LXR linux/include/linux/genhd.h

   1#ifndef _LINUX_GENHD_H
   2#define _LINUX_GENHD_H
   3
   4/*
   5 *      genhd.h Copyright (C) 1992 Drew Eckhardt
   6 *      Generic hard disk header file by  
   7 *              Drew Eckhardt
   8 *
   9 *              <drew@colorado.edu>
  10 */
  11
  12#include <linux/types.h>
  13#include <linux/kdev_t.h>
  14#include <linux/rcupdate.h>
  15
  16#ifdef CONFIG_BLOCK
  17
  18#define kobj_to_dev(k)          container_of((k), struct device, kobj)
  19#define dev_to_disk(device)     container_of((device), struct gendisk, part0.__dev)
  20#define dev_to_part(device)     container_of((device), struct hd_struct, __dev)
  21#define disk_to_dev(disk)       (&(disk)->part0.__dev)
  22#define part_to_dev(part)       (&((part)->__dev))
  23
  24extern struct device_type part_type;
  25extern struct kobject *block_depr;
  26extern struct class block_class;
  27
  28enum {
  29/* These three have identical behaviour; use the second one if DOS FDISK gets
  30   confused about extended/logical partitions starting past cylinder 1023. */
  31        DOS_EXTENDED_PARTITION = 5,
  32        LINUX_EXTENDED_PARTITION = 0x85,
  33        WIN98_EXTENDED_PARTITION = 0x0f,
  34
  35        SUN_WHOLE_DISK = DOS_EXTENDED_PARTITION,
  36
  37        LINUX_SWAP_PARTITION = 0x82,
  38        LINUX_DATA_PARTITION = 0x83,
  39        LINUX_LVM_PARTITION = 0x8e,
  40        LINUX_RAID_PARTITION = 0xfd,    /* autodetect RAID partition */
  41
  42        SOLARIS_X86_PARTITION = LINUX_SWAP_PARTITION,
  43        NEW_SOLARIS_X86_PARTITION = 0xbf,
  44
  45        DM6_AUX1PARTITION = 0x51,       /* no DDO:  use xlated geom */
  46        DM6_AUX3PARTITION = 0x53,       /* no DDO:  use xlated geom */
  47        DM6_PARTITION = 0x54,           /* has DDO: use xlated geom & offset */
  48        EZD_PARTITION = 0x55,           /* EZ-DRIVE */
  49
  50        FREEBSD_PARTITION = 0xa5,       /* FreeBSD Partition ID */
  51        OPENBSD_PARTITION = 0xa6,       /* OpenBSD Partition ID */
  52        NETBSD_PARTITION = 0xa9,        /* NetBSD Partition ID */
  53        BSDI_PARTITION = 0xb7,          /* BSDI Partition ID */
  54        MINIX_PARTITION = 0x81,         /* Minix Partition ID */
  55        UNIXWARE_PARTITION = 0x63,      /* Same as GNU_HURD and SCO Unix */
  56};
  57
  58#define DISK_MAX_PARTS                  256
  59#define DISK_NAME_LEN                   32
  60
  61#include <linux/major.h>
  62#include <linux/device.h>
  63#include <linux/smp.h>
  64#include <linux/string.h>
  65#include <linux/fs.h>
  66#include <linux/workqueue.h>
  67
  68struct partition {
  69        unsigned char boot_ind;         /* 0x80 - active */
  70        unsigned char head;             /* starting head */
  71        unsigned char sector;           /* starting sector */
  72        unsigned char cyl;              /* starting cylinder */
  73        unsigned char sys_ind;          /* What partition type */
  74        unsigned char end_head;         /* end head */
  75        unsigned char end_sector;       /* end sector */
  76        unsigned char end_cyl;          /* end cylinder */
  77        __le32 start_sect;      /* starting sector counting from 0 */
  78        __le32 nr_sects;                /* nr of sectors in partition */
  79} __attribute__((packed));
  80
  81struct disk_stats {
  82        unsigned long sectors[2];       /* READs and WRITEs */
  83        unsigned long ios[2];
  84        unsigned long merges[2];
  85        unsigned long ticks[2];
  86        unsigned long io_ticks;
  87        unsigned long time_in_queue;
  88};
  89        
  90struct hd_struct {
  91        sector_t start_sect;
  92        sector_t nr_sects;
  93        sector_t alignment_offset;
  94        unsigned int discard_alignment;
  95        struct device __dev;
  96        struct kobject *holder_dir;
  97        int policy, partno;
  98#ifdef CONFIG_FAIL_MAKE_REQUEST
