xref: /linux-6.15/include/linux/blkdev.h (revision 5499b451)
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 };
86 
87 /*
88  * request type modified bits. first four bits match BIO_RW* bits, important
89  */
90 enum rq_flag_bits {
91 	__REQ_RW,		/* not set, read. set, write */
92 	__REQ_FAILFAST_DEV,	/* no driver retries of device errors */
93 	__REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
94 	__REQ_FAILFAST_DRIVER,	/* no driver retries of driver errors */
95 	/* above flags must match BIO_RW_* */
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_MIXED_MERGE,	/* merge of different types, fail separately */
118 	__REQ_NR_BITS,		/* stops here */
119 };
120 
121 #define REQ_RW		(1 << __REQ_RW)
122 #define REQ_FAILFAST_DEV	(1 << __REQ_FAILFAST_DEV)
123 #define REQ_FAILFAST_TRANSPORT	(1 << __REQ_FAILFAST_TRANSPORT)
124 #define REQ_FAILFAST_DRIVER	(1 << __REQ_FAILFAST_DRIVER)
125 #define REQ_DISCARD	(1 << __REQ_DISCARD)
126 #define REQ_SORTED	(1 << __REQ_SORTED)
127 #define REQ_SOFTBARRIER	(1 << __REQ_SOFTBARRIER)
128 #define REQ_HARDBARRIER	(1 << __REQ_HARDBARRIER)
129 #define REQ_FUA		(1 << __REQ_FUA)
130 #define REQ_NOMERGE	(1 << __REQ_NOMERGE)
131 #define REQ_STARTED	(1 << __REQ_STARTED)
132 #define REQ_DONTPREP	(1 << __REQ_DONTPREP)
133 #define REQ_QUEUED	(1 << __REQ_QUEUED)
134 #define REQ_ELVPRIV	(1 << __REQ_ELVPRIV)
135 #define REQ_FAILED	(1 << __REQ_FAILED)
136 #define REQ_QUIET	(1 << __REQ_QUIET)
137 #define REQ_PREEMPT	(1 << __REQ_PREEMPT)
138 #define REQ_ORDERED_COLOR	(1 << __REQ_ORDERED_COLOR)
139 #define REQ_RW_SYNC	(1 << __REQ_RW_SYNC)
140 #define REQ_ALLOCED	(1 << __REQ_ALLOCED)
141 #define REQ_RW_META	(1 << __REQ_RW_META)
142 #define REQ_COPY_USER	(1 << __REQ_COPY_USER)
143 #define REQ_INTEGRITY	(1 << __REQ_INTEGRITY)
144 #define REQ_NOIDLE	(1 << __REQ_NOIDLE)
145 #define REQ_IO_STAT	(1 << __REQ_IO_STAT)
146 #define REQ_MIXED_MERGE	(1 << __REQ_MIXED_MERGE)
147 
148 #define REQ_FAILFAST_MASK	(REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | \
149 				 REQ_FAILFAST_DRIVER)
150 
151 #define BLK_MAX_CDB	16
152 
153 /*
154  * try to put the fields that are referenced together in the same cacheline.
155  * if you modify this structure, be sure to check block/blk-core.c:rq_init()
156  * as well!
157  */
158 struct request {
159 	struct list_head queuelist;
160 	struct call_single_data csd;
161 	int cpu;
162 
163 	struct request_queue *q;
164 
165 	unsigned int cmd_flags;
166 	enum rq_cmd_type_bits cmd_type;
167 	unsigned long atomic_flags;
168 
169 	/* the following two fields are internal, NEVER access directly */
170 	sector_t __sector;		/* sector cursor */
171 	unsigned int __data_len;	/* total data len */
172 
173 	struct bio *bio;
174 	struct bio *biotail;
175 
176 	struct hlist_node hash;	/* merge hash */
177 	/*
178 	 * The rb_node is only used inside the io scheduler, requests
179 	 * are pruned when moved to the dispatch queue. So let the
180 	 * completion_data share space with the rb_node.
181 	 */
182 	union {
183 		struct rb_node rb_node;	/* sort/lookup */
184 		void *completion_data;
185 	};
186 
187 	/*
188 	 * two pointers are available for the IO schedulers, if they need
189 	 * more they have to dynamically allocate it.
190 	 */
191 	void *elevator_private;
192 	void *elevator_private2;
193 
194 	struct gendisk *rq_disk;
195 	unsigned long start_time;
196 
197 	/* Number of scatter-gather DMA addr+len pairs after
198 	 * physical address coalescing is performed.
199 	 */
200 	unsigned short nr_phys_segments;
201 
202 	unsigned short ioprio;
203 
204 	void *special;		/* opaque pointer available for LLD use */
205 	char *buffer;		/* kaddr of the current segment if available */
206 
207 	int tag;
208 	int errors;
209 
210 	int ref_count;
211 
212 	/*
213 	 * when request is used as a packet command carrier
214 	 */
215 	unsigned short cmd_len;
216 	unsigned char __cmd[BLK_MAX_CDB];
217 	unsigned char *cmd;
218 
219 	unsigned int extra_len;	/* length of alignment and padding */
220 	unsigned int sense_len;
221 	unsigned int resid_len;	/* residual count */
222 	void *sense;
223 
224 	unsigned long deadline;
225 	struct list_head timeout_list;
226 	unsigned int timeout;
227 	int retries;
228 
229 	/*
230 	 * completion callback.
231 	 */
232 	rq_end_io_fn *end_io;
233 	void *end_io_data;
234 
235 	/* for bidi */
236 	struct request *next_rq;
237 };
238 
239 static inline unsigned short req_get_ioprio(struct request *req)
240 {
241 	return req->ioprio;
242 }
243 
244 /*
245  * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
246  * requests. Some step values could eventually be made generic.
