[PATCH v3 0/3] Fix undefined behaviour during device synchronization

@@ -8429,14 +8429,14 @@ static int is_mddev_idle(struct mddev *mddev, int init)
 {
 	struct md_rdev *rdev;
 	int idle;
-	int curr_events;
+	s64 curr_events;
 
 	idle = 1;
 	rcu_read_lock();
 	rdev_for_each_rcu(rdev, mddev) {
 		struct gendisk *disk = rdev->bdev->bd_disk;
-		curr_events = (int)part_stat_read_accum(disk->part0, sectors) -
-			      atomic_read(&disk->sync_io);
+		curr_events = (s64)part_stat_read_accum(disk->part0, sectors) -
+			      atomic64_read(&disk->sync_io);
 		/* sync IO will cause sync_io to increase before the disk_stats
 		 * as sync_io is counted when a request starts, and
 		 * disk_stats is counted when it completes.

@@ -50,7 +50,7 @@ struct md_rdev {
 
 	sector_t sectors;		/* Device size (in 512bytes sectors) */
 	struct mddev *mddev;		/* RAID array if running */
-	int last_events;		/* IO event timestamp */
+	s64 last_events;		/* IO event timestamp */
 
 	/*
 	 * If meta_bdev is non-NULL, it means that a separate device is

@@ -551,7 +551,7 @@ extern void mddev_unlock(struct mddev *mddev);
 
 static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
 {
-	atomic_add(nr_sectors, &bdev->bd_disk->sync_io);
+	atomic64_add(nr_sectors, &bdev->bd_disk->sync_io);
 }
 
 static inline void md_sync_acct_bio(struct bio *bio, unsigned long nr_sectors)

@@ -150,7 +150,7 @@ struct gendisk {
 	struct list_head slave_bdevs;
 #endif
 	struct timer_rand_state *random;
-	atomic_t sync_io;		/* RAID */
+	atomic64_t sync_io;		/* RAID */
 	struct disk_events *ev;
 #ifdef  CONFIG_BLK_DEV_INTEGRITY
 	struct kobject integrity_kobj;

@@ -955,7 +955,6 @@ struct drbd_device {
 	char congestion_reason;  /* Why we where congested... */
 	atomic_t rs_sect_in; /* for incoming resync data rate, SyncTarget */
 	atomic64_t rs_sect_ev; /* for submitted resync data rate, both */
-	int rs_last_sect_ev; /* counter to compare with */
 	s64 rs_last_events;  /* counter of read or write "events" (unit sectors)
 			      * on the lower level device when we last looked. */
 	int c_sync_rate; /* current resync rate after syncer throttle magic */

@@ -2046,7 +2046,6 @@ void drbd_device_cleanup(struct drbd_device *device)
 	device->rs_total     =
 	device->rs_failed    = 0;
 	device->rs_last_events = 0;
-	device->rs_last_sect_ev = 0;
 	for (i = 0; i < DRBD_SYNC_MARKS; i++) {
 		device->rs_mark_left[i] = 0;
 		device->rs_mark_time[i] = 0;

@@ -1389,7 +1389,6 @@ _drbd_set_state(struct drbd_device *device, union drbd_state ns,
 
 		set_ov_position(device, ns.conn);
 		device->rs_start = now;
-		device->rs_last_sect_ev = 0;
 		device->ov_last_oos_size = 0;
 		device->ov_last_oos_start = 0;
 

@@ -1829,7 +1829,6 @@ void drbd_start_resync(struct drbd_device *device, enum drbd_conns side)
 		device->rs_failed    = 0;
 		device->rs_paused    = 0;
 		device->rs_same_csum = 0;
-		device->rs_last_sect_ev = 0;
 		device->rs_total     = tw;
 		device->rs_start     = now;
 		for (i = 0; i < DRBD_SYNC_MARKS; i++) {

@@ -1021,7 +1021,7 @@ static void bm_page_io_async(struct drbd_bm_aio_ctx *ctx, int page_nr) __must_ho
 		submit_bio(bio);
 		/* this should not count as user activity and cause the
 		 * resync to throttle -- see drbd_rs_should_slow_down(). */
-		atomic_add(len >> 9, &device->rs_sect_ev);
+		atomic64_add(len >> 9, &device->rs_sect_ev);
 	}
 }
 

