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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_BLKDEV_H
2#define _LINUX_BLKDEV_H
3
Jens Axboef5ff8422007-09-21 09:19:54 +02004#ifdef CONFIG_BLOCK
5
Andrew Mortonbcfd8d32006-08-31 12:56:06 +02006#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007#include <linux/major.h>
8#include <linux/genhd.h>
9#include <linux/list.h>
10#include <linux/timer.h>
11#include <linux/workqueue.h>
12#include <linux/pagemap.h>
13#include <linux/backing-dev.h>
14#include <linux/wait.h>
15#include <linux/mempool.h>
16#include <linux/bio.h>
17#include <linux/module.h>
18#include <linux/stringify.h>
Hugh Dickins3e6053d2008-09-11 10:57:55 +020019#include <linux/gfp.h>
FUJITA Tomonorid351af02007-07-09 12:40:35 +020020#include <linux/bsg.h>
Jens Axboec7c22e42008-09-13 20:26:01 +020021#include <linux/smp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
23#include <asm/scatterlist.h>
24
Christoph Hellwig21b2f0c2006-03-22 17:52:04 +010025struct scsi_ioctl_command;
26
Linus Torvalds1da177e2005-04-16 15:20:36 -070027struct request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -070028struct elevator_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -070029struct request_pm_state;
Jens Axboe2056a782006-03-23 20:00:26 +010030struct blk_trace;
Jens Axboe3d6392c2007-07-09 12:38:05 +020031struct request;
32struct sg_io_hdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34#define BLKDEV_MIN_RQ 4
35#define BLKDEV_MAX_RQ 128 /* Default maximum */
36
Linus Torvalds1da177e2005-04-16 15:20:36 -070037struct request;
Tejun Heo8ffdc652006-01-06 09:49:03 +010038typedef void (rq_end_io_fn)(struct request *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40struct request_list {
Jens Axboe1faa16d2009-04-06 14:48:01 +020041 /*
42 * count[], starved[], and wait[] are indexed by
43 * BLK_RW_SYNC/BLK_RW_ASYNC
44 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 int count[2];
46 int starved[2];
Tejun Heocb98fc82005-10-28 08:29:39 +020047 int elvpriv;
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 mempool_t *rq_pool;
49 wait_queue_head_t wait[2];
Linus Torvalds1da177e2005-04-16 15:20:36 -070050};
51
Jens Axboe4aff5e22006-08-10 08:44:47 +020052/*
53 * request command types
54 */
55enum rq_cmd_type_bits {
56 REQ_TYPE_FS = 1, /* fs request */
57 REQ_TYPE_BLOCK_PC, /* scsi command */
58 REQ_TYPE_SENSE, /* sense request */
59 REQ_TYPE_PM_SUSPEND, /* suspend request */
60 REQ_TYPE_PM_RESUME, /* resume request */
61 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
Jens Axboe4aff5e22006-08-10 08:44:47 +020062 REQ_TYPE_SPECIAL, /* driver defined type */
63 REQ_TYPE_LINUX_BLOCK, /* generic block layer message */
64 /*
65 * for ATA/ATAPI devices. this really doesn't belong here, ide should
66 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
67 * private REQ_LB opcodes to differentiate what type of request this is
68 */
Jens Axboe4aff5e22006-08-10 08:44:47 +020069 REQ_TYPE_ATA_TASKFILE,
Jens Axboecea28852006-10-12 15:08:45 +020070 REQ_TYPE_ATA_PC,
Jens Axboe4aff5e22006-08-10 08:44:47 +020071};
72
73/*
74 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
75 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
76 * SCSI cdb.
77 *
78 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
79 * typically to differentiate REQ_TYPE_SPECIAL requests.
80 *
81 */
82enum {
Jens Axboe4aff5e22006-08-10 08:44:47 +020083 REQ_LB_OP_EJECT = 0x40, /* eject request */
David Woodhouse1a8e2bd2008-08-13 12:35:09 +010084 REQ_LB_OP_FLUSH = 0x41, /* flush request */
David Woodhouseeae9acd2008-08-05 18:08:25 +010085 REQ_LB_OP_DISCARD = 0x42, /* discard sectors */
Jens Axboe4aff5e22006-08-10 08:44:47 +020086};
87
88/*
Jens Axboe1f98a132009-09-11 14:32:04 +020089 * request type modified bits. first four bits match BIO_RW* bits, important
Jens Axboe4aff5e22006-08-10 08:44:47 +020090 */
91enum rq_flag_bits {
92 __REQ_RW, /* not set, read. set, write */
Mike Christie6000a362008-08-19 18:45:30 -050093 __REQ_FAILFAST_DEV, /* no driver retries of device errors */
94 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
95 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
Tejun Heoa82afdf2009-07-03 17:48:16 +090096 /* above flags must match BIO_RW_* */
David Woodhousefb2dce82008-08-05 18:01:53 +010097 __REQ_DISCARD, /* request to discard sectors */
Jens Axboe4aff5e22006-08-10 08:44:47 +020098 __REQ_SORTED, /* elevator knows about this request */
99 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
100 __REQ_HARDBARRIER, /* may not be passed by drive either */
101 __REQ_FUA, /* forced unit access */
102 __REQ_NOMERGE, /* don't touch this for merging */
103 __REQ_STARTED, /* drive already may have started this one */
104 __REQ_DONTPREP, /* don't call prep for this one */
105 __REQ_QUEUED, /* uses queueing */
106 __REQ_ELVPRIV, /* elevator private data attached */
107 __REQ_FAILED, /* set if the request failed */
108 __REQ_QUIET, /* don't worry about errors */
109 __REQ_PREEMPT, /* set for "ide_preempt" requests */
110 __REQ_ORDERED_COLOR, /* is before or after barrier */
Jens Axboe1faa16d2009-04-06 14:48:01 +0200111 __REQ_RW_SYNC, /* request is sync (sync write or read) */
Jens Axboe49171e52006-08-10 08:59:11 +0200112 __REQ_ALLOCED, /* request came from our alloc pool */
Jens Axboe5404bc72006-08-10 09:01:02 +0200113 __REQ_RW_META, /* metadata io request */
FUJITA Tomonorif18573a2008-04-11 12:56:52 +0200114 __REQ_COPY_USER, /* contains copies of user pages */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200115 __REQ_INTEGRITY, /* integrity metadata has been remapped */
Jens Axboeaeb6faf2009-04-06 14:48:07 +0200116 __REQ_NOIDLE, /* Don't anticipate more IO after this one */
Jerome Marchand42dad762009-04-22 14:01:49 +0200117 __REQ_IO_STAT, /* account I/O stat */
Tejun Heo80a761f2009-07-03 17:48:17 +0900118 __REQ_MIXED_MERGE, /* merge of different types, fail separately */
Jens Axboe4aff5e22006-08-10 08:44:47 +0200119 __REQ_NR_BITS, /* stops here */
120};
121
122#define REQ_RW (1 << __REQ_RW)
Mike Christie6000a362008-08-19 18:45:30 -0500123#define REQ_FAILFAST_DEV (1 << __REQ_FAILFAST_DEV)
124#define REQ_FAILFAST_TRANSPORT (1 << __REQ_FAILFAST_TRANSPORT)
125#define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER)
David Woodhousefb2dce82008-08-05 18:01:53 +0100126#define REQ_DISCARD (1 << __REQ_DISCARD)
Jens Axboe4aff5e22006-08-10 08:44:47 +0200127#define REQ_SORTED (1 << __REQ_SORTED)
128#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
129#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
130#define REQ_FUA (1 << __REQ_FUA)
131#define REQ_NOMERGE (1 << __REQ_NOMERGE)
132#define REQ_STARTED (1 << __REQ_STARTED)
133#define REQ_DONTPREP (1 << __REQ_DONTPREP)
134#define REQ_QUEUED (1 << __REQ_QUEUED)
135#define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
136#define REQ_FAILED (1 << __REQ_FAILED)
137#define REQ_QUIET (1 << __REQ_QUIET)
138#define REQ_PREEMPT (1 << __REQ_PREEMPT)
139#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
140#define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
Jens Axboe49171e52006-08-10 08:59:11 +0200141#define REQ_ALLOCED (1 << __REQ_ALLOCED)
Jens Axboe5404bc72006-08-10 09:01:02 +0200142#define REQ_RW_META (1 << __REQ_RW_META)
FUJITA Tomonorif18573a2008-04-11 12:56:52 +0200143#define REQ_COPY_USER (1 << __REQ_COPY_USER)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200144#define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
Jens Axboeaeb6faf2009-04-06 14:48:07 +0200145#define REQ_NOIDLE (1 << __REQ_NOIDLE)
Jerome Marchand42dad762009-04-22 14:01:49 +0200146#define REQ_IO_STAT (1 << __REQ_IO_STAT)
Tejun Heo80a761f2009-07-03 17:48:17 +0900147#define REQ_MIXED_MERGE (1 << __REQ_MIXED_MERGE)
Jens Axboe4aff5e22006-08-10 08:44:47 +0200148
Tejun Heoa82afdf2009-07-03 17:48:16 +0900149#define REQ_FAILFAST_MASK (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | \
150 REQ_FAILFAST_DRIVER)
151
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152#define BLK_MAX_CDB 16
153
154/*
Jens Axboe63a71382008-02-08 12:41:03 +0100155 * try to put the fields that are referenced together in the same cacheline.
