dss-0.1.3.

[dss.git] / dss.c

diff --git a/dss.c b/dss.c
index d2afc10d59d266e0db54cdae04c283feca68c306..40eccab2b993ccab5c2f83f85fe6e06c664c40c1 100644 (file)
--- a/dss.c
+++ b/dss.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2008-2009 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -52,10 +52,11 @@ static struct timeval next_snapshot_time;
 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. */
@@ -313,6 +314,13 @@ 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 +349,8 @@ 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;
@@ -380,6 +390,8 @@ static struct snapshot *find_outdated_snapshot(struct snapshot_list *sl)
        FOR_EACH_SNAPSHOT(s, i, sl) {
                if (snapshot_is_being_created(s))
                        continue;
+               if (is_reference_snapshot(s))
+                       continue;
                if (s->interval <= conf.num_intervals_arg)
                        continue;
                return s;
@@ -389,14 +401,17 @@ 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)
@@ -432,6 +447,9 @@ static int try_to_free_disk_space(int low_disk_space)
        if (!low_disk_space && conf.keep_redundant_given)
                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 +459,6 @@ 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 +469,7 @@ 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:
@@ -694,6 +711,8 @@ 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;
@@ -916,12 +935,13 @@ 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 +950,12 @@ 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);