From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- include/linux/blkdev.h | 759 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 759 insertions(+) create mode 100644 include/linux/blkdev.h (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h new file mode 100644 index 0000000..70ac286 --- /dev/null +++ b/include/linux/blkdev.h @@ -0,0 +1,759 @@ +#ifndef _LINUX_BLKDEV_H +#define _LINUX_BLKDEV_H + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +struct request_queue; +typedef struct request_queue request_queue_t; +struct elevator_queue; +typedef struct elevator_queue elevator_t; +struct request_pm_state; + +#define BLKDEV_MIN_RQ 4 +#define BLKDEV_MAX_RQ 128 /* Default maximum */ + +/* + * This is the per-process anticipatory I/O scheduler state. + */ +struct as_io_context { + spinlock_t lock; + + void (*dtor)(struct as_io_context *aic); /* destructor */ + void (*exit)(struct as_io_context *aic); /* called on task exit */ + + unsigned long state; + atomic_t nr_queued; /* queued reads & sync writes */ + atomic_t nr_dispatched; /* number of requests gone to the drivers */ + + /* IO History tracking */ + /* Thinktime */ + unsigned long last_end_request; + unsigned long ttime_total; + unsigned long ttime_samples; + unsigned long ttime_mean; + /* Layout pattern */ + unsigned int seek_samples; + sector_t last_request_pos; + u64 seek_total; + sector_t seek_mean; +}; + +struct cfq_queue; +struct cfq_io_context { + void (*dtor)(struct cfq_io_context *); + void (*exit)(struct cfq_io_context *); + + struct io_context *ioc; + + /* + * circular list of cfq_io_contexts belonging to a process io context + */ + struct list_head list; + struct cfq_queue *cfqq; +}; + +/* + * This is the per-process I/O subsystem state. It is refcounted and + * kmalloc'ed. Currently all fields are modified in process io context + * (apart from the atomic refcount), so require no locking. + */ +struct io_context { + atomic_t refcount; + pid_t pid; + + /* + * For request batching + */ + unsigned long last_waited; /* Time last woken after wait for request */ + int nr_batch_requests; /* Number of requests left in the batch */ + + spinlock_t lock; + + struct as_io_context *aic; + struct cfq_io_context *cic; +}; + +void put_io_context(struct io_context *ioc); +void exit_io_context(void); +struct io_context *get_io_context(int gfp_flags); +void copy_io_context(struct io_context **pdst, struct io_context **psrc); +void swap_io_context(struct io_context **ioc1, struct io_context **ioc2); + +struct request; +typedef void (rq_end_io_fn)(struct request *); + +struct request_list { + int count[2]; + int starved[2]; + mempool_t *rq_pool; + wait_queue_head_t wait[2]; + wait_queue_head_t drain; +}; + +#define BLK_MAX_CDB 16 + +/* + * try to put the fields that are referenced together in the same cacheline + */ +struct request { + struct list_head queuelist; /* looking for ->queue? you must _not_ + * access it directly, use + * blkdev_dequeue_request! */ + unsigned long flags; /* see REQ_ bits below */ + + /* 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 */ + unsigned long nr_sectors; /* no. of sectors left to submit */ + /* no. of sectors left to submit in the current segment */ + unsigned int current_nr_sectors; + + sector_t hard_sector; /* next sector to complete */ + unsigned long hard_nr_sectors; /* no. of sectors left to complete */ + /* no. of sectors left to complete in the current segment */ + unsigned int hard_cur_sectors; + + struct bio *bio; + struct bio *biotail; + + void *elevator_private; + + int rq_status; /* should split this into a few status bits */ + struct gendisk *rq_disk; + int errors; + 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; + + int tag; + char *buffer; + + int ref_count; + request_queue_t *q; + struct request_list *rl; + + struct completion *waiting; + void *special; + + /* + * when request is used as a packet command carrier + */ + unsigned int cmd_len; + unsigned char cmd[BLK_MAX_CDB]; + + unsigned int data_len; + void *data; + + unsigned int sense_len; + void *sense; + + unsigned int timeout; + + /* + * For Power Management requests + */ + struct request_pm_state *pm; + + /* + * completion callback. end_io_data should be folded in with waiting + */ + rq_end_io_fn *end_io; + void *end_io_data; +}; + +/* + * 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_SOFTBARRIER, /* may not be passed by