156 * if you modify this structure, be sure to check block/blk-core.c:rq_init()
157 * as well!
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 */
159struct request {
Jens Axboeff856ba2006-01-09 16:02:34 +0100160 struct list_head queuelist;
Jens Axboec7c22e42008-09-13 20:26:01 +0200161 struct call_single_data csd;
162 int cpu;
Jens Axboeff856ba2006-01-09 16:02:34 +0100163
Jens Axboe165125e2007-07-24 09:28:11 +0200164 struct request_queue *q;
Jens Axboee6a1c872006-08-10 09:00:21 +0200165
Jens Axboe4aff5e22006-08-10 08:44:47 +0200166 unsigned int cmd_flags;
167 enum rq_cmd_type_bits cmd_type;
Jens Axboe242f9dc2008-09-14 05:55:09 -0700168 unsigned long atomic_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
Tejun Heoa2dec7b2009-05-07 22:24:44 +0900170 /* the following two fields are internal, NEVER access directly */
171 sector_t __sector; /* sector cursor */
172 unsigned int __data_len; /* total data len */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173
174 struct bio *bio;
175 struct bio *biotail;
176
Jens Axboe98170642006-07-28 09:23:08 +0200177 struct hlist_node hash; /* merge hash */
Jens Axboee6a1c872006-08-10 09:00:21 +0200178 /*
179 * The rb_node is only used inside the io scheduler, requests
180 * are pruned when moved to the dispatch queue. So let the
181 * completion_data share space with the rb_node.
182 */
183 union {
184 struct rb_node rb_node; /* sort/lookup */
185 void *completion_data;
186 };
Jens Axboe98170642006-07-28 09:23:08 +0200187
Jens Axboeff7d1452006-07-12 14:04:37 +0200188 /*
189 * two pointers are available for the IO schedulers, if they need
190 * more they have to dynamically allocate it.
191 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 void *elevator_private;
Jens Axboeff7d1452006-07-12 14:04:37 +0200193 void *elevator_private2;
194
Jens Axboe8f34ee72006-06-13 09:02:34 +0200195 struct gendisk *rq_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 unsigned long start_time;
197
198 /* Number of scatter-gather DMA addr+len pairs after
199 * physical address coalescing is performed.
200 */
201 unsigned short nr_phys_segments;
202
Jens Axboe8f34ee72006-06-13 09:02:34 +0200203 unsigned short ioprio;
204
Tejun Heo731ec492009-04-23 11:05:20 +0900205 void *special; /* opaque pointer available for LLD use */
206 char *buffer; /* kaddr of the current segment if available */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207
Jens Axboecdd60262006-07-28 09:32:07 +0200208 int tag;
209 int errors;
210
211 int ref_count;
212
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 /*
214 * when request is used as a packet command carrier
215 */
FUJITA Tomonorid7e3c322008-04-29 09:54:39 +0200216 unsigned short cmd_len;
217 unsigned char __cmd[BLK_MAX_CDB];
218 unsigned char *cmd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
FUJITA Tomonori7a85f882008-03-04 11:17:11 +0100220 unsigned int extra_len; /* length of alignment and padding */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 unsigned int sense_len;
Tejun Heoc3a4d782009-05-07 22:24:37 +0900222 unsigned int resid_len; /* residual count */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 void *sense;
224
Jens Axboe242f9dc2008-09-14 05:55:09 -0700225 unsigned long deadline;
226 struct list_head timeout_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 unsigned int timeout;
Mike Christie17e01f22005-11-11 05:31:37 -0600228 int retries;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
230 /*
Jens Axboec00895a2006-09-30 20:29:12 +0200231 * completion callback.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 */
233 rq_end_io_fn *end_io;
234 void *end_io_data;
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200235
236 /* for bidi */
237 struct request *next_rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238};
239
Fernando Luis Vázquez Cao766ca442008-08-14 09:59:13 +0200240static inline unsigned short req_get_ioprio(struct request *req)
241{
242 return req->ioprio;
243}
244
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245/*
Jens Axboe4aff5e22006-08-10 08:44:47 +0200246 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 * requests. Some step values could eventually be made generic.
