xref: /linux-6.15/include/linux/blkdev.h (revision 4b2a108c)
1 #ifndef _LINUX_BLKDEV_H
2 #define _LINUX_BLKDEV_H
3 
4 #ifdef CONFIG_BLOCK
5 
6 #include <linux/sched.h>
7 #include <linux/major.h>
8 #include <linux/genhd.h>
9 #include <linux/list.h>
10 #include <linux/timer.h>
11 #include <linux/workqueue.h>
12 #include <linux/pagemap.h>
13 #include <linux/backing-dev.h>
14 #include <linux/wait.h>
15 #include <linux/mempool.h>
16 #include <linux/bio.h>
17 #include <linux/module.h>
18 #include <linux/stringify.h>
19 #include <linux/gfp.h>
20 #include <linux/bsg.h>
21 #include <linux/smp.h>
22 
23 #include <asm/scatterlist.h>
24 
25 struct scsi_ioctl_command;
26 
27 struct request_queue;
28 struct elevator_queue;
29 struct request_pm_state;
30 struct blk_trace;
31 struct request;
32 struct sg_io_hdr;
33 
34 #define BLKDEV_MIN_RQ	4
35 #define BLKDEV_MAX_RQ	128	/* Default maximum */
36 
37 struct request;
38 typedef void (rq_end_io_fn)(struct request *, int);
39 
40 struct request_list {
41 	/*
42 	 * count[], starved[], and wait[] are indexed by
43 	 * BLK_RW_SYNC/BLK_RW_ASYNC
44 	 */
45 	int count[2];
46 	int starved[2];
47 	int elvpriv;
48 	mempool_t *rq_pool;
49 	wait_queue_head_t wait[2];
50 };
51 
52 /*
53  * request command types
54  */
55 enum rq_cmd_type_bits {
56 	REQ_TYPE_FS		= 1,	/* fs request */
57 	REQ_TYPE_BLOCK_PC,		/* scsi command */
58 	REQ_TYPE_SENSE,			/* sense request */
59 	REQ_TYPE_PM_SUSPEND,		/* suspend request */
60 	REQ_TYPE_PM_RESUME,		/* resume request */
61 	REQ_TYPE_PM_SHUTDOWN,		/* shutdown request */
62 	REQ_TYPE_SPECIAL,		/* driver defined type */
63 	REQ_TYPE_LINUX_BLOCK,		/* generic block layer message */
64 	/*
65 	 * for ATA/ATAPI devices. this really doesn't belong here, ide should
66 	 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
67 	 * private REQ_LB opcodes to differentiate what type of request this is
68 	 */
69 	REQ_TYPE_ATA_TASKFILE,
70 	REQ_TYPE_ATA_PC,
71 };
72 
73 /*
74  * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
75  * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
76  * SCSI cdb.
77  *
78  * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
79  * typically to differentiate REQ_TYPE_SPECIAL requests.
80  *
81  */
82 enum {
83 	REQ_LB_OP_EJECT	= 0x40,		/* eject request */
84 	REQ_LB_OP_FLUSH = 0x41,		/* flush request */
85 	REQ_LB_OP_DISCARD = 0x42,	/* discard sectors */
86 };
87 
88 /*
89  * request type modified bits. first two bits match BIO_RW* bits, important
90  */
91 enum rq_flag_bits {
92 	__REQ_RW,		/* not set, read. set, write */
93 	__REQ_FAILFAST_DEV,	/* no driver retries of device errors */
94 	__REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
95 	__REQ_FAILFAST_DRIVER,	/* no driver retries of driver errors */
96 	__REQ_DISCARD,		/* request to discard sectors */
97 	__REQ_SORTED,		/* elevator knows about this request */
98 	__REQ_SOFTBARRIER,	/* may not be passed by ioscheduler */
99 	__REQ_HARDBARRIER,	/* may not be passed by drive either */
100 	__REQ_FUA,		/* forced unit access */
101 	__REQ_NOMERGE,		/* don't touch this for merging */
102 	__REQ_STARTED,		/* drive already may have started this one */
103 	__REQ_DONTPREP,		/* don't call prep for this one */
104 	__REQ_QUEUED,		/* uses queueing */
105 	__REQ_ELVPRIV,		/* elevator private data attached */
106 	__REQ_FAILED,		/* set if the request failed */
107 	__REQ_QUIET,		/* don't worry about errors */
108 	__REQ_PREEMPT,		/* set for "ide_preempt" requests */
109 	__REQ_ORDERED_COLOR,	/* is before or after barrier */
110 	__REQ_RW_SYNC,		/* request is sync (sync write or read) */
111 	__REQ_ALLOCED,		/* request came from our alloc pool */
112 	__REQ_RW_META,		/* metadata io request */
113 	__REQ_COPY_USER,	/* contains copies of user pages */
114 	__REQ_INTEGRITY,	/* integrity metadata has been remapped */
115 	__REQ_NOIDLE,		/* Don't anticipate more IO after this one */
116 	__REQ_IO_STAT,		/* account I/O stat */
117 	__REQ_NR_BITS,		/* stops here */
118 };
119 
120 #define REQ_RW		(1 << __REQ_RW)
121 #define REQ_FAILFAST_DEV	(1 << __REQ_FAILFAST_DEV)
122 #define REQ_FAILFAST_TRANSPORT	(1 << __REQ_FAILFAST_TRANSPORT)
123 #define REQ_FAILFAST_DRIVER	(1 << __REQ_FAILFAST_DRIVER)
124 #define REQ_DISCARD	(1 << __REQ_DISCARD)
125 #define REQ_SORTED	(1 << __REQ_SORTED)
126 #define REQ_SOFTBARRIER	(1 << __REQ_SOFTBARRIER)
127 #define REQ_HARDBARRIER	(1 << __REQ_HARDBARRIER)
128 #define REQ_FUA		(1 << __REQ_FUA)
129 #define REQ_NOMERGE	(1 << __REQ_NOMERGE)
130 #define REQ_STARTED	(1 << __REQ_STARTED)
131 #define REQ_DONTPREP	(1 << __REQ_DONTPREP)
132 #define REQ_QUEUED	(1 << __REQ_QUEUED)
133 #define REQ_ELVPRIV	(1 << __REQ_ELVPRIV)
134 #define REQ_FAILED	(1 << __REQ_FAILED)
135 #define REQ_QUIET	(1 << __REQ_QUIET)
136 #define REQ_PREEMPT	(1 << __REQ_PREEMPT)
137 #define REQ_ORDERED_COLOR	(1 << __REQ_ORDERED_COLOR)
138 #define REQ_RW_SYNC	(1 << __REQ_RW_SYNC)
139 #define REQ_ALLOCED	(1 << __REQ_ALLOCED)
140 #define REQ_RW_META	(1 << __REQ_RW_META)
141 #define REQ_COPY_USER	(1 << __REQ_COPY_USER)
142 #define REQ_INTEGRITY	(1 << __REQ_INTEGRITY)
143 #define REQ_NOIDLE	(1 << __REQ_NOIDLE)
144 #define REQ_IO_STAT	(1 << __REQ_IO_STAT)
145 
146 #define BLK_MAX_CDB	16
147 
148 /*
149  * try to put the fields that are referenced together in the same cacheline.
