nbd_aio_opt_structured_reply - Man Page

request the server to enable structured replies

Synopsis

 #include <libnbd.h>

 typedef struct {
   int (*callback) (void *user_data, int *error);
   void *user_data;
   void (*free) (void *user_data);
 } nbd_completion_callback;

 int nbd_aio_opt_structured_reply (struct nbd_handle *h,
                                   nbd_completion_callback completion_callback);

Description

Request that the server use structured replies, by sending NBD_OPT_STRUCTURED_REPLY.  This behaves like the synchronous counterpart nbd_opt_structured_reply(3), except that it does not wait for the server's response.

To determine when the request completes, wait for nbd_aio_is_connecting(3) to return false.  Or supply the optional completion_callback which will be invoked as described in “Completion callbacks” in libnbd(3), except that it is automatically retired regardless of return value.  Note that detecting whether the server returns an error (as is done by the return value of the synchronous counterpart) is only possible with a completion callback.

Return Value

If the call is successful the function returns 0.

Errors

On error -1 is returned.

Refer to “ERROR HANDLING” in libnbd(3) for how to get further details of the error.

The following parameters must not be NULL: h. For more information see “Non-NULL parameters” in libnbd(3).

Handle State

The handle must be negotiating, otherwise this call will return an error.

Version

This function first appeared in libnbd 1.16.

If you need to test if this function is available at compile time check if the following macro is defined:

 #define LIBNBD_HAVE_NBD_AIO_OPT_STRUCTURED_REPLY 1

See Also

nbd_aio_is_connecting(3), nbd_create(3), nbd_opt_structured_reply(3), nbd_set_opt_mode(3), libnbd(3).

Authors

Eric Blake

Richard W.M. Jones

License

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

Referenced By

libnbd(3), nbd_opt_structured_reply(3).

2022-11-03 libnbd-1.15.7