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-rw-r--r--kernel/include/linux/blkdev.h1674
1 files changed, 1674 insertions, 0 deletions
diff --git a/kernel/include/linux/blkdev.h b/kernel/include/linux/blkdev.h
new file mode 100644
index 000000000..37faf63af
--- /dev/null
+++ b/kernel/include/linux/blkdev.h
@@ -0,0 +1,1674 @@
+#ifndef _LINUX_BLKDEV_H
+#define _LINUX_BLKDEV_H
+
+#include <linux/sched.h>
+
+#ifdef CONFIG_BLOCK
+
+#include <linux/major.h>
+#include <linux/genhd.h>
+#include <linux/list.h>
+#include <linux/llist.h>
+#include <linux/timer.h>
+#include <linux/workqueue.h>
+#include <linux/pagemap.h>
+#include <linux/backing-dev.h>
+#include <linux/wait.h>
+#include <linux/mempool.h>
+#include <linux/bio.h>
+#include <linux/stringify.h>
+#include <linux/gfp.h>
+#include <linux/bsg.h>
+#include <linux/smp.h>
+#include <linux/rcupdate.h>
+#include <linux/percpu-refcount.h>
+
+#include <asm/scatterlist.h>
+
+struct module;
+struct scsi_ioctl_command;
+
+struct request_queue;
+struct elevator_queue;
+struct request_pm_state;
+struct blk_trace;
+struct request;
+struct sg_io_hdr;
+struct bsg_job;
+struct blkcg_gq;
+struct blk_flush_queue;
+
+#define BLKDEV_MIN_RQ 4
+#define BLKDEV_MAX_RQ 128 /* Default maximum */
+
+/*
+ * Maximum number of blkcg policies allowed to be registered concurrently.
+ * Defined here to simplify include dependency.
+ */
+#define BLKCG_MAX_POLS 2
+
+struct request;
+typedef void (rq_end_io_fn)(struct request *, int);
+
+#define BLK_RL_SYNCFULL (1U << 0)
+#define BLK_RL_ASYNCFULL (1U << 1)
+
+struct request_list {
+ struct request_queue *q; /* the queue this rl belongs to */
+#ifdef CONFIG_BLK_CGROUP
+ struct blkcg_gq *blkg; /* blkg this request pool belongs to */
+#endif
+ /*
+ * count[], starved[], and wait[] are indexed by
+ * BLK_RW_SYNC/BLK_RW_ASYNC
+ */
+ int count[2];
+ int starved[2];
+ mempool_t *rq_pool;
+ wait_queue_head_t wait[2];
+ unsigned int flags;
+};
+
+/*
+ * request command types
+ */
+enum rq_cmd_type_bits {
+ REQ_TYPE_FS = 1, /* fs request */
+ REQ_TYPE_BLOCK_PC, /* scsi command */
+ REQ_TYPE_SENSE, /* sense request */
+ REQ_TYPE_PM_SUSPEND, /* suspend request */
+ REQ_TYPE_PM_RESUME, /* resume request */
+ REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
+ REQ_TYPE_SPECIAL, /* driver defined type */
+ /*
+ * for ATA/ATAPI devices. this really doesn't belong here, ide should
+ * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
+ * private REQ_LB opcodes to differentiate what type of request this is
+ */
+ REQ_TYPE_ATA_TASKFILE,
+ REQ_TYPE_ATA_PC,
+};
+
+#define BLK_MAX_CDB 16
+
+/*
+ * Try to put the fields that are referenced together in the same cacheline.
+ *
+ * If you modify this structure, make sure to update blk_rq_init() and
+ * especially blk_mq_rq_ctx_init() to take care of the added fields.
+ */
+struct request {
+ struct list_head queuelist;
+ union {
+ struct call_single_data csd;
+ struct work_struct work;
+ unsigned long fifo_time;
+ };
+
+ struct request_queue *q;
+ struct blk_mq_ctx *mq_ctx;
+
+ u64 cmd_flags;
+ enum rq_cmd_type_bits cmd_type;
+ unsigned long atomic_flags;
+
+ int cpu;
+
+ /* the following two fields are internal, NEVER access directly */
+ unsigned int __data_len; /* total data len */
+ sector_t __sector; /* sector cursor */
+
+ struct bio *bio;
+ struct bio *biotail;
+
+ /*
+ * The hash is used inside the scheduler, and killed once the
+ * request reaches the dispatch list. The ipi_list is only used
+ * to queue the request for softirq completion, which is long
+ * after the request has been unhashed (and even removed from
+ * the dispatch list).
+ */
+ union {
+ struct hlist_node hash; /* merge hash */
+ struct list_head ipi_list;
+ };
+
+ /*
+ * The rb_node is only used inside the io scheduler, requests
+ * are pruned when moved to the dispatch queue. So let the
+ * completion_data share space with the rb_node.
+ */
+ union {
+ struct rb_node rb_node; /* sort/lookup */
+ void *completion_data;
+ };
+
+ /*
+ * Three pointers are available for the IO schedulers, if they need
+ * more they have to dynamically allocate it. Flush requests are
+ * never put on the IO scheduler. So let the flush fields share
+ * space with the elevator data.
+ */
+ union {
+ struct {
+ struct io_cq *icq;
+ void *priv[2];
+ } elv;
+
+ struct {
+ unsigned int seq;
+ struct list_head list;
+ rq_end_io_fn *saved_end_io;
+ } flush;
+ };
+
+ struct gendisk *rq_disk;
+ struct hd_struct *part;
+ unsigned long start_time;
+#ifdef CONFIG_BLK_CGROUP
+ struct request_list *rl; /* rl this rq is alloced from */
+ unsigned long long start_time_ns;
+ unsigned long long io_start_time_ns; /* when passed to hardware */
+#endif
+ /* Number of scatter-gather DMA addr+len pairs after
+ * physical address coalescing is performed.
