[linux-block.git] / include / linux / genhd.h

/* SPDX-License-Identifier: GPL-2.0 */
#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>
#include <linux/percpu-refcount.h>
#include <linux/uuid.h>
#include <linux/blk_types.h>
#include <asm/local.h>

#ifdef CONFIG_BLOCK

#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 class block_class;

#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 disk_stats {
	u64 nsecs[NR_STAT_GROUPS];
	unsigned long sectors[NR_STAT_GROUPS];
	unsigned long ios[NR_STAT_GROUPS];
	unsigned long merges[NR_STAT_GROUPS];
	unsigned long io_ticks;
	local_t in_flight[2];
};

#define PARTITION_META_INFO_VOLNAMELTH	64
/*
 * Enough for the string representation of any kind of UUID plus NULL.
 * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
 */
#define PARTITION_META_INFO_UUIDLTH	(UUID_STRING_LEN + 1)

struct partition_meta_info {
	char uuid[PARTITION_META_INFO_UUIDLTH];
	u8 volname[PARTITION_META_INFO_VOLNAMELTH];
};

struct hd_struct {
	sector_t start_sect;
	/*
	 * nr_sects is protected by sequence counter. One might extend a
	 * partition while IO is happening to it and update of nr_sects
	 * can be non-atomic on 32bit machines with 64bit sector_t.
	 */
	sector_t nr_sects;
	seqcount_t nr_sects_seq;
	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;
#ifdef	CONFIG_SMP
	struct disk_stats __percpu *dkstats;
#else
	struct disk_stats dkstats;
#endif
	struct percpu_ref ref;
	struct rcu_work rcu_work;
};

/**
 * DOC: genhd capability flags
 *
 * ``GENHD_FL_REMOVABLE`` (0x0001): indicates that the block device
 * gives access to removable media.
 * When set, the device remains present even when media is not
 * inserted.
 * Must not be set for devices which are removed entirely when the
 * media is removed.
 *
 * ``GENHD_FL_CD`` (0x0008): the block device is a CD-ROM-style
 * device.
 * Affects responses to the ``CDROM_GET_CAPABILITY`` ioctl.
 *
 * ``GENHD_FL_UP`` (0x0010): indicates that the block device is "up",
 * with a similar meaning to network interfaces.
 *
 * ``GENHD_FL_SUPPRESS_PARTITION_INFO`` (0x0020): don't include
 * partition information in ``/proc/partitions`` or in the output of
 * printk_all_partitions().
 * Used for the null block device and some MMC devices.
 *
 * ``GENHD_FL_EXT_DEVT`` (0x0040): the driver supports extended
 * dynamic ``dev_t``, i.e. it wants extended device numbers
 * (``BLOCK_EXT_MAJOR``).
 * This affects the maximum number of partitions.
 *
 * ``GENHD_FL_NATIVE_CAPACITY`` (0x0080): based on information in the
 * partition table, the device's capacity has been extended to its
 * native capacity; i.e. the device has hidden capacity used by one
 * of the partitions (this is a flag used so that native capacity is
 * only ever unlocked once).
 *
 * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
 * blocked whenever a writer holds an exclusive lock.
 *
 * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
 * Used for loop devices in their default settings and some MMC
 * devices.
 *
 * ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
 * doesn't produce events, doesn't appear in sysfs, and doesn't have
 * an associated ``bdev``.
 * Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
 * ``GENHD_FL_NO_PART_SCAN``.
 * Used for multipath devices.
 */
#define GENHD_FL_REMOVABLE			0x0001
/* 2 is unused (used to be GENHD_FL_DRIVERFS) */
/* 4 is unused (used to be GENHD_FL_MEDIA_CHANGE_NOTIFY) */
#define GENHD_FL_CD				0x0008
#define GENHD_FL_UP				0x0010
#define GENHD_FL_SUPPRESS_PARTITION_INFO	0x0020
#define GENHD_FL_EXT_DEVT			0x0040
#define GENHD_FL_NATIVE_CAPACITY		0x0080
#define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE	0x0100
#define GENHD_FL_NO_PART_SCAN			0x0200
#define GENHD_FL_HIDDEN				0x0400

