35082fc2c — BusyBox

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blockdev: code shrink

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Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

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util-linux/blockdev.c +58 -81

util-linux/blockdev.c+58 -81

@@ -34,6 +34,35 @@
	#include "libbb.h"
	#include <linux/fs.h>

+	/* Takes less space is separate arrays than one array of struct */
+	static const char bdcmd_names[] ALIGN1 =
+	"setro" "\0"
+	#define CMD_SETRO 0
+	"setrw" "\0"
+	"getro" "\0"
+	"getss" "\0"
+	"getbsz" "\0"
+	"setbsz" "\0"
+	#define CMD_SETBSZ 5
+	"getsz" "\0"
+	"getsize" "\0"
+	"getsize64" "\0"
+	"flushbufs" "\0"
+	"rereadpt" "\0"
+	;
+	static const uint32_t bdcmd_ioctl[] = {
+	BLKROSET, //setro
+	BLKROSET, //setrw
+	BLKROGET, //getro
+	BLKSSZGET, //getss
+	BLKBSZGET, //getbsz
+	BLKBSZSET, //setbsz
+	BLKGETSIZE64, //getsz
+	BLKGETSIZE, //getsize
+	BLKGETSIZE64, //getsize64
+	BLKFLSBUF, //flushbufs
+	BLKRRPART, //rereadpt
+	};
	enum {
	ARG_NONE = 0,
	ARG_INT = 1,
@@ -46,83 +75,26 @@ enum {
	FL_NORESULT = 8,
	FL_SCALE512 = 16,
	};
-
-	struct bdc {
-	uint32_t ioc; /* ioctl code */
-	const char name[sizeof("flushbufs")]; /* "--setfoo" wothout "--" */
-	uint8_t flags;
-	int8_t argval; /* default argument value */
+	static const uint8_t bdcmd_flags[] ALIGN1 = {
+	ARG_INT + FL_NORESULT, //setro
+	ARG_INT + FL_NORESULT, //setrw
+	ARG_INT, //getro
+	ARG_INT, //getss
+	ARG_INT, //getbsz
+	ARG_INT + FL_NORESULT + FL_USRARG, //setbsz
+	ARG_U64 + FL_SCALE512, //getsz
+	ARG_ULONG, //getsize
+	ARG_U64, //getsize64
+	ARG_NONE + FL_NORESULT, //flushbufs
+	ARG_NONE + FL_NORESULT, //rereadpt
	};

-	static const struct bdc bdcommands[] = {
-	{
-	.ioc = BLKROSET,
-	.name = "setro",
-	.flags = ARG_INT + FL_NORESULT,
-	.argval = 1,
-	},{
-	.ioc = BLKROSET,
-	.name = "setrw",
-	.flags = ARG_INT + FL_NORESULT,
-	.argval = 0,
-	},{
-	.ioc = BLKROGET,
-	.name = "getro",
-	.flags = ARG_INT,
-	.argval = -1,
-	},{
-	.ioc = BLKSSZGET,
-	.name = "getss",
-	.flags = ARG_INT,
-	.argval = -1,
-	},{
-	.ioc = BLKBSZGET,
-	.name = "getbsz",
-	.flags = ARG_INT,
-	.argval = -1,
-	},{
-	.ioc = BLKBSZSET,
-	.name = "setbsz",
-	.flags = ARG_INT + FL_NORESULT + FL_USRARG,
-	.argval = 0,
-	},{
-	.ioc = BLKGETSIZE64,
-	.name = "getsz",
-	.flags = ARG_U64 + FL_SCALE512,
-	.argval = -1,
-	},{
-	.ioc = BLKGETSIZE,
-	.name = "getsize",
-	.flags = ARG_ULONG,
-	.argval = -1,
-	},{
-	.ioc = BLKGETSIZE64,
-	.name = "getsize64",
-	.flags = ARG_U64,
-	.argval = -1,
-	},{
-	.ioc = BLKFLSBUF,
-	.name = "flushbufs",
-	.flags = ARG_NONE + FL_NORESULT,
-	.argval = 0,
-	},{
-	.ioc = BLKRRPART,
-	.name = "rereadpt",
-	.flags = ARG_NONE + FL_NORESULT,
-	.argval = 0,
-	}
-	};
-
-	static const struct bdc find_cmd(const char s)
+	static unsigned find_cmd(const char *s)
	{
-	const struct bdc *bdcmd = bdcommands;
	if (s[0] == '-' && s[1] == '-') {
-	s += 2;
-	do {
-	if (strcmp(s, bdcmd->name) == 0)
-	return bdcmd;
-	bdcmd++;
-	} while (bdcmd != bdcommands + ARRAY_SIZE(bdcommands));
+	int n = index_in_strings(bdcmd_names, s + 2);
+	if (n >= 0)
+	return n;
	}
	bb_show_usage();
	}
@@ -130,7 +102,8 @@ static const struct bdc find_cmd(const char s)
	int blockdev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
	int blockdev_main(int argc UNUSED_PARAM, char **argv)
	{
-	const struct bdc *bdcmd;
+	unsigned bdcmd;
+	unsigned flags;
	int fd;
	uint64_t u64;
	union {
@@ -144,10 +117,13 @@ int blockdev_main(int argc UNUSED_PARAM, char **argv)
	bb_show_usage();

	bdcmd = find_cmd(*argv);
-
-	u64 = (int)bdcmd->argval;
-	if (bdcmd->flags & FL_USRARG)
+	/* setrw translates to BLKROSET(0), most other ioctls don't care... */
+	/* ...setro will do BLKROSET(1) */
+	u64 = (bdcmd == CMD_SETRO);
+	if (bdcmd == CMD_SETBSZ) {
+	/* ...setbsz is BLKBSZSET(bytes) */
	u64 = xatoi_positive(*++argv);
+	}

	argv++;
	if (!argv[0] \|\| argv[1])
@@ -155,6 +131,7 @@ int blockdev_main(int argc UNUSED_PARAM, char **argv)
	fd = xopen(argv[0], O_RDONLY);

	ioctl_val_on_stack.u64 = u64;
+	flags = bdcmd_flags[bdcmd];
	#if BB_BIG_ENDIAN
	/* Store data properly wrt data size.
	* (1) It's no-op for little-endian.
@@ -162,7 +139,7 @@ int blockdev_main(int argc UNUSED_PARAM, char **argv)
	* and it is ARG_INT. --setbsz USER_VAL is also ARG_INT.
	* Thus, we don't need to handle ARG_ULONG.
	*/
-	switch (bdcmd->flags & ARG_MASK) {
+	switch (flags & ARG_MASK) {
	case ARG_INT:
	ioctl_val_on_stack.i = (int)u64;
	break;
@@ -174,17 +151,17 @@ int blockdev_main(int argc UNUSED_PARAM, char **argv)
	}
	#endif

-	if (ioctl(fd, bdcmd->ioc, &ioctl_val_on_stack.u64) == -1)
+	if (ioctl(fd, bdcmd_ioctl[bdcmd], &ioctl_val_on_stack.u64) == -1)
	bb_simple_perror_msg_and_die(*argv);

	/* Fetch it into register(s) */
	u64 = ioctl_val_on_stack.u64;

-	if (bdcmd->flags & FL_SCALE512)
+	if (flags & FL_SCALE512)
	u64 >>= 9;

	/* Zero- or one-extend the value if needed, then print */
-	switch (bdcmd->flags & (ARG_MASK+FL_NORESULT)) {
+	switch (flags & (ARG_MASK+FL_NORESULT)) {
	case ARG_INT:
	/* Smaller code when we use long long
	* (gcc tail-merges printf call)