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[dss.git] / dss.c

diff --git a/dss.c b/dss.c
index 006cd27c333e097231ae140374fffdf3b8d689f6..0bc891373bd7e6096063ebc45aa953582433d68c 100644 (file)
--- a/dss.c
+++ b/dss.c
@@ -45,6 +45,8 @@ static int signal_pipe;
 static pid_t create_pid;
 /** Whether the pre-create-hook/rsync/post-create-hook is currently stopped. */
 static int create_process_stopped;
+/** How many times in a row the rsync command failed. */
+static int num_consecutive_rsync_errors;
 /** Process id of current pre-remove/rm/post-remove process. */
 static pid_t remove_pid;
 /** When the next snapshot is due. */
@@ -125,6 +127,7 @@ static void dump_dss_config(const char *msg)
                "reference_snapshot: %s\n"
                "snapshot_creation_status: %s\n"
                "snapshot_removal_status: %s\n"
+               "num_consecutive_rsync_errors: %d\n"
                ,
                (int) getpid(),
                logfile? conf.logfile_arg : "stderr",
@@ -135,7 +138,8 @@ static void dump_dss_config(const char *msg)
                name_of_reference_snapshot?
                        name_of_reference_snapshot : "(none)",
                hook_status_description[snapshot_creation_status],
-               hook_status_description[snapshot_removal_status]
+               hook_status_description[snapshot_removal_status],
+               num_consecutive_rsync_errors
        );
        if (create_pid != 0)
                fprintf(log,
@@ -602,9 +606,18 @@ static int try_to_free_disk_space(void)
                if (next_snapshot_is_due())
                        return 0;
        }
+       /*
+        * Idle and --keep_redundant not given, or low disk space. Look at
+        * existing snapshots.
+        */
        dss_get_snapshot_list(&sl);
        ret = 0;
-       if (!low_disk_space && sl.num_snapshots <= 1)
+       /*
+        * Don't remove anything if there is free space and we have fewer
+        * snapshots than configured, plus one. This way there is always one
+        * snapshot that can be recycled.
+        */
+       if (!low_disk_space && sl.num_snapshots <= 1 << conf.num_intervals_arg)
                goto out;
        why = "outdated";
        victim = find_outdated_snapshot(&sl);
@@ -614,13 +627,13 @@ static int try_to_free_disk_space(void)
        victim = find_redundant_snapshot(&sl);
        if (victim)
                goto remove;
-       /* try harder only if disk space is low */
-       if (!low_disk_space)
-               goto out;
        why = "orphaned";
        victim = find_orphaned_snapshot(&sl);
        if (victim)
                goto remove;
+       /* try harder only if disk space is low */
+       if (!low_disk_space)
+               goto out;
        DSS_WARNING_LOG(("disk space low and nothing obvious to remove\n"));
        victim = find_oldest_removable_snapshot(&sl);
        if (victim)
@@ -844,23 +857,27 @@ static int handle_rsync_exit(int status)
        es = WEXITSTATUS(status);
        /*
         * Restart rsync on non-fatal errors:
-        * 12: Error in rsync protocol data stream
-        * 13: Errors with program diagnostics
+        * 24: Partial transfer due to vanished source files
         */
-       if (es == 12 || es == 13) {
-               DSS_WARNING_LOG(("rsync process %d returned %d -- restarting\n",
-                       (int)create_pid, es));
+       if (es != 0 && es != 24) {
+               DSS_WARNING_LOG(("rsync exit code %d, error count %d\n",
+                       es, ++num_consecutive_rsync_errors));
+               if (conf.create_given) {
+                       ret = -E_BAD_EXIT_CODE;
+                       goto out;
+               }
+               if (num_consecutive_rsync_errors > conf.max_rsync_errors_arg) {
+                       ret = -E_TOO_MANY_RSYNC_ERRORS;
+                       snapshot_creation_status = HS_READY;
+                       goto out;
+               }
+               DSS_WARNING_LOG(("restarting rsync process\n"));
                snapshot_creation_status = HS_NEEDS_RESTART;
                next_snapshot_time = get_current_time() + 60;
                ret = 1;
                goto out;
        }
-       if (es != 0 && es != 23 && es != 24) {
-               DSS_ERROR_LOG(("rsync process %d returned %d\n", (int)create_pid, es));
-               ret = -E_BAD_EXIT_CODE;
-               snapshot_creation_status = HS_READY;
-               goto out;
-       }
+       num_consecutive_rsync_errors = 0;
        ret = rename_incomplete_snapshot(current_snapshot_creation_time);
        if (ret < 0)
                goto out;
@@ -1476,12 +1493,6 @@ static int setup_signal_handling(void)
        return install_sighandler(SIGCHLD);
 }
 
-/**
- * The main function of dss.
- *
- * \param argc Usual argument count.
- * \param argv Usual argument vector.
- */
 int main(int argc, char **argv)
 {
        int ret;
@@ -1520,6 +1531,7 @@ int main(int argc, char **argv)
        if (ret < 0)
                goto out;
        ret = call_command_handler();
+       signal_shutdown();
 out:
        if (ret < 0)
                DSS_EMERG_LOG(("%s\n", dss_strerror(-ret)));