Re: [PATCH 1/4] lightnvm: add sync and close block I/O types

["Matias Bjørling" <mb@lightnvm.io>]

On 05/04/2016 05:31 PM, Javier González wrote:
> Within a target, I/O requests stem from different paths, which might vary
> in terms of the data structures being allocated, context, etc. This
> might impact how the request is treated, or how memory is freed once
> the bio is completed.
>
> Add two different types of I/Os: (i) NVM_IOTYPE_SYNC, which indicates
> that the I/O is synchronous; and  (ii) NVM_IOTYPE_CLOSE_BLK, which
> indicates that the I/O closes the block to which all the ppas on the
> request belong to.
>
> Signed-off-by: Javier González <javier@cnexlabs.com>
> ---
>   include/linux/lightnvm.h | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
> index 29a6890..6c02209 100644
> --- a/include/linux/lightnvm.h
> +++ b/include/linux/lightnvm.h
> @@ -11,6 +11,8 @@ enum {
>
>   	NVM_IOTYPE_NONE = 0,
>   	NVM_IOTYPE_GC = 1,
> +	NVM_IOTYPE_SYNC = 2,
> +	NVM_IOTYPE_CLOSE_BLK = 4,
>   };
>
>   #define NVM_BLK_BITS (16)
>

The sync should not be necessary when the read path is implemented using 
bio_clone. Similarly for NVM_IOTYPE_CLOSE_BLK. The write completion can 
be handled in the bio completion path.