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35 .\" @(#)disklabel.5.5 8.1 (Berkeley) 6/5/93
36 .\" $FreeBSD: src/sbin/disklabel/disklabel.5,v 1.7.2.4 2002/08/21 18:58:16 trhodes Exp $
37 .\" $DragonFly: src/sbin/disklabel/disklabel.5,v 1.3 2003/11/03 19:51:04 eirikn Exp $
48 Each disk or disk pack on a system may contain a disk label
49 which provides detailed information
50 about the geometry of the disk and the partitions into which the disk
52 It should be initialized when the disk is formatted,
53 and may be changed later with the
56 This information is used by the system disk driver and by the bootstrap
57 program to determine how to program the drive
58 and where to find the file systems on the disk partitions.
59 Additional information is used by the file system in order
60 to use the disk most efficiently and to locate important file system information.
61 The description of each partition contains an identifier for the partition
62 type (standard file system, swap area, etc.).
63 The file system updates the in-core copy of the label if it contains
64 incomplete information about the file system.
66 The label is located in sector number
68 of the drive, usually sector 0 where it may be found
69 without any information about the disk geometry.
72 from the beginning of the sector, to allow room for the initial bootstrap.
73 The disk sector containing the label is normally made read-only
74 so that it is not accidentally overwritten by pack-to-pack copies
79 which is done as needed by the
83 A copy of the in-core label for a disk can be obtained with the
86 this works with a file descriptor for a block or character (``raw'') device
87 for any partition of the disk.
88 The in-core copy of the label is set by the
91 The offset of a partition cannot generally be changed while it is open,
92 nor can it be made smaller while it is open.
93 One exception is that any change is allowed if no label was found
94 on the disk, and the driver was able to construct only a skeletal label
95 without partition information.
99 operation sets the in-core label and then updates the on-disk label;
100 there must be an existing label on the disk for this operation to succeed.
101 Thus, the initial label for a disk or disk pack must be installed
102 by writing to the raw disk.
103 All of these operations are normally done using
106 The format of the disk label, as specified in
107 .Pa <sys/disklabel.h> ,
110 #ifndef _SYS_DISKLABEL_H_
111 #define _SYS_DISKLABEL_H_
114 #include <sys/types.h>
116 #include <sys/ioccom.h>
119 * Disk description table, see disktab(5)
121 #define _PATH_DISKTAB "/etc/disktab"
122 #define DISKTAB "/etc/disktab" /* deprecated */
125 * Each disk has a label which includes information about the hardware
126 * disk geometry, filesystem partitions, and drive specific information.
127 * The label is in block 0 or 1, possibly offset from the beginning
128 * to leave room for a bootstrap, etc.
131 /* XXX these should be defined per controller (or drive) elsewhere, not here! */
133 #define LABELSECTOR 1 /* sector containing label */
134 #define LABELOFFSET 0 /* offset of label in sector */
138 #define LABELSECTOR 0
139 #define LABELOFFSET 64
143 #define LABELSECTOR 0 /* sector containing label */
147 #define LABELOFFSET 64 /* offset of label in sector */
150 #define DISKMAGIC ((u_int32_t)0x82564557) /* The disk magic number */
151 #ifndef MAXPARTITIONS
152 #define MAXPARTITIONS 8
155 #define LABEL_PART 2 /* partition containing label */
156 #define RAW_PART 2 /* partition containing whole disk */
157 #define SWAP_PART 1 /* partition normally containing swap */
161 u_int32_t d_magic; /* the magic number */
162 u_int16_t d_type; /* drive type */
163 u_int16_t d_subtype; /* controller/d_type specific */
164 char d_typename[16]; /* type name, e.g. "eagle" */
167 * d_packname contains the pack identifier and is returned when
168 * the disklabel is read off the disk or in-core copy.
169 * d_boot0 and d_boot1 are the (optional) names of the
170 * primary (block 0) and secondary (block 1-15) bootstraps
171 * as found in /boot. These are returned when using
172 * getdiskbyname(3) to retrieve the values from /etc/disktab.
