Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #ifndef _LINUX_BLKDEV_H |
| 2 | #define _LINUX_BLKDEV_H |
| 3 | |
Andrew Morton | bcfd8d3 | 2006-08-31 12:56:06 +0200 | [diff] [blame] | 4 | #include <linux/sched.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
| 18 | #include <asm/scatterlist.h> |
| 19 | |
David Howells | 9361401 | 2006-09-30 20:45:40 +0200 | [diff] [blame] | 20 | #ifdef CONFIG_LBD |
| 21 | # include <asm/div64.h> |
| 22 | # define sector_div(a, b) do_div(a, b) |
| 23 | #else |
| 24 | # define sector_div(n, b)( \ |
| 25 | { \ |
| 26 | int _res; \ |
| 27 | _res = (n) % (b); \ |
| 28 | (n) /= (b); \ |
| 29 | _res; \ |
| 30 | } \ |
| 31 | ) |
| 32 | #endif |
| 33 | |
| 34 | #ifdef CONFIG_BLOCK |
| 35 | |
Christoph Hellwig | 21b2f0c | 2006-03-22 17:52:04 +0100 | [diff] [blame] | 36 | struct scsi_ioctl_command; |
| 37 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | struct request_queue; |
| 39 | typedef struct request_queue request_queue_t; |
| 40 | struct elevator_queue; |
| 41 | typedef struct elevator_queue elevator_t; |
| 42 | struct request_pm_state; |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 43 | struct blk_trace; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | |
| 45 | #define BLKDEV_MIN_RQ 4 |
| 46 | #define BLKDEV_MAX_RQ 128 /* Default maximum */ |
| 47 | |
| 48 | /* |
| 49 | * This is the per-process anticipatory I/O scheduler state. |
| 50 | */ |
| 51 | struct as_io_context { |
| 52 | spinlock_t lock; |
| 53 | |
| 54 | void (*dtor)(struct as_io_context *aic); /* destructor */ |
| 55 | void (*exit)(struct as_io_context *aic); /* called on task exit */ |
| 56 | |
| 57 | unsigned long state; |
| 58 | atomic_t nr_queued; /* queued reads & sync writes */ |
| 59 | atomic_t nr_dispatched; /* number of requests gone to the drivers */ |
| 60 | |
| 61 | /* IO History tracking */ |
| 62 | /* Thinktime */ |
| 63 | unsigned long last_end_request; |
| 64 | unsigned long ttime_total; |
| 65 | unsigned long ttime_samples; |
| 66 | unsigned long ttime_mean; |
| 67 | /* Layout pattern */ |
| 68 | unsigned int seek_samples; |
| 69 | sector_t last_request_pos; |
| 70 | u64 seek_total; |
| 71 | sector_t seek_mean; |
| 72 | }; |
| 73 | |
| 74 | struct cfq_queue; |
| 75 | struct cfq_io_context { |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 76 | struct rb_node rb_node; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 77 | void *key; |
| 78 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 79 | struct cfq_queue *cfqq[2]; |
| 80 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 81 | struct io_context *ioc; |
| 82 | |
| 83 | unsigned long last_end_request; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 84 | sector_t last_request_pos; |
| 85 | unsigned long last_queue; |
| 86 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 87 | unsigned long ttime_total; |
| 88 | unsigned long ttime_samples; |
| 89 | unsigned long ttime_mean; |
| 90 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 91 | unsigned int seek_samples; |
| 92 | u64 seek_total; |
| 93 | sector_t seek_mean; |
| 94 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 95 | struct list_head queue_list; |
| 96 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 97 | void (*dtor)(struct io_context *); /* destructor */ |
| 98 | void (*exit)(struct io_context *); /* called on task exit */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | }; |
| 100 | |
| 101 | /* |
| 102 | * This is the per-process I/O subsystem state. It is refcounted and |
| 103 | * kmalloc'ed. Currently all fields are modified in process io context |
| 104 | * (apart from the atomic refcount), so require no locking. |
| 105 | */ |
| 106 | struct io_context { |
| 107 | atomic_t refcount; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 108 | struct task_struct *task; |
| 109 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 110 | unsigned int ioprio_changed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | |
| 112 | /* |
| 113 | * For request batching |
| 114 | */ |
| 115 | unsigned long last_waited; /* Time last woken after wait for request */ |
| 116 | int nr_batch_requests; /* Number of requests left in the batch */ |
| 117 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | struct as_io_context *aic; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 119 | struct rb_root cic_root; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | }; |
| 121 | |
| 122 | void put_io_context(struct io_context *ioc); |
| 123 | void exit_io_context(void); |
Jens Axboe | b5deef9 | 2006-07-19 23:39:40 +0200 | [diff] [blame] | 124 | struct io_context *get_io_context(gfp_t gfp_flags, int node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | void copy_io_context(struct io_context **pdst, struct io_context **psrc); |
| 126 | void swap_io_context(struct io_context **ioc1, struct io_context **ioc2); |
| 127 | |
| 128 | struct request; |
Tejun Heo | 8ffdc65 | 2006-01-06 09:49:03 +0100 | [diff] [blame] | 129 | typedef void (rq_end_io_fn)(struct request *, int); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | |
| 131 | struct request_list { |
| 132 | int count[2]; |
| 133 | int starved[2]; |
Tejun Heo | cb98fc8 | 2005-10-28 08:29:39 +0200 | [diff] [blame] | 134 | int elvpriv; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | mempool_t *rq_pool; |
| 136 | wait_queue_head_t wait[2]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | }; |
