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scsi: simplify the bidi completion
[linux-2.6-block.git] / include / linux / blkdev.h
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CommitLineData
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
25struct scsi_ioctl_command;
26
27struct request_queue;
28struct elevator_queue;
29struct request_pm_state;
30struct blk_trace;
31struct request;
32struct sg_io_hdr;
33
34#define BLKDEV_MIN_RQ 4
35#define BLKDEV_MAX_RQ 128 /* Default maximum */
36
37struct request;
38typedef void (rq_end_io_fn)(struct request *, int);
39
40struct 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 */
55enum 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
73enum {
74 BLK_RW_ASYNC = 0,
75 BLK_RW_SYNC = 1,
76};
77
78/*
79 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
80 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
81 * SCSI cdb.
82 *
83 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
84 * typically to differentiate REQ_TYPE_SPECIAL requests.
85 *
86 */
87enum {
88 REQ_LB_OP_EJECT = 0x40, /* eject request */
89 REQ_LB_OP_FLUSH = 0x41, /* flush request */
90 REQ_LB_OP_DISCARD = 0x42, /* discard sectors */
91};
92
93/*
94 * request type modified bits. first two bits match BIO_RW* bits, important
95 */
96enum rq_flag_bits {
97 __REQ_RW, /* not set, read. set, write */
98 __REQ_FAILFAST_DEV, /* no driver retries of device errors */
99 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
100 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
101 __REQ_DISCARD, /* request to discard sectors */
102 __REQ_SORTED, /* elevator knows about this request */
103 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
104 __REQ_HARDBARRIER, /* may not be passed by drive either */
105 __REQ_FUA, /* forced unit access */
106 __REQ_NOMERGE, /* don't touch this for merging */
107 __REQ_STARTED, /* drive already may have started this one */
108 __REQ_DONTPREP, /* don't call prep for this one */
109 __REQ_QUEUED, /* uses queueing */
110 __REQ_ELVPRIV, /* elevator private data attached */
111 __REQ_FAILED, /* set if the request failed */
112 __REQ_QUIET, /* don't worry about errors */
113 __REQ_PREEMPT, /* set for "ide_preempt" requests */
114 __REQ_ORDERED_COLOR, /* is before or after barrier */
115 __REQ_RW_SYNC, /* request is sync (sync write or read) */
116 __REQ_ALLOCED, /* request came from our alloc pool */
117 __REQ_RW_META, /* metadata io request */
118 __REQ_COPY_USER, /* contains copies of user pages */
119 __REQ_INTEGRITY, /* integrity metadata has been remapped */
120 __REQ_NOIDLE, /* Don't anticipate more IO after this one */
121 __REQ_IO_STAT, /* account I/O stat */
122 __REQ_NR_BITS, /* stops here */
123};
124
125#define REQ_RW (1 << __REQ_RW)
126#define REQ_FAILFAST_DEV (1 << __REQ_FAILFAST_DEV)
127#define REQ_FAILFAST_TRANSPORT (1 << __REQ_FAILFAST_TRANSPORT)
128#define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER)
129#define REQ_DISCARD (1 << __REQ_DISCARD)
130#define REQ_SORTED (1 << __REQ_SORTED)
131#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
132#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
133#define REQ_FUA (1 << __REQ_FUA)
134#define REQ_NOMERGE (1 << __REQ_NOMERGE)
135#define REQ_STARTED (1 << __REQ_STARTED)
136#define REQ_DONTPREP (1 << __REQ_DONTPREP)
137#define REQ_QUEUED (1 << __REQ_QUEUED)
138#define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
139#define REQ_FAILED (1 << __REQ_FAILED)
140#define REQ_QUIET (1 << __REQ_QUIET)
141#define REQ_PREEMPT (1 << __REQ_PREEMPT)
142#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
143#define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
144#define REQ_ALLOCED (1 << __REQ_ALLOCED)
145#define REQ_RW_META (1 << __REQ_RW_META)
