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The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch up to that fact and revert to their recommended match of BSD-2-Clause. Discussed with: pfg MFC After: 3 days Sponsored by: Netflix
114 lines
3.4 KiB
Groff
114 lines
3.4 KiB
Groff
.\"
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.\" SPDX-License-Identifier: BSD-2-Clause
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.\"
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.\" Copyright (c) 2021 The FreeBSD Foundation
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.\"
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.\" This manual page was written by Ka Ho Ng under sponsorship from
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.\" the FreeBSD Foundation.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.Dd August 25, 2021
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.Dt VN_DEALLOCATE 9
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.Os
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.Sh NAME
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.Nm vn_deallocate
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.Nd zero and/or deallocate storage from a file
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.Sh SYNOPSIS
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.In sys/param.h
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.In sys/vnode.h
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.Ft int
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.Fo vn_deallocate
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.Fa "struct vnode *vp"
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.Fa "off_t *offset"
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.Fa "off_t *length"
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.Fa "int flags"
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.Fa "int ioflag"
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.Fa "struct ucred *active_cred"
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.Fa "struct ucred *file_cred"
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.Fc
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.Sh DESCRIPTION
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The
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.Fn vn_deallocate
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function zeros and/or deallocates backing storage space from a file.
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This function only works on vnodes with
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.Dv VREG
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type.
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.Pp
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The arguments are:
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.Bl -tag -width active_cred
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.It Fa vp
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The vnode of the file.
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.It Fa offset
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The starting offset of the operation range.
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.It Fa length
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The length of the operation range.
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This must be greater than 0.
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.It Fa flags
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The control flags of the operation.
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This should be set to 0 for now.
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.It Fa ioflag
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Directives and hints to be given to the file system.
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.It Fa active_cred
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The user credentials of the calling thread.
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.It Fa file_cred
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The credentials installed on the file description pointing to the vnode or NOCRED.
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.El
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.Pp
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The
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.Fn ioflag
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argument gives directives and hints to the file system.
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It may include one or more of the following flags:
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.Bl -tag -width IO_RANGELOCKED
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.It Dv IO_NODELOCKED
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The vnode was locked before the call.
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.It Dv IO_RANGELOCKED
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Rangelock was owned around the call.
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.It Dv IO_NOMACCHECK
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Skip MAC checking in the call.
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.It Dv IO_SYNC
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Do I/O synchronously.
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.It Dv IO_DIRECT
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Attempt to bypass buffer cache.
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.El
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.Pp
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.Fa *offset
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and
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.Fa *length
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are updated to reflect the unprocessed operation range of the call.
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For a successful completion,
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.Fa *length
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is updated to be the value 0, and
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.Fa *offset
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is incremented by the number of bytes zeroed before the end-of-file.
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.Sh RETURN VALUES
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Upon successful completion, the value 0 is returned; otherwise the
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appropriate error is returned.
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.Sh SEE ALSO
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.Xr vnode 9 ,
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.Xr VOP_DEALLOCATE 9
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.Sh AUTHORS
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.Nm
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and this manual page was written by
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.An Ka Ho Ng Aq Mt khng@FreeBSD.org
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under sponsorship from the FreeBSD Foundation.
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