blkdev.h 38 KB

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  1. #ifndef _LINUX_BLKDEV_H
  2. #define _LINUX_BLKDEV_H
  3. #ifdef CONFIG_BLOCK
  4. #include <linux/sched.h>
  5. #include <linux/major.h>
  6. #include <linux/genhd.h>
  7. #include <linux/list.h>
  8. #include <linux/timer.h>
  9. #include <linux/workqueue.h>
  10. #include <linux/pagemap.h>
  11. #include <linux/backing-dev.h>
  12. #include <linux/wait.h>
  13. #include <linux/mempool.h>
  14. #include <linux/bio.h>
  15. #include <linux/module.h>
  16. #include <linux/stringify.h>
  17. #include <linux/gfp.h>
  18. #include <linux/bsg.h>
  19. #include <linux/smp.h>
  20. #include <asm/scatterlist.h>
  21. struct scsi_ioctl_command;
  22. struct request_queue;
  23. struct elevator_queue;
  24. struct request_pm_state;
  25. struct blk_trace;
  26. struct request;
  27. struct sg_io_hdr;
  28. #define BLKDEV_MIN_RQ 4
  29. #define BLKDEV_MAX_RQ 128 /* Default maximum */
  30. struct request;
  31. typedef void (rq_end_io_fn)(struct request *, int);
  32. struct request_list {
  33. /*
  34. * count[], starved[], and wait[] are indexed by
  35. * BLK_RW_SYNC/BLK_RW_ASYNC
  36. */
  37. int count[2];
  38. int starved[2];
  39. int elvpriv;
  40. mempool_t *rq_pool;
  41. wait_queue_head_t wait[2];
  42. };
  43. /*
  44. * request command types
  45. */
  46. enum rq_cmd_type_bits {
  47. REQ_TYPE_FS = 1, /* fs request */
  48. REQ_TYPE_BLOCK_PC, /* scsi command */
  49. REQ_TYPE_SENSE, /* sense request */
  50. REQ_TYPE_PM_SUSPEND, /* suspend request */
  51. REQ_TYPE_PM_RESUME, /* resume request */
  52. REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
  53. REQ_TYPE_SPECIAL, /* driver defined type */
  54. /*
  55. * for ATA/ATAPI devices. this really doesn't belong here, ide should
  56. * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
  57. * private REQ_LB opcodes to differentiate what type of request this is
  58. */
  59. REQ_TYPE_ATA_TASKFILE,
  60. REQ_TYPE_ATA_PC,
  61. };
  62. #define BLK_MAX_CDB 16
  63. /*
  64. * try to put the fields that are referenced together in the same cacheline.
  65. * if you modify this structure, be sure to check block/blk-core.c:rq_init()
  66. * as well!
  67. */
  68. struct request {
  69. struct list_head queuelist;
  70. struct call_single_data csd;
  71. struct request_queue *q;
  72. unsigned int cmd_flags;
  73. enum rq_cmd_type_bits cmd_type;
  74. unsigned long atomic_flags;
  75. int cpu;
  76. /* the following two fields are internal, NEVER access directly */
  77. unsigned int __data_len; /* total data len */
  78. sector_t __sector; /* sector cursor */
  79. struct bio *bio;
  80. struct bio *biotail;
  81. struct hlist_node hash; /* merge hash */
  82. /*
  83. * The rb_node is only used inside the io scheduler, requests
  84. * are pruned when moved to the dispatch queue. So let the
  85. * completion_data share space with the rb_node.
  86. */
  87. union {
  88. struct rb_node rb_node; /* sort/lookup */
  89. void *completion_data;
  90. };
  91. /*
  92. * Three pointers are available for the IO schedulers, if they need
  93. * more they have to dynamically allocate it.
  94. */
  95. void *elevator_private;
  96. void *elevator_private2;
  97. void *elevator_private3;
  98. struct gendisk *rq_disk;
  99. unsigned long start_time;
  100. #ifdef CONFIG_BLK_CGROUP
  101. unsigned long long start_time_ns;
  102. unsigned long long io_start_time_ns; /* when passed to hardware */
  103. #endif
  104. /* Number of scatter-gather DMA addr+len pairs after
  105. * physical address coalescing is performed.
  106. */
  107. unsigned short nr_phys_segments;
  108. #if defined(CONFIG_BLK_DEV_INTEGRITY)
  109. unsigned short nr_integrity_segments;
  110. #endif
  111. unsigned short ioprio;
  112. int ref_count;
  113. void *special; /* opaque pointer available for LLD use */
  114. char *buffer; /* kaddr of the current segment if available */
  115. int tag;
  116. int errors;
  117. /*
  118. * when request is used as a packet command carrier
  119. */
  120. unsigned char __cmd[BLK_MAX_CDB];
  121. unsigned char *cmd;
  122. unsigned short cmd_len;
  123. unsigned int extra_len; /* length of alignment and padding */
  124. unsigned int sense_len;
  125. unsigned int resid_len; /* residual count */
  126. void *sense;
  127. unsigned long deadline;
  128. struct list_head timeout_list;
  129. unsigned int timeout;
  130. int retries;
  131. /*
  132. * completion callback.
