NAME

       nbd_aio_trim - send trim command to the NBD server

SYNOPSIS

        #include <libnbd.h>

        typedef struct {
          int (*callback) (void *user_data, int *error);
          void *user_data;
          void (*free) (void *user_data);
        } nbd_completion_callback;

        int64_t nbd_aio_trim (
                  struct nbd_handle *h, uint64_t count,
                  uint64_t offset,
                  nbd_completion_callback completion_callback,
                  uint32_t flags
                );

DESCRIPTION

       Issue a trim command to the NBD server.

       To check if the command completed, call nbd_aio_command_completed(3).  Or supply the
       optional "completion_callback" which will be invoked as described in "Completion
       callbacks" in libnbd(3).

       Other parameters behave as documented in nbd_trim(3).

       By default, libnbd will reject attempts to use this function with parameters that are
       likely to result in server failure, such as requesting an unknown command flag.  The
       nbd_set_strict_mode(3) function can be used to alter which scenarios should await a server
       reply rather than failing fast.

RETURN VALUE

       This call returns the 64 bit cookie of the command.  The cookie is ≥ 1.  Cookies are
       unique (per libnbd handle, not globally).

ERRORS

       On error -1 is returned.

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

       The following parameters must not be NULL: "h".  For more information see "Non-NULL
       parameters" in libnbd(3).

HANDLE STATE

       nbd_aio_trim can be called when the handle is in the following state:

        ┌─────────────────────────────────────┬─────────────────────────┐
        │ Handle created, before connecting   │ ❌ error                │
        │ Connecting                          │ ❌ error                │
        │ Connecting & handshaking (opt_mode) │ ❌ error                │
        │ Connected to the server             │ ✅ allowed              │
        │ Connection shut down                │ ❌ error                │
        │ Handle dead                         │ ❌ error                │
        └─────────────────────────────────────┴─────────────────────────┘

VERSION

       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_AIO_TRIM 1

SEE ALSO

       nbd_aio_command_completed(3), nbd_can_trim(3), nbd_create(3), nbd_set_strict_mode(3),
       nbd_trim(3), "Issuing asynchronous commands" in libnbd(3), libnbd(3).

AUTHORS

       Eric Blake

       Richard W.M. Jones

COPYRIGHT

       Copyright Red Hat

LICENSE

       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