1nbd_get_nr_meta_contexts(3)         LIBNBD         nbd_get_nr_meta_contexts(3)
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NAME

6       nbd_get_nr_meta_contexts - return the current number of requested meta
7       contexts
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SYNOPSIS

10        #include <libnbd.h>
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12        ssize_t nbd_get_nr_meta_contexts (
13                  struct nbd_handle *h
14                );
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DESCRIPTION

17       During connection libnbd can negotiate zero or more metadata contexts
18       with the server.  Metadata contexts are features (such as
19       "base:allocation") which describe information returned by the
20       nbd_block_status(3) command (for "base:allocation" this is whether
21       blocks of data are allocated, zero or sparse).
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23       This command returns how many meta contexts have been added to the list
24       to request from the server via nbd_add_meta_context(3).  The server is
25       not obligated to honor all of the requests; to see what it actually
26       supports, see nbd_can_meta_context(3).
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RETURN VALUE

29       This call returns an integer size ≥ 0.
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ERRORS

32       On error -1 is returned.
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34       Refer to "ERROR HANDLING" in libnbd(3) for how to get further details
35       of the error.
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37       The following parameters must not be NULL: "h".  For more information
38       see "Non-NULL parameters" in libnbd(3).
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VERSION

41       This function first appeared in libnbd 1.6.
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43       If you need to test if this function is available at compile time check
44       if the following macro is defined:
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46        #define LIBNBD_HAVE_NBD_GET_NR_META_CONTEXTS 1
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SEE ALSO

49       nbd_add_meta_context(3), nbd_block_status(3), nbd_can_meta_context(3),
50       nbd_clear_meta_contexts(3), nbd_create(3), nbd_get_meta_context(3),
51       libnbd(3).
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AUTHORS

54       Eric Blake
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56       Richard W.M. Jones
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59       Copyright Red Hat
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LICENSE

62       This library is free software; you can redistribute it and/or modify it
63       under the terms of the GNU Lesser General Public License as published
64       by the Free Software Foundation; either version 2 of the License, or
65       (at your option) any later version.
66
67       This library is distributed in the hope that it will be useful, but
68       WITHOUT ANY WARRANTY; without even the implied warranty of
69       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
70       Lesser General Public License for more details.
71
72       You should have received a copy of the GNU Lesser General Public
73       License along with this library; if not, write to the Free Software
74       Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
75       02110-1301 USA
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79libnbd-1.16.5                     2023-09-26       nbd_get_nr_meta_contexts(3)
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