+ int ret;
+
+ ret = complete_name(start, get_current_time(), &new_name);
+ if (ret < 0)
return ret;
+ old_name = incomplete_name(start);
+ ret = dss_rename(old_name, new_name);
+ if (ret >= 0)
+ DSS_NOTICE_LOG("%s -> %s\n", old_name, new_name);
+ free(old_name);
+ free(new_name);
+ return ret;
+}
+
+
+int handle_rsync_exit(int status)
+{
+ int es, ret;
+
+ if (!WIFEXITED(status)) {
+ make_err_msg("rsync process %d died involuntary", (int)rsync_pid);
+ ret = -E_INVOLUNTARY_EXIT;
+ goto out;
+ }
+ es = WEXITSTATUS(status);
+ if (es != 0 && es != 23 && es != 24) {
+ make_err_msg("rsync process %d returned %d", (int)rsync_pid, es);
+ ret = -E_BAD_EXIT_CODE;
+ goto out;
}
+ ret = rename_incomplete_snapshot(current_snapshot_creation_time);
+out:
+ rsync_pid = 0;
+ current_snapshot_creation_time = 0;
+ rsync_stopped = 0;
+ return ret;
+}
+
+
+void compute_next_snapshot_time(struct snapshot_list *sl)
+{
+ struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
+ tmp, diff;
+ int64_t x = 0;
+ unsigned wanted = num_snapshots(0), num_complete_snapshots = 0;
+ int i, ret;
+ struct snapshot *s;
+
+ gettimeofday(&now, NULL);
+ FOR_EACH_SNAPSHOT(s, i, sl) {
+ if (!(s->flags & SS_COMPLETE))
+ continue;
+ num_complete_snapshots++;
+ 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); /* time between creation */
+ if (ret < 0) {
+ next_snapshot_time = now;
+ return;
+ }
+ tv_divide(wanted, &diff, &tmp);
+ tv_add(&now, &tmp, &next_snapshot_time);
+}
+
+void handle_signal(struct snapshot_list *sl)
+{
+ int sig, ret = next_signal();
+
+ if (ret <= 0)
+ goto out;
+ sig = ret;
+ switch (sig) {
+ int status;
+ pid_t pid;
+ case SIGINT:
+ case SIGTERM:
+ restart_rsync_process();
+ kill_process(rsync_pid);
+ kill_process(rm_pid);
+ exit(EXIT_FAILURE);
+ case SIGHUP:
+ handle_sighup();
+ break;
+ case SIGCHLD:
+ ret = reap_child(&pid, &status);
+ if (ret <= 0)
+ break;
+ assert(pid == rsync_pid || pid == rm_pid);
+ if (pid == rsync_pid)
+ ret = handle_rsync_exit(status);
+ else
+ ret = handle_rm_exit(status);
+ free_snapshot_list(sl);
+ get_snapshot_list(sl);
+ compute_next_snapshot_time(sl);
+ }
+out:
+ if (ret < 0)
+ log_err_msg(ERROR, -ret);
+}
+
+int get_oldest(const char *dirname, void *private)
+{
+ struct edge_snapshot_data *esd = private;
+ struct snapshot s;
+ int ret = is_snapshot(dirname, esd->now, &s);
+
+ if (ret <= 0)
+ return 1;
+ if (s.creation_time > esd->snap.creation_time)
+ return 1;
+ free(esd->snap.name);
+ esd->snap = s;
return 1;
}
+int remove_oldest_snapshot()
+{
+ int ret;
+ struct edge_snapshot_data esd = {
+ .now = get_current_time(),
+ .snap = {.creation_time = LLONG_MAX}
+ };
+ for_each_subdir(get_oldest, &esd);
+ if (!esd.snap.name) /* no snapshot found */
+ return 0;
+ DSS_INFO_LOG("oldest snapshot: %s\n", esd.snap.name);
+ ret = 0;
+ if (esd.snap.creation_time == current_snapshot_creation_time)
+ goto out; /* do not remove the snapshot currently being created */
+ ret = remove_snapshot(&esd.snap);
+out:
+ free(esd.snap.name);