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

enum {
	/* Poll even if events_poll_msecs is unset */
	DISK_EVENT_FLAG_POLL			= 1 << 0,
	/* Forward events to udev */
	DISK_EVENT_FLAG_UEVENT			= 1 << 1,
};

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 badblocks;

#if defined(CONFIG_BLK_DEV_INTEGRITY)

struct blk_integrity {
	const struct blk_integrity_profile	*profile;
	unsigned char				flags;
	unsigned char				tuple_size;
	unsigned char				interval_exp;
	unsigned char				tag_size;
};

#endif	/* CONFIG_BLK_DEV_INTEGRITY */

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 */

	unsigned short events;		/* supported events */
	unsigned short event_flags;	/* flags related to event processing */

	/* 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 rw_semaphore lookup_sem;
	struct kobject *slave_dir;

	struct timer_rand_state *random;
	atomic_t sync_io;		/* RAID */
	struct disk_events *ev;
#ifdef  CONFIG_BLK_DEV_INTEGRITY
	struct kobject integrity_kobj;
#endif	/* CONFIG_BLK_DEV_INTEGRITY */
	int node_id;
	struct badblocks *bb;
	struct lockdep_map lockdep_map;
};

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 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 MKDEV(disk->major, disk->first_minor);
}

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);
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 bool disk_has_partitions(struct gendisk *disk);

/* block/genhd.c */
extern void device_add_disk(struct device *parent, struct gendisk *disk,
			    const struct attribute_group **groups);
static inline void add_disk(struct gendisk *disk)
{
	device_add_disk(NULL, disk, NULL);
}
extern void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk);
static inline void add_disk_no_queue_reg(struct gendisk *disk)
{
	device_add_disk_no_queue_reg(NULL, 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 void set_capacity_revalidate_and_notify(struct gendisk *disk,
			sector_t size, bool revalidate);
extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);

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

extern dev_t blk_lookup_devt(const char *name, int partno);

int bdev_disk_changed(struct block_device *bdev, bool invalidate);
int blk_add_partitions(struct gendisk *disk, struct block_device *bdev);
int blk_drop_partitions(struct gendisk *disk, struct block_device *bdev);
extern void printk_all_partitions(void);

extern struct gendisk *__alloc_disk_node(int minors, int node_id);
extern struct kobject *get_disk_and_module(struct gendisk *disk);
extern void put_disk(struct gendisk *disk);
extern void put_disk_and_module(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);

#define alloc_disk_node(minors, node_id)				\
({									\
	static struct lock_class_key __key;				\
	const char *__name;						\
	struct gendisk *__disk;						\
									\
	__name = "(gendisk_completion)"#minors"("#node_id")";		\
									\
	__disk = __alloc_disk_node(minors, node_id);			\
									\
	if (__disk)							\
		lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \
									\
	__disk;								\
})

#define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)

