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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
Jens Axboe1faa16d2009-04-06 14:48:01 +020073enum {
74 BLK_RW_ASYNC = 0,
75 BLK_RW_SYNC = 1,
76};
77
Jens Axboe4aff5e22006-08-10 08:44:47 +020078/*
79 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
80 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
81 * SCSI cdb.
82 *
83 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
84 * typically to differentiate REQ_TYPE_SPECIAL requests.
85 *
86 */
87enum {
Jens Axboe4aff5e22006-08-10 08:44:47 +020088 REQ_LB_OP_EJECT = 0x40, /* eject request */
David Woodhouse1a8e2bd2008-08-13 12:35:09 +010089 REQ_LB_OP_FLUSH = 0x41, /* flush request */
David Woodhouseeae9acd2008-08-05 18:08:25 +010090 REQ_LB_OP_DISCARD = 0x42, /* discard sectors */
Jens Axboe4aff5e22006-08-10 08:44:47 +020091};
92
93/*
David Woodhoused628eae2008-08-09 16:22:17 +010094 * request type modified bits. first two bits match BIO_RW* bits, important
Jens Axboe4aff5e22006-08-10 08:44:47 +020095 */
96enum rq_flag_bits {
97 __REQ_RW, /* not set, read. set, write */
Mike Christie6000a362008-08-19 18:45:30 -050098 __REQ_FAILFAST_DEV, /* no driver retries of device errors */
99 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
100 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
David Woodhousefb2dce82008-08-05 18:01:53 +0100101 __REQ_DISCARD, /* request to discard sectors */
Jens Axboe4aff5e22006-08-10 08:44:47 +0200102 __REQ_SORTED, /* elevator knows about this request */
103 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
104 __REQ_HARDBARRIER, /* may not be passed by drive either */
105 __REQ_FUA, /* forced unit access */
106 __REQ_NOMERGE, /* don't touch this for merging */
107 __REQ_STARTED, /* drive already may have started this one */
108 __REQ_DONTPREP, /* don't call prep for this one */
109 __REQ_QUEUED, /* uses queueing */
110 __REQ_ELVPRIV, /* elevator private data attached */
111 __REQ_FAILED, /* set if the request failed */
112 __REQ_QUIET, /* don't worry about errors */
113 __REQ_PREEMPT, /* set for "ide_preempt" requests */
114 __REQ_ORDERED_COLOR, /* is before or after barrier */
Jens Axboe1faa16d2009-04-06 14:48:01 +0200115 __REQ_RW_SYNC, /* request is sync (sync write or read) */
Jens Axboe49171e52006-08-10 08:59:11 +0200116 __REQ_ALLOCED, /* request came from our alloc pool */
Jens Axboe5404bc72006-08-10 09:01:02 +0200117 __REQ_RW_META, /* metadata io request */
FUJITA Tomonorif18573a2008-04-11 12:56:52 +0200118 __REQ_COPY_USER, /* contains copies of user pages */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200119 __REQ_INTEGRITY, /* integrity metadata has been remapped */
Jens Axboeaeb6faf2009-04-06 14:48:07 +0200120 __REQ_NOIDLE, /* Don't anticipate more IO after this one */
Jens Axboe4aff5e22006-08-10 08:44:47 +0200121 __REQ_NR_BITS, /* stops here */
122};
123
124#define REQ_RW (1 << __REQ_RW)
Mike Christie6000a362008-08-19 18:45:30 -0500125#define REQ_FAILFAST_DEV (1 << __REQ_FAILFAST_DEV)
126#define REQ_FAILFAST_TRANSPORT (1 << __REQ_FAILFAST_TRANSPORT)
127#define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER)
David Woodhousefb2dce82008-08-05 18:01:53 +0100128#define REQ_DISCARD (1 << __REQ_DISCARD)
Jens Axboe4aff5e22006-08-10 08:44:47 +0200129#define REQ_SORTED (1 << __REQ_SORTED)
130#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
131#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
132#define REQ_FUA (1 << __REQ_FUA)
133#define REQ_NOMERGE (1 << __REQ_NOMERGE)
134#define REQ_STARTED (1 << __REQ_STARTED)
135#define REQ_DONTPREP (1 << __REQ_DONTPREP)
136#define REQ_QUEUED (1 << __REQ_QUEUED)
137#define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
138#define REQ_FAILED (1 << __REQ_FAILED)
139#define REQ_QUIET (1 << __REQ_QUIET)
140#define REQ_PREEMPT (1 << __REQ_PREEMPT)
141#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
142#define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
Jens Axboe49171e52006-08-10 08:59:11 +0200143#define REQ_ALLOCED (1 << __REQ_ALLOCED)
Jens Axboe5404bc72006-08-10 09:01:02 +0200144#define REQ_RW_META (1 << __REQ_RW_META)
FUJITA Tomonorif18573a2008-04-11 12:56:52 +0200145#define REQ_COPY_USER (1 << __REQ_COPY_USER)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200146#define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
Jens Axboeaeb6faf2009-04-06 14:48:07 +0200147#define REQ_NOIDLE (1 << __REQ_NOIDLE)
Jens Axboe4aff5e22006-08-10 08:44:47 +0200148
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149#define BLK_MAX_CDB 16
150
151/*
Jens Axboe63a71382008-02-08 12:41:03 +0100152 * try to put the fields that are referenced together in the same cacheline.
153 * if you modify this structure, be sure to check block/blk-core.c:rq_init()
154 * as well!
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 */
156struct request {
Jens Axboeff856ba2006-01-09 16:02:34 +0100157 struct list_head queuelist;
Jens Axboec7c22e42008-09-13 20:26:01 +0200158 struct call_single_data csd;
159 int cpu;
Jens Axboeff856ba2006-01-09 16:02:34 +0100160
Jens Axboe165125e2007-07-24 09:28:11 +0200161 struct request_queue *q;
Jens Axboee6a1c872006-08-10 09:00:21 +0200162
Jens Axboe4aff5e22006-08-10 08:44:47 +0200163 unsigned int cmd_flags;
164 enum rq_cmd_type_bits cmd_type;
Jens Axboe242f9dc2008-09-14 05:55:09 -0700165 unsigned long atomic_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166
167 /* Maintain bio traversal state for part by part I/O submission.
