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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;
29typedef struct elevator_queue elevator_t;
30struct request_pm_state;
Jens Axboe2056a782006-03-23 20:00:26 +010031struct blk_trace;
Jens Axboe3d6392c2007-07-09 12:38:05 +020032struct request;
33struct sg_io_hdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35#define BLKDEV_MIN_RQ 4
36#define BLKDEV_MAX_RQ 128 /* Default maximum */
37
Linus Torvalds1da177e2005-04-16 15:20:36 -070038struct request;
Tejun Heo8ffdc652006-01-06 09:49:03 +010039typedef void (rq_end_io_fn)(struct request *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
41struct request_list {
42 int count[2];
43 int starved[2];
Tejun Heocb98fc82005-10-28 08:29:39 +020044 int elvpriv;
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 mempool_t *rq_pool;
46 wait_queue_head_t wait[2];
Linus Torvalds1da177e2005-04-16 15:20:36 -070047};
48
Jens Axboe4aff5e22006-08-10 08:44:47 +020049/*
50 * request command types
51 */
52enum rq_cmd_type_bits {
53 REQ_TYPE_FS = 1, /* fs request */
54 REQ_TYPE_BLOCK_PC, /* scsi command */
55 REQ_TYPE_SENSE, /* sense request */
56 REQ_TYPE_PM_SUSPEND, /* suspend request */
57 REQ_TYPE_PM_RESUME, /* resume request */
58 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
Jens Axboe4aff5e22006-08-10 08:44:47 +020059 REQ_TYPE_SPECIAL, /* driver defined type */
60 REQ_TYPE_LINUX_BLOCK, /* generic block layer message */
61 /*
62 * for ATA/ATAPI devices. this really doesn't belong here, ide should
63 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
64 * private REQ_LB opcodes to differentiate what type of request this is
65 */
Jens Axboe4aff5e22006-08-10 08:44:47 +020066 REQ_TYPE_ATA_TASKFILE,
Jens Axboecea28852006-10-12 15:08:45 +020067 REQ_TYPE_ATA_PC,
Jens Axboe4aff5e22006-08-10 08:44:47 +020068};
69
70/*
71 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
72 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
73 * SCSI cdb.
74 *
75 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
76 * typically to differentiate REQ_TYPE_SPECIAL requests.
77 *
78 */
79enum {
Jens Axboe4aff5e22006-08-10 08:44:47 +020080 REQ_LB_OP_EJECT = 0x40, /* eject request */
David Woodhouse1a8e2bd2008-08-13 12:35:09 +010081 REQ_LB_OP_FLUSH = 0x41, /* flush request */
David Woodhouseeae9acd2008-08-05 18:08:25 +010082 REQ_LB_OP_DISCARD = 0x42, /* discard sectors */
Jens Axboe4aff5e22006-08-10 08:44:47 +020083};
84
85/*
David Woodhoused628eae2008-08-09 16:22:17 +010086 * request type modified bits. first two bits match BIO_RW* bits, important
Jens Axboe4aff5e22006-08-10 08:44:47 +020087 */
88enum rq_flag_bits {
89 __REQ_RW, /* not set, read. set, write */
Mike Christie6000a362008-08-19 18:45:30 -050090 __REQ_FAILFAST_DEV, /* no driver retries of device errors */
91 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
92 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
David Woodhousefb2dce82008-08-05 18:01:53 +010093 __REQ_DISCARD, /* request to discard sectors */
Jens Axboe4aff5e22006-08-10 08:44:47 +020094 __REQ_SORTED, /* elevator knows about this request */
95 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
96 __REQ_HARDBARRIER, /* may not be passed by drive either */
97 __REQ_FUA, /* forced unit access */
98 __REQ_NOMERGE, /* don't touch this for merging */
99 __REQ_STARTED, /* drive already may have started this one */
100 __REQ_DONTPREP, /* don't call prep for this one */
101 __REQ_QUEUED, /* uses queueing */
102 __REQ_ELVPRIV, /* elevator private data attached */
103 __REQ_FAILED, /* set if the request failed */
104 __REQ_QUIET, /* don't worry about errors */
105 __REQ_PREEMPT, /* set for "ide_preempt" requests */
106 __REQ_ORDERED_COLOR, /* is before or after barrier */
107 __REQ_RW_SYNC, /* request is sync (O_DIRECT) */
Jens Axboe49171e52006-08-10 08:59:11 +0200108 __REQ_ALLOCED, /* request came from our alloc pool */
Jens Axboe5404bc72006-08-10 09:01:02 +0200109 __REQ_RW_META, /* metadata io request */
FUJITA Tomonorif18573a2008-04-11 12:56:52 +0200110 __REQ_COPY_USER, /* contains copies of user pages */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200111 __REQ_INTEGRITY, /* integrity metadata has been remapped */
Jens Axboe4aff5e22006-08-10 08:44:47 +0200112 __REQ_NR_BITS, /* stops here */
113};
114
115#define REQ_RW (1 << __REQ_RW)
Mike Christie6000a362008-08-19 18:45:30 -0500116#define REQ_FAILFAST_DEV (1 << __REQ_FAILFAST_DEV)
117#define REQ_FAILFAST_TRANSPORT (1 << __REQ_FAILFAST_TRANSPORT)
118#define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER)
David Woodhousefb2dce82008-08-05 18:01:53 +0100119#define REQ_DISCARD (1 << __REQ_DISCARD)
Jens Axboe4aff5e22006-08-10 08:44:47 +0200120#define REQ_SORTED (1 << __REQ_SORTED)
121#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
122#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
123#define REQ_FUA (1 << __REQ_FUA)
124#define REQ_NOMERGE (1 << __REQ_NOMERGE)
125#define REQ_STARTED (1 << __REQ_STARTED)
126#define REQ_DONTPREP (1 << __REQ_DONTPREP)
127#define REQ_QUEUED (1 << __REQ_QUEUED)
128#define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
129#define REQ_FAILED (1 << __REQ_FAILED)
130#define REQ_QUIET (1 << __REQ_QUIET)
131#define REQ_PREEMPT (1 << __REQ_PREEMPT)
132#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
133#define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
Jens Axboe49171e52006-08-10 08:59:11 +0200134#define REQ_ALLOCED (1 << __REQ_ALLOCED)
Jens Axboe5404bc72006-08-10 09:01:02 +0200135#define REQ_RW_META (1 << __REQ_RW_META)
FUJITA Tomonorif18573a2008-04-11 12:56:52 +0200136#define REQ_COPY_USER (1 << __REQ_COPY_USER)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200137#define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
Jens Axboe4aff5e22006-08-10 08:44:47 +0200138
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139#define BLK_MAX_CDB 16
140
141/*
Jens Axboe63a71382008-02-08 12:41:03 +0100142 * try to put the fields that are referenced together in the same cacheline.
