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From: Hannes Reinecke <hare@suse.de>
To: Ilya Dryomov <idryomov@gmail.com>
Cc: Sage Weil <sage@redhat.com>, Daniel Disseldorp <ddiss@suse.com>,
	Jens Axboe <axboe@kernel.dk>,
	ceph-devel@vger.kernel.org, linux-block@vger.kernel.org,
	Hannes Reinecke <hare@suse.de>
Subject: [PATCH 05/15] rbd: reorder switch statement in rbd_advance_write()
Date: Fri, 31 Jan 2020 11:37:29 +0100	[thread overview]
Message-ID: <20200131103739.136098-6-hare@suse.de> (raw)
In-Reply-To: <20200131103739.136098-1-hare@suse.de>

Reorder switch statement to avoid the use of a label/goto
statement and add a 'done' state to indicate that the state
machine has completed.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/block/rbd.c | 36 +++++++++++++++++++++++++-----------
 1 file changed, 25 insertions(+), 11 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 4d7857667e9c..766d67e4d5e5 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -267,7 +267,8 @@ enum rbd_obj_read_state {
  * even if there is a parent).
  */
 enum rbd_obj_write_state {
-	RBD_OBJ_WRITE_START = 1,
+	RBD_OBJ_WRITE_DONE,
+	RBD_OBJ_WRITE_START,
 	RBD_OBJ_WRITE_PRE_OBJECT_MAP,
 	RBD_OBJ_WRITE_OBJECT,
 	__RBD_OBJ_WRITE_COPYUP,
@@ -3382,31 +3383,37 @@ static bool rbd_obj_advance_write(struct rbd_obj_request *obj_req, int *result)
 	int ret;
 
 again:
+	dout("%s: obj %p state %d\n", __func__, obj_req, obj_req->write_state);
 	switch (obj_req->write_state) {
 	case RBD_OBJ_WRITE_START:
 		rbd_assert(!*result);
 
-		if (rbd_obj_write_is_noop(obj_req))
+		if (rbd_obj_write_is_noop(obj_req)) {
+			obj_req->write_state = RBD_OBJ_WRITE_DONE;
 			return true;
+		}
 
 		ret = rbd_obj_write_pre_object_map(obj_req);
 		if (ret < 0) {
 			*result = ret;
+			obj_req->write_state = RBD_OBJ_WRITE_DONE;
 			return true;
 		}
 		obj_req->write_state = RBD_OBJ_WRITE_PRE_OBJECT_MAP;
-		if (ret > 0)
-			goto again;
-		return false;
+		if (ret == 0)
+			return false;
+		/* fall through */
 	case RBD_OBJ_WRITE_PRE_OBJECT_MAP:
 		if (*result) {
 			rbd_warn(rbd_dev, "pre object map update failed: %d",
 				 *result);
+			obj_req->write_state = RBD_OBJ_WRITE_DONE;
 			return true;
 		}
 		ret = rbd_obj_write_object(obj_req);
 		if (ret) {
 			*result = ret;
+			obj_req->write_state = RBD_OBJ_WRITE_DONE;
 			return true;
 		}
 		obj_req->write_state = RBD_OBJ_WRITE_OBJECT;
@@ -3426,33 +3433,40 @@ static bool rbd_obj_advance_write(struct rbd_obj_request *obj_req, int *result)
 			if (obj_req->flags & RBD_OBJ_FLAG_DELETION)
 				*result = 0;
 		}
-		if (*result)
+		if (*result) {
+			obj_req->write_state = RBD_OBJ_WRITE_DONE;
 			return true;
-
+		}
 		obj_req->write_state = RBD_OBJ_WRITE_COPYUP;
 		goto again;
 	case __RBD_OBJ_WRITE_COPYUP:
 		if (!rbd_obj_advance_copyup(obj_req, result))
 			return false;
+		obj_req->write_state = RBD_OBJ_WRITE_COPYUP;
 		/* fall through */
 	case RBD_OBJ_WRITE_COPYUP:
 		if (*result) {
 			rbd_warn(rbd_dev, "copyup failed: %d", *result);
+			obj_req->write_state = RBD_OBJ_WRITE_DONE;
 			return true;
 		}
+		obj_req->write_state = RBD_OBJ_WRITE_POST_OBJECT_MAP;
 		ret = rbd_obj_write_post_object_map(obj_req);
 		if (ret < 0) {
 			*result = ret;
+			obj_req->write_state = RBD_OBJ_WRITE_DONE;
 			return true;
 		}
-		obj_req->write_state = RBD_OBJ_WRITE_POST_OBJECT_MAP;
-		if (ret > 0)
-			goto again;
-		return false;
+		if (ret == 0)
+			return false;
+		/* fall through */
 	case RBD_OBJ_WRITE_POST_OBJECT_MAP:
 		if (*result)
 			rbd_warn(rbd_dev, "post object map update failed: %d",
 				 *result);
+		obj_req->write_state = RBD_OBJ_WRITE_DONE;
+		/* fall through */
+	case RBD_OBJ_WRITE_DONE:
 		return true;
 	default:
 		BUG();
-- 
2.16.4


  parent reply	other threads:[~2020-01-31 10:38 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-31 10:37 [PATCH 00/15] rbd: switch to blk-mq Hannes Reinecke
2020-01-31 10:37 ` [PATCH 01/15] rbd: lock object request list Hannes Reinecke
2020-02-03 16:38   ` Ilya Dryomov
2020-01-31 10:37 ` [PATCH 02/15] rbd: use READ_ONCE() when checking the mapping size Hannes Reinecke
2020-02-03 16:50   ` Ilya Dryomov
2020-02-04  7:05     ` Hannes Reinecke
2020-01-31 10:37 ` [PATCH 03/15] rbd: reorder rbd_img_advance() Hannes Reinecke
2020-01-31 10:37 ` [PATCH 04/15] rbd: reorder switch statement in rbd_advance_read() Hannes Reinecke
2020-01-31 10:37 ` Hannes Reinecke [this message]
2020-01-31 10:37 ` [PATCH 06/15] rbd: add 'done' state for rbd_obj_advance_copyup() Hannes Reinecke
2020-01-31 10:37 ` [PATCH 07/15] rbd: use callback for image request completion Hannes Reinecke
2020-02-03 17:13   ` Ilya Dryomov
2020-01-31 10:37 ` [PATCH 08/15] rbd: add debugging statements for the state machine Hannes Reinecke
2020-01-31 10:37 ` [PATCH 09/15] rbd: count pending object requests in-line Hannes Reinecke
2020-02-03 17:47   ` Ilya Dryomov
2020-02-04  6:59     ` Hannes Reinecke
2020-01-31 10:37 ` [PATCH 10/15] rbd: kill 'work_result' Hannes Reinecke
2020-01-31 10:37 ` [PATCH 11/15] rbd: drop state_mutex in __rbd_img_handle_request() Hannes Reinecke
2020-02-03 18:01   ` Ilya Dryomov
2020-01-31 10:37 ` [PATCH 12/15] rbd: kill img_request kref Hannes Reinecke
2020-01-31 10:37 ` [PATCH 13/15] rbd: schedule image_request after preparation Hannes Reinecke
2020-02-03 18:40   ` Ilya Dryomov
2020-01-31 10:37 ` [PATCH 14/15] rbd: embed image request as blk_mq request payload Hannes Reinecke
2020-01-31 10:37 ` [PATCH 15/15] rbd: switch to blk-mq Hannes Reinecke
2020-02-03  8:36   ` Christoph Hellwig

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