/* 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/srcu.h>
#include <linux/uuid.h>
#include <linux/xarray.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 struct device_type part_type;
extern struct class block_class;

/* Must be consistent with blk_mq_poll_stats_bkt() */
#define BLK_MQ_POLL_STATS_BKTS 16

/* Doing classic polling */
#define BLK_MQ_POLL_CLASSIC -1

/*
 * 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                           interval_exp;
        unsigned char                           tag_size;
};

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;

        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                        4
#define GD_SUPPRESS_PART_SCAN           5

        struct mutex open_mutex;        /* open/close mutex */
        unsigned open_partitions;       /* number of open partitions */

        struct backing_dev_info *bdi;
        struct kobject *slave_dir;
#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
        struct list_head slave_bdevs;
#endif
        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 */
#if IS_ENABLED(CONFIG_CDROM)
        struct cdrom_device_info *cdi;
#endif
        int node_id;
        struct badblocks *bb;
        struct lockdep_map lockdep_map;
        u64 diskseq;
};

static inline bool disk_live(struct gendisk *disk)
{
        return !inode_unhashed(disk->part0->bd_inode);
}

/**
 * disk_openers - returns how many openers are there for a disk
 * @disk: disk to check
 *
 * This returns the number of openers for a disk.  Note that this value is only
 * stable if disk->open_mutex is held.
 *
 * Note: Due to a quirk in the block layer open code, each open partition is
 * only counted once even if there are multiple openers.
 */
static inline unsigned int disk_openers(struct gendisk *disk)
{
        return atomic_read(&disk->part0->bd_openers);
}

/*
 * The gendisk is refcounted by the part0 block_device, and the bd_device
 * therein is also used for device model presentation in sysfs.
 */
#define dev_to_disk(device) \
        (dev_to_bdev(device)->bd_disk)
#define disk_to_dev(disk) \
        (&((disk)->part0->bd_device))

#if IS_REACHABLE(CONFIG_CDROM)
#define disk_to_cdi(disk)       ((disk)->cdi)
#else
#define disk_to_cdi(disk)       NULL
#endif

static inline dev_t disk_devt(struct gendisk *disk)
{
        return MKDEV(disk->major, disk->first_minor);
}

static inline int blk_validate_block_size(unsigned long bsize)
{
        if (bsize < 512 || bsize > PAGE_SIZE || !is_power_of_2(bsize))
                return -EINVAL;

        return 0;
}

static inline bool blk_op_is_passthrough(unsigned int op)
{
        op &= REQ_OP_MASK;
        return op == REQ_OP_DRV_IN || op == REQ_OP_DRV_OUT;
}

/*
 * Zoned block device models (zoned limit).
 *
 * Note: This needs to be ordered from the least to the most severe
 * restrictions for the inheritance in blk_stack_limits() to work.
 */
enum blk_zoned_model {
        BLK_ZONED_NONE = 0,     /* Regular block device */
        BLK_ZONED_HA,           /* Host-aware zoned block device */
        BLK_ZONED_HM,           /* Host-managed zoned block device */
};

/*
 * BLK_BOUNCE_NONE:     never bounce (default)
 * BLK_BOUNCE_HIGH:     bounce all highmem pages
 */
enum blk_bounce {
        BLK_BOUNCE_NONE,
        BLK_BOUNCE_HIGH,
};

struct queue_limits {
        enum blk_bounce         bounce;
        unsigned long           seg_boundary_mask;
        unsigned long           virt_boundary_mask;

        unsigned int            max_hw_sectors;
        unsigned int            max_dev_sectors;
        unsigned int            chunk_sectors;
        unsigned int            max_sectors;
        unsigned int            max_segment_size;
        unsigned int            physical_block_size;
        unsigned int            logical_block_size;
        unsigned int            alignment_offset;
        unsigned int            io_min;
        unsigned int            io_opt;
        unsigned int            max_discard_sectors;
        unsigned int            max_hw_discard_sectors;
        unsigned int            max_secure_erase_sectors;
        unsigned int            max_write_zeroes_sectors;
        unsigned int            max_zone_append_sectors;
        unsigned int            discard_granularity;
        unsigned int            discard_alignment;
        unsigned int            zone_write_granularity;

        unsigned short          max_segments;
        unsigned short          max_integrity_segments;
        unsigned short          max_discard_segments;

        unsigned char           misaligned;
        unsigned char           discard_misaligned;
        unsigned char           raid_partial_stripes_expensive;
        enum blk_zoned_model    zoned;
};

typedef int (*report_zones_cb)(struct blk_zone *zone, unsigned int idx,
                               void *data);

void blk_queue_set_zoned(struct gendisk *disk, enum blk_zoned_model model);

#ifdef CONFIG_BLK_DEV_ZONED

#define BLK_ALL_ZONES  ((unsigned int)-1)
int blkdev_report_zones(struct block_device *bdev, sector_t sector,
                        unsigned int nr_zones, report_zones_cb cb, void *data);
unsigned int blkdev_nr_zones(struct gendisk *disk);
extern int blkdev_zone_mgmt(struct block_device *bdev, enum req_opf op,
                            sector_t sectors, sector_t nr_sectors,
                            gfp_t gfp_mask);
int blk_revalidate_disk_zones(struct gendisk *disk,
                              void (*update_driver_data)(struct gendisk *disk));

extern int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
                                     unsigned int cmd, unsigned long arg);
extern int blkdev_zone_mgmt_ioctl(struct block_device *bdev, fmode_t mode,
                                  unsigned int cmd, unsigned long arg);

#else /* CONFIG_BLK_DEV_ZONED */

static inline unsigned int blkdev_nr_zones(struct gendisk *disk)
{
        return 0;
}

static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
                                            fmode_t mode, unsigned int cmd,
                                            unsigned long arg)
{
        return -ENOTTY;
}

static inline int blkdev_zone_mgmt_ioctl(struct block_device *bdev,
                                         fmode_t mode, unsigned int cmd,
                                         unsigned long arg)
{
        return -ENOTTY;
}

