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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. Petersen86b37282009-11-10 11:50:21 +0100315 unsigned int discard_granularity;
316 unsigned int discard_alignment;
Martin K. Petersen025146e2009-05-22 17:17:51 -0400317
318 unsigned short logical_block_size;
Martin K. Petersen8a783622010-02-26 00:20:39 -0500319 unsigned short max_segments;
Martin K. Petersen025146e2009-05-22 17:17:51 -0400320
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400321 unsigned char misaligned;
Martin K. Petersen86b37282009-11-10 11:50:21 +0100322 unsigned char discard_misaligned;
Martin K. Petersen025146e2009-05-22 17:17:51 -0400323 unsigned char no_cluster;
Martin K. Petersen98262f22009-12-03 09:24:48 +0100324 signed char discard_zeroes_data;
Martin K. Petersen025146e2009-05-22 17:17:51 -0400325};
326
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327struct request_queue
328{
329 /*
330 * Together with queue_head for cacheline sharing
331 */
332 struct list_head queue_head;
333 struct request *last_merge;
Jens Axboeb374d182008-10-31 10:05:07 +0100334 struct elevator_queue *elevator;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335
336 /*
337 * the queue request freelist, one for reads and one for writes
338 */
339 struct request_list rq;
340
341 request_fn_proc *request_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 make_request_fn *make_request_fn;
343 prep_rq_fn *prep_rq_fn;
344 unplug_fn *unplug_fn;
345 merge_bvec_fn *merge_bvec_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 prepare_flush_fn *prepare_flush_fn;
Jens Axboeff856ba2006-01-09 16:02:34 +0100347 softirq_done_fn *softirq_done_fn;
Jens Axboe242f9dc2008-09-14 05:55:09 -0700348 rq_timed_out_fn *rq_timed_out_fn;
Tejun Heo2fb98e82008-02-19 11:36:53 +0100349 dma_drain_needed_fn *dma_drain_needed;
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200350 lld_busy_fn *lld_busy_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351
352 /*
Tejun Heo8922e162005-10-20 16:23:44 +0200353 * Dispatch queue sorting
354 */
Jens Axboe1b47f532005-10-20 16:37:00 +0200355 sector_t end_sector;
Tejun Heo8922e162005-10-20 16:23:44 +0200356 struct request *boundary_rq;
Tejun Heo8922e162005-10-20 16:23:44 +0200357
358 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 * Auto-unplugging state
360 */
361 struct timer_list unplug_timer;
362 int unplug_thresh; /* After this many requests */
363 unsigned long unplug_delay; /* After this many jiffies */
364 struct work_struct unplug_work;
365
366 struct backing_dev_info backing_dev_info;
367
368 /*
369 * The queue owner gets to use this for whatever they like.
370 * ll_rw_blk doesn't touch it.
371 */
372 void *queuedata;
373
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 /*
375 * queue needs bounce pages for pages above this limit
376 */
Al Viro8267e262005-10-21 03:20:53 -0400377 gfp_t bounce_gfp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378
379 /*
380 * various queue flags, see QUEUE_* below
381 */
382 unsigned long queue_flags;
383
384 /*
152587d2005-04-12 16:22:06 -0500385 * protects queue structures from reentrancy. ->__queue_lock should
386 * _never_ be used directly, it is queue private. always use
387 * ->queue_lock.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 */
152587d2005-04-12 16:22:06 -0500389 spinlock_t __queue_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 spinlock_t *queue_lock;
391
392 /*
393 * queue kobject
394 */
395 struct kobject kobj;
396
397 /*
398 * queue settings
399 */
400 unsigned long nr_requests; /* Max # of requests */
401 unsigned int nr_congestion_on;
402 unsigned int nr_congestion_off;
403 unsigned int nr_batching;
404
James Bottomleyfa0ccd82008-01-10 11:30:36 -0600405 void *dma_drain_buffer;
406 unsigned int dma_drain_size;
Tejun Heoe3790c72008-03-04 11:18:17 +0100407 unsigned int dma_pad_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 unsigned int dma_alignment;
409
410 struct blk_queue_tag *queue_tags;
Jens Axboe6eca9002007-10-25 10:14:47 +0200411 struct list_head tag_busy_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412
Tejun Heo15853af2005-11-10 08:52:05 +0100413 unsigned int nr_sorted;
Jens Axboe0a7ae2f2009-05-20 08:54:31 +0200414 unsigned int in_flight[2];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415
Jens Axboe242f9dc2008-09-14 05:55:09 -0700416 unsigned int rq_timeout;
417 struct timer_list timeout;
418 struct list_head timeout_list;
419
Martin K. Petersen025146e2009-05-22 17:17:51 -0400420 struct queue_limits limits;
421
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 /*
423 * sg stuff
424 */
425 unsigned int sg_timeout;
426 unsigned int sg_reserved_size;
Christoph Lameter19460892005-06-23 00:08:19 -0700427 int node;
Alexey Dobriyan6c5c9342006-09-29 01:59:40 -0700428#ifdef CONFIG_BLK_DEV_IO_TRACE
Jens Axboe2056a782006-03-23 20:00:26 +0100429 struct blk_trace *blk_trace;
Alexey Dobriyan6c5c9342006-09-29 01:59:40 -0700430#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 /*
432 * reserved for flush operations
433 */
Tejun Heo797e7db2006-01-06 09:51:03 +0100434 unsigned int ordered, next_ordered, ordseq;
435 int orderr, ordcolor;
436 struct request pre_flush_rq, bar_rq, post_flush_rq;
437 struct request *orig_bar_rq;
Al Viro483f4af2006-03-18 18:34:37 -0500438
439 struct mutex sysfs_lock;
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200440
441#if defined(CONFIG_BLK_DEV_BSG)
442 struct bsg_class_device bsg_dev;
443#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444};
445
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446#define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
447#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