248 */
249struct request_pm_state
250{
251 /* PM state machine step value, currently driver specific */
252 int pm_step;
253 /* requested PM state value (S1, S2, S3, S4, ...) */
254 u32 pm_state;
255 void* data; /* for driver use */
256};
257
258#include <linux/elevator.h>
259
Jens Axboe165125e2007-07-24 09:28:11 +0200260typedef void (request_fn_proc) (struct request_queue *q);
261typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
262typedef int (prep_rq_fn) (struct request_queue *, struct request *);
263typedef void (unplug_fn) (struct request_queue *);
David Woodhousefb2dce82008-08-05 18:01:53 +0100264typedef int (prepare_discard_fn) (struct request_queue *, struct request *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265
266struct bio_vec;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200267struct bvec_merge_data {
268 struct block_device *bi_bdev;
269 sector_t bi_sector;
270 unsigned bi_size;
271 unsigned long bi_rw;
272};
273typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
274 struct bio_vec *);
Jens Axboe165125e2007-07-24 09:28:11 +0200275typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
Jens Axboeff856ba2006-01-09 16:02:34 +0100276typedef void (softirq_done_fn)(struct request *);
Tejun Heo2fb98e82008-02-19 11:36:53 +0100277typedef int (dma_drain_needed_fn)(struct request *);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200278typedef int (lld_busy_fn) (struct request_queue *q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279
Jens Axboe242f9dc2008-09-14 05:55:09 -0700280enum blk_eh_timer_return {
281 BLK_EH_NOT_HANDLED,
282 BLK_EH_HANDLED,
283 BLK_EH_RESET_TIMER,
284};
285
286typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
287
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288enum blk_queue_state {
289 Queue_down,
290 Queue_up,
291};
292
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293struct blk_queue_tag {
294 struct request **tag_index; /* map of busy tags */
295 unsigned long *tag_map; /* bit map of free/busy tags */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 int busy; /* current depth */
297 int max_depth; /* what we will send to device */
Tejun Heoba025082005-08-05 13:28:11 -0700298 int real_max_depth; /* what the array can hold */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 atomic_t refcnt; /* map can be shared */
300};
301
FUJITA Tomonoriabf54392008-08-16 14:10:05 +0900302#define BLK_SCSI_MAX_CMDS (256)
303#define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
304
Martin K. Petersen025146e2009-05-22 17:17:51 -0400305struct queue_limits {
306 unsigned long bounce_pfn;
307 unsigned long seg_boundary_mask;
308
309 unsigned int max_hw_sectors;
310 unsigned int max_sectors;
311 unsigned int max_segment_size;
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400312 unsigned int physical_block_size;
313 unsigned int alignment_offset;
314 unsigned int io_min;
315 unsigned int io_opt;
Martin K. Petersen025146e2009-05-22 17:17:51 -0400316
317 unsigned short logical_block_size;
318 unsigned short max_hw_segments;
319 unsigned short max_phys_segments;
320
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400321 unsigned char misaligned;
Martin K. Petersen025146e2009-05-22 17:17:51 -0400322 unsigned char no_cluster;
323};
324
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325struct request_queue
326{
327 /*
328 * Together with queue_head for cacheline sharing
329 */
330 struct list_head queue_head;
331 struct request *last_merge;
Jens Axboeb374d182008-10-31 10:05:07 +0100332 struct elevator_queue *elevator;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333
334 /*
335 * the queue request freelist, one for reads and one for writes
336 */
337 struct request_list rq;
338
339 request_fn_proc *request_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 make_request_fn *make_request_fn;
341 prep_rq_fn *prep_rq_fn;
342 unplug_fn *unplug_fn;
David Woodhousefb2dce82008-08-05 18:01:53 +0100343 prepare_discard_fn *prepare_discard_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 merge_bvec_fn *merge_bvec_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 prepare_flush_fn *prepare_flush_fn;
Jens Axboeff856ba2006-01-09 16:02:34 +0100346 softirq_done_fn *softirq_done_fn;
Jens Axboe242f9dc2008-09-14 05:55:09 -0700347 rq_timed_out_fn *rq_timed_out_fn;
Tejun Heo2fb98e82008-02-19 11:36:53 +0100348 dma_drain_needed_fn *dma_drain_needed;
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200349 lld_busy_fn *lld_busy_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350
351 /*
Tejun Heo8922e162005-10-20 16:23:44 +0200352 * Dispatch queue sorting
353 */
Jens Axboe1b47f532005-10-20 16:37:00 +0200354 sector_t end_sector;
Tejun Heo8922e162005-10-20 16:23:44 +0200355 struct request *boundary_rq;
Tejun Heo8922e162005-10-20 16:23:44 +0200356
357 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 * Auto-unplugging state
359 */
360 struct timer_list unplug_timer;
361 int unplug_thresh; /* After this many requests */
362 unsigned long unplug_delay; /* After this many jiffies */
363 struct work_struct unplug_work;
364
365 struct backing_dev_info backing_dev_info;
366
367 /*
368 * The queue owner gets to use this for whatever they like.
369 * ll_rw_blk doesn't touch it.
370 */
371 void *queuedata;
372
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 /*
374 * queue needs bounce pages for pages above this limit
375 */
Al Viro8267e262005-10-21 03:20:53 -0400376 gfp_t bounce_gfp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377
378 /*
379 * various queue flags, see QUEUE_* below
380 */
381 unsigned long queue_flags;
382
383 /*
152587d2005-04-12 16:22:06 -0500384 * protects queue structures from reentrancy. ->__queue_lock should
385 * _never_ be used directly, it is queue private. always use
386 * ->queue_lock.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 */
152587d2005-04-12 16:22:06 -0500388 spinlock_t __queue_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 spinlock_t *queue_lock;
390
391 /*
392 * queue kobject
393 */
394 struct kobject kobj;
395
396 /*
397 * queue settings
398 */
399 unsigned long nr_requests; /* Max # of requests */
400 unsigned int nr_congestion_on;
401 unsigned int nr_congestion_off;
402 unsigned int nr_batching;
403
James Bottomleyfa0ccd82008-01-10 11:30:36 -0600404 void *dma_drain_buffer;
405 unsigned int dma_drain_size;
Tejun Heoe3790c72008-03-04 11:18:17 +0100406 unsigned int dma_pad_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 unsigned int dma_alignment;
408
409 struct blk_queue_tag *queue_tags;
Jens Axboe6eca9002007-10-25 10:14:47 +0200410 struct list_head tag_busy_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411
Tejun Heo15853af2005-11-10 08:52:05 +0100412 unsigned int nr_sorted;
Jens Axboe0a7ae2f2009-05-20 08:54:31 +0200413 unsigned int in_flight[2];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414
Jens Axboe242f9dc2008-09-14 05:55:09 -0700415 unsigned int rq_timeout;
416 struct timer_list timeout;
417 struct list_head timeout_list;
418
Martin K. Petersen025146e2009-05-22 17:17:51 -0400419 struct queue_limits limits;
420
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 /*
422 * sg stuff
423 */
424 unsigned int sg_timeout;
425 unsigned int sg_reserved_size;
Christoph Lameter19460892005-06-23 00:08:19 -0700426 int node;
Alexey Dobriyan6c5c9342006-09-29 01:59:40 -0700427#ifdef CONFIG_BLK_DEV_IO_TRACE
Jens Axboe2056a782006-03-23 20:00:26 +0100428 struct blk_trace *blk_trace;
Alexey Dobriyan6c5c9342006-09-29 01:59:40 -0700429#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 /*
431 * reserved for flush operations
432 */
Tejun Heo797e7db2006-01-06 09:51:03 +0100433 unsigned int ordered, next_ordered, ordseq;
434 int orderr, ordcolor;
435 struct request pre_flush_rq, bar_rq, post_flush_rq;
436 struct request *orig_bar_rq;
Al Viro483f4af2006-03-18 18:34:37 -0500437
438 struct mutex sysfs_lock;
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200439
440#if defined(CONFIG_BLK_DEV_BSG)
441 struct bsg_class_device bsg_dev;
442#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443};
444
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445#define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
446#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
447#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
Jens Axboe1faa16d2009-04-06 14:48:01 +0200448#define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
449#define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450#define QUEUE_FLAG_DEAD 5 /* queue being torn down */
451#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
452#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
Jens Axboe64521d12005-10-28 08:30:39 +0200453#define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200454#define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200455#define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
Jens Axboec7c22e42008-09-13 20:26:01 +0200456#define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
Jens Axboe581d4e22008-09-14 05:56:33 -0700457#define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
Kiyoshi Ueda4ee5eaf2008-09-18 10:46:13 -0400458#define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
Jens Axboea68bbdd2008-09-24 13:03:33 +0200459#define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
Fernando Luis Vázquez Cao88e740f2008-10-27 18:44:46 +0900460#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
Jens Axboebc58ba92009-01-23 10:54:44 +0100461#define QUEUE_FLAG_IO_STAT 15 /* do IO stats */
Jens Axboefb1e7532009-07-30 08:18:24 +0200462#define QUEUE_FLAG_CQ 16 /* hardware does queuing */
Jens Axboebc58ba92009-01-23 10:54:44 +0100463
464#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
465 (1 << QUEUE_FLAG_CLUSTER) | \
Jens Axboe01e97f62009-09-03 20:06:47 +0200466 (1 << QUEUE_FLAG_STACKABLE) | \
467 (1 << QUEUE_FLAG_SAME_COMP))
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
Jens Axboe0a7ae2f2009-05-20 08:54:31 +0200523static inline int queue_in_flight(struct request_queue *q)
524{
525 return q->in_flight[0] + q->in_flight[1];
526}
527
Nick Piggin75ad23b2008-04-29 14:48:33 +0200528static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
529{
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700530 WARN_ON_ONCE(!queue_is_locked(q));
Nick Piggin75ad23b2008-04-29 14:48:33 +0200531 __clear_bit(flag, &q->queue_flags);
532}
533
Tejun Heo797e7db2006-01-06 09:51:03 +0100534enum {
535 /*
536 * Hardbarrier is supported with one of the following methods.
