diff options
Diffstat (limited to 'linux/dev/drivers/block/genhd.c')
| -rw-r--r-- | linux/dev/drivers/block/genhd.c | 785 |
1 files changed, 785 insertions, 0 deletions
diff --git a/linux/dev/drivers/block/genhd.c b/linux/dev/drivers/block/genhd.c new file mode 100644 index 0000000..37c41a6 --- /dev/null +++ b/linux/dev/drivers/block/genhd.c @@ -0,0 +1,785 @@ +/* + * Code extracted from + * linux/kernel/hd.c + * + * Copyright (C) 1991, 1992 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 + */ + +#include <linux/config.h> +#include <linux/fs.h> +#include <linux/genhd.h> +#include <linux/kernel.h> +#include <linux/major.h> +#include <linux/string.h> +#ifdef CONFIG_BLK_DEV_INITRD +#include <linux/blk.h> +#endif + +#include <asm/system.h> + +/* + * Many architectures don't like unaligned accesses, which is + * frequently the case with the nr_sects and start_sect partition + * table entries. + */ +#include <asm/unaligned.h> + +#ifdef MACH +#include <machine/spl.h> +#endif + +#define SYS_IND(p) get_unaligned(&p->sys_ind) +#define NR_SECTS(p) get_unaligned(&p->nr_sects) +#define START_SECT(p) get_unaligned(&p->start_sect) + + +struct gendisk *gendisk_head = NULL; + +static int current_minor = 0; +extern int *blk_size[]; +extern void rd_load(void); +extern void initrd_load(void); + +extern int chr_dev_init(void); +extern int blk_dev_init(void); +extern int scsi_dev_init(void); +extern int net_dev_init(void); + +/* + * disk_name() is used by genhd.c and md.c. + * It formats the devicename of the indicated disk + * into the supplied buffer, and returns a pointer + * to that same buffer (for convenience). + */ +char *disk_name (struct gendisk *hd, int minor, char *buf) +{ + unsigned int part; + const char *maj = hd->major_name; +#ifdef MACH + char unit = (minor >> hd->minor_shift) + '0'; +#else + char unit = (minor >> hd->minor_shift) + 'a'; +#endif + +#ifdef CONFIG_BLK_DEV_IDE + /* + * IDE devices use multiple major numbers, but the drives + * are named as: {hda,hdb}, {hdc,hdd}, {hde,hdf}, {hdg,hdh}.. + * This requires special handling here. + */ + switch (hd->major) { + case IDE3_MAJOR: + unit += 2; + case IDE2_MAJOR: + unit += 2; + case IDE1_MAJOR: + unit += 2; + case IDE0_MAJOR: + maj = "hd"; + } +#endif + part = minor & ((1 << hd->minor_shift) - 1); + if (part) +#ifdef MACH + sprintf(buf, "%s%cs%d", maj, unit, part); +#else + sprintf(buf, "%s%c%d", maj, unit, part); +#endif + else + sprintf(buf, "%s%c", maj, unit); + return buf; +} + +static void add_partition (struct gendisk *hd, int minor, int start, int size) +{ + char buf[8]; + hd->part[minor].start_sect = start; + hd->part[minor].nr_sects = size; + printk(" %s", disk_name(hd, minor, buf)); +} + +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); +} + +#ifdef CONFIG_MSDOS_PARTITION +/* + * 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 extended_partition(struct gendisk *hd, kdev_t dev) +{ + struct buffer_head *bh; + struct partition *p; + unsigned long first_sector, first_size, this_sector, this_size; + int mask = (1 << hd->minor_shift) - 1; + int i; + + first_sector = hd->part[MINOR(dev)].start_sect; + first_size = hd->part[MINOR(dev)].nr_sects; + this_sector = first_sector; + + while (1) { + if ((current_minor & mask) == 0) + return; + if (!