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/* vi: set sw=4 ts=4: */
/*
* freeramdisk and fdflush implementations for busybox
*
* Copyright (C) 2000 and written by Emanuele Caratti <wiz@iol.it>
* Adjusted a bit by Erik Andersen <andersen@codepoet.org>
* Unified with fdflush by Tito Ragusa <farmatito@tiscali.it>
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
//config:config FDFLUSH
//config: bool "fdflush (1.6 kb)"
//config: default y
//config: help
//config: fdflush is only needed when changing media on slightly-broken
//config: removable media drives. It is used to make Linux believe that a
//config: hardware disk-change switch has been actuated, which causes Linux to
//config: forget anything it has cached from the previous media. If you have
//config: such a slightly-broken drive, you will need to run fdflush every time
//config: you change a disk. Most people have working hardware and can safely
//config: leave this disabled.
//config:
//config:config FREERAMDISK
//config: bool "freeramdisk (1.6 kb)"
//config: default y
//config: help
//config: Linux allows you to create ramdisks. This utility allows you to
//config: delete them and completely free all memory that was used for the
//config: ramdisk. For example, if you boot Linux into a ramdisk and later
//config: pivot_root, you may want to free the memory that is allocated to the
//config: ramdisk. If you have no use for freeing memory from a ramdisk, leave
//config: this disabled.
// APPLET_ODDNAME:name main location suid_type help
//applet:IF_FDFLUSH( APPLET_ODDNAME(fdflush, freeramdisk, BB_DIR_BIN, BB_SUID_DROP, fdflush ))
//applet:IF_FREERAMDISK(APPLET_NOEXEC(freeramdisk, freeramdisk, BB_DIR_SBIN, BB_SUID_DROP, freeramdisk))
//kbuild:lib-$(CONFIG_FDFLUSH) += freeramdisk.o
//kbuild:lib-$(CONFIG_FREERAMDISK) += freeramdisk.o
//usage:#define freeramdisk_trivial_usage
//usage: "DEVICE"
//usage:#define freeramdisk_full_usage "\n\n"
//usage: "Free all memory used by the specified ramdisk"
//usage:
//usage:#define freeramdisk_example_usage
//usage: "$ freeramdisk /dev/ram2\n"
//usage:
//usage:#define fdflush_trivial_usage
//usage: "DEVICE"
//usage:#define fdflush_full_usage "\n\n"
//usage: "Force floppy disk drive to detect disk change"
#include <sys/mount.h>
#include "libbb.h"
/* From <linux/fd.h> */
#define FDFLUSH _IO(2,0x4b)
int freeramdisk_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int freeramdisk_main(int argc UNUSED_PARAM, char **argv)
{
int fd;
fd = xopen(single_argv(argv), O_RDWR);
// Act like freeramdisk, fdflush, or both depending on configuration.
ioctl_or_perror_and_die(fd,
((ENABLE_FREERAMDISK && applet_name[1] == 'r') || !ENABLE_FDFLUSH)
? BLKFLSBUF
: FDFLUSH,
NULL, "%s", argv[1]
);
if (ENABLE_FEATURE_CLEAN_UP) close(fd);
return EXIT_SUCCESS;
}
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