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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_BLKDEV_H
2#define _LINUX_BLKDEV_H
3
Russell King85fd0bc2012-05-14 08:29:23 +02004#include <linux/sched.h>
5
Jens Axboef5ff8422007-09-21 09:19:54 +02006#ifdef CONFIG_BLOCK
7
Linus Torvalds1da177e2005-04-16 15:20:36 -07008#include <linux/major.h>
9#include <linux/genhd.h>
10#include <linux/list.h>
Jens Axboe320ae512013-10-24 09:20:05 +010011#include <linux/llist.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/timer.h>
13#include <linux/workqueue.h>
14#include <linux/pagemap.h>
15#include <linux/backing-dev.h>
16#include <linux/wait.h>
17#include <linux/mempool.h>
18#include <linux/bio.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/stringify.h>
Hugh Dickins3e6053d2008-09-11 10:57:55 +020020#include <linux/gfp.h>
FUJITA Tomonorid351af02007-07-09 12:40:35 +020021#include <linux/bsg.h>
Jens Axboec7c22e42008-09-13 20:26:01 +020022#include <linux/smp.h>
Tejun Heo548bc8e2013-01-09 08:05:13 -080023#include <linux/rcupdate.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
25#include <asm/scatterlist.h>
26
Paul Gortmakerde477252011-05-26 13:46:22 -040027struct module;
Christoph Hellwig21b2f0c2006-03-22 17:52:04 +010028struct scsi_ioctl_command;
29
Linus Torvalds1da177e2005-04-16 15:20:36 -070030struct request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -070031struct elevator_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -070032struct request_pm_state;
Jens Axboe2056a782006-03-23 20:00:26 +010033struct blk_trace;
Jens Axboe3d6392c2007-07-09 12:38:05 +020034struct request;
35struct sg_io_hdr;
Mike Christieaa387cc2011-07-31 22:05:09 +020036struct bsg_job;
Tejun Heo3c798392012-04-16 13:57:25 -070037struct blkcg_gq;
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39#define BLKDEV_MIN_RQ 4
40#define BLKDEV_MAX_RQ 128 /* Default maximum */
41
Tejun Heo8bd435b2012-04-13 13:11:28 -070042/*
43 * Maximum number of blkcg policies allowed to be registered concurrently.
44 * Defined here to simplify include dependency.
45 */
46#define BLKCG_MAX_POLS 2
47
Linus Torvalds1da177e2005-04-16 15:20:36 -070048struct request;
Tejun Heo8ffdc652006-01-06 09:49:03 +010049typedef void (rq_end_io_fn)(struct request *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070050
Tejun Heo5b788ce2012-06-04 20:40:59 -070051#define BLK_RL_SYNCFULL (1U << 0)
52#define BLK_RL_ASYNCFULL (1U << 1)
53
Linus Torvalds1da177e2005-04-16 15:20:36 -070054struct request_list {
Tejun Heo5b788ce2012-06-04 20:40:59 -070055 struct request_queue *q; /* the queue this rl belongs to */
Tejun Heoa0516612012-06-26 15:05:44 -070056#ifdef CONFIG_BLK_CGROUP
57 struct blkcg_gq *blkg; /* blkg this request pool belongs to */
58#endif
Jens Axboe1faa16d2009-04-06 14:48:01 +020059 /*
60 * count[], starved[], and wait[] are indexed by
61 * BLK_RW_SYNC/BLK_RW_ASYNC
62 */
Tejun Heo8a5ecdd2012-06-04 20:40:58 -070063 int count[2];
64 int starved[2];
65 mempool_t *rq_pool;
66 wait_queue_head_t wait[2];
Tejun Heo5b788ce2012-06-04 20:40:59 -070067 unsigned int flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -070068};
69
Jens Axboe4aff5e22006-08-10 08:44:47 +020070/*
71 * request command types
72 */
73enum rq_cmd_type_bits {
74 REQ_TYPE_FS = 1, /* fs request */
75 REQ_TYPE_BLOCK_PC, /* scsi command */
76 REQ_TYPE_SENSE, /* sense request */
77 REQ_TYPE_PM_SUSPEND, /* suspend request */
78 REQ_TYPE_PM_RESUME, /* resume request */
79 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
Jens Axboe4aff5e22006-08-10 08:44:47 +020080 REQ_TYPE_SPECIAL, /* driver defined type */
Jens Axboe4aff5e22006-08-10 08:44:47 +020081 /*
82 * for ATA/ATAPI devices. this really doesn't belong here, ide should
83 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
84 * private REQ_LB opcodes to differentiate what type of request this is
85 */
Jens Axboe4aff5e22006-08-10 08:44:47 +020086 REQ_TYPE_ATA_TASKFILE,
Jens Axboecea28852006-10-12 15:08:45 +020087 REQ_TYPE_ATA_PC,
Jens Axboe4aff5e22006-08-10 08:44:47 +020088};
89
Linus Torvalds1da177e2005-04-16 15:20:36 -070090#define BLK_MAX_CDB 16
91
92/*
Jens Axboe63a71382008-02-08 12:41:03 +010093 * try to put the fields that are referenced together in the same cacheline.
Wanlong Gao4d0d98b62011-06-13 10:45:38 +020094 * if you modify this structure, be sure to check block/blk-core.c:blk_rq_init()
Jens Axboe63a71382008-02-08 12:41:03 +010095 * as well!
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 */
97struct request {
Christoph Hellwig6897fc22014-01-30 15:45:47 -080098 struct list_head queuelist;
Jens Axboe320ae512013-10-24 09:20:05 +010099 union {
100 struct call_single_data csd;
Christoph Hellwig18741982014-02-10 09:29:00 -0700101 struct work_struct mq_flush_work;
Jan Kara8b4922d2014-02-24 16:39:52 +0100102 unsigned long fifo_time;
Jens Axboe320ae512013-10-24 09:20:05 +0100103 };
Jens Axboeff856ba2006-01-09 16:02:34 +0100104
Jens Axboe165125e2007-07-24 09:28:11 +0200105 struct request_queue *q;
Jens Axboe320ae512013-10-24 09:20:05 +0100106 struct blk_mq_ctx *mq_ctx;
Jens Axboee6a1c872006-08-10 09:00:21 +0200107
Jens Axboe59533162013-05-23 12:25:08 +0200108 u64 cmd_flags;
Jens Axboe4aff5e22006-08-10 08:44:47 +0200109 enum rq_cmd_type_bits cmd_type;
Jens Axboe242f9dc2008-09-14 05:55:09 -0700110 unsigned long atomic_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111
Richard Kennedy181fdde2010-03-19 08:58:16 +0100112 int cpu;
113
Tejun Heoa2dec7b2009-05-07 22:24:44 +0900114 /* the following two fields are internal, NEVER access directly */
Tejun Heoa2dec7b2009-05-07 22:24:44 +0900115 unsigned int __data_len; /* total data len */
Richard Kennedy181fdde2010-03-19 08:58:16 +0100116 sector_t __sector; /* sector cursor */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117
118 struct bio *bio;
119 struct bio *biotail;
120
Jens Axboe360f92c2014-04-09 20:27:01 -0600121 /*
122 * The hash is used inside the scheduler, and killed once the
123 * request reaches the dispatch list. The ipi_list is only used
124 * to queue the request for softirq completion, which is long
125 * after the request has been unhashed (and even removed from
126 * the dispatch list).
127 */
128 union {
129 struct hlist_node hash; /* merge hash */
130 struct list_head ipi_list;
131 };
132
Jens Axboee6a1c872006-08-10 09:00:21 +0200133 /*
134 * The rb_node is only used inside the io scheduler, requests
135 * are pruned when moved to the dispatch queue. So let the
Mike Snitzerc1867942011-02-11 11:08:00 +0100136 * completion_data share space with the rb_node.
Jens Axboee6a1c872006-08-10 09:00:21 +0200137 */
138 union {
139 struct rb_node rb_node; /* sort/lookup */
Mike Snitzerc1867942011-02-11 11:08:00 +0100140 void *completion_data;
Jens Axboee6a1c872006-08-10 09:00:21 +0200141 };
Jens Axboe98170642006-07-28 09:23:08 +0200142
Jens Axboeff7d1452006-07-12 14:04:37 +0200143 /*
Vivek Goyal7f1dc8a2010-04-21 17:44:16 +0200144 * Three pointers are available for the IO schedulers, if they need
Mike Snitzerc1867942011-02-11 11:08:00 +0100145 * more they have to dynamically allocate it. Flush requests are
146 * never put on the IO scheduler. So let the flush fields share
Tejun Heoa612fdd2011-12-14 00:33:41 +0100147 * space with the elevator data.
Jens Axboeff7d1452006-07-12 14:04:37 +0200148 */
Mike Snitzerc1867942011-02-11 11:08:00 +0100149 union {
Tejun Heoa612fdd2011-12-14 00:33:41 +0100150 struct {
151 struct io_cq *icq;
152 void *priv[2];
153 } elv;
154
Mike Snitzerc1867942011-02-11 11:08:00 +0100155 struct {
156 unsigned int seq;
157 struct list_head list;
Jeff Moyer4853aba2011-08-15 21:37:25 +0200158 rq_end_io_fn *saved_end_io;
Mike Snitzerc1867942011-02-11 11:08:00 +0100159 } flush;
160 };
Jens Axboeff7d1452006-07-12 14:04:37 +0200161
Jens Axboe8f34ee72006-06-13 09:02:34 +0200162 struct gendisk *rq_disk;
Jerome Marchand09e099d2011-01-05 16:57:38 +0100163 struct hd_struct *part;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 unsigned long start_time;
Divyesh Shah91952912010-04-01 15:01:41 -0700165#ifdef CONFIG_BLK_CGROUP
Tejun Heoa0516612012-06-26 15:05:44 -0700166 struct request_list *rl; /* rl this rq is alloced from */
Divyesh Shah91952912010-04-01 15:01:41 -0700167 unsigned long long start_time_ns;
168 unsigned long long io_start_time_ns; /* when passed to hardware */
169#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 /* Number of scatter-gather DMA addr+len pairs after
171 * physical address coalescing is performed.