150  * if you modify this structure, be sure to check block/blk-core.c:rq_init()
151  * as well!
152  */
153 struct request {
154 	struct list_head queuelist;
155 	struct call_single_data csd;
156 	int cpu;
157 
158 	struct request_queue *q;
159 
160 	unsigned int cmd_flags;
161 	enum rq_cmd_type_bits cmd_type;
162 	unsigned long atomic_flags;
163 
164 	/* the following two fields are internal, NEVER access directly */
165 	sector_t __sector;		/* sector cursor */
166 	unsigned int __data_len;	/* total data len */
167 
168 	struct bio *bio;
169 	struct bio *biotail;
170 
171 	struct hlist_node hash;	/* merge hash */
172 	/*
173 	 * The rb_node is only used inside the io scheduler, requests
174 	 * are pruned when moved to the dispatch queue. So let the
175 	 * completion_data share space with the rb_node.
176 	 */
177 	union {
178 		struct rb_node rb_node;	/* sort/lookup */
179 		void *completion_data;
180 	};
181 
182 	/*
183 	 * two pointers are available for the IO schedulers, if they need
184 	 * more they have to dynamically allocate it.
185 	 */
186 	void *elevator_private;
187 	void *elevator_private2;
188 
189 	struct gendisk *rq_disk;
190 	unsigned long start_time;
191 
192 	/* Number of scatter-gather DMA addr+len pairs after
193 	 * physical address coalescing is performed.
194 	 */
195 	unsigned short nr_phys_segments;
196 
197 	unsigned short ioprio;
198 
199 	void *special;		/* opaque pointer available for LLD use */
200 	char *buffer;		/* kaddr of the current segment if available */
201 
202 	int tag;
203 	int errors;
204 
205 	int ref_count;
206 
207 	/*
208 	 * when request is used as a packet command carrier
209 	 */
210 	unsigned short cmd_len;
211 	unsigned char __cmd[BLK_MAX_CDB];
212 	unsigned char *cmd;
213 
214 	unsigned int extra_len;	/* length of alignment and padding */
215 	unsigned int sense_len;
216 	unsigned int resid_len;	/* residual count */
217 	void *sense;
218 
219 	unsigned long deadline;
220 	struct list_head timeout_list;
221 	unsigned int timeout;
222 	int retries;
223 
224 	/*
225 	 * completion callback.
226 	 */
227 	rq_end_io_fn *end_io;
228 	void *end_io_data;
229 
230 	/* for bidi */
231 	struct request *next_rq;
232 };
233 
234 static inline unsigned short req_get_ioprio(struct request *req)
235 {
236 	return req->ioprio;
237 }
238 
239 /*
240  * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
241  * requests. Some step values could eventually be made generic.
