summaryrefslogtreecommitdiffstats
path: root/include/linux/genhd.h
blob: e61d3192448e90f2942a32a048ddd10d812d855e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
#ifndef _LINUX_GENHD_H
#define _LINUX_GENHD_H

/*
 * 	genhd.h Copyright (C) 1992 Drew Eckhardt
 *	Generic hard disk header file by  
 * 		Drew Eckhardt
 *
 *		<drew@colorado.edu>
 */

#include <linux/types.h>
#include <linux/kdev_t.h>
#include <linux/rcupdate.h>
#include <linux/slab.h>

#ifdef CONFIG_BLOCK

#define kobj_to_dev(k)		container_of((k), struct device, kobj)
#define dev_to_disk(device)	container_of((device), struct gendisk, part0.__dev)
#define dev_to_part(device)	container_of((device), struct hd_struct, __dev)
#define disk_to_dev(disk)	(&(disk)->part0.__dev)
#define part_to_dev(part)	(&((part)->__dev))

extern struct device_type part_type;
extern struct kobject *block_depr;
extern struct class block_class;

enum {
/* These three have identical behaviour; use the second one if DOS FDISK gets
   confused about extended/logical partitions starting past cylinder 1023. */
	DOS_EXTENDED_PARTITION = 5,
	LINUX_EXTENDED_PARTITION = 0x85,
	WIN98_EXTENDED_PARTITION = 0x0f,

	SUN_WHOLE_DISK = DOS_EXTENDED_PARTITION,

	LINUX_SWAP_PARTITION = 0x82,
	LINUX_DATA_PARTITION = 0x83,
	LINUX_LVM_PARTITION = 0x8e,
	LINUX_RAID_PARTITION = 0xfd,	/* autodetect RAID partition */

	SOLARIS_X86_PARTITION =	LINUX_SWAP_PARTITION,
	NEW_SOLARIS_X86_PARTITION = 0xbf,

	DM6_AUX1PARTITION = 0x51,	/* no DDO:  use xlated geom */
	DM6_AUX3PARTITION = 0x53,	/* no DDO:  use xlated geom */
	DM6_PARTITION =	0x54,		/* has DDO: use xlated geom & offset */
	EZD_PARTITION =	0x55,		/* EZ-DRIVE */

	FREEBSD_PARTITION = 0xa5,	/* FreeBSD Partition ID */
	OPENBSD_PARTITION = 0xa6,	/* OpenBSD Partition ID */
	NETBSD_PARTITION = 0xa9,	/* NetBSD Partition ID */
	BSDI_PARTITION = 0xb7,		/* BSDI Partition ID */
	MINIX_PARTITION = 0x81,		/* Minix Partition ID */
	UNIXWARE_PARTITION = 0x63,	/* Same as GNU_HURD and SCO Unix */
};

#define DISK_MAX_PARTS			256
#define DISK_NAME_LEN			32

#include <linux/major.h>
#include <linux/device.h>
#include <linux/smp.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/workqueue.h>

struct partition {
	unsigned char boot_ind;		/* 0x80 - active */
	unsigned char head;		/* starting head */
	unsigned char sector;		/* starting sector */
	unsigned char cyl;		/* starting cylinder */
	unsigned char sys_ind;		/* What partition type */
	unsigned char end_head;		/* end head */
	unsigned char end_sector;	/* end sector */
	unsigned char end_cyl;		/* end cylinder */
	__le32 start_sect;	/* starting sector counting from 0 */
	__le32 nr_sects;		/* nr of sectors in partition */
} __attribute__((packed));

struct disk_stats {
	unsigned long sectors[2];	/* READs and WRITEs */
	unsigned long ios[2];
	unsigned long merges[2];
	unsigned long ticks[2];
	unsigned long io_ticks;
	unsigned long time_in_queue;
};

