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6b00769fe1
linux-next/include/linux/blkdev.h
Tejun Heo 6b00769fe1 block: add request->raw_data_len 
With padding and draining moved into it, block layer now may extend
requests as directed by queue parameters, so now a request has two
sizes - the original request size and the extended size which matches
the size of area pointed to by bios and later by sgs.  The latter size
is what lower layers are primarily interested in when allocating,
filling up DMA tables and setting up the controller.

Both padding and draining extend the data area to accomodate
controller characteristics.  As any controller which speaks SCSI can
handle underflows, feeding larger data area is safe.

So, this patch makes the primary data length field, request->data_len,
indicate the size of full data area and add a separate length field,
request->raw_data_len, for the unmodified request size.  The latter is
used to report to higher layer (userland) and where the original
request size should be fed to the controller or device.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-02-19 11:36:35 +01:00

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#ifndef _LINUX_BLKDEV_H
#define _LINUX_BLKDEV_H
#ifdef CONFIG_BLOCK
#include <linux/sched.h>
#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/module.h>
#include <linux/stringify.h>
#include <linux/bsg.h>
#include <asm/scatterlist.h>
struct scsi_ioctl_command;
struct request_queue;
typedef struct request_queue request_queue_t __deprecated;
struct elevator_queue;
typedef struct elevator_queue elevator_t;
struct request_pm_state;
struct blk_trace;
struct request;
struct sg_io_hdr;
#define BLKDEV_MIN_RQ 4
#define BLKDEV_MAX_RQ 128 /* Default maximum */
int put_io_context(struct io_context *ioc);
void exit_io_context(void);
struct io_context *get_io_context(gfp_t gfp_flags, int node);
struct io_context *alloc_io_context(gfp_t gfp_flags, int node);
void copy_io_context(struct io_context **pdst, struct io_context **psrc);
struct request;
typedef void (rq_end_io_fn)(struct request *, int);
struct request_list {
int count[2];
int starved[2];
int elvpriv;
mempool_t *rq_pool;
wait_queue_head_t wait[2];
};
/*
* 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_FLUSH, /* flush request */
REQ_TYPE_SPECIAL, /* driver defined type */
REQ_TYPE_LINUX_BLOCK, /* generic block layer message */
/*
* 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,
};
/*
* For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
* sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
* SCSI cdb.
*
* 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
* typically to differentiate REQ_TYPE_SPECIAL requests.
*
*/
enum {
/*
* just examples for now
*/
REQ_LB_OP_EJECT = 0x40, /* eject request */
REQ_LB_OP_FLUSH = 0x41, /* flush device */
};
/*
* request type modified bits. first three bits match BIO_RW* bits, important
*/
enum rq_flag_bits {
__REQ_RW, /* not set, read. set, write */
__REQ_FAILFAST, /* no low level driver retries */
__REQ_SORTED, /* elevator knows about this request */
__REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
__REQ_HARDBARRIER, /* may not be passed by drive either */
__REQ_FUA, /* forced unit access */
__REQ_NOMERGE, /* don't touch this for merging */
__REQ_STARTED, /* drive already may have started this one */
__REQ_DONTPREP, /* don't call prep for this one */
__REQ_QUEUED, /* uses queueing */
__REQ_ELVPRIV, /* elevator private data attached */
__REQ_FAILED, /* set if the request failed */
__REQ_QUIET, /* don't worry about errors */
__REQ_PREEMPT, /* set for "ide_preempt" requests */
__REQ_ORDERED_COLOR, /* is before or after barrier */
__REQ_RW_SYNC, /* request is sync (O_DIRECT) */
__REQ_ALLOCED, /* request came from our alloc pool */
__REQ_RW_META, /* metadata io request */
__REQ_NR_BITS, /* stops here */
};
#define REQ_RW (1 << __REQ_RW)
#define REQ_FAILFAST (1 << __REQ_FAILFAST)
#define REQ_SORTED (1 << __REQ_SORTED)
#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
#define REQ_FUA (1 << __REQ_FUA)
#define REQ_NOMERGE (1 << __REQ_NOMERGE)
#define REQ_STARTED (1 << __REQ_STARTED)
#define REQ_DONTPREP (1 << __REQ_DONTPREP)
#define REQ_QUEUED (1 << __REQ_QUEUED)
#define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
#define REQ_FAILED (1 << __REQ_FAILED)
#define REQ_QUIET (1 << __REQ_QUIET)
#define REQ_PREEMPT (1 << __REQ_PREEMPT)
#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
#define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
#define REQ_ALLOCED (1 << __REQ_ALLOCED)
#define REQ_RW_META (1 << __REQ_RW_META)
#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:rq_init()
* as well!