172 */
173 unsigned short nr_phys_segments;
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200174#if defined(CONFIG_BLK_DEV_INTEGRITY)
175 unsigned short nr_integrity_segments;
176#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177
Jens Axboe8f34ee72006-06-13 09:02:34 +0200178 unsigned short ioprio;
179
Tejun Heo731ec492009-04-23 11:05:20 +0900180 void *special; /* opaque pointer available for LLD use */
181 char *buffer; /* kaddr of the current segment if available */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
Jens Axboecdd60262006-07-28 09:32:07 +0200183 int tag;
184 int errors;
185
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 /*
187 * when request is used as a packet command carrier
188 */
FUJITA Tomonorid7e3c322008-04-29 09:54:39 +0200189 unsigned char __cmd[BLK_MAX_CDB];
190 unsigned char *cmd;
Richard Kennedy181fdde2010-03-19 08:58:16 +0100191 unsigned short cmd_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192
FUJITA Tomonori7a85f882008-03-04 11:17:11 +0100193 unsigned int extra_len; /* length of alignment and padding */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 unsigned int sense_len;
Tejun Heoc3a4d782009-05-07 22:24:37 +0900195 unsigned int resid_len; /* residual count */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 void *sense;
197
Jens Axboe242f9dc2008-09-14 05:55:09 -0700198 unsigned long deadline;
199 struct list_head timeout_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 unsigned int timeout;
Mike Christie17e01f22005-11-11 05:31:37 -0600201 int retries;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202
203 /*
Jens Axboec00895a2006-09-30 20:29:12 +0200204 * completion callback.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 */
206 rq_end_io_fn *end_io;
207 void *end_io_data;
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200208
209 /* for bidi */
210 struct request *next_rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211};
212
Fernando Luis Vázquez Cao766ca442008-08-14 09:59:13 +0200213static inline unsigned short req_get_ioprio(struct request *req)
214{
215 return req->ioprio;
216}
217
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218/*
Jens Axboe4aff5e22006-08-10 08:44:47 +0200219 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 * requests. Some step values could eventually be made generic.
221 */
222struct request_pm_state
223{
224 /* PM state machine step value, currently driver specific */
225 int pm_step;
226 /* requested PM state value (S1, S2, S3, S4, ...) */
227 u32 pm_state;
228 void* data; /* for driver use */
229};
230
231#include <linux/elevator.h>
232
Jens Axboe320ae512013-10-24 09:20:05 +0100233struct blk_queue_ctx;
234
Jens Axboe165125e2007-07-24 09:28:11 +0200235typedef void (request_fn_proc) (struct request_queue *q);
Christoph Hellwig5a7bbad2011-09-12 12:12:01 +0200236typedef void (make_request_fn) (struct request_queue *q, struct bio *bio);
Jens Axboe165125e2007-07-24 09:28:11 +0200237typedef int (prep_rq_fn) (struct request_queue *, struct request *);
James Bottomley28018c22010-07-01 19:49:17 +0900238typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239
240struct bio_vec;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200241struct bvec_merge_data {
242 struct block_device *bi_bdev;
243 sector_t bi_sector;
244 unsigned bi_size;
245 unsigned long bi_rw;
246};
247typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
248 struct bio_vec *);
Jens Axboeff856ba2006-01-09 16:02:34 +0100249typedef void (softirq_done_fn)(struct request *);
Tejun Heo2fb98e82008-02-19 11:36:53 +0100250typedef int (dma_drain_needed_fn)(struct request *);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200251typedef int (lld_busy_fn) (struct request_queue *q);
Mike Christieaa387cc2011-07-31 22:05:09 +0200252typedef int (bsg_job_fn) (struct bsg_job *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253
Jens Axboe242f9dc2008-09-14 05:55:09 -0700254enum blk_eh_timer_return {
255 BLK_EH_NOT_HANDLED,
256 BLK_EH_HANDLED,
257 BLK_EH_RESET_TIMER,
258};
259
260typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
261
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262enum blk_queue_state {
263 Queue_down,
264 Queue_up,
265};
266
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267struct blk_queue_tag {
268 struct request **tag_index; /* map of busy tags */
269 unsigned long *tag_map; /* bit map of free/busy tags */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 int busy; /* current depth */
271 int max_depth; /* what we will send to device */
Tejun Heoba025082005-08-05 13:28:11 -0700272 int real_max_depth; /* what the array can hold */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 atomic_t refcnt; /* map can be shared */
274};
275
FUJITA Tomonoriabf54392008-08-16 14:10:05 +0900276#define BLK_SCSI_MAX_CMDS (256)
277#define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
278
Martin K. Petersen025146e2009-05-22 17:17:51 -0400279struct queue_limits {
280 unsigned long bounce_pfn;
281 unsigned long seg_boundary_mask;
282
283 unsigned int max_hw_sectors;
284 unsigned int max_sectors;
285 unsigned int max_segment_size;
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400286 unsigned int physical_block_size;
287 unsigned int alignment_offset;
288 unsigned int io_min;
289 unsigned int io_opt;
Christoph Hellwig67efc922009-09-30 13:54:20 +0200290 unsigned int max_discard_sectors;
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400291 unsigned int max_write_same_sectors;
Martin K. Petersen86b37282009-11-10 11:50:21 +0100292 unsigned int discard_granularity;
293 unsigned int discard_alignment;
Martin K. Petersen025146e2009-05-22 17:17:51 -0400294
295 unsigned short logical_block_size;
Martin K. Petersen8a783622010-02-26 00:20:39 -0500296 unsigned short max_segments;
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200297 unsigned short max_integrity_segments;
Martin K. Petersen025146e2009-05-22 17:17:51 -0400298
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400299 unsigned char misaligned;
Martin K. Petersen86b37282009-11-10 11:50:21 +0100300 unsigned char discard_misaligned;
Martin K. Petersene692cb62010-12-01 19:41:49 +0100301 unsigned char cluster;
Martin K. Petersena934a002011-05-18 10:37:35 +0200302 unsigned char discard_zeroes_data;
Kent Overstreetc78afc62013-07-11 22:39:53 -0700303 unsigned char raid_partial_stripes_expensive;
Martin K. Petersen025146e2009-05-22 17:17:51 -0400304};
305
Richard Kennedyd7b76302011-07-13 21:17:23 +0200306struct request_queue {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 /*
308 * Together with queue_head for cacheline sharing
309 */
310 struct list_head queue_head;
311 struct request *last_merge;
Jens Axboeb374d182008-10-31 10:05:07 +0100312 struct elevator_queue *elevator;
Tejun Heo8a5ecdd2012-06-04 20:40:58 -0700313 int nr_rqs[2]; /* # allocated [a]sync rqs */
314 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315
316 /*
Tejun Heoa0516612012-06-26 15:05:44 -0700317 * If blkcg is not used, @q->root_rl serves all requests. If blkcg
318 * is used, root blkg allocates from @q->root_rl and all other
319 * blkgs from their own blkg->rl. Which one to use should be
320 * determined using bio_request_list().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 */
Tejun Heoa0516612012-06-26 15:05:44 -0700322 struct request_list root_rl;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323
324 request_fn_proc *request_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 make_request_fn *make_request_fn;
326 prep_rq_fn *prep_rq_fn;
James Bottomley28018c22010-07-01 19:49:17 +0900327 unprep_rq_fn *unprep_rq_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 merge_bvec_fn *merge_bvec_fn;
Jens Axboeff856ba2006-01-09 16:02:34 +0100329 softirq_done_fn *softirq_done_fn;
Jens Axboe242f9dc2008-09-14 05:55:09 -0700330 rq_timed_out_fn *rq_timed_out_fn;
Tejun Heo2fb98e82008-02-19 11:36:53 +0100331 dma_drain_needed_fn *dma_drain_needed;
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200332 lld_busy_fn *lld_busy_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333
Jens Axboe320ae512013-10-24 09:20:05 +0100334 struct blk_mq_ops *mq_ops;
335
336 unsigned int *mq_map;
337
338 /* sw queues */
339 struct blk_mq_ctx *queue_ctx;
340 unsigned int nr_queues;
341
342 /* hw dispatch queues */
343 struct blk_mq_hw_ctx **queue_hw_ctx;
344 unsigned int nr_hw_queues;
345
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 /*
Tejun Heo8922e162005-10-20 16:23:44 +0200347 * Dispatch queue sorting
348 */
Jens Axboe1b47f532005-10-20 16:37:00 +0200349 sector_t end_sector;
Tejun Heo8922e162005-10-20 16:23:44 +0200350 struct request *boundary_rq;
Tejun Heo8922e162005-10-20 16:23:44 +0200351
352 /*
Jens Axboe3cca6dc2011-03-02 11:08:00 -0500353 * Delayed queue handling
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 */
Jens Axboe3cca6dc2011-03-02 11:08:00 -0500355 struct delayed_work delay_work;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356
357 struct backing_dev_info backing_dev_info;
358
359 /*
360 * The queue owner gets to use this for whatever they like.
361 * ll_rw_blk doesn't touch it.
362 */
363 void *queuedata;
364
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 * various queue flags, see QUEUE_* below
367 */
368 unsigned long queue_flags;
369
370 /*
Tejun Heoa73f7302011-12-14 00:33:37 +0100371 * ida allocated id for this queue. Used to index queues from
372 * ioctx.