247  */
248 struct request_pm_state
249 {
250 	/* PM state machine step value, currently driver specific */
251 	int	pm_step;
252 	/* requested PM state value (S1, S2, S3, S4, ...) */
253 	u32	pm_state;
254 	void*	data;		/* for driver use */
255 };
256 
257 #include <linux/elevator.h>
258 
259 typedef void (request_fn_proc) (struct request_queue *q);
260 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
261 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
262 typedef void (unplug_fn) (struct request_queue *);
263 
264 struct bio_vec;
265 struct bvec_merge_data {
266 	struct block_device *bi_bdev;
267 	sector_t bi_sector;
268 	unsigned bi_size;
269 	unsigned long bi_rw;
270 };
271 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
272 			     struct bio_vec *);
273 typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
274 typedef void (softirq_done_fn)(struct request *);
275 typedef int (dma_drain_needed_fn)(struct request *);
276 typedef int (lld_busy_fn) (struct request_queue *q);
277 
278 enum blk_eh_timer_return {
279 	BLK_EH_NOT_HANDLED,
280 	BLK_EH_HANDLED,
281 	BLK_EH_RESET_TIMER,
282 };
283 
284 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
285 
286 enum blk_queue_state {
287 	Queue_down,
288 	Queue_up,
289 };
290 
291 struct blk_queue_tag {
292 	struct request **tag_index;	/* map of busy tags */
293 	unsigned long *tag_map;		/* bit map of free/busy tags */
294 	int busy;			/* current depth */
295 	int max_depth;			/* what we will send to device */
296 	int real_max_depth;		/* what the array can hold */
297 	atomic_t refcnt;		/* map can be shared */
298 };
299 
300 #define BLK_SCSI_MAX_CMDS	(256)
301 #define BLK_SCSI_CMD_PER_LONG	(BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
302 
303 struct queue_limits {
304 	unsigned long		bounce_pfn;
305 	unsigned long		seg_boundary_mask;
306 
307 	unsigned int		max_hw_sectors;
308 	unsigned int		max_sectors;
309 	unsigned int		max_segment_size;
310 	unsigned int		physical_block_size;
311 	unsigned int		alignment_offset;
312 	unsigned int		io_min;
313 	unsigned int		io_opt;
314 	unsigned int		max_discard_sectors;
315 	unsigned int		discard_granularity;
316 	unsigned int		discard_alignment;
317 
318 	unsigned short		logical_block_size;
319 	unsigned short		max_hw_segments;
320 	unsigned short		max_phys_segments;
321 
322 	unsigned char		misaligned;
323 	unsigned char		discard_misaligned;
324 	unsigned char		no_cluster;
325 	signed char		discard_zeroes_data;
326 };
327 
328 struct request_queue
329 {
330 	/*
331 	 * Together with queue_head for cacheline sharing
332 	 */
333 	struct list_head	queue_head;
334 	struct request		*last_merge;
335 	struct elevator_queue	*elevator;
336 
337 	/*
338 	 * the queue request freelist, one for reads and one for writes
339 	 */
340 	struct request_list	rq;
341 
342 	request_fn_proc		*request_fn;
343 	make_request_fn		*make_request_fn;
344 	prep_rq_fn		*prep_rq_fn;
345 	unplug_fn		*unplug_fn;
346 	merge_bvec_fn		*merge_bvec_fn;
347 	prepare_flush_fn	*prepare_flush_fn;
348 	softirq_done_fn		*softirq_done_fn;
349 	rq_timed_out_fn		*rq_timed_out_fn;
350 	dma_drain_needed_fn	*dma_drain_needed;
351 	lld_busy_fn		*lld_busy_fn;
352 
353 	/*
354 	 * Dispatch queue sorting
355 	 */
356 	sector_t		end_sector;
357 	struct request		*boundary_rq;
358 
359 	/*
360 	 * Auto-unplugging state
361 	 */
362 	struct timer_list	unplug_timer;
363 	int			unplug_thresh;	/* After this many requests */
364 	unsigned long		unplug_delay;	/* After this many jiffies */
365 	struct work_struct	unplug_work;
366 
367 	struct backing_dev_info	backing_dev_info;
368 
369 	/*
370 	 * The queue owner gets to use this for whatever they like.
371 	 * ll_rw_blk doesn't touch it.
372 	 */
373 	void			*queuedata;
374 
375 	/*
376 	 * queue needs bounce pages for pages above this limit
377 	 */
378 	gfp_t			bounce_gfp;
379 
380 	/*
381 	 * various queue flags, see QUEUE_* below
382 	 */
383 	unsigned long		queue_flags;
384 
385 	/*
386 	 * protects queue structures from reentrancy. ->__queue_lock should
387 	 * _never_ be used directly, it is queue private. always use
388 	 * ->queue_lock.
