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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_BLKDEV_H
2#define _LINUX_BLKDEV_H
3
Jens Axboef5ff8422007-09-21 09:19:54 +02004#ifdef CONFIG_BLOCK
5
Andrew Mortonbcfd8d32006-08-31 12:56:06 +02006#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007#include <linux/major.h>
8#include <linux/genhd.h>
9#include <linux/list.h>
10#include <linux/timer.h>
11#include <linux/workqueue.h>
12#include <linux/pagemap.h>
13#include <linux/backing-dev.h>
14#include <linux/wait.h>
15#include <linux/mempool.h>
16#include <linux/bio.h>
17#include <linux/module.h>
18#include <linux/stringify.h>
Hugh Dickins3e6053d2008-09-11 10:57:55 +020019#include <linux/gfp.h>
FUJITA Tomonorid351af02007-07-09 12:40:35 +020020#include <linux/bsg.h>
Jens Axboec7c22e42008-09-13 20:26:01 +020021#include <linux/smp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
23#include <asm/scatterlist.h>
24
Christoph Hellwig21b2f0c2006-03-22 17:52:04 +010025struct scsi_ioctl_command;
26
Linus Torvalds1da177e2005-04-16 15:20:36 -070027struct request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -070028struct elevator_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -070029struct request_pm_state;
Jens Axboe2056a782006-03-23 20:00:26 +010030struct blk_trace;
Jens Axboe3d6392c2007-07-09 12:38:05 +020031struct request;
32struct sg_io_hdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34#define BLKDEV_MIN_RQ 4
35#define BLKDEV_MAX_RQ 128 /* Default maximum */
36
Linus Torvalds1da177e2005-04-16 15:20:36 -070037struct request;
Tejun Heo8ffdc652006-01-06 09:49:03 +010038typedef void (rq_end_io_fn)(struct request *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40struct request_list {
Jens Axboe1faa16d2009-04-06 14:48:01 +020041 /*
42 * count[], starved[], and wait[] are indexed by
43 * BLK_RW_SYNC/BLK_RW_ASYNC
44 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 int count[2];
46 int starved[2];
Tejun Heocb98fc82005-10-28 08:29:39 +020047 int elvpriv;
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 mempool_t *rq_pool;
49 wait_queue_head_t wait[2];
Linus Torvalds1da177e2005-04-16 15:20:36 -070050};
51
Jens Axboe4aff5e22006-08-10 08:44:47 +020052/*
53 * request command types
54 */
55enum rq_cmd_type_bits {
56 REQ_TYPE_FS = 1, /* fs request */
57 REQ_TYPE_BLOCK_PC, /* scsi command */
58 REQ_TYPE_SENSE, /* sense request */
59 REQ_TYPE_PM_SUSPEND, /* suspend request */
60 REQ_TYPE_PM_RESUME, /* resume request */
61 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
Jens Axboe4aff5e22006-08-10 08:44:47 +020062 REQ_TYPE_SPECIAL, /* driver defined type */
63 REQ_TYPE_LINUX_BLOCK, /* generic block layer message */
64 /*
65 * for ATA/ATAPI devices. this really doesn't belong here, ide should
66 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
67 * private REQ_LB opcodes to differentiate what type of request this is
68 */
Jens Axboe4aff5e22006-08-10 08:44:47 +020069 REQ_TYPE_ATA_TASKFILE,
Jens Axboecea28852006-10-12 15:08:45 +020070 REQ_TYPE_ATA_PC,
Jens Axboe4aff5e22006-08-10 08:44:47 +020071};
72
73/*
74 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
75 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
76 * SCSI cdb.
77 *
78 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
79 * typically to differentiate REQ_TYPE_SPECIAL requests.
80 *
81 */
82enum {
Jens Axboe4aff5e22006-08-10 08:44:47 +020083 REQ_LB_OP_EJECT = 0x40, /* eject request */
David Woodhouse1a8e2bd2008-08-13 12:35:09 +010084 REQ_LB_OP_FLUSH = 0x41, /* flush request */
Jens Axboe4aff5e22006-08-10 08:44:47 +020085};
86
87/*
Jens Axboe1f98a132009-09-11 14:32:04 +020088 * request type modified bits. first four bits match BIO_RW* bits, important
Jens Axboe4aff5e22006-08-10 08:44:47 +020089 */
90enum rq_flag_bits {
91 __REQ_RW, /* not set, read. set, write */
Mike Christie6000a362008-08-19 18:45:30 -050092 __REQ_FAILFAST_DEV, /* no driver retries of device errors */
93 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
94 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
Tejun Heoa82afdf2009-07-03 17:48:16 +090095 /* above flags must match BIO_RW_* */
David Woodhousefb2dce82008-08-05 18:01:53 +010096 __REQ_DISCARD, /* request to discard sectors */
Jens Axboe4aff5e22006-08-10 08:44:47 +020097 __REQ_SORTED, /* elevator knows about this request */
98 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
99 __REQ_HARDBARRIER, /* may not be passed by drive either */
100 __REQ_FUA, /* forced unit access */
101 __REQ_NOMERGE, /* don't touch this for merging */
102 __REQ_STARTED, /* drive already may have started this one */
103 __REQ_DONTPREP, /* don't call prep for this one */
104 __REQ_QUEUED, /* uses queueing */
105 __REQ_ELVPRIV, /* elevator private data attached */
106 __REQ_FAILED, /* set if the request failed */
107 __REQ_QUIET, /* don't worry about errors */
108 __REQ_PREEMPT, /* set for "ide_preempt" requests */
109 __REQ_ORDERED_COLOR, /* is before or after barrier */
Jens Axboe1faa16d2009-04-06 14:48:01 +0200110 __REQ_RW_SYNC, /* request is sync (sync write or read) */
Jens Axboe49171e52006-08-10 08:59:11 +0200111 __REQ_ALLOCED, /* request came from our alloc pool */
Jens Axboe5404bc72006-08-10 09:01:02 +0200112 __REQ_RW_META, /* metadata io request */
FUJITA Tomonorif18573a2008-04-11 12:56:52 +0200113 __REQ_COPY_USER, /* contains copies of user pages */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200114 __REQ_INTEGRITY, /* integrity metadata has been remapped */
Jens Axboeaeb6faf2009-04-06 14:48:07 +0200115 __REQ_NOIDLE, /* Don't anticipate more IO after this one */
Jerome Marchand42dad762009-04-22 14:01:49 +0200116 __REQ_IO_STAT, /* account I/O stat */
Tejun Heo80a761f2009-07-03 17:48:17 +0900117 __REQ_MIXED_MERGE, /* merge of different types, fail separately */
Jens Axboe4aff5e22006-08-10 08:44:47 +0200118 __REQ_NR_BITS, /* stops here */
119};
120
121#define REQ_RW (1 << __REQ_RW)
Mike Christie6000a362008-08-19 18:45:30 -0500122#define REQ_FAILFAST_DEV (1 << __REQ_FAILFAST_DEV)
123#define REQ_FAILFAST_TRANSPORT (1 << __REQ_FAILFAST_TRANSPORT)
124#define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER)
David Woodhousefb2dce82008-08-05 18:01:53 +0100125#define REQ_DISCARD (1 << __REQ_DISCARD)
Jens Axboe4aff5e22006-08-10 08:44:47 +0200126#define REQ_SORTED (1 << __REQ_SORTED)
127#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
128#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
129#define REQ_FUA (1 << __REQ_FUA)
130#define REQ_NOMERGE (1 << __REQ_NOMERGE)
131#define REQ_STARTED (1 << __REQ_STARTED)
132#define REQ_DONTPREP (1 << __REQ_DONTPREP)
133#define REQ_QUEUED (1 << __REQ_QUEUED)
134#define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
135#define REQ_FAILED (1 << __REQ_FAILED)
136#define REQ_QUIET (1 << __REQ_QUIET)
137#define REQ_PREEMPT (1 << __REQ_PREEMPT)
138#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
139#define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
Jens Axboe49171e52006-08-10 08:59:11 +0200140#define REQ_ALLOCED (1 << __REQ_ALLOCED)
Jens Axboe5404bc72006-08-10 09:01:02 +0200141#define REQ_RW_META (1 << __REQ_RW_META)
FUJITA Tomonorif18573a2008-04-11 12:56:52 +0200142#define REQ_COPY_USER (1 << __REQ_COPY_USER)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200143#define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
Jens Axboeaeb6faf2009-04-06 14:48:07 +0200144#define REQ_NOIDLE (1 << __REQ_NOIDLE)
Jerome Marchand42dad762009-04-22 14:01:49 +0200145#define REQ_IO_STAT (1 << __REQ_IO_STAT)
Tejun Heo80a761f2009-07-03 17:48:17 +0900146#define REQ_MIXED_MERGE (1 << __REQ_MIXED_MERGE)
Jens Axboe4aff5e22006-08-10 08:44:47 +0200147
Tejun Heoa82afdf2009-07-03 17:48:16 +0900148#define REQ_FAILFAST_MASK (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | \
149 REQ_FAILFAST_DRIVER)
150
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151#define BLK_MAX_CDB 16
152
153/*
Jens Axboe63a71382008-02-08 12:41:03 +0100154 * try to put the fields that are referenced together in the same cacheline.