| 138 | |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 139 | /* |
| 140 | * request command types |
| 141 | */ |
| 142 | enum rq_cmd_type_bits { |
| 143 | REQ_TYPE_FS = 1, /* fs request */ |
| 144 | REQ_TYPE_BLOCK_PC, /* scsi command */ |
| 145 | REQ_TYPE_SENSE, /* sense request */ |
| 146 | REQ_TYPE_PM_SUSPEND, /* suspend request */ |
| 147 | REQ_TYPE_PM_RESUME, /* resume request */ |
| 148 | REQ_TYPE_PM_SHUTDOWN, /* shutdown request */ |
| 149 | REQ_TYPE_FLUSH, /* flush request */ |
| 150 | REQ_TYPE_SPECIAL, /* driver defined type */ |
| 151 | REQ_TYPE_LINUX_BLOCK, /* generic block layer message */ |
| 152 | /* |
| 153 | * for ATA/ATAPI devices. this really doesn't belong here, ide should |
| 154 | * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver |
| 155 | * private REQ_LB opcodes to differentiate what type of request this is |
| 156 | */ |
| 157 | REQ_TYPE_ATA_CMD, |
| 158 | REQ_TYPE_ATA_TASK, |
| 159 | REQ_TYPE_ATA_TASKFILE, |
Jens Axboe | cea2885 | 2006-10-12 15:08:45 +0200 | [diff] [blame] | 160 | REQ_TYPE_ATA_PC, |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 161 | }; |
| 162 | |
| 163 | /* |
| 164 | * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being |
| 165 | * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a |
| 166 | * SCSI cdb. |
| 167 | * |
| 168 | * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need, |
| 169 | * typically to differentiate REQ_TYPE_SPECIAL requests. |
| 170 | * |
| 171 | */ |
| 172 | enum { |
| 173 | /* |
| 174 | * just examples for now |
| 175 | */ |
| 176 | REQ_LB_OP_EJECT = 0x40, /* eject request */ |
| 177 | REQ_LB_OP_FLUSH = 0x41, /* flush device */ |
| 178 | }; |
| 179 | |
| 180 | /* |
| 181 | * request type modified bits. first three bits match BIO_RW* bits, important |
| 182 | */ |
| 183 | enum rq_flag_bits { |
| 184 | __REQ_RW, /* not set, read. set, write */ |
| 185 | __REQ_FAILFAST, /* no low level driver retries */ |
| 186 | __REQ_SORTED, /* elevator knows about this request */ |
| 187 | __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ |
| 188 | __REQ_HARDBARRIER, /* may not be passed by drive either */ |
| 189 | __REQ_FUA, /* forced unit access */ |
| 190 | __REQ_NOMERGE, /* don't touch this for merging */ |
| 191 | __REQ_STARTED, /* drive already may have started this one */ |
| 192 | __REQ_DONTPREP, /* don't call prep for this one */ |
| 193 | __REQ_QUEUED, /* uses queueing */ |
| 194 | __REQ_ELVPRIV, /* elevator private data attached */ |
| 195 | __REQ_FAILED, /* set if the request failed */ |
| 196 | __REQ_QUIET, /* don't worry about errors */ |
| 197 | __REQ_PREEMPT, /* set for "ide_preempt" requests */ |
| 198 | __REQ_ORDERED_COLOR, /* is before or after barrier */ |
| 199 | __REQ_RW_SYNC, /* request is sync (O_DIRECT) */ |
Jens Axboe | 49171e5 | 2006-08-10 08:59:11 +0200 | [diff] [blame] | 200 | __REQ_ALLOCED, /* request came from our alloc pool */ |
Jens Axboe | 5404bc7 | 2006-08-10 09:01:02 +0200 | [diff] [blame] | 201 | __REQ_RW_META, /* metadata io request */ |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 202 | __REQ_NR_BITS, /* stops here */ |
| 203 | }; |
| 204 | |
| 205 | #define REQ_RW (1 << __REQ_RW) |
| 206 | #define REQ_FAILFAST (1 << __REQ_FAILFAST) |
| 207 | #define REQ_SORTED (1 << __REQ_SORTED) |
| 208 | #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) |
| 209 | #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) |
| 210 | #define REQ_FUA (1 << __REQ_FUA) |
| 211 | #define REQ_NOMERGE (1 << __REQ_NOMERGE) |
| 212 | #define REQ_STARTED (1 << __REQ_STARTED) |
| 213 | #define REQ_DONTPREP (1 << __REQ_DONTPREP) |
| 214 | #define REQ_QUEUED (1 << __REQ_QUEUED) |
| 215 | #define REQ_ELVPRIV (1 << __REQ_ELVPRIV) |
| 216 | #define REQ_FAILED (1 << __REQ_FAILED) |
| 217 | #define REQ_QUIET (1 << __REQ_QUIET) |
| 218 | #define REQ_PREEMPT (1 << __REQ_PREEMPT) |
| 219 | #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR) |
| 220 | #define REQ_RW_SYNC (1 << __REQ_RW_SYNC) |
Jens Axboe | 49171e5 | 2006-08-10 08:59:11 +0200 | [diff] [blame] | 221 | #define REQ_ALLOCED (1 << __REQ_ALLOCED) |
Jens Axboe | 5404bc7 | 2006-08-10 09:01:02 +0200 | [diff] [blame] | 222 | #define REQ_RW_META (1 << __REQ_RW_META) |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 223 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | #define BLK_MAX_CDB 16 |
| 225 | |
| 226 | /* |
| 227 | * try to put the fields that are referenced together in the same cacheline |
| 228 | */ |
| 229 | struct request { |
Jens Axboe | ff856ba | 2006-01-09 16:02:34 +0100 | [diff] [blame] | 230 | struct list_head queuelist; |
| 231 | struct list_head donelist; |
| 232 | |
Jens Axboe | e6a1c87 | 2006-08-10 09:00:21 +0200 | [diff] [blame] | 233 | request_queue_t *q; |
| 234 | |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 235 | unsigned int cmd_flags; |
| 236 | enum rq_cmd_type_bits cmd_type; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | |
| 238 | /* Maintain bio traversal state for part by part I/O submission. |
| 239 | * hard_* are block layer internals, no driver should touch them! |
| 240 | */ |
| 241 | |
| 242 | sector_t sector; /* next sector to submit */ |
Jens Axboe | e6a1c87 | 2006-08-10 09:00:21 +0200 | [diff] [blame] | 243 | sector_t hard_sector; /* next sector to complete */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 244 | unsigned long nr_sectors; /* no. of sectors left to submit */ |