448#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
Jens Axboe1faa16d2009-04-06 14:48:01 +0200449#define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
450#define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451#define QUEUE_FLAG_DEAD 5 /* queue being torn down */
452#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
453#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
Jens Axboe64521d12005-10-28 08:30:39 +0200454#define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200455#define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200456#define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
Jens Axboec7c22e42008-09-13 20:26:01 +0200457#define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
Jens Axboe581d4e22008-09-14 05:56:33 -0700458#define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
Kiyoshi Ueda4ee5eaf2008-09-18 10:46:13 -0400459#define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
Jens Axboea68bbdd2008-09-24 13:03:33 +0200460#define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
Fernando Luis Vázquez Cao88e740f2008-10-27 18:44:46 +0900461#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
Jens Axboebc58ba92009-01-23 10:54:44 +0100462#define QUEUE_FLAG_IO_STAT 15 /* do IO stats */
Jens Axboe79da0642010-02-23 08:40:43 +0100463#define QUEUE_FLAG_DISCARD 16 /* supports DISCARD */
Jens Axboe7f032922010-02-25 08:48:05 +0100464#define QUEUE_FLAG_NOXMERGES 17 /* No extended merges */
Jens Axboebc58ba92009-01-23 10:54:44 +0100465
466#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
467 (1 << QUEUE_FLAG_CLUSTER) | \
Jens Axboe01e97f62009-09-03 20:06:47 +0200468 (1 << QUEUE_FLAG_STACKABLE) | \
469 (1 << QUEUE_FLAG_SAME_COMP))
Tejun Heo797e7db2006-01-06 09:51:03 +0100470
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700471static inline int queue_is_locked(struct request_queue *q)
472{
Jens Axboe7663c1e2008-04-29 21:31:27 +0200473#ifdef CONFIG_SMP
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700474 spinlock_t *lock = q->queue_lock;
475 return lock && spin_is_locked(lock);
Jens Axboe7663c1e2008-04-29 21:31:27 +0200476#else
477 return 1;
478#endif
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700479}
480
Nick Piggin75ad23b2008-04-29 14:48:33 +0200481static inline void queue_flag_set_unlocked(unsigned int flag,
482 struct request_queue *q)
483{
484 __set_bit(flag, &q->queue_flags);
485}
486
Jens Axboee48ec692008-07-03 13:18:54 +0200487static inline int queue_flag_test_and_clear(unsigned int flag,
488 struct request_queue *q)
489{
490 WARN_ON_ONCE(!queue_is_locked(q));
491
492 if (test_bit(flag, &q->queue_flags)) {
493 __clear_bit(flag, &q->queue_flags);
494 return 1;
495 }
496
497 return 0;
498}
499
500static inline int queue_flag_test_and_set(unsigned int flag,
501 struct request_queue *q)
502{
503 WARN_ON_ONCE(!queue_is_locked(q));
504
505 if (!test_bit(flag, &q->queue_flags)) {
506 __set_bit(flag, &q->queue_flags);
507 return 0;
508 }
509
510 return 1;
511}
512
Nick Piggin75ad23b2008-04-29 14:48:33 +0200513static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
514{
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700515 WARN_ON_ONCE(!queue_is_locked(q));
Nick Piggin75ad23b2008-04-29 14:48:33 +0200516 __set_bit(flag, &q->queue_flags);
517}
518
519static inline void queue_flag_clear_unlocked(unsigned int flag,
520 struct request_queue *q)
521{
522 __clear_bit(flag, &q->queue_flags);
523}
524
Jens Axboe0a7ae2f2009-05-20 08:54:31 +0200525static inline int queue_in_flight(struct request_queue *q)
526{
527 return q->in_flight[0] + q->in_flight[1];
528}
529
Nick Piggin75ad23b2008-04-29 14:48:33 +0200530static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
531{
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700532 WARN_ON_ONCE(!queue_is_locked(q));
Nick Piggin75ad23b2008-04-29 14:48:33 +0200533 __clear_bit(flag, &q->queue_flags);
534}
535
Tejun Heo797e7db2006-01-06 09:51:03 +0100536enum {
537 /*
538 * Hardbarrier is supported with one of the following methods.
539 *
540 * NONE : hardbarrier unsupported
541 * DRAIN : ordering by draining is enough
542 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
543 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
544 * TAG : ordering by tag is enough
545 * TAG_FLUSH : ordering by tag w/ pre and post flushes
546 * TAG_FUA : ordering by tag w/ pre flush and FUA write
547 */
Tejun Heo313e4292008-11-28 13:32:02 +0900548 QUEUE_ORDERED_BY_DRAIN = 0x01,
549 QUEUE_ORDERED_BY_TAG = 0x02,
550 QUEUE_ORDERED_DO_PREFLUSH = 0x10,
Tejun Heof6716202008-11-28 13:32:04 +0900551 QUEUE_ORDERED_DO_BAR = 0x20,
Tejun Heo313e4292008-11-28 13:32:02 +0900552 QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
553 QUEUE_ORDERED_DO_FUA = 0x80,
Tejun Heo797e7db2006-01-06 09:51:03 +0100554
Tejun Heo313e4292008-11-28 13:32:02 +0900555 QUEUE_ORDERED_NONE = 0x00,
Tejun Heo797e7db2006-01-06 09:51:03 +0100556
Tejun Heof6716202008-11-28 13:32:04 +0900557 QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_BY_DRAIN |
558 QUEUE_ORDERED_DO_BAR,
Tejun Heo313e4292008-11-28 13:32:02 +0900559 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
560 QUEUE_ORDERED_DO_PREFLUSH |
561 QUEUE_ORDERED_DO_POSTFLUSH,
562 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
563 QUEUE_ORDERED_DO_PREFLUSH |
564 QUEUE_ORDERED_DO_FUA,
565
Tejun Heof6716202008-11-28 13:32:04 +0900566 QUEUE_ORDERED_TAG = QUEUE_ORDERED_BY_TAG |
567 QUEUE_ORDERED_DO_BAR,
Tejun Heo313e4292008-11-28 13:32:02 +0900568 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
569 QUEUE_ORDERED_DO_PREFLUSH |
570 QUEUE_ORDERED_DO_POSTFLUSH,
571 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
572 QUEUE_ORDERED_DO_PREFLUSH |
573 QUEUE_ORDERED_DO_FUA,
Tejun Heo797e7db2006-01-06 09:51:03 +0100574
