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authorIlya Dryomov <ilya.dryomov@inktank.com>2014-09-12 12:02:01 (GMT)
committerIlya Dryomov <idryomov@redhat.com>2014-10-14 17:03:28 (GMT)
commit70d045f660c7331bce8c9377929b52a9738a12cb (patch)
tree8d944c45f5a57e100b6b5f1fac18c72bbf908dbb
parent4e752f0ab0e8114f4edd7574081dc625d679dd15 (diff)
downloadlinux-70d045f660c7331bce8c9377929b52a9738a12cb.tar.xz
rbd: add img_obj_request_simple() helper
To clarify the conditions and make it easier to add new ones. Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
-rw-r--r--drivers/block/rbd.c44
1 files changed, 28 insertions, 16 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index eea44ce..6dae658 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -2743,11 +2743,10 @@ out:
return ret;
}
-static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
+static bool img_obj_request_simple(struct rbd_obj_request *obj_request)
{
struct rbd_img_request *img_request;
struct rbd_device *rbd_dev;
- bool known;
rbd_assert(obj_request_img_data_test(obj_request));
@@ -2755,22 +2754,35 @@ static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
rbd_assert(img_request);
rbd_dev = img_request->rbd_dev;
+ /* Reads */
+ if (!img_request_write_test(img_request))
+ return true;
+
+ /* Non-layered writes */
+ if (!img_request_layered_test(img_request))
+ return true;
+
/*
- * Only writes to layered images need special handling.
- * Reads and non-layered writes are simple object requests.
- * Layered writes that start beyond the end of the overlap
- * with the parent have no parent data, so they too are
- * simple object requests. Finally, if the target object is
- * known to already exist, its parent data has already been
- * copied, so a write to the object can also be handled as a
- * simple object request.
+ * Layered writes outside of the parent overlap range don't
+ * share any data with the parent.
*/
- if (!img_request_write_test(img_request) ||
- !img_request_layered_test(img_request) ||
- !obj_request_overlaps_parent(obj_request) ||
- ((known = obj_request_known_test(obj_request)) &&
- obj_request_exists_test(obj_request))) {
+ if (!obj_request_overlaps_parent(obj_request))
+ return true;
+ /*
+ * If the object is known to already exist, its parent data has
+ * already been copied.
+ */
+ if (obj_request_known_test(obj_request) &&
+ obj_request_exists_test(obj_request))
+ return true;
+
+ return false;
+}
+
+static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
+{
+ if (img_obj_request_simple(obj_request)) {
struct rbd_device *rbd_dev;
struct ceph_osd_client *osdc;
@@ -2786,7 +2798,7 @@ static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
* start by reading the data for the full target object from
* the parent so we can use it for a copyup to the target.
*/
- if (known)
+ if (obj_request_known_test(obj_request))
return rbd_img_obj_parent_read_full(obj_request);
/* We don't know whether the target exists. Go find out. */