block: remove delayed holder registration

Now that dm has been fixed to track of holder registrations before
add_disk, the somewhat buggy block layer code can be safely removed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20221115141054.1051801-8-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/genhd.c b/block/genhd.c
index 6271ad0..075d8da 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -478,10 +478,6 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
                goto out_put_holder_dir;
        }
 
-       ret = bd_register_pending_holders(disk);
-       if (ret < 0)
-               goto out_put_slave_dir;
-
        ret = blk_register_queue(disk);
        if (ret)
                goto out_put_slave_dir;

diff --git a/block/holder.c b/block/holder.c
index 5283bc8..dd9327b 100644 (file)
--- a/block/holder.c
+++ b/block/holder.c
@@ -29,19 +29,6 @@ static void del_symlink(struct kobject *from, struct kobject *to)
        sysfs_remove_link(from, kobject_name(to));
 }
 
-static int __link_disk_holder(struct block_device *bdev, struct gendisk *disk)
-{
-       int ret;
-
-       ret = add_symlink(disk->slave_dir, bdev_kobj(bdev));
-       if (ret)
-               return ret;
-       ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj);
-       if (ret)
-               del_symlink(disk->slave_dir, bdev_kobj(bdev));
-       return ret;
-}
-
 /**
  * bd_link_disk_holder - create symlinks between holding disk and slave bdev
  * @bdev: the claimed slave bdev
@@ -75,6 +62,9 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
        struct bd_holder_disk *holder;
        int ret = 0;
 
+       if (WARN_ON_ONCE(!disk->slave_dir))
+               return -EINVAL;
+
        mutex_lock(&disk->open_mutex);
 
        WARN_ON_ONCE(!bdev->bd_holder);
@@ -94,34 +84,32 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
        INIT_LIST_HEAD(&holder->list);
        holder->bdev = bdev;
        holder->refcnt = 1;
-       if (disk->slave_dir) {
-               ret = __link_disk_holder(bdev, disk);
-               if (ret) {
-                       kfree(holder);
-                       goto out_unlock;
-               }
-       }
-
+       ret = add_symlink(disk->slave_dir, bdev_kobj(bdev));
+       if (ret)
+               goto out_free_holder;
+       ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj);
+       if (ret)
+               goto out_del_symlink;
        list_add(&holder->list, &disk->slave_bdevs);
+
        /*
         * del_gendisk drops the initial reference to bd_holder_dir, so we need
         * to keep our own here to allow for cleanup past that point.
         */
        kobject_get(bdev->bd_holder_dir);
+       mutex_unlock(&disk->open_mutex);
+       return 0;
 
+out_del_symlink:
+       del_symlink(disk->slave_dir, bdev_kobj(bdev));
+out_free_holder:
+       kfree(holder);
 out_unlock:
        mutex_unlock(&disk->open_mutex);
        return ret;
 }
 EXPORT_SYMBOL_GPL(bd_link_disk_holder);
 
-static void __unlink_disk_holder(struct block_device *bdev,
-               struct gendisk *disk)
-{
-       del_symlink(disk->slave_dir, bdev_kobj(bdev));
-       del_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj);
-}
-
 /**
  * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder()
  * @bdev: the calimed slave bdev
@@ -136,11 +124,14 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
 {
        struct bd_holder_disk *holder;
 
+       if (WARN_ON_ONCE(!disk->slave_dir))
+               return;
+
        mutex_lock(&disk->open_mutex);
        holder = bd_find_holder_disk(bdev, disk);
        if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) {
-               if (disk->slave_dir)
-                       __unlink_disk_holder(bdev, disk);
+               del_symlink(disk->slave_dir, bdev_kobj(bdev));
+               del_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj);
                kobject_put(bdev->bd_holder_dir);
                list_del_init(&holder->list);
                kfree(holder);
@@ -148,24 +139,3 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
        mutex_unlock(&disk->open_mutex);
 }
 EXPORT_SYMBOL_GPL(bd_unlink_disk_holder);
-
-int bd_register_pending_holders(struct gendisk *disk)
-{
-       struct bd_holder_disk *holder;
-       int ret;
-
-       mutex_lock(&disk->open_mutex);
-       list_for_each_entry(holder, &disk->slave_bdevs, list) {
-               ret = __link_disk_holder(holder->bdev, disk);
-               if (ret)
-                       goto out_undo;
-       }
-       mutex_unlock(&disk->open_mutex);
-       return 0;
-
-out_undo:
-       list_for_each_entry_continue_reverse(holder, &disk->slave_bdevs, list)
-               __unlink_disk_holder(holder->bdev, disk);
-       mutex_unlock(&disk->open_mutex);
-       return ret;
-}

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 9188aa3..516e452 100644 (file)
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -833,7 +833,6 @@ void set_capacity(struct gendisk *disk, sector_t size);
 #ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
 int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
 void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
-int bd_register_pending_holders(struct gendisk *disk);
 #else
 static inline int bd_link_disk_holder(struct block_device *bdev,
                                      struct gendisk *disk)
@@ -844,10 +843,6 @@ static inline void bd_unlink_disk_holder(struct block_device *bdev,
                                         struct gendisk *disk)
 {
 }
-static inline int bd_register_pending_holders(struct gendisk *disk)
-{
-       return 0;
-}
 #endif /* CONFIG_BLOCK_HOLDER_DEPRECATED */
 
 dev_t part_devt(struct gendisk *disk, u8 partno);