]> git.tuebingen.mpg.de Git - dss.git/blobdiff - dss.c
Implement --reload.
[dss.git] / dss.c
diff --git a/dss.c b/dss.c
index e32e7e20a1efcad97f213b7da6212bb881ccc248..793e9194b1c695fb89d50d3fae5f63703dceeccd 100644 (file)
--- a/dss.c
+++ b/dss.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008-2009 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2008-2010 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -33,6 +33,7 @@
 #include "df.h"
 #include "time.h"
 #include "snap.h"
+#include "ipc.h"
 
 /** Command line and config file options. */
 static struct gengetopt_args_info conf;
@@ -64,14 +65,116 @@ enum hook_status snapshot_removal_status;
 
 
 DEFINE_DSS_ERRLIST;
+static const char const *hook_status_description[] = {HOOK_STATUS_ARRAY};
 
+/* may be called with ds == NULL. */
+static int disk_space_low(struct disk_space *ds)
+{
+       struct disk_space ds_struct;
+
+       if (!ds) {
+               int ret = get_disk_space(".", &ds_struct);
+               if (ret < 0)
+                       return ret;
+               ds = &ds_struct;
+       }
+       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;
+       if (conf.min_free_percent_inodes_arg)
+               if (ds->percent_free_inodes < conf.min_free_percent_inodes_arg)
+                       return 1;
+       return 0;
+}
+
+static void dump_dss_config(const char *msg)
+{
+       const char dash[] = "-----------------------------";
+       int ret;
+       FILE *log = logfile? logfile : stderr;
+       struct disk_space ds;
+       int64_t now = get_current_time();
+
+       if (conf.loglevel_arg > INFO)
+               return;
+
+       fprintf(log, "%s <%s config> %s\n", dash, msg, dash);
+       fprintf(log, "\n*** disk space ***\n\n");
+       ret = get_disk_space(".", &ds);
+       if (ret >= 0) {
+               DSS_INFO_LOG("disk space low: %s\n", disk_space_low(&ds)?
+                       "yes" : "no");
+               log_disk_space(&ds);
+       } else
+               DSS_ERROR_LOG("can not get free disk space: %s\n",
+                       dss_strerror(-ret));
+
+       /* we continue on errors from get_disk_space */
+
+       fprintf(log, "\n*** command line and config file options ***\n\n");
+       cmdline_parser_dump(log, &conf);
+       fprintf(log, "\n*** internal state ***\n\n");
+       fprintf(log,
+               "pid: %d\n"
+               "logile: %s\n"
+               "snapshot_currently_being_removed: %s\n"
+               "path_to_last_complete_snapshot: %s\n"
+               "reference_snapshot: %s\n"
+               "snapshot_creation_status: %s\n"
+               "snapshot_removal_status: %s\n"
+               ,
+               (int) getpid(),
+               logfile? conf.logfile_arg : "stderr",
+               snapshot_currently_being_removed?
+                       snapshot_currently_being_removed->name : "(none)",
+               path_to_last_complete_snapshot?
+                       path_to_last_complete_snapshot : "(none)",
+               name_of_reference_snapshot?
+                       name_of_reference_snapshot : "(none)",
+               hook_status_description[snapshot_creation_status],
+               hook_status_description[snapshot_removal_status]
+       );
+       if (create_pid != 0)
+               fprintf(log,
+                       "create_pid: %" PRId32 "\n"
+                       "create process is %sstopped\n"
+                       ,
+                       create_pid,
+                       create_process_stopped? "" : "not "
+               );
+       if (remove_pid != 0)
+               fprintf(log, "remove_pid: %" PRId32 "\n", remove_pid);
+       if (next_snapshot_time != 0)
+               fprintf(log, "next snapshot due in %" PRId64 " seconds\n",
+                       next_snapshot_time - now);
+       if (current_snapshot_creation_time != 0)
+               fprintf(log, "current_snapshot_creation_time: %"
+                       PRId64 " (%" PRId64 " seconds ago)\n",
+                       current_snapshot_creation_time,
+                       now - current_snapshot_creation_time
+               );
+       if (next_removal_check.tv_sec != 0) {
+               fprintf(log, "next removal check: %llu (%llu seconds ago)\n",
+                       (long long unsigned)next_removal_check.tv_sec,
+                       now - (long long unsigned)next_removal_check.tv_sec
+               );
+
+       }
+       fprintf(log, "%s </%s config> %s\n", dash, msg, dash);
+}
 