242  */
243 struct request_pm_state
244 {
245 	/* PM state machine step value, currently driver specific */
246 	int	pm_step;
247 	/* requested PM state value (S1, S2, S3, S4, ...) */
248 	u32	pm_state;
249 	void*	data;		/* for driver use */
250 };
251 
252 #include <linux/elevator.h>
253 
254 typedef void (request_fn_proc) (struct request_queue *q);
255 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
256 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
257 typedef void (unplug_fn) (struct request_queue *);
258 typedef int (prepare_discard_fn) (struct request_queue *, struct request *);
259 
260 struct bio_vec;
261 struct bvec_merge_data {
262 	struct block_device *bi_bdev;
263 	sector_t bi_sector;
264 	unsigned bi_size;
265 	unsigned long bi_rw;
266 };
267 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
268 			     struct bio_vec *);
269 typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
270 typedef void (softirq_done_fn)(struct request *);
271 typedef int (dma_drain_needed_fn)(struct request *);
272 typedef int (lld_busy_fn) (struct request_queue *q);
273 
274 enum blk_eh_timer_return {
275 	BLK_EH_NOT_HANDLED,
276 	BLK_EH_HANDLED,
277 	BLK_EH_RESET_TIMER,
278 };
279 
280 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
281 
282 enum blk_queue_state {
283 	Queue_down,
284 	Queue_up,
285 };
286 
287 struct blk_queue_tag {
288 	struct request **tag_index;	/* map of busy tags */
289 	unsigned long *tag_map;		/* bit map of free/busy tags */
290 	int busy;			/* current depth */
291 	int max_depth;			/* what we will send to device */
292 	int real_max_depth;		/* what the array can hold */
293 	atomic_t refcnt;		/* map can be shared */
294 };
295 
296 #define BLK_SCSI_MAX_CMDS	(256)
297 #define BLK_SCSI_CMD_PER_LONG	(BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
298 
299 struct queue_limits {
300 	unsigned long		bounce_pfn;
301 	unsigned long		seg_boundary_mask;
302 
303 	unsigned int		max_hw_sectors;
304 	unsigned int		max_sectors;
305 	unsigned int		max_segment_size;
306 	unsigned int		physical_block_size;
307 	unsigned int		alignment_offset;
308 	unsigned int		io_min;
309 	unsigned int		io_opt;
310 
311 	unsigned short		logical_block_size;
312 	unsigned short		max_hw_segments;
313 	unsigned short		max_phys_segments;
314 
315 	unsigned char		misaligned;
316 	unsigned char		no_cluster;
317 };
318 
319 struct request_queue
320 {
321 	/*
322 	 * Together with queue_head for cacheline sharing
323 	 */
324 	struct list_head	queue_head;
325 	struct request		*last_merge;
326 	struct elevator_queue	*elevator;
327 
328 	/*
329 	 * the queue request freelist, one for reads and one for writes
330 	 */
331 	struct request_list	rq;
332 
333 	request_fn_proc		*request_fn;
334 	make_request_fn		*make_request_fn;
335 	prep_rq_fn		*prep_rq_fn;
336 	unplug_fn		*unplug_fn;
337 	prepare_discard_fn	*prepare_discard_fn;
338 	merge_bvec_fn		*merge_bvec_fn;
339 	prepare_flush_fn	*prepare_flush_fn;
340 	softirq_done_fn		*softirq_done_fn;
341 	rq_timed_out_fn		*rq_timed_out_fn;
342 	dma_drain_needed_fn	*dma_drain_needed;
343 	lld_busy_fn		*lld_busy_fn;
344 
345 	/*
346 	 * Dispatch queue sorting
347 	 */
348 	sector_t		end_sector;
349 	struct request		*boundary_rq;
350 
351 	/*
352 	 * Auto-unplugging state
353 	 */
354 	struct timer_list	unplug_timer;
355 	int			unplug_thresh;	/* After this many requests */
356 	unsigned long		unplug_delay;	/* After this many jiffies */
357 	struct work_struct	unplug_work;
358 
359 	struct backing_dev_info	backing_dev_info;
360 
361 	/*
362 	 * The queue owner gets to use this for whatever they like.
363 	 * ll_rw_blk doesn't touch it.
364 	 */
365 	void			*queuedata;
366 
367 	/*
368 	 * queue needs bounce pages for pages above this limit
369 	 */
370 	gfp_t			bounce_gfp;
371 
372 	/*
373 	 * various queue flags, see QUEUE_* below
374 	 */
375 	unsigned long		queue_flags;
376 
377 	/*
378 	 * protects queue structures from reentrancy. ->__queue_lock should
379 	 * _never_ be used directly, it is queue private. always use
380 	 * ->queue_lock.
381 	 */
382 	spinlock_t		__queue_lock;
383 	spinlock_t		*queue_lock;
384 
385 	/*
386 	 * queue kobject
387 	 */
388 	struct kobject kobj;
389 
390 	/*
391 	 * queue settings
392 	 */
393 	unsigned long		nr_requests;	/* Max # of requests */
394 	unsigned int		nr_congestion_on;
395 	unsigned int		nr_congestion_off;
396 	unsigned int		nr_batching;
397 
398 	void			*dma_drain_buffer;
399 	unsigned int		dma_drain_size;
400 	unsigned int		dma_pad_mask;
401 	unsigned int		dma_alignment;
402 
403 	struct blk_queue_tag	*queue_tags;
404 	struct list_head	tag_busy_list;
405 
406 	unsigned int		nr_sorted;
407 	unsigned int		in_flight[2];
408 
409 	unsigned int		rq_timeout;
410 	struct timer_list	timeout;
411 	struct list_head	timeout_list;
412 
413 	struct queue_limits	limits;
414 
415 	/*
416 	 * sg stuff
417 	 */
418 	unsigned int		sg_timeout;
419 	unsigned int		sg_reserved_size;
420 	int			node;
421 #ifdef CONFIG_BLK_DEV_IO_TRACE
422 	struct blk_trace	*blk_trace;
423 #endif
424 	/*
425 	 * reserved for flush operations
426 	 */
427 	unsigned int		ordered, next_ordered, ordseq;
428 	int			orderr, ordcolor;
429 	struct request		pre_flush_rq, bar_rq, post_flush_rq;
430 	struct request		*orig_bar_rq;
431 
432 	struct mutex		sysfs_lock;
433 
434 #if defined(CONFIG_BLK_DEV_BSG)