146#define REQ_COPY_USER (1 << __REQ_COPY_USER)
147#define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
148#define REQ_NOIDLE (1 << __REQ_NOIDLE)
149#define REQ_IO_STAT (1 << __REQ_IO_STAT)
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 */
158struct 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
239static 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 */
248struct 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
259typedef void (request_fn_proc) (struct request_queue *q);
260typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
261typedef int (prep_rq_fn) (struct request_queue *, struct request *);
262typedef void (unplug_fn) (struct request_queue *);
263typedef int (prepare_discard_fn) (struct request_queue *, struct request *);
264
265struct bio_vec;
266struct bvec_merge_data {
267 struct block_device *bi_bdev;
268 sector_t bi_sector;
269 unsigned bi_size;
270 unsigned long bi_rw;
271};
272typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
273 struct bio_vec *);
274typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
275typedef void (softirq_done_fn)(struct request *);
276typedef int (dma_drain_needed_fn)(struct request *);
277typedef int (lld_busy_fn) (struct request_queue *q);
278
279enum blk_eh_timer_return {
280 BLK_EH_NOT_HANDLED,
281 BLK_EH_HANDLED,
282 BLK_EH_RESET_TIMER,
283};
284
285typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
286
287enum blk_queue_state {
288 Queue_down,
289 Queue_up,
290};
291
292struct blk_queue_tag {
293 struct request **tag_index; /* map of busy tags */
294 unsigned long *tag_map; /* bit map of free/busy tags */
295 int busy; /* current depth */
296 int max_depth; /* what we will send to device */
297 int real_max_depth; /* what the array can hold */
298 atomic_t refcnt; /* map can be shared */
299};
300
301#define BLK_SCSI_MAX_CMDS (256)
302#define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
303
304struct blk_cmd_filter {
305 unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
306 unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
307 struct kobject kobj;
308};
309
310struct request_queue
311{
312 /*
313 * Together with queue_head for cacheline sharing
314 */
315 struct list_head queue_head;
316 struct request *last_merge;
317 struct elevator_queue *elevator;
318
319 /*
320 * the queue request freelist, one for reads and one for writes
321 */
322 struct request_list rq;
323
324 request_fn_proc *request_fn;
325 make_request_fn *make_request_fn;
326 prep_rq_fn *prep_rq_fn;
327 unplug_fn *unplug_fn;
328 prepare_discard_fn *prepare_discard_fn;
329 merge_bvec_fn *merge_bvec_fn;
330 prepare_flush_fn *prepare_flush_fn;
331 softirq_done_fn *softirq_done_fn;
332 rq_timed_out_fn *rq_timed_out_fn;
333 dma_drain_needed_fn *dma_drain_needed;
334 lld_busy_fn *lld_busy_fn;
335
336 /*
337 * Dispatch queue sorting
338 */
339 sector_t end_sector;
340 struct request *boundary_rq;
341
342 /*
343 * Auto-unplugging state
344 */
345 struct timer_list unplug_timer;
346 int unplug_thresh; /* After this many requests */
347 unsigned long unplug_delay; /* After this many jiffies */
348 struct work_struct unplug_work;
349
350 struct backing_dev_info backing_dev_info;
351
352 /*
353 * The queue owner gets to use this for whatever they like.
354 * ll_rw_blk doesn't touch it.
355 */
356 void *queuedata;
357
358 /*
359 * queue needs bounce pages for pages above this limit
360 */
361 unsigned long bounce_pfn;
362 gfp_t bounce_gfp;
363
364 /*
365 * various queue flags, see QUEUE_* below
366 */
367 unsigned long queue_flags;
368
369 /*
370 * protects queue structures from reentrancy. ->__queue_lock should
371 * _never_ be used directly, it is queue private. always use
372 * ->queue_lock.
