mkfs.minix: more cleanups, -~300 bytes of code.

Added debugging support.

1 files changed, 204 insertions, 202 deletions

diff --git a/util-linux/mkfs_minix.c b/util-linux/mkfs_minix.c
index e9ba50046..687cf675f 100644
--- a/util-linux/mkfs_minix.c
+++ b/util-linux/mkfs_minix.c
@@ -33,8 +33,8 @@
  * 03.01.94  -	Added support for file system valid flag.
  *		(Dr. Wettstein, greg%wind.uucp@plains.nodak.edu)
  *
- * 30.10.94 - added support for v2 filesystem
- *	      (Andreas Schwab, schwab@issan.informatik.uni-dortmund.de)
+ * 30.10.94  -  added support for v2 filesystem
+ *	        (Andreas Schwab, schwab@issan.informatik.uni-dortmund.de)
  *
  * 09.11.94  -	Added test to prevent overwrite of mounted fs adapted
  *		from Theodore Ts'o's (tytso@athena.mit.edu) mke2fs
@@ -65,32 +65,24 @@
 #include "busybox.h"
 #include <mntent.h>
 
-#define MINIX_ROOT_INO 1
-#define MINIX_LINK_MAX	250
-#define MINIX2_LINK_MAX	65530
+#define DEBUG 0
 
-#define MINIX_I_MAP_SLOTS	8
-#define MINIX_Z_MAP_SLOTS	64
-#define MINIX_SUPER_MAGIC	0x137F		/* original minix fs */
-#define MINIX_SUPER_MAGIC2	0x138F		/* minix fs, 30 char names */
-#define MINIX2_SUPER_MAGIC	0x2468		/* minix V2 fs */
-#define MINIX2_SUPER_MAGIC2	0x2478		/* minix V2 fs, 30 char names */
-#define MINIX_VALID_FS		0x0001		/* Clean fs. */
-#define MINIX_ERROR_FS		0x0002		/* fs has errors. */
-
-#define MINIX_INODES_PER_BLOCK ((BLOCK_SIZE)/(sizeof (struct minix_inode)))
-#define MINIX2_INODES_PER_BLOCK ((BLOCK_SIZE)/(sizeof (struct minix2_inode)))
-
-#define MINIX_V1		0x0001		/* original minix fs */
-#define MINIX_V2		0x0002		/* minix V2 fs */
-
-#define INODE_VERSION(inode)	inode->i_sb->u.minix_sb.s_version
+/* If debugging, store the very same times/uids/gids for image consistency */
+#if DEBUG
+# define CUR_TIME 0
+# define GETUID 0
+# define GETGID 0
+#else
+# define CUR_TIME time(NULL)
+# define GETUID getuid()
+# define GETGID getgid()
+#endif
 
 /*
  * This is the original minix inode layout on disk.
  * Note the 8-bit gid and atime and ctime.
  */
-struct minix_inode {
+struct minix1_inode {
 	uint16_t i_mode;
 	uint16_t i_uid;
 	uint32_t i_size;
@@ -139,107 +131,106 @@ struct minix_dir_entry {
 	char name[0];
 };
 