435 	struct bsg_class_device bsg_dev;
436 #endif
437 };
438 
439 #define QUEUE_FLAG_CLUSTER	0	/* cluster several segments into 1 */
440 #define QUEUE_FLAG_QUEUED	1	/* uses generic tag queueing */
441 #define QUEUE_FLAG_STOPPED	2	/* queue is stopped */
442 #define	QUEUE_FLAG_SYNCFULL	3	/* read queue has been filled */
443 #define QUEUE_FLAG_ASYNCFULL	4	/* write queue has been filled */
444 #define QUEUE_FLAG_DEAD		5	/* queue being torn down */
445 #define QUEUE_FLAG_REENTER	6	/* Re-entrancy avoidance */
446 #define QUEUE_FLAG_PLUGGED	7	/* queue is plugged */
447 #define QUEUE_FLAG_ELVSWITCH	8	/* don't use elevator, just do FIFO */
448 #define QUEUE_FLAG_BIDI		9	/* queue supports bidi requests */
449 #define QUEUE_FLAG_NOMERGES    10	/* disable merge attempts */
450 #define QUEUE_FLAG_SAME_COMP   11	/* force complete on same CPU */
451 #define QUEUE_FLAG_FAIL_IO     12	/* fake timeout */
452 #define QUEUE_FLAG_STACKABLE   13	/* supports request stacking */
453 #define QUEUE_FLAG_NONROT      14	/* non-rotational device (SSD) */
454 #define QUEUE_FLAG_VIRT        QUEUE_FLAG_NONROT /* paravirt device */
455 #define QUEUE_FLAG_IO_STAT     15	/* do IO stats */
456 
457 #define QUEUE_FLAG_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
458 				 (1 << QUEUE_FLAG_CLUSTER) |		\
459 				 (1 << QUEUE_FLAG_STACKABLE))
460 
461 static inline int queue_is_locked(struct request_queue *q)
462 {
463 #ifdef CONFIG_SMP
464 	spinlock_t *lock = q->queue_lock;
465 	return lock && spin_is_locked(lock);
466 #else
467 	return 1;
468 #endif
469 }
470 
471 static inline void queue_flag_set_unlocked(unsigned int flag,
472 					   struct request_queue *q)
473 {
474 	__set_bit(flag, &q->queue_flags);
475 }
476 
477 static inline int queue_flag_test_and_clear(unsigned int flag,
478 					    struct request_queue *q)
479 {
480 	WARN_ON_ONCE(!queue_is_locked(q));
481 
482 	if (test_bit(flag, &q->queue_flags)) {
483 		__clear_bit(flag, &q->queue_flags);
484 		return 1;
485 	}
486 
487 	return 0;
488 }
489 
490 static inline int queue_flag_test_and_set(unsigned int flag,
491 					  struct request_queue *q)
492 {
493 	WARN_ON_ONCE(!queue_is_locked(q));
494 
495 	if (!test_bit(flag, &q->queue_flags)) {
496 		__set_bit(flag, &q->queue_flags);
497 		return 0;
498 	}
499 
500 	return 1;
501 }
502 
503 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
504 {
505 	WARN_ON_ONCE(!queue_is_locked(q));
506 	__set_bit(flag, &q->queue_flags);
507 }
508 
509 static inline void queue_flag_clear_unlocked(unsigned int flag,
510 					     struct request_queue *q)
511 {
512 	__clear_bit(flag, &q->queue_flags);
513 }
514 
515 static inline int queue_in_flight(struct request_queue *q)
516 {
517 	return q->in_flight[0] + q->in_flight[1];
518 }
519 
520 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
521 {
522 	WARN_ON_ONCE(!queue_is_locked(q));
523 	__clear_bit(flag, &q->queue_flags);
524 }
525 
526 enum {
527 	/*
528 	 * Hardbarrier is supported with one of the following methods.
529 	 *
530 	 * NONE		: hardbarrier unsupported
531 	 * DRAIN	: ordering by draining is enough
532 	 * DRAIN_FLUSH	: ordering by draining w/ pre and post flushes
533 	 * DRAIN_FUA	: ordering by draining w/ pre flush and FUA write
534 	 * TAG		: ordering by tag is enough
535 	 * TAG_FLUSH	: ordering by tag w/ pre and post flushes
536 	 * TAG_FUA	: ordering by tag w/ pre flush and FUA write
537 	 */
538 	QUEUE_ORDERED_BY_DRAIN		= 0x01,
539 	QUEUE_ORDERED_BY_TAG		= 0x02,
540 	QUEUE_ORDERED_DO_PREFLUSH	= 0x10,
541 	QUEUE_ORDERED_DO_BAR		= 0x20,
542 	QUEUE_ORDERED_DO_POSTFLUSH	= 0x40,
543 	QUEUE_ORDERED_DO_FUA		= 0x80,
544 
545 	QUEUE_ORDERED_NONE		= 0x00,
546 
547 	QUEUE_ORDERED_DRAIN		= QUEUE_ORDERED_BY_DRAIN |
548 					  QUEUE_ORDERED_DO_BAR,
549 	QUEUE_ORDERED_DRAIN_FLUSH	= QUEUE_ORDERED_DRAIN |
550 					  QUEUE_ORDERED_DO_PREFLUSH |
551 					  QUEUE_ORDERED_DO_POSTFLUSH,
552 	QUEUE_ORDERED_DRAIN_FUA		= QUEUE_ORDERED_DRAIN |
553 					  QUEUE_ORDERED_DO_PREFLUSH |
554 					  QUEUE_ORDERED_DO_FUA,
555 
556 	QUEUE_ORDERED_TAG		= QUEUE_ORDERED_BY_TAG |
557 					  QUEUE_ORDERED_DO_BAR,
558 	QUEUE_ORDERED_TAG_FLUSH		= QUEUE_ORDERED_TAG |
559 					  QUEUE_ORDERED_DO_PREFLUSH |
560 					  QUEUE_ORDERED_DO_POSTFLUSH,
561 	QUEUE_ORDERED_TAG_FUA		= QUEUE_ORDERED_TAG |
562 					  QUEUE_ORDERED_DO_PREFLUSH |
563 					  QUEUE_ORDERED_DO_FUA,
564 
565 	/*
566 	 * Ordered operation sequence
567 	 */
568 	QUEUE_ORDSEQ_STARTED	= 0x01,	/* flushing in progress */
569 	QUEUE_ORDSEQ_DRAIN	= 0x02,	/* waiting for the queue to be drained */
570 	QUEUE_ORDSEQ_PREFLUSH	= 0x04,	/* pre-flushing in progress */
571 	QUEUE_ORDSEQ_BAR	= 0x08,	/* original barrier req in progress */
572 	QUEUE_ORDSEQ_POSTFLUSH	= 0x10,	/* post-flushing in progress */
573 	QUEUE_ORDSEQ_DONE	= 0x20,
574 };
575 
576 #define blk_queue_plugged(q)	test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
577 #define blk_queue_tagged(q)	test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
578 #define blk_queue_stopped(q)	test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
579 #define blk_queue_nomerges(q)	test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
580 #define blk_queue_nonrot(q)	test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
581 #define blk_queue_io_stat(q)	test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
582 #define blk_queue_flushing(q)	((q)->ordseq)
