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GETDISKBYNAME(3) UNIX Programmer's Manual GETDISKBYNAME(3) NAME getdiskbyname - get disk description by its name SYNOPSIS #include <sys/types.h> #include <sys/disktab.h> struct disklabel * getdiskbyname(name) char *name; DESCRIPTION Getdiskbyname takes a disk name (e.g. rm03) and returns a structure describing its geometry information and the stan- dard disk partition tables. Information obtained from the disktab(5) file has the following form: /* * Copyright (c) 1987, 1988, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)disklabel.h 8.1.1 (2.11BSD) 1995/04/13 */ Printed 11/26/99 September 8, 1995 1 GETDISKBYNAME(3) UNIX Programmer's Manual GETDISKBYNAME(3) #ifndef _SYS_DISKLABEL_H_ #define _SYS_DISKLABEL_H_ /* * Disk description table, see disktab(5) */ #define _PATH_DISKTAB "/etc/disktab" #define DISKTAB "/etc/disktab" /* deprecated */ /* * Each disk has a label which includes information about the hardware * disk geometry, filesystem partitions, and drive specific information. * The label is in block 0 or 1, possibly offset from the beginning * to leave room for a bootstrap, etc. */ /* XXX these should be defined per controller (or drive) elsewhere, not here! */ #define LABELSECTOR 1 /* sector containing label */ #define LABELOFFSET 0 /* offset of label in sector */ #define DISKMAGIC ((u_long) 0x82564557) /* The disk magic number */ #define MAXPARTITIONS 8 /* * 2.11BSD's disklabels are different than 4.4BSD for a couple reasons: * * 1) D space is precious in the 2.11 kernel. Many of the fields do * not need to be a 'long' (or even a 'short'), a 'short' (or 'char') * is more than adequate. If anyone ever ports the FFS to a PDP11 * changing the label format will be the least of the problems. * * 2) There is no need to support a bootblock more than 512 bytes long. * The hardware (disk bootroms) only read the first sector, thus the * label is always at sector 1 (the second half of the first filesystem * block). * * Almost all of the fields have been retained but with reduced sizes. This * is for future expansion and to ease the porting of the various utilities * which use the disklabel structure. The 2.11 kernel uses very little other * than the partition tables. Indeed only the partition tables are resident * in the kernel address space, the actual label block is allocated external to * the kernel and mapped in as needed. */ struct disklabel { u_long d_magic; /* the magic number */ u_char d_type; /* drive type */ u_char d_subtype; /* controller/d_type specific */ char d_typename[16]; /* type name, e.g. "eagle" */ /* * d_packname contains the pack identifier and is returned when * the disklabel is read off the disk or in-core copy. Printed 11/26/99 September 8, 1995 2 GETDISKBYNAME(3) UNIX Programmer's Manual GETDISKBYNAME(3) * d_boot0 is the (optional) name of the primary (block 0) bootstrap * as found in /mdec. This is returned when using * getdiskbyname(3) to retrieve the values from /etc/disktab. */ #if defined(KERNEL) || defined(STANDALONE) char d_packname[16]; /* pack identifier */ #else union { char un_d_packname[16]; /* pack identifier */ char *un_d_boot0; /* primary bootstrap name */ } d_un; #define d_packname d_un.un_d_packname #define d_boot0 d_un.un_d_boot0 #endif /* ! KERNEL or STANDALONE */ /* disk geometry: */ u_short d_secsize; /* # of bytes per sector */ u_short d_nsectors; /* # of data sectors per track */ u_short d_ntracks; /* # of tracks per cylinder */ u_short d_ncylinders; /* # of data cylinders per unit */ u_short d_secpercyl; /* # of data sectors per cylinder */ u_long d_secperunit; /* # of data sectors per unit */ /* * Spares (bad sector replacements) below * are not counted in d_nsectors or d_secpercyl. * Spare sectors are assumed to be physical sectors * which occupy space at the end of each track and/or cylinder. */ u_short d_sparespertrack; /* # of spare sectors per track */ u_short d_sparespercyl; /* # of spare sectors per cylinder */ /* * Alternate cylinders include maintenance, replacement, * configuration description areas, etc. */ u_short d_acylinders; /* # of alt. cylinders per unit */ /* hardware characteristics: */ /* * d_interleave, d_trackskew and d_cylskew describe perturbations * in the media format used to compensate for a slow controller. * Interleave is physical sector interleave, set up by the formatter * or controller when formatting. When interleaving is in use, * logically adjacent sectors are not physically contiguous, * but instead are separated by some number of sectors. * It is specified as the ratio of physical sectors traversed * per logical sector. Thus an interleave of 1:1 implies contiguous * layout, while 2:1 implies that logical sector 0 is separated * by one sector from logical sector 1. * d_trackskew is the offset of sector 0 on track N * relative to sector 0 on track N-1 on the same cylinder. * Finally, d_cylskew is the offset of sector 0 on cylinder N * relative to sector 0 on cylinder N-1. */ Printed 11/26/99 September 8, 1995 3 GETDISKBYNAME(3) UNIX Programmer's Manual