-#define NAME_MAX         255   /* # chars in a file name */
-
-#define MINIX_INODES_PER_BLOCK ((BLOCK_SIZE)/(sizeof (struct minix_inode)))
-
-#define MINIX_VALID_FS               0x0001          /* Clean fs. */
-#define MINIX_ERROR_FS               0x0002          /* fs has errors. */
-
-#define MINIX_SUPER_MAGIC    0x137F          /* original minix fs */
-#define MINIX_SUPER_MAGIC2   0x138F          /* minix fs, 30 char names */
-
-#ifndef BLKGETSIZE
-#define BLKGETSIZE _IO(0x12,96)    /* return device size */
-#endif
-
-
-#ifndef __linux__
-#define volatile
-#endif
-
-#define MINIX_ROOT_INO 1
-#define MINIX_BAD_INO 2
-
-#define TEST_BUFFER_BLOCKS 16
-#define MAX_GOOD_BLOCKS 512
-
-#define UPPER(size,n) (((size)+((n)-1))/(n))
-#define INODE_SIZE (sizeof(struct minix_inode))
+/* Believe it or not, but mount.h has this one */
+#undef BLOCK_SIZE
+enum {
+	BLOCK_SIZE              = 1024,
+	BITS_PER_BLOCK          = BLOCK_SIZE << 3,
+
+	MINIX_ROOT_INO          = 1,
+	MINIX_BAD_INO           = 2,
+	MAX_GOOD_BLOCKS         = 512,
+
+	MINIX1_SUPER_MAGIC      = 0x137F,       /* original minix fs */
+	MINIX1_SUPER_MAGIC2     = 0x138F,       /* minix fs, 30 char names */
+	MINIX2_SUPER_MAGIC      = 0x2468,       /* minix V2 fs */
+	MINIX2_SUPER_MAGIC2     = 0x2478,       /* minix V2 fs, 30 char names */
+	MINIX_VALID_FS          = 0x0001,       /* clean fs */
+	MINIX_ERROR_FS          = 0x0002,       /* fs has errors */
+
+	INODE_SIZE1             = sizeof(struct minix1_inode),
+	INODE_SIZE2             = sizeof(struct minix2_inode),
+	MINIX1_INODES_PER_BLOCK = BLOCK_SIZE / sizeof(struct minix1_inode),
+	MINIX2_INODES_PER_BLOCK = BLOCK_SIZE / sizeof(struct minix2_inode),
+
+	TEST_BUFFER_BLOCKS      = 16,
+};
 
 #if ENABLE_FEATURE_MINIX2
-# define INODE_SIZE2 (sizeof(struct minix2_inode))
-# define INODE_BLOCKS UPPER(INODES, (version2 ? MINIX2_INODES_PER_BLOCK \
-				    : MINIX_INODES_PER_BLOCK))
+static int version2;
 #else
-# define INODE_BLOCKS UPPER(INODES, (MINIX_INODES_PER_BLOCK))
+enum { version2 = 0 };
 #endif
 
-#define INODE_BUFFER_SIZE (INODE_BLOCKS * BLOCK_SIZE)
-
-#define BITS_PER_BLOCK (BLOCK_SIZE<<3)
-
 static char *device_name;
-static int DEV = -1;
-static uint32_t BLOCKS;
+static int dev_fd = -1;
+static uint32_t total_blocks;
 static int badblocks;
 /* default (changed to 30, per Linus's suggestion, Sun Nov 21 08:05:07 1993) */
 static int namelen = 30;
 static int dirsize = 32;
-static int magic = MINIX_SUPER_MAGIC2;
-#if ENABLE_FEATURE_MINIX2
-static int version2;
-#else
-enum { version2 = 0 };
-#endif
+static int magic = MINIX1_SUPER_MAGIC2;
 
 static char root_block[BLOCK_SIZE];
-
-static char *inode_buffer;
-
-#define Inode (((struct minix_inode *) inode_buffer)-1)
-#if ENABLE_FEATURE_MINIX2
-#define Inode2 (((struct minix2_inode *) inode_buffer)-1)
-#endif
 static char super_block_buffer[BLOCK_SIZE];
 static char boot_block_buffer[512];
-
-#define Super (*(struct minix_super_block *)super_block_buffer)
-
-#define INODES (Super.s_ninodes)
-#if ENABLE_FEATURE_MINIX2
-# define ZONES (version2 ? Super.s_zones : Super.s_nzones)
-#else
-# define ZONES (Super.s_nzones)
-#endif
-
-#define IMAPS (Super.s_imap_blocks)
-#define ZMAPS (Super.s_zmap_blocks)
-#define FIRSTZONE (Super.s_firstdatazone)
-#define ZONESIZE (Super.s_log_zone_size)
-#define MAXSIZE (Super.s_max_size)
-#define MAGIC (Super.s_magic)
-#define NORM_FIRSTZONE (2+IMAPS+ZMAPS+INODE_BLOCKS)
+static char *inode_buffer;
 
 static char *inode_map;
 static char *zone_map;
 