155 * if you modify this structure, be sure to check block/blk-core.c:rq_init()
156 * as well!
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 */
158struct request {
Jens Axboeff856ba2006-01-09 16:02:34 +0100159 struct list_head queuelist;
Jens Axboec7c22e42008-09-13 20:26:01 +0200160 struct call_single_data csd;
161 int cpu;
Jens Axboeff856ba2006-01-09 16:02:34 +0100162
Jens Axboe165125e2007-07-24 09:28:11 +0200163 struct request_queue *q;
Jens Axboee6a1c872006-08-10 09:00:21 +0200164
Jens Axboe4aff5e22006-08-10 08:44:47 +0200165 unsigned int cmd_flags;
166 enum rq_cmd_type_bits cmd_type;
Jens Axboe242f9dc2008-09-14 05:55:09 -0700167 unsigned long atomic_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168
Tejun Heoa2dec7b2009-05-07 22:24:44 +0900169 /* the following two fields are internal, NEVER access directly */
170 sector_t __sector; /* sector cursor */
171 unsigned int __data_len; /* total data len */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172
173 struct bio *bio;
174 struct bio *biotail;
175
Jens Axboe98170642006-07-28 09:23:08 +0200176 struct hlist_node hash; /* merge hash */
Jens Axboee6a1c872006-08-10 09:00:21 +0200177 /*
178 * The rb_node is only used inside the io scheduler, requests
179 * are pruned when moved to the dispatch queue. So let the
180 * completion_data share space with the rb_node.
181 */
182 union {
183 struct rb_node rb_node; /* sort/lookup */
184 void *completion_data;
185 };
Jens Axboe98170642006-07-28 09:23:08 +0200186
Jens Axboeff7d1452006-07-12 14:04:37 +0200187 /*
188 * two pointers are available for the IO schedulers, if they need
189 * more they have to dynamically allocate it.
190 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 void *elevator_private;
Jens Axboeff7d1452006-07-12 14:04:37 +0200192 void *elevator_private2;
193
Jens Axboe8f34ee72006-06-13 09:02:34 +0200194 struct gendisk *rq_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 unsigned long start_time;
196
197 /* Number of scatter-gather DMA addr+len pairs after
198 * physical address coalescing is performed.
199 */
200 unsigned short nr_phys_segments;
201
Jens Axboe8f34ee72006-06-13 09:02:34 +0200202 unsigned short ioprio;
203
Tejun Heo731ec492009-04-23 11:05:20 +0900204 void *special; /* opaque pointer available for LLD use */
205 char *buffer; /* kaddr of the current segment if available */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206
Jens Axboecdd60262006-07-28 09:32:07 +0200207 int tag;
208 int errors;
209
210 int ref_count;
211
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 /*
213 * when request is used as a packet command carrier
214 */
FUJITA Tomonorid7e3c322008-04-29 09:54:39 +0200215 unsigned short cmd_len;
216 unsigned char __cmd[BLK_MAX_CDB];
217 unsigned char *cmd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218
FUJITA Tomonori7a85f882008-03-04 11:17:11 +0100219 unsigned int extra_len; /* length of alignment and padding */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 unsigned int sense_len;
Tejun Heoc3a4d782009-05-07 22:24:37 +0900221 unsigned int resid_len; /* residual count */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 void *sense;
223
Jens Axboe242f9dc2008-09-14 05:55:09 -0700224 unsigned long deadline;
225 struct list_head timeout_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 unsigned int timeout;
Mike Christie17e01f22005-11-11 05:31:37 -0600227 int retries;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228
229 /*
Jens Axboec00895a2006-09-30 20:29:12 +0200230 * completion callback.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 */
232 rq_end_io_fn *end_io;
233 void *end_io_data;
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200234
235 /* for bidi */
236 struct request *next_rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237};
238
Fernando Luis Vázquez Cao766ca442008-08-14 09:59:13 +0200239static inline unsigned short req_get_ioprio(struct request *req)
240{
241 return req->ioprio;
242}
243
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244/*
Jens Axboe4aff5e22006-08-10 08:44:47 +0200245 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 * requests. Some step values could eventually be made generic.