ioscheduler */ + __REQ_HARDBARRIER, /* may not be passed by drive either */ + __REQ_CMD, /* is a regular fs rw request */ + __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 */ + /* + * for ATA/ATAPI devices + */ + __REQ_PC, /* packet command (special) */ + __REQ_BLOCK_PC, /* queued down pc from block layer */ + __REQ_SENSE, /* sense retrival */ + + __REQ_FAILED, /* set if the request failed */ + __REQ_QUIET, /* don't worry about errors */ + __REQ_SPECIAL, /* driver suplied command */ + __REQ_DRIVE_CMD, + __REQ_DRIVE_TASK, + __REQ_DRIVE_TASKFILE, + __REQ_PREEMPT, /* set for "ide_preempt" requests */ + __REQ_PM_SUSPEND, /* suspend request */ + __REQ_PM_RESUME, /* resume request */ + __REQ_PM_SHUTDOWN, /* shutdown request */ + __REQ_BAR_PREFLUSH, /* barrier pre-flush done */ + __REQ_BAR_POSTFLUSH, /* barrier post-flush */ + __REQ_BAR_FLUSH, /* rq is the flush request */ + __REQ_NR_BITS, /* stops here */ +}; + +#define REQ_RW (1 << __REQ_RW) +#define REQ_FAILFAST (1 << __REQ_FAILFAST) +#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) +#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) +#define REQ_CMD (1 << __REQ_CMD) +#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_PC (1 << __REQ_PC) +#define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC) +#define REQ_SENSE (1 << __REQ_SENSE) +#define REQ_FAILED (1 << __REQ_FAILED) +#define REQ_QUIET (1 << __REQ_QUIET) +#define REQ_SPECIAL (1 << __REQ_SPECIAL) +#define REQ_DRIVE_CMD (1 << __REQ_DRIVE_CMD) +#define REQ_DRIVE_TASK (1 << __REQ_DRIVE_TASK) +#define REQ_DRIVE_TASKFILE (1 << __REQ_DRIVE_TASKFILE) +#define REQ_PREEMPT (1 << __REQ_PREEMPT) +#define REQ_PM_SUSPEND (1 << __REQ_PM_SUSPEND) +#define REQ_PM_RESUME (1 << __REQ_PM_RESUME) +#define REQ_PM_SHUTDOWN (1 << __REQ_PM_SHUTDOWN) +#define REQ_BAR_PREFLUSH (1 << __REQ_BAR_PREFLUSH) +#define REQ_BAR_POSTFLUSH (1 << __REQ_BAR_POSTFLUSH) +#define REQ_BAR_FLUSH (1 << __REQ_BAR_FLUSH) + +/* + * State information carried for REQ_PM_SUSPEND and REQ_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 + +typedef int (merge_request_fn) (request_queue_t *, struct request *, + struct bio *); +typedef int (merge_requests_fn) (request_queue_t *, struct request *, + struct request *); +typedef void (request_fn_proc) (request_queue_t *q); +typedef int (make_request_fn) (request_queue_t *q, struct bio *bio); +typedef int (prep_rq_fn) (request_queue_t *, struct request *); +typedef void (unplug_fn) (request_queue_t *); + +struct bio_vec; +typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *); +typedef void (activity_fn) (void *data, int rw); +typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *); +typedef int (prepare_flush_fn) (request_queue_t *, struct request *); +typedef void (end_flush_fn) (request_queue_t *, struct request *); + +enum blk_queue_state { + Queue_down, + Queue_up, +}; + +#define BLK_TAGS_PER_LONG (sizeof(unsigned long) * 8) +#define BLK_TAGS_MASK (BLK_TAGS_PER_LONG - 1) + +struct blk_queue_tag { + struct request **tag_index; /* map of busy tags */ + unsigned long *tag_map; /* bit map of free/busy tags */ + struct list_head busy_list; /* fifo list of 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; + merge_request_fn *back_merge_fn; + merge_request_fn *front_merge_fn; + merge_requests_fn *merge_requests_fn; + make_request_fn *make_request_fn; + prep_rq_fn *prep_rq_fn; + unplug_fn *unplug_fn; + merge_bvec_fn *merge_bvec_fn; + activity_fn *activity_fn; + issue_flush_fn *issue_flush_fn; + prepare_flush_fn *prepare_flush_fn; + end_flush_fn *end_flush_fn; + + /* + * 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; + + void *activity_data; + + /* + * queue needs bounce pages for pages above this limit + */ + unsigned long bounce_pfn; + unsigned int bounce_gfp; + + /* + * various queue flags, see QUEUE_* below + */ + unsigned long queue_flags; + + /* + * protects queue structures from reentrancy + */ + 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 short max_sectors; + unsigned short 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; + unsigned int dma_alignment; + + struct blk_queue_tag *queue_tags; + + atomic_t refcnt; + + unsigned int in_flight; + + /* + * sg stuff + */ + unsigned int sg_timeout; + unsigned int sg_reserved_size; + + struct list_head drain_list; + + /* + * reserved for flush operations + */ + struct request *flush_rq; + unsigned char