busybox/util-linux/fsfreeze.c

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/* 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 (3.5 kb)"
//config: default y
//config: select LONG_OPTS
//config: help
//config: Halt new accesses and flush writes on a mounted filesystem.
//applet:IF_FSFREEZE(APPLET_NOEXEC(fsfreeze, fsfreeze, BB_DIR_USR_SBIN, BB_SUID_DROP, fsfreeze))
//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;
/* exactly one non-option arg: the mountpoint */
/* one of opts is required */
/* opts are mutually exclusive */
getopt32: remove opt_complementary function old new delta vgetopt32 1318 1392 +74 runsvdir_main 703 713 +10 bb_make_directory 423 425 +2 collect_cpu 546 545 -1 opt_chars 3 - -3 opt_complementary 4 - -4 tftpd_main 567 562 -5 ntp_init 476 471 -5 zcip_main 1266 1256 -10 xxd_main 428 418 -10 whois_main 140 130 -10 who_main 463 453 -10 which_main 212 202 -10 wget_main 2535 2525 -10 watchdog_main 291 281 -10 watch_main 222 212 -10 vlock_main 399 389 -10 uuencode_main 332 322 -10 uudecode_main 316 306 -10 unlink_main 45 35 -10 udhcpd_main 1482 1472 -10 udhcpc_main 2762 2752 -10 tune2fs_main 290 280 -10 tunctl_main 366 356 -10 truncate_main 218 208 -10 tr_main 518 508 -10 time_main 1134 1124 -10 tftp_main 286 276 -10 telnetd_main 1873 1863 -10 tcpudpsvd_main 1785 1775 -10 taskset_main 521 511 -10 tar_main 1009 999 -10 tail_main 1644 1634 -10 syslogd_main 1967 1957 -10 switch_root_main 368 358 -10 svlogd_main 1454 1444 -10 sv 1296 1286 -10 stat_main 104 94 -10 start_stop_daemon_main 1028 1018 -10 split_main 542 532 -10 sort_main 796 786 -10 slattach_main 624 614 -10 shuf_main 504 494 -10 setsid_main 96 86 -10 setserial_main 1132 1122 -10 setfont_main 388 378 -10 setconsole_main 78 68 -10 sendmail_main 1209 1199 -10 sed_main 677 667 -10 script_main 1077 1067 -10 run_parts_main 325 315 -10 rtcwake_main 454 444 -10 rm_main 175 165 -10 reformime_main 119 109 -10 readlink_main 123 113 -10 rdate_main 246 236 -10 pwdx_main 189 179 -10 pstree_main 317 307 -10 pscan_main 663 653 -10 popmaildir_main 818 808 -10 pmap_main 80 70 -10 nc_main 1042 1032 -10 mv_main 558 548 -10 mountpoint_main 477 467 -10 mount_main 1264 1254 -10 modprobe_main 768 758 -10 modinfo_main 333 323 -10 mktemp_main 200 190 -10 mkswap_main 324 314 -10 mkfs_vfat_main 1489 1479 -10 microcom_main 715 705 -10 md5_sha1_sum_main 521 511 -10 man_main 867 857 -10 makedevs_main 1052 1042 -10 ls_main 563 553 -10 losetup_main 432 422 -10 loadfont_main 89 79 -10 ln_main 524 514 -10 link_main 75 65 -10 ipcalc_main 544 534 -10 iostat_main 2397 2387 -10 install_main 768 758 -10 id_main 480 470 -10 i2cset_main 1239 1229 -10 i2cget_main 380 370 -10 i2cdump_main 1482 1472 -10 i2cdetect_main 682 672 -10 hwclock_main 406 396 -10 httpd_main 741 731 -10 grep_main 837 827 -10 getty_main 1559 1549 -10 fuser_main 297 287 -10 ftpgetput_main 345 335 -10 ftpd_main 2232 2222 -10 fstrim_main 251 241 -10 fsfreeze_main 77 67 -10 fsck_minix_main 2921 2911 -10 flock_main 314 304 -10 flashcp_main 740 730 -10 flash_eraseall_main 833 823 -10 fdformat_main 532 522 -10 expand_main 680 670 -10 eject_main 335 325 -10 dumpleases_main 630 620 -10 du_main 314 304 -10 dos2unix_main 441 431 -10 diff_main 1350 1340 -10 df_main 1064 1054 -10 date_main 1095 1085 -10 cut_main 961 951 -10 cryptpw_main 228 218 -10 crontab_main 575 565 -10 crond_main 1149 1139 -10 cp_main 370 360 -10 common_traceroute_main 3834 3824 -10 common_ping_main 1767 1757 -10 comm_main 239 229 -10 cmp_main 655 645 -10 chrt_main 379 369 -10 chpst_main 704 694 -10 chpasswd_main 308 298 -10 chown_main 171 161 -10 chmod_main 158 148 -10 cat_main 428 418 -10 bzip2_main 120 110 -10 blkdiscard_main 264 254 -10 base64_main 221 211 -10 arping_main 1665 1655 -10 ar_main 556 546 -10 adjtimex_main 406 396 -10 adduser_main 882 872 -10 addgroup_main 411 401 -10 acpid_main 1198 1188 -10 optstring 11 - -11 opt_string 18 - -18 OPT_STR 25 - -25 ubi_tools_main 1288 1258 -30 ls_options 31 - -31 ------------------------------------------------------------------------------ (add/remove: 0/6 grow/shrink: 3/129 up/down: 86/-1383) Total: -1297 bytes text data bss dec hex filename 915428 485 6876 922789 e14a5 busybox_old 914629 485 6872 921986 e1182 busybox_unstripped Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-08-09 01:25:02 +05:30