  133. */
  134. rq_end_io_fn *end_io;
  135. void *end_io_data;
  136. /* for bidi */
  137. struct request *next_rq;
  138. };
  139. static inline unsigned short req_get_ioprio(struct request *req)
  140. {
  141. return req->ioprio;
  142. }
  143. /*
  144. * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
  145. * requests. Some step values could eventually be made generic.
  146. */
  147. struct request_pm_state
  148. {
  149. /* PM state machine step value, currently driver specific */
  150. int pm_step;
  151. /* requested PM state value (S1, S2, S3, S4, ...) */
  152. u32 pm_state;
  153. void* data; /* for driver use */
  154. };
  155. #include <linux/elevator.h>
  156. typedef void (request_fn_proc) (struct request_queue *q);
  157. typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
  158. typedef int (prep_rq_fn) (struct request_queue *, struct request *);
  159. typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
  160. typedef void (unplug_fn) (struct request_queue *);
  161. struct bio_vec;
  162. struct bvec_merge_data {
  163. struct block_device *bi_bdev;
  164. sector_t bi_sector;
  165. unsigned bi_size;
  166. unsigned long bi_rw;
  167. };
  168. typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
  169. struct bio_vec *);
  170. typedef void (softirq_done_fn)(struct request *);
  171. typedef int (dma_drain_needed_fn)(struct request *);
  172. typedef int (lld_busy_fn) (struct request_queue *q);
  173. enum blk_eh_timer_return {
  174. BLK_EH_NOT_HANDLED,
  175. BLK_EH_HANDLED,
  176. BLK_EH_RESET_TIMER,
  177. };
  178. typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
  179. enum blk_queue_state {
  180. Queue_down,
  181. Queue_up,
  182. };
  183. struct blk_queue_tag {
  184. struct request **tag_index; /* map of busy tags */
  185. unsigned long *tag_map; /* bit map of free/busy tags */
  186. int busy; /* current depth */
  187. int max_depth; /* what we will send to device */
  188. int real_max_depth; /* what the array can hold */
  189. atomic_t refcnt; /* map can be shared */
  190. };
  191. #define BLK_SCSI_MAX_CMDS (256)
  192. #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
  193. struct queue_limits {
  194. unsigned long bounce_pfn;
  195. unsigned long seg_boundary_mask;
  196. unsigned int max_hw_sectors;
  197. unsigned int max_sectors;
  198. unsigned int max_segment_size;
  199. unsigned int physical_block_size;
  200. unsigned int alignment_offset;
  201. unsigned int io_min;
  202. unsigned int io_opt;
  203. unsigned int max_discard_sectors;
  204. unsigned int discard_granularity;
  205. unsigned int discard_alignment;
  206. unsigned short logical_block_size;
  207. unsigned short max_segments;
  208. unsigned short max_integrity_segments;
  209. unsigned char misaligned;
  210. unsigned char discard_misaligned;
  211. unsigned char no_cluster;
  212. signed char discard_zeroes_data;
  213. };
  214. struct request_queue
  215. {
  216. /*
  217. * Together with queue_head for cacheline sharing
  218. */
  219. struct list_head queue_head;
  220. struct request *last_merge;
  221. struct elevator_queue *elevator;
  222. /*
  223. * the queue request freelist, one for reads and one for writes
  224. */
  225. struct request_list rq;
  226. request_fn_proc *request_fn;
  227. make_request_fn *make_request_fn;
  228. prep_rq_fn *prep_rq_fn;
  229. unprep_rq_fn *unprep_rq_fn;
  230. unplug_fn *unplug_fn;
  231. merge_bvec_fn *merge_bvec_fn;
  232. softirq_done_fn *softirq_done_fn;
  233. rq_timed_out_fn *rq_timed_out_fn;
  234. dma_drain_needed_fn *dma_drain_needed;
  235. lld_busy_fn *lld_busy_fn;
  236. /*
  237. * Dispatch queue sorting
  238. */
  239. sector_t end_sector;
  240. struct request *boundary_rq;
  241. /*
  242. * Auto-unplugging state
  243. */
  244. struct timer_list unplug_timer;
  245. int unplug_thresh; /* After this many requests */
  246. unsigned long unplug_delay; /* After this many jiffies */
  247. struct work_struct unplug_work;
  248. struct backing_dev_info backing_dev_info;
  249. /*
  250. * The queue owner gets to use this for whatever they like.
  251. * ll_rw_blk doesn't touch it.
  252. */
  253. void *queuedata;
  254. /*
  255. * queue needs bounce pages for pages above this limit
  256. */
  257. gfp_t bounce_gfp;
  258. /*
  259. * various queue flags, see QUEUE_* below
  260. */
  261. unsigned long queue_flags;
  262. /*
  263. * protects queue structures from reentrancy. ->__queue_lock should
  264. * _never_ be used directly, it is queue private. always use
  265. * ->queue_lock.
