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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_BLKDEV_H
2#define _LINUX_BLKDEV_H
3
Jens Axboef5ff8422007-09-21 09:19:54 +02004#ifdef CONFIG_BLOCK
5
Andrew Mortonbcfd8d32006-08-31 12:56:06 +02006#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007#include <linux/major.h>
8#include <linux/genhd.h>
9#include <linux/list.h>
10#include <linux/timer.h>
11#include <linux/workqueue.h>
12#include <linux/pagemap.h>
13#include <linux/backing-dev.h>
14#include <linux/wait.h>
15#include <linux/mempool.h>
16#include <linux/bio.h>
17#include <linux/module.h>
18#include <linux/stringify.h>
Hugh Dickins3e6053d2008-09-11 10:57:55 +020019#include <linux/gfp.h>
FUJITA Tomonorid351af02007-07-09 12:40:35 +020020#include <linux/bsg.h>
Jens Axboec7c22e42008-09-13 20:26:01 +020021#include <linux/smp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
23#include <asm/scatterlist.h>
24
Christoph Hellwig21b2f0c2006-03-22 17:52:04 +010025struct scsi_ioctl_command;
26
Linus Torvalds1da177e2005-04-16 15:20:36 -070027struct request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -070028struct elevator_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -070029struct request_pm_state;
Jens Axboe2056a782006-03-23 20:00:26 +010030struct blk_trace;
Jens Axboe3d6392c2007-07-09 12:38:05 +020031struct request;
32struct sg_io_hdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34#define BLKDEV_MIN_RQ 4
35#define BLKDEV_MAX_RQ 128 /* Default maximum */
36
Linus Torvalds1da177e2005-04-16 15:20:36 -070037struct request;
Tejun Heo8ffdc652006-01-06 09:49:03 +010038typedef void (rq_end_io_fn)(struct request *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40struct request_list {
Jens Axboe1faa16d2009-04-06 14:48:01 +020041 /*
42 * count[], starved[], and wait[] are indexed by
43 * BLK_RW_SYNC/BLK_RW_ASYNC
44 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 int count[2];
46 int starved[2];
Tejun Heocb98fc82005-10-28 08:29:39 +020047 int elvpriv;
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 mempool_t *rq_pool;
49 wait_queue_head_t wait[2];
Linus Torvalds1da177e2005-04-16 15:20:36 -070050};
51
Jens Axboe4aff5e22006-08-10 08:44:47 +020052/*
53 * request command types
54 */
55enum rq_cmd_type_bits {
56 REQ_TYPE_FS = 1, /* fs request */
57 REQ_TYPE_BLOCK_PC, /* scsi command */
58 REQ_TYPE_SENSE, /* sense request */
59 REQ_TYPE_PM_SUSPEND, /* suspend request */
60 REQ_TYPE_PM_RESUME, /* resume request */
61 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
Jens Axboe4aff5e22006-08-10 08:44:47 +020062 REQ_TYPE_SPECIAL, /* driver defined type */
63 REQ_TYPE_LINUX_BLOCK, /* generic block layer message */
64 /*
65 * for ATA/ATAPI devices. this really doesn't belong here, ide should
66 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
67 * private REQ_LB opcodes to differentiate what type of request this is
68 */
Jens Axboe4aff5e22006-08-10 08:44:47 +020069 REQ_TYPE_ATA_TASKFILE,
Jens Axboecea28852006-10-12 15:08:45 +020070 REQ_TYPE_ATA_PC,
Jens Axboe4aff5e22006-08-10 08:44:47 +020071};
72
Jens Axboe1faa16d2009-04-06 14:48:01 +020073enum {
74 BLK_RW_ASYNC = 0,
75 BLK_RW_SYNC = 1,
76};
77
Jens Axboe4aff5e22006-08-10 08:44:47 +020078/*
79 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
80 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
81 * SCSI cdb.
82 *
83 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
84 * typically to differentiate REQ_TYPE_SPECIAL requests.
85 *
86 */
87enum {
Jens Axboe4aff5e22006-08-10 08:44:47 +020088 REQ_LB_OP_EJECT = 0x40, /* eject request */
David Woodhouse1a8e2bd2008-08-13 12:35:09 +010089 REQ_LB_OP_FLUSH = 0x41, /* flush request */
David Woodhouseeae9acd2008-08-05 18:08:25 +010090 REQ_LB_OP_DISCARD = 0x42, /* discard sectors */
Jens Axboe4aff5e22006-08-10 08:44:47 +020091};
92
93/*
David Woodhoused628eae2008-08-09 16:22:17 +010094 * request type modified bits. first two bits match BIO_RW* bits, important
Jens Axboe4aff5e22006-08-10 08:44:47 +020095 */
96enum rq_flag_bits {
97 __REQ_RW, /* not set, read. set, write */
Mike Christie6000a362008-08-19 18:45:30 -050098 __REQ_FAILFAST_DEV, /* no driver retries of device errors */
99 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
100 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
David Woodhousefb2dce82008-08-05 18:01:53 +0100101 __REQ_DISCARD, /* request to discard sectors */
Jens Axboe4aff5e22006-08-10 08:44:47 +0200102 __REQ_SORTED, /* elevator knows about this request */
103 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
104 __REQ_HARDBARRIER, /* may not be passed by drive either */
105 __REQ_FUA, /* forced unit access */
106 __REQ_NOMERGE, /* don't touch this for merging */
107 __REQ_STARTED, /* drive already may have started this one */
108 __REQ_DONTPREP, /* don't call prep for this one */
109 __REQ_QUEUED, /* uses queueing */
110 __REQ_ELVPRIV, /* elevator private data attached */
111 __REQ_FAILED, /* set if the request failed */
112 __REQ_QUIET, /* don't worry about errors */
113 __REQ_PREEMPT, /* set for "ide_preempt" requests */
114 __REQ_ORDERED_COLOR, /* is before or after barrier */
Jens Axboe1faa16d2009-04-06 14:48:01 +0200115 __REQ_RW_SYNC, /* request is sync (sync write or read) */
Jens Axboe49171e52006-08-10 08:59:11 +0200116 __REQ_ALLOCED, /* request came from our alloc pool */
Jens Axboe5404bc72006-08-10 09:01:02 +0200117 __REQ_RW_META, /* metadata io request */
FUJITA Tomonorif18573a2008-04-11 12:56:52 +0200118 __REQ_COPY_USER, /* contains copies of user pages */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200119 __REQ_INTEGRITY, /* integrity metadata has been remapped */
Jens Axboeaeb6faf2009-04-06 14:48:07 +0200120 __REQ_NOIDLE, /* Don't anticipate more IO after this one */
Jerome Marchand42dad762009-04-22 14:01:49 +0200121 __REQ_IO_STAT, /* account I/O stat */
Jens Axboe4aff5e22006-08-10 08:44:47 +0200122 __REQ_NR_BITS, /* stops here */
123};
124
125#define REQ_RW (1 << __REQ_RW)
Mike Christie6000a362008-08-19 18:45:30 -0500126#define REQ_FAILFAST_DEV (1 << __REQ_FAILFAST_DEV)
127#define REQ_FAILFAST_TRANSPORT (1 << __REQ_FAILFAST_TRANSPORT)
128#define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER)
David Woodhousefb2dce82008-08-05 18:01:53 +0100129#define REQ_DISCARD (1 << __REQ_DISCARD)
Jens Axboe4aff5e22006-08-10 08:44:47 +0200130#define REQ_SORTED (1 << __REQ_SORTED)
131#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
132#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
133#define REQ_FUA (1 << __REQ_FUA)
134#define REQ_NOMERGE (1 << __REQ_NOMERGE)
135#define REQ_STARTED (1 << __REQ_STARTED)
136#define REQ_DONTPREP (1 << __REQ_DONTPREP)
137#define REQ_QUEUED (1 << __REQ_QUEUED)
138#define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
139#define REQ_FAILED (1 << __REQ_FAILED)
140#define REQ_QUIET (1 << __REQ_QUIET)
141#define REQ_PREEMPT (1 << __REQ_PREEMPT)
142#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
143#define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
Jens Axboe49171e52006-08-10 08:59:11 +0200144#define REQ_ALLOCED (1 << __REQ_ALLOCED)
Jens Axboe5404bc72006-08-10 09:01:02 +0200145#define REQ_RW_META (1 << __REQ_RW_META)
FUJITA Tomonorif18573a2008-04-11 12:56:52 +0200146#define REQ_COPY_USER (1 << __REQ_COPY_USER)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200147#define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
Jens Axboeaeb6faf2009-04-06 14:48:07 +0200148#define REQ_NOIDLE (1 << __REQ_NOIDLE)
Jerome Marchand42dad762009-04-22 14:01:49 +0200149#define REQ_IO_STAT (1 << __REQ_IO_STAT)
Jens Axboe4aff5e22006-08-10 08:44:47 +0200150
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151#define BLK_MAX_CDB 16
152
153/*
Jens Axboe63a71382008-02-08 12:41:03 +0100154 * try to put the fields that are referenced together in the same cacheline.
