SPDX-License-Identifier: BSD-2-Clause

Copyright (c) 2021 The FreeBSD Foundation

This manual page was written by Ka Ho Ng under sponsorship from
the FreeBSD Foundation.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.

.Dd August 25, 2021 .Dt VOP_DEALLOCATE 9 .Os .Sh NAME .Nm VOP_DEALLOCATE .Nd zero and/or deallocate storage from a file .Sh SYNOPSIS n sys/param.h n sys/vnode.h .Ft int .Fo VOP_DEALLOCATE .Fa "struct vnode *vp" .Fa "off_t *offset" .Fa "off_t *len" .Fa "int flags" .Fa "int ioflag" .Fa "struct ucred *cred" .Fc .Sh DESCRIPTION This VOP call zeroes/deallocates storage for an offset range in a file. It is used to implement the .Xr fspacectl 2 system call.

p Its arguments are: l -tag -width offset t Fa vp The vnode of the file. t Fa offset The start of the range to deallocate storage in the file. t Fa len The length of the range to deallocate storage in the file. t Fa flags The flags of this call. This should be set to 0 for now. t Fa ioflag Directives and hints to be given to the file system. t Fa cred The credentials of the caller. .El

p .Fa *offset and .Fa *len are updated to reflect the portion of the range that still needs to be zeroed/deallocated on return. Partial result is considered a successful operation. For a non-partial successful completion, .Fa *len is updated to be the value 0, and .Fa *offset is incremented by the number of bytes zeroed before the end-of-file. .Sh LOCKS The vnode should be locked on entry and will still be locked on exit. .Sh RETURN VALUES Zero is returned if the call is successful, otherwise an appropriate error code is returned. .Sh ERRORS l -tag -width Er t Bq Er EINVAL Invalid .Fa offset , len or .Fa flags parameters are passed into this VOP call. t Bq Er ENODEV The vnode type is not supported by this VOP call. t Bq Er ENOSPC The file system is full. t Bq Er EPERM An append-only flag is set on the file, but the caller is attempting to zero before the current end of file. .El .Sh SEE ALSO .Xr vnode 9 .Sh AUTHORS .Nm and this manual page was written by .An Ka Ho Ng Aq Mt khng@FreeBSD.org under sponsorship from the FreeBSD Foundation.