From: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Adds qio_channel_readv_full_all_eof() and qio_channel_readv_full_all()
to read both data and FDs. Refactors existing code to use these helpers.
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Acked-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: b059c4cc0fb741e794d644c144cc21372cad877d.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
include/io/channel.h | 53 +++++++++++++++++++++++
io/channel.c | 101 ++++++++++++++++++++++++++++++++++---------
2 files changed, 134 insertions(+), 20 deletions(-)
diff --git a/include/io/channel.h b/include/io/channel.h
index 19e76fc32f..88988979f8 100644
@@ -777,6 +777,59 @@ void qio_channel_set_aio_fd_handler(QIOChannel *ioc,
IOHandler *io_write,
void *opaque);
+/**
+ * qio_channel_readv_full_all_eof:
+ * @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
+ *
+ *
+ * Performs same function as qio_channel_readv_all_eof.
+ * Additionally, attempts to read file descriptors shared
+ * over the channel. The function will wait for all
+ * requested data to be read, yielding from the current
+ * coroutine if required. data refers to both file
+ * descriptors and the iovs.
+ *
+ * Returns: 1 if all bytes were read, 0 if end-of-file
+ * occurs without data, or -1 on error
+ */
+
+int qio_channel_readv_full_all_eof(QIOChannel *ioc,
+ const struct iovec *iov,
+ size_t niov,
+ int **fds, size_t *nfds,
+ Error **errp);
+
+/**
+ * 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
+ *
+ *
+ * Performs same function as qio_channel_readv_all_eof.
+ * Additionally, attempts to read file descriptors shared
+ * over the channel. The function will wait for all
+ * requested data to be read, yielding from the current
+ * coroutine if required. data refers to both file
+ * descriptors and the iovs.
+ *
+ * Returns: 0 if all bytes were read, or -1 on error
+ */
+
+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 0d4b8b5160..4555021b62 100644
@@ -91,20 +91,48 @@ int qio_channel_readv_all_eof(QIOChannel *ioc,
const struct iovec *iov,
size_t niov,
Error **errp)
+{
+ return qio_channel_readv_full_all_eof(ioc, iov, niov, NULL, NULL, errp);
+}
+
+int qio_channel_readv_all(QIOChannel *ioc,
+ const struct iovec *iov,
+ size_t niov,
+ Error **errp)
+{
+ return qio_channel_readv_full_all(ioc, iov, niov, NULL, NULL, errp);
+}
+
+int qio_channel_readv_full_all_eof(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;
+ if (nfds) {
+ *nfds = 0;
+ }
+
+ if (fds) {
+ *fds = NULL;
+ }
+
nlocal_iov = iov_copy(local_iov, nlocal_iov,
iov, niov,
0, iov_size(iov, niov));
- while (nlocal_iov > 0) {
+ while ((nlocal_iov > 0) || local_fds) {
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 +140,50 @@ 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");
- } else {
+ }
+
+ if (len == 0) {
+ if (local_nfds && *local_nfds) {
+ /*
+ * Got some FDs, but no data yet. This isn't an EOF
+ * scenario (yet), so carry on to try to read data
+ * on next loop iteration
+ */
+ goto next_iter;
+ } else if (!partial) {
+ /* No fds and no data - EOF before any data read */
ret = 0;
+ goto cleanup;
+ } else {
+ len = -1;
+ error_setg(errp,
+ "Unexpected end-of-file before all data were read");
+ /* Fallthrough into len < 0 handling */
+ }
+ }
+
+ if (len < 0) {
+ /* Close any FDs we previously received */
+ if (nfds && fds) {
+ size_t i;
+ for (i = 0; i < (*nfds); i++) {
+ close((*fds)[i]);
+ }
+ g_free(*fds);
+ *fds = NULL;
+ *nfds = 0;
}
goto cleanup;
}
+ if (nlocal_iov) {
+ iov_discard_front(&local_iov, &nlocal_iov, len);
+ }
+
+next_iter:
partial = true;
- iov_discard_front(&local_iov, &nlocal_iov, len);
+ local_fds = NULL;
+ local_nfds = NULL;
}
ret = 1;
@@ -135,20 +193,23 @@ 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 qio_channel_readv_full_all(QIOChannel *ioc,
+ const struct iovec *iov,
+ size_t niov,
+ int **fds, size_t *nfds,
+ Error **errp)
{
- int ret = qio_channel_readv_all_eof(ioc, iov, niov, errp);
+ int ret = qio_channel_readv_full_all_eof(ioc, iov, niov, fds, nfds, errp);
if (ret == 0) {
- ret = -1;
- error_setg(errp,
- "Unexpected end-of-file before all bytes were read");
- } else if (ret == 1) {
- ret = 0;
+ error_prepend(errp,
+ "Unexpected end-of-file before all data were read.");
+ return -1;
}
+ if (ret == 1) {
+ return 0;
+ }
+
return ret;
}
--
2.29.2