[Linux-NTFS-cvs] CVS: dynamic-disk/linux/fs/partitions ldm.c,1.55,1.56

[Jakob K. <jk...@us...>]

Changes by: jkemi

Update of /cvsroot/linux-ntfs/dynamic-disk/linux/fs/partitions
In directory usw-pr-cvs1:/tmp/cvs-serv6801

Modified Files:
	ldm.c 
Log Message:
ldm_parse_guid(), ldm_parse_hex*(): comments, cleanups.
ldm_validate_tocblocks(), ldm_validate_privheads(): rewritten.


Index: ldm.c
===================================================================
RCS file: /cvsroot/linux-ntfs/dynamic-disk/linux/fs/partitions/ldm.c,v
retrieving revision 1.55
retrieving revision 1.56
diff -U2 -r1.55 -r1.56
--- ldm.c	9 Feb 2002 13:43:05 -0000	1.55
+++ ldm.c	9 Feb 2002 16:39:33 -0000	1.56
@@ -81,73 +81,62 @@
 }
 #endif
-/**
- * ldm_hex
- */
-static int ldm_hex (u8 ch)
-{
-        if (ch >= 'a' && ch <= 'f')
-                return ch-'a'+10;
-        if (ch >= '0' && ch <= '9')
-                return ch-'0';
-        if (ch >= 'A' && ch <= 'F')
-                return ch-'A'+10;
-        return -1;
-}
 
 /**
- * ldm_parse_hex
+ * ldm_parse_hexbyte - Convert a ASCII hex number to a byte
+ * @src: Pointer to at least 2 characters to convert.
+ *
+ * Return: integer in the range [0,255] on success
+ *         -1 on error.
  */
-static int ldm_parse_hex (const u8 *data)
+static int ldm_parse_hexbyte (const u8 *src)
 {
-	int val, ch;
+	unsigned int a, b, c;	/* For correct wrapping */
+	int h;
 
-	if (!data)
-		return -1;
-
-	ch = ldm_hex (data[0]);
-	if (ch < 0)
-		return -1;
-	val = ch << 4;
-	ch = ldm_hex (data[1]);
-	if (ch < 0)
-		return -1;
-	val += ch;
+	/* high part */
+	if      ((a = src[0] - '0') <= '9'-'0') h = a;
+	else if ((b = src[0] - 'A') <= 'F'-'A') h = b+10;
+	else if ((c = src[0] - 'a') <= 'f'-'a') h = c+10;
+	else return -1;
+	h = h << 4;
 
-	return val;
+	/* low part */
+	if      ((a = src[1] - '0') <= '9'-'0') return h | a;
+	else if ((b = src[1] - 'A') <= 'F'-'A') return h | (b+10);
+	else if ((c = src[1] - 'a') <= 'f'-'a') return h | (c+10);
+	return -1;
 }
 
 /**
- * ldm_parse_guid
- * 36 char string -> unambiguous binary
- * fa50ff2b-f2e8-45de-83fa-65417f2f49ba
+ * ldm_parse_guid - Convert GUID from ASCII to binary
+ * @src:  36 char string on the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
+ * @dest: memory block to hold binary GUID (16 bytes)
+ *
  * NB not NULL terminated!
+ *
+ * Return: TRUE   @dest contains binary GUID
+ *         FALSE  @dest contents are undefined
  */
-static int ldm_parse_guid (const u8 *data, u8 *buffer)
+static BOOL ldm_parse_guid (const u8 *src, u8 *dest)
 {
-	static int size[] = { 4, 2, 2, 2, 6 };
-	int i, j, val;
+	const int size[] = { 4, 2, 2, 2, 6 };
+	int i, j, v;
 
-	if (!data || !buffer)
-		return 0;
-
-	if ((data[8]  != '-') || (data[13] != '-') ||
-	    (data[18] != '-') || (data[23] != '-'))
-		return 0;
+	if (src[8]  != '-' || src[13] != '-' ||
+	    src[18] != '-' || src[23] != '-')
+		return FALSE;
 
 	for (j = 0; j < 5; j++) {
-		for (i = 0; i < size[j]; i++, data+=2, buffer++)
-		{
-			val = ldm_parse_hex (data);
-			if (val < 0)
+		for (i = 0; i < size[j]; i++, src+=2, dest++) {
+			if ((v = ldm_parse_hexbyte(src)) < 0)
 				return 0;
-			*buffer = val;
+			*dest = v;
 		}
-		data++;
+		src++;
 	}
 
-	return 1;
+	return TRUE;
 }
 
-
 /**
  * ldm_parse_privhead - Read the LDM Database PRIVHEAD structure
@@ -414,49 +403,33 @@
 	Sector sect;
 	u8 *data;
-	struct privhead *ph2, *ph3;
-	BOOL result = FALSE;
-
-	BUG_ON (!bdev || !ph1);
+	struct privhead ph2, ph3;
+	struct privhead *ph[3] = {NULL, &ph2, &ph3};
+	const int off[3] = {OFF_PRIVHEAD1, OFF_PRIVHEAD2, OFF_PRIVHEAD3};
+	int i;
+
+	/* Read and parse ph 2 & 3 */
+	// FIXME can ph 3 fail on odd-sized disks?
+	for (i = 1; i < 3; i++) {
+		int r;
+		if (!(data = read_dev_sector (bdev, base + off[i], &sect))) {
+			printk (LDM_CRIT "Disk read failed.\n");
+			return FALSE;
+		}
+		r = ldm_parse_privhead(data, ph[i]);
+		put_dev_sector (sect);
 