168 * hard_* are block layer internals, no driver should touch them!
169 */
170
171 sector_t sector; /* next sector to submit */
Jens Axboee6a1c872006-08-10 09:00:21 +0200172 sector_t hard_sector; /* next sector to complete */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 unsigned long nr_sectors; /* no. of sectors left to submit */
Jens Axboee6a1c872006-08-10 09:00:21 +0200174 unsigned long hard_nr_sectors; /* no. of sectors left to complete */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 /* no. of sectors left to submit in the current segment */
176 unsigned int current_nr_sectors;
177
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 /* no. of sectors left to complete in the current segment */
179 unsigned int hard_cur_sectors;
180
181 struct bio *bio;
182 struct bio *biotail;
183
Jens Axboe98170642006-07-28 09:23:08 +0200184 struct hlist_node hash; /* merge hash */
Jens Axboee6a1c872006-08-10 09:00:21 +0200185 /*
186 * The rb_node is only used inside the io scheduler, requests
187 * are pruned when moved to the dispatch queue. So let the
188 * completion_data share space with the rb_node.
189 */
190 union {
191 struct rb_node rb_node; /* sort/lookup */
192 void *completion_data;
193 };
Jens Axboe98170642006-07-28 09:23:08 +0200194
Jens Axboeff7d1452006-07-12 14:04:37 +0200195 /*
196 * two pointers are available for the IO schedulers, if they need
197 * more they have to dynamically allocate it.
198 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 void *elevator_private;
Jens Axboeff7d1452006-07-12 14:04:37 +0200200 void *elevator_private2;
201
Jens Axboe8f34ee72006-06-13 09:02:34 +0200202 struct gendisk *rq_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 unsigned long start_time;
204
205 /* Number of scatter-gather DMA addr+len pairs after
206 * physical address coalescing is performed.
207 */
208 unsigned short nr_phys_segments;
209
Jens Axboe8f34ee72006-06-13 09:02:34 +0200210 unsigned short ioprio;
211
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 void *special;
Jens Axboe8f34ee72006-06-13 09:02:34 +0200213 char *buffer;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214
Jens Axboecdd60262006-07-28 09:32:07 +0200215 int tag;
216 int errors;
217
218 int ref_count;
219
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 /*
221 * when request is used as a packet command carrier
222 */
FUJITA Tomonorid7e3c322008-04-29 09:54:39 +0200223 unsigned short cmd_len;
224 unsigned char __cmd[BLK_MAX_CDB];
225 unsigned char *cmd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
227 unsigned int data_len;
FUJITA Tomonori7a85f882008-03-04 11:17:11 +0100228 unsigned int extra_len; /* length of alignment and padding */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 unsigned int sense_len;
Jens Axboe8f34ee72006-06-13 09:02:34 +0200230 void *data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 void *sense;
232
Jens Axboe242f9dc2008-09-14 05:55:09 -0700233 unsigned long deadline;
234 struct list_head timeout_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 unsigned int timeout;
Mike Christie17e01f22005-11-11 05:31:37 -0600236 int retries;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237
238 /*
Jens Axboec00895a2006-09-30 20:29:12 +0200239 * completion callback.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 */
241 rq_end_io_fn *end_io;
242 void *end_io_data;
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200243
244 /* for bidi */
245 struct request *next_rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246};
247
Fernando Luis Vázquez Cao766ca442008-08-14 09:59:13 +0200248static inline unsigned short req_get_ioprio(struct request *req)
249{
250 return req->ioprio;
251}
252
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253/*
Jens Axboe4aff5e22006-08-10 08:44:47 +0200254 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 * requests. Some step values could eventually be made generic.
256 */
257struct request_pm_state
258{
259 /* PM state machine step value, currently driver specific */
260 int pm_step;
261 /* requested PM state value (S1, S2, S3, S4, ...) */
262 u32 pm_state;
263 void* data; /* for driver use */
264};
265
266#include <linux/elevator.h>
267
Jens Axboe165125e2007-07-24 09:28:11 +0200268typedef void (request_fn_proc) (struct request_queue *q);
269typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
270typedef int (prep_rq_fn) (struct request_queue *, struct request *);
271typedef void (unplug_fn) (struct request_queue *);
David Woodhousefb2dce82008-08-05 18:01:53 +0100272typedef int (prepare_discard_fn) (struct request_queue *, struct request *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273
274struct bio_vec;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200275struct bvec_merge_data {
276 struct block_device *bi_bdev;
277 sector_t bi_sector;
278 unsigned bi_size;
279 unsigned long bi_rw;
280};
281typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
282 struct bio_vec *);
Jens Axboe165125e2007-07-24 09:28:11 +0200283typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
Jens Axboeff856ba2006-01-09 16:02:34 +0100284typedef void (softirq_done_fn)(struct request *);
Tejun Heo2fb98e82008-02-19 11:36:53 +0100285typedef int (dma_drain_needed_fn)(struct request *);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200286typedef int (lld_busy_fn) (struct request_queue *q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287
Jens Axboe242f9dc2008-09-14 05:55:09 -0700288enum blk_eh_timer_return {
289 BLK_EH_NOT_HANDLED,
290 BLK_EH_HANDLED,
291 BLK_EH_RESET_TIMER,
292};
293
294typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
295
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296enum blk_queue_state {
297 Queue_down,
298 Queue_up,
299};
300
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301struct blk_queue_tag {
302 struct request **tag_index; /* map of busy tags */
303 unsigned long *tag_map; /* bit map of free/busy tags */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 int busy; /* current depth */
305 int max_depth; /* what we will send to device */
Tejun Heoba025082005-08-05 13:28:11 -0700306 int real_max_depth; /* what the array can hold */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 atomic_t refcnt; /* map can be shared */
308};
309
FUJITA Tomonoriabf54392008-08-16 14:10:05 +0900310#define BLK_SCSI_MAX_CMDS (256)
311#define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
312
FUJITA Tomonori4beab5c2008-07-26 18:03:25 +0900313struct blk_cmd_filter {
FUJITA Tomonoriabf54392008-08-16 14:10:05 +0900314 unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
315 unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
316 struct kobject kobj;
317};
318
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319struct request_queue
320{
321 /*
322 * Together with queue_head for cacheline sharing
323 */
324 struct list_head queue_head;
325 struct request *last_merge;
Jens Axboeb374d182008-10-31 10:05:07 +0100326 struct elevator_queue *elevator;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327
328 /*
329 * the queue request freelist, one for reads and one for writes
330 */
331 struct request_list rq;
332
333 request_fn_proc *request_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 make_request_fn *make_request_fn;
335 prep_rq_fn *prep_rq_fn;
336 unplug_fn *unplug_fn;