175 char un_d_packname[16]; /* pack identifier */
177 char *un_d_boot0; /* primary bootstrap name */
178 char *un_d_boot1; /* secondary bootstrap name */
181 #define d_packname d_un.un_d_packname
182 #define d_boot0 d_un.un_b.un_d_boot0
183 #define d_boot1 d_un.un_b.un_d_boot1
186 u_int32_t d_secsize; /* # of bytes per sector */
187 u_int32_t d_nsectors; /* # of data sectors per track */
188 u_int32_t d_ntracks; /* # of tracks per cylinder */
189 u_int32_t d_ncylinders; /* # of data cylinders per unit */
190 u_int32_t d_secpercyl; /* # of data sectors per cylinder */
191 u_int32_t d_secperunit; /* # of data sectors per unit */
194 * Spares (bad sector replacements) below are not counted in
195 * d_nsectors or d_secpercyl. Spare sectors are assumed to
196 * be physical sectors which occupy space at the end of each
197 * track and/or cylinder.
199 u_int16_t d_sparespertrack; /* # of spare sectors per track */
200 u_int16_t d_sparespercyl; /* # of spare sectors per cylinder */
202 * Alternate cylinders include maintenance, replacement, configuration
203 * description areas, etc.
205 u_int32_t d_acylinders; /* # of alt. cylinders per unit */
207 /* hardware characteristics: */
209 * d_interleave, d_trackskew and d_cylskew describe perturbations
210 * in the media format used to compensate for a slow controller.
211 * Interleave is physical sector interleave, set up by the
212 * formatter or controller when formatting. When interleaving is
213 * in use, logically adjacent sectors are not physically
214 * contiguous, but instead are separated by some number of
215 * sectors. It is specified as the ratio of physical sectors
216 * traversed per logical sector. Thus an interleave of 1:1
217 * implies contiguous layout, while 2:1 implies that logical
218 * sector 0 is separated by one sector from logical sector 1.
219 * d_trackskew is the offset of sector 0 on track N relative to
220 * sector 0 on track N-1 on the same cylinder. Finally, d_cylskew
221 * is the offset of sector 0 on cylinder N relative to sector 0
224 u_int16_t d_rpm; /* rotational speed */
225 u_int16_t d_interleave; /* hardware sector interleave */
226 u_int16_t d_trackskew; /* sector 0 skew, per track */
227 u_int16_t d_cylskew; /* sector 0 skew, per cylinder */
228 u_int32_t d_headswitch; /* head switch time, usec */
229 u_int32_t d_trkseek; /* track-to-track seek, usec */
230 u_int32_t d_flags; /* generic flags */
232 u_int32_t d_drivedata[NDDATA]; /* drive-type specific information */
234 u_int32_t d_spare[NSPARE]; /* reserved for future use */
235 u_int32_t d_magic2; /* the magic number (again) */
236 u_int16_t d_checksum; /* xor of data incl. partitions */
238 /* filesystem and partition information: */
239 u_int16_t d_npartitions; /* number of partitions in following */
240 u_int32_t d_bbsize; /* size of boot area at sn0, bytes */
241 u_int32_t d_sbsize; /* max size of fs superblock, bytes */
242 struct partition { /* the partition table */
243 u_int32_t p_size; /* number of sectors in partition */
244 u_int32_t p_offset; /* starting sector */
245 u_int32_t p_fsize; /* filesystem basic fragment size */
246 u_int8_t p_fstype; /* filesystem type, see below */
247 u_int8_t p_frag; /* filesystem fragments per block */
249 u_int16_t cpg; /* UFS: FS cylinders per group */
250 u_int16_t sgs; /* LFS: FS segment shift */
252 #define p_cpg __partition_u1.cpg
253 #define p_sgs __partition_u1.sgs
254 } d_partitions[MAXPARTITIONS]; /* actually may be more */
258 * offsets for asm boot files.
