[PATCH 4/6] block: add a rq_list type

[Nathan Chancellor]

Hi Christoph,

On Wed, Nov 13, 2024 at 04:20:44PM +0100, Christoph Hellwig wrote:
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 65f37ae70712..ce8b65503ff0 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -1006,6 +1006,11 @@ extern void blk_put_queue(struct request_queue *);
>  void blk_mark_disk_dead(struct gendisk *disk);
>  
>  #ifdef CONFIG_BLOCK
> +struct rq_list {
> +	struct request *head;
> +	struct request *tail;
> +};
> +
>  /*
>   * blk_plug permits building a queue of related requests by holding the I/O
>   * fragments for a short period. This allows merging of sequential requests
> @@ -1018,10 +1023,10 @@ void blk_mark_disk_dead(struct gendisk *disk);
>   * blk_flush_plug() is called.
>   */
>  struct blk_plug {
> -	struct request *mq_list; /* blk-mq requests */
> +	struct rq_list mq_list; /* blk-mq requests */
>  
>  	/* if ios_left is > 1, we can batch tag/rq allocations */
> -	struct request *cached_rq;
> +	struct rq_list cached_rqs;
>  	u64 cur_ktime;
>  	unsigned short nr_ios;
>  
> @@ -1683,7 +1688,7 @@ int bdev_thaw(struct block_device *bdev);
>  void bdev_fput(struct file *bdev_file);
>  
>  struct io_comp_batch {
> -	struct request *req_list;
> +	struct rq_list req_list;

This change as commit a3396b99990d ("block: add a rq_list type") in
next-20241114 causes errors when CONFIG_BLOCK is disabled because the
definition of 'struct rq_list' is under CONFIG_BLOCK. Should it be moved
out?

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 00212e96261a..a1fd0ddce5cf 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1006,12 +1006,12 @@ extern void blk_put_queue(struct request_queue *);
 
 void blk_mark_disk_dead(struct gendisk *disk);
 
-#ifdef CONFIG_BLOCK
 struct rq_list {
 	struct request *head;
 	struct request *tail;
 };
 
+#ifdef CONFIG_BLOCK
 /*
  * blk_plug permits building a queue of related requests by holding the I/O
  * fragments for a short period. This allows merging of sequential requests

>  	bool need_ts;
>  	void (*complete)(struct io_comp_batch *);
>  };