-static unsigned short good_blocks_table[MAX_GOOD_BLOCKS];
 static int used_good_blocks;
+static unsigned short good_blocks_table[MAX_GOOD_BLOCKS];
 static unsigned long req_nr_inodes;
 
-static int bit(char* a, unsigned i)
+extern inline unsigned div_roundup(unsigned size, unsigned n)
+{
+	return (size + n-1) / n;
+}
+
+#define INODE_BUF1              (((struct minix1_inode*)inode_buffer) - 1)
+#define INODE_BUF2              (((struct minix2_inode*)inode_buffer) - 1)
+
+#define SB                      (*(struct minix_super_block*)super_block_buffer)
+
+#define SB_INODES               (SB.s_ninodes)
+#define SB_IMAPS                (SB.s_imap_blocks)
+#define SB_ZMAPS                (SB.s_zmap_blocks)
+#define SB_FIRSTZONE            (SB.s_firstdatazone)
+#define SB_ZONE_SIZE            (SB.s_log_zone_size)
+#define SB_MAXSIZE              (SB.s_max_size)
+#define SB_MAGIC                (SB.s_magic)
+
+#if !ENABLE_FEATURE_MINIX2
+# define SB_ZONES               (SB.s_nzones)
+# define INODE_BLOCKS           div_roundup(SB_INODES, MINIX1_INODES_PER_BLOCK)
+#else
+# define SB_ZONES               (version2 ? SB.s_zones : SB.s_nzones)
+# define INODE_BLOCKS           div_roundup(SB_INODES, \
+                                version2 ? MINIX2_INODES_PER_BLOCK : MINIX1_INODES_PER_BLOCK)
+#endif
+
+#define INODE_BUFFER_SIZE       (INODE_BLOCKS * BLOCK_SIZE)
+#define NORM_FIRSTZONE          (2 + SB_IMAPS + SB_ZMAPS + INODE_BLOCKS)
+
+static int bit(const char* a, unsigned i)
 {
-	  return (a[i >> 3] & (1<<(i & 7))) != 0;
+	  return a[i >> 3] & (1<<(i & 7));
 }
-#define inode_in_use(x) (bit(inode_map,(x)))
-#define zone_in_use(x) (bit(zone_map,(x)-FIRSTZONE+1))
 
-#define mark_inode(x) (setbit(inode_map,(x)))
-#define unmark_inode(x) (clrbit(inode_map,(x)))
+/* Note: do not assume 0/1, it is 0/nonzero */
+#define inode_in_use(x) bit(inode_map,(x))
+#define zone_in_use(x)  bit(zone_map,(x)-SB_FIRSTZONE+1)
+
+#define mark_inode(x)   setbit(inode_map,(x))
+#define unmark_inode(x) clrbit(inode_map,(x))
+#define mark_zone(x)    setbit(zone_map,(x)-SB_FIRSTZONE+1)
+#define unmark_zone(x)  clrbit(zone_map,(x)-SB_FIRSTZONE+1)
+
+#ifndef BLKGETSIZE
+# define BLKGETSIZE     _IO(0x12,96)    /* return device size */
+#endif
 
-#define mark_zone(x) (setbit(zone_map,(x)-FIRSTZONE+1))
-#define unmark_zone(x) (clrbit(zone_map,(x)-FIRSTZONE+1))
 
 static long valid_offset(int fd, int offset)
 {
@@ -291,37 +282,37 @@ static int get_size(const char *file)
 static void write_tables(void)
 {
 	/* Mark the super block valid. */
-	Super.s_state |= MINIX_VALID_FS;
-	Super.s_state &= ~MINIX_ERROR_FS;
+	SB.s_state |= MINIX_VALID_FS;
+	SB.s_state &= ~MINIX_ERROR_FS;
 
 	msg_eol = "seek to 0 failed";
-	xlseek(DEV, 0, SEEK_SET);
+	xlseek(dev_fd, 0, SEEK_SET);
 