373 */
374 int id;
375
376 /*
Richard Kennedyd7b76302011-07-13 21:17:23 +0200377 * queue needs bounce pages for pages above this limit
378 */
379 gfp_t bounce_gfp;
380
381 /*
152587d2005-04-12 16:22:06 -0500382 * protects queue structures from reentrancy. ->__queue_lock should
383 * _never_ be used directly, it is queue private. always use
384 * ->queue_lock.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 */
152587d2005-04-12 16:22:06 -0500386 spinlock_t __queue_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 spinlock_t *queue_lock;
388
389 /*
390 * queue kobject
391 */
392 struct kobject kobj;
393
Jens Axboe320ae512013-10-24 09:20:05 +0100394 /*
395 * mq queue kobject
396 */
397 struct kobject mq_kobj;
398
Lin Ming6c954662013-03-23 11:42:26 +0800399#ifdef CONFIG_PM_RUNTIME
400 struct device *dev;
401 int rpm_status;
402 unsigned int nr_pending;
403#endif
404
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 /*
406 * queue settings
407 */
408 unsigned long nr_requests; /* Max # of requests */
409 unsigned int nr_congestion_on;
410 unsigned int nr_congestion_off;
411 unsigned int nr_batching;
412
James Bottomleyfa0ccd82008-01-10 11:30:36 -0600413 unsigned int dma_drain_size;
Richard Kennedyd7b76302011-07-13 21:17:23 +0200414 void *dma_drain_buffer;
Tejun Heoe3790c72008-03-04 11:18:17 +0100415 unsigned int dma_pad_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 unsigned int dma_alignment;
417
418 struct blk_queue_tag *queue_tags;
Jens Axboe6eca9002007-10-25 10:14:47 +0200419 struct list_head tag_busy_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420
Tejun Heo15853af2005-11-10 08:52:05 +0100421 unsigned int nr_sorted;
Jens Axboe0a7ae2f2009-05-20 08:54:31 +0200422 unsigned int in_flight[2];
Bart Van Assche24faf6f2012-11-28 13:46:45 +0100423 /*
424 * Number of active block driver functions for which blk_drain_queue()
425 * must wait. Must be incremented around functions that unlock the
426 * queue_lock internally, e.g. scsi_request_fn().
427 */
428 unsigned int request_fn_active;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429
Jens Axboe242f9dc2008-09-14 05:55:09 -0700430 unsigned int rq_timeout;
431 struct timer_list timeout;
432 struct list_head timeout_list;
433
Tejun Heoa612fdd2011-12-14 00:33:41 +0100434 struct list_head icq_list;
Tejun Heo4eef3042012-03-05 13:15:18 -0800435#ifdef CONFIG_BLK_CGROUP
Tejun Heoa2b16932012-04-13 13:11:33 -0700436 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS);
Tejun Heo3c798392012-04-16 13:57:25 -0700437 struct blkcg_gq *root_blkg;
Tejun Heo03aa2642012-03-05 13:15:19 -0800438 struct list_head blkg_list;
Tejun Heo4eef3042012-03-05 13:15:18 -0800439#endif
Tejun Heoa612fdd2011-12-14 00:33:41 +0100440
Martin K. Petersen025146e2009-05-22 17:17:51 -0400441 struct queue_limits limits;
442
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 /*
444 * sg stuff
445 */
446 unsigned int sg_timeout;
447 unsigned int sg_reserved_size;
Christoph Lameter19460892005-06-23 00:08:19 -0700448 int node;
Alexey Dobriyan6c5c9342006-09-29 01:59:40 -0700449#ifdef CONFIG_BLK_DEV_IO_TRACE
Jens Axboe2056a782006-03-23 20:00:26 +0100450 struct blk_trace *blk_trace;
Alexey Dobriyan6c5c9342006-09-29 01:59:40 -0700451#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 /*
Tejun Heo4913efe2010-09-03 11:56:16 +0200453 * for flush operations
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 */
Tejun Heo4913efe2010-09-03 11:56:16 +0200455 unsigned int flush_flags;
shaohua.li@intel.comf3876932011-05-06 11:34:32 -0600456 unsigned int flush_not_queueable:1;
shaohua.li@intel.com3ac0cc42011-05-06 11:34:41 -0600457 unsigned int flush_queue_delayed:1;
Tejun Heoae1b1532011-01-25 12:43:54 +0100458 unsigned int flush_pending_idx:1;
459 unsigned int flush_running_idx:1;
460 unsigned long flush_pending_since;
461 struct list_head flush_queue[2];
462 struct list_head flush_data_in_flight;
Christoph Hellwig18741982014-02-10 09:29:00 -0700463 struct request *flush_rq;
464 spinlock_t mq_flush_lock;
Al Viro483f4af2006-03-18 18:34:37 -0500465
466 struct mutex sysfs_lock;
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200467
Tejun Heod7325802012-03-05 13:14:58 -0800468 int bypass_depth;
469
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200470#if defined(CONFIG_BLK_DEV_BSG)
Mike Christieaa387cc2011-07-31 22:05:09 +0200471 bsg_job_fn *bsg_job_fn;
472 int bsg_job_size;
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200473 struct bsg_class_device bsg_dev;
474#endif
Vivek Goyale43473b2010-09-15 17:06:35 -0400475
476#ifdef CONFIG_BLK_DEV_THROTTLING
477 /* Throttle data */
478 struct throtl_data *td;
479#endif
Tejun Heo548bc8e2013-01-09 08:05:13 -0800480 struct rcu_head rcu_head;
Jens Axboe320ae512013-10-24 09:20:05 +0100481 wait_queue_head_t mq_freeze_wq;
482 struct percpu_counter mq_usage_counter;
483 struct list_head all_q_node;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484};
485
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
487#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
Jens Axboe1faa16d2009-04-06 14:48:01 +0200488#define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
489#define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
Bart Van Assche3f3299d2012-11-28 13:42:38 +0100490#define QUEUE_FLAG_DYING 5 /* queue being torn down */
Tejun Heod7325802012-03-05 13:14:58 -0800491#define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */
Jens Axboec21e6be2011-04-19 13:32:46 +0200492#define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
493#define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
Dan Williams5757a6d2011-07-23 20:44:25 +0200494#define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
Jens Axboec21e6be2011-04-19 13:32:46 +0200495#define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
496#define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
497#define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
Fernando Luis Vázquez Cao88e740f2008-10-27 18:44:46 +0900498#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
Jens Axboec21e6be2011-04-19 13:32:46 +0200499#define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
500#define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
501#define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
502#define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
503#define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
Dan Williams5757a6d2011-07-23 20:44:25 +0200504#define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
Bart Van Asschec246e802012-12-06 14:32:01 +0100505#define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */
Jens Axboe320ae512013-10-24 09:20:05 +0100506#define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */
Jens Axboebc58ba92009-01-23 10:54:44 +0100507
508#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
Jens Axboe01e97f62009-09-03 20:06:47 +0200509 (1 << QUEUE_FLAG_STACKABLE) | \
Jens Axboee2e1a142010-06-09 10:42:09 +0200510 (1 << QUEUE_FLAG_SAME_COMP) | \
511 (1 << QUEUE_FLAG_ADD_RANDOM))
Tejun Heo797e7db2006-01-06 09:51:03 +0100512
Jens Axboe94eddfb2013-11-19 09:25:07 -0700513#define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
514 (1 << QUEUE_FLAG_SAME_COMP))
515
Andi Kleen8bcb6c72012-03-30 12:33:28 +0200516static inline void queue_lockdep_assert_held(struct request_queue *q)
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700517{
Andi Kleen8bcb6c72012-03-30 12:33:28 +0200518 if (q->queue_lock)
519 lockdep_assert_held(q->queue_lock);
Linus Torvalds8f45c1a2008-04-29 10:16:38 -0700520}
521
Nick Piggin75ad23b2008-04-29 14:48:33 +0200522static inline void queue_flag_set_unlocked(unsigned int flag,
523 struct request_queue *q)
524{
525 __set_bit(flag, &q->queue_flags);
526}
527
Jens Axboee48ec692008-07-03 13:18:54 +0200528static inline int queue_flag_test_and_clear(unsigned int flag,
529 struct request_queue *q)
530{
Andi Kleen8bcb6c72012-03-30 12:33:28 +0200531 queue_lockdep_assert_held(q);
Jens Axboee48ec692008-07-03 13:18:54 +0200532
533 if (test_bit(flag, &q->queue_flags)) {
534 __clear_bit(flag, &q->queue_flags);
535 return 1;
536 }
537
538 return 0;
539}
540
541static inline int queue_flag_test_and_set(unsigned int flag,
542 struct request_queue *q)
543{
Andi Kleen8bcb6c72012-03-30 12:33:28 +0200544 queue_lockdep_assert_held(q);
Jens Axboee48ec692008-07-03 13:18:54 +0200545
546 if (!test_bit(flag, &q->queue_flags)) {
547 __set_bit(flag, &q->queue_flags);
548 return 0;
549 }
550
551 return 1;
552}
553
Nick Piggin75ad23b2008-04-29 14:48:33 +0200554static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
555{
Andi Kleen8bcb6c72012-03-30 12:33:28 +0200556 queue_lockdep_assert_held(q);
Nick Piggin75ad23b2008-04-29 14:48:33 +0200557 __set_bit(flag, &q->queue_flags);
558}
559
560static inline void queue_flag_clear_unlocked(unsigned int flag,
561 struct request_queue *q)
562{
563 __clear_bit(flag, &q->queue_flags);
564}
565
Jens Axboe0a7ae2f2009-05-20 08:54:31 +0200566static inline int queue_in_flight(struct request_queue *q)
567{
568 return q->in_flight[0] + q->in_flight[1];
569}
570
Nick Piggin75ad23b2008-04-29 14:48:33 +0200571static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
572{
Andi Kleen8bcb6c72012-03-30 12:33:28 +0200573 queue_lockdep_assert_held(q);
Nick Piggin75ad23b2008-04-29 14:48:33 +0200574 __clear_bit(flag, &q->queue_flags);
575}
576
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
578#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
Bart Van Assche3f3299d2012-11-28 13:42:38 +0100579#define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
Bart Van Asschec246e802012-12-06 14:32:01 +0100580#define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
Tejun Heod7325802012-03-05 13:14:58 -0800581#define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
Jens Axboe320ae512013-10-24 09:20:05 +0100582#define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200583#define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
Alan D. Brunelle488991e2010-01-29 09:04:08 +0100584#define blk_queue_noxmerges(q) \
585 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
Jens Axboea68bbddba2008-09-24 13:03:33 +0200586#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
Jens Axboebc58ba92009-01-23 10:54:44 +0100587#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
Jens Axboee2e1a142010-06-09 10:42:09 +0200588#define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
Kiyoshi Ueda4ee5eaf2008-09-18 10:46:13 -0400589#define blk_queue_stackable(q) \
590 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
Christoph Hellwigc15227d2009-09-30 13:52:12 +0200591#define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
Adrian Hunter8d57a982010-08-11 14:17:49 -0700592#define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