#endif /* CONFIG_BLK_DEV_ZONED */

/*
 * Independent access ranges: struct blk_independent_access_range describes
 * a range of contiguous sectors that can be accessed using device command
 * execution resources that are independent from the resources used for
 * other access ranges. This is typically found with single-LUN multi-actuator
 * HDDs where each access range is served by a different set of heads.
 * The set of independent ranges supported by the device is defined using
 * struct blk_independent_access_ranges. The independent ranges must not overlap
 * and must include all sectors within the disk capacity (no sector holes
 * allowed).
 * For a device with multiple ranges, requests targeting sectors in different
 * ranges can be executed in parallel. A request can straddle an access range
 * boundary.
 */
struct blk_independent_access_range {
        struct kobject          kobj;
        sector_t                sector;
        sector_t                nr_sectors;
};

struct blk_independent_access_ranges {
        struct kobject                          kobj;
        bool                                    sysfs_registered;
        unsigned int                            nr_ia_ranges;
        struct blk_independent_access_range     ia_range[];
};

struct request_queue {
        struct request          *last_merge;
        struct elevator_queue   *elevator;

        struct percpu_ref       q_usage_counter;

        struct blk_queue_stats  *stats;
        struct rq_qos           *rq_qos;

        const struct blk_mq_ops *mq_ops;

        /* sw queues */
        struct blk_mq_ctx __percpu      *queue_ctx;

        unsigned int            queue_depth;

        /* hw dispatch queues */
        struct xarray           hctx_table;
        unsigned int            nr_hw_queues;

        /*
         * The queue owner gets to use this for whatever they like.
         * ll_rw_blk doesn't touch it.
         */
        void                    *queuedata;

        /*
         * various queue flags, see QUEUE_* below
         */
        unsigned long           queue_flags;
        /*
         * Number of contexts that have called blk_set_pm_only(). If this
         * counter is above zero then only RQF_PM requests are processed.
         */
        atomic_t                pm_only;

        /*
         * ida allocated id for this queue.  Used to index queues from
         * ioctx.
         */
        int                     id;

        spinlock_t              queue_lock;

        struct gendisk          *disk;

        /*
         * queue kobject
         */
        struct kobject kobj;

        /*
         * mq queue kobject
         */
        struct kobject *mq_kobj;

#ifdef  CONFIG_BLK_DEV_INTEGRITY
        struct blk_integrity integrity;
#endif  /* CONFIG_BLK_DEV_INTEGRITY */

#ifdef CONFIG_PM
        struct device           *dev;
        enum rpm_status         rpm_status;
#endif

        /*
         * queue settings
         */
        unsigned long           nr_requests;    /* Max # of requests */

        unsigned int            dma_pad_mask;
        unsigned int            dma_alignment;

#ifdef CONFIG_BLK_INLINE_ENCRYPTION
        struct blk_crypto_profile *crypto_profile;
        struct kobject *crypto_kobject;
#endif

        unsigned int            rq_timeout;
        int                     poll_nsec;

        struct blk_stat_callback        *poll_cb;
        struct blk_rq_stat      *poll_stat;

        struct timer_list       timeout;
        struct work_struct      timeout_work;

        atomic_t                nr_active_requests_shared_tags;

        struct blk_mq_tags      *sched_shared_tags;

        struct list_head        icq_list;
#ifdef CONFIG_BLK_CGROUP
        DECLARE_BITMAP          (blkcg_pols, BLKCG_MAX_POLS);
        struct blkcg_gq         *root_blkg;
        struct list_head        blkg_list;
#endif

        struct queue_limits     limits;

        unsigned int            required_elevator_features;

#ifdef CONFIG_BLK_DEV_ZONED
        /*
         * Zoned block device information for request dispatch control.
         * nr_zones is the total number of zones of the device. This is always
         * 0 for regular block devices. conv_zones_bitmap is a bitmap of nr_zones
         * bits which indicates if a zone is conventional (bit set) or
         * sequential (bit clear). seq_zones_wlock is a bitmap of nr_zones
         * bits which indicates if a zone is write locked, that is, if a write
         * request targeting the zone was dispatched. All three fields are
         * initialized by the low level device driver (e.g. scsi/sd.c).
         * Stacking drivers (device mappers) may or may not initialize
         * these fields.
         *
         * Reads of this information must be protected with blk_queue_enter() /
         * blk_queue_exit(). Modifying this information is only allowed while
         * no requests are being processed. See also blk_mq_freeze_queue() and
         * blk_mq_unfreeze_queue().
         */
        unsigned int            nr_zones;
        unsigned long           *conv_zones_bitmap;
        unsigned long           *seq_zones_wlock;
        unsigned int            max_open_zones;
        unsigned int            max_active_zones;
#endif /* CONFIG_BLK_DEV_ZONED */

        int                     node;
#ifdef CONFIG_BLK_DEV_IO_TRACE
        struct blk_trace __rcu  *blk_trace;
#endif
        /*
         * for flush operations
         */
        struct blk_flush_queue  *fq;

        struct list_head        requeue_list;
        spinlock_t              requeue_lock;
        struct delayed_work     requeue_work;

        struct mutex            sysfs_lock;
        struct mutex            sysfs_dir_lock;

        /*
         * for reusing dead hctx instance in case of updating
         * nr_hw_queues
         */
        struct list_head        unused_hctx_list;
        spinlock_t              unused_hctx_lock;

        int                     mq_freeze_depth;

