Provided by: libnbd-dev_1.2.2-1ubuntu2_amd64 bug


       nbd_trim - send trim command to the NBD server


        #include <libnbd.h>

        int nbd_trim (struct nbd_handle *h, uint64_t count,
                      uint64_t offset, uint32_t flags);


       Issue a trim command to the NBD server, which if supported by the server causes a hole to
       be punched in the backing store starting at "offset" and ending at "offset" + "count" - 1.
       The call returns when the command has been acknowledged by the server, or there is an

       The "flags" parameter may be 0 for no flags, or may contain "LIBNBD_CMD_FLAG_FUA" meaning
       that the server should not return until the data has been committed to permanent storage
       (if that is supported - some servers cannot do this, see nbd_can_fua(3)).


       If the call is successful the function returns 0.


       On error "-1" is returned.

       Refer to "ERROR HANDLING" in libnbd(3) for how to get further details of the error.


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


       This function first appeared in libnbd 1.0.

       If you need to test if this function is available at compile time check if the following
       macro is defined:

        #define LIBNBD_HAVE_NBD_TRIM 1


       nbd_can_fua(3), nbd_can_trim(3), nbd_aio_trim(3), nbd_create(3), libnbd(3).


       Eric Blake

       Richard W.M. Jones


       Copyright (C) 2019 Red Hat Inc.


       This library is free software; you can redistribute it and/or modify it under the terms of
       the GNU Lesser General Public License as published by the Free Software Foundation; either
       version 2 of the License, or (at your option) any later version.

       This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
       without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
       See the GNU Lesser General Public License for more details.

       You should have received a copy of the GNU Lesser General Public License along with this
       library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
       Floor, Boston, MA 02110-1301 USA