537 *
538 * NONE : hardbarrier unsupported
539 * DRAIN : ordering by draining is enough
540 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
541 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
542 * TAG : ordering by tag is enough
543 * TAG_FLUSH : ordering by tag w/ pre and post flushes
544 * TAG_FUA : ordering by tag w/ pre flush and FUA write
545 */
Tejun Heo313e4292008-11-28 13:32:02 +0900546 QUEUE_ORDERED_BY_DRAIN = 0x01,
547 QUEUE_ORDERED_BY_TAG = 0x02,
548 QUEUE_ORDERED_DO_PREFLUSH = 0x10,
Tejun Heof6716202008-11-28 13:32:04 +0900549 QUEUE_ORDERED_DO_BAR = 0x20,
Tejun Heo313e4292008-11-28 13:32:02 +0900550 QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
551 QUEUE_ORDERED_DO_FUA = 0x80,
Tejun Heo797e7db2006-01-06 09:51:03 +0100552
Tejun Heo313e4292008-11-28 13:32:02 +0900553 QUEUE_ORDERED_NONE = 0x00,
Tejun Heo797e7db2006-01-06 09:51:03 +0100554
Tejun Heof6716202008-11-28 13:32:04 +0900555 QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_BY_DRAIN |
556 QUEUE_ORDERED_DO_BAR,
Tejun Heo313e4292008-11-28 13:32:02 +0900557 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
558 QUEUE_ORDERED_DO_PREFLUSH |
559 QUEUE_ORDERED_DO_POSTFLUSH,
560 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
561 QUEUE_ORDERED_DO_PREFLUSH |
562 QUEUE_ORDERED_DO_FUA,
563
Tejun Heof6716202008-11-28 13:32:04 +0900564 QUEUE_ORDERED_TAG = QUEUE_ORDERED_BY_TAG |
565 QUEUE_ORDERED_DO_BAR,
Tejun Heo313e4292008-11-28 13:32:02 +0900566 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
567 QUEUE_ORDERED_DO_PREFLUSH |
568 QUEUE_ORDERED_DO_POSTFLUSH,
569 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
570 QUEUE_ORDERED_DO_PREFLUSH |
571 QUEUE_ORDERED_DO_FUA,
Tejun Heo797e7db2006-01-06 09:51:03 +0100572
573 /*
574 * Ordered operation sequence
575 */
576 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
577 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
578 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
579 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
580 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
581 QUEUE_ORDSEQ_DONE = 0x20,
582};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583
584#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
585#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
Jens Axboefb1e7532009-07-30 08:18:24 +0200586#define blk_queue_queuing(q) test_bit(QUEUE_FLAG_CQ, &(q)->queue_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200588#define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
Jens Axboea68bbdd2008-09-24 13:03:33 +0200589#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
Jens Axboebc58ba92009-01-23 10:54:44 +0100590#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
Tejun Heo797e7db2006-01-06 09:51:03 +0100591#define blk_queue_flushing(q) ((q)->ordseq)
Kiyoshi Ueda4ee5eaf2008-09-18 10:46:13 -0400592#define blk_queue_stackable(q) \
593 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594
Jens Axboe4aff5e22006-08-10 08:44:47 +0200595#define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
596#define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
597#define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
598#define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
599
Mike Christie6000a362008-08-19 18:45:30 -0500600#define blk_failfast_dev(rq) ((rq)->cmd_flags & REQ_FAILFAST_DEV)
601#define blk_failfast_transport(rq) ((rq)->cmd_flags & REQ_FAILFAST_TRANSPORT)
602#define blk_failfast_driver(rq) ((rq)->cmd_flags & REQ_FAILFAST_DRIVER)
603#define blk_noretry_request(rq) (blk_failfast_dev(rq) || \
604 blk_failfast_transport(rq) || \
605 blk_failfast_driver(rq))
Jens Axboe4aff5e22006-08-10 08:44:47 +0200606#define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
Jerome Marchand42dad762009-04-22 14:01:49 +0200607#define blk_rq_io_stat(rq) ((rq)->cmd_flags & REQ_IO_STAT)
Borislav Petkov96c16742009-04-30 18:24:34 +0200608#define blk_rq_quiet(rq) ((rq)->cmd_flags & REQ_QUIET)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609
David Woodhousee17fc0a2008-08-09 16:42:20 +0100610#define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611
Jens Axboe4aff5e22006-08-10 08:44:47 +0200612#define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
613#define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614#define blk_pm_request(rq) \
Jens Axboe4aff5e22006-08-10 08:44:47 +0200615 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616
Jens Axboeab780f12008-08-26 10:25:02 +0200617#define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
Jens Axboe4aff5e22006-08-10 08:44:47 +0200618#define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
619#define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
620#define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
David Woodhousefb2dce82008-08-05 18:01:53 +0100621#define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200622#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
Kiyoshi Ueda336cdb42007-12-11 17:40:30 -0500623/* rq->queuelist of dequeued request must be list_empty() */
624#define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625
626#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
627
Jens Axboe4aff5e22006-08-10 08:44:47 +0200628#define rq_data_dir(rq) ((rq)->cmd_flags & 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629
Jens Axboe9e2585a2006-07-28 09:26:13 +0200630/*
Jens Axboe1faa16d2009-04-06 14:48:01 +0200631 * We regard a request as sync, if either a read or a sync write
Jens Axboe9e2585a2006-07-28 09:26:13 +0200632 */
Jens Axboe1faa16d2009-04-06 14:48:01 +0200633static inline bool rw_is_sync(unsigned int rw_flags)
634{
635 return !(rw_flags & REQ_RW) || (rw_flags & REQ_RW_SYNC);
636}
637
638static inline bool rq_is_sync(struct request *rq)
639{
640 return rw_is_sync(rq->cmd_flags);
641}
642
Jens Axboe5404bc72006-08-10 09:01:02 +0200643#define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
Jens Axboeaeb6faf2009-04-06 14:48:07 +0200644#define rq_noidle(rq) ((rq)->cmd_flags & REQ_NOIDLE)
Jens Axboe9e2585a2006-07-28 09:26:13 +0200645
Jens Axboe1faa16d2009-04-06 14:48:01 +0200646static inline int blk_queue_full(struct request_queue *q, int sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647{
Jens Axboe1faa16d2009-04-06 14:48:01 +0200648 if (sync)
649 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
650 return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651}
652
Jens Axboe1faa16d2009-04-06 14:48:01 +0200653static inline void blk_set_queue_full(struct request_queue *q, int sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654{
Jens Axboe1faa16d2009-04-06 14:48:01 +0200655 if (sync)
656 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 else
Jens Axboe1faa16d2009-04-06 14:48:01 +0200658 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659}
660
Jens Axboe1faa16d2009-04-06 14:48:01 +0200661static inline void blk_clear_queue_full(struct request_queue *q, int sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662{
Jens Axboe1faa16d2009-04-06 14:48:01 +0200663 if (sync)
664 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 else
Jens Axboe1faa16d2009-04-06 14:48:01 +0200666 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667}
668
669
670/*
671 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
672 * it already be started by driver.
