Re: [Qemu-devel] [PATCH 13/19] nbd/server: return original error codes

[Eric Blake]

On 05/30/2017 09:30 AM, Vladimir Sementsov-Ogievskiy wrote:
> The code in many cases return -EINVAL or -EIO instead of original error
> code from, for example, write_sync(). Following patch will need EPIPE
> handling, so, let's refactor this where possible (the only exclusion
> is nbd_co_receive_request, with own return-code convention)

Do we still want/need EPIPE handling, given the discussion on the
previous two patches?

> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
> ---
>  nbd/server.c | 124 
> +++++++++++++++++++++++++++++++++++++----------------------
>  1 file changed, 77 insertions(+), 47 deletions(-)
> 

Feels weird to have a net gain in code, but maybe worthwhile.

> diff --git a/nbd/server.c b/nbd/server.c
> index a47f13e4fb..30dfb81a5c 100644
> --- a/nbd/server.c
> +++ b/nbd/server.c
> @@ -136,30 +136,38 @@ static void nbd_client_receive_next_request(NBDClient 
> *client);
>  static int nbd_negotiate_send_rep_len(QIOChannel *ioc, uint32_t type,
>                                        uint32_t opt, uint32_t len)
>  {
> +    int ret;
>      uint64_t magic;
>  
>      TRACE("Reply opt=%" PRIx32 " type=%" PRIx32 " len=%" PRIu32,
>            type, opt, len);
>  
>      magic = cpu_to_be64(NBD_REP_MAGIC);
> -    if (write_sync(ioc, &magic, sizeof(magic), NULL) < 0) {
> +    ret = write_sync(ioc, &magic, sizeof(magic), NULL);
> +    if (ret < 0) {
>          LOG("write failed (rep magic)");
> -        return -EINVAL;
> +        return ret;
>      }

Constructs like this should get shorter once we plumb errp all the way
through.  Okay, I can live with the temporary verbosity.

You may still have to make changes due to rebasing (in which case I'll
definitely want to review again); but if this patch doesn't need further
rework, you can add:
Reviewed-by: Eric Blake <address@hidden>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

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