David Woodhousefb2dce82008-08-05 18:01:53 +0100337 prepare_discard_fn *prepare_discard_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 merge_bvec_fn *merge_bvec_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 prepare_flush_fn *prepare_flush_fn;
Jens Axboeff856ba2006-01-09 16:02:34 +0100340 softirq_done_fn *softirq_done_fn;
Jens Axboe242f9dc2008-09-14 05:55:09 -0700341 rq_timed_out_fn *rq_timed_out_fn;
Tejun Heo2fb98e82008-02-19 11:36:53 +0100342 dma_drain_needed_fn *dma_drain_needed;
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200343 lld_busy_fn *lld_busy_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344
345 /*
Tejun Heo8922e162005-10-20 16:23:44 +0200346 * Dispatch queue sorting
347 */
Jens Axboe1b47f532005-10-20 16:37:00 +0200348 sector_t end_sector;
Tejun Heo8922e162005-10-20 16:23:44 +0200349 struct request *boundary_rq;
Tejun Heo8922e162005-10-20 16:23:44 +0200350
351 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 * Auto-unplugging state
353 */
354 struct timer_list unplug_timer;
355 int unplug_thresh; /* After this many requests */
356 unsigned long unplug_delay; /* After this many jiffies */
357 struct work_struct unplug_work;
358
359 struct backing_dev_info backing_dev_info;
360
361 /*
362 * The queue owner gets to use this for whatever they like.
363 * ll_rw_blk doesn't touch it.
364 */
365 void *queuedata;
366
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 /*
368 * queue needs bounce pages for pages above this limit
369 */
370 unsigned long bounce_pfn;
Al Viro8267e262005-10-21 03:20:53 -0400371 gfp_t bounce_gfp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372
373 /*
374 * various queue flags, see QUEUE_* below
375 */
376 unsigned long queue_flags;
377
378 /*
152587d2005-04-12 16:22:06 -0500379 * protects queue structures from reentrancy. ->__queue_lock should
380 * _never_ be used directly, it is queue private. always use
381 * ->queue_lock.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 */
152587d2005-04-12 16:22:06 -0500383 spinlock_t __queue_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 spinlock_t *queue_lock;
385
386 /*
387 * queue kobject
388 */
389 struct kobject kobj;
390
391 /*
392 * queue settings
393 */
394 unsigned long nr_requests; /* Max # of requests */
395 unsigned int nr_congestion_on;
396 unsigned int nr_congestion_off;
397 unsigned int nr_batching;
398
Jens Axboe2cb2e142006-01-17 09:04:32 +0100399 unsigned int max_sectors;
400 unsigned int max_hw_sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 unsigned short max_phys_segments;
402 unsigned short max_hw_segments;
403 unsigned short hardsect_size;
404 unsigned int max_segment_size;
405
406 unsigned long seg_boundary_mask;
James Bottomleyfa0ccd82008-01-10 11:30:36 -0600407 void *dma_drain_buffer;
408 unsigned int dma_drain_size;
Tejun Heoe3790c72008-03-04 11:18:17 +0100409 unsigned int dma_pad_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 unsigned int dma_alignment;
411
412 struct blk_queue_tag *queue_tags;
Jens Axboe6eca9002007-10-25 10:14:47 +0200413 struct list_head tag_busy_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414
Tejun Heo15853af2005-11-10 08:52:05 +0100415 unsigned int nr_sorted;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 unsigned int in_flight;
417
Jens Axboe242f9dc2008-09-14 05:55:09 -0700418 unsigned int rq_timeout;
419 struct timer_list timeout;
420 struct list_head timeout_list;
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
FUJITA Tomonori4beab5c2008-07-26 18:03:25 +0900444 struct blk_cmd_filter cmd_filter;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445};
446
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447#define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
448#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
449#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
Jens Axboe1faa16d2009-04-06 14:48:01 +0200450#define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
451#define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452#define QUEUE_FLAG_DEAD 5 /* queue being torn down */
453#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
454#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
Jens Axboe64521d12005-10-28 08:30:39 +0200455#define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200456#define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200457#define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
Jens Axboec7c22e42008-09-13 20:26:01 +0200458#define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
Jens Axboe581d4e22008-09-14 05:56:33 -0700459#define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
Kiyoshi Ueda4ee5eaf2008-09-18 10:46:13 -0400460#define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
Jens Axboea68bbdd2008-09-24 13:03:33 +0200461#define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
Fernando Luis Vázquez Cao88e740f2008-10-27 18:44:46 +0900462#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
Jens Axboebc58ba92009-01-23 10:54:44 +0100463#define QUEUE_FLAG_IO_STAT 15 /* do IO stats */
464
465#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
466 (1 << QUEUE_FLAG_CLUSTER) | \
Jens Axboe0648e102009-02-02 08:43:48 +0100467 (1 << QUEUE_FLAG_STACKABLE))
Tejun Heo797e7db2006-01-06 09:51:03 +0100468
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700469static inline int queue_is_locked(struct request_queue *q)
470{
Jens Axboe7663c1e2008-04-29 21:31:27 +0200471#ifdef CONFIG_SMP
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700472 spinlock_t *lock = q->queue_lock;
473 return lock && spin_is_locked(lock);
Jens Axboe7663c1e2008-04-29 21:31:27 +0200474#else
475 return 1;
476#endif
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700477}
478
Nick Piggin75ad23b2008-04-29 14:48:33 +0200479static inline void queue_flag_set_unlocked(unsigned int flag,
480 struct request_queue *q)
481{
482 __set_bit(flag, &q->queue_flags);
483}
484
Jens Axboee48ec692008-07-03 13:18:54 +0200485static inline int queue_flag_test_and_clear(unsigned int flag,
486 struct request_queue *q)
487{
488 WARN_ON_ONCE(!queue_is_locked(q));
489
490 if (test_bit(flag, &q->queue_flags)) {
491 __clear_bit(flag, &q->queue_flags);
492 return 1;
493 }
494
495 return 0;
496}
497
498static inline int queue_flag_test_and_set(unsigned int flag,
499 struct request_queue *q)
500{
501 WARN_ON_ONCE(!queue_is_locked(q));
502
503 if (!test_bit(flag, &q->queue_flags)) {
504 __set_bit(flag, &q->queue_flags);
505 return 0;
506 }
507
508 return 1;
509}
510
Nick Piggin75ad23b2008-04-29 14:48:33 +0200511static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
512{
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700513 WARN_ON_ONCE(!queue_is_locked(q));
Nick Piggin75ad23b2008-04-29 14:48:33 +0200514 __set_bit(flag, &q->queue_flags);
515}
516
517static inline void queue_flag_clear_unlocked(unsigned int flag,
518 struct request_queue *q)
519{
520 __clear_bit(flag, &q->queue_flags);
521}
522
523static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
524{
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700525 WARN_ON_ONCE(!queue_is_locked(q));
Nick Piggin75ad23b2008-04-29 14:48:33 +0200526 __clear_bit(flag, &q->queue_flags);
527}
528
Tejun Heo797e7db2006-01-06 09:51:03 +0100529enum {
530 /*
531 * Hardbarrier is supported with one of the following methods.