155 * if you modify this structure, be sure to check block/blk-core.c:rq_init()
156 * as well!
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 */
158struct request {
Jens Axboeff856ba2006-01-09 16:02:34 +0100159 struct list_head queuelist;
Jens Axboec7c22e42008-09-13 20:26:01 +0200160 struct call_single_data csd;
161 int cpu;
Jens Axboeff856ba2006-01-09 16:02:34 +0100162
Jens Axboe165125e2007-07-24 09:28:11 +0200163 struct request_queue *q;
Jens Axboee6a1c872006-08-10 09:00:21 +0200164
Jens Axboe4aff5e22006-08-10 08:44:47 +0200165 unsigned int cmd_flags;
166 enum rq_cmd_type_bits cmd_type;
Jens Axboe242f9dc2008-09-14 05:55:09 -0700167 unsigned long atomic_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168
Tejun Heoa2dec7b2009-05-07 22:24:44 +0900169 /* the following two fields are internal, NEVER access directly */
170 sector_t __sector; /* sector cursor */
171 unsigned int __data_len; /* total data len */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172
173 struct bio *bio;
174 struct bio *biotail;
175
Jens Axboe98170642006-07-28 09:23:08 +0200176 struct hlist_node hash; /* merge hash */
Jens Axboee6a1c872006-08-10 09:00:21 +0200177 /*
178 * The rb_node is only used inside the io scheduler, requests
179 * are pruned when moved to the dispatch queue. So let the
180 * completion_data share space with the rb_node.
181 */
182 union {
183 struct rb_node rb_node; /* sort/lookup */
184 void *completion_data;
185 };
Jens Axboe98170642006-07-28 09:23:08 +0200186
Jens Axboeff7d1452006-07-12 14:04:37 +0200187 /*
188 * two pointers are available for the IO schedulers, if they need
189 * more they have to dynamically allocate it.
190 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 void *elevator_private;
Jens Axboeff7d1452006-07-12 14:04:37 +0200192 void *elevator_private2;
193
Jens Axboe8f34ee72006-06-13 09:02:34 +0200194 struct gendisk *rq_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 unsigned long start_time;
196
197 /* Number of scatter-gather DMA addr+len pairs after
198 * physical address coalescing is performed.
199 */
200 unsigned short nr_phys_segments;
201
Jens Axboe8f34ee72006-06-13 09:02:34 +0200202 unsigned short ioprio;
203
Tejun Heo731ec492009-04-23 11:05:20 +0900204 void *special; /* opaque pointer available for LLD use */
205 char *buffer; /* kaddr of the current segment if available */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206
Jens Axboecdd60262006-07-28 09:32:07 +0200207 int tag;
208 int errors;
209
210 int ref_count;
211
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 /*
213 * when request is used as a packet command carrier
214 */
FUJITA Tomonorid7e3c322008-04-29 09:54:39 +0200215 unsigned short cmd_len;
216 unsigned char __cmd[BLK_MAX_CDB];
217 unsigned char *cmd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218
FUJITA Tomonori7a85f882008-03-04 11:17:11 +0100219 unsigned int extra_len; /* length of alignment and padding */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 unsigned int sense_len;
Tejun Heoc3a4d782009-05-07 22:24:37 +0900221 unsigned int resid_len; /* residual count */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 void *sense;
223
Jens Axboe242f9dc2008-09-14 05:55:09 -0700224 unsigned long deadline;
225 struct list_head timeout_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 unsigned int timeout;
Mike Christie17e01f22005-11-11 05:31:37 -0600227 int retries;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228
229 /*
Jens Axboec00895a2006-09-30 20:29:12 +0200230 * completion callback.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 */
232 rq_end_io_fn *end_io;
233 void *end_io_data;
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200234
235 /* for bidi */
236 struct request *next_rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237};
238
Fernando Luis Vázquez Cao766ca442008-08-14 09:59:13 +0200239static inline unsigned short req_get_ioprio(struct request *req)
240{
241 return req->ioprio;
242}
243
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244/*
Jens Axboe4aff5e22006-08-10 08:44:47 +0200245 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 * requests. Some step values could eventually be made generic.