673 */
674#define RQ_NOMERGE_FLAGS \
675 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
676#define rq_mergeable(rq) \
David Woodhousee17fc0a2008-08-09 16:42:20 +0100677 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
678 (blk_discard_rq(rq) || blk_fs_request((rq))))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679
680/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 * q->prep_rq_fn return values
682 */
683#define BLKPREP_OK 0 /* serve it */
684#define BLKPREP_KILL 1 /* fatal error, kill */
685#define BLKPREP_DEFER 2 /* leave on queue */
686
687extern unsigned long blk_max_low_pfn, blk_max_pfn;
688
689/*
690 * standard bounce addresses:
691 *
692 * BLK_BOUNCE_HIGH : bounce all highmem pages
693 * BLK_BOUNCE_ANY : don't bounce anything
694 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
695 */
Andi Kleen24728922008-04-21 09:51:05 +0200696
697#if BITS_PER_LONG == 32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
Andi Kleen24728922008-04-21 09:51:05 +0200699#else
700#define BLK_BOUNCE_HIGH -1ULL
701#endif
702#define BLK_BOUNCE_ANY (-1ULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703#define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
704
Jens Axboe3d6392c2007-07-09 12:38:05 +0200705/*
706 * default timeout for SG_IO if none specified
707 */
708#define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
Linus Torvaldsf2f1fa72008-12-05 14:49:18 -0800709#define BLK_MIN_SG_TIMEOUT (7 * HZ)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200710
Christoph Lameter2a7326b2007-07-17 04:03:37 -0700711#ifdef CONFIG_BOUNCE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712extern int init_emergency_isa_pool(void);
Jens Axboe165125e2007-07-24 09:28:11 +0200713extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714#else
715static inline int init_emergency_isa_pool(void)
716{
717 return 0;
718}
Jens Axboe165125e2007-07-24 09:28:11 +0200719static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720{
721}
722#endif /* CONFIG_MMU */
723
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900724struct rq_map_data {
725 struct page **pages;
726 int page_order;
727 int nr_entries;
FUJITA Tomonori56c451f2008-12-18 14:49:37 +0900728 unsigned long offset;
FUJITA Tomonori97ae77a2008-12-18 14:49:38 +0900729 int null_mapped;
FUJITA Tomonoriecb554a2009-07-09 14:46:53 +0200730 int from_user;
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900731};
732
NeilBrown5705f702007-09-25 12:35:59 +0200733struct req_iterator {
734 int i;
735 struct bio *bio;
736};
737
738/* This should not be used directly - use rq_for_each_segment */
Jens Axboe1e428072009-02-23 09:03:10 +0100739#define for_each_bio(_bio) \
740 for (; _bio; _bio = _bio->bi_next)
NeilBrown5705f702007-09-25 12:35:59 +0200741#define __rq_for_each_bio(_bio, rq) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 if ((rq->bio)) \
743 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
744
NeilBrown5705f702007-09-25 12:35:59 +0200745#define rq_for_each_segment(bvl, _rq, _iter) \
746 __rq_for_each_bio(_iter.bio, _rq) \
747 bio_for_each_segment(bvl, _iter.bio, _iter.i)
748
749#define rq_iter_last(rq, _iter) \
750 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
751
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752extern int blk_register_queue(struct gendisk *disk);
753extern void blk_unregister_queue(struct gendisk *disk);
754extern void register_disk(struct gendisk *dev);
755extern void generic_make_request(struct bio *bio);
FUJITA Tomonori2a4aa302008-04-29 09:54:36 +0200756extern void blk_rq_init(struct request_queue *q, struct request *rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757extern void blk_put_request(struct request *);
Jens Axboe165125e2007-07-24 09:28:11 +0200758extern void __blk_put_request(struct request_queue *, struct request *);
Jens Axboe165125e2007-07-24 09:28:11 +0200759extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
Boaz Harrosh79eb63e2009-05-17 18:57:15 +0300760extern struct request *blk_make_request(struct request_queue *, struct bio *,
761 gfp_t);
Jens Axboe165125e2007-07-24 09:28:11 +0200762extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
763extern void blk_requeue_request(struct request_queue *, struct request *);
Kiyoshi Ueda82124d62008-09-18 10:45:38 -0400764extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200765extern int blk_lld_busy(struct request_queue *q);
Kiyoshi Uedab0fd2712009-06-11 13:10:16 +0200766extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
767 struct bio_set *bs, gfp_t gfp_mask,
768 int (*bio_ctr)(struct bio *, struct bio *, void *),
769 void *data);
770extern void blk_rq_unprep_clone(struct request *rq);
Kiyoshi Ueda82124d62008-09-18 10:45:38 -0400771extern int blk_insert_cloned_request(struct request_queue *q,
772 struct request *rq);
Jens Axboe165125e2007-07-24 09:28:11 +0200773extern void blk_plug_device(struct request_queue *);
Jens Axboe6c5e0c42008-08-01 20:31:32 +0200774extern void blk_plug_device_unlocked(struct request_queue *);
Jens Axboe165125e2007-07-24 09:28:11 +0200775extern int blk_remove_plug(struct request_queue *);
776extern void blk_recount_segments(struct request_queue *, struct bio *);
Al Viro74f3c8a2007-08-27 15:38:10 -0400777extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
778 unsigned int, void __user *);
Al Viroe915e872008-09-02 17:16:41 -0400779extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
780 struct scsi_ioctl_command __user *);
Andrew Morton3fcfab12006-10-19 23:28:16 -0700781
782/*
783 * A queue has just exitted congestion. Note this in the global counter of
784 * congested queues, and wake up anyone who was waiting for requests to be
785 * put back.
786 */
Jens Axboe8aa7e842009-07-09 14:52:32 +0200787static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
Andrew Morton3fcfab12006-10-19 23:28:16 -0700788{
Jens Axboe8aa7e842009-07-09 14:52:32 +0200789 clear_bdi_congested(&q->backing_dev_info, sync);
Andrew Morton3fcfab12006-10-19 23:28:16 -0700790}
791
792/*
793 * A queue has just entered congestion. Flag that in the queue's VM-visible
794 * state flags and increment the global gounter of congested queues.
