1nbd_opt_info(3) LIBNBD nbd_opt_info(3)
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6 nbd_opt_info - request the server for information about an export
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9 #include <libnbd.h>
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11 int nbd_opt_info (struct nbd_handle *h);
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14 Request that the server supply information about the export name
15 previously specified by the most recent nbd_set_export_name(3) or
16 nbd_connect_uri(3). This can only be used if nbd_set_opt_mode(3)
17 enabled option mode.
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19 If successful, functions like nbd_is_read_only(3) and nbd_get_size(3)
20 will report details about that export. In general, if nbd_opt_go(3) is
21 called next, that call will likely succeed with the details remaining
22 the same, although this is not guaranteed by all servers.
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24 Not all servers understand this request, and even when it is
25 understood, the server might fail the request even when a corresponding
26 nbd_opt_go(3) would succeed.
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29 If the call is successful the function returns 0.
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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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38 The handle must be negotiating, otherwise this call will return an
39 error.
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42 This function first appeared in libnbd 1.4.
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44 If you need to test if this function is available at compile time check
45 if the following macro is defined:
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47 #define LIBNBD_HAVE_NBD_OPT_INFO 1
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50 nbd_aio_opt_info(3), nbd_connect_uri(3), nbd_create(3),
51 nbd_get_size(3), nbd_is_read_only(3), nbd_opt_go(3),
52 nbd_set_export_name(3), nbd_set_opt_mode(3), libnbd(3).
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55 Eric Blake
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57 Richard W.M. Jones
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60 Copyright (C) 2019-2021 Red Hat Inc.
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63 This library is free software; you can redistribute it and/or modify it
64 under the terms of the GNU Lesser General Public License as published
65 by the Free Software Foundation; either version 2 of the License, or
66 (at your option) any later version.
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68 This library is distributed in the hope that it will be useful, but
69 WITHOUT ANY WARRANTY; without even the implied warranty of
70 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
71 Lesser General Public License for more details.
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73 You should have received a copy of the GNU Lesser General Public
74 License along with this library; if not, write to the Free Software
75 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
76 02110-1301 USA
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80libnbd-1.12.5 2022-07-10 nbd_opt_info(3)