247 */
248struct request_pm_state
249{
250 /* PM state machine step value, currently driver specific */
251 int pm_step;
252 /* requested PM state value (S1, S2, S3, S4, ...) */
253 u32 pm_state;
254 void* data; /* for driver use */
255};
256
257#include <linux/elevator.h>
258
Jens Axboe165125e2007-07-24 09:28:11 +0200259typedef void (request_fn_proc) (struct request_queue *q);
260typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
261typedef int (prep_rq_fn) (struct request_queue *, struct request *);
262typedef void (unplug_fn) (struct request_queue *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263
264struct bio_vec;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200265struct bvec_merge_data {
266 struct block_device *bi_bdev;
267 sector_t bi_sector;
268 unsigned bi_size;
269 unsigned long bi_rw;
270};
271typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
272 struct bio_vec *);
Jens Axboe165125e2007-07-24 09:28:11 +0200273typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
Jens Axboeff856ba2006-01-09 16:02:34 +0100274typedef void (softirq_done_fn)(struct request *);
Tejun Heo2fb98e82008-02-19 11:36:53 +0100275typedef int (dma_drain_needed_fn)(struct request *);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200276typedef int (lld_busy_fn) (struct request_queue *q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277
Jens Axboe242f9dc2008-09-14 05:55:09 -0700278enum blk_eh_timer_return {
279 BLK_EH_NOT_HANDLED,
280 BLK_EH_HANDLED,
281 BLK_EH_RESET_TIMER,
282};
283
284typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
285
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286enum blk_queue_state {
287 Queue_down,
288 Queue_up,
289};
290
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291struct blk_queue_tag {
292 struct request **tag_index; /* map of busy tags */
293 unsigned long *tag_map; /* bit map of free/busy tags */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 int busy; /* current depth */
295 int max_depth; /* what we will send to device */
Tejun Heoba025082005-08-05 13:28:11 -0700296 int real_max_depth; /* what the array can hold */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 atomic_t refcnt; /* map can be shared */
298};
299
FUJITA Tomonoriabf54392008-08-16 14:10:05 +0900300#define BLK_SCSI_MAX_CMDS (256)
301#define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
302
Martin K. Petersen025146e2009-05-22 17:17:51 -0400303struct queue_limits {
304 unsigned long bounce_pfn;
305 unsigned long seg_boundary_mask;
306
307 unsigned int max_hw_sectors;
308 unsigned int max_sectors;
309 unsigned int max_segment_size;
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400310 unsigned int physical_block_size;
311 unsigned int alignment_offset;
312 unsigned int io_min;
313 unsigned int io_opt;
Christoph Hellwig67efc922009-09-30 13:54:20 +0200314 unsigned int max_discard_sectors;
Martin K. Petersen025146e2009-05-22 17:17:51 -0400315
316 unsigned short logical_block_size;
317 unsigned short max_hw_segments;
318 unsigned short max_phys_segments;
319
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400320 unsigned char misaligned;
Martin K. Petersen025146e2009-05-22 17:17:51 -0400321 unsigned char no_cluster;
322};
323
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324struct request_queue
325{
326 /*
327 * Together with queue_head for cacheline sharing
328 */
329 struct list_head queue_head;
330 struct request *last_merge;
Jens Axboeb374d182008-10-31 10:05:07 +0100331 struct elevator_queue *elevator;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332
333 /*
334 * the queue request freelist, one for reads and one for writes
335 */
336 struct request_list rq;
337
338 request_fn_proc *request_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 make_request_fn *make_request_fn;
340 prep_rq_fn *prep_rq_fn;
341 unplug_fn *unplug_fn;
342 merge_bvec_fn *merge_bvec_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 prepare_flush_fn *prepare_flush_fn;
Jens Axboeff856ba2006-01-09 16:02:34 +0100344 softirq_done_fn *softirq_done_fn;
Jens Axboe242f9dc2008-09-14 05:55:09 -0700345 rq_timed_out_fn *rq_timed_out_fn;
Tejun Heo2fb98e82008-02-19 11:36:53 +0100346 dma_drain_needed_fn *dma_drain_needed;
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200347 lld_busy_fn *lld_busy_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348
349 /*
Tejun Heo8922e162005-10-20 16:23:44 +0200350 * Dispatch queue sorting
351 */
Jens Axboe1b47f532005-10-20 16:37:00 +0200352 sector_t end_sector;
Tejun Heo8922e162005-10-20 16:23:44 +0200353 struct request *boundary_rq;
Tejun Heo8922e162005-10-20 16:23:44 +0200354
355 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 * Auto-unplugging state
357 */
358 struct timer_list unplug_timer;
359 int unplug_thresh; /* After this many requests */
360 unsigned long unplug_delay; /* After this many jiffies */
361 struct work_struct unplug_work;
362
363 struct backing_dev_info backing_dev_info;
364
365 /*
366 * The queue owner gets to use this for whatever they like.
367 * ll_rw_blk doesn't touch it.
368 */
369 void *queuedata;
370
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 /*
372 * queue needs bounce pages for pages above this limit
373 */
Al Viro8267e262005-10-21 03:20:53 -0400374 gfp_t bounce_gfp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375
376 /*
377 * various queue flags, see QUEUE_* below
378 */
379 unsigned long queue_flags;
380
381 /*
152587d2005-04-12 16:22:06 -0500382 * protects queue structures from reentrancy. ->__queue_lock should
383 * _never_ be used directly, it is queue private. always use
384 * ->queue_lock.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 */
152587d2005-04-12 16:22:06 -0500386 spinlock_t __queue_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 spinlock_t *queue_lock;
388
389 /*
390 * queue kobject
391 */
392 struct kobject kobj;
393
394 /*
395 * queue settings
396 */
397 unsigned long nr_requests; /* Max # of requests */
398 unsigned int nr_congestion_on;
399 unsigned int nr_congestion_off;
400 unsigned int nr_batching;
401
James Bottomleyfa0ccd82008-01-10 11:30:36 -0600402 void *dma_drain_buffer;
403 unsigned int dma_drain_size;
Tejun Heoe3790c72008-03-04 11:18:17 +0100404 unsigned int dma_pad_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 unsigned int dma_alignment;
406
407 struct blk_queue_tag *queue_tags;
Jens Axboe6eca9002007-10-25 10:14:47 +0200408 struct list_head tag_busy_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409
Tejun Heo15853af2005-11-10 08:52:05 +0100410 unsigned int nr_sorted;
Jens Axboe0a7ae2f2009-05-20 08:54:31 +0200411 unsigned int in_flight[2];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412
Jens Axboe242f9dc2008-09-14 05:55:09 -0700413 unsigned int rq_timeout;
414 struct timer_list timeout;
415 struct list_head timeout_list;
416
Martin K. Petersen025146e2009-05-22 17:17:51 -0400417 struct queue_limits limits;
418
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 /*
420 * sg stuff
421 */
422 unsigned int sg_timeout;
423 unsigned int sg_reserved_size;
Christoph Lameter19460892005-06-23 00:08:19 -0700424 int node;
Alexey Dobriyan6c5c9342006-09-29 01:59:40 -0700425#ifdef CONFIG_BLK_DEV_IO_TRACE
Jens Axboe2056a782006-03-23 20:00:26 +0100426 struct blk_trace *blk_trace;
Alexey Dobriyan6c5c9342006-09-29 01:59:40 -0700427#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 /*
429 * reserved for flush operations
430 */
Tejun Heo797e7db2006-01-06 09:51:03 +0100431 unsigned int ordered, next_ordered, ordseq;
432 int orderr, ordcolor;
433 struct request pre_flush_rq, bar_rq, post_flush_rq;
434 struct request *orig_bar_rq;
Al Viro483f4af2006-03-18 18:34:37 -0500435
436 struct mutex sysfs_lock;
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200437
438#if defined(CONFIG_BLK_DEV_BSG)
439 struct bsg_class_device bsg_dev;
440#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441};
442
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443#define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
444#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
445#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
Jens Axboe1faa16d2009-04-06 14:48:01 +0200446#define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
447#define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448#define QUEUE_FLAG_DEAD 5 /* queue being torn down */
449#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
450#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
Jens Axboe64521d12005-10-28 08:30:39 +0200451#define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200452#define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200453#define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
Jens Axboec7c22e42008-09-13 20:26:01 +0200454#define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
Jens Axboe581d4e22008-09-14 05:56:33 -0700455#define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
Kiyoshi Ueda4ee5eaf2008-09-18 10:46:13 -0400456#define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
Jens Axboea68bbdd2008-09-24 13:03:33 +0200457#define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
Fernando Luis Vázquez Cao88e740f2008-10-27 18:44:46 +0900458#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
Jens Axboebc58ba92009-01-23 10:54:44 +0100459#define QUEUE_FLAG_IO_STAT 15 /* do IO stats */
Jens Axboefb1e7532009-07-30 08:18:24 +0200460#define QUEUE_FLAG_CQ 16 /* hardware does queuing */
Christoph Hellwigc15227d2009-09-30 13:52:12 +0200461#define QUEUE_FLAG_DISCARD 17 /* supports DISCARD */
Jens Axboebc58ba92009-01-23 10:54:44 +0100462
463#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
464 (1 << QUEUE_FLAG_CLUSTER) | \
Jens Axboe01e97f62009-09-03 20:06:47 +0200465 (1 << QUEUE_FLAG_STACKABLE) | \