*/
struct request {
struct list_head queuelist;
struct list_head donelist;
struct request_queue *q;
unsigned int cmd_flags;
enum rq_cmd_type_bits cmd_type;
/* Maintain bio traversal state for part by part I/O submission.
* hard_* are block layer internals, no driver should touch them!
*/
sector_t sector; /* next sector to submit */
sector_t hard_sector; /* next sector to complete */
unsigned long nr_sectors; /* no. of sectors left to submit */
unsigned long hard_nr_sectors; /* no. of sectors left to complete */
/* no. of sectors left to submit in the current segment */
unsigned int current_nr_sectors;
/* no. of sectors left to complete in the current segment */
unsigned int hard_cur_sectors;
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;
};
/*
* two pointers are available for the IO schedulers, if they need
* more they have to dynamically allocate it.
*/
void *elevator_private;
void *elevator_private2;
struct gendisk *rq_disk;
unsigned long start_time;
/* Number of scatter-gather DMA addr+len pairs after
* physical address coalescing is performed.
*/
unsigned short nr_phys_segments;
/* Number of scatter-gather addr+len pairs after
* physical and DMA remapping hardware coalescing is performed.
* This is the number of scatter-gather entries the driver
* will actually have to deal with after DMA mapping is done.
*/
unsigned short nr_hw_segments;
unsigned short ioprio;
void *special;
char *buffer;
int tag;
int errors;
int ref_count;
/*
* when request is used as a packet command carrier
*/
unsigned int cmd_len;
unsigned char cmd[BLK_MAX_CDB];
unsigned int raw_data_len;
unsigned int data_len;
unsigned int sense_len;
void *data;
void *sense;
unsigned int timeout;
int retries;
/*
* completion callback.
*/
rq_end_io_fn *end_io;
void *end_io_data;
/* for bidi */
struct request *next_rq;
};
/*
* 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 int (make_request_fn) (struct request_queue *q, struct bio *bio);
typedef int (prep_rq_fn) (struct request_queue *, struct request *);
typedef void (unplug_fn) (struct request_queue *);
struct bio_vec;
typedef int (merge_bvec_fn) (struct request_queue *, struct bio *, struct bio_vec *);
typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
typedef void (softirq_done_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 */
};
struct request_queue
{
/*
* Together with queue_head for cacheline sharing
*/
struct list_head queue_head;
struct request *last_merge;
elevator_t *elevator;
/*
* the queue request freelist, one for reads and one for writes
*/
struct request_list rq;
request_fn_proc *request_fn;
make_request_fn *make_request_fn;
prep_rq_fn *prep_rq_fn;
unplug_fn *unplug_fn;
merge_bvec_fn *merge_bvec_fn;
prepare_flush_fn *prepare_flush_fn;
softirq_done_fn *softirq_done_fn;
/*
* Dispatch queue sorting
*/
sector_t end_sector;
struct request *boundary_rq;
/*
* Auto-unplugging state
*/
struct timer_list unplug_timer;
int unplug_thresh; /* After this many requests */
unsigned long unplug_delay; /* After this many jiffies */
struct work_struct unplug_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;
/*
* queue needs bounce pages for pages above this limit
*/
unsigned long bounce_pfn;
gfp_t bounce_gfp;
/*
* various queue flags, see QUEUE_* below
*/
unsigned long queue_flags;
/*
* 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;
/*
* 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 max_sectors;
unsigned int max_hw_sectors;
unsigned short max_phys_segments;
unsigned short max_hw_segments;
unsigned short hardsect_size;
unsigned int max_segment_size;
unsigned long seg_boundary_mask;
void *dma_drain_buffer;
unsigned int dma_drain_size;
unsigned int dma_alignment;
struct blk_queue_tag *queue_tags;
struct list_head tag_busy_list;
unsigned int nr_sorted;
unsigned int in_flight;
/*
* 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
/*
* reserved for flush operations
*/
unsigned int ordered, next_ordered, ordseq;
int orderr, ordcolor;
struct request pre_flush_rq, bar_rq, post_flush_rq;
struct request *orig_bar_rq;
struct mutex sysfs_lock;
#if defined(CONFIG_BLK_DEV_BSG)
struct bsg_class_device bsg_dev;
#endif
};
#define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
#define QUEUE_FLAG_READFULL 3 /* read queue has been filled */
#define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */
#define QUEUE_FLAG_DEAD 5 /* queue being torn down */
#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
#define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
#define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
enum {
/*
* Hardbarrier is supported with one of the following methods.
