Hi
On Wed, Dec 23, 2020 at 10:17 AM <elena.ufimts...@oracle.com> wrote:
> From: Elena Ufimtseva <elena.ufimts...@oracle.com>
>
> Adds qio_channel_readv_full_all() to read both data and FDs.
> Refactors existing code to use this function.
>
> Signed-off-by: Elena Ufimtseva <elena.ufimts...@oracle.com>
> Signed-off-by: John G Johnson <john.g.john...@oracle.com>
> Signed-off-by: Jagannathan Raman <jag.ra...@oracle.com>
> ---
> include/io/channel.h | 25 +++++++++++++
> io/channel.c | 85 +++++++++++++++++++++++++++++++-------------
> 2 files changed, 85 insertions(+), 25 deletions(-)
>
> diff --git a/include/io/channel.h b/include/io/channel.h
> index 2378567d4b..429ece9a05 100644
> --- a/include/io/channel.h
> +++ b/include/io/channel.h
> @@ -774,6 +774,31 @@ void qio_channel_set_aio_fd_handler(QIOChannel *ioc,
> IOHandler *io_write,
> void *opaque);
>
> +/**
> + * qio_channel_readv_full_all:
> + * @ioc: the channel object
> + * @iov: the array of memory regions to read data to
> + * @niov: the length of the @iov array
> + * @fds: an array of file handles to read
> + * @nfds: number of file handles in @fds
> + * @errp: pointer to a NULL-initialized error object
> + *
> + *
> + * Behaves like qio_channel_readv_full but will attempt
> + * to read all data specified (file handles and memory regions).
> + * The function will wait for all requested data
> + * to be read, yielding from the current coroutine
> + * if required.
> + *
> + * Returns: 0 if all bytes were read, or -1 on error
>
It may also returns -ECANCEL. I am not sure it's a good idea.
+ */
> +
> +int qio_channel_readv_full_all(QIOChannel *ioc,
> + const struct iovec *iov,
> + size_t niov,
> + int **fds, size_t *nfds,
> + Error **errp);
> +
> /**
> * qio_channel_writev_full_all:
> * @ioc: the channel object
> diff --git a/io/channel.c b/io/channel.c
> index bde1f6d0f4..5edaea1fac 100644
> --- a/io/channel.c
> +++ b/io/channel.c
> @@ -91,11 +91,49 @@ int qio_channel_readv_all_eof(QIOChannel *ioc,
> const struct iovec *iov,
> size_t niov,
> Error **errp)
> +{
> + int ret = qio_channel_readv_full_all(ioc, iov, niov, NULL, NULL,
> errp);
> +
>
+ if (ret == -ECANCELED) {
>
No io/ functions use -errno return values so far.
Maybe the simplest is to use the same return values as read_all_eof:
* Returns: 1 if all bytes were read, 0 if end-of-file occurs
* without data, or -1 on error
+ error_prepend(errp,
> + "Unexpected end-of-file before all bytes were read:
> ");
> + ret = -1;
> + }
> +
> + return ret;
> +}
> +
> +int qio_channel_readv_all(QIOChannel *ioc,
> + const struct iovec *iov,
> + size_t niov,
> + Error **errp)
> +{
> + int ret = qio_channel_readv_all_eof(ioc, iov, niov, errp);
>
+
>
It looks like it would make more sense to call readv_full_all directly
instead now.
+ if (ret == 0) {
> + error_setg(errp,
> + "Unexpected end-of-file before all bytes were read");
> + return -1;
> + }
> + if (ret == 1) {
> + return 0;
> + }
> +
> + return ret;
> +}
> +
> +int qio_channel_readv_full_all(QIOChannel *ioc,
> + const struct iovec *iov,
> + size_t niov,
> + int **fds, size_t *nfds,
> + Error **errp)
> {
> int ret = -1;
> struct iovec *local_iov = g_new(struct iovec, niov);
> struct iovec *local_iov_head = local_iov;
> unsigned int nlocal_iov = niov;
> + int **local_fds = fds;
> + size_t *local_nfds = nfds;
> bool partial = false;
>
> nlocal_iov = iov_copy(local_iov, nlocal_iov,
> @@ -104,7 +142,8 @@ int qio_channel_readv_all_eof(QIOChannel *ioc,
>
> while (nlocal_iov > 0) {
> ssize_t len;
> - len = qio_channel_readv(ioc, local_iov, nlocal_iov, errp);
> + len = qio_channel_readv_full(ioc, local_iov, nlocal_iov,
> local_fds,
> + local_nfds, errp);
> if (len == QIO_CHANNEL_ERR_BLOCK) {
> if (qemu_in_coroutine()) {
> qio_channel_yield(ioc, G_IO_IN);
> @@ -112,20 +151,33 @@ int qio_channel_readv_all_eof(QIOChannel *ioc,
> qio_channel_wait(ioc, G_IO_IN);
> }
> continue;
> - } else if (len < 0) {
> - goto cleanup;
> - } else if (len == 0) {
> - if (partial) {
> - error_setg(errp,
> - "Unexpected end-of-file before all bytes were
> read");
> + }
> +
> + if (len <= 0) {
> + size_t fd_idx = nfds ? *nfds : 0;
> + if (partial && (len == 0)) {
> + ret = -ECANCELED;
> } else {
> - ret = 0;
> + ret = len;
> + }
> +
> + while (fds && fd_idx) {
> + close(*fds[fd_idx - 1]);
> + fd_idx--;
> + }
> +
> + if (fds) {
> + g_free(*fds);
> }
> +
> goto cleanup;
> }
>
> partial = true;
> iov_discard_front(&local_iov, &nlocal_iov, len);
> +
> + local_fds = NULL;
> + local_nfds = 0;
> }
>
> ret = 1;
> @@ -135,23 +187,6 @@ int qio_channel_readv_all_eof(QIOChannel *ioc,
> return ret;
> }
>
> -int qio_channel_readv_all(QIOChannel *ioc,
> - const struct iovec *iov,
> - size_t niov,
> - Error **errp)
> -{
> - int ret = qio_channel_readv_all_eof(ioc, iov, niov, errp);
> -
> - if (ret == 0) {
> - ret = -1;
> - error_setg(errp,
> - "Unexpected end-of-file before all bytes were read");
> - } else if (ret == 1) {
> - ret = 0;
> - }
> - return ret;
> -}
> -
> int qio_channel_writev_all(QIOChannel *ioc,
> const struct iovec *iov,
> size_t niov,
> --
> 2.25.GIT
>
>
--
Marc-André Lureau