Jens Axboe | e6a1c87 | 2006-08-10 09:00:21 +0200 | [diff] [blame] | 245 | unsigned long hard_nr_sectors; /* no. of sectors left to complete */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | /* no. of sectors left to submit in the current segment */ |
| 247 | unsigned int current_nr_sectors; |
| 248 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | /* no. of sectors left to complete in the current segment */ |
| 250 | unsigned int hard_cur_sectors; |
| 251 | |
| 252 | struct bio *bio; |
| 253 | struct bio *biotail; |
| 254 | |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 255 | struct hlist_node hash; /* merge hash */ |
Jens Axboe | e6a1c87 | 2006-08-10 09:00:21 +0200 | [diff] [blame] | 256 | /* |
| 257 | * The rb_node is only used inside the io scheduler, requests |
| 258 | * are pruned when moved to the dispatch queue. So let the |
| 259 | * completion_data share space with the rb_node. |
| 260 | */ |
| 261 | union { |
| 262 | struct rb_node rb_node; /* sort/lookup */ |
| 263 | void *completion_data; |
| 264 | }; |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 265 | |
Jens Axboe | ff7d145 | 2006-07-12 14:04:37 +0200 | [diff] [blame] | 266 | /* |
| 267 | * two pointers are available for the IO schedulers, if they need |
| 268 | * more they have to dynamically allocate it. |
| 269 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | void *elevator_private; |
Jens Axboe | ff7d145 | 2006-07-12 14:04:37 +0200 | [diff] [blame] | 271 | void *elevator_private2; |
| 272 | |
Jens Axboe | 8f34ee7 | 2006-06-13 09:02:34 +0200 | [diff] [blame] | 273 | struct gendisk *rq_disk; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | unsigned long start_time; |
| 275 | |
| 276 | /* Number of scatter-gather DMA addr+len pairs after |
| 277 | * physical address coalescing is performed. |
| 278 | */ |
| 279 | unsigned short nr_phys_segments; |
| 280 | |
| 281 | /* Number of scatter-gather addr+len pairs after |
| 282 | * physical and DMA remapping hardware coalescing is performed. |
| 283 | * This is the number of scatter-gather entries the driver |
| 284 | * will actually have to deal with after DMA mapping is done. |
| 285 | */ |
| 286 | unsigned short nr_hw_segments; |
| 287 | |
Jens Axboe | 8f34ee7 | 2006-06-13 09:02:34 +0200 | [diff] [blame] | 288 | unsigned short ioprio; |
| 289 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 290 | void *special; |
Jens Axboe | 8f34ee7 | 2006-06-13 09:02:34 +0200 | [diff] [blame] | 291 | char *buffer; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | |
Jens Axboe | cdd6026 | 2006-07-28 09:32:07 +0200 | [diff] [blame] | 293 | int tag; |
| 294 | int errors; |
| 295 | |
| 296 | int ref_count; |
| 297 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | /* |
| 299 | * when request is used as a packet command carrier |
| 300 | */ |
| 301 | unsigned int cmd_len; |
| 302 | unsigned char cmd[BLK_MAX_CDB]; |
| 303 | |
| 304 | unsigned int data_len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 305 | unsigned int sense_len; |
Jens Axboe | 8f34ee7 | 2006-06-13 09:02:34 +0200 | [diff] [blame] | 306 | void *data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | void *sense; |
| 308 | |
| 309 | unsigned int timeout; |
Mike Christie | 17e01f2 | 2005-11-11 05:31:37 -0600 | [diff] [blame] | 310 | int retries; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | |
| 312 | /* |
Jens Axboe | c00895a | 2006-09-30 20:29:12 +0200 | [diff] [blame] | 313 | * completion callback. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | */ |
| 315 | rq_end_io_fn *end_io; |
| 316 | void *end_io_data; |
| 317 | }; |
| 318 | |
| 319 | /* |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 320 | * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 321 | * requests. Some step values could eventually be made generic. |
| 322 | */ |
| 323 | struct request_pm_state |
| 324 | { |
| 325 | /* PM state machine step value, currently driver specific */ |
| 326 | int pm_step; |
| 327 | /* requested PM state value (S1, S2, S3, S4, ...) */ |
| 328 | u32 pm_state; |
| 329 | void* data; /* for driver use */ |
| 330 | }; |
| 331 | |
| 332 | #include <linux/elevator.h> |
| 333 | |
| 334 | typedef int (merge_request_fn) (request_queue_t *, struct request *, |
| 335 | struct bio *); |
| 336 | typedef int (merge_requests_fn) (request_queue_t *, struct request *, |
| 337 | struct request *); |
| 338 | typedef void (request_fn_proc) (request_queue_t *q); |
| 339 | typedef int (make_request_fn) (request_queue_t *q, struct bio *bio); |
| 340 | typedef int (prep_rq_fn) (request_queue_t *, struct request *); |
| 341 | typedef void (unplug_fn) (request_queue_t *); |
| 342 | |
| 343 | struct bio_vec; |
| 344 | typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *); |
| 345 | typedef void (activity_fn) (void *data, int rw); |
| 346 | typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *); |
Tejun Heo | 797e7db | 2006-01-06 09:51:03 +0100 | [diff] [blame] | 347 | typedef void (prepare_flush_fn) (request_queue_t *, struct request *); |
Jens Axboe | ff856ba | 2006-01-09 16:02:34 +0100 | [diff] [blame] | 348 | typedef void (softirq_done_fn)(struct request *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 349 | |
| 350 | enum blk_queue_state { |
| 351 | Queue_down, |
| 352 | Queue_up, |
| 353 | }; |
| 354 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 355 | struct blk_queue_tag { |
| 356 | struct request **tag_index; /* map of busy tags */ |
| 357 | unsigned long *tag_map; /* bit map of free/busy tags */ |
