nbd: refactor tracing

Reorganize traces: move, reword, add information, drop extra ones.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170707152918.23086-10-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

nbd/client.c

@@ -489,12 +489,10 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
         TRACE("Global flags are %" PRIx32, globalflags);
         if (globalflags & NBD_FLAG_FIXED_NEWSTYLE) {
             fixedNewStyle = true;
-            TRACE("Server supports fixed new style");
             clientflags |= NBD_FLAG_C_FIXED_NEWSTYLE;
         }
         if (globalflags & NBD_FLAG_NO_ZEROES) {
             zeroes = false;
-            TRACE("Server supports no zeroes");
             clientflags |= NBD_FLAG_C_NO_ZEROES;
         }
         /* client requested flags */
@@ -565,7 +563,6 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
             goto fail;
         }
         *size = be64_to_cpu(s);
-        TRACE("Size is %" PRIu64, *size);
 
         if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) {
             error_prepend(errp, "Failed to read export flags");

nbd/server.c

@@ -1000,6 +1000,10 @@ static int nbd_co_send_reply(NBDRequestData *req, NBDReply *reply, int len,
     int ret;
 
     g_assert(qemu_in_coroutine());
+
+    TRACE("Send reply: handle = %" PRIu64 ", error = %" PRIu32 ", len = %d",
+          reply->handle, reply->error, len);
+
     qemu_co_mutex_lock(&client->send_lock);
     client->send_coroutine = qemu_coroutine_self();
 
@@ -1039,7 +1043,8 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request,
         return -EIO;
     }
 
-    TRACE("Decoding type");
+    TRACE("Decoding type: handle = %" PRIu64 ", type = %" PRIu16,
+          request->handle, request->type);
 
     if (request->type != NBD_CMD_WRITE) {
         /* No payload, we are ready to read the next request.  */
@@ -1049,7 +1054,6 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request,
     if (request->type == NBD_CMD_DISC) {
         /* Special case: we're going to disconnect without a reply,
          * whether or not flags, from, or len are bogus */
-        TRACE("Request type is DISCONNECT");
         return -EIO;
     }
 
@@ -1076,13 +1080,14 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request,
         }
     }
     if (request->type == NBD_CMD_WRITE) {
-        TRACE("Reading %" PRIu32 " byte(s)", request->len);
-
         if (nbd_read(client->ioc, req->data, request->len, errp) < 0) {
             error_prepend(errp, "reading from socket failed: ");
             return -EIO;
         }
         req->complete = true;
+
+        TRACE("Payload received: handle = %" PRIu64 ", len = %" PRIu32,
+              request->handle, request->len);
     }
 
     /* Sanity checks, part 2. */
@@ -1150,8 +1155,6 @@ static coroutine_fn void nbd_trip(void *opaque)
 
     switch (request.type) {
     case NBD_CMD_READ:
-        TRACE("Request type is READ");
-
         /* XXX: NBD Protocol only documents use of FUA with WRITE */
         if (request.flags & NBD_CMD_FLAG_FUA) {
             ret = blk_co_flush(exp->blk);
@@ -1171,20 +1174,14 @@ static coroutine_fn void nbd_trip(void *opaque)
         }
 
         reply_data_len = request.len;
-        TRACE("Read %" PRIu32" byte(s)", request.len);
 
         break;
     case NBD_CMD_WRITE:
-        TRACE("Request type is WRITE");
-
         if (exp->nbdflags & NBD_FLAG_READ_ONLY) {
-            TRACE("Server is read-only, return error");
             reply.error = EROFS;
             break;
         }
 
-        TRACE("Writing to device");
-
         flags = 0;
         if (request.flags & NBD_CMD_FLAG_FUA) {
             flags |= BDRV_REQ_FUA;
@@ -1198,16 +1195,12 @@ static coroutine_fn void nbd_trip(void *opaque)
 
         break;
     case NBD_CMD_WRITE_ZEROES:
-        TRACE("Request type is WRITE_ZEROES");
-
         if (exp->nbdflags & NBD_FLAG_READ_ONLY) {
             error_setg(&local_err, "Server is read-only, return error");
             reply.error = EROFS;
             break;
         }
 
-        TRACE("Writing to device");
-
         flags = 0;
         if (request.flags & NBD_CMD_FLAG_FUA) {
             flags |= BDRV_REQ_FUA;
@@ -1228,8 +1221,6 @@ static coroutine_fn void nbd_trip(void *opaque)
         abort();
 
     case NBD_CMD_FLUSH:
-        TRACE("Request type is FLUSH");
-
         ret = blk_co_flush(exp->blk);
         if (ret < 0) {
             error_setg_errno(&local_err, -ret, "flush failed");
@@ -1238,7 +1229,6 @@ static coroutine_fn void nbd_trip(void *opaque)
 
         break;
     case NBD_CMD_TRIM:
-        TRACE("Request type is TRIM");
         ret = blk_co_pdiscard(exp->blk, request.from + exp->dev_offset,
                               request.len);
         if (ret < 0) {
@@ -1274,8 +1264,6 @@ static coroutine_fn void nbd_trip(void *opaque)
         goto disconnect;
     }
 
-    TRACE("Request/Reply complete");
-
 done:
     nbd_request_put(req);
     nbd_client_put(client);