583 #define blk_queue_stackable(q)	\
584 	test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
585 
586 #define blk_fs_request(rq)	((rq)->cmd_type == REQ_TYPE_FS)
587 #define blk_pc_request(rq)	((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
588 #define blk_special_request(rq)	((rq)->cmd_type == REQ_TYPE_SPECIAL)
589 #define blk_sense_request(rq)	((rq)->cmd_type == REQ_TYPE_SENSE)
590 
591 #define blk_failfast_dev(rq)	((rq)->cmd_flags & REQ_FAILFAST_DEV)
592 #define blk_failfast_transport(rq) ((rq)->cmd_flags & REQ_FAILFAST_TRANSPORT)
593 #define blk_failfast_driver(rq)	((rq)->cmd_flags & REQ_FAILFAST_DRIVER)
594 #define blk_noretry_request(rq)	(blk_failfast_dev(rq) ||	\
595 				 blk_failfast_transport(rq) ||	\
596 				 blk_failfast_driver(rq))
597 #define blk_rq_started(rq)	((rq)->cmd_flags & REQ_STARTED)
598 #define blk_rq_io_stat(rq)	((rq)->cmd_flags & REQ_IO_STAT)
599 #define blk_rq_quiet(rq)	((rq)->cmd_flags & REQ_QUIET)
600 
601 #define blk_account_rq(rq)	(blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
602 
603 #define blk_pm_suspend_request(rq)	((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
604 #define blk_pm_resume_request(rq)	((rq)->cmd_type == REQ_TYPE_PM_RESUME)
605 #define blk_pm_request(rq)	\
606 	(blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
607 
608 #define blk_rq_cpu_valid(rq)	((rq)->cpu != -1)
609 #define blk_sorted_rq(rq)	((rq)->cmd_flags & REQ_SORTED)
610 #define blk_barrier_rq(rq)	((rq)->cmd_flags & REQ_HARDBARRIER)
611 #define blk_fua_rq(rq)		((rq)->cmd_flags & REQ_FUA)
612 #define blk_discard_rq(rq)	((rq)->cmd_flags & REQ_DISCARD)
613 #define blk_bidi_rq(rq)		((rq)->next_rq != NULL)
614 /* rq->queuelist of dequeued request must be list_empty() */
615 #define blk_queued_rq(rq)	(!list_empty(&(rq)->queuelist))
616 
617 #define list_entry_rq(ptr)	list_entry((ptr), struct request, queuelist)
618 
619 #define rq_data_dir(rq)		((rq)->cmd_flags & 1)
620 
621 /*
622  * We regard a request as sync, if either a read or a sync write
623  */
624 static inline bool rw_is_sync(unsigned int rw_flags)
625 {
626 	return !(rw_flags & REQ_RW) || (rw_flags & REQ_RW_SYNC);
627 }
628 
629 static inline bool rq_is_sync(struct request *rq)
630 {
631 	return rw_is_sync(rq->cmd_flags);
632 }
633 
634 #define rq_is_meta(rq)		((rq)->cmd_flags & REQ_RW_META)
635 #define rq_noidle(rq)		((rq)->cmd_flags & REQ_NOIDLE)
636 
637 static inline int blk_queue_full(struct request_queue *q, int sync)
638 {
639 	if (sync)
640 		return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
641 	return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
642 }
643 
644 static inline void blk_set_queue_full(struct request_queue *q, int sync)
645 {
646 	if (sync)
647 		queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
648 	else
649 		queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
650 }
651 
652 static inline void blk_clear_queue_full(struct request_queue *q, int sync)
653 {
654 	if (sync)
655 		queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
656 	else
657 		queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
658 }
659 
660 
661 /*
662  * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
663  * it already be started by driver.
664  */
665 #define RQ_NOMERGE_FLAGS	\
666 	(REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
667 #define rq_mergeable(rq)	\
668 	(!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
669 	 (blk_discard_rq(rq) || blk_fs_request((rq))))
670 
671 /*
672  * q->prep_rq_fn return values
673  */
674 #define BLKPREP_OK		0	/* serve it */
675 #define BLKPREP_KILL		1	/* fatal error, kill */
676 #define BLKPREP_DEFER		2	/* leave on queue */
677 
678 extern unsigned long blk_max_low_pfn, blk_max_pfn;
679 
680 /*
681  * standard bounce addresses:
682  *
683  * BLK_BOUNCE_HIGH	: bounce all highmem pages
684  * BLK_BOUNCE_ANY	: don't bounce anything
685  * BLK_BOUNCE_ISA	: bounce pages above ISA DMA boundary
686  */
687 
688 #if BITS_PER_LONG == 32
689 #define BLK_BOUNCE_HIGH		((u64)blk_max_low_pfn << PAGE_SHIFT)
690 #else
691 #define BLK_BOUNCE_HIGH		-1ULL
692 #endif
693 #define BLK_BOUNCE_ANY		(-1ULL)
694 #define BLK_BOUNCE_ISA		(ISA_DMA_THRESHOLD)
695 
696 /*
697  * default timeout for SG_IO if none specified
698  */
699 #define BLK_DEFAULT_SG_TIMEOUT	(60 * HZ)
700 #define BLK_MIN_SG_TIMEOUT	(7 * HZ)
701 
702 #ifdef CONFIG_BOUNCE
703 extern int init_emergency_isa_pool(void);
704 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
705 #else
706 static inline int init_emergency_isa_pool(void)
707 {
708 	return 0;
709 }
710 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
711 {
712 }
713 #endif /* CONFIG_MMU */
714 
715 struct rq_map_data {
716 	struct page **pages;
717 	int page_order;
718 	int nr_entries;
719 	unsigned long offset;
720 	int null_mapped;
721 	int from_user;
722 };
723 
724 struct req_iterator {
725 	int i;
726 	struct bio *bio;
727 };
728 
729 /* This should not be used directly - use rq_for_each_segment */
730 #define for_each_bio(_bio)		\
731 	for (; _bio; _bio = _bio->bi_next)
732 #define __rq_for_each_bio(_bio, rq)	\
733 	if ((rq->bio))			\
734 		for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
735 
736 #define rq_for_each_segment(bvl, _rq, _iter)			\
737 	__rq_for_each_bio(_iter.bio, _rq)			\
738 		bio_for_each_segment(bvl, _iter.bio, _iter.i)
