[PATCH v2 07/19] libmultipath: use shared_ptr for checker classes

[Martin Wilck]

Utilize the share_ptr code for tracking the refcount of checker classes.

Signed-off-by: Martin Wilck <mwi...@suse.com>
---
 libmultipath/checkers.c | 58 ++++++++++++++---------------------------
 libmultipath/checkers.h |  2 --
 2 files changed, 19 insertions(+), 41 deletions(-)

diff --git a/libmultipath/checkers.c b/libmultipath/checkers.c
index 5655146..a3b9cc8 100644
--- a/libmultipath/checkers.c
+++ b/libmultipath/checkers.c
@@ -39,41 +39,11 @@ const char *checker_state_name(int i)
        return checker_state_names[i];
 }
 
-static struct checker_class *alloc_checker_class(void)
+static void free_checker_class(void *ptr)
 {
-       struct checker_class *c;
-
-       c = calloc(1, sizeof(struct checker_class));
-       if (c) {
-               INIT_LIST_HEAD(&c->node);
-               uatomic_set(&c->refcount, 1);
-       }
-       return c;
-}
-
-/* Use uatomic_{sub,add}_return() to ensure proper memory barriers */
-static int checker_class_ref(struct checker_class *cls)
-{
-       return uatomic_add_return(&cls->refcount, 1);
-}
-
-static int checker_class_unref(struct checker_class *cls)
-{
-       return uatomic_sub_return(&cls->refcount, 1);
-}
-
-void free_checker_class(struct checker_class *c)
-{
-       int cnt;
-
+       struct checker_class *c = ptr;
        if (!c)
                return;
-       cnt = checker_class_unref(c);
-       if (cnt != 0) {
-               condlog(cnt < 0 ? 1 : 4, "%s checker refcount %d",
-                       c->name, cnt);
-               return;
-       }
        condlog(3, "unloading %s checker", c->name);
        list_del(&c->node);
        if (c->reset)
@@ -84,7 +54,18 @@ void free_checker_class(struct checker_class *c)
                                c->name, dlerror());
                }
        }
-       free(c);
+}
+
+static struct checker_class *alloc_checker_class(void)
+{
+       struct checker_class *c;
+
+       c = alloc_shared_ptr(sizeof(*c), free_checker_class);
+       if (c) {
+               memset(c, 0, sizeof(*c));
+               INIT_LIST_HEAD(&c->node);
+       }
+       return c;
 }
 
 void cleanup_checkers (void)
@@ -92,9 +73,8 @@ void cleanup_checkers (void)
        struct checker_class *checker_loop;
        struct checker_class *checker_temp;
 
-       list_for_each_entry_safe(checker_loop, checker_temp, &checkers, node) {
-               free_checker_class(checker_loop);
-       }
+       list_for_each_entry_safe(checker_loop, checker_temp, &checkers, node)
+               put_shared_ptr(checker_loop);
 }
 
 static struct checker_class *checker_class_lookup(const char *name)
@@ -198,7 +178,7 @@ done:
        list_add(&c->node, &checkers);
        return c;
 out:
-       free_checker_class(c);
+       put_shared_ptr(c);
        return NULL;
 }
 
@@ -284,7 +264,7 @@ void checker_put (struct checker * dst)
        if (src && src->free)
                src->free(dst);
        checker_clear(dst);
-       free_checker_class(src);
+       put_shared_ptr(src);
 }
 
 int checker_get_state(struct checker *c)
@@ -393,7 +373,7 @@ void checker_get(struct checker *dst, const char *name)
        if (!src)
                return;
 
-       (void)checker_class_ref(dst->cls);
+       get_shared_ptr(dst->cls);
 }
 
 int init_checkers(void)
diff --git a/libmultipath/checkers.h b/libmultipath/checkers.h
index e69dfd9..7ff8e01 100644
--- a/libmultipath/checkers.h
+++ b/libmultipath/checkers.h
@@ -135,7 +135,6 @@ struct checker;
 struct checker_class {
        struct list_head node;
        void *handle;
-       int refcount;
        int sync;
        char name[CHECKER_NAME_LEN];
        int (*check)(struct checker *);
@@ -200,7 +199,6 @@ void checker_get(struct checker *, const char *);
 int libcheck_check(struct checker *);
 int libcheck_init(struct checker *);
 void libcheck_free(struct checker *);
-void *libcheck_thread(struct checker_context *ctx);
 void libcheck_reset(void);
 int libcheck_mp_init(struct checker *);
 int libcheck_pending(struct checker *c);
-- 
2.54.0