ordered; +}; + +enum { + QUEUE_ORDERED_NONE, + QUEUE_ORDERED_TAG, + QUEUE_ORDERED_FLUSH, +}; + +#define RQ_INACTIVE (-1) +#define RQ_ACTIVE 1 +#define RQ_SCSI_BUSY 0xffff +#define RQ_SCSI_DONE 0xfffe +#define RQ_SCSI_DISCONNECTING 0xffe0 + +#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 /* write queue has been filled */ +#define QUEUE_FLAG_WRITEFULL 4 /* read 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_DRAIN 8 /* draining queue for sched switch */ +#define QUEUE_FLAG_FLUSH 9 /* doing barrier flush sequence */ + +#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) test_bit(QUEUE_FLAG_FLUSH, &(q)->queue_flags) + +#define blk_fs_request(rq) ((rq)->flags & REQ_CMD) +#define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC) +#define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST) +#define blk_rq_started(rq) ((rq)->flags & REQ_STARTED) + +#define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) + +#define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND) +#define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME) +#define blk_pm_request(rq) \ + ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME)) + +#define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER) +#define blk_barrier_preflush(rq) ((rq)->flags & REQ_BAR_PREFLUSH) +#define blk_barrier_postflush(rq) ((rq)->flags & REQ_BAR_POSTFLUSH) + +#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) + +#define rq_data_dir(rq) ((rq)->flags & 1) + +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)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) + +/* + * noop, requests are automagically marked as active/inactive by I/O + * scheduler -- see elv_next_request + */ +#define blk_queue_headactive(q, head_active) + +/* + * 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) + +#ifdef CONFIG_MMU +extern int init_emergency_isa_pool(void); +extern void blk_queue_bounce(request_queue_t *q, struct bio **bio); +#else +static inline int init_emergency_isa_pool(void) +{ + return 0; +} +static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio) +{ +} +#endif /* CONFIG_MMU */ + +#define rq_for_each_bio(_bio, rq) \ + if ((rq->bio)) \ + for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) + +struct sec_size { + unsigned block_size; + unsigned block_size_bits; +}; + +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_end_sync_rq(struct request *rq); +extern void blk_attempt_remerge(request_queue_t *, struct request *); +extern void __blk_attempt_remerge(request_queue_t *, struct request *); +extern struct request *blk_get_request(request_queue_t *, int, int); +extern void blk_insert_request(request_queue_t *, struct request *, int, void *, int); +extern void blk_requeue_request(request_queue_t *, struct request *); +extern void blk_plug_device(request_queue_t *); +extern int blk_remove_plug(request_queue_t *); +extern void blk_recount_segments(request_queue_t *, struct bio *); +extern int blk_phys_contig_segment(request_queue_t *q, struct bio *, struct bio *); +extern int blk_hw_contig_segment(request_queue_t *q, struct bio *, struct bio *); +extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *); +extern void blk_start_queue(request_queue_t *q); +extern void blk_stop_queue(request_queue_t *q); +extern void blk_sync_queue(struct request_queue *q); +extern void __blk_stop_queue(request_queue_t *q); +extern void blk_run_queue(request_queue_t *); +extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *); +extern struct request *blk_rq_map_user(request_queue_t *, int, void __user *, unsigned int); +extern int blk_rq_unmap_user(struct request *, struct bio *, unsigned int); +extern int blk_execute_rq(request_queue_t *, struct gendisk *, struct request *); + +static inline request_queue_t *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); +} + +/* + * end_request() and friends. Must be called with the request queue spinlock + * acquired. All functions called within end_request() _must_be_ atomic. + * + * Several drivers define their own end_request and call + * end_that_request_first() and end_that_request_last() + * for parts of the original function. This prevents + * code duplication in drivers. + */ +extern int end_that_request_first(struct request *, int, int); +extern int end_that_request_chunk(struct request *, int, int); +extern void end_that_request_last(struct request *); +extern void end_request(struct request *req, int uptodate); + +/* + * end_that_request_first/chunk() takes an uptodate argument. we account + * any value <= as an io error. 