373 */
374 spinlock_t __queue_lock;
375 spinlock_t *queue_lock;
376
377 /*
378 * queue kobject
379 */
380 struct kobject kobj;
381
382 /*
383 * queue settings
384 */
385 unsigned long nr_requests; /* Max # of requests */
386 unsigned int nr_congestion_on;
387 unsigned int nr_congestion_off;
388 unsigned int nr_batching;
389
390 unsigned int max_sectors;
391 unsigned int max_hw_sectors;
392 unsigned short max_phys_segments;
393 unsigned short max_hw_segments;
394 unsigned short hardsect_size;
395 unsigned int max_segment_size;
396
397 unsigned long seg_boundary_mask;
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;
408
409 unsigned int rq_timeout;
410 struct timer_list timeout;
411 struct list_head timeout_list;
412
413 /*
414 * sg stuff
415 */
416 unsigned int sg_timeout;
417 unsigned int sg_reserved_size;
418 int node;
419#ifdef CONFIG_BLK_DEV_IO_TRACE
420 struct blk_trace *blk_trace;
421#endif
422 /*
423 * reserved for flush operations
424 */
425 unsigned int ordered, next_ordered, ordseq;
426 int orderr, ordcolor;
427 struct request pre_flush_rq, bar_rq, post_flush_rq;
428 struct request *orig_bar_rq;
429
430 struct mutex sysfs_lock;
431
432#if defined(CONFIG_BLK_DEV_BSG)
433 struct bsg_class_device bsg_dev;
434#endif
435 struct blk_cmd_filter cmd_filter;
436};
437
438#define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
439#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
440#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
441#define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
442#define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
443#define QUEUE_FLAG_DEAD 5 /* queue being torn down */
444#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
445#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
446#define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
447#define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
448#define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
449#define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
450#define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
451#define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
452#define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
453#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
454#define QUEUE_FLAG_IO_STAT 15 /* do IO stats */
455
456#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
457 (1 << QUEUE_FLAG_CLUSTER) | \
458 (1 << QUEUE_FLAG_STACKABLE))
459
460static inline int queue_is_locked(struct request_queue *q)
461{
462#ifdef CONFIG_SMP
463 spinlock_t *lock = q->queue_lock;
464 return lock && spin_is_locked(lock);
465#else
466 return 1;
467#endif
468}
469
470static inline void queue_flag_set_unlocked(unsigned int flag,
471 struct request_queue *q)
472{
473 __set_bit(flag, &q->queue_flags);
474}
475
476static inline int queue_flag_test_and_clear(unsigned int flag,
477 struct request_queue *q)
478{
479 WARN_ON_ONCE(!queue_is_locked(q));
480
481 if (test_bit(flag, &q->queue_flags)) {
482 __clear_bit(flag, &q->queue_flags);
483 return 1;
484 }
485
486 return 0;
487}
488
489static inline int queue_flag_test_and_set(unsigned int flag,
490 struct request_queue *q)
491{
492 WARN_ON_ONCE(!queue_is_locked(q));
493
494 if (!test_bit(flag, &q->queue_flags)) {
495 __set_bit(flag, &q->queue_flags);
496 return 0;
497 }
498
499 return 1;
500}
501
502static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
503{
504 WARN_ON_ONCE(!queue_is_locked(q));
505 __set_bit(flag, &q->queue_flags);
506}
507
508static inline void queue_flag_clear_unlocked(unsigned int flag,
509 struct request_queue *q)
510{
511 __clear_bit(flag, &q->queue_flags);
512}
513
514static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
515{
516 WARN_ON_ONCE(!queue_is_locked(q));
517 __clear_bit(flag, &q->queue_flags);
518}
519
520enum {
521 /*
522 * Hardbarrier is supported with one of the following methods.
523 *
524 * NONE : hardbarrier unsupported
525 * DRAIN : ordering by draining is enough
526 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
527 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
528 * TAG : ordering by tag is enough
529 * TAG_FLUSH : ordering by tag w/ pre and post flushes
530 * TAG_FUA : ordering by tag w/ pre flush and FUA write
531 */
532 QUEUE_ORDERED_BY_DRAIN = 0x01,
533 QUEUE_ORDERED_BY_TAG = 0x02,
534 QUEUE_ORDERED_DO_PREFLUSH = 0x10,
535 QUEUE_ORDERED_DO_BAR = 0x20,
536 QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
537 QUEUE_ORDERED_DO_FUA = 0x80,
538
539 QUEUE_ORDERED_NONE = 0x00,
540
541 QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_BY_DRAIN |
542 QUEUE_ORDERED_DO_BAR,
543 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
544 QUEUE_ORDERED_DO_PREFLUSH |
545 QUEUE_ORDERED_DO_POSTFLUSH,
546 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
547 QUEUE_ORDERED_DO_PREFLUSH |
548 QUEUE_ORDERED_DO_FUA,
549
550 QUEUE_ORDERED_TAG = QUEUE_ORDERED_BY_TAG |
551 QUEUE_ORDERED_DO_BAR,
552 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
553 QUEUE_ORDERED_DO_PREFLUSH |
554 QUEUE_ORDERED_DO_POSTFLUSH,
555 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
556 QUEUE_ORDERED_DO_PREFLUSH |
557 QUEUE_ORDERED_DO_FUA,
558
559 /*
560 * Ordered operation sequence
561 */
562 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
563 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
564 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
565 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
566 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
567 QUEUE_ORDSEQ_DONE = 0x20,
568};
569
570#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
571#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
572#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
573#define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
574#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
575#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
576#define blk_queue_flushing(q) ((q)->ordseq)
577#define blk_queue_stackable(q) \
578 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
579
580#define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
581#define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
