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