1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
|
/*
* Mini blkdiscard implementation for busybox
*
* Copyright (C) 2015 by Ari Sundholm <ari@tuxera.com> and Tuxera Inc.
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//config:config BLKDISCARD
//config: bool "blkdiscard (5.3 kb)"
//config: default y
//config: help
//config: blkdiscard discards sectors on a given device.
//applet:IF_BLKDISCARD(APPLET_NOEXEC(blkdiscard, blkdiscard, BB_DIR_USR_BIN, BB_SUID_DROP, blkdiscard))
//kbuild:lib-$(CONFIG_BLKDISCARD) += blkdiscard.o
//usage:#define blkdiscard_trivial_usage
//usage: "[-o OFS] [-l LEN] [-s] DEVICE"
//usage:#define blkdiscard_full_usage "\n\n"
//usage: "Discard sectors on DEVICE\n"
//usage: "\n -o OFS Byte offset into device"
//usage: "\n -l LEN Number of bytes to discard"
//usage: "\n -s Perform a secure discard"
//usage:
//usage:#define blkdiscard_example_usage
//usage: "$ blkdiscard -o 0 -l 1G /dev/sdb"
#include "libbb.h"
#include <linux/fs.h>
#ifndef BLKDISCARD
#define BLKDISCARD 0x1277
#endif
#ifndef BLKSECDISCARD
#define BLKSECDISCARD 0x127d
#endif
int blkdiscard_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int blkdiscard_main(int argc UNUSED_PARAM, char **argv)
{
unsigned opts;
const char *offset_str = "0";
const char *length_str;
uint64_t offset; /* Leaving these two variables out does not */
uint64_t length; /* shrink code size and hampers readability. */
uint64_t range[2];
int fd;
enum {
OPT_OFFSET = (1 << 0),
OPT_LENGTH = (1 << 1),
OPT_SECURE = (1 << 2),
};
opt_complementary = "=1";
opts = getopt32(argv, "o:l:s", &offset_str, &length_str);
argv += optind;
fd = xopen(argv[0], O_RDWR|O_EXCL);
//Why bother, BLK[SEC]DISCARD will fail on non-blockdevs anyway?
// xfstat(fd, &st);
// if (!S_ISBLK(st.st_mode))
// bb_error_msg_and_die("%s: not a block device", argv[0]);
offset = xatoull_sfx(offset_str, kMG_suffixes);
if (opts & OPT_LENGTH)
length = xatoull_sfx(length_str, kMG_suffixes);
else {
xioctl(fd, BLKGETSIZE64, &length);
length -= offset;
}
range[0] = offset;
range[1] = length;
ioctl_or_perror_and_die(fd,
(opts & OPT_SECURE) ? BLKSECDISCARD : BLKDISCARD,
&range,
"%s: %s failed",
argv[0],
(opts & OPT_SECURE) ? "BLKSECDISCARD" : "BLKDISCARD"
);
if (ENABLE_FEATURE_CLEAN_UP)
close(fd);
return EXIT_SUCCESS;
}
|
