Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 | #ifndef _LINUX_BLKDEV_H #define _LINUX_BLKDEV_H #include <linux/major.h> #include <linux/genhd.h> #include <linux/list.h> #include <linux/pagemap.h> #include <linux/backing-dev.h> #include <linux/wait.h> #include <asm/scatterlist.h> struct request_queue; typedef struct request_queue request_queue_t; struct elevator_s; typedef struct elevator_s elevator_t; struct request_list { unsigned int count; struct list_head free; wait_queue_head_t wait; }; /* * try to put the fields that are referenced together in the same cacheline */ struct request { struct list_head queuelist; /* looking for ->queue? you must _not_ * access it directly, use * blkdev_dequeue_request! */ unsigned long flags; /* see REQ_ bits below */ sector_t sector; unsigned long nr_sectors; unsigned int current_nr_sectors; void *elevator_private; int rq_status; /* should split this into a few status bits */ struct gendisk *rq_disk; int errors; unsigned long start_time; sector_t hard_sector; /* the hard_* are block layer * internals, no driver should * touch them */ unsigned long hard_nr_sectors; unsigned int hard_cur_sectors; struct bio *bio; struct bio *biotail; /* Number of scatter-gather DMA addr+len pairs after * physical address coalescing is performed. */ unsigned short nr_phys_segments; /* Number of scatter-gather addr+len pairs after * physical and DMA remapping hardware coalescing is performed. * This is the number of scatter-gather entries the driver * will actually have to deal with after DMA mapping is done. */ unsigned short nr_hw_segments; int tag; char *buffer; int ref_count; request_queue_t *q; struct request_list *rl; struct completion *waiting; void *special; /* * when request is used as a packet command carrier */ unsigned int cmd_len; unsigned char cmd[16]; unsigned int data_len; void *data; unsigned int sense_len; void *sense; unsigned int timeout; }; /* * first three bits match BIO_RW* bits, important */ enum rq_flag_bits { __REQ_RW, /* not set, read. set, write */ __REQ_RW_AHEAD, /* READA */ __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ __REQ_HARDBARRIER, /* may not be passed by drive either */ __REQ_CMD, /* is a regular fs rw request */ __REQ_NOMERGE, /* don't touch this for merging */ __REQ_STARTED, /* drive already may have started this one */ __REQ_DONTPREP, /* don't call prep for this one */ __REQ_QUEUED, /* uses queueing */ /* * for ATA/ATAPI devices */ __REQ_PC, /* packet command (special) */ __REQ_BLOCK_PC, /* queued down pc from block layer */ __REQ_SENSE, /* sense retrival */ __REQ_FAILED, /* set if the request failed */ __REQ_QUIET, /* don't worry about errors */ __REQ_SPECIAL, /* driver suplied command */ __REQ_DRIVE_CMD, __REQ_DRIVE_TASK, __REQ_DRIVE_TASKFILE, __REQ_NR_BITS, /* stops here */ }; #define REQ_RW (1 << __REQ_RW) #define REQ_RW_AHEAD (1 << __REQ_RW_AHEAD) #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) #define REQ_CMD (1 << __REQ_CMD) #define REQ_NOMERGE (1 << __REQ_NOMERGE) #define REQ_STARTED (1 << __REQ_STARTED) #define REQ_DONTPREP (1 << __REQ_DONTPREP) #define REQ_QUEUED (1 << __REQ_QUEUED) #define REQ_PC (1 << __REQ_PC) #define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC) #define REQ_SENSE (1 << __REQ_SENSE) #define REQ_FAILED (1 << __REQ_FAILED) #define REQ_QUIET (1 << __REQ_QUIET) #define REQ_SPECIAL (1 << __REQ_SPECIAL) #define REQ_DRIVE_CMD (1 << __REQ_DRIVE_CMD) #define REQ_DRIVE_TASK (1 << __REQ_DRIVE_TASK) #define REQ_DRIVE_TASKFILE (1 << __REQ_DRIVE_TASKFILE) #include <linux/elevator.h> typedef int (merge_request_fn) (request_queue_t *, struct request *, struct bio *); typedef int (merge_requests_fn) (request_queue_t *, struct request *, struct request *); typedef void (request_fn_proc) (request_queue_t *q); typedef int (make_request_fn) (request_queue_t *q, struct bio *bio); typedef int (prep_rq_fn) (request_queue_t *, struct request *); typedef void (unplug_fn) (void *q); struct bio_vec; typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *); enum blk_queue_state { Queue_down, Queue_up, }; #define BLK_TAGS_PER_LONG (sizeof(unsigned long) * 8) #define BLK_TAGS_MASK (BLK_TAGS_PER_LONG - 1) struct blk_queue_tag { struct request **tag_index; /* map of busy tags */ unsigned long *tag_map; /* bit map of free/busy tags */ struct list_head busy_list; /* fifo list of busy tags */ int busy; /* current depth */ int max_depth; }; struct request_queue { /* * Together with queue_head for cacheline sharing */ struct list_head queue_head; struct list_head *last_merge; elevator_t elevator; /* * the queue request freelist, one for reads and one for writes */ struct request_list rq[2]; request_fn_proc *request_fn; merge_request_fn *back_merge_fn; merge_request_fn *front_merge_fn; merge_requests_fn *merge_requests_fn; make_request_fn *make_request_fn; prep_rq_fn *prep_rq_fn; unplug_fn *unplug_fn; merge_bvec_fn *merge_bvec_fn; struct backing_dev_info backing_dev_info; /* * The queue owner gets to use this for whatever they like. * ll_rw_blk doesn't touch it. */ void *queuedata; /* * queue needs bounce pages for pages above this limit */ unsigned long bounce_pfn; int bounce_gfp; struct list_head plug_list; /* * various queue flags, see QUEUE_* below */ unsigned long queue_flags; /* * protects queue structures from reentrancy */ spinlock_t *queue_lock; /* * queue settings */ unsigned short max_sectors; unsigned short max_phys_segments; unsigned short max_hw_segments; unsigned short hardsect_size; unsigned int max_segment_size; unsigned long seg_boundary_mask; unsigned int dma_alignment; wait_queue_head_t queue_wait; struct blk_queue_tag *queue_tags; /* * sg stuff */ unsigned int sg_timeout; unsigned int sg_reserved_size; }; #define RQ_INACTIVE (-1) #define RQ_ACTIVE 1 #define RQ_SCSI_BUSY 0xffff #define RQ_SCSI_DONE 0xfffe #define RQ_SCSI_DISCONNECTING 0xffe0 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ #define blk_queue_plugged(q) !list_empty(&(q)->plug_list) #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) #define blk_queue_empty(q) elv_queue_empty(q) #define blk_fs_request(rq) ((rq)->flags & REQ_CMD) #define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC) #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) #define rq_data_dir(rq) ((rq)->flags & 1) /* * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may * it already be started by driver. */ #define RQ_NOMERGE_FLAGS \ (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) #define rq_mergeable(rq) \ (!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) /* * noop, requests are automagically marked as active/inactive by I/O * scheduler -- see elv_next_request */ #define blk_queue_headactive(q, head_active) /* * q->prep_rq_fn return values */ #define BLKPREP_OK 0 /* serve it */ #define BLKPREP_KILL 1 /* fatal error, kill */ #define BLKPREP_DEFER 2 /* leave on queue */ extern unsigned long blk_max_low_pfn, blk_max_pfn; /* * standard bounce addresses: * * BLK_BOUNCE_HIGH : bounce all highmem pages * BLK_BOUNCE_ANY : don't bounce anything * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary */ #define BLK_BOUNCE_HIGH (blk_max_low_pfn << PAGE_SHIFT) #define BLK_BOUNCE_ANY (blk_max_pfn << PAGE_SHIFT) #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) extern int init_emergency_isa_pool(void); inline void blk_queue_bounce(request_queue_t *q, struct bio **bio); #define rq_for_each_bio(bio, rq) \ if ((rq->bio)) \ for (bio = (rq)->bio; bio; bio = bio->bi_next) struct sec_size { unsigned block_size; unsigned block_size_bits; }; extern void register_disk(struct gendisk *dev); extern void generic_make_request(struct bio *bio); extern void blk_put_request(struct request *); extern void blk_attempt_remerge(request_queue_t *, struct request *); extern void __blk_attempt_remerge(request_queue_t *, struct request *); extern struct request *blk_get_request(request_queue_t *, int, int); extern struct request *__blk_get_request(request_queue_t *, int); extern void blk_put_request(struct request *); extern void blk_insert_request(request_queue_t *, struct request *, int, void *); extern void blk_plug_device(request_queue_t *); extern int blk_remove_plug(request_queue_t *); extern void blk_recount_segments(request_queue_t *, struct bio *); extern inline int blk_phys_contig_segment(request_queue_t *q, struct bio *, struct bio *); extern inline int blk_hw_contig_segment(request_queue_t *q, struct bio *, struct bio *); extern int scsi_cmd_ioctl(struct block_device *, unsigned int, unsigned long); extern void blk_start_queue(request_queue_t *q); extern void blk_stop_queue(request_queue_t *q); extern void __blk_stop_queue(request_queue_t *q); extern void __blk_run_queue(request_queue_t *q); static inline request_queue_t *bdev_get_queue(struct block_device *bdev) { return bdev->bd_disk->queue; } /* * get ready for proper ref counting */ #define blk_put_queue(q) do { } while (0) /* * Access functions for manipulating queue properties */ extern int blk_init_queue(request_queue_t *, request_fn_proc *, spinlock_t *); extern void blk_cleanup_queue(request_queue_t *); extern void blk_queue_make_request(request_queue_t *, make_request_fn *); extern void blk_queue_bounce_limit(request_queue_t *, u64); extern void blk_queue_max_sectors(request_queue_t *, unsigned short); extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short); extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short); extern void blk_queue_max_segment_size(request_queue_t *, unsigned int); extern void blk_queue_hardsect_size(request_queue_t *, unsigned short); extern void blk_queue_segment_boundary(request_queue_t *, unsigned long); extern void blk_queue_assign_lock(request_queue_t *, spinlock_t *); extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn); extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *); extern void blk_queue_dma_alignment(request_queue_t *, int); extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *); extern void blk_dump_rq_flags(struct request *, char *); extern void generic_unplug_device(void *); extern long nr_blockdev_pages(void); /* * tag stuff */ #define blk_queue_tag_depth(q) ((q)->queue_tags->busy) #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth) #define blk_rq_tagged(rq) ((rq)->flags & REQ_QUEUED) extern int blk_queue_start_tag(request_queue_t *, struct request *); extern struct request *blk_queue_find_tag(request_queue_t *, int); extern void blk_queue_end_tag(request_queue_t *, struct request *); extern int blk_queue_init_tags(request_queue_t *, int); extern void blk_queue_free_tags(request_queue_t *); extern void blk_queue_invalidate_tags(request_queue_t *); extern void blk_congestion_wait(int rw, long timeout); #define MAX_PHYS_SEGMENTS 128 #define MAX_HW_SEGMENTS 128 #define MAX_SECTORS 255 #define MAX_SEGMENT_SIZE 65536 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) extern void drive_stat_acct(struct request *, int, int); static inline int queue_hardsect_size(request_queue_t *q) { int retval = 512; if (q && q->hardsect_size) retval = q->hardsect_size; return retval; } static inline int bdev_hardsect_size(struct block_device *bdev) { return queue_hardsect_size(bdev_get_queue(bdev)); } static inline int queue_dma_alignment(request_queue_t *q) { int retval = 511; if (q && q->dma_alignment) retval = q->dma_alignment; return retval; } static inline int bdev_dma_aligment(struct block_device *bdev) { return queue_dma_alignment(bdev_get_queue(bdev)); } #define blk_finished_io(nsects) do { } while (0) #define blk_started_io(nsects) do { } while (0) /* assumes size > 256 */ static inline unsigned int blksize_bits(unsigned int size) { unsigned int bits = 8; do { bits++; size >>= 1; } while (size > 256); return bits; } extern inline unsigned int block_size(struct block_device *bdev) { return bdev->bd_block_size; } typedef struct {struct page *v;} Sector; unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); static inline void put_dev_sector(Sector p) { page_cache_release(p.v); } #ifdef CONFIG_LBD # include <asm/div64.h> # define sector_div(a, b) do_div(a, b) #else # define sector_div(n, b)( \ { \ int _res; \ _res = (n) % (b); \ (n) /= (b); \ _res; \ } \ ) #endif #endif |