143 * if you modify this structure, be sure to check block/blk-core.c:rq_init()
144 * as well!
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 */
146struct request {
Jens Axboeff856ba2006-01-09 16:02:34 +0100147 struct list_head queuelist;
Jens Axboec7c22e42008-09-13 20:26:01 +0200148 struct call_single_data csd;
149 int cpu;
Jens Axboeff856ba2006-01-09 16:02:34 +0100150
Jens Axboe165125e2007-07-24 09:28:11 +0200151 struct request_queue *q;
Jens Axboee6a1c872006-08-10 09:00:21 +0200152
Jens Axboe4aff5e22006-08-10 08:44:47 +0200153 unsigned int cmd_flags;
154 enum rq_cmd_type_bits cmd_type;
Jens Axboe242f9dc2008-09-14 05:55:09 -0700155 unsigned long atomic_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156
157 /* Maintain bio traversal state for part by part I/O submission.
158 * hard_* are block layer internals, no driver should touch them!
159 */
160
161 sector_t sector; /* next sector to submit */
Jens Axboee6a1c872006-08-10 09:00:21 +0200162 sector_t hard_sector; /* next sector to complete */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 unsigned long nr_sectors; /* no. of sectors left to submit */
Jens Axboee6a1c872006-08-10 09:00:21 +0200164 unsigned long hard_nr_sectors; /* no. of sectors left to complete */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 /* no. of sectors left to submit in the current segment */
166 unsigned int current_nr_sectors;
167
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 /* no. of sectors left to complete in the current segment */
169 unsigned int hard_cur_sectors;
170
171 struct bio *bio;
172 struct bio *biotail;
173
Jens Axboe98170642006-07-28 09:23:08 +0200174 struct hlist_node hash; /* merge hash */
Jens Axboee6a1c872006-08-10 09:00:21 +0200175 /*
176 * The rb_node is only used inside the io scheduler, requests
177 * are pruned when moved to the dispatch queue. So let the
178 * completion_data share space with the rb_node.
179 */
180 union {
181 struct rb_node rb_node; /* sort/lookup */
182 void *completion_data;
183 };
Jens Axboe98170642006-07-28 09:23:08 +0200184
Jens Axboeff7d1452006-07-12 14:04:37 +0200185 /*
186 * two pointers are available for the IO schedulers, if they need
187 * more they have to dynamically allocate it.
188 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 void *elevator_private;
Jens Axboeff7d1452006-07-12 14:04:37 +0200190 void *elevator_private2;
191
Jens Axboe8f34ee72006-06-13 09:02:34 +0200192 struct gendisk *rq_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 unsigned long start_time;
194
195 /* Number of scatter-gather DMA addr+len pairs after
196 * physical address coalescing is performed.
197 */
198 unsigned short nr_phys_segments;
199
Jens Axboe8f34ee72006-06-13 09:02:34 +0200200 unsigned short ioprio;
201
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 void *special;
Jens Axboe8f34ee72006-06-13 09:02:34 +0200203 char *buffer;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204
Jens Axboecdd60262006-07-28 09:32:07 +0200205 int tag;
206 int errors;
207
208 int ref_count;
209
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 /*
211 * when request is used as a packet command carrier
212 */
FUJITA Tomonorid7e3c322008-04-29 09:54:39 +0200213 unsigned short cmd_len;
214 unsigned char __cmd[BLK_MAX_CDB];
215 unsigned char *cmd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216
217 unsigned int data_len;
FUJITA Tomonori7a85f882008-03-04 11:17:11 +0100218 unsigned int extra_len; /* length of alignment and padding */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 unsigned int sense_len;
Jens Axboe8f34ee72006-06-13 09:02:34 +0200220 void *data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 void *sense;
222
Jens Axboe242f9dc2008-09-14 05:55:09 -0700223 unsigned long deadline;
224 struct list_head timeout_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 unsigned int timeout;
Mike Christie17e01f22005-11-11 05:31:37 -0600226 int retries;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227
228 /*
Jens Axboec00895a2006-09-30 20:29:12 +0200229 * completion callback.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 */
231 rq_end_io_fn *end_io;
232 void *end_io_data;
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200233
234 /* for bidi */
235 struct request *next_rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236};
237
Fernando Luis Vázquez Cao766ca442008-08-14 09:59:13 +0200238static inline unsigned short req_get_ioprio(struct request *req)
239{
240 return req->ioprio;
241}
242
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243/*
Jens Axboe4aff5e22006-08-10 08:44:47 +0200244 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 * requests. Some step values could eventually be made generic.