389 	 */
390 	spinlock_t		__queue_lock;
391 	spinlock_t		*queue_lock;
392 
393 	/*
394 	 * queue kobject
395 	 */
396 	struct kobject kobj;
397 
398 	/*
399 	 * queue settings
400 	 */
401 	unsigned long		nr_requests;	/* Max # of requests */
402 	unsigned int		nr_congestion_on;
403 	unsigned int		nr_congestion_off;
404 	unsigned int		nr_batching;
405 
406 	void			*dma_drain_buffer;
407 	unsigned int		dma_drain_size;
408 	unsigned int		dma_pad_mask;
409 	unsigned int		dma_alignment;
410 
411 	struct blk_queue_tag	*queue_tags;
412 	struct list_head	tag_busy_list;
413 
414 	unsigned int		nr_sorted;
415 	unsigned int		in_flight[2];
416 
417 	unsigned int		rq_timeout;
418 	struct timer_list	timeout;
419 	struct list_head	timeout_list;
420 
421 	struct queue_limits	limits;
422 
423 	/*
424 	 * sg stuff
425 	 */
426 	unsigned int		sg_timeout;
427 	unsigned int		sg_reserved_size;
428 	int			node;
429 #ifdef CONFIG_BLK_DEV_IO_TRACE
430 	struct blk_trace	*blk_trace;
431 #endif
432 	/*
433 	 * reserved for flush operations
434 	 */
435 	unsigned int		ordered, next_ordered, ordseq;
436 	int			orderr, ordcolor;
437 	struct request		pre_flush_rq, bar_rq, post_flush_rq;
438 	struct request		*orig_bar_rq;
439 
440 	struct mutex		sysfs_lock;
441 
442 #if defined(CONFIG_BLK_DEV_BSG)
443 	struct bsg_class_device bsg_dev;
444 #endif
445 };
446 
447 #define QUEUE_FLAG_CLUSTER	0	/* cluster several segments into 1 */
448 #define QUEUE_FLAG_QUEUED	1	/* uses generic tag queueing */
449 #define QUEUE_FLAG_STOPPED	2	/* queue is stopped */
450 #define	QUEUE_FLAG_SYNCFULL	3	/* read queue has been filled */
451 #define QUEUE_FLAG_ASYNCFULL	4	/* write queue has been filled */
452 #define QUEUE_FLAG_DEAD		5	/* queue being torn down */
453 #define QUEUE_FLAG_REENTER	6	/* Re-entrancy avoidance */
454 #define QUEUE_FLAG_PLUGGED	7	/* queue is plugged */
455 #define QUEUE_FLAG_ELVSWITCH	8	/* don't use elevator, just do FIFO */
456 #define QUEUE_FLAG_BIDI		9	/* queue supports bidi requests */
457 #define QUEUE_FLAG_NOMERGES    10	/* disable merge attempts */
458 #define QUEUE_FLAG_SAME_COMP   11	/* force complete on same CPU */
459 #define QUEUE_FLAG_FAIL_IO     12	/* fake timeout */
460 #define QUEUE_FLAG_STACKABLE   13	/* supports request stacking */
461 #define QUEUE_FLAG_NONROT      14	/* non-rotational device (SSD) */
462 #define QUEUE_FLAG_VIRT        QUEUE_FLAG_NONROT /* paravirt device */
463 #define QUEUE_FLAG_IO_STAT     15	/* do IO stats */
464 #define QUEUE_FLAG_DISCARD     16	/* supports DISCARD */
465 
466 #define QUEUE_FLAG_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
467 				 (1 << QUEUE_FLAG_CLUSTER) |		\
468 				 (1 << QUEUE_FLAG_STACKABLE)	|	\
469 				 (1 << QUEUE_FLAG_SAME_COMP))
470 
471 static inline int queue_is_locked(struct request_queue *q)
472 {
473 #ifdef CONFIG_SMP
474 	spinlock_t *lock = q->queue_lock;
475 	return lock && spin_is_locked(lock);
476 #else
477 	return 1;
478 #endif
479 }
480 
481 static inline void queue_flag_set_unlocked(unsigned int flag,
482 					   struct request_queue *q)
483 {
484 	__set_bit(flag, &q->queue_flags);
485 }
486 
487 static inline int queue_flag_test_and_clear(unsigned int flag,
488 					    struct request_queue *q)
489 {
490 	WARN_ON_ONCE(!queue_is_locked(q));
491 
492 	if (test_bit(flag, &q->queue_flags)) {
493 		__clear_bit(flag, &q->queue_flags);
494 		return 1;
495 	}
496 
497 	return 0;
498 }
499 
500 static inline int queue_flag_test_and_set(unsigned int flag,
501 					  struct request_queue *q)
502 {
503 	WARN_ON_ONCE(!queue_is_locked(q));
504 
505 	if (!test_bit(flag, &q->queue_flags)) {
506 		__set_bit(flag, &q->queue_flags);
507 		return 0;
508 	}
509 
510 	return 1;
511 }
512 
513 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
514 {
515 	WARN_ON_ONCE(!queue_is_locked(q));
516 	__set_bit(flag, &q->queue_flags);
517 }
518 
519 static inline void queue_flag_clear_unlocked(unsigned int flag,
520 					     struct request_queue *q)
521 {
522 	__clear_bit(flag, &q->queue_flags);
523 }
524 
525 static inline int queue_in_flight(struct request_queue *q)
526 {
527 	return q->in_flight[0] + q->in_flight[1];
528 }
529 
530 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
531 {
532 	WARN_ON_ONCE(!queue_is_locked(q));
533 	__clear_bit(flag, &q->queue_flags);
534 }
535 
536 enum {
537 	/*
538 	 * Hardbarrier is supported with one of the following methods.
