Initial import of modified Linux 2.6.28 tree

Original upstream URL:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y

1 files changed, 529 insertions, 0 deletions

diff --git a/fs/partitions/msdos.c b/fs/partitions/msdos.c
new file mode 100644
index 0000000..7965118
--- /dev/null
+++ b/fs/partitions/msdos.c
@@ -0,0 +1,529 @@
+/*
+ *  fs/partitions/msdos.c
+ *
+ *  Code extracted from drivers/block/genhd.c
+ *  Copyright (C) 1991-1998  Linus Torvalds
+ *
+ *  Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug
+ *  in the early extended-partition checks and added DM partitions
+ *
+ *  Support for DiskManager v6.0x added by Mark Lord,
+ *  with information provided by OnTrack.  This now works for linux fdisk
+ *  and LILO, as well as loadlin and bootln.  Note that disks other than
+ *  /dev/hda *must* have a "DOS" type 0x51 partition in the first slot (hda1).
+ *
+ *  More flexible handling of extended partitions - aeb, 950831
+ *
+ *  Check partition table on IDE disks for common CHS translations
+ *
+ *  Re-organised Feb 1998 Russell King
+ */
+#include <linux/msdos_fs.h>
+
+#include "check.h"
+#include "msdos.h"
+#include "efi.h"
+
+/*
+ * Many architectures don't like unaligned accesses, while
+ * the nr_sects and start_sect partition table entries are
+ * at a 2 (mod 4) address.
+ */
+#include <asm/unaligned.h>
+
+#define SYS_IND(p)	(get_unaligned(&p->sys_ind))
+#define NR_SECTS(p)	({ __le32 __a =	get_unaligned(&p->nr_sects);	\
+				le32_to_cpu(__a); \
+			})
+
+#define START_SECT(p)	({ __le32 __a =	get_unaligned(&p->start_sect);	\
+				le32_to_cpu(__a); \
+			})
+
+static inline int is_extended_partition(struct partition *p)
+{
+	return (SYS_IND(p) == DOS_EXTENDED_PARTITION ||
+		SYS_IND(p) == WIN98_EXTENDED_PARTITION ||
+		SYS_IND(p) == LINUX_EXTENDED_PARTITION);
+}
+
+#define MSDOS_LABEL_MAGIC1	0x55
+#define MSDOS_LABEL_MAGIC2	0xAA
+
+static inline int
+msdos_magic_present(unsigned char *p)
+{
+	return (p[0] == MSDOS_LABEL_MAGIC1 && p[1] == MSDOS_LABEL_MAGIC2);
+}
+
+/* Value is EBCDIC 'IBMA' */
+#define AIX_LABEL_MAGIC1	0xC9
+#define AIX_LABEL_MAGIC2	0xC2
+#define AIX_LABEL_MAGIC3	0xD4
+#define AIX_LABEL_MAGIC4	0xC1
+static int aix_magic_present(unsigned char *p, struct block_device *bdev)
+{
+	struct partition *pt = (struct partition *) (p + 0x1be);
+	Sector sect;
+	unsigned char *d;
+	int slot, ret = 0;
+
+	if (!(p[0] == AIX_LABEL_MAGIC1 &&
+		p[1] == AIX_LABEL_MAGIC2 &&
+		p[2] == AIX_LABEL_MAGIC3 &&
+		p[3] == AIX_LABEL_MAGIC4))
+		return 0;
+	/* Assume the partition table is valid if Linux partitions exists */
+	for (slot = 1; slot <= 4; slot++, pt++) {
+		if (pt->sys_ind == LINUX_SWAP_PARTITION ||
+			pt->sys_ind == LINUX_RAID_PARTITION ||
+			pt->sys_ind == LINUX_DATA_PARTITION ||
+			pt->sys_ind == LINUX_LVM_PARTITION ||
+			is_extended_partition(pt))
+			return 0;
+	}
+	d = read_dev_sector(bdev, 7, &sect);
+	if (d) {
+		if (d[0] == '_' && d[1] == 'L' && d[2] == 'V' && d[3] == 'M')
+			ret = 1;
+		put_dev_sector(sect);
+	};
+	return ret;
+}
+
+/*
+ * Create devices for each logical partition in an extended partition.
