original development tree for Linux kernel GTP module; now long in mainline.
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#ifndef _LINUX_BLKDEV_H
#define _LINUX_BLKDEV_H
#include <linux/sched.h>
#ifdef CONFIG_BLOCK
#include <linux/major.h>
#include <linux/genhd.h>
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <linux/pagemap.h>
#include <linux/backing-dev.h>
#include <linux/wait.h>
#include <linux/mempool.h>
#include <linux/bio.h>
#include <linux/stringify.h>
#include <linux/gfp.h>
#include <linux/bsg.h>
#include <linux/smp.h>
#include <linux/rcupdate.h>
#include <asm/scatterlist.h>
struct module;
struct scsi_ioctl_command;
struct request_queue;
struct elevator_queue;
struct request_pm_state;
struct blk_trace;
struct request;
struct sg_io_hdr;
struct bsg_job;
struct blkcg_gq;
#define BLKDEV_MIN_RQ 4
#define BLKDEV_MAX_RQ 128 /* Default maximum */
/*
* Maximum number of blkcg policies allowed to be registered concurrently.
* Defined here to simplify include dependency.
*/
#define BLKCG_MAX_POLS 2
struct request;
typedef void (rq_end_io_fn)(struct request *, int);
#define BLK_RL_SYNCFULL (1U << 0)
#define BLK_RL_ASYNCFULL (1U << 1)
struct request_list {
struct request_queue *q; /* the queue this rl belongs to */
#ifdef CONFIG_BLK_CGROUP
struct blkcg_gq *blkg; /* blkg this request pool belongs to */
#endif
/*
* count[], starved[], and wait[] are indexed by
* BLK_RW_SYNC/BLK_RW_ASYNC
*/
int count[2];
int starved[2];
mempool_t *rq_pool;
wait_queue_head_t wait[2];
unsigned int flags;
};
/*
* request command types
*/
enum rq_cmd_type_bits {
REQ_TYPE_FS = 1, /* fs request */
REQ_TYPE_BLOCK_PC, /* scsi command */
REQ_TYPE_SENSE, /* sense request */
REQ_TYPE_PM_SUSPEND, /* suspend request */
REQ_TYPE_PM_RESUME, /* resume request */
REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
REQ_TYPE_SPECIAL, /* driver defined type */
/*
* for ATA/ATAPI devices. this really doesn't belong here, ide should
* use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
* private REQ_LB opcodes to differentiate what type of request this is
*/
REQ_TYPE_ATA_TASKFILE,
REQ_TYPE_ATA_PC,
};
#define BLK_MAX_CDB 16
/*
* try to put the fields that are referenced together in the same cacheline.
* if you modify this structure, be sure to check block/blk-core.c:blk_rq_init()
* as well!
*/
struct request {
struct list_head queuelist;
struct call_single_data csd;
struct request_queue *q;
unsigned int cmd_flags;
enum rq_cmd_type_bits cmd_type;
unsigned long atomic_flags;
int cpu;
/* the following two fields are internal, NEVER access directly */
unsigned int __data_len; /* total data len */
sector_t __sector; /* sector cursor */
struct bio *bio;
struct bio *biotail;
struct hlist_node hash; /* merge hash */
/*
* The rb_node is only used inside the io scheduler, requests
* are pruned when moved to the dispatch queue. So let the
* completion_data share space with the rb_node.
*/
union {
struct rb_node rb_node; /* sort/lookup */
void *completion_data;
};
/*
* Three pointers are available for the IO schedulers, if they need
* more they have to dynamically allocate it. Flush requests are
* never put on the IO scheduler. So let the flush fields share
* space with the elevator data.
*/
union {
struct {
struct io_cq *icq;
void *priv[2];
} elv;
struct {
unsigned int seq;
struct list_head list;
rq_end_io_fn *saved_end_io;
} flush;
};
struct gendisk *rq_disk;
struct hd_struct *part;
unsigned long start_time;
#ifdef CONFIG_BLK_CGROUP
struct request_list *rl; /* rl this rq is alloced from */
unsigned long long start_time_ns;
unsigned long long io_start_time_ns; /* when passed to hardware */
#endif
/* Number of scatter-gather DMA addr+len pairs after
* physical address coalescing is performed.