539 	 *
540 	 * NONE		: hardbarrier unsupported
541 	 * DRAIN	: ordering by draining is enough
542 	 * DRAIN_FLUSH	: ordering by draining w/ pre and post flushes
543 	 * DRAIN_FUA	: ordering by draining w/ pre flush and FUA write
544 	 * TAG		: ordering by tag is enough
545 	 * TAG_FLUSH	: ordering by tag w/ pre and post flushes
546 	 * TAG_FUA	: ordering by tag w/ pre flush and FUA write
547 	 */
548 	QUEUE_ORDERED_BY_DRAIN		= 0x01,
549 	QUEUE_ORDERED_BY_TAG		= 0x02,
550 	QUEUE_ORDERED_DO_PREFLUSH	= 0x10,
551 	QUEUE_ORDERED_DO_BAR		= 0x20,
552 	QUEUE_ORDERED_DO_POSTFLUSH	= 0x40,
553 	QUEUE_ORDERED_DO_FUA		= 0x80,
554 
555 	QUEUE_ORDERED_NONE		= 0x00,
556 
557 	QUEUE_ORDERED_DRAIN		= QUEUE_ORDERED_BY_DRAIN |
558 					  QUEUE_ORDERED_DO_BAR,
559 	QUEUE_ORDERED_DRAIN_FLUSH	= QUEUE_ORDERED_DRAIN |
560 					  QUEUE_ORDERED_DO_PREFLUSH |
561 					  QUEUE_ORDERED_DO_POSTFLUSH,
562 	QUEUE_ORDERED_DRAIN_FUA		= QUEUE_ORDERED_DRAIN |
563 					  QUEUE_ORDERED_DO_PREFLUSH |
564 					  QUEUE_ORDERED_DO_FUA,
565 
566 	QUEUE_ORDERED_TAG		= QUEUE_ORDERED_BY_TAG |
567 					  QUEUE_ORDERED_DO_BAR,
568 	QUEUE_ORDERED_TAG_FLUSH		= QUEUE_ORDERED_TAG |
569 					  QUEUE_ORDERED_DO_PREFLUSH |
570 					  QUEUE_ORDERED_DO_POSTFLUSH,
571 	QUEUE_ORDERED_TAG_FUA		= QUEUE_ORDERED_TAG |
572 					  QUEUE_ORDERED_DO_PREFLUSH |
573 					  QUEUE_ORDERED_DO_FUA,
574 
575 	/*
576 	 * Ordered operation sequence
577 	 */
578 	QUEUE_ORDSEQ_STARTED	= 0x01,	/* flushing in progress */
579 	QUEUE_ORDSEQ_DRAIN	= 0x02,	/* waiting for the queue to be drained */
580 	QUEUE_ORDSEQ_PREFLUSH	= 0x04,	/* pre-flushing in progress */
581 	QUEUE_ORDSEQ_BAR	= 0x08,	/* original barrier req in progress */
582 	QUEUE_ORDSEQ_POSTFLUSH	= 0x10,	/* post-flushing in progress */
583 	QUEUE_ORDSEQ_DONE	= 0x20,
584 };
585 
586 #define blk_queue_plugged(q)	test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
587 #define blk_queue_tagged(q)	test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
588 #define blk_queue_stopped(q)	test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
589 #define blk_queue_nomerges(q)	test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
590 #define blk_queue_nonrot(q)	test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
591 #define blk_queue_io_stat(q)	test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
592 #define blk_queue_flushing(q)	((q)->ordseq)
593 #define blk_queue_stackable(q)	\
594 	test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
595 #define blk_queue_discard(q)	test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
596 
597 #define blk_fs_request(rq)	((rq)->cmd_type == REQ_TYPE_FS)
598 #define blk_pc_request(rq)	((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
599 #define blk_special_request(rq)	((rq)->cmd_type == REQ_TYPE_SPECIAL)
600 #define blk_sense_request(rq)	((rq)->cmd_type == REQ_TYPE_SENSE)
601 
602 #define blk_failfast_dev(rq)	((rq)->cmd_flags & REQ_FAILFAST_DEV)
603 #define blk_failfast_transport(rq) ((rq)->cmd_flags & REQ_FAILFAST_TRANSPORT)
604 #define blk_failfast_driver(rq)	((rq)->cmd_flags & REQ_FAILFAST_DRIVER)
605 #define blk_noretry_request(rq)	(blk_failfast_dev(rq) ||	\
606 				 blk_failfast_transport(rq) ||	\
607 				 blk_failfast_driver(rq))
608 #define blk_rq_started(rq)	((rq)->cmd_flags & REQ_STARTED)
609 #define blk_rq_io_stat(rq)	((rq)->cmd_flags & REQ_IO_STAT)
610 #define blk_rq_quiet(rq)	((rq)->cmd_flags & REQ_QUIET)
611 
612 #define blk_account_rq(rq)	(blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
613 
614 #define blk_pm_suspend_request(rq)	((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
615 #define blk_pm_resume_request(rq)	((rq)->cmd_type == REQ_TYPE_PM_RESUME)
616 #define blk_pm_request(rq)	\
617 	(blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
618 
619 #define blk_rq_cpu_valid(rq)	((rq)->cpu != -1)
620 #define blk_sorted_rq(rq)	((rq)->cmd_flags & REQ_SORTED)
621 #define blk_barrier_rq(rq)	((rq)->cmd_flags & REQ_HARDBARRIER)
622 #define blk_fua_rq(rq)		((rq)->cmd_flags & REQ_FUA)
623 #define blk_discard_rq(rq)	((rq)->cmd_flags & REQ_DISCARD)
624 #define blk_bidi_rq(rq)		((rq)->next_rq != NULL)
625 /* rq->queuelist of dequeued request must be list_empty() */
626 #define blk_queued_rq(rq)	(!list_empty(&(rq)->queuelist))
627 
628 #define list_entry_rq(ptr)	list_entry((ptr), struct request, queuelist)
629 
630 #define rq_data_dir(rq)		((rq)->cmd_flags & 1)
631 
632 /*
633  * We regard a request as sync, if either a read or a sync write
634  */
635 static inline bool rw_is_sync(unsigned int rw_flags)
636 {
637 	return !(rw_flags & REQ_RW) || (rw_flags & REQ_RW_SYNC);
638 }
639 
640 static inline bool rq_is_sync(struct request *rq)
641 {
642 	return rw_is_sync(rq->cmd_flags);
643 }
644 
645 #define rq_is_meta(rq)		((rq)->cmd_flags & REQ_RW_META)
646 #define rq_noidle(rq)		((rq)->cmd_flags & REQ_NOIDLE)
647 
648 static inline int blk_queue_full(struct request_queue *q, int sync)
649 {
650 	if (sync)
651 		return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
652 	return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
653 }
654 
655 static inline void blk_set_queue_full(struct request_queue *q, int sync)
656 {
657 	if (sync)
658 		queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
659 	else
660 		queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
661 }
662 
663 static inline void blk_clear_queue_full(struct request_queue *q, int sync)
664 {
665 	if (sync)
666 		queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
667 	else
668 		queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
669 }
670 
671 
672 /*
673  * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
674  * it already be started by driver.