246 */
247struct request_pm_state
248{
249 /* PM state machine step value, currently driver specific */
250 int pm_step;
251 /* requested PM state value (S1, S2, S3, S4, ...) */
252 u32 pm_state;
253 void* data; /* for driver use */
254};
255
256#include <linux/elevator.h>
257
Jens Axboe165125e2007-07-24 09:28:11 +0200258typedef void (request_fn_proc) (struct request_queue *q);
259typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
260typedef int (prep_rq_fn) (struct request_queue *, struct request *);
261typedef void (unplug_fn) (struct request_queue *);
David Woodhousefb2dce82008-08-05 18:01:53 +0100262typedef int (prepare_discard_fn) (struct request_queue *, struct request *);
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
FUJITA Tomonori4beab5c2008-07-26 18:03:25 +0900303struct blk_cmd_filter {
FUJITA Tomonoriabf54392008-08-16 14:10:05 +0900304 unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
305 unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
306 struct kobject kobj;
307};
308
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309struct request_queue
310{
311 /*
312 * Together with queue_head for cacheline sharing
313 */
314 struct list_head queue_head;
315 struct request *last_merge;
316 elevator_t *elevator;
317
318 /*
319 * the queue request freelist, one for reads and one for writes
320 */
321 struct request_list rq;
322
323 request_fn_proc *request_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 make_request_fn *make_request_fn;
325 prep_rq_fn *prep_rq_fn;
326 unplug_fn *unplug_fn;
David Woodhousefb2dce82008-08-05 18:01:53 +0100327 prepare_discard_fn *prepare_discard_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 merge_bvec_fn *merge_bvec_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 prepare_flush_fn *prepare_flush_fn;
Jens Axboeff856ba2006-01-09 16:02:34 +0100330 softirq_done_fn *softirq_done_fn;
Jens Axboe242f9dc2008-09-14 05:55:09 -0700331 rq_timed_out_fn *rq_timed_out_fn;
Tejun Heo2fb98e82008-02-19 11:36:53 +0100332 dma_drain_needed_fn *dma_drain_needed;
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200333 lld_busy_fn *lld_busy_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334
335 /*
Tejun Heo8922e162005-10-20 16:23:44 +0200336 * Dispatch queue sorting
337 */
Jens Axboe1b47f532005-10-20 16:37:00 +0200338 sector_t end_sector;
Tejun Heo8922e162005-10-20 16:23:44 +0200339 struct request *boundary_rq;
Tejun Heo8922e162005-10-20 16:23:44 +0200340
341 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 * Auto-unplugging state
343 */
344 struct timer_list unplug_timer;
345 int unplug_thresh; /* After this many requests */
346 unsigned long unplug_delay; /* After this many jiffies */
347 struct work_struct unplug_work;
348
349 struct backing_dev_info backing_dev_info;
350
351 /*
352 * The queue owner gets to use this for whatever they like.
353 * ll_rw_blk doesn't touch it.
354 */
355 void *queuedata;
356
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 /*
358 * queue needs bounce pages for pages above this limit
359 */
360 unsigned long bounce_pfn;
Al Viro8267e262005-10-21 03:20:53 -0400361 gfp_t bounce_gfp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362
363 /*
364 * various queue flags, see QUEUE_* below
365 */
366 unsigned long queue_flags;
367
368 /*
152587d2005-04-12 16:22:06 -0500369 * protects queue structures from reentrancy. ->__queue_lock should
370 * _never_ be used directly, it is queue private. always use
371 * ->queue_lock.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 */
152587d2005-04-12 16:22:06 -0500373 spinlock_t __queue_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 spinlock_t *queue_lock;
375
376 /*
377 * queue kobject
378 */
379 struct kobject kobj;
380
381 /*
382 * queue settings
383 */
384 unsigned long nr_requests; /* Max # of requests */
385 unsigned int nr_congestion_on;
386 unsigned int nr_congestion_off;
387 unsigned int nr_batching;
388
Jens Axboe2cb2e142006-01-17 09:04:32 +0100389 unsigned int max_sectors;
390 unsigned int max_hw_sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 unsigned short max_phys_segments;
392 unsigned short max_hw_segments;
393 unsigned short hardsect_size;
394 unsigned int max_segment_size;
395
396 unsigned long seg_boundary_mask;
James Bottomleyfa0ccd82008-01-10 11:30:36 -0600397 void *dma_drain_buffer;
398 unsigned int dma_drain_size;
Tejun Heoe3790c72008-03-04 11:18:17 +0100399 unsigned int dma_pad_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 unsigned int dma_alignment;
401
402 struct blk_queue_tag *queue_tags;
Jens Axboe6eca9002007-10-25 10:14:47 +0200403 struct list_head tag_busy_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404
Tejun Heo15853af2005-11-10 08:52:05 +0100405 unsigned int nr_sorted;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 unsigned int in_flight;
407
Jens Axboe242f9dc2008-09-14 05:55:09 -0700408 unsigned int rq_timeout;
409 struct timer_list timeout;
410 struct list_head timeout_list;
411
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 /*
413 * sg stuff
414 */
415 unsigned int sg_timeout;
416 unsigned int sg_reserved_size;
Christoph Lameter19460892005-06-23 00:08:19 -0700417 int node;
Alexey Dobriyan6c5c9342006-09-29 01:59:40 -0700418#ifdef CONFIG_BLK_DEV_IO_TRACE
Jens Axboe2056a782006-03-23 20:00:26 +0100419 struct blk_trace *blk_trace;
Alexey Dobriyan6c5c9342006-09-29 01:59:40 -0700420#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 /*
422 * reserved for flush operations
423 */
Tejun Heo797e7db2006-01-06 09:51:03 +0100424 unsigned int ordered, next_ordered, ordseq;
425 int orderr, ordcolor;
426 struct request pre_flush_rq, bar_rq, post_flush_rq;
427 struct request *orig_bar_rq;
Al Viro483f4af2006-03-18 18:34:37 -0500428
429 struct mutex sysfs_lock;
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200430
431#if defined(CONFIG_BLK_DEV_BSG)
432 struct bsg_class_device bsg_dev;
433#endif
FUJITA Tomonori4beab5c2008-07-26 18:03:25 +0900434 struct blk_cmd_filter cmd_filter;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435};
436
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437#define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
438#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
439#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
Qi Yong4e971822007-07-25 08:45:51 +0200440#define QUEUE_FLAG_READFULL 3 /* read queue has been filled */
441#define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442#define QUEUE_FLAG_DEAD 5 /* queue being torn down */
443#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
444#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
Jens Axboe64521d12005-10-28 08:30:39 +0200445#define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200446#define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200447#define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
