blob: 8bc2c443b6ebe0e6c255f922f18a1e409d4a1686
| 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" |
| 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" |
| 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:IF_FDFLUSH(APPLET_ODDNAME(fdflush, freeramdisk, BB_DIR_BIN, BB_SUID_DROP, fdflush)) |
| 37 | //applet:IF_FREERAMDISK(APPLET(freeramdisk, BB_DIR_SBIN, BB_SUID_DROP)) |
| 38 | |
| 39 | //kbuild:lib-$(CONFIG_FDFLUSH) += freeramdisk.o |
| 40 | //kbuild:lib-$(CONFIG_FREERAMDISK) += freeramdisk.o |
| 41 | |
| 42 | //usage:#define freeramdisk_trivial_usage |
| 43 | //usage: "DEVICE" |
| 44 | //usage:#define freeramdisk_full_usage "\n\n" |
| 45 | //usage: "Free all memory used by the specified ramdisk" |
| 46 | //usage: |
| 47 | //usage:#define freeramdisk_example_usage |
| 48 | //usage: "$ freeramdisk /dev/ram2\n" |
| 49 | //usage: |
| 50 | //usage:#define fdflush_trivial_usage |
| 51 | //usage: "DEVICE" |
| 52 | //usage:#define fdflush_full_usage "\n\n" |
| 53 | //usage: "Force floppy disk drive to detect disk change" |
| 54 | |
| 55 | #include <sys/mount.h> |
| 56 | #include "libbb.h" |
| 57 | |
| 58 | /* From <linux/fd.h> */ |
| 59 | #define FDFLUSH _IO(2,0x4b) |
| 60 | |
| 61 | int freeramdisk_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| 62 | int freeramdisk_main(int argc UNUSED_PARAM, char **argv) |
| 63 | { |
| 64 | int fd; |
| 65 | |
| 66 | fd = xopen(single_argv(argv), O_RDWR); |
| 67 | |
| 68 | // Act like freeramdisk, fdflush, or both depending on configuration. |
| 69 | ioctl_or_perror_and_die(fd, (ENABLE_FREERAMDISK && applet_name[1] == 'r') |
| 70 | || !ENABLE_FDFLUSH ? BLKFLSBUF : FDFLUSH, NULL, "%s", argv[1]); |
| 71 | |
| 72 | if (ENABLE_FEATURE_CLEAN_UP) close(fd); |
| 73 | |
| 74 | return EXIT_SUCCESS; |
| 75 | } |
| 76 |