247 */
248struct request_pm_state
249{
250 /* PM state machine step value, currently driver specific */
251 int pm_step;
252 /* requested PM state value (S1, S2, S3, S4, ...) */
253 u32 pm_state;
254 void* data; /* for driver use */
255};
256
257#include <linux/elevator.h>
258
Jens Axboe165125e2007-07-24 09:28:11 +0200259typedef void (request_fn_proc) (struct request_queue *q);
260typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
261typedef int (prep_rq_fn) (struct request_queue *, struct request *);
262typedef void (unplug_fn) (struct request_queue *);
David Woodhousefb2dce82008-08-05 18:01:53 +0100263typedef int (prepare_discard_fn) (struct request_queue *, struct request *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
265struct bio_vec;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200266struct bvec_merge_data {
267 struct block_device *bi_bdev;
268 sector_t bi_sector;
269 unsigned bi_size;
270 unsigned long bi_rw;
271};
272typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
273 struct bio_vec *);
Jens Axboe165125e2007-07-24 09:28:11 +0200274typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
Jens Axboeff856ba2006-01-09 16:02:34 +0100275typedef void (softirq_done_fn)(struct request *);
Tejun Heo2fb98e82008-02-19 11:36:53 +0100276typedef int (dma_drain_needed_fn)(struct request *);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200277typedef int (lld_busy_fn) (struct request_queue *q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278
Jens Axboe242f9dc2008-09-14 05:55:09 -0700279enum blk_eh_timer_return {
280 BLK_EH_NOT_HANDLED,
281 BLK_EH_HANDLED,
282 BLK_EH_RESET_TIMER,
283};
284
285typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
286
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287enum blk_queue_state {
288 Queue_down,
289 Queue_up,
290};
291
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292struct blk_queue_tag {
293 struct request **tag_index; /* map of busy tags */
294 unsigned long *tag_map; /* bit map of free/busy tags */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 int busy; /* current depth */
296 int max_depth; /* what we will send to device */
Tejun Heoba025082005-08-05 13:28:11 -0700297 int real_max_depth; /* what the array can hold */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 atomic_t refcnt; /* map can be shared */
299};
300
FUJITA Tomonoriabf54392008-08-16 14:10:05 +0900301#define BLK_SCSI_MAX_CMDS (256)
302#define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
303
FUJITA Tomonori4beab5c2008-07-26 18:03:25 +0900304struct blk_cmd_filter {
FUJITA Tomonoriabf54392008-08-16 14:10:05 +0900305 unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
306 unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
307 struct kobject kobj;
308};
309
Martin K. Petersen025146e2009-05-22 17:17:51 -0400310struct queue_limits {
311 unsigned long bounce_pfn;
312 unsigned long seg_boundary_mask;
313
314 unsigned int max_hw_sectors;
315 unsigned int max_sectors;
316 unsigned int max_segment_size;
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400317 unsigned int physical_block_size;
318 unsigned int alignment_offset;
319 unsigned int io_min;
320 unsigned int io_opt;
Martin K. Petersen025146e2009-05-22 17:17:51 -0400321
322 unsigned short logical_block_size;
323 unsigned short max_hw_segments;
324 unsigned short max_phys_segments;
325
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400326 unsigned char misaligned;
Martin K. Petersen025146e2009-05-22 17:17:51 -0400327 unsigned char no_cluster;
328};
329
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330struct request_queue
331{
332 /*
333 * Together with queue_head for cacheline sharing
334 */
335 struct list_head queue_head;
336 struct request *last_merge;
Jens Axboeb374d182008-10-31 10:05:07 +0100337 struct elevator_queue *elevator;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338
339 /*
340 * the queue request freelist, one for reads and one for writes
341 */
342 struct request_list rq;
343
344 request_fn_proc *request_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 make_request_fn *make_request_fn;
346 prep_rq_fn *prep_rq_fn;
347 unplug_fn *unplug_fn;
David Woodhousefb2dce82008-08-05 18:01:53 +0100348 prepare_discard_fn *prepare_discard_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 merge_bvec_fn *merge_bvec_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 prepare_flush_fn *prepare_flush_fn;
Jens Axboeff856ba2006-01-09 16:02:34 +0100351 softirq_done_fn *softirq_done_fn;
Jens Axboe242f9dc2008-09-14 05:55:09 -0700352 rq_timed_out_fn *rq_timed_out_fn;
Tejun Heo2fb98e82008-02-19 11:36:53 +0100353 dma_drain_needed_fn *dma_drain_needed;
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200354 lld_busy_fn *lld_busy_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355
356 /*
Tejun Heo8922e162005-10-20 16:23:44 +0200357 * Dispatch queue sorting
358 */
Jens Axboe1b47f532005-10-20 16:37:00 +0200359 sector_t end_sector;
Tejun Heo8922e162005-10-20 16:23:44 +0200360 struct request *boundary_rq;
Tejun Heo8922e162005-10-20 16:23:44 +0200361
362 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 * Auto-unplugging state
364 */
365 struct timer_list unplug_timer;
366 int unplug_thresh; /* After this many requests */
367 unsigned long unplug_delay; /* After this many jiffies */
368 struct work_struct unplug_work;
369
370 struct backing_dev_info backing_dev_info;
371
372 /*
373 * The queue owner gets to use this for whatever they like.
374 * ll_rw_blk doesn't touch it.
375 */
376 void *queuedata;
377
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 /*
379 * queue needs bounce pages for pages above this limit
380 */
Al Viro8267e262005-10-21 03:20:53 -0400381 gfp_t bounce_gfp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382
383 /*
384 * various queue flags, see QUEUE_* below
385 */
386 unsigned long queue_flags;
387
388 /*
152587d2005-04-12 16:22:06 -0500389 * protects queue structures from reentrancy. ->__queue_lock should
390 * _never_ be used directly, it is queue private. always use
391 * ->queue_lock.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 */
152587d2005-04-12 16:22:06 -0500393 spinlock_t __queue_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 spinlock_t *queue_lock;
395
396 /*
397 * queue kobject
398 */
399 struct kobject kobj;
400
401 /*
402 * queue settings
403 */
404 unsigned long nr_requests; /* Max # of requests */
405 unsigned int nr_congestion_on;
406 unsigned int nr_congestion_off;
407 unsigned int nr_batching;
408
James Bottomleyfa0ccd82008-01-10 11:30:36 -0600409 void *dma_drain_buffer;
410 unsigned int dma_drain_size;
Tejun Heoe3790c72008-03-04 11:18:17 +0100411 unsigned int dma_pad_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 unsigned int dma_alignment;
413
414 struct blk_queue_tag *queue_tags;
Jens Axboe6eca9002007-10-25 10:14:47 +0200415 struct list_head tag_busy_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416
Tejun Heo15853af2005-11-10 08:52:05 +0100417 unsigned int nr_sorted;
Jens Axboe0a7ae2f2009-05-20 08:54:31 +0200418 unsigned int in_flight[2];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419
Jens Axboe242f9dc2008-09-14 05:55:09 -0700420 unsigned int rq_timeout;
421 struct timer_list timeout;
422 struct list_head timeout_list;
423
Martin K. Petersen025146e2009-05-22 17:17:51 -0400424 struct queue_limits limits;
425
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 /*
427 * sg stuff
428 */
429 unsigned int sg_timeout;
430 unsigned int sg_reserved_size;
Christoph Lameter19460892005-06-23 00:08:19 -0700431 int node;
Alexey Dobriyan6c5c9342006-09-29 01:59:40 -0700432#ifdef CONFIG_BLK_DEV_IO_TRACE
Jens Axboe2056a782006-03-23 20:00:26 +0100433 struct blk_trace *blk_trace;
Alexey Dobriyan6c5c9342006-09-29 01:59:40 -0700434#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 /*
436 * reserved for flush operations
437 */
Tejun Heo797e7db2006-01-06 09:51:03 +0100438 unsigned int ordered, next_ordered, ordseq;
439 int orderr, ordcolor;
440 struct request pre_flush_rq, bar_rq, post_flush_rq;
441 struct request *orig_bar_rq;
Al Viro483f4af2006-03-18 18:34:37 -0500442
443 struct mutex sysfs_lock;
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200444
445#if defined(CONFIG_BLK_DEV_BSG)
446 struct bsg_class_device bsg_dev;
447#endif
FUJITA Tomonori4beab5c2008-07-26 18:03:25 +0900448 struct blk_cmd_filter cmd_filter;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449};