266 .set d_end_,276 /* size of disk label */
270 #define DTYPE_SMD 1 /* SMD, XSMD; VAX hp/up */
271 #define DTYPE_MSCP 2 /* MSCP */
272 #define DTYPE_DEC 3 /* other DEC (rk, rl) */
273 #define DTYPE_SCSI 4 /* SCSI */
274 #define DTYPE_ESDI 5 /* ESDI interface */
275 #define DTYPE_ST506 6 /* ST506 etc. */
276 #define DTYPE_HPIB 7 /* CS/80 on HP-IB */
277 #define DTYPE_HPFL 8 /* HP Fiber-link */
278 #define DTYPE_FLOPPY 10 /* floppy */
279 #define DTYPE_CCD 11 /* concatenated disk */
280 #define DTYPE_VINUM 12 /* vinum volume */
281 #define DTYPE_DOC2K 13 /* Msys DiskOnChip */
283 #if defined(PC98) && !defined(PC98_ATCOMPAT)
284 #define DSTYPE_SEC256 0x80 /* physical sector size=256 */
288 static char *dktypenames[] = {
305 #define DKMAXTYPES (sizeof(dktypenames) / sizeof(dktypenames[0]) - 1)
309 * Filesystem type and version.
310 * Used to interpret other filesystem-specific
311 * per-partition information.
313 #define FS_UNUSED 0 /* unused */
314 #define FS_SWAP 1 /* swap */
315 #define FS_V6 2 /* Sixth Edition */
316 #define FS_V7 3 /* Seventh Edition */
317 #define FS_SYSV 4 /* System V */
318 #define FS_V71K 5 /* V7 with 1K blocks (4.1, 2.9) */
319 #define FS_V8 6 /* Eighth Edition, 4K blocks */
320 #define FS_BSDFFS 7 /* 4.2BSD fast file system */
321 #define FS_MSDOS 8 /* MSDOS file system */
322 #define FS_BSDLFS 9 /* 4.4BSD log-structured file system */
323 #define FS_OTHER 10 /* in use, but unknown/unsupported */
324 #define FS_HPFS 11 /* OS/2 high-performance file system */
325 #define FS_ISO9660 12 /* ISO 9660, normally CD-ROM */
326 #define FS_BOOT 13 /* partition contains bootstrap */
327 #define FS_VINUM 14 /* Vinum drive */
330 static char *fstypenames[] = {
348 #define FSMAXTYPES (sizeof(fstypenames) / sizeof(fstypenames[0]) - 1)
352 * flags shared by various drives:
354 #define D_REMOVABLE 0x01 /* removable media */
355 #define D_ECC 0x02 /* supports ECC */
356 #define D_BADSECT 0x04 /* supports bad sector forw. */
357 #define D_RAMDISK 0x08 /* disk emulator */
358 #define D_CHAIN 0x10 /* can do back-back transfers */
361 * Drive data for SMD.
363 #define d_smdflags d_drivedata[0]
364 #define D_SSE 0x1 /* supports skip sectoring */
365 #define d_mindist d_drivedata[1]
366 #define d_maxdist d_drivedata[2]
367 #define d_sdist d_drivedata[3]
370 * Drive data for ST506.
372 #define d_precompcyl d_drivedata[0]
373 #define d_gap3 d_drivedata[1] /* used only when formatting */
376 * Drive data for SCSI.
378 #define d_blind d_drivedata[0]
382 * Structure used to perform a format or other raw operation, returning
383 * data and/or register values. Register identification and format
384 * are device- and driver-dependent.
