1 files changed, 31 insertions, 21 deletions

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index bca448e11878..327de03a5bdf 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -377,13 +377,14 @@ static void free_tio(struct mapped_device *md, struct dm_target_io *tio)
 static void start_io_acct(struct dm_io *io)
 {
         struct mapped_device *md = io->md;
+        int cpu;
 
         io->start_time = jiffies;
 
-        preempt_disable();
-        disk_round_stats(dm_disk(md));
-        preempt_enable();
-        dm_disk(md)->in_flight = atomic_inc_return(&md->pending);
+        cpu = part_stat_lock();
+        part_round_stats(cpu, &dm_disk(md)->part0);
+        part_stat_unlock();
+        dm_disk(md)->part0.in_flight = atomic_inc_return(&md->pending);
 }
 
 static int end_io_acct(struct dm_io *io)
@@ -391,15 +392,16 @@ static int end_io_acct(struct dm_io *io)
         struct mapped_device *md = io->md;
         struct bio *bio = io->bio;
         unsigned long duration = jiffies - io->start_time;
-        int pending;
+        int pending, cpu;
         int rw = bio_data_dir(bio);
 
-        preempt_disable();
-        disk_round_stats(dm_disk(md));
-        preempt_enable();
-        dm_disk(md)->in_flight = pending = atomic_dec_return(&md->pending);
+        cpu = part_stat_lock();
+        part_round_stats(cpu, &dm_disk(md)->part0);
+        part_stat_add(cpu, &dm_disk(md)->part0, ticks[rw], duration);
+        part_stat_unlock();
 
-        disk_stat_add(dm_disk(md), ticks[rw], duration);
+        dm_disk(md)->part0.in_flight = pending =
+                atomic_dec_return(&md->pending);
 
         return !pending;
 }
@@ -837,12 +839,14 @@ static int dm_merge_bvec(struct request_queue *q,
         struct dm_table *map = dm_get_table(md);
         struct dm_target *ti;
         sector_t max_sectors;
-        int max_size;
+        int max_size = 0;
 
         if (unlikely(!map))
-                return 0;
+                goto out;
 
         ti = dm_table_find_target(map, bvm->bi_sector);
+        if (!dm_target_is_valid(ti))
+                goto out_table;
 
         /*
          * Find maximum amount of I/O that won't need splitting
@@ -861,14 +865,16 @@ static int dm_merge_bvec(struct request_queue *q,
         if (max_size && ti->type->merge)
                 max_size = ti->type->merge(ti, bvm, biovec, max_size);
 
+out_table:
+        dm_table_put(map);
+
+out:
         /*
          * Always allow an entire first page
          */
         if (max_size <= biovec->bv_len && !(bvm->bi_size >> SECTOR_SHIFT))
                 max_size = biovec->bv_len;
 
-        dm_table_put(map);
-
         return max_size;
 }
 
@@ -881,6 +887,7 @@ static int dm_request(struct request_queue *q, struct bio *bio)
         int r = -EIO;
         int rw = bio_data_dir(bio);
         struct mapped_device *md = q->queuedata;
+        int cpu;
 
         /*
          * There is no use in forwarding any barrier request since we can't
@@ -893,8 +900,10 @@ static int dm_request(struct request_queue *q, struct bio *bio)
 
         down_read(&md->io_lock);
 
-        disk_stat_inc(dm_disk(md), ios[rw]);
-        disk_stat_add(dm_disk(md), sectors[rw], bio_sectors(bio));
+        cpu = part_stat_lock();
+        part_stat_inc(cpu, &dm_disk(md)->part0, ios[rw]);
+        part_stat_add(cpu, &dm_disk(md)->part0, sectors[rw], bio_sectors(bio));
+        part_stat_unlock();
 
         /*
          * If we're suspended we have to queue
@@ -1142,7 +1151,7 @@ static void unlock_fs(struct mapped_device *md);
 
 static void free_dev(struct mapped_device *md)
 {
-        int minor = md->disk->first_minor;
+        int minor = MINOR(disk_devt(md->disk));
 
         if (md->suspended_bdev) {
                 unlock_fs(md);
@@ -1178,7 +1187,7 @@ static void event_callback(void *context)
         list_splice_init(&md->uevent_list, &uevents);
         spin_unlock_irqrestore(&md->uevent_lock, flags);
 
-        dm_send_uevents(&uevents, &md->disk->dev.kobj);
+        dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj);
 
         atomic_inc(&md->event_nr);
         wake_up(&md->eventq);
@@ -1263,7 +1272,7 @@ static struct mapped_device *dm_find_md(dev_t dev)
 
         md = idr_find(&_minor_idr, minor);
         if (md && (md == MINOR_ALLOCED ||
-                   (dm_disk(md)->first_minor != minor) ||
+                   (MINOR(disk_devt(dm_disk(md))) != minor) ||
                    test_bit(DMF_FREEING, &md->flags))) {
                 md = NULL;
                 goto out;
@@ -1314,7 +1323,8 @@ void dm_put(struct mapped_device *md)
 
         if (atomic_dec_and_lock(&md->holders, &_minor_lock)) {
                 map = dm_get_table(md);
-                idr_replace(&_minor_idr, MINOR_ALLOCED, dm_disk(md)->first_minor);
+                idr_replace(&_minor_idr, MINOR_ALLOCED,
+                            MINOR(disk_devt(dm_disk(md))));
                 set_bit(DMF_FREEING, &md->flags);
                 spin_unlock(&_minor_lock);
                 if (!dm_suspended(md)) {
@@ -1634,7 +1644,7 @@ out:
  *---------------------------------------------------------------*/
 void dm_kobject_uevent(struct mapped_device *md)
 {
-        kobject_uevent(&md->disk->dev.kobj, KOBJ_CHANGE);
+        kobject_uevent(&disk_to_dev(md->disk)->kobj, KOBJ_CHANGE);
 }
 
 uint32_t dm_next_uevent_seq(struct mapped_device *md)