466 (1 << QUEUE_FLAG_SAME_COMP))
Tejun Heo797e7db2006-01-06 09:51:03 +0100467
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700468static inline int queue_is_locked(struct request_queue *q)
469{
Jens Axboe7663c1e2008-04-29 21:31:27 +0200470#ifdef CONFIG_SMP
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700471 spinlock_t *lock = q->queue_lock;
472 return lock && spin_is_locked(lock);
Jens Axboe7663c1e2008-04-29 21:31:27 +0200473#else
474 return 1;
475#endif
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700476}
477
Nick Piggin75ad23b2008-04-29 14:48:33 +0200478static inline void queue_flag_set_unlocked(unsigned int flag,
479 struct request_queue *q)
480{
481 __set_bit(flag, &q->queue_flags);
482}
483
Jens Axboee48ec692008-07-03 13:18:54 +0200484static inline int queue_flag_test_and_clear(unsigned int flag,
485 struct request_queue *q)
486{
487 WARN_ON_ONCE(!queue_is_locked(q));
488
489 if (test_bit(flag, &q->queue_flags)) {
490 __clear_bit(flag, &q->queue_flags);
491 return 1;
492 }
493
494 return 0;
495}
496
497static inline int queue_flag_test_and_set(unsigned int flag,
498 struct request_queue *q)
499{
500 WARN_ON_ONCE(!queue_is_locked(q));
501
502 if (!test_bit(flag, &q->queue_flags)) {
503 __set_bit(flag, &q->queue_flags);
504 return 0;
505 }
506
507 return 1;
508}
509
Nick Piggin75ad23b2008-04-29 14:48:33 +0200510static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
511{
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700512 WARN_ON_ONCE(!queue_is_locked(q));
Nick Piggin75ad23b2008-04-29 14:48:33 +0200513 __set_bit(flag, &q->queue_flags);
514}
515
516static inline void queue_flag_clear_unlocked(unsigned int flag,
517 struct request_queue *q)
518{
519 __clear_bit(flag, &q->queue_flags);
520}
521
Jens Axboe0a7ae2f2009-05-20 08:54:31 +0200522static inline int queue_in_flight(struct request_queue *q)
523{
524 return q->in_flight[0] + q->in_flight[1];
525}
526
Nick Piggin75ad23b2008-04-29 14:48:33 +0200527static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
528{
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700529 WARN_ON_ONCE(!queue_is_locked(q));
Nick Piggin75ad23b2008-04-29 14:48:33 +0200530 __clear_bit(flag, &q->queue_flags);
531}
532
Tejun Heo797e7db2006-01-06 09:51:03 +0100533enum {
534 /*
535 * Hardbarrier is supported with one of the following methods.
536 *
537 * NONE : hardbarrier unsupported
538 * DRAIN : ordering by draining is enough
539 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
540 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
541 * TAG : ordering by tag is enough
542 * TAG_FLUSH : ordering by tag w/ pre and post flushes
543 * TAG_FUA : ordering by tag w/ pre flush and FUA write
544 */
Tejun Heo313e4292008-11-28 13:32:02 +0900545 QUEUE_ORDERED_BY_DRAIN = 0x01,
546 QUEUE_ORDERED_BY_TAG = 0x02,
547 QUEUE_ORDERED_DO_PREFLUSH = 0x10,
Tejun Heof6716202008-11-28 13:32:04 +0900548 QUEUE_ORDERED_DO_BAR = 0x20,
Tejun Heo313e4292008-11-28 13:32:02 +0900549 QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
550 QUEUE_ORDERED_DO_FUA = 0x80,
Tejun Heo797e7db2006-01-06 09:51:03 +0100551
Tejun Heo313e4292008-11-28 13:32:02 +0900552 QUEUE_ORDERED_NONE = 0x00,
Tejun Heo797e7db2006-01-06 09:51:03 +0100553
Tejun Heof6716202008-11-28 13:32:04 +0900554 QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_BY_DRAIN |
555 QUEUE_ORDERED_DO_BAR,
Tejun Heo313e4292008-11-28 13:32:02 +0900556 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
557 QUEUE_ORDERED_DO_PREFLUSH |
558 QUEUE_ORDERED_DO_POSTFLUSH,
559 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
560 QUEUE_ORDERED_DO_PREFLUSH |
561 QUEUE_ORDERED_DO_FUA,
562
Tejun Heof6716202008-11-28 13:32:04 +0900563 QUEUE_ORDERED_TAG = QUEUE_ORDERED_BY_TAG |
564 QUEUE_ORDERED_DO_BAR,
Tejun Heo313e4292008-11-28 13:32:02 +0900565 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
566 QUEUE_ORDERED_DO_PREFLUSH |
567 QUEUE_ORDERED_DO_POSTFLUSH,
568 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
569 QUEUE_ORDERED_DO_PREFLUSH |
570 QUEUE_ORDERED_DO_FUA,
Tejun Heo797e7db2006-01-06 09:51:03 +0100571
572 /*
573 * Ordered operation sequence
574 */
575 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
576 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
577 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
578 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
579 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
580 QUEUE_ORDSEQ_DONE = 0x20,
581};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582
583#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
584#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
Jens Axboefb1e7532009-07-30 08:18:24 +0200585#define blk_queue_queuing(q) test_bit(QUEUE_FLAG_CQ, &(q)->queue_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200587#define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
Jens Axboea68bbdd2008-09-24 13:03:33 +0200588#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
Jens Axboebc58ba92009-01-23 10:54:44 +0100589#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
Tejun Heo797e7db2006-01-06 09:51:03 +0100590#define blk_queue_flushing(q) ((q)->ordseq)
Kiyoshi Ueda4ee5eaf2008-09-18 10:46:13 -0400591#define blk_queue_stackable(q) \
592 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
Christoph Hellwigc15227d2009-09-30 13:52:12 +0200593#define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594
Jens Axboe4aff5e22006-08-10 08:44:47 +0200595#define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
596#define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
597#define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
598#define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
599
Mike Christie6000a362008-08-19 18:45:30 -0500600#define blk_failfast_dev(rq) ((rq)->cmd_flags & REQ_FAILFAST_DEV)
601#define blk_failfast_transport(rq) ((rq)->cmd_flags & REQ_FAILFAST_TRANSPORT)
602#define blk_failfast_driver(rq) ((rq)->cmd_flags & REQ_FAILFAST_DRIVER)
603#define blk_noretry_request(rq) (blk_failfast_dev(rq) || \
604 blk_failfast_transport(rq) || \
605 blk_failfast_driver(rq))
Jens Axboe4aff5e22006-08-10 08:44:47 +0200606#define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
Jerome Marchand42dad762009-04-22 14:01:49 +0200607#define blk_rq_io_stat(rq) ((rq)->cmd_flags & REQ_IO_STAT)
Borislav Petkov96c16742009-04-30 18:24:34 +0200608#define blk_rq_quiet(rq) ((rq)->cmd_flags & REQ_QUIET)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609
David Woodhousee17fc0a2008-08-09 16:42:20 +0100610#define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611
Jens Axboe4aff5e22006-08-10 08:44:47 +0200612#define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
613#define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614#define blk_pm_request(rq) \
Jens Axboe4aff5e22006-08-10 08:44:47 +0200615 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616
Jens Axboeab780f12008-08-26 10:25:02 +0200617#define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
Jens Axboe4aff5e22006-08-10 08:44:47 +0200618#define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
619#define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
620#define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
David Woodhousefb2dce82008-08-05 18:01:53 +0100621#define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200622#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
Kiyoshi Ueda336cdb42007-12-11 17:40:30 -0500623/* rq->queuelist of dequeued request must be list_empty() */
624#define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625
626#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
627
Jens Axboe4aff5e22006-08-10 08:44:47 +0200628#define rq_data_dir(rq) ((rq)->cmd_flags & 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629
Jens Axboe9e2585a2006-07-28 09:26:13 +0200630/*
Jens Axboe1faa16d2009-04-06 14:48:01 +0200631 * We regard a request as sync, if either a read or a sync write
Jens Axboe9e2585a2006-07-28 09:26:13 +0200632 */
Jens Axboe1faa16d2009-04-06 14:48:01 +0200633static inline bool rw_is_sync(unsigned int rw_flags)
634{
635 return !(rw_flags & REQ_RW) || (rw_flags & REQ_RW_SYNC);
636}
637
638static inline bool rq_is_sync(struct request *rq)
639{
640 return rw_is_sync(rq->cmd_flags);
641}
642
Jens Axboe5404bc72006-08-10 09:01:02 +0200643#define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
Jens Axboeaeb6faf2009-04-06 14:48:07 +0200644#define rq_noidle(rq) ((rq)->cmd_flags & REQ_NOIDLE)
Jens Axboe9e2585a2006-07-28 09:26:13 +0200645
Jens Axboe1faa16d2009-04-06 14:48:01 +0200646static inline int blk_queue_full(struct request_queue *q, int sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647{
Jens Axboe1faa16d2009-04-06 14:48:01 +0200648 if (sync)
649 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
650 return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651}
652
Jens Axboe1faa16d2009-04-06 14:48:01 +0200653static inline void blk_set_queue_full(struct request_queue *q, int sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654{
Jens Axboe1faa16d2009-04-06 14:48:01 +0200655 if (sync)
656 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 else
Jens Axboe1faa16d2009-04-06 14:48:01 +0200658 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659}
660
Jens Axboe1faa16d2009-04-06 14:48:01 +0200661static inline void blk_clear_queue_full(struct request_queue *q, int sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662{
Jens Axboe1faa16d2009-04-06 14:48:01 +0200663 if (sync)
664 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 else
Jens Axboe1faa16d2009-04-06 14:48:01 +0200666 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667}
668
669
670/*
671 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
672 * it already be started by driver.