450
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451#define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
452#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
453#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
Jens Axboe1faa16d2009-04-06 14:48:01 +0200454#define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
455#define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456#define QUEUE_FLAG_DEAD 5 /* queue being torn down */
457#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
458#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
Jens Axboe64521d12005-10-28 08:30:39 +0200459#define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200460#define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200461#define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
Jens Axboec7c22e42008-09-13 20:26:01 +0200462#define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
Jens Axboe581d4e22008-09-14 05:56:33 -0700463#define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
Kiyoshi Ueda4ee5eaf2008-09-18 10:46:13 -0400464#define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
Jens Axboea68bbdd2008-09-24 13:03:33 +0200465#define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
Fernando Luis Vázquez Cao88e740f2008-10-27 18:44:46 +0900466#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
Jens Axboebc58ba92009-01-23 10:54:44 +0100467#define QUEUE_FLAG_IO_STAT 15 /* do IO stats */
468
469#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
470 (1 << QUEUE_FLAG_CLUSTER) | \
Jens Axboe0648e102009-02-02 08:43:48 +0100471 (1 << QUEUE_FLAG_STACKABLE))
Tejun Heo797e7db2006-01-06 09:51:03 +0100472
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700473static inline int queue_is_locked(struct request_queue *q)
474{
Jens Axboe7663c1e2008-04-29 21:31:27 +0200475#ifdef CONFIG_SMP
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700476 spinlock_t *lock = q->queue_lock;
477 return lock && spin_is_locked(lock);
Jens Axboe7663c1e2008-04-29 21:31:27 +0200478#else
479 return 1;
480#endif
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700481}
482
Nick Piggin75ad23b2008-04-29 14:48:33 +0200483static inline void queue_flag_set_unlocked(unsigned int flag,
484 struct request_queue *q)
485{
486 __set_bit(flag, &q->queue_flags);
487}
488
Jens Axboee48ec692008-07-03 13:18:54 +0200489static inline int queue_flag_test_and_clear(unsigned int flag,
490 struct request_queue *q)
491{
492 WARN_ON_ONCE(!queue_is_locked(q));
493
494 if (test_bit(flag, &q->queue_flags)) {
495 __clear_bit(flag, &q->queue_flags);
496 return 1;
497 }
498
499 return 0;
500}
501
502static inline int queue_flag_test_and_set(unsigned int flag,
503 struct request_queue *q)
504{
505 WARN_ON_ONCE(!queue_is_locked(q));
506
507 if (!test_bit(flag, &q->queue_flags)) {
508 __set_bit(flag, &q->queue_flags);
509 return 0;
510 }
511
512 return 1;
513}
514
Nick Piggin75ad23b2008-04-29 14:48:33 +0200515static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
516{
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700517 WARN_ON_ONCE(!queue_is_locked(q));
Nick Piggin75ad23b2008-04-29 14:48:33 +0200518 __set_bit(flag, &q->queue_flags);
519}
520
521static inline void queue_flag_clear_unlocked(unsigned int flag,
522 struct request_queue *q)
523{
524 __clear_bit(flag, &q->queue_flags);
525}
526
Jens Axboe0a7ae2f2009-05-20 08:54:31 +0200527static inline int queue_in_flight(struct request_queue *q)
528{
529 return q->in_flight[0] + q->in_flight[1];
530}
531
Nick Piggin75ad23b2008-04-29 14:48:33 +0200532static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
533{
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700534 WARN_ON_ONCE(!queue_is_locked(q));
Nick Piggin75ad23b2008-04-29 14:48:33 +0200535 __clear_bit(flag, &q->queue_flags);
536}
537
Tejun Heo797e7db2006-01-06 09:51:03 +0100538enum {
539 /*
540 * Hardbarrier is supported with one of the following methods.
541 *
542 * NONE : hardbarrier unsupported
543 * DRAIN : ordering by draining is enough
544 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
545 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
546 * TAG : ordering by tag is enough
547 * TAG_FLUSH : ordering by tag w/ pre and post flushes
548 * TAG_FUA : ordering by tag w/ pre flush and FUA write
549 */
Tejun Heo313e4292008-11-28 13:32:02 +0900550 QUEUE_ORDERED_BY_DRAIN = 0x01,
551 QUEUE_ORDERED_BY_TAG = 0x02,
552 QUEUE_ORDERED_DO_PREFLUSH = 0x10,
Tejun Heof6716202008-11-28 13:32:04 +0900553 QUEUE_ORDERED_DO_BAR = 0x20,
Tejun Heo313e4292008-11-28 13:32:02 +0900554 QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
555 QUEUE_ORDERED_DO_FUA = 0x80,
Tejun Heo797e7db2006-01-06 09:51:03 +0100556
Tejun Heo313e4292008-11-28 13:32:02 +0900557 QUEUE_ORDERED_NONE = 0x00,
Tejun Heo797e7db2006-01-06 09:51:03 +0100558
Tejun Heof6716202008-11-28 13:32:04 +0900559 QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_BY_DRAIN |
560 QUEUE_ORDERED_DO_BAR,
Tejun Heo313e4292008-11-28 13:32:02 +0900561 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
562 QUEUE_ORDERED_DO_PREFLUSH |
563 QUEUE_ORDERED_DO_POSTFLUSH,
564 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
565 QUEUE_ORDERED_DO_PREFLUSH |
566 QUEUE_ORDERED_DO_FUA,
567
Tejun Heof6716202008-11-28 13:32:04 +0900568 QUEUE_ORDERED_TAG = QUEUE_ORDERED_BY_TAG |
569 QUEUE_ORDERED_DO_BAR,
Tejun Heo313e4292008-11-28 13:32:02 +0900570 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
571 QUEUE_ORDERED_DO_PREFLUSH |
572 QUEUE_ORDERED_DO_POSTFLUSH,
573 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
574 QUEUE_ORDERED_DO_PREFLUSH |
575 QUEUE_ORDERED_DO_FUA,
Tejun Heo797e7db2006-01-06 09:51:03 +0100576
577 /*
578 * Ordered operation sequence
579 */
580 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
581 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
582 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
583 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
584 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
585 QUEUE_ORDSEQ_DONE = 0x20,
586};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587
588#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
589#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
590#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200591#define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
Jens Axboea68bbdd2008-09-24 13:03:33 +0200592#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
Jens Axboebc58ba92009-01-23 10:54:44 +0100593#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
Tejun Heo797e7db2006-01-06 09:51:03 +0100594#define blk_queue_flushing(q) ((q)->ordseq)
Kiyoshi Ueda4ee5eaf2008-09-18 10:46:13 -0400595#define blk_queue_stackable(q) \
596 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597
Jens Axboe4aff5e22006-08-10 08:44:47 +0200598#define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
599#define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
600#define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
601#define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
602
Mike Christie6000a362008-08-19 18:45:30 -0500603#define blk_failfast_dev(rq) ((rq)->cmd_flags & REQ_FAILFAST_DEV)
604#define blk_failfast_transport(rq) ((rq)->cmd_flags & REQ_FAILFAST_TRANSPORT)
605#define blk_failfast_driver(rq) ((rq)->cmd_flags & REQ_FAILFAST_DRIVER)
606#define blk_noretry_request(rq) (blk_failfast_dev(rq) || \
607 blk_failfast_transport(rq) || \
608 blk_failfast_driver(rq))
Jens Axboe4aff5e22006-08-10 08:44:47 +0200609#define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
Jerome Marchand42dad762009-04-22 14:01:49 +0200610#define blk_rq_io_stat(rq) ((rq)->cmd_flags & REQ_IO_STAT)
Borislav Petkov96c16742009-04-30 18:24:34 +0200611#define blk_rq_quiet(rq) ((rq)->cmd_flags & REQ_QUIET)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612
David Woodhousee17fc0a2008-08-09 16:42:20 +0100613#define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614
Jens Axboe4aff5e22006-08-10 08:44:47 +0200615#define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
616#define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617#define blk_pm_request(rq) \
Jens Axboe4aff5e22006-08-10 08:44:47 +0200618 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619
Jens Axboeab780f12008-08-26 10:25:02 +0200620#define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
