]> git.tuebingen.mpg.de Git - dss.git/blobdiff - dss.c
Simplify exec functions.
[dss.git] / dss.c
diff --git a/dss.c b/dss.c
index db065c689b95dc0274231c9923cb9be6dd852839..968ba597d74eb4fbcd03804f7e0cdd3fa4cab841 100644 (file)
--- a/dss.c
+++ b/dss.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008-2010 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2008-2011 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -287,29 +287,22 @@ static int next_snapshot_is_due(void)
        return 0;
 }
 
-static int pre_create_hook(void)
+static void 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();
        DSS_DEBUG_LOG("executing %s\n", conf.pre_create_hook_arg);
-       ret = dss_exec_cmdline_pid(&create_pid,
-               conf.pre_create_hook_arg, fds);
-       if (ret < 0)
-               return ret;
+       dss_exec_cmdline_pid(&create_pid, conf.pre_create_hook_arg);
        snapshot_creation_status = HS_PRE_RUNNING;
-       return ret;
 }
 
-static int pre_remove_hook(struct snapshot *s, const char *why)
+static void pre_remove_hook(struct snapshot *s, const char *why)
 {
-       int ret, fds[3] = {0, 0, 0};
        char *cmd;
 
        if (!s)
-               return 0;
+               return;
        DSS_DEBUG_LOG("%s snapshot %s\n", why, s->name);
        assert(snapshot_removal_status == HS_READY);
        assert(remove_pid == 0);
@@ -322,18 +315,14 @@ static int pre_remove_hook(struct snapshot *s, const char *why)
        cmd = make_message("%s %s/%s", conf.pre_remove_hook_arg,
                conf.dest_dir_arg, s->name);
        DSS_DEBUG_LOG("executing %s\n", cmd);
-       ret = dss_exec_cmdline_pid(&remove_pid, cmd, fds);
+       dss_exec_cmdline_pid(&remove_pid, cmd);
        free(cmd);
-       if (ret < 0)
-               return ret;
        snapshot_removal_status = HS_PRE_RUNNING;
-       return ret;
 }
 
 static int exec_rm(void)
 {
        struct snapshot *s = snapshot_currently_being_removed;
-       int fds[3] = {0, 0, 0};
        char *new_name = being_deleted_name(s);
        char *argv[] = {"rm", "-rf", new_name, NULL};
        int ret;
@@ -345,9 +334,7 @@ static int exec_rm(void)
        ret = dss_rename(s->name, new_name);
        if (ret < 0)
                goto out;
-       ret = dss_exec(&remove_pid, argv[0], argv, fds);
-       if (ret < 0)
-               goto out;
+       dss_exec(&remove_pid, argv[0], argv);
        snapshot_removal_status = HS_RUNNING;
 out:
        free(new_name);
@@ -563,31 +550,24 @@ static int try_to_free_disk_space(void)
        ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
        goto out;
 remove:
-       ret = pre_remove_hook(victim, why);
+       pre_remove_hook(victim, why);
 out:
        free_snapshot_list(&sl);
        return ret;
 }
 
-static int post_create_hook(void)
+static void post_create_hook(void)
 {
-       int ret, fds[3] = {0, 0, 0};
-       char *cmd;
-
-       cmd = make_message("%s %s/%s", conf.post_create_hook_arg,
+       char *cmd = make_message("%s %s/%s", conf.post_create_hook_arg,
                conf.dest_dir_arg, path_to_last_complete_snapshot);
        DSS_NOTICE_LOG("executing %s\n", cmd);
-       ret = dss_exec_cmdline_pid(&create_pid, cmd, fds);
+       dss_exec_cmdline_pid(&create_pid, cmd);
        free(cmd);
-       if (ret < 0)
-               return ret;
        snapshot_creation_status = HS_POST_RUNNING;
-       return ret;
 }
 
-static int post_remove_hook(void)
+static void post_remove_hook(void)
 {
-       int ret, fds[3] = {0, 0, 0};
        char *cmd;
        struct snapshot *s = snapshot_currently_being_removed;
 
