ceph: refactor ceph_unreserve_caps()

The code of ceph_unreserve_caps() and error handling in
ceph_reserve_caps() are duplicated, so introduce a helper
__ceph_unreserve_caps() to reduce duplicated code.
Signed-off-by: NChengguang Xu <cgxu519@gmx.com>
Reviewed-by: N"Yan, Zheng" <zyan@redhat.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

fs/ceph/caps.c

@@ -156,6 +156,37 @@ void ceph_adjust_min_caps(struct ceph_mds_client *mdsc, int delta)
 	spin_unlock(&mdsc->caps_list_lock);
 }
 
+static void __ceph_unreserve_caps(struct ceph_mds_client *mdsc, int nr_caps)
+{
+	struct ceph_cap *cap;
+	int i;
+
+	if (nr_caps) {
+		BUG_ON(mdsc->caps_reserve_count < nr_caps);
+		mdsc->caps_reserve_count -= nr_caps;
+		if (mdsc->caps_avail_count >=
+		    mdsc->caps_reserve_count + mdsc->caps_min_count) {
+			mdsc->caps_total_count -= nr_caps;
+			for (i = 0; i < nr_caps; i++) {
+				cap = list_first_entry(&mdsc->caps_list,
+					struct ceph_cap, caps_item);
+				list_del(&cap->caps_item);
+				kmem_cache_free(ceph_cap_cachep, cap);
+			}
+		} else {
+			mdsc->caps_avail_count += nr_caps;
+		}
+
+		dout("%s: caps %d = %d used + %d resv + %d avail\n",
+		     __func__,
+		     mdsc->caps_total_count, mdsc->caps_use_count,
+		     mdsc->caps_reserve_count, mdsc->caps_avail_count);
+		BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
+						 mdsc->caps_reserve_count +
+						 mdsc->caps_avail_count);
+	}
+}
+
 /*
  * Called under mdsc->mutex.
  */
@@ -283,39 +314,14 @@ int ceph_reserve_caps(struct ceph_mds_client *mdsc,
 	return -ENOMEM;
 }
 
-int ceph_unreserve_caps(struct ceph_mds_client *mdsc,
+void ceph_unreserve_caps(struct ceph_mds_client *mdsc,
 			struct ceph_cap_reservation *ctx)
 {
-	int i;
-	struct ceph_cap *cap;
-
 	dout("unreserve caps ctx=%p count=%d\n", ctx, ctx->count);
-	if (ctx->count) {
-		spin_lock(&mdsc->caps_list_lock);
-		BUG_ON(mdsc->caps_reserve_count < ctx->count);
-		mdsc->caps_reserve_count -= ctx->count;
-		if (mdsc->caps_avail_count >=
-		    mdsc->caps_reserve_count + mdsc->caps_min_count) {
-			mdsc->caps_total_count -= ctx->count;
-			for (i = 0; i < ctx->count; i++) {
-				cap = list_first_entry(&mdsc->caps_list,
-					struct ceph_cap, caps_item);
-				list_del(&cap->caps_item);
-				kmem_cache_free(ceph_cap_cachep, cap);
-			}
-		} else {
-			mdsc->caps_avail_count += ctx->count;
-		}
-		ctx->count = 0;
-		dout("unreserve caps %d = %d used + %d resv + %d avail\n",
-		     mdsc->caps_total_count, mdsc->caps_use_count,
-		     mdsc->caps_reserve_count, mdsc->caps_avail_count);
-		BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
-						 mdsc->caps_reserve_count +
-						 mdsc->caps_avail_count);
-		spin_unlock(&mdsc->caps_list_lock);
-	}
-	return 0;
+	spin_lock(&mdsc->caps_list_lock);
+	__ceph_unreserve_caps(mdsc, ctx->count);
+	ctx->count = 0;
+	spin_unlock(&mdsc->caps_list_lock);
 }
 
 struct ceph_cap *ceph_get_cap(struct ceph_mds_client *mdsc,

fs/ceph/super.h

@@ -656,7 +656,7 @@ extern void ceph_caps_finalize(struct ceph_mds_client *mdsc);
 extern void ceph_adjust_min_caps(struct ceph_mds_client *mdsc, int delta);
 extern int ceph_reserve_caps(struct ceph_mds_client *mdsc,
 			     struct ceph_cap_reservation *ctx, int need);
-extern int ceph_unreserve_caps(struct ceph_mds_client *mdsc,
+extern void ceph_unreserve_caps(struct ceph_mds_client *mdsc,
 			       struct ceph_cap_reservation *ctx);
 extern void ceph_reservation_status(struct ceph_fs_client *client,
 				    int *total, int *avail, int *used,