+ */
+ unsigned short nr_phys_segments;
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+ unsigned short nr_integrity_segments;
+#endif
+
+ unsigned short ioprio;
+
+ void *special; /* opaque pointer available for LLD use */
+
+ int tag;
+ int errors;
+
+ /*
+ * when request is used as a packet command carrier
+ */
+ unsigned char __cmd[BLK_MAX_CDB];
+ unsigned char *cmd;
+ unsigned short cmd_len;
+
+ unsigned int extra_len; /* length of alignment and padding */
+ unsigned int sense_len;
+ unsigned int resid_len; /* residual count */
+ void *sense;
+
+ unsigned long deadline;
+ struct list_head timeout_list;
+ unsigned int timeout;
+ int retries;
+
+ /*
+ * completion callback.
+ */
+ rq_end_io_fn *end_io;
+ void *end_io_data;
+
+ /* for bidi */
+ struct request *next_rq;
+};
+
+static inline unsigned short req_get_ioprio(struct request *req)
+{
+ return req->ioprio;
+}
+
+/*
+ * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
+ * requests. Some step values could eventually be made generic.
+ */
+struct request_pm_state
+{
+ /* PM state machine step value, currently driver specific */
+ int pm_step;
+ /* requested PM state value (S1, S2, S3, S4, ...) */
+ u32 pm_state;
+ void* data; /* for driver use */
+};
+
+#include <linux/elevator.h>
+
+struct blk_queue_ctx;
+
+typedef void (request_fn_proc) (struct request_queue *q);
+typedef void (make_request_fn) (struct request_queue *q, struct bio *bio);
+typedef int (prep_rq_fn) (struct request_queue *, struct request *);
+typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
+
+struct bio_vec;
+struct bvec_merge_data {
+ struct block_device *bi_bdev;
+ sector_t bi_sector;
+ unsigned bi_size;
+ unsigned long bi_rw;
+};
+typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
+ struct bio_vec *);
+typedef void (softirq_done_fn)(struct request *);
+typedef int (dma_drain_needed_fn)(struct request *);
+typedef int (lld_busy_fn) (struct request_queue *q);
+typedef int (bsg_job_fn) (struct bsg_job *);
+
+enum blk_eh_timer_return {
+ BLK_EH_NOT_HANDLED,
+ BLK_EH_HANDLED,
+ BLK_EH_RESET_TIMER,
+};
+
+typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
+
+enum blk_queue_state {
+ Queue_down,
+ Queue_up,
+};
+
+struct blk_queue_tag {
+ struct request **tag_index; /* map of busy tags */
+ unsigned long *tag_map; /* bit map of free/busy tags */
+ int busy; /* current depth */
+ int max_depth; /* what we will send to device */
+ int real_max_depth; /* what the array can hold */
+ atomic_t refcnt; /* map can be shared */
+ int alloc_policy; /* tag allocation policy */
+ int next_tag; /* next tag */
+};
+#define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
+#define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
+
+#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 chunk_sectors;
+ unsigned int max_sectors;
+ unsigned int max_segment_size;
+ unsigned int physical_block_size;
+ unsigned int alignment_offset;
+ unsigned int io_min;
+ unsigned int io_opt;
+ unsigned int max_discard_sectors;
+ unsigned int max_write_same_sectors;
+ unsigned int discard_granularity;
+ unsigned int discard_alignment;
+
+ unsigned short logical_block_size;
+ unsigned short max_segments;
+ unsigned short max_integrity_segments;
+
+ unsigned char misaligned;
+ unsigned char discard_misaligned;
+ unsigned char cluster;
+ unsigned char discard_zeroes_data;
+ unsigned char raid_partial_stripes_expensive;
+};
+
+struct request_queue {
+ /*
+ * Together with queue_head for cacheline sharing
+ */
+ struct list_head queue_head;
+ struct request *last_merge;
+ struct elevator_queue *elevator;
+ int nr_rqs[2]; /* # allocated [a]sync rqs */
+ int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */
+
+ /*
+ * If blkcg is not used, @q->root_rl serves all requests. If blkcg
+ * is used, root blkg allocates from @q->root_rl and all other
+ * blkgs from their own blkg->rl. Which one to use should be
+ * determined using bio_request_list().
+ */
+ struct request_list root_rl;
+
+ request_fn_proc *request_fn;
+ make_request_fn *make_request_fn;
+ prep_rq_fn *prep_rq_fn;
+ unprep_rq_fn *unprep_rq_fn;
+ merge_bvec_fn *merge_bvec_fn;
+ softirq_done_fn *softirq_done_fn;
+ rq_timed_out_fn *rq_timed_out_fn;
+ dma_drain_needed_fn *dma_drain_needed;
+ lld_busy_fn *lld_busy_fn;
+
+ struct blk_mq_ops *mq_ops;
+
+ unsigned int *mq_map;
+
+ /* sw queues */
+ struct blk_mq_ctx __percpu *queue_ctx;
+ unsigned int nr_queues;
+
+ /* hw dispatch queues */
+ struct blk_mq_hw_ctx **queue_hw_ctx;
+ unsigned int nr_hw_queues;
+
+ /*
+ * Dispatch queue sorting
+ */
+ sector_t end_sector;
+ struct request *boundary_rq;
+
+ /*
+ * Delayed queue handling
+ */
+ struct delayed_work delay_work;
+
+ struct backing_dev_info backing_dev_info;
+
+ /*
+ * The queue owner gets to use this for whatever they like.
+ * ll_rw_blk doesn't touch it.
+ */
+ void *queuedata;
+
+ /*
+ * various queue flags, see QUEUE_* below
+ */
+ unsigned long queue_flags;
+
+ /*
+ * ida allocated id for this queue. Used to index queues from
+ * ioctx.