Jens Axboec7c22e42008-09-13 20:26:01 +0200448#define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
Jens Axboe581d4e22008-09-14 05:56:33 -0700449#define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
Kiyoshi Ueda4ee5eaf2008-09-18 10:46:13 -0400450#define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
Jens Axboea68bbdd2008-09-24 13:03:33 +0200451#define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
Tejun Heo797e7db2006-01-06 09:51:03 +0100452
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700453static inline int queue_is_locked(struct request_queue *q)
454{
Jens Axboe7663c1e2008-04-29 21:31:27 +0200455#ifdef CONFIG_SMP
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700456 spinlock_t *lock = q->queue_lock;
457 return lock && spin_is_locked(lock);
Jens Axboe7663c1e2008-04-29 21:31:27 +0200458#else
459 return 1;
460#endif
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700461}
462
Nick Piggin75ad23b2008-04-29 14:48:33 +0200463static inline void queue_flag_set_unlocked(unsigned int flag,
464 struct request_queue *q)
465{
466 __set_bit(flag, &q->queue_flags);
467}
468
Jens Axboee48ec692008-07-03 13:18:54 +0200469static inline int queue_flag_test_and_clear(unsigned int flag,
470 struct request_queue *q)
471{
472 WARN_ON_ONCE(!queue_is_locked(q));
473
474 if (test_bit(flag, &q->queue_flags)) {
475 __clear_bit(flag, &q->queue_flags);
476 return 1;
477 }
478
479 return 0;
480}
481
482static inline int queue_flag_test_and_set(unsigned int flag,
483 struct request_queue *q)
484{
485 WARN_ON_ONCE(!queue_is_locked(q));
486
487 if (!test_bit(flag, &q->queue_flags)) {
488 __set_bit(flag, &q->queue_flags);
489 return 0;
490 }
491
492 return 1;
493}
494
Nick Piggin75ad23b2008-04-29 14:48:33 +0200495static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
496{
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700497 WARN_ON_ONCE(!queue_is_locked(q));
Nick Piggin75ad23b2008-04-29 14:48:33 +0200498 __set_bit(flag, &q->queue_flags);
499}
500
501static inline void queue_flag_clear_unlocked(unsigned int flag,
502 struct request_queue *q)
503{
504 __clear_bit(flag, &q->queue_flags);
505}
506
507static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
508{
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700509 WARN_ON_ONCE(!queue_is_locked(q));
Nick Piggin75ad23b2008-04-29 14:48:33 +0200510 __clear_bit(flag, &q->queue_flags);
511}
512
Tejun Heo797e7db2006-01-06 09:51:03 +0100513enum {
514 /*
515 * Hardbarrier is supported with one of the following methods.
516 *
517 * NONE : hardbarrier unsupported
518 * DRAIN : ordering by draining is enough
519 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
520 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
521 * TAG : ordering by tag is enough
522 * TAG_FLUSH : ordering by tag w/ pre and post flushes
523 * TAG_FUA : ordering by tag w/ pre flush and FUA write
524 */
525 QUEUE_ORDERED_NONE = 0x00,
526 QUEUE_ORDERED_DRAIN = 0x01,
527 QUEUE_ORDERED_TAG = 0x02,
528
529 QUEUE_ORDERED_PREFLUSH = 0x10,
530 QUEUE_ORDERED_POSTFLUSH = 0x20,
531 QUEUE_ORDERED_FUA = 0x40,
532
533 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
534 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
535 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
536 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
537 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
538 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
539 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
540 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
541
542 /*
543 * Ordered operation sequence
544 */
545 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
546 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
547 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
548 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
549 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
550 QUEUE_ORDSEQ_DONE = 0x20,
551};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552
553#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
554#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
555#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200556#define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
Jens Axboea68bbdd2008-09-24 13:03:33 +0200557#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
Tejun Heo797e7db2006-01-06 09:51:03 +0100558#define blk_queue_flushing(q) ((q)->ordseq)
Kiyoshi Ueda4ee5eaf2008-09-18 10:46:13 -0400559#define blk_queue_stackable(q) \
560 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561
Jens Axboe4aff5e22006-08-10 08:44:47 +0200562#define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
563#define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
564#define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
565#define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
566
Mike Christie6000a362008-08-19 18:45:30 -0500567#define blk_failfast_dev(rq) ((rq)->cmd_flags & REQ_FAILFAST_DEV)
568#define blk_failfast_transport(rq) ((rq)->cmd_flags & REQ_FAILFAST_TRANSPORT)
569#define blk_failfast_driver(rq) ((rq)->cmd_flags & REQ_FAILFAST_DRIVER)
570#define blk_noretry_request(rq) (blk_failfast_dev(rq) || \
571 blk_failfast_transport(rq) || \
572 blk_failfast_driver(rq))
Jens Axboe4aff5e22006-08-10 08:44:47 +0200573#define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574
David Woodhousee17fc0a2008-08-09 16:42:20 +0100575#define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576
Jens Axboe4aff5e22006-08-10 08:44:47 +0200577#define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
578#define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579#define blk_pm_request(rq) \
Jens Axboe4aff5e22006-08-10 08:44:47 +0200580 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581
Jens Axboeab780f12008-08-26 10:25:02 +0200582#define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
Jens Axboe4aff5e22006-08-10 08:44:47 +0200583#define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
584#define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
585#define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
David Woodhousefb2dce82008-08-05 18:01:53 +0100586#define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200587#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
Jens Axboebf2de6f2007-09-27 13:01:25 +0200588#define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors)
Kiyoshi Ueda336cdb42007-12-11 17:40:30 -0500589/* rq->queuelist of dequeued request must be list_empty() */
590#define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591
592#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
593
Jens Axboe4aff5e22006-08-10 08:44:47 +0200594#define rq_data_dir(rq) ((rq)->cmd_flags & 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595
Jens Axboe9e2585a2006-07-28 09:26:13 +0200596/*
597 * We regard a request as sync, if it's a READ or a SYNC write.
