[PATCH 7/7] libvhost-user: rename struct VuDev fields from "slave" to "backend"

[Paolo Bonzini <pbonzini@redhat.com>]

Technically these are parts of the API, but the file descriptor seems
to be managed by libvhost-user itself only.

Nevertheless, I am keeping this as a separate change.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 subprojects/libvhost-user/libvhost-user.c | 46 +++++++++++------------
 subprojects/libvhost-user/libvhost-user.h |  6 +--
 2 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c
index b7aef17e4e..53fa8b8f38 100644
--- a/subprojects/libvhost-user/libvhost-user.c
+++ b/subprojects/libvhost-user/libvhost-user.c
@@ -400,8 +400,8 @@ vu_send_reply(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
 }
 
 /*
- * Processes a reply on the slave channel.
- * Entered with slave_mutex held and releases it before exit.
+ * Processes a reply from the frontend on the backend channel.
+ * Entered with backend_mutex held and releases it before exit.
  * Returns true on success.
  */
 static bool
@@ -415,7 +415,7 @@ vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg)
         goto out;
     }
 
-    if (!vu_message_read_default(dev, dev->slave_fd, &msg_reply)) {
+    if (!vu_message_read_default(dev, dev->backend_fd, &msg_reply)) {
         goto out;
     }
 
@@ -428,7 +428,7 @@ vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg)
     result = msg_reply.payload.u64 == 0;
 
 out:
-    pthread_mutex_unlock(&dev->slave_mutex);
+    pthread_mutex_unlock(&dev->backend_mutex);
     return result;
 }
 
@@ -1335,13 +1335,13 @@ bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd,
         return false;
     }
 
-    pthread_mutex_lock(&dev->slave_mutex);
-    if (!vu_message_write(dev, dev->slave_fd, &vmsg)) {
-        pthread_mutex_unlock(&dev->slave_mutex);
+    pthread_mutex_lock(&dev->backend_mutex);
+    if (!vu_message_write(dev, dev->backend_fd, &vmsg)) {
+        pthread_mutex_unlock(&dev->backend_mutex);
         return false;
     }
 
-    /* Also unlocks the slave_mutex */
+    /* Also unlocks the backend_mutex */
     return vu_process_message_reply(dev, &vmsg);
 }
 
@@ -1492,18 +1492,18 @@ vu_set_vring_enable_exec(VuDev *dev, VhostUserMsg *vmsg)
 }
 
 static bool
-vu_set_slave_req_fd(VuDev *dev, VhostUserMsg *vmsg)
+vu_set_backend_req_fd(VuDev *dev, VhostUserMsg *vmsg)
 {
     if (vmsg->fd_num != 1) {
-        vu_panic(dev, "Invalid slave_req_fd message (%d fd's)", vmsg->fd_num);
+        vu_panic(dev, "Invalid backend_req_fd message (%d fd's)", vmsg->fd_num);
         return false;
     }
 
-    if (dev->slave_fd != -1) {
-        close(dev->slave_fd);
+    if (dev->backend_fd != -1) {
+        close(dev->backend_fd);
     }
-    dev->slave_fd = vmsg->fds[0];
-    DPRINT("Got slave_fd: %d\n", vmsg->fds[0]);
+    dev->backend_fd = vmsg->fds[0];
+    DPRINT("Got backend_fd: %d\n", vmsg->fds[0]);
 
     return false;
 }
@@ -1865,7 +1865,7 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
     case VHOST_USER_SET_VRING_ENABLE:
         return vu_set_vring_enable_exec(dev, vmsg);
     case VHOST_USER_SET_BACKEND_REQ_FD:
-        return vu_set_slave_req_fd(dev, vmsg);
+        return vu_set_backend_req_fd(dev, vmsg);
     case VHOST_USER_GET_CONFIG:
         return vu_get_config(dev, vmsg);
     case VHOST_USER_SET_CONFIG:
@@ -1986,11 +1986,11 @@ vu_deinit(VuDev *dev)
     }
 
     vu_close_log(dev);
-    if (dev->slave_fd != -1) {
-        close(dev->slave_fd);
-        dev->slave_fd = -1;
+    if (dev->backend_fd != -1) {
+        close(dev->backend_fd);
+        dev->backend_fd = -1;
     }
-    pthread_mutex_destroy(&dev->slave_mutex);
+    pthread_mutex_destroy(&dev->backend_mutex);
 
     if (dev->sock != -1) {
         close(dev->sock);
@@ -2028,8 +2028,8 @@ vu_init(VuDev *dev,
     dev->remove_watch = remove_watch;
     dev->iface = iface;
     dev->log_call_fd = -1;
-    pthread_mutex_init(&dev->slave_mutex, NULL);
-    dev->slave_fd = -1;
+    pthread_mutex_init(&dev->backend_mutex, NULL);
+    dev->backend_fd = -1;
     dev->max_queues = max_queues;
 
     dev->vq = malloc(max_queues * sizeof(dev->vq[0]));
@@ -2387,9 +2387,9 @@ static void _vu_queue_notify(VuDev *dev, VuVirtq *vq, bool sync)
             vmsg.flags |= VHOST_USER_NEED_REPLY_MASK;
         }
 
-        vu_message_write(dev, dev->slave_fd, &vmsg);
+        vu_message_write(dev, dev->backend_fd, &vmsg);
         if (ack) {
-            vu_message_read_default(dev, dev->slave_fd, &vmsg);
+            vu_message_read_default(dev, dev->backend_fd, &vmsg);
         }
         return;
     }
diff --git a/subprojects/libvhost-user/libvhost-user.h b/subprojects/libvhost-user/libvhost-user.h
index eba3e1fc05..f29cbf4754 100644
--- a/subprojects/libvhost-user/libvhost-user.h
+++ b/subprojects/libvhost-user/libvhost-user.h
@@ -397,9 +397,9 @@ struct VuDev {
     VuVirtq *vq;
     VuDevInflightInfo inflight_info;
     int log_call_fd;
-    /* Must be held while using slave_fd */
-    pthread_mutex_t slave_mutex;
-    int slave_fd;
+    /* Must be held while using backend */
+    pthread_mutex_t backend_mutex;
+    int backend_fd;
     uint64_t log_size;
     uint8_t *log_table;
     uint64_t features;
-- 
2.26.2