-	ph2 = (struct privhead*)kmalloc (sizeof (*ph2), GFP_KERNEL);
-	ph3 = (struct privhead*)kmalloc (sizeof (*ph3), GFP_KERNEL);
-	if (!ph2 || !ph3) {
-		printk (LDM_CRIT "Not enough memory for required buffers.\n");
-		goto free_mem;
+		if (!r)
+			return FALSE;
 	}
 
-	/* Read and parse second privhead. */
-	data = read_dev_sector (bdev, base + OFF_PRIVHEAD2, &sect);
-	if (!data)
-		goto out;
-	if (!ldm_parse_privhead (data, ph2))
-		goto out;
-	put_dev_sector (sect);
-
-	/* Read and parse third privhead. */
-	//FIXME this /could/ fail on odd-sized disks - might have to ignore errors
-	data = read_dev_sector (bdev, base + OFF_PRIVHEAD3, &sect);
-	if (!data)
-		goto out;
-	if (!ldm_parse_privhead (data, ph3))
-		goto out;
-
-	if ((!ldm_compare_privheads (ph1, ph2)) ||
-	    (!ldm_compare_privheads (ph1, ph3))) {
+	/* Compare privheads */
+	if (!ldm_compare_privheads (ph1, ph[1]) ||
+	    !ldm_compare_privheads (ph1, ph[2])) {
 		printk (LDM_CRIT "Primary and backup PRIVHEADs don't match.\n");
-	} else {
-		ldm_debug ("Validated PRIVHEADs successfully.\n");
-		result = TRUE;
+		return FALSE;
 	}
-	/* We _could_ have checked more. */
-out:
-	if (data)
-		put_dev_sector (sect);
-	else
-		printk (LDM_CRIT "Disk read failed.\n");
-free_mem:
-	kfree (ph2);
-	kfree (ph3);
-	return result;
+
+	ldm_debug ("Validated PRIVHEADs successfully.\n");
+	return TRUE;
 }
 
@@ -478,56 +451,35 @@
 	Sector sect;
 	u8 *data;
-	struct tocblock *toc2, *toc3, *toc4;
-	BOOL result = FALSE;
-
-	BUG_ON (!bdev || !toc1);
-
-	toc2 = (struct tocblock*)kmalloc (sizeof (*toc2), GFP_KERNEL);
-	toc3 = (struct tocblock*)kmalloc (sizeof (*toc3), GFP_KERNEL);
-	toc4 = (struct tocblock*)kmalloc (sizeof (*toc4), GFP_KERNEL);
-	if (!toc2 || !toc3 || !toc4) {
-		printk (LDM_CRIT "Not enough memory to allocate required "
-			"buffers.\n");
-		goto free_mem;
-	}
+	struct tocblock toc2, toc3, toc4;
+	struct tocblock* tb[4] = {toc1, &toc2, &toc3, &toc4};
+	const int off[4] = {
+		OFF_TOCBLOCK1, OFF_TOCBLOCK2, OFF_TOCBLOCK3, OFF_TOCBLOCK4};
+	int i;
 
 	/* Read and parse all four toc's. */
-	data = read_dev_sector (bdev, base + OFF_TOCBLOCK1, &sect);
-	if (!data || !ldm_parse_tocblock (data, toc1))
-		goto out;
-	put_dev_sector (sect);
-
-	data = read_dev_sector (bdev, base + OFF_TOCBLOCK2, &sect);
-	if (!data || !ldm_parse_tocblock (data, toc2))
-		goto out;
-	put_dev_sector (sect);
-
-	data = read_dev_sector (bdev, base + OFF_TOCBLOCK3, &sect);
-	if (!data || !ldm_parse_tocblock (data, toc3))
-		goto out;
-	put_dev_sector (sect);
+	for (i = 0; i < 4; i++)
+	{
+		int r;
+		if (!(data = read_dev_sector (bdev, base + off[i], &sect))) {
+			printk (LDM_CRIT "Disk read failed.\n");
+			return FALSE;
+		}
+		r = ldm_parse_tocblock (data, tb[i]);
+		put_dev_sector (sect);
 
-	data = read_dev_sector (bdev, base + OFF_TOCBLOCK4, &sect);
-	if (!data || !ldm_parse_tocblock (data, toc4))
-		goto out;
+		if (!r)
+			return FALSE;
+	}
 
-	if ((!ldm_compare_tocblocks (toc1, toc2)) ||	/* Compare all tocs. */
-	    (!ldm_compare_tocblocks (toc1, toc3)) ||
-	    (!ldm_compare_tocblocks (toc1, toc4))) {
+	/* Compare all tocs. */
+	if (!ldm_compare_tocblocks (tb[0], tb[1]) ||
+	    !ldm_compare_tocblocks (tb[0], tb[2]) ||
+	    !ldm_compare_tocblocks (tb[0], tb[3])) {
 		printk (LDM_CRIT "The TOCBLOCKs don't match.\n");
-	} else {
-		ldm_debug ("Validated TOCBLOCKs successfully.\n");
-		result = TRUE;
+		return FALSE;
 	}
-out:
-	if (data)
-		put_dev_sector (sect);
-	else
-		printk (LDM_CRIT "Disk read failed.\n");
-free_mem:
-	kfree (toc2);
-	kfree (toc3);
-	kfree (toc4);
-	return result;
+
+	ldm_debug ("Validated TOCBLOCKs successfully.\n");
+	return TRUE;
 }
 
@@ -1601,4 +1553,2 @@
 	return err;
 }
-
-