575 /*
576 * Ordered operation sequence
577 */
578 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
579 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
580 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
581 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
582 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
583 QUEUE_ORDSEQ_DONE = 0x20,
584};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585
586#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
587#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
588#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200589#define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
Alan D. Brunelle488991e2010-01-29 09:04:08 +0100590#define blk_queue_noxmerges(q) \
591 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
Jens Axboea68bbdd2008-09-24 13:03:33 +0200592#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
Jens Axboebc58ba92009-01-23 10:54:44 +0100593#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
Tejun Heo797e7db2006-01-06 09:51:03 +0100594#define blk_queue_flushing(q) ((q)->ordseq)
Kiyoshi Ueda4ee5eaf2008-09-18 10:46:13 -0400595#define blk_queue_stackable(q) \
596 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
Christoph Hellwigc15227d2009-09-30 13:52:12 +0200597#define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598
Jens Axboe4aff5e22006-08-10 08:44:47 +0200599#define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
600#define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
601#define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
602#define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
603
Mike Christie6000a362008-08-19 18:45:30 -0500604#define blk_failfast_dev(rq) ((rq)->cmd_flags & REQ_FAILFAST_DEV)
605#define blk_failfast_transport(rq) ((rq)->cmd_flags & REQ_FAILFAST_TRANSPORT)
606#define blk_failfast_driver(rq) ((rq)->cmd_flags & REQ_FAILFAST_DRIVER)
607#define blk_noretry_request(rq) (blk_failfast_dev(rq) || \
608 blk_failfast_transport(rq) || \
609 blk_failfast_driver(rq))
Jens Axboe4aff5e22006-08-10 08:44:47 +0200610#define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
Jerome Marchand42dad762009-04-22 14:01:49 +0200611#define blk_rq_io_stat(rq) ((rq)->cmd_flags & REQ_IO_STAT)
Borislav Petkov96c16742009-04-30 18:24:34 +0200612#define blk_rq_quiet(rq) ((rq)->cmd_flags & REQ_QUIET)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613
David Woodhousee17fc0a2008-08-09 16:42:20 +0100614#define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615
Jens Axboe4aff5e22006-08-10 08:44:47 +0200616#define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
617#define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618#define blk_pm_request(rq) \
Jens Axboe4aff5e22006-08-10 08:44:47 +0200619 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620
Jens Axboeab780f12008-08-26 10:25:02 +0200621#define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
Jens Axboe4aff5e22006-08-10 08:44:47 +0200622#define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
623#define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
624#define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
David Woodhousefb2dce82008-08-05 18:01:53 +0100625#define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200626#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
Kiyoshi Ueda336cdb42007-12-11 17:40:30 -0500627/* rq->queuelist of dequeued request must be list_empty() */
628#define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629
630#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
631
Jens Axboe4aff5e22006-08-10 08:44:47 +0200632#define rq_data_dir(rq) ((rq)->cmd_flags & 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633
Jens Axboe9e2585a2006-07-28 09:26:13 +0200634/*
Jens Axboe1faa16d2009-04-06 14:48:01 +0200635 * We regard a request as sync, if either a read or a sync write
Jens Axboe9e2585a2006-07-28 09:26:13 +0200636 */
Jens Axboe1faa16d2009-04-06 14:48:01 +0200637static inline bool rw_is_sync(unsigned int rw_flags)
638{
639 return !(rw_flags & REQ_RW) || (rw_flags & REQ_RW_SYNC);
640}
641
642static inline bool rq_is_sync(struct request *rq)
643{
644 return rw_is_sync(rq->cmd_flags);
645}
646
Jens Axboe5404bc72006-08-10 09:01:02 +0200647#define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
Jens Axboeaeb6faf2009-04-06 14:48:07 +0200648#define rq_noidle(rq) ((rq)->cmd_flags & REQ_NOIDLE)
Jens Axboe9e2585a2006-07-28 09:26:13 +0200649
Jens Axboe1faa16d2009-04-06 14:48:01 +0200650static inline int blk_queue_full(struct request_queue *q, int sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651{
Jens Axboe1faa16d2009-04-06 14:48:01 +0200652 if (sync)
653 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
654 return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655}
656
Jens Axboe1faa16d2009-04-06 14:48:01 +0200657static inline void blk_set_queue_full(struct request_queue *q, int sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658{
Jens Axboe1faa16d2009-04-06 14:48:01 +0200659 if (sync)
660 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 else
Jens Axboe1faa16d2009-04-06 14:48:01 +0200662 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663}
664
Jens Axboe1faa16d2009-04-06 14:48:01 +0200665static inline void blk_clear_queue_full(struct request_queue *q, int sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666{
Jens Axboe1faa16d2009-04-06 14:48:01 +0200667 if (sync)
668 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 else
Jens Axboe1faa16d2009-04-06 14:48:01 +0200670 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671}
672
673
674/*
675 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
676 * it already be started by driver.