| 358 | struct list_head busy_list; /* fifo list of busy tags */ |
| 359 | int busy; /* current depth */ |
| 360 | int max_depth; /* what we will send to device */ |
Tejun Heo | ba02508 | 2005-08-05 13:28:11 -0700 | [diff] [blame] | 361 | int real_max_depth; /* what the array can hold */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 362 | atomic_t refcnt; /* map can be shared */ |
| 363 | }; |
| 364 | |
| 365 | struct request_queue |
| 366 | { |
| 367 | /* |
| 368 | * Together with queue_head for cacheline sharing |
| 369 | */ |
| 370 | struct list_head queue_head; |
| 371 | struct request *last_merge; |
| 372 | elevator_t *elevator; |
| 373 | |
| 374 | /* |
| 375 | * the queue request freelist, one for reads and one for writes |
| 376 | */ |
| 377 | struct request_list rq; |
| 378 | |
| 379 | request_fn_proc *request_fn; |
| 380 | merge_request_fn *back_merge_fn; |
| 381 | merge_request_fn *front_merge_fn; |
| 382 | merge_requests_fn *merge_requests_fn; |
| 383 | make_request_fn *make_request_fn; |
| 384 | prep_rq_fn *prep_rq_fn; |
| 385 | unplug_fn *unplug_fn; |
| 386 | merge_bvec_fn *merge_bvec_fn; |
| 387 | activity_fn *activity_fn; |
| 388 | issue_flush_fn *issue_flush_fn; |
| 389 | prepare_flush_fn *prepare_flush_fn; |
Jens Axboe | ff856ba | 2006-01-09 16:02:34 +0100 | [diff] [blame] | 390 | softirq_done_fn *softirq_done_fn; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | |
| 392 | /* |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 393 | * Dispatch queue sorting |
| 394 | */ |
Jens Axboe | 1b47f53 | 2005-10-20 16:37:00 +0200 | [diff] [blame] | 395 | sector_t end_sector; |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 396 | struct request *boundary_rq; |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 397 | |
| 398 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | * Auto-unplugging state |
| 400 | */ |
| 401 | struct timer_list unplug_timer; |
| 402 | int unplug_thresh; /* After this many requests */ |
| 403 | unsigned long unplug_delay; /* After this many jiffies */ |
| 404 | struct work_struct unplug_work; |
| 405 | |
| 406 | struct backing_dev_info backing_dev_info; |
| 407 | |
| 408 | /* |
| 409 | * The queue owner gets to use this for whatever they like. |
| 410 | * ll_rw_blk doesn't touch it. |
| 411 | */ |
| 412 | void *queuedata; |
| 413 | |
| 414 | void *activity_data; |
| 415 | |
| 416 | /* |
| 417 | * queue needs bounce pages for pages above this limit |
| 418 | */ |
| 419 | unsigned long bounce_pfn; |
Al Viro | 8267e26 | 2005-10-21 03:20:53 -0400 | [diff] [blame] | 420 | gfp_t bounce_gfp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 421 | |
| 422 | /* |
| 423 | * various queue flags, see QUEUE_* below |
| 424 | */ |
| 425 | unsigned long queue_flags; |
| 426 | |
| 427 | /* |
| 152587d | 2005-04-12 16:22:06 -0500 | [diff] [blame] | 428 | * protects queue structures from reentrancy. ->__queue_lock should |
| 429 | * _never_ be used directly, it is queue private. always use |
| 430 | * ->queue_lock. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 431 | */ |
| 152587d | 2005-04-12 16:22:06 -0500 | [diff] [blame] | 432 | spinlock_t __queue_lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | spinlock_t *queue_lock; |
| 434 | |
| 435 | /* |
| 436 | * queue kobject |
| 437 | */ |
| 438 | struct kobject kobj; |
| 439 | |
| 440 | /* |
| 441 | * queue settings |
| 442 | */ |
| 443 | unsigned long nr_requests; /* Max # of requests */ |
| 444 | unsigned int nr_congestion_on; |
| 445 | unsigned int nr_congestion_off; |
| 446 | unsigned int nr_batching; |
| 447 | |
Jens Axboe | 2cb2e14 | 2006-01-17 09:04:32 +0100 | [diff] [blame] | 448 | unsigned int max_sectors; |
| 449 | unsigned int max_hw_sectors; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | unsigned short max_phys_segments; |
| 451 | unsigned short max_hw_segments; |
| 452 | unsigned short hardsect_size; |
| 453 | unsigned int max_segment_size; |
| 454 | |
| 455 | unsigned long seg_boundary_mask; |
| 456 | unsigned int dma_alignment; |
| 457 | |
| 458 | struct blk_queue_tag *queue_tags; |
| 459 | |
Tejun Heo | 15853af | 2005-11-10 08:52:05 +0100 | [diff] [blame] | 460 | unsigned int nr_sorted; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 461 | unsigned int in_flight; |
| 462 | |
| 463 | /* |
| 464 | * sg stuff |
| 465 | */ |
| 466 | unsigned int sg_timeout; |
| 467 | unsigned int sg_reserved_size; |
Christoph Lameter | 1946089 | 2005-06-23 00:08:19 -0700 | [diff] [blame] | 468 | int node; |
Alexey Dobriyan | 6c5c934 | 2006-09-29 01:59:40 -0700 | [diff] [blame] | 469 | #ifdef CONFIG_BLK_DEV_IO_TRACE |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 470 | struct blk_trace *blk_trace; |
Alexey Dobriyan | 6c5c934 | 2006-09-29 01:59:40 -0700 | [diff] [blame] | 471 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | /* |
| 473 | * reserved for flush operations |
| 474 | */ |
Tejun Heo | 797e7db | 2006-01-06 09:51:03 +0100 | [diff] [blame] | 475 | unsigned int ordered, next_ordered, ordseq; |
| 476 | int orderr, ordcolor; |
| 477 | struct request pre_flush_rq, bar_rq, post_flush_rq; |
| 478 | struct request *orig_bar_rq; |
| 479 | unsigned int bi_size; |
Al Viro | 483f4af | 2006-03-18 18:34:37 -0500 | [diff] [blame] | 480 | |
| 481 | struct mutex sysfs_lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | }; |
| 483 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ |
| 485 | #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ |
| 486 | #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ |
| 487 | #define QUEUE_FLAG_READFULL 3 /* write queue has been filled */ |
| 488 | #define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */ |
| 489 | #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ |
| 490 | #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ |
| 491 | #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ |
Jens Axboe | 64521d1 | 2005-10-28 08:30:39 +0200 | [diff] [blame] | 492 | #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ |
Tejun Heo | 797e7db | 2006-01-06 09:51:03 +0100 | [diff] [blame] | 493 | |
| 494 | enum { |
| 495 | /* |
| 496 | * Hardbarrier is supported with one of the following methods. |
| 497 | * |
| 498 | * NONE : hardbarrier unsupported |
| 499 | * DRAIN : ordering by draining is enough |
| 500 | * DRAIN_FLUSH : ordering by draining w/ pre and post flushes |
| 501 | * DRAIN_FUA : ordering by draining w/ pre flush and FUA write |
| 502 | * TAG : ordering by tag is enough |
| 503 | * TAG_FLUSH : ordering by tag w/ pre and post flushes |
| 504 | * TAG_FUA : ordering by tag w/ pre flush and FUA write |
| 505 | */ |
| 506 | QUEUE_ORDERED_NONE = 0x00, |
| 507 | QUEUE_ORDERED_DRAIN = 0x01, |
| 508 | QUEUE_ORDERED_TAG = 0x02, |
| 509 | |
| 510 | QUEUE_ORDERED_PREFLUSH = 0x10, |
| 511 | QUEUE_ORDERED_POSTFLUSH = 0x20, |
| 512 | QUEUE_ORDERED_FUA = 0x40, |
| 513 | |
| 514 | QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | |
| 515 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, |
| 516 | QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | |
| 517 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, |
| 518 | QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | |
| 519 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, |
| 520 | QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | |
| 521 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, |
| 522 | |
| 523 | /* |
| 524 | * Ordered operation sequence |
| 525 | */ |
| 526 | QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */ |
| 527 | QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */ |
| 528 | QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */ |
| 529 | QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */ |
| 530 | QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */ |
| 531 | QUEUE_ORDSEQ_DONE = 0x20, |
| 532 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | |
| 534 | #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) |
| 535 | #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) |
| 536 | #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) |
Tejun Heo | 797e7db | 2006-01-06 09:51:03 +0100 | [diff] [blame] | 537 | #define blk_queue_flushing(q) ((q)->ordseq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 538 | |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 539 | #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS) |
| 540 | #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC) |
| 541 | #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL) |
| 542 | #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE) |
| 543 | |
| 544 | #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST) |
| 545 | #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 546 | |
| 547 | #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) |
| 548 | |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 549 | #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND) |
| 550 | #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 551 | #define blk_pm_request(rq) \ |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 552 | (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 553 | |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 554 | #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED) |
| 555 | #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER) |
| 556 | #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | |
| 558 | #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) |
| 559 | |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 560 | #define rq_data_dir(rq) ((rq)->cmd_flags & 1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 561 | |
Jens Axboe | 9e2585a | 2006-07-28 09:26:13 +0200 | [diff] [blame] | 562 | /* |
| 563 | * We regard a request as sync, if it's a READ or a SYNC write. |
| 564 | */ |
| 565 | #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC) |
Jens Axboe | 5404bc7 | 2006-08-10 09:01:02 +0200 | [diff] [blame] | 566 | #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META) |
Jens Axboe | 9e2585a | 2006-07-28 09:26:13 +0200 | [diff] [blame] | 567 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 568 | static inline int blk_queue_full(struct request_queue *q, int rw) |
| 569 | { |
| 570 | if (rw == READ) |
| 571 | return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); |
| 572 | return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); |
| 573 | } |
| 574 | |
| 575 | static inline void blk_set_queue_full(struct request_queue *q, int rw) |
| 576 | { |
| 577 | if (rw == READ) |
| 578 | set_bit(QUEUE_FLAG_READFULL, &q->queue_flags); |
| 579 | else |
| 580 | set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); |
| 581 | } |
| 582 | |
| 583 | static inline void blk_clear_queue_full(struct request_queue *q, int rw) |
| 584 | { |
| 585 | if (rw == READ) |
| 586 | clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags); |
| 587 | else |
| 588 | clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); |
