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/* vi: set sw=4 ts=4: */
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* Copyright (C) 2017 Denys Vlasenko <vda.linux@googlemail.com>
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* Licensed under GPLv2, see file LICENSE in this source tree.
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//config:config FSFREEZE
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//config: bool "fsfreeze (3.7 kb)"
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//config: select LONG_OPTS
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//config: Halt new accesses and flush writes on a mounted filesystem.
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//applet:IF_FSFREEZE(APPLET_NOEXEC(fsfreeze, fsfreeze, BB_DIR_USR_SBIN, BB_SUID_DROP, fsfreeze))
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//kbuild:lib-$(CONFIG_FSFREEZE) += fsfreeze.o
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//usage:#define fsfreeze_trivial_usage
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//usage: "--[un]freeze MOUNTPOINT"
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//usage:#define fsfreeze_full_usage "\n\n"
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//usage: "Flush and halt writes to MOUNTPOINT"
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# define FIFREEZE _IOWR('X', 119, int)
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# define FITHAW _IOWR('X', 120, int)
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int fsfreeze_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int fsfreeze_main(int argc UNUSED_PARAM, char **argv)
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/* exactly one non-option arg: the mountpoint */
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/* one of opts is required */
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/* opts are mutually exclusive */
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opts = getopt32long(argv, "^"
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"\0" "=1:""\xff:\xfe:""\xff--\xfe:\xfe--\xff",
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"freeze\0" No_argument "\xff"
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"unfreeze\0" No_argument "\xfe"
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fd = xopen(argv[optind], O_RDONLY);
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/* Works with NULL arg on linux-4.8.0 */
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xioctl(fd, (opts & 1) ? FIFREEZE : FITHAW, NULL);