598 */
599#define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC)
Jens Axboe5404bc72006-08-10 09:01:02 +0200600#define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
Jens Axboe9e2585a2006-07-28 09:26:13 +0200601
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602static inline int blk_queue_full(struct request_queue *q, int rw)
603{
604 if (rw == READ)
605 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
606 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
607}
608
609static inline void blk_set_queue_full(struct request_queue *q, int rw)
610{
611 if (rw == READ)
Nick Piggin75ad23b2008-04-29 14:48:33 +0200612 queue_flag_set(QUEUE_FLAG_READFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 else
Nick Piggin75ad23b2008-04-29 14:48:33 +0200614 queue_flag_set(QUEUE_FLAG_WRITEFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615}
616
617static inline void blk_clear_queue_full(struct request_queue *q, int rw)
618{
619 if (rw == READ)
Nick Piggin75ad23b2008-04-29 14:48:33 +0200620 queue_flag_clear(QUEUE_FLAG_READFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 else
Nick Piggin75ad23b2008-04-29 14:48:33 +0200622 queue_flag_clear(QUEUE_FLAG_WRITEFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623}
624
625
626/*
627 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
628 * it already be started by driver.
629 */
630#define RQ_NOMERGE_FLAGS \
631 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
632#define rq_mergeable(rq) \
David Woodhousee17fc0a2008-08-09 16:42:20 +0100633 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
634 (blk_discard_rq(rq) || blk_fs_request((rq))))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635
636/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 * q->prep_rq_fn return values
638 */
639#define BLKPREP_OK 0 /* serve it */
640#define BLKPREP_KILL 1 /* fatal error, kill */
641#define BLKPREP_DEFER 2 /* leave on queue */
642
643extern unsigned long blk_max_low_pfn, blk_max_pfn;
644
645/*
646 * standard bounce addresses:
647 *
648 * BLK_BOUNCE_HIGH : bounce all highmem pages
649 * BLK_BOUNCE_ANY : don't bounce anything
650 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
651 */
Andi Kleen24728922008-04-21 09:51:05 +0200652
653#if BITS_PER_LONG == 32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
Andi Kleen24728922008-04-21 09:51:05 +0200655#else
656#define BLK_BOUNCE_HIGH -1ULL
657#endif
658#define BLK_BOUNCE_ANY (-1ULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659#define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
660
Jens Axboe3d6392c2007-07-09 12:38:05 +0200661/*
662 * default timeout for SG_IO if none specified
663 */
664#define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
665
Christoph Lameter2a7326b2007-07-17 04:03:37 -0700666#ifdef CONFIG_BOUNCE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667extern int init_emergency_isa_pool(void);
Jens Axboe165125e2007-07-24 09:28:11 +0200668extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669#else
670static inline int init_emergency_isa_pool(void)
671{
672 return 0;
673}
Jens Axboe165125e2007-07-24 09:28:11 +0200674static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675{
676}
677#endif /* CONFIG_MMU */
678
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900679struct rq_map_data {
680 struct page **pages;
681 int page_order;
682 int nr_entries;
683};
684
NeilBrown5705f702007-09-25 12:35:59 +0200685struct req_iterator {
686 int i;
687 struct bio *bio;
688};
689
690/* This should not be used directly - use rq_for_each_segment */
691#define __rq_for_each_bio(_bio, rq) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 if ((rq->bio)) \
693 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
694
NeilBrown5705f702007-09-25 12:35:59 +0200695#define rq_for_each_segment(bvl, _rq, _iter) \
696 __rq_for_each_bio(_iter.bio, _rq) \
697 bio_for_each_segment(bvl, _iter.bio, _iter.i)
698
699#define rq_iter_last(rq, _iter) \
700 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
701
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702extern int blk_register_queue(struct gendisk *disk);
703extern void blk_unregister_queue(struct gendisk *disk);
704extern void register_disk(struct gendisk *dev);
705extern void generic_make_request(struct bio *bio);
FUJITA Tomonori2a4aa302008-04-29 09:54:36 +0200706extern void blk_rq_init(struct request_queue *q, struct request *rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707extern void blk_put_request(struct request *);
Jens Axboe165125e2007-07-24 09:28:11 +0200708extern void __blk_put_request(struct request_queue *, struct request *);
Jens Axboe165125e2007-07-24 09:28:11 +0200709extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
710extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
711extern void blk_requeue_request(struct request_queue *, struct request *);
Kiyoshi Ueda82124d62008-09-18 10:45:38 -0400712extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200713extern int blk_lld_busy(struct request_queue *q);
Kiyoshi Ueda82124d62008-09-18 10:45:38 -0400714extern int blk_insert_cloned_request(struct request_queue *q,
715 struct request *rq);
Jens Axboe165125e2007-07-24 09:28:11 +0200716extern void blk_plug_device(struct request_queue *);
Jens Axboe6c5e0c42008-08-01 20:31:32 +0200717extern void blk_plug_device_unlocked(struct request_queue *);
Jens Axboe165125e2007-07-24 09:28:11 +0200718extern int blk_remove_plug(struct request_queue *);
719extern void blk_recount_segments(struct request_queue *, struct bio *);
FUJITA Tomonori45e79a32007-07-09 12:39:20 +0200720extern int scsi_cmd_ioctl(struct file *, struct request_queue *,
721 struct gendisk *, unsigned int, void __user *);
Christoph Hellwig21b2f0c2006-03-22 17:52:04 +0100722extern int sg_scsi_ioctl(struct file *, struct request_queue *,
723 struct gendisk *, struct scsi_ioctl_command __user *);
Andrew Morton3fcfab12006-10-19 23:28:16 -0700724
725/*
Jens Axboe1aa4f242006-12-19 08:33:11 +0100726 * Temporary export, until SCSI gets fixed up.
