104 lines
2.4 KiB
C
104 lines
2.4 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* Mini sync implementation for busybox
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*
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* Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
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* Copyright (C) 2015 by Ari Sundholm <ari@tuxera.com>
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*
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* Licensed under GPLv2 or later, see file LICENSE in this source tree.
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*/
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//config:config SYNC
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//config: bool "sync (769 bytes)"
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//config: default y
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//config: help
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//config: sync is used to flush filesystem buffers.
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//config:config FEATURE_SYNC_FANCY
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//config: bool "Enable -d and -f flags (requires syncfs(2) in libc)"
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//config: default y
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//config: depends on SYNC
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//config: help
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//config: sync -d FILE... executes fdatasync() on each FILE.
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//config: sync -f FILE... executes syncfs() on each FILE.
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//applet:IF_SYNC(APPLET_NOFORK(sync, sync, BB_DIR_BIN, BB_SUID_DROP, sync))
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//kbuild:lib-$(CONFIG_SYNC) += sync.o
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/* BB_AUDIT SUSv3 N/A -- Matches GNU behavior. */
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//usage:#define sync_trivial_usage
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//usage: ""IF_FEATURE_SYNC_FANCY("[-df] [FILE]...")
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//usage:#define sync_full_usage "\n\n"
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//usage: IF_NOT_FEATURE_SYNC_FANCY(
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//usage: "Write all buffered blocks to disk"
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//usage: )
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//usage: IF_FEATURE_SYNC_FANCY(
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//usage: "Write all buffered blocks (in FILEs) to disk"
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//usage: "\n -d Avoid syncing metadata"
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//usage: "\n -f Sync filesystems underlying FILEs"
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//usage: )
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#include "libbb.h"
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/* This is a NOFORK applet. Be very careful! */
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int sync_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int sync_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
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{
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#if !ENABLE_FEATURE_SYNC_FANCY
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/* coreutils-6.9 compat */
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bb_warn_ignoring_args(argv[1]);
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sync();
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return EXIT_SUCCESS;
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#else
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unsigned opts;
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int ret = EXIT_SUCCESS;
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enum {
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OPT_DATASYNC = (1 << 0),
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OPT_SYNCFS = (1 << 1),
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};
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opt_complementary = "d--f:f--d";
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opts = getopt32(argv, "df");
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argv += optind;
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/* Handle the no-argument case. */
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if (!argv[0])
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sync();
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while (*argv) {
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int fd = open_or_warn(*argv, O_RDONLY);
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if (fd < 0) {
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ret = EXIT_FAILURE;
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goto next;
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}
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if (opts & OPT_DATASYNC) {
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if (fdatasync(fd))
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goto err;
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goto do_close;
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}
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if (opts & OPT_SYNCFS) {
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/*
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* syncfs is documented to only fail with EBADF,
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* which can't happen here. So, no error checks.
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*/
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syncfs(fd);
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goto do_close;
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}
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if (fsync(fd)) {
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err:
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bb_simple_perror_msg(*argv);
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ret = EXIT_FAILURE;
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}
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do_close:
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close(fd);
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next:
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++argv;
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}
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return ret;
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#endif
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}
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