0 means -EIO for compatability reasons, + * any other < 0 value is the direct error type. An uptodate value of + * 1 indicates successful io completion + */ +#define end_io_error(uptodate) (unlikely((uptodate) <= 0)) + +static inline void blkdev_dequeue_request(struct request *req) +{ + BUG_ON(list_empty(&req->queuelist)); + + list_del_init(&req->queuelist); + + if (req->rl) + elv_remove_request(req->q, req); +} + +/* + * Access functions for manipulating queue properties + */ +extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *); +extern void blk_cleanup_queue(request_queue_t *); +extern void blk_queue_make_request(request_queue_t *, make_request_fn *); +extern void blk_queue_bounce_limit(request_queue_t *, u64); +extern void blk_queue_max_sectors(request_queue_t *, unsigned short); +extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short); +extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short); +extern void blk_queue_max_segment_size(request_queue_t *, unsigned int); +extern void blk_queue_hardsect_size(request_queue_t *, unsigned short); +extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b); +extern void blk_queue_segment_boundary(request_queue_t *, unsigned long); +extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn); +extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *); +extern void blk_queue_dma_alignment(request_queue_t *, int); +extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); +extern void blk_queue_ordered(request_queue_t *, int); +extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *); +extern int blkdev_scsi_issue_flush_fn(request_queue_t *, struct gendisk *, sector_t *); +extern struct request *blk_start_pre_flush(request_queue_t *,struct request *); +extern int blk_complete_barrier_rq(request_queue_t *, struct request *, int); +extern int blk_complete_barrier_rq_locked(request_queue_t *, struct request *, int); + +extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *); +extern void blk_dump_rq_flags(struct request *, char *); +extern void generic_unplug_device(request_queue_t *); +extern void __generic_unplug_device(request_queue_t *); +extern long nr_blockdev_pages(void); +extern void blk_wait_queue_drained(request_queue_t *, int); +extern void blk_finish_queue_drain(request_queue_t *); + +int blk_get_queue(request_queue_t *); +request_queue_t *blk_alloc_queue(int); +#define blk_put_queue(q) blk_cleanup_queue((q)) + +/* + * 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)->flags & REQ_QUEUED) +extern int blk_queue_start_tag(request_queue_t *, struct request *); +extern struct request *blk_queue_find_tag(request_queue_t *, int); +extern void blk_queue_end_tag(request_queue_t *, struct request *); +extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *); +extern void blk_queue_free_tags(request_queue_t *); +extern int blk_queue_resize_tags(request_queue_t *, int); +extern void blk_queue_invalidate_tags(request_queue_t *); +extern long blk_congestion_wait(int rw, long timeout); + +extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *); +extern int blkdev_issue_flush(struct block_device *, sector_t *); + +#define MAX_PHYS_SEGMENTS 128 +#define MAX_HW_SEGMENTS 128 +#define MAX_SECTORS 255 + +#define MAX_SEGMENT_SIZE 65536 + +#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) + +extern void drive_stat_acct(struct request *, int, int); + +static inline int queue_hardsect_size(request_queue_t *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(request_queue_t *q) +{ + int retval = 511; + + if (q && q->dma_alignment) + retval = q->dma_alignment; + + return retval; +} + +static inline int bdev_dma_aligment(struct block_device *bdev) +{ + return queue_dma_alignment(bdev_get_queue(bdev)); +} + +#define blk_finished_io(nsects) do { } while (0) +#define blk_started_io(nsects) do { } while (0) + +/* 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; +} + +extern 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(void); + +#ifdef CONFIG_LBD +# include +# define sector_div(a, b) do_div(a, b) +#else +# define sector_div(n, b)( \ +{ \ + int _res; \ + _res = (n) % (b); \ + (n) /= (b); \ + _res; \ +} \ +) +#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) "-*") + + +#endif -- cgit v1.1