1nbd_clear_meta_contexts(3) LIBNBD nbd_clear_meta_contexts(3)
2
3
4
6 nbd_clear_meta_contexts - reset the list of requested meta contexts
7
9 #include <libnbd.h>
10
11 int nbd_clear_meta_contexts (
12 struct nbd_handle *h
13 );
14
16 During connection libnbd can negotiate zero or more metadata contexts
17 with the server. Metadata contexts are features (such as
18 "base:allocation") which describe information returned by the
19 nbd_block_status(3) command (for "base:allocation" this is whether
20 blocks of data are allocated, zero or sparse).
21
22 This command resets the list of meta contexts to request back to an
23 empty list, for re-population by further use of
24 nbd_add_meta_context(3). It is primarily useful when option
25 negotiation mode is selected (see nbd_set_opt_mode(3)), for altering
26 the list of attempted contexts between subsequent export queries.
27
29 If the call is successful the function returns 0.
30
32 On error -1 is returned.
33
34 Refer to "ERROR HANDLING" in libnbd(3) for how to get further details
35 of the error.
36
37 The following parameters must not be NULL: "h". For more information
38 see "Non-NULL parameters" in libnbd(3).
39
41 The handle must be newly created, or negotiating, otherwise this call
42 will return an error.
43
45 This function first appeared in libnbd 1.6.
46
47 If you need to test if this function is available at compile time check
48 if the following macro is defined:
49
50 #define LIBNBD_HAVE_NBD_CLEAR_META_CONTEXTS 1
51
53 nbd_add_meta_context(3), nbd_block_status(3), nbd_can_meta_context(3),
54 nbd_create(3), nbd_get_meta_context(3), nbd_get_nr_meta_contexts(3),
55 nbd_set_opt_mode(3), libnbd(3).
56
58 Eric Blake
59
60 Richard W.M. Jones
61
63 Copyright Red Hat
64
66 This library is free software; you can redistribute it and/or modify it
67 under the terms of the GNU Lesser General Public License as published
68 by the Free Software Foundation; either version 2 of the License, or
69 (at your option) any later version.
70
71 This library is distributed in the hope that it will be useful, but
72 WITHOUT ANY WARRANTY; without even the implied warranty of
73 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
74 Lesser General Public License for more details.
75
76 You should have received a copy of the GNU Lesser General Public
77 License along with this library; if not, write to the Free Software
78 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
79 02110-1301 USA
80
81
82
83libnbd-1.16.5 2023-09-26 nbd_clear_meta_contexts(3)