2 * blockdev implementation for busybox
4 * Copyright (C) 2010 Sergey Naumov <sknaumov@gmail.com>
6 * Licensed under GPLv2, see file LICENSE in this source tree.
9 //applet:IF_BLOCKDEV(APPLET(blockdev, BB_DIR_SBIN, BB_SUID_DROP))
11 //kbuild:lib-$(CONFIG_BLOCKDEV) += blockdev.o
13 //config:config BLOCKDEV
14 //config: bool "blockdev"
17 //config: Performs some ioctls with block devices.
19 //usage:#define blockdev_trivial_usage
20 //usage: "OPTION BLOCKDEV"
21 //usage:#define blockdev_full_usage "\n\n"
23 //usage: "\n --setro Set ro"
24 //usage: "\n --setrw Set rw"
25 //usage: "\n --getro Get ro"
26 //usage: "\n --getss Get sector size"
27 //usage: "\n --getbsz Get block size"
28 //usage: "\n --setbsz BYTES Set block size"
29 //usage: "\n --getsize Get device size in 512-byte sectors"
30 //usage: "\n --getsize64 Get device size in bytes"
31 //usage: "\n --flushbufs Flush buffers"
32 //usage: "\n --rereadpt Reread partition table"
42 /* Yes, BLKGETSIZE64 takes pointer to uint64_t, not ullong! */
46 FL_USRARG = 4, /* argument is provided by user */
51 uint32_t ioc; /* ioctl code */
52 const char name[sizeof("flushbufs")]; /* "--setfoo" wothout "--" */
54 int8_t argval; /* default argument value */
57 static const struct bdc bdcommands[] = {
61 .flags = ARG_INT + FL_NORESULT,
66 .flags = ARG_INT + FL_NORESULT,
86 .flags = ARG_INT + FL_NORESULT + FL_USRARG,
101 .flags = ARG_NONE + FL_NORESULT,
106 .flags = ARG_NONE + FL_NORESULT,
111 static const struct bdc *find_cmd(const char *s)
113 const struct bdc *bdcmd = bdcommands;
114 if (s[0] == '-' && s[1] == '-') {
117 if (strcmp(s, bdcmd->name) == 0)
120 } while (bdcmd != bdcommands + ARRAY_SIZE(bdcommands));
125 int blockdev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
126 int blockdev_main(int argc, char **argv)
128 const struct bdc *bdcmd;
135 } ioctl_val_on_stack;
137 if ((unsigned)(argc - 3) > 1) /* must have 2 or 3 args */
140 bdcmd = find_cmd(*++argv);
142 u64 = (int)bdcmd->argval;
143 if (bdcmd->flags & FL_USRARG)
144 u64 = xatoi_positive(*++argv);
146 if (!*++argv || argv[1])
148 fd = xopen(*argv, O_RDONLY);
150 ioctl_val_on_stack.u64 = u64;
152 /* Store data properly wrt data size.
153 * (1) It's no-op for little-endian.
154 * (2) it's no-op for 0 and -1. Only --setro uses arg != 0 and != -1,
155 * and it is ARG_INT. --setbsz USER_VAL is also ARG_INT.
156 * Thus, we don't need to handle ARG_ULONG.
158 switch (bdcmd->flags & ARG_MASK) {
160 ioctl_val_on_stack.i = (int)u64;
164 ioctl_val_on_stack.lu = (unsigned long)u64;
170 if (ioctl(fd, bdcmd->ioc, &ioctl_val_on_stack.u64) == -1)
171 bb_simple_perror_msg_and_die(*argv);
173 /* Fetch it into register(s) */
174 u64 = ioctl_val_on_stack.u64;
176 /* Zero- or one-extend the value if needed, then print */
177 switch (bdcmd->flags & (ARG_MASK+FL_NORESULT)) {
179 /* Smaller code when we use long long
180 * (gcc tail-merges printf call)
182 printf("%lld\n", (long long)(int)u64);
185 u64 = (unsigned long)u64;
188 printf("%llu\n", (unsigned long long)u64);
192 if (ENABLE_FEATURE_CLEAN_UP)