On Mon, Oct 10, 2022 at 04:34:02PM +0300, Nikolay Borisov wrote:
> Add a bunch of auxiliarry methods and a feature flag to work with
> SEEKABLE channels. Currently the only channel considered seekable is
> QIOChannelFile. Also add a bunch of helper functions to QEMUFile that
> can make use of this channel feature. All of this is in prepration for
> supporting 'fixed-ram' migration stream feature.
QIOChannelBuffer/Null are also seekable.
>
> Signed-off-by: Nikolay Borisov <nbori...@suse.com>
> ---
> include/io/channel.h | 1 +
> include/migration/qemu-file-types.h | 2 +
> io/channel-file.c | 5 +++
> migration/qemu-file.c | 59 +++++++++++++++++++++++++++++
> migration/qemu-file.h | 3 ++
> 5 files changed, 70 insertions(+)
Can you separate the migration/ tree bits into a second patch
that follows the io/ bits.
>
> diff --git a/include/io/channel.h b/include/io/channel.h
> index c680ee748021..4fc37c78e68c 100644
> --- a/include/io/channel.h
> +++ b/include/io/channel.h
> @@ -41,6 +41,7 @@ enum QIOChannelFeature {
> QIO_CHANNEL_FEATURE_SHUTDOWN,
> QIO_CHANNEL_FEATURE_LISTEN,
> QIO_CHANNEL_FEATURE_WRITE_ZERO_COPY,
> + QIO_CHANNEL_FEATURE_SEEKABLE,
> };
>
>
> diff --git a/include/migration/qemu-file-types.h
> b/include/migration/qemu-file-types.h
> index 2867e3da84ab..eb0325ee8687 100644
> --- a/include/migration/qemu-file-types.h
> +++ b/include/migration/qemu-file-types.h
> @@ -50,6 +50,8 @@ unsigned int qemu_get_be16(QEMUFile *f);
> unsigned int qemu_get_be32(QEMUFile *f);
> uint64_t qemu_get_be64(QEMUFile *f);
>
> +bool qemu_file_is_seekable(QEMUFile *f);
> +
> static inline void qemu_put_be64s(QEMUFile *f, const uint64_t *pv)
> {
> qemu_put_be64(f, *pv);
> diff --git a/io/channel-file.c b/io/channel-file.c
> index da17d0a11ba7..d84a6737f2f7 100644
> --- a/io/channel-file.c
> +++ b/io/channel-file.c
> @@ -35,6 +35,7 @@ qio_channel_file_new_fd(int fd)
>
> ioc->fd = fd;
>
> + qio_channel_set_feature(QIO_CHANNEL(ioc), QIO_CHANNEL_FEATURE_SEEKABLE);
> trace_qio_channel_file_new_fd(ioc, fd);
>
> return ioc;
> @@ -59,6 +60,10 @@ qio_channel_file_new_path(const char *path,
> return NULL;
> }
>
> + if (lseek(ioc->fd, 0, SEEK_CUR) != (off_t)-1) {
> + qio_channel_set_feature(QIO_CHANNEL(ioc),
> QIO_CHANNEL_FEATURE_SEEKABLE);
> + }
> +
> trace_qio_channel_file_new_path(ioc, path, flags, mode, ioc->fd);
Wondering why you do the lseek() sanitytest for only one of the
two constructors ? Shouldn't we do it for both ?
With regards,
Daniel
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