virtio-blk: use blk_io_plug/unplug for Linux AIO batching

[qemu.git] / nbd.c

diff --git a/nbd.c b/nbd.c
index cb1b9bbf7c6063e8e4c05b199cd94dacb5c55b98..07240bd3e301e5b043d4c7b9e504036d76b80034 100644 (file)
--- a/nbd.c
+++ b/nbd.c
@@ -86,6 +86,59 @@
 #define NBD_OPT_ABORT           (2)
 #define NBD_OPT_LIST            (3)
 
+/* NBD errors are based on errno numbers, so there is a 1:1 mapping,
+ * but only a limited set of errno values is specified in the protocol.
+ * Everything else is squashed to EINVAL.
+ */
+#define NBD_SUCCESS    0
+#define NBD_EPERM      1
+#define NBD_EIO        5
+#define NBD_ENOMEM     12
+#define NBD_EINVAL     22
+#define NBD_ENOSPC     28
+
+static int system_errno_to_nbd_errno(int err)
+{
+    switch (err) {
+    case 0:
+        return NBD_SUCCESS;
+    case EPERM:
+        return NBD_EPERM;
+    case EIO:
+        return NBD_EIO;
+    case ENOMEM:
+        return NBD_ENOMEM;
+#ifdef EDQUOT
+    case EDQUOT:
+#endif
+    case EFBIG:
+    case ENOSPC:
+        return NBD_ENOSPC;
+    case EINVAL:
+    default:
+        return NBD_EINVAL;
+    }
+}
+
+static int nbd_errno_to_system_errno(int err)
+{
+    switch (err) {
+    case NBD_SUCCESS:
+        return 0;
+    case NBD_EPERM:
+        return EPERM;
+    case NBD_EIO:
+        return EIO;
+    case NBD_ENOMEM:
+        return ENOMEM;
+    case NBD_ENOSPC:
+        return ENOSPC;
+    case NBD_EINVAL:
+    default:
+        return EINVAL;
+    }
+}
+
 /* Definitions for opaque data types */
 
 typedef struct NBDRequest NBDRequest;
@@ -856,6 +909,8 @@ ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply)
     reply->error  = be32_to_cpup((uint32_t*)(buf + 4));
     reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
 
+    reply->error = nbd_errno_to_system_errno(reply->error);
+
     TRACE("Got reply: "
           "{ magic = 0x%x, .error = %d, handle = %" PRIu64" }",
           magic, reply->error, reply->handle);
@@ -872,6 +927,8 @@ static ssize_t nbd_send_reply(int csock, struct nbd_reply *reply)
     uint8_t buf[NBD_REPLY_SIZE];
     ssize_t ret;
 
+    reply->error = system_errno_to_nbd_errno(reply->error);
+
     /* Reply
        [ 0 ..  3]    magic   (NBD_REPLY_MAGIC)
        [ 4 ..  7]    error   (0 == no error)
@@ -1074,12 +1131,6 @@ void nbd_export_close(NBDExport *exp)
     }
     nbd_export_set_name(exp, NULL);
     nbd_export_put(exp);
-    if (exp->blk) {
-        blk_remove_aio_context_notifier(exp->blk, blk_aio_attached,
-                                        blk_aio_detach, exp);
-        blk_unref(exp->blk);
-        exp->blk = NULL;
-    }
 }
 
 void nbd_export_get(NBDExport *exp)
@@ -1102,6 +1153,13 @@ void nbd_export_put(NBDExport *exp)
             exp->close(exp);
         }
 
+        if (exp->blk) {
+            blk_remove_aio_context_notifier(exp->blk, blk_aio_attached,
+                                            blk_aio_detach, exp);
+            blk_unref(exp->blk);
+            exp->blk = NULL;
+        }
+
         g_free(exp);
     }
 }
@@ -1248,6 +1306,14 @@ static void nbd_trip(void *opaque)
         goto invalid_request;
     }
 
+    if (client->closing) {
+        /*
+         * The client may be closed when we are blocked in
+         * nbd_co_receive_request()
+         */
+        goto done;
+    }
+
     switch (command) {
     case NBD_CMD_READ:
         TRACE("Request type is READ");