Subject: Re: linux-next: manual merge of the block tree with the mmc-fixes tree

From: Stephen Rothwell <[email-masked]>
Date: Mon, 12 Jul 2021 09:02:12 +1000

Hi all,

On Fri, 9 Jul 2021 10:32:44 +1000 Stephen Rothwell <[email-masked]> wrote:
>
> Today's linux-next merge of the block tree got a conflict in:
> 
>   drivers/mmc/core/block.c
> 
> between commit:
> 
>   5c0777665b3e ("mmc: core: Use kref in place of struct mmc_blk_data::usage")
> 
> from the mmc-fixes tree and commits:
> 
>   249cda3325e0 ("mmc: remove an extra blk_{get,put}_queue pair")
>   607d968a5769 ("mmc: switch to blk_mq_alloc_disk")
> 
> from the block tree.
> 
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging.  You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.
> 
> diff --cc drivers/mmc/core/block.c
> index d7b5c5ab75fa,9890a1532cb0..000000000000
> --- a/drivers/mmc/core/block.c
> +++ b/drivers/mmc/core/block.c
> @@@ -195,26 -196,18 +195,25 @@@ static inline int mmc_get_devidx(struc
>   	return devidx;
>   }
>   
>  -static void mmc_blk_put(struct mmc_blk_data *md)
>  +static void mmc_blk_kref_release(struct kref *ref)
>   {
>  -	mutex_lock(&open_lock);
>  -	md->usage--;
>  -	if (md->usage == 0) {
>  -		int devidx = mmc_get_devidx(md->disk);
>  +	struct mmc_blk_data *md = container_of(ref, struct mmc_blk_data, kref);
>  +	int devidx;
>   
>  -		ida_simple_remove(&mmc_blk_ida, devidx);
>  -		put_disk(md->disk);
>  -		kfree(md);
>  -	}
>  +	devidx = mmc_get_devidx(md->disk);
> - 	blk_put_queue(md->queue.queue);
>  +	ida_simple_remove(&mmc_blk_ida, devidx);
>  +
>  +	mutex_lock(&open_lock);
>  +	md->disk->private_data = NULL;
>   	mutex_unlock(&open_lock);
>  +
>  +	put_disk(md->disk);
>  +	kfree(md);
>  +}
>  +
>  +static void mmc_blk_put(struct mmc_blk_data *md)
>  +{
>  +	kref_put(&md->kref, mmc_blk_kref_release);
>   }
>   
>   static ssize_t power_ro_lock_show(struct device *dev,
> @@@ -2334,27 -2327,11 +2333,11 @@@ static struct mmc_blk_data *mmc_blk_all
>   
>   	INIT_LIST_HEAD(&md->part);
>   	INIT_LIST_HEAD(&md->rpmbs);
>  -	md->usage = 1;
>  +	kref_init(&md->kref);
> - 
> - 	ret = mmc_init_queue(&md->queue, card);
> - 	if (ret)
> - 		goto err_putdisk;
> - 
>   	md->queue.blkdata = md;
>   
> - 	/*
> - 	 * Keep an extra reference to the queue so that we can shutdown the
> - 	 * queue (i.e. call blk_cleanup_queue()) while there are still
> - 	 * references to the 'md'. The corresponding blk_put_queue() is in
> - 	 * mmc_blk_put().
> - 	 */
> - 	if (!blk_get_queue(md->queue.queue)) {
> - 		mmc_cleanup_queue(&md->queue);
> - 		ret = -ENODEV;
> - 		goto err_putdisk;
> - 	}
> - 
>   	md->disk->major	= MMC_BLOCK_MAJOR;
> + 	md->disk->minors = perdev_minors;
>   	md->disk->first_minor = devidx * perdev_minors;
>   	md->disk->fops = &mmc_bdops;
>   	md->disk->private_data = md;

This is now a conflict between the mmc-fixes tree and Linus' tree.

-- 
Cheers,
Stephen Rothwell