  266. */
  267. spinlock_t __queue_lock;
  268. spinlock_t *queue_lock;
  269. /*
  270. * queue kobject
  271. */
  272. struct kobject kobj;
  273. /*
  274. * queue settings
  275. */
  276. unsigned long nr_requests; /* Max # of requests */
  277. unsigned int nr_congestion_on;
  278. unsigned int nr_congestion_off;
  279. unsigned int nr_batching;
  280. void *dma_drain_buffer;
  281. unsigned int dma_drain_size;
  282. unsigned int dma_pad_mask;
  283. unsigned int dma_alignment;
  284. struct blk_queue_tag *queue_tags;
  285. struct list_head tag_busy_list;
  286. unsigned int nr_sorted;
  287. unsigned int in_flight[2];
  288. unsigned int rq_timeout;
  289. struct timer_list timeout;
  290. struct list_head timeout_list;
  291. struct queue_limits limits;
  292. /*
  293. * sg stuff
  294. */
  295. unsigned int sg_timeout;
  296. unsigned int sg_reserved_size;
  297. int node;
  298. #ifdef CONFIG_BLK_DEV_IO_TRACE
  299. struct blk_trace *blk_trace;
  300. #endif
  301. /*
  302. * for flush operations
  303. */
  304. unsigned int flush_flags;
  305. unsigned int flush_seq;
  306. int flush_err;
  307. struct request flush_rq;
  308. struct request *orig_flush_rq;
  309. struct list_head pending_flushes;
  310. struct mutex sysfs_lock;
  311. #if defined(CONFIG_BLK_DEV_BSG)
  312. struct bsg_class_device bsg_dev;
  313. #endif
  314. #ifdef CONFIG_BLK_DEV_THROTTLING
  315. /* Throttle data */
  316. struct throtl_data *td;
  317. #endif
  318. };
  319. #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
  320. #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
  321. #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
  322. #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
  323. #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
  324. #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
  325. #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
  326. #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
  327. #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
  328. #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
  329. #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
  330. #define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
  331. #define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
  332. #define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
  333. #define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
  334. #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
  335. #define QUEUE_FLAG_IO_STAT 15 /* do IO stats */
  336. #define QUEUE_FLAG_DISCARD 16 /* supports DISCARD */
  337. #define QUEUE_FLAG_NOXMERGES 17 /* No extended merges */
  338. #define QUEUE_FLAG_ADD_RANDOM 18 /* Contributes to random pool */
  339. #define QUEUE_FLAG_SECDISCARD 19 /* supports SECDISCARD */
  340. #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
  341. (1 << QUEUE_FLAG_CLUSTER) | \
  342. (1 << QUEUE_FLAG_STACKABLE) | \
  343. (1 << QUEUE_FLAG_SAME_COMP) | \
  344. (1 << QUEUE_FLAG_ADD_RANDOM))
  345. static inline int queue_is_locked(struct request_queue *q)
  346. {
  347. #ifdef CONFIG_SMP
  348. spinlock_t *lock = q->queue_lock;
  349. return lock && spin_is_locked(lock);
  350. #else
  351. return 1;
  352. #endif
  353. }
  354. static inline void queue_flag_set_unlocked(unsigned int flag,
  355. struct request_queue *q)
  356. {
  357. __set_bit(flag, &q->queue_flags);
  358. }
  359. static inline int queue_flag_test_and_clear(unsigned int flag,
  360. struct request_queue *q)
  361. {
  362. WARN_ON_ONCE(!queue_is_locked(q));
  363. if (test_bit(flag, &q->queue_flags)) {
  364. __clear_bit(flag, &q->queue_flags);
  365. return 1;
  366. }
  367. return 0;
  368. }
  369. static inline int queue_flag_test_and_set(unsigned int flag,
  370. struct request_queue *q)
  371. {
  372. WARN_ON_ONCE(!queue_is_locked(q));
  373. if (!test_bit(flag, &q->queue_flags)) {
  374. __set_bit(flag, &q->queue_flags);
  375. return 0;
  376. }
  377. return 1;
  378. }
  379. static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
  380. {
  381. WARN_ON_ONCE(!queue_is_locked(q));
  382. __set_bit(flag, &q->queue_flags);
  383. }
  384. static inline void queue_flag_clear_unlocked(unsigned int flag,
  385. struct request_queue *q)
  386. {
  387. __clear_bit(flag, &q->queue_flags);
  388. }
  389. static inline int queue_in_flight(struct request_queue *q)
  390. {
  391. return q->in_flight[0] + q->in_flight[1];
  392. }
  393. static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
  394. {
  395. WARN_ON_ONCE(!queue_is_locked(q));
  396. __clear_bit(flag, &q->queue_flags);
  397. }
  398. #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
  399. #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
  400. #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
  401. #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
  402. #define blk_queue_noxmerges(q) \
  403. test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
  404. #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
  405. #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
  406. #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
  407. #define blk_queue_stackable(q) \
  408. test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
  409. #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
  410. #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
  411. test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
  412. #define blk_noretry_request(rq) \
  413. ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
  414. REQ_FAILFAST_DRIVER))
  415. #define blk_account_rq(rq) \
  416. (((rq)->cmd_flags & REQ_STARTED) && \
  417. ((rq)->cmd_type == REQ_TYPE_FS || \
  418. ((rq)->cmd_flags & REQ_DISCARD)))
  419. #define blk_pm_request(rq) \
  420. ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
  421. (rq)->cmd_type == REQ_TYPE_PM_RESUME)
  422. #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
  423. #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
  424. /* rq->queuelist of dequeued request must be list_empty() */
  425. #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
  426. #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
  427. #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
  428. /*
  429. * We regard a request as sync, if either a read or a sync write
  430. */
  431. static inline bool rw_is_sync(unsigned int rw_flags)
  432. {
  433. return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
  434. }
  435. static inline bool rq_is_sync(struct request *rq)
  436. {
  437. return rw_is_sync(rq->cmd_flags);
  438. }
  439. static inline int blk_queue_full(struct request_queue *q, int sync)
  440. {
  441. if (sync)
  442. return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
  443. return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
  444. }
  445. static inline void blk_set_queue_full(struct request_queue *q, int sync)
  446. {
  447. if (sync)
  448. queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
  449. else
  450. queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
  451. }
  452. static inline void blk_clear_queue_full(struct request_queue *q, int sync)
  453. {
  454. if (sync)
  455. queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
  456. else
  457. queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
  458. }
  459. /*
  460. * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
  461. * it already be started by driver.