+ return ret;
+}
+
+/* TODO: Also consider number of inodes. */
+int disk_space_low(void)
+{
+ struct disk_space ds;
+ int ret = get_disk_space(".", &ds);
+
+ if (ret < 0)
+ return ret;
+ if (conf.min_free_mb_arg)
+ if (ds.free_mb < conf.min_free_mb_arg)
+ return 1;
+ if (conf.min_free_percent_arg)
+ if (ds.percent_free < conf.min_free_percent_arg)
+ return 1;
+ return 0;
+}
+
+int try_to_free_disk_space(int low_disk_space, struct snapshot_list *sl)
+{
+ int ret;
+
+ ret = remove_outdated_snapshot(sl);
+ if (ret) /* error, or we are removing something */
+ return ret;
+ /* no outdated snapshot */
+ ret = remove_redundant_snapshot(sl);
+ if (ret)
+ return ret;
+ if (!low_disk_space)
+ return 0;
+ DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
+ ret = remove_oldest_snapshot();
+ if (ret)
+ return ret;
+ make_err_msg("uhuhu: not enough disk space for a single snapshot");
+ return -ENOSPC;
+}
+
+int select_loop(void)
+{
+ int ret;
+ struct timeval tv = {.tv_sec = 60, .tv_usec = 0};
+ struct snapshot_list sl = {.num_snapshots = 0};
+
+ get_snapshot_list(&sl);
+ compute_next_snapshot_time(&sl);
+ for (;;) {
+ struct timeval now;
+ fd_set rfds;
+ int low_disk_space;
+
+ FD_ZERO(&rfds);
+ ret = dss_select(signal_pipe + 1, &rfds, NULL, &tv);
+ if (ret < 0)
+ return ret;
+ if (FD_ISSET(signal_pipe, &rfds))
+ handle_signal(&sl);
+ if (rm_pid)
+ continue;
+ ret = disk_space_low();
+ if (ret < 0)
+ break;
+ low_disk_space = ret;
+ if (low_disk_space)
+ stop_rsync_process();
+ ret = try_to_free_disk_space(low_disk_space, &sl);
+ if (ret < 0)
+ break;
+ if (rm_pid)
+ continue;
+ if (rsync_pid) {
+ restart_rsync_process();
+ continue;
+ }
+ /* neither rsync nor rm are running. Start rsync? */
+ gettimeofday(&now, NULL);
+ if (tv_diff(&now, &next_snapshot_time, NULL) < 0)
+ continue;
+ }
+ free_snapshot_list(&sl);
+ return ret;
+}
+
int com_run(void)
{
int ret;
ret = install_sighandler(SIGHUP);
if (ret < 0)
return ret;
- return 42;
+ return select_loop();
}
void log_disk_space(struct disk_space *ds)
{
int ret;
struct snapshot_list sl;
- pid_t pid;
struct disk_space ds;
ret = get_disk_space(".", &ds);
log_disk_space(&ds);
for (;;) {
get_snapshot_list(&sl);
- ret = remove_old_snapshot(&sl, &pid);
+ ret = remove_outdated_snapshot(&sl);
free_snapshot_list(&sl);
if (ret < 0)
return ret;
if (!ret)
break;
- ret = wait_for_rm_process(pid);
+ ret = wait_for_rm_process();
if (ret < 0)
goto out;
}
for (;;) {
get_snapshot_list(&sl);
- ret = remove_redundant_snapshot(&sl, &pid);
+ ret = remove_redundant_snapshot(&sl);
free_snapshot_list(&sl);
if (ret < 0)
return ret;
if (!ret)
break;
- ret = wait_for_rm_process(pid);
+ ret = wait_for_rm_process();
if (ret < 0)
goto out;
}
return ret;
}
-struct newest_snapshot_data {
- char * newest_name;
- int64_t newest_creation_time;
- int64_t now;
-};
-
int get_newest_complete(const char *dirname, void *private)
{
- struct newest_snapshot_data *nsd = private;
+ struct edge_snapshot_data *esd = private;
struct snapshot s;