582#define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
583#define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
584
585#define blk_failfast_dev(rq) ((rq)->cmd_flags & REQ_FAILFAST_DEV)
586#define blk_failfast_transport(rq) ((rq)->cmd_flags & REQ_FAILFAST_TRANSPORT)
587#define blk_failfast_driver(rq) ((rq)->cmd_flags & REQ_FAILFAST_DRIVER)
588#define blk_noretry_request(rq) (blk_failfast_dev(rq) || \
589 blk_failfast_transport(rq) || \
590 blk_failfast_driver(rq))
591#define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
592#define blk_rq_io_stat(rq) ((rq)->cmd_flags & REQ_IO_STAT)
593
594#define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
595
596#define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
597#define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
598#define blk_pm_request(rq) \
599 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
600
601#define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
602#define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
603#define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
604#define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
605#define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
606#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
607/* rq->queuelist of dequeued request must be list_empty() */
608#define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
609
610#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
611
612#define rq_data_dir(rq) ((rq)->cmd_flags & 1)
613
614/*
615 * We regard a request as sync, if either a read or a sync write
616 */
617static inline bool rw_is_sync(unsigned int rw_flags)
618{
619 return !(rw_flags & REQ_RW) || (rw_flags & REQ_RW_SYNC);
620}
621
622static inline bool rq_is_sync(struct request *rq)
623{
624 return rw_is_sync(rq->cmd_flags);
625}
626
627#define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
628#define rq_noidle(rq) ((rq)->cmd_flags & REQ_NOIDLE)
629
630static inline int blk_queue_full(struct request_queue *q, int sync)
631{
632 if (sync)
633 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
634 return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
635}
636
637static inline void blk_set_queue_full(struct request_queue *q, int sync)
638{
639 if (sync)
640 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
641 else
642 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
643}
644
645static inline void blk_clear_queue_full(struct request_queue *q, int sync)
646{
647 if (sync)
648 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
649 else
650 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
651}
652
653
654/*
655 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
656 * it already be started by driver.
657 */
658#define RQ_NOMERGE_FLAGS \
659 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
660#define rq_mergeable(rq) \
661 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
662 (blk_discard_rq(rq) || blk_fs_request((rq))))
663
664/*
665 * q->prep_rq_fn return values
666 */
667#define BLKPREP_OK 0 /* serve it */
668#define BLKPREP_KILL 1 /* fatal error, kill */
669#define BLKPREP_DEFER 2 /* leave on queue */
670
671extern unsigned long blk_max_low_pfn, blk_max_pfn;
672
673/*
674 * standard bounce addresses:
675 *
676 * BLK_BOUNCE_HIGH : bounce all highmem pages
677 * BLK_BOUNCE_ANY : don't bounce anything
678 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
679 */
680
681#if BITS_PER_LONG == 32
682#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
683#else
684#define BLK_BOUNCE_HIGH -1ULL
685#endif
686#define BLK_BOUNCE_ANY (-1ULL)
687#define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
688
689/*
690 * default timeout for SG_IO if none specified
691 */
692#define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
693#define BLK_MIN_SG_TIMEOUT (7 * HZ)
694
695#ifdef CONFIG_BOUNCE
696extern int init_emergency_isa_pool(void);
697extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
698#else
699static inline int init_emergency_isa_pool(void)
700{
701 return 0;
702}
703static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
704{
705}
706#endif /* CONFIG_MMU */
707
708struct rq_map_data {
709 struct page **pages;
710 int page_order;
711 int nr_entries;
712 unsigned long offset;
713 int null_mapped;
714};
715
716struct req_iterator {
717 int i;
718 struct bio *bio;
719};
720
721/* This should not be used directly - use rq_for_each_segment */
722#define for_each_bio(_bio) \
723 for (; _bio; _bio = _bio->bi_next)
724#define __rq_for_each_bio(_bio, rq) \
725 if ((rq->bio)) \
726 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
727
728#define rq_for_each_segment(bvl, _rq, _iter) \
729 __rq_for_each_bio(_iter.bio, _rq) \
730 bio_for_each_segment(bvl, _iter.bio, _iter.i)
731
732#define rq_iter_last(rq, _iter) \
733 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
734
735extern int blk_register_queue(struct gendisk *disk);
736extern void blk_unregister_queue(struct gendisk *disk);
737extern void register_disk(struct gendisk *dev);
738extern void generic_make_request(struct bio *bio);
739extern void blk_rq_init(struct request_queue *q, struct request *rq);
740extern void blk_put_request(struct request *);
741extern void __blk_put_request(struct request_queue *, struct request *);
742extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
743extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
744extern void blk_requeue_request(struct request_queue *, struct request *);
745extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
746extern int blk_lld_busy(struct request_queue *q);
747extern int blk_insert_cloned_request(struct request_queue *q,
748 struct request *rq);
749extern void blk_plug_device(struct request_queue *);
750extern void blk_plug_device_unlocked(struct request_queue *);
751extern int blk_remove_plug(struct request_queue *);
752extern void blk_recount_segments(struct request_queue *, struct bio *);
753extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
754 unsigned int, void __user *);
755extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
756 struct scsi_ioctl_command __user *);
757
758/*
759 * Temporary export, until SCSI gets fixed up.