+ */
+ int id;
+
+ /*
+ * queue needs bounce pages for pages above this limit
+ */
+ gfp_t bounce_gfp;
+
+ /*
+ * protects queue structures from reentrancy. ->__queue_lock should
+ * _never_ be used directly, it is queue private. always use
+ * ->queue_lock.
+ */
+ spinlock_t __queue_lock;
+ spinlock_t *queue_lock;
+
+ /*
+ * queue kobject
+ */
+ struct kobject kobj;
+
+ /*
+ * mq queue kobject
+ */
+ struct kobject mq_kobj;
+
+#ifdef CONFIG_PM
+ struct device *dev;
+ int rpm_status;
+ unsigned int nr_pending;
+#endif
+
+ /*
+ * queue settings
+ */
+ unsigned long nr_requests; /* Max # of requests */
+ unsigned int nr_congestion_on;
+ unsigned int nr_congestion_off;
+ unsigned int nr_batching;
+
+ unsigned int dma_drain_size;
+ void *dma_drain_buffer;
+ unsigned int dma_pad_mask;
+ unsigned int dma_alignment;
+
+ struct blk_queue_tag *queue_tags;
+ struct list_head tag_busy_list;
+
+ unsigned int nr_sorted;
+ unsigned int in_flight[2];
+ /*
+ * Number of active block driver functions for which blk_drain_queue()
+ * must wait. Must be incremented around functions that unlock the
+ * queue_lock internally, e.g. scsi_request_fn().
+ */
+ unsigned int request_fn_active;
+
+ unsigned int rq_timeout;
+ struct timer_list timeout;
+ struct list_head timeout_list;
+
+ struct list_head icq_list;
+#ifdef CONFIG_BLK_CGROUP
+ DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS);
+ struct blkcg_gq *root_blkg;
+ struct list_head blkg_list;
+#endif
+
+ struct queue_limits limits;
+
+ /*
+ * sg stuff
+ */
+ unsigned int sg_timeout;
+ unsigned int sg_reserved_size;
+ int node;
+#ifdef CONFIG_BLK_DEV_IO_TRACE
+ struct blk_trace *blk_trace;
+#endif
+ /*
+ * for flush operations
+ */
+ unsigned int flush_flags;
+ unsigned int flush_not_queueable:1;
+ struct blk_flush_queue *fq;
+
+ struct list_head requeue_list;
+ spinlock_t requeue_lock;
+ struct work_struct requeue_work;
+
+ struct mutex sysfs_lock;
+
+ int bypass_depth;
+ int mq_freeze_depth;
+
+#if defined(CONFIG_BLK_DEV_BSG)
+ bsg_job_fn *bsg_job_fn;
+ int bsg_job_size;
+ struct bsg_class_device bsg_dev;
+#endif
+
+#ifdef CONFIG_BLK_DEV_THROTTLING
+ /* Throttle data */
+ struct throtl_data *td;
+#endif
+ struct rcu_head rcu_head;
+ struct swait_head mq_freeze_wq;
+ struct percpu_ref mq_usage_counter;
+ struct list_head all_q_node;
+
+ struct blk_mq_tag_set *tag_set;
+ struct list_head tag_set_list;
+};
+
+#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
+#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
+#define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
+#define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
+#define QUEUE_FLAG_DYING 5 /* queue being torn down */
+#define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */
+#define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
+#define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
+#define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
+#define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
+#define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
+#define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
+#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
+#define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
+#define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
+#define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
+#define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
+#define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
+#define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
+#define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */
+#define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */
+#define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/
+#define QUEUE_FLAG_SG_GAPS 22 /* queue doesn't support SG gaps */
+
+#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
+ (1 << QUEUE_FLAG_STACKABLE) | \
+ (1 << QUEUE_FLAG_SAME_COMP) | \
+ (1 << QUEUE_FLAG_ADD_RANDOM))
+
+#define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
+ (1 << QUEUE_FLAG_STACKABLE) | \
+ (1 << QUEUE_FLAG_SAME_COMP))
+
+static inline void queue_lockdep_assert_held(struct request_queue *q)
+{
+ if (q->queue_lock)
+ lockdep_assert_held(q->queue_lock);
+}
+
+static inline void queue_flag_set_unlocked(unsigned int flag,
+ struct request_queue *q)
+{
+ __set_bit(flag, &q->queue_flags);
+}
+
+static inline int queue_flag_test_and_clear(unsigned int flag,
+ struct request_queue *q)
+{
+ queue_lockdep_assert_held(q);
+
+ if (test_bit(flag, &q->queue_flags)) {
+ __clear_bit(flag, &q->queue_flags);
+ return 1;
+ }
+
+ return 0;
+}
+
+static inline int queue_flag_test_and_set(unsigned int flag,
+ struct request_queue *q)
+{
+ queue_lockdep_assert_held(q);
+
+ if (!test_bit(flag, &q->queue_flags)) {
+ __set_bit(flag, &q->queue_flags);
+ return 0;
+ }
+
+ return 1;
+}
+
+static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
+{
+ queue_lockdep_assert_held(q);
+ __set_bit(flag, &q->queue_flags);
+}
+
+static inline void queue_flag_clear_unlocked(unsigned int flag,
+ struct request_queue *q)
+{
+ __clear_bit(flag, &q->queue_flags);
+}
+
+static inline int queue_in_flight(struct request_queue *q)
+{
+ return q->in_flight[0] + q->in_flight[1];
+}
+
+static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
+{
+ queue_lockdep_assert_held(q);
+ __clear_bit(flag, &q->queue_flags);
+}
+
+#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
+#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
+#define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
+#define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
+#define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
+#define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
+#define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
+#define blk_queue_noxmerges(q) \
+ test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
+#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
+#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
+#define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
+#define blk_queue_stackable(q) \
+ test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
+#define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
+#define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
+ test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
+
+#define blk_noretry_request(rq) \
+ ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
+ REQ_FAILFAST_DRIVER))
+
+#define blk_account_rq(rq) \
+ (((rq)->cmd_flags & REQ_STARTED) && \
+ ((rq)->cmd_type == REQ_TYPE_FS))
+
+#define blk_pm_request(rq) \
+ ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
+ (rq)->cmd_type == REQ_TYPE_PM_RESUME)
+
+#define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
+#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
+/* rq->queuelist of dequeued request must be list_empty() */
+#define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
+
+#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
+
+#define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0)
+
+/*
+ * Driver can handle struct request, if it either has an old style
+ * request_fn defined, or is blk-mq based.
