From 694d818a8c99b68700c7e505e6f65612ceb5ec6a Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Fri, 28 Oct 2022 13:39:06 +0300 Subject: [PATCH] io: add and implement QIO_CHANNEL_FEATURE_SEEKABLE for channel file MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add a generic QIOChannel feature SEEKABLE which would be used by the qemu_file* apis. For the time being this will be only implemented for file channels. Signed-off-by: Nikolay Borisov Signed-off-by: Fabiano Rosas Reviewed-by: Daniel P. Berrangé --- include/io/channel.h | 1 + io/channel-file.c | 8 ++++++++ 2 files changed, 9 insertions(+) diff --git a/include/io/channel.h b/include/io/channel.h index 5f9dbaab65..fcb19fd672 100644 --- a/include/io/channel.h +++ b/include/io/channel.h @@ -44,6 +44,7 @@ enum QIOChannelFeature { QIO_CHANNEL_FEATURE_LISTEN, QIO_CHANNEL_FEATURE_WRITE_ZERO_COPY, QIO_CHANNEL_FEATURE_READ_MSG_PEEK, + QIO_CHANNEL_FEATURE_SEEKABLE, }; diff --git a/io/channel-file.c b/io/channel-file.c index 4a12c61886..f91bf6db1c 100644 --- a/io/channel-file.c +++ b/io/channel-file.c @@ -36,6 +36,10 @@ qio_channel_file_new_fd(int fd) ioc->fd = fd; + if (lseek(fd, 0, SEEK_CUR) != (off_t)-1) { + qio_channel_set_feature(QIO_CHANNEL(ioc), QIO_CHANNEL_FEATURE_SEEKABLE); + } + trace_qio_channel_file_new_fd(ioc, fd); return ioc; @@ -60,6 +64,10 @@ 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); return ioc;