d18d7682c1
Some partitioning systems create special partitions that span the entire disk. One example are Sun partitions, and this whole-disk partition exists to tell the firmware the extent of the entire device so it can load the boot block and do other things. Such partitions should not be treated as normal partitions, because all the other partitions overlap this whole-disk one. So we'd see multiple instances of the same UUID etc. which we do not want. udev and friends can thus search for this 'whole_disk' attribute and use it to decide to ignore the partition. Signed-off-by: Fabio Massimo Di Nitto <fabbione@ubuntu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
503 lines
13 KiB
C
503 lines
13 KiB
C
/*
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* fs/partitions/msdos.c
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*
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* Code extracted from drivers/block/genhd.c
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* Copyright (C) 1991-1998 Linus Torvalds
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*
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* Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug
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* in the early extended-partition checks and added DM partitions
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*
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* Support for DiskManager v6.0x added by Mark Lord,
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* with information provided by OnTrack. This now works for linux fdisk
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* and LILO, as well as loadlin and bootln. Note that disks other than
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* /dev/hda *must* have a "DOS" type 0x51 partition in the first slot (hda1).
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*
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* More flexible handling of extended partitions - aeb, 950831
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*
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* Check partition table on IDE disks for common CHS translations
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*
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* Re-organised Feb 1998 Russell King
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*/
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#include "check.h"
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#include "msdos.h"
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#include "efi.h"
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/*
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* Many architectures don't like unaligned accesses, while
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* the nr_sects and start_sect partition table entries are
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* at a 2 (mod 4) address.
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*/
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#include <asm/unaligned.h>
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#define SYS_IND(p) (get_unaligned(&p->sys_ind))
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#define NR_SECTS(p) ({ __le32 __a = get_unaligned(&p->nr_sects); \
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le32_to_cpu(__a); \
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})
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#define START_SECT(p) ({ __le32 __a = get_unaligned(&p->start_sect); \
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le32_to_cpu(__a); \
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})
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static inline int is_extended_partition(struct partition *p)
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{
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return (SYS_IND(p) == DOS_EXTENDED_PARTITION ||
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SYS_IND(p) == WIN98_EXTENDED_PARTITION ||
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SYS_IND(p) == LINUX_EXTENDED_PARTITION);
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}
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#define MSDOS_LABEL_MAGIC1 0x55
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#define MSDOS_LABEL_MAGIC2 0xAA
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static inline int
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msdos_magic_present(unsigned char *p)
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{
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return (p[0] == MSDOS_LABEL_MAGIC1 && p[1] == MSDOS_LABEL_MAGIC2);
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}
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/* Value is EBCDIC 'IBMA' */
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#define AIX_LABEL_MAGIC1 0xC9
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#define AIX_LABEL_MAGIC2 0xC2
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#define AIX_LABEL_MAGIC3 0xD4
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#define AIX_LABEL_MAGIC4 0xC1
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static int aix_magic_present(unsigned char *p, struct block_device *bdev)
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{
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Sector sect;
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unsigned char *d;
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int ret = 0;
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if (p[0] != AIX_LABEL_MAGIC1 &&
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p[1] != AIX_LABEL_MAGIC2 &&
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p[2] != AIX_LABEL_MAGIC3 &&
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p[3] != AIX_LABEL_MAGIC4)
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return 0;
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d = read_dev_sector(bdev, 7, §);
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if (d) {
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if (d[0] == '_' && d[1] == 'L' && d[2] == 'V' && d[3] == 'M')
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ret = 1;
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put_dev_sector(sect);
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};
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return ret;
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}
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/*
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* Create devices for each logical partition in an extended partition.
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* The logical partitions form a linked list, with each entry being
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* a partition table with two entries. The first entry
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* is the real data partition (with a start relative to the partition
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* table start). The second is a pointer to the next logical partition
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* (with a start relative to the entire extended partition).
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* We do not create a Linux partition for the partition tables, but
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* only for the actual data partitions.
