@@ -89,6 +89,11 @@ qio_channel_file_new_path(const char *path,
mode_t mode,
Error **errp);
+ssize_t qio_channel_file_preadv(QIOChannel *ioc,
+ const struct iovec *iov,
+ size_t niov,
+ off_t offset,
+ Error **errp);
ssize_t qio_channel_file_pwritev(QIOChannel *ioc,
const struct iovec *iov,
size_t niov,
@@ -141,6 +141,32 @@ static ssize_t qio_channel_file_writev(QIOChannel *ioc,
return ret;
}
+ssize_t qio_channel_file_preadv(QIOChannel *ioc,
+ const struct iovec *iov,
+ size_t niov,
+ off_t offset,
+ Error **errp)
+{
+ QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+ ssize_t ret;
+
+ retry:
+ ret = preadv(fioc->fd, iov, niov, offset);
+ if (ret < 0) {
+ if (errno == EAGAIN) {
+ return QIO_CHANNEL_ERR_BLOCK;
+ }
+ if (errno == EINTR) {
+ goto retry;
+ }
+
+ error_setg_errno(errp, errno, "Unable to read from file");
+ return -1;
+ }
+
+ return ret;
+}
+
ssize_t qio_channel_file_pwritev(QIOChannel *ioc,
const struct iovec *iov,
size_t niov,
preadv is going to be needed when 'fixed-ram'-enabled stream are to be restored. Simply add a wrapper around preadv that's specific to QIOChannelFile. Signed-off-by: Nikolay Borisov <nborisov@suse.com> --- include/io/channel-file.h | 5 +++++ io/channel-file.c | 26 ++++++++++++++++++++++++++ 2 files changed, 31 insertions(+)