+ */
+static inline bool queue_is_rq_based(struct request_queue *q)
+{
+ return q->request_fn || q->mq_ops;
+}
+
+static inline unsigned int blk_queue_cluster(struct request_queue *q)
+{
+ return q->limits.cluster;
+}
+
+/*
+ * We regard a request as sync, if either a read or a sync write
+ */
+static inline bool rw_is_sync(unsigned int rw_flags)
+{
+ return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
+}
+
+static inline bool rq_is_sync(struct request *rq)
+{
+ return rw_is_sync(rq->cmd_flags);
+}
+
+static inline bool blk_rl_full(struct request_list *rl, bool sync)
+{
+ unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
+
+ return rl->flags & flag;
+}
+
+static inline void blk_set_rl_full(struct request_list *rl, bool sync)
+{
+ unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
+
+ rl->flags |= flag;
+}
+
+static inline void blk_clear_rl_full(struct request_list *rl, bool sync)
+{
+ unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
+
+ rl->flags &= ~flag;
+}
+
+static inline bool rq_mergeable(struct request *rq)
+{
+ if (rq->cmd_type != REQ_TYPE_FS)
+ return false;
+
+ if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
+ return false;
+
+ return true;
+}
+
+static inline bool blk_check_merge_flags(unsigned int flags1,
+ unsigned int flags2)
+{
+ if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD))
+ return false;
+
+ if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE))
+ return false;
+
+ if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME))
+ return false;
+
+ return true;
+}
+
+static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
+{
+ if (bio_data(a) == bio_data(b))
+ return true;
+
+ return false;
+}
+
+/*
+ * q->prep_rq_fn return values
+ */
+#define BLKPREP_OK 0 /* serve it */
+#define BLKPREP_KILL 1 /* fatal error, kill */
+#define BLKPREP_DEFER 2 /* leave on queue */
+
+extern unsigned long blk_max_low_pfn, blk_max_pfn;
+
+/*
+ * standard bounce addresses:
+ *
+ * BLK_BOUNCE_HIGH : bounce all highmem pages
+ * BLK_BOUNCE_ANY : don't bounce anything
+ * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
+ */
+
+#if BITS_PER_LONG == 32
+#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
+#else
+#define BLK_BOUNCE_HIGH -1ULL
+#endif
+#define BLK_BOUNCE_ANY (-1ULL)
+#define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
+
+/*
+ * default timeout for SG_IO if none specified
+ */
+#define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
+#define BLK_MIN_SG_TIMEOUT (7 * HZ)
+
+#ifdef CONFIG_BOUNCE
+extern int init_emergency_isa_pool(void);
+extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
+#else
+static inline int init_emergency_isa_pool(void)
+{
+ return 0;
+}
+static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
+{
+}
+#endif /* CONFIG_MMU */
+
+struct rq_map_data {
+ struct page **pages;
+ int page_order;
+ int nr_entries;
+ unsigned long offset;
+ int null_mapped;
+ int from_user;
+};
+
+struct req_iterator {
+ struct bvec_iter iter;
+ 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.iter)
+
+#define rq_iter_last(bvec, _iter) \
+ (_iter.bio->bi_next == NULL && \
+ bio_iter_last(bvec, _iter.iter))
+
+#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
+#endif
+#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+extern void rq_flush_dcache_pages(struct request *rq);
+#else
+static inline void rq_flush_dcache_pages(struct request *rq)
+{
+}
+#endif
+
+extern int blk_register_queue(struct gendisk *disk);
+extern void blk_unregister_queue(struct gendisk *disk);
+extern void generic_make_request(struct bio *bio);
+extern void blk_rq_init(struct request_queue *q, struct request *rq);
+extern void blk_put_request(struct request *);
+extern void __blk_put_request(struct request_queue *, struct request *);
+extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
+extern struct request *blk_make_request(struct request_queue *, struct bio *,
+ gfp_t);
+extern void blk_rq_set_block_pc(struct request *);
+extern void blk_requeue_request(struct request_queue *, struct request *);
+extern void blk_add_request_payload(struct request *rq, struct page *page,
+ unsigned int len);
+extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
+extern int blk_lld_busy(struct request_queue *q);
+extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
+ struct bio_set *bs, gfp_t gfp_mask,
+ int (*bio_ctr)(struct bio *, struct bio *, void *),
+ void *data);
+extern void blk_rq_unprep_clone(struct request *rq);
+extern int blk_insert_cloned_request(struct request_queue *q,
+ struct request *rq);
+extern void blk_delay_queue(struct request_queue *, unsigned long);
+extern void blk_recount_segments(struct request_queue *, struct bio *);
+extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
+extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
+ unsigned int, void __user *);
+extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
+ unsigned int, void __user *);
+extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
+ struct scsi_ioctl_command __user *);
+
+/*
+ * A queue has just exitted congestion. Note this in the global counter of
+ * congested queues, and wake up anyone who was waiting for requests to be
+ * put back.
+ */
+static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
+{
+ clear_bdi_congested(&q->backing_dev_info, sync);
+}
+
+/*
+ * A queue has just entered congestion. Flag that in the queue's VM-visible
+ * state flags and increment the global gounter of congested queues.