@@ -596,12 +576,9 @@ static int post_remove_hook(void)
        cmd = make_message("%s %s/%s", conf.post_remove_hook_arg,
                conf.dest_dir_arg, s->name);
        DSS_NOTICE_LOG("executing %s\n", cmd);
-       ret = dss_exec_cmdline_pid(&remove_pid, cmd, fds);
+       dss_exec_cmdline_pid(&remove_pid, cmd);
        free(cmd);
-       if (ret < 0)
-               return ret;
        snapshot_removal_status = HS_POST_RUNNING;
-       return ret;
 }
 
 static void dss_kill(pid_t pid, int sig, const char *msg)
@@ -964,7 +941,7 @@ static int parse_config_file(int override)
                        conf.logfile_given = 1;
                }
        }
-       if (conf.logfile_given) {
+       if (conf.logfile_given && conf.run_given && conf.daemon_given) {
                logfile = open_log(conf.logfile_arg);
                log_welcome(conf.loglevel_arg);
        }
@@ -1043,22 +1020,48 @@ 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);
@@ -1117,14 +1120,12 @@ static void free_rsync_argv(char **argv)
 
 static int create_snapshot(char **argv)
 {
-       int ret, fds[3] = {0, 0, 0};
+       int ret;
 
        ret = rename_resume_snap(current_snapshot_creation_time);
        if (ret < 0)
                return ret;
-       ret = dss_exec(&create_pid, argv[0], argv, fds);
-       if (ret < 0)
-               return ret;
+       dss_exec(&create_pid, argv[0], argv);
        snapshot_creation_status = HS_RUNNING;
        return ret;
 }
@@ -1166,9 +1167,7 @@ static int select_loop(void)
                        continue;
                }
                if (snapshot_removal_status == HS_SUCCESS) {
-                       ret = post_remove_hook();
-                       if (ret < 0)
-                               goto out;
+                       post_remove_hook();
                        continue;
                }
                ret = try_to_free_disk_space();
@@ -1183,9 +1182,7 @@ static int select_loop(void)
                case HS_READY:
                        if (!next_snapshot_is_due())
                                continue;
-                       ret = pre_create_hook();
-                       if (ret < 0)
-                               goto out;
+                       pre_create_hook();
                        continue;
                case HS_PRE_RUNNING:
                case HS_RUNNING:
@@ -1208,9 +1205,7 @@ static int select_loop(void)
                                goto out;
                        continue;
                case HS_SUCCESS:
-                       ret = post_create_hook();
-                       if (ret < 0)
-                               goto out;
+                       post_create_hook();
                        continue;
                }
        }
@@ -1220,12 +1215,11 @@ out:
 
 static void exit_hook(int exit_code)
 {
-       int fds[3] = {0, 0, 0};
        char *argv[] = {conf.exit_hook_arg, dss_strerror(-exit_code), NULL};
        pid_t pid;
 
        DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]);
-       dss_exec(&pid, conf.exit_hook_arg, argv, fds);
+       dss_exec(&pid, conf.exit_hook_arg, argv);
 }
 
 static int com_run(void)
@@ -1276,9 +1270,7 @@ rm:
                ret = 0;
                goto out;
        }
-       ret = pre_remove_hook(victim, why);
-       if (ret < 0)
-               goto out;
+       pre_remove_hook(victim, why);
        if (snapshot_removal_status == HS_PRE_RUNNING) {
                ret = wait_for_remove_process();
                if (ret < 0)
@@ -1294,9 +1286,7 @@ rm:
                goto out;
        if (snapshot_removal_status != HS_SUCCESS)
                goto out;
-       ret = post_remove_hook();
-       if (ret < 0)
-               goto out;
+       post_remove_hook();
        if (snapshot_removal_status != HS_POST_RUNNING)
                goto out;
        ret = wait_for_remove_process();
@@ -1328,9 +1318,7 @@ static int com_create(void)
                free(msg);
                return 1;
        }
-       ret = pre_create_hook();
-       if (ret < 0)
-               return ret;
+       pre_create_hook();
        if (create_pid) {
                ret = wait_for_process(create_pid, &status);
                if (ret < 0)