  99        int make_it_fail;
 100#endif
 101        unsigned long stamp;
 102        int in_flight[2];
 103#ifdef  CONFIG_SMP
 104        struct disk_stats __percpu *dkstats;
 105#else
 106        struct disk_stats dkstats;
 107#endif
 108        struct rcu_head rcu_head;
 109};
 110
 111#define GENHD_FL_REMOVABLE                      1
 112/* 2 is unused */
 113#define GENHD_FL_MEDIA_CHANGE_NOTIFY            4
 114#define GENHD_FL_CD                             8
 115#define GENHD_FL_UP                             16
 116#define GENHD_FL_SUPPRESS_PARTITION_INFO        32
 117#define GENHD_FL_EXT_DEVT                       64 /* allow extended devt */
 118#define GENHD_FL_NATIVE_CAPACITY                128
 119
 120#define BLK_SCSI_MAX_CMDS       (256)
 121#define BLK_SCSI_CMD_PER_LONG   (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
 122
 123struct blk_scsi_cmd_filter {
 124        unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
 125        unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
 126        struct kobject kobj;
 127};
 128
 129struct disk_part_tbl {
 130        struct rcu_head rcu_head;
 131        int len;
 132        struct hd_struct *last_lookup;
 133        struct hd_struct *part[];
 134};
 135
 136struct gendisk {
 137        /* major, first_minor and minors are input parameters only,
 138         * don't use directly.  Use disk_devt() and disk_max_parts().
 139         */
 140        int major;                      /* major number of driver */
 141        int first_minor;
 142        int minors;                     /* maximum number of minors, =1 for
 143                                         * disks that can't be partitioned. */
 144
 145        char disk_name[DISK_NAME_LEN];  /* name of major driver */
 146        char *(*devnode)(struct gendisk *gd, mode_t *mode);
 147        /* Array of pointers to partitions indexed by partno.
 148         * Protected with matching bdev lock but stat and other
 149         * non-critical accesses use RCU.  Always access through
 150         * helpers.
 151         */
 152        struct disk_part_tbl *part_tbl;
 153        struct hd_struct part0;
 154
 155        const struct block_device_operations *fops;
 156        struct request_queue *queue;
 157        void *private_data;
 158
 159        int flags;
 160        struct device *driverfs_dev;  // FIXME: remove
 161        struct kobject *slave_dir;
 162
 163        struct timer_rand_state *random;
 164
 165        atomic_t sync_io;               /* RAID */
 166        struct work_struct async_notify;
 167#ifdef  CONFIG_BLK_DEV_INTEGRITY
 168        struct blk_integrity *integrity;
 169#endif
 170        int node_id;
 171};
 172
 173static inline struct gendisk *part_to_disk(struct hd_struct *part)
 174{
 175        if (likely(part)) {
 176                if (part->partno)
 177                        return dev_to_disk(part_to_dev(part)->parent);
 178                else
 179                        return dev_to_disk(part_to_dev(part));
 180        }
 181        return NULL;
 182}
 183
 184static inline int disk_max_parts(struct gendisk *disk)
 185{
 186        if (disk->flags & GENHD_FL_EXT_DEVT)
 187                return DISK_MAX_PARTS;
 188        return disk->minors;
 189}
 190
 191static inline bool disk_partitionable(struct gendisk *disk)
 192{
 193        return disk_max_parts(disk) > 1;
 194}
 195
 196static inline dev_t disk_devt(struct gendisk *disk)
 197{
 198        return disk_to_dev(disk)->devt;
 199}
 200
 201static inline dev_t part_devt(struct hd_struct *part)
 202{
 203        return part_to_dev(part)->devt;
 204}
 205
 206extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
 207
 208static inline void disk_put_part(struct hd_struct *part)
 209{
 210        if (likely(part))
 211                put_device(part_to_dev(part));
 212}
 213
 214/*
 215 * Smarter partition iterator without context limits.