739 
740 #define rq_iter_last(rq, _iter)					\
741 		(_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
742 
743 extern int blk_register_queue(struct gendisk *disk);
744 extern void blk_unregister_queue(struct gendisk *disk);
745 extern void register_disk(struct gendisk *dev);
746 extern void generic_make_request(struct bio *bio);
747 extern void blk_rq_init(struct request_queue *q, struct request *rq);
748 extern void blk_put_request(struct request *);
749 extern void __blk_put_request(struct request_queue *, struct request *);
750 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
751 extern struct request *blk_make_request(struct request_queue *, struct bio *,
752 					gfp_t);
753 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
754 extern void blk_requeue_request(struct request_queue *, struct request *);
755 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
756 extern int blk_lld_busy(struct request_queue *q);
757 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
758 			     struct bio_set *bs, gfp_t gfp_mask,
759 			     int (*bio_ctr)(struct bio *, struct bio *, void *),
760 			     void *data);
761 extern void blk_rq_unprep_clone(struct request *rq);
762 extern int blk_insert_cloned_request(struct request_queue *q,
763 				     struct request *rq);
764 extern void blk_plug_device(struct request_queue *);
765 extern void blk_plug_device_unlocked(struct request_queue *);
766 extern int blk_remove_plug(struct request_queue *);
767 extern void blk_recount_segments(struct request_queue *, struct bio *);
768 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
769 			  unsigned int, void __user *);
770 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
771 			 struct scsi_ioctl_command __user *);
772 
773 /*
774  * A queue has just exitted congestion.  Note this in the global counter of
775  * congested queues, and wake up anyone who was waiting for requests to be
776  * put back.
777  */
778 static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
779 {
780 	clear_bdi_congested(&q->backing_dev_info, sync);
781 }
782 
783 /*
784  * A queue has just entered congestion.  Flag that in the queue's VM-visible
785  * state flags and increment the global gounter of congested queues.
786  */
787 static inline void blk_set_queue_congested(struct request_queue *q, int sync)
788 {
789 	set_bdi_congested(&q->backing_dev_info, sync);
790 }
791 
792 extern void blk_start_queue(struct request_queue *q);
793 extern void blk_stop_queue(struct request_queue *q);
794 extern void blk_sync_queue(struct request_queue *q);
795 extern void __blk_stop_queue(struct request_queue *q);
796 extern void __blk_run_queue(struct request_queue *);
797 extern void blk_run_queue(struct request_queue *);
798 extern int blk_rq_map_user(struct request_queue *, struct request *,
799 			   struct rq_map_data *, void __user *, unsigned long,
800 			   gfp_t);
801 extern int blk_rq_unmap_user(struct bio *);
802 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
803 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
804 			       struct rq_map_data *, struct sg_iovec *, int,
805 			       unsigned int, gfp_t);
806 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
807 			  struct request *, int);
808 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
809 				  struct request *, int, rq_end_io_fn *);
810 extern void blk_unplug(struct request_queue *q);
811 
812 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
813 {
814 	return bdev->bd_disk->queue;
815 }
816 
817 static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
818 				       struct page *page)
819 {
820 	if (bdi && bdi->unplug_io_fn)
821 		bdi->unplug_io_fn(bdi, page);
822 }
823 
824 static inline void blk_run_address_space(struct address_space *mapping)
825 {
826 	if (mapping)
827 		blk_run_backing_dev(mapping->backing_dev_info, NULL);
828 }
829 
830 /*
831  * blk_rq_pos()		: the current sector
832  * blk_rq_bytes()	: bytes left in the entire request
833  * blk_rq_cur_bytes()	: bytes left in the current segment
834  * blk_rq_sectors()	: sectors left in the entire request
835  * blk_rq_cur_sectors()	: sectors left in the current segment
836  */
837 static inline sector_t blk_rq_pos(const struct request *rq)
838 {
839 	return rq->__sector;
840 }
841 
842 static inline unsigned int blk_rq_bytes(const struct request *rq)
843 {
844 	return rq->__data_len;
845 }
846 
847 static inline int blk_rq_cur_bytes(const struct request *rq)
848 {
849 	return rq->bio ? bio_cur_bytes(rq->bio) : 0;
850 }
851 
852 static inline unsigned int blk_rq_sectors(const struct request *rq)
853 {
854 	return blk_rq_bytes(rq) >> 9;
855 }
856 
857 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
858 {
859 	return blk_rq_cur_bytes(rq) >> 9;
860 }
861 
862 /*
863  * Request issue related functions.
864  */
865 extern struct request *blk_peek_request(struct request_queue *q);
866 extern void blk_start_request(struct request *rq);
867 extern struct request *blk_fetch_request(struct request_queue *q);
868 
869 /*
870  * Request completion related functions.
871  *
872  * blk_update_request() completes given number of bytes and updates
873  * the request without completing it.
874  *
875  * blk_end_request() and friends.  __blk_end_request() must be called
876  * with the request queue spinlock acquired.