593 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200595#define blk_noretry_request(rq) \
596 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
597 REQ_FAILFAST_DRIVER))
Jens Axboe4aff5e22006-08-10 08:44:47 +0200598
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200599#define blk_account_rq(rq) \
600 (((rq)->cmd_flags & REQ_STARTED) && \
Martin K. Petersene2a60da2012-09-18 12:19:25 -0400601 ((rq)->cmd_type == REQ_TYPE_FS))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603#define blk_pm_request(rq) \
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200604 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
605 (rq)->cmd_type == REQ_TYPE_PM_RESUME)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606
Jens Axboeab780f12008-08-26 10:25:02 +0200607#define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
FUJITA Tomonoriabae1fd2007-07-16 08:52:14 +0200608#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
Kiyoshi Ueda336cdb42007-12-11 17:40:30 -0500609/* rq->queuelist of dequeued request must be list_empty() */
610#define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611
612#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
613
Jens Axboe59533162013-05-23 12:25:08 +0200614#define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615
Martin K. Petersene692cb62010-12-01 19:41:49 +0100616static inline unsigned int blk_queue_cluster(struct request_queue *q)
617{
618 return q->limits.cluster;
619}
620
Jens Axboe9e2585a2006-07-28 09:26:13 +0200621/*
Jens Axboe1faa16d2009-04-06 14:48:01 +0200622 * We regard a request as sync, if either a read or a sync write
Jens Axboe9e2585a2006-07-28 09:26:13 +0200623 */
Jens Axboe1faa16d2009-04-06 14:48:01 +0200624static inline bool rw_is_sync(unsigned int rw_flags)
625{
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +0200626 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
Jens Axboe1faa16d2009-04-06 14:48:01 +0200627}
628
629static inline bool rq_is_sync(struct request *rq)
630{
631 return rw_is_sync(rq->cmd_flags);
632}
633
Tejun Heo5b788ce2012-06-04 20:40:59 -0700634static inline bool blk_rl_full(struct request_list *rl, bool sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635{
Tejun Heo5b788ce2012-06-04 20:40:59 -0700636 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
637
638 return rl->flags & flag;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639}
640
Tejun Heo5b788ce2012-06-04 20:40:59 -0700641static inline void blk_set_rl_full(struct request_list *rl, bool sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642{
Tejun Heo5b788ce2012-06-04 20:40:59 -0700643 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
644
645 rl->flags |= flag;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646}
647
Tejun Heo5b788ce2012-06-04 20:40:59 -0700648static inline void blk_clear_rl_full(struct request_list *rl, bool sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649{
Tejun Heo5b788ce2012-06-04 20:40:59 -0700650 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
651
652 rl->flags &= ~flag;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653}
654
Martin K. Petersene2a60da2012-09-18 12:19:25 -0400655static inline bool rq_mergeable(struct request *rq)
656{
657 if (rq->cmd_type != REQ_TYPE_FS)
658 return false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659
Martin K. Petersene2a60da2012-09-18 12:19:25 -0400660 if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
661 return false;
662
663 return true;
664}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665
Martin K. Petersenf31dc1c2012-09-18 12:19:26 -0400666static inline bool blk_check_merge_flags(unsigned int flags1,
667 unsigned int flags2)
668{
669 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD))
670 return false;
671
672 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE))
673 return false;
674
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400675 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME))
676 return false;
677
Martin K. Petersenf31dc1c2012-09-18 12:19:26 -0400678 return true;
679}
680
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400681static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
682{
683 if (bio_data(a) == bio_data(b))
684 return true;
685
686 return false;
687}
688
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 * q->prep_rq_fn return values
691 */
692#define BLKPREP_OK 0 /* serve it */
693#define BLKPREP_KILL 1 /* fatal error, kill */
694#define BLKPREP_DEFER 2 /* leave on queue */
695
696extern unsigned long blk_max_low_pfn, blk_max_pfn;
697
698/*
699 * standard bounce addresses:
700 *
701 * BLK_BOUNCE_HIGH : bounce all highmem pages
702 * BLK_BOUNCE_ANY : don't bounce anything
703 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
704 */
Andi Kleen24728922008-04-21 09:51:05 +0200705
706#if BITS_PER_LONG == 32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
Andi Kleen24728922008-04-21 09:51:05 +0200708#else
709#define BLK_BOUNCE_HIGH -1ULL
710#endif
711#define BLK_BOUNCE_ANY (-1ULL)
FUJITA Tomonoribfe17232010-05-31 15:59:03 +0900712#define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713
Jens Axboe3d6392c2007-07-09 12:38:05 +0200714/*
715 * default timeout for SG_IO if none specified
716 */
717#define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
Linus Torvaldsf2f1fa72008-12-05 14:49:18 -0800718#define BLK_MIN_SG_TIMEOUT (7 * HZ)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200719
Christoph Lameter2a7326b2007-07-17 04:03:37 -0700720#ifdef CONFIG_BOUNCE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721extern int init_emergency_isa_pool(void);
Jens Axboe165125e2007-07-24 09:28:11 +0200722extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723#else
724static inline int init_emergency_isa_pool(void)
725{
726 return 0;
727}
Jens Axboe165125e2007-07-24 09:28:11 +0200728static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729{
730}
731#endif /* CONFIG_MMU */
732
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900733struct rq_map_data {
734 struct page **pages;
735 int page_order;
736 int nr_entries;
FUJITA Tomonori56c451f2008-12-18 14:49:37 +0900737 unsigned long offset;
FUJITA Tomonori97ae77a2008-12-18 14:49:38 +0900738 int null_mapped;
FUJITA Tomonoriecb554a2009-07-09 14:46:53 +0200739 int from_user;
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900740};
741
NeilBrown5705f702007-09-25 12:35:59 +0200742struct req_iterator {
Kent Overstreet79886132013-11-23 17:19:00 -0800743 struct bvec_iter iter;
NeilBrown5705f702007-09-25 12:35:59 +0200744 struct bio *bio;
745};
746
747/* This should not be used directly - use rq_for_each_segment */
Jens Axboe1e428072009-02-23 09:03:10 +0100748#define for_each_bio(_bio) \
749 for (; _bio; _bio = _bio->bi_next)
NeilBrown5705f702007-09-25 12:35:59 +0200750#define __rq_for_each_bio(_bio, rq) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 if ((rq->bio)) \
752 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
753
NeilBrown5705f702007-09-25 12:35:59 +0200754#define rq_for_each_segment(bvl, _rq, _iter) \
755 __rq_for_each_bio(_iter.bio, _rq) \
Kent Overstreet79886132013-11-23 17:19:00 -0800756 bio_for_each_segment(bvl, _iter.bio, _iter.iter)
NeilBrown5705f702007-09-25 12:35:59 +0200757
Kent Overstreet4550dd62013-08-07 14:26:21 -0700758#define rq_iter_last(bvec, _iter) \
Kent Overstreet79886132013-11-23 17:19:00 -0800759 (_iter.bio->bi_next == NULL && \
Kent Overstreet4550dd62013-08-07 14:26:21 -0700760 bio_iter_last(bvec, _iter.iter))
NeilBrown5705f702007-09-25 12:35:59 +0200761
Ilya Loginov2d4dc892009-11-26 09:16:19 +0100762#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
763# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
764#endif
765#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
766extern void rq_flush_dcache_pages(struct request *rq);
767#else
768static inline void rq_flush_dcache_pages(struct request *rq)
769{
770}
771#endif
772
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773extern int blk_register_queue(struct gendisk *disk);
774extern void blk_unregister_queue(struct gendisk *disk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775extern void generic_make_request(struct bio *bio);
FUJITA Tomonori2a4aa302008-04-29 09:54:36 +0200776extern void blk_rq_init(struct request_queue *q, struct request *rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777extern void blk_put_request(struct request *);
Jens Axboe165125e2007-07-24 09:28:11 +0200778extern void __blk_put_request(struct request_queue *, struct request *);
Jens Axboe165125e2007-07-24 09:28:11 +0200779extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
Boaz Harrosh79eb63e2009-05-17 18:57:15 +0300780extern struct request *blk_make_request(struct request_queue *, struct bio *,
781 gfp_t);
Jens Axboe165125e2007-07-24 09:28:11 +0200782extern void blk_requeue_request(struct request_queue *, struct request *);
Christoph Hellwig66ac0282010-06-18 16:59:42 +0200783extern void blk_add_request_payload(struct request *rq, struct page *page,
784 unsigned int len);
Kiyoshi Ueda82124d62008-09-18 10:45:38 -0400785extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200786extern int blk_lld_busy(struct request_queue *q);
Kiyoshi Uedab0fd2712009-06-11 13:10:16 +0200787extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
788 struct bio_set *bs, gfp_t gfp_mask,
789 int (*bio_ctr)(struct bio *, struct bio *, void *),
790 void *data);
791extern void blk_rq_unprep_clone(struct request *rq);
Kiyoshi Ueda82124d62008-09-18 10:45:38 -0400792extern int blk_insert_cloned_request(struct request_queue *q,
793 struct request *rq);
Jens Axboe3cca6dc2011-03-02 11:08:00 -0500794extern void blk_delay_queue(struct request_queue *, unsigned long);
Jens Axboe165125e2007-07-24 09:28:11 +0200795extern void blk_recount_segments(struct request_queue *, struct bio *);
Paolo Bonzini0bfc96c2012-01-12 16:01:28 +0100796extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
Paolo Bonzini577ebb32012-01-12 16:01:27 +0100797extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
798 unsigned int, void __user *);
Al Viro74f3c8a2007-08-27 15:38:10 -0400799extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
800 unsigned int, void __user *);
Al Viroe915e872008-09-02 17:16:41 -0400801extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
802 struct scsi_ioctl_command __user *);
Andrew Morton3fcfab12006-10-19 23:28:16 -0700803
Christoph Hellwig5a7bbad2011-09-12 12:12:01 +0200804extern void blk_queue_bio(struct request_queue *q, struct bio *bio);
Christoph Hellwig166e1f92011-09-12 12:08:27 +0200805
Andrew Morton3fcfab12006-10-19 23:28:16 -0700806/*
807 * A queue has just exitted congestion. Note this in the global counter of
808 * congested queues, and wake up anyone who was waiting for requests to be
809 * put back.