| 589 | } |
| 590 | |
| 591 | |
| 592 | /* |
| 593 | * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may |
| 594 | * it already be started by driver. |
| 595 | */ |
| 596 | #define RQ_NOMERGE_FLAGS \ |
| 597 | (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) |
| 598 | #define rq_mergeable(rq) \ |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 599 | (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 600 | |
| 601 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 602 | * q->prep_rq_fn return values |
| 603 | */ |
| 604 | #define BLKPREP_OK 0 /* serve it */ |
| 605 | #define BLKPREP_KILL 1 /* fatal error, kill */ |
| 606 | #define BLKPREP_DEFER 2 /* leave on queue */ |
| 607 | |
| 608 | extern unsigned long blk_max_low_pfn, blk_max_pfn; |
| 609 | |
| 610 | /* |
| 611 | * standard bounce addresses: |
| 612 | * |
| 613 | * BLK_BOUNCE_HIGH : bounce all highmem pages |
| 614 | * BLK_BOUNCE_ANY : don't bounce anything |
| 615 | * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary |
| 616 | */ |
| 617 | #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) |
| 618 | #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT) |
| 619 | #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) |
| 620 | |
| 621 | #ifdef CONFIG_MMU |
| 622 | extern int init_emergency_isa_pool(void); |
| 623 | extern void blk_queue_bounce(request_queue_t *q, struct bio **bio); |
| 624 | #else |
| 625 | static inline int init_emergency_isa_pool(void) |
| 626 | { |
| 627 | return 0; |
| 628 | } |
| 629 | static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio) |
| 630 | { |
| 631 | } |
| 632 | #endif /* CONFIG_MMU */ |
| 633 | |
| 634 | #define rq_for_each_bio(_bio, rq) \ |
| 635 | if ((rq->bio)) \ |
| 636 | for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) |
| 637 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 638 | extern int blk_register_queue(struct gendisk *disk); |
| 639 | extern void blk_unregister_queue(struct gendisk *disk); |
| 640 | extern void register_disk(struct gendisk *dev); |
| 641 | extern void generic_make_request(struct bio *bio); |
| 642 | extern void blk_put_request(struct request *); |
Mike Christie | 6e39b69 | 2005-11-11 05:30:24 -0600 | [diff] [blame] | 643 | extern void __blk_put_request(request_queue_t *, struct request *); |
Tejun Heo | 8ffdc65 | 2006-01-06 09:49:03 +0100 | [diff] [blame] | 644 | extern void blk_end_sync_rq(struct request *rq, int error); |
Al Viro | 8267e26 | 2005-10-21 03:20:53 -0400 | [diff] [blame] | 645 | extern struct request *blk_get_request(request_queue_t *, int, gfp_t); |
Tejun Heo | 867d119 | 2005-04-24 02:06:05 -0500 | [diff] [blame] | 646 | extern void blk_insert_request(request_queue_t *, struct request *, int, void *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 647 | extern void blk_requeue_request(request_queue_t *, struct request *); |
| 648 | extern void blk_plug_device(request_queue_t *); |
| 649 | extern int blk_remove_plug(request_queue_t *); |
| 650 | extern void blk_recount_segments(request_queue_t *, struct bio *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 651 | extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *); |
Christoph Hellwig | 21b2f0c | 2006-03-22 17:52:04 +0100 | [diff] [blame] | 652 | extern int sg_scsi_ioctl(struct file *, struct request_queue *, |
| 653 | struct gendisk *, struct scsi_ioctl_command __user *); |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 654 | |
| 655 | /* |
| 656 | * A queue has just exitted congestion. Note this in the global counter of |
| 657 | * congested queues, and wake up anyone who was waiting for requests to be |
| 658 | * put back. |
| 659 | */ |
| 660 | static inline void blk_clear_queue_congested(request_queue_t *q, int rw) |
| 661 | { |
| 662 | clear_bdi_congested(&q->backing_dev_info, rw); |
| 663 | } |
| 664 | |
| 665 | /* |
| 666 | * A queue has just entered congestion. Flag that in the queue's VM-visible |
| 667 | * state flags and increment the global gounter of congested queues. |
| 668 | */ |
| 669 | static inline void blk_set_queue_congested(request_queue_t *q, int rw) |
| 670 | { |
| 671 | set_bdi_congested(&q->backing_dev_info, rw); |
| 672 | } |
| 673 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 674 | extern void blk_start_queue(request_queue_t *q); |
| 675 | extern void blk_stop_queue(request_queue_t *q); |
| 676 | extern void blk_sync_queue(struct request_queue *q); |
| 677 | extern void __blk_stop_queue(request_queue_t *q); |
| 678 | extern void blk_run_queue(request_queue_t *); |
Jens Axboe | dc72ef4 | 2006-07-20 14:54:05 +0200 | [diff] [blame] | 679 | extern void blk_start_queueing(request_queue_t *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 680 | extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *); |
Mike Christie | 0e75f90 | 2006-12-01 10:40:55 +0100 | [diff] [blame] | 681 | extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned long); |
| 682 | extern int blk_rq_unmap_user(struct request *); |
Al Viro | 8267e26 | 2005-10-21 03:20:53 -0400 | [diff] [blame] | 683 | extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, gfp_t); |
Mike Christie | 0e75f90 | 2006-12-01 10:40:55 +0100 | [diff] [blame] | 684 | extern int blk_rq_map_user_iov(request_queue_t *, struct request *, |
| 685 | struct sg_iovec *, int, unsigned int); |
James Bottomley | 994ca9a | 2005-06-20 14:11:09 +0200 | [diff] [blame] | 686 | extern int blk_execute_rq(request_queue_t *, struct gendisk *, |