#ifdef CONFIG_BLK_DEV_THROTTLING
        /* Throttle data */
        struct throtl_data *td;
#endif
        struct rcu_head         rcu_head;
        wait_queue_head_t       mq_freeze_wq;
        /*
         * Protect concurrent access to q_usage_counter by
         * percpu_ref_kill() and percpu_ref_reinit().
         */
        struct mutex            mq_freeze_lock;

        int                     quiesce_depth;

        struct blk_mq_tag_set   *tag_set;
        struct list_head        tag_set_list;
        struct bio_set          bio_split;

        struct dentry           *debugfs_dir;
        struct dentry           *sched_debugfs_dir;
        struct dentry           *rqos_debugfs_dir;
        /*
         * Serializes all debugfs metadata operations using the above dentries.
         */
        struct mutex            debugfs_mutex;

        bool                    mq_sysfs_init_done;

        /*
         * Independent sector access ranges. This is always NULL for
         * devices that do not have multiple independent access ranges.
         */
        struct blk_independent_access_ranges *ia_ranges;

        /**
         * @srcu: Sleepable RCU. Use as lock when type of the request queue
         * is blocking (BLK_MQ_F_BLOCKING). Must be the last member
         */
        struct srcu_struct      srcu[];
};

/* Keep blk_queue_flag_name[] in sync with the definitions below */
#define QUEUE_FLAG_STOPPED      0       /* queue is stopped */
#define QUEUE_FLAG_DYING        1       /* queue being torn down */
#define QUEUE_FLAG_HAS_SRCU     2       /* SRCU is allocated */
#define QUEUE_FLAG_NOMERGES     3       /* disable merge attempts */
#define QUEUE_FLAG_SAME_COMP    4       /* complete on same CPU-group */
#define QUEUE_FLAG_FAIL_IO      5       /* fake timeout */
#define QUEUE_FLAG_NONROT       6       /* non-rotational device (SSD) */
#define QUEUE_FLAG_VIRT         QUEUE_FLAG_NONROT /* paravirt device */
#define QUEUE_FLAG_IO_STAT      7       /* do disk/partitions IO accounting */
#define QUEUE_FLAG_NOXMERGES    9       /* No extended merges */
#define QUEUE_FLAG_ADD_RANDOM   10      /* Contributes to random pool */
#define QUEUE_FLAG_SAME_FORCE   12      /* force complete on same CPU */
#define QUEUE_FLAG_DEAD         13      /* queue tear-down finished */
#define QUEUE_FLAG_INIT_DONE    14      /* queue is initialized */
#define QUEUE_FLAG_STABLE_WRITES 15     /* don't modify blks until WB is done */
#define QUEUE_FLAG_POLL         16      /* IO polling enabled if set */
#define QUEUE_FLAG_WC           17      /* Write back caching */
#define QUEUE_FLAG_FUA          18      /* device supports FUA writes */
#define QUEUE_FLAG_DAX          19      /* device supports DAX */
#define QUEUE_FLAG_STATS        20      /* track IO start and completion times */
#define QUEUE_FLAG_REGISTERED   22      /* queue has been registered to a disk */
#define QUEUE_FLAG_QUIESCED     24      /* queue has been quiesced */
#define QUEUE_FLAG_PCI_P2PDMA   25      /* device supports PCI p2p requests */
#define QUEUE_FLAG_ZONE_RESETALL 26     /* supports Zone Reset All */
#define QUEUE_FLAG_RQ_ALLOC_TIME 27     /* record rq->alloc_time_ns */
#define QUEUE_FLAG_HCTX_ACTIVE  28      /* at least one blk-mq hctx is active */
#define QUEUE_FLAG_NOWAIT       29      /* device supports NOWAIT */
#define QUEUE_FLAG_SQ_SCHED     30      /* single queue style io dispatch */

#define QUEUE_FLAG_MQ_DEFAULT   ((1 << QUEUE_FLAG_IO_STAT) |            \
                                 (1 << QUEUE_FLAG_SAME_COMP) |          \
                                 (1 << QUEUE_FLAG_NOWAIT))

void blk_queue_flag_set(unsigned int flag, struct request_queue *q);
void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);

#define blk_queue_stopped(q)    test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
#define blk_queue_dying(q)      test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
#define blk_queue_has_srcu(q)   test_bit(QUEUE_FLAG_HAS_SRCU, &(q)->queue_flags)
#define blk_queue_dead(q)       test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
#define blk_queue_init_done(q)  test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
#define blk_queue_nomerges(q)   test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
#define blk_queue_noxmerges(q)  \
        test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
#define blk_queue_nonrot(q)     test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
#define blk_queue_stable_writes(q) \
        test_bit(QUEUE_FLAG_STABLE_WRITES, &(q)->queue_flags)
#define blk_queue_io_stat(q)    test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
#define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
#define blk_queue_zone_resetall(q)      \
        test_bit(QUEUE_FLAG_ZONE_RESETALL, &(q)->queue_flags)
#define blk_queue_dax(q)        test_bit(QUEUE_FLAG_DAX, &(q)->queue_flags)
#define blk_queue_pci_p2pdma(q) \
        test_bit(QUEUE_FLAG_PCI_P2PDMA, &(q)->queue_flags)
#ifdef CONFIG_BLK_RQ_ALLOC_TIME
#define blk_queue_rq_alloc_time(q)      \
        test_bit(QUEUE_FLAG_RQ_ALLOC_TIME, &(q)->queue_flags)
#else
#define blk_queue_rq_alloc_time(q)      false
#endif

#define blk_noretry_request(rq) \
        ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
                             REQ_FAILFAST_DRIVER))
#define blk_queue_quiesced(q)   test_bit(QUEUE_FLAG_QUIESCED, &(q)->queue_flags)
#define blk_queue_pm_only(q)    atomic_read(&(q)->pm_only)
#define blk_queue_registered(q) test_bit(QUEUE_FLAG_REGISTERED, &(q)->queue_flags)
#define blk_queue_nowait(q)     test_bit(QUEUE_FLAG_NOWAIT, &(q)->queue_flags)
#define blk_queue_sq_sched(q)   test_bit(QUEUE_FLAG_SQ_SCHED, &(q)->queue_flags)

extern void blk_set_pm_only(struct request_queue *q);
extern void blk_clear_pm_only(struct request_queue *q);