  462. */
  463. #define RQ_NOMERGE_FLAGS \
  464. (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
  465. #define rq_mergeable(rq) \
  466. (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
  467. (((rq)->cmd_flags & REQ_DISCARD) || \
  468. (rq)->cmd_type == REQ_TYPE_FS))
  469. /*
  470. * q->prep_rq_fn return values
  471. */
  472. #define BLKPREP_OK 0 /* serve it */
  473. #define BLKPREP_KILL 1 /* fatal error, kill */
  474. #define BLKPREP_DEFER 2 /* leave on queue */
  475. extern unsigned long blk_max_low_pfn, blk_max_pfn;
  476. /*
  477. * standard bounce addresses:
  478. *
  479. * BLK_BOUNCE_HIGH : bounce all highmem pages
  480. * BLK_BOUNCE_ANY : don't bounce anything
  481. * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
  482. */
  483. #if BITS_PER_LONG == 32
  484. #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
  485. #else
  486. #define BLK_BOUNCE_HIGH -1ULL
  487. #endif
  488. #define BLK_BOUNCE_ANY (-1ULL)
  489. #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
  490. /*
  491. * default timeout for SG_IO if none specified
  492. */
  493. #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
  494. #define BLK_MIN_SG_TIMEOUT (7 * HZ)
  495. #ifdef CONFIG_BOUNCE
  496. extern int init_emergency_isa_pool(void);
  497. extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
  498. #else
  499. static inline int init_emergency_isa_pool(void)
  500. {
  501. return 0;
  502. }
  503. static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
  504. {
  505. }
  506. #endif /* CONFIG_MMU */
  507. struct rq_map_data {
  508. struct page **pages;
  509. int page_order;
  510. int nr_entries;
  511. unsigned long offset;
  512. int null_mapped;
  513. int from_user;
  514. };
  515. struct req_iterator {
  516. int i;
  517. struct bio *bio;
  518. };
  519. /* This should not be used directly - use rq_for_each_segment */
  520. #define for_each_bio(_bio) \
  521. for (; _bio; _bio = _bio->bi_next)
  522. #define __rq_for_each_bio(_bio, rq) \
  523. if ((rq->bio)) \
  524. for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
  525. #define rq_for_each_segment(bvl, _rq, _iter) \
  526. __rq_for_each_bio(_iter.bio, _rq) \
  527. bio_for_each_segment(bvl, _iter.bio, _iter.i)
  528. #define rq_iter_last(rq, _iter) \
  529. (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
  530. #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
  531. # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
  532. #endif
  533. #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
  534. extern void rq_flush_dcache_pages(struct request *rq);
  535. #else
  536. static inline void rq_flush_dcache_pages(struct request *rq)
  537. {
  538. }
  539. #endif
  540. extern int blk_register_queue(struct gendisk *disk);
  541. extern void blk_unregister_queue(struct gendisk *disk);
  542. extern void generic_make_request(struct bio *bio);
  543. extern void blk_rq_init(struct request_queue *q, struct request *rq);
  544. extern void blk_put_request(struct request *);
  545. extern void __blk_put_request(struct request_queue *, struct request *);
  546. extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
  547. extern struct request *blk_make_request(struct request_queue *, struct bio *,
  548. gfp_t);
  549. extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
  550. extern void blk_requeue_request(struct request_queue *, struct request *);
  551. extern void blk_add_request_payload(struct request *rq, struct page *page,
  552. unsigned int len);
  553. extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
  554. extern int blk_lld_busy(struct request_queue *q);
  555. extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
  556. struct bio_set *bs, gfp_t gfp_mask,
  557. int (*bio_ctr)(struct bio *, struct bio *, void *),
  558. void *data);
  559. extern void blk_rq_unprep_clone(struct request *rq);
  560. extern int blk_insert_cloned_request(struct request_queue *q,
  561. struct request *rq);
  562. extern void blk_plug_device(struct request_queue *);
  563. extern void blk_plug_device_unlocked(struct request_queue *);
  564. extern int blk_remove_plug(struct request_queue *);
  565. extern void blk_recount_segments(struct request_queue *, struct bio *);
  566. extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
  567. unsigned int, void __user *);
  568. extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
  569. struct scsi_ioctl_command __user *);
  570. /*
  571. * A queue has just exitted congestion. Note this in the global counter of
  572. * congested queues, and wake up anyone who was waiting for requests to be
  573. * put back.
