diff options
Diffstat (limited to 'include/linux/blkdev.h')
| -rw-r--r-- | include/linux/blkdev.h | 1320 |
1 files changed, 1320 insertions, 0 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h new file mode 100644 index 00000000000..1896e868854 --- /dev/null +++ b/include/linux/blkdev.h @@ -0,0 +1,1320 @@ +#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/gfp.h> +#include <linux/bsg.h> +#include <linux/smp.h> + +#include <asm/scatterlist.h> + +struct scsi_ioctl_command; + +struct request_queue; +struct elevator_queue; +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 */ + +struct request; +typedef void (rq_end_io_fn)(struct request *, int); + +struct request_list { + /* + * count[], starved[], and wait[] are indexed by + * BLK_RW_SYNC/BLK_RW_ASYNC + */ + 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_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 { + REQ_LB_OP_EJECT = 0x40, /* eject request */ + REQ_LB_OP_FLUSH = 0x41, /* flush request */ +}; + +/* + * request type modified bits. first four bits match BIO_RW* bits, important + */ +enum rq_flag_bits { + __REQ_RW, /* not set, read. set, write */ + __REQ_FAILFAST_DEV, /* no driver retries of device errors */ + __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */ + __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */ + /* above flags must match BIO_RW_* */ + __REQ_DISCARD, /* request to discard sectors */ + __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 (sync write or read) */ + __REQ_ALLOCED, /* request came from our alloc pool */ + __REQ_RW_META, /* metadata io request */ + __REQ_COPY_USER, /* contains copies of user pages */ + __REQ_INTEGRITY, /* integrity metadata has been remapped */ + __REQ_NOIDLE, /* Don't anticipate more IO after this one */ + __REQ_IO_STAT, /* account I/O stat */ + __REQ_MIXED_MERGE, /* merge of different types, fail separately */ + __REQ_NR_BITS, /* stops here */ +}; + +#define REQ_RW (1 << __REQ_RW) +#define REQ_FAILFAST_DEV (1 << __REQ_FAILFAST_DEV) +#define REQ_FAILFAST_TRANSPORT (1 << __REQ_FAILFAST_TRANSPORT) +#define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER) +#define REQ_DISCARD (1 << __REQ_DISCARD) +#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 REQ_COPY_USER (1 << __REQ_COPY_USER) +#define REQ_INTEGRITY (1 << __REQ_INTEGRITY) +#define REQ_NOIDLE (1 << __REQ_NOIDLE) +#define REQ_IO_STAT (1 << __REQ_IO_STAT) +#define REQ_MIXED_MERGE (1 << __REQ_MIXED_MERGE) + +#define REQ_FAILFAST_MASK (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | \ + REQ_FAILFAST_DRIVER) + +#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 call_single_data csd; + int cpu; + + struct request_queue *q; + + unsigned int cmd_flags; + enum rq_cmd_type_bits cmd_type; + unsigned long atomic_flags; + + /* the following two fields are internal, NEVER access directly */ + sector_t __sector; /* sector cursor */ + unsigned int __data_len; /* total data len */ + + 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; + + unsigned short ioprio; + + void *special; /* opaque pointer available for LLD use */ + char *buffer; /* kaddr of the current segment if available */ + + int tag; + int errors; + + int ref_count; + + /* + * when request is used as a packet command carrier + */ + unsigned short cmd_len; + unsigned char __cmd[BLK_MAX_CDB]; + unsigned char *cmd; + + 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 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; +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 (prepare_flush_fn) (struct request_queue *, struct request *); +typedef void (softirq_done_fn)(struct request *); +typedef int (dma_drain_needed_fn)(struct request *); +typedef int (lld_busy_fn) (struct request_queue *q); + +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 discard_granularity; + unsigned int discard_alignment; + + unsigned short logical_block_size; + unsigned short max_hw_segments; + unsigned short max_phys_segments; + + unsigned char misaligned; + unsigned char discard_misaligned; + unsigned char no_cluster; + signed 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; + + /* + * 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; + 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; + + /* + * 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 + */ + 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; + + void *dma_drain_buffer; + unsigned int dma_drain_size; + 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]; + + unsigned int rq_timeout; + struct timer_list timeout; + struct list_head timeout_list; + + 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 + /* + * 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_SYNCFULL 3 /* read queue has been filled */ +#define QUEUE_FLAG_ASYNCFULL 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 */ +#define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */ +#define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */ +#define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */ +#define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */ +#define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */ +#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ +#define QUEUE_FLAG_IO_STAT 15 /* do IO stats */ +#define QUEUE_FLAG_DISCARD 16 /* supports DISCARD */ + +#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ + (1 << QUEUE_FLAG_CLUSTER) | \ + (1 << QUEUE_FLAG_STACKABLE) | \ + (1 << QUEUE_FLAG_SAME_COMP)) + +static inline int queue_is_locked(struct request_queue *q) +{ +#ifdef CONFIG_SMP + spinlock_t *lock = q->queue_lock; + return lock && spin_is_locked(lock); +#else + return 1; +#endif +} + +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) +{ + WARN_ON_ONCE(!queue_is_locked(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) +{ + WARN_ON_ONCE(!queue_is_locked(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) +{ + WARN_ON_ONCE(!queue_is_locked(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) +{ + WARN_ON_ONCE(!queue_is_locked(q)); + __clear_bit(flag, &q->queue_flags); +} + +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_BY_DRAIN = 0x01, + QUEUE_ORDERED_BY_TAG = 0x02, + QUEUE_ORDERED_DO_PREFLUSH = 0x10, + QUEUE_ORDERED_DO_BAR = 0x20, + QUEUE_ORDERED_DO_POSTFLUSH = 0x40, + QUEUE_ORDERED_DO_FUA = 0x80, + + QUEUE_ORDERED_NONE = 0x00, + + QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_BY_DRAIN | + QUEUE_ORDERED_DO_BAR, + QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | + QUEUE_ORDERED_DO_PREFLUSH | + QUEUE_ORDERED_DO_POSTFLUSH, + QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | + QUEUE_ORDERED_DO_PREFLUSH | + QUEUE_ORDERED_DO_FUA, + + QUEUE_ORDERED_TAG = QUEUE_ORDERED_BY_TAG | + QUEUE_ORDERED_DO_BAR, + QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | + QUEUE_ORDERED_DO_PREFLUSH | + QUEUE_ORDERED_DO_POSTFLUSH, + QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | + QUEUE_ORDERED_DO_PREFLUSH | + QUEUE_ORDERED_DO_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_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(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_flushing(q) ((q)->ordseq) +#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_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_failfast_dev(rq) ((rq)->cmd_flags & REQ_FAILFAST_DEV) +#define blk_failfast_transport(rq) ((rq)->cmd_flags & REQ_FAILFAST_TRANSPORT) +#define blk_failfast_driver(rq) ((rq)->cmd_flags & REQ_FAILFAST_DRIVER) +#define blk_noretry_request(rq) (blk_failfast_dev(rq) || \ + blk_failfast_transport(rq) || \ + blk_failfast_driver(rq)) +#define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED) +#define blk_rq_io_stat(rq) ((rq)->cmd_flags & REQ_IO_STAT) +#define blk_rq_quiet(rq) ((rq)->cmd_flags & REQ_QUIET) + +#define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(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_rq_cpu_valid(rq) ((rq)->cpu != -1) +#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_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD) +#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) + +/* + * 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_RW) || (rw_flags & REQ_RW_SYNC); +} + +static inline bool rq_is_sync(struct request *rq) +{ + return rw_is_sync(rq->cmd_flags); +} + +#define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META) +#define rq_noidle(rq) ((rq)->cmd_flags & REQ_NOIDLE) + +static inline int blk_queue_full(struct request_queue *q, int sync) +{ + if (sync) + return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags); + return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags); +} + +static inline void blk_set_queue_full(struct request_queue *q, int sync) +{ + if (sync) + queue_flag_set(QUEUE_FLAG_SYNCFULL, q); + else + queue_flag_set(QUEUE_FLAG_ASYNCFULL, q); +} + +static inline void blk_clear_queue_full(struct request_queue *q, int sync) +{ + if (sync) + queue_flag_clear(QUEUE_FLAG_SYNCFULL, q); + else + queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q); +} + + +/* + * 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_discard_rq(rq) || 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 + */ + +#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 (ISA_DMA_THRESHOLD) + +/* + * 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 register_disk(struct gendisk *dev); +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_insert_request(struct request_queue *, struct request *, int, void *); +extern void blk_requeue_request(struct request_queue *, struct request *); +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_plug_device(struct request_queue *); +extern