#define list_entry_rq(ptr)      list_entry((ptr), struct request, queuelist)

#define dma_map_bvec(dev, bv, dir, attrs) \
        dma_map_page_attrs(dev, (bv)->bv_page, (bv)->bv_offset, (bv)->bv_len, \
        (dir), (attrs))

static inline bool queue_is_mq(struct request_queue *q)
{
        return q->mq_ops;
}

#ifdef CONFIG_PM
static inline enum rpm_status queue_rpm_status(struct request_queue *q)
{
        return q->rpm_status;
}
#else
static inline enum rpm_status queue_rpm_status(struct request_queue *q)
{
        return RPM_ACTIVE;
}
#endif

static inline enum blk_zoned_model
blk_queue_zoned_model(struct request_queue *q)
{
        if (IS_ENABLED(CONFIG_BLK_DEV_ZONED))
                return q->limits.zoned;
        return BLK_ZONED_NONE;
}

static inline bool blk_queue_is_zoned(struct request_queue *q)
{
        switch (blk_queue_zoned_model(q)) {
        case BLK_ZONED_HA:
        case BLK_ZONED_HM:
                return true;
        default:
                return false;
        }
}

static inline sector_t blk_queue_zone_sectors(struct request_queue *q)
{
        return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0;
}

#ifdef CONFIG_BLK_DEV_ZONED
static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
{
        return blk_queue_is_zoned(q) ? q->nr_zones : 0;
}

static inline unsigned int blk_queue_zone_no(struct request_queue *q,
                                             sector_t sector)
{
        if (!blk_queue_is_zoned(q))
                return 0;
        return sector >> ilog2(q->limits.chunk_sectors);
}

static inline bool blk_queue_zone_is_seq(struct request_queue *q,
                                         sector_t sector)
{
        if (!blk_queue_is_zoned(q))
                return false;
        if (!q->conv_zones_bitmap)
                return true;
        return !test_bit(blk_queue_zone_no(q, sector), q->conv_zones_bitmap);
}

static inline void blk_queue_max_open_zones(struct request_queue *q,
                unsigned int max_open_zones)
{
        q->max_open_zones = max_open_zones;
}

static inline unsigned int queue_max_open_zones(const struct request_queue *q)
{
        return q->max_open_zones;
}

static inline void blk_queue_max_active_zones(struct request_queue *q,
                unsigned int max_active_zones)
{
        q->max_active_zones = max_active_zones;
}

static inline unsigned int queue_max_active_zones(const struct request_queue *q)
{
        return q->max_active_zones;
}
#else /* CONFIG_BLK_DEV_ZONED */
static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
{
        return 0;
}
static inline bool blk_queue_zone_is_seq(struct request_queue *q,
                                         sector_t sector)
{
        return false;
}
static inline unsigned int blk_queue_zone_no(struct request_queue *q,
                                             sector_t sector)
{
        return 0;
}
static inline unsigned int queue_max_open_zones(const struct request_queue *q)
{
        return 0;
}
static inline unsigned int queue_max_active_zones(const struct request_queue *q)
{
        return 0;
}
#endif /* CONFIG_BLK_DEV_ZONED */

static inline unsigned int blk_queue_depth(struct request_queue *q)
{
        if (q->queue_depth)
                return q->queue_depth;

        return q->nr_requests;
}

/*
 * default timeout for SG_IO if none specified
 */
#define BLK_DEFAULT_SG_TIMEOUT  (60 * HZ)
#define BLK_MIN_SG_TIMEOUT      (7 * HZ)

/* This should not be used directly - use rq_for_each_segment */
#define for_each_bio(_bio)              \
        for (; _bio; _bio = _bio->bi_next)

int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
                                 const struct attribute_group **groups);
static inline int __must_check add_disk(struct gendisk *disk)
{
        return device_add_disk(NULL, disk, NULL);
}
void del_gendisk(struct gendisk *gp);
void invalidate_disk(struct gendisk *disk);
void set_disk_ro(struct gendisk *disk, bool read_only);
void disk_uevent(struct gendisk *disk, enum kobject_action action);

static inline int get_disk_ro(struct gendisk *disk)
{
        return disk->part0->bd_read_only ||
                test_bit(GD_READ_ONLY, &disk->state);
}

static inline int bdev_read_only(struct block_device *bdev)
{
        return bdev->bd_read_only || get_disk_ro(bdev->bd_disk);
}

bool set_capacity_and_notify(struct gendisk *disk, sector_t size);
bool disk_force_media_change(struct gendisk *disk, unsigned int events);

void add_disk_randomness(struct gendisk *disk) __latent_entropy;
void rand_initialize_disk(struct gendisk *disk);

static inline sector_t get_start_sect(struct block_device *bdev)
{
        return bdev->bd_start_sect;
}

static inline sector_t bdev_nr_sectors(struct block_device *bdev)
{
        return bdev->bd_nr_sectors;
}

static inline loff_t bdev_nr_bytes(struct block_device *bdev)
{
        return (loff_t)bdev_nr_sectors(bdev) << SECTOR_SHIFT;
}

static inline sector_t get_capacity(struct gendisk *disk)
{
        return bdev_nr_sectors(disk->part0);
}

static inline u64 sb_bdev_nr_blocks(struct super_block *sb)
{
        return bdev_nr_sectors(sb->s_bdev) >>
                (sb->s_blocksize_bits - SECTOR_SHIFT);
}

int bdev_disk_changed(struct gendisk *disk, bool invalidate);

struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
                struct lock_class_key *lkclass);
void put_disk(struct gendisk *disk);
struct gendisk *__blk_alloc_disk(int node, struct lock_class_key *lkclass);