+ * The logical partitions form a linked list, with each entry being
+ * a partition table with two entries.  The first entry
+ * is the real data partition (with a start relative to the partition
+ * table start).  The second is a pointer to the next logical partition
+ * (with a start relative to the entire extended partition).
+ * We do not create a Linux partition for the partition tables, but
+ * only for the actual data partitions.
+ */
+
+static void
+parse_extended(struct parsed_partitions *state, struct block_device *bdev,
+			u32 first_sector, u32 first_size)
+{
+	struct partition *p;
+	Sector sect;
+	unsigned char *data;
+	u32 this_sector, this_size;
+	int sector_size = bdev_hardsect_size(bdev) / 512;
+	int loopct = 0;		/* number of links followed
+				   without finding a data partition */
+	int i;
+
+	this_sector = first_sector;
+	this_size = first_size;
+
+	while (1) {
+		if (++loopct > 100)
+			return;
+		if (state->next == state->limit)
+			return;
+		data = read_dev_sector(bdev, this_sector, &sect);
+		if (!data)
+			return;
+
+		if (!msdos_magic_present(data + 510))
+			goto done; 
+
+		p = (struct partition *) (data + 0x1be);
+
+		/*
+		 * Usually, the first entry is the real data partition,
+		 * the 2nd entry is the next extended partition, or empty,
+		 * and the 3rd and 4th entries are unused.
+		 * However, DRDOS sometimes has the extended partition as
+		 * the first entry (when the data partition is empty),
+		 * and OS/2 seems to use all four entries.
+		 */
+
+		/* 
+		 * First process the data partition(s)
+		 */
+		for (i=0; i<4; i++, p++) {
+			u32 offs, size, next;
+			if (!NR_SECTS(p) || is_extended_partition(p))
+				continue;
+
+			/* Check the 3rd and 4th entries -
+			   these sometimes contain random garbage */
+			offs = START_SECT(p)*sector_size;
+			size = NR_SECTS(p)*sector_size;
+			next = this_sector + offs;
+			if (i >= 2) {
+				if (offs + size > this_size)
+					continue;
+				if (next < first_sector)
+					continue;
+				if (next + size > first_sector + first_size)
+					continue;
+			}
+
+			put_partition(state, state->next, next, size);
+			if (SYS_IND(p) == LINUX_RAID_PARTITION)
+				state->parts[state->next].flags = ADDPART_FLAG_RAID;
+			loopct = 0;
+			if (++state->next == state->limit)
+				goto done;
+		}
+		/*
+		 * Next, process the (first) extended partition, if present.
+		 * (So far, there seems to be no reason to make
+		 *  parse_extended()  recursive and allow a tree
+		 *  of extended partitions.)
+		 * It should be a link to the next logical partition.