*
* NONE : hardbarrier unsupported
* DRAIN : ordering by draining is enough
* DRAIN_FLUSH : ordering by draining w/ pre and post flushes
* DRAIN_FUA : ordering by draining w/ pre flush and FUA write
* TAG : ordering by tag is enough
* TAG_FLUSH : ordering by tag w/ pre and post flushes
* TAG_FUA : ordering by tag w/ pre flush and FUA write
*/
QUEUE_ORDERED_NONE = 0x00,
QUEUE_ORDERED_DRAIN = 0x01,
QUEUE_ORDERED_TAG = 0x02,
QUEUE_ORDERED_PREFLUSH = 0x10,
QUEUE_ORDERED_POSTFLUSH = 0x20,
QUEUE_ORDERED_FUA = 0x40,
QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
/*
* Ordered operation sequence
*/
QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
QUEUE_ORDSEQ_DONE = 0x20,
};
#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(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_flushing(q) ((q)->ordseq)
#define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
#define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
#define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
#define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
#define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST)
#define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
#define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq))
#define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
#define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
#define blk_pm_request(rq) \
(blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
#define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
#define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
#define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
#define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors)
/* 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)
/*
* We regard a request as sync, if it's a READ or a SYNC write.
*/
#define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC)
#define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
static inline int blk_queue_full(struct request_queue *q, int rw)
{
if (rw == READ)
return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
}
static inline void blk_set_queue_full(struct request_queue *q, int rw)
{
if (rw == READ)
set_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
else
set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
}
static inline void blk_clear_queue_full(struct request_queue *q, int rw)
{
if (rw == READ)
clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
else
clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
}
/*
* mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
* it already be started by driver.
*/
#define RQ_NOMERGE_FLAGS \
(REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
#define rq_mergeable(rq) \
(!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq)))
/*
* 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
*/
#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
#define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT)
#define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
/*
* default timeout for SG_IO if none specified
*/
#define BLK_DEFAULT_SG_TIMEOUT (60 * 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 req_iterator {
int i;
struct bio *bio;
};
/* This should not be used directly - use rq_for_each_segment */
#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)
extern int blk_register_queue(struct gendisk *disk);
extern void blk_unregister_queue(struct gendisk *disk);
extern void register_disk(struct gendisk *dev);
extern void generic_make_request(struct bio *bio);
extern void blk_put_request(struct request *);
extern void __blk_put_request(struct request_queue *, struct request *);
extern void blk_end_sync_rq(struct request *rq, int error);
extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
extern void blk_requeue_request(struct request_queue *, struct request *);
extern void blk_plug_device(struct request_queue *);
extern int blk_remove_plug(struct request_queue *);
extern void blk_recount_segments(struct request_queue *, struct bio *);
extern int scsi_cmd_ioctl(struct file *, struct request_queue *,
struct gendisk *, unsigned int, void __user *);
extern int sg_scsi_ioctl(struct file *, struct request_queue *,
struct gendisk *, struct scsi_ioctl_command __user *);
/*
* Temporary export, until SCSI gets fixed up.
