qemu-nbd: print error messages from the daemon through a pipe

[qemu.git] / nbd.c

diff --git a/nbd.c b/nbd.c
index 47ecb2234b2647cfd5783a1354299a70d90271b8..e6c931c5ceed95387dd7455bfb2110a23a96caf7 100644 (file)
--- a/nbd.c
+++ b/nbd.c
@@ -67,6 +67,8 @@
 #define NBD_PRINT_DEBUG         _IO(0xab, 6)
 #define NBD_SET_SIZE_BLOCKS     _IO(0xab, 7)
 #define NBD_DISCONNECT          _IO(0xab, 8)
+#define NBD_SET_TIMEOUT         _IO(0xab, 9)
+#define NBD_SET_FLAGS           _IO(0xab, 10)
 
 #define NBD_OPT_EXPORT_NAME     (1 << 0)
 
@@ -376,6 +378,14 @@ int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize)
         }
     }
 
+    if (ioctl(fd, NBD_SET_FLAGS, flags) < 0
+        && errno != ENOTTY) {
+        int serrno = errno;
+        LOG("Failed setting flags");
+        errno = serrno;
+        return -1;
+    }
+
     TRACE("Clearing NBD socket");
 
     if (ioctl(fd, NBD_CLEAR_SOCK) == -1) {
@@ -415,6 +425,13 @@ int nbd_client(int fd)
     TRACE("Doing NBD loop");
 
     ret = ioctl(fd, NBD_DO_IT);
+    if (ret == -1 && errno == EPIPE) {
+        /* NBD_DO_IT normally returns EPIPE when someone has disconnected
+         * the socket via NBD_DISCONNECT.  We do not want to return 1 in
+         * that case.
+         */
+        ret = 0;
+    }
     serrno = errno;
 
     TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
@@ -429,7 +446,7 @@ int nbd_client(int fd)
     return ret;
 }
 #else
-int nbd_init(int fd, int csock, off_t size, size_t blocksize)
+int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize)
 {
     errno = ENOTSUP;
     return -1;