810 */
Jens Axboe8aa7e842009-07-09 14:52:32 +0200811static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
Andrew Morton3fcfab12006-10-19 23:28:16 -0700812{
Jens Axboe8aa7e842009-07-09 14:52:32 +0200813 clear_bdi_congested(&q->backing_dev_info, sync);
Andrew Morton3fcfab12006-10-19 23:28:16 -0700814}
815
816/*
817 * A queue has just entered congestion. Flag that in the queue's VM-visible
818 * state flags and increment the global gounter of congested queues.
819 */
Jens Axboe8aa7e842009-07-09 14:52:32 +0200820static inline void blk_set_queue_congested(struct request_queue *q, int sync)
Andrew Morton3fcfab12006-10-19 23:28:16 -0700821{
Jens Axboe8aa7e842009-07-09 14:52:32 +0200822 set_bdi_congested(&q->backing_dev_info, sync);
Andrew Morton3fcfab12006-10-19 23:28:16 -0700823}
824
Jens Axboe165125e2007-07-24 09:28:11 +0200825extern void blk_start_queue(struct request_queue *q);
826extern void blk_stop_queue(struct request_queue *q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827extern void blk_sync_queue(struct request_queue *q);
Jens Axboe165125e2007-07-24 09:28:11 +0200828extern void __blk_stop_queue(struct request_queue *q);
Christoph Hellwig24ecfbe2011-04-18 11:41:33 +0200829extern void __blk_run_queue(struct request_queue *q);
Jens Axboe165125e2007-07-24 09:28:11 +0200830extern void blk_run_queue(struct request_queue *);
Jens Axboec21e6be2011-04-19 13:32:46 +0200831extern void blk_run_queue_async(struct request_queue *q);
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900832extern int blk_rq_map_user(struct request_queue *, struct request *,
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900833 struct rq_map_data *, void __user *, unsigned long,
834 gfp_t);
Jens Axboe8e5cfc42006-12-19 11:12:46 +0100835extern int blk_rq_unmap_user(struct bio *);
Jens Axboe165125e2007-07-24 09:28:11 +0200836extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
837extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
Al Viro86d564c2014-02-08 20:42:52 -0500838 struct rq_map_data *, const struct sg_iovec *,
839 int, unsigned int, gfp_t);
Jens Axboe165125e2007-07-24 09:28:11 +0200840extern int blk_execute_rq(struct request_queue *, struct gendisk *,
James Bottomley 994ca9a2005-06-20 14:11:09 +0200841 struct request *, int);
Jens Axboe165125e2007-07-24 09:28:11 +0200842extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
Jens Axboe15fc8582006-01-06 10:00:50 +0100843 struct request *, int, rq_end_io_fn *);
Mike Christie6e39b692005-11-11 05:30:24 -0600844
Jens Axboe165125e2007-07-24 09:28:11 +0200845static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846{
847 return bdev->bd_disk->queue;
848}
849
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850/*
Tejun Heo80a761f2009-07-03 17:48:17 +0900851 * blk_rq_pos() : the current sector
852 * blk_rq_bytes() : bytes left in the entire request
853 * blk_rq_cur_bytes() : bytes left in the current segment
854 * blk_rq_err_bytes() : bytes left till the next error boundary
855 * blk_rq_sectors() : sectors left in the entire request
856 * blk_rq_cur_sectors() : sectors left in the current segment
Tejun Heo5efccd12009-04-23 11:05:18 +0900857 */
Tejun Heo5b936292009-05-07 22:24:38 +0900858static inline sector_t blk_rq_pos(const struct request *rq)
859{
Tejun Heoa2dec7b2009-05-07 22:24:44 +0900860 return rq->__sector;
Tejun Heo5b936292009-05-07 22:24:38 +0900861}
862
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900863static inline unsigned int blk_rq_bytes(const struct request *rq)
864{
Tejun Heoa2dec7b2009-05-07 22:24:44 +0900865 return rq->__data_len;
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900866}
867
868static inline int blk_rq_cur_bytes(const struct request *rq)
869{
870 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
871}
Tejun Heo5efccd12009-04-23 11:05:18 +0900872
Tejun Heo80a761f2009-07-03 17:48:17 +0900873extern unsigned int blk_rq_err_bytes(const struct request *rq);
874
Tejun Heo5b936292009-05-07 22:24:38 +0900875static inline unsigned int blk_rq_sectors(const struct request *rq)
876{
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900877 return blk_rq_bytes(rq) >> 9;
Tejun Heo5b936292009-05-07 22:24:38 +0900878}
879
880static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
881{
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900882 return blk_rq_cur_bytes(rq) >> 9;
Tejun Heo5b936292009-05-07 22:24:38 +0900883}
884
Martin K. Petersenf31dc1c2012-09-18 12:19:26 -0400885static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
886 unsigned int cmd_flags)
887{
888 if (unlikely(cmd_flags & REQ_DISCARD))
James Bottomley871dd922013-04-24 08:52:50 -0600889 return min(q->limits.max_discard_sectors, UINT_MAX >> 9);
Martin K. Petersenf31dc1c2012-09-18 12:19:26 -0400890
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400891 if (unlikely(cmd_flags & REQ_WRITE_SAME))
892 return q->limits.max_write_same_sectors;
893
Martin K. Petersenf31dc1c2012-09-18 12:19:26 -0400894 return q->limits.max_sectors;
895}
896
897static inline unsigned int blk_rq_get_max_sectors(struct request *rq)
898{
899 struct request_queue *q = rq->q;
900
901 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC))
902 return q->limits.max_hw_sectors;
903
904 return blk_queue_get_max_sectors(q, rq->cmd_flags);
905}
906
Jun'ichi Nomura75afb352013-09-21 13:57:47 -0600907static inline unsigned int blk_rq_count_bios(struct request *rq)
908{
909 unsigned int nr_bios = 0;
910 struct bio *bio;
911
912 __rq_for_each_bio(bio, rq)
913 nr_bios++;
914
915 return nr_bios;
916}
917
Tejun Heo5efccd12009-04-23 11:05:18 +0900918/*
Tejun Heo9934c8c2009-05-08 11:54:16 +0900919 * Request issue related functions.
920 */
921extern struct request *blk_peek_request(struct request_queue *q);
922extern void blk_start_request(struct request *rq);
923extern struct request *blk_fetch_request(struct request_queue *q);
924
925/*
Tejun Heo2e60e022009-04-23 11:05:18 +0900926 * Request completion related functions.
927 *
928 * blk_update_request() completes given number of bytes and updates
929 * the request without completing it.
930 *
Tejun Heof06d9a22009-04-23 11:05:19 +0900931 * blk_end_request() and friends. __blk_end_request() must be called
932 * with the request queue spinlock acquired.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933 *
934 * Several drivers define their own end_request and call
Kiyoshi Ueda3bcddea2007-12-11 17:52:28 -0500935 * blk_end_request() for parts of the original function.
