1 files changed, 16 insertions, 4 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index a0dc2e72fcbb..d6128d9ad601 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -60,7 +60,9 @@ static void drive_stat_acct(struct request *rq, int new_io)
         if (!blk_fs_request(rq) || !rq->rq_disk)
                 return;
 
-        part = disk_map_sector(rq->rq_disk, rq->sector);
+        rcu_read_lock();
+
+        part = disk_map_sector_rcu(rq->rq_disk, rq->sector);
         if (!new_io)
                 __all_stat_inc(rq->rq_disk, part, merges[rw], rq->sector);
         else {
@@ -71,6 +73,8 @@ static void drive_stat_acct(struct request *rq, int new_io)
                         part->in_flight++;
                 }
         }
+
+        rcu_read_unlock();
 }
 
 void blk_queue_congestion_threshold(struct request_queue *q)
@@ -1557,12 +1561,14 @@ static int __end_that_request_first(struct request *req, int error,
         }
 
         if (blk_fs_request(req) && req->rq_disk) {
-                struct hd_struct *part =
-                        disk_map_sector(req->rq_disk, req->sector);
                 const int rw = rq_data_dir(req);
+                struct hd_struct *part;
 
+                rcu_read_lock();
+                part = disk_map_sector_rcu(req->rq_disk, req->sector);
                 all_stat_add(req->rq_disk, part, sectors[rw],
                                 nr_bytes >> 9, req->sector);
+                rcu_read_unlock();
         }
 
         total_bytes = bio_nbytes = 0;
@@ -1746,7 +1752,11 @@ static void end_that_request_last(struct request *req, int error)
         if (disk && blk_fs_request(req) && req != &req->q->bar_rq) {
                 unsigned long duration = jiffies - req->start_time;
                 const int rw = rq_data_dir(req);
-                struct hd_struct *part = disk_map_sector(disk, req->sector);
+                struct hd_struct *part;
+
+                rcu_read_lock();
+
+                part = disk_map_sector_rcu(disk, req->sector);
 
                 __all_stat_inc(disk, part, ios[rw], req->sector);
                 __all_stat_add(disk, part, ticks[rw], duration, req->sector);
@@ -1756,6 +1766,8 @@ static void end_that_request_last(struct request *req, int error)
                         part_round_stats(part);
                         part->in_flight--;
                 }
+
+                rcu_read_unlock();
         }
 
         if (req->end_io)