*/
unsigned short nr_phys_segments;
#if defined(CONFIG_BLK_DEV_INTEGRITY)
unsigned short nr_integrity_segments;
#endif
unsigned short ioprio;
int ref_count;
void *special; /* opaque pointer available for LLD use */
char *buffer; /* kaddr of the current segment if available */
int tag;
int errors;
/*
* when request is used as a packet command carrier
*/
unsigned char __cmd[BLK_MAX_CDB];
unsigned char *cmd;
unsigned short cmd_len;
unsigned int extra_len; /* length of alignment and padding */
unsigned int sense_len;
unsigned int resid_len; /* residual count */
void *sense;
unsigned long deadline;
struct list_head timeout_list;
unsigned int timeout;
int retries;
/*
* completion callback.
*/
rq_end_io_fn *end_io;
void *end_io_data;
/* for bidi */
struct request *next_rq;
};
static inline unsigned short req_get_ioprio(struct request *req)
{
return req->ioprio;
}
/*
* State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
* requests. Some step values could eventually be made generic.
*/
struct request_pm_state
{
/* PM state machine step value, currently driver specific */
int pm_step;
/* requested PM state value (S1, S2, S3, S4, ...) */
u32 pm_state;
void* data; /* for driver use */
};
#include <linux/elevator.h>
typedef void (request_fn_proc) (struct request_queue *q);
typedef void (make_request_fn) (struct request_queue *q, struct bio *bio);
typedef int (prep_rq_fn) (struct request_queue *, struct request *);
typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
struct bio_vec;
struct bvec_merge_data {
struct block_device *bi_bdev;
sector_t bi_sector;
unsigned bi_size;
unsigned long bi_rw;
};
typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
struct bio_vec *);
typedef void (softirq_done_fn)(struct request *);
typedef int (dma_drain_needed_fn)(struct request *);
typedef int (lld_busy_fn) (struct request_queue *q);
typedef int (bsg_job_fn) (struct bsg_job *);
enum blk_eh_timer_return {
BLK_EH_NOT_HANDLED,
BLK_EH_HANDLED,
BLK_EH_RESET_TIMER,
};
typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
enum blk_queue_state {
Queue_down,
Queue_up,
};
struct blk_queue_tag {
struct request **tag_index; /* map of busy tags */
unsigned long *tag_map; /* bit map of free/busy tags */
int busy; /* current depth */
int max_depth; /* what we will send to device */
int real_max_depth; /* what the array can hold */
atomic_t refcnt; /* map can be shared */
};
#define BLK_SCSI_MAX_CMDS (256)
#define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
struct queue_limits {
unsigned long bounce_pfn;
unsigned long seg_boundary_mask;
unsigned int max_hw_sectors;
unsigned int max_sectors;
unsigned int max_segment_size;
unsigned int physical_block_size;
unsigned int alignment_offset;
unsigned int io_min;
unsigned int io_opt;
unsigned int max_discard_sectors;
unsigned int max_write_same_sectors;
unsigned int discard_granularity;
unsigned int discard_alignment;
unsigned short logical_block_size;
unsigned short max_segments;
unsigned short max_integrity_segments;
unsigned char misaligned;
unsigned char discard_misaligned;
unsigned char cluster;
unsigned char discard_zeroes_data;
};
struct request_queue {
/*
* Together with queue_head for cacheline sharing
*/
struct list_head queue_head;
struct request *last_merge;
struct elevator_queue *elevator;
int nr_rqs[2]; /* # allocated [a]sync rqs */
int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */
/*
* If blkcg is not used, @q->root_rl serves all requests. If blkcg
* is used, root blkg allocates from @q->root_rl and all other
* blkgs from their own blkg->rl. Which one to use should be
* determined using bio_request_list().
*/
struct request_list root_rl;
request_fn_proc *request_fn;
make_request_fn *make_request_fn;
prep_rq_fn *prep_rq_fn;
unprep_rq_fn *unprep_rq_fn;
merge_bvec_fn *merge_bvec_fn;
softirq_done_fn *softirq_done_fn;
rq_timed_out_fn *rq_timed_out_fn;
dma_drain_needed_fn *dma_drain_needed;
lld_busy_fn *lld_busy_fn;
/*
* Dispatch queue sorting
*/
sector_t end_sector;
struct request *boundary_rq;
/*
* Delayed queue handling
*/
struct delayed_work delay_work;
struct backing_dev_info backing_dev_info;
/*
* 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;
/*
* ida allocated id for this queue. Used to index queues from
* ioctx.