532 *
533 * NONE : hardbarrier unsupported
534 * DRAIN : ordering by draining is enough
535 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
536 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
537 * TAG : ordering by tag is enough
538 * TAG_FLUSH : ordering by tag w/ pre and post flushes
539 * TAG_FUA : ordering by tag w/ pre flush and FUA write
540 */
Tejun Heo313e4292008-11-28 13:32:02 +0900541 QUEUE_ORDERED_BY_DRAIN = 0x01,
542 QUEUE_ORDERED_BY_TAG = 0x02,
543 QUEUE_ORDERED_DO_PREFLUSH = 0x10,
Tejun Heof6716202008-11-28 13:32:04 +0900544 QUEUE_ORDERED_DO_BAR = 0x20,
Tejun Heo313e4292008-11-28 13:32:02 +0900545 QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
546 QUEUE_ORDERED_DO_FUA = 0x80,
Tejun Heo797e7db2006-01-06 09:51:03 +0100547
Tejun Heo313e4292008-11-28 13:32:02 +0900548 QUEUE_ORDERED_NONE = 0x00,
Tejun Heo797e7db2006-01-06 09:51:03 +0100549
Tejun Heof6716202008-11-28 13:32:04 +0900550 QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_BY_DRAIN |
551 QUEUE_ORDERED_DO_BAR,
Tejun Heo313e4292008-11-28 13:32:02 +0900552 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
553 QUEUE_ORDERED_DO_PREFLUSH |
554 QUEUE_ORDERED_DO_POSTFLUSH,
555 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
556 QUEUE_ORDERED_DO_PREFLUSH |
557 QUEUE_ORDERED_DO_FUA,
558
Tejun Heof6716202008-11-28 13:32:04 +0900559 QUEUE_ORDERED_TAG = QUEUE_ORDERED_BY_TAG |
560 QUEUE_ORDERED_DO_BAR,
Tejun Heo313e4292008-11-28 13:32:02 +0900561 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
562 QUEUE_ORDERED_DO_PREFLUSH |
563 QUEUE_ORDERED_DO_POSTFLUSH,
564 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
565 QUEUE_ORDERED_DO_PREFLUSH |
566 QUEUE_ORDERED_DO_FUA,
Tejun Heo797e7db2006-01-06 09:51:03 +0100567
568 /*
569 * Ordered operation sequence
570 */
571 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
572 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
573 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
574 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
575 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
576 QUEUE_ORDSEQ_DONE = 0x20,
577};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578
579#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
580#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
581#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200582#define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
Jens Axboea68bbdd2008-09-24 13:03:33 +0200583#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
Jens Axboebc58ba92009-01-23 10:54:44 +0100584#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
Tejun Heo797e7db2006-01-06 09:51:03 +0100585#define blk_queue_flushing(q) ((q)->ordseq)
Kiyoshi Ueda4ee5eaf2008-09-18 10:46:13 -0400586#define blk_queue_stackable(q) \
587 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588
Jens Axboe4aff5e22006-08-10 08:44:47 +0200589#define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
590#define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
591#define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
592#define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
593
Mike Christie6000a362008-08-19 18:45:30 -0500594#define blk_failfast_dev(rq) ((rq)->cmd_flags & REQ_FAILFAST_DEV)
595#define blk_failfast_transport(rq) ((rq)->cmd_flags & REQ_FAILFAST_TRANSPORT)
596#define blk_failfast_driver(rq) ((rq)->cmd_flags & REQ_FAILFAST_DRIVER)
597#define blk_noretry_request(rq) (blk_failfast_dev(rq) || \
598 blk_failfast_transport(rq) || \
599 blk_failfast_driver(rq))
Jens Axboe4aff5e22006-08-10 08:44:47 +0200600#define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601
David Woodhousee17fc0a2008-08-09 16:42:20 +0100602#define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603
Jens Axboe4aff5e22006-08-10 08:44:47 +0200604#define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
605#define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606#define blk_pm_request(rq) \
Jens Axboe4aff5e22006-08-10 08:44:47 +0200607 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608
Jens Axboeab780f12008-08-26 10:25:02 +0200609#define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
Jens Axboe4aff5e22006-08-10 08:44:47 +0200610#define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
611#define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
612#define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
David Woodhousefb2dce82008-08-05 18:01:53 +0100613#define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200614#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
Kiyoshi Ueda336cdb42007-12-11 17:40:30 -0500615/* rq->queuelist of dequeued request must be list_empty() */
616#define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617
618#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
619
Jens Axboe4aff5e22006-08-10 08:44:47 +0200620#define rq_data_dir(rq) ((rq)->cmd_flags & 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621
Jens Axboe9e2585a2006-07-28 09:26:13 +0200622/*
Jens Axboe1faa16d2009-04-06 14:48:01 +0200623 * We regard a request as sync, if either a read or a sync write
Jens Axboe9e2585a2006-07-28 09:26:13 +0200624 */
Jens Axboe1faa16d2009-04-06 14:48:01 +0200625static inline bool rw_is_sync(unsigned int rw_flags)
626{
627 return !(rw_flags & REQ_RW) || (rw_flags & REQ_RW_SYNC);
628}
629
630static inline bool rq_is_sync(struct request *rq)
631{
632 return rw_is_sync(rq->cmd_flags);
633}
634
Jens Axboe5404bc72006-08-10 09:01:02 +0200635#define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
Jens Axboeaeb6faf2009-04-06 14:48:07 +0200636#define rq_noidle(rq) ((rq)->cmd_flags & REQ_NOIDLE)
Jens Axboe9e2585a2006-07-28 09:26:13 +0200637
Jens Axboe1faa16d2009-04-06 14:48:01 +0200638static inline int blk_queue_full(struct request_queue *q, int sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639{
Jens Axboe1faa16d2009-04-06 14:48:01 +0200640 if (sync)
641 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