#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 */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4 LT	2	#ifndef _LINUX_GENHD_H
	3	#define _LINUX_GENHD_H
	4
	5	/*
	6	* genhd.h Copyright (C) 1992 Drew Eckhardt
	7	* Generic hard disk header file by
	8	* Drew Eckhardt
	9	*
	10	* <drew@colorado.edu>
	11	*/
	12
1da177e4	13	#include <linux/types.h>
edfaa7c3	14	#include <linux/kdev_t.h>
e71bf0d0	15	#include <linux/rcupdate.h>
6d1d8050	16	#include <linux/slab.h>
6c71013e	17	#include <linux/percpu-refcount.h>
63579785	18	#include <linux/uuid.h>
dbae2c55	19	#include <linux/blk_types.h>
1226b8dd	20	#include <asm/local.h>
1da177e4	21
9361401e DH	22	#ifdef CONFIG_BLOCK
9361401e DH	23
548b10eb	24	#define dev_to_disk(device) container_of((device), struct gendisk, part0.__dev)
ed9e1982	25	#define dev_to_part(device) container_of((device), struct hd_struct, __dev)
548b10eb	26	#define disk_to_dev(disk) (&(disk)->part0.__dev)
ed9e1982	27	#define part_to_dev(part) (&((part)->__dev))
edfaa7c3	28
edfaa7c3	29	extern struct device_type part_type;
edfaa7c3 KS	30	extern struct class block_class;
edfaa7c3 KS	31
689d6fac	32	#define DISK_MAX_PARTS 256
3e1a7ff8	33	#define DISK_NAME_LEN 32
689d6fac	34
34186efc DW	35	#include <linux/major.h>
	36	#include <linux/device.h>
	37	#include <linux/smp.h>
	38	#include <linux/string.h>
	39	#include <linux/fs.h>
8ce7ad7b	40	#include <linux/workqueue.h>
34186efc	41
ea5c48ab	42	struct disk_stats {
b57e99b4	43	u64 nsecs[NR_STAT_GROUPS];
dbae2c55 MC	44	unsigned long sectors[NR_STAT_GROUPS];
	45	unsigned long ios[NR_STAT_GROUPS];
	46	unsigned long merges[NR_STAT_GROUPS];
ea5c48ab	47	unsigned long io_ticks;
1226b8dd	48	local_t in_flight[2];
ea5c48ab	49	};
6d1d8050 WD	50
6d1d8050 WD	51	#define PARTITION_META_INFO_VOLNAMELTH 64
1ad7e899 SW	52	/*
	53	* Enough for the string representation of any kind of UUID plus NULL.
	54	* EFI UUID is 36 characters. MSDOS UUID is 11 characters.
	55	*/
63579785	56	#define PARTITION_META_INFO_UUIDLTH (UUID_STRING_LEN + 1)
6d1d8050 WD	57
6d1d8050 WD	58	struct partition_meta_info {
1ad7e899	59	char uuid[PARTITION_META_INFO_UUIDLTH];
6d1d8050 WD	60	u8 volname[PARTITION_META_INFO_VOLNAMELTH];
	61	};
	62
1da177e4 LT	63	struct hd_struct {
1da177e4 LT	64	sector_t start_sect;
c83f6bf9 VG	65	/*
	66	* nr_sects is protected by sequence counter. One might extend a
	67	* partition while IO is happening to it and update of nr_sects
	68	* can be non-atomic on 32bit machines with 64bit sector_t.
	69	*/
1da177e4	70	sector_t nr_sects;
c83f6bf9	71	seqcount_t nr_sects_seq;
c72758f3	72	sector_t alignment_offset;
a1706ac4	73	unsigned int discard_alignment;
ed9e1982	74	struct device __dev;
6a4d44c1	75	struct kobject *holder_dir;
1da177e4	76	int policy, partno;
6d1d8050	77	struct partition_meta_info *info;
c17bb495 AM	78	#ifdef CONFIG_FAIL_MAKE_REQUEST
c17bb495 AM	79	int make_it_fail;
ea5c48ab JM	80	#endif
ea5c48ab JM	81	unsigned long stamp;
ea5c48ab	82	#ifdef CONFIG_SMP
43cf38eb	83	struct disk_stats __percpu *dkstats;
ea5c48ab JM	84	#else
ea5c48ab JM	85	struct disk_stats dkstats;
c17bb495	86	#endif
6c71013e	87	struct percpu_ref ref;
94a2c3a3	88	struct rcu_work rcu_work;
1da177e4 LT	89	};
1da177e4 LT	90
9243c6f3 SK	91	/**
	92	* DOC: genhd capability flags
	93	*
	94	* ``GENHD_FL_REMOVABLE`` (0x0001): indicates that the block device
	95	* gives access to removable media.
	96	* When set, the device remains present even when media is not
	97	* inserted.
	98	* Must not be set for devices which are removed entirely when the
	99	* media is removed.
	100	*
	101	* ``GENHD_FL_CD`` (0x0008): the block device is a CD-ROM-style
	102	* device.