*/
int id;
/*
* queue needs bounce pages for pages above this limit
*/
gfp_t bounce_gfp;
/*
* protects queue structures from reentrancy. ->__queue_lock should
* _never_ be used directly, it is queue private. always use
* ->queue_lock.
*/
spinlock_t __queue_lock;
spinlock_t *queue_lock;
/*
* queue kobject
*/
struct kobject kobj;
#ifdef CONFIG_PM_RUNTIME
struct device *dev;
int rpm_status;
unsigned int nr_pending;
#endif
/*
* queue settings
*/
unsigned long nr_requests; /* Max # of requests */
unsigned int nr_congestion_on;
unsigned int nr_congestion_off;
unsigned int nr_batching;
unsigned int dma_drain_size;
void *dma_drain_buffer;
unsigned int dma_pad_mask;
unsigned int dma_alignment;
struct blk_queue_tag *queue_tags;
struct list_head tag_busy_list;
unsigned int nr_sorted;
unsigned int in_flight[2];
/*
* Number of active block driver functions for which blk_drain_queue()
* must wait. Must be incremented around functions that unlock the
* queue_lock internally, e.g. scsi_request_fn().
*/
unsigned int request_fn_active;
unsigned int rq_timeout;
struct timer_list timeout;
struct list_head timeout_list;
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;
/*
* sg stuff
*/
unsigned int sg_timeout;
unsigned int sg_reserved_size;
int node;
#ifdef CONFIG_BLK_DEV_IO_TRACE
struct blk_trace *blk_trace;
#endif
/*
* for flush operations
*/
unsigned int flush_flags;
unsigned int flush_not_queueable:1;
unsigned int flush_queue_delayed:1;
unsigned int flush_pending_idx:1;
unsigned int flush_running_idx:1;
unsigned long flush_pending_since;
struct list_head flush_queue[2];
struct list_head flush_data_in_flight;
struct request flush_rq;
struct mutex sysfs_lock;
int bypass_depth;
#if defined(CONFIG_BLK_DEV_BSG)
bsg_job_fn *bsg_job_fn;
int bsg_job_size;
struct bsg_class_device bsg_dev;
#endif
#ifdef CONFIG_BLK_CGROUP
struct list_head all_q_node;
#endif
#ifdef CONFIG_BLK_DEV_THROTTLING
/* Throttle data */
struct throtl_data *td;
#endif
struct rcu_head rcu_head;
};
#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
#define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
#define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
#define QUEUE_FLAG_DYING 5 /* queue being torn down */
#define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */
#define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
#define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
#define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
#define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
#define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
#define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
#define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
#define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
#define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
#define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
#define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
#define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
#define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */
#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
(1 << QUEUE_FLAG_STACKABLE) | \
(1 << QUEUE_FLAG_SAME_COMP) | \
(1 << QUEUE_FLAG_ADD_RANDOM))
static inline void queue_lockdep_assert_held(struct request_queue *q)
{
if (q->queue_lock)
lockdep_assert_held(q->queue_lock);
}
static inline void queue_flag_set_unlocked(unsigned int flag,
struct request_queue *q)
{
__set_bit(flag, &q->queue_flags);
}
static inline int queue_flag_test_and_clear(unsigned int flag,
struct request_queue *q)
{
queue_lockdep_assert_held(q);
if (test_bit(flag, &q->queue_flags)) {
__clear_bit(flag, &q->queue_flags);
return 1;
}
return 0;
}
static inline int queue_flag_test_and_set(unsigned int flag,
struct request_queue *q)
{
queue_lockdep_assert_held(q);
if (!test_bit(flag, &q->queue_flags)) {
__set_bit(flag, &q->queue_flags);
return 0;
}
return 1;
}
static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
{
queue_lockdep_assert_held(q);
__set_bit(flag, &q->queue_flags);
}
static inline void queue_flag_clear_unlocked(unsigned int flag,
struct request_queue *q)
{
__clear_bit(flag, &q->queue_flags);
}
static inline int queue_in_flight(struct request_queue *q)
{
return q->in_flight[0] + q->in_flight[1];
}
static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
{
queue_lockdep_assert_held(q);
__clear_bit(flag, &q->queue_flags);
}
#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
#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_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
#define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(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_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_stackable(q) \
test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
#define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
#define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
#define blk_noretry_request(rq) \
((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
REQ_FAILFAST_DRIVER))
#define blk_account_rq(rq) \
(((rq)->cmd_flags & REQ_STARTED) && \
((rq)->cmd_type == REQ_TYPE_FS))
#define blk_pm_request(rq) \
((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
(rq)->cmd_type == REQ_TYPE_PM_RESUME)