+ */
+static inline void blk_set_queue_congested(struct request_queue *q, int sync)
+{
+ set_bdi_congested(&q->backing_dev_info, sync);
+}
+
+extern void blk_start_queue(struct request_queue *q);
+extern void blk_stop_queue(struct request_queue *q);
+extern void blk_sync_queue(struct request_queue *q);
+extern void __blk_stop_queue(struct request_queue *q);
+extern void __blk_run_queue(struct request_queue *q);
+extern void blk_run_queue(struct request_queue *);
+extern void blk_run_queue_async(struct request_queue *q);
+extern int blk_rq_map_user(struct request_queue *, struct request *,
+ struct rq_map_data *, void __user *, unsigned long,
+ gfp_t);
+extern int blk_rq_unmap_user(struct bio *);
+extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
+extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
+ struct rq_map_data *, const struct iov_iter *,
+ gfp_t);
+extern int blk_execute_rq(struct request_queue *, struct gendisk *,
+ struct request *, int);
+extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
+ struct request *, int, rq_end_io_fn *);
+
+static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
+{
+ return bdev->bd_disk->queue; /* this is never NULL */
+}
+
+/*
+ * blk_rq_pos() : the current sector
+ * blk_rq_bytes() : bytes left in the entire request
+ * blk_rq_cur_bytes() : bytes left in the current segment
+ * blk_rq_err_bytes() : bytes left till the next error boundary
+ * blk_rq_sectors() : sectors left in the entire request
+ * blk_rq_cur_sectors() : sectors left in the current segment
+ */
+static inline sector_t blk_rq_pos(const struct request *rq)
+{
+ return rq->__sector;
+}
+
+static inline unsigned int blk_rq_bytes(const struct request *rq)
+{
+ return rq->__data_len;
+}
+
+static inline int blk_rq_cur_bytes(const struct request *rq)
+{
+ return rq->bio ? bio_cur_bytes(rq->bio) : 0;
+}
+
+extern unsigned int blk_rq_err_bytes(const struct request *rq);
+
+static inline unsigned int blk_rq_sectors(const struct request *rq)
+{
+ return blk_rq_bytes(rq) >> 9;
+}
+
+static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
+{
+ return blk_rq_cur_bytes(rq) >> 9;
+}
+
+static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
+ unsigned int cmd_flags)
+{
+ if (unlikely(cmd_flags & REQ_DISCARD))
+ return min(q->limits.max_discard_sectors, UINT_MAX >> 9);
+
+ if (unlikely(cmd_flags & REQ_WRITE_SAME))
+ return q->limits.max_write_same_sectors;
+
+ return q->limits.max_sectors;
+}
+
+/*
+ * Return maximum size of a request at given offset. Only valid for
+ * file system requests.
+ */
+static inline unsigned int blk_max_size_offset(struct request_queue *q,
+ sector_t offset)
+{
+ if (!q->limits.chunk_sectors)
+ return q->limits.max_sectors;
+
+ return q->limits.chunk_sectors -
+ (offset & (q->limits.chunk_sectors - 1));
+}
+
+static inline unsigned int blk_rq_get_max_sectors(struct request *rq)
+{
+ struct request_queue *q = rq->q;
+
+ if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC))
+ return q->limits.max_hw_sectors;
+
+ if (!q->limits.chunk_sectors)
+ return blk_queue_get_max_sectors(q, rq->cmd_flags);
+
+ return min(blk_max_size_offset(q, blk_rq_pos(rq)),
+ blk_queue_get_max_sectors(q, rq->cmd_flags));
+}
+
+static inline unsigned int blk_rq_count_bios(struct request *rq)
+{
+ unsigned int nr_bios = 0;
+ struct bio *bio;
+
+ __rq_for_each_bio(bio, rq)
+ nr_bios++;
+
+ return nr_bios;
+}
+
+/*
+ * Request issue related functions.
+ */
+extern struct request *blk_peek_request(struct request_queue *q);
+extern void blk_start_request(struct request *rq);
+extern struct request *blk_fetch_request(struct request_queue *q);
+
+/*
+ * Request completion related functions.
+ *
+ * blk_update_request() completes given number of bytes and updates
+ * the request without completing it.
+ *
+ * blk_end_request() and friends. __blk_end_request() must be called
+ * with the request queue spinlock acquired.
+ *
+ * Several drivers define their own end_request and call
+ * blk_end_request() for parts of the original function.
+ * This prevents code duplication in drivers.