(bh = bread(dev,0,1024))) + return; + /* + * This block is from a device that we're about to stomp on. + * So make sure nobody thinks this block is usable. + */ + bh->b_state = 0; + + if (*(unsigned short *) (bh->b_data+510) != 0xAA55) + goto done; + + p = (struct partition *) (0x1BE + bh->b_data); + + this_size = hd->part[MINOR(dev)].nr_sects; + + /* + * 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++) { + if (!NR_SECTS(p) || is_extended_partition(p)) + continue; + + /* Check the 3rd and 4th entries - + these sometimes contain random garbage */ + if (i >= 2 + && START_SECT(p) + NR_SECTS(p) > this_size + && (this_sector + START_SECT(p) < first_sector || + this_sector + START_SECT(p) + NR_SECTS(p) > + first_sector + first_size)) + continue; + + add_partition(hd, current_minor, this_sector+START_SECT(p), NR_SECTS(p)); + current_minor++; + if ((current_minor & mask) == 0) + goto done; + } + /* + * Next, process the (first) extended partition, if present. + * (So far, there seems to be no reason to make + * extended_partition() recursive and allow a tree + * of extended partitions.) + * It should be a link to the next logical partition. + * Create a minor for this just long enough to get the next + * partition table. The minor will be reused for the next + * data 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 */ + + hd->part[current_minor].nr_sects = NR_SECTS(p); + hd->part[current_minor].start_sect = first_sector + START_SECT(p); + this_sector = first_sector + START_SECT(p); + dev = MKDEV(hd->major, current_minor); + brelse(bh); + } +done: + brelse(bh); +} + +#ifdef CONFIG_BSD_DISKLABEL +/* + * Create devices for BSD partitions listed in a disklabel, under a + * dos-like partition. See extended_partition() for more information. + */ +static void bsd_disklabel_partition(struct gendisk *hd, kdev_t dev) +{ + struct buffer_head *bh; + struct bsd_disklabel *l; + struct bsd_partition *p; + int mask = (1 << hd->minor_shift) - 1; + + if (!(bh = bread(dev,0,1024))) + return; + bh->b_state = 0; + l = (struct bsd_disklabel *) (bh->b_data+512); + if (l->d_magic != BSD_DISKMAGIC) { + brelse(bh); + return; + } + + p = &l->d_partitions[0]; + while (p - &l->d_partitions[0] <= BSD_MAXPARTITIONS) { + if ((current_minor & mask) >= (4 + hd->max_p)) + break; + + if (p->p_fstype != BSD_FS_UNUSED) { + add_partition(hd, current_minor, p->p_offset, p->p_size); + current_minor++; + } + p++; + } + brelse(bh); + +} +#endif + +static int msdos_partition(struct gendisk *hd, kdev_t dev, unsigned long first_sector) +{ + int i, minor = current_minor; + struct buffer_head *bh; + struct partition *p; + unsigned char *data; + int mask = (1 << hd->minor_shift) - 1; +#ifdef CONFIG_BLK_DEV_IDE + int tested_for_xlate = 0; + +read_mbr: +#endif + if (!(bh = bread(dev,0,1024))) { + printk(" unable to read partition table\n"); + return -1; + } + data = bh->b_data; + /* In some cases we modify the geometry */ + /* of the drive (below), so ensure that */ + /* nobody else tries to re-use this data. */ + bh->b_state = 0; +#ifdef CONFIG_BLK_DEV_IDE +check_table: +#endif + if (*(unsigned short *) (0x1fe + data) != 0xAA55) { + brelse(bh); + return 0; + } + p = (struct partition *) (0x1be + data); + +#ifdef CONFIG_BLK_DEV_IDE + if (!tested_for_xlate++) { /* Do this only once per disk */ + /* + * Look for various forms of IDE disk geometry translation + */ + extern int ide_xlate_1024(kdev_t, int, const char *); + unsigned int sig = *(unsigned short *)(data + 2); + if (SYS_IND(p) == EZD_PARTITION) { + /* + * The remainder of the disk must be accessed using + * a translated geometry that reduces the number of + * apparent cylinders to less than 1024 if possible. + * + * ide_xlate_1024() will take care of the necessary + * adjustments to fool fdisk/LILO and partition check. + */ + if (ide_xlate_1024(dev, -1, " [EZD]")) { + data += 512; + goto check_table; + } + } else if (SYS_IND(p) == DM6_PARTITION) { + + /* + * Everything on the disk is offset by 63 sectors, + * including a "new" MBR with its own partition table, + * and the remainder of the disk must be accessed using + * a translated geometry that reduces the number of + * apparent cylinders to less than 1024 if possible. + * + * ide_xlate_1024() will take care of the necessary + * adjustments to fool fdisk/LILO and partition check. + */ + if (ide_xlate_1024(dev, 1, " [DM6:DDO]")) { + brelse(bh); + goto read_mbr; /* start over with new MBR */ + } + } else if (sig <= 0x1ae && *(unsigned short *)(data + sig) == 0x55AA + && (1 & *(unsigned char *)(data + sig + 2)) ) + { + /* + * DM6 signature in MBR, courtesy of OnTrack + */ + (void) ide_xlate_1024 (dev, 0, " [DM6:MBR]"); + } else if (SYS_IND(p) == DM6_AUX1PARTITION || SYS_IND(p) == DM6_AUX3PARTITION) { + /* + * DM6 on other than the first (boot) drive + */ + (void) ide_xlate_1024(dev, 0, " [DM6:AUX]"); + } else { + /* + * Examine the partition table for common translations. + * This is necessary for drives for situations where + * the translated geometry is unavailable from the BIOS. + */ + for (i = 0; i < 4 ; i++) { + struct partition *q = &p[i]; + if (NR_SECTS(q) + && (q->sector & 63) == 1 + && (q->end_sector & 63) == 63) { + unsigned int heads = q->end_head + 1; + if (heads == 32 || heads == 64 || heads == 128 || heads == 255) { + + (void) ide_xlate_1024(dev, heads, " [PTBL]"); + break; + } + } + } + } + } +#endif /* CONFIG_BLK_DEV_IDE */ + + current_minor += 4; /* first "extra" minor (for extended partitions) */ + for (i=1 ; i<=4 ; minor++,i++,p++) { + if (!NR_SECTS(p)) + continue; + add_partition(hd, minor, first_sector+START_SECT(p), NR_SECTS(p)); + if (is_extended_partition(p)) { + printk(" <"); + /* + * If we are rereading the partition table, we need + * to set the size of the partition so that we will + * be able to bread the block containing the extended + * partition info. + */ + hd->sizes[minor] = hd->part[minor].nr_sects + >> (BLOCK_SIZE_BITS - 9); + extended_partition(hd, MKDEV(hd->major, minor)); + printk(" >"); + /* prevent someone doing mkfs or mkswap on an + extended partition, but leave room for LILO */ + if (hd->part[minor].nr_sects > 2) + hd->part[minor].nr_sects = 2; + } +#ifdef CONFIG_BSD_DISKLABEL + if (SYS_IND(p) == BSD_PARTITION) { + printk(" <"); + bsd_disklabel_partition(hd, MKDEV(hd->major, minor)); + printk(" >"); + } +#endif + } + /* + * Check for old-style Disk Manager partition table + */ + if (*(unsigned short *) (data+0xfc) == 0x55AA) { + p = (struct partition *) (0x1be + data); + for (i = 4 ; i < 16 ; i++, current_minor++) { + p--; + if ((current_minor & mask) == 0) + break; + if (!