388 int df_count; /* value-result */
390 int df_reg[8]; /* result */
394 * Structure used internally to retrieve information about a partition
398 struct disklabel *disklab;
399 struct partition *part;
402 /* DOS partition table -- located in boot block */
404 #if defined(PC98) && !defined(PC98_ATCOMPAT)
405 #define DOSBBSECTOR 0 /* DOS boot block relative sector number */
406 #define DOSLABELSECTOR 1 /* 0: 256b/s, 1: 512b/s */
409 #define DOSPTYP_386BSD 0x94 /* 386BSD partition type */
410 #define MBR_PTYPE_FreeBSD 0x94 /* FreeBSD partition type */
412 struct dos_partition {
413 unsigned char dp_mid;
414 #define DOSMID_386BSD (0x14|0x80) /* 386bsd|bootable */
415 unsigned char dp_sid;
416 #define DOSSID_386BSD (0x44|0x80) /* 386bsd|active */
417 unsigned char dp_dum1;
418 unsigned char dp_dum2;
419 unsigned char dp_ipl_sct;
420 unsigned char dp_ipl_head;
421 unsigned short dp_ipl_cyl;
422 unsigned char dp_ssect; /* starting sector */
423 unsigned char dp_shd; /* starting head */
424 unsigned short dp_scyl; /* starting cylinder */
425 unsigned char dp_esect; /* end sector */
426 unsigned char dp_ehd; /* end head */
427 unsigned short dp_ecyl; /* end cylinder */
428 unsigned char dp_name[16];
432 #define DOSBBSECTOR 0 /* DOS boot block relative sector number */
433 #define DOSPARTOFF 446
435 #define DOSPTYP_386BSD 0xa5 /* 386BSD partition type */
437 struct dos_partition {
438 unsigned char dp_flag; /* bootstrap flags */
439 unsigned char dp_shd; /* starting head */
440 unsigned char dp_ssect; /* starting sector */
441 unsigned char dp_scyl; /* starting cylinder */
442 unsigned char dp_typ; /* partition type */
443 unsigned char dp_ehd; /* end head */
444 unsigned char dp_esect; /* end sector */
445 unsigned char dp_ecyl; /* end cylinder */
446 u_int32_t dp_start; /* absolute starting sector number */
447 u_int32_t dp_size; /* partition size in sectors */
451 #define DPSECT(s) ((s) & 0x3f) /* isolate relevant bits of sector */
452 #define DPCYL(c, s) ((c) + (((s) & 0xc0)<<2)) /* and those that are cylinder */
455 * Disk-specific ioctls.
457 /* get and set disklabel; DIOCGPART used internally */
458 #define DIOCGDINFO _IOR('d', 101, struct disklabel)/* get */
459 #define DIOCSDINFO _IOW('d', 102, struct disklabel)/* set */
460 #define DIOCWDINFO _IOW('d', 103, struct disklabel)/* set, update disk */
461 #define DIOCGPART _IOW('d', 104, struct partinfo) /* get partition */
463 #define DIOCWLABEL _IOW('d', 109, int) /* write en/disable label */
468 * XXX encoding of disk minor numbers, should be elsewhere.
470 * See <sys/reboot.h> for a possibly better encoding.
472 * "cpio -H newc" can be used to back up device files with large minor
473 * numbers (but not ones >= 2^31). Old cpio formats and all tar formats
474 * don't have enough bits, and cpio and tar don't notice the lossage.
475 * There are also some sign extension bugs.
480 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
481 _________________________________________________________________
482 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
483 -----------------------------------------------------------------
484 | TYPE |UNIT_2 | SLICE | MAJOR? | UNIT |PART |
485 -----------------------------------------------------------------
487 #define dkmakeminor(unit, slice, part) \e
488 (((slice) << 16) | (((unit) & 0x1e0) << 16) | \e
489 (((unit) & 0x1f) << 3) | (part))
490 static __inline dev_t
491 dkmodpart(dev_t dev, int part)
493 return (makedev(major(dev), (minor(dev) & ~7) | part));
496 static __inline dev_t
497 dkmodslice(dev_t dev, int slice)
499 return (makedev(major(dev), (minor(dev) & ~0x1f0000) | (slice << 16)));
502 #define dkpart(dev) (minor(dev) & 7)
503 #define dkslice(dev) ((minor(dev) >> 16) & 0x1f)
504 #define dktype(dev) ((minor(dev) >> 25) & 0x7f)
506 static __inline u_int
509 return (((minor(dev) >> 16) & 0x1e0) | ((minor(dev) >> 3) & 0x1f));
513 struct buf_queue_head;
515 int bounds_check_with_label(struct buf *bp, struct disklabel *lp,
517 void diskerr(struct buf *bp, char *what, int pri, int blkdone,
518 struct disklabel *lp);
519 void disksort(struct buf *ap, struct buf *bp));
520 u_int dkcksum(struct disklabel *lp);
521 char *readdisklabel(dev_t dev, struct disklabel *lp);
522 void bufqdisksort(struct buf_queue_head *ap, struct buf *bp);
523 int setdisklabel(struct disklabel *olp, struct disklabel *nlp,
525 int writedisklabel((dev_t dev, struct disklabel *lp);
527 void alpha_fix_srm_checksum(struct buf *bp);
536 struct disklabel *getdiskbyname(const char *);
540 #endif /* !_SYS_DISKLABEL_H_ */