675  */
676 #define RQ_NOMERGE_FLAGS	\
677 	(REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
678 #define rq_mergeable(rq)	\
679 	(!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
680 	 (blk_discard_rq(rq) || blk_fs_request((rq))))
681 
682 /*
683  * q->prep_rq_fn return values
684  */
685 #define BLKPREP_OK		0	/* serve it */
686 #define BLKPREP_KILL		1	/* fatal error, kill */
687 #define BLKPREP_DEFER		2	/* leave on queue */
688 
689 extern unsigned long blk_max_low_pfn, blk_max_pfn;
690 
691 /*
692  * standard bounce addresses:
693  *
694  * BLK_BOUNCE_HIGH	: bounce all highmem pages
695  * BLK_BOUNCE_ANY	: don't bounce anything
696  * BLK_BOUNCE_ISA	: bounce pages above ISA DMA boundary
697  */
698 
699 #if BITS_PER_LONG == 32
700 #define BLK_BOUNCE_HIGH		((u64)blk_max_low_pfn << PAGE_SHIFT)
701 #else
702 #define BLK_BOUNCE_HIGH		-1ULL
703 #endif
704 #define BLK_BOUNCE_ANY		(-1ULL)
705 #define BLK_BOUNCE_ISA		(ISA_DMA_THRESHOLD)
706 
707 /*
708  * default timeout for SG_IO if none specified
709  */
710 #define BLK_DEFAULT_SG_TIMEOUT	(60 * HZ)
711 #define BLK_MIN_SG_TIMEOUT	(7 * HZ)
712 
713 #ifdef CONFIG_BOUNCE
714 extern int init_emergency_isa_pool(void);
715 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
716 #else
717 static inline int init_emergency_isa_pool(void)
718 {
719 	return 0;
720 }
721 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
722 {
723 }
724 #endif /* CONFIG_MMU */
725 
726 struct rq_map_data {
727 	struct page **pages;
728 	int page_order;
729 	int nr_entries;
730 	unsigned long offset;
731 	int null_mapped;
732 	int from_user;
733 };
734 
735 struct req_iterator {
736 	int i;
737 	struct bio *bio;
738 };
739 
740 /* This should not be used directly - use rq_for_each_segment */
741 #define for_each_bio(_bio)		\
742 	for (; _bio; _bio = _bio->bi_next)
743 #define __rq_for_each_bio(_bio, rq)	\
744 	if ((rq->bio))			\
745 		for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
746 
747 #define rq_for_each_segment(bvl, _rq, _iter)			\
748 	__rq_for_each_bio(_iter.bio, _rq)			\
749 		bio_for_each_segment(bvl, _iter.bio, _iter.i)
750 
751 #define rq_iter_last(rq, _iter)					\
752 		(_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
753 
754 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
755 # error	"You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
756 #endif
757 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
758 extern void rq_flush_dcache_pages(struct request *rq);
759 #else
760 static inline void rq_flush_dcache_pages(struct request *rq)
761 {
762 }
763 #endif
764 
765 extern int blk_register_queue(struct gendisk *disk);
766 extern void blk_unregister_queue(struct gendisk *disk);
767 extern void register_disk(struct gendisk *dev);
768 extern void generic_make_request(struct bio *bio);
769 extern void blk_rq_init(struct request_queue *q, struct request *rq);
770 extern void blk_put_request(struct request *);
771 extern void __blk_put_request(struct request_queue *, struct request *);
772 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
773 extern struct request *blk_make_request(struct request_queue *, struct bio *,
774 					gfp_t);
775 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
776 extern void blk_requeue_request(struct request_queue *, struct request *);
777 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
778 extern int blk_lld_busy(struct request_queue *q);
779 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
780 			     struct bio_set *bs, gfp_t gfp_mask,
781 			     int (*bio_ctr)(struct bio *, struct bio *, void *),
782 			     void *data);
783 extern void blk_rq_unprep_clone(struct request *rq);
784 extern int blk_insert_cloned_request(struct request_queue *q,
785 				     struct request *rq);
786 extern void blk_plug_device(struct request_queue *);
787 extern void blk_plug_device_unlocked(struct request_queue *);
788 extern int blk_remove_plug(struct request_queue *);
789 extern void blk_recount_segments(struct request_queue *, struct bio *);
790 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
791 			  unsigned int, void __user *);
792 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
793 			 struct scsi_ioctl_command __user *);
794 
795 /*
796  * A queue has just exitted congestion.  Note this in the global counter of
797  * congested queues, and wake up anyone who was waiting for requests to be
798  * put back.
799  */
800 static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
801 {
802 	clear_bdi_congested(&q->backing_dev_info, sync);
803 }
804 
805 /*
806  * A queue has just entered congestion.  Flag that in the queue's VM-visible
807  * state flags and increment the global gounter of congested queues.