 /* a litte cpp magic helps to DRY */
 #define COMMANDS \
        COMMAND(ls) \
        COMMAND(create) \
        COMMAND(prune) \
-       COMMAND(run)
+       COMMAND(run) \
+       COMMAND(kill) \
+       COMMAND(reload) \
+
 #define COMMAND(x) static int com_ ##x(void);
 COMMANDS
 #undef COMMAND
@@ -127,23 +230,45 @@ static __printf_1_2 void dss_msg(const char* fmt,...)
        va_end(argp);
 }
 
-static int disk_space_low(void)
+static char *get_config_file_name(void)
 {
-       struct disk_space ds;
-       int ret = get_disk_space(".", &ds);
+       char *home, *config_file;
 
+       if (conf.config_file_given)
+               return dss_strdup(conf.config_file_arg);
+       home = get_homedir();
+       config_file = make_message("%s/.dssrc", home);
+       free(home);
+       return config_file;
+}
+
+static int send_signal(int sig)
+{
+       pid_t pid;
+       char *config_file = get_config_file_name();
+       int ret = get_dss_pid(config_file, &pid);
+
+       free(config_file);
        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;
-       if (conf.min_free_percent_inodes_arg)
-               if (ds.percent_free_inodes < conf.min_free_percent_inodes_arg)
-                       return 1;
-       return 0;
+       if (conf.dry_run_given) {
+               dss_msg("%d\n", (int)pid);
+               return 0;
+       }
+       ret = kill(pid, sig);
+       if (ret < 0)
+               return -ERRNO_TO_DSS_ERROR(errno);
+       return 1;
+}
+
+static int com_kill(void)
+{
+       return send_signal(SIGTERM);
+}
+
+static int com_reload(void)
+{
+       return send_signal(SIGHUP);
 }
 
 static void dss_get_snapshot_list(struct snapshot_list *sl)
@@ -441,7 +566,7 @@ static int try_to_free_disk_space(void)
        const char *why;
        int low_disk_space;
 
-       ret = disk_space_low();
+       ret = disk_space_low(NULL);
        if (ret < 0)
                return ret;
        low_disk_space = ret;
@@ -826,18 +951,11 @@ static int check_config(void)
 static int parse_config_file(int override)
 {
        int ret, config_file_exists;
-       char *config_file;
+       char *config_file = get_config_file_name();
        struct stat statbuf;
        char *old_logfile_arg = NULL;
        int old_daemon_given = 0;
 
-       if (conf.config_file_given)
-               config_file = dss_strdup(conf.config_file_arg);
-       else {
-               char *home = get_homedir();
-               config_file = make_message("%s/.dssrc", home);
-               free(home);
-       }
        if (override) { /* SIGHUP */
                if (conf.logfile_given)
                        old_logfile_arg = dss_strdup(conf.logfile_arg);
@@ -903,24 +1021,16 @@ static int change_to_dest_dir(void)
        return dss_chdir(conf.dest_dir_arg);
 }
 
-static void dump_dss_config(const char *msg)
-{
-       if (conf.loglevel_arg > INFO)
-               return;
-       DSS_INFO_LOG("%s\n", msg);
-       cmdline_parser_dump(logfile? logfile : stderr, &conf);
-}
-
 static int handle_sighup(void)
 {
        int ret;
 
