fsfreeze: new applet

NAME
       fsfreeze - suspend access to a filesystem (Ext3/4, ReiserFS, JFS, XFS)
SYNOPSIS
       fsfreeze --freeze|--unfreeze mountpoint
DESCRIPTION
       fsfreeze suspends or resumes access to a filesystem.
       fsfreeze halts any new access to the filesystem and creates a stable
       image on disk.
AVAILABILITY
       The fsfreeze command is part of the util-linux 2.28

function                                             old     new   delta
fsfreeze_main                                          -      81     +81
applet_names                                        2597    2606      +9
applet_main                                         1504    1508      +4
applet_suid                                           94      95      +1
applet_install_loc                                   188     189      +1

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2017-04-11 11:53:05 +02:00
parent a976aaab0b
commit b9512fa6b3

54
util-linux/fsfreeze.c Normal file
View File

@ -0,0 +1,54 @@
/* vi: set sw=4 ts=4: */
/*
* Copyright (C) 2017 Denys Vlasenko <vda.linux@googlemail.com>
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
//config:config FSFREEZE
//config: bool "fsfreeze"
//config: default y
//config: select PLATFORM_LINUX
//config: select LONG_OPTS
//config: help
//config: Halt new accesses and flush writes on a mounted filesystem.
//applet:IF_FSFREEZE(APPLET(fsfreeze, BB_DIR_SBIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_FSFREEZE) += fsfreeze.o
//usage:#define fsfreeze_trivial_usage
//usage: "--[un]freeze MOUNTPOINT"
//usage:#define fsfreeze_full_usage "\n\n"
//usage: "Flush and halt writes to MOUNTPOINT"
#include "libbb.h"
#include <linux/fs.h>
#ifndef FIFREEZE
# define FIFREEZE _IOWR('X', 119, int)
# define FITHAW _IOWR('X', 120, int)
#endif
int fsfreeze_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int fsfreeze_main(int argc UNUSED_PARAM, char **argv)
{
unsigned opts;
int fd;
applet_long_options =
"freeze\0" No_argument "\xff"
"unfreeze\0" No_argument "\xfe"
;
/* exactly one non-option arg: the mountpoint */
/* one of opts is required */
/* opts are mutually exclusive */
opt_complementary = "=1:""\xff:\xfe:""\xff--\xfe:\xfe--\xff";
opts = getopt32(argv, "");
fd = xopen(argv[optind], O_RDONLY);
/* Works with NULL arg on linux-4.8.0 */
xioctl(fd, (opts & 1) ? FIFREEZE : FITHAW, NULL);
return EXIT_SUCCESS;
}