795 */
Jens Axboe8aa7e842009-07-09 14:52:32 +0200796static inline void blk_set_queue_congested(struct request_queue *q, int sync)
Andrew Morton3fcfab12006-10-19 23:28:16 -0700797{
Jens Axboe8aa7e842009-07-09 14:52:32 +0200798 set_bdi_congested(&q->backing_dev_info, sync);
Andrew Morton3fcfab12006-10-19 23:28:16 -0700799}
800
Jens Axboe165125e2007-07-24 09:28:11 +0200801extern void blk_start_queue(struct request_queue *q);
802extern void blk_stop_queue(struct request_queue *q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803extern void blk_sync_queue(struct request_queue *q);
Jens Axboe165125e2007-07-24 09:28:11 +0200804extern void __blk_stop_queue(struct request_queue *q);
Nick Piggin75ad23b2008-04-29 14:48:33 +0200805extern void __blk_run_queue(struct request_queue *);
Jens Axboe165125e2007-07-24 09:28:11 +0200806extern void blk_run_queue(struct request_queue *);
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900807extern int blk_rq_map_user(struct request_queue *, struct request *,
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900808 struct rq_map_data *, void __user *, unsigned long,
809 gfp_t);
Jens Axboe8e5cfc42006-12-19 11:12:46 +0100810extern int blk_rq_unmap_user(struct bio *);
Jens Axboe165125e2007-07-24 09:28:11 +0200811extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
812extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900813 struct rq_map_data *, struct sg_iovec *, int,
814 unsigned int, gfp_t);
Jens Axboe165125e2007-07-24 09:28:11 +0200815extern int blk_execute_rq(struct request_queue *, struct gendisk *,
James Bottomley 994ca9a2005-06-20 14:11:09 +0200816 struct request *, int);
Jens Axboe165125e2007-07-24 09:28:11 +0200817extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
Jens Axboe15fc8582006-01-06 10:00:50 +0100818 struct request *, int, rq_end_io_fn *);
Alan D. Brunelle2ad8b1e2007-11-07 14:26:56 -0500819extern void blk_unplug(struct request_queue *q);
Mike Christie6e39b692005-11-11 05:30:24 -0600820
Jens Axboe165125e2007-07-24 09:28:11 +0200821static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822{
823 return bdev->bd_disk->queue;
824}
825
826static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
827 struct page *page)
828{
829 if (bdi && bdi->unplug_io_fn)
830 bdi->unplug_io_fn(bdi, page);
831}
832
833static inline void blk_run_address_space(struct address_space *mapping)
834{
835 if (mapping)
836 blk_run_backing_dev(mapping->backing_dev_info, NULL);
837}
838
839/*
Tejun Heo80a761f2009-07-03 17:48:17 +0900840 * blk_rq_pos() : the current sector
841 * blk_rq_bytes() : bytes left in the entire request
842 * blk_rq_cur_bytes() : bytes left in the current segment
843 * blk_rq_err_bytes() : bytes left till the next error boundary
844 * blk_rq_sectors() : sectors left in the entire request
845 * blk_rq_cur_sectors() : sectors left in the current segment
846 * blk_rq_err_sectors() : sectors left till the next error boundary
Tejun Heo5efccd12009-04-23 11:05:18 +0900847 */
Tejun Heo5b936292009-05-07 22:24:38 +0900848static inline sector_t blk_rq_pos(const struct request *rq)
849{
Tejun Heoa2dec7b2009-05-07 22:24:44 +0900850 return rq->__sector;
Tejun Heo5b936292009-05-07 22:24:38 +0900851}
852
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900853static inline unsigned int blk_rq_bytes(const struct request *rq)
854{
Tejun Heoa2dec7b2009-05-07 22:24:44 +0900855 return rq->__data_len;
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900856}
857
858static inline int blk_rq_cur_bytes(const struct request *rq)
859{
860 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
861}
Tejun Heo5efccd12009-04-23 11:05:18 +0900862
Tejun Heo80a761f2009-07-03 17:48:17 +0900863extern unsigned int blk_rq_err_bytes(const struct request *rq);
864
Tejun Heo5b936292009-05-07 22:24:38 +0900865static inline unsigned int blk_rq_sectors(const struct request *rq)
866{
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900867 return blk_rq_bytes(rq) >> 9;
Tejun Heo5b936292009-05-07 22:24:38 +0900868}
869
870static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
871{
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900872 return blk_rq_cur_bytes(rq) >> 9;
Tejun Heo5b936292009-05-07 22:24:38 +0900873}
874
Tejun Heo80a761f2009-07-03 17:48:17 +0900875static inline unsigned int blk_rq_err_sectors(const struct request *rq)
876{
877 return blk_rq_err_bytes(rq) >> 9;
878}
879
Tejun Heo5efccd12009-04-23 11:05:18 +0900880/*
Tejun Heo9934c8c2009-05-08 11:54:16 +0900881 * Request issue related functions.
882 */
883extern struct request *blk_peek_request(struct request_queue *q);
884extern void blk_start_request(struct request *rq);
885extern struct request *blk_fetch_request(struct request_queue *q);
886
887/*
Tejun Heo2e60e022009-04-23 11:05:18 +0900888 * Request completion related functions.
889 *
890 * blk_update_request() completes given number of bytes and updates
891 * the request without completing it.
892 *
Tejun Heof06d9a22009-04-23 11:05:19 +0900893 * blk_end_request() and friends. __blk_end_request() must be called
894 * with the request queue spinlock acquired.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895 *
896 * Several drivers define their own end_request and call
Kiyoshi Ueda3bcddea2007-12-11 17:52:28 -0500897 * blk_end_request() for parts of the original function.