760 */
761extern int blk_rq_append_bio(struct request_queue *q, struct request *rq,
762 struct bio *bio);
763
764/*
765 * A queue has just exitted congestion. Note this in the global counter of
766 * congested queues, and wake up anyone who was waiting for requests to be
767 * put back.
768 */
769static inline void blk_clear_queue_congested(struct request_queue *q, int rw)
770{
771 clear_bdi_congested(&q->backing_dev_info, rw);
772}
773
774/*
775 * A queue has just entered congestion. Flag that in the queue's VM-visible
776 * state flags and increment the global gounter of congested queues.
777 */
778static inline void blk_set_queue_congested(struct request_queue *q, int rw)
779{
780 set_bdi_congested(&q->backing_dev_info, rw);
781}
782
783extern void blk_start_queue(struct request_queue *q);
784extern void blk_stop_queue(struct request_queue *q);
785extern void blk_sync_queue(struct request_queue *q);
786extern void __blk_stop_queue(struct request_queue *q);
787extern void __blk_run_queue(struct request_queue *);
788extern void blk_run_queue(struct request_queue *);
789extern int blk_rq_map_user(struct request_queue *, struct request *,
790 struct rq_map_data *, void __user *, unsigned long,
791 gfp_t);
792extern int blk_rq_unmap_user(struct bio *);
793extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
794extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
795 struct rq_map_data *, struct sg_iovec *, int,
796 unsigned int, gfp_t);
797extern int blk_execute_rq(struct request_queue *, struct gendisk *,
798 struct request *, int);
799extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
800 struct request *, int, rq_end_io_fn *);
801extern void blk_unplug(struct request_queue *q);
802
803static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
804{
805 return bdev->bd_disk->queue;
806}
807
808static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
809 struct page *page)
810{
811 if (bdi && bdi->unplug_io_fn)
812 bdi->unplug_io_fn(bdi, page);
813}
814
815static inline void blk_run_address_space(struct address_space *mapping)
816{
817 if (mapping)
818 blk_run_backing_dev(mapping->backing_dev_info, NULL);
819}
820
821/*
822 * blk_rq_pos() : the current sector
823 * blk_rq_bytes() : bytes left in the entire request
824 * blk_rq_cur_bytes() : bytes left in the current segment
825 * blk_rq_sectors() : sectors left in the entire request
826 * blk_rq_cur_sectors() : sectors left in the current segment
827 */
828static inline sector_t blk_rq_pos(const struct request *rq)
829{
830 return rq->__sector;
831}
832
833static inline unsigned int blk_rq_bytes(const struct request *rq)
834{
835 return rq->__data_len;
836}
837
838static inline int blk_rq_cur_bytes(const struct request *rq)
839{
840 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
841}
842
843static inline unsigned int blk_rq_sectors(const struct request *rq)
844{
845 return blk_rq_bytes(rq) >> 9;
846}
847
848static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
849{
850 return blk_rq_cur_bytes(rq) >> 9;
851}
852
853/*
854 * Request issue related functions.
855 */
856extern struct request *blk_peek_request(struct request_queue *q);
857extern void blk_start_request(struct request *rq);
858extern struct request *blk_fetch_request(struct request_queue *q);
859
860/*
861 * Request completion related functions.