727 */
NeilBrown3001ca72007-08-16 13:31:27 +0200728extern int blk_rq_append_bio(struct request_queue *q, struct request *rq,
729 struct bio *bio);
Jens Axboe1aa4f242006-12-19 08:33:11 +0100730
731/*
Andrew Morton3fcfab12006-10-19 23:28:16 -0700732 * A queue has just exitted congestion. Note this in the global counter of
733 * congested queues, and wake up anyone who was waiting for requests to be
734 * put back.
735 */
Jens Axboe165125e2007-07-24 09:28:11 +0200736static inline void blk_clear_queue_congested(struct request_queue *q, int rw)
Andrew Morton3fcfab12006-10-19 23:28:16 -0700737{
738 clear_bdi_congested(&q->backing_dev_info, rw);
739}
740
741/*
742 * A queue has just entered congestion. Flag that in the queue's VM-visible
743 * state flags and increment the global gounter of congested queues.
744 */
Jens Axboe165125e2007-07-24 09:28:11 +0200745static inline void blk_set_queue_congested(struct request_queue *q, int rw)
Andrew Morton3fcfab12006-10-19 23:28:16 -0700746{
747 set_bdi_congested(&q->backing_dev_info, rw);
748}
749
Jens Axboe165125e2007-07-24 09:28:11 +0200750extern void blk_start_queue(struct request_queue *q);
751extern void blk_stop_queue(struct request_queue *q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752extern void blk_sync_queue(struct request_queue *q);
Jens Axboe165125e2007-07-24 09:28:11 +0200753extern void __blk_stop_queue(struct request_queue *q);
Nick Piggin75ad23b2008-04-29 14:48:33 +0200754extern void __blk_run_queue(struct request_queue *);
Jens Axboe165125e2007-07-24 09:28:11 +0200755extern void blk_run_queue(struct request_queue *);
756extern void blk_start_queueing(struct request_queue *);
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900757extern int blk_rq_map_user(struct request_queue *, struct request *,
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900758 struct rq_map_data *, void __user *, unsigned long,
759 gfp_t);
Jens Axboe8e5cfc42006-12-19 11:12:46 +0100760extern int blk_rq_unmap_user(struct bio *);
Jens Axboe165125e2007-07-24 09:28:11 +0200761extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
762extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900763 struct rq_map_data *, struct sg_iovec *, int,
764 unsigned int, gfp_t);
Jens Axboe165125e2007-07-24 09:28:11 +0200765extern int blk_execute_rq(struct request_queue *, struct gendisk *,
James Bottomley 994ca9a2005-06-20 14:11:09 +0200766 struct request *, int);
Jens Axboe165125e2007-07-24 09:28:11 +0200767extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
Jens Axboe15fc8582006-01-06 10:00:50 +0100768 struct request *, int, rq_end_io_fn *);
Alan D. Brunelle2ad8b1e2007-11-07 14:26:56 -0500769extern void blk_unplug(struct request_queue *q);
Mike Christie6e39b692005-11-11 05:30:24 -0600770
Jens Axboe165125e2007-07-24 09:28:11 +0200771static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772{
773 return bdev->bd_disk->queue;
774}
775
776static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
777 struct page *page)
778{
779 if (bdi && bdi->unplug_io_fn)
780 bdi->unplug_io_fn(bdi, page);
781}
782
783static inline void blk_run_address_space(struct address_space *mapping)
784{
785 if (mapping)
786 blk_run_backing_dev(mapping->backing_dev_info, NULL);
787}
788
789/*
Kiyoshi Ueda3bcddea2007-12-11 17:52:28 -0500790 * blk_end_request() and friends.
791 * __blk_end_request() and end_request() must be called with
792 * the request queue spinlock acquired.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 *
794 * Several drivers define their own end_request and call
Kiyoshi Ueda3bcddea2007-12-11 17:52:28 -0500795 * blk_end_request() for parts of the original function.
796 * This prevents code duplication in drivers.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797 */
Jens Axboe22b13212008-01-31 12:36:19 +0100798extern int blk_end_request(struct request *rq, int error,
799 unsigned int nr_bytes);
800extern int __blk_end_request(struct request *rq, int error,
801 unsigned int nr_bytes);
802extern int blk_end_bidi_request(struct request *rq, int error,
803 unsigned int nr_bytes, unsigned int bidi_bytes);
Jens Axboea0cd1282007-09-21 10:41:07 +0200804extern void end_request(struct request *, int);
Jens Axboe22b13212008-01-31 12:36:19 +0100805extern int blk_end_request_callback(struct request *rq, int error,
806 unsigned int nr_bytes,
807 int (drv_callback)(struct request *));
Jens Axboeff856ba2006-01-09 16:02:34 +0100808extern void blk_complete_request(struct request *);
Jens Axboe242f9dc2008-09-14 05:55:09 -0700809extern void __blk_complete_request(struct request *);
810extern void blk_abort_request(struct request *);
Mike Anderson11914a52008-09-13 20:31:27 +0200811extern void blk_abort_queue(struct request_queue *);
Kiyoshi Ueda32fab442008-09-18 10:45:09 -0400812extern void blk_update_request(struct request *rq, int error,
813 unsigned int nr_bytes);
Jens Axboeff856ba2006-01-09 16:02:34 +0100814
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815/*
Kiyoshi Ueda3b113132007-12-11 17:41:17 -0500816 * blk_end_request() takes bytes instead of sectors as a complete size.