677 */
678#define RQ_NOMERGE_FLAGS \
679 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
680#define rq_mergeable(rq) \
David Woodhousee17fc0a2008-08-09 16:42:20 +0100681 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
682 (blk_discard_rq(rq) || blk_fs_request((rq))))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683
684/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 * q->prep_rq_fn return values
686 */
687#define BLKPREP_OK 0 /* serve it */
688#define BLKPREP_KILL 1 /* fatal error, kill */
689#define BLKPREP_DEFER 2 /* leave on queue */
690
691extern unsigned long blk_max_low_pfn, blk_max_pfn;
692
693/*
694 * standard bounce addresses:
695 *
696 * BLK_BOUNCE_HIGH : bounce all highmem pages
697 * BLK_BOUNCE_ANY : don't bounce anything
698 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
699 */
Andi Kleen24728922008-04-21 09:51:05 +0200700
701#if BITS_PER_LONG == 32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
Andi Kleen24728922008-04-21 09:51:05 +0200703#else
704#define BLK_BOUNCE_HIGH -1ULL
705#endif
706#define BLK_BOUNCE_ANY (-1ULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707#define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
708
Jens Axboe3d6392c2007-07-09 12:38:05 +0200709/*
710 * default timeout for SG_IO if none specified
711 */
712#define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
Linus Torvaldsf2f1fa72008-12-05 14:49:18 -0800713#define BLK_MIN_SG_TIMEOUT (7 * HZ)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200714
Christoph Lameter2a7326b2007-07-17 04:03:37 -0700715#ifdef CONFIG_BOUNCE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716extern int init_emergency_isa_pool(void);
Jens Axboe165125e2007-07-24 09:28:11 +0200717extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718#else
719static inline int init_emergency_isa_pool(void)
720{
721 return 0;
722}
Jens Axboe165125e2007-07-24 09:28:11 +0200723static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724{
725}
726#endif /* CONFIG_MMU */
727
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900728struct rq_map_data {
729 struct page **pages;
730 int page_order;
731 int nr_entries;
FUJITA Tomonori56c451f2008-12-18 14:49:37 +0900732 unsigned long offset;
FUJITA Tomonori97ae77a2008-12-18 14:49:38 +0900733 int null_mapped;
FUJITA Tomonoriecb554a2009-07-09 14:46:53 +0200734 int from_user;
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900735};
736
NeilBrown5705f702007-09-25 12:35:59 +0200737struct req_iterator {
738 int i;
739 struct bio *bio;
740};
741
742/* This should not be used directly - use rq_for_each_segment */
Jens Axboe1e428072009-02-23 09:03:10 +0100743#define for_each_bio(_bio) \
744 for (; _bio; _bio = _bio->bi_next)
NeilBrown5705f702007-09-25 12:35:59 +0200745#define __rq_for_each_bio(_bio, rq) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 if ((rq->bio)) \
747 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
748
NeilBrown5705f702007-09-25 12:35:59 +0200749#define rq_for_each_segment(bvl, _rq, _iter) \
750 __rq_for_each_bio(_iter.bio, _rq) \
751 bio_for_each_segment(bvl, _iter.bio, _iter.i)
752
753#define rq_iter_last(rq, _iter) \
754 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
755
Ilya Loginov2d4dc892009-11-26 09:16:19 +0100756#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
757# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
758#endif
759#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
760extern void rq_flush_dcache_pages(struct request *rq);
761#else
762static inline void rq_flush_dcache_pages(struct request *rq)
763{
764}
765#endif
766
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767extern int blk_register_queue(struct gendisk *disk);
768extern void blk_unregister_queue(struct gendisk *disk);
769extern void register_disk(struct gendisk *dev);
770extern void generic_make_request(struct bio *bio);
FUJITA Tomonori2a4aa302008-04-29 09:54:36 +0200771extern void blk_rq_init(struct request_queue *q, struct request *rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772extern void blk_put_request(struct request *);
Jens Axboe165125e2007-07-24 09:28:11 +0200773extern void __blk_put_request(struct request_queue *, struct request *);
Jens Axboe165125e2007-07-24 09:28:11 +0200774extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
Boaz Harrosh79eb63e2009-05-17 18:57:15 +0300775extern struct request *blk_make_request(struct request_queue *, struct bio *,
776 gfp_t);
Jens Axboe165125e2007-07-24 09:28:11 +0200777extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
778extern void blk_requeue_request(struct request_queue *, struct request *);
Kiyoshi Ueda82124d62008-09-18 10:45:38 -0400779extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200780extern int blk_lld_busy(struct request_queue *q);
Kiyoshi Uedab0fd2712009-06-11 13:10:16 +0200781extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
782 struct bio_set *bs, gfp_t gfp_mask,
783 int (*bio_ctr)(struct bio *, struct bio *, void *),
784 void *data);
785extern void blk_rq_unprep_clone(struct request *rq);
Kiyoshi Ueda82124d62008-09-18 10:45:38 -0400786extern int blk_insert_cloned_request(struct request_queue *q,
787 struct request *rq);
Jens Axboe165125e2007-07-24 09:28:11 +0200788extern void blk_plug_device(struct request_queue *);
Jens Axboe6c5e0c42008-08-01 20:31:32 +0200789extern void blk_plug_device_unlocked(struct request_queue *);
Jens Axboe165125e2007-07-24 09:28:11 +0200790extern int blk_remove_plug(struct request_queue *);
791extern void blk_recount_segments(struct request_queue *, struct bio *);
Al Viro74f3c8a2007-08-27 15:38:10 -0400792extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
793 unsigned int, void __user *);
Al Viroe915e872008-09-02 17:16:41 -0400794extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
795 struct scsi_ioctl_command __user *);
Andrew Morton3fcfab12006-10-19 23:28:16 -0700796
797/*
798 * A queue has just exitted congestion. Note this in the global counter of
799 * congested queues, and wake up anyone who was waiting for requests to be
800 * put back.
801 */
Jens Axboe8aa7e842009-07-09 14:52:32 +0200802static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
Andrew Morton3fcfab12006-10-19 23:28:16 -0700803{
Jens Axboe8aa7e842009-07-09 14:52:32 +0200804 clear_bdi_congested(&q->backing_dev_info, sync);
Andrew Morton3fcfab12006-10-19 23:28:16 -0700805}
806
807/*
808 * A queue has just entered congestion. Flag that in the queue's VM-visible
809 * state flags and increment the global gounter of congested queues.