(START_SECT(p) && NR_SECTS(p))) + continue; + add_partition(hd, current_minor, START_SECT(p), NR_SECTS(p)); + } + } + printk("\n"); + brelse(bh); + return 1; +} + +#endif /* CONFIG_MSDOS_PARTITION */ + +#ifdef CONFIG_OSF_PARTITION + +static int osf_partition(struct gendisk *hd, unsigned int dev, unsigned long first_sector) +{ + int i; + int mask = (1 << hd->minor_shift) - 1; + struct buffer_head *bh; + struct disklabel { + u32 d_magic; + u16 d_type,d_subtype; + u8 d_typename[16]; + u8 d_packname[16]; + u32 d_secsize; + u32 d_nsectors; + u32 d_ntracks; + u32 d_ncylinders; + u32 d_secpercyl; + u32 d_secprtunit; + u16 d_sparespertrack; + u16 d_sparespercyl; + u32 d_acylinders; + u16 d_rpm, d_interleave, d_trackskew, d_cylskew; + u32 d_headswitch, d_trkseek, d_flags; + u32 d_drivedata[5]; + u32 d_spare[5]; + u32 d_magic2; + u16 d_checksum; + u16 d_npartitions; + u32 d_bbsize, d_sbsize; + struct d_partition { + u32 p_size; + u32 p_offset; + u32 p_fsize; + u8 p_fstype; + u8 p_frag; + u16 p_cpg; + } d_partitions[8]; + } * label; + struct d_partition * partition; +#define DISKLABELMAGIC (0x82564557UL) + + if (!(bh = bread(dev,0,1024))) { + printk("unable to read partition table\n"); + return -1; + } + label = (struct disklabel *) (bh->b_data+64); + partition = label->d_partitions; + if (label->d_magic != DISKLABELMAGIC) { + printk("magic: %08x\n", label->d_magic); + brelse(bh); + return 0; + } + if (label->d_magic2 != DISKLABELMAGIC) { + printk("magic2: %08x\n", label->d_magic2); + brelse(bh); + return 0; + } + for (i = 0 ; i < label->d_npartitions; i++, partition++) { + if ((current_minor & mask) == 0) + break; + if (partition->p_size) + add_partition(hd, current_minor, + first_sector+partition->p_offset, + partition->p_size); + current_minor++; + } + printk("\n"); + brelse(bh); + return 1; +} + +#endif /* CONFIG_OSF_PARTITION */ + +#ifdef CONFIG_SUN_PARTITION + +static int sun_partition(struct gendisk *hd, kdev_t dev, unsigned long first_sector) +{ + int i, csum; + unsigned short *ush; + struct buffer_head *bh; + struct sun_disklabel { + unsigned char info[128]; /* Informative text string */ + unsigned char spare[292]; /* Boot information etc. */ + unsigned short rspeed; /* Disk rotational speed */ + unsigned short pcylcount; /* Physical cylinder count */ + unsigned short sparecyl; /* extra sects per cylinder */ + unsigned char spare2[4]; /* More magic... */ + unsigned short ilfact; /* Interleave factor */ + unsigned short ncyl; /* Data cylinder count */ + unsigned short nacyl; /* Alt. cylinder count */ + unsigned short ntrks; /* Tracks per cylinder */ + unsigned short nsect; /* Sectors per track */ + unsigned char spare3[4]; /* Even more magic... */ + struct sun_partition { + __u32 start_cylinder; + __u32 num_sectors; + } partitions[8]; + unsigned short magic; /* Magic number */ + unsigned short csum; /* Label xor'd checksum */ + } * label; + struct sun_partition *p; + int other_endian; + unsigned long spc; +#define SUN_LABEL_MAGIC 0xDABE +#define SUN_LABEL_MAGIC_SWAPPED 0xBEDA +/* No need to optimize these macros since they are called only when reading + * the partition table. This occurs only at each disk change. */ +#define SWAP16(x) (other_endian ? (((__u16)(x) & 0xFF) << 8) \ + | (((__u16)(x) & 0xFF00) >> 8) \ + : (__u16)(x)) +#define SWAP32(x) (other_endian ? (((__u32)(x) & 0xFF) << 24) \ + | (((__u32)(x) & 0xFF00) << 8) \ + | (((__u32)(x) & 0xFF0000) >> 8) \ + | (((__u32)(x) & 0xFF000000) >> 24) \ + : (__u32)(x)) + + if(!