+ */
+extern bool blk_update_request(struct request *rq, int error,
+ unsigned int nr_bytes);
+extern void blk_finish_request(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 bool __blk_end_request(struct request *rq, int error,
+ unsigned int nr_bytes);
+extern void __blk_end_request_all(struct request *rq, int error);
+extern bool __blk_end_request_cur(struct request *rq, int error);
+extern bool __blk_end_request_err(struct request *rq, int error);
+
+extern void blk_complete_request(struct request *);
+extern void __blk_complete_request(struct request *);
+extern void blk_abort_request(struct request *);
+extern void blk_unprep_request(struct request *);
+
+/*
+ * Access functions for manipulating queue properties
+ */
+extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
+ spinlock_t *lock, int node_id);
+extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
+extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
+ request_fn_proc *, spinlock_t *);
+extern void blk_cleanup_queue(struct request_queue *);
+extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
+extern void blk_queue_bounce_limit(struct request_queue *, u64);
+extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
+extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
+extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
+extern void blk_queue_max_segments(struct request_queue *, unsigned short);
+extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
+extern void blk_queue_max_discard_sectors(struct request_queue *q,
+ unsigned int max_discard_sectors);
+extern void blk_queue_max_write_same_sectors(struct request_queue *q,
+ unsigned int max_write_same_sectors);
+extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
+extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
+extern void blk_queue_alignment_offset(struct request_queue *q,
+ unsigned int alignment);
+extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
+extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
+extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
+extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
+extern void blk_set_default_limits(struct queue_limits *lim);
+extern void blk_set_stacking_limits(struct queue_limits *lim);
+extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
+ sector_t offset);
+extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
+ sector_t offset);
+extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
+ sector_t offset);
+extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
+extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
+extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
+extern int blk_queue_dma_drain(struct request_queue *q,
+ dma_drain_needed_fn *dma_drain_needed,
+ void *buf, unsigned int size);
+extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
+extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
+extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
+extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
+extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
+extern void blk_queue_dma_alignment(struct request_queue *, int);
+extern void blk_queue_update_dma_alignment(struct request_queue *, int);
+extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
+extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
+extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
+extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
+extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
+extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
+
+extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
+extern void blk_dump_rq_flags(struct request *, char *);
+extern long nr_blockdev_pages(void);
+
+bool __must_check blk_get_queue(struct request_queue *);
+struct request_queue *blk_alloc_queue(gfp_t);
+struct request_queue *blk_alloc_queue_node(gfp_t, int);
+extern void blk_put_queue(struct request_queue *);
+
+/*
+ * block layer runtime pm functions
+ */
+#ifdef CONFIG_PM
+extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev);
+extern int blk_pre_runtime_suspend(struct request_queue *q);
+extern void blk_post_runtime_suspend(struct request_queue *q, int err);
+extern void blk_pre_runtime_resume(struct request_queue *q);
+extern void blk_post_runtime_resume(struct request_queue *q, int err);
+#else
+static inline void blk_pm_runtime_init(struct request_queue *q,
+ struct device *dev) {}
+static inline int blk_pre_runtime_suspend(struct request_queue *q)
+{
+ return -ENOSYS;
+}
+static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {}
+static inline void blk_pre_runtime_resume(struct request_queue *q) {}
+static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
+#endif
+
+/*
+ * blk_plug permits building a queue of related requests by holding the I/O
+ * fragments for a short period. This allows merging of sequential requests
+ * into single larger request. As the requests are moved from a per-task list to
+ * the device's request_queue in a batch, this results in improved scalability
+ * as the lock contention for request_queue lock is reduced.
+ *
+ * It is ok not to disable preemption when adding the request to the plug list
+ * or when attempting a merge, because blk_schedule_flush_list() will only flush
+ * the plug list when the task sleeps by itself. For details, please see
+ * schedule() where blk_schedule_flush_plug() is called.
+ */
+struct blk_plug {
+ struct list_head list; /* requests */
+ struct list_head mq_list; /* blk-mq requests */
+ struct list_head cb_list; /* md requires an unplug callback */
+};
+#define BLK_MAX_REQUEST_COUNT 16
+
+struct blk_plug_cb;
+typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
+struct blk_plug_cb {
+ struct list_head list;
+ blk_plug_cb_fn callback;
+ void *data;
+};
+extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
+ void *data, int size);
+extern void blk_start_plug(struct blk_plug *);
+extern void blk_finish_plug(struct blk_plug *);
+extern void blk_flush_plug_list(struct blk_plug *, bool);
+
+static inline void blk_flush_plug(struct task_struct *tsk)
+{
+ struct blk_plug *plug = tsk->plug;
+
+ if (plug)
+ blk_flush_plug_list(plug, false);
+}
+
+static inline void blk_schedule_flush_plug(struct task_struct *tsk)
+{
+ struct blk_plug *plug = tsk->plug;
+
+ if (plug)
+ blk_flush_plug_list(plug, true);
+}
+
+static inline bool blk_needs_flush_plug(struct task_struct *tsk)
+{
+ struct blk_plug *plug = tsk->plug;
+
+ return plug &&
+ (!list_empty(&plug->list) ||
+ !list_empty(&plug->mq_list) ||
+ !list_empty(&plug->cb_list));
+}
+
+/*
+ * tag stuff
+ */
+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 *, int);
+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, int);
+extern void blk_free_tags(struct blk_queue_tag *);
