[PATCH v13 07/19] multi-process: add qio channel function to transmit data and fds

[Jagannathan Raman]

From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

Adds QIO channel functions that transmit and receive iovs along with fds.

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>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 include/io/channel.h | 50 +++++++++++++++++++++++++++++++++++++++++
 io/channel.c         | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 112 insertions(+), 1 deletion(-)

diff --git a/include/io/channel.h b/include/io/channel.h
index 4d6fe45..c2d9836 100644
--- a/include/io/channel.h
+++ b/include/io/channel.h
@@ -774,4 +774,54 @@ void qio_channel_set_aio_fd_handler(QIOChannel *ioc,
                                     IOHandler *io_write,
                                     void *opaque);
 
+/**
+ * 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
+ *
+ *
+ * Behaves like qio_channel_readvv_full but will attempt
+ * to read all data specified (file handles and memory regions).
+ * The function will wait for all requested data
+ * to be read, yielding from the current coroutine
+ * if required.
+ *
+ * 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
+ * @iov: the array of memory regions to write data from
+ * @niov: the length of the @iov array
+ * @fds: an array of file handles to send
+ * @nfds: number of file handles in @fds
+ * @errp: pointer to a NULL-initialized error object
+ *
+ *
+ * Behaves like qio_channel_writev_full but will attempt
+ * to send all data passed (file handles and memory regions).
+ * The function will wait for all requested data
+ * to be written, yielding from the current coroutine
+ * if required.
+ *
+ * Returns: 0 if all bytes were written, or -1 on error
+ */
+
+int qio_channel_writev_full_all(QIOChannel *ioc,
+                           const struct iovec *iov,
+                           size_t niov,
+                           int *fds, size_t nfds,
+                           Error **errp);
+
 #endif /* QIO_CHANNEL_H */
diff --git a/io/channel.c b/io/channel.c
index 93d449d..13b0e7a 100644
--- a/io/channel.c
+++ b/io/channel.c
@@ -152,15 +152,72 @@ int qio_channel_readv_all(QIOChannel *ioc,
     return ret;
 }
 
+int qio_channel_readv_full_all(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;
+
+    nlocal_iov = iov_copy(local_iov, nlocal_iov,
+                          iov, niov,
+                          0, iov_size(iov, niov));
+
+    while (nlocal_iov > 0) {
+        ssize_t len;
+        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_OUT);
+            } else {
+                qio_channel_wait(ioc, G_IO_OUT);
+            }
+            continue;
+        }
+        if (len <= 0) {
+            ret = len;
+            goto cleanup;
+        }
+
+        iov_discard_front(&local_iov, &nlocal_iov, len);
+
+        local_fds = NULL;
+        local_nfds = 0;
+    }
+
+    ret = 1;
+ cleanup:
+    g_free(local_iov_head);
+    return ret;
+}
+
 int qio_channel_writev_all(QIOChannel *ioc,
                            const struct iovec *iov,
                            size_t niov,
                            Error **errp)
 {
+    return qio_channel_writev_full_all(ioc, iov, niov, NULL, 0, errp);
+}
+
+int qio_channel_writev_full_all(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;
 
     nlocal_iov = iov_copy(local_iov, nlocal_iov,
                           iov, niov,
@@ -168,7 +225,8 @@ int qio_channel_writev_all(QIOChannel *ioc,
 
     while (nlocal_iov > 0) {
         ssize_t len;
-        len = qio_channel_writev(ioc, local_iov, nlocal_iov, errp);
+        len = qio_channel_writev_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_OUT);
@@ -182,6 +240,9 @@ int qio_channel_writev_all(QIOChannel *ioc,
         }
 
         iov_discard_front(&local_iov, &nlocal_iov, len);
+
+        local_fds = NULL;
+        local_nfds = 0;
     }
 
     ret = 0;
-- 
1.8.3.1