block: make add_partition() return pointer to hd_struct

Make add_partition() return pointer to the new hd_struct on success
and ERR_PTR() value on failure.  This change will be used to fix md
autodetection bug.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 3 insertions, 4 deletions

diff --git a/block/ioctl.c b/block/ioctl.c
index c832d639b6e2..d03985b04d67 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -18,7 +18,6 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
         struct disk_part_iter piter;
         long long start, length;
         int partno;
-        int err;
 
         if (!capable(CAP_SYS_ADMIN))
                 return -EACCES;
@@ -61,10 +60,10 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
                         disk_part_iter_exit(&piter);
 
                         /* all seems OK */
-                        err = add_partition(disk, partno, start, length,
-                                            ADDPART_FLAG_NONE);
+                        part = add_partition(disk, partno, start, length,
+                                             ADDPART_FLAG_NONE);
                         mutex_unlock(&bdev->bd_mutex);
-                        return err;
+                        return IS_ERR(part) ? PTR_ERR(part) : 0;
                 case BLKPG_DEL_PARTITION:
                         part = disk_get_part(disk, partno);
                         if (!part)