*/
extern int blk_rq_append_bio(struct request_queue *q, struct request *rq,
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 rw)
{
clear_bdi_congested(&q->backing_dev_info, rw);
}
/*
* 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 rw)
{
set_bdi_congested(&q->backing_dev_info, rw);
}
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 *);
extern void blk_start_queueing(struct request_queue *);
extern int blk_rq_map_user(struct request_queue *, struct request *, void __user *, unsigned long);
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 sg_iovec *, int, unsigned int);
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 *);
extern int blk_verify_command(unsigned char *, int);
extern void blk_unplug(struct request_queue *q);
static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
{
return bdev->bd_disk->queue;
}
static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
struct page *page)
{
if (bdi && bdi->unplug_io_fn)
bdi->unplug_io_fn(bdi, page);
}
static inline void blk_run_address_space(struct address_space *mapping)
{
if (mapping)
blk_run_backing_dev(mapping->backing_dev_info, NULL);
}
/*
* blk_end_request() and friends.
* __blk_end_request() and 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 int blk_end_request(struct request *rq, int error,
unsigned int nr_bytes);
extern int __blk_end_request(struct request *rq, int error,
unsigned int nr_bytes);
extern int blk_end_bidi_request(struct request *rq, int error,
unsigned int nr_bytes, unsigned int bidi_bytes);
extern void end_request(struct request *, int);
extern void end_queued_request(struct request *, int);
extern void end_dequeued_request(struct request *, int);
extern int blk_end_request_callback(struct request *rq, int error,
unsigned int nr_bytes,
int (drv_callback)(struct request *));
extern void blk_complete_request(struct request *);
/*
* blk_end_request() takes bytes instead of sectors as a complete size.
* blk_rq_bytes() returns bytes left to complete in the entire request.
* blk_rq_cur_bytes() returns bytes left to complete in the current segment.
*/
extern unsigned int blk_rq_bytes(struct request *rq);
extern unsigned int blk_rq_cur_bytes(struct request *rq);
static inline void blkdev_dequeue_request(struct request *req)
{
elv_dequeue_request(req->q, req);
}
/*
* 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 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_queue_max_sectors(struct request_queue *, unsigned int);
extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short);
extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short);
extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
extern void blk_queue_hardsect_size(struct request_queue *, unsigned short);
extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
extern int blk_queue_dma_drain(struct request_queue *q, void *buf,
unsigned int size);
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_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 struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
extern int blk_do_ordered(struct request_queue *, struct request **);
extern unsigned blk_ordered_cur_seq(struct request_queue *);
extern unsigned blk_ordered_req_seq(struct request *);
extern void blk_ordered_complete_seq(struct request_queue *, unsigned, int);
extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
extern void blk_dump_rq_flags(struct request *, char *);
extern void generic_unplug_device(struct request_queue *);
extern void __generic_unplug_device(struct request_queue *);
extern long nr_blockdev_pages(void);
int 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 *);
/*
* tag stuff
*/
#define blk_queue_tag_depth(q) ((q)->queue_tags->busy)
#define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth)
#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];
}
extern int blkdev_issue_flush(struct block_device *, sector_t *);
#define MAX_PHYS_SEGMENTS 128
#define MAX_HW_SEGMENTS 128
#define SAFE_MAX_SECTORS 255
#define BLK_DEF_MAX_SECTORS 1024
#define MAX_SEGMENT_SIZE 65536
#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
static inline int queue_hardsect_size(struct request_queue *q)
{
int retval = 512;
if (q && q->hardsect_size)
retval = q->hardsect_size;
return retval;
}
static inline int bdev_hardsect_size(struct block_device *bdev)
{
return queue_hardsect_size(bdev_get_queue(bdev));
}
static inline int queue_dma_alignment(struct request_queue *q)
{
return q ? q->dma_alignment : 511;
}
/* 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;
}
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 work_struct *work);
void kblockd_flush_work(struct work_struct *work);
#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) "-*")
#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;
}
static inline void exit_io_context(void)
{
}
struct io_context;
static inline int put_io_context(struct io_context *ioc)
{
return 1;
}
#endif /* CONFIG_BLOCK */
#endif
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