9e202d036d
rmsr.r_offset now is set to rqsr.r_offset plus the number of bytes zeroed before hitting the end-of-file. After this change rmsr.r_offset no longer contains the EOF when the requested operation range is completely beyond the end-of-file. Instead in such case rmsr.r_offset is equal to rqsr.r_offset. Callers can obtain the number of bytes zeroed by subtracting rqsr.r_offset from rmsr.r_offset. Sponsored by: The FreeBSD Foundation Reviewed by: kib Differential Revision: https://reviews.freebsd.org/D31677
110 lines
3.4 KiB
Groff
110 lines
3.4 KiB
Groff
.\"
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.\" SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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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 VOP_DEALLOCATE 9
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.Os
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.Sh NAME
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.Nm VOP_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 VOP_DEALLOCATE
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.Fa "struct vnode *vp"
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.Fa "off_t *offset"
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.Fa "off_t *len"
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.Fa "int flags"
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.Fa "int ioflag"
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.Fa "struct ucred *cred"
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.Fc
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.Sh DESCRIPTION
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This VOP call zeroes/deallocates storage for an offset range in a file.
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It is used to implement the
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.Xr fspacectl 2
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system call.
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.Pp
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Its arguments are:
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.Bl -tag -width offset
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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 start of the range to deallocate storage in the file.
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.It Fa len
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The length of the range to deallocate storage in the file.
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.It Fa flags
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The flags of this call.
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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 cred
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The credentials of the caller.
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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 *len
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are updated to reflect the portion of the range that
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still needs to be zeroed/deallocated on return.
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Partial result is considered a successful operation.
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For a non-partial successful completion,
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.Fa *len
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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 LOCKS
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The vnode should be locked on entry and will still be locked on exit.
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.Sh RETURN VALUES
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Zero is returned if the call is successful, otherwise an appropriate
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error code is returned.
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.Sh ERRORS
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.Bl -tag -width Er
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.It Bq Er EINVAL
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Invalid
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.Fa offset , len
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or
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.Fa flags
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parameters are passed into this VOP call.
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.It Bq Er ENODEV
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The vnode type is not supported by this VOP call.
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.It Bq Er ENOSPC
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The file system is full.
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.It Bq Er EPERM
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An append-only flag is set on the file, but the caller is attempting to
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zero before the current end of file.
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.El
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.Sh SEE ALSO
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.Xr vnode 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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