1nbd_aio_pwrite(3)                   LIBNBD                   nbd_aio_pwrite(3)
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NAME

6       nbd_aio_pwrite - write 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_pwrite (
18                  struct nbd_handle *h, const void *buf,
19                  size_t count, uint64_t offset,
20                  nbd_completion_callback completion_callback,
21                  uint32_t flags
22                );
23

DESCRIPTION

25       Issue a write command to the NBD server.
26
27       To check if the command completed, call nbd_aio_command_completed(3).
28       Or supply the optional "completion_callback" which will be invoked as
29       described in "Completion callbacks" in libnbd(3).
30
31       Note that you must ensure "buf" is valid until the command has
32       completed.  Other parameters behave as documented in nbd_pwrite(3).
33
34       By default, libnbd will reject attempts to use this function with
35       parameters that are likely to result in server failure, such as
36       requesting an unknown command flag.  The nbd_set_strict_mode(3)
37       function can be used to alter which scenarios should await a server
38       reply rather than failing fast.
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RETURN VALUE

41       This call returns the 64 bit cookie of the command.  The cookie is ≥ 1.
42       Cookies are unique (per libnbd handle, not globally).
43

ERRORS

45       On error -1 is returned.
46
47       Refer to "ERROR HANDLING" in libnbd(3) for how to get further details
48       of the error.
49
50       The following parameters must not be NULL: "h", "buf".  For more
51       information see "Non-NULL parameters" in libnbd(3).
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HANDLE STATE

54       The handle must be connected with the server, otherwise this call will
55       return an error.
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VERSION

58       This function first appeared in libnbd 1.0.
59
60       If you need to test if this function is available at compile time check
61       if the following macro is defined:
62
63        #define LIBNBD_HAVE_NBD_AIO_PWRITE 1
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SEE ALSO

66       nbd_aio_command_completed(3), nbd_create(3), nbd_is_read_only(3),
67       nbd_pwrite(3), nbd_set_strict_mode(3), "Issuing asynchronous commands"
68       in libnbd(3), libnbd(3).
69

AUTHORS

71       Eric Blake
72
73       Richard W.M. Jones
74

76       Copyright Red Hat
77

LICENSE

79       This library is free software; you can redistribute it and/or modify it
80       under the terms of the GNU Lesser General Public License as published
81       by the Free Software Foundation; either version 2 of the License, or
82       (at your option) any later version.
83
84       This library is distributed in the hope that it will be useful, but
85       WITHOUT ANY WARRANTY; without even the implied warranty of
86       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
87       Lesser General Public License for more details.
88
89       You should have received a copy of the GNU Lesser General Public
90       License along with this library; if not, write to the Free Software
91       Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
92       02110-1301 USA
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96libnbd-1.16.5                     2023-09-26                 nbd_aio_pwrite(3)
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