freebsd-dev/usr.bin/truncate/truncate.c
Ka Ho Ng 5ee2c35751 truncate(1): Add hole-punching support
This commit adds hole-punching support to the truncate(1) utility. If
the option -d is specified, truncate(1) performs zeroing, and if
possible hole-punching in case the operation is supported by the
underlying file system of the specified files.

Sponsored by:	The FreeBSD Foundation
Reviewed by:	kib
Differential Revision:	https://reviews.freebsd.org/D31556
2021-08-19 18:30:41 +08:00

230 lines
5.6 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2000 Sheldon Hearn <sheldonh@FreeBSD.org>.
* All rights reserved.
*
* Copyright (c) 2021 The FreeBSD Foundation
*
* Portions of this software were developed by Ka Ho Ng <khng@FreeBSD.org>
* 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.
*
*/
static const char rcsid[] =
"$FreeBSD$";
#include <sys/stat.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <libutil.h>
static void usage(void);
int
main(int argc, char **argv)
{
struct stat sb;
mode_t omode;
off_t oflow, rsize, sz, tsize, round, off, len;
uint64_t usz;
int ch, error, fd, oflags, r;
int do_dealloc;
int do_truncate;
int no_create;
int do_relative;
int do_round;
int do_refer;
int got_size;
char *fname, *rname;
struct spacectl_range sr;
fd = -1;
rsize = tsize = sz = off = 0;
len = -1;
do_dealloc = no_create = do_relative = do_round = do_refer =
got_size = 0;
do_truncate = 1;
error = r = 0;
rname = NULL;
while ((ch = getopt(argc, argv, "cdr:s:o:l:")) != -1)
switch (ch) {
case 'c':
no_create = 1;
break;
case 'd':
do_dealloc = 1;
do_truncate = 0;
break;
case 'r':
do_refer = 1;
rname = optarg;
break;
case 's':
if (*optarg == '+' || *optarg == '-') {
do_relative = 1;
} else if (*optarg == '%' || *optarg == '/') {
do_round = 1;
}
if (expand_number(do_relative || do_round ?
optarg + 1 : optarg,
&usz) == -1 || (off_t)usz < 0)
errx(EXIT_FAILURE,
"invalid size argument `%s'", optarg);
sz = (*optarg == '-' || *optarg == '/') ?
-(off_t)usz : (off_t)usz;
got_size = 1;
break;
case 'o':
if (expand_number(optarg, &usz) == -1 ||
(off_t)usz < 0)
errx(EXIT_FAILURE,
"invalid offset argument `%s'", optarg);
off = usz;
break;
case 'l':
if (expand_number(optarg, &usz) == -1 ||
(off_t)usz <= 0)
errx(EXIT_FAILURE,
"invalid length argument `%s'", optarg);
len = usz;
break;
default:
usage();
/* NOTREACHED */
}
argv += optind;
argc -= optind;
/*
* Exactly one of do_refer, got_size or do_dealloc must be specified.
* Since do_relative implies got_size, do_relative, do_refer and
* do_dealloc are also mutually exclusive. If do_dealloc is specified,
* the length argument must be set. See usage() for allowed
* invocations.
*/
if (argc < 1 || do_refer + got_size + do_dealloc != 1 ||
(do_dealloc == 1 && len == -1))
usage();
if (do_refer == 1) {
if (stat(rname, &sb) == -1)
err(EXIT_FAILURE, "%s", rname);
tsize = sb.st_size;
} else if (do_relative == 1 || do_round == 1)
rsize = sz;
else if (do_dealloc == 0)
tsize = sz;
if (no_create)
oflags = O_WRONLY;
else
oflags = O_WRONLY | O_CREAT;
omode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
while ((fname = *argv++) != NULL) {
if (fd != -1)
close(fd);
if ((fd = open(fname, oflags, omode)) == -1) {
if (errno != ENOENT) {
warn("%s", fname);
error++;
}
continue;
}
if (do_relative == 1) {
if (fstat(fd, &sb) == -1) {
warn("%s", fname);
error++;
continue;
}
oflow = sb.st_size + rsize;
if (oflow < (sb.st_size + rsize)) {
errno = EFBIG;
warn("%s", fname);
error++;
continue;
}
tsize = oflow;
}
if (do_round == 1) {
if (fstat(fd, &sb) == -1) {
warn("%s", fname);
error++;
continue;
}
sz = rsize;
if (sz < 0)
sz = -sz;
if (sb.st_size % sz) {
round = sb.st_size / sz;
if (round != sz && rsize < 0)
round--;
else if (rsize > 0)
round++;
tsize = (round < 0 ? 0 : round) * sz;
} else
tsize = sb.st_size;
}
if (tsize < 0)
tsize = 0;
if (do_dealloc == 1) {
sr.r_offset = off;
sr.r_len = len;
r = fspacectl(fd, SPACECTL_DEALLOC, &sr, 0, &sr);
}
if (do_truncate == 1)
r = ftruncate(fd, tsize);
if (r == -1) {
warn("%s", fname);
error++;
}
}
if (fd != -1)
close(fd);
return (error ? EXIT_FAILURE : EXIT_SUCCESS);
}
static void
usage(void)
{
fprintf(stderr, "%s\n%s\n%s\n",
"usage: truncate [-c] -s [+|-|%|/]size[K|k|M|m|G|g|T|t] file ...",
" truncate [-c] -r rfile file ...",
" truncate [-c] -d [-o offset[K|k|M|m|G|g|T|t]] -l length[K|k|M|m|G|g|T|t] file ...");
exit(EXIT_FAILURE);
}