862 *
863 * blk_update_request() completes given number of bytes and updates
864 * the request without completing it.
865 *
866 * blk_end_request() and friends. __blk_end_request() must be called
867 * with the request queue spinlock acquired.
868 *
869 * Several drivers define their own end_request and call
870 * blk_end_request() for parts of the original function.
871 * This prevents code duplication in drivers.
872 */
873extern bool blk_update_request(struct request *rq, int error,
874 unsigned int nr_bytes);
875extern bool blk_end_bidi_request(struct request *rq, int error,
876 unsigned int nr_bytes,
877 unsigned int bidi_bytes);
878extern bool __blk_end_bidi_request(struct request *rq, int error,
879 unsigned int nr_bytes,
880 unsigned int bidi_bytes);
881
882/**
883 * blk_end_request - Helper function for drivers to complete the request.
884 * @rq: the request being processed
885 * @error: %0 for success, < %0 for error
886 * @nr_bytes: number of bytes to complete
887 *
888 * Description:
889 * Ends I/O on a number of bytes attached to @rq.
890 * If @rq has leftover, sets it up for the next range of segments.
891 *
892 * Return:
893 * %false - we are done with this request
894 * %true - still buffers pending for this request
895 **/
896static inline bool blk_end_request(struct request *rq, int error,
897 unsigned int nr_bytes)
898{
899 return blk_end_bidi_request(rq, error, nr_bytes, 0);
900}
901
902/**
903 * blk_end_request_all - Helper function for drives to finish the request.
904 * @rq: the request to finish
905 * @err: %0 for success, < %0 for error
906 *
907 * Description:
908 * Completely finish @rq.
909 */
910static inline void blk_end_request_all(struct request *rq, int error)
911{
912 bool pending;
913 unsigned int bidi_bytes = 0;
914
915 if (unlikely(blk_bidi_rq(rq)))
916 bidi_bytes = blk_rq_bytes(rq->next_rq);
917
918 pending = blk_end_bidi_request(rq, error, blk_rq_bytes(rq), bidi_bytes);
919 BUG_ON(pending);
920}
921
922/**
923 * blk_end_request_cur - Helper function to finish the current request chunk.
924 * @rq: the request to finish the current chunk for
925 * @err: %0 for success, < %0 for error
926 *
927 * Description:
928 * Complete the current consecutively mapped chunk from @rq.
929 *
930 * Return:
931 * %false - we are done with this request
932 * %true - still buffers pending for this request
933 */
934static inline bool blk_end_request_cur(struct request *rq, int error)
935{
936 return blk_end_request(rq, error, blk_rq_cur_bytes(rq));
937}
938
939/**
940 * __blk_end_request - Helper function for drivers to complete the request.
941 * @rq: the request being processed
942 * @error: %0 for success, < %0 for error
943 * @nr_bytes: number of bytes to complete
944 *
945 * Description:
946 * Must be called with queue lock held unlike blk_end_request().
947 *
948 * Return:
949 * %false - we are done with this request
950 * %true - still buffers pending for this request
951 **/
952static inline bool __blk_end_request(struct request *rq, int error,
953 unsigned int nr_bytes)
954{
955 return __blk_end_bidi_request(rq, error, nr_bytes, 0);
956}
957
958/**
959 * __blk_end_request_all - Helper function for drives to finish the request.
960 * @rq: the request to finish
961 * @err: %0 for success, < %0 for error
962 *
963 * Description:
964 * Completely finish @rq. Must be called with queue lock held.
965 */
966static inline void __blk_end_request_all(struct request *rq, int error)
967{
968 bool pending;
969 unsigned int bidi_bytes = 0;
970
971 if (unlikely(blk_bidi_rq(rq)))
972 bidi_bytes = blk_rq_bytes(rq->next_rq);
973
974 pending = __blk_end_bidi_request(rq, error, blk_rq_bytes(rq), bidi_bytes);
975 BUG_ON(pending);
976}
977
978/**
979 * __blk_end_request_cur - Helper function to finish the current request chunk.
980 * @rq: the request to finish the current chunk for
981 * @err: %0 for success, < %0 for error
982 *
983 * Description:
984 * Complete the current consecutively mapped chunk from @rq. Must
985 * be called with queue lock held.