 	msg_eol = "cannot clear boot sector";
-	xwrite(DEV, boot_block_buffer, 512);
+	xwrite(dev_fd, boot_block_buffer, 512);
 
 	msg_eol = "seek to BLOCK_SIZE failed";
-	xlseek(DEV, BLOCK_SIZE, SEEK_SET);
+	xlseek(dev_fd, BLOCK_SIZE, SEEK_SET);
 
 	msg_eol = "cannot write superblock";
-	xwrite(DEV, super_block_buffer, BLOCK_SIZE);
+	xwrite(dev_fd, super_block_buffer, BLOCK_SIZE);
 
 	msg_eol = "cannot write inode map";
-	xwrite(DEV, inode_map, IMAPS * BLOCK_SIZE);
+	xwrite(dev_fd, inode_map, SB_IMAPS * BLOCK_SIZE);
 
 	msg_eol = "cannot write zone map";
-	xwrite(DEV, zone_map, ZMAPS * BLOCK_SIZE);
+	xwrite(dev_fd, zone_map, SB_ZMAPS * BLOCK_SIZE);
 
 	msg_eol = "cannot write inodes";
-	xwrite(DEV, inode_buffer, INODE_BUFFER_SIZE);
+	xwrite(dev_fd, inode_buffer, INODE_BUFFER_SIZE);
 
 	msg_eol = "\n";
 }
 
 static void write_block(int blk, char *buffer)
 {
-	xlseek(DEV, blk * BLOCK_SIZE, SEEK_SET);
-	xwrite(DEV, buffer, BLOCK_SIZE);
+	xlseek(dev_fd, blk * BLOCK_SIZE, SEEK_SET);
+	xwrite(dev_fd, buffer, BLOCK_SIZE);
 }
 
 static int get_free_block(void)
@@ -333,10 +324,10 @@ static int get_free_block(void)
 	if (used_good_blocks)
 		blk = good_blocks_table[used_good_blocks - 1] + 1;
 	else
-		blk = FIRSTZONE;
-	while (blk < ZONES && zone_in_use(blk))
+		blk = SB_FIRSTZONE;
+	while (blk < SB_ZONES && zone_in_use(blk))
 		blk++;
-	if (blk >= ZONES)
+	if (blk >= SB_ZONES)
 		bb_error_msg_and_die("not enough good blocks");
 	good_blocks_table[used_good_blocks] = blk;
 	used_good_blocks++;
@@ -354,8 +345,8 @@ static void mark_good_blocks(void)
 static int next(int zone)
 {
 	if (!zone)
-		zone = FIRSTZONE - 1;
-	while (++zone < ZONES)
+		zone = SB_FIRSTZONE - 1;
+	while (++zone < SB_ZONES)
 		if (zone_in_use(zone))
 			return zone;
 	return 0;
@@ -363,7 +354,7 @@ static int next(int zone)
 