        DSS_NOTICE_LOG("SIGHUP, re-reading config\n");
-       dump_dss_config("current config");
+       dump_dss_config("old");
        ret = parse_config_file(1);
        if (ret < 0)
                return ret;
-       dump_dss_config("new config");
+       dump_dss_config("reloaded");
        invalidate_next_snapshot_time();
        return change_to_dest_dir();
 }
@@ -971,22 +1081,48 @@ static int use_rsync_locally(char *logname)
 static int rename_resume_snap(int64_t creation_time)
 {
        struct snapshot_list sl = {.num_snapshots = 0};
-       struct snapshot *s;
+       struct snapshot *s = NULL;
        char *new_name = incomplete_name(creation_time);
        int ret;
+       const char *why;
 
        ret = 0;
        if (conf.no_resume_given)
                goto out;
        dss_get_snapshot_list(&sl);
+       /*
+        * Snapshot recycling: We first look at the newest snapshot. If this
+        * snapshot happens to be incomplete, the last rsync process was
+        * aborted and we reuse this one. Otherwise we look at snapshots which
+        * could be removed (outdated and redundant snapshots) as candidates
+        * for recycling. If no outdated/redundant snapshot exists, we check if
+        * there is an orphaned snapshot, which likely is useless anyway.
+        *
+        * Only if no existing snapshot is suitable for recycling, we bite the
+        * bullet and create a new one.
+        */
        s = get_newest_snapshot(&sl);
-       if (!s)
+       if (!s) /* no snapshots at all */
                goto out;
-       if ((s->flags & SS_COMPLETE) != 0) /* complete */
+       /* re-use last snapshot if it is incomplete */
+       why = "aborted";
+       if ((s->flags & SS_COMPLETE) == 0)
                goto out;
-       DSS_INFO_LOG("resuming: reusing %s as destination dir\n", s->name);
-       ret = dss_rename(s->name, new_name);
+       why = "outdated";
+       s = find_outdated_snapshot(&sl);
+       if (s)
+               goto out;
+       why = "redundant";
+       s = find_redundant_snapshot(&sl);
+       if (s)
+               goto out;
+       why = "orphaned";
+       s = find_orphaned_snapshot(&sl);
 out:
+       if (s) {
+               DSS_INFO_LOG("reusing %s snapshot %s\n", why, s->name);
+               ret = dss_rename(s->name, new_name);
+       }
        if (ret >= 0)
                DSS_NOTICE_LOG("creating new snapshot %s\n", new_name);
        free(new_name);
@@ -1156,10 +1292,23 @@ static void exit_hook(int exit_code)
        dss_exec(&pid, conf.exit_hook_arg, argv, fds);
 }
 
+static void lock_dss_or_die(void)
+{
+       char *config_file = get_config_file_name();
+       int ret = lock_dss(config_file);
+
+       free(config_file);
+       if (ret < 0) {
+               DSS_EMERG_LOG("failed to lock: %s\n", dss_strerror(-ret));
+               exit(EXIT_FAILURE);
+       }
+}
+
 static int com_run(void)
 {
        int ret;
 
+       lock_dss_or_die();
        if (conf.dry_run_given) {
                DSS_ERROR_LOG("dry_run not supported by this command\n");
                return -E_SYNTAX;
@@ -1182,6 +1331,7 @@ static int com_prune(void)
        struct disk_space ds;
        const char *why;
 
+       lock_dss_or_die();
        ret = get_disk_space(".", &ds);
        if (ret < 0)
                return ret;
@@ -1241,6 +1391,7 @@ static int com_create(void)
        int ret, status;
        char **rsync_argv;
 
+       lock_dss_or_die();
        if (conf.dry_run_given) {
                int i;
                char *msg = NULL;
@@ -1354,10 +1505,10 @@ int main(int argc, char **argv)
        }
        if (conf.daemon_given)
                daemon_init();
-       dump_dss_config("dss configuration");
        ret = change_to_dest_dir();
        if (ret < 0)
                goto out;
+       dump_dss_config("startup");
        ret = setup_signal_handling();
        if (ret < 0)
                goto out;