opts = getopt32long(argv, "^"
"" /* no opts */
"\0" "=1:""\xff:\xfe:""\xff--\xfe:\xfe--\xff",
getopt32: remove applet_long_options FEATURE_GETOPT_LONG made dependent on LONG_OPTS. The folloving options are removed, now LONG_OPTS enables long options for affected applets: FEATURE_ENV_LONG_OPTIONS FEATURE_EXPAND_LONG_OPTIONS FEATURE_UNEXPAND_LONG_OPTIONS FEATURE_MKDIR_LONG_OPTIONS FEATURE_MV_LONG_OPTIONS FEATURE_RMDIR_LONG_OPTIONS FEATURE_ADDGROUP_LONG_OPTIONS FEATURE_ADDUSER_LONG_OPTIONS FEATURE_HWCLOCK_LONG_OPTIONS FEATURE_NSENTER_LONG_OPTS FEATURE_CHCON_LONG_OPTIONS FEATURE_RUNCON_LONG_OPTIONS They either had a small number of long options, or their long options are essential. Example: upstream addgroup and adduser have ONLY longopts, we should probably go further and get rid of non-standard short options. To this end, make addgroup and adduser "select LONG_OPTS". We had this breakage caused by us even in our own package! #if ENABLE_LONG_OPTS || !ENABLE_ADDGROUP /* We try to use --gid, not -g, because "standard" addgroup * has no short option -g, it has only long --gid. */ argv[1] = (char*)"--gid"; #else /* Breaks if system in fact does NOT use busybox addgroup */ argv[1] = (char*)"-g"; #endif xargs: its lone longopt no longer depends on DESKTOP, only on LONG_OPTS. hwclock TODO: get rid of incompatible -t, -l aliases to --systz, --localtime Shorten help texts by omitting long option when short opt alternative exists. Reduction of size comes from the fact that store of an immediate (an address of longopts) to a fixed address (global variable) is a longer insn than pushing that immediate or passing it in a register. This effect is CPU-agnostic. function old new delta getopt32 1350 22 -1328 vgetopt32 - 1318 +1318 getopt32long - 24 +24 tftpd_main 562 567 +5 scan_recursive 376 380 +4 collect_cpu 545 546 +1 date_main 1096 1095 -1 hostname_main 262 259 -3 uname_main 259 255 -4 setpriv_main 362 358 -4 rmdir_main 191 187 -4 mv_main 562 558 -4 ipcalc_main 548 544 -4 ifenslave_main 641 637 -4 gzip_main 192 188 -4 gunzip_main 77 73 -4 fsfreeze_main 81 77 -4 flock_main 318 314 -4 deluser_main 337 333 -4 cp_main 374 370 -4 chown_main 175 171 -4 applet_long_options 4 - -4 xargs_main 894 889 -5 wget_main 2540 2535 -5 udhcpc_main 2767 2762 -5 touch_main 436 431 -5 tar_main 1014 1009 -5 start_stop_daemon_main 1033 1028 -5 sed_main 682 677 -5 script_main 1082 1077 -5 run_parts_main 330 325 -5 rtcwake_main 459 454 -5 od_main 2169 2164 -5 nl_main 201 196 -5 modprobe_main 773 768 -5 mkdir_main 160 155 -5 ls_main 568 563 -5 install_main 773 768 -5 hwclock_main 411 406 -5 getopt_main 622 617 -5 fstrim_main 256 251 -5 env_main 198 193 -5 dumpleases_main 635 630 -5 dpkg_main 3991 3986 -5 diff_main 1355 1350 -5 cryptpw_main 233 228 -5 cpio_main 593 588 -5 conspy_main 1135 1130 -5 chpasswd_main 313 308 -5 adduser_main 887 882 -5 addgroup_main 416 411 -5 ftpgetput_main 351 345 -6 get_terminal_width_height 242 234 -8 expand_main 690 680 -10 static.expand_longopts 18 - -18 static.unexpand_longopts 27 - -27 mkdir_longopts 28 - -28 env_longopts 30 - -30 static.ifenslave_longopts 34 - -34 mv_longopts 46 - -46 static.rmdir_longopts 48 - -48 packed_usage 31739 31687 -52 ------------------------------------------------------------------------------ (add/remove: 2/8 grow/shrink: 3/49 up/down: 1352/-1840) Total: -488 bytes text data bss dec hex filename 915681 485 6880 923046 e15a6 busybox_old 915428 485 6876 922789 e14a5 busybox_unstripped Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-08-08 20:08:18 +05:30
"freeze\0" No_argument "\xff"
"unfreeze\0" No_argument "\xfe"
);
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;
}