810 */
Jens Axboe8aa7e842009-07-09 14:52:32 +0200811static inline void blk_set_queue_congested(struct request_queue *q, int sync)
Andrew Morton3fcfab12006-10-19 23:28:16 -0700812{
Jens Axboe8aa7e842009-07-09 14:52:32 +0200813 set_bdi_congested(&q->backing_dev_info, sync);
Andrew Morton3fcfab12006-10-19 23:28:16 -0700814}
815
Jens Axboe165125e2007-07-24 09:28:11 +0200816extern void blk_start_queue(struct request_queue *q);
817extern void blk_stop_queue(struct request_queue *q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818extern void blk_sync_queue(struct request_queue *q);
Jens Axboe165125e2007-07-24 09:28:11 +0200819extern void __blk_stop_queue(struct request_queue *q);
Nick Piggin75ad23b2008-04-29 14:48:33 +0200820extern void __blk_run_queue(struct request_queue *);
Jens Axboe165125e2007-07-24 09:28:11 +0200821extern void blk_run_queue(struct request_queue *);
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900822extern int blk_rq_map_user(struct request_queue *, struct request *,
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900823 struct rq_map_data *, void __user *, unsigned long,
824 gfp_t);
Jens Axboe8e5cfc42006-12-19 11:12:46 +0100825extern int blk_rq_unmap_user(struct bio *);
Jens Axboe165125e2007-07-24 09:28:11 +0200826extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
827extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900828 struct rq_map_data *, struct sg_iovec *, int,
829 unsigned int, gfp_t);
Jens Axboe165125e2007-07-24 09:28:11 +0200830extern int blk_execute_rq(struct request_queue *, struct gendisk *,
James Bottomley 994ca9a2005-06-20 14:11:09 +0200831 struct request *, int);
Jens Axboe165125e2007-07-24 09:28:11 +0200832extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
Jens Axboe15fc8582006-01-06 10:00:50 +0100833 struct request *, int, rq_end_io_fn *);
Alan D. Brunelle2ad8b1e2007-11-07 14:26:56 -0500834extern void blk_unplug(struct request_queue *q);
Mike Christie6e39b692005-11-11 05:30:24 -0600835
Jens Axboe165125e2007-07-24 09:28:11 +0200836static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837{
838 return bdev->bd_disk->queue;
839}
840
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841/*
Tejun Heo80a761f2009-07-03 17:48:17 +0900842 * blk_rq_pos() : the current sector
843 * blk_rq_bytes() : bytes left in the entire request
844 * blk_rq_cur_bytes() : bytes left in the current segment
845 * blk_rq_err_bytes() : bytes left till the next error boundary
846 * blk_rq_sectors() : sectors left in the entire request
847 * blk_rq_cur_sectors() : sectors left in the current segment
Tejun Heo5efccd12009-04-23 11:05:18 +0900848 */
Tejun Heo5b936292009-05-07 22:24:38 +0900849static inline sector_t blk_rq_pos(const struct request *rq)
850{
Tejun Heoa2dec7b2009-05-07 22:24:44 +0900851 return rq->__sector;
Tejun Heo5b936292009-05-07 22:24:38 +0900852}
853
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900854static inline unsigned int blk_rq_bytes(const struct request *rq)
855{
Tejun Heoa2dec7b2009-05-07 22:24:44 +0900856 return rq->__data_len;
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900857}
858
859static inline int blk_rq_cur_bytes(const struct request *rq)
860{
861 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
862}
Tejun Heo5efccd12009-04-23 11:05:18 +0900863
Tejun Heo80a761f2009-07-03 17:48:17 +0900864extern unsigned int blk_rq_err_bytes(const struct request *rq);
865
Tejun Heo5b936292009-05-07 22:24:38 +0900866static inline unsigned int blk_rq_sectors(const struct request *rq)
867{
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900868 return blk_rq_bytes(rq) >> 9;
Tejun Heo5b936292009-05-07 22:24:38 +0900869}
870
871static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
872{
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900873 return blk_rq_cur_bytes(rq) >> 9;
Tejun Heo5b936292009-05-07 22:24:38 +0900874}
875
Tejun Heo5efccd12009-04-23 11:05:18 +0900876/*
Tejun Heo9934c8c2009-05-08 11:54:16 +0900877 * Request issue related functions.
878 */
879extern struct request *blk_peek_request(struct request_queue *q);
880extern void blk_start_request(struct request *rq);
881extern struct request *blk_fetch_request(struct request_queue *q);
882
883/*
Tejun Heo2e60e022009-04-23 11:05:18 +0900884 * Request completion related functions.
885 *
886 * blk_update_request() completes given number of bytes and updates
887 * the request without completing it.
888 *
Tejun Heof06d9a22009-04-23 11:05:19 +0900889 * blk_end_request() and friends. __blk_end_request() must be called
890 * with the request queue spinlock acquired.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891 *
892 * Several drivers define their own end_request and call
Kiyoshi Ueda3bcddea2007-12-11 17:52:28 -0500893 * blk_end_request() for parts of the original function.