 static void make_bad_inode(void)
 {
-	struct minix_inode *inode = &Inode[MINIX_BAD_INO];
+	struct minix1_inode *inode = &INODE_BUF1[MINIX_BAD_INO];
 	int i, j, zone;
 	int ind = 0, dind = 0;
 	unsigned short ind_block[BLOCK_SIZE >> 1];
@@ -377,7 +368,7 @@ static void make_bad_inode(void)
 	inode->i_nlinks = 1;
 	/* BTW, setting this makes all images different */
 	/* it's harder to check for bugs then - diff isn't helpful :(... */
-	inode->i_time = time(NULL);
+	inode->i_time = CUR_TIME;
 	inode->i_mode = S_IFREG + 0000;
 	inode->i_size = badblocks * BLOCK_SIZE;
 	zone = next(0);
@@ -406,7 +397,7 @@ static void make_bad_inode(void)
 		}
 	}
 	bb_error_msg_and_die("too many bad blocks");
-  end_bad:
+ end_bad:
 	if (ind)
 		write_block(ind, (char *) ind_block);
 	if (dind)
@@ -416,7 +407,7 @@ static void make_bad_inode(void)
 #if ENABLE_FEATURE_MINIX2
 static void make_bad_inode2(void)
 {
-	struct minix2_inode *inode = &Inode2[MINIX_BAD_INO];
+	struct minix2_inode *inode = &INODE_BUF2[MINIX_BAD_INO];
 	int i, j, zone;
 	int ind = 0, dind = 0;
 	unsigned long ind_block[BLOCK_SIZE >> 2];
@@ -426,7 +417,7 @@ static void make_bad_inode2(void)
 		return;
 	mark_inode(MINIX_BAD_INO);
 	inode->i_nlinks = 1;
-	inode->i_atime = inode->i_mtime = inode->i_ctime = time(NULL);
+	inode->i_atime = inode->i_mtime = inode->i_ctime = CUR_TIME;
 	inode->i_mode = S_IFREG + 0000;
 	inode->i_size = badblocks * BLOCK_SIZE;
 	zone = next(0);
@@ -456,7 +447,7 @@ static void make_bad_inode2(void)
 	}
 	/* Could make triple indirect block here */
 	bb_error_msg_and_die("too many bad blocks");
-  end_bad:
+ end_bad:
 	if (ind)
 		write_block(ind, (char *) ind_block);
 	if (dind)
@@ -466,12 +457,12 @@ static void make_bad_inode2(void)
 
 static void make_root_inode(void)
 {
-	struct minix_inode *inode = &Inode[MINIX_ROOT_INO];
+	struct minix1_inode *inode = &INODE_BUF1[MINIX_ROOT_INO];
 
 	mark_inode(MINIX_ROOT_INO);
 	inode->i_zone[0] = get_free_block();
 	inode->i_nlinks = 2;
-	inode->i_time = time(NULL);
+	inode->i_time = CUR_TIME;
 	if (badblocks)
 		inode->i_size = 3 * dirsize;
 	else {
@@ -480,21 +471,21 @@ static void make_root_inode(void)
 		inode->i_size = 2 * dirsize;
 	}
 	inode->i_mode = S_IFDIR + 0755;
-	inode->i_uid = getuid();
+	inode->i_uid = GETUID;
 	if (inode->i_uid)
-		inode->i_gid = getgid();
+		inode->i_gid = GETGID;
 	write_block(inode->i_zone[0], root_block);
 }
 
 #if ENABLE_FEATURE_MINIX2
 static void make_root_inode2(void)
 {
-	struct minix2_inode *inode = &Inode2[MINIX_ROOT_INO];
+	struct minix2_inode *inode = &INODE_BUF2[MINIX_ROOT_INO];
 
 	mark_inode(MINIX_ROOT_INO);
 	inode->i_zone[0] = get_free_block();
 	inode->i_nlinks = 2;
-	inode->i_atime = inode->i_mtime = inode->i_ctime = time(NULL);
+	inode->i_atime = inode->i_mtime = inode->i_ctime = CUR_TIME;
 	if (badblocks)
 		inode->i_size = 3 * dirsize;
 	else {
@@ -503,9 +494,9 @@ static void make_root_inode2(void)
 		inode->i_size = 2 * dirsize;
 	}
 	inode->i_mode = S_IFDIR + 0755;
-	inode->i_uid = getuid();
+	inode->i_uid = GETUID;
 	if (inode->i_uid)
-		inode->i_gid = getgid();
+		inode->i_gid = GETGID;
 	write_block(inode->i_zone[0], root_block);
 }
 #endif
@@ -517,65 +508,64 @@ static void setup_tables(void)
 
 	memset(super_block_buffer, 0, BLOCK_SIZE);
 	memset(boot_block_buffer, 0, 512);
-	MAGIC = magic;
-	ZONESIZE = 0;
-	MAXSIZE = version2 ? 0x7fffffff : (7 + 512 + 512 * 512) * 1024;
-	if (version2) {
-		Super.s_zones =  BLOCKS;
-	} else
-		Super.s_nzones = BLOCKS;
+	SB_MAGIC = magic;
+	SB_ZONE_SIZE = 0;
+	SB_MAXSIZE = version2 ? 0x7fffffff : (7 + 512 + 512 * 512) * 1024;
+	if (version2)
+		SB.s_zones = total_blocks;
+	else
+		SB.s_nzones = total_blocks;
 