 216 */
 217#define DISK_PITER_REVERSE      (1 << 0) /* iterate in the reverse direction */
 218#define DISK_PITER_INCL_EMPTY   (1 << 1) /* include 0-sized parts */
 219#define DISK_PITER_INCL_PART0   (1 << 2) /* include partition 0 */
 220#define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
 221
 222struct disk_part_iter {
 223        struct gendisk          *disk;
 224        struct hd_struct        *part;
 225        int                     idx;
 226        unsigned int            flags;
 227};
 228
 229extern void disk_part_iter_init(struct disk_part_iter *piter,
 230                                 struct gendisk *disk, unsigned int flags);
 231extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
 232extern void disk_part_iter_exit(struct disk_part_iter *piter);
 233
 234extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
 235                                             sector_t sector);
 236
 237/*
 238 * Macros to operate on percpu disk statistics:
 239 *
 240 * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
 241 * and should be called between disk_stat_lock() and
 242 * disk_stat_unlock().
 243 *
 244 * part_stat_read() can be called at any time.
 245 *
 246 * part_stat_{add|set_all}() and {init|free}_part_stats are for
 247 * internal use only.
 248 */
 249#ifdef  CONFIG_SMP
 250#define part_stat_lock()        ({ rcu_read_lock(); get_cpu(); })
 251#define part_stat_unlock()      do { put_cpu(); rcu_read_unlock(); } while (0)
 252
 253#define __part_stat_add(cpu, part, field, addnd)                        \
 254        (per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd))
 255
 256#define part_stat_read(part, field)                                     \
 257({                                                                      \
 258        typeof((part)->dkstats->field) res = 0;                         \
 259        unsigned int _cpu;                                              \
 260        for_each_possible_cpu(_cpu)                                     \
 261                res += per_cpu_ptr((part)->dkstats, _cpu)->field;       \
 262        res;                                                            \
 263})
 264
 265static inline void part_stat_set_all(struct hd_struct *part, int value)
 266{
 267        int i;
 268
 269        for_each_possible_cpu(i)
 270                memset(per_cpu_ptr(part->dkstats, i), value,
 271                                sizeof(struct disk_stats));
 272}
 273
 274static inline int init_part_stats(struct hd_struct *part)
 275{
 276        part->dkstats = alloc_percpu(struct disk_stats);
 277        if (!part->dkstats)
 278                return 0;
 279        return 1;
 280}
 281
 282static inline void free_part_stats(struct hd_struct *part)
 283{
 284        free_percpu(part->dkstats);
 285}
 286
 287#else /* !CONFIG_SMP */
 288#define part_stat_lock()        ({ rcu_read_lock(); 0; })
 289#define part_stat_unlock()      rcu_read_unlock()
 290
 291#define __part_stat_add(cpu, part, field, addnd)                                \
 292        ((part)->dkstats.field += addnd)
 293
 294#define part_stat_read(part, field)     ((part)->dkstats.field)
 295
 296static inline void part_stat_set_all(struct hd_struct *part, int value)
 297{
 298        memset(&part->dkstats, value, sizeof(struct disk_stats));
 299}
 300
 301static inline int init_part_stats(struct hd_struct *part)
 302{
 303        return 1;
 304}
 305
 306static inline void free_part_stats(struct hd_struct *part)
 307{
 308}
 309
 310#endif /* CONFIG_SMP */
 311
 312#define part_stat_add(cpu, part, field, addnd)  do {                    \
 313        __part_stat_add((cpu), (part), field, addnd);                   \
 314        if ((part)->partno)                                             \
 315                __part_stat_add((cpu), &part_to_disk((part))->part0,    \
 316                                field, addnd);                          \
 317} while (0)
 318
 319#define part_stat_dec(cpu, gendiskp, field)                             \
 320        part_stat_add(cpu, gendiskp, field, -1)
