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