refcount: return pointer to the structure instead of a counter

There are no real users of the counter. It was thought of a handy tool
to track and debug refcounting, but it is not used at all. Some parts of
the code would benefit from a pointer getting returned instead.

BUG: 1399780
Change-Id: I97e52c48420fed61be942ea27ff4849b803eed12
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: http://review.gluster.org/15971
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Xavier Hernandez <xhernandez@datalab.es>
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>

3 files changed, 18 insertions, 23 deletions

diff --git a/libglusterfs/src/refcount.c b/libglusterfs/src/refcount.c
index 96edc10982a..9d33b733cf0 100644
--- a/libglusterfs/src/refcount.c
+++ b/libglusterfs/src/refcount.c
@@ -13,7 +13,7 @@
 
 #ifndef REFCOUNT_NEEDS_LOCK
 
-unsigned int
+void *
 _gf_ref_get (gf_ref_t *ref)
 {
         unsigned int cnt = __sync_fetch_and_add (&ref->cnt, 1);
@@ -27,10 +27,10 @@ _gf_ref_get (gf_ref_t *ref)
          */
         GF_ASSERT (cnt != 0);
 
-        return cnt;
+        return cnt ? ref->data : NULL;
 }
 
-unsigned int
+void
 _gf_ref_put (gf_ref_t *ref)
 {
         unsigned int cnt = __sync_fetch_and_sub (&ref->cnt, 1);
@@ -43,18 +43,13 @@ _gf_ref_put (gf_ref_t *ref)
          */
         GF_ASSERT (cnt != 0);
 
-        if (cnt == 1 && ref->release) {
+        if (cnt == 1 && ref->release)
                 ref->release (ref->data);
-                /* set return value to 0 to inform the caller correctly */
-                cnt = 0;
-        }
-
-        return cnt;
 }
 
 #else
 
-unsigned int
+void *
 _gf_ref_get (gf_ref_t *ref)
 {
         unsigned int cnt = 0;
@@ -69,10 +64,10 @@ _gf_ref_get (gf_ref_t *ref)
         }
         UNLOCK (&ref->lk);
 
-        return cnt;
+        return cnt ? ref->data : NULL;
 }
 
-unsigned int
+void
 _gf_ref_put (gf_ref_t *ref)
 {
         unsigned int cnt = 0;
@@ -91,8 +86,6 @@ _gf_ref_put (gf_ref_t *ref)
 
         if (release && ref->release)
                 ref->release (ref->data);
-
-        return cnt;
 }
 
 #endif /* REFCOUNT_NEEDS_LOCK */
diff --git a/libglusterfs/src/refcount.h b/libglusterfs/src/refcount.h
index e850e6389ae..db9432acbbc 100644
--- a/libglusterfs/src/refcount.h
+++ b/libglusterfs/src/refcount.h
@@ -42,7 +42,7 @@ typedef struct _gf_ref_t gf_ref_t;
  *
  * @return: greater then 0 when a reference was taken, 0 when not
  */
-unsigned int
+void *
 _gf_ref_get (gf_ref_t *ref);
 
 /* _gf_ref_put -- decrease the refcount
@@ -50,7 +50,7 @@ _gf_ref_get (gf_ref_t *ref);
  * @return: greater then 0 when there are still references, 0 when cleanup
  *          should be done, gf_ref_release_t is called on cleanup
  */
-unsigned int
+void
 _gf_ref_put (gf_ref_t *ref);
 
 /* _gf_ref_init -- initalize an embedded refcount object
@@ -84,20 +84,20 @@ _gf_ref_init (gf_ref_t *ref, gf_ref_release_t release, void *data);
  *
  * Sets the refcount to 1.
  */
-#define GF_REF_INIT(p, d)   _gf_ref_init (&p->_ref, d, p)
+#define GF_REF_INIT(p, d)   _gf_ref_init (&(p)->_ref, d, p)
 
 /* GF_REF_GET -- increase the refcount of a GF_REF_DECL structure
  *
  * @return: greater then 0 when a reference was taken, 0 when not
  */
-#define GF_REF_GET(p)       _gf_ref_get (&p->_ref)
+#define GF_REF_GET(p)       _gf_ref_get (&(p)->_ref)
 
 /* GF_REF_PUT -- decrease the refcount of a GF_REF_DECL structure
  *
  * @return: greater then 0 when there are still references, 0 when cleanup
  *          should be done, gf_ref_release_t is called on cleanup
  */
-#define GF_REF_PUT(p)       _gf_ref_put (&p->_ref)
+#define GF_REF_PUT(p)       _gf_ref_put (&(p)->_ref)
 
 
 #endif /* _REFCOUNT_H */
diff --git a/xlators/nfs/server/src/auth-cache.c b/xlators/nfs/server/src/auth-cache.c
index 71e300ddf11..2b37a7f06bd 100644
--- a/xlators/nfs/server/src/auth-cache.c
+++ b/xlators/nfs/server/src/auth-cache.c
@@ -145,8 +145,9 @@ auth_cache_add (struct auth_cache *cache, char *hashkey,
         GF_VALIDATE_OR_GOTO (GF_NFS, cache, out);
         GF_VALIDATE_OR_GOTO (GF_NFS, cache->cache_dict, out);
 
-        ret = GF_REF_GET (entry);
-        if (ret == 0) {
+        /* FIXME: entry is passed as parameter, this can never fail? */
+        entry = GF_REF_GET (entry);
+        if (!entry) {
                 /* entry does not have any references */
                 ret = -1;
                 goto out;
@@ -221,8 +222,9 @@ auth_cache_get (struct auth_cache *cache, char *hashkey,
                 if (!entry_data)
                         goto unlock;
 
-                lookup_res = (struct auth_cache_entry *)(entry_data->data);
-                if (GF_REF_GET (lookup_res) == 0) {
+                /* FIXME: this is dangerous use of entry_data */
+                lookup_res = GF_REF_GET ((struct auth_cache_entry *) entry_data->data);
+                if (lookup_res == NULL) {
                         /* entry has been free'd */
                         ret = ENTRY_EXPIRED;
                         goto unlock;