-/* some magic nrs: 1 inode / 3 blocks */
+	/* some magic nrs: 1 inode / 3 blocks */
 	if (req_nr_inodes == 0)
-		inodes = BLOCKS / 3;
+		inodes = total_blocks / 3;
 	else
 		inodes = req_nr_inodes;
 	/* Round up inode count to fill block size */
 	if (version2)
-		inodes = ((inodes + MINIX2_INODES_PER_BLOCK - 1) &
-				  ~(MINIX2_INODES_PER_BLOCK - 1));
+		inodes = (inodes + MINIX2_INODES_PER_BLOCK - 1) &
+		                 ~(MINIX2_INODES_PER_BLOCK - 1);
 	else
-		inodes = ((inodes + MINIX_INODES_PER_BLOCK - 1) &
-				  ~(MINIX_INODES_PER_BLOCK - 1));
+		inodes = (inodes + MINIX1_INODES_PER_BLOCK - 1) &
+		                 ~(MINIX1_INODES_PER_BLOCK - 1);
 	if (inodes > 65535)
 		inodes = 65535;
-	INODES = inodes;
-	IMAPS = UPPER(INODES + 1, BITS_PER_BLOCK);
-	ZMAPS = 0;
-	i = 0;
-	while (ZMAPS !=
-		   UPPER(BLOCKS - (2 + IMAPS + ZMAPS + INODE_BLOCKS) + 1,
-				 BITS_PER_BLOCK) && i < 1000) {
-		ZMAPS =
-			UPPER(BLOCKS - (2 + IMAPS + ZMAPS + INODE_BLOCKS) + 1,
-				  BITS_PER_BLOCK);
-		i++;
-	}
+	SB_INODES = inodes;
+	SB_IMAPS = div_roundup(SB_INODES + 1, BITS_PER_BLOCK);
+
 	/* Real bad hack but overwise mkfs.minix can be thrown
 	 * in infinite loop...
 	 * try:
 	 * dd if=/dev/zero of=test.fs count=10 bs=1024
-	 * /sbin/mkfs.minix -i 200 test.fs
-	 * */
-	if (i >= 999) {
-		bb_error_msg_and_die("cannot allocate buffers for maps");
-	}
-	FIRSTZONE = NORM_FIRSTZONE;
-	inode_map = xmalloc(IMAPS * BLOCK_SIZE);
-	zone_map = xmalloc(ZMAPS * BLOCK_SIZE);
-	memset(inode_map, 0xff, IMAPS * BLOCK_SIZE);
-	memset(zone_map, 0xff, ZMAPS * BLOCK_SIZE);
-	for (i = FIRSTZONE; i < ZONES; i++)
+	 * mkfs.minix -i 200 test.fs
+	 */
+	/* This code is not insane: NORM_FIRSTZONE is not a constant, */
+	/* it uses previous value of SB_ZMAPS inside */
+	i = 999;
+	SB_ZMAPS = 0;
+	do {
+		uint16_t t = div_roundup(total_blocks - NORM_FIRSTZONE + 1, BITS_PER_BLOCK);
+		if (SB_ZMAPS == t) goto got_it;
+		SB_ZMAPS = t;
+	} while (--i);
+	bb_error_msg_and_die("incompatible size/inode count, try different -i N");
+ got_it:
+
+	SB_FIRSTZONE = NORM_FIRSTZONE;
+	inode_map = xmalloc(SB_IMAPS * BLOCK_SIZE);
+	zone_map = xmalloc(SB_ZMAPS * BLOCK_SIZE);
+	memset(inode_map, 0xff, SB_IMAPS * BLOCK_SIZE);
+	memset(zone_map, 0xff, SB_ZMAPS * BLOCK_SIZE);
+	for (i = SB_FIRSTZONE; i < SB_ZONES; i++)
 		unmark_zone(i);
-	for (i = MINIX_ROOT_INO; i <= INODES; i++)
+	for (i = MINIX_ROOT_INO; i <= SB_INODES; i++)
 		unmark_inode(i);
-	inode_buffer = xmalloc(INODE_BUFFER_SIZE);
-	memset(inode_buffer, 0, INODE_BUFFER_SIZE);
-	printf("%ld inodes\n", (long)INODES);
-	printf("%ld blocks\n", (long)ZONES);
-	printf("Firstdatazone=%ld (%ld)\n", (long)FIRSTZONE, (long)NORM_FIRSTZONE);
-	printf("Zonesize=%d\n", BLOCK_SIZE << ZONESIZE);
-	printf("Maxsize=%ld\n\n", (long)MAXSIZE);
+	inode_buffer = xzalloc(INODE_BUFFER_SIZE);
+	printf("%ld inodes\n", (long)SB_INODES);
+	printf("%ld blocks\n", (long)SB_ZONES);
+	printf("Firstdatazone=%ld (%ld)\n", (long)SB_FIRSTZONE, (long)NORM_FIRSTZONE);
+	printf("Zonesize=%d\n", BLOCK_SIZE << SB_ZONE_SIZE);
+	printf("Maxsize=%ld\n", (long)SB_MAXSIZE);
 }
 