#define PARTITION_META_INFO_VOLNAMELTH	64
#define PARTITION_META_INFO_UUIDLTH	16

struct partition_meta_info {
	u8 uuid[PARTITION_META_INFO_UUIDLTH];	/* always big endian */
	u8 volname[PARTITION_META_INFO_VOLNAMELTH];
};

struct hd_struct {
	sector_t start_sect;
	sector_t nr_sects;
	sector_t alignment_offset;
	unsigned int discard_alignment;
	struct device __dev;
	struct kobject *holder_dir;
	int policy, partno;
	struct partition_meta_info *info;
#ifdef CONFIG_FAIL_MAKE_REQUEST
	int make_it_fail;
#endif
	unsigned long stamp;
	atomic_t in_flight[2];
#ifdef	CONFIG_SMP
	struct disk_stats __percpu *dkstats;
#else
	struct disk_stats dkstats;
#endif
	atomic_t ref;
	struct rcu_head rcu_head;
};

#define GENHD_FL_REMOVABLE			1
/* 2 is unused */
#define GENHD_FL_MEDIA_CHANGE_NOTIFY		4
#define GENHD_FL_CD				8
#define GENHD_FL_UP				16
#define GENHD_FL_SUPPRESS_PARTITION_INFO	32
#define GENHD_FL_EXT_DEVT			64 /* allow extended devt */
#define GENHD_FL_NATIVE_CAPACITY		128
#define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE	256
#define GENHD_FL_NO_PART_SCAN			512

enum {
	DISK_EVENT_MEDIA_CHANGE			= 1 << 0, /* media changed */
	DISK_EVENT_EJECT_REQUEST		= 1 << 1, /* eject requested */
};

#define BLK_SCSI_MAX_CMDS	(256)
#define BLK_SCSI_CMD_PER_LONG	(BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))

struct blk_scsi_cmd_filter {
	unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
	unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
	struct kobject kobj;
};

struct disk_part_tbl {
	struct rcu_head rcu_head;
	int len;
	struct hd_struct __rcu *last_lookup;
	struct hd_struct __rcu *part[];
};

struct disk_events;

struct gendisk {
	/* major, first_minor and minors are input parameters only,
	 * don't use directly.  Use disk_devt() and disk_max_parts().
	 */
	int major;			/* major number of driver */
	int first_minor;
	int minors;                     /* maximum number of minors, =1 for
                                         * disks that can't be partitioned. */

	char disk_name[DISK_NAME_LEN];	/* name of major driver */
	char *(*devnode)(struct gendisk *gd, umode_t *mode);

	unsigned int events;		/* supported events */
	unsigned int async_events;	/* async events, subset of all */

	/* Array of pointers to partitions indexed by partno.
	 * Protected with matching bdev lock but stat and other
	 * non-critical accesses use RCU.  Always access through
	 * helpers.
	 */
	struct disk_part_tbl __rcu *part_tbl;
	struct hd_struct part0;

	const struct block_device_operations *fops;
	struct request_queue *queue;
	void *private_data;

	int flags;
	struct device *driverfs_dev;  // FIXME: remove
	struct kobject *slave_dir;

	struct timer_rand_state *random;
	atomic_t sync_io;		/* RAID */
	struct disk_events *ev;
#ifdef  CONFIG_BLK_DEV_INTEGRITY
	struct blk_integrity *integrity;
#endif
	int node_id;
};

static inline struct gendisk *part_to_disk(struct hd_struct *part)
{
	if (likely(part)) {
		if (part->partno)
			return dev_to_disk(part_to_dev(part)->parent);
		else
			return dev_to_disk(part_to_dev(part));
	}
	return NULL;
}

static inline void part_pack_uuid(const u8 *uuid_str, u8 *to)
{
	int i;
	for (i = 0; i < 16; ++i) {
		*to++ = (hex_to_bin(*uuid_str) << 4) |
			(hex_to_bin(*(uuid_str + 1)));
		uuid_str += 2;
		switch (i) {
		case 3:
		case 5:
		case 7:
		case 9:
			uuid_str++;
			continue;
		}
	}
}

static inline char *part_unpack_uuid(const u8 *uuid, char *out)
{
	sprintf(out, "%pU", uuid);
	return out;
}

