On Mon, Oct 23, 2023 at 05:35:49PM -0300, Fabiano Rosas wrote:
> From: Nikolay Borisov <nbori...@suse.com>
>
> Introduce basic pwritev/preadv support in the generic channel layer.
> Specific implementation will follow for the file channel as this is
> required in order to support migration streams with fixed location of
> each ram page.
>
> Signed-off-by: Nikolay Borisov <nbori...@suse.com>
> Signed-off-by: Fabiano Rosas <faro...@suse.de>
> ---
> include/io/channel.h | 82 ++++++++++++++++++++++++++++++++++++++++++++
> io/channel.c | 58 +++++++++++++++++++++++++++++++
> 2 files changed, 140 insertions(+)
>
> diff --git a/include/io/channel.h b/include/io/channel.h
> index fcb19fd672..a8181d576a 100644
> --- a/include/io/channel.h
> +++ b/include/io/channel.h
> @@ -131,6 +131,16 @@ struct QIOChannelClass {
> Error **errp);
>
> /* Optional callbacks */
> + ssize_t (*io_pwritev)(QIOChannel *ioc,
> + const struct iovec *iov,
> + size_t niov,
> + off_t offset,
> + Error **errp);
> + ssize_t (*io_preadv)(QIOChannel *ioc,
> + const struct iovec *iov,
> + size_t niov,
> + off_t offset,
> + Error **errp);
> int (*io_shutdown)(QIOChannel *ioc,
> QIOChannelShutdown how,
> Error **errp);
> @@ -529,6 +539,78 @@ void qio_channel_set_follow_coroutine_ctx(QIOChannel
> *ioc, bool enabled);
> int qio_channel_close(QIOChannel *ioc,
> Error **errp);
>
> +/**
> + * qio_channel_pwritev_full
> + * @ioc: the channel object
> + * @iov: the array of memory regions to write data from
> + * @niov: the length of the @iov array
> + * @offset: offset in the channel where writes should begin
> + * @errp: pointer to a NULL-initialized error object
> + *
> + * Not all implementations will support this facility, so may report
> + * an error. To avoid errors, the caller may check for the feature
> + * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
> + *
> + * Behaves as qio_channel_writev_full, apart from not supporting
> + * sending of file handles as well as beginning the write at the
> + * passed @offset
> + *
> + */
> +ssize_t qio_channel_pwritev_full(QIOChannel *ioc, const struct iovec *iov,
> + size_t niov, off_t offset, Error **errp);
In terms of naming this should be just "_pwritev".
We don't support FD passing, so the "_full" suffix is not
appropriate
> +
> +/**
> + * qio_channel_pwritev
> + * @ioc: the channel object
> + * @buf: the memory region to write data into
> + * @buflen: the number of bytes to @buf
> + * @offset: offset in the channel where writes should begin
> + * @errp: pointer to a NULL-initialized error object
> + *
> + * Not all implementations will support this facility, so may report
> + * an error. To avoid errors, the caller may check for the feature
> + * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
> + *
> + */
> +ssize_t qio_channel_pwritev(QIOChannel *ioc, char *buf, size_t buflen,
> + off_t offset, Error **errp);
This isn't passing a vector of buffers, so it should be just
"pwrite", not "pwritev".
> +
> +/**
> + * qio_channel_preadv_full
> + * @ioc: the channel object
> + * @iov: the array of memory regions to read data into
> + * @niov: the length of the @iov array
> + * @offset: offset in the channel where writes should begin
> + * @errp: pointer to a NULL-initialized error object
> + *
> + * Not all implementations will support this facility, so may report
> + * an error. To avoid errors, the caller may check for the feature
> + * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
> + *
> + * Behaves as qio_channel_readv_full, apart from not supporting
> + * receiving of file handles as well as beginning the read at the
> + * passed @offset
> + *
> + */
> +ssize_t qio_channel_preadv_full(QIOChannel *ioc, const struct iovec *iov,
> + size_t niov, off_t offset, Error **errp);
"preadv"
> +
> +/**
> + * qio_channel_preadv
> + * @ioc: the channel object
> + * @buf: the memory region to write data into
> + * @buflen: the number of bytes to @buf
> + * @offset: offset in the channel where writes should begin
> + * @errp: pointer to a NULL-initialized error object
> + *
> + * Not all implementations will support this facility, so may report
> + * an error. To avoid errors, the caller may check for the feature
> + * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
> + *
> + */
> +ssize_t qio_channel_preadv(QIOChannel *ioc, char *buf, size_t buflen,
> + off_t offset, Error **errp);
"pread"
With regards,
Daniel
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