817 * blk_rq_bytes() returns bytes left to complete in the entire request.
818 * blk_rq_cur_bytes() returns bytes left to complete in the current segment.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700819 */
Kiyoshi Ueda3b113132007-12-11 17:41:17 -0500820extern unsigned int blk_rq_bytes(struct request *rq);
821extern unsigned int blk_rq_cur_bytes(struct request *rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822
823static inline void blkdev_dequeue_request(struct request *req)
824{
Tejun Heo8922e162005-10-20 16:23:44 +0200825 elv_dequeue_request(req->q, req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828/*
829 * Access functions for manipulating queue properties
830 */
Jens Axboe165125e2007-07-24 09:28:11 +0200831extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
Christoph Lameter19460892005-06-23 00:08:19 -0700832 spinlock_t *lock, int node_id);
Jens Axboe165125e2007-07-24 09:28:11 +0200833extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
834extern void blk_cleanup_queue(struct request_queue *);
835extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
836extern void blk_queue_bounce_limit(struct request_queue *, u64);
837extern void blk_queue_max_sectors(struct request_queue *, unsigned int);
838extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short);
839extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short);
840extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
841extern void blk_queue_hardsect_size(struct request_queue *, unsigned short);
842extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
Tejun Heoe3790c72008-03-04 11:18:17 +0100843extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
FUJITA Tomonori27f82212008-07-04 09:30:03 +0200844extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
Tejun Heo2fb98e82008-02-19 11:36:53 +0100845extern int blk_queue_dma_drain(struct request_queue *q,
846 dma_drain_needed_fn *dma_drain_needed,
847 void *buf, unsigned int size);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200848extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
Jens Axboe165125e2007-07-24 09:28:11 +0200849extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
850extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
851extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
852extern void blk_queue_dma_alignment(struct request_queue *, int);
James Bottomley11c3e682007-12-31 16:37:00 -0600853extern void blk_queue_update_dma_alignment(struct request_queue *, int);
Jens Axboe165125e2007-07-24 09:28:11 +0200854extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
David Woodhousefb2dce82008-08-05 18:01:53 +0100855extern void blk_queue_set_discard(struct request_queue *, prepare_discard_fn *);
Jens Axboe242f9dc2008-09-14 05:55:09 -0700856extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
857extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
Jens Axboe165125e2007-07-24 09:28:11 +0200859extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
Jens Axboe165125e2007-07-24 09:28:11 +0200860extern int blk_do_ordered(struct request_queue *, struct request **);
861extern unsigned blk_ordered_cur_seq(struct request_queue *);
Tejun Heo797e7db2006-01-06 09:51:03 +0100862extern unsigned blk_ordered_req_seq(struct request *);
Jens Axboe165125e2007-07-24 09:28:11 +0200863extern void blk_ordered_complete_seq(struct request_queue *, unsigned, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864
Jens Axboe165125e2007-07-24 09:28:11 +0200865extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866extern void blk_dump_rq_flags(struct request *, char *);
Jens Axboe165125e2007-07-24 09:28:11 +0200867extern void generic_unplug_device(struct request_queue *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868extern long nr_blockdev_pages(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869
Jens Axboe165125e2007-07-24 09:28:11 +0200870int blk_get_queue(struct request_queue *);
871struct request_queue *blk_alloc_queue(gfp_t);
872struct request_queue *blk_alloc_queue_node(gfp_t, int);
873extern void blk_put_queue(struct request_queue *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874
875/*
876 * tag stuff
877 */
Jens Axboe4aff5e22006-08-10 08:44:47 +0200878#define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
Jens Axboe165125e2007-07-24 09:28:11 +0200879extern int blk_queue_start_tag(struct request_queue *, struct request *);
880extern struct request *blk_queue_find_tag(struct request_queue *, int);
881extern void blk_queue_end_tag(struct request_queue *, struct request *);
882extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
883extern void blk_queue_free_tags(struct request_queue *);
884extern int blk_queue_resize_tags(struct request_queue *, int);
885extern void blk_queue_invalidate_tags(struct request_queue *);
James Bottomley492dfb42006-08-30 15:48:45 -0400886extern struct blk_queue_tag *blk_init_tags(int);
887extern void blk_free_tags(struct blk_queue_tag *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888
David C Somayajuluf583f492006-10-04 08:27:25 +0200889static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
890 int tag)
891{
892 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
893 return NULL;
894 return bqt->tag_index[tag];
895}
896
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897extern int blkdev_issue_flush(struct block_device *, sector_t *);
Hugh Dickins3e6053d2008-09-11 10:57:55 +0200898extern int blkdev_issue_discard(struct block_device *,
899 sector_t sector, sector_t nr_sects, gfp_t);
David Woodhousefb2dce82008-08-05 18:01:53 +0100900
901static inline int sb_issue_discard(struct super_block *sb,
Hugh Dickins3e6053d2008-09-11 10:57:55 +0200902 sector_t block, sector_t nr_blocks)
David Woodhousefb2dce82008-08-05 18:01:53 +0100903{
904 block <<= (sb->s_blocksize_bits - 9);
905 nr_blocks <<= (sb->s_blocksize_bits - 9);
Hugh Dickins3e6053d2008-09-11 10:57:55 +0200906 return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL);
David Woodhousefb2dce82008-08-05 18:01:53 +0100907}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908
Adel Gadllah0b07de82008-06-26 13:48:27 +0200909/*