void blk_plug_device_unlocked(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 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 *); + +/* + * 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 *); +extern void blk_run_queue(struct request_queue *); +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 *); +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; +} + +/* + * 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; +} + +/* + * 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_abort_queue(struct request_queue *); + +/* + * 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_hw_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_max_discard_sectors(struct request_queue *q, + unsigned int max_discard_sectors); +extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); +extern void blk_queue_physical_block_size(struct request_queue *, unsigned short); +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 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_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 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 bool 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 bool 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 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_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 DISCARD_FL_WAIT 0x01 /* wait for completion */ +#define DISCARD_FL_BARRIER 0x02 /* issue DISCARD_BARRIER request */ +extern int blkdev_issue_discard(struct block_device *, sector_t sector, + sector_t nr_sects, gfp_t, int flags); + +static inline int sb_issue_discard(struct super_block *sb, + sector_t block, sector_t nr_blocks) +{ + block <<= (sb->s_blocksize_bits - 9); + nr_blocks <<= (sb->s_blocksize_bits - 9); + return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL, + DISCARD_FL_BARRIER); +} + +extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); + +#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 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_hw_segments(struct request_queue *q) +{ + return q->limits.max_hw_segments; +} + +static inline unsigned short queue_max_phys_segments(struct request_queue *q) +{ + return q->limits.max_phys_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 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 offset) +{ + unsigned int granularity = max(lim->physical_block_size, lim->io_min); + + offset &= granularity - 1; + return (granularity + lim->alignment_offset - offset) & (granularity - 1); +} + +static inline int queue_sector_alignment_offset(struct request_queue *q, + sector_t sector) +{ + return queue_limit_alignment_offset(&q->limits, sector << 9); +} + +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_sector_discard_alignment(struct request_queue *q, + sector_t sector) +{ + struct queue_limits *lim = &q->limits; + unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1); + + return (lim->discard_granularity + lim->discard_alignment - alignment) + & (lim->discard_granularity - 1); +} + +static inline unsigned int queue_discard_zeroes_data(struct request_queue *q) +{ + if (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 int queue_dma_alignment(struct request_queue *q) +{ + return q ? q->dma_alignment : 511; +} + +static inline int blk_rq_aligned(struct request_queue *q, void *addr, + unsigned int len) +{ + unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; + return !((unsigned long)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; +} + +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); + +#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 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 *, struct scatterlist *); +extern int blk_rq_count_integrity_sg(struct request *); + +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); +} + +#else /* CONFIG_BLK_DEV_INTEGRITY */ + +#define blk_integrity_rq(rq) (0) +#define blk_rq_count_integrity_sg(a) (0) +#define blk_rq_map_integrity_sg(a, b) (0) +#define bdev_get_integrity(a) (0) +#define blk_get_integrity(a) (0) +#define blk_integrity_compare(a, b) (0) +#define blk_integrity_register(a, b) (0) +#define blk_integrity_unregister(a) do { } while (0); + +#endif /* CONFIG_BLK_DEV_INTEGRITY */ + +struct block_device_operations { + int (*open) (struct block_device *, fmode_t); + int (*release) (struct gendisk *, fmode_t); + int (*locked_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); + 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 *); + int (*media_changed) (struct gendisk *); + unsigned long long (*set_capacity) (struct gendisk *, + unsigned long long); + int (*revalidate_disk) (struct gendisk *); + int (*getgeo)(struct block_device *, struct hd_geometry *); + 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; +} + +#endif /* CONFIG_BLOCK */ + +#endif |