808  */
809 static inline void blk_set_queue_congested(struct request_queue *q, int sync)
810 {
811 	set_bdi_congested(&q->backing_dev_info, sync);
812 }
813 
814 extern void blk_start_queue(struct request_queue *q);
815 extern void blk_stop_queue(struct request_queue *q);
816 extern void blk_sync_queue(struct request_queue *q);
817 extern void __blk_stop_queue(struct request_queue *q);
818 extern void __blk_run_queue(struct request_queue *);
819 extern void blk_run_queue(struct request_queue *);
820 extern int blk_rq_map_user(struct request_queue *, struct request *,
821 			   struct rq_map_data *, void __user *, unsigned long,
822 			   gfp_t);
823 extern int blk_rq_unmap_user(struct bio *);
824 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
825 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
826 			       struct rq_map_data *, struct sg_iovec *, int,
827 			       unsigned int, gfp_t);
828 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
829 			  struct request *, int);
830 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
831 				  struct request *, int, rq_end_io_fn *);
832 extern void blk_unplug(struct request_queue *q);
833 
834 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
835 {
836 	return bdev->bd_disk->queue;
837 }
838 
839 /*
840  * blk_rq_pos()			: the current sector
841  * blk_rq_bytes()		: bytes left in the entire request
842  * blk_rq_cur_bytes()		: bytes left in the current segment
843  * blk_rq_err_bytes()		: bytes left till the next error boundary
844  * blk_rq_sectors()		: sectors left in the entire request
845  * blk_rq_cur_sectors()		: sectors left in the current segment
846  */
847 static inline sector_t blk_rq_pos(const struct request *rq)
848 {
849 	return rq->__sector;
850 }
851 
852 static inline unsigned int blk_rq_bytes(const struct request *rq)
853 {
854 	return rq->__data_len;
855 }
856 
857 static inline int blk_rq_cur_bytes(const struct request *rq)
858 {
859 	return rq->bio ? bio_cur_bytes(rq->bio) : 0;
860 }
861 
862 extern unsigned int blk_rq_err_bytes(const struct request *rq);
863 
864 static inline unsigned int blk_rq_sectors(const struct request *rq)
865 {
866 	return blk_rq_bytes(rq) >> 9;
867 }
868 
869 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
870 {
871 	return blk_rq_cur_bytes(rq) >> 9;
872 }
873 
874 /*
875  * Request issue related functions.
876  */
877 extern struct request *blk_peek_request(struct request_queue *q);
878 extern void blk_start_request(struct request *rq);
879 extern struct request *blk_fetch_request(struct request_queue *q);
880 
881 /*
882  * Request completion related functions.
883  *
884  * blk_update_request() completes given number of bytes and updates
885  * the request without completing it.
886  *
887  * blk_end_request() and friends.  __blk_end_request() must be called
888  * with the request queue spinlock acquired.
889  *
890  * Several drivers define their own end_request and call
891  * blk_end_request() for parts of the original function.
892  * This prevents code duplication in drivers.
893  */
894 extern bool blk_update_request(struct request *rq, int error,
895 			       unsigned int nr_bytes);
896 extern bool blk_end_request(struct request *rq, int error,
897 			    unsigned int nr_bytes);
898 extern void blk_end_request_all(struct request *rq, int error);
899 extern bool blk_end_request_cur(struct request *rq, int error);
900 extern bool blk_end_request_err(struct request *rq, int error);
901 extern bool __blk_end_request(struct request *rq, int error,
902 			      unsigned int nr_bytes);
903 extern void __blk_end_request_all(struct request *rq, int error);
904 extern bool __blk_end_request_cur(struct request *rq, int error);
905 extern bool __blk_end_request_err(struct request *rq, int error);
906 
907 extern void blk_complete_request(struct request *);
908 extern void __blk_complete_request(struct request *);
909 extern void blk_abort_request(struct request *);
910 extern void blk_abort_queue(struct request_queue *);
911 
912 /*
913  * Access functions for manipulating queue properties
914  */
915 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
916 					spinlock_t *lock, int node_id);
917 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
918 extern void blk_cleanup_queue(struct request_queue *);
919 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
920 extern void blk_queue_bounce_limit(struct request_queue *, u64);
921 extern void blk_queue_max_sectors(struct request_queue *, unsigned int);
922 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
923 extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short);
924 extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short);
925 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
926 extern void blk_queue_max_discard_sectors(struct request_queue *q,
927 		unsigned int max_discard_sectors);
928 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
929 extern void blk_queue_physical_block_size(struct request_queue *, unsigned short);
930 extern void blk_queue_alignment_offset(struct request_queue *q,
931 				       unsigned int alignment);
932 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
933 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
934 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
935 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
936 extern void blk_set_default_limits(struct queue_limits *lim);
937 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
938 			    sector_t offset);
939 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
940 			    sector_t offset);
941 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
942 			      sector_t offset);
943 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
944 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
945 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
946 extern int blk_queue_dma_drain(struct request_queue *q,
947 			       dma_drain_needed_fn *dma_drain_needed,