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*/
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static void
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parse_extended(struct parsed_partitions *state, struct block_device *bdev,
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u32 first_sector, u32 first_size)
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{
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struct partition *p;
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Sector sect;
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unsigned char *data;
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u32 this_sector, this_size;
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int sector_size = bdev_hardsect_size(bdev) / 512;
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int loopct = 0; /* number of links followed
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without finding a data partition */
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int i;
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this_sector = first_sector;
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this_size = first_size;
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while (1) {
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if (++loopct > 100)
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return;
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if (state->next == state->limit)
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return;
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data = read_dev_sector(bdev, this_sector, §);
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if (!data)
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return;
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if (!msdos_magic_present(data + 510))
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goto done;
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p = (struct partition *) (data + 0x1be);
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/*
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* Usually, the first entry is the real data partition,
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* the 2nd entry is the next extended partition, or empty,
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* and the 3rd and 4th entries are unused.
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* However, DRDOS sometimes has the extended partition as
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* the first entry (when the data partition is empty),
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* and OS/2 seems to use all four entries.
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*/
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/*
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* First process the data partition(s)
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*/
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for (i=0; i<4; i++, p++) {
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u32 offs, size, next;
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if (!NR_SECTS(p) || is_extended_partition(p))
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continue;
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/* Check the 3rd and 4th entries -
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these sometimes contain random garbage */
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offs = START_SECT(p)*sector_size;
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size = NR_SECTS(p)*sector_size;
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next = this_sector + offs;
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if (i >= 2) {
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if (offs + size > this_size)
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continue;
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if (next < first_sector)
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continue;
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if (next + size > first_sector + first_size)
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continue;
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}
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put_partition(state, state->next, next, size);
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if (SYS_IND(p) == LINUX_RAID_PARTITION)
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state->parts[state->next].flags = ADDPART_FLAG_RAID;
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loopct = 0;
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if (++state->next == state->limit)
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goto done;
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}
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/*
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* Next, process the (first) extended partition, if present.
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* (So far, there seems to be no reason to make
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* parse_extended() recursive and allow a tree
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* of extended partitions.)
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* It should be a link to the next logical partition.
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*/
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p -= 4;
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for (i=0; i<4; i++, p++)
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if (NR_SECTS(p) && is_extended_partition(p))
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break;
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if (i == 4)
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goto done; /* nothing left to do */
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this_sector = first_sector + START_SECT(p) * sector_size;
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this_size = NR_SECTS(p) * sector_size;
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put_dev_sector(sect);
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}
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done:
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put_dev_sector(sect);
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}
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/* james@bpgc.com: Solaris has a nasty indicator: 0x82 which also
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indicates linux swap. Be careful before believing this is Solaris. */
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static void
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parse_solaris_x86(struct parsed_partitions *state, struct block_device *bdev,
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u32 offset, u32 size, int origin)
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{
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#ifdef CONFIG_SOLARIS_X86_PARTITION
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Sector sect;
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struct solaris_x86_vtoc *v;
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int i;
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v = (struct solaris_x86_vtoc *)read_dev_sector(bdev, offset+1, §);
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if (!v)
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return;
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if (le32_to_cpu(v->v_sanity) != SOLARIS_X86_VTOC_SANE) {
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put_dev_sector(sect);
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return;
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}
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printk(" %s%d: <solaris:", state->name, origin);
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if (le32_to_cpu(v->v_version) != 1) {
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printk(" cannot handle version %d vtoc>\n",
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le32_to_cpu(v->v_version));
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put_dev_sector(sect);
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return;
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}
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for (i=0; i<SOLARIS_X86_NUMSLICE && state->next<state->limit; i++) {
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struct solaris_x86_slice *s = &v->v_slice[i];
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if (s->s_size == 0)
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continue;
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printk(" [s%d]", i);
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/* solaris partitions are relative to current MS-DOS
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* one; must add the offset of the current partition */
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put_partition(state, state->next++,
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le32_to_cpu(s->s_start)+offset,
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le32_to_cpu(s->s_size));
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}
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put_dev_sector(sect);
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printk(" >\n");
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#endif
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}
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#if defined(CONFIG_BSD_DISKLABEL)
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/*
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* Create devices for BSD partitions listed in a disklabel, under a
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* dos-like partition. See parse_extended() for more information.