936 * This prevents code duplication in drivers.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 */
Tejun Heo2e60e022009-04-23 11:05:18 +0900938extern bool blk_update_request(struct request *rq, int error,
939 unsigned int nr_bytes);
FUJITA Tomonorib1f74492009-05-11 17:56:09 +0900940extern bool blk_end_request(struct request *rq, int error,
941 unsigned int nr_bytes);
942extern void blk_end_request_all(struct request *rq, int error);
943extern bool blk_end_request_cur(struct request *rq, int error);
Tejun Heo80a761f2009-07-03 17:48:17 +0900944extern bool blk_end_request_err(struct request *rq, int error);
FUJITA Tomonorib1f74492009-05-11 17:56:09 +0900945extern bool __blk_end_request(struct request *rq, int error,
946 unsigned int nr_bytes);
947extern void __blk_end_request_all(struct request *rq, int error);
948extern bool __blk_end_request_cur(struct request *rq, int error);
Tejun Heo80a761f2009-07-03 17:48:17 +0900949extern bool __blk_end_request_err(struct request *rq, int error);
Tejun Heo2e60e022009-04-23 11:05:18 +0900950
Jens Axboeff856ba2006-01-09 16:02:34 +0100951extern void blk_complete_request(struct request *);
Jens Axboe242f9dc2008-09-14 05:55:09 -0700952extern void __blk_complete_request(struct request *);
953extern void blk_abort_request(struct request *);
James Bottomley28018c22010-07-01 19:49:17 +0900954extern void blk_unprep_request(struct request *);
Jens Axboeff856ba2006-01-09 16:02:34 +0100955
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957 * Access functions for manipulating queue properties
958 */
Jens Axboe165125e2007-07-24 09:28:11 +0200959extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
Christoph Lameter19460892005-06-23 00:08:19 -0700960 spinlock_t *lock, int node_id);
Jens Axboe165125e2007-07-24 09:28:11 +0200961extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
Mike Snitzer01effb02010-05-11 08:57:42 +0200962extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
963 request_fn_proc *, spinlock_t *);
Jens Axboe165125e2007-07-24 09:28:11 +0200964extern void blk_cleanup_queue(struct request_queue *);
965extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
966extern void blk_queue_bounce_limit(struct request_queue *, u64);
Mike Snitzer72d4cd92010-12-17 08:34:20 +0100967extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
Martin K. Petersen086fa5f2010-02-26 00:20:38 -0500968extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
Martin K. Petersen8a783622010-02-26 00:20:39 -0500969extern void blk_queue_max_segments(struct request_queue *, unsigned short);
Jens Axboe165125e2007-07-24 09:28:11 +0200970extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
Christoph Hellwig67efc922009-09-30 13:54:20 +0200971extern void blk_queue_max_discard_sectors(struct request_queue *q,
972 unsigned int max_discard_sectors);
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400973extern void blk_queue_max_write_same_sectors(struct request_queue *q,
974 unsigned int max_write_same_sectors);
Martin K. Petersene1defc42009-05-22 17:17:49 -0400975extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
Martin K. Petersen892b6f92010-10-13 21:18:03 +0200976extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400977extern void blk_queue_alignment_offset(struct request_queue *q,
978 unsigned int alignment);
Martin K. Petersen7c958e32009-07-31 11:49:11 -0400979extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400980extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
Martin K. Petersen3c5820c2009-09-11 21:54:52 +0200981extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400982extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
Martin K. Petersene475bba2009-06-16 08:23:52 +0200983extern void blk_set_default_limits(struct queue_limits *lim);
Martin K. Petersenb1bd0552012-01-11 16:27:11 +0100984extern void blk_set_stacking_limits(struct queue_limits *lim);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400985extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
986 sector_t offset);
Martin K. Petersen17be8c22010-01-11 03:21:49 -0500987extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
988 sector_t offset);
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400989extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
990 sector_t offset);
Jens Axboe165125e2007-07-24 09:28:11 +0200991extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
Tejun Heoe3790c72008-03-04 11:18:17 +0100992extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
FUJITA Tomonori27f82212008-07-04 09:30:03 +0200993extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
Tejun Heo2fb98e82008-02-19 11:36:53 +0100994extern int blk_queue_dma_drain(struct request_queue *q,
995 dma_drain_needed_fn *dma_drain_needed,
996 void *buf, unsigned int size);
Kiyoshi Uedaef9e3fa2008-10-01 16:12:15 +0200997extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
Jens Axboe165125e2007-07-24 09:28:11 +0200998extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
999extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
James Bottomley28018c22010-07-01 19:49:17 +09001000extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
Jens Axboe165125e2007-07-24 09:28:11 +02001001extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
1002extern void blk_queue_dma_alignment(struct request_queue *, int);
James Bottomley11c3e682007-12-31 16:37:00 -06001003extern void blk_queue_update_dma_alignment(struct request_queue *, int);
Jens Axboe165125e2007-07-24 09:28:11 +02001004extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
Jens Axboe242f9dc2008-09-14 05:55:09 -07001005extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
1006extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
Tejun Heo4913efe2010-09-03 11:56:16 +02001007extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
shaohua.li@intel.comf3876932011-05-06 11:34:32 -06001008extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010
Jens Axboe165125e2007-07-24 09:28:11 +02001011extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
Asias He85b9f662012-08-02 23:42:04 +02001012extern int blk_bio_map_sg(struct request_queue *q, struct bio *bio,
1013 struct scatterlist *sglist);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014extern void blk_dump_rq_flags(struct request *, char *);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015extern long nr_blockdev_pages(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016
Tejun Heo09ac46c2011-12-14 00:33:38 +01001017bool __must_check blk_get_queue(struct request_queue *);
Jens Axboe165125e2007-07-24 09:28:11 +02001018struct request_queue *blk_alloc_queue(gfp_t);
1019struct request_queue *blk_alloc_queue_node(gfp_t, int);
1020extern void blk_put_queue(struct request_queue *);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021
Shaohua Li316cc672011-07-08 08:19:21 +02001022/*
Lin Ming6c954662013-03-23 11:42:26 +08001023 * block layer runtime pm functions
1024 */
1025#ifdef CONFIG_PM_RUNTIME
1026extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev);
1027extern int blk_pre_runtime_suspend(struct request_queue *q);
1028extern void blk_post_runtime_suspend(struct request_queue *q, int err);
1029extern void blk_pre_runtime_resume(struct request_queue *q);
1030extern void blk_post_runtime_resume(struct request_queue *q, int err);
1031#else
1032static inline void blk_pm_runtime_init(struct request_queue *q,
1033 struct device *dev) {}
1034static inline int blk_pre_runtime_suspend(struct request_queue *q)
1035{
1036 return -ENOSYS;
1037}
1038static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {}
1039static inline void blk_pre_runtime_resume(struct request_queue *q) {}
1040static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
1041#endif
1042
1043/*
Suresh Jayaraman75df7132011-09-21 10:00:16 +02001044 * blk_plug permits building a queue of related requests by holding the I/O
1045 * fragments for a short period. This allows merging of sequential requests
1046 * into single larger request. As the requests are moved from a per-task list to
1047 * the device's request_queue in a batch, this results in improved scalability
1048 * as the lock contention for request_queue lock is reduced.
1049 *
1050 * It is ok not to disable preemption when adding the request to the plug list
1051 * or when attempting a merge, because blk_schedule_flush_list() will only flush
1052 * the plug list when the task sleeps by itself. For details, please see
1053 * schedule() where blk_schedule_flush_plug() is called.
Shaohua Li316cc672011-07-08 08:19:21 +02001054 */
Jens Axboe73c10102011-03-08 13:19:51 +01001055struct blk_plug {
Suresh Jayaraman75df7132011-09-21 10:00:16 +02001056 unsigned long magic; /* detect uninitialized use-cases */
1057 struct list_head list; /* requests */
Jens Axboe320ae512013-10-24 09:20:05 +01001058 struct list_head mq_list; /* blk-mq requests */
Suresh Jayaraman75df7132011-09-21 10:00:16 +02001059 struct list_head cb_list; /* md requires an unplug callback */
Jens Axboe73c10102011-03-08 13:19:51 +01001060};
Shaohua Li55c022b2011-07-08 08:19:20 +02001061#define BLK_MAX_REQUEST_COUNT 16
1062
NeilBrown9cbb1752012-07-31 09:08:14 +02001063struct blk_plug_cb;
NeilBrown74018dc2012-07-31 09:08:15 +02001064typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
NeilBrown048c9372011-04-18 09:52:22 +02001065struct blk_plug_cb {
1066 struct list_head list;
NeilBrown9cbb1752012-07-31 09:08:14 +02001067 blk_plug_cb_fn callback;
1068 void *data;
NeilBrown048c9372011-04-18 09:52:22 +02001069};
NeilBrown9cbb1752012-07-31 09:08:14 +02001070extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1071 void *data, int size);
Jens Axboe73c10102011-03-08 13:19:51 +01001072extern void blk_start_plug(struct blk_plug *);
1073extern void blk_finish_plug(struct blk_plug *);
Jens Axboef6603782011-04-15 15:49:07 +02001074extern void blk_flush_plug_list(struct blk_plug *, bool);
Jens Axboe73c10102011-03-08 13:19:51 +01001075
1076static inline void blk_flush_plug(struct task_struct *tsk)
1077{
1078 struct blk_plug *plug = tsk->plug;
1079
Christoph Hellwig88b996c2011-04-15 15:20:10 +02001080 if (plug)
Jens Axboea237c1c2011-04-16 13:27:55 +02001081 blk_flush_plug_list(plug, false);
1082}
1083
1084static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1085{
1086 struct blk_plug *plug = tsk->plug;
1087
1088 if (plug)
Jens Axboef6603782011-04-15 15:49:07 +02001089 blk_flush_plug_list(plug, true);
Jens Axboe73c10102011-03-08 13:19:51 +01001090}
1091
1092static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1093{
1094 struct blk_plug *plug = tsk->plug;
1095
Jens Axboe320ae512013-10-24 09:20:05 +01001096 return plug &&
1097 (!list_empty(&plug->list) ||
1098 !list_empty(&plug->mq_list) ||
1099 !list_empty(&plug->cb_list));
Jens Axboe73c10102011-03-08 13:19:51 +01001100}
1101
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102/*
1103 * tag stuff
1104 */
Jens Axboe4aff5e22006-08-10 08:44:47 +02001105#define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
Jens Axboe165125e2007-07-24 09:28:11 +02001106extern int blk_queue_start_tag(struct request_queue *, struct request *);
1107extern struct request *blk_queue_find_tag(struct request_queue *, int);
1108extern void blk_queue_end_tag(struct request_queue *, struct request *);
1109extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
1110extern void blk_queue_free_tags(struct request_queue *);
1111extern int blk_queue_resize_tags(struct request_queue *, int);
1112extern void blk_queue_invalidate_tags(struct request_queue *);
James Bottomley492dfb42006-08-30 15:48:45 -04001113extern struct blk_queue_tag *blk_init_tags(int);
1114extern void blk_free_tags(struct blk_queue_tag *);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115
David C Somayajuluf583f492006-10-04 08:27:25 +02001116static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
