1nbd_trim(3)                         LIBNBD                         nbd_trim(3)
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NAME

6       nbd_trim - send trim command to the NBD server
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SYNOPSIS

9        #include <libnbd.h>
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11        int nbd_trim (struct nbd_handle *h, uint64_t count,
12                      uint64_t offset, uint32_t flags);
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DESCRIPTION

15       Issue a trim command to the NBD server, which if supported by the
16       server causes a hole to be punched in the backing store starting at
17       "offset" and ending at "offset" + "count" - 1.  The call returns when
18       the command has been acknowledged by the server, or there is an error.
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20       The "flags" parameter may be 0 for no flags, or may contain
21       "LIBNBD_CMD_FLAG_FUA" meaning that the server should not return until
22       the data has been committed to permanent storage (if that is supported
23       - some servers cannot do this, see nbd_can_fua(3)).
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RETURN VALUE

26       If the call is successful the function returns 0.
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ERRORS

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

35       The handle must be connected and finished handshaking with the server,
36       otherwise this call will return an error.
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VERSION

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

47       nbd_can_fua(3), nbd_can_trim(3), nbd_aio_trim(3), nbd_create(3),
48       libnbd(3).
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AUTHORS

51       Eric Blake
52
53       Richard W.M. Jones
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56       Copyright (C) 2019 Red Hat Inc.
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LICENSE

59       This library is free software; you can redistribute it and/or modify it
60       under the terms of the GNU Lesser General Public License as published
61       by the Free Software Foundation; either version 2 of the License, or
62       (at your option) any later version.
63
64       This library is distributed in the hope that it will be useful, but
65       WITHOUT ANY WARRANTY; without even the implied warranty of
66       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
67       Lesser General Public License for more details.
68
69       You should have received a copy of the GNU Lesser General Public
70       License along with this library; if not, write to the Free Software
71       Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
72       02110-1301 USA
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76libnbd-1.2.1                      2019-11-14                       nbd_trim(3)
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