- int ret = is_snapshot(dirname, nsd->now, &s);
+ int ret = is_snapshot(dirname, esd->now, &s);
if (ret <= 0)
return 1;
- if (s.creation_time < nsd->newest_creation_time)
+ if (s.flags != SS_COMPLETE) /* incomplete or being deleted */
+ return 1;
+ if (s.creation_time < esd->snap.creation_time)
return 1;
- nsd->newest_creation_time = s.creation_time;
- free(nsd->newest_name);
- nsd->newest_name = s.name;
+ free(esd->snap.name);
+ esd->snap = s;
return 1;
}
__malloc char *name_of_newest_complete_snapshot(void)
{
- struct newest_snapshot_data nsd = {
+ struct edge_snapshot_data esd = {
.now = get_current_time(),
- .newest_creation_time = -1
+ .snap = {.creation_time = -1}
};
- for_each_subdir(get_newest_complete, &nsd);
- return nsd.newest_name;
+ for_each_subdir(get_newest_complete, &esd);
+ return esd.snap.name;
}
void create_rsync_argv(char ***argv, int64_t *num)
free(argv);
}
-int create_snapshot(char **argv, pid_t *pid)
+int create_snapshot(char **argv)
{
int fds[3] = {0, 0, 0};
- return dss_exec(pid, argv[0], argv, fds);
-}
-
-int rename_incomplete_snapshot(int64_t start)
-{
- char *old_name, *new_name;
- int ret;
-
- ret = complete_name(start, get_current_time(), &new_name);
- if (ret < 0)
- return ret;
- old_name = incomplete_name(start);
- ret = dss_rename(old_name, new_name);
- if (ret >= 0)
- DSS_NOTICE_LOG("%s -> %s\n", old_name, new_name);
- free(old_name);
- free(new_name);
- return ret;
+ return dss_exec(&rsync_pid, argv[0], argv, fds);
}
int com_create(void)
{
- int ret, status, es;
+ int ret, status;
char **rsync_argv;
- int64_t snapshot_num;
- pid_t pid;
- create_rsync_argv(&rsync_argv, &snapshot_num);
+ create_rsync_argv(&rsync_argv, ¤t_snapshot_creation_time);
if (conf.dry_run_given) {
int i;
char *msg = NULL;
free(msg);
return 1;
}
- DSS_NOTICE_LOG("creating snapshot %lli\n", (long long)snapshot_num);
- ret = create_snapshot(rsync_argv, &pid);
+ DSS_NOTICE_LOG("creating snapshot %lli\n",
+ (long long)current_snapshot_creation_time);
+ ret = create_snapshot(rsync_argv);
if (ret < 0)
goto out;
- ret = wait_for_process(pid, &status);
+ ret = wait_for_process(rsync_pid, &status);
if (ret < 0)
goto out;
- if (!WIFEXITED(status)) {
- ret = E_INVOLUNTARY_EXIT;
- make_err_msg("rsync process %d died involuntary", (int)pid);
- goto out;
- }
- es = WEXITSTATUS(status);
- if (es != 0 && es != 23 && es != 24) {
- ret = -E_BAD_EXIT_CODE;
- make_err_msg("rsync process %d returned %d", (int)pid, es);
- goto out;
- }
- ret = rename_incomplete_snapshot(snapshot_num);
+ ret = handle_rsync_exit(status);
out:
free_rsync_argv(rsync_argv);
return ret;
--- /dev/null
+#include <sys/time.h>
+#include <time.h>
+#include <inttypes.h>
+
+/*
+ * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
+ *
+ * Licensed under the GPL v2. For licencing details see COPYING.
+ */
+
+/** \file time.c Helper functions for dealing with time values. */
+
+/**
+ * Convert struct timeval to milliseconds.
+ *
+ * \param tv The time value value to convert.