986 *
987 * Return:
988 * %false - we are done with this request
989 * %true - still buffers pending for this request
990 */
991static inline bool __blk_end_request_cur(struct request *rq, int error)
992{
993 return __blk_end_request(rq, error, blk_rq_cur_bytes(rq));
994}
995
996extern void blk_complete_request(struct request *);
997extern void __blk_complete_request(struct request *);
998extern void blk_abort_request(struct request *);
999extern void blk_abort_queue(struct request_queue *);
1000
1001/*
1002 * Access functions for manipulating queue properties
1003 */
1004extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
1005 spinlock_t *lock, int node_id);
1006extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
1007extern void blk_cleanup_queue(struct request_queue *);
1008extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
1009extern void blk_queue_bounce_limit(struct request_queue *, u64);
1010extern void blk_queue_max_sectors(struct request_queue *, unsigned int);
1011extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short);
1012extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short);
1013extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
1014extern void blk_queue_hardsect_size(struct request_queue *, unsigned short);
1015extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
1016extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
1017extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
1018extern int blk_queue_dma_drain(struct request_queue *q,
1019 dma_drain_needed_fn *dma_drain_needed,
1020 void *buf, unsigned int size);
1021extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
1022extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
1023extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
1024extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
1025extern void blk_queue_dma_alignment(struct request_queue *, int);
1026extern void blk_queue_update_dma_alignment(struct request_queue *, int);
1027extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
1028extern void blk_queue_set_discard(struct request_queue *, prepare_discard_fn *);
1029extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
1030extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1031extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
1032extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
1033extern bool blk_do_ordered(struct request_queue *, struct request **);
1034extern unsigned blk_ordered_cur_seq(struct request_queue *);
1035extern unsigned blk_ordered_req_seq(struct request *);
1036extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
1037
1038extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
1039extern void blk_dump_rq_flags(struct request *, char *);
1040extern void generic_unplug_device(struct request_queue *);
1041extern long nr_blockdev_pages(void);
1042
1043int blk_get_queue(struct request_queue *);
1044struct request_queue *blk_alloc_queue(gfp_t);
1045struct request_queue *blk_alloc_queue_node(gfp_t, int);
1046extern void blk_put_queue(struct request_queue *);
1047
1048/*
1049 * tag stuff
1050 */
1051#define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
1052extern int blk_queue_start_tag(struct request_queue *, struct request *);
1053extern struct request *blk_queue_find_tag(struct request_queue *, int);
1054extern void blk_queue_end_tag(struct request_queue *, struct request *);
1055extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
1056extern void blk_queue_free_tags(struct request_queue *);
1057extern int blk_queue_resize_tags(struct request_queue *, int);
1058extern void blk_queue_invalidate_tags(struct request_queue *);
1059extern struct blk_queue_tag *blk_init_tags(int);
1060extern void blk_free_tags(struct blk_queue_tag *);
1061
1062static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
1063 int tag)
1064{
1065 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
1066 return NULL;
1067 return bqt->tag_index[tag];
1068}
1069
1070extern int blkdev_issue_flush(struct block_device *, sector_t *);
1071extern int blkdev_issue_discard(struct block_device *,
1072 sector_t sector, sector_t nr_sects, gfp_t);
1073
1074static inline int sb_issue_discard(struct super_block *sb,
1075 sector_t block, sector_t nr_blocks)
1076{
1077 block <<= (sb->s_blocksize_bits - 9);
1078 nr_blocks <<= (sb->s_blocksize_bits - 9);
1079 return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL);
1080}
1081
1082/*
1083* command filter functions
1084*/
1085extern int blk_verify_command(struct blk_cmd_filter *filter,
1086 unsigned char *cmd, fmode_t has_write_perm);
1087extern void blk_unregister_filter(struct gendisk *disk);
1088extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter);
1089
1090#define MAX_PHYS_SEGMENTS 128
1091#define MAX_HW_SEGMENTS 128
1092#define SAFE_MAX_SECTORS 255
1093#define BLK_DEF_MAX_SECTORS 1024
1094