1117 int tag)
1118{
1119 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
1120 return NULL;
1121 return bqt->tag_index[tag];
1122}
Christoph Hellwigdd3932e2010-09-16 20:51:46 +02001123
1124#define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
1125
1126extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
Dmitry Monakhovfbd9b092010-04-28 17:55:06 +04001127extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1128 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
Martin K. Petersen4363ac72012-09-18 12:19:27 -04001129extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1130 sector_t nr_sects, gfp_t gfp_mask, struct page *page);
Dmitry Monakhov3f14d792010-04-28 17:55:09 +04001131extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
Christoph Hellwigdd3932e2010-09-16 20:51:46 +02001132 sector_t nr_sects, gfp_t gfp_mask);
Christoph Hellwig2cf6d262010-08-18 05:29:10 -04001133static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1134 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
David Woodhousefb2dce82008-08-05 18:01:53 +01001135{
Christoph Hellwig2cf6d262010-08-18 05:29:10 -04001136 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
1137 nr_blocks << (sb->s_blocksize_bits - 9),
1138 gfp_mask, flags);
David Woodhousefb2dce82008-08-05 18:01:53 +01001139}
Lukas Czernere6fa0be2010-10-27 21:30:04 -04001140static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
Theodore Ts'oa107e5a2010-10-27 23:44:47 -04001141 sector_t nr_blocks, gfp_t gfp_mask)
Lukas Czernere6fa0be2010-10-27 21:30:04 -04001142{
1143 return blkdev_issue_zeroout(sb->s_bdev,
1144 block << (sb->s_blocksize_bits - 9),
1145 nr_blocks << (sb->s_blocksize_bits - 9),
Theodore Ts'oa107e5a2010-10-27 23:44:47 -04001146 gfp_mask);
Lukas Czernere6fa0be2010-10-27 21:30:04 -04001147}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148
Jens Axboe018e0442009-06-26 16:27:10 +02001149extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
Adel Gadllah0b07de82008-06-26 13:48:27 +02001150
Martin K. Peterseneb28d312010-02-26 00:20:37 -05001151enum blk_default_limits {
1152 BLK_MAX_SEGMENTS = 128,
1153 BLK_SAFE_MAX_SECTORS = 255,
1154 BLK_DEF_MAX_SECTORS = 1024,
1155 BLK_MAX_SEGMENT_SIZE = 65536,
1156 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
1157};
Milan Broz0e435ac2008-12-03 12:55:08 +01001158
Linus Torvalds1da177e2005-04-16 15:20:36 -07001159#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1160
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001161static inline unsigned long queue_bounce_pfn(struct request_queue *q)
1162{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001163 return q->limits.bounce_pfn;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001164}
1165
1166static inline unsigned long queue_segment_boundary(struct request_queue *q)
1167{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001168 return q->limits.seg_boundary_mask;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001169}
1170
1171static inline unsigned int queue_max_sectors(struct request_queue *q)
1172{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001173 return q->limits.max_sectors;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001174}
1175
1176static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1177{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001178 return q->limits.max_hw_sectors;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001179}
1180
Martin K. Petersen8a783622010-02-26 00:20:39 -05001181static inline unsigned short queue_max_segments(struct request_queue *q)
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001182{
Martin K. Petersen8a783622010-02-26 00:20:39 -05001183 return q->limits.max_segments;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001184}
1185
1186static inline unsigned int queue_max_segment_size(struct request_queue *q)
1187{
Martin K. Petersen025146e2009-05-22 17:17:51 -04001188 return q->limits.max_segment_size;
Martin K. Petersenae03bf62009-05-22 17:17:50 -04001189}
1190
Martin K. Petersene1defc42009-05-22 17:17:49 -04001191static inline unsigned short queue_logical_block_size(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192{
1193 int retval = 512;
1194
Martin K. Petersen025146e2009-05-22 17:17:51 -04001195 if (q && q->limits.logical_block_size)
1196 retval = q->limits.logical_block_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197
1198 return retval;
1199}
1200
Martin K. Petersene1defc42009-05-22 17:17:49 -04001201static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001202{
Martin K. Petersene1defc42009-05-22 17:17:49 -04001203 return queue_logical_block_size(bdev_get_queue(bdev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001204}
1205
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001206static inline unsigned int queue_physical_block_size(struct request_queue *q)
1207{
1208 return q->limits.physical_block_size;
1209}
1210
Martin K. Petersen892b6f92010-10-13 21:18:03 +02001211static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
Martin K. Petersenac481c22009-10-03 20:52:01 +02001212{
1213 return queue_physical_block_size(bdev_get_queue(bdev));
1214}
1215
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001216static inline unsigned int queue_io_min(struct request_queue *q)
1217{
1218 return q->limits.io_min;
1219}
1220
Martin K. Petersenac481c22009-10-03 20:52:01 +02001221static inline int bdev_io_min(struct block_device *bdev)
1222{
1223 return queue_io_min(bdev_get_queue(bdev));
1224}
1225
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001226static inline unsigned int queue_io_opt(struct request_queue *q)
1227{
1228 return q->limits.io_opt;
1229}
1230
Martin K. Petersenac481c22009-10-03 20:52:01 +02001231static inline int bdev_io_opt(struct block_device *bdev)
1232{
1233 return queue_io_opt(bdev_get_queue(bdev));
1234}
1235
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001236static inline int queue_alignment_offset(struct request_queue *q)
1237{
Martin K. Petersenac481c22009-10-03 20:52:01 +02001238 if (q->limits.misaligned)
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001239 return -1;
1240
Martin K. Petersenac481c22009-10-03 20:52:01 +02001241 return q->limits.alignment_offset;
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001242}
1243
Martin K. Petersene03a72e2010-01-11 03:21:51 -05001244static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
Martin K. Petersen81744ee2009-12-29 08:35:35 +01001245{
1246 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
Martin K. Petersene03a72e2010-01-11 03:21:51 -05001247 unsigned int alignment = (sector << 9) & (granularity - 1);
Martin K. Petersen81744ee2009-12-29 08:35:35 +01001248
Martin K. Petersene03a72e2010-01-11 03:21:51 -05001249 return (granularity + lim->alignment_offset - alignment)
1250 & (granularity - 1);
Martin K. Petersenc72758f2009-05-22 17:17:53 -04001251}
1252
Martin K. Petersenac481c22009-10-03 20:52:01 +02001253static inline int bdev_alignment_offset(struct block_device *bdev)
1254{
1255 struct request_queue *q = bdev_get_queue(bdev);
1256
1257 if (q->limits.misaligned)
1258 return -1;
1259
1260 if (bdev != bdev->bd_contains)
1261 return bdev->bd_part->alignment_offset;
1262
1263 return q->limits.alignment_offset;
1264}
1265
Martin K. Petersen86b37282009-11-10 11:50:21 +01001266static inline int queue_discard_alignment(struct request_queue *q)
1267{
1268 if (q->limits.discard_misaligned)
1269 return -1;
1270
1271 return q->limits.discard_alignment;
1272}
1273
Martin K. Petersene03a72e2010-01-11 03:21:51 -05001274static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
Martin K. Petersen86b37282009-11-10 11:50:21 +01001275{
Linus Torvalds59771072012-12-19 07:18:35 -08001276 unsigned int alignment, granularity, offset;
Martin K. Petersendd3d1452010-01-11 03:21:48 -05001277
Martin K. Petersena934a002011-05-18 10:37:35 +02001278 if (!lim->max_discard_sectors)
1279 return 0;
1280
Linus Torvalds59771072012-12-19 07:18:35 -08001281 /* Why are these in bytes, not sectors? */
1282 alignment = lim->discard_alignment >> 9;
1283 granularity = lim->discard_granularity >> 9;
1284 if (!granularity)
1285 return 0;
1286
1287 /* Offset of the partition start in 'granularity' sectors */
1288 offset = sector_div(sector, granularity);
1289
1290 /* And why do we do this modulus *again* in blkdev_issue_discard()? */
1291 offset = (granularity + alignment - offset) % granularity;
1292
1293 /* Turn it back into bytes, gaah */
1294 return offset << 9;
Martin K. Petersen86b37282009-11-10 11:50:21 +01001295}
1296
Paolo Bonzinic6e66632012-08-02 09:48:50 +02001297static inline int bdev_discard_alignment(struct block_device *bdev)
1298{
1299 struct request_queue *q = bdev_get_queue(bdev);
1300
1301 if (bdev != bdev->bd_contains)
1302 return bdev->bd_part->discard_alignment;
1303
1304 return q->limits.discard_alignment;
1305}
1306
Martin K. Petersen98262f22009-12-03 09:24:48 +01001307static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1308{
Martin K. Petersena934a002011-05-18 10:37:35 +02001309 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
Martin K. Petersen98262f22009-12-03 09:24:48 +01001310 return 1;
1311
1312 return 0;
1313}
1314
1315static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1316{
1317 return queue_discard_zeroes_data(bdev_get_queue(bdev));
1318}
1319
Martin K. Petersen4363ac72012-09-18 12:19:27 -04001320static inline unsigned int bdev_write_same(struct block_device *bdev)
1321{
1322 struct request_queue *q = bdev_get_queue(bdev);
1323
1324 if (q)
1325 return q->limits.max_write_same_sectors;
1326
1327 return 0;
1328}
1329
Jens Axboe165125e2007-07-24 09:28:11 +02001330static inline int queue_dma_alignment(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331{
Pete Wyckoff482eb682008-01-01 10:23:02 -05001332 return q ? q->dma_alignment : 511;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001333}
1334
Namhyung Kim14417792010-09-15 13:08:27 +02001335static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
FUJITA Tomonori87904072008-08-28 15:05:58 +09001336 unsigned int len)
1337{
1338 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
Namhyung Kim14417792010-09-15 13:08:27 +02001339 return !(addr & alignment) && !(len & alignment);
FUJITA Tomonori87904072008-08-28 15:05:58 +09001340}
1341
Linus Torvalds1da177e2005-04-16 15:20:36 -07001342/* assumes size > 256 */
1343static inline unsigned int blksize_bits(unsigned int size)
1344{
1345 unsigned int bits = 8;
1346 do {
1347 bits++;
1348 size >>= 1;
1349 } while (size > 256);
1350 return bits;
1351}
1352
Adrian Bunk2befb9e2005-09-10 00:27:17 -07001353static inline unsigned int block_size(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001354{
1355 return bdev->bd_block_size;
1356}
1357
shaohua.li@intel.comf3876932011-05-06 11:34:32 -06001358static inline bool queue_flush_queueable(struct request_queue *q)
1359{
1360 return !q->flush_not_queueable;
1361}
1362
Linus Torvalds1da177e2005-04-16 15:20:36 -07001363typedef struct {struct page *v;} Sector;
1364
1365unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1366
1367static inline void put_dev_sector(Sector p)
1368{
1369 page_cache_release(p.v);
1370}
1371
1372struct work_struct;
Jens Axboe18887ad2008-07-28 13:08:45 +02001373int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
Jens Axboe320ae512013-10-24 09:20:05 +01001374int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001375
Divyesh Shah91952912010-04-01 15:01:41 -07001376#ifdef CONFIG_BLK_CGROUP
Jens Axboe28f41972010-06-01 12:23:18 +02001377/*
1378 * This should not be using sched_clock(). A real patch is in progress
1379 * to fix this up, until that is in place we need to disable preemption
1380 * around sched_clock() in this function and set_io_start_time_ns().