/**
 * blk_alloc_disk - allocate a gendisk structure
 * @node_id: numa node to allocate on
 *
 * Allocate and pre-initialize a gendisk structure for use with BIO based
 * drivers.
 *
 * Context: can sleep
 */
#define blk_alloc_disk(node_id)                                         \
({                                                                      \
        static struct lock_class_key __key;                             \
                                                                        \
        __blk_alloc_disk(node_id, &__key);                              \
})
void blk_cleanup_disk(struct gendisk *disk);

int __register_blkdev(unsigned int major, const char *name,
                void (*probe)(dev_t devt));
#define register_blkdev(major, name) \
        __register_blkdev(major, name, NULL)
void unregister_blkdev(unsigned int major, const char *name);

bool bdev_check_media_change(struct block_device *bdev);
int __invalidate_device(struct block_device *bdev, bool kill_dirty);
void set_capacity(struct gendisk *disk, sector_t size);

#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
int bd_register_pending_holders(struct gendisk *disk);
#else
static inline int bd_link_disk_holder(struct block_device *bdev,
                                      struct gendisk *disk)
{
        return 0;
}
static inline void bd_unlink_disk_holder(struct block_device *bdev,
                                         struct gendisk *disk)
{
}
static inline int bd_register_pending_holders(struct gendisk *disk)
{
        return 0;
}
#endif /* CONFIG_BLOCK_HOLDER_DEPRECATED */

dev_t part_devt(struct gendisk *disk, u8 partno);
void inc_diskseq(struct gendisk *disk);
dev_t blk_lookup_devt(const char *name, int partno);
void blk_request_module(dev_t devt);

extern int blk_register_queue(struct gendisk *disk);
extern void blk_unregister_queue(struct gendisk *disk);
void submit_bio_noacct(struct bio *bio);

extern int blk_lld_busy(struct request_queue *q);
extern void blk_queue_split(struct bio **);
extern int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags);
extern void blk_queue_exit(struct request_queue *q);
extern void blk_sync_queue(struct request_queue *q);

/* Helper to convert REQ_OP_XXX to its string format XXX */
extern const char *blk_op_str(unsigned int op);

int blk_status_to_errno(blk_status_t status);
blk_status_t errno_to_blk_status(int errno);

/* only poll the hardware once, don't continue until a completion was found */
#define BLK_POLL_ONESHOT                (1 << 0)
/* do not sleep to wait for the expected completion time */
#define BLK_POLL_NOSLEEP                (1 << 1)
int bio_poll(struct bio *bio, struct io_comp_batch *iob, unsigned int flags);
int iocb_bio_iopoll(struct kiocb *kiocb, struct io_comp_batch *iob,
                        unsigned int flags);

static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
{
        return bdev->bd_queue;  /* this is never NULL */
}

#ifdef CONFIG_BLK_DEV_ZONED

/* Helper to convert BLK_ZONE_ZONE_XXX to its string format XXX */
const char *blk_zone_cond_str(enum blk_zone_cond zone_cond);

static inline unsigned int bio_zone_no(struct bio *bio)
{
        return blk_queue_zone_no(bdev_get_queue(bio->bi_bdev),
                                 bio->bi_iter.bi_sector);
}

static inline unsigned int bio_zone_is_seq(struct bio *bio)
{
        return blk_queue_zone_is_seq(bdev_get_queue(bio->bi_bdev),
                                     bio->bi_iter.bi_sector);
}
#endif /* CONFIG_BLK_DEV_ZONED */

static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
                                                     int op)
{
        if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
                return min(q->limits.max_discard_sectors,
                           UINT_MAX >> SECTOR_SHIFT);

        if (unlikely(op == REQ_OP_WRITE_ZEROES))
                return q->limits.max_write_zeroes_sectors;

        return q->limits.max_sectors;
}

/*
 * Return maximum size of a request at given offset. Only valid for
 * file system requests.
 */
static inline unsigned int blk_max_size_offset(struct request_queue *q,
                                               sector_t offset,
                                               unsigned int chunk_sectors)
{
        if (!chunk_sectors) {
                if (q->limits.chunk_sectors)
                        chunk_sectors = q->limits.chunk_sectors;
                else
                        return q->limits.max_sectors;
        }

        if (likely(is_power_of_2(chunk_sectors)))
                chunk_sectors -= offset & (chunk_sectors - 1);
        else
                chunk_sectors -= sector_div(offset, chunk_sectors);

        return min(q->limits.max_sectors, chunk_sectors);
}

/*
 * Access functions for manipulating queue properties
 */
extern void blk_cleanup_queue(struct request_queue *);
void blk_queue_bounce_limit(struct request_queue *q, enum blk_bounce limit);
extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
extern void blk_queue_max_segments(struct request_queue *, unsigned short);
extern void blk_queue_max_discard_segments(struct request_queue *,
                unsigned short);
void blk_queue_max_secure_erase_sectors(struct request_queue *q,
                unsigned int max_sectors);
extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
extern void blk_queue_max_discard_sectors(struct request_queue *q,
                unsigned int max_discard_sectors);
extern void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
                unsigned int max_write_same_sectors);
extern void blk_queue_logical_block_size(struct request_queue *, unsigned int);
extern void blk_queue_max_zone_append_sectors(struct request_queue *q,
                unsigned int max_zone_append_sectors);
extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
void blk_queue_zone_write_granularity(struct request_queue *q,
                                      unsigned int size);
extern void blk_queue_alignment_offset(struct request_queue *q,
                                       unsigned int alignment);
void disk_update_readahead(struct gendisk *disk);
extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
extern void blk_set_queue_depth(struct request_queue *q, unsigned int depth);
extern void blk_set_default_limits(struct queue_limits *lim);
extern void blk_set_stacking_limits(struct queue_limits *lim);
extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
                            sector_t offset);
extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
                              sector_t offset);
extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
extern void blk_queue_virt_boundary(struct request_queue *, unsigned long);
extern void blk_queue_dma_alignment(struct request_queue *, int);
extern void blk_queue_update_dma_alignment(struct request_queue *, int);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua);

struct blk_independent_access_ranges *

disk_alloc_independent_access_ranges(struct gendisk *disk, int nr_ia_ranges);
void disk_set_independent_access_ranges(struct gendisk *disk,
                                struct blk_independent_access_ranges *iars);