+ *
+ * \return The number off milliseconds in \a tv.
+ */
+long unsigned tv2ms(const struct timeval *tv)
+{
+ return tv->tv_sec * 1000 + (tv->tv_usec + 500)/ 1000;
+}
+
+/**
+ * Convert milliseconds to a struct timeval.
+ *
+ * \param n The number of milliseconds.
+ * \param tv Result pointer.
+ */
+void ms2tv(long unsigned n, struct timeval *tv)
+{
+ tv->tv_sec = n / 1000;
+ tv->tv_usec = (n % 1000) * 1000;
+}
+
+/**
+ * Convert a double to a struct timeval.
+ *
+ * \param x The value to convert.
+ * \param tv Result pointer.
+ */
+void d2tv(double x, struct timeval *tv)
+{
+ tv->tv_sec = x;
+ tv->tv_usec = (x - (double)tv->tv_sec) * 1000.0 * 1000.0 + 0.5;
+}
+
+/**
+ * Compute the difference of two time values.
+ *
+ * \param b Minuend.
+ * \param a Subtrahend.
+ * \param diff Result pointer.
+ *
+ * If \a diff is not \p NULL, it contains the absolute value |\a b - \a a| on
+ * return.
+ *
+ * \return If \a b < \a a, this function returns -1, otherwise it returns 1.
+ */
+int tv_diff(const struct timeval *b, const struct timeval *a, struct timeval *diff)
+{
+ int ret = 1;
+
+ if ((b->tv_sec < a->tv_sec) ||
+ ((b->tv_sec == a->tv_sec) && (b->tv_usec < a->tv_usec))) {
+ const struct timeval *tmp = a;
+ a = b;
+ b = tmp;
+ ret = -1;
+ }
+ if (!diff)
+ return ret;
+ diff->tv_sec = b->tv_sec - a->tv_sec;
+ if (b->tv_usec < a->tv_usec) {
+ diff->tv_sec--;
+ diff->tv_usec = 1000 * 1000 - a->tv_usec + b->tv_usec;
+ } else
+ diff->tv_usec = b->tv_usec - a->tv_usec;
+ return ret;
+}
+
+/**
+ * Add two time values.
+ *
+ * \param a First addend.
+ * \param b Second addend.
+ * \param sum Contains the sum \a + \a b on return.
+ */
+void tv_add(const struct timeval *a, const struct timeval *b,
+ struct timeval *sum)
+{
+ sum->tv_sec = a->tv_sec + b->tv_sec;
+ if (a->tv_usec + b->tv_usec >= 1000 * 1000) {
+ sum->tv_sec++;
+ sum->tv_usec = a->tv_usec + b->tv_usec - 1000 * 1000;
+ } else
+ sum->tv_usec = a->tv_usec + b->tv_usec;
+}
+
+/**
+ * Compute integer multiple of given struct timeval.
+ *
+ * \param mult The integer value to multiply with.
+ * \param tv The timevalue to multiply.
+ *
+ * \param result Contains \a mult * \a tv on return.
+ */
+void tv_scale(const unsigned long mult, const struct timeval *tv,
+ struct timeval *result)
+{
+ result->tv_sec = mult * tv->tv_sec;
+ result->tv_sec += tv->tv_usec * mult / 1000 / 1000;
+ result->tv_usec = tv->tv_usec * mult % (1000 * 1000);
+}
+
+/**
+ * Compute a fraction of given struct timeval.
+ *
+ * \param divisor The integer value to divide by.
+ * \param tv The timevalue to divide.
+ * \param result Contains (1 / mult) * tv on return.
+ */
+void tv_divide(const unsigned long divisor, const struct timeval *tv,
+ struct timeval *result)
+{
+ uint64_t x = ((uint64_t)tv->tv_sec * 1000 * 1000 + tv->tv_usec) / divisor;
+
+ result->tv_sec = x / 1000 / 1000;
+ result->tv_usec = x % (1000 * 1000);
+}
projects / dss.git / commitdiff