Re: [PATCH 1/2] btrfs: Return number of compressed extents directly in compress_file_range

[Anand Jain <anand.jain@oracle.com>]

On 2/7/19 12:50 AM, Nikolay Borisov wrote:
> compress_file_range returns a void, yet uses a function parameter as a
> return value. Make that more idiomatic by simply returning the number
> of compressed extents directly. Also track such extents in more aptly
> named variables. No functional changes
> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>

Looks good.

Reviewed-by: Anand Jain <anand.jain@oracle.com>


> ---
>   fs/btrfs/inode.c | 20 +++++++++++---------
>   1 file changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 4e183c2d3555..3b0bf5ea9eb6 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -440,8 +440,7 @@ static inline void inode_should_defrag(struct btrfs_inode *inode,
>    * are written in the same order that the flusher thread sent them
>    * down.
>    */
> -static noinline void compress_file_range(struct async_chunk *async_chunk,
> -					 int *num_added)
> +static noinline int compress_file_range(struct async_chunk *async_chunk)
>   {
>   	struct inode *inode = async_chunk->inode;
>   	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
> @@ -457,6 +456,7 @@ static noinline void compress_file_range(struct async_chunk *async_chunk,
>   	int i;
>   	int will_compress;
>   	int compress_type = fs_info->compress_type;
> +	int compressed_extents = 0;
>   	int redirty = 0;
>   
>   	inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
> @@ -619,7 +619,7 @@ static noinline void compress_file_range(struct async_chunk *async_chunk,
>   		 */
>   		total_in = ALIGN(total_in, PAGE_SIZE);
>   		if (total_compressed + blocksize <= total_in) {
> -			*num_added += 1;
> +			compressed_extents += 1;
>   
>   			/*
>   			 * The async work queues will take care of doing actual
> @@ -636,7 +636,7 @@ static noinline void compress_file_range(struct async_chunk *async_chunk,
>   				cond_resched();
>   				goto again;
>   			}
> -			return;
> +			return compressed_extents;
>   		}
>   	}
>   	if (pages) {
> @@ -675,9 +675,9 @@ static noinline void compress_file_range(struct async_chunk *async_chunk,
>   		extent_range_redirty_for_io(inode, start, end);
>   	add_async_extent(async_chunk, start, end - start + 1, 0, NULL, 0,
>   			 BTRFS_COMPRESS_NONE);
> -	*num_added += 1;
> +	compressed_extents += 1;
>   
> -	return;
> +	return compressed_extents;
>   
>   free_pages_out:
>   	for (i = 0; i < nr_pages; i++) {
> @@ -685,6 +685,8 @@ static noinline void compress_file_range(struct async_chunk *async_chunk,
>   		put_page(pages[i]);
>   	}
>   	kfree(pages);
> +
> +	return 0;
>   }
>   
>   static void free_async_extent_pages(struct async_extent *async_extent)
> @@ -1122,12 +1124,12 @@ static noinline int cow_file_range(struct inode *inode,
>   static noinline void async_cow_start(struct btrfs_work *work)
>   {
>   	struct async_chunk *async_chunk;
> -	int num_added = 0;
> +	int compressed_extents = 0;
>   
>   	async_chunk = container_of(work, struct async_chunk, work);
>   
> -	compress_file_range(async_chunk, &num_added);
> -	if (num_added == 0) {
> +	compressed_extents = compress_file_range(async_chunk);
> +	if (compressed_extents == 0) {
>   		btrfs_add_delayed_iput(async_chunk->inode);
>   		async_chunk->inode = NULL;
>   	}
>