	103	* Affects responses to the ``CDROM_GET_CAPABILITY`` ioctl.
	104	*
	105	* ``GENHD_FL_UP`` (0x0010): indicates that the block device is "up",
	106	* with a similar meaning to network interfaces.
	107	*
	108	* ``GENHD_FL_SUPPRESS_PARTITION_INFO`` (0x0020): don't include
	109	* partition information in ``/proc/partitions`` or in the output of
	110	* printk_all_partitions().
	111	* Used for the null block device and some MMC devices.
	112	*
	113	* ``GENHD_FL_EXT_DEVT`` (0x0040): the driver supports extended
	114	* dynamic ``dev_t``, i.e. it wants extended device numbers
	115	* (``BLOCK_EXT_MAJOR``).
	116	* This affects the maximum number of partitions.
	117	*
	118	* ``GENHD_FL_NATIVE_CAPACITY`` (0x0080): based on information in the
	119	* partition table, the device's capacity has been extended to its
	120	* native capacity; i.e. the device has hidden capacity used by one
	121	* of the partitions (this is a flag used so that native capacity is
	122	* only ever unlocked once).
	123	*
	124	* ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
	125	* blocked whenever a writer holds an exclusive lock.
	126	*
	127	* ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
	128	* Used for loop devices in their default settings and some MMC
	129	* devices.
	130	*
	131	* ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
	132	* doesn't produce events, doesn't appear in sysfs, and doesn't have
	133	* an associated ``bdev``.
	134	* Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
	135	* ``GENHD_FL_NO_PART_SCAN``.
	136	* Used for multipath devices.
	137	*/
	138	#define GENHD_FL_REMOVABLE 0x0001
	139	/* 2 is unused (used to be GENHD_FL_DRIVERFS) */
	140	/* 4 is unused (used to be GENHD_FL_MEDIA_CHANGE_NOTIFY) */
	141	#define GENHD_FL_CD 0x0008
	142	#define GENHD_FL_UP 0x0010
	143	#define GENHD_FL_SUPPRESS_PARTITION_INFO 0x0020
	144	#define GENHD_FL_EXT_DEVT 0x0040
	145	#define GENHD_FL_NATIVE_CAPACITY 0x0080
	146	#define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 0x0100
	147	#define GENHD_FL_NO_PART_SCAN 0x0200
	148	#define GENHD_FL_HIDDEN 0x0400
1da177e4	149
77ea887e TH	150	enum {
	151	DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */
	152	DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */
	153	};
	154
c92e2f04 MW	155	enum {
	156	/* Poll even if events_poll_msecs is unset */
	157	DISK_EVENT_FLAG_POLL = 1 << 0,
	158	/* Forward events to udev */
	159	DISK_EVENT_FLAG_UEVENT = 1 << 1,
	160	};
	161
540eed56 TH	162	struct disk_part_tbl {
	163	struct rcu_head rcu_head;
	164	int len;
4d2deb40 AB	165	struct hd_struct __rcu *last_lookup;
4d2deb40 AB	166	struct hd_struct __rcu *part[];
540eed56 TH	167	};
540eed56 TH	168
77ea887e	169	struct disk_events;
99e6608c	170	struct badblocks;
77ea887e	171
25520d55 MP	172	#if defined(CONFIG_BLK_DEV_INTEGRITY)
	173
	174	struct blk_integrity {
869ab90f EB	175	const struct blk_integrity_profile *profile;
	176	unsigned char flags;
	177	unsigned char tuple_size;
	178	unsigned char interval_exp;
	179	unsigned char tag_size;
25520d55 MP	180	};
	181
	182	#endif /* CONFIG_BLK_DEV_INTEGRITY */
	183
1da177e4	184	struct gendisk {
689d6fac TH	185	/* major, first_minor and minors are input parameters only,
689d6fac TH	186	* don't use directly. Use disk_devt() and disk_max_parts().
f331c029	187	*/
1da177e4 LT	188	int major; /* major number of driver */
	189	int first_minor;
	190	int minors; /* maximum number of minors, =1 for
	191	* disks that can't be partitioned. */
f331c029	192
3e1a7ff8	193	char disk_name[DISK_NAME_LEN]; /* name of major driver */
77ea887e	194
c92e2f04 MW	195	unsigned short events; /* supported events */
