---

yaml
---
r: 230605
b: refs/heads/master
c: 09e099d
h: refs/heads/master
i:
  230603: c2cd27a
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e4a683c899cd5a49f8d684a054c95bd115a0c005
+refs/heads/master: 09e099d4bafea3b15be003d548bdf94b4b6e0e17

trunk/block/blk-core.c

@@ -64,13 +64,27 @@ static void drive_stat_acct(struct request *rq, int new_io)
 		return;
 
 	cpu = part_stat_lock();
-	part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq));
 
-	if (!new_io)
+	if (!new_io) {
+		part = rq->part;
 		part_stat_inc(cpu, part, merges[rw]);
-	else {
+	} else {
+		part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq));
+		if (!kref_test_and_get(&part->ref)) {
+			/*
+			 * The partition is already being removed,
+			 * the request will be accounted on the disk only
+			 *
+			 * We take a reference on disk->part0 although that
+			 * partition will never be deleted, so we can treat
+			 * it as any other partition.
+			 */
+			part = &rq->rq_disk->part0;
+			kref_get(&part->ref);
+		}
 		part_round_stats(cpu, part);
 		part_inc_in_flight(part, rw);
+		rq->part = part;
 	}
 
 	part_stat_unlock();
@@ -128,6 +142,7 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
 	rq->ref_count = 1;
 	rq->start_time = jiffies;
 	set_start_time_ns(rq);
+	rq->part = NULL;
 }
 EXPORT_SYMBOL(blk_rq_init);
 
@@ -1776,7 +1791,7 @@ static void blk_account_io_completion(struct request *req, unsigned int bytes)
 		int cpu;
 
 		cpu = part_stat_lock();
-		part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req));
+		part = req->part;
 		part_stat_add(cpu, part, sectors[rw], bytes >> 9);
 		part_stat_unlock();
 	}
@@ -1796,13 +1811,14 @@ static void blk_account_io_done(struct request *req)
 		int cpu;
 
 		cpu = part_stat_lock();
-		part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req));
+		part = req->part;
 
 		part_stat_inc(cpu, part, ios[rw]);
 		part_stat_add(cpu, part, ticks[rw], duration);
 		part_round_stats(cpu, part);
 		part_dec_in_flight(part, rw);
 
+		kref_put(&part->ref, __delete_partition);
 		part_stat_unlock();
 	}
 }

trunk/block/blk-merge.c

@@ -351,11 +351,12 @@ static void blk_account_io_merge(struct request *req)
 		int cpu;
 
 		cpu = part_stat_lock();
-		part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req));
+		part = req->part;
 
 		part_round_stats(cpu, part);
 		part_dec_in_flight(part, rq_data_dir(req));
 
+		kref_put(&part->ref, __delete_partition);
 		part_stat_unlock();
 	}
 }

trunk/block/genhd.c

@@ -1192,6 +1192,7 @@ struct gendisk *alloc_disk_node(int minors, int node_id)
 			return NULL;
 		}
 		disk->part_tbl->part[0] = &disk->part0;
+		kref_init(&disk->part0.ref);
 
 		disk->minors = minors;
 		rand_initialize_disk(disk);

trunk/fs/partitions/check.c

@@ -381,6 +381,13 @@ static void delete_partition_rcu_cb(struct rcu_head *head)
 	put_device(part_to_dev(part));
 }
 
+void __delete_partition(struct kref *ref)
+{
+	struct hd_struct *part = container_of(ref, struct hd_struct, ref);
+
+	call_rcu(&part->rcu_head, delete_partition_rcu_cb);
+}
+
 void delete_partition(struct gendisk *disk, int partno)
 {
 	struct disk_part_tbl *ptbl = disk->part_tbl;
@@ -399,7 +406,7 @@ void delete_partition(struct gendisk *disk, int partno)
 	kobject_put(part->holder_dir);
 	device_del(part_to_dev(part));
 
-	call_rcu(&part->rcu_head, delete_partition_rcu_cb);
+	kref_put(&part->ref, __delete_partition);
 }
 
 static ssize_t whole_disk_show(struct device *dev,
@@ -498,6 +505,7 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno,
 	if (!dev_get_uevent_suppress(ddev))
 		kobject_uevent(&pdev->kobj, KOBJ_ADD);
 
+	kref_init(&p->ref);
 	return p;
 
 out_free_info:

trunk/include/linux/blkdev.h

@@ -115,6 +115,7 @@ struct request {
 	void *elevator_private3;
 
 	struct gendisk *rq_disk;
+	struct hd_struct *part;
 	unsigned long start_time;
 #ifdef CONFIG_BLK_CGROUP
 	unsigned long long start_time_ns;

trunk/include/linux/genhd.h

@@ -116,6 +116,7 @@ struct hd_struct {
 	struct disk_stats dkstats;
 #endif
 	struct rcu_head rcu_head;
+	struct kref ref;
 };
 
 #define GENHD_FL_REMOVABLE			1
@@ -583,6 +584,7 @@ extern struct hd_struct * __must_check add_partition(struct gendisk *disk,
 						     sector_t len, int flags,
 						     struct partition_meta_info
 						       *info);
+extern void __delete_partition(struct kref *ref);
 extern void delete_partition(struct gendisk *, int);
 extern void printk_all_partitions(void);