ndk-busybox/coreutils/sync.c
Denys Vlasenko 2f28b2bdbb fsync,sync: merge into one source module
With FEATURE_SYNC_FANCY not set:

function                                             old     new   delta
fsync_main                                           130     123      -7

With FEATURE_SYNC_FANCY set, should be much larger code size savings.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-04-02 14:55:29 +02:00

141 lines
3.7 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini sync implementation for busybox
*
* Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
* Copyright (C) 2015 by Ari Sundholm <ari@tuxera.com>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//config:config SYNC
//config: bool "sync (3.8 kb)"
//config: default y
//config: help
//config: sync is used to flush filesystem buffers.
//config:config FEATURE_SYNC_FANCY
//config: bool "Enable -d and -f flags (requires syncfs(2) in libc)"
//config: default y
//config: depends on SYNC
//config: help
//config: sync -d FILE... executes fdatasync() on each FILE.
//config: sync -f FILE... executes syncfs() on each FILE.
// APPLET_NOFORK:name main location suid_type help
//applet:IF_SYNC(APPLET_NOFORK(sync, sync, BB_DIR_BIN, BB_SUID_DROP, sync))
//kbuild:lib-$(CONFIG_SYNC) += sync.o
/* BB_AUDIT SUSv3 N/A -- Matches GNU behavior. */
//usage:#define sync_trivial_usage
//usage: ""IF_FEATURE_SYNC_FANCY("[-df] [FILE]...")
//usage:#define sync_full_usage "\n\n"
//usage: IF_NOT_FEATURE_SYNC_FANCY(
//usage: "Write all buffered blocks to disk"
//usage: )
//usage: IF_FEATURE_SYNC_FANCY(
//usage: "Write all buffered blocks (in FILEs) to disk"
//usage: "\n -d Avoid syncing metadata"
//usage: "\n -f Sync filesystems underlying FILEs"
//usage: )
#include "libbb.h"
/* This is a NOFORK applet. Be very careful! */
#if ENABLE_FEATURE_SYNC_FANCY || ENABLE_FSYNC
static int sync_common(int opts, char **argv)
{
int ret;
enum {
OPT_DATASYNC = (1 << 0),
OPT_SYNCFS = (1 << 1),
};
ret = EXIT_SUCCESS;
do {
/* GNU "sync FILE" uses O_NONBLOCK open */
int fd = open_or_warn(*argv, /*O_NOATIME |*/ O_NOCTTY | O_RDONLY | O_NONBLOCK);
/* open(NOATIME) can only be used by owner or root, don't use NOATIME here */
if (fd < 0) {
ret = EXIT_FAILURE;
goto next;
}
# if ENABLE_FEATURE_SYNC_FANCY
if (opts & OPT_SYNCFS) {
/*
* syncfs is documented to only fail with EBADF,
* which can't happen here. So, no error checks.
*/
syncfs(fd);
} else
# endif
if (((opts & OPT_DATASYNC) ? fdatasync(fd) : fsync(fd)) != 0) {
bb_simple_perror_msg(*argv);
ret = EXIT_FAILURE;
}
close(fd);
next:
argv++;
} while (*argv);
return ret;
}
#endif
#if ENABLE_SYNC
int sync_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int sync_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
{
# if !ENABLE_FEATURE_SYNC_FANCY
/* coreutils-6.9 compat */
bb_warn_ignoring_args(argv[1]);
sync();
return EXIT_SUCCESS;
# else
unsigned opts = getopt32(argv, "^" "df" "\0" "d--f:f--d");
argv += optind;
if (!argv[0]) {
sync();
return EXIT_SUCCESS;
}
return sync_common(opts, argv);
# endif
}
#endif
/*
* Mini fsync implementation for busybox
*
* Copyright (C) 2008 Nokia Corporation. All rights reserved.
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//config:config FSYNC
//config: bool "fsync (3.6 kb)"
//config: default y
//config: help
//config: fsync is used to flush file-related cached blocks to disk.
// APPLET_NOFORK:name main location suid_type help
//applet:IF_FSYNC(APPLET_NOFORK(fsync, fsync, BB_DIR_BIN, BB_SUID_DROP, fsync))
//kbuild:lib-$(CONFIG_FSYNC) += sync.o
//usage:#define fsync_trivial_usage
//usage: "[-d] FILE..."
//usage:#define fsync_full_usage "\n\n"
//usage: "Write all buffered blocks in FILEs to disk\n"
//usage: "\n -d Avoid syncing metadata"
#if ENABLE_FSYNC
int fsync_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int fsync_main(int argc UNUSED_PARAM, char **argv)
{
int opts = getopt32(argv, "^" "d" "\0" "-1"/*min 1 arg*/);
argv += optind;
return sync_common(opts, argv);
}
#endif