894 * This prevents code duplication in drivers.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895 */
Tejun Heo2e60e022009-04-23 11:05:18 +0900896extern bool blk_update_request(struct request *rq, int error,
897 unsigned int nr_bytes);
FUJITA Tomonorib1f74492009-05-11 17:56:09 +0900898extern bool blk_end_request(struct request *rq, int error,
899 unsigned int nr_bytes);
900extern void blk_end_request_all(struct request *rq, int error);
901extern bool blk_end_request_cur(struct request *rq, int error);
Tejun Heo80a761f2009-07-03 17:48:17 +0900902extern bool blk_end_request_err(struct request *rq, int error);
FUJITA Tomonorib1f74492009-05-11 17:56:09 +0900903extern bool __blk_end_request(struct request *rq, int error,
904 unsigned int nr_bytes);
905extern void __blk_end_request_all(struct request *rq, int error);
906extern bool __blk_end_request_cur(struct request *rq, int error);
Tejun Heo80a761f2009-07-03 17:48:17 +0900907extern bool __blk_end_request_err(struct request *rq, int error);
Tejun Heo2e60e022009-04-23 11:05:18 +0900908
Jens Axboeff856ba2006-01-09 16:02:34 +0100909extern void blk_complete_request(struct request *);
Jens Axboe242f9dc2008-09-14 05:55:09 -0700910extern void __blk_complete_request(struct request *);
911extern void blk_abort_request(struct request *);
Mike Anderson11914a52008-09-13 20:31:27 +0200912extern void blk_abort_queue(struct request_queue *);
Jens Axboeff856ba2006-01-09 16:02:34 +0100913
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 * Access functions for manipulating queue properties
916 */
Jens Axboe165125e2007-07-24 09:28:11 +0200917extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
Christoph Lameter19460892005-06-23 00:08:19 -0700918 spinlock_t *lock, int node_id);
Jens Axboe165125e2007-07-24 09:28:11 +0200919extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
920extern void blk_cleanup_queue(struct request_queue *);
921extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
922extern void blk_queue_bounce_limit(struct request_queue *, u64);
Martin K. Petersen086fa5f2010-02-26 00:20:38 -0500923extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
924
925/* Temporary compatibility wrapper */
926static inline void blk_queue_max_sectors(struct request_queue *q, unsigned int max)
927{
928 blk_queue_max_hw_sectors(q, max);
929}
930
Martin K. Petersen8a783622010-02-26 00:20:39 -0500931extern void blk_queue_max_segments(struct request_queue *, unsigned short);
932
933static inline void blk_queue_max_phys_segments(struct request_queue *q, unsigned short max)
934{
935 blk_queue_max_segments(q, max);
936}
937
938static inline void blk_queue_max_hw_segments(struct request_queue *q, unsigned short max)
939{
940 blk_queue_max_segments(q, max);
941}
942
943
Jens Axboe165125e2007-07-24 09:28:11 +0200944extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
Christoph Hellwig67efc922009-09-30 13:54:20 +0200945extern void blk_queue_max_discard_sectors(struct request_queue *q,
946 unsigned int max_discard_sectors);
Martin K. Petersene1defc42009-05-22 17:17:49 -0400947extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400948extern void blk_queue_physical_block_size(struct request_queue *, unsigned short);
949extern void blk_queue_alignment_offset(struct request_queue *q,
950 unsigned int alignment);
Martin K. Petersen7c958e32009-07-31 11:49:11 -0400951extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400952extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
Martin K. Petersen3c5820c2009-09-11 21:54:52 +0200953extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400954extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
Martin K. Petersene475bba2009-06-16 08:23:52 +0200955extern void blk_set_default_limits(struct queue_limits *lim);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400956extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
957 sector_t offset);
Martin K. Petersen17be8c22010-01-11 03:21:49 -0500958extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
959 sector_t offset);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400960extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
961 sector_t offset);
Jens Axboe165125e2007-07-24 09:28:11 +0200962extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
Tejun Heoe3790c72008-03-04 11:18:17 +0100963extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
FUJITA Tomonori27f82212008-07-04 09:30:03 +0200964extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
Tejun Heo2fb98e82008-02-19 11:36:53 +0100965extern int blk_queue_dma_drain(struct request_queue *q,
966 dma_drain_needed_fn *dma_drain_needed,
967 void *buf, unsigned int size);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200968extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
Jens Axboe165125e2007-07-24 09:28:11 +0200969extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
970extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
971extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
972extern void blk_queue_dma_alignment(struct request_queue *, int);
James Bottomley11c3e682007-12-31 16:37:00 -0600973extern void blk_queue_update_dma_alignment(struct request_queue *, int);
Jens Axboe165125e2007-07-24 09:28:11 +0200974extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
Jens Axboe242f9dc2008-09-14 05:55:09 -0700975extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
976extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
Jens Axboe165125e2007-07-24 09:28:11 +0200978extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
Tejun Heo8f11b3e2008-11-28 13:32:05 +0900979extern bool blk_do_ordered(struct request_queue *, struct request **);
Jens Axboe165125e2007-07-24 09:28:11 +0200980extern unsigned blk_ordered_cur_seq(struct request_queue *);
Tejun Heo797e7db2006-01-06 09:51:03 +0100981extern unsigned blk_ordered_req_seq(struct request *);
Tejun Heo8f11b3e2008-11-28 13:32:05 +0900982extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983
Jens Axboe165125e2007-07-24 09:28:11 +0200984extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985extern void blk_dump_rq_flags(struct request *, char *);
Jens Axboe165125e2007-07-24 09:28:11 +0200986extern void generic_unplug_device(struct request_queue *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987extern long nr_blockdev_pages(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988
Jens Axboe165125e2007-07-24 09:28:11 +0200989int blk_get_queue(struct request_queue *);
990struct request_queue *blk_alloc_queue(gfp_t);
991struct request_queue *blk_alloc_queue_node(gfp_t, int);
992extern void blk_put_queue(struct request_queue *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993
994/*
995 * tag stuff
996 */
Jens Axboe4aff5e22006-08-10 08:44:47 +0200997#define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
Jens Axboe165125e2007-07-24 09:28:11 +0200998extern int blk_queue_start_tag(struct request_queue *, struct request *);
999extern struct request *blk_queue_find_tag(struct request_queue *, int);
1000extern void blk_queue_end_tag(struct request_queue *, struct request *);