642 return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643}
644
Jens Axboe1faa16d2009-04-06 14:48:01 +0200645static inline void blk_set_queue_full(struct request_queue *q, int sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646{
Jens Axboe1faa16d2009-04-06 14:48:01 +0200647 if (sync)
648 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 else
Jens Axboe1faa16d2009-04-06 14:48:01 +0200650 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651}
652
Jens Axboe1faa16d2009-04-06 14:48:01 +0200653static inline void blk_clear_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_clear(QUEUE_FLAG_SYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 else
Jens Axboe1faa16d2009-04-06 14:48:01 +0200658 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659}
660
661
662/*
663 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
664 * it already be started by driver.
665 */
666#define RQ_NOMERGE_FLAGS \
667 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
668#define rq_mergeable(rq) \
David Woodhousee17fc0a2008-08-09 16:42:20 +0100669 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
670 (blk_discard_rq(rq) || blk_fs_request((rq))))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671
672/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 * q->prep_rq_fn return values
674 */
675#define BLKPREP_OK 0 /* serve it */
676#define BLKPREP_KILL 1 /* fatal error, kill */
677#define BLKPREP_DEFER 2 /* leave on queue */
678
679extern unsigned long blk_max_low_pfn, blk_max_pfn;
680
681/*
682 * standard bounce addresses:
683 *
684 * BLK_BOUNCE_HIGH : bounce all highmem pages
685 * BLK_BOUNCE_ANY : don't bounce anything
686 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
687 */
Andi Kleen24728922008-04-21 09:51:05 +0200688
689#if BITS_PER_LONG == 32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
Andi Kleen24728922008-04-21 09:51:05 +0200691#else
692#define BLK_BOUNCE_HIGH -1ULL
693#endif
694#define BLK_BOUNCE_ANY (-1ULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695#define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
696
Jens Axboe3d6392c2007-07-09 12:38:05 +0200697/*
698 * default timeout for SG_IO if none specified
699 */
700#define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
Linus Torvaldsf2f1fa72008-12-05 14:49:18 -0800701#define BLK_MIN_SG_TIMEOUT (7 * HZ)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200702
Christoph Lameter2a7326b2007-07-17 04:03:37 -0700703#ifdef CONFIG_BOUNCE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704extern int init_emergency_isa_pool(void);
Jens Axboe165125e2007-07-24 09:28:11 +0200705extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706#else
707static inline int init_emergency_isa_pool(void)
708{
709 return 0;
710}
Jens Axboe165125e2007-07-24 09:28:11 +0200711static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712{
713}
714#endif /* CONFIG_MMU */
715
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900716struct rq_map_data {
717 struct page **pages;
718 int page_order;
719 int nr_entries;
FUJITA Tomonori56c451f2008-12-18 14:49:37 +0900720 unsigned long offset;
FUJITA Tomonori97ae77a2008-12-18 14:49:38 +0900721 int null_mapped;
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900722};
723
NeilBrown5705f702007-09-25 12:35:59 +0200724struct req_iterator {
725 int i;
726 struct bio *bio;
727};
728
729/* This should not be used directly - use rq_for_each_segment */
Jens Axboe1e428072009-02-23 09:03:10 +0100730#define for_each_bio(_bio) \
731 for (; _bio; _bio = _bio->bi_next)
NeilBrown5705f702007-09-25 12:35:59 +0200732#define __rq_for_each_bio(_bio, rq) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 if ((rq->bio)) \
734 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
735
NeilBrown5705f702007-09-25 12:35:59 +0200736#define rq_for_each_segment(bvl, _rq, _iter) \
737 __rq_for_each_bio(_iter.bio, _rq) \
738 bio_for_each_segment(bvl, _iter.bio, _iter.i)
739
740#define rq_iter_last(rq, _iter) \
741 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
742
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743extern int blk_register_queue(struct gendisk *disk);
744extern void blk_unregister_queue(struct gendisk *disk);
745extern void register_disk(struct gendisk *dev);
746extern void generic_make_request(struct bio *bio);
FUJITA Tomonori2a4aa302008-04-29 09:54:36 +0200747extern void blk_rq_init(struct request_queue *q, struct request *rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748extern void blk_put_request(struct request *);
Jens Axboe165125e2007-07-24 09:28:11 +0200749extern void __blk_put_request(struct request_queue *, struct request *);
Jens Axboe165125e2007-07-24 09:28:11 +0200750extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
751extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
752extern void blk_requeue_request(struct request_queue *, struct request *);
Kiyoshi Ueda82124d62008-09-18 10:45:38 -0400753extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200754extern int blk_lld_busy(struct request_queue *q);
Kiyoshi Ueda82124d62008-09-18 10:45:38 -0400755extern int blk_insert_cloned_request(struct request_queue *q,
756 struct request *rq);
Jens Axboe165125e2007-07-24 09:28:11 +0200757extern void blk_plug_device(struct request_queue *);
Jens Axboe6c5e0c42008-08-01 20:31:32 +0200758extern void blk_plug_device_unlocked(struct request_queue *);
Jens Axboe165125e2007-07-24 09:28:11 +0200759extern int blk_remove_plug(struct request_queue *);
760extern void blk_recount_segments(struct request_queue *, struct bio *);
Al Viro74f3c8a2007-08-27 15:38:10 -0400761extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
762 unsigned int, void __user *);
Al Viroe915e872008-09-02 17:16:41 -0400763extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
764 struct scsi_ioctl_command __user *);
Andrew Morton3fcfab12006-10-19 23:28:16 -0700765
766/*
Jens Axboe1aa4f242006-12-19 08:33:11 +0100767 * Temporary export, until SCSI gets fixed up.