+		 */
+		p -= 4;
+		for (i=0; i<4; i++, p++)
+			if (NR_SECTS(p) && is_extended_partition(p))
+				break;
+		if (i == 4)
+			goto done;	 /* nothing left to do */
+
+		this_sector = first_sector + START_SECT(p) * sector_size;
+		this_size = NR_SECTS(p) * sector_size;
+		put_dev_sector(sect);
+	}
+done:
+	put_dev_sector(sect);
+}
+
+/* james@bpgc.com: Solaris has a nasty indicator: 0x82 which also
+   indicates linux swap.  Be careful before believing this is Solaris. */
+
+static void
+parse_solaris_x86(struct parsed_partitions *state, struct block_device *bdev,
+			u32 offset, u32 size, int origin)
+{
+#ifdef CONFIG_SOLARIS_X86_PARTITION
+	Sector sect;
+	struct solaris_x86_vtoc *v;
+	int i;
+	short max_nparts;
+
+	v = (struct solaris_x86_vtoc *)read_dev_sector(bdev, offset+1, &sect);
+	if (!v)
+		return;
+	if (le32_to_cpu(v->v_sanity) != SOLARIS_X86_VTOC_SANE) {
+		put_dev_sector(sect);
+		return;
+	}
+	printk(" %s%d: <solaris:", state->name, origin);
+	if (le32_to_cpu(v->v_version) != 1) {
+		printk("  cannot handle version %d vtoc>\n",
+			le32_to_cpu(v->v_version));
+		put_dev_sector(sect);
+		return;
+	}
+	/* Ensure we can handle previous case of VTOC with 8 entries gracefully */
+	max_nparts = le16_to_cpu (v->v_nparts) > 8 ? SOLARIS_X86_NUMSLICE : 8;
+	for (i=0; i<max_nparts && state->next<state->limit; i++) {
+		struct solaris_x86_slice *s = &v->v_slice[i];
+		if (s->s_size == 0)
+			continue;
+		printk(" [s%d]", i);
+		/* solaris partitions are relative to current MS-DOS
+		 * one; must add the offset of the current partition */
+		put_partition(state, state->next++,
+				 le32_to_cpu(s->s_start)+offset,
+				 le32_to_cpu(s->s_size));
+	}
+	put_dev_sector(sect);
+	printk(" >\n");
+#endif
+}
+
+#if defined(CONFIG_BSD_DISKLABEL)
+/* 
+ * Create devices for BSD partitions listed in a disklabel, under a
+ * dos-like partition. See parse_extended() for more information.
+ */
+static void
+parse_bsd(struct parsed_partitions *state, struct block_device *bdev,
+		u32 offset, u32 size, int origin, char *flavour,
+		int max_partitions)
+{
+	Sector sect;
+	struct bsd_disklabel *l;
+	struct bsd_partition *p;
+
+	l = (struct bsd_disklabel *)read_dev_sector(bdev, offset+1, &sect);
+	if (!l)
+		return;
+	if (le32_to_cpu(l->d_magic) != BSD_DISKMAGIC) {
+		put_dev_sector(sect);
+		return;
+	}
+	printk(" %s%d: <%s:", state->name, origin, flavour);
+
+	if (le16_to_cpu(l->d_npartitions) < max_partitions)
+		max_partitions = le16_to_cpu(l->d_npartitions);
+	for (p = l->d_partitions; p - l->d_partitions < max_partitions; p++) {
+		u32 bsd_start, bsd_size;
+
+		if (state->next == state->limit)
+			break;
+		if (p->p_fstype == BSD_FS_UNUSED) 
+			continue;
+		bsd_start = le32_to_cpu(p->p_offset);
+		bsd_size = le32_to_cpu(p->p_size);
+		if (offset == bsd_start && size == bsd_size)
+			/* full parent partition, we have it already */
+			continue;
+		if (offset > bsd_start || offset+size < bsd_start+bsd_size) {
+			printk("bad subpartition - ignored\n");
+			continue;
+		}
+		put_partition(state, state->next++, bsd_start, bsd_size);
+	}
+	put_dev_sector(sect);
+	if (le16_to_cpu(l->d_npartitions) > max_partitions)
+		printk(" (ignored %d more)",
+		       le16_to_cpu(l->d_npartitions) - max_partitions);
+	printk(" >\n");
+}
+#endif
+
+static void
+parse_freebsd(struct parsed_partitions *state, struct block_device *bdev,
+		u32 offset, u32 size, int origin)
+{
+#ifdef CONFIG_BSD_DISKLABEL
+	parse_bsd(state, bdev, offset, size, origin,
+			"bsd", BSD_MAXPARTITIONS);
+#endif
+}
+
+static void
+parse_netbsd(struct parsed_partitions *state, struct block_device *bdev,
+		u32 offset, u32 size, int origin)
+{
+#ifdef CONFIG_BSD_DISKLABEL
+	parse_bsd(state, bdev, offset, size, origin,
+			"netbsd", BSD_MAXPARTITIONS);
+#endif
+}
+
+static void
+parse_openbsd(struct parsed_partitions *state, struct block_device *bdev,
+		u32 offset, u32 size, int origin)
+{
+#ifdef CONFIG_BSD_DISKLABEL
+	parse_bsd(state, bdev, offset, size, origin,
+			"openbsd", OPENBSD_MAXPARTITIONS);
+#endif
+}
+
+/*
+ * Create devices for Unixware partitions listed in a disklabel, under a
+ * dos-like partition. See parse_extended() for more information.
