migration: use migration_in_postcopy() to check POSTCOPY_ACTIVE

[mirror_qemu.git] / nbd / client.c

diff --git a/nbd/client.c b/nbd/client.c
index 10a52ad7d0c3bfb15616a937e713c9130001ec48..4de30630c73802b699ea795635c79bbf6d50cd1e 100644 (file)
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -426,6 +426,14 @@ static int nbd_opt_info_or_go(QIOChannel *ioc, uint32_t opt,
                 nbd_send_opt_abort(ioc);
                 return -1;
             }
+            if (info->min_block &&
+                !QEMU_IS_ALIGNED(info->size, info->min_block)) {
+                error_setg(errp, "export size %" PRIu64 " is not multiple of "
+                           "minimum block size %" PRIu32, info->size,
+                           info->min_block);
+                nbd_send_opt_abort(ioc);
+                return -1;
+            }
             trace_nbd_receive_negotiate_size_flags(info->size, info->flags);
             break;
 
@@ -1387,17 +1395,65 @@ static int nbd_receive_structured_reply_chunk(QIOChannel *ioc,
     return 0;
 }
 
+/* nbd_read_eof
+ * Tries to read @size bytes from @ioc.
+ * Returns 1 on success
+ *         0 on eof, when no data was read (errp is not set)
+ *         negative errno on failure (errp is set)
+ */
+static inline int coroutine_fn
+nbd_read_eof(BlockDriverState *bs, QIOChannel *ioc, void *buffer, size_t size,
+             Error **errp)
+{
+    bool partial = false;
+
+    assert(size);
+    while (size > 0) {
+        struct iovec iov = { .iov_base = buffer, .iov_len = size };
+        ssize_t len;
+
+        len = qio_channel_readv(ioc, &iov, 1, errp);
+        if (len == QIO_CHANNEL_ERR_BLOCK) {
+            bdrv_dec_in_flight(bs);
+            qio_channel_yield(ioc, G_IO_IN);
+            bdrv_inc_in_flight(bs);
+            continue;
+        } else if (len < 0) {
+            return -EIO;
+        } else if (len == 0) {
+            if (partial) {
+                error_setg(errp,
+                           "Unexpected end-of-file before all bytes were read");
+                return -EIO;
+            } else {
+                return 0;
+            }
+        }
+
+        partial = true;
+        size -= len;
+        buffer = (uint8_t*) buffer + len;
+    }
+    return 1;
+}
+
 /* nbd_receive_reply
+ *
+ * Decreases bs->in_flight while waiting for a new reply. This yield is where
+ * we wait indefinitely and the coroutine must be able to be safely reentered
+ * for nbd_client_attach_aio_context().
+ *
  * Returns 1 on success
  *         0 on eof, when no data was read (errp is not set)
  *         negative errno on failure (errp is set)
  */
-int nbd_receive_reply(QIOChannel *ioc, NBDReply *reply, Error **errp)
+int coroutine_fn nbd_receive_reply(BlockDriverState *bs, QIOChannel *ioc,
+                                   NBDReply *reply, Error **errp)
 {
     int ret;
     const char *type;
 
-    ret = nbd_read_eof(ioc, &reply->magic, sizeof(reply->magic), errp);
+    ret = nbd_read_eof(bs, ioc, &reply->magic, sizeof(reply->magic), errp);
     if (ret <= 0) {
         return ret;
     }