#define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
/* rq->queuelist of dequeued request must be list_empty() */
#define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
#define rq_data_dir(rq) ((rq)->cmd_flags & 1)
static inline unsigned int blk_queue_cluster(struct request_queue *q)
{
return q->limits.cluster;
}
/*
* We regard a request as sync, if either a read or a sync write
*/
static inline bool rw_is_sync(unsigned int rw_flags)
{
return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
}
static inline bool rq_is_sync(struct request *rq)
{
return rw_is_sync(rq->cmd_flags);
}
static inline bool blk_rl_full(struct request_list *rl, bool sync)
{
unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
return rl->flags & flag;
}
static inline void blk_set_rl_full(struct request_list *rl, bool sync)
{
unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
rl->flags |= flag;
}
static inline void blk_clear_rl_full(struct request_list *rl, bool sync)
{
unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
rl->flags &= ~flag;
}
static inline bool rq_mergeable(struct request *rq)
{
if (rq->cmd_type != REQ_TYPE_FS)
return false;
if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
return false;
return true;
}
static inline bool blk_check_merge_flags(unsigned int flags1,
unsigned int flags2)
{
if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD))
return false;
if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE))
return false;
if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME))
return false;
return true;
}
static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
{
if (bio_data(a) == bio_data(b))
return true;
return false;
}
/*
* q->prep_rq_fn return values
*/
#define BLKPREP_OK 0 /* serve it */
#define BLKPREP_KILL 1 /* fatal error, kill */
#define BLKPREP_DEFER 2 /* leave on queue */
extern unsigned long blk_max_low_pfn, blk_max_pfn;
/*
* standard bounce addresses:
*
* BLK_BOUNCE_HIGH : bounce all highmem pages
* BLK_BOUNCE_ANY : don't bounce anything
* BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
*/
#if BITS_PER_LONG == 32
#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
#else
#define BLK_BOUNCE_HIGH -1ULL
#endif
#define BLK_BOUNCE_ANY (-1ULL)
#define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
/*
* default timeout for SG_IO if none specified
*/
#define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
#define BLK_MIN_SG_TIMEOUT (7 * HZ)
#ifdef CONFIG_BOUNCE
extern int init_emergency_isa_pool(void);
extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
#else
static inline int init_emergency_isa_pool(void)
{
return 0;
}
static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
{
}
#endif /* CONFIG_MMU */
struct rq_map_data {
struct page **pages;
int page_order;
int nr_entries;
unsigned long offset;
int null_mapped;
int from_user;
};
struct req_iterator {
int i;
struct bio *bio;
};
/* This should not be used directly - use rq_for_each_segment */
#define for_each_bio(_bio) \
for (; _bio; _bio = _bio->bi_next)
#define __rq_for_each_bio(_bio, rq) \
if ((rq->bio)) \
for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
#define rq_for_each_segment(bvl, _rq, _iter) \
__rq_for_each_bio(_iter.bio, _rq) \
bio_for_each_segment(bvl, _iter.bio, _iter.i)
#define rq_iter_last(rq, _iter) \
(_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
#endif
#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
extern void rq_flush_dcache_pages(struct request *rq);
#else
static inline void rq_flush_dcache_pages(struct request *rq)
{
}
#endif
extern int blk_register_queue(struct gendisk *disk);
extern void blk_unregister_queue(struct gendisk *disk);
extern void generic_make_request(struct bio *bio);
extern void blk_rq_init(struct request_queue *q, struct request *rq);
extern void blk_put_request(struct request *);
extern void __blk_put_request(struct request_queue *, struct request *);
extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
extern struct request *blk_make_request(struct request_queue *, struct bio *,
gfp_t);
extern void blk_requeue_request(struct request_queue *, struct request *);
extern void blk_add_request_payload(struct request *rq, struct page *page,
unsigned int len);
extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
extern int blk_lld_busy(struct request_queue *q);
extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
struct bio_set *bs, gfp_t gfp_mask,
int (*bio_ctr)(struct bio *, struct bio *, void *),
void *data);
extern void blk_rq_unprep_clone(struct request *rq);
extern int blk_insert_cloned_request(struct request_queue *q,
struct request *rq);
extern void blk_delay_queue(struct request_queue *, unsigned long);
extern void blk_recount_segments(struct request_queue *, struct bio *);
extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
unsigned int, void __user *);
extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
unsigned int, void __user *);
extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
struct scsi_ioctl_command __user *);
extern void blk_queue_bio(struct request_queue *q, struct bio *bio);
/*
* A queue has just exitted congestion. Note this in the global counter of
* congested queues, and wake up anyone who was waiting for requests to be
* put back.