static inline int disk_max_parts(struct gendisk *disk)
{
	if (disk->flags & GENHD_FL_EXT_DEVT)
		return DISK_MAX_PARTS;
	return disk->minors;
}

static inline bool disk_part_scan_enabled(struct gendisk *disk)
{
	return disk_max_parts(disk) > 1 &&
		!(disk->flags & GENHD_FL_NO_PART_SCAN);
}

static inline dev_t disk_devt(struct gendisk *disk)
{
	return disk_to_dev(disk)->devt;
}

static inline dev_t part_devt(struct hd_struct *part)
{
	return part_to_dev(part)->devt;
}

extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);

static inline void disk_put_part(struct hd_struct *part)
{
	if (likely(part))
		put_device(part_to_dev(part));
}

/*
 * Smarter partition iterator without context limits.
 */
#define DISK_PITER_REVERSE	(1 << 0) /* iterate in the reverse direction */
#define DISK_PITER_INCL_EMPTY	(1 << 1) /* include 0-sized parts */
#define DISK_PITER_INCL_PART0	(1 << 2) /* include partition 0 */
#define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */

struct disk_part_iter {
	struct gendisk		*disk;
	struct hd_struct	*part;
	int			idx;
	unsigned int		flags;
};

extern void disk_part_iter_init(struct disk_part_iter *piter,
				 struct gendisk *disk, unsigned int flags);
extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
extern void disk_part_iter_exit(struct disk_part_iter *piter);

extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
					     sector_t sector);

/*
 * Macros to operate on percpu disk statistics:
 *
 * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
 * and should be called between disk_stat_lock() and
 * disk_stat_unlock().
 *
 * part_stat_read() can be called at any time.
 *
 * part_stat_{add|set_all}() and {init|free}_part_stats are for
 * internal use only.
 */
#ifdef	CONFIG_SMP
#define part_stat_lock()	({ rcu_read_lock(); get_cpu(); })
#define part_stat_unlock()	do { put_cpu(); rcu_read_unlock(); } while (0)

#define __part_stat_add(cpu, part, field, addnd)			\
	(per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd))

#define part_stat_read(part, field)					\
({									\
	typeof((part)->dkstats->field) res = 0;				\
	unsigned int _cpu;						\
	for_each_possible_cpu(_cpu)					\
		res += per_cpu_ptr((part)->dkstats, _cpu)->field;	\
	res;								\
})

static inline void part_stat_set_all(struct hd_struct *part, int value)
{
	int i;

	for_each_possible_cpu(i)
		memset(per_cpu_ptr(part->dkstats, i), value,
				sizeof(struct disk_stats));
}

static inline int init_part_stats(struct hd_struct *part)
{
	part->dkstats = alloc_percpu(struct disk_stats);
	if (!part->dkstats)
		return 0;
	return 1;
}

static inline void free_part_stats(struct hd_struct *part)
{
	free_percpu(part->dkstats);
}

#else /* !CONFIG_SMP */
#define part_stat_lock()	({ rcu_read_lock(); 0; })
#define part_stat_unlock()	rcu_read_unlock()

#define __part_stat_add(cpu, part, field, addnd)				\
	((part)->dkstats.field += addnd)

#define part_stat_read(part, field)	((part)->dkstats.field)

static inline void part_stat_set_all(struct hd_struct *part, int value)
{
	memset(&part->dkstats, value, sizeof(struct disk_stats));
}

static inline int init_part_stats(struct hd_struct *part)
{
	return 1;
}

static inline void free_part_stats(struct hd_struct *part)
{
}

#endif /* CONFIG_SMP */

#define part_stat_add(cpu, part, field, addnd)	do {			\
	__part_stat_add((cpu), (part), field, addnd);			\
	if ((part)->partno)						\
		__part_stat_add((cpu), &part_to_disk((part))->part0,	\
				field, addnd);				\
} while (0)

