1nbd_aio_zero(3)                     LIBNBD                     nbd_aio_zero(3)
2
3
4

NAME

6       nbd_aio_zero - send write zeroes command to the NBD server
7

SYNOPSIS

9        #include <libnbd.h>
10
11        typedef struct {
12          int (*callback) (void *user_data, int *error);
13          void *user_data;
14          void (*free) (void *user_data);
15        } nbd_completion_callback;
16
17        int64_t nbd_aio_zero (struct nbd_handle *h, uint64_t count,
18                              uint64_t offset,
19                              nbd_completion_callback completion_callback,
20                              uint32_t flags);
21

DESCRIPTION

23       Issue a write zeroes command to the NBD server.
24
25       To check if the command completed, call nbd_aio_command_completed(3).
26       Or supply the optional "completion_callback" which will be invoked as
27       described in "Completion callbacks" in libnbd(3).
28
29       Other parameters behave as documented in nbd_zero(3).
30

RETURN VALUE

32       This call returns the 64 bit cookie of the command.  The cookie is ≥ 1.
33       Cookies are unique (per libnbd handle, not globally).
34

ERRORS

36       On error "-1" is returned.
37
38       Refer to "ERROR HANDLING" in libnbd(3) for how to get further details
39       of the error.
40

HANDLE STATE

42       The handle must be connected and finished handshaking with the server,
43       otherwise this call will return an error.
44

VERSION

46       This function first appeared in libnbd 1.0.
47
48       If you need to test if this function is available at compile time check
49       if the following macro is defined:
50
51        #define LIBNBD_HAVE_NBD_AIO_ZERO 1
52

SEE ALSO

54       nbd_aio_command_completed(3), nbd_can_fast_zero(3), nbd_can_zero(3),
55       nbd_create(3), nbd_zero(3), "Issuing asynchronous commands" in
56       libnbd(3), libnbd(3).
57

AUTHORS

59       Eric Blake
60
61       Richard W.M. Jones
62

64       Copyright (C) 2019 Red Hat Inc.
65

LICENSE

67       This library is free software; you can redistribute it and/or modify it
68       under the terms of the GNU Lesser General Public License as published
69       by the Free Software Foundation; either version 2 of the License, or
70       (at your option) any later version.
71
72       This library is distributed in the hope that it will be useful, but
73       WITHOUT ANY WARRANTY; without even the implied warranty of
74       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
75       Lesser General Public License for more details.
76
77       You should have received a copy of the GNU Lesser General Public
78       License along with this library; if not, write to the Free Software
79       Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
80       02110-1301 USA
81
82
83
84libnbd-1.3.7                      2020-04-23                   nbd_aio_zero(3)
Impressum