It need to copyup the parent's content when layered writing,
but an entire object write would overwrite it, so skip it.
Signed-off-by: Guangliang Zhao <lucienchao@xxxxxxxxx>
---
drivers/block/rbd.c | 49 ++++++++++++++++++++++++++++++++++---------------
1 file changed, 34 insertions(+), 15 deletions(-)
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index b365e0d..e425be7 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -2624,34 +2624,53 @@ out:
return ret;
}
-static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
+static bool rbd_img_obj_request_simple(struct rbd_obj_request *obj_request)
{
struct rbd_img_request *img_request;
struct rbd_device *rbd_dev;
- bool known;
+ u64 obj_size;
rbd_assert(obj_request_img_data_test(obj_request));
img_request = obj_request->img_request;
rbd_assert(img_request);
rbd_dev = img_request->rbd_dev;
+ obj_size = (u64) 1 << rbd_dev->header.obj_order;
+ /* Read requests didn't need special handling */
+ if (!img_request_write_test(img_request))
+ return true;
+ /* No-layered writes are simple requests*/
+ 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.
+ * with the parent have no parent data, so they are simple
+ * object requests.
*/
- if (!img_request_write_test(img_request) ||
- !img_request_layered_test(img_request) ||
- rbd_dev->parent_overlap <= obj_request->img_offset ||
- ((known = obj_request_known_test(obj_request)) &&
- obj_request_exists_test(obj_request))) {
+ if (rbd_dev->parent_overlap <= obj_request->img_offset)
+ return true;
+ /*
+ * If the obj_request aligns with the boundary and equals
+ * to the size of an object, it doesn't need copyup, because
+ * the obj_request will overwrite it finally.
+ */
+ if ((!obj_request->offset) && (obj_request->length == obj_size))
+ return true;
+ /*
+ * 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
+ */
+ 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 (rbd_img_obj_request_simple(obj_request)) {
struct rbd_device *rbd_dev;
struct ceph_osd_client *osdc;
@@ -2667,7 +2686,7 @@ 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. */
--
1.7.9.5
--
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