@@ -954,9 +954,9 @@ struct drbd_device {
 	struct mutex *state_mutex; /* either own_state_mutex or first_peer_device(device)->connection->cstate_mutex */
 	char congestion_reason;  /* Why we where congested... */
 	atomic_t rs_sect_in; /* for incoming resync data rate, SyncTarget */
-	atomic_t rs_sect_ev; /* for submitted resync data rate, both */
+	atomic64_t rs_sect_ev; /* for submitted resync data rate, both */
 	int rs_last_sect_ev; /* counter to compare with */
-	int rs_last_events;  /* counter of read or write "events" (unit sectors)
+	s64 rs_last_events;  /* counter of read or write "events" (unit sectors)
 			      * on the lower level device when we last looked. */
 	int c_sync_rate; /* current resync rate after syncer throttle magic */
 	struct fifo_buffer *rs_plan_s; /* correction values of resync planer (RCU, connection->conn_update) */

@@ -1974,7 +1974,7 @@ void drbd_init_set_defaults(struct drbd_device *device)
 	atomic_set(&device->local_cnt, 0);
 	atomic_set(&device->pp_in_use_by_net, 0);
 	atomic_set(&device->rs_sect_in, 0);
-	atomic_set(&device->rs_sect_ev, 0);
+	atomic64_set(&device->rs_sect_ev, 0);
 	atomic_set(&device->ap_in_flight, 0);
 	atomic_set(&device->md_io.in_use, 0);
 

@@ -2106,7 +2106,7 @@ static int recv_resync_read(struct drbd_peer_device *peer_device, sector_t secto
 	list_add_tail(&peer_req->w.list, &device->sync_ee);
 	spin_unlock_irq(&device->resource->req_lock);
 
-	atomic_add(pi->size >> 9, &device->rs_sect_ev);
+	atomic64_add(pi->size >> 9, &device->rs_sect_ev);
 	if (drbd_submit_peer_request(device, peer_req, REQ_OP_WRITE, 0,
 				     DRBD_FAULT_RS_WR) == 0)
 		return 0;

@@ -2792,7 +2792,7 @@ bool drbd_rs_c_min_rate_throttle(struct drbd_device *device)
 	struct gendisk *disk = device->ldev->backing_bdev->bd_disk;
 	unsigned long db, dt, dbdt;
 	unsigned int c_min_rate;
-	int curr_events;
+	s64 curr_events;
 
 	rcu_read_lock();
 	c_min_rate = rcu_dereference(device->ldev->disk_conf)->c_min_rate;

@@ -2802,8 +2802,8 @@ bool drbd_rs_c_min_rate_throttle(struct drbd_device *device)
 	if (c_min_rate == 0)
 		return false;
 
-	curr_events = (int)part_stat_read_accum(disk->part0, sectors) -
-			atomic_read(&device->rs_sect_ev);
+	curr_events = (s64)part_stat_read_accum(disk->part0, sectors) -
+			atomic64_read(&device->rs_sect_ev);
 
 	if (atomic_read(&device->ap_actlog_cnt)
 	    || curr_events - device->rs_last_events > 64) {

@@ -3023,7 +3023,7 @@ static int receive_DataRequest(struct drbd_connection *connection, struct packet
 		goto out_free_e;
 
 submit_for_resync:
-	atomic_add(size >> 9, &device->rs_sect_ev);
+	atomic64_add(size >> 9, &device->rs_sect_ev);
 
 submit:
 	update_receiver_timing_details(connection, drbd_submit_peer_request);

@@ -5019,7 +5019,7 @@ static int receive_rs_deallocated(struct drbd_connection *connection, struct pac
 		list_add_tail(&peer_req->w.list, &device->sync_ee);
 		spin_unlock_irq(&device->resource->req_lock);
 
-		atomic_add(pi->size >> 9, &device->rs_sect_ev);
+		atomic64_add(pi->size >> 9, &device->rs_sect_ev);
 		err = drbd_submit_peer_request(device, peer_req, op, 0, DRBD_FAULT_RS_WR);
 
 		if (err) {

@@ -409,7 +409,7 @@ static int read_for_csum(struct drbd_peer_device *peer_device, sector_t sector,
 	list_add_tail(&peer_req->w.list, &device->read_ee);
 	spin_unlock_irq(&device->resource->req_lock);
 
-	atomic_add(size >> 9, &device->rs_sect_ev);
+	atomic64_add(size >> 9, &device->rs_sect_ev);
 	if (drbd_submit_peer_request(device, peer_req, REQ_OP_READ, 0,
 				     DRBD_FAULT_RS_RD) == 0)
 		return 0;

@@ -1679,7 +1679,7 @@ void drbd_rs_controller_reset(struct drbd_device *device)
 	struct fifo_buffer *plan;
 
 	atomic_set(&device->rs_sect_in, 0);
-	atomic_set(&device->rs_sect_ev, 0);
+	atomic64_set(&device->rs_sect_ev, 0);
 	device->rs_in_flight = 0;
 	device->rs_last_events =
 		(int)part_stat_read_accum(disk->part0, sectors);