*/
static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
{
clear_bdi_congested(&q->backing_dev_info, sync);
}
/*
* A queue has just entered congestion. Flag that in the queue's VM-visible
* state flags and increment the global gounter of congested queues.
*/
static inline void blk_set_queue_congested(struct request_queue *q, int sync)
{
set_bdi_congested(&q->backing_dev_info, sync);
}
extern void blk_start_queue(struct request_queue *q);
extern void blk_stop_queue(struct request_queue *q);
extern void blk_sync_queue(struct request_queue *q);
extern void __blk_stop_queue(struct request_queue *q);
extern void __blk_run_queue(struct request_queue *q);
extern void blk_run_queue(struct request_queue *);
extern void blk_run_queue_async(struct request_queue *q);
extern int blk_rq_map_user(struct request_queue *, struct request *,
struct rq_map_data *, void __user *, unsigned long,
gfp_t);
extern int blk_rq_unmap_user(struct bio *);
extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
struct rq_map_data *, struct sg_iovec *, int,
unsigned int, gfp_t);
extern int blk_execute_rq(struct request_queue *, struct gendisk *,
struct request *, int);
extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
struct request *, int, rq_end_io_fn *);
static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
{
return bdev->bd_disk->queue;
}
/*
* blk_rq_pos() : the current sector
* blk_rq_bytes() : bytes left in the entire request
* blk_rq_cur_bytes() : bytes left in the current segment
* blk_rq_err_bytes() : bytes left till the next error boundary
* blk_rq_sectors() : sectors left in the entire request
* blk_rq_cur_sectors() : sectors left in the current segment
*/
static inline sector_t blk_rq_pos(const struct request *rq)
{
return rq->__sector;
}
static inline unsigned int blk_rq_bytes(const struct request *rq)
{
return rq->__data_len;
}
static inline int blk_rq_cur_bytes(const struct request *rq)
{
return rq->bio ? bio_cur_bytes(rq->bio) : 0;
}
extern unsigned int blk_rq_err_bytes(const struct request *rq);
static inline unsigned int blk_rq_sectors(const struct request *rq)
{
return blk_rq_bytes(rq) >> 9;
}
static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
{
return blk_rq_cur_bytes(rq) >> 9;
}
static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
unsigned int cmd_flags)
{
if (unlikely(cmd_flags & REQ_DISCARD))
return min(q->limits.max_discard_sectors, UINT_MAX >> 9);
if (unlikely(cmd_flags & REQ_WRITE_SAME))
return q->limits.max_write_same_sectors;
return q->limits.max_sectors;
}
static inline unsigned int blk_rq_get_max_sectors(struct request *rq)
{
struct request_queue *q = rq->q;
if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC))
return q->limits.max_hw_sectors;
return blk_queue_get_max_sectors(q, rq->cmd_flags);
}
static inline unsigned int blk_rq_count_bios(struct request *rq)
{
unsigned int nr_bios = 0;
struct bio *bio;
__rq_for_each_bio(bio, rq)
nr_bios++;
return nr_bios;
}
/*
* Request issue related functions.
*/
extern struct request *blk_peek_request(struct request_queue *q);
extern void blk_start_request(struct request *rq);
extern struct request *blk_fetch_request(struct request_queue *q);
/*
* Request completion related functions.
*
* blk_update_request() completes given number of bytes and updates
* the request without completing it.
*
* blk_end_request() and friends. __blk_end_request() must be called
* with the request queue spinlock acquired.
*
* Several drivers define their own end_request and call
* blk_end_request() for parts of the original function.
* This prevents code duplication in drivers.
