Improve comment of snapshot_currently_being_removed.

[dss.git] / dss.c

diff --git a/dss.c b/dss.c
index 24d77eb79dbd2ab0862b2b7012b73babde542c93..c2aef361287fef0d9a2aafcf787a96ae24f9d37f 100644 (file)
--- a/dss.c
+++ b/dss.c
@@ -1,8 +1,4 @@
-/*
- * Copyright (C) 2008-2011 Andre Noll <maan@tuebingen.mpg.de>
- *
- * Licensed under the GPL v2. For licencing details see COPYING.
- */
+/* SPDX-License-Identifier: GPL-2.0 */
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -85,7 +81,7 @@ static int64_t 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. */
+/* Set by the pre-rm hook, cleared by handle_remove_exit(). */
 struct snapshot *snapshot_currently_being_removed;
 /** Needed by the post-create hook. */
 static char *path_to_last_complete_snapshot;
@@ -162,7 +158,7 @@ static void dump_dss_config(const char *msg)
        fprintf(log, "\n*** internal state ***\n\n");
        fprintf(log,
                "pid: %d\n"
-               "logile: %s\n"
+               "logfile: %s\n"
                "snapshot_currently_being_removed: %s\n"
                "path_to_last_complete_snapshot: %s\n"
                "reference_snapshot: %s\n"
@@ -287,11 +283,13 @@ static char *get_config_file_name(void)
        return config_file;
 }
 
-static int send_signal(int sig)
+static int send_signal(int sig, bool wait)
 {
        pid_t pid;
        char *config_file = get_config_file_name();
        int ret = get_dss_pid(config_file, &pid);
+       unsigned ms = 32;
+       struct timespec ts;
 
        free(config_file);
        if (ret < 0)
@@ -304,7 +302,23 @@ static int send_signal(int sig)
        ret = kill(pid, sig);
        if (ret < 0)
                return -ERRNO_TO_DSS_ERROR(errno);
-       return 1;
+       if (!wait)
+               return 1;
+       while (ms < 5000) {
+               ts.tv_sec = ms / 1000;
+               ts.tv_nsec = (ms % 1000) * 1000 * 1000;
+               ret = nanosleep(&ts, NULL);
+               if (ret < 0)
+                       return -ERRNO_TO_DSS_ERROR(errno);
+               ret = kill(pid, 0);
+               if (ret < 0) {
+                       if (errno != ESRCH)
+                               return -ERRNO_TO_DSS_ERROR(errno);
+                       return 1;
+               }
+               ms *= 2;
+       }
+       return -E_KILL_TIMEOUT;
 }
 
 struct signal_info {
@@ -363,6 +377,7 @@ static const struct signal_info signal_table[] = {
 
 static int com_kill(void)
 {
+       bool w_given = OPT_GIVEN(KILL, WAIT);
        const char *arg = OPT_STRING_VAL(KILL, SIGNAL);
        int ret, i;
 
@@ -373,17 +388,17 @@ static int com_kill(void)
                        return ret;
                if (val < 0 || val > SIGRTMAX)
                        return -ERRNO_TO_DSS_ERROR(EINVAL);
-               return send_signal(val);
+               return send_signal(val, w_given);
        }
        if (strncasecmp(arg, "sig", 3) == 0)
                arg += 3;
        if (strcasecmp(arg, "CLD") == 0)
-               return send_signal(SIGCHLD);
+               return send_signal(SIGCHLD, w_given);
        if (strcasecmp(arg, "IOT") == 0)
-               return send_signal(SIGABRT);
+               return send_signal(SIGABRT, w_given);
        for (i = 0; i < SIGNAL_TABLE_SIZE; i++)
                if (strcasecmp(arg, signal_table[i].name) == 0)
-                       return send_signal(signal_table[i].num);
+                       return send_signal(signal_table[i].num, w_given);
        DSS_ERROR_LOG(("invalid sigspec: %s\n", arg));
        return -ERRNO_TO_DSS_ERROR(EINVAL);
 }
@@ -398,7 +413,8 @@ static void dss_get_snapshot_list(struct snapshot_list *sl)
 static int64_t compute_next_snapshot_time(void)
 {
        int64_t x = 0, now = get_current_time(), unit_interval
-               = 24 * 3600 * OPT_UINT32_VAL(DSS, UNIT_INTERVAL), ret;
+               = 24 * 3600 * OPT_UINT32_VAL(DSS, UNIT_INTERVAL), ret,
+               last_completion_time;
        unsigned wanted = desired_number_of_snapshots(0,
                OPT_UINT32_VAL(DSS, NUM_INTERVALS)),
                num_complete = 0;
@@ -412,6 +428,7 @@ static int64_t compute_next_snapshot_time(void)
                        continue;
                num_complete++;
                x += s->completion_time - s->creation_time;
+               last_completion_time = s->completion_time;
        }
        assert(x >= 0);
 
@@ -421,7 +438,7 @@ static int64_t compute_next_snapshot_time(void)
        x /= num_complete; /* avg time to create one snapshot */
        if (unit_interval < x * wanted) /* oops, no sleep at all */
                goto out;
-       ret = s->completion_time + unit_interval / wanted - x;
+       ret = last_completion_time + unit_interval / wanted - x;
 out:
        free_snapshot_list(&sl);
        return ret;
@@ -1284,9 +1301,7 @@ static int handle_signal(void)
        switch (sig) {
        case SIGINT:
        case SIGTERM:
-               kill_children();
-               ret = -E_SIGNAL;
-               break;
+               return -E_SIGNAL;
        case SIGHUP:
                ret = handle_sighup();
                break;
@@ -1433,6 +1448,7 @@ static int create_snapshot(char **argv)
 {
        int ret;
 
+       assert(argv);
        ret = rename_resume_snap(current_snapshot_creation_time);
        if (ret < 0)
                return ret;
@@ -1526,15 +1542,18 @@ out:
 
 static void exit_hook(int exit_code)
 {
-       const char *argv[3];
        pid_t pid;
-
-       argv[0] = OPT_STRING_VAL(DSS, EXIT_HOOK);
-       argv[1] = dss_strerror(-exit_code);
-       argv[2] = NULL;
-
-       DSS_NOTICE_LOG(("executing %s %s\n", argv[0], argv[1]));
-       dss_exec(&pid, argv[0], (char **)argv);
+       char **argv, *tmp = dss_strdup(OPT_STRING_VAL(DSS, EXIT_HOOK));
+       unsigned n = split_args(tmp, &argv, " \t");
+
+       n++;
+       argv = dss_realloc(argv, (n + 1) * sizeof(char *));
+       argv[n - 1] = dss_strdup(dss_strerror(-exit_code));
+       argv[n] = NULL;
+       dss_exec(&pid, argv[0], argv);
+       free(argv[n - 1]);
+       free(argv);
+       free(tmp);
 }
 
 static void lock_dss_or_die(void)
@@ -1591,6 +1610,8 @@ static int com_run(void)
                ret = -E_BUG;
        kill_children();
        exit_hook(ret);
+       while (wait(NULL) >= 0 || errno != ECHILD)
+               ; /* still have children to wait for */
        return ret;
 }
 EXPORT_CMD_HANDLER(run);
@@ -1757,7 +1778,7 @@ static void handle_version_and_help(void)
        else if (OPT_GIVEN(DSS, HELP))
                txt = lls_short_help(CMD_PTR(DSS));
        else if (OPT_GIVEN(DSS, VERSION))
-               txt = dss_strdup(VERSION_STRING);
+               txt = make_message("%s\n", VERSION_STRING);
        else
                return;
        printf("%s", txt);