| 687 | struct request *, int); |
Mike Christie | 6e39b69 | 2005-11-11 05:30:24 -0600 | [diff] [blame] | 688 | extern void blk_execute_rq_nowait(request_queue_t *, struct gendisk *, |
Jens Axboe | 15fc858 | 2006-01-06 10:00:50 +0100 | [diff] [blame] | 689 | struct request *, int, rq_end_io_fn *); |
Mike Christie | 6e39b69 | 2005-11-11 05:30:24 -0600 | [diff] [blame] | 690 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | static inline request_queue_t *bdev_get_queue(struct block_device *bdev) |
| 692 | { |
| 693 | return bdev->bd_disk->queue; |
| 694 | } |
| 695 | |
| 696 | static inline void blk_run_backing_dev(struct backing_dev_info *bdi, |
| 697 | struct page *page) |
| 698 | { |
| 699 | if (bdi && bdi->unplug_io_fn) |
| 700 | bdi->unplug_io_fn(bdi, page); |
| 701 | } |
| 702 | |
| 703 | static inline void blk_run_address_space(struct address_space *mapping) |
| 704 | { |
| 705 | if (mapping) |
| 706 | blk_run_backing_dev(mapping->backing_dev_info, NULL); |
| 707 | } |
| 708 | |
| 709 | /* |
| 710 | * end_request() and friends. Must be called with the request queue spinlock |
| 711 | * acquired. All functions called within end_request() _must_be_ atomic. |
| 712 | * |
| 713 | * Several drivers define their own end_request and call |
| 714 | * end_that_request_first() and end_that_request_last() |
| 715 | * for parts of the original function. This prevents |
| 716 | * code duplication in drivers. |
| 717 | */ |
| 718 | extern int end_that_request_first(struct request *, int, int); |
| 719 | extern int end_that_request_chunk(struct request *, int, int); |
Tejun Heo | 8ffdc65 | 2006-01-06 09:49:03 +0100 | [diff] [blame] | 720 | extern void end_that_request_last(struct request *, int); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 721 | extern void end_request(struct request *req, int uptodate); |
Jens Axboe | ff856ba | 2006-01-09 16:02:34 +0100 | [diff] [blame] | 722 | extern void blk_complete_request(struct request *); |
| 723 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | /* |
| 725 | * end_that_request_first/chunk() takes an uptodate argument. we account |
| 726 | * any value <= as an io error. 0 means -EIO for compatability reasons, |
| 727 | * any other < 0 value is the direct error type. An uptodate value of |
| 728 | * 1 indicates successful io completion |
| 729 | */ |
| 730 | #define end_io_error(uptodate) (unlikely((uptodate) <= 0)) |
| 731 | |
| 732 | static inline void blkdev_dequeue_request(struct request *req) |
| 733 | { |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 734 | elv_dequeue_request(req->q, req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 735 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 736 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 737 | /* |
| 738 | * Access functions for manipulating queue properties |
| 739 | */ |
Christoph Lameter | 1946089 | 2005-06-23 00:08:19 -0700 | [diff] [blame] | 740 | extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn, |
| 741 | spinlock_t *lock, int node_id); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 742 | extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *); |
| 743 | extern void blk_cleanup_queue(request_queue_t *); |
| 744 | extern void blk_queue_make_request(request_queue_t *, make_request_fn *); |
| 745 | extern void blk_queue_bounce_limit(request_queue_t *, u64); |
Jens Axboe | 2cb2e14 | 2006-01-17 09:04:32 +0100 | [diff] [blame] | 746 | extern void blk_queue_max_sectors(request_queue_t *, unsigned int); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 747 | extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short); |
| 748 | extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short); |
| 749 | extern void blk_queue_max_segment_size(request_queue_t *, unsigned int); |
| 750 | extern void blk_queue_hardsect_size(request_queue_t *, unsigned short); |
| 751 | extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b); |
| 752 | extern void blk_queue_segment_boundary(request_queue_t *, unsigned long); |
| 753 | extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn); |
| 754 | extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *); |
| 755 | extern void blk_queue_dma_alignment(request_queue_t *, int); |
Jens Axboe | ff856ba | 2006-01-09 16:02:34 +0100 | [diff] [blame] | 756 | extern void blk_queue_softirq_done(request_queue_t *, softirq_done_fn *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 757 | extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); |
Tejun Heo | 797e7db | 2006-01-06 09:51:03 +0100 | [diff] [blame] | 758 | extern int blk_queue_ordered(request_queue_t *, unsigned, prepare_flush_fn *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 759 | extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *); |
Tejun Heo | 797e7db | 2006-01-06 09:51:03 +0100 | [diff] [blame] | 760 | extern int blk_do_ordered(request_queue_t *, struct request **); |
| 761 | extern unsigned blk_ordered_cur_seq(request_queue_t *); |
| 762 | extern unsigned blk_ordered_req_seq(struct request *); |
| 763 | extern void blk_ordered_complete_seq(request_queue_t *, unsigned, int); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 764 | |
| 765 | extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *); |
| 766 | extern void blk_dump_rq_flags(struct request *, char *); |
| 767 | extern void generic_unplug_device(request_queue_t *); |
| 768 | extern void __generic_unplug_device(request_queue_t *); |