Jens Axboe4aff5e22006-08-10 08:44:47 +0200621#define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
622#define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
623#define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
David Woodhousefb2dce82008-08-05 18:01:53 +0100624#define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200625#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
Kiyoshi Ueda336cdb42007-12-11 17:40:30 -0500626/* rq->queuelist of dequeued request must be list_empty() */
627#define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628
629#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
630
Jens Axboe4aff5e22006-08-10 08:44:47 +0200631#define rq_data_dir(rq) ((rq)->cmd_flags & 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632
Jens Axboe9e2585a2006-07-28 09:26:13 +0200633/*
Jens Axboe1faa16d2009-04-06 14:48:01 +0200634 * We regard a request as sync, if either a read or a sync write
Jens Axboe9e2585a2006-07-28 09:26:13 +0200635 */
Jens Axboe1faa16d2009-04-06 14:48:01 +0200636static inline bool rw_is_sync(unsigned int rw_flags)
637{
638 return !(rw_flags & REQ_RW) || (rw_flags & REQ_RW_SYNC);
639}
640
641static inline bool rq_is_sync(struct request *rq)
642{
643 return rw_is_sync(rq->cmd_flags);
644}
645
Jens Axboe5404bc72006-08-10 09:01:02 +0200646#define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
Jens Axboeaeb6faf2009-04-06 14:48:07 +0200647#define rq_noidle(rq) ((rq)->cmd_flags & REQ_NOIDLE)
Jens Axboe9e2585a2006-07-28 09:26:13 +0200648
Jens Axboe1faa16d2009-04-06 14:48:01 +0200649static inline int blk_queue_full(struct request_queue *q, int sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650{
Jens Axboe1faa16d2009-04-06 14:48:01 +0200651 if (sync)
652 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
653 return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654}
655
Jens Axboe1faa16d2009-04-06 14:48:01 +0200656static inline void blk_set_queue_full(struct request_queue *q, int sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657{
Jens Axboe1faa16d2009-04-06 14:48:01 +0200658 if (sync)
659 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 else
Jens Axboe1faa16d2009-04-06 14:48:01 +0200661 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662}
663
Jens Axboe1faa16d2009-04-06 14:48:01 +0200664static inline void blk_clear_queue_full(struct request_queue *q, int sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665{
Jens Axboe1faa16d2009-04-06 14:48:01 +0200666 if (sync)
667 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 else
Jens Axboe1faa16d2009-04-06 14:48:01 +0200669 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670}
671
672
673/*
674 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
675 * it already be started by driver.
676 */
677#define RQ_NOMERGE_FLAGS \
678 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
679#define rq_mergeable(rq) \
David Woodhousee17fc0a2008-08-09 16:42:20 +0100680 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
681 (blk_discard_rq(rq) || blk_fs_request((rq))))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682
683/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 * q->prep_rq_fn return values
685 */
686#define BLKPREP_OK 0 /* serve it */
687#define BLKPREP_KILL 1 /* fatal error, kill */
688#define BLKPREP_DEFER 2 /* leave on queue */
689
690extern unsigned long blk_max_low_pfn, blk_max_pfn;
691
692/*
693 * standard bounce addresses:
694 *
695 * BLK_BOUNCE_HIGH : bounce all highmem pages
696 * BLK_BOUNCE_ANY : don't bounce anything
697 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
698 */
Andi Kleen24728922008-04-21 09:51:05 +0200699
700#if BITS_PER_LONG == 32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
Andi Kleen24728922008-04-21 09:51:05 +0200702#else
703#define BLK_BOUNCE_HIGH -1ULL
704#endif
705#define BLK_BOUNCE_ANY (-1ULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706#define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
707
Jens Axboe3d6392c2007-07-09 12:38:05 +0200708/*
709 * default timeout for SG_IO if none specified
710 */
711#define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
Linus Torvaldsf2f1fa72008-12-05 14:49:18 -0800712#define BLK_MIN_SG_TIMEOUT (7 * HZ)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200713
Christoph Lameter2a7326b2007-07-17 04:03:37 -0700714#ifdef CONFIG_BOUNCE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715extern int init_emergency_isa_pool(void);
Jens Axboe165125e2007-07-24 09:28:11 +0200716extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717#else
718static inline int init_emergency_isa_pool(void)
719{
720 return 0;
721}
Jens Axboe165125e2007-07-24 09:28:11 +0200722static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723{
724}
725#endif /* CONFIG_MMU */
726
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900727struct rq_map_data {
728 struct page **pages;
729 int page_order;
730 int nr_entries;
FUJITA Tomonori56c451f2008-12-18 14:49:37 +0900731 unsigned long offset;
FUJITA Tomonori97ae77a2008-12-18 14:49:38 +0900732 int null_mapped;
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900733};
734
NeilBrown5705f702007-09-25 12:35:59 +0200735struct req_iterator {
736 int i;
737 struct bio *bio;
738};
739
740/* This should not be used directly - use rq_for_each_segment */
Jens Axboe1e428072009-02-23 09:03:10 +0100741#define for_each_bio(_bio) \
742 for (; _bio; _bio = _bio->bi_next)
NeilBrown5705f702007-09-25 12:35:59 +0200743#define __rq_for_each_bio(_bio, rq) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 if ((rq->bio)) \
745 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
746
NeilBrown5705f702007-09-25 12:35:59 +0200747#define rq_for_each_segment(bvl, _rq, _iter) \
748 __rq_for_each_bio(_iter.bio, _rq) \
749 bio_for_each_segment(bvl, _iter.bio, _iter.i)
750
751#define rq_iter_last(rq, _iter) \
752 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
753
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754extern int blk_register_queue(struct gendisk *disk);
755extern void blk_unregister_queue(struct gendisk *disk);
756extern void register_disk(struct gendisk *dev);
757extern void generic_make_request(struct bio *bio);
FUJITA Tomonori2a4aa302008-04-29 09:54:36 +0200758extern void blk_rq_init(struct request_queue *q, struct request *rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759extern void blk_put_request(struct request *);
Jens Axboe165125e2007-07-24 09:28:11 +0200760extern void __blk_put_request(struct request_queue *, struct request *);
Jens Axboe165125e2007-07-24 09:28:11 +0200761extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
Boaz Harrosh79eb63e2009-05-17 18:57:15 +0300762extern struct request *blk_make_request(struct request_queue *, struct bio *,
763 gfp_t);
Jens Axboe165125e2007-07-24 09:28:11 +0200764extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
765extern void blk_requeue_request(struct request_queue *, struct request *);
Kiyoshi Ueda82124d62008-09-18 10:45:38 -0400766extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200767extern int blk_lld_busy(struct request_queue *q);
Kiyoshi Uedab0fd2712009-06-11 13:10:16 +0200768extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
769 struct bio_set *bs, gfp_t gfp_mask,
770 int (*bio_ctr)(struct bio *, struct bio *, void *),
771 void *data);
772extern void blk_rq_unprep_clone(struct request *rq);
Kiyoshi Ueda82124d62008-09-18 10:45:38 -0400773extern int blk_insert_cloned_request(struct request_queue *q,
774 struct request *rq);
Jens Axboe165125e2007-07-24 09:28:11 +0200775extern void blk_plug_device(struct request_queue *);
Jens Axboe6c5e0c42008-08-01 20:31:32 +0200776extern void blk_plug_device_unlocked(struct request_queue *);
Jens Axboe165125e2007-07-24 09:28:11 +0200777extern int blk_remove_plug(struct request_queue *);
778extern void blk_recount_segments(struct request_queue *, struct bio *);
Al Viro74f3c8a2007-08-27 15:38:10 -0400779extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
780 unsigned int, void __user *);
Al Viroe915e872008-09-02 17:16:41 -0400781extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
782 struct scsi_ioctl_command __user *);
Andrew Morton3fcfab12006-10-19 23:28:16 -0700783
784/*
785 * A queue has just exitted congestion. Note this in the global counter of
786 * congested queues, and wake up anyone who was waiting for requests to be
787 * put back.
