1nbd_can_meta_context(3)             LIBNBD             nbd_can_meta_context(3)
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NAME

6       nbd_can_meta_context - does the server support a specific meta context?
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SYNOPSIS

9        #include <libnbd.h>
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11        int nbd_can_meta_context (struct nbd_handle *h,
12                                  const char *metacontext);
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DESCRIPTION

15       Returns true if the server supports the given meta context (see
16       nbd_add_meta_context(3)).  Returns false if the server does not.
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18       The single parameter is the name of the metadata context, for example
19       "LIBNBD_CONTEXT_BASE_ALLOCATION".  <libnbd.h> includes defined
20       constants for well-known namespace contexts beginning with
21       "LIBNBD_CONTEXT_", but you are free to pass in other contexts.
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23       This call does not block, because it returns data that is saved in the
24       handle from the NBD protocol handshake.
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RETURN VALUE

27       This call returns a boolean value.
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ERRORS

30       On error "-1" is returned.
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32       Refer to "ERROR HANDLING" in libnbd(3) for how to get further details
33       of the error.
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HANDLE STATE

36       The handle must be negotiating, or connected with the server, or shut
37       down, otherwise this call will return an error.
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VERSION

40       This function first appeared in libnbd 1.0.
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42       If you need to test if this function is available at compile time check
43       if the following macro is defined:
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45        #define LIBNBD_HAVE_NBD_CAN_META_CONTEXT 1
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SEE ALSO

48       nbd_add_meta_context(3), nbd_aio_block_status(3), nbd_block_status(3),
49       nbd_create(3), nbd_opt_info(3), "Flag calls" in libnbd(3), libnbd(3).
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AUTHORS

52       Eric Blake
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54       Richard W.M. Jones
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57       Copyright (C) 2019-2020 Red Hat Inc.
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LICENSE

60       This library is free software; you can redistribute it and/or modify it
61       under the terms of the GNU Lesser General Public License as published
62       by the Free Software Foundation; either version 2 of the License, or
63       (at your option) any later version.
64
65       This library is distributed in the hope that it will be useful, but
66       WITHOUT ANY WARRANTY; without even the implied warranty of
67       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
68       Lesser General Public License for more details.
69
70       You should have received a copy of the GNU Lesser General Public
71       License along with this library; if not, write to the Free Software
72       Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
73       02110-1301 USA
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77libnbd-1.6.2                      2021-03-02           nbd_can_meta_context(3)
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