#define part_stat_dec(cpu, gendiskp, field)				\
	part_stat_add(cpu, gendiskp, field, -1)
#define part_stat_inc(cpu, gendiskp, field)				\
	part_stat_add(cpu, gendiskp, field, 1)
#define part_stat_sub(cpu, gendiskp, field, subnd)			\
	part_stat_add(cpu, gendiskp, field, -subnd)

static inline void part_inc_in_flight(struct hd_struct *part, int rw)
{
	atomic_inc(&part->in_flight[rw]);
	if (part->partno)
		atomic_inc(&part_to_disk(part)->part0.in_flight[rw]);
}

static inline void part_dec_in_flight(struct hd_struct *part, int rw)
{
	atomic_dec(&part->in_flight[rw]);
	if (part->partno)
		atomic_dec(&part_to_disk(part)->part0.in_flight[rw]);
}

static inline int part_in_flight(struct hd_struct *part)
{
	return atomic_read(&part->in_flight[0]) + atomic_read(&part->in_flight[1]);
}

static inline struct partition_meta_info *alloc_part_info(struct gendisk *disk)
{
	if (disk)
		return kzalloc_node(sizeof(struct partition_meta_info),
				    GFP_KERNEL, disk->node_id);
	return kzalloc(sizeof(struct partition_meta_info), GFP_KERNEL);
}

static inline void free_part_info(struct hd_struct *part)
{
	kfree(part->info);
}

/* block/blk-core.c */
extern void part_round_stats(int cpu, struct hd_struct *part);

/* block/genhd.c */
extern void add_disk(struct gendisk *disk);
extern void del_gendisk(struct gendisk *gp);
extern struct gendisk *get_gendisk(dev_t dev, int *partno);
extern struct block_device *bdget_disk(struct gendisk *disk, int partno);

extern void set_device_ro(struct block_device *bdev, int flag);
extern void set_disk_ro(struct gendisk *disk, int flag);

static inline int get_disk_ro(struct gendisk *disk)
{
	return disk->part0.policy;
}

extern void disk_block_events(struct gendisk *disk);
extern void disk_unblock_events(struct gendisk *disk);
extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);

/* drivers/char/random.c */
extern void add_disk_randomness(struct gendisk *disk);
extern void rand_initialize_disk(struct gendisk *disk);

static inline sector_t get_start_sect(struct block_device *bdev)
{
	return bdev->bd_part->start_sect;
}
static inline sector_t get_capacity(struct gendisk *disk)
{
	return disk->part0.nr_sects;
}
static inline void set_capacity(struct gendisk *disk, sector_t size)
{
	disk->part0.nr_sects = size;
}

#ifdef CONFIG_SOLARIS_X86_PARTITION

#define SOLARIS_X86_NUMSLICE	16
#define SOLARIS_X86_VTOC_SANE	(0x600DDEEEUL)

struct solaris_x86_slice {
	__le16 s_tag;		/* ID tag of partition */
	__le16 s_flag;		/* permission flags */
	__le32 s_start;		/* start sector no of partition */
	__le32 s_size;		/* # of blocks in partition */
};

struct solaris_x86_vtoc {
	unsigned int v_bootinfo[3];	/* info needed by mboot (unsupported) */
	__le32 v_sanity;		/* to verify vtoc sanity */
	__le32 v_version;		/* layout version */
	char	v_volume[8];		/* volume name */
	__le16	v_sectorsz;		/* sector size in bytes */
	__le16	v_nparts;		/* number of partitions */
	unsigned int v_reserved[10];	/* free space */
	struct solaris_x86_slice
		v_slice[SOLARIS_X86_NUMSLICE]; /* slice headers */
	unsigned int timestamp[SOLARIS_X86_NUMSLICE]; /* timestamp (unsupported) */
	char	v_asciilabel[128];	/* for compatibility */
};

#endif /* CONFIG_SOLARIS_X86_PARTITION */

#ifdef CONFIG_BSD_DISKLABEL
/*
 * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il>
 * updated by Marc Espie <Marc.Espie@openbsd.org>
 */