*/
extern bool blk_update_request(struct request *rq, int error,
unsigned int nr_bytes);
extern bool blk_end_request(struct request *rq, int error,
unsigned int nr_bytes);
extern void blk_end_request_all(struct request *rq, int error);
extern bool blk_end_request_cur(struct request *rq, int error);
extern bool blk_end_request_err(struct request *rq, int error);
extern bool __blk_end_request(struct request *rq, int error,
unsigned int nr_bytes);
extern void __blk_end_request_all(struct request *rq, int error);
extern bool __blk_end_request_cur(struct request *rq, int error);
extern bool __blk_end_request_err(struct request *rq, int error);
extern void blk_complete_request(struct request *);
extern void __blk_complete_request(struct request *);
extern void blk_abort_request(struct request *);
extern void blk_unprep_request(struct request *);
/*
* Access functions for manipulating queue properties
*/
extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
spinlock_t *lock, int node_id);
extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
request_fn_proc *, spinlock_t *);
extern void blk_cleanup_queue(struct request_queue *);
extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
extern void blk_queue_bounce_limit(struct request_queue *, u64);
extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
extern void blk_queue_max_segments(struct request_queue *, unsigned short);
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_same_sectors(struct request_queue *q,
unsigned int max_write_same_sectors);
extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
extern void blk_queue_alignment_offset(struct request_queue *q,
unsigned int alignment);
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_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 int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
sector_t offset);
extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
sector_t offset);
extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
extern int blk_queue_dma_drain(struct request_queue *q,
dma_drain_needed_fn *dma_drain_needed,
void *buf, unsigned int size);
extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
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_softirq_done(struct request_queue *, softirq_done_fn *);
extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
extern int blk_bio_map_sg(struct request_queue *q, struct bio *bio,
struct scatterlist *sglist);
extern void blk_dump_rq_flags(struct request *, char *);
extern long nr_blockdev_pages(void);
bool __must_check blk_get_queue(struct request_queue *);
struct request_queue *blk_alloc_queue(gfp_t);
struct request_queue *blk_alloc_queue_node(gfp_t, int);
extern void blk_put_queue(struct request_queue *);
/*
* block layer runtime pm functions
*/
#ifdef CONFIG_PM_RUNTIME
extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev);
extern int blk_pre_runtime_suspend(struct request_queue *q);
extern void blk_post_runtime_suspend(struct request_queue *q, int err);
extern void blk_pre_runtime_resume(struct request_queue *q);
extern void blk_post_runtime_resume(struct request_queue *q, int err);
#else
static inline void blk_pm_runtime_init(struct request_queue *q,
struct device *dev) {}
static inline int blk_pre_runtime_suspend(struct request_queue *q)
{
return -ENOSYS;
}
static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {}
static inline void blk_pre_runtime_resume(struct request_queue *q) {}
static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
#endif
/*
* 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, because blk_schedule_flush_list() will only flush
* the plug list when the task sleeps by itself. For details, please see
* schedule() where blk_schedule_flush_plug() is called.
*/
struct blk_plug {
unsigned long magic; /* detect uninitialized use-cases */
struct list_head list; /* requests */
struct list_head cb_list; /* md requires an unplug callback */
};
#define BLK_MAX_REQUEST_COUNT 16
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_finish_plug(struct blk_plug *);
extern void blk_flush_plug_list(struct blk_plug *, bool);
static inline void blk_flush_plug(struct task_struct *tsk)
{
struct blk_plug *plug = tsk->plug;
if (plug)
blk_flush_plug_list(plug, false);
}
static inline void blk_schedule_flush_plug(struct task_struct *tsk)
{
struct blk_plug *plug = tsk->plug;
if (plug)
blk_flush_plug_list(plug, true);
}
static inline bool blk_needs_flush_plug(struct task_struct *tsk)
{
struct blk_plug *plug = tsk->plug;
return plug && (!list_empty(&plug->list) || !list_empty(&plug->cb_list));
}
/*
* tag stuff
*/
#define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
extern int blk_queue_start_tag(struct request_queue *, struct request *);
extern struct request *blk_queue_find_tag(struct request_queue *, int);
extern void blk_queue_end_tag(struct request_queue *, struct request *);
extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