1001extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
1002extern void blk_queue_free_tags(struct request_queue *);
1003extern int blk_queue_resize_tags(struct request_queue *, int);
1004extern void blk_queue_invalidate_tags(struct request_queue *);
James Bottomley492dfb42006-08-30 15:48:45 -04001005extern struct blk_queue_tag *blk_init_tags(int);
1006extern void blk_free_tags(struct blk_queue_tag *);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007
David C Somayajuluf583f492006-10-04 08:27:25 +02001008static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
1009 int tag)
1010{
1011 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
1012 return NULL;
1013 return bqt->tag_index[tag];
1014}
1015
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016extern int blkdev_issue_flush(struct block_device *, sector_t *);
Christoph Hellwig746cd1e2009-09-12 07:35:43 +02001017#define DISCARD_FL_WAIT 0x01 /* wait for completion */
1018#define DISCARD_FL_BARRIER 0x02 /* issue DISCARD_BARRIER request */
1019extern int blkdev_issue_discard(struct block_device *, sector_t sector,
1020 sector_t nr_sects, gfp_t, int flags);
David Woodhousefb2dce82008-08-05 18:01:53 +01001021
1022static inline int sb_issue_discard(struct super_block *sb,
Hugh Dickins3e6053d2008-09-11 10:57:55 +02001023 sector_t block, sector_t nr_blocks)
David Woodhousefb2dce82008-08-05 18:01:53 +01001024{
1025 block <<= (sb->s_blocksize_bits - 9);
1026 nr_blocks <<= (sb->s_blocksize_bits - 9);
Christoph Hellwig746cd1e2009-09-12 07:35:43 +02001027 return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL,
1028 DISCARD_FL_BARRIER);
David Woodhousefb2dce82008-08-05 18:01:53 +01001029}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030
Jens Axboe018e0442009-06-26 16:27:10 +02001031extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
Adel Gadllah0b07de82008-06-26 13:48:27 +02001032
Linus Torvalds1da177e2005-04-16 15:20:36 -07001033#define MAX_PHYS_SEGMENTS 128
1034#define MAX_HW_SEGMENTS 128
Mike Christiedefd94b2005-12-05 02:37:06 -06001035#define SAFE_MAX_SECTORS 255
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036#define MAX_SEGMENT_SIZE 65536
1037
Martin K. Peterseneb28d312010-02-26 00:20:37 -05001038enum blk_default_limits {
1039 BLK_MAX_SEGMENTS = 128,
1040 BLK_SAFE_MAX_SECTORS = 255,
1041 BLK_DEF_MAX_SECTORS = 1024,
1042 BLK_MAX_SEGMENT_SIZE = 65536,
1043 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
1044};
Milan Broz0e435ac2008-12-03 12:55:08 +01001045
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1047
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001048static inline unsigned long queue_bounce_pfn(struct request_queue *q)
1049{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001050 return q->limits.bounce_pfn;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001051}
1052
1053static inline unsigned long queue_segment_boundary(struct request_queue *q)
1054{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001055 return q->limits.seg_boundary_mask;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001056}
1057
1058static inline unsigned int queue_max_sectors(struct request_queue *q)
1059{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001060 return q->limits.max_sectors;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001061}
1062
1063static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1064{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001065 return q->limits.max_hw_sectors;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001066}
1067
Martin K. Petersen8a783622010-02-26 00:20:39 -05001068static inline unsigned short queue_max_segments(struct request_queue *q)
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001069{
Martin K. Petersen8a783622010-02-26 00:20:39 -05001070 return q->limits.max_segments;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001071}
1072
1073static inline unsigned int queue_max_segment_size(struct request_queue *q)
1074{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001075 return q->limits.max_segment_size;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001076}
1077
Martin K. Petersene1defc42009-05-22 17:17:49 -04001078static inline unsigned short queue_logical_block_size(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079{
1080 int retval = 512;
1081
Martin K. Petersen025146e2009-05-22 17:17:51 -04001082 if (q && q->limits.logical_block_size)
1083 retval = q->limits.logical_block_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001084
1085 return retval;
1086}
1087
Martin K. Petersene1defc42009-05-22 17:17:49 -04001088static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001089{
Martin K. Petersene1defc42009-05-22 17:17:49 -04001090 return queue_logical_block_size(bdev_get_queue(bdev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001091}
1092
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001093static inline unsigned int queue_physical_block_size(struct request_queue *q)
1094{
1095 return q->limits.physical_block_size;
1096}
1097
Martin K. Petersenac481c22009-10-03 20:52:01 +02001098static inline int bdev_physical_block_size(struct block_device *bdev)
1099{
1100 return queue_physical_block_size(bdev_get_queue(bdev));
1101}
1102
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001103static inline unsigned int queue_io_min(struct request_queue *q)
1104{
1105 return q->limits.io_min;
1106}
1107
Martin K. Petersenac481c22009-10-03 20:52:01 +02001108static inline int bdev_io_min(struct block_device *bdev)
1109{
1110 return queue_io_min(bdev_get_queue(bdev));
1111}
1112
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001113static inline unsigned int queue_io_opt(struct request_queue *q)
1114{
1115 return q->limits.io_opt;
1116}
1117
Martin K. Petersenac481c22009-10-03 20:52:01 +02001118static inline int bdev_io_opt(struct block_device *bdev)
1119{
1120 return queue_io_opt(bdev_get_queue(bdev));
1121}
1122
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001123static inline int queue_alignment_offset(struct request_queue *q)
1124{
Martin K. Petersenac481c22009-10-03 20:52:01 +02001125 if (q->limits.misaligned)
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001126 return -1;
1127
Martin K. Petersenac481c22009-10-03 20:52:01 +02001128 return q->limits.alignment_offset;
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001129}
1130
Martin K. Petersene03a72e2010-01-11 03:21:51 -05001131static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
Martin K. Petersen81744ee2009-12-29 08:35:35 +01001132{
1133 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
Martin K. Petersene03a72e2010-01-11 03:21:51 -05001134 unsigned int alignment = (sector << 9) & (granularity - 1);
Martin K. Petersen81744ee2009-12-29 08:35:35 +01001135
Martin K. Petersene03a72e2010-01-11 03:21:51 -05001136 return (granularity + lim->alignment_offset - alignment)
1137 & (granularity - 1);
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001138}
1139
Martin K. Petersenac481c22009-10-03 20:52:01 +02001140static inline int bdev_alignment_offset(struct block_device *bdev)
1141{
1142 struct request_queue *q = bdev_get_queue(bdev);