/* check against BSD src/sys/sys/disklabel.h for consistency */

#define BSD_DISKMAGIC	(0x82564557UL)	/* The disk magic number */
#define BSD_MAXPARTITIONS	16
#define OPENBSD_MAXPARTITIONS	16
#define BSD_FS_UNUSED		0	/* disklabel unused partition entry ID */
struct bsd_disklabel {
	__le32	d_magic;		/* the magic number */
	__s16	d_type;			/* drive type */
	__s16	d_subtype;		/* controller/d_type specific */
	char	d_typename[16];		/* type name, e.g. "eagle" */
	char	d_packname[16];			/* pack identifier */ 
	__u32	d_secsize;		/* # of bytes per sector */
	__u32	d_nsectors;		/* # of data sectors per track */
	__u32	d_ntracks;		/* # of tracks per cylinder */
	__u32	d_ncylinders;		/* # of data cylinders per unit */
	__u32	d_secpercyl;		/* # of data sectors per cylinder */
	__u32	d_secperunit;		/* # of data sectors per unit */
	__u16	d_sparespertrack;	/* # of spare sectors per track */
	__u16	d_sparespercyl;		/* # of spare sectors per cylinder */
	__u32	d_acylinders;		/* # of alt. cylinders per unit */
	__u16	d_rpm;			/* rotational speed */
	__u16	d_interleave;		/* hardware sector interleave */
	__u16	d_trackskew;		/* sector 0 skew, per track */
	__u16	d_cylskew;		/* sector 0 skew, per cylinder */
	__u32	d_headswitch;		/* head switch time, usec */
	__u32	d_trkseek;		/* track-to-track seek, usec */
	__u32	d_flags;		/* generic flags */
#define NDDATA 5
	__u32	d_drivedata[NDDATA];	/* drive-type specific information */
#define NSPARE 5
	__u32	d_spare[NSPARE];	/* reserved for future use */
	__le32	d_magic2;		/* the magic number (again) */
	__le16	d_checksum;		/* xor of data incl. partitions */

			/* filesystem and partition information: */
	__le16	d_npartitions;		/* number of partitions in following */
	__le32	d_bbsize;		/* size of boot area at sn0, bytes */
	__le32	d_sbsize;		/* max size of fs superblock, bytes */
	struct	bsd_partition {		/* the partition table */
		__le32	p_size;		/* number of sectors in partition */
		__le32	p_offset;	/* starting sector */
		__le32	p_fsize;	/* filesystem basic fragment size */
		__u8	p_fstype;	/* filesystem type, see below */
		__u8	p_frag;		/* filesystem fragments per block */
		__le16	p_cpg;		/* filesystem cylinders per group */
	} d_partitions[BSD_MAXPARTITIONS];	/* actually may be more */
};

#endif	/* CONFIG_BSD_DISKLABEL */

#ifdef CONFIG_UNIXWARE_DISKLABEL
/*
 * Unixware slices support by Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl>
 * and Krzysztof G. Baranowski <kgb@knm.org.pl>
 */

#define UNIXWARE_DISKMAGIC     (0xCA5E600DUL)	/* The disk magic number */
#define UNIXWARE_DISKMAGIC2    (0x600DDEEEUL)	/* The slice table magic nr */
#define UNIXWARE_NUMSLICE      16
#define UNIXWARE_FS_UNUSED     0		/* Unused slice entry ID */

struct unixware_slice {
	__le16   s_label;	/* label */
	__le16   s_flags;	/* permission flags */
	__le32   start_sect;	/* starting sector */
	__le32   nr_sects;	/* number of sectors in slice */
};

struct unixware_disklabel {
	__le32   d_type;               	/* drive type */
	__le32   d_magic;                /* the magic number */
	__le32   d_version;              /* version number */
	char    d_serial[12];           /* serial number of the device */
	__le32   d_ncylinders;           /* # of data cylinders per device */
	__le32   d_ntracks;              /* # of tracks per cylinder */
	__le32   d_nsectors;             /* # of data sectors per track */
	__le32   d_secsize;              /* # of bytes per sector */
	__le32   d_part_start;           /* # of first sector of this partition */
	__le32   d_unknown1[12];         /* ? */
 	__le32	d_alt_tbl;              /* byte offset of alternate table */
 	__le32	d_alt_len;              /* byte length of alternate table */
 	__le32	d_phys_cyl;             /* # of physical cylinders per device */
 	__le32	d_phys_trk;             /* # of physical tracks per cylinder */
 	__le32	d_phys_sec;             /* # of physical sectors per track */
 	__le32	d_phys_bytes;           /* # of physical bytes per sector */
 	__le32	d_unknown2;             /* ? */
	__le32   d_unknown3;             /* ? */
	__le32	d_pad[8];               /* pad */