/*
 * Elevator features for blk_queue_required_elevator_features:
 */
/* Supports zoned block devices sequential write constraint */
#define ELEVATOR_F_ZBD_SEQ_WRITE        (1U << 0)

extern void blk_queue_required_elevator_features(struct request_queue *q,
                                                 unsigned int features);
extern bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
                                              struct device *dev);

bool __must_check blk_get_queue(struct request_queue *);
extern void blk_put_queue(struct request_queue *);

void blk_mark_disk_dead(struct gendisk *disk);

#ifdef CONFIG_BLOCK
/*
 * blk_plug permits building a queue of related requests by holding the I/O
 * fragments for a short period. This allows merging of sequential requests
 * into single larger request. As the requests are moved from a per-task list to
 * the device's request_queue in a batch, this results in improved scalability
 * as the lock contention for request_queue lock is reduced.
 *
 * It is ok not to disable preemption when adding the request to the plug list
 * or when attempting a merge. For details, please see schedule() where
 * blk_flush_plug() is called.
 */
struct blk_plug {
        struct request *mq_list; /* blk-mq requests */

        /* if ios_left is > 1, we can batch tag/rq allocations */
        struct request *cached_rq;
        unsigned short nr_ios;

        unsigned short rq_count;

        bool multiple_queues;
        bool has_elevator;
        bool nowait;

        struct list_head cb_list; /* md requires an unplug callback */
};

struct blk_plug_cb;
typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
struct blk_plug_cb {
        struct list_head list;
        blk_plug_cb_fn callback;
        void *data;
};
extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
                                             void *data, int size);
extern void blk_start_plug(struct blk_plug *);
extern void blk_start_plug_nr_ios(struct blk_plug *, unsigned short);
extern void blk_finish_plug(struct blk_plug *);

void __blk_flush_plug(struct blk_plug *plug, bool from_schedule);
static inline void blk_flush_plug(struct blk_plug *plug, bool async)
{
        if (plug)
                __blk_flush_plug(plug, async);
}

int blkdev_issue_flush(struct block_device *bdev);
long nr_blockdev_pages(void);
#else /* CONFIG_BLOCK */
struct blk_plug {
};

static inline void blk_start_plug_nr_ios(struct blk_plug *plug,
                                         unsigned short nr_ios)
{
}

static inline void blk_start_plug(struct blk_plug *plug)
{
}

static inline void blk_finish_plug(struct blk_plug *plug)
{
}

static inline void blk_flush_plug(struct blk_plug *plug, bool async)
{
}

static inline int blkdev_issue_flush(struct block_device *bdev)
{
        return 0;
}

static inline long nr_blockdev_pages(void)
{
        return 0;
}
#endif /* CONFIG_BLOCK */

extern void blk_io_schedule(void);

int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
                sector_t nr_sects, gfp_t gfp_mask);
int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
                sector_t nr_sects, gfp_t gfp_mask, struct bio **biop);
int blkdev_issue_secure_erase(struct block_device *bdev, sector_t sector,
                sector_t nr_sects, gfp_t gfp);

#define BLKDEV_ZERO_NOUNMAP     (1 << 0)  /* do not free blocks */
#define BLKDEV_ZERO_NOFALLBACK  (1 << 1)  /* don't write explicit zeroes */

extern int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
                sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
                unsigned flags);
extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
                sector_t nr_sects, gfp_t gfp_mask, unsigned flags);

static inline int sb_issue_discard(struct super_block *sb, sector_t block,
                sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
{
        return blkdev_issue_discard(sb->s_bdev,
                                    block << (sb->s_blocksize_bits -
                                              SECTOR_SHIFT),
                                    nr_blocks << (sb->s_blocksize_bits -
                                                  SECTOR_SHIFT),
                                    gfp_mask);
}
static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
                sector_t nr_blocks, gfp_t gfp_mask)
{
        return blkdev_issue_zeroout(sb->s_bdev,
                                    block << (sb->s_blocksize_bits -
                                              SECTOR_SHIFT),
                                    nr_blocks << (sb->s_blocksize_bits -
                                                  SECTOR_SHIFT),
                                    gfp_mask, 0);
}

static inline bool bdev_is_partition(struct block_device *bdev)
{
        return bdev->bd_partno;
}

enum blk_default_limits {
        BLK_MAX_SEGMENTS        = 128,
        BLK_SAFE_MAX_SECTORS    = 255,
        BLK_DEF_MAX_SECTORS     = 2560,
        BLK_MAX_SEGMENT_SIZE    = 65536,
        BLK_SEG_BOUNDARY_MASK   = 0xFFFFFFFFUL,
};

static inline unsigned long queue_segment_boundary(const struct request_queue *q)
{
        return q->limits.seg_boundary_mask;
}

static inline unsigned long queue_virt_boundary(const struct request_queue *q)
{
        return q->limits.virt_boundary_mask;
}

static inline unsigned int queue_max_sectors(const struct request_queue *q)
{
        return q->limits.max_sectors;
}

static inline unsigned int queue_max_bytes(struct request_queue *q)
{
        return min_t(unsigned int, queue_max_sectors(q), INT_MAX >> 9) << 9;
}

static inline unsigned int queue_max_hw_sectors(const struct request_queue *q)
{
        return q->limits.max_hw_sectors;
}

static inline unsigned short queue_max_segments(const struct request_queue *q)
{
        return q->limits.max_segments;
}

static inline unsigned short queue_max_discard_segments(const struct request_queue *q)
{
        return q->limits.max_discard_segments;
}