673 */
674#define RQ_NOMERGE_FLAGS \
675 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
676#define rq_mergeable(rq) \
David Woodhousee17fc0a2008-08-09 16:42:20 +0100677 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
678 (blk_discard_rq(rq) || blk_fs_request((rq))))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679
680/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 * q->prep_rq_fn return values
682 */
683#define BLKPREP_OK 0 /* serve it */
684#define BLKPREP_KILL 1 /* fatal error, kill */
685#define BLKPREP_DEFER 2 /* leave on queue */
686
687extern unsigned long blk_max_low_pfn, blk_max_pfn;
688
689/*
690 * standard bounce addresses:
691 *
692 * BLK_BOUNCE_HIGH : bounce all highmem pages
693 * BLK_BOUNCE_ANY : don't bounce anything
694 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
695 */
Andi Kleen24728922008-04-21 09:51:05 +0200696
697#if BITS_PER_LONG == 32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
Andi Kleen24728922008-04-21 09:51:05 +0200699#else
700#define BLK_BOUNCE_HIGH -1ULL
701#endif
702#define BLK_BOUNCE_ANY (-1ULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703#define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
704
Jens Axboe3d6392c2007-07-09 12:38:05 +0200705/*
706 * default timeout for SG_IO if none specified
707 */
708#define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
Linus Torvaldsf2f1fa72008-12-05 14:49:18 -0800709#define BLK_MIN_SG_TIMEOUT (7 * HZ)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200710
Christoph Lameter2a7326b2007-07-17 04:03:37 -0700711#ifdef CONFIG_BOUNCE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712extern int init_emergency_isa_pool(void);
Jens Axboe165125e2007-07-24 09:28:11 +0200713extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714#else
715static inline int init_emergency_isa_pool(void)
716{
717 return 0;
718}
Jens Axboe165125e2007-07-24 09:28:11 +0200719static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720{
721}
722#endif /* CONFIG_MMU */
723
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900724struct rq_map_data {
725 struct page **pages;
726 int page_order;
727 int nr_entries;
FUJITA Tomonori56c451f2008-12-18 14:49:37 +0900728 unsigned long offset;
FUJITA Tomonori97ae77a2008-12-18 14:49:38 +0900729 int null_mapped;
FUJITA Tomonoriecb554a2009-07-09 14:46:53 +0200730 int from_user;
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900731};
732
NeilBrown5705f702007-09-25 12:35:59 +0200733struct req_iterator {
734 int i;
735 struct bio *bio;
736};
737
738/* This should not be used directly - use rq_for_each_segment */
Jens Axboe1e428072009-02-23 09:03:10 +0100739#define for_each_bio(_bio) \
740 for (; _bio; _bio = _bio->bi_next)
NeilBrown5705f702007-09-25 12:35:59 +0200741#define __rq_for_each_bio(_bio, rq) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 if ((rq->bio)) \
743 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
744
NeilBrown5705f702007-09-25 12:35:59 +0200745#define rq_for_each_segment(bvl, _rq, _iter) \
746 __rq_for_each_bio(_iter.bio, _rq) \
747 bio_for_each_segment(bvl, _iter.bio, _iter.i)
748
749#define rq_iter_last(rq, _iter) \
750 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
751
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752extern int blk_register_queue(struct gendisk *disk);
753extern void blk_unregister_queue(struct gendisk *disk);
754extern void register_disk(struct gendisk *dev);
755extern void generic_make_request(struct bio *bio);
FUJITA Tomonori2a4aa302008-04-29 09:54:36 +0200756extern void blk_rq_init(struct request_queue *q, struct request *rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757extern void blk_put_request(struct request *);
Jens Axboe165125e2007-07-24 09:28:11 +0200758extern void __blk_put_request(struct request_queue *, struct request *);
Jens Axboe165125e2007-07-24 09:28:11 +0200759extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
Boaz Harrosh79eb63e2009-05-17 18:57:15 +0300760extern struct request *blk_make_request(struct request_queue *, struct bio *,
761 gfp_t);
Jens Axboe165125e2007-07-24 09:28:11 +0200762extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
763extern void blk_requeue_request(struct request_queue *, struct request *);
Kiyoshi Ueda82124d62008-09-18 10:45:38 -0400764extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200765extern int blk_lld_busy(struct request_queue *q);
Kiyoshi Uedab0fd2712009-06-11 13:10:16 +0200766extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
767 struct bio_set *bs, gfp_t gfp_mask,
768 int (*bio_ctr)(struct bio *, struct bio *, void *),
769 void *data);
770extern void blk_rq_unprep_clone(struct request *rq);
Kiyoshi Ueda82124d62008-09-18 10:45:38 -0400771extern int blk_insert_cloned_request(struct request_queue *q,
772 struct request *rq);
Jens Axboe165125e2007-07-24 09:28:11 +0200773extern void blk_plug_device(struct request_queue *);
Jens Axboe6c5e0c42008-08-01 20:31:32 +0200774extern void blk_plug_device_unlocked(struct request_queue *);
Jens Axboe165125e2007-07-24 09:28:11 +0200775extern int blk_remove_plug(struct request_queue *);
776extern void blk_recount_segments(struct request_queue *, struct bio *);
Al Viro74f3c8a2007-08-27 15:38:10 -0400777extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
778 unsigned int, void __user *);
Al Viroe915e872008-09-02 17:16:41 -0400779extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
780 struct scsi_ioctl_command __user *);
Andrew Morton3fcfab12006-10-19 23:28:16 -0700781
782/*
783 * A queue has just exitted congestion. Note this in the global counter of
784 * congested queues, and wake up anyone who was waiting for requests to be
785 * put back.