768 */
NeilBrown3001ca72007-08-16 13:31:27 +0200769extern int blk_rq_append_bio(struct request_queue *q, struct request *rq,
770 struct bio *bio);
Jens Axboe1aa4f242006-12-19 08:33:11 +0100771
772/*
Andrew Morton3fcfab12006-10-19 23:28:16 -0700773 * A queue has just exitted congestion. Note this in the global counter of
774 * congested queues, and wake up anyone who was waiting for requests to be
775 * put back.
776 */
Jens Axboe165125e2007-07-24 09:28:11 +0200777static inline void blk_clear_queue_congested(struct request_queue *q, int rw)
Andrew Morton3fcfab12006-10-19 23:28:16 -0700778{
779 clear_bdi_congested(&q->backing_dev_info, rw);
780}
781
782/*
783 * A queue has just entered congestion. Flag that in the queue's VM-visible
784 * state flags and increment the global gounter of congested queues.
785 */
Jens Axboe165125e2007-07-24 09:28:11 +0200786static inline void blk_set_queue_congested(struct request_queue *q, int rw)
Andrew Morton3fcfab12006-10-19 23:28:16 -0700787{
788 set_bdi_congested(&q->backing_dev_info, rw);
789}
790
Jens Axboe165125e2007-07-24 09:28:11 +0200791extern void blk_start_queue(struct request_queue *q);
792extern void blk_stop_queue(struct request_queue *q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793extern void blk_sync_queue(struct request_queue *q);
Jens Axboe165125e2007-07-24 09:28:11 +0200794extern void __blk_stop_queue(struct request_queue *q);
Nick Piggin75ad23b2008-04-29 14:48:33 +0200795extern void __blk_run_queue(struct request_queue *);
Jens Axboe165125e2007-07-24 09:28:11 +0200796extern void blk_run_queue(struct request_queue *);
797extern void blk_start_queueing(struct request_queue *);
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900798extern int blk_rq_map_user(struct request_queue *, struct request *,
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900799 struct rq_map_data *, void __user *, unsigned long,
800 gfp_t);
Jens Axboe8e5cfc42006-12-19 11:12:46 +0100801extern int blk_rq_unmap_user(struct bio *);
Jens Axboe165125e2007-07-24 09:28:11 +0200802extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
803extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900804 struct rq_map_data *, struct sg_iovec *, int,
805 unsigned int, gfp_t);
Jens Axboe165125e2007-07-24 09:28:11 +0200806extern int blk_execute_rq(struct request_queue *, struct gendisk *,
James Bottomley 994ca9a2005-06-20 14:11:09 +0200807 struct request *, int);
Jens Axboe165125e2007-07-24 09:28:11 +0200808extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
Jens Axboe15fc8582006-01-06 10:00:50 +0100809 struct request *, int, rq_end_io_fn *);
Alan D. Brunelle2ad8b1e2007-11-07 14:26:56 -0500810extern void blk_unplug(struct request_queue *q);
Mike Christie6e39b69e2005-11-11 05:30:24 -0600811
Jens Axboe165125e2007-07-24 09:28:11 +0200812static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813{
814 return bdev->bd_disk->queue;
815}
816
817static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
818 struct page *page)
819{
820 if (bdi && bdi->unplug_io_fn)
821 bdi->unplug_io_fn(bdi, page);
822}
823
824static inline void blk_run_address_space(struct address_space *mapping)
825{
826 if (mapping)
827 blk_run_backing_dev(mapping->backing_dev_info, NULL);
828}
829
Tejun Heo53a08802008-12-03 12:41:26 +0100830extern void blkdev_dequeue_request(struct request *req);
831
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832/*
Kiyoshi Ueda3bcddea2007-12-11 17:52:28 -0500833 * blk_end_request() and friends.
834 * __blk_end_request() and end_request() must be called with
835 * the request queue spinlock acquired.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836 *
837 * Several drivers define their own end_request and call
Kiyoshi Ueda3bcddea2007-12-11 17:52:28 -0500838 * blk_end_request() for parts of the original function.
839 * This prevents code duplication in drivers.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700840 */
Jens Axboe22b13212008-01-31 12:36:19 +0100841extern int blk_end_request(struct request *rq, int error,
842 unsigned int nr_bytes);
843extern int __blk_end_request(struct request *rq, int error,
844 unsigned int nr_bytes);
845extern int blk_end_bidi_request(struct request *rq, int error,
846 unsigned int nr_bytes, unsigned int bidi_bytes);
Jens Axboea0cd1282007-09-21 10:41:07 +0200847extern void end_request(struct request *, int);
Jens Axboe22b13212008-01-31 12:36:19 +0100848extern int blk_end_request_callback(struct request *rq, int error,
849 unsigned int nr_bytes,
850 int (drv_callback)(struct request *));
Jens Axboeff856ba2006-01-09 16:02:34 +0100851extern void blk_complete_request(struct request *);
Jens Axboe242f9dc2008-09-14 05:55:09 -0700852extern void __blk_complete_request(struct request *);
853extern void blk_abort_request(struct request *);
Mike Anderson11914a52008-09-13 20:31:27 +0200854extern void blk_abort_queue(struct request_queue *);
Kiyoshi Ueda32fab442008-09-18 10:45:09 -0400855extern void blk_update_request(struct request *rq, int error,
856 unsigned int nr_bytes);
Jens Axboeff856ba2006-01-09 16:02:34 +0100857
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858/*
Kiyoshi Ueda3b113132007-12-11 17:41:17 -0500859 * blk_end_request() takes bytes instead of sectors as a complete size.