c92e2f04 MW	196	unsigned short event_flags; /* flags related to event processing */
77ea887e	197
b5d0b9df	198	/* Array of pointers to partitions indexed by partno.
e71bf0d0 TH	199	* Protected with matching bdev lock but stat and other
	200	* non-critical accesses use RCU. Always access through
	201	* helpers.
	202	*/
4d2deb40	203	struct disk_part_tbl __rcu *part_tbl;
b5d0b9df	204	struct hd_struct part0;
e71bf0d0	205
83d5cde4	206	const struct block_device_operations *fops;
1da177e4 LT	207	struct request_queue *queue;
1da177e4 LT	208	void *private_data;
1da177e4 LT	209
1da177e4 LT	210	int flags;
56c0908c	211	struct rw_semaphore lookup_sem;
6a4d44c1	212	struct kobject *slave_dir;
1da177e4 LT	213
1da177e4 LT	214	struct timer_rand_state *random;
1da177e4	215	atomic_t sync_io; /* RAID */
77ea887e	216	struct disk_events *ev;
7ba1ba12	217	#ifdef CONFIG_BLK_DEV_INTEGRITY
aff34e19	218	struct kobject integrity_kobj;
25520d55	219	#endif /* CONFIG_BLK_DEV_INTEGRITY */
540eed56	220	int node_id;
99e6608c	221	struct badblocks *bb;
e319e1fb	222	struct lockdep_map lockdep_map;
1da177e4 LT	223	};
1da177e4 LT	224
310a2c10 TH	225	static inline struct gendisk part_to_disk(struct hd_struct part)
310a2c10 TH	226	{
548b10eb TH	227	if (likely(part)) {
	228	if (part->partno)
	229	return dev_to_disk(part_to_dev(part)->parent);
	230	else
	231	return dev_to_disk(part_to_dev(part));
	232	}
310a2c10 TH	233	return NULL;
	234	}
	235
f331c029 TH	236	static inline int disk_max_parts(struct gendisk *disk)
f331c029 TH	237	{
689d6fac TH	238	if (disk->flags & GENHD_FL_EXT_DEVT)
	239	return DISK_MAX_PARTS;
	240	return disk->minors;
b5d0b9df TH	241	}
b5d0b9df TH	242
d27769ec	243	static inline bool disk_part_scan_enabled(struct gendisk *disk)
b5d0b9df	244	{
d27769ec TH	245	return disk_max_parts(disk) > 1 &&
d27769ec TH	246	!(disk->flags & GENHD_FL_NO_PART_SCAN);
f331c029 TH	247	}
	248
	249	static inline dev_t disk_devt(struct gendisk *disk)
	250	{
517bf3c3	251	return MKDEV(disk->major, disk->first_minor);
f331c029 TH	252	}
	253
	254	static inline dev_t part_devt(struct hd_struct *part)
	255	{
ed9e1982	256	return part_to_dev(part)->devt;
f331c029 TH	257	}
f331c029 TH	258
67f2519f	259	extern struct hd_struct __disk_get_part(struct gendisk disk, int partno);
e71bf0d0 TH	260	extern struct hd_struct disk_get_part(struct gendisk disk, int partno);
	261
	262	static inline void disk_put_part(struct hd_struct *part)
	263	{
	264	if (likely(part))
ed9e1982	265	put_device(part_to_dev(part));
e71bf0d0 TH	266	}
	267
	268	/*
	269	* Smarter partition iterator without context limits.
	270	*/
	271	#define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */
	272	#define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */
b5d0b9df	273	#define DISK_PITER_INCL_PART0 (1 << 2) /* include partition 0 */
71982a40	274	#define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
e71bf0d0 TH	275
	276	struct disk_part_iter {
	277	struct gendisk *disk;
	278	struct hd_struct *part;
	279	int idx;
	280	unsigned int flags;
	281	};
	282
	283	extern void disk_part_iter_init(struct disk_part_iter *piter,
	284	struct gendisk *disk, unsigned int flags);
	285	extern struct hd_struct disk_part_iter_next(struct disk_part_iter piter);
	286	extern void disk_part_iter_exit(struct disk_part_iter *piter);
10f36b1e	287	extern bool disk_has_partitions(struct gendisk *disk);
1da177e4	288
32ca163c	289	/* block/genhd.c */
fef912bf HR	290	extern void device_add_disk(struct device parent, struct gendisk disk,
fef912bf HR	291	const struct attribute_group **groups);
e63a46be DW	292	static inline void add_disk(struct gendisk *disk)
e63a46be DW	293	{
fef912bf	294	device_add_disk(NULL, disk, NULL);