 321#define part_stat_inc(cpu, gendiskp, field)                             \
 322        part_stat_add(cpu, gendiskp, field, 1)
 323#define part_stat_sub(cpu, gendiskp, field, subnd)                      \
 324        part_stat_add(cpu, gendiskp, field, -subnd)
 325
 326static inline void part_inc_in_flight(struct hd_struct *part, int rw)
 327{
 328        part->in_flight[rw]++;
 329        if (part->partno)
 330                part_to_disk(part)->part0.in_flight[rw]++;
 331}
 332
 333static inline void part_dec_in_flight(struct hd_struct *part, int rw)
 334{
 335        part->in_flight[rw]--;
 336        if (part->partno)
 337                part_to_disk(part)->part0.in_flight[rw]--;
 338}
 339
 340static inline int part_in_flight(struct hd_struct *part)
 341{
 342        return part->in_flight[0] + part->in_flight[1];
 343}
 344
 345/* block/blk-core.c */
 346extern void part_round_stats(int cpu, struct hd_struct *part);
 347
 348/* block/genhd.c */
 349extern void add_disk(struct gendisk *disk);
 350extern void del_gendisk(struct gendisk *gp);
 351extern void unlink_gendisk(struct gendisk *gp);
 352extern struct gendisk *get_gendisk(dev_t dev, int *partno);
 353extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
 354
 355extern void set_device_ro(struct block_device *bdev, int flag);
 356extern void set_disk_ro(struct gendisk *disk, int flag);
 357
 358static inline int get_disk_ro(struct gendisk *disk)
 359{
 360        return disk->part0.policy;
 361}
 362
 363/* drivers/char/random.c */
 364extern void add_disk_randomness(struct gendisk *disk);
 365extern void rand_initialize_disk(struct gendisk *disk);
 366
 367static inline sector_t get_start_sect(struct block_device *bdev)
 368{
 369        return bdev->bd_part->start_sect;
 370}
 371static inline sector_t get_capacity(struct gendisk *disk)
 372{
 373        return disk->part0.nr_sects;
 374}
 375static inline void set_capacity(struct gendisk *disk, sector_t size)
 376{
 377        disk->part0.nr_sects = size;
 378}
 379
 380#ifdef CONFIG_SOLARIS_X86_PARTITION
 381
 382#define SOLARIS_X86_NUMSLICE    16
 383#define SOLARIS_X86_VTOC_SANE   (0x600DDEEEUL)
 384
 385struct solaris_x86_slice {
 386        __le16 s_tag;           /* ID tag of partition */
 387        __le16 s_flag;          /* permission flags */
 388        __le32 s_start;         /* start sector no of partition */
 389        __le32 s_size;          /* # of blocks in partition */
 390};
 391
 392struct solaris_x86_vtoc {
 393        unsigned int v_bootinfo[3];     /* info needed by mboot (unsupported) */
 394        __le32 v_sanity;                /* to verify vtoc sanity */
 395        __le32 v_version;               /* layout version */
 396        char    v_volume[8];            /* volume name */
 397        __le16  v_sectorsz;             /* sector size in bytes */
 398        __le16  v_nparts;               /* number of partitions */
 399        unsigned int v_reserved[10];    /* free space */
 400        struct solaris_x86_slice
 401                v_slice[SOLARIS_X86_NUMSLICE]; /* slice headers */
 402        unsigned int timestamp[SOLARIS_X86_NUMSLICE]; /* timestamp (unsupported) */
 403        char    v_asciilabel[128];      /* for compatibility */
 404};
 405
 406#endif /* CONFIG_SOLARIS_X86_PARTITION */
 407
 408#ifdef CONFIG_BSD_DISKLABEL
 409/*
 410 * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il>
 411 * updated by Marc Espie <Marc.Espie@openbsd.org>
 412 */
 413
 414/* check against BSD src/sys/sys/disklabel.h for consistency */
 415
 416#define BSD_DISKMAGIC   (0x82564557UL)  /* The disk magic number */
 417#define BSD_MAXPARTITIONS       16
 418#define OPENBSD_MAXPARTITIONS   16
 419#define BSD_FS_UNUSED           0       /* disklabel unused partition entry ID */
 420struct bsd_disklabel {
 421        __le32  d_magic;                /* the magic number */
 422        __s16   d_type;                 /* drive type */
 423        __s16   d_subtype;              /* controller/d_type specific */
 424        char    d_typename[16];         /* type name, e.g. "eagle" */