  574. */
  575. static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
  576. {
  577. clear_bdi_congested(&q->backing_dev_info, sync);
  578. }
  579. /*
  580. * A queue has just entered congestion. Flag that in the queue's VM-visible
  581. * state flags and increment the global gounter of congested queues.
  582. */
  583. static inline void blk_set_queue_congested(struct request_queue *q, int sync)
  584. {
  585. set_bdi_congested(&q->backing_dev_info, sync);
  586. }
  587. extern void blk_start_queue(struct request_queue *q);
  588. extern void blk_stop_queue(struct request_queue *q);
  589. extern void blk_sync_queue(struct request_queue *q);
  590. extern void __blk_stop_queue(struct request_queue *q);
  591. extern void __blk_run_queue(struct request_queue *);
  592. extern void blk_run_queue(struct request_queue *);
  593. extern int blk_rq_map_user(struct request_queue *, struct request *,
  594. struct rq_map_data *, void __user *, unsigned long,
  595. gfp_t);
  596. extern int blk_rq_unmap_user(struct bio *);
  597. extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
  598. extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
  599. struct rq_map_data *, struct sg_iovec *, int,
  600. unsigned int, gfp_t);
  601. extern int blk_execute_rq(struct request_queue *, struct gendisk *,
  602. struct request *, int);
  603. extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
  604. struct request *, int, rq_end_io_fn *);
  605. extern void blk_unplug(struct request_queue *q);
  606. static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
  607. {
  608. return bdev->bd_disk->queue;
  609. }
  610. /*
  611. * blk_rq_pos() : the current sector
  612. * blk_rq_bytes() : bytes left in the entire request
  613. * blk_rq_cur_bytes() : bytes left in the current segment
  614. * blk_rq_err_bytes() : bytes left till the next error boundary
  615. * blk_rq_sectors() : sectors left in the entire request
  616. * blk_rq_cur_sectors() : sectors left in the current segment
  617. */
  618. static inline sector_t blk_rq_pos(const struct request *rq)
  619. {
  620. return rq->__sector;
  621. }
  622. static inline unsigned int blk_rq_bytes(const struct request *rq)
  623. {
  624. return rq->__data_len;
  625. }
  626. static inline int blk_rq_cur_bytes(const struct request *rq)
  627. {
  628. return rq->bio ? bio_cur_bytes(rq->bio) : 0;
  629. }
  630. extern unsigned int blk_rq_err_bytes(const struct request *rq);
  631. static inline unsigned int blk_rq_sectors(const struct request *rq)
  632. {
  633. return blk_rq_bytes(rq) >> 9;
  634. }
  635. static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
  636. {
  637. return blk_rq_cur_bytes(rq) >> 9;
  638. }
  639. /*
  640. * Request issue related functions.
  641. */
  642. extern struct request *blk_peek_request(struct request_queue *q);
  643. extern void blk_start_request(struct request *rq);
  644. extern struct request *blk_fetch_request(struct request_queue *q);
  645. /*
  646. * Request completion related functions.
  647. *
  648. * blk_update_request() completes given number of bytes and updates
  649. * the request without completing it.
  650. *
  651. * blk_end_request() and friends. __blk_end_request() must be called
  652. * with the request queue spinlock acquired.
  653. *
  654. * Several drivers define their own end_request and call
  655. * blk_end_request() for parts of the original function.
  656. * This prevents code duplication in drivers.