e63a46be	295	}
fa70d2e2 MS	296	extern void device_add_disk_no_queue_reg(struct device parent, struct gendisk disk);
	297	static inline void add_disk_no_queue_reg(struct gendisk *disk)
	298	{
	299	device_add_disk_no_queue_reg(NULL, disk);
	300	}
e63a46be	301
1da177e4	302	extern void del_gendisk(struct gendisk *gp);
cf771cb5	303	extern struct gendisk get_gendisk(dev_t dev, int partno);
f331c029	304	extern struct block_device bdget_disk(struct gendisk disk, int partno);
1da177e4 LT	305
	306	extern void set_device_ro(struct block_device *bdev, int flag);
	307	extern void set_disk_ro(struct gendisk *disk, int flag);
	308
b7db9956 TH	309	static inline int get_disk_ro(struct gendisk *disk)
	310	{
	311	return disk->part0.policy;
	312	}
	313
77ea887e TH	314	extern void disk_block_events(struct gendisk *disk);
77ea887e TH	315	extern void disk_unblock_events(struct gendisk *disk);
85ef06d1	316	extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
e598a72f BS	317	extern void set_capacity_revalidate_and_notify(struct gendisk *disk,
e598a72f BS	318	sector_t size, bool revalidate);
77ea887e TH	319	extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
77ea887e TH	320
1da177e4	321	/* drivers/char/random.c */
0766f788	322	extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
1da177e4 LT	323	extern void rand_initialize_disk(struct gendisk *disk);
	324
	325	static inline sector_t get_start_sect(struct block_device *bdev)
	326	{
0762b8bd	327	return bdev->bd_part->start_sect;
1da177e4 LT	328	}
	329	static inline sector_t get_capacity(struct gendisk *disk)
	330	{
80795aef	331	return disk->part0.nr_sects;
1da177e4 LT	332	}
	333	static inline void set_capacity(struct gendisk *disk, sector_t size)
	334	{
80795aef	335	disk->part0.nr_sects = size;
1da177e4 LT	336	}
1da177e4 LT	337
cf771cb5	338	extern dev_t blk_lookup_devt(const char *name, int partno);
1da177e4	339
142fe8f4	340	int bdev_disk_changed(struct block_device *bdev, bool invalidate);
a1548b67 CH	341	int blk_add_partitions(struct gendisk disk, struct block_device bdev);
a1548b67 CH	342	int blk_drop_partitions(struct gendisk disk, struct block_device bdev);
dd2a345f	343	extern void printk_all_partitions(void);
1da177e4	344
e319e1fb	345	extern struct gendisk *__alloc_disk_node(int minors, int node_id);
3079c22e	346	extern struct kobject get_disk_and_module(struct gendisk disk);
1da177e4	347	extern void put_disk(struct gendisk *disk);
9df6c299	348	extern void put_disk_and_module(struct gendisk *disk);
edfaa7c3	349	extern void blk_register_region(dev_t devt, unsigned long range,
1da177e4 LT	350	struct module *module,
	351	struct kobject (probe)(dev_t, int , void ),
	352	int (lock)(dev_t, void ),
	353	void *data);
edfaa7c3	354	extern void blk_unregister_region(dev_t devt, unsigned long range);
1da177e4	355
e319e1fb BP	356	#define alloc_disk_node(minors, node_id) \
	357	({ \
	358	static struct lock_class_key __key; \
	359	const char *__name; \
	360	struct gendisk *__disk; \
	361	\
	362	__name = "(gendisk_completion)"#minors"("#node_id")"; \
	363	\
	364	__disk = __alloc_disk_node(minors, node_id); \
	365	\
	366	if (__disk) \
	367	lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \
	368	\
	369	__disk; \
	370	})
	371
	372	#define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
	373
87c1efbf JA	374	#else /* CONFIG_BLOCK */
	375
	376	static inline void printk_all_partitions(void) { }
	377
cf771cb5	378	static inline dev_t blk_lookup_devt(const char *name, int partno)
edfaa7c3 KS	379	{
	380	dev_t devt = MKDEV(0, 0);
	381	return devt;
	382	}
87c1efbf	383	#endif /* CONFIG_BLOCK */
9361401e	384
a8ae50ba	385	#endif /* _LINUX_GENHD_H */