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author | Karel Zak | 2009-08-18 13:33:27 +0200 |
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committer | Karel Zak | 2009-09-22 15:26:18 +0200 |
commit | d46a54994e30da03385b82f64eaecffe5c170c92 (patch) | |
tree | 8e6b308066d1744e4801cae9186f44661f69100c /sys-utils/fallocate.c | |
parent | mount: document changed semantics of tmpfs size option in mount.8 (diff) | |
download | kernel-qcow2-util-linux-d46a54994e30da03385b82f64eaecffe5c170c92.tar.gz kernel-qcow2-util-linux-d46a54994e30da03385b82f64eaecffe5c170c92.tar.xz kernel-qcow2-util-linux-d46a54994e30da03385b82f64eaecffe5c170c92.zip |
fallocate: new command
The fallocate(1) utility is used to preallocate blocks to a file.
This can be useful for virtual images, database files, testing, etc.
Normally we'd hope that various tools will start using preallocation
internally, but until then such a utility may be useful, and could be
scripted as well.
The original Eric's version is available at:
http://thread.gmane.org/gmane.linux.utilities.util-linux-ng/2490
This version:
- checks for fallocate glibc function and kernel syscall
- does not provide a fallback and does not call posix_fallocate()
- adds long options
- uses err.h for errro messages
- adds NLS support
- cleanups man page
Co-Author: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
Diffstat (limited to 'sys-utils/fallocate.c')
-rw-r--r-- | sys-utils/fallocate.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/sys-utils/fallocate.c b/sys-utils/fallocate.c new file mode 100644 index 000000000..66e976492 --- /dev/null +++ b/sys-utils/fallocate.c @@ -0,0 +1,173 @@ +/* + * fallocate - utility to use the fallocate system call + * + * Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved. + * Written by Eric Sandeen <sandeen@redhat.com> + * Karel Zak <kzak@redhat.com> + * + * cvtnum routine taken from xfsprogs, + * Copyright (c) 2003-2005 Silicon Graphics, Inc. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#include <sys/stat.h> +#include <sys/types.h> +#include <ctype.h> +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <getopt.h> +#include <err.h> + +#ifndef HAVE_FALLOCATE +# include <sys/syscall.h> +#endif + +#include <linux/falloc.h> /* for FALLOC_FL_* flags */ + +#include "nls.h" + + +static void __attribute__((__noreturn__)) usage(FILE *out) +{ + fprintf(out, _("Usage: %s [options] <filename>\n\nOptions:\n"), + program_invocation_short_name); + + fprintf(out, _( + " -h, --help this help\n" + " -n, --keep-size don't modify the length of the file\n" + " -o, --offset <num> offset of the allocation, in bytes\n" + " -l, --length <num> length of the allocation, in bytes\n")); + + fprintf(out, _("\nFor more information see fallocate(1).\n")); + + exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS); +} + +#define EXABYTES(x) ((x) << 60) +#define PETABYTES(x) ((x) << 50) +#define TERABYTES(x) ((x) << 40) +#define GIGABYTES(x) ((x) << 30) +#define MEGABYTES(x) ((x) << 20) +#define KILOBYTES(x) ((x) << 10) + +static loff_t cvtnum(char *s) +{ + loff_t i; + char *sp; + + i = strtoll(s, &sp, 0); + if (i == 0 && sp == s) + return -1LL; + if (*sp == '\0') + return i; + if (sp[1] != '\0') + return -1LL; + + switch (tolower(*sp)) { + case 'k': + return KILOBYTES(i); + case 'm': + return MEGABYTES(i); + case 'g': + return GIGABYTES(i); + case 't': + return TERABYTES(i); + case 'p': + return PETABYTES(i); + case 'e': + return EXABYTES(i); + } + + return -1LL; +} + +int main(int argc, char **argv) +{ + char *fname; + int c; + int error; + int fd; + int mode = 0; + loff_t length = -2LL; + loff_t offset = 0; + + struct option longopts[] = { + { "help", 0, 0, 'h' }, + { "keep-size", 0, 0, 'n' }, + { "offset", 1, 0, 'o' }, + { "lenght", 1, 0, 'l' }, + { NULL, 0, 0, 0 } + }; + + setlocale(LC_ALL, ""); + bindtextdomain(PACKAGE, LOCALEDIR); + textdomain(PACKAGE); + + while ((c = getopt_long(argc, argv, "hnl:o:", longopts, NULL)) != -1) { + switch(c) { + case 'h': + usage(stdout); + break; + case 'n': + mode |= FALLOC_FL_KEEP_SIZE; + break; + case 'l': + length = cvtnum(optarg); + break; + case 'o': + offset = cvtnum(optarg); + break; + default: + usage(stderr); + break; + } + } + + if (length == -2LL) + errx(EXIT_FAILURE, _("no length argument specified")); + if (length <= 0) + errx(EXIT_FAILURE, _("invalid length value specified")); + if (offset < 0) + errx(EXIT_FAILURE, _("invalid offset value specified")); + if (optind == argc) + errx(EXIT_FAILURE, _("no filename specified.")); + + fname = argv[optind++]; + + fd = open(fname, O_WRONLY|O_CREAT, 0644); + if (fd < 0) + err(EXIT_FAILURE, _("%s: open failed"), fname); + +#ifdef HAVE_FALLOCATE + error = fallocate(fd, mode, offset, length); +#else + error = syscall(SYS_fallocate, fd, mode, offset, length); +#endif + /* + * EOPNOTSUPP: The FALLOC_FL_KEEP_SIZE is unsupported + * ENOSYS: The filesystem does not support sys_fallocate + */ + if (error < 0) { + if ((mode & FALLOC_FL_KEEP_SIZE) && errno == EOPNOTSUPP) + errx(EXIT_FAILURE, + _("keep size mode (-n option) unsupported")); + err(EXIT_FAILURE, _("%s: fallocate failed"), fname); + } + + close(fd); + return EXIT_SUCCESS; +} |