(bh = bread(dev, 0, 1024))) { + printk("Dev %s: unable to read partition table\n", + kdevname(dev)); + return -1; + } + label = (struct sun_disklabel *) bh->b_data; + p = label->partitions; + if (label->magic != SUN_LABEL_MAGIC && label->magic != SUN_LABEL_MAGIC_SWAPPED) { + printk("Dev %s Sun disklabel: bad magic %04x\n", + kdevname(dev), label->magic); + brelse(bh); + return 0; + } + other_endian = (label->magic == SUN_LABEL_MAGIC_SWAPPED); + /* Look at the checksum */ + ush = ((unsigned short *) (label+1)) - 1; + for(csum = 0; ush >= ((unsigned short *) label);) + csum ^= *ush--; + if(csum) { + printk("Dev %s Sun disklabel: Csum bad, label corrupted\n", + kdevname(dev)); + brelse(bh); + return 0; + } + /* All Sun disks have 8 partition entries */ + spc = SWAP16(label->ntrks) * SWAP16(label->nsect); + for(i=0; i < 8; i++, p++) { + unsigned long st_sector; + + /* We register all partitions, even if zero size, so that + * the minor numbers end up ok as per SunOS interpretation. + */ + st_sector = first_sector + SWAP32(p->start_cylinder) * spc; + add_partition(hd, current_minor, st_sector, SWAP32(p->num_sectors)); + current_minor++; + } + printk("\n"); + brelse(bh); + return 1; +#undef SWAP16 +#undef SWAP32 +} + +#endif /* CONFIG_SUN_PARTITION */ + +#ifdef CONFIG_AMIGA_PARTITION +#include <asm/byteorder.h> +#include <linux/affs_hardblocks.h> + +static __inline__ __u32 +checksum_block(__u32 *m, int size) +{ + __u32 sum = 0; + + while (size--) + sum += htonl(*m++); + return sum; +} + +static int +amiga_partition(struct gendisk *hd, unsigned int dev, unsigned long first_sector) +{ + struct buffer_head *bh; + struct RigidDiskBlock *rdb; + struct PartitionBlock *pb; + int start_sect; + int nr_sects; + int blk; + int part, res; + + set_blocksize(dev,512); + res = 0; + + for (blk = 0; blk < RDB_ALLOCATION_LIMIT; blk++) { + if(!(bh = bread(dev,blk,512))) { + printk("Dev %d: unable to read RDB block %d\n",dev,blk); + goto rdb_done; + } + if (*(__u32 *)bh->b_data == htonl(IDNAME_RIGIDDISK)) { + rdb = (struct RigidDiskBlock *)bh->b_data; + if (checksum_block((__u32 *)bh->b_data,htonl(rdb->rdb_SummedLongs) & 0x7F)) { + printk("Dev %d: RDB in block %d has bad checksum\n",dev,blk); + brelse(bh); + continue; + } + printk(" RDSK"); + blk = htonl(rdb->rdb_PartitionList); + brelse(bh); + for (part = 1; blk > 0 && part <= 16; part++) { + if (!(bh = bread(dev,blk,512))) { + printk("Dev %d: unable to read partition block %d\n", + dev,blk); + goto rdb_done; + } + pb = (struct PartitionBlock *)bh->b_data; + blk = htonl(pb->pb_Next); + if (pb->pb_ID == htonl(IDNAME_PARTITION) && checksum_block( + (__u32 *)pb,htonl(pb->pb_SummedLongs) & 0x7F) == 0 ) { + + /* Tell Kernel about it */ + + if (!(nr_sects = (htonl(pb->pb_Environment[10]) + 1 - + htonl(pb->pb_Environment[9])) * + htonl(pb->pb_Environment[3]) * + htonl(pb->pb_Environment[5]))) { + continue; + } + start_sect = htonl(pb->pb_Environment[9]) * + htonl(pb->pb_Environment[3]) * + htonl(pb->pb_Environment[5]); + add_partition(hd,current_minor,start_sect,nr_sects); + current_minor++; + res = 1; + } + brelse(bh); + } + printk("\n"); + break; + } + } + +rdb_done: + set_blocksize(dev,BLOCK_SIZE); + return res; +} +#endif /* CONFIG_AMIGA_PARTITION */ + +static void