nbd: Create struct for tracking export info

The NBD Protocol is introducing some additional information
about exports, such as minimum request size and alignment, as
well as an advertised maximum request size.  It will be easier
to feed this information back to the block layer if we gather
all the information into a struct, rather than adding yet more
pointer parameters during negotiation.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170707203049.534-2-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 4 insertions, 6 deletions

diff --git a/qemu-nbd.c b/qemu-nbd.c
index 4dd3fd4732..c8bd47fe77 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -255,8 +255,7 @@ static void *show_parts(void *arg)
 static void *nbd_client_thread(void *arg)
 {
     char *device = arg;
-    off_t size;
-    uint16_t nbdflags;
+    NBDExportInfo info;
     QIOChannelSocket *sioc;
     int fd;
     int ret;
@@ -271,9 +270,8 @@ static void *nbd_client_thread(void *arg)
         goto out;
     }
 
-    ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL, &nbdflags,
-                                NULL, NULL, NULL,
-                                &size, &local_error);
+    ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL,
+                                NULL, NULL, NULL, &info, &local_error);
     if (ret < 0) {
         if (local_error) {
             error_report_err(local_error);
@@ -288,7 +286,7 @@ static void *nbd_client_thread(void *arg)
         goto out_socket;
     }
 
-    ret = nbd_init(fd, sioc, nbdflags, size, &local_error);
+    ret = nbd_init(fd, sioc, &info, &local_error);
     if (ret < 0) {
         error_report_err(local_error);
         goto out_fd;