Re: [PATCH v3 02/25] include/block/block: split header into I/O and global state API

[Eric Blake]

On Tue, Oct 12, 2021 at 04:48:43AM -0400, Emanuele Giuseppe Esposito wrote:
> block.h currently contains a mix of functions:
> some of them run under the BQL and modify the block layer graph,
> others are instead thread-safe and perform I/O in iothreads.
> It is not easy to understand which function is part of which
> group (I/O vs GS), and this patch aims to clarify it.
> 
> The "GS" functions need the BQL, and often use
> aio_context_acquire/release and/or drain to be sure they
> can modify the graph safely.
> The I/O function are instead thread safe, and can run in
> any AioContext.
> 
> By splitting the header in two files, block-io.h
> and block-global-state.h we have a clearer view on what
> needs what kind of protection. block-common.h
> instead contains common structures shared by both headers.

s/instead //

> 
> block.h is left there for legacy and to avoid changing
> all includes in all c files that use the block APIs.
> 
> Assertions are added in the next patch.
> 
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> ---

> diff --git a/include/block/block-common.h b/include/block/block-common.h
> new file mode 100644
> index 0000000000..4f1fd8de21
> --- /dev/null
> +++ b/include/block/block-common.h
> @@ -0,0 +1,389 @@
> +#ifndef BLOCK_COMMON_H
> +#define BLOCK_COMMON_H

As a new file, it probably deserves a copyright/license blurb copied
from the file it is split out of.

> diff --git a/include/block/block-global-state.h 
> b/include/block/block-global-state.h
> new file mode 100644
> index 0000000000..b57e275da9
> --- /dev/null
> +++ b/include/block/block-global-state.h
> @@ -0,0 +1,263 @@
> +#ifndef BLOCK_GLOBAL_STATE_H
> +#define BLOCK_GLOBAL_STATE_H

Likewise, here and in all other newly-split files in your series.

> +++ b/include/block/block.h
> @@ -1,864 +1,9 @@
>  #ifndef BLOCK_H
>  #define BLOCK_H

Oh. There wasn't one to copy from :( Well, now's as good a time to fix
that as any.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
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