[v14,RESEND,08/21] multi-process: add qio channel write function

Commit Message

Elena Ufimtseva Dec. 18, 2020, 5:40 a.m. UTC

From: Elena Ufimtseva <[e-mail]>

Adds qio_channel_writev_full_all() to transmit both data and FDs.
Refactors existing code to use this function.

Signed-off-by: Elena Ufimtseva <[e-mail]>
Signed-off-by: John G Johnson <[e-mail]>
Signed-off-by: Jagannathan Raman <[e-mail]>
---
 include/io/channel.h | 25 +++++++++++++++++++++++++
 io/channel.c         | 17 ++++++++++++++++-
 2 files changed, 41 insertions(+), 1 deletion(-)

Comments

Stefan Hajnoczi Dec. 22, 2020, 10:24 a.m. UTC | #1

On Thu, Dec 17, 2020 at 09:40:38PM -0800, [e-mail] wrote:
> From: Elena Ufimtseva <[e-mail]>
> 
> Adds qio_channel_writev_full_all() to transmit both data and FDs.
> Refactors existing code to use this function.
> 
> Signed-off-by: Elena Ufimtseva <[e-mail]>
> Signed-off-by: John G Johnson <[e-mail]>
> Signed-off-by: Jagannathan Raman <[e-mail]>
> ---
>  include/io/channel.h | 25 +++++++++++++++++++++++++
>  io/channel.c         | 17 ++++++++++++++++-
>  2 files changed, 41 insertions(+), 1 deletion(-)

Reviewed-by: Stefan Hajnoczi <[e-mail]>

Patch

diff --git a/include/io/channel.h b/include/io/channel.h
index 4d6fe45f63..2378567d4b 100644
--- a/include/io/channel.h
+++ b/include/io/channel.h
@@ -774,4 +774,29 @@  void qio_channel_set_aio_fd_handler(QIOChannel *ioc,
                                     IOHandler *io_write,
                                     void *opaque);
 
+/**
+ * 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 93d449dee2..bde1f6d0f4 100644
--- a/io/channel.c
+++ b/io/channel.c
@@ -156,11 +156,22 @@  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 +179,8 @@  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 +194,9 @@  int qio_channel_writev_all(QIOChannel *ioc,
         }
 
         iov_discard_front(&local_iov, &nlocal_iov, len);
+
+        local_fds = NULL;
+        local_nfds = 0;
     }
 
     ret = 0;