GETDISKBYNAME(3) u_short d_rpm; /* rotational speed */ u_char d_interleave; /* hardware sector interleave */ u_char d_trackskew; /* sector 0 skew, per track */ u_char d_cylskew; /* sector 0 skew, per cylinder */ u_char d_headswitch; /* head swith time, usec */ u_short d_trkseek; /* track-to-track seek, msec */ u_short d_flags; /* generic flags */ #define NDDATA 5 u_long d_drivedata[NDDATA]; /* drive-type specific information */ #define NSPARE 5 u_long d_spare[NSPARE]; /* reserved for future use */ u_long d_magic2; /* the magic number (again) */ u_short d_checksum; /* xor of data incl. partitions */ /* filesystem and partition information: */ u_short d_npartitions; /* number of partitions in following */ u_short d_bbsize; /* size of boot area at sn0, bytes */ u_short d_sbsize; /* max size of fs superblock, bytes */ struct partition { /* the partition table */ u_long p_size; /* number of sectors in partition */ u_long p_offset; /* starting sector */ u_short p_fsize; /* filesystem basic fragment size */ u_char p_fstype; /* filesystem type, see below */ u_char p_frag; /* filesystem fragments per block */ } d_partitions[MAXPARTITIONS]; /* actually may be more */ }; /* d_type values: */ #define DTYPE_SMD 1 /* SMD, XSMD; VAX hp/up */ #define DTYPE_MSCP 2 /* MSCP */ #define DTYPE_DEC 3 /* other DEC (rk, rl) */ #define DTYPE_SCSI 4 /* SCSI */ #define DTYPE_ESDI 5 /* ESDI interface */ #define DTYPE_ST506 6 /* ST506 etc. */ #define DTYPE_FLOPPY 7 /* floppy */ #ifdef DKTYPENAMES static char *dktypenames[] = { "unknown", "SMD", "MSCP", "old DEC", "SCSI", "ESDI", "ST506", "floppy", 0 }; #define DKMAXTYPES (sizeof(dktypenames) / sizeof(dktypenames[0]) - 1) #endif /* Printed 11/26/99 September 8, 1995 4 GETDISKBYNAME(3) UNIX Programmer's Manual GETDISKBYNAME(3) * Filesystem type and version. * Used to interpret other filesystem-specific * per-partition information. */ #define FS_UNUSED 0 /* unused */ #define FS_SWAP 1 /* swap */ #define FS_V6 2 /* Sixth Edition */ #define FS_V7 3 /* Seventh Edition */ #define FS_SYSV 4 /* System V */ /* * 2.11BSD uses type 5 filesystems even though block numbers are 4 bytes * (rather than the packed 3 byte format) and the directory structure is * that of 4.3BSD (long filenames). */ #define FS_V71K 5 /* V7 with 1K blocks (4.1, 2.9, 2.11) */ #define FS_V8 6 /* Eighth Edition, 4K blocks */ #define FS_BSDFFS 7 /* 4.2BSD fast file system */ #define FS_MSDOS 8 /* MSDOS file system */ #define FS_BSDLFS 9 /* 4.4BSD log-structured file system */ #define FS_OTHER 10 /* in use, but unknown/unsupported */ #define FS_HPFS 11 /* OS/2 high-performance file system */ #define FS_ISO9660 12 /* ISO 9660, normally CD-ROM */ #ifdef DKTYPENAMES static char *fstypenames[] = { "unused", "swap", "Version 6", "Version 7", "System V", "2.11BSD", "Eighth Edition", "4.2BSD", "MSDOS", "4.4LFS", "unknown", "HPFS", "ISO9660", 0 }; #define FSMAXTYPES (sizeof(fstypenames) / sizeof(fstypenames[0]) - 1) #endif /* * flags shared by various drives: */ #define D_REMOVABLE 0x01 /* removable media */ #define D_ECC 0x02 /* supports ECC */ #define D_BADSECT 0x04 /* supports bad sector forw. */ #define D_RAMDISK 0x08 /* disk emulator */ /* Printed 11/26/99 September 8, 1995 5 GETDISKBYNAME(3) UNIX Programmer's Manual GETDISKBYNAME(3) * Structure used to perform a format * or other raw operation, returning data * and/or register values. * Register identification and format * are device- and driver-dependent. */ struct format_op { char *df_buf; int df_count; /* value-result */ daddr_t df_startblk; int df_reg[8]; /* result */ }; /* * Structure used internally to retrieve * information about a partition on a disk. */ struct partinfo { struct disklabel *disklab; struct partition *part; }; /* * Disk-specific ioctls. */ /* get and set disklabel; DIOCGPART used internally */ #define DIOCGDINFO _IOR(d, 101, struct disklabel) /* get */ #define DIOCSDINFO _IOW(d, 102, struct disklabel) /* set */ #define DIOCWDINFO _IOW(d, 103, struct disklabel) /* set, update disk */ #define DIOCGPART _IOW(d, 104, struct partinfo) /* get partition */ /* do format operation, read or write */ #define DIOCRFORMAT _IOWR(d, 105, struct format_op) #define DIOCWFORMAT _IOWR(d, 106, struct format_op) #define DIOCSSTEP _IOW(d, 107, int) /* set step rate */ #define DIOCSRETRIES _IOW(d, 108, int) /* set # of retries */ #define DIOCWLABEL _IOW(d, 109, int) /* write en/disable label */ #define DIOCSBAD _IOW(d, 110, struct dkbad) /* set kernel dkbad */ #ifndef KERNEL struct disklabel *getdiskbyname(); #endif #if defined(KERNEL) && !defined(SUPERVISOR) memaddr disklabelalloc(); #define LABELDESC (((btoc(sizeof (struct disklabel)) - 1) << 8) | RW) #endif #endif /* !_SYS_DISKLABEL_H_ */ Printed 11/26/99 September 8, 1995 6 GETDISKBYNAME(3) UNIX Programmer's Manual GETDISKBYNAME(3) SEE ALSO disktab(5), disklabel(8) BUGS This routine is primarily used when the underlying disk driver does not support labels. The other use is for sup- plying default information to the disklabel(8) program. Printed 11/26/99 September 8, 1995 7
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