Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2019-02-04' into staging

nbd patches for 2019-02-04

- deprecate 'qemu-nbd --partition'
- preparation for NBD reconnect, including better logging of read errors

# gpg: Signature made Tue 05 Feb 2019 03:50:56 GMT
# gpg:                using RSA key A7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2019-02-04:
  block/nbd-client: rename read_reply_co to connection_co
  block/nbd-client: don't check ioc
  block/nbd-client: fix nbd_reply_chunk_iter_receive
  block/nbd-client: split connection from initialization
  block/nbd: move connection code from block/nbd to block/nbd-client
  block/nbd-client: split channel errors from export errors
  nbd: generalize usage of nbd_read
  qemu-nbd: Deprecate qemu-nbd --partition

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 30 insertions, 2 deletions

diff --git a/include/block/nbd.h b/include/block/nbd.h
index 4faf394e34..96cfb1d7d5 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -23,6 +23,7 @@
 #include "qapi/qapi-types-block.h"
 #include "io/channel-socket.h"
 #include "crypto/tlscreds.h"
+#include "qapi/error.h"
 
 /* Handshake phase structs - this struct is passed on the wire */
 
@@ -336,11 +337,38 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds,
  * Reads @size bytes from @ioc. Returns 0 on success.
  */
 static inline int nbd_read(QIOChannel *ioc, void *buffer, size_t size,
-                           Error **errp)
+                           const char *desc, Error **errp)
 {
-    return qio_channel_read_all(ioc, buffer, size, errp) < 0 ? -EIO : 0;
+    int ret = qio_channel_read_all(ioc, buffer, size, errp) < 0 ? -EIO : 0;
+
+    if (ret < 0) {
+        if (desc) {
+            error_prepend(errp, "Failed to read %s: ", desc);
+        }
+        return -1;
+    }
+
+    return 0;
+}
+
+#define DEF_NBD_READ_N(bits)                                            \
+static inline int nbd_read##bits(QIOChannel *ioc,                       \
+                                 uint##bits##_t *val,                   \
+                                 const char *desc, Error **errp)        \
+{                                                                       \
+    if (nbd_read(ioc, val, sizeof(*val), desc, errp) < 0) {             \
+        return -1;                                                      \
+    }                                                                   \
+    *val = be##bits##_to_cpu(*val);                                     \
+    return 0;                                                           \
 }
 
+DEF_NBD_READ_N(16) /* Defines nbd_read16(). */
+DEF_NBD_READ_N(32) /* Defines nbd_read32(). */
+DEF_NBD_READ_N(64) /* Defines nbd_read64(). */
+
+#undef DEF_NBD_READ_N
+
 static inline bool nbd_reply_is_simple(NBDReply *reply)
 {
     return reply->magic == NBD_SIMPLE_REPLY_MAGIC;