877  *
878  * Several drivers define their own end_request and call
879  * blk_end_request() for parts of the original function.
880  * This prevents code duplication in drivers.
881  */
882 extern bool blk_update_request(struct request *rq, int error,
883 			       unsigned int nr_bytes);
884 extern bool blk_end_request(struct request *rq, int error,
885 			    unsigned int nr_bytes);
886 extern void blk_end_request_all(struct request *rq, int error);
887 extern bool blk_end_request_cur(struct request *rq, int error);
888 extern bool __blk_end_request(struct request *rq, int error,
889 			      unsigned int nr_bytes);
890 extern void __blk_end_request_all(struct request *rq, int error);
891 extern bool __blk_end_request_cur(struct request *rq, int error);
892 
893 extern void blk_complete_request(struct request *);
894 extern void __blk_complete_request(struct request *);
895 extern void blk_abort_request(struct request *);
896 extern void blk_abort_queue(struct request_queue *);
897 
898 /*
899  * Access functions for manipulating queue properties
900  */
901 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
902 					spinlock_t *lock, int node_id);
903 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
904 extern void blk_cleanup_queue(struct request_queue *);
905 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
906 extern void blk_queue_bounce_limit(struct request_queue *, u64);
907 extern void blk_queue_max_sectors(struct request_queue *, unsigned int);
908 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
909 extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short);
910 extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short);
911 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
912 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
913 extern void blk_queue_physical_block_size(struct request_queue *, unsigned short);
914 extern void blk_queue_alignment_offset(struct request_queue *q,
915 				       unsigned int alignment);
916 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
917 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
918 extern void blk_set_default_limits(struct queue_limits *lim);
919 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
920 			    sector_t offset);
921 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
922 			      sector_t offset);
923 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
924 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
925 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
926 extern int blk_queue_dma_drain(struct request_queue *q,
927 			       dma_drain_needed_fn *dma_drain_needed,
928 			       void *buf, unsigned int size);
929 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
930 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
931 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
932 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
933 extern void blk_queue_dma_alignment(struct request_queue *, int);
934 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
935 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
936 extern void blk_queue_set_discard(struct request_queue *, prepare_discard_fn *);
937 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
938 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
939 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
940 extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
941 extern bool blk_do_ordered(struct request_queue *, struct request **);
942 extern unsigned blk_ordered_cur_seq(struct request_queue *);
943 extern unsigned blk_ordered_req_seq(struct request *);
944 extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
945 
946 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
947 extern void blk_dump_rq_flags(struct request *, char *);
948 extern void generic_unplug_device(struct request_queue *);
949 extern long nr_blockdev_pages(void);
950 
951 int blk_get_queue(struct request_queue *);
952 struct request_queue *blk_alloc_queue(gfp_t);
953 struct request_queue *blk_alloc_queue_node(gfp_t, int);
954 extern void blk_put_queue(struct request_queue *);
955 
956 /*
957  * tag stuff
958  */
959 #define blk_rq_tagged(rq)		((rq)->cmd_flags & REQ_QUEUED)
960 extern int blk_queue_start_tag(struct request_queue *, struct request *);
961 extern struct request *blk_queue_find_tag(struct request_queue *, int);
962 extern void blk_queue_end_tag(struct request_queue *, struct request *);
963 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
964 extern void blk_queue_free_tags(struct request_queue *);
965 extern int blk_queue_resize_tags(struct request_queue *, int);
966 extern void blk_queue_invalidate_tags(struct request_queue *);
967 extern struct blk_queue_tag *blk_init_tags(int);
968 extern void blk_free_tags(struct blk_queue_tag *);
969 
970 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
971 						int tag)
972 {
973 	if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
974 		return NULL;
975 	return bqt->tag_index[tag];
976 }
977 
978 extern int blkdev_issue_flush(struct block_device *, sector_t *);
979 extern int blkdev_issue_discard(struct block_device *,
980 				sector_t sector, sector_t nr_sects, gfp_t);
981 
982 static inline int sb_issue_discard(struct super_block *sb,
983 				   sector_t block, sector_t nr_blocks)
984 {
985 	block <<= (sb->s_blocksize_bits - 9);
986 	nr_blocks <<= (sb->s_blocksize_bits - 9);
987 	return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL);
988 }
989 
990 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
991 
992 #define MAX_PHYS_SEGMENTS 128
993 #define MAX_HW_SEGMENTS 128
994 #define SAFE_MAX_SECTORS 255
995 #define BLK_DEF_MAX_SECTORS 1024
996 
997 #define MAX_SEGMENT_SIZE	65536
998 
999 #define BLK_SEG_BOUNDARY_MASK	0xFFFFFFFFUL
1000 
1001 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1002 
1003 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
1004 {
1005 	return q->limits.bounce_pfn;
1006 }
1007 
1008 static inline unsigned long queue_segment_boundary(struct request_queue *q)
1009 {
1010 	return q->limits.seg_boundary_mask;
1011 }
1012 
1013 static inline unsigned int queue_max_sectors(struct request_queue *q)
1014 {
1015 	return q->limits.max_sectors;
1016 }
1017 
1018 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1019 {
1020 	return q->limits.max_hw_sectors;