1143
1144 if (q->limits.misaligned)
1145 return -1;
1146
1147 if (bdev != bdev->bd_contains)
1148 return bdev->bd_part->alignment_offset;
1149
1150 return q->limits.alignment_offset;
1151}
1152
Martin K. Petersen86b37282009-11-10 11:50:21 +01001153static inline int queue_discard_alignment(struct request_queue *q)
1154{
1155 if (q->limits.discard_misaligned)
1156 return -1;
1157
1158 return q->limits.discard_alignment;
1159}
1160
Martin K. Petersene03a72e2010-01-11 03:21:51 -05001161static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
Martin K. Petersen86b37282009-11-10 11:50:21 +01001162{
Martin K. Petersendd3d1452010-01-11 03:21:48 -05001163 unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
1164
1165 return (lim->discard_granularity + lim->discard_alignment - alignment)
1166 & (lim->discard_granularity - 1);
Martin K. Petersen86b37282009-11-10 11:50:21 +01001167}
1168
Martin K. Petersen98262f22009-12-03 09:24:48 +01001169static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1170{
1171 if (q->limits.discard_zeroes_data == 1)
1172 return 1;
1173
1174 return 0;
1175}
1176
1177static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1178{
1179 return queue_discard_zeroes_data(bdev_get_queue(bdev));
1180}
1181
Jens Axboe165125e2007-07-24 09:28:11 +02001182static inline int queue_dma_alignment(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183{
Pete Wyckoff482eb682008-01-01 10:23:02 -05001184 return q ? q->dma_alignment : 511;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185}
1186
FUJITA Tomonori87904072008-08-28 15:05:58 +09001187static inline int blk_rq_aligned(struct request_queue *q, void *addr,
1188 unsigned int len)
1189{
1190 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1191 return !((unsigned long)addr & alignment) && !(len & alignment);
1192}
1193
Linus Torvalds1da177e2005-04-16 15:20:36 -07001194/* assumes size > 256 */
1195static inline unsigned int blksize_bits(unsigned int size)
1196{
1197 unsigned int bits = 8;
1198 do {
1199 bits++;
1200 size >>= 1;
1201 } while (size > 256);
1202 return bits;
1203}
1204
Adrian Bunk2befb9e2005-09-10 00:27:17 -07001205static inline unsigned int block_size(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001206{
1207 return bdev->bd_block_size;
1208}
1209
1210typedef struct {struct page *v;} Sector;
1211
1212unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1213
1214static inline void put_dev_sector(Sector p)
1215{
1216 page_cache_release(p.v);
1217}
1218
1219struct work_struct;
Jens Axboe18887ad2008-07-28 13:08:45 +02001220int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001221
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222#define MODULE_ALIAS_BLOCKDEV(major,minor) \
1223 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1224#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1225 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1226
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001227#if defined(CONFIG_BLK_DEV_INTEGRITY)
1228
Jens Axboeb24498d2008-06-27 09:12:09 +02001229#define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1230#define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001231
1232struct blk_integrity_exchg {
1233 void *prot_buf;
1234 void *data_buf;
1235 sector_t sector;
1236 unsigned int data_size;
1237 unsigned short sector_size;
1238 const char *disk_name;
1239};
1240
1241typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1242typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1243typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1244typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1245
1246struct blk_integrity {
1247 integrity_gen_fn *generate_fn;
1248 integrity_vrfy_fn *verify_fn;
1249 integrity_set_tag_fn *set_tag_fn;
1250 integrity_get_tag_fn *get_tag_fn;
1251
1252 unsigned short flags;
1253 unsigned short tuple_size;
1254 unsigned short sector_size;
1255 unsigned short tag_size;
1256
1257 const char *name;
1258
1259 struct kobject kobj;
1260};
1261
1262extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1263extern void blk_integrity_unregister(struct gendisk *);
Martin K. Petersenad7fce92008-10-01 03:38:39 -04001264extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001265extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
1266extern int blk_rq_count_integrity_sg(struct request *);
1267
Jens Axboeb04accc2008-10-02 12:53:22 +02001268static inline
1269struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1270{
1271 return bdev->bd_disk->integrity;
1272}
1273
Martin K. Petersenb02739b2008-10-02 18:47:49 +02001274static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1275{
1276 return disk->integrity;
1277}
1278
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001279static inline int blk_integrity_rq(struct request *rq)
1280{
Martin K. Petersend442cc42008-07-16 16:09:06 -04001281 if (rq->bio == NULL)
1282 return 0;
1283
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001284 return bio_integrity(rq->bio);
1285}
1286
1287#else /* CONFIG_BLK_DEV_INTEGRITY */
1288
1289#define blk_integrity_rq(rq) (0)
1290#define blk_rq_count_integrity_sg(a) (0)
1291#define blk_rq_map_integrity_sg(a, b) (0)
Jens Axboeb04accc2008-10-02 12:53:22 +02001292#define bdev_get_integrity(a) (0)
Martin K. Petersenb02739b2008-10-02 18:47:49 +02001293#define blk_get_integrity(a) (0)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001294#define blk_integrity_compare(a, b) (0)
1295#define blk_integrity_register(a, b) (0)
1296#define blk_integrity_unregister(a) do { } while (0);
1297
1298#endif /* CONFIG_BLK_DEV_INTEGRITY */
1299
Al Viro08f85852007-10-08 13:26:20 -04001300struct block_device_operations {
Al Virod4430d62008-03-02 09:09:22 -05001301 int (*open) (struct block_device *, fmode_t);
1302 int (*release) (struct gendisk *, fmode_t);
1303 int (*locked_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1304 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1305 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
Al Viro08f85852007-10-08 13:26:20 -04001306 int (*direct_access) (struct block_device *, sector_t,
1307 void **, unsigned long *);
1308 int (*media_changed) (struct gendisk *);
Bartlomiej Zolnierkiewiczdb429e92009-06-07 13:52:52 +02001309 unsigned long long (*set_capacity) (struct gendisk *,
1310 unsigned long long);
Al Viro08f85852007-10-08 13:26:20 -04001311 int (*revalidate_disk) (struct gendisk *);
1312 int (*getgeo)(struct block_device *, struct hd_geometry *);
1313 struct module *owner;
1314};
1315
Al Viro633a08b2007-08-29 20:34:12 -04001316extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1317 unsigned long);
David Howells93614012006-09-30 20:45:40 +02001318#else /* CONFIG_BLOCK */
1319/*
1320 * stubs for when the block layer is configured out
1321 */
1322#define buffer_heads_over_limit 0
1323
David Howells93614012006-09-30 20:45:40 +02001324static inline long nr_blockdev_pages(void)
1325{
1326 return 0;
1327}
1328
David Howells93614012006-09-30 20:45:40 +02001329#endif /* CONFIG_BLOCK */
1330
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331#endif