  657. */
  658. extern bool blk_update_request(struct request *rq, int error,
  659. unsigned int nr_bytes);
  660. extern bool blk_end_request(struct request *rq, int error,
  661. unsigned int nr_bytes);
  662. extern void blk_end_request_all(struct request *rq, int error);
  663. extern bool blk_end_request_cur(struct request *rq, int error);
  664. extern bool blk_end_request_err(struct request *rq, int error);
  665. extern bool __blk_end_request(struct request *rq, int error,
  666. unsigned int nr_bytes);
  667. extern void __blk_end_request_all(struct request *rq, int error);
  668. extern bool __blk_end_request_cur(struct request *rq, int error);
  669. extern bool __blk_end_request_err(struct request *rq, int error);
  670. extern void blk_complete_request(struct request *);
  671. extern void __blk_complete_request(struct request *);
  672. extern void blk_abort_request(struct request *);
  673. extern void blk_abort_queue(struct request_queue *);
  674. extern void blk_unprep_request(struct request *);
  675. /*
  676. * Access functions for manipulating queue properties
  677. */
  678. extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
  679. spinlock_t *lock, int node_id);
  680. extern struct request_queue *blk_init_allocated_queue_node(struct request_queue *,
  681. request_fn_proc *,
  682. spinlock_t *, int node_id);
  683. extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
  684. extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
  685. request_fn_proc *, spinlock_t *);
  686. extern void blk_cleanup_queue(struct request_queue *);
  687. extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
  688. extern void blk_queue_bounce_limit(struct request_queue *, u64);
  689. extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
  690. extern void blk_queue_max_segments(struct request_queue *, unsigned short);
  691. extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
  692. extern void blk_queue_max_discard_sectors(struct request_queue *q,
  693. unsigned int max_discard_sectors);
  694. extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
  695. extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
  696. extern void blk_queue_alignment_offset(struct request_queue *q,
  697. unsigned int alignment);
  698. extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
  699. extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
  700. extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
  701. extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
  702. extern void blk_set_default_limits(struct queue_limits *lim);
  703. extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
  704. sector_t offset);
  705. extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
  706. sector_t offset);
  707. extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
  708. sector_t offset);
  709. extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
  710. extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
  711. extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
  712. extern int blk_queue_dma_drain(struct request_queue *q,
  713. dma_drain_needed_fn *dma_drain_needed,
  714. void *buf, unsigned int size);
  715. extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
  716. extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
  717. extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
  718. extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
  719. extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
  720. extern void blk_queue_dma_alignment(struct request_queue *, int);
  721. extern void blk_queue_update_dma_alignment(struct request_queue *, int);
  722. extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
  723. extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
  724. extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
  725. extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
  726. extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
  727. extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
  728. extern void blk_dump_rq_flags(struct request *, char *);
  729. extern void generic_unplug_device(struct request_queue *);
  730. extern long nr_blockdev_pages(void);
  731. int blk_get_queue(struct request_queue *);
  732. struct request_queue *blk_alloc_queue(gfp_t);
  733. struct request_queue *blk_alloc_queue_node(gfp_t, int);
  734. extern void blk_put_queue(struct request_queue *);
  735. /*
  736. * tag stuff
  737. */
  738. #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
  739. extern int blk_queue_start_tag(struct request_queue *, struct request *);
  740. extern struct request *blk_queue_find_tag(struct request_queue *, int);
  741. extern void blk_queue_end_tag(struct request_queue *, struct request *);
  742. extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
  743. extern void blk_queue_free_tags(struct request_queue *);
  744. extern int blk_queue_resize_tags(struct request_queue *, int);
  745. extern void blk_queue_invalidate_tags(struct request_queue *);
  746. extern struct blk_queue_tag *blk_init_tags(int);
  747. extern void blk_free_tags(struct blk_queue_tag *);
  748. static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
  749. int tag)
  750. {
  751. if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
  752. return NULL;
  753. return bqt->tag_index[tag];
  754. }
  755. #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
  756. extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
  757. extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
  758. sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
  759. extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
  760. sector_t nr_sects, gfp_t gfp_mask);
  761. static inline int sb_issue_discard(struct super_block *sb, sector_t block,