1381 */
Divyesh Shah91952912010-04-01 15:01:41 -07001382static inline void set_start_time_ns(struct request *req)
1383{
Jens Axboe28f41972010-06-01 12:23:18 +02001384 preempt_disable();
Divyesh Shah91952912010-04-01 15:01:41 -07001385 req->start_time_ns = sched_clock();
Jens Axboe28f41972010-06-01 12:23:18 +02001386 preempt_enable();
Divyesh Shah91952912010-04-01 15:01:41 -07001387}
1388
1389static inline void set_io_start_time_ns(struct request *req)
1390{
Jens Axboe28f41972010-06-01 12:23:18 +02001391 preempt_disable();
Divyesh Shah91952912010-04-01 15:01:41 -07001392 req->io_start_time_ns = sched_clock();
Jens Axboe28f41972010-06-01 12:23:18 +02001393 preempt_enable();
Divyesh Shah91952912010-04-01 15:01:41 -07001394}
Divyesh Shah84c124d2010-04-09 08:31:19 +02001395
1396static inline uint64_t rq_start_time_ns(struct request *req)
1397{
1398 return req->start_time_ns;
1399}
1400
1401static inline uint64_t rq_io_start_time_ns(struct request *req)
1402{
1403 return req->io_start_time_ns;
1404}
Divyesh Shah91952912010-04-01 15:01:41 -07001405#else
1406static inline void set_start_time_ns(struct request *req) {}
1407static inline void set_io_start_time_ns(struct request *req) {}
Divyesh Shah84c124d2010-04-09 08:31:19 +02001408static inline uint64_t rq_start_time_ns(struct request *req)
1409{
1410 return 0;
1411}
1412static inline uint64_t rq_io_start_time_ns(struct request *req)
1413{
1414 return 0;
1415}
Divyesh Shah91952912010-04-01 15:01:41 -07001416#endif
1417
Linus Torvalds1da177e2005-04-16 15:20:36 -07001418#define MODULE_ALIAS_BLOCKDEV(major,minor) \
1419 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1420#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1421 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1422
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001423#if defined(CONFIG_BLK_DEV_INTEGRITY)
1424
Jens Axboeb24498d2008-06-27 09:12:09 +02001425#define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1426#define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001427
1428struct blk_integrity_exchg {
1429 void *prot_buf;
1430 void *data_buf;
1431 sector_t sector;
1432 unsigned int data_size;
1433 unsigned short sector_size;
1434 const char *disk_name;
1435};
1436
1437typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1438typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1439typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1440typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1441
1442struct blk_integrity {
1443 integrity_gen_fn *generate_fn;
1444 integrity_vrfy_fn *verify_fn;
1445 integrity_set_tag_fn *set_tag_fn;
1446 integrity_get_tag_fn *get_tag_fn;
1447
1448 unsigned short flags;
1449 unsigned short tuple_size;
1450 unsigned short sector_size;
1451 unsigned short tag_size;
1452
1453 const char *name;
1454
1455 struct kobject kobj;
1456};
1457
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001458extern bool blk_integrity_is_initialized(struct gendisk *);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001459extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1460extern void blk_integrity_unregister(struct gendisk *);
Martin K. Petersenad7fce92008-10-01 03:38:39 -04001461extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001462extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1463 struct scatterlist *);
1464extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1465extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
1466 struct request *);
1467extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
1468 struct bio *);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001469
Jens Axboeb04accc2008-10-02 12:53:22 +02001470static inline
1471struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1472{
1473 return bdev->bd_disk->integrity;
1474}
1475
Martin K. Petersenb02739b2008-10-02 18:47:49 +02001476static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1477{
1478 return disk->integrity;
1479}
1480
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001481static inline int blk_integrity_rq(struct request *rq)
1482{
Martin K. Petersend442cc42008-07-16 16:09:06 -04001483 if (rq->bio == NULL)
1484 return 0;
1485
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001486 return bio_integrity(rq->bio);
1487}
1488
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001489static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1490 unsigned int segs)
1491{
1492 q->limits.max_integrity_segments = segs;
1493}
1494
1495static inline unsigned short
1496queue_max_integrity_segments(struct request_queue *q)
1497{
1498 return q->limits.max_integrity_segments;
1499}
1500
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001501#else /* CONFIG_BLK_DEV_INTEGRITY */
1502
Stephen Rothwellfd832402012-01-12 09:17:30 +01001503struct bio;
1504struct block_device;
1505struct gendisk;
1506struct blk_integrity;
1507
1508static inline int blk_integrity_rq(struct request *rq)
1509{
1510 return 0;
1511}
1512static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1513 struct bio *b)
1514{
1515 return 0;
1516}
1517static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1518 struct bio *b,
1519 struct scatterlist *s)
1520{
1521 return 0;
1522}
1523static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1524{
1525 return 0;
1526}
1527static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1528{
1529 return NULL;
1530}
1531static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1532{
1533 return 0;
1534}
1535static inline int blk_integrity_register(struct gendisk *d,
1536 struct blk_integrity *b)
1537{
1538 return 0;
1539}
1540static inline void blk_integrity_unregister(struct gendisk *d)
1541{
1542}
1543static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1544 unsigned int segs)
1545{
1546}
1547static inline unsigned short queue_max_integrity_segments(struct request_queue *q)
1548{
1549 return 0;
1550}
1551static inline int blk_integrity_merge_rq(struct request_queue *rq,
1552 struct request *r1,
1553 struct request *r2)
1554{
1555 return 0;
1556}
1557static inline int blk_integrity_merge_bio(struct request_queue *rq,
1558 struct request *r,
1559 struct bio *b)
1560{
1561 return 0;
1562}
1563static inline bool blk_integrity_is_initialized(struct gendisk *g)
1564{
1565 return 0;
1566}
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001567
1568#endif /* CONFIG_BLK_DEV_INTEGRITY */
1569
Al Viro08f85852007-10-08 13:26:20 -04001570struct block_device_operations {
Al Virod4430d62008-03-02 09:09:22 -05001571 int (*open) (struct block_device *, fmode_t);
Al Virodb2a1442013-05-05 21:52:57 -04001572 void (*release) (struct gendisk *, fmode_t);
Al Virod4430d62008-03-02 09:09:22 -05001573 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1574 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
Al Viro08f85852007-10-08 13:26:20 -04001575 int (*direct_access) (struct block_device *, sector_t,
1576 void **, unsigned long *);
Tejun Heo77ea8872010-12-08 20:57:37 +01001577 unsigned int (*check_events) (struct gendisk *disk,
1578 unsigned int clearing);
1579 /* ->media_changed() is DEPRECATED, use ->check_events() instead */
Al Viro08f85852007-10-08 13:26:20 -04001580 int (*media_changed) (struct gendisk *);
Tejun Heoc3e33e02010-05-15 20:09:29 +02001581 void (*unlock_native_capacity) (struct gendisk *);
Al Viro08f85852007-10-08 13:26:20 -04001582 int (*revalidate_disk) (struct gendisk *);
1583 int (*getgeo)(struct block_device *, struct hd_geometry *);
Nitin Guptab3a27d02010-05-17 11:02:43 +05301584 /* this callback is with swap_lock and sometimes page table lock held */
1585 void (*swap_slot_free_notify) (struct block_device *, unsigned long);
Al Viro08f85852007-10-08 13:26:20 -04001586 struct module *owner;
1587};
1588
Al Viro633a08b2007-08-29 20:34:12 -04001589extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1590 unsigned long);
David Howells93614012006-09-30 20:45:40 +02001591#else /* CONFIG_BLOCK */
1592/*
1593 * stubs for when the block layer is configured out
1594 */
1595#define buffer_heads_over_limit 0
1596
David Howells93614012006-09-30 20:45:40 +02001597static inline long nr_blockdev_pages(void)
1598{
1599 return 0;
1600}
1601
Jens Axboe1f940bd2011-03-11 20:17:08 +01001602struct blk_plug {
1603};
1604
1605static inline void blk_start_plug(struct blk_plug *plug)
Jens Axboe73c10102011-03-08 13:19:51 +01001606{
1607}
1608
Jens Axboe1f940bd2011-03-11 20:17:08 +01001609static inline void blk_finish_plug(struct blk_plug *plug)
Jens Axboe73c10102011-03-08 13:19:51 +01001610{
1611}
1612
Jens Axboe1f940bd2011-03-11 20:17:08 +01001613static inline void blk_flush_plug(struct task_struct *task)
Jens Axboe73c10102011-03-08 13:19:51 +01001614{
1615}
1616
Jens Axboea237c1c2011-04-16 13:27:55 +02001617static inline void blk_schedule_flush_plug(struct task_struct *task)
1618{
1619}
1620
1621
Jens Axboe73c10102011-03-08 13:19:51 +01001622static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1623{
1624 return false;
1625}
1626
David Howells93614012006-09-30 20:45:40 +02001627#endif /* CONFIG_BLOCK */
1628
Linus Torvalds1da177e2005-04-16 15:20:36 -07001629#endif