898 * This prevents code duplication in drivers.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 */
Tejun Heo2e60e022009-04-23 11:05:18 +0900900extern bool blk_update_request(struct request *rq, int error,
901 unsigned int nr_bytes);
FUJITA Tomonorib1f74492009-05-11 17:56:09 +0900902extern bool blk_end_request(struct request *rq, int error,
903 unsigned int nr_bytes);
904extern void blk_end_request_all(struct request *rq, int error);
905extern bool blk_end_request_cur(struct request *rq, int error);
Tejun Heo80a761f2009-07-03 17:48:17 +0900906extern bool blk_end_request_err(struct request *rq, int error);
FUJITA Tomonorib1f74492009-05-11 17:56:09 +0900907extern bool __blk_end_request(struct request *rq, int error,
908 unsigned int nr_bytes);
909extern void __blk_end_request_all(struct request *rq, int error);
910extern bool __blk_end_request_cur(struct request *rq, int error);
Tejun Heo80a761f2009-07-03 17:48:17 +0900911extern bool __blk_end_request_err(struct request *rq, int error);
Tejun Heo2e60e022009-04-23 11:05:18 +0900912
Jens Axboeff856ba2006-01-09 16:02:34 +0100913extern void blk_complete_request(struct request *);
Jens Axboe242f9dc2008-09-14 05:55:09 -0700914extern void __blk_complete_request(struct request *);
915extern void blk_abort_request(struct request *);
Mike Anderson11914a52008-09-13 20:31:27 +0200916extern void blk_abort_queue(struct request_queue *);
Jens Axboeff856ba2006-01-09 16:02:34 +0100917
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919 * Access functions for manipulating queue properties
920 */
Jens Axboe165125e2007-07-24 09:28:11 +0200921extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
Christoph Lameter19460892005-06-23 00:08:19 -0700922 spinlock_t *lock, int node_id);
Jens Axboe165125e2007-07-24 09:28:11 +0200923extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
924extern void blk_cleanup_queue(struct request_queue *);
925extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
926extern void blk_queue_bounce_limit(struct request_queue *, u64);
927extern void blk_queue_max_sectors(struct request_queue *, unsigned int);
Martin K. Petersenae03bf62009-05-22 17:17:50 -0400928extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
Jens Axboe165125e2007-07-24 09:28:11 +0200929extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short);
930extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short);
931extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
Martin K. Petersene1defc42009-05-22 17:17:49 -0400932extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400933extern void blk_queue_physical_block_size(struct request_queue *, unsigned short);
934extern void blk_queue_alignment_offset(struct request_queue *q,
935 unsigned int alignment);
Martin K. Petersen7c958e32009-07-31 11:49:11 -0400936extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400937extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
Martin K. Petersen3c5820c2009-09-11 21:54:52 +0200938extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400939extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
Martin K. Petersene475bba2009-06-16 08:23:52 +0200940extern void blk_set_default_limits(struct queue_limits *lim);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400941extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
942 sector_t offset);
943extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
944 sector_t offset);
Jens Axboe165125e2007-07-24 09:28:11 +0200945extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
Tejun Heoe3790c72008-03-04 11:18:17 +0100946extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
FUJITA Tomonori27f82212008-07-04 09:30:03 +0200947extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
Tejun Heo2fb98e82008-02-19 11:36:53 +0100948extern int blk_queue_dma_drain(struct request_queue *q,
949 dma_drain_needed_fn *dma_drain_needed,
950 void *buf, unsigned int size);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200951extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
Jens Axboe165125e2007-07-24 09:28:11 +0200952extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
953extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
954extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
955extern void blk_queue_dma_alignment(struct request_queue *, int);
James Bottomley11c3e682007-12-31 16:37:00 -0600956extern void blk_queue_update_dma_alignment(struct request_queue *, int);
Jens Axboe165125e2007-07-24 09:28:11 +0200957extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
David Woodhousefb2dce82008-08-05 18:01:53 +0100958extern void blk_queue_set_discard(struct request_queue *, prepare_discard_fn *);
Jens Axboe242f9dc2008-09-14 05:55:09 -0700959extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
960extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
Jens Axboe165125e2007-07-24 09:28:11 +0200962extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
Tejun Heo8f11b3e2008-11-28 13:32:05 +0900963extern bool blk_do_ordered(struct request_queue *, struct request **);
Jens Axboe165125e2007-07-24 09:28:11 +0200964extern unsigned blk_ordered_cur_seq(struct request_queue *);
Tejun Heo797e7db2006-01-06 09:51:03 +0100965extern unsigned blk_ordered_req_seq(struct request *);
Tejun Heo8f11b3e2008-11-28 13:32:05 +0900966extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967
Jens Axboe165125e2007-07-24 09:28:11 +0200968extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969extern void blk_dump_rq_flags(struct request *, char *);
Jens Axboe165125e2007-07-24 09:28:11 +0200970extern void generic_unplug_device(struct request_queue *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971extern long nr_blockdev_pages(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972
Jens Axboe165125e2007-07-24 09:28:11 +0200973int blk_get_queue(struct request_queue *);
974struct request_queue *blk_alloc_queue(gfp_t);
975struct request_queue *blk_alloc_queue_node(gfp_t, int);
976extern void blk_put_queue(struct request_queue *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977
978/*
979 * tag stuff
980 */
Jens Axboe4aff5e22006-08-10 08:44:47 +0200981#define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
Jens Axboe165125e2007-07-24 09:28:11 +0200982extern int blk_queue_start_tag(struct request_queue *, struct request *);
983extern struct request *blk_queue_find_tag(struct request_queue *, int);
984extern void blk_queue_end_tag(struct request_queue *, struct request *);
985extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
986extern void blk_queue_free_tags(struct request_queue *);
987extern int blk_queue_resize_tags(struct request_queue *, int);
988extern void blk_queue_invalidate_tags(struct request_queue *);
James Bottomley492dfb42006-08-30 15:48:45 -0400989extern struct blk_queue_tag *blk_init_tags(int);
990extern void blk_free_tags(struct blk_queue_tag *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991
David C Somayajuluf583f492006-10-04 08:27:25 +0200992static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
993 int tag)
994{
995 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
996 return NULL;
997 return bqt->tag_index[tag];
998}
999
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000extern int blkdev_issue_flush(struct block_device *, sector_t *);
Christoph Hellwig746cd1e2009-09-12 07:35:43 +02001001#define DISCARD_FL_WAIT 0x01 /* wait for completion */
1002#define DISCARD_FL_BARRIER 0x02 /* issue DISCARD_BARRIER request */
1003extern int blkdev_issue_discard(struct block_device *, sector_t sector,
1004 sector_t nr_sects, gfp_t, int flags);
David Woodhousefb2dce82008-08-05 18:01:53 +01001005
1006static inline int sb_issue_discard(struct super_block *sb,
Hugh Dickins3e6053d2008-09-11 10:57:55 +02001007 sector_t block, sector_t nr_blocks)
David Woodhousefb2dce82008-08-05 18:01:53 +01001008{
1009 block <<= (sb->s_blocksize_bits - 9);
1010 nr_blocks <<= (sb->s_blocksize_bits - 9);
Christoph Hellwig746cd1e2009-09-12 07:35:43 +02001011 return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL,
1012 DISCARD_FL_BARRIER);
David Woodhousefb2dce82008-08-05 18:01:53 +01001013}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014
Jens Axboe018e0442009-06-26 16:27:10 +02001015extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
Adel Gadllah0b07de82008-06-26 13:48:27 +02001016
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017#define MAX_PHYS_SEGMENTS 128
1018#define MAX_HW_SEGMENTS 128
Mike Christiedefd94b2005-12-05 02:37:06 -06001019#define SAFE_MAX_SECTORS 255
1020#define BLK_DEF_MAX_SECTORS 1024
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021
1022#define MAX_SEGMENT_SIZE 65536
1023
Milan Broz0e435ac2008-12-03 12:55:08 +01001024#define BLK_SEG_BOUNDARY_MASK 0xFFFFFFFFUL
1025
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1027
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001028static inline unsigned long queue_bounce_pfn(struct request_queue *q)