+
+static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
+ int tag)
+{
+ if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
+ return NULL;
+ return bqt->tag_index[tag];
+}
+
+#define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
+
+extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
+extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
+ sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
+extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
+ sector_t nr_sects, gfp_t gfp_mask, struct page *page);
+extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
+ sector_t nr_sects, gfp_t gfp_mask, bool discard);
+static inline int sb_issue_discard(struct super_block *sb, sector_t block,
+ sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
+{
+ return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
+ nr_blocks << (sb->s_blocksize_bits - 9),
+ gfp_mask, flags);
+}
+static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
+ sector_t nr_blocks, gfp_t gfp_mask)
+{
+ return blkdev_issue_zeroout(sb->s_bdev,
+ block << (sb->s_blocksize_bits - 9),
+ nr_blocks << (sb->s_blocksize_bits - 9),
+ gfp_mask, true);
+}
+
+extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
+
+enum blk_default_limits {
+ BLK_MAX_SEGMENTS = 128,
+ BLK_SAFE_MAX_SECTORS = 255,
+ BLK_MAX_SEGMENT_SIZE = 65536,
+ BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
+};
+
+#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
+
+static inline unsigned long queue_bounce_pfn(struct request_queue *q)
+{
+ return q->limits.bounce_pfn;
+}
+
+static inline unsigned long queue_segment_boundary(struct request_queue *q)
+{
+ return q->limits.seg_boundary_mask;
+}
+
+static inline unsigned int queue_max_sectors(struct request_queue *q)
+{
+ return q->limits.max_sectors;
+}
+
+static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
+{
+ return q->limits.max_hw_sectors;
+}
+
+static inline unsigned short queue_max_segments(struct request_queue *q)
+{
+ return q->limits.max_segments;
+}
+
+static inline unsigned int queue_max_segment_size(struct request_queue *q)
+{
+ return q->limits.max_segment_size;
+}
+
+static inline unsigned short queue_logical_block_size(struct request_queue *q)
+{
+ int retval = 512;
+
+ if (q && q->limits.logical_block_size)
+ retval = q->limits.logical_block_size;
+
+ return retval;
+}
+
+static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
+{
+ return queue_logical_block_size(bdev_get_queue(bdev));
+}
+
+static inline unsigned int queue_physical_block_size(struct request_queue *q)
+{
+ return q->limits.physical_block_size;
+}
+
+static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
+{
+ return queue_physical_block_size(bdev_get_queue(bdev));
+}
+
+static inline unsigned int queue_io_min(struct request_queue *q)
+{
+ return q->limits.io_min;
+}
+
+static inline int bdev_io_min(struct block_device *bdev)
+{
+ return queue_io_min(bdev_get_queue(bdev));
+}
+
+static inline unsigned int queue_io_opt(struct request_queue *q)
+{
+ return q->limits.io_opt;
+}
+
+static inline int bdev_io_opt(struct block_device *bdev)
+{
+ return queue_io_opt(bdev_get_queue(bdev));
+}
+
+static inline int queue_alignment_offset(struct request_queue *q)
+{
+ if (q->limits.misaligned)
+ return -1;
+
+ return q->limits.alignment_offset;
+}
+
+static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
+{
+ unsigned int granularity = max(lim->physical_block_size, lim->io_min);
+ unsigned int alignment = sector_div(sector, granularity >> 9) << 9;
+
+ return (granularity + lim->alignment_offset - alignment) % granularity;
+}
+
+static inline int bdev_alignment_offset(struct block_device *bdev)
+{
+ struct request_queue *q = bdev_get_queue(bdev);
+
+ if (q->limits.misaligned)
+ return -1;
+
+ if (bdev != bdev->bd_contains)
+ return bdev->bd_part->alignment_offset;
+
+ return q->limits.alignment_offset;
+}
+
+static inline int queue_discard_alignment(struct request_queue *q)
+{
+ if (q->limits.discard_misaligned)
+ return -1;
+
+ return q->limits.discard_alignment;
+}
+
+static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
+{
+ unsigned int alignment, granularity, offset;
+
+ if (!lim->max_discard_sectors)
+ return 0;
+
+ /* Why are these in bytes, not sectors? */
+ alignment = lim->discard_alignment >> 9;
+ granularity = lim->discard_granularity >> 9;
+ if (!granularity)
+ return 0;
+
+ /* Offset of the partition start in 'granularity' sectors */
+ offset = sector_div(sector, granularity);
+
+ /* And why do we do this modulus *again* in blkdev_issue_discard()? */
+ offset = (granularity + alignment - offset) % granularity;
+
+ /* Turn it back into bytes, gaah */
+ return offset << 9;
+}
+
+static inline int bdev_discard_alignment(struct block_device *bdev)
+{
+ struct request_queue *q = bdev_get_queue(bdev);
+
+ if (bdev != bdev->bd_contains)
+ return bdev->bd_part->discard_alignment;
+
+ return q->limits.discard_alignment;
+}
+
+static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
+{
+ if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
+ return 1;
+
+ return 0;
+}
+
+static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
+{
+ return queue_discard_zeroes_data(bdev_get_queue(bdev));
+}
+
+static inline unsigned int bdev_write_same(struct block_device *bdev)
+{
+ struct request_queue *q = bdev_get_queue(bdev);
+
+ if (q)
+ return q->limits.max_write_same_sectors;
+
+ return 0;
+}
+
+static inline int queue_dma_alignment(struct request_queue *q)
+{
+ return q ? q->dma_alignment : 511;
+}
+
+static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
+ unsigned int len)
+{
+ unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
+ return !(addr & alignment) && !(len & alignment);
+}
+
+/* assumes size > 256 */
+static inline unsigned int blksize_bits(unsigned int size)
+{
+ unsigned int bits = 8;
+ do {
+ bits++;
+ size >>= 1;
+ } while (size > 256);
+ return bits;
+}
+
+static inline unsigned int block_size(struct block_device *bdev)
+{
+ return bdev->bd_block_size;
+}
+
+static inline bool queue_flush_queueable(struct request_queue *q)
+{
+ return !q->flush_not_queueable;
+}
+
+typedef struct {struct page *v;} Sector;
+
+unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
+
+static inline void put_dev_sector(Sector p)
+{
+ page_cache_release(p.v);
+}
+
+struct work_struct;
+int kblockd_schedule_work(struct work_struct *work);
+int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay);
+int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
+
+#ifdef CONFIG_BLK_CGROUP
+/*
+ * This should not be using sched_clock(). A real patch is in progress
+ * to fix this up, until that is in place we need to disable preemption
+ * around sched_clock() in this function and set_io_start_time_ns().