786 */
Jens Axboe8aa7e842009-07-09 14:52:32 +0200787static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
Andrew Morton3fcfab12006-10-19 23:28:16 -0700788{
Jens Axboe8aa7e842009-07-09 14:52:32 +0200789 clear_bdi_congested(&q->backing_dev_info, sync);
Andrew Morton3fcfab12006-10-19 23:28:16 -0700790}
791
792/*
793 * A queue has just entered congestion. Flag that in the queue's VM-visible
794 * state flags and increment the global gounter of congested queues.
795 */
Jens Axboe8aa7e842009-07-09 14:52:32 +0200796static inline void blk_set_queue_congested(struct request_queue *q, int sync)
Andrew Morton3fcfab12006-10-19 23:28:16 -0700797{
Jens Axboe8aa7e842009-07-09 14:52:32 +0200798 set_bdi_congested(&q->backing_dev_info, sync);
Andrew Morton3fcfab12006-10-19 23:28:16 -0700799}
800
Jens Axboe165125e2007-07-24 09:28:11 +0200801extern void blk_start_queue(struct request_queue *q);
802extern void blk_stop_queue(struct request_queue *q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803extern void blk_sync_queue(struct request_queue *q);
Jens Axboe165125e2007-07-24 09:28:11 +0200804extern void __blk_stop_queue(struct request_queue *q);
Nick Piggin75ad23b2008-04-29 14:48:33 +0200805extern void __blk_run_queue(struct request_queue *);
Jens Axboe165125e2007-07-24 09:28:11 +0200806extern void blk_run_queue(struct request_queue *);
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900807extern int blk_rq_map_user(struct request_queue *, struct request *,
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900808 struct rq_map_data *, void __user *, unsigned long,
809 gfp_t);
Jens Axboe8e5cfc42006-12-19 11:12:46 +0100810extern int blk_rq_unmap_user(struct bio *);
Jens Axboe165125e2007-07-24 09:28:11 +0200811extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
812extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900813 struct rq_map_data *, struct sg_iovec *, int,
814 unsigned int, gfp_t);
Jens Axboe165125e2007-07-24 09:28:11 +0200815extern int blk_execute_rq(struct request_queue *, struct gendisk *,
James Bottomley 994ca9a2005-06-20 14:11:09 +0200816 struct request *, int);
Jens Axboe165125e2007-07-24 09:28:11 +0200817extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
Jens Axboe15fc8582006-01-06 10:00:50 +0100818 struct request *, int, rq_end_io_fn *);
Alan D. Brunelle2ad8b1e2007-11-07 14:26:56 -0500819extern void blk_unplug(struct request_queue *q);
Mike Christie6e39b692005-11-11 05:30:24 -0600820
Jens Axboe165125e2007-07-24 09:28:11 +0200821static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822{
823 return bdev->bd_disk->queue;
824}
825
826static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
827 struct page *page)
828{
829 if (bdi && bdi->unplug_io_fn)
830 bdi->unplug_io_fn(bdi, page);
831}
832
833static inline void blk_run_address_space(struct address_space *mapping)
834{
835 if (mapping)
836 blk_run_backing_dev(mapping->backing_dev_info, NULL);
837}
838
839/*
Tejun Heo80a761f2009-07-03 17:48:17 +0900840 * blk_rq_pos() : the current sector
841 * blk_rq_bytes() : bytes left in the entire request
842 * blk_rq_cur_bytes() : bytes left in the current segment
843 * blk_rq_err_bytes() : bytes left till the next error boundary
844 * blk_rq_sectors() : sectors left in the entire request
845 * blk_rq_cur_sectors() : sectors left in the current segment
846 * blk_rq_err_sectors() : sectors left till the next error boundary
Tejun Heo5efccd12009-04-23 11:05:18 +0900847 */
Tejun Heo5b936292009-05-07 22:24:38 +0900848static inline sector_t blk_rq_pos(const struct request *rq)
849{
Tejun Heoa2dec7b2009-05-07 22:24:44 +0900850 return rq->__sector;
Tejun Heo5b936292009-05-07 22:24:38 +0900851}
852
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900853static inline unsigned int blk_rq_bytes(const struct request *rq)
854{
Tejun Heoa2dec7b2009-05-07 22:24:44 +0900855 return rq->__data_len;
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900856}
857
858static inline int blk_rq_cur_bytes(const struct request *rq)
859{
860 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
861}
Tejun Heo5efccd12009-04-23 11:05:18 +0900862
Tejun Heo80a761f2009-07-03 17:48:17 +0900863extern unsigned int blk_rq_err_bytes(const struct request *rq);
864
Tejun Heo5b936292009-05-07 22:24:38 +0900865static inline unsigned int blk_rq_sectors(const struct request *rq)
866{
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900867 return blk_rq_bytes(rq) >> 9;
Tejun Heo5b936292009-05-07 22:24:38 +0900868}
869
870static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
871{
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900872 return blk_rq_cur_bytes(rq) >> 9;
Tejun Heo5b936292009-05-07 22:24:38 +0900873}
874
Tejun Heo80a761f2009-07-03 17:48:17 +0900875static inline unsigned int blk_rq_err_sectors(const struct request *rq)
876{
877 return blk_rq_err_bytes(rq) >> 9;
878}
879
Tejun Heo5efccd12009-04-23 11:05:18 +0900880/*
Tejun Heo9934c8c2009-05-08 11:54:16 +0900881 * Request issue related functions.
882 */
883extern struct request *blk_peek_request(struct request_queue *q);
884extern void blk_start_request(struct request *rq);
885extern struct request *blk_fetch_request(struct request_queue *q);
886
887/*
Tejun Heo2e60e022009-04-23 11:05:18 +0900888 * Request completion related functions.
889 *
890 * blk_update_request() completes given number of bytes and updates
891 * the request without completing it.
892 *
Tejun Heof06d9a22009-04-23 11:05:19 +0900893 * blk_end_request() and friends. __blk_end_request() must be called
894 * with the request queue spinlock acquired.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895 *
896 * Several drivers define their own end_request and call
Kiyoshi Ueda3bcddea2007-12-11 17:52:28 -0500897 * blk_end_request() for parts of the original function.