788 */
Jens Axboe165125e2007-07-24 09:28:11 +0200789static inline void blk_clear_queue_congested(struct request_queue *q, int rw)
Andrew Morton3fcfab12006-10-19 23:28:16 -0700790{
791 clear_bdi_congested(&q->backing_dev_info, rw);
792}
793
794/*
795 * A queue has just entered congestion. Flag that in the queue's VM-visible
796 * state flags and increment the global gounter of congested queues.
797 */
Jens Axboe165125e2007-07-24 09:28:11 +0200798static inline void blk_set_queue_congested(struct request_queue *q, int rw)
Andrew Morton3fcfab12006-10-19 23:28:16 -0700799{
800 set_bdi_congested(&q->backing_dev_info, rw);
801}
802
Jens Axboe165125e2007-07-24 09:28:11 +0200803extern void blk_start_queue(struct request_queue *q);
804extern void blk_stop_queue(struct request_queue *q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805extern void blk_sync_queue(struct request_queue *q);
Jens Axboe165125e2007-07-24 09:28:11 +0200806extern void __blk_stop_queue(struct request_queue *q);
Nick Piggin75ad23b2008-04-29 14:48:33 +0200807extern void __blk_run_queue(struct request_queue *);
Jens Axboe165125e2007-07-24 09:28:11 +0200808extern void blk_run_queue(struct request_queue *);
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900809extern int blk_rq_map_user(struct request_queue *, struct request *,
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900810 struct rq_map_data *, void __user *, unsigned long,
811 gfp_t);
Jens Axboe8e5cfc42006-12-19 11:12:46 +0100812extern int blk_rq_unmap_user(struct bio *);
Jens Axboe165125e2007-07-24 09:28:11 +0200813extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
814extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900815 struct rq_map_data *, struct sg_iovec *, int,
816 unsigned int, gfp_t);
Jens Axboe165125e2007-07-24 09:28:11 +0200817extern int blk_execute_rq(struct request_queue *, struct gendisk *,
James Bottomley 994ca9a2005-06-20 14:11:09 +0200818 struct request *, int);
Jens Axboe165125e2007-07-24 09:28:11 +0200819extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
Jens Axboe15fc8582006-01-06 10:00:50 +0100820 struct request *, int, rq_end_io_fn *);
Alan D. Brunelle2ad8b1e2007-11-07 14:26:56 -0500821extern void blk_unplug(struct request_queue *q);
Mike Christie6e39b69e2005-11-11 05:30:24 -0600822
Jens Axboe165125e2007-07-24 09:28:11 +0200823static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824{
825 return bdev->bd_disk->queue;
826}
827
828static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
829 struct page *page)
830{
831 if (bdi && bdi->unplug_io_fn)
832 bdi->unplug_io_fn(bdi, page);
833}
834
835static inline void blk_run_address_space(struct address_space *mapping)
836{
837 if (mapping)
838 blk_run_backing_dev(mapping->backing_dev_info, NULL);
839}
840
841/*
Tejun Heo5b936292009-05-07 22:24:38 +0900842 * blk_rq_pos() : the current sector
843 * blk_rq_bytes() : bytes left in the entire request
844 * blk_rq_cur_bytes() : bytes left in the current segment
845 * blk_rq_sectors() : sectors left in the entire request
846 * blk_rq_cur_sectors() : sectors left in the current segment
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 Heo5b936292009-05-07 22:24:38 +0900863static inline unsigned int blk_rq_sectors(const struct request *rq)
864{
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900865 return blk_rq_bytes(rq) >> 9;
Tejun Heo5b936292009-05-07 22:24:38 +0900866}
867
868static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
869{
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900870 return blk_rq_cur_bytes(rq) >> 9;
Tejun Heo5b936292009-05-07 22:24:38 +0900871}
872
Tejun Heo5efccd12009-04-23 11:05:18 +0900873/*
Tejun Heo9934c8c2009-05-08 11:54:16 +0900874 * Request issue related functions.
875 */
876extern struct request *blk_peek_request(struct request_queue *q);
877extern void blk_start_request(struct request *rq);
878extern struct request *blk_fetch_request(struct request_queue *q);
879
880/*
Tejun Heo2e60e022009-04-23 11:05:18 +0900881 * Request completion related functions.
882 *
883 * blk_update_request() completes given number of bytes and updates
884 * the request without completing it.
885 *
Tejun Heof06d9a22009-04-23 11:05:19 +0900886 * blk_end_request() and friends. __blk_end_request() must be called
887 * with the request queue spinlock acquired.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888 *
889 * Several drivers define their own end_request and call
Kiyoshi Ueda3bcddea2007-12-11 17:52:28 -0500890 * blk_end_request() for parts of the original function.
