Merge tag 'nvme-5.9-2020-10-07' of git://git.infradead.org/nvme into block-5.9

[linux-2.6-microblaze.git] / block / partitions / core.c

diff --git a/block/partitions/core.c b/block/partitions/core.c
index e62a98a..722406b 100644 (file)
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -278,6 +278,15 @@ static void hd_struct_free_work(struct work_struct *work)
 {
        struct hd_struct *part =
                container_of(to_rcu_work(work), struct hd_struct, rcu_work);
+       struct gendisk *disk = part_to_disk(part);
+
+       /*
+        * Release the disk reference acquired in delete_partition here.
+        * We can't release it in hd_struct_free because the final put_device
+        * needs process context and thus can't be run directly from a
+        * percpu_ref ->release handler.
+        */
+       put_device(disk_to_dev(disk));
 
        part->start_sect = 0;
        part->nr_sects = 0;
@@ -293,7 +302,6 @@ static void hd_struct_free(struct percpu_ref *ref)
                rcu_dereference_protected(disk->part_tbl, 1);
 
        rcu_assign_pointer(ptbl->last_lookup, NULL);
-       put_device(disk_to_dev(disk));
 
        INIT_RCU_WORK(&part->rcu_work, hd_struct_free_work);
        queue_rcu_work(system_wq, &part->rcu_work);
@@ -524,19 +532,20 @@ int bdev_add_partition(struct block_device *bdev, int partno,
 int bdev_del_partition(struct block_device *bdev, int partno)
 {
        struct block_device *bdevp;
-       struct hd_struct *part;
-       int ret = 0;
+       struct hd_struct *part = NULL;
+       int ret;
 
-       part = disk_get_part(bdev->bd_disk, partno);
-       if (!part)
-               return -ENXIO;
-
-       ret = -ENOMEM;
-       bdevp = bdget(part_devt(part));
+       bdevp = bdget_disk(bdev->bd_disk, partno);
        if (!bdevp)
-               goto out_put_part;
+               return -ENXIO;
 
        mutex_lock(&bdevp->bd_mutex);
+       mutex_lock_nested(&bdev->bd_mutex, 1);
+
+       ret = -ENXIO;
+       part = disk_get_part(bdev->bd_disk, partno);
+       if (!part)
+               goto out_unlock;
 
        ret = -EBUSY;
        if (bdevp->bd_openers)
@@ -545,16 +554,14 @@ int bdev_del_partition(struct block_device *bdev, int partno)
        sync_blockdev(bdevp);
        invalidate_bdev(bdevp);
 
-       mutex_lock_nested(&bdev->bd_mutex, 1);
        delete_partition(bdev->bd_disk, part);
-       mutex_unlock(&bdev->bd_mutex);
-
        ret = 0;
 out_unlock:
+       mutex_unlock(&bdev->bd_mutex);
        mutex_unlock(&bdevp->bd_mutex);
        bdput(bdevp);
-out_put_part:
-       disk_put_part(part);
+       if (part)
+               disk_put_part(part);
        return ret;
 }