static inline unsigned int queue_max_segment_size(const struct request_queue *q)
{
        return q->limits.max_segment_size;
}

static inline unsigned int queue_max_zone_append_sectors(const struct request_queue *q)
{

        const struct queue_limits *l = &q->limits;

        return min(l->max_zone_append_sectors, l->max_sectors);
}

static inline unsigned int
bdev_max_zone_append_sectors(struct block_device *bdev)
{
        return queue_max_zone_append_sectors(bdev_get_queue(bdev));
}

static inline unsigned queue_logical_block_size(const struct request_queue *q)
{
        int retval = 512;

        if (q && q->limits.logical_block_size)
                retval = q->limits.logical_block_size;

        return retval;
}

static inline unsigned int bdev_logical_block_size(struct block_device *bdev)
{
        return queue_logical_block_size(bdev_get_queue(bdev));
}

static inline unsigned int queue_physical_block_size(const struct request_queue *q)
{
        return q->limits.physical_block_size;
}

static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
{
        return queue_physical_block_size(bdev_get_queue(bdev));
}

static inline unsigned int queue_io_min(const struct request_queue *q)
{
        return q->limits.io_min;
}

static inline int bdev_io_min(struct block_device *bdev)
{
        return queue_io_min(bdev_get_queue(bdev));
}

static inline unsigned int queue_io_opt(const struct request_queue *q)
{
        return q->limits.io_opt;
}

static inline int bdev_io_opt(struct block_device *bdev)
{
        return queue_io_opt(bdev_get_queue(bdev));
}

static inline unsigned int
queue_zone_write_granularity(const struct request_queue *q)
{
        return q->limits.zone_write_granularity;
}

static inline unsigned int
bdev_zone_write_granularity(struct block_device *bdev)
{
        return queue_zone_write_granularity(bdev_get_queue(bdev));
}

int bdev_alignment_offset(struct block_device *bdev);
unsigned int bdev_discard_alignment(struct block_device *bdev);

static inline unsigned int bdev_max_discard_sectors(struct block_device *bdev)
{
        return bdev_get_queue(bdev)->limits.max_discard_sectors;
}

static inline unsigned int bdev_discard_granularity(struct block_device *bdev)
{
        return bdev_get_queue(bdev)->limits.discard_granularity;
}

static inline unsigned int
bdev_max_secure_erase_sectors(struct block_device *bdev)
{
        return bdev_get_queue(bdev)->limits.max_secure_erase_sectors;
}

static inline unsigned int bdev_write_zeroes_sectors(struct block_device *bdev)
{
        struct request_queue *q = bdev_get_queue(bdev);

        if (q)
                return q->limits.max_write_zeroes_sectors;

        return 0;
}

static inline bool bdev_nonrot(struct block_device *bdev)
{
        return blk_queue_nonrot(bdev_get_queue(bdev));
}

static inline bool bdev_stable_writes(struct block_device *bdev)
{
        return test_bit(QUEUE_FLAG_STABLE_WRITES,
                        &bdev_get_queue(bdev)->queue_flags);
}

static inline bool bdev_write_cache(struct block_device *bdev)
{
        return test_bit(QUEUE_FLAG_WC, &bdev_get_queue(bdev)->queue_flags);
}

static inline bool bdev_fua(struct block_device *bdev)
{
        return test_bit(QUEUE_FLAG_FUA, &bdev_get_queue(bdev)->queue_flags);
}

static inline enum blk_zoned_model bdev_zoned_model(struct block_device *bdev)
{
        struct request_queue *q = bdev_get_queue(bdev);

        if (q)
                return blk_queue_zoned_model(q);

        return BLK_ZONED_NONE;
}

static inline bool bdev_is_zoned(struct block_device *bdev)
{
        struct request_queue *q = bdev_get_queue(bdev);

        if (q)
                return blk_queue_is_zoned(q);

        return false;
}

static inline sector_t bdev_zone_sectors(struct block_device *bdev)
{
        struct request_queue *q = bdev_get_queue(bdev);

        if (q)
                return blk_queue_zone_sectors(q);
        return 0;
}

static inline unsigned int bdev_max_open_zones(struct block_device *bdev)
{
        struct request_queue *q = bdev_get_queue(bdev);

        if (q)
                return queue_max_open_zones(q);
        return 0;
}

static inline unsigned int bdev_max_active_zones(struct block_device *bdev)
{
        struct request_queue *q = bdev_get_queue(bdev);

        if (q)
                return queue_max_active_zones(q);
        return 0;
}

static inline int queue_dma_alignment(const struct request_queue *q)
{
        return q ? q->dma_alignment : 511;
}

static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
                                 unsigned int len)
{
        unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
        return !(addr & alignment) && !(len & alignment);
}

/* assumes size > 256 */
static inline unsigned int blksize_bits(unsigned int size)
{
        unsigned int bits = 8;
        do {
                bits++;
                size >>= 1;
        } while (size > 256);
        return bits;
}

static inline unsigned int block_size(struct block_device *bdev)
{
        return 1 << bdev->bd_inode->i_blkbits;
}

int kblockd_schedule_work(struct work_struct *work);
int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);

#define MODULE_ALIAS_BLOCKDEV(major,minor) \
        MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
        MODULE_ALIAS("block-major-" __stringify(major) "-*")

#ifdef CONFIG_BLK_INLINE_ENCRYPTION

bool blk_crypto_register(struct blk_crypto_profile *profile,
                         struct request_queue *q);

#else /* CONFIG_BLK_INLINE_ENCRYPTION */

static inline bool blk_crypto_register(struct blk_crypto_profile *profile,
                                       struct request_queue *q)
{
        return true;
}

#endif /* CONFIG_BLK_INLINE_ENCRYPTION */

enum blk_unique_id {
        /* these match the Designator Types specified in SPC */
        BLK_UID_T10     = 1,
        BLK_UID_EUI64   = 2,
        BLK_UID_NAA     = 3,
};

