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 |