948 			       void *buf, unsigned int size);
949 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
950 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
951 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
952 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
953 extern void blk_queue_dma_alignment(struct request_queue *, int);
954 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
955 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
956 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
957 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
958 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
959 extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
960 extern bool blk_do_ordered(struct request_queue *, struct request **);
961 extern unsigned blk_ordered_cur_seq(struct request_queue *);
962 extern unsigned blk_ordered_req_seq(struct request *);
963 extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
964 
965 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
966 extern void blk_dump_rq_flags(struct request *, char *);
967 extern void generic_unplug_device(struct request_queue *);
968 extern long nr_blockdev_pages(void);
969 
970 int blk_get_queue(struct request_queue *);
971 struct request_queue *blk_alloc_queue(gfp_t);
972 struct request_queue *blk_alloc_queue_node(gfp_t, int);
973 extern void blk_put_queue(struct request_queue *);
974 
975 /*
976  * tag stuff
977  */
978 #define blk_rq_tagged(rq)		((rq)->cmd_flags & REQ_QUEUED)
979 extern int blk_queue_start_tag(struct request_queue *, struct request *);
980 extern struct request *blk_queue_find_tag(struct request_queue *, int);
981 extern void blk_queue_end_tag(struct request_queue *, struct request *);
982 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
983 extern void blk_queue_free_tags(struct request_queue *);
984 extern int blk_queue_resize_tags(struct request_queue *, int);
985 extern void blk_queue_invalidate_tags(struct request_queue *);
986 extern struct blk_queue_tag *blk_init_tags(int);
987 extern void blk_free_tags(struct blk_queue_tag *);
988 
989 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
990 						int tag)
991 {
992 	if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
993 		return NULL;
994 	return bqt->tag_index[tag];
995 }
996 
997 extern int blkdev_issue_flush(struct block_device *, sector_t *);
998 #define DISCARD_FL_WAIT		0x01	/* wait for completion */
999 #define DISCARD_FL_BARRIER	0x02	/* issue DISCARD_BARRIER request */
1000 extern int blkdev_issue_discard(struct block_device *, sector_t sector,
1001 		sector_t nr_sects, gfp_t, int flags);
1002 
1003 static inline int sb_issue_discard(struct super_block *sb,
1004 				   sector_t block, sector_t nr_blocks)
1005 {
1006 	block <<= (sb->s_blocksize_bits - 9);
1007 	nr_blocks <<= (sb->s_blocksize_bits - 9);
1008 	return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL,
1009 				    DISCARD_FL_BARRIER);
1010 }
1011 
1012 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
1013 
1014 #define MAX_PHYS_SEGMENTS 128
1015 #define MAX_HW_SEGMENTS 128
1016 #define SAFE_MAX_SECTORS 255
1017 #define BLK_DEF_MAX_SECTORS 1024
1018 
1019 #define MAX_SEGMENT_SIZE	65536
1020 
1021 #define BLK_SEG_BOUNDARY_MASK	0xFFFFFFFFUL
1022 
1023 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1024 
1025 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
1026 {
1027 	return q->limits.bounce_pfn;
1028 }
1029 
1030 static inline unsigned long queue_segment_boundary(struct request_queue *q)
1031 {
1032 	return q->limits.seg_boundary_mask;
1033 }
1034 
1035 static inline unsigned int queue_max_sectors(struct request_queue *q)
1036 {
1037 	return q->limits.max_sectors;
1038 }
1039 
1040 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1041 {
1042 	return q->limits.max_hw_sectors;
1043 }
1044 
1045 static inline unsigned short queue_max_hw_segments(struct request_queue *q)
1046 {
1047 	return q->limits.max_hw_segments;
1048 }
1049 
1050 static inline unsigned short queue_max_phys_segments(struct request_queue *q)
1051 {
1052 	return q->limits.max_phys_segments;
1053 }
1054 
1055 static inline unsigned int queue_max_segment_size(struct request_queue *q)
1056 {
1057 	return q->limits.max_segment_size;
1058 }
1059 
1060 static inline unsigned short queue_logical_block_size(struct request_queue *q)
1061 {
1062 	int retval = 512;
1063 
1064 	if (q && q->limits.logical_block_size)
1065 		retval = q->limits.logical_block_size;
1066 
1067 	return retval;
1068 }
1069 
1070 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1071 {
1072 	return queue_logical_block_size(bdev_get_queue(bdev));
1073 }
1074 
1075 static inline unsigned int queue_physical_block_size(struct request_queue *q)
1076 {
1077 	return q->limits.physical_block_size;
1078 }
1079 
1080 static inline int bdev_physical_block_size(struct block_device *bdev)
1081 {
1082 	return queue_physical_block_size(bdev_get_queue(bdev));
1083 }
1084 
1085 static inline unsigned int queue_io_min(struct request_queue *q)
1086 {
1087 	return q->limits.io_min;
1088 }
1089 
1090 static inline int bdev_io_min(struct block_device *bdev)
1091 {
1092 	return queue_io_min(bdev_get_queue(bdev));
1093 }
1094 
1095 static inline unsigned int queue_io_opt(struct request_queue *q)
1096 {
1097 	return q->limits.io_opt;
1098 }
1099 
1100 static inline int bdev_io_opt(struct block_device *bdev)
1101 {
1102 	return queue_io_opt(bdev_get_queue(bdev));
1103 }
1104 
1105 static inline int queue_alignment_offset(struct request_queue *q)
1106 {
1107 	if (q->limits.misaligned)
1108 		return -1;
1109 
1110 	return q->limits.alignment_offset;
1111 }
1112 
1113 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t offset)
1114 {
1115 	unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1116 
1117 	offset &= granularity - 1;
1118 	return (granularity + lim->alignment_offset - offset) & (granularity - 1);
1119 }
1120 
1121 static inline int queue_sector_alignment_offset(struct request_queue *q,