1029{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001030 return q->limits.bounce_pfn;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001031}
1032
1033static inline unsigned long queue_segment_boundary(struct request_queue *q)
1034{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001035 return q->limits.seg_boundary_mask;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001036}
1037
1038static inline unsigned int queue_max_sectors(struct request_queue *q)
1039{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001040 return q->limits.max_sectors;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001041}
1042
1043static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1044{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001045 return q->limits.max_hw_sectors;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001046}
1047
1048static inline unsigned short queue_max_hw_segments(struct request_queue *q)
1049{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001050 return q->limits.max_hw_segments;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001051}
1052
1053static inline unsigned short queue_max_phys_segments(struct request_queue *q)
1054{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001055 return q->limits.max_phys_segments;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001056}
1057
1058static inline unsigned int queue_max_segment_size(struct request_queue *q)
1059{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001060 return q->limits.max_segment_size;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001061}
1062
Martin K. Petersene1defc42009-05-22 17:17:49 -04001063static inline unsigned short queue_logical_block_size(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001064{
1065 int retval = 512;
1066
Martin K. Petersen025146e2009-05-22 17:17:51 -04001067 if (q && q->limits.logical_block_size)
1068 retval = q->limits.logical_block_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001069
1070 return retval;
1071}
1072
Martin K. Petersene1defc42009-05-22 17:17:49 -04001073static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001074{
Martin K. Petersene1defc42009-05-22 17:17:49 -04001075 return queue_logical_block_size(bdev_get_queue(bdev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001076}
1077
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001078static inline unsigned int queue_physical_block_size(struct request_queue *q)
1079{
1080 return q->limits.physical_block_size;
1081}
1082
1083static inline unsigned int queue_io_min(struct request_queue *q)
1084{
1085 return q->limits.io_min;
1086}
1087
1088static inline unsigned int queue_io_opt(struct request_queue *q)
1089{
1090 return q->limits.io_opt;
1091}
1092
1093static inline int queue_alignment_offset(struct request_queue *q)
1094{
1095 if (q && q->limits.misaligned)
1096 return -1;
1097
1098 if (q && q->limits.alignment_offset)
1099 return q->limits.alignment_offset;
1100
1101 return 0;
1102}
1103
1104static inline int queue_sector_alignment_offset(struct request_queue *q,
1105 sector_t sector)
1106{
1107 return ((sector << 9) - q->limits.alignment_offset)
1108 & (q->limits.io_min - 1);
1109}
1110
Jens Axboe165125e2007-07-24 09:28:11 +02001111static inline int queue_dma_alignment(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001112{
Pete Wyckoff482eb682008-01-01 10:23:02 -05001113 return q ? q->dma_alignment : 511;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001114}
1115
FUJITA Tomonori87904072008-08-28 15:05:58 +09001116static inline int blk_rq_aligned(struct request_queue *q, void *addr,
1117 unsigned int len)
1118{
1119 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1120 return !((unsigned long)addr & alignment) && !(len & alignment);
1121}
1122
Linus Torvalds1da177e2005-04-16 15:20:36 -07001123/* assumes size > 256 */
1124static inline unsigned int blksize_bits(unsigned int size)
1125{
1126 unsigned int bits = 8;
1127 do {
1128 bits++;
1129 size >>= 1;
1130 } while (size > 256);
1131 return bits;
1132}
1133
Adrian Bunk2befb9e2005-09-10 00:27:17 -07001134static inline unsigned int block_size(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001135{
1136 return bdev->bd_block_size;
1137}
1138
1139typedef struct {struct page *v;} Sector;
1140
1141unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1142
1143static inline void put_dev_sector(Sector p)
1144{
1145 page_cache_release(p.v);
1146}
1147
1148struct work_struct;
Jens Axboe18887ad2008-07-28 13:08:45 +02001149int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001150
Linus Torvalds1da177e2005-04-16 15:20:36 -07001151#define MODULE_ALIAS_BLOCKDEV(major,minor) \
1152 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1153#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1154 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1155
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001156#if defined(CONFIG_BLK_DEV_INTEGRITY)
1157
Jens Axboeb24498d2008-06-27 09:12:09 +02001158#define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1159#define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001160
1161struct blk_integrity_exchg {
1162 void *prot_buf;
1163 void *data_buf;
1164 sector_t sector;
1165 unsigned int data_size;
1166 unsigned short sector_size;
1167 const char *disk_name;
1168};
1169
1170typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1171typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1172typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1173typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1174
1175struct blk_integrity {
1176 integrity_gen_fn *generate_fn;
1177 integrity_vrfy_fn *verify_fn;
1178 integrity_set_tag_fn *set_tag_fn;
1179 integrity_get_tag_fn *get_tag_fn;
1180
1181 unsigned short flags;
1182 unsigned short tuple_size;
1183 unsigned short sector_size;
1184 unsigned short tag_size;
1185
1186 const char *name;
1187
1188 struct kobject kobj;
1189};
1190
1191extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1192extern void blk_integrity_unregister(struct gendisk *);
Martin K. Petersenad7fce92008-10-01 03:38:39 -04001193extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001194extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
1195extern int blk_rq_count_integrity_sg(struct request *);
1196
Jens Axboeb04accc2008-10-02 12:53:22 +02001197static inline
1198struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1199{
1200 return bdev->bd_disk->integrity;
1201}
1202
Martin K. Petersenb02739b2008-10-02 18:47:49 +02001203static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1204{
1205 return disk->integrity;
1206}
1207
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001208static inline int blk_integrity_rq(struct request *rq)
1209{
Martin K. Petersend442cc42008-07-16 16:09:06 -04001210 if (rq->bio == NULL)
1211 return 0;
1212
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001213 return bio_integrity(rq->bio);
1214}
1215
1216#else /* CONFIG_BLK_DEV_INTEGRITY */
1217
1218#define blk_integrity_rq(rq) (0)
1219#define blk_rq_count_integrity_sg(a) (0)
1220#define blk_rq_map_integrity_sg(a, b) (0)
Jens Axboeb04accc2008-10-02 12:53:22 +02001221#define bdev_get_integrity(a) (0)
Martin K. Petersenb02739b2008-10-02 18:47:49 +02001222#define blk_get_integrity(a) (0)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001223#define blk_integrity_compare(a, b) (0)
1224#define blk_integrity_register(a, b) (0)
1225#define blk_integrity_unregister(a) do { } while (0);
1226
1227#endif /* CONFIG_BLK_DEV_INTEGRITY */
1228
Al Viro08f85852007-10-08 13:26:20 -04001229struct block_device_operations {
Al Virod4430d62008-03-02 09:09:22 -05001230 int (*open) (struct block_device *, fmode_t);
1231 int (*release) (struct gendisk *, fmode_t);
1232 int (*locked_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1233 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1234 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
Al Viro08f85852007-10-08 13:26:20 -04001235 int (*direct_access) (struct block_device *, sector_t,
1236 void **, unsigned long *);
1237 int (*media_changed) (struct gendisk *);
Bartlomiej Zolnierkiewiczdb429e92009-06-07 13:52:52 +02001238 unsigned long long (*set_capacity) (struct gendisk *,
1239 unsigned long long);
Al Viro08f85852007-10-08 13:26:20 -04001240 int (*revalidate_disk) (struct gendisk *);
1241 int (*getgeo)(struct block_device *, struct hd_geometry *);
1242 struct module *owner;
1243};
1244
Al Viro633a08b2007-08-29 20:34:12 -04001245extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1246 unsigned long);
David Howells93614012006-09-30 20:45:40 +02001247#else /* CONFIG_BLOCK */
1248/*
1249 * stubs for when the block layer is configured out
1250 */
1251#define buffer_heads_over_limit 0
1252
David Howells93614012006-09-30 20:45:40 +02001253static inline long nr_blockdev_pages(void)
1254{
1255 return 0;
1256}
1257
David Howells93614012006-09-30 20:45:40 +02001258#endif /* CONFIG_BLOCK */
1259
Linus Torvalds1da177e2005-04-16 15:20:36 -07001260#endif