rbd: define an rbd object request flags field

We're going to need some more Boolean values for object requests,
so create a flags bit field and use it to record whether the request
is done.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 2d2711537537033185d7d9cad8ec08f27f611a88..f7046e976bb0069433573deed0ad2b9cb52c3185 100644 (file)
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -170,10 +170,15 @@ enum obj_request_type {
        OBJ_REQUEST_NODATA, OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES
 };
 
+enum obj_req_flags {
+       OBJ_REQ_DONE,           /* completion flag: not done = 0, done = 1 */
+};
+
 struct rbd_obj_request {
        const char              *object_name;
        u64                     offset;         /* object start byte */
        u64                     length;         /* bytes from offset */
+       unsigned long           flags;
 
        struct rbd_img_request  *img_request;
        u64                     img_offset;     /* image relative offset */
@@ -194,7 +199,6 @@ struct rbd_obj_request {
        u64                     xferred;        /* bytes transferred */
        u64                     version;
        int                     result;
-       atomic_t                done;
 
        rbd_obj_callback_t      callback;
        struct completion       completion;
@@ -1072,6 +1076,29 @@ out_err:
        return NULL;
 }
 
+/*
+ * The default/initial value for all object request flags is 0.  For
+ * each flag, once its value is set to 1 it is never reset to 0
+ * again.
+ */
+static void obj_request_done_set(struct rbd_obj_request *obj_request)
+{
+       if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
+               struct rbd_img_request *img_request = obj_request->img_request;
+               struct rbd_device *rbd_dev;
+
+               rbd_dev = img_request ? img_request->rbd_dev : NULL;
+               rbd_warn(rbd_dev, "obj_request %p already marked done\n",
+                       obj_request);
+       }
+}
+
+static bool obj_request_done_test(struct rbd_obj_request *obj_request)
+{
+       smp_mb();
+       return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
+}
+
 static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
 {
        dout("%s: obj %p (was %d)\n", __func__, obj_request,
@@ -1192,33 +1219,6 @@ static int rbd_obj_request_wait(struct rbd_obj_request *obj_request)
        return wait_for_completion_interruptible(&obj_request->completion);
 }
 
-static void obj_request_done_init(struct rbd_obj_request *obj_request)
-{
-       atomic_set(&obj_request->done, 0);
-       smp_wmb();
-}
-
-static void obj_request_done_set(struct rbd_obj_request *obj_request)
-{
-       int done;
-
-       done = atomic_inc_return(&obj_request->done);
-       if (done > 1) {
-               struct rbd_img_request *img_request = obj_request->img_request;
-               struct rbd_device *rbd_dev;
-
-               rbd_dev = img_request ? img_request->rbd_dev : NULL;
-               rbd_warn(rbd_dev, "obj_request %p was already done\n",
-                       obj_request);
-       }
-}
-
-static bool obj_request_done_test(struct rbd_obj_request *obj_request)
-{
-       smp_mb();
-       return atomic_read(&obj_request->done) != 0;
-}
-
 /*
  * The default/initial value for all image request flags is 0.  Each
  * is conditionally set to 1 at image request initialization time
@@ -1475,10 +1475,10 @@ static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
        obj_request->object_name = memcpy(name, object_name, size);
        obj_request->offset = offset;
        obj_request->length = length;
+       obj_request->flags = 0;
        obj_request->which = BAD_WHICH;
        obj_request->type = type;
        INIT_LIST_HEAD(&obj_request->links);
-       obj_request_done_init(obj_request);
        init_completion(&obj_request->completion);
        kref_init(&obj_request->kref);