898 * This prevents code duplication in drivers.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 */
Tejun Heo2e60e022009-04-23 11:05:18 +0900900extern bool blk_update_request(struct request *rq, int error,
901 unsigned int nr_bytes);
FUJITA Tomonorib1f74492009-05-11 17:56:09 +0900902extern bool blk_end_request(struct request *rq, int error,
903 unsigned int nr_bytes);
904extern void blk_end_request_all(struct request *rq, int error);
905extern bool blk_end_request_cur(struct request *rq, int error);
Tejun Heo80a761f2009-07-03 17:48:17 +0900906extern bool blk_end_request_err(struct request *rq, int error);
FUJITA Tomonorib1f74492009-05-11 17:56:09 +0900907extern bool __blk_end_request(struct request *rq, int error,
908 unsigned int nr_bytes);
909extern void __blk_end_request_all(struct request *rq, int error);
910extern bool __blk_end_request_cur(struct request *rq, int error);
Tejun Heo80a761f2009-07-03 17:48:17 +0900911extern bool __blk_end_request_err(struct request *rq, int error);
Tejun Heo2e60e022009-04-23 11:05:18 +0900912
Jens Axboeff856ba2006-01-09 16:02:34 +0100913extern void blk_complete_request(struct request *);
Jens Axboe242f9dc2008-09-14 05:55:09 -0700914extern void __blk_complete_request(struct request *);
915extern void blk_abort_request(struct request *);
Mike Anderson11914a52008-09-13 20:31:27 +0200916extern void blk_abort_queue(struct request_queue *);
Jens Axboeff856ba2006-01-09 16:02:34 +0100917
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919 * Access functions for manipulating queue properties
920 */
Jens Axboe165125e2007-07-24 09:28:11 +0200921extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
Christoph Lameter19460892005-06-23 00:08:19 -0700922 spinlock_t *lock, int node_id);
Jens Axboe165125e2007-07-24 09:28:11 +0200923extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
924extern void blk_cleanup_queue(struct request_queue *);
925extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
926extern void blk_queue_bounce_limit(struct request_queue *, u64);
927extern void blk_queue_max_sectors(struct request_queue *, unsigned int);
Martin K. Petersenae03bf62009-05-22 17:17:50 -0400928extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
Jens Axboe165125e2007-07-24 09:28:11 +0200929extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short);
930extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short);
931extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
Christoph Hellwig67efc922009-09-30 13:54:20 +0200932extern void blk_queue_max_discard_sectors(struct request_queue *q,
933 unsigned int max_discard_sectors);
Martin K. Petersene1defc42009-05-22 17:17:49 -0400934extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400935extern void blk_queue_physical_block_size(struct request_queue *, unsigned short);
936extern void blk_queue_alignment_offset(struct request_queue *q,
937 unsigned int alignment);
Martin K. Petersen7c958e32009-07-31 11:49:11 -0400938extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400939extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
Martin K. Petersen3c5820c2009-09-11 21:54:52 +0200940extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400941extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
Martin K. Petersene475bba2009-06-16 08:23:52 +0200942extern void blk_set_default_limits(struct queue_limits *lim);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400943extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
944 sector_t offset);
945extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
946 sector_t offset);
Jens Axboe165125e2007-07-24 09:28:11 +0200947extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
Tejun Heoe3790c72008-03-04 11:18:17 +0100948extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
FUJITA Tomonori27f82212008-07-04 09:30:03 +0200949extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
Tejun Heo2fb98e82008-02-19 11:36:53 +0100950extern int blk_queue_dma_drain(struct request_queue *q,
951 dma_drain_needed_fn *dma_drain_needed,
952 void *buf, unsigned int size);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200953extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
Jens Axboe165125e2007-07-24 09:28:11 +0200954extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
955extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
956extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
957extern void blk_queue_dma_alignment(struct request_queue *, int);
James Bottomley11c3e682007-12-31 16:37:00 -0600958extern void blk_queue_update_dma_alignment(struct request_queue *, int);
Jens Axboe165125e2007-07-24 09:28:11 +0200959extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
Jens Axboe242f9dc2008-09-14 05:55:09 -0700960extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
961extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
Jens Axboe165125e2007-07-24 09:28:11 +0200963extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
Tejun Heo8f11b3e2008-11-28 13:32:05 +0900964extern bool blk_do_ordered(struct request_queue *, struct request **);
Jens Axboe165125e2007-07-24 09:28:11 +0200965extern unsigned blk_ordered_cur_seq(struct request_queue *);
Tejun Heo797e7db2006-01-06 09:51:03 +0100966extern unsigned blk_ordered_req_seq(struct request *);
Tejun Heo8f11b3e2008-11-28 13:32:05 +0900967extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968
Jens Axboe165125e2007-07-24 09:28:11 +0200969extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970extern void blk_dump_rq_flags(struct request *, char *);
Jens Axboe165125e2007-07-24 09:28:11 +0200971extern void generic_unplug_device(struct request_queue *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972extern long nr_blockdev_pages(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973
Jens Axboe165125e2007-07-24 09:28:11 +0200974int blk_get_queue(struct request_queue *);
975struct request_queue *blk_alloc_queue(gfp_t);
976struct request_queue *blk_alloc_queue_node(gfp_t, int);
977extern void blk_put_queue(struct request_queue *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978
979/*
980 * tag stuff
981 */
Jens Axboe4aff5e22006-08-10 08:44:47 +0200982#define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
Jens Axboe165125e2007-07-24 09:28:11 +0200983extern int blk_queue_start_tag(struct request_queue *, struct request *);
984extern struct request *blk_queue_find_tag(struct request_queue *, int);
985extern void blk_queue_end_tag(struct request_queue *, struct request *);
986extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
987extern void blk_queue_free_tags(struct request_queue *);
988extern int blk_queue_resize_tags(struct request_queue *, int);
989extern void blk_queue_invalidate_tags(struct request_queue *);
James Bottomley492dfb42006-08-30 15:48:45 -0400990extern struct blk_queue_tag *blk_init_tags(int);
991extern void blk_free_tags(struct blk_queue_tag *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992
David C Somayajuluf583f492006-10-04 08:27:25 +0200993static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
994 int tag)
995{
996 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
997 return NULL;
998 return bqt->tag_index[tag];
999}
1000
Linus Torvalds1da177e2005-04-16 15:20:36 -07001001extern int blkdev_issue_flush(struct block_device *, sector_t *);
Christoph Hellwig746cd1e2009-09-12 07:35:43 +02001002#define DISCARD_FL_WAIT 0x01 /* wait for completion */
1003#define DISCARD_FL_BARRIER 0x02 /* issue DISCARD_BARRIER request */
1004extern int blkdev_issue_discard(struct block_device *, sector_t sector,
1005 sector_t nr_sects, gfp_t, int flags);
David Woodhousefb2dce82008-08-05 18:01:53 +01001006
1007static inline int sb_issue_discard(struct super_block *sb,
Hugh Dickins3e6053d2008-09-11 10:57:55 +02001008 sector_t block, sector_t nr_blocks)
David Woodhousefb2dce82008-08-05 18:01:53 +01001009{
1010 block <<= (sb->s_blocksize_bits - 9);
1011 nr_blocks <<= (sb->s_blocksize_bits - 9);
Christoph Hellwig746cd1e2009-09-12 07:35:43 +02001012 return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL,
1013 DISCARD_FL_BARRIER);
David Woodhousefb2dce82008-08-05 18:01:53 +01001014}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015
Jens Axboe018e0442009-06-26 16:27:10 +02001016extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
Adel Gadllah0b07de82008-06-26 13:48:27 +02001017
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018#define MAX_PHYS_SEGMENTS 128
1019#define MAX_HW_SEGMENTS 128
Mike Christiedefd94b2005-12-05 02:37:06 -06001020#define SAFE_MAX_SECTORS 255
1021#define BLK_DEF_MAX_SECTORS 1024
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022
1023#define MAX_SEGMENT_SIZE 65536
1024
Milan Broz0e435ac2008-12-03 12:55:08 +01001025#define BLK_SEG_BOUNDARY_MASK 0xFFFFFFFFUL
1026
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1028
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001029static inline unsigned long queue_bounce_pfn(struct request_queue *q)
1030{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001031 return q->limits.bounce_pfn;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001032}
1033