1095#define MAX_SEGMENT_SIZE 65536
1096
1097#define BLK_SEG_BOUNDARY_MASK 0xFFFFFFFFUL
1098
1099#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1100
1101static inline int queue_hardsect_size(struct request_queue *q)
1102{
1103 int retval = 512;
1104
1105 if (q && q->hardsect_size)
1106 retval = q->hardsect_size;
1107
1108 return retval;
1109}
1110
1111static inline int bdev_hardsect_size(struct block_device *bdev)
1112{
1113 return queue_hardsect_size(bdev_get_queue(bdev));
1114}
1115
1116static inline int queue_dma_alignment(struct request_queue *q)
1117{
1118 return q ? q->dma_alignment : 511;
1119}
1120
1121static inline int blk_rq_aligned(struct request_queue *q, void *addr,
1122 unsigned int len)
1123{
1124 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1125 return !((unsigned long)addr & alignment) && !(len & alignment);
1126}
1127
1128/* assumes size > 256 */
1129static inline unsigned int blksize_bits(unsigned int size)
1130{
1131 unsigned int bits = 8;
1132 do {
1133 bits++;
1134 size >>= 1;
1135 } while (size > 256);
1136 return bits;
1137}
1138
1139static inline unsigned int block_size(struct block_device *bdev)
1140{
1141 return bdev->bd_block_size;
1142}
1143
1144typedef struct {struct page *v;} Sector;
1145
1146unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1147
1148static inline void put_dev_sector(Sector p)
1149{
1150 page_cache_release(p.v);
1151}
1152
1153struct work_struct;
1154int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1155
1156#define MODULE_ALIAS_BLOCKDEV(major,minor) \
1157 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1158#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1159 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1160
1161#if defined(CONFIG_BLK_DEV_INTEGRITY)
1162
1163#define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1164#define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
1165
1166struct blk_integrity_exchg {
1167 void *prot_buf;
1168 void *data_buf;
1169 sector_t sector;
1170 unsigned int data_size;
1171 unsigned short sector_size;
1172 const char *disk_name;
1173};
1174
1175typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1176typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1177typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1178typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1179
1180struct blk_integrity {
1181 integrity_gen_fn *generate_fn;
1182 integrity_vrfy_fn *verify_fn;
1183 integrity_set_tag_fn *set_tag_fn;
1184 integrity_get_tag_fn *get_tag_fn;
1185
1186 unsigned short flags;
1187 unsigned short tuple_size;
1188 unsigned short sector_size;
1189 unsigned short tag_size;
1190
1191 const char *name;
1192
1193 struct kobject kobj;
1194};
1195
1196extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1197extern void blk_integrity_unregister(struct gendisk *);
1198extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1199extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
1200extern int blk_rq_count_integrity_sg(struct request *);
1201
1202static inline
1203struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1204{
1205 return bdev->bd_disk->integrity;
1206}
1207
1208static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1209{
1210 return disk->integrity;
1211}
1212
1213static inline int blk_integrity_rq(struct request *rq)
1214{
1215 if (rq->bio == NULL)
1216 return 0;
1217
1218 return bio_integrity(rq->bio);
1219}
1220
1221#else /* CONFIG_BLK_DEV_INTEGRITY */
1222
1223#define blk_integrity_rq(rq) (0)
1224#define blk_rq_count_integrity_sg(a) (0)
1225#define blk_rq_map_integrity_sg(a, b) (0)
1226#define bdev_get_integrity(a) (0)
1227#define blk_get_integrity(a) (0)
1228#define blk_integrity_compare(a, b) (0)
1229#define blk_integrity_register(a, b) (0)
1230#define blk_integrity_unregister(a) do { } while (0);
1231
1232#endif /* CONFIG_BLK_DEV_INTEGRITY */
1233
1234struct block_device_operations {
1235 int (*open) (struct block_device *, fmode_t);
1236 int (*release) (struct gendisk *, fmode_t);
1237 int (*locked_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1238 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1239 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1240 int (*direct_access) (struct block_device *, sector_t,
1241 void **, unsigned long *);
1242 int (*media_changed) (struct gendisk *);
1243 int (*revalidate_disk) (struct gendisk *);
1244 int (*getgeo)(struct block_device *, struct hd_geometry *);
1245 struct module *owner;
1246};
1247
1248extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1249 unsigned long);
1250#else /* CONFIG_BLOCK */
1251/*
1252 * stubs for when the block layer is configured out
1253 */
1254#define buffer_heads_over_limit 0
1255
1256static inline long nr_blockdev_pages(void)
1257{
1258 return 0;
1259}
1260
1261#endif /* CONFIG_BLOCK */
1262
1263#endif
Linux 6.x block layer and io_uring tree(s)