860 * blk_rq_bytes() returns bytes left to complete in the entire request.
861 * blk_rq_cur_bytes() returns bytes left to complete in the current segment.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862 */
Kiyoshi Ueda3b113132007-12-11 17:41:17 -0500863extern unsigned int blk_rq_bytes(struct request *rq);
864extern unsigned int blk_rq_cur_bytes(struct request *rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866/*
867 * Access functions for manipulating queue properties
868 */
Jens Axboe165125e2007-07-24 09:28:11 +0200869extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
Christoph Lameter19460892005-06-23 00:08:19 -0700870 spinlock_t *lock, int node_id);
Jens Axboe165125e2007-07-24 09:28:11 +0200871extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
872extern void blk_cleanup_queue(struct request_queue *);
873extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
874extern void blk_queue_bounce_limit(struct request_queue *, u64);
875extern void blk_queue_max_sectors(struct request_queue *, unsigned int);
876extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short);
877extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short);
878extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
879extern void blk_queue_hardsect_size(struct request_queue *, unsigned short);
880extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
Tejun Heoe3790c72008-03-04 11:18:17 +0100881extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
FUJITA Tomonori27f82212008-07-04 09:30:03 +0200882extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
Tejun Heo2fb98e82008-02-19 11:36:53 +0100883extern int blk_queue_dma_drain(struct request_queue *q,
884 dma_drain_needed_fn *dma_drain_needed,
885 void *buf, unsigned int size);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200886extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
Jens Axboe165125e2007-07-24 09:28:11 +0200887extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
888extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
889extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
890extern void blk_queue_dma_alignment(struct request_queue *, int);
James Bottomley11c3e682007-12-31 16:37:00 -0600891extern void blk_queue_update_dma_alignment(struct request_queue *, int);
Jens Axboe165125e2007-07-24 09:28:11 +0200892extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
David Woodhousefb2dce82008-08-05 18:01:53 +0100893extern void blk_queue_set_discard(struct request_queue *, prepare_discard_fn *);
Jens Axboe242f9dc2008-09-14 05:55:09 -0700894extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
895extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
Jens Axboe165125e2007-07-24 09:28:11 +0200897extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
Tejun Heo8f11b3e2008-11-28 13:32:05 +0900898extern bool blk_do_ordered(struct request_queue *, struct request **);
Jens Axboe165125e2007-07-24 09:28:11 +0200899extern unsigned blk_ordered_cur_seq(struct request_queue *);
Tejun Heo797e7db2006-01-06 09:51:03 +0100900extern unsigned blk_ordered_req_seq(struct request *);
Tejun Heo8f11b3e2008-11-28 13:32:05 +0900901extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902
Jens Axboe165125e2007-07-24 09:28:11 +0200903extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904extern void blk_dump_rq_flags(struct request *, char *);
Jens Axboe165125e2007-07-24 09:28:11 +0200905extern void generic_unplug_device(struct request_queue *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906extern long nr_blockdev_pages(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907
Jens Axboe165125e2007-07-24 09:28:11 +0200908int blk_get_queue(struct request_queue *);
909struct request_queue *blk_alloc_queue(gfp_t);
910struct request_queue *blk_alloc_queue_node(gfp_t, int);
911extern void blk_put_queue(struct request_queue *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912
913/*
914 * tag stuff
915 */
Jens Axboe4aff5e22006-08-10 08:44:47 +0200916#define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
Jens Axboe165125e2007-07-24 09:28:11 +0200917extern int blk_queue_start_tag(struct request_queue *, struct request *);
918extern struct request *blk_queue_find_tag(struct request_queue *, int);
919extern void blk_queue_end_tag(struct request_queue *, struct request *);
920extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
921extern void blk_queue_free_tags(struct request_queue *);
922extern int blk_queue_resize_tags(struct request_queue *, int);
923extern void blk_queue_invalidate_tags(struct request_queue *);
James Bottomley492dfb42006-08-30 15:48:45 -0400924extern struct blk_queue_tag *blk_init_tags(int);
925extern void blk_free_tags(struct blk_queue_tag *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926
David C Somayajuluf583f492006-10-04 08:27:25 +0200927static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
928 int tag)
929{
930 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
931 return NULL;
932 return bqt->tag_index[tag];
933}
934
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935extern int blkdev_issue_flush(struct block_device *, sector_t *);
Hugh Dickins3e6053d2008-09-11 10:57:55 +0200936extern int blkdev_issue_discard(struct block_device *,
937 sector_t sector, sector_t nr_sects, gfp_t);
David Woodhousefb2dce82008-08-05 18:01:53 +0100938
939static inline int sb_issue_discard(struct super_block *sb,
Hugh Dickins3e6053d2008-09-11 10:57:55 +0200940 sector_t block, sector_t nr_blocks)
David Woodhousefb2dce82008-08-05 18:01:53 +0100941{
942 block <<= (sb->s_blocksize_bits - 9);
943 nr_blocks <<= (sb->s_blocksize_bits - 9);
Hugh Dickins3e6053d2008-09-11 10:57:55 +0200944 return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL);
David Woodhousefb2dce82008-08-05 18:01:53 +0100945}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946
Adel Gadllah0b07de82008-06-26 13:48:27 +0200947/*
948* command filter functions
949*/
FUJITA Tomonori4beab5c2008-07-26 18:03:25 +0900950extern int blk_verify_command(struct blk_cmd_filter *filter,
Al Viroaeb5d722008-09-02 15:28:45 -0400951 unsigned char *cmd, fmode_t has_write_perm);
952extern void blk_unregister_filter(struct gendisk *disk);
FUJITA Tomonori4beab5c2008-07-26 18:03:25 +0900953extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter);
Adel Gadllah0b07de82008-06-26 13:48:27 +0200954
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955#define MAX_PHYS_SEGMENTS 128