  762. sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
  763. {
  764. return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
  765. nr_blocks << (sb->s_blocksize_bits - 9),
  766. gfp_mask, flags);
  767. }
  768. static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
  769. sector_t nr_blocks, gfp_t gfp_mask)
  770. {
  771. return blkdev_issue_zeroout(sb->s_bdev,
  772. block << (sb->s_blocksize_bits - 9),
  773. nr_blocks << (sb->s_blocksize_bits - 9),
  774. gfp_mask);
  775. }
  776. extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
  777. enum blk_default_limits {
  778. BLK_MAX_SEGMENTS = 128,
  779. BLK_SAFE_MAX_SECTORS = 255,
  780. BLK_DEF_MAX_SECTORS = 1024,
  781. BLK_MAX_SEGMENT_SIZE = 65536,
  782. BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
  783. };
  784. #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
  785. static inline unsigned long queue_bounce_pfn(struct request_queue *q)
  786. {
  787. return q->limits.bounce_pfn;
  788. }
  789. static inline unsigned long queue_segment_boundary(struct request_queue *q)
  790. {
  791. return q->limits.seg_boundary_mask;
  792. }
  793. static inline unsigned int queue_max_sectors(struct request_queue *q)
  794. {
  795. return q->limits.max_sectors;
  796. }
  797. static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
  798. {
  799. return q->limits.max_hw_sectors;
  800. }
  801. static inline unsigned short queue_max_segments(struct request_queue *q)
  802. {
  803. return q->limits.max_segments;
  804. }
  805. static inline unsigned int queue_max_segment_size(struct request_queue *q)
  806. {
  807. return q->limits.max_segment_size;
  808. }
  809. static inline unsigned short queue_logical_block_size(struct request_queue *q)
  810. {
  811. int retval = 512;
  812. if (q && q->limits.logical_block_size)
  813. retval = q->limits.logical_block_size;
  814. return retval;
  815. }
  816. static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
  817. {
  818. return queue_logical_block_size(bdev_get_queue(bdev));
  819. }
  820. static inline unsigned int queue_physical_block_size(struct request_queue *q)
  821. {
  822. return q->limits.physical_block_size;
  823. }
  824. static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
  825. {
  826. return queue_physical_block_size(bdev_get_queue(bdev));
  827. }
  828. static inline unsigned int queue_io_min(struct request_queue *q)
  829. {
  830. return q->limits.io_min;
  831. }
  832. static inline int bdev_io_min(struct block_device *bdev)
  833. {
  834. return queue_io_min(bdev_get_queue(bdev));
  835. }
  836. static inline unsigned int queue_io_opt(struct request_queue *q)
  837. {
  838. return q->limits.io_opt;
  839. }
  840. static inline int bdev_io_opt(struct block_device *bdev)
  841. {
  842. return queue_io_opt(bdev_get_queue(bdev));
  843. }
  844. static inline int queue_alignment_offset(struct request_queue *q)
  845. {
  846. if (q->limits.misaligned)
  847. return -1;
  848. return q->limits.alignment_offset;
  849. }
  850. static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
  851. {
  852. unsigned int granularity = max(lim->physical_block_size, lim->io_min);
  853. unsigned int alignment = (sector << 9) & (granularity - 1);
  854. return (granularity + lim->alignment_offset - alignment)
  855. & (granularity - 1);
  856. }
  857. static inline int bdev_alignment_offset(struct block_device *bdev)
  858. {
  859. struct request_queue *q = bdev_get_queue(bdev);
  860. if (q->limits.misaligned)
  861. return -1;
  862. if (bdev != bdev->bd_contains)
  863. return bdev->bd_part->alignment_offset;
  864. return q->limits.alignment_offset;
  865. }
  866. static inline int queue_discard_alignment(struct request_queue *q)
  867. {
  868. if (q->limits.discard_misaligned)
  869. return -1;
  870. return q->limits.discard_alignment;
  871. }
  872. static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
  873. {
  874. unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
  875. return (lim->discard_granularity + lim->discard_alignment - alignment)
  876. & (lim->discard_granularity - 1);
  877. }
  878. static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
  879. {
  880. if (q->limits.discard_zeroes_data == 1)
  881. return 1;
  882. return 0;
  883. }
  884. static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
  885. {
  886. return queue_discard_zeroes_data(bdev_get_queue(bdev));
  887. }
  888. static inline int queue_dma_alignment(struct request_queue *q)
  889. {
  890. return q ? q->dma_alignment : 511;
  891. }
  892. static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
  893. unsigned int len)
  894. {
  895. unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
  896. return !(addr & alignment) && !(len & alignment);
  897. }
  898. /* assumes size > 256 */
  899. static inline unsigned int blksize_bits(unsigned int size)
  900. {
  901. unsigned int bits = 8;
  902. do {
  903. bits++;
  904. size >>= 1;
  905. } while (size > 256);
  906. return bits;
  907. }
  908. static inline unsigned int block_size(struct block_device *bdev)
  909. {
  910. return bdev->bd_block_size;
  911. }
  912. typedef struct {struct page *v;} Sector;
  913. unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
  914. static inline void put_dev_sector(Sector p)
  915. {
  916. page_cache_release(p.v);
  917. }
  918. struct work_struct;
  919. int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
  920. int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay);
  921. #ifdef CONFIG_BLK_CGROUP
  922. /*
  923. * This should not be using sched_clock(). A real patch is in progress
  924. * to fix this up, until that is in place we need to disable preemption
  925. * around sched_clock() in this function and set_io_start_time_ns().