891 * This prevents code duplication in drivers.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892 */
Tejun Heo2e60e022009-04-23 11:05:18 +0900893extern bool blk_update_request(struct request *rq, int error,
894 unsigned int nr_bytes);
FUJITA Tomonorib1f74492009-05-11 17:56:09 +0900895extern bool blk_end_request(struct request *rq, int error,
896 unsigned int nr_bytes);
897extern void blk_end_request_all(struct request *rq, int error);
898extern bool blk_end_request_cur(struct request *rq, int error);
899extern bool __blk_end_request(struct request *rq, int error,
900 unsigned int nr_bytes);
901extern void __blk_end_request_all(struct request *rq, int error);
902extern bool __blk_end_request_cur(struct request *rq, int error);
Tejun Heo2e60e022009-04-23 11:05:18 +0900903
Jens Axboeff856ba2006-01-09 16:02:34 +0100904extern void blk_complete_request(struct request *);
Jens Axboe242f9dc2008-09-14 05:55:09 -0700905extern void __blk_complete_request(struct request *);
906extern void blk_abort_request(struct request *);
Mike Anderson11914a52008-09-13 20:31:27 +0200907extern void blk_abort_queue(struct request_queue *);
Jens Axboeff856ba2006-01-09 16:02:34 +0100908
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910 * Access functions for manipulating queue properties
911 */
Jens Axboe165125e2007-07-24 09:28:11 +0200912extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
Christoph Lameter19460892005-06-23 00:08:19 -0700913 spinlock_t *lock, int node_id);
Jens Axboe165125e2007-07-24 09:28:11 +0200914extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
915extern void blk_cleanup_queue(struct request_queue *);
916extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
917extern void blk_queue_bounce_limit(struct request_queue *, u64);
918extern void blk_queue_max_sectors(struct request_queue *, unsigned int);
Martin K. Petersenae03bf62009-05-22 17:17:50 -0400919extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
Jens Axboe165125e2007-07-24 09:28:11 +0200920extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short);
921extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short);
922extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
Martin K. Petersene1defc42009-05-22 17:17:49 -0400923extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400924extern void blk_queue_physical_block_size(struct request_queue *, unsigned short);
925extern void blk_queue_alignment_offset(struct request_queue *q,
926 unsigned int alignment);
927extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
928extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
Martin K. Petersene475bba2009-06-16 08:23:52 +0200929extern void blk_set_default_limits(struct queue_limits *lim);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400930extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
931 sector_t offset);
932extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
933 sector_t offset);
Jens Axboe165125e2007-07-24 09:28:11 +0200934extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
Tejun Heoe3790c72008-03-04 11:18:17 +0100935extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
FUJITA Tomonori27f82212008-07-04 09:30:03 +0200936extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
Tejun Heo2fb98e82008-02-19 11:36:53 +0100937extern int blk_queue_dma_drain(struct request_queue *q,
938 dma_drain_needed_fn *dma_drain_needed,
939 void *buf, unsigned int size);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200940extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
Jens Axboe165125e2007-07-24 09:28:11 +0200941extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
942extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
943extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
944extern void blk_queue_dma_alignment(struct request_queue *, int);
James Bottomley11c3e682007-12-31 16:37:00 -0600945extern void blk_queue_update_dma_alignment(struct request_queue *, int);
Jens Axboe165125e2007-07-24 09:28:11 +0200946extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
David Woodhousefb2dce82008-08-05 18:01:53 +0100947extern void blk_queue_set_discard(struct request_queue *, prepare_discard_fn *);
Jens Axboe242f9dc2008-09-14 05:55:09 -0700948extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
949extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
Jens Axboe165125e2007-07-24 09:28:11 +0200951extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
Tejun Heo8f11b3e2008-11-28 13:32:05 +0900952extern bool blk_do_ordered(struct request_queue *, struct request **);
Jens Axboe165125e2007-07-24 09:28:11 +0200953extern unsigned blk_ordered_cur_seq(struct request_queue *);
Tejun Heo797e7db2006-01-06 09:51:03 +0100954extern unsigned blk_ordered_req_seq(struct request *);
Tejun Heo8f11b3e2008-11-28 13:32:05 +0900955extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956
Jens Axboe165125e2007-07-24 09:28:11 +0200957extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958extern void blk_dump_rq_flags(struct request *, char *);
Jens Axboe165125e2007-07-24 09:28:11 +0200959extern void generic_unplug_device(struct request_queue *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960extern long nr_blockdev_pages(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961
Jens Axboe165125e2007-07-24 09:28:11 +0200962int blk_get_queue(struct request_queue *);
963struct request_queue *blk_alloc_queue(gfp_t);
964struct request_queue *blk_alloc_queue_node(gfp_t, int);
965extern void blk_put_queue(struct request_queue *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966
967/*
968 * tag stuff
969 */
Jens Axboe4aff5e22006-08-10 08:44:47 +0200970#define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
Jens Axboe165125e2007-07-24 09:28:11 +0200971extern int blk_queue_start_tag(struct request_queue *, struct request *);
972extern struct request *blk_queue_find_tag(struct request_queue *, int);
973extern void blk_queue_end_tag(struct request_queue *, struct request *);
974extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
975extern void blk_queue_free_tags(struct request_queue *);
976extern int blk_queue_resize_tags(struct request_queue *, int);
977extern void blk_queue_invalidate_tags(struct request_queue *);
James Bottomley492dfb42006-08-30 15:48:45 -0400978extern struct blk_queue_tag *blk_init_tags(int);
979extern void blk_free_tags(struct blk_queue_tag *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980
David C Somayajuluf583f492006-10-04 08:27:25 +0200981static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
982 int tag)
983{
984 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
985 return NULL;
986 return bqt->tag_index[tag];
987}
988
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989extern int blkdev_issue_flush(struct block_device *, sector_t *);
Hugh Dickins3e6053d2008-09-11 10:57:55 +0200990extern int blkdev_issue_discard(struct block_device *,
991 sector_t sector, sector_t nr_sects, gfp_t);
David Woodhousefb2dce82008-08-05 18:01:53 +0100992
993static inline int sb_issue_discard(struct super_block *sb,
Hugh Dickins3e6053d2008-09-11 10:57:55 +0200994 sector_t block, sector_t nr_blocks)
David Woodhousefb2dce82008-08-05 18:01:53 +0100995{
996 block <<= (sb->s_blocksize_bits - 9);
997 nr_blocks <<= (sb->s_blocksize_bits - 9);
Hugh Dickins3e6053d2008-09-11 10:57:55 +0200998 return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL);
David Woodhousefb2dce82008-08-05 18:01:53 +0100999}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000
Adel Gadllah0b07de82008-06-26 13:48:27 +02001001/*
1002* command filter functions
1003*/
FUJITA Tomonori4beab5c2008-07-26 18:03:25 +09001004extern int blk_verify_command(struct blk_cmd_filter *filter,
Al Viroaeb5d722008-09-02 15:28:45 -04001005 unsigned char *cmd, fmode_t has_write_perm);
1006extern void blk_unregister_filter(struct gendisk *disk);
FUJITA Tomonori4beab5c2008-07-26 18:03:25 +09001007extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter);
Adel Gadllah0b07de82008-06-26 13:48:27 +02001008
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009#define MAX_PHYS_SEGMENTS 128
1010#define MAX_HW_SEGMENTS 128
Mike Christiedefd94b2005-12-05 02:37:06 -06001011#define SAFE_MAX_SECTORS 255
1012#define BLK_DEF_MAX_SECTORS 1024
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013
1014#define MAX_SEGMENT_SIZE 65536
1015
Milan Broz0e435ac2008-12-03 12:55:08 +01001016#define BLK_SEG_BOUNDARY_MASK 0xFFFFFFFFUL
1017
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1019
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001020static inline unsigned long queue_bounce_pfn(struct request_queue *q)
1021{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001022 return q->limits.bounce_pfn;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001023}
1024
