1nbd_aio_block_status(3)             LIBNBD             nbd_aio_block_status(3)
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3
4

NAME

6       nbd_aio_block_status - send block status command to the NBD server
7

SYNOPSIS

9        #include <libnbd.h>
10
11        typedef struct {
12          int (*callback) (void *user_data,
13                           const char *metacontext,
14                           uint64_t offset, uint32_t *entries,
15                           size_t nr_entries, int *error);
16          void *user_data;
17          void (*free) (void *user_data);
18        } nbd_extent_callback;
19
20        typedef struct {
21          int (*callback) (void *user_data, int *error);
22          void *user_data;
23          void (*free) (void *user_data);
24        } nbd_completion_callback;
25
26        int64_t nbd_aio_block_status (struct nbd_handle *h,
27                                      uint64_t count,
28                                      uint64_t offset,
29                                      nbd_extent_callback extent_callback,
30                                      nbd_completion_callback completion_callback,
31                                      uint32_t flags);
32

DESCRIPTION

34       Send the block status command to the NBD server.
35
36       To check if the command completed, call nbd_aio_command_completed(3).
37       Or supply the optional "completion_callback" which will be invoked as
38       described in "Completion callbacks" in libnbd(3).
39
40       Other parameters behave as documented in nbd_block_status(3).
41
42       By default, libnbd will reject attempts to use this function with
43       parameters that are likely to result in server failure, such as
44       requesting an unknown command flag.  The nbd_set_strict_mode(3)
45       function can be used to alter which scenarios should await a server
46       reply rather than failing fast.
47

RETURN VALUE

49       This call returns the 64 bit cookie of the command.  The cookie is ≥ 1.
50       Cookies are unique (per libnbd handle, not globally).
51

ERRORS

53       On error "-1" is returned.
54
55       Refer to "ERROR HANDLING" in libnbd(3) for how to get further details
56       of the error.
57

HANDLE STATE

59       The handle must be connected with the server, otherwise this call will
60       return an error.
61

VERSION

63       This function first appeared in libnbd 1.0.
64
65       If you need to test if this function is available at compile time check
66       if the following macro is defined:
67
68        #define LIBNBD_HAVE_NBD_AIO_BLOCK_STATUS 1
69

SEE ALSO

71       nbd_aio_command_completed(3), nbd_block_status(3),
72       nbd_can_meta_context(3), nbd_create(3), nbd_set_strict_mode(3),
73       "Issuing asynchronous commands" in libnbd(3), libnbd(3).
74

AUTHORS

76       Eric Blake
77
78       Richard W.M. Jones
79

81       Copyright (C) 2019-2021 Red Hat Inc.
82

LICENSE

84       This library is free software; you can redistribute it and/or modify it
85       under the terms of the GNU Lesser General Public License as published
86       by the Free Software Foundation; either version 2 of the License, or
87       (at your option) any later version.
88
89       This library is distributed in the hope that it will be useful, but
90       WITHOUT ANY WARRANTY; without even the implied warranty of
91       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
92       Lesser General Public License for more details.
93
94       You should have received a copy of the GNU Lesser General Public
95       License along with this library; if not, write to the Free Software
96       Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
97       02110-1301 USA
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101libnbd-1.7.12                     2021-05-29           nbd_aio_block_status(3)
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