910* command filter functions
911*/
FUJITA Tomonori4beab5c2008-07-26 18:03:25 +0900912extern int blk_verify_command(struct blk_cmd_filter *filter,
Al Viroaeb5d722008-09-02 15:28:45 -0400913 unsigned char *cmd, fmode_t has_write_perm);
914extern void blk_unregister_filter(struct gendisk *disk);
FUJITA Tomonori4beab5c2008-07-26 18:03:25 +0900915extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter);
Adel Gadllah0b07de82008-06-26 13:48:27 +0200916
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917#define MAX_PHYS_SEGMENTS 128
918#define MAX_HW_SEGMENTS 128
Mike Christiedefd94b2005-12-05 02:37:06 -0600919#define SAFE_MAX_SECTORS 255
920#define BLK_DEF_MAX_SECTORS 1024
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921
922#define MAX_SEGMENT_SIZE 65536
923
924#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
925
Jens Axboe165125e2007-07-24 09:28:11 +0200926static inline int queue_hardsect_size(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927{
928 int retval = 512;
929
930 if (q && q->hardsect_size)
931 retval = q->hardsect_size;
932
933 return retval;
934}
935
936static inline int bdev_hardsect_size(struct block_device *bdev)
937{
938 return queue_hardsect_size(bdev_get_queue(bdev));
939}
940
Jens Axboe165125e2007-07-24 09:28:11 +0200941static inline int queue_dma_alignment(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700942{
Pete Wyckoff482eb682008-01-01 10:23:02 -0500943 return q ? q->dma_alignment : 511;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944}
945
FUJITA Tomonori87904072008-08-28 15:05:58 +0900946static inline int blk_rq_aligned(struct request_queue *q, void *addr,
947 unsigned int len)
948{
949 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
950 return !((unsigned long)addr & alignment) && !(len & alignment);
951}
952
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953/* assumes size > 256 */
954static inline unsigned int blksize_bits(unsigned int size)
955{
956 unsigned int bits = 8;
957 do {
958 bits++;
959 size >>= 1;
960 } while (size > 256);
961 return bits;
962}
963
Adrian Bunk2befb9e2005-09-10 00:27:17 -0700964static inline unsigned int block_size(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965{
966 return bdev->bd_block_size;
967}
968
969typedef struct {struct page *v;} Sector;
970
971unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
972
973static inline void put_dev_sector(Sector p)
974{
975 page_cache_release(p.v);
976}
977
978struct work_struct;
Jens Axboe18887ad2008-07-28 13:08:45 +0200979int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
Andrew Morton19a75d82007-05-09 02:33:56 -0700980void kblockd_flush_work(struct work_struct *work);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982#define MODULE_ALIAS_BLOCKDEV(major,minor) \
983 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
984#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
985 MODULE_ALIAS("block-major-" __stringify(major) "-*")
986
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200987#if defined(CONFIG_BLK_DEV_INTEGRITY)
988
Jens Axboeb24498d2008-06-27 09:12:09 +0200989#define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
990#define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200991
992struct blk_integrity_exchg {
993 void *prot_buf;
994 void *data_buf;
995 sector_t sector;
996 unsigned int data_size;
997 unsigned short sector_size;
998 const char *disk_name;
999};
1000
1001typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1002typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1003typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1004typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1005
1006struct blk_integrity {
1007 integrity_gen_fn *generate_fn;
1008 integrity_vrfy_fn *verify_fn;
1009 integrity_set_tag_fn *set_tag_fn;
1010 integrity_get_tag_fn *get_tag_fn;
1011
1012 unsigned short flags;
1013 unsigned short tuple_size;
1014 unsigned short sector_size;
1015 unsigned short tag_size;
1016
1017 const char *name;
1018
1019 struct kobject kobj;
1020};
1021
1022extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1023extern void blk_integrity_unregister(struct gendisk *);
Martin K. Petersenad7fce92008-10-01 03:38:39 -04001024extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001025extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
1026extern int blk_rq_count_integrity_sg(struct request *);
1027
Jens Axboeb04accc2008-10-02 12:53:22 +02001028static inline
1029struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1030{
1031 return bdev->bd_disk->integrity;
1032}
1033
Martin K. Petersenb02739b2008-10-02 18:47:49 +02001034static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1035{
1036 return disk->integrity;
1037}
1038
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001039static inline int blk_integrity_rq(struct request *rq)
1040{
Martin K. Petersend442cc42008-07-16 16:09:06 -04001041 if (rq->bio == NULL)
1042 return 0;
1043
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001044 return bio_integrity(rq->bio);
1045}
1046
1047#else /* CONFIG_BLK_DEV_INTEGRITY */
1048
1049#define blk_integrity_rq(rq) (0)
1050#define blk_rq_count_integrity_sg(a) (0)
1051#define blk_rq_map_integrity_sg(a, b) (0)
Jens Axboeb04accc2008-10-02 12:53:22 +02001052#define bdev_get_integrity(a) (0)
Martin K. Petersenb02739b2008-10-02 18:47:49 +02001053#define blk_get_integrity(a) (0)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001054#define blk_integrity_compare(a, b) (0)
1055#define blk_integrity_register(a, b) (0)
1056#define blk_integrity_unregister(a) do { } while (0);
1057
1058#endif /* CONFIG_BLK_DEV_INTEGRITY */
1059
David Howells93614012006-09-30 20:45:40 +02001060#else /* CONFIG_BLOCK */
1061/*
1062 * stubs for when the block layer is configured out
1063 */
1064#define buffer_heads_over_limit 0
1065
David Howells93614012006-09-30 20:45:40 +02001066static inline long nr_blockdev_pages(void)
1067{
1068 return 0;
1069}
1070
David Howells93614012006-09-30 20:45:40 +02001071#endif /* CONFIG_BLOCK */
1072
Linus Torvalds1da177e2005-04-16 15:20:36 -07001073#endif