 /*
@@ -588,11 +578,11 @@ static long do_check(char *buffer, int try, unsigned current_block)
 
 	/* Seek to the correct loc. */
 	msg_eol = "seek failed during testing of blocks";
-	xlseek(DEV, current_block * BLOCK_SIZE, SEEK_SET);
+	xlseek(dev_fd, current_block * BLOCK_SIZE, SEEK_SET);
 	msg_eol = "\n";
 
 	/* Try the read */
-	got = read(DEV, buffer, try * BLOCK_SIZE);
+	got = read(dev_fd, buffer, try * BLOCK_SIZE);
 	if (got < 0)
 		got = 0;
 	if (got & (BLOCK_SIZE - 1)) {
@@ -606,7 +596,7 @@ static unsigned currently_testing;
 
 static void alarm_intr(int alnum)
 {
-	if (currently_testing >= ZONES)
+	if (currently_testing >= SB_ZONES)
 		return;
 	signal(SIGALRM, alarm_intr);
 	alarm(5);
@@ -624,18 +614,18 @@ static void check_blocks(void)
 	currently_testing = 0;
 	signal(SIGALRM, alarm_intr);
 	alarm(5);
-	while (currently_testing < ZONES) {
+	while (currently_testing < SB_ZONES) {
 		msg_eol = "seek failed in check_blocks";
-		xlseek(DEV, currently_testing * BLOCK_SIZE, SEEK_SET);
+		xlseek(dev_fd, currently_testing * BLOCK_SIZE, SEEK_SET);
 		msg_eol = "\n";
 		try = TEST_BUFFER_BLOCKS;
-		if (currently_testing + try > ZONES)
-			try = ZONES - currently_testing;
+		if (currently_testing + try > SB_ZONES)
+			try = SB_ZONES - currently_testing;
 		got = do_check(buffer, try, currently_testing);
 		currently_testing += got;
 		if (got == try)
 			continue;
-		if (currently_testing < FIRSTZONE)
+		if (currently_testing < SB_FIRSTZONE)
 			bb_error_msg_and_die("bad blocks before data-area: cannot make fs");
 		mark_zone(currently_testing);
 		badblocks++;
@@ -660,13 +650,14 @@ static void get_list_blocks(char *filename)
 
 int mkfs_minix_main(int argc, char **argv)
 {
+	struct mntent *mp;
 	unsigned opt;
 	char *tmp;
 	struct stat statbuf;
 	char *str_i, *str_n;
 	char *listfile = NULL;
 