1025static inline unsigned long queue_segment_boundary(struct request_queue *q)
1026{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001027 return q->limits.seg_boundary_mask;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001028}
1029
1030static inline unsigned int queue_max_sectors(struct request_queue *q)
1031{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001032 return q->limits.max_sectors;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001033}
1034
1035static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1036{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001037 return q->limits.max_hw_sectors;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001038}
1039
1040static inline unsigned short queue_max_hw_segments(struct request_queue *q)
1041{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001042 return q->limits.max_hw_segments;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001043}
1044
1045static inline unsigned short queue_max_phys_segments(struct request_queue *q)
1046{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001047 return q->limits.max_phys_segments;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001048}
1049
1050static inline unsigned int queue_max_segment_size(struct request_queue *q)
1051{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001052 return q->limits.max_segment_size;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001053}
1054
Martin K. Petersene1defc42009-05-22 17:17:49 -04001055static inline unsigned short queue_logical_block_size(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001056{
1057 int retval = 512;
1058
Martin K. Petersen025146e2009-05-22 17:17:51 -04001059 if (q && q->limits.logical_block_size)
1060 retval = q->limits.logical_block_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001061
1062 return retval;
1063}
1064
Martin K. Petersene1defc42009-05-22 17:17:49 -04001065static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066{
Martin K. Petersene1defc42009-05-22 17:17:49 -04001067 return queue_logical_block_size(bdev_get_queue(bdev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001068}
1069
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001070static inline unsigned int queue_physical_block_size(struct request_queue *q)
1071{
1072 return q->limits.physical_block_size;
1073}
1074
1075static inline unsigned int queue_io_min(struct request_queue *q)
1076{
1077 return q->limits.io_min;
1078}
1079
1080static inline unsigned int queue_io_opt(struct request_queue *q)
1081{
1082 return q->limits.io_opt;
1083}
1084
1085static inline int queue_alignment_offset(struct request_queue *q)
1086{
1087 if (q && q->limits.misaligned)
1088 return -1;
1089
1090 if (q && q->limits.alignment_offset)
1091 return q->limits.alignment_offset;
1092
1093 return 0;
1094}
1095
1096static inline int queue_sector_alignment_offset(struct request_queue *q,
1097 sector_t sector)
1098{
1099 return ((sector << 9) - q->limits.alignment_offset)
1100 & (q->limits.io_min - 1);
1101}
1102
Jens Axboe165125e2007-07-24 09:28:11 +02001103static inline int queue_dma_alignment(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001104{
Pete Wyckoff482eb682008-01-01 10:23:02 -05001105 return q ? q->dma_alignment : 511;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001106}
1107
FUJITA Tomonori87904072008-08-28 15:05:58 +09001108static inline int blk_rq_aligned(struct request_queue *q, void *addr,
1109 unsigned int len)
1110{
1111 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1112 return !((unsigned long)addr & alignment) && !(len & alignment);
1113}
1114
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115/* assumes size > 256 */
1116static inline unsigned int blksize_bits(unsigned int size)
1117{
1118 unsigned int bits = 8;
1119 do {
1120 bits++;
1121 size >>= 1;
1122 } while (size > 256);
1123 return bits;
1124}
1125
Adrian Bunk2befb9e2005-09-10 00:27:17 -07001126static inline unsigned int block_size(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001127{
1128 return bdev->bd_block_size;
1129}
1130
1131typedef struct {struct page *v;} Sector;
1132
1133unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1134
1135static inline void put_dev_sector(Sector p)
1136{
1137 page_cache_release(p.v);
1138}
1139
1140struct work_struct;
Jens Axboe18887ad2008-07-28 13:08:45 +02001141int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001142
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143#define MODULE_ALIAS_BLOCKDEV(major,minor) \
1144 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1145#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1146 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1147
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001148#if defined(CONFIG_BLK_DEV_INTEGRITY)
1149
Jens Axboeb24498d2008-06-27 09:12:09 +02001150#define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1151#define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001152
1153struct blk_integrity_exchg {
1154 void *prot_buf;
1155 void *data_buf;
1156 sector_t sector;
1157 unsigned int data_size;
1158 unsigned short sector_size;
1159 const char *disk_name;
1160};
1161
1162typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1163typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1164typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1165typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1166
1167struct blk_integrity {
1168 integrity_gen_fn *generate_fn;
1169 integrity_vrfy_fn *verify_fn;
1170 integrity_set_tag_fn *set_tag_fn;
1171 integrity_get_tag_fn *get_tag_fn;
1172
1173 unsigned short flags;
1174 unsigned short tuple_size;
1175 unsigned short sector_size;
1176 unsigned short tag_size;
1177
1178 const char *name;
1179
1180 struct kobject kobj;
1181};
1182
1183extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1184extern void blk_integrity_unregister(struct gendisk *);
Martin K. Petersenad7fce92008-10-01 03:38:39 -04001185extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001186extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
1187extern int blk_rq_count_integrity_sg(struct request *);
1188
Jens Axboeb04accc2008-10-02 12:53:22 +02001189static inline
1190struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1191{
1192 return bdev->bd_disk->integrity;
1193}
1194
Martin K. Petersenb02739b2008-10-02 18:47:49 +02001195static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1196{
1197 return disk->integrity;
1198}
1199
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001200static inline int blk_integrity_rq(struct request *rq)
1201{
Martin K. Petersend442cc42008-07-16 16:09:06 -04001202 if (rq->bio == NULL)
1203 return 0;
1204
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001205 return bio_integrity(rq->bio);
1206}
1207
1208#else /* CONFIG_BLK_DEV_INTEGRITY */
1209
1210#define blk_integrity_rq(rq) (0)
1211#define blk_rq_count_integrity_sg(a) (0)
1212#define blk_rq_map_integrity_sg(a, b) (0)
Jens Axboeb04accc2008-10-02 12:53:22 +02001213#define bdev_get_integrity(a) (0)
Martin K. Petersenb02739b2008-10-02 18:47:49 +02001214#define blk_get_integrity(a) (0)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001215#define blk_integrity_compare(a, b) (0)
1216#define blk_integrity_register(a, b) (0)
1217#define blk_integrity_unregister(a) do { } while (0);
1218
1219#endif /* CONFIG_BLK_DEV_INTEGRITY */
1220
Al Viro08f85852007-10-08 13:26:20 -04001221struct block_device_operations {
Al Virod4430d622008-03-02 09:09:22 -05001222 int (*open) (struct block_device *, fmode_t);
1223 int (*release) (struct gendisk *, fmode_t);
1224 int (*locked_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1225 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1226 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
Al Viro08f85852007-10-08 13:26:20 -04001227 int (*direct_access) (struct block_device *, sector_t,
1228 void **, unsigned long *);
1229 int (*media_changed) (struct gendisk *);
Bartlomiej Zolnierkiewiczdb429e92009-06-07 13:52:52 +02001230 unsigned long long (*set_capacity) (struct gendisk *,
1231 unsigned long long);
Al Viro08f85852007-10-08 13:26:20 -04001232 int (*revalidate_disk) (struct gendisk *);
1233 int (*getgeo)(struct block_device *, struct hd_geometry *);
1234 struct module *owner;
1235};
1236
Al Viro633a08b2007-08-29 20:34:12 -04001237extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1238 unsigned long);
David Howells93614012006-09-30 20:45:40 +02001239#else /* CONFIG_BLOCK */
1240/*
1241 * stubs for when the block layer is configured out
1242 */
1243#define buffer_heads_over_limit 0
1244
David Howells93614012006-09-30 20:45:40 +02001245static inline long nr_blockdev_pages(void)
1246{
1247 return 0;
1248}
1249
David Howells93614012006-09-30 20:45:40 +02001250#endif /* CONFIG_BLOCK */
1251
Linus Torvalds1da177e2005-04-16 15:20:36 -07001252#endif