	struct unixware_vtoc {
		__le32	v_magic;		/* the magic number */
		__le32	v_version;		/* version number */
		char	v_name[8];		/* volume name */
		__le16	v_nslices;		/* # of slices */
		__le16	v_unknown1;		/* ? */
		__le32	v_reserved[10];		/* reserved */
		struct unixware_slice
			v_slice[UNIXWARE_NUMSLICE];	/* slice headers */
	} vtoc;

};  /* 408 */

#endif /* CONFIG_UNIXWARE_DISKLABEL */

#ifdef CONFIG_MINIX_SUBPARTITION
#   define MINIX_NR_SUBPARTITIONS  4
#endif /* CONFIG_MINIX_SUBPARTITION */

#define ADDPART_FLAG_NONE	0
#define ADDPART_FLAG_RAID	1
#define ADDPART_FLAG_WHOLEDISK	2

extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
extern void blk_free_devt(dev_t devt);
extern dev_t blk_lookup_devt(const char *name, int partno);
extern char *disk_name (struct gendisk *hd, int partno, char *buf);

extern int disk_expand_part_tbl(struct gendisk *disk, int target);
extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
extern int invalidate_partitions(struct gendisk *disk, struct block_device *bdev);
extern struct hd_struct * __must_check add_partition(struct gendisk *disk,
						     int partno, sector_t start,
						     sector_t len, int flags,
						     struct partition_meta_info
						       *info);
extern void __delete_partition(struct hd_struct *);
extern void delete_partition(struct gendisk *, int);
extern void printk_all_partitions(void);

extern struct gendisk *alloc_disk_node(int minors, int node_id);
extern struct gendisk *alloc_disk(int minors);
extern struct kobject *get_disk(struct gendisk *disk);
extern void put_disk(struct gendisk *disk);
extern void blk_register_region(dev_t devt, unsigned long range,
			struct module *module,
			struct kobject *(*probe)(dev_t, int *, void *),
			int (*lock)(dev_t, void *),
			void *data);
extern void blk_unregister_region(dev_t devt, unsigned long range);

extern ssize_t part_size_show(struct device *dev,
			      struct device_attribute *attr, char *buf);
extern ssize_t part_stat_show(struct device *dev,
			      struct device_attribute *attr, char *buf);
extern ssize_t part_inflight_show(struct device *dev,
			      struct device_attribute *attr, char *buf);
#ifdef CONFIG_FAIL_MAKE_REQUEST
extern ssize_t part_fail_show(struct device *dev,
			      struct device_attribute *attr, char *buf);
extern ssize_t part_fail_store(struct device *dev,
			       struct device_attribute *attr,
			       const char *buf, size_t count);
#endif /* CONFIG_FAIL_MAKE_REQUEST */

static inline void hd_ref_init(struct hd_struct *part)
{
	atomic_set(&part->ref, 1);
	smp_mb();
}

static inline void hd_struct_get(struct hd_struct *part)
{
	atomic_inc(&part->ref);
	smp_mb__after_atomic_inc();
}

static inline int hd_struct_try_get(struct hd_struct *part)
{
	return atomic_inc_not_zero(&part->ref);
}

static inline void hd_struct_put(struct hd_struct *part)
{
	if (atomic_dec_and_test(&part->ref))
		__delete_partition(part);
}

#else /* CONFIG_BLOCK */

static inline void printk_all_partitions(void) { }

static inline dev_t blk_lookup_devt(const char *name, int partno)
{
	dev_t devt = MKDEV(0, 0);
	return devt;
}

#endif /* CONFIG_BLOCK */

#endif /* _LINUX_GENHD_H */