+ */
+static inline void set_start_time_ns(struct request *req)
+{
+ preempt_disable();
+ req->start_time_ns = sched_clock();
+ preempt_enable();
+}
+
+static inline void set_io_start_time_ns(struct request *req)
+{
+ preempt_disable();
+ req->io_start_time_ns = sched_clock();
+ preempt_enable();
+}
+
+static inline uint64_t rq_start_time_ns(struct request *req)
+{
+ return req->start_time_ns;
+}
+
+static inline uint64_t rq_io_start_time_ns(struct request *req)
+{
+ return req->io_start_time_ns;
+}
+#else
+static inline void set_start_time_ns(struct request *req) {}
+static inline void set_io_start_time_ns(struct request *req) {}
+static inline uint64_t rq_start_time_ns(struct request *req)
+{
+ return 0;
+}
+static inline uint64_t rq_io_start_time_ns(struct request *req)
+{
+ return 0;
+}
+#endif
+
+#define MODULE_ALIAS_BLOCKDEV(major,minor) \
+ MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
+#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
+ MODULE_ALIAS("block-major-" __stringify(major) "-*")
+
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+
+enum blk_integrity_flags {
+ BLK_INTEGRITY_VERIFY = 1 << 0,
+ BLK_INTEGRITY_GENERATE = 1 << 1,
+ BLK_INTEGRITY_DEVICE_CAPABLE = 1 << 2,
+ BLK_INTEGRITY_IP_CHECKSUM = 1 << 3,
+};
+
+struct blk_integrity_iter {
+ void *prot_buf;
+ void *data_buf;
+ sector_t seed;
+ unsigned int data_size;
+ unsigned short interval;
+ const char *disk_name;
+};
+
+typedef int (integrity_processing_fn) (struct blk_integrity_iter *);
+
+struct blk_integrity {
+ integrity_processing_fn *generate_fn;
+ integrity_processing_fn *verify_fn;
+
+ unsigned short flags;
+ unsigned short tuple_size;
+ unsigned short interval;
+ unsigned short tag_size;
+
+ const char *name;
+
+ struct kobject kobj;
+};
+
+extern bool blk_integrity_is_initialized(struct gendisk *);
+extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
+extern void blk_integrity_unregister(struct gendisk *);
+extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
+extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
+ struct scatterlist *);
+extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
+extern bool blk_integrity_merge_rq(struct request_queue *, struct request *,
+ struct request *);
+extern bool blk_integrity_merge_bio(struct request_queue *, struct request *,
+ struct bio *);
+
+static inline
+struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
+{
+ return bdev->bd_disk->integrity;
+}
+
+static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
+{
+ return disk->integrity;
+}
+
+static inline bool blk_integrity_rq(struct request *rq)
+{
+ return rq->cmd_flags & REQ_INTEGRITY;
+}
+
+static inline void blk_queue_max_integrity_segments(struct request_queue *q,
+ unsigned int segs)
+{
+ q->limits.max_integrity_segments = segs;
+}
+
+static inline unsigned short
+queue_max_integrity_segments(struct request_queue *q)
+{
+ return q->limits.max_integrity_segments;
+}
+
+#else /* CONFIG_BLK_DEV_INTEGRITY */
+
+struct bio;
+struct block_device;
+struct gendisk;
+struct blk_integrity;
+
+static inline int blk_integrity_rq(struct request *rq)
+{
+ return 0;
+}
+static inline int blk_rq_count_integrity_sg(struct request_queue *q,
+ struct bio *b)
+{
+ return 0;
+}
+static inline int blk_rq_map_integrity_sg(struct request_queue *q,
+ struct bio *b,
+ struct scatterlist *s)
+{
+ return 0;
+}
+static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
+{
+ return NULL;
+}
+static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
+{
+ return NULL;
+}
+static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
+{
+ return 0;
+}
+static inline int blk_integrity_register(struct gendisk *d,
+ struct blk_integrity *b)
+{
+ return 0;
+}
+static inline void blk_integrity_unregister(struct gendisk *d)
+{
+}
+static inline void blk_queue_max_integrity_segments(struct request_queue *q,
+ unsigned int segs)
+{
+}
+static inline unsigned short queue_max_integrity_segments(struct request_queue *q)
+{
+ return 0;
+}
+static inline bool blk_integrity_merge_rq(struct request_queue *rq,
+ struct request *r1,
+ struct request *r2)
+{
+ return true;
+}
+static inline bool blk_integrity_merge_bio(struct request_queue *rq,
+ struct request *r,
+ struct bio *b)
+{
+ return true;
+}
+static inline bool blk_integrity_is_initialized(struct gendisk *g)
+{
+ return 0;
+}
+
+#endif /* CONFIG_BLK_DEV_INTEGRITY */
+
+struct block_device_operations {
+ int (*open) (struct block_device *, fmode_t);
+ void (*release) (struct gendisk *, fmode_t);
+ int (*rw_page)(struct block_device *, sector_t, struct page *, int rw);
+ int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
+ int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
+ long (*direct_access)(struct block_device *, sector_t,
+ void **, unsigned long *pfn, long size);
+ unsigned int (*check_events) (struct gendisk *disk,
+ unsigned int clearing);
+ /* ->media_changed() is DEPRECATED, use ->check_events() instead */
+ int (*media_changed) (struct gendisk *);
+ void (*unlock_native_capacity) (struct gendisk *);
+ int (*revalidate_disk) (struct gendisk *);
+ int (*getgeo)(struct block_device *, struct hd_geometry *);
+ /* this callback is with swap_lock and sometimes page table lock held */
+ void (*swap_slot_free_notify) (struct block_device *, unsigned long);
+ struct module *owner;
+};
+
+extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
+ unsigned long);
+extern int bdev_read_page(struct block_device *, sector_t, struct page *);
+extern int bdev_write_page(struct block_device *, sector_t, struct page *,
+ struct writeback_control *);
+extern long bdev_direct_access(struct block_device *, sector_t, void **addr,
+ unsigned long *pfn, long size);
+#else /* CONFIG_BLOCK */
+
+struct block_device;
+
+/*
+ * stubs for when the block layer is configured out
+ */
+#define buffer_heads_over_limit 0
+
+static inline long nr_blockdev_pages(void)
+{
+ return 0;
+}
+
+struct blk_plug {
+};
+
+static inline void blk_start_plug(struct blk_plug *plug)
+{
+}
+
+static inline void blk_finish_plug(struct blk_plug *plug)
+{
+}
+
+static inline void blk_flush_plug(struct task_struct *task)
+{
+}
+
+static inline void blk_schedule_flush_plug(struct task_struct *task)
+{
+}
+
+
+static inline bool blk_needs_flush_plug(struct task_struct *tsk)
+{
+ return false;
+}
+
+static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
+ sector_t *error_sector)
+{
+ return 0;
+}
+
+#endif /* CONFIG_BLOCK */
+
+#endif