1122 						sector_t sector)
1123 {
1124 	return queue_limit_alignment_offset(&q->limits, sector << 9);
1125 }
1126 
1127 static inline int bdev_alignment_offset(struct block_device *bdev)
1128 {
1129 	struct request_queue *q = bdev_get_queue(bdev);
1130 
1131 	if (q->limits.misaligned)
1132 		return -1;
1133 
1134 	if (bdev != bdev->bd_contains)
1135 		return bdev->bd_part->alignment_offset;
1136 
1137 	return q->limits.alignment_offset;
1138 }
1139 
1140 static inline int queue_discard_alignment(struct request_queue *q)
1141 {
1142 	if (q->limits.discard_misaligned)
1143 		return -1;
1144 
1145 	return q->limits.discard_alignment;
1146 }
1147 
1148 static inline int queue_sector_discard_alignment(struct request_queue *q,
1149 						 sector_t sector)
1150 {
1151 	struct queue_limits *lim = &q->limits;
1152 	unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
1153 
1154 	return (lim->discard_granularity + lim->discard_alignment - alignment)
1155 		& (lim->discard_granularity - 1);
1156 }
1157 
1158 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1159 {
1160 	if (q->limits.discard_zeroes_data == 1)
1161 		return 1;
1162 
1163 	return 0;
1164 }
1165 
1166 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1167 {
1168 	return queue_discard_zeroes_data(bdev_get_queue(bdev));
1169 }
1170 
1171 static inline int queue_dma_alignment(struct request_queue *q)
1172 {
1173 	return q ? q->dma_alignment : 511;
1174 }
1175 
1176 static inline int blk_rq_aligned(struct request_queue *q, void *addr,
1177 				 unsigned int len)
1178 {
1179 	unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1180 	return !((unsigned long)addr & alignment) && !(len & alignment);
1181 }
1182 
1183 /* assumes size > 256 */
1184 static inline unsigned int blksize_bits(unsigned int size)
1185 {
1186 	unsigned int bits = 8;
1187 	do {
1188 		bits++;
1189 		size >>= 1;
1190 	} while (size > 256);
1191 	return bits;
1192 }
1193 
1194 static inline unsigned int block_size(struct block_device *bdev)
1195 {
1196 	return bdev->bd_block_size;
1197 }
1198 
1199 typedef struct {struct page *v;} Sector;
1200 
1201 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1202 
1203 static inline void put_dev_sector(Sector p)
1204 {
1205 	page_cache_release(p.v);
1206 }
1207 
1208 struct work_struct;
1209 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1210 
1211 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1212 	MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1213 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1214 	MODULE_ALIAS("block-major-" __stringify(major) "-*")
1215 
1216 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1217 
1218 #define INTEGRITY_FLAG_READ	2	/* verify data integrity on read */
1219 #define INTEGRITY_FLAG_WRITE	4	/* generate data integrity on write */
1220 
1221 struct blk_integrity_exchg {
1222 	void			*prot_buf;
1223 	void			*data_buf;
1224 	sector_t		sector;
1225 	unsigned int		data_size;
1226 	unsigned short		sector_size;
1227 	const char		*disk_name;
1228 };
1229 
1230 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1231 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1232 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1233 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1234 
1235 struct blk_integrity {
1236 	integrity_gen_fn	*generate_fn;
1237 	integrity_vrfy_fn	*verify_fn;
1238 	integrity_set_tag_fn	*set_tag_fn;
1239 	integrity_get_tag_fn	*get_tag_fn;
1240 
1241 	unsigned short		flags;
1242 	unsigned short		tuple_size;
1243 	unsigned short		sector_size;
1244 	unsigned short		tag_size;
1245 
1246 	const char		*name;
1247 
1248 	struct kobject		kobj;
1249 };
1250 
1251 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1252 extern void blk_integrity_unregister(struct gendisk *);
1253 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1254 extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
1255 extern int blk_rq_count_integrity_sg(struct request *);
1256 
1257 static inline
1258 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1259 {
1260 	return bdev->bd_disk->integrity;
1261 }
1262 
1263 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1264 {
1265 	return disk->integrity;
1266 }
1267 
1268 static inline int blk_integrity_rq(struct request *rq)
1269 {
1270 	if (rq->bio == NULL)
1271 		return 0;
1272 
1273 	return bio_integrity(rq->bio);
1274 }
1275 
1276 #else /* CONFIG_BLK_DEV_INTEGRITY */
1277 
1278 #define blk_integrity_rq(rq)			(0)
1279 #define blk_rq_count_integrity_sg(a)		(0)
1280 #define blk_rq_map_integrity_sg(a, b)		(0)
1281 #define bdev_get_integrity(a)			(0)
1282 #define blk_get_integrity(a)			(0)
1283 #define blk_integrity_compare(a, b)		(0)
1284 #define blk_integrity_register(a, b)		(0)
1285 #define blk_integrity_unregister(a)		do { } while (0);
1286 
1287 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1288 
1289 struct block_device_operations {
1290 	int (*open) (struct block_device *, fmode_t);
1291 	int (*release) (struct gendisk *, fmode_t);
1292 	int (*locked_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1293 	int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1294 	int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1295 	int (*direct_access) (struct block_device *, sector_t,
1296 						void **, unsigned long *);
1297 	int (*media_changed) (struct gendisk *);
1298 	unsigned long long (*set_capacity) (struct gendisk *,
1299 						unsigned long long);
1300 	int (*revalidate_disk) (struct gendisk *);
1301 	int (*getgeo)(struct block_device *, struct hd_geometry *);
1302 	struct module *owner;
1303 };
1304 
1305 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1306 				 unsigned long);
1307 #else /* CONFIG_BLOCK */
1308 /*
1309  * stubs for when the block layer is configured out
1310  */
1311 #define buffer_heads_over_limit 0
1312 
1313 static inline long nr_blockdev_pages(void)
1314 {
1315 	return 0;
1316 }
1317 
1318 #endif /* CONFIG_BLOCK */
1319 
1320 #endif
1321