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*/
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static void
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parse_bsd(struct parsed_partitions *state, struct block_device *bdev,
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u32 offset, u32 size, int origin, char *flavour,
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int max_partitions)
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{
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Sector sect;
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struct bsd_disklabel *l;
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struct bsd_partition *p;
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l = (struct bsd_disklabel *)read_dev_sector(bdev, offset+1, §);
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if (!l)
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return;
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if (le32_to_cpu(l->d_magic) != BSD_DISKMAGIC) {
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put_dev_sector(sect);
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return;
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}
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printk(" %s%d: <%s:", state->name, origin, flavour);
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if (le16_to_cpu(l->d_npartitions) < max_partitions)
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max_partitions = le16_to_cpu(l->d_npartitions);
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for (p = l->d_partitions; p - l->d_partitions < max_partitions; p++) {
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u32 bsd_start, bsd_size;
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if (state->next == state->limit)
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break;
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if (p->p_fstype == BSD_FS_UNUSED)
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continue;
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bsd_start = le32_to_cpu(p->p_offset);
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bsd_size = le32_to_cpu(p->p_size);
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if (offset == bsd_start && size == bsd_size)
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/* full parent partition, we have it already */
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continue;
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if (offset > bsd_start || offset+size < bsd_start+bsd_size) {
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printk("bad subpartition - ignored\n");
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continue;
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}
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put_partition(state, state->next++, bsd_start, bsd_size);
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}
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put_dev_sector(sect);
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if (le16_to_cpu(l->d_npartitions) > max_partitions)
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printk(" (ignored %d more)",
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le16_to_cpu(l->d_npartitions) - max_partitions);
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printk(" >\n");
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}
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#endif
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static void
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parse_freebsd(struct parsed_partitions *state, struct block_device *bdev,
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u32 offset, u32 size, int origin)
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{
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#ifdef CONFIG_BSD_DISKLABEL
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parse_bsd(state, bdev, offset, size, origin,
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"bsd", BSD_MAXPARTITIONS);
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#endif
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}
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static void
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parse_netbsd(struct parsed_partitions *state, struct block_device *bdev,
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u32 offset, u32 size, int origin)
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{
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#ifdef CONFIG_BSD_DISKLABEL
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parse_bsd(state, bdev, offset, size, origin,
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"netbsd", BSD_MAXPARTITIONS);
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#endif
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}
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static void
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parse_openbsd(struct parsed_partitions *state, struct block_device *bdev,
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u32 offset, u32 size, int origin)
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{
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#ifdef CONFIG_BSD_DISKLABEL
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parse_bsd(state, bdev, offset, size, origin,
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"openbsd", OPENBSD_MAXPARTITIONS);
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#endif
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}
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/*
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* Create devices for Unixware partitions listed in a disklabel, under a
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* dos-like partition. See parse_extended() for more information.
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*/
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static void
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parse_unixware(struct parsed_partitions *state, struct block_device *bdev,
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u32 offset, u32 size, int origin)
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{
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#ifdef CONFIG_UNIXWARE_DISKLABEL
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Sector sect;
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struct unixware_disklabel *l;
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struct unixware_slice *p;
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l = (struct unixware_disklabel *)read_dev_sector(bdev, offset+29, §);
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if (!l)
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return;
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if (le32_to_cpu(l->d_magic) != UNIXWARE_DISKMAGIC ||
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le32_to_cpu(l->vtoc.v_magic) != UNIXWARE_DISKMAGIC2) {
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put_dev_sector(sect);
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return;
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}
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printk(" %s%d: <unixware:", state->name, origin);
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p = &l->vtoc.v_slice[1];
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/* I omit the 0th slice as it is the same as whole disk. */
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while (p - &l->vtoc.v_slice[0] < UNIXWARE_NUMSLICE) {
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if (state->next == state->limit)
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break;
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if (p->s_label != UNIXWARE_FS_UNUSED)
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put_partition(state, state->next++,
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START_SECT(p), NR_SECTS(p));
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p++;
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}
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put_dev_sector(sect);
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printk(" >\n");
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#endif
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}
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/*
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* Minix 2.0.0/2.0.2 subpartition support.