-	if (INODE_SIZE * MINIX_INODES_PER_BLOCK != BLOCK_SIZE)
+	if (INODE_SIZE1 * MINIX1_INODES_PER_BLOCK != BLOCK_SIZE)
 		bb_error_msg_and_die("bad inode size");
 #if ENABLE_FEATURE_MINIX2
 	if (INODE_SIZE2 * MINIX2_INODES_PER_BLOCK != BLOCK_SIZE)
@@ -680,8 +671,8 @@ int mkfs_minix_main(int argc, char **argv)
 	//if (opt & 4) -l
 	if (opt & 8) { // -n
 		namelen = xatoi_u(str_n);
-		if (namelen == 14) magic = MINIX_SUPER_MAGIC;
-		else if (namelen == 30) magic = MINIX_SUPER_MAGIC2;
+		if (namelen == 14) magic = MINIX1_SUPER_MAGIC;
+		else if (namelen == 30) magic = MINIX1_SUPER_MAGIC2;
 		else bb_show_usage();
 		dirsize = namelen + 2;
 	}
@@ -697,23 +688,42 @@ int mkfs_minix_main(int argc, char **argv)
 	device_name = *argv++;
 	if (!device_name)
 		bb_show_usage();
-	if (*argv) {
-		BLOCKS = xatou32(*argv);
-		if (BLOCKS < 10)
-			bb_show_usage();
-	} else
-		BLOCKS = get_size(device_name) / 1024;
+	if (*argv)
+		total_blocks = xatou32(*argv);
+	else
+		total_blocks = get_size(device_name) / 1024;
+
+	if (total_blocks < 10)
+		bb_error_msg_and_die("must have at least 10 blocks");
 
 	if (version2) {
 		magic = MINIX2_SUPER_MAGIC2;
 		if (namelen == 14)
 			magic = MINIX2_SUPER_MAGIC;
-	} else if (BLOCKS > 65535)
-		BLOCKS = 65535;
+	} else if (total_blocks > 65535)
+		total_blocks = 65535;
+
+	/* Check if it is mounted */
+	mp = find_mount_point(device_name, NULL);
+	if (mp && strcmp(device_name, mp->mnt_fsname) == 0)
+		bb_error_msg_and_die("%s is mounted on %s; "
+				"refusing to make a filesystem",
+				device_name, mp->mnt_dir);
+
+	dev_fd = xopen(device_name, O_RDWR);
+	if (fstat(dev_fd, &statbuf) < 0)
+		bb_error_msg_and_die("cannot stat %s", device_name);
+	if (!S_ISBLK(statbuf.st_mode))
+		opt &= ~1; // clear -c (check)
 
-	if (find_mount_point(device_name, NULL))
-		bb_error_msg_and_die("%s is mounted; refusing to make "
-			"a filesystem", device_name);
+/* I don't know why someone has special code to prevent mkfs.minix
+ * on IDE devices. Why IDE but not SCSI, etc?... */
+#if 0
+	else if (statbuf.st_rdev == 0x0300 || statbuf.st_rdev == 0x0340)
+		/* what is this? */
+		bb_error_msg_and_die("will not try "
+			"to make filesystem on '%s'", device_name);
+#endif
 
 	tmp = root_block;
 	*(short *) tmp = 1;
@@ -725,14 +735,6 @@ int mkfs_minix_main(int argc, char **argv)
 	*(short *) tmp = 2;
 	strcpy(tmp + 2, ".badblocks");
 
-	DEV = xopen(device_name, O_RDWR);
-	if (fstat(DEV, &statbuf) < 0)
-		bb_error_msg_and_die("cannot stat %s", device_name);
-	if (!S_ISBLK(statbuf.st_mode))
-		opt &= ~1; // clear -c (check)
-	else if (statbuf.st_rdev == 0x0300 || statbuf.st_rdev == 0x0340)
-		bb_error_msg_and_die("will not try to make filesystem on '%s'", device_name);
-
 	setup_tables();
 
 	if (opt & 1) // -c ?