  926. */
  927. static inline void set_start_time_ns(struct request *req)
  928. {
  929. preempt_disable();
  930. req->start_time_ns = sched_clock();
  931. preempt_enable();
  932. }
  933. static inline void set_io_start_time_ns(struct request *req)
  934. {
  935. preempt_disable();
  936. req->io_start_time_ns = sched_clock();
  937. preempt_enable();
  938. }
  939. static inline uint64_t rq_start_time_ns(struct request *req)
  940. {
  941. return req->start_time_ns;
  942. }
  943. static inline uint64_t rq_io_start_time_ns(struct request *req)
  944. {
  945. return req->io_start_time_ns;
  946. }
  947. #else
  948. static inline void set_start_time_ns(struct request *req) {}
  949. static inline void set_io_start_time_ns(struct request *req) {}
  950. static inline uint64_t rq_start_time_ns(struct request *req)
  951. {
  952. return 0;
  953. }
  954. static inline uint64_t rq_io_start_time_ns(struct request *req)
  955. {
  956. return 0;
  957. }
  958. #endif
  959. #ifdef CONFIG_BLK_DEV_THROTTLING
  960. extern int blk_throtl_init(struct request_queue *q);
  961. extern void blk_throtl_exit(struct request_queue *q);
  962. extern int blk_throtl_bio(struct request_queue *q, struct bio **bio);
  963. extern void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay);
  964. extern void throtl_shutdown_timer_wq(struct request_queue *q);
  965. #else /* CONFIG_BLK_DEV_THROTTLING */
  966. static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio)
  967. {
  968. return 0;
  969. }
  970. static inline int blk_throtl_init(struct request_queue *q) { return 0; }
  971. static inline int blk_throtl_exit(struct request_queue *q) { return 0; }
  972. static inline void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay) {}
  973. static inline void throtl_shutdown_timer_wq(struct request_queue *q) {}
  974. #endif /* CONFIG_BLK_DEV_THROTTLING */
  975. #define MODULE_ALIAS_BLOCKDEV(major,minor) \
  976. MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
  977. #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
  978. MODULE_ALIAS("block-major-" __stringify(major) "-*")
  979. #if defined(CONFIG_BLK_DEV_INTEGRITY)
  980. #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
  981. #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
  982. struct blk_integrity_exchg {
  983. void *prot_buf;
  984. void *data_buf;
  985. sector_t sector;
  986. unsigned int data_size;
  987. unsigned short sector_size;
  988. const char *disk_name;
  989. };
  990. typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
  991. typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
  992. typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
  993. typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
  994. struct blk_integrity {
  995. integrity_gen_fn *generate_fn;
  996. integrity_vrfy_fn *verify_fn;
  997. integrity_set_tag_fn *set_tag_fn;
  998. integrity_get_tag_fn *get_tag_fn;
  999. unsigned short flags;
  1000. unsigned short tuple_size;
  1001. unsigned short sector_size;
  1002. unsigned short tag_size;
  1003. const char *name;
  1004. struct kobject kobj;
  1005. };
  1006. extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
  1007. extern void blk_integrity_unregister(struct gendisk *);
  1008. extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
  1009. extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
  1010. struct scatterlist *);
  1011. extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
  1012. extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
  1013. struct request *);
  1014. extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
  1015. struct bio *);
  1016. static inline
  1017. struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
  1018. {
  1019. return bdev->bd_disk->integrity;
  1020. }
  1021. static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
  1022. {
  1023. return disk->integrity;
  1024. }
  1025. static inline int blk_integrity_rq(struct request *rq)
  1026. {
  1027. if (rq->bio == NULL)
  1028. return 0;
  1029. return bio_integrity(rq->bio);
  1030. }
  1031. static inline void blk_queue_max_integrity_segments(struct request_queue *q,
  1032. unsigned int segs)
  1033. {
  1034. q->limits.max_integrity_segments = segs;
  1035. }
  1036. static inline unsigned short
  1037. queue_max_integrity_segments(struct request_queue *q)
  1038. {
  1039. return q->limits.max_integrity_segments;
  1040. }
  1041. #else /* CONFIG_BLK_DEV_INTEGRITY */
  1042. #define blk_integrity_rq(rq) (0)
  1043. #define blk_rq_count_integrity_sg(a, b) (0)
  1044. #define blk_rq_map_integrity_sg(a, b, c) (0)
  1045. #define bdev_get_integrity(a) (0)
  1046. #define blk_get_integrity(a) (0)
  1047. #define blk_integrity_compare(a, b) (0)
  1048. #define blk_integrity_register(a, b) (0)
  1049. #define blk_integrity_unregister(a) do { } while (0);
  1050. #define blk_queue_max_integrity_segments(a, b) do { } while (0);
  1051. #define queue_max_integrity_segments(a) (0)
  1052. #define blk_integrity_merge_rq(a, b, c) (0)
  1053. #define blk_integrity_merge_bio(a, b, c) (0)
  1054. #endif /* CONFIG_BLK_DEV_INTEGRITY */
  1055. struct block_device_operations {
  1056. int (*open) (struct block_device *, fmode_t);
  1057. int (*release) (struct gendisk *, fmode_t);
  1058. int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
  1059. int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
  1060. int (*direct_access) (struct block_device *, sector_t,
  1061. void **, unsigned long *);
  1062. unsigned int (*check_events) (struct gendisk *disk,
  1063. unsigned int clearing);
  1064. /* ->media_changed() is DEPRECATED, use ->check_events() instead */
  1065. int (*media_changed) (struct gendisk *);
  1066. void (*unlock_native_capacity) (struct gendisk *);
  1067. int (*revalidate_disk) (struct gendisk *);
  1068. int (*getgeo)(struct block_device *, struct hd_geometry *);
  1069. /* this callback is with swap_lock and sometimes page table lock held */
  1070. void (*swap_slot_free_notify) (struct block_device *, unsigned long);
  1071. struct module *owner;
  1072. };
  1073. extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
  1074. unsigned long);
  1075. #else /* CONFIG_BLOCK */
  1076. /*
  1077. * stubs for when the block layer is configured out
  1078. */
  1079. #define buffer_heads_over_limit 0
  1080. static inline long nr_blockdev_pages(void)
  1081. {
  1082. return 0;
  1083. }
  1084. #endif /* CONFIG_BLOCK */
  1085. #endif