 425        char    d_packname[16];                 /* pack identifier */ 
 426        __u32   d_secsize;              /* # of bytes per sector */
 427        __u32   d_nsectors;             /* # of data sectors per track */
 428        __u32   d_ntracks;              /* # of tracks per cylinder */
 429        __u32   d_ncylinders;           /* # of data cylinders per unit */
 430        __u32   d_secpercyl;            /* # of data sectors per cylinder */
 431        __u32   d_secperunit;           /* # of data sectors per unit */
 432        __u16   d_sparespertrack;       /* # of spare sectors per track */
 433        __u16   d_sparespercyl;         /* # of spare sectors per cylinder */
 434        __u32   d_acylinders;           /* # of alt. cylinders per unit */
 435        __u16   d_rpm;                  /* rotational speed */
 436        __u16   d_interleave;           /* hardware sector interleave */
 437        __u16   d_trackskew;            /* sector 0 skew, per track */
 438        __u16   d_cylskew;              /* sector 0 skew, per cylinder */
 439        __u32   d_headswitch;           /* head switch time, usec */
 440        __u32   d_trkseek;              /* track-to-track seek, usec */
 441        __u32   d_flags;                /* generic flags */
 442#define NDDATA 5
 443        __u32   d_drivedata[NDDATA];    /* drive-type specific information */
 444#define NSPARE 5
 445        __u32   d_spare[NSPARE];        /* reserved for future use */
 446        __le32  d_magic2;               /* the magic number (again) */
 447        __le16  d_checksum;             /* xor of data incl. partitions */
 448
 449                        /* filesystem and partition information: */
 450        __le16  d_npartitions;          /* number of partitions in following */
 451        __le32  d_bbsize;               /* size of boot area at sn0, bytes */
 452        __le32  d_sbsize;               /* max size of fs superblock, bytes */
 453        struct  bsd_partition {         /* the partition table */
 454                __le32  p_size;         /* number of sectors in partition */
 455                __le32  p_offset;       /* starting sector */
 456                __le32  p_fsize;        /* filesystem basic fragment size */
 457                __u8    p_fstype;       /* filesystem type, see below */
 458                __u8    p_frag;         /* filesystem fragments per block */
 459                __le16  p_cpg;          /* filesystem cylinders per group */
 460        } d_partitions[BSD_MAXPARTITIONS];      /* actually may be more */
 461};
 462
 463#endif  /* CONFIG_BSD_DISKLABEL */
 464
 465#ifdef CONFIG_UNIXWARE_DISKLABEL
 466/*
 467 * Unixware slices support by Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl>
 468 * and Krzysztof G. Baranowski <kgb@knm.org.pl>
 469 */
 470
 471#define UNIXWARE_DISKMAGIC     (0xCA5E600DUL)   /* The disk magic number */
 472#define UNIXWARE_DISKMAGIC2    (0x600DDEEEUL)   /* The slice table magic nr */
 473#define UNIXWARE_NUMSLICE      16
 474#define UNIXWARE_FS_UNUSED     0                /* Unused slice entry ID */
 475
 476struct unixware_slice {
 477        __le16   s_label;       /* label */
 478        __le16   s_flags;       /* permission flags */
 479        __le32   start_sect;    /* starting sector */
 480        __le32   nr_sects;      /* number of sectors in slice */
 481};
 482
 483struct unixware_disklabel {
 484        __le32   d_type;                /* drive type */
 485        __le32   d_magic;                /* the magic number */
 486        __le32   d_version;              /* version number */
 487        char    d_serial[12];           /* serial number of the device */
 488        __le32   d_ncylinders;           /* # of data cylinders per device */
 489        __le32   d_ntracks;              /* # of tracks per cylinder */
 490        __le32   d_nsectors;             /* # of data sectors per track */
 491        __le32   d_secsize;              /* # of bytes per sector */
 492        __le32   d_part_start;           /* # of first sector of this partition */