#define NFL4_UFLG_MASK                  0x0000003F

struct block_device_operations {
        void (*submit_bio)(struct bio *bio);
        int (*poll_bio)(struct bio *bio, struct io_comp_batch *iob,
                        unsigned int flags);
        int (*open) (struct block_device *, fmode_t);
        void (*release) (struct gendisk *, fmode_t);
        int (*rw_page)(struct block_device *, sector_t, struct page *, unsigned int);
        int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
        int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
        unsigned int (*check_events) (struct gendisk *disk,
                                      unsigned int clearing);
        void (*unlock_native_capacity) (struct gendisk *);
        int (*getgeo)(struct block_device *, struct hd_geometry *);
        int (*set_read_only)(struct block_device *bdev, bool ro);
        void (*free_disk)(struct gendisk *disk);
        /* this callback is with swap_lock and sometimes page table lock held */
        void (*swap_slot_free_notify) (struct block_device *, unsigned long);
        int (*report_zones)(struct gendisk *, sector_t sector,
                        unsigned int nr_zones, report_zones_cb cb, void *data);
        char *(*devnode)(struct gendisk *disk, umode_t *mode);
        /* returns the length of the identifier or a negative errno: */
        int (*get_unique_id)(struct gendisk *disk, u8 id[16],
                        enum blk_unique_id id_type);
        struct module *owner;
        const struct pr_ops *pr_ops;

        /*
         * Special callback for probing GPT entry at a given sector.
         * Needed by Android devices, used by GPT scanner and MMC blk
         * driver.
         */
        int (*alternative_gpt_sector)(struct gendisk *disk, sector_t *sector);
};

#ifdef CONFIG_COMPAT
extern int blkdev_compat_ptr_ioctl(struct block_device *, fmode_t,
                                      unsigned int, unsigned long);
#else
#define blkdev_compat_ptr_ioctl NULL
#endif

extern int bdev_read_page(struct block_device *, sector_t, struct page *);
extern int bdev_write_page(struct block_device *, sector_t, struct page *,
                                                struct writeback_control *);

static inline void blk_wake_io_task(struct task_struct *waiter)
{
        /*
         * If we're polling, the task itself is doing the completions. For
         * that case, we don't need to signal a wakeup, it's enough to just
         * mark us as RUNNING.
         */
        if (waiter == current)
                __set_current_state(TASK_RUNNING);
        else
                wake_up_process(waiter);
}

unsigned long bdev_start_io_acct(struct block_device *bdev,
                                 unsigned int sectors, unsigned int op,
                                 unsigned long start_time);
void bdev_end_io_acct(struct block_device *bdev, unsigned int op,
                unsigned long start_time);

void bio_start_io_acct_time(struct bio *bio, unsigned long start_time);
unsigned long bio_start_io_acct(struct bio *bio);
void bio_end_io_acct_remapped(struct bio *bio, unsigned long start_time,
                struct block_device *orig_bdev);

/**
 * bio_end_io_acct - end I/O accounting for bio based drivers
 * @bio:        bio to end account for
 * @start_time: start time returned by bio_start_io_acct()
 */
static inline void bio_end_io_acct(struct bio *bio, unsigned long start_time)
{
        return bio_end_io_acct_remapped(bio, start_time, bio->bi_bdev);
}

int bdev_read_only(struct block_device *bdev);
int set_blocksize(struct block_device *bdev, int size);

const char *bdevname(struct block_device *bdev, char *buffer);
int lookup_bdev(const char *pathname, dev_t *dev);

void blkdev_show(struct seq_file *seqf, off_t offset);

#define BDEVNAME_SIZE   32      /* Largest string for a blockdev identifier */
#define BDEVT_SIZE      10      /* Largest string for MAJ:MIN for blkdev */
#ifdef CONFIG_BLOCK
#define BLKDEV_MAJOR_MAX        512
#else
#define BLKDEV_MAJOR_MAX        0
#endif

struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
                void *holder);
struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder);
int bd_prepare_to_claim(struct block_device *bdev, void *holder);
void bd_abort_claiming(struct block_device *bdev, void *holder);
void blkdev_put(struct block_device *bdev, fmode_t mode);

/* just for blk-cgroup, don't use elsewhere */
struct block_device *blkdev_get_no_open(dev_t dev);
void blkdev_put_no_open(struct block_device *bdev);

struct block_device *bdev_alloc(struct gendisk *disk, u8 partno);
void bdev_add(struct block_device *bdev, dev_t dev);
struct block_device *I_BDEV(struct inode *inode);
int truncate_bdev_range(struct block_device *bdev, fmode_t mode, loff_t lstart,
                loff_t lend);

#ifdef CONFIG_BLOCK
void invalidate_bdev(struct block_device *bdev);
int sync_blockdev(struct block_device *bdev);
int sync_blockdev_range(struct block_device *bdev, loff_t lstart, loff_t lend);
int sync_blockdev_nowait(struct block_device *bdev);
void sync_bdevs(bool wait);
void printk_all_partitions(void);
#else
static inline void invalidate_bdev(struct block_device *bdev)
{
}
static inline int sync_blockdev(struct block_device *bdev)
{
        return 0;
}
static inline int sync_blockdev_nowait(struct block_device *bdev)
{
        return 0;
}
static inline void sync_bdevs(bool wait)
{
}
static inline void printk_all_partitions(void)
{
}
#endif /* CONFIG_BLOCK */

int fsync_bdev(struct block_device *bdev);

int freeze_bdev(struct block_device *bdev);
int thaw_bdev(struct block_device *bdev);

struct io_comp_batch {
        struct request *req_list;
        bool need_ts;
        void (*complete)(struct io_comp_batch *);
};

#define DEFINE_IO_COMP_BATCH(name)      struct io_comp_batch name = { }

#endif /* _LINUX_BLKDEV_H */