extern void blk_queue_free_tags(struct request_queue *);
extern int blk_queue_resize_tags(struct request_queue *, int);
extern void blk_queue_invalidate_tags(struct request_queue *);
extern struct blk_queue_tag *blk_init_tags(int);
extern void blk_free_tags(struct blk_queue_tag *);
static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
int tag)
{
if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
return NULL;
return bqt->tag_index[tag];
}
#define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask, struct page *page);
extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask);
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 - 9),
nr_blocks << (sb->s_blocksize_bits - 9),
gfp_mask, flags);
}
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 - 9),
nr_blocks << (sb->s_blocksize_bits - 9),
gfp_mask);
}
extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
enum blk_default_limits {
BLK_MAX_SEGMENTS = 128,
BLK_SAFE_MAX_SECTORS = 255,
BLK_DEF_MAX_SECTORS = 1024,
BLK_MAX_SEGMENT_SIZE = 65536,
BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
};
#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
static inline unsigned long queue_bounce_pfn(struct request_queue *q)
{
return q->limits.bounce_pfn;
}
static inline unsigned long queue_segment_boundary(struct request_queue *q)
{
return q->limits.seg_boundary_mask;
}
static inline unsigned int queue_max_sectors(struct request_queue *q)
{
return q->limits.max_sectors;
}
static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
{
return q->limits.max_hw_sectors;
}
static inline unsigned short queue_max_segments(struct request_queue *q)
{
return q->limits.max_segments;
}
static inline unsigned int queue_max_segment_size(struct request_queue *q)
{
return q->limits.max_segment_size;
}
static inline unsigned short queue_logical_block_size(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 short 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(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(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(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 int queue_alignment_offset(struct request_queue *q)
{
if (q->limits.misaligned)
return -1;
return q->limits.alignment_offset;
}
static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
{
unsigned int granularity = max(lim->physical_block_size, lim->io_min);
unsigned int alignment = (sector << 9) & (granularity - 1);
return (granularity + lim->alignment_offset - alignment)
& (granularity - 1);
}
static inline int bdev_alignment_offset(struct block_device *bdev)
{
struct request_queue *q = bdev_get_queue(bdev);
if (q->limits.misaligned)
return -1;
if (bdev != bdev->bd_contains)
return bdev->bd_part->alignment_offset;
return q->limits.alignment_offset;
}
static inline int queue_discard_alignment(struct request_queue *q)
{
if (q->limits.discard_misaligned)
return -1;
return q->limits.discard_alignment;
}
static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
{
unsigned int alignment, granularity, offset;
if (!lim->max_discard_sectors)
return 0;
/* Why are these in bytes, not sectors? */
alignment = lim->discard_alignment >> 9;
granularity = lim->discard_granularity >> 9;
if (!granularity)
return 0;
/* Offset of the partition start in 'granularity' sectors */
offset = sector_div(sector, granularity);
/* And why do we do this modulus *again* in blkdev_issue_discard()? */
offset = (granularity + alignment - offset) % granularity;
/* Turn it back into bytes, gaah */
return offset << 9;
}
static inline int bdev_discard_alignment(struct block_device *bdev)
{
struct request_queue *q = bdev_get_queue(bdev);
if (bdev != bdev->bd_contains)
return bdev->bd_part->discard_alignment;
return q->limits.discard_alignment;
}
static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
{
if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
return 1;
return 0;
}
static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
{
return queue_discard_zeroes_data(bdev_get_queue(bdev));
}
static inline unsigned int bdev_write_same(struct block_device *bdev)
{
struct request_queue *q = bdev_get_queue(bdev);
if (q)
return q->limits.max_write_same_sectors;
return 0;
}
static inline int queue_dma_alignment(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 bdev->bd_block_size;
}
static inline bool queue_flush_queueable(struct request_queue *q)
{
return !q->flush_not_queueable;
}
typedef struct {struct page *v;} Sector;
unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
static inline void put_dev_sector(Sector p)
{
page_cache_release(p.v);
}
struct work_struct;
int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
#ifdef CONFIG_BLK_CGROUP
/*
* This should not be using sched_clock(). A real patch is in progress
* to fix this up, until that is in place we need to disable preemption
* around sched_clock() in this function and set_io_start_time_ns().
