2 files changed, 33 insertions, 17 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 6ad2b8602c1d..d836c84ad3da 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1470,17 +1470,12 @@ static void add_acct_request(struct request_queue *q, struct request *rq,
 }
 
 static void part_round_stats_single(struct request_queue *q, int cpu,
-                                    struct hd_struct *part, unsigned long now)
+                                    struct hd_struct *part, unsigned long now,
+                                    unsigned int inflight)
 {
-        int inflight[2];
-
-        if (now == part->stamp)
-                return;
-
-        part_in_flight(q, part, inflight);
-        if (inflight[0]) {
+        if (inflight) {
                 __part_stat_add(cpu, part, time_in_queue,
-                                inflight[0] * (now - part->stamp));
+                                inflight * (now - part->stamp));
                 __part_stat_add(cpu, part, io_ticks, (now - part->stamp));
         }
         part->stamp = now;
@@ -1505,12 +1500,29 @@ static void part_round_stats_single(struct request_queue *q, int cpu,
  */
 void part_round_stats(struct request_queue *q, int cpu, struct hd_struct *part)
 {
+        struct hd_struct *part2 = NULL;
         unsigned long now = jiffies;
+        unsigned int inflight[2];
+        int stats = 0;
+
+        if (part->stamp != now)
+                stats |= 1;
+
+        if (part->partno) {
+                part2 = &part_to_disk(part)->part0;
+                if (part2->stamp != now)
+                        stats |= 2;
+        }
+
+        if (!stats)
+                return;
+
+        part_in_flight(q, part, inflight);
 
-        if (part->partno)
-                part_round_stats_single(q, cpu, &part_to_disk(part)->part0,
-                                                now);
-        part_round_stats_single(q, cpu, part, now);
+        if (stats & 2)
+                part_round_stats_single(q, cpu, part2, now, inflight[1]);
+        if (stats & 1)
+                part_round_stats_single(q, cpu, part, now, inflight[0]);
 }
 EXPORT_SYMBOL_GPL(part_round_stats);
 
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 0dfc7a9984b6..fe764ca16993 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -97,11 +97,15 @@ static void blk_mq_check_inflight(struct blk_mq_hw_ctx *hctx,
         if (test_bit(REQ_ATOM_STARTED, &rq->atomic_flags) &&
             !test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) {
                 /*
-                 * Count as inflight if it either matches the partition we
-                 * asked for, or if it's the root
+                 * index[0] counts the specific partition that was asked
+                 * for. index[1] counts the ones that are active on the
+                 * whole device, so increment that if mi->part is indeed
+                 * a partition, and not a whole device.
                  */
-                if (rq->part == mi->part || mi->part->partno)
+                if (rq->part == mi->part)
                         mi->inflight[0]++;
+                if (mi->part->partno)
+                        mi->inflight[1]++;
         }
 }
 
@@ -110,7 +114,7 @@ void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
 {
         struct mq_inflight mi = { .part = part, .inflight = inflight, };
 
-        inflight[0] = 0;
+        inflight[0] = inflight[1] = 0;
         blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi);
 }