lib-master: Keep track of config paths in "instances" file.

Normally it can be looked up from base_dir/dovecot.conf symlink, but
base_dir may get deleted when system starts up.

diff --git a/src/lib-master/master-instance.c b/src/lib-master/master-instance.c
index 54cf03e278528597ea188d2d9ce2d96efe556c19..2c843e4f21331bc03215c76cb4606a19ba856776 100644 (file)
--- a/src/lib-master/master-instance.c
+++ b/src/lib-master/master-instance.c
@@ -1,6 +1,7 @@
 /* Copyright (c) 2012 Dovecot authors, see the included COPYING file */
 
 #include "lib.h"
+#include "abspath.h"
 #include "array.h"
 #include "istream.h"
 #include "ostream.h"
@@ -17,6 +18,9 @@ struct master_instance_list {
        const char *path;
 
        ARRAY_DEFINE(instances, struct master_instance);
+
+       unsigned int locked:1;
+       unsigned int config_paths_changed:1;
 };
 
 struct master_instance_list_iter {
@@ -50,6 +54,22 @@ void master_instance_list_deinit(struct master_instance_list **_list)
        pool_unref(&list->pool);
 }
 
+static void
+master_instance_update_config_path(struct master_instance_list *list,
+                                  struct master_instance *inst)
+{
+       const char *path, *config_path;
+
+       /* update instance's config path if it has changed */
+       path = t_strconcat(inst->base_dir, "/"PACKAGE".conf", NULL);
+       if (t_readlink(path, &config_path) == 0) {
+               if (null_strcmp(inst->config_path, config_path) != 0) {
+                       inst->config_path = p_strdup(list->pool, config_path);
+                       list->config_paths_changed = TRUE;
+               }
+       }
+}
+
 static int
 master_instance_list_add_line(struct master_instance_list *list,
                              const char *line)
@@ -58,9 +78,9 @@ master_instance_list_add_line(struct master_instance_list *list,
        const char *const *args;
        time_t last_used;
 
-       /* <last used> <name> <base dir> */
+       /* <last used> <name> <base dir> [<config path>] */
        args = t_strsplit_tabescaped(line);
-       if (str_array_length(args) != 3)
+       if (str_array_length(args) < 3)
                return -1;
        if (str_to_time(args[0], &last_used) < 0)
                return -1;
@@ -69,6 +89,8 @@ master_instance_list_add_line(struct master_instance_list *list,
        inst->last_used = last_used;
        inst->name = p_strdup(list->pool, args[1]);
        inst->base_dir = p_strdup(list->pool, args[2]);
+       inst->config_path = p_strdup_empty(list->pool, args[3]);
+       master_instance_update_config_path(list, inst);
        return 0;
 }
 
@@ -117,6 +139,9 @@ master_instance_list_write(struct master_instance_list *list,
                str_tabescape_write(str, inst->name);
                str_append_c(str, '\t');
                str_tabescape_write(str, inst->base_dir);
+               str_append_c(str, '\t');
+               if (inst->config_path != NULL)
+                       str_tabescape_write(str, inst->config_path);
                str_append_c(str, '\n');
                (void)o_stream_send(output, str_data(str), str_len(str));
        }
@@ -135,6 +160,8 @@ static int master_instance_write_init(struct master_instance_list *list,
 {
        int fd;
 
+       i_assert(!list->locked);
+
        *dotlock_r = NULL;
 
        fd = file_dotlock_open_mode(&dotlock_set, list->path, 0, 0644,
@@ -147,6 +174,7 @@ static int master_instance_write_init(struct master_instance_list *list,
                (void)file_dotlock_delete(dotlock_r);
                return -1;
        }
+       list->locked = TRUE;
        return fd;
 }
 
@@ -156,9 +184,13 @@ static int master_instance_write_finish(struct master_instance_list *list,
        const char *lock_path = file_dotlock_get_lock_path(*dotlock);
        int ret;
 
+       i_assert(list->locked);
+
        T_BEGIN {
                ret = master_instance_list_write(list, fd, lock_path);
        } T_END;
+
+       list->locked = FALSE;
        if (ret < 0) {
                (void)file_dotlock_delete(dotlock);
                return -1;
@@ -168,6 +200,7 @@ static int master_instance_write_finish(struct master_instance_list *list,
                (void)file_dotlock_delete(dotlock);
                return -1;
        }
+       list->config_paths_changed = FALSE;
        return file_dotlock_replace(dotlock, 0);
 }
 
@@ -201,6 +234,7 @@ int master_instance_list_update(struct master_instance_list *list,
                inst->base_dir = p_strdup(list->pool, base_dir);
        }
        inst->last_used = time(NULL);
+       master_instance_update_config_path(list, inst);
 
        return master_instance_write_finish(list, fd, &dotlock);
 }
@@ -263,6 +297,24 @@ int master_instance_list_remove(struct master_instance_list *list,
        return master_instance_write_finish(list, fd, &dotlock) < 0 ? -1 : 1;
 }
 
+static int
+master_instance_list_refresh_and_update(struct master_instance_list *list)
+{
+       struct dotlock *dotlock;
+       int fd;
+
+       if (master_instance_list_refresh(list) < 0)
+               return -1;
+       if (list->config_paths_changed && !list->locked) {
+               /* write new config paths */
+               if ((fd = master_instance_write_init(list, &dotlock)) == -1)
+                       return -1;
+               if (master_instance_write_finish(list, fd, &dotlock) < 0)
+                       return -1;
+       }
+       return 0;
+}
+
 const struct master_instance *
 master_instance_list_find_by_name(struct master_instance_list *list,
                                  const char *name)
@@ -272,7 +324,7 @@ master_instance_list_find_by_name(struct master_instance_list *list,
        i_assert(*name != '\0');
 
        if (array_count(&list->instances) == 0)
-               (void)master_instance_list_refresh(list);
+               (void)master_instance_list_refresh_and_update(list);
 
        array_foreach(&list->instances, inst) {
                if (strcmp(inst->name, name) == 0)
@@ -288,7 +340,7 @@ master_instance_list_iterate_init(struct master_instance_list *list)
 
        iter = i_new(struct master_instance_list_iter, 1);
        iter->list = list;
-       (void)master_instance_list_refresh(list);
+       (void)master_instance_list_refresh_and_update(list);
        return iter;
 }
 

diff --git a/src/lib-master/master-instance.h b/src/lib-master/master-instance.h
index b48dcb611ac106b3a260eef96450e3614f97e442..568e005a512dfb05d3465c992df0102f8d1f9eee 100644 (file)
--- a/src/lib-master/master-instance.h
+++ b/src/lib-master/master-instance.h
@@ -9,6 +9,7 @@ struct master_instance {
        time_t last_used;
        const char *name;
        const char *base_dir;
+       const char *config_path;
 };
 
 struct master_instance_list *master_instance_list_init(const char *path);