+ */
+static void
+parse_unixware(struct parsed_partitions *state, struct block_device *bdev,
+		u32 offset, u32 size, int origin)
+{
+#ifdef CONFIG_UNIXWARE_DISKLABEL
+	Sector sect;
+	struct unixware_disklabel *l;
+	struct unixware_slice *p;
+
+	l = (struct unixware_disklabel *)read_dev_sector(bdev, offset+29, &sect);
+	if (!l)
+		return;
+	if (le32_to_cpu(l->d_magic) != UNIXWARE_DISKMAGIC ||
+	    le32_to_cpu(l->vtoc.v_magic) != UNIXWARE_DISKMAGIC2) {
+		put_dev_sector(sect);
+		return;
+	}
+	printk(" %s%d: <unixware:", state->name, origin);
+	p = &l->vtoc.v_slice[1];
+	/* I omit the 0th slice as it is the same as whole disk. */
+	while (p - &l->vtoc.v_slice[0] < UNIXWARE_NUMSLICE) {
+		if (state->next == state->limit)
+			break;
+
+		if (p->s_label != UNIXWARE_FS_UNUSED)
+			put_partition(state, state->next++,
+						START_SECT(p), NR_SECTS(p));
+		p++;
+	}
+	put_dev_sector(sect);
+	printk(" >\n");
+#endif
+}
+
+/*
+ * Minix 2.0.0/2.0.2 subpartition support.
+ * Anand Krishnamurthy <anandk@wiproge.med.ge.com>
+ * Rajeev V. Pillai    <rajeevvp@yahoo.com>
+ */
+static void
+parse_minix(struct parsed_partitions *state, struct block_device *bdev,
+		u32 offset, u32 size, int origin)
+{
+#ifdef CONFIG_MINIX_SUBPARTITION
+	Sector sect;
+	unsigned char *data;
+	struct partition *p;
+	int i;
+
+	data = read_dev_sector(bdev, offset, &sect);
+	if (!data)
+		return;
+
+	p = (struct partition *)(data + 0x1be);
+
+	/* The first sector of a Minix partition can have either
+	 * a secondary MBR describing its subpartitions, or
+	 * the normal boot sector. */
+	if (msdos_magic_present (data + 510) &&
+	    SYS_IND(p) == MINIX_PARTITION) { /* subpartition table present */
+
+		printk(" %s%d: <minix:", state->name, origin);
+		for (i = 0; i < MINIX_NR_SUBPARTITIONS; i++, p++) {
+			if (state->next == state->limit)
+				break;
+			/* add each partition in use */
+			if (SYS_IND(p) == MINIX_PARTITION)
+				put_partition(state, state->next++,
+					      START_SECT(p), NR_SECTS(p));
+		}
+		printk(" >\n");
+	}
+	put_dev_sector(sect);
+#endif /* CONFIG_MINIX_SUBPARTITION */
+}
+
+static struct {
+	unsigned char id;
+	void (*parse)(struct parsed_partitions *, struct block_device *,
+			u32, u32, int);
+} subtypes[] = {
+	{FREEBSD_PARTITION, parse_freebsd},
+	{NETBSD_PARTITION, parse_netbsd},
+	{OPENBSD_PARTITION, parse_openbsd},
+	{MINIX_PARTITION, parse_minix},
+	{UNIXWARE_PARTITION, parse_unixware},
+	{SOLARIS_X86_PARTITION, parse_solaris_x86},
+	{NEW_SOLARIS_X86_PARTITION, parse_solaris_x86},
+	{0, NULL},
+};
+ 
+int msdos_partition(struct parsed_partitions *state, struct block_device *bdev)
+{
+	int sector_size = bdev_hardsect_size(bdev) / 512;
+	Sector sect;
+	unsigned char *data;
+	struct partition *p;
+	struct fat_boot_sector *fb;
+	int slot;
+
+	data = read_dev_sector(bdev, 0, &sect);
+	if (!data)
+		return -1;
+	if (!msdos_magic_present(data + 510)) {
+		put_dev_sector(sect);
+		return 0;
+	}
+
+	if (aix_magic_present(data, bdev)) {
+		put_dev_sector(sect);
+		printk( " [AIX]");
+		return 0;
+	}
+
+	/*
+	 * Now that the 55aa signature is present, this is probably
+	 * either the boot sector of a FAT filesystem or a DOS-type
+	 * partition table. Reject this in case the boot indicator
+	 * is not 0 or 0x80.
