Merge branch 'block-6.17' into for-next

* block-6.17:
  blk-wbt: doc: Update the doc of the wbt_lat_usec interface
  blk-wbt: Eliminate ambiguity in the comments of struct rq_wb
  blk-wbt: Optimize wbt_done() for non-throttled writes

Author: axboe

Documentation/ABI/stable/sysfs-block

@@ -731,7 +731,7 @@ Contact:	[email protected]
 Description:
 		[RW] If the device is registered for writeback throttling, then
 		this file shows the target minimum read latency. If this latency
-		is exceeded in a given window of time (see wb_window_usec), then
+		is exceeded in a given window of time (see curr_win_nsec), then
 		the writeback throttling will start scaling back writes. Writing
 		a value of '0' to this file disables the feature. Writing a
 		value of '-1' to this file resets the value to the default

block/blk-wbt.c

@@ -85,8 +85,8 @@ struct rq_wb {
 	u64 sync_issue;
 	void *sync_cookie;
 
-	unsigned long last_issue;		/* last non-throttled issue */
-	unsigned long last_comp;		/* last non-throttled comp */
+	unsigned long last_issue;	/* issue time of last read rq */
+	unsigned long last_comp;	/* completion time of last read rq */
 	unsigned long min_lat_nsec;
 	struct rq_qos rqos;
 	struct rq_wait rq_wait[WBT_NUM_RWQ];
@@ -248,13 +248,14 @@ static void wbt_done(struct rq_qos *rqos, struct request *rq)
 	struct rq_wb *rwb = RQWB(rqos);
 
 	if (!wbt_is_tracked(rq)) {
-		if (rwb->sync_cookie == rq) {
-			rwb->sync_issue = 0;
-			rwb->sync_cookie = NULL;
-		}
+		if (wbt_is_read(rq)) {
+			if (rwb->sync_cookie == rq) {
+				rwb->sync_issue = 0;
+				rwb->sync_cookie = NULL;
+			}
 
-		if (wbt_is_read(rq))
 			wb_timestamp(rwb, &rwb->last_comp);
+		}
 	} else {
 		WARN_ON_ONCE(rq == rwb->sync_cookie);
 		__wbt_done(rqos, wbt_flags(rq));