Re: [Qemu-devel] [PATCH] curl: Add override_accept_ranges flag to force sending range requests.

[Daniel H Barboza <danielhb@linux.vnet.ibm.com>]

On 08/26/2014 05:48 PM, Richard W.M. Jones wrote:
> Some servers (notably VMware ESX) accept range requests, but don't
> send back the Accept-Ranges: bytes header in their initial response.
>
> For these servers you can set override_accept_ranges to 'on' which
> forces this block driver to send range requests anyway.
>
> Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
> ---
>   block/curl.c    | 10 +++++++++-
>   qemu-options.hx |  5 +++++
>   2 files changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/block/curl.c b/block/curl.c
> index 095b5a4..3905c6e 100644
> --- a/block/curl.c
> +++ b/block/curl.c
> @@ -71,6 +71,7 @@ static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
>   #define CURL_BLOCK_OPT_URL       "url"
>   #define CURL_BLOCK_OPT_READAHEAD "readahead"
>   #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
> +#define CURL_BLOCK_OPT_OVERRIDE_ACCEPT_RANGES "override_accept_ranges"
>
>   struct BDRVCURLState;
>
> @@ -489,6 +490,11 @@ static QemuOptsList runtime_opts = {
>               .type = QEMU_OPT_BOOL,
>               .help = "Verify SSL certificate"
>           },
> +        {
> +            .name = CURL_BLOCK_OPT_OVERRIDE_ACCEPT_RANGES,
> +            .type = QEMU_OPT_BOOL,
> +            .help = "Server accepts range requests"
> +        },
>           { /* end of list */ }
>       },
>   };
> @@ -547,7 +553,9 @@ static int curl_open(BlockDriverState *bs, QDict *options, int flags,
>
>       // Get file size
>
> -    s->accept_range = false;
> +    s->accept_range =
> +        qemu_opt_get_bool(opts, CURL_BLOCK_OPT_OVERRIDE_ACCEPT_RANGES,
> +                          false);
>       curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
>       curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
>                        curl_header_cb);
> diff --git a/qemu-options.hx b/qemu-options.hx
> index c573dd8..626ebb3 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -2351,6 +2351,11 @@ multiple of 512 bytes. It defaults to 256k.
>   @item sslverify
>   Whether to verify the remote server's certificate when connecting over SSL. It
>   can have the value 'on' or 'off'. It defaults to 'on'.
> +
> +@item override_accept_ranges
> +Some servers (notably VMware ESX) accept range requests, but don't
> +declare this fact in the headers that they return. Setting this option
> +to 'on' forces CURL to use range requests. The default is 'off'.
>   @end table
>
>   Note that when passing options to qemu explicitly, @option{driver} is the value
Reviewed-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
Tested-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>