*/
static inline void set_start_time_ns(struct request *req)
{
preempt_disable();
req->start_time_ns = sched_clock();
preempt_enable();
}
static inline void set_io_start_time_ns(struct request *req)
{
preempt_disable();
req->io_start_time_ns = sched_clock();
preempt_enable();
}
static inline uint64_t rq_start_time_ns(struct request *req)
{
return req->start_time_ns;
}
static inline uint64_t rq_io_start_time_ns(struct request *req)
{
return req->io_start_time_ns;
}
#else
static inline void set_start_time_ns(struct request *req) {}
static inline void set_io_start_time_ns(struct request *req) {}
static inline uint64_t rq_start_time_ns(struct request *req)
{
return 0;
}
static inline uint64_t rq_io_start_time_ns(struct request *req)
{
return 0;
}
#endif
#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) "-*")
#if defined(CONFIG_BLK_DEV_INTEGRITY)
#define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
#define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
struct blk_integrity_exchg {
void *prot_buf;
void *data_buf;
sector_t sector;
unsigned int data_size;
unsigned short sector_size;
const char *disk_name;
};
typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
struct blk_integrity {
integrity_gen_fn *generate_fn;
integrity_vrfy_fn *verify_fn;
integrity_set_tag_fn *set_tag_fn;
integrity_get_tag_fn *get_tag_fn;
unsigned short flags;
unsigned short tuple_size;
unsigned short sector_size;
unsigned short tag_size;
const char *name;
struct kobject kobj;
};
extern bool blk_integrity_is_initialized(struct gendisk *);
extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
extern void blk_integrity_unregister(struct gendisk *);
extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
struct scatterlist *);
extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
struct request *);
extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
struct bio *);
static inline
struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
{
return bdev->bd_disk->integrity;
}
static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
{
return disk->integrity;
}
static inline int blk_integrity_rq(struct request *rq)
{
if (rq->bio == NULL)
return 0;
return bio_integrity(rq->bio);
}
static inline void blk_queue_max_integrity_segments(struct request_queue *q,
unsigned int segs)
{
q->limits.max_integrity_segments = segs;
}
static inline unsigned short
queue_max_integrity_segments(struct request_queue *q)
{
return q->limits.max_integrity_segments;
}
#else /* CONFIG_BLK_DEV_INTEGRITY */
struct bio;
struct block_device;
struct gendisk;
struct blk_integrity;
static inline int blk_integrity_rq(struct request *rq)
{
return 0;
}
static inline int blk_rq_count_integrity_sg(struct request_queue *q,
struct bio *b)
{
return 0;
}
static inline int blk_rq_map_integrity_sg(struct request_queue *q,
struct bio *b,
struct scatterlist *s)
{
return 0;
}
static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
{
return 0;
}
static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
{
return NULL;
}
static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
{
return 0;
}
static inline int blk_integrity_register(struct gendisk *d,
struct blk_integrity *b)
{
return 0;
}
static inline void blk_integrity_unregister(struct gendisk *d)
{
}
static inline void blk_queue_max_integrity_segments(struct request_queue *q,
unsigned int segs)
{
}
static inline unsigned short queue_max_integrity_segments(struct request_queue *q)
{
return 0;
}
static inline int blk_integrity_merge_rq(struct request_queue *rq,
struct request *r1,
struct request *r2)
{
return 0;
}
static inline int blk_integrity_merge_bio(struct request_queue *rq,
struct request *r,
struct bio *b)
{
return 0;
}
static inline bool blk_integrity_is_initialized(struct gendisk *g)
{
return 0;
}
#endif /* CONFIG_BLK_DEV_INTEGRITY */
struct block_device_operations {
int (*open) (struct block_device *, fmode_t);
void (*release) (struct gendisk *, fmode_t);
int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
int (*direct_access) (struct block_device *, sector_t,
void **, unsigned long *);
unsigned int (*check_events) (struct gendisk *disk,
unsigned int clearing);
/* ->media_changed() is DEPRECATED, use ->check_events() instead */
int (*media_changed) (struct gendisk *);
void (*unlock_native_capacity) (struct gendisk *);
int (*revalidate_disk) (struct gendisk *);
int (*getgeo)(struct block_device *, struct hd_geometry *);
/* this callback is with swap_lock and sometimes page table lock held */
void (*swap_slot_free_notify) (struct block_device *, unsigned long);
struct module *owner;
};
extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
unsigned long);
#else /* CONFIG_BLOCK */
/*
* stubs for when the block layer is configured out
*/
#define buffer_heads_over_limit 0
static inline long nr_blockdev_pages(void)
{
return 0;
}
struct blk_plug {
};
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 task_struct *task)
{
}
static inline void blk_schedule_flush_plug(struct task_struct *task)
{
}
static inline bool blk_needs_flush_plug(struct task_struct *tsk)
{
return false;
}
#endif /* CONFIG_BLOCK */
#endif