1034static inline unsigned long queue_segment_boundary(struct request_queue *q)
1035{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001036 return q->limits.seg_boundary_mask;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001037}
1038
1039static inline unsigned int queue_max_sectors(struct request_queue *q)
1040{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001041 return q->limits.max_sectors;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001042}
1043
1044static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1045{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001046 return q->limits.max_hw_sectors;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001047}
1048
1049static inline unsigned short queue_max_hw_segments(struct request_queue *q)
1050{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001051 return q->limits.max_hw_segments;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001052}
1053
1054static inline unsigned short queue_max_phys_segments(struct request_queue *q)
1055{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001056 return q->limits.max_phys_segments;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001057}
1058
1059static inline unsigned int queue_max_segment_size(struct request_queue *q)
1060{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001061 return q->limits.max_segment_size;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001062}
1063
Martin K. Petersene1defc42009-05-22 17:17:49 -04001064static inline unsigned short queue_logical_block_size(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001065{
1066 int retval = 512;
1067
Martin K. Petersen025146e2009-05-22 17:17:51 -04001068 if (q && q->limits.logical_block_size)
1069 retval = q->limits.logical_block_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001070
1071 return retval;
1072}
1073
Martin K. Petersene1defc42009-05-22 17:17:49 -04001074static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075{
Martin K. Petersene1defc42009-05-22 17:17:49 -04001076 return queue_logical_block_size(bdev_get_queue(bdev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001077}
1078
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001079static inline unsigned int queue_physical_block_size(struct request_queue *q)
1080{
1081 return q->limits.physical_block_size;
1082}
1083
1084static inline unsigned int queue_io_min(struct request_queue *q)
1085{
1086 return q->limits.io_min;
1087}
1088
1089static inline unsigned int queue_io_opt(struct request_queue *q)
1090{
1091 return q->limits.io_opt;
1092}
1093
1094static inline int queue_alignment_offset(struct request_queue *q)
1095{
1096 if (q && q->limits.misaligned)
1097 return -1;
1098
1099 if (q && q->limits.alignment_offset)
1100 return q->limits.alignment_offset;
1101
1102 return 0;
1103}
1104
1105static inline int queue_sector_alignment_offset(struct request_queue *q,
1106 sector_t sector)
1107{
1108 return ((sector << 9) - q->limits.alignment_offset)
1109 & (q->limits.io_min - 1);
1110}
1111
Jens Axboe165125e2007-07-24 09:28:11 +02001112static inline int queue_dma_alignment(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001113{
Pete Wyckoff482eb682008-01-01 10:23:02 -05001114 return q ? q->dma_alignment : 511;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115}
1116
FUJITA Tomonori87904072008-08-28 15:05:58 +09001117static inline int blk_rq_aligned(struct request_queue *q, void *addr,
1118 unsigned int len)
1119{
1120 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1121 return !((unsigned long)addr & alignment) && !(len & alignment);
1122}
1123
Linus Torvalds1da177e2005-04-16 15:20:36 -07001124/* assumes size > 256 */
1125static inline unsigned int blksize_bits(unsigned int size)
1126{
1127 unsigned int bits = 8;
1128 do {
1129 bits++;
1130 size >>= 1;
1131 } while (size > 256);
1132 return bits;
1133}
1134
Adrian Bunk2befb9e2005-09-10 00:27:17 -07001135static inline unsigned int block_size(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136{
1137 return bdev->bd_block_size;
1138}
1139
1140typedef struct {struct page *v;} Sector;
1141
1142unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1143
1144static inline void put_dev_sector(Sector p)
1145{
1146 page_cache_release(p.v);
1147}
1148
1149struct work_struct;
Jens Axboe8e296752009-10-03 16:26:03 +02001150struct delayed_work;
Jens Axboe18887ad2008-07-28 13:08:45 +02001151int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
Jens Axboe8e296752009-10-03 16:26:03 +02001152int kblockd_schedule_delayed_work(struct request_queue *q,
1153 struct delayed_work *work,
1154 unsigned long delay);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001155
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156#define MODULE_ALIAS_BLOCKDEV(major,minor) \
1157 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1158#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1159 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1160
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001161#if defined(CONFIG_BLK_DEV_INTEGRITY)
1162
Jens Axboeb24498d2008-06-27 09:12:09 +02001163#define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1164#define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001165
1166struct blk_integrity_exchg {
1167 void *prot_buf;
1168 void *data_buf;
1169 sector_t sector;
1170 unsigned int data_size;
1171 unsigned short sector_size;
1172 const char *disk_name;
1173};
1174
1175typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1176typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1177typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1178typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1179
1180struct blk_integrity {
1181 integrity_gen_fn *generate_fn;
1182 integrity_vrfy_fn *verify_fn;
1183 integrity_set_tag_fn *set_tag_fn;
1184 integrity_get_tag_fn *get_tag_fn;
1185
1186 unsigned short flags;
1187 unsigned short tuple_size;
1188 unsigned short sector_size;
1189 unsigned short tag_size;
1190
1191 const char *name;
1192
1193 struct kobject kobj;
1194};
1195
1196extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1197extern void blk_integrity_unregister(struct gendisk *);
Martin K. Petersenad7fce92008-10-01 03:38:39 -04001198extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001199extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
1200extern int blk_rq_count_integrity_sg(struct request *);
1201
Jens Axboeb04accc2008-10-02 12:53:22 +02001202static inline
1203struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1204{
1205 return bdev->bd_disk->integrity;
1206}
1207
Martin K. Petersenb02739b2008-10-02 18:47:49 +02001208static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1209{
1210 return disk->integrity;
1211}
1212
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001213static inline int blk_integrity_rq(struct request *rq)
1214{
Martin K. Petersend442cc42008-07-16 16:09:06 -04001215 if (rq->bio == NULL)
1216 return 0;
1217
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001218 return bio_integrity(rq->bio);
1219}
1220
1221#else /* CONFIG_BLK_DEV_INTEGRITY */
1222
1223#define blk_integrity_rq(rq) (0)
1224#define blk_rq_count_integrity_sg(a) (0)
1225#define blk_rq_map_integrity_sg(a, b) (0)
Jens Axboeb04accc2008-10-02 12:53:22 +02001226#define bdev_get_integrity(a) (0)
Martin K. Petersenb02739b2008-10-02 18:47:49 +02001227#define blk_get_integrity(a) (0)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001228#define blk_integrity_compare(a, b) (0)
1229#define blk_integrity_register(a, b) (0)
1230#define blk_integrity_unregister(a) do { } while (0);
1231
1232#endif /* CONFIG_BLK_DEV_INTEGRITY */
1233
Al Viro08f85852007-10-08 13:26:20 -04001234struct block_device_operations {
Al Virod4430d62008-03-02 09:09:22 -05001235 int (*open) (struct block_device *, fmode_t);
1236 int (*release) (struct gendisk *, fmode_t);
1237 int (*locked_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1238 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1239 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
Al Viro08f85852007-10-08 13:26:20 -04001240 int (*direct_access) (struct block_device *, sector_t,
1241 void **, unsigned long *);
1242 int (*media_changed) (struct gendisk *);
Bartlomiej Zolnierkiewiczdb429e92009-06-07 13:52:52 +02001243 unsigned long long (*set_capacity) (struct gendisk *,
1244 unsigned long long);
Al Viro08f85852007-10-08 13:26:20 -04001245 int (*revalidate_disk) (struct gendisk *);
1246 int (*getgeo)(struct block_device *, struct hd_geometry *);
1247 struct module *owner;
1248};
1249
Al Viro633a08b2007-08-29 20:34:12 -04001250extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1251 unsigned long);
David Howells93614012006-09-30 20:45:40 +02001252#else /* CONFIG_BLOCK */
1253/*
1254 * stubs for when the block layer is configured out
1255 */
1256#define buffer_heads_over_limit 0
1257
David Howells93614012006-09-30 20:45:40 +02001258static inline long nr_blockdev_pages(void)
1259{
1260 return 0;
1261}
1262
David Howells93614012006-09-30 20:45:40 +02001263#endif /* CONFIG_BLOCK */
1264
Linus Torvalds1da177e2005-04-16 15:20:36 -07001265#endif