On 5/21/21 1:51 PM, Christoph Hellwig wrote:
> Convert the bcache driver to use the blk_alloc_disk and blk_cleanup_disk
> helpers to simplify gendisk and request_queue allocation.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> drivers/md/bcache/super.c | 15 ++++-----------
> 1 file changed, 4 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
> index bea8c4429ae8..185246a0d855 100644
> --- a/drivers/md/bcache/super.c
> +++ b/drivers/md/bcache/super.c
> @@ -890,13 +890,9 @@ static void bcache_device_free(struct bcache_device *d)
> if (disk_added)
> del_gendisk(disk);
>
> - if (disk->queue)
> - blk_cleanup_queue(disk->queue);
> -
> + blk_cleanup_disk(disk);
> ida_simple_remove(&bcache_device_idx,
> first_minor_to_idx(disk->first_minor));
> - if (disk_added)
> - put_disk(disk);
The above 2 lines are added on purpose to prevent an refcount
underflow. It is from commit 86da9f736740 ("bcache: fix refcount
underflow in bcache_device_free()").
Maybe add a parameter to blk_cleanup_disk() or checking (disk->flags &
GENHD_FL_UP) inside blk_cleanup_disk() ?
Coly Li
> }
>
> bioset_exit(&d->bio_split);
> @@ -946,7 +942,7 @@ static int bcache_device_init(struct bcache_device *d, unsigned int block_size,
> BIOSET_NEED_BVECS|BIOSET_NEED_RESCUER))
> goto err;
>
> - d->disk = alloc_disk(BCACHE_MINORS);
> + d->disk = blk_alloc_disk(NUMA_NO_NODE);
> if (!d->disk)
> goto err;
>
> @@ -955,14 +951,11 @@ static int bcache_device_init(struct bcache_device *d, unsigned int block_size,
>
> d->disk->major = bcache_major;
> d->disk->first_minor = idx_to_first_minor(idx);
> + d->disk->minors = BCACHE_MINORS;
> d->disk->fops = ops;
> d->disk->private_data = d;
>
> - q = blk_alloc_queue(NUMA_NO_NODE);
> - if (!q)
> - return -ENOMEM;
> -
> - d->disk->queue = q;
> + q = d->disk->queue;
> q->limits.max_hw_sectors = UINT_MAX;
> q->limits.max_sectors = UINT_MAX;
> q->limits.max_segment_size = UINT_MAX;
>
The rested looks fine to me.
Thanks.
Coly Li
