On Fri, Feb 17, 2017 at 05:39:01PM +0100, Peter Lieven wrote:
> if the passed qiov contains exactly one iov we can
> pass the buffer directly.
>
> Signed-off-by: Peter Lieven <p...@kamp.de>
> ---
> block/nfs.c | 23 ++++++++++++++++-------
> 1 file changed, 16 insertions(+), 7 deletions(-)
>
> diff --git a/block/nfs.c b/block/nfs.c
> index ab5dcc2..bb4b75f 100644
> --- a/block/nfs.c
> +++ b/block/nfs.c
> @@ -295,20 +295,27 @@ static int coroutine_fn nfs_co_pwritev(BlockDriverState
> *bs, uint64_t offset,
> NFSClient *client = bs->opaque;
> NFSRPC task;
> char *buf = NULL;
> + bool my_buffer = false;
g_free() is a nop if buf is NULL, so there is no need for the my_buffer
variable & check.
>
> nfs_co_init_task(bs, &task);
>
> - buf = g_try_malloc(bytes);
> - if (bytes && buf == NULL) {
> - return -ENOMEM;
> + if (iov->niov != 1) {
> + buf = g_try_malloc(bytes);
> + if (bytes && buf == NULL) {
> + return -ENOMEM;
> + }
> + qemu_iovec_to_buf(iov, 0, buf, bytes);
> + my_buffer = true;
> + } else {
> + buf = iov->iov[0].iov_base;
> }
>
> - qemu_iovec_to_buf(iov, 0, buf, bytes);
> -
> if (nfs_pwrite_async(client->context, client->fh,
> offset, bytes, buf,
> nfs_co_generic_cb, &task) != 0) {
> - g_free(buf);
> + if (my_buffer) {
> + g_free(buf);
> + }
> return -ENOMEM;
> }
>
> @@ -317,7 +324,9 @@ static int coroutine_fn nfs_co_pwritev(BlockDriverState
> *bs, uint64_t offset,
> qemu_coroutine_yield();
> }
>
> - g_free(buf);
> + if (my_buffer) {
> + g_free(buf);
> + }
>
> if (task.ret != bytes) {
> return task.ret < 0 ? task.ret : -EIO;
> --
> 1.9.1
>