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* Anand Krishnamurthy <anandk@wiproge.med.ge.com>
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* Rajeev V. Pillai <rajeevvp@yahoo.com>
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*/
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static void
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parse_minix(struct parsed_partitions *state, struct block_device *bdev,
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u32 offset, u32 size, int origin)
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{
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#ifdef CONFIG_MINIX_SUBPARTITION
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Sector sect;
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unsigned char *data;
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struct partition *p;
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int i;
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data = read_dev_sector(bdev, offset, §);
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if (!data)
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return;
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p = (struct partition *)(data + 0x1be);
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/* The first sector of a Minix partition can have either
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* a secondary MBR describing its subpartitions, or
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* the normal boot sector. */
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if (msdos_magic_present (data + 510) &&
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SYS_IND(p) == MINIX_PARTITION) { /* subpartition table present */
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printk(" %s%d: <minix:", state->name, origin);
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for (i = 0; i < MINIX_NR_SUBPARTITIONS; i++, p++) {
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if (state->next == state->limit)
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break;
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/* add each partition in use */
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if (SYS_IND(p) == MINIX_PARTITION)
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put_partition(state, state->next++,
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START_SECT(p), NR_SECTS(p));
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}
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printk(" >\n");
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}
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put_dev_sector(sect);
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#endif /* CONFIG_MINIX_SUBPARTITION */
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}
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static struct {
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unsigned char id;
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void (*parse)(struct parsed_partitions *, struct block_device *,
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u32, u32, int);
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} subtypes[] = {
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{FREEBSD_PARTITION, parse_freebsd},
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{NETBSD_PARTITION, parse_netbsd},
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{OPENBSD_PARTITION, parse_openbsd},
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{MINIX_PARTITION, parse_minix},
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{UNIXWARE_PARTITION, parse_unixware},
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{SOLARIS_X86_PARTITION, parse_solaris_x86},
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{NEW_SOLARIS_X86_PARTITION, parse_solaris_x86},
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{0, NULL},
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};
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int msdos_partition(struct parsed_partitions *state, struct block_device *bdev)
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{
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int sector_size = bdev_hardsect_size(bdev) / 512;
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Sector sect;
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unsigned char *data;
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struct partition *p;
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int slot;
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data = read_dev_sector(bdev, 0, §);
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if (!data)
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return -1;
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if (!msdos_magic_present(data + 510)) {
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put_dev_sector(sect);
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return 0;
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}
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if (aix_magic_present(data, bdev)) {
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put_dev_sector(sect);
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printk( " [AIX]");
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return 0;
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}
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/*
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* Now that the 55aa signature is present, this is probably
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* either the boot sector of a FAT filesystem or a DOS-type
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* partition table. Reject this in case the boot indicator
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* is not 0 or 0x80.
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*/
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p = (struct partition *) (data + 0x1be);
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for (slot = 1; slot <= 4; slot++, p++) {
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if (p->boot_ind != 0 && p->boot_ind != 0x80) {
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put_dev_sector(sect);
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return 0;
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}
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}
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#ifdef CONFIG_EFI_PARTITION
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p = (struct partition *) (data + 0x1be);
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for (slot = 1 ; slot <= 4 ; slot++, p++) {
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/* If this is an EFI GPT disk, msdos should ignore it. */
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if (SYS_IND(p) == EFI_PMBR_OSTYPE_EFI_GPT) {
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put_dev_sector(sect);
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return 0;
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}
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}
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#endif
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p = (struct partition *) (data + 0x1be);
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/*
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* Look for partitions in two passes:
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* First find the primary and DOS-type extended partitions.
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* On the second pass look inside *BSD, Unixware and Solaris partitions.
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*/
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state->next = 5;
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for (slot = 1 ; slot <= 4 ; slot++, p++) {
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u32 start = START_SECT(p)*sector_size;
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u32 size = NR_SECTS(p)*sector_size;
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if (!size)
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continue;
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if (is_extended_partition(p)) {
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/* prevent someone doing mkfs or mkswap on an
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extended partition, but leave room for LILO */
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put_partition(state, slot, start, size == 1 ? 1 : 2);
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printk(" <");
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parse_extended(state, bdev, start, size);
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printk(" >");
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continue;
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}
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put_partition(state, slot, start, size);
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if (SYS_IND(p) == LINUX_RAID_PARTITION)
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state->parts[slot].flags = 1;
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if (SYS_IND(p) == DM6_PARTITION)
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printk("[DM]");
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if (SYS_IND(p) == EZD_PARTITION)
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printk("[EZD]");
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}
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printk("\n");
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/* second pass - output for each on a separate line */
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p = (struct partition *) (0x1be + data);
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for (slot = 1 ; slot <= 4 ; slot++, p++) {
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unsigned char id = SYS_IND(p);
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int n;
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if (!NR_SECTS(p))
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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;
|
|
}
|