| 769 | extern long nr_blockdev_pages(void); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 770 | |
| 771 | int blk_get_queue(request_queue_t *); |
Al Viro | 8267e26 | 2005-10-21 03:20:53 -0400 | [diff] [blame] | 772 | request_queue_t *blk_alloc_queue(gfp_t); |
| 773 | request_queue_t *blk_alloc_queue_node(gfp_t, int); |
Al Viro | 483f4af | 2006-03-18 18:34:37 -0500 | [diff] [blame] | 774 | extern void blk_put_queue(request_queue_t *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 775 | |
| 776 | /* |
| 777 | * tag stuff |
| 778 | */ |
| 779 | #define blk_queue_tag_depth(q) ((q)->queue_tags->busy) |
| 780 | #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth) |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 781 | #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 782 | extern int blk_queue_start_tag(request_queue_t *, struct request *); |
| 783 | extern struct request *blk_queue_find_tag(request_queue_t *, int); |
| 784 | extern void blk_queue_end_tag(request_queue_t *, struct request *); |
| 785 | extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *); |
| 786 | extern void blk_queue_free_tags(request_queue_t *); |
| 787 | extern int blk_queue_resize_tags(request_queue_t *, int); |
| 788 | extern void blk_queue_invalidate_tags(request_queue_t *); |
James Bottomley | 492dfb4 | 2006-08-30 15:48:45 -0400 | [diff] [blame] | 789 | extern struct blk_queue_tag *blk_init_tags(int); |
| 790 | extern void blk_free_tags(struct blk_queue_tag *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 791 | |
David C Somayajulu | f583f49 | 2006-10-04 08:27:25 +0200 | [diff] [blame] | 792 | static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, |
| 793 | int tag) |
| 794 | { |
| 795 | if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) |
| 796 | return NULL; |
| 797 | return bqt->tag_index[tag]; |
| 798 | } |
| 799 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 800 | extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *); |
| 801 | extern int blkdev_issue_flush(struct block_device *, sector_t *); |
| 802 | |
| 803 | #define MAX_PHYS_SEGMENTS 128 |
| 804 | #define MAX_HW_SEGMENTS 128 |
Mike Christie | defd94b | 2005-12-05 02:37:06 -0600 | [diff] [blame] | 805 | #define SAFE_MAX_SECTORS 255 |
| 806 | #define BLK_DEF_MAX_SECTORS 1024 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 807 | |
| 808 | #define MAX_SEGMENT_SIZE 65536 |
| 809 | |
| 810 | #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) |
| 811 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 812 | static inline int queue_hardsect_size(request_queue_t *q) |
| 813 | { |
| 814 | int retval = 512; |
| 815 | |
| 816 | if (q && q->hardsect_size) |
| 817 | retval = q->hardsect_size; |
| 818 | |
| 819 | return retval; |
| 820 | } |
| 821 | |
| 822 | static inline int bdev_hardsect_size(struct block_device *bdev) |
| 823 | { |
| 824 | return queue_hardsect_size(bdev_get_queue(bdev)); |
| 825 | } |
| 826 | |
| 827 | static inline int queue_dma_alignment(request_queue_t *q) |
| 828 | { |
| 829 | int retval = 511; |
| 830 | |
| 831 | if (q && q->dma_alignment) |
| 832 | retval = q->dma_alignment; |
| 833 | |
| 834 | return retval; |
| 835 | } |
| 836 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 837 | /* assumes size > 256 */ |
| 838 | static inline unsigned int blksize_bits(unsigned int size) |
| 839 | { |
| 840 | unsigned int bits = 8; |
| 841 | do { |
| 842 | bits++; |
| 843 | size >>= 1; |
| 844 | } while (size > 256); |
| 845 | return bits; |
| 846 | } |
| 847 | |
Adrian Bunk | 2befb9e | 2005-09-10 00:27:17 -0700 | [diff] [blame] | 848 | static inline unsigned int block_size(struct block_device *bdev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 849 | { |
| 850 | return bdev->bd_block_size; |
| 851 | } |
| 852 | |
| 853 | typedef struct {struct page *v;} Sector; |
| 854 | |
| 855 | unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); |
| 856 | |
| 857 | static inline void put_dev_sector(Sector p) |
| 858 | { |
| 859 | page_cache_release(p.v); |
| 860 | } |
| 861 | |
| 862 | struct work_struct; |
| 863 | int kblockd_schedule_work(struct work_struct *work); |
| 864 | void kblockd_flush(void); |
| 865 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 866 | #define MODULE_ALIAS_BLOCKDEV(major,minor) \ |
| 867 | MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) |
| 868 | #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ |
| 869 | MODULE_ALIAS("block-major-" __stringify(major) "-*") |
| 870 | |
| 871 | |
David Howells | 9361401 | 2006-09-30 20:45:40 +0200 | [diff] [blame] | 872 | #else /* CONFIG_BLOCK */ |
| 873 | /* |
| 874 | * stubs for when the block layer is configured out |
| 875 | */ |
| 876 | #define buffer_heads_over_limit 0 |
| 877 | |
| 878 | static inline long blk_congestion_wait(int rw, long timeout) |
| 879 | { |
Andrew Morton | bcfd8d3 | 2006-08-31 12:56:06 +0200 | [diff] [blame] | 880 | return io_schedule_timeout(timeout); |
David Howells | 9361401 | 2006-09-30 20:45:40 +0200 | [diff] [blame] | 881 | } |
| 882 | |
| 883 | static inline long nr_blockdev_pages(void) |
| 884 | { |
| 885 | return 0; |
| 886 | } |
| 887 | |
Andrew Morton | bcfd8d3 | 2006-08-31 12:56:06 +0200 | [diff] [blame] | 888 | static inline void exit_io_context(void) |
| 889 | { |
| 890 | } |
David Howells | 9361401 | 2006-09-30 20:45:40 +0200 | [diff] [blame] | 891 | |
| 892 | #endif /* CONFIG_BLOCK */ |
| 893 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 894 | #endif |