1021 }
1022 
1023 static inline unsigned short queue_max_hw_segments(struct request_queue *q)
1024 {
1025 	return q->limits.max_hw_segments;
1026 }
1027 
1028 static inline unsigned short queue_max_phys_segments(struct request_queue *q)
1029 {
1030 	return q->limits.max_phys_segments;
1031 }
1032 
1033 static inline unsigned int queue_max_segment_size(struct request_queue *q)
1034 {
1035 	return q->limits.max_segment_size;
1036 }
1037 
1038 static inline unsigned short queue_logical_block_size(struct request_queue *q)
1039 {
1040 	int retval = 512;
1041 
1042 	if (q && q->limits.logical_block_size)
1043 		retval = q->limits.logical_block_size;
1044 
1045 	return retval;
1046 }
1047 
1048 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1049 {
1050 	return queue_logical_block_size(bdev_get_queue(bdev));
1051 }
1052 
1053 static inline unsigned int queue_physical_block_size(struct request_queue *q)
1054 {
1055 	return q->limits.physical_block_size;
1056 }
1057 
1058 static inline unsigned int queue_io_min(struct request_queue *q)
1059 {
1060 	return q->limits.io_min;
1061 }
1062 
1063 static inline unsigned int queue_io_opt(struct request_queue *q)
1064 {
1065 	return q->limits.io_opt;
1066 }
1067 
1068 static inline int queue_alignment_offset(struct request_queue *q)
1069 {
1070 	if (q && q->limits.misaligned)
1071 		return -1;
1072 
1073 	if (q && q->limits.alignment_offset)
1074 		return q->limits.alignment_offset;
1075 
1076 	return 0;
1077 }
1078 
1079 static inline int queue_sector_alignment_offset(struct request_queue *q,
1080 						sector_t sector)
1081 {
1082 	return ((sector << 9) - q->limits.alignment_offset)
1083 		& (q->limits.io_min - 1);
1084 }
1085 
1086 static inline int queue_dma_alignment(struct request_queue *q)
1087 {
1088 	return q ? q->dma_alignment : 511;
1089 }
1090 
1091 static inline int blk_rq_aligned(struct request_queue *q, void *addr,
1092 				 unsigned int len)
1093 {
1094 	unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1095 	return !((unsigned long)addr & alignment) && !(len & alignment);
1096 }
1097 
1098 /* assumes size > 256 */
1099 static inline unsigned int blksize_bits(unsigned int size)
1100 {
1101 	unsigned int bits = 8;
1102 	do {
1103 		bits++;
1104 		size >>= 1;
1105 	} while (size > 256);
1106 	return bits;
1107 }
1108 
1109 static inline unsigned int block_size(struct block_device *bdev)
1110 {
1111 	return bdev->bd_block_size;
1112 }
1113 
1114 typedef struct {struct page *v;} Sector;
1115 
1116 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1117 
1118 static inline void put_dev_sector(Sector p)
1119 {
1120 	page_cache_release(p.v);
1121 }
1122 
1123 struct work_struct;
1124 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1125 
1126 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1127 	MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1128 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1129 	MODULE_ALIAS("block-major-" __stringify(major) "-*")
1130 
1131 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1132 
1133 #define INTEGRITY_FLAG_READ	2	/* verify data integrity on read */
1134 #define INTEGRITY_FLAG_WRITE	4	/* generate data integrity on write */
1135 
1136 struct blk_integrity_exchg {
1137 	void			*prot_buf;
1138 	void			*data_buf;
1139 	sector_t		sector;
1140 	unsigned int		data_size;
1141 	unsigned short		sector_size;
1142 	const char		*disk_name;
1143 };
1144 
1145 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1146 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1147 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1148 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1149 
1150 struct blk_integrity {
1151 	integrity_gen_fn	*generate_fn;
1152 	integrity_vrfy_fn	*verify_fn;
1153 	integrity_set_tag_fn	*set_tag_fn;
1154 	integrity_get_tag_fn	*get_tag_fn;
1155 
1156 	unsigned short		flags;
1157 	unsigned short		tuple_size;
1158 	unsigned short		sector_size;
1159 	unsigned short		tag_size;
1160 
1161 	const char		*name;
1162 
1163 	struct kobject		kobj;
1164 };
1165 
1166 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1167 extern void blk_integrity_unregister(struct gendisk *);
1168 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1169 extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
1170 extern int blk_rq_count_integrity_sg(struct request *);
1171 
1172 static inline
1173 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1174 {
1175 	return bdev->bd_disk->integrity;
1176 }
1177 
1178 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1179 {
1180 	return disk->integrity;
1181 }
1182 
1183 static inline int blk_integrity_rq(struct request *rq)
1184 {
1185 	if (rq->bio == NULL)
1186 		return 0;
1187 
1188 	return bio_integrity(rq->bio);
1189 }
1190 
1191 #else /* CONFIG_BLK_DEV_INTEGRITY */
1192 
1193 #define blk_integrity_rq(rq)			(0)
1194 #define blk_rq_count_integrity_sg(a)		(0)
1195 #define blk_rq_map_integrity_sg(a, b)		(0)
1196 #define bdev_get_integrity(a)			(0)
1197 #define blk_get_integrity(a)			(0)
1198 #define blk_integrity_compare(a, b)		(0)
1199 #define blk_integrity_register(a, b)		(0)
1200 #define blk_integrity_unregister(a)		do { } while (0);
1201 
1202 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1203 
1204 struct block_device_operations {
1205 	int (*open) (struct block_device *, fmode_t);
1206 	int (*release) (struct gendisk *, fmode_t);
1207 	int (*locked_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1208 	int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1209 	int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1210 	int (*direct_access) (struct block_device *, sector_t,
1211 						void **, unsigned long *);
1212 	int (*media_changed) (struct gendisk *);
1213 	unsigned long long (*set_capacity) (struct gendisk *,
1214 						unsigned long long);
1215 	int (*revalidate_disk) (struct gendisk *);
1216 	int (*getgeo)(struct block_device *, struct hd_geometry *);
1217 	struct module *owner;
1218 };
1219 
1220 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1221 				 unsigned long);
1222 #else /* CONFIG_BLOCK */
1223 /*
1224  * stubs for when the block layer is configured out
1225  */
1226 #define buffer_heads_over_limit 0
1227 
1228 static inline long nr_blockdev_pages(void)
1229 {
1230 	return 0;
1231 }
1232 
1233 #endif /* CONFIG_BLOCK */
1234 
1235 #endif
1236