path: root/include/linux/blkdev.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Portions Copyright (C) 1992 Drew Eckhardt
 */
#ifndef _LINUX_BLKDEV_H
#define _LINUX_BLKDEV_H

#include <linux/types.h>
#include <linux/blk_types.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/llist.h>
#include <linux/minmax.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <linux/wait.h>
#include <linux/bio.h>
#include <linux/gfp.h>
#include <linux/kdev_t.h>
#include <linux/rcupdate.h>
#include <linux/percpu-refcount.h>
#include <linux/blkzoned.h>
#include <linux/sched.h>
#include <linux/sbitmap.h>
#include <linux/uuid.h>
#include <linux/xarray.h>
#include <linux/file.h>

struct module;
struct request_queue;
struct elevator_queue;
struct blk_trace;
struct request;
struct sg_io_hdr;
struct blkcg_gq;
struct blk_flush_queue;
struct kiocb;
struct pr_ops;
struct rq_qos;
struct blk_queue_stats;
struct blk_stat_callback;
struct blk_crypto_profile;

extern const struct device_type disk_type;
extern const struct device_type part_type;
extern const struct class block_class;

/*
 * Maximum number of blkcg policies allowed to be registered concurrently.
 * Defined here to simplify include dependency.
 */
#define BLKCG_MAX_POLS		6

#define DISK_MAX_PARTS			256
#define DISK_NAME_LEN			32

#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];
};

/**
 * DOC: genhd capability flags
 *
 * ``GENHD_FL_REMOVABLE``: indicates that the block device gives access to
 * removable media.  When set, the device remains present even when media is not
 * inserted.  Shall not be set for devices which are removed entirely when the
 * media is removed.
 *
 * ``GENHD_FL_HIDDEN``: the block device is hidden; it doesn't produce events,
 * doesn't appear in sysfs, and can't be opened from userspace or using
 * blkdev_get*. Used for the underlying components of multipath devices.
 *
 * ``GENHD_FL_NO_PART``: partition support is disabled.  The kernel will not
 * scan for partitions from add_disk, and users can't add partitions manually.
 *
 */
enum {
	GENHD_FL_REMOVABLE			= 1 << 0,
	GENHD_FL_HIDDEN				= 1 << 1,
	GENHD_FL_NO_PART			= 1 << 2,
};

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,
	/* Block event polling when open for exclusive write */
	DISK_EVENT_FLAG_BLOCK_ON_EXCL_WRITE	= 1 << 2,
};

struct disk_events;
struct badblocks;

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

typedef unsigned int __bitwise blk_mode_t;

/* open for reading */
#define BLK_OPEN_READ		((__force blk_mode_t)(1 << 0))
/* open for writing */
#define BLK_OPEN_WRITE		((__force blk_mode_t)(1 << 1))
/* open exclusively (vs other exclusive openers */
#define BLK_OPEN_EXCL		((__force blk_mode_t)(1 << 2))
/* opened with O_NDELAY */
#define BLK_OPEN_NDELAY		((__force blk_mode_t)(1 << 3))
/* open for "writes" only for ioctls (specialy hack for floppy.c) */
#define BLK_OPEN_WRITE_IOCTL	((__force blk_mode_t)(1 << 4))
/* open is exclusive wrt all other BLK_OPEN_WRITE opens to the device */
#define BLK_OPEN_RESTRICT_WRITES	((__force blk_mode_t)(1 << 5))
/* return partition scanning errors */
#define BLK_OPEN_STRICT_SCAN	((__force blk_mode_t)(1 << 6))

struct gendisk {
	/*
	 * major/first_minor/minors should not be set by any new driver, the
	 * block core will take care of allocating them automatically.
	 */
	int major;
	int first_minor;
	int minors;

	char disk_name[DISK_NAME_LEN];	/* name of major driver */

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

	struct xarray part_tbl;
	struct block_device *part0;

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

	struct bio_set bio_split;

	int flags;
	unsigned long state;
#define GD_NEED_PART_SCAN		0
#define GD_READ_ONLY			1
#define GD_DEAD				2
#define GD_NATIVE_CAPACITY		3
#define GD_ADDED