check_partition(struct gendisk *hd, kdev_t dev) +{ + static int first_time = 1; + unsigned long first_sector; + char buf[8]; + + if (first_time) + printk("Partition check:\n"); + first_time = 0; + first_sector = hd->part[MINOR(dev)].start_sect; + + /* + * This is a kludge to allow the partition check to be + * skipped for specific drives (e.g. IDE cd-rom drives) + */ + if ((int)first_sector == -1) { + hd->part[MINOR(dev)].start_sect = 0; + return; + } + + printk(" %s:", disk_name(hd, MINOR(dev), buf)); +#ifdef CONFIG_MSDOS_PARTITION + if (msdos_partition(hd, dev, first_sector)) + return; +#endif +#ifdef CONFIG_OSF_PARTITION + if (osf_partition(hd, dev, first_sector)) + return; +#endif +#ifdef CONFIG_SUN_PARTITION + if(sun_partition(hd, dev, first_sector)) + return; +#endif +#ifdef CONFIG_AMIGA_PARTITION + if(amiga_partition(hd, dev, first_sector)) + return; +#endif + printk(" unknown partition table\n"); +} + +/* This function is used to re-read partition tables for removable disks. + Much of the cleanup from the old partition tables should have already been + done */ + +/* This function will re-read the partition tables for a given device, +and set things back up again. There are some important caveats, +however. You must ensure that no one is using the device, and no one +can start using the device while this function is being executed. */ + +void resetup_one_dev(struct gendisk *dev, int drive) +{ + int i; + int first_minor = drive << dev->minor_shift; + int end_minor = first_minor + dev->max_p; + + blk_size[dev->major] = NULL; + current_minor = 1 + first_minor; + check_partition(dev, MKDEV(dev->major, first_minor)); + + /* + * We need to set the sizes array before we will be able to access + * any of the partitions on this device. + */ + if (dev->sizes != NULL) { /* optional safeguard in ll_rw_blk.c */ + for (i = first_minor; i < end_minor; i++) + dev->sizes[i] = dev->part[i].nr_sects >> (BLOCK_SIZE_BITS - 9); + blk_size[dev->major] = dev->sizes; + } +} + +static void setup_dev(struct gendisk *dev) +{ + int i, drive; + int end_minor = dev->max_nr * dev->max_p; + + blk_size[dev->major] = NULL; + for (i = 0 ; i < end_minor; i++) { + dev->part[i].start_sect = 0; + dev->part[i].nr_sects = 0; + } + dev->init(dev); + for (drive = 0 ; drive < dev->nr_real ; drive++) { + int first_minor = drive << dev->minor_shift; + current_minor = 1 + first_minor; + check_partition(dev, MKDEV(dev->major, first_minor)); + } + if (dev->sizes != NULL) { /* optional safeguard in ll_rw_blk.c */ + for (i = 0; i < end_minor; i++) + dev->sizes[i] = dev->part[i].nr_sects >> (BLOCK_SIZE_BITS - 9); + blk_size[dev->major] = dev->sizes; + } +} + +void device_setup(void) +{ + extern void console_map_init(void); + struct gendisk *p; + int nr=0; +#ifdef MACH + extern int linux_intr_pri; + + linux_intr_pri = SPL5; +#endif + +#ifndef MACH + chr_dev_init(); +#endif + blk_dev_init(); + sti(); +#ifdef CONFIG_SCSI + scsi_dev_init(); +#endif +#ifdef CONFIG_INET +#ifdef MACH + linux_intr_pri = SPL6; +#endif + net_dev_init(); +#endif +#ifndef MACH + console_map_init(); +#endif + + for (p = gendisk_head ; p ; p=p->next) { + setup_dev(p); + nr += p->nr_real; + } +#ifdef CONFIG_BLK_DEV_RAM +#ifdef CONFIG_BLK_DEV_INITRD + if (initrd_start && mount_initrd) initrd_load(); + else +#endif + rd_load(); +#endif +} |