1/* vi: set sw=4 ts=4: */ 2/* 3 * freeramdisk and fdflush implementations for busybox 4 * 5 * Copyright (C) 2000 and written by Emanuele Caratti <wiz@iol.it> 6 * Adjusted a bit by Erik Andersen <andersen@codepoet.org> 7 * Unified with fdflush by Tito Ragusa <farmatito@tiscali.it> 8 * 9 * Licensed under GPLv2, see file LICENSE in this source tree. 10 */ 11//config:config FDFLUSH 12//config: bool "fdflush (1.3 kb)" 13//config: default y 14//config: select PLATFORM_LINUX 15//config: help 16//config: fdflush is only needed when changing media on slightly-broken 17//config: removable media drives. It is used to make Linux believe that a 18//config: hardware disk-change switch has been actuated, which causes Linux to 19//config: forget anything it has cached from the previous media. If you have 20//config: such a slightly-broken drive, you will need to run fdflush every time 21//config: you change a disk. Most people have working hardware and can safely 22//config: leave this disabled. 23//config: 24//config:config FREERAMDISK 25//config: bool "freeramdisk (1.3 kb)" 26//config: default y 27//config: select PLATFORM_LINUX 28//config: help 29//config: Linux allows you to create ramdisks. This utility allows you to 30//config: delete them and completely free all memory that was used for the 31//config: ramdisk. For example, if you boot Linux into a ramdisk and later 32//config: pivot_root, you may want to free the memory that is allocated to the 33//config: ramdisk. If you have no use for freeing memory from a ramdisk, leave 34//config: this disabled. 35 36// APPLET_ODDNAME:name main location suid_type help 37//applet:IF_FDFLUSH( APPLET_ODDNAME(fdflush, freeramdisk, BB_DIR_BIN, BB_SUID_DROP, fdflush )) 38//applet:IF_FREERAMDISK(APPLET_NOEXEC(freeramdisk, freeramdisk, BB_DIR_SBIN, BB_SUID_DROP, freeramdisk)) 39 40//kbuild:lib-$(CONFIG_FDFLUSH) += freeramdisk.o 41//kbuild:lib-$(CONFIG_FREERAMDISK) += freeramdisk.o 42 43//usage:#define freeramdisk_trivial_usage 44//usage: "DEVICE" 45//usage:#define freeramdisk_full_usage "\n\n" 46//usage: "Free all memory used by the specified ramdisk" 47//usage: 48//usage:#define freeramdisk_example_usage 49//usage: "$ freeramdisk /dev/ram2\n" 50//usage: 51//usage:#define fdflush_trivial_usage 52//usage: "DEVICE" 53//usage:#define fdflush_full_usage "\n\n" 54//usage: "Force floppy disk drive to detect disk change" 55 56#include <sys/mount.h> 57#include "libbb.h" 58 59/* From <linux/fd.h> */ 60#define FDFLUSH _IO(2,0x4b) 61 62int freeramdisk_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; 63int freeramdisk_main(int argc UNUSED_PARAM, char **argv) 64{ 65 int fd; 66 67 fd = xopen(single_argv(argv), O_RDWR); 68 69 // Act like freeramdisk, fdflush, or both depending on configuration. 70 ioctl_or_perror_and_die(fd, 71 ((ENABLE_FREERAMDISK && applet_name[1] == 'r') || !ENABLE_FDFLUSH) 72 ? BLKFLSBUF 73 : FDFLUSH, 74 NULL, "%s", argv[1] 75 ); 76 77 if (ENABLE_FEATURE_CLEAN_UP) close(fd); 78 79 return EXIT_SUCCESS; 80} 81