 493        __le32   d_unknown1[12];         /* ? */
 494        __le32  d_alt_tbl;              /* byte offset of alternate table */
 495        __le32  d_alt_len;              /* byte length of alternate table */
 496        __le32  d_phys_cyl;             /* # of physical cylinders per device */
 497        __le32  d_phys_trk;             /* # of physical tracks per cylinder */
 498        __le32  d_phys_sec;             /* # of physical sectors per track */
 499        __le32  d_phys_bytes;           /* # of physical bytes per sector */
 500        __le32  d_unknown2;             /* ? */
 501        __le32   d_unknown3;             /* ? */
 502        __le32  d_pad[8];               /* pad */
 503
 504        struct unixware_vtoc {
 505                __le32  v_magic;                /* the magic number */
 506                __le32  v_version;              /* version number */
 507                char    v_name[8];              /* volume name */
 508                __le16  v_nslices;              /* # of slices */
 509                __le16  v_unknown1;             /* ? */
 510                __le32  v_reserved[10];         /* reserved */
 511                struct unixware_slice
 512                        v_slice[UNIXWARE_NUMSLICE];     /* slice headers */
 513        } vtoc;
 514
 515};  /* 408 */
 516
 517#endif /* CONFIG_UNIXWARE_DISKLABEL */
 518
 519#ifdef CONFIG_MINIX_SUBPARTITION
 520#   define MINIX_NR_SUBPARTITIONS  4
 521#endif /* CONFIG_MINIX_SUBPARTITION */
 522
 523#define ADDPART_FLAG_NONE       0
 524#define ADDPART_FLAG_RAID       1
 525#define ADDPART_FLAG_WHOLEDISK  2
 526
 527extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
 528extern void blk_free_devt(dev_t devt);
 529extern dev_t blk_lookup_devt(const char *name, int partno);
 530extern char *disk_name (struct gendisk *hd, int partno, char *buf);
 531
 532extern int disk_expand_part_tbl(struct gendisk *disk, int target);
 533extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
 534extern struct hd_struct * __must_check add_partition(struct gendisk *disk,
 535                                                     int partno, sector_t start,
 536                                                     sector_t len, int flags);
 537extern void delete_partition(struct gendisk *, int);
 538extern void printk_all_partitions(void);
 539
 540extern struct gendisk *alloc_disk_node(int minors, int node_id);
 541extern struct gendisk *alloc_disk(int minors);
 542extern struct kobject *get_disk(struct gendisk *disk);
 543extern void put_disk(struct gendisk *disk);
 544extern void blk_register_region(dev_t devt, unsigned long range,
 545                        struct module *module,
 546                        struct kobject *(*probe)(dev_t, int *, void *),
 547                        int (*lock)(dev_t, void *),
 548                        void *data);
 549extern void blk_unregister_region(dev_t devt, unsigned long range);
 550
 551extern ssize_t part_size_show(struct device *dev,
 552                              struct device_attribute *attr, char *buf);
 553extern ssize_t part_stat_show(struct device *dev,
 554                              struct device_attribute *attr, char *buf);
 555extern ssize_t part_inflight_show(struct device *dev,
 556                              struct device_attribute *attr, char *buf);
 557#ifdef CONFIG_FAIL_MAKE_REQUEST
 558extern ssize_t part_fail_show(struct device *dev,
 559                              struct device_attribute *attr, char *buf);
 560extern ssize_t part_fail_store(struct device *dev,
 561                               struct device_attribute *attr,
 562                               const char *buf, size_t count);
 563#endif /* CONFIG_FAIL_MAKE_REQUEST */
 564
 565#else /* CONFIG_BLOCK */
 566
 567static inline void printk_all_partitions(void) { }
 568
 569static inline dev_t blk_lookup_devt(const char *name, int partno)
 570{
 571        dev_t devt = MKDEV(0, 0);
 572        return devt;
 573}
 574
 575#endif /* CONFIG_BLOCK */
 576
 577#endif /* _LINUX_GENHD_H */
 578