Re: [PATCH 2/6] btrfs: store encoded read state in struct btrfs_encoded_read_private

[David Sterba <dsterba@suse.cz>]

On Fri, Aug 23, 2024 at 05:27:44PM +0100, Mark Harmstone wrote:
> Move the various stack variables needed for encoded reads into struct
> btrfs_encoded_read_private, so that we can split it into several
> functions.
> 
> Signed-off-by: Mark Harmstone <maharmstone@fb.com>
> ---
>  fs/btrfs/btrfs_inode.h |  20 ++++-
>  fs/btrfs/inode.c       | 170 +++++++++++++++++++++--------------------
>  fs/btrfs/ioctl.c       |  60 ++++++++-------
>  3 files changed, 135 insertions(+), 115 deletions(-)
> 
> diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
> index affe70929234..5cd4308bd337 100644
> --- a/fs/btrfs/btrfs_inode.h
> +++ b/fs/btrfs/btrfs_inode.h
> @@ -605,9 +605,23 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode,
>  					  u64 file_offset, u64 disk_bytenr,
>  					  u64 disk_io_size,
>  					  struct page **pages);
> -ssize_t btrfs_encoded_read(struct file *file, loff_t offset,
> -			   struct iov_iter *iter,
> -			   struct btrfs_ioctl_encoded_io_args *encoded);
> +
> +struct btrfs_encoded_read_private {
> +	wait_queue_head_t wait;
> +	atomic_t pending;
> +	blk_status_t status;
> +	unsigned long nr_pages;
> +	struct page **pages;
> +	struct extent_state *cached_state;
> +	size_t count;
> +	struct iovec iovstack[UIO_FASTIOV];
> +	struct iovec *iov;
> +	struct iov_iter iter;
> +	struct btrfs_ioctl_encoded_io_args args;
> +	struct file *file;
> +};
> +
> +ssize_t btrfs_encoded_read(struct btrfs_encoded_read_private *priv);
>  ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
>  			       const struct btrfs_ioctl_encoded_io_args *encoded);
>  
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index a0cc029d95ed..c1292e58366a 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -9078,12 +9078,6 @@ static ssize_t btrfs_encoded_read_inline(
>  	return ret;
>  }
>  
> -struct btrfs_encoded_read_private {
> -	wait_queue_head_t wait;
> -	atomic_t pending;
> -	blk_status_t status;
> -};
> -
>  static void btrfs_encoded_read_endio(struct btrfs_bio *bbio)
>  {
>  	struct btrfs_encoded_read_private *priv = bbio->private;
> @@ -9104,33 +9098,31 @@ static void btrfs_encoded_read_endio(struct btrfs_bio *bbio)
>  	bio_put(&bbio->bio);
>  }
>  
> -int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode,
> -					  u64 file_offset, u64 disk_bytenr,
> -					  u64 disk_io_size, struct page **pages)
> +static void _btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode,

Please don't use underscores in function names

https://btrfs.readthedocs.io/en/latest/dev/Development-notes.html#function-declarations