956#define MAX_HW_SEGMENTS 128
Mike Christiedefd94b2005-12-05 02:37:06 -0600957#define SAFE_MAX_SECTORS 255
958#define BLK_DEF_MAX_SECTORS 1024
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959
960#define MAX_SEGMENT_SIZE 65536
961
Milan Broz0e435ac2008-12-03 12:55:08 +0100962#define BLK_SEG_BOUNDARY_MASK 0xFFFFFFFFUL
963
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
965
Jens Axboe165125e2007-07-24 09:28:11 +0200966static inline int queue_hardsect_size(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967{
968 int retval = 512;
969
970 if (q && q->hardsect_size)
971 retval = q->hardsect_size;
972
973 return retval;
974}
975
976static inline int bdev_hardsect_size(struct block_device *bdev)
977{
978 return queue_hardsect_size(bdev_get_queue(bdev));
979}
980
Jens Axboe165125e2007-07-24 09:28:11 +0200981static inline int queue_dma_alignment(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982{
Pete Wyckoff482eb682008-01-01 10:23:02 -0500983 return q ? q->dma_alignment : 511;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700984}
985
FUJITA Tomonori87904072008-08-28 15:05:58 +0900986static inline int blk_rq_aligned(struct request_queue *q, void *addr,
987 unsigned int len)
988{
989 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
990 return !((unsigned long)addr & alignment) && !(len & alignment);
991}
992
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993/* assumes size > 256 */
994static inline unsigned int blksize_bits(unsigned int size)
995{
996 unsigned int bits = 8;
997 do {
998 bits++;
999 size >>= 1;
1000 } while (size > 256);
1001 return bits;
1002}
1003
Adrian Bunk2befb9e2005-09-10 00:27:17 -07001004static inline unsigned int block_size(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005{
1006 return bdev->bd_block_size;
1007}
1008
1009typedef struct {struct page *v;} Sector;
1010
1011unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1012
1013static inline void put_dev_sector(Sector p)
1014{
1015 page_cache_release(p.v);
1016}
1017
1018struct work_struct;
Jens Axboe18887ad2008-07-28 13:08:45 +02001019int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021#define MODULE_ALIAS_BLOCKDEV(major,minor) \
1022 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1023#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1024 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1025
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001026#if defined(CONFIG_BLK_DEV_INTEGRITY)
1027
Jens Axboeb24498d2008-06-27 09:12:09 +02001028#define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1029#define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001030
1031struct blk_integrity_exchg {
1032 void *prot_buf;
1033 void *data_buf;
1034 sector_t sector;
1035 unsigned int data_size;
1036 unsigned short sector_size;
1037 const char *disk_name;
1038};
1039
1040typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1041typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1042typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1043typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1044
1045struct blk_integrity {
1046 integrity_gen_fn *generate_fn;
1047 integrity_vrfy_fn *verify_fn;
1048 integrity_set_tag_fn *set_tag_fn;
1049 integrity_get_tag_fn *get_tag_fn;
1050
1051 unsigned short flags;
1052 unsigned short tuple_size;
1053 unsigned short sector_size;
1054 unsigned short tag_size;
1055
1056 const char *name;
1057
1058 struct kobject kobj;
1059};
1060
1061extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1062extern void blk_integrity_unregister(struct gendisk *);
Martin K. Petersenad7fce92008-10-01 03:38:39 -04001063extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001064extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
1065extern int blk_rq_count_integrity_sg(struct request *);
1066
Jens Axboeb04accc2008-10-02 12:53:22 +02001067static inline
1068struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1069{
1070 return bdev->bd_disk->integrity;
1071}
1072
Martin K. Petersenb02739b2008-10-02 18:47:49 +02001073static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1074{
1075 return disk->integrity;
1076}
1077
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001078static inline int blk_integrity_rq(struct request *rq)
1079{
Martin K. Petersend442cc42008-07-16 16:09:06 -04001080 if (rq->bio == NULL)
1081 return 0;
1082
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001083 return bio_integrity(rq->bio);
1084}
1085
1086#else /* CONFIG_BLK_DEV_INTEGRITY */
1087
1088#define blk_integrity_rq(rq) (0)
1089#define blk_rq_count_integrity_sg(a) (0)
1090#define blk_rq_map_integrity_sg(a, b) (0)
Jens Axboeb04accc2008-10-02 12:53:22 +02001091#define bdev_get_integrity(a) (0)
Martin K. Petersenb02739b2008-10-02 18:47:49 +02001092#define blk_get_integrity(a) (0)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001093#define blk_integrity_compare(a, b) (0)
1094#define blk_integrity_register(a, b) (0)
1095#define blk_integrity_unregister(a) do { } while (0);
1096
1097#endif /* CONFIG_BLK_DEV_INTEGRITY */
1098
Al Viro08f85852007-10-08 13:26:20 -04001099struct block_device_operations {
Al Virod4430d622008-03-02 09:09:22 -05001100 int (*open) (struct block_device *, fmode_t);
1101 int (*release) (struct gendisk *, fmode_t);
1102 int (*locked_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1103 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1104 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
Al Viro08f85852007-10-08 13:26:20 -04001105 int (*direct_access) (struct block_device *, sector_t,
1106 void **, unsigned long *);
1107 int (*media_changed) (struct gendisk *);
1108 int (*revalidate_disk) (struct gendisk *);
1109 int (*getgeo)(struct block_device *, struct hd_geometry *);
1110 struct module *owner;
1111};
1112
Al Viro633a08b2007-08-29 20:34:12 -04001113extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1114 unsigned long);
David Howells93614012006-09-30 20:45:40 +02001115#else /* CONFIG_BLOCK */
1116/*
1117 * stubs for when the block layer is configured out
1118 */
1119#define buffer_heads_over_limit 0
1120
David Howells93614012006-09-30 20:45:40 +02001121static inline long nr_blockdev_pages(void)
1122{
1123 return 0;
1124}
1125
David Howells93614012006-09-30 20:45:40 +02001126#endif /* CONFIG_BLOCK */
1127
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128#endif