+	 */
+	p = (struct partition *) (data + 0x1be);
+	for (slot = 1; slot <= 4; slot++, p++) {
+		if (p->boot_ind != 0 && p->boot_ind != 0x80) {
+			/*
+			 * Even without a valid boot inidicator value
+			 * its still possible this is valid FAT filesystem
+			 * without a partition table.
+			 */
+			fb = (struct fat_boot_sector *) data;
+			if (slot == 1 && fb->reserved && fb->fats
+				&& fat_valid_media(fb->media)) {
+				printk("\n");
+				put_dev_sector(sect);
+				return 1;
+			} else {
+				put_dev_sector(sect);
+				return 0;
+			}
+		}
+	}
+
+#ifdef CONFIG_EFI_PARTITION
+	p = (struct partition *) (data + 0x1be);
+	for (slot = 1 ; slot <= 4 ; slot++, p++) {
+		/* If this is an EFI GPT disk, msdos should ignore it. */
+		if (SYS_IND(p) == EFI_PMBR_OSTYPE_EFI_GPT) {
+			put_dev_sector(sect);
+			return 0;
+		}
+	}
+#endif
+	p = (struct partition *) (data + 0x1be);
+
+	/*
+	 * Look for partitions in two passes:
+	 * First find the primary and DOS-type extended partitions.
+	 * On the second pass look inside *BSD, Unixware and Solaris partitions.
+	 */
+
+	state->next = 5;
+	for (slot = 1 ; slot <= 4 ; slot++, p++) {
+		u32 start = START_SECT(p)*sector_size;
+		u32 size = NR_SECTS(p)*sector_size;
+		if (!size)
+			continue;
+		if (is_extended_partition(p)) {
+			/* prevent someone doing mkfs or mkswap on an
+			   extended partition, but leave room for LILO */
+			put_partition(state, slot, start, size == 1 ? 1 : 2);
+			printk(" <");
+			parse_extended(state, bdev, start, size);
+			printk(" >");
+			continue;
+		}
+		put_partition(state, slot, start, size);
+		if (SYS_IND(p) == LINUX_RAID_PARTITION)
+			state->parts[slot].flags = 1;
+		if (SYS_IND(p) == DM6_PARTITION)
+			printk("[DM]");
+		if (SYS_IND(p) == EZD_PARTITION)
+			printk("[EZD]");
+	}
+
+	printk("\n");
+
+	/* second pass - output for each on a separate line */
+	p = (struct partition *) (0x1be + data);
+	for (slot = 1 ; slot <= 4 ; slot++, p++) {
+		unsigned char id = SYS_IND(p);
+		int n;
+
+		if (!NR_SECTS(p))
+			continue;
+
+		for (n = 0; subtypes[n].parse && id != subtypes[n].id; n++)
+			;
+
+		if (!subtypes[n].parse)
+			continue;
+		subtypes[n].parse(state, bdev, START_SECT(p)*sector_size,
+						NR_SECTS(p)*sector_size, slot);
+	}
+	put_dev_sector(sect);
+	return 1;
+}