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Jens Axboe2056a782006-03-23 20:00:26 +01001#ifndef BLKTRACE_H
2#define BLKTRACE_H
3
Jens Axboe2056a782006-03-23 20:00:26 +01004#include <linux/blkdev.h>
5#include <linux/relay.h>
6
7/*
8 * Trace categories
9 */
10enum blktrace_cat {
11 BLK_TC_READ = 1 << 0, /* reads */
12 BLK_TC_WRITE = 1 << 1, /* writes */
13 BLK_TC_BARRIER = 1 << 2, /* barrier */
Nathan Scottfc0a75c2006-07-06 09:56:30 +020014 BLK_TC_SYNC = 1 << 3, /* sync IO */
Jens Axboe2056a782006-03-23 20:00:26 +010015 BLK_TC_QUEUE = 1 << 4, /* queueing/merging */
16 BLK_TC_REQUEUE = 1 << 5, /* requeueing */
17 BLK_TC_ISSUE = 1 << 6, /* issue */
18 BLK_TC_COMPLETE = 1 << 7, /* completions */
19 BLK_TC_FS = 1 << 8, /* fs requests */
20 BLK_TC_PC = 1 << 9, /* pc requests */
21 BLK_TC_NOTIFY = 1 << 10, /* special message */
22
23 BLK_TC_END = 1 << 15, /* only 16-bits, reminder */
24};
25
26#define BLK_TC_SHIFT (16)
27#define BLK_TC_ACT(act) ((act) << BLK_TC_SHIFT)
28
29/*
30 * Basic trace actions
31 */
32enum blktrace_act {
33 __BLK_TA_QUEUE = 1, /* queued */
34 __BLK_TA_BACKMERGE, /* back merged to existing rq */
35 __BLK_TA_FRONTMERGE, /* front merge to existing rq */
36 __BLK_TA_GETRQ, /* allocated new request */
37 __BLK_TA_SLEEPRQ, /* sleeping on rq allocation */
38 __BLK_TA_REQUEUE, /* request requeued */
39 __BLK_TA_ISSUE, /* sent to driver */
40 __BLK_TA_COMPLETE, /* completed by driver */
41 __BLK_TA_PLUG, /* queue was plugged */
42 __BLK_TA_UNPLUG_IO, /* queue was unplugged by io */
43 __BLK_TA_UNPLUG_TIMER, /* queue was unplugged by timer */
44 __BLK_TA_INSERT, /* insert request */
45 __BLK_TA_SPLIT, /* bio was split */
46 __BLK_TA_BOUNCE, /* bio was bounced */
47 __BLK_TA_REMAP, /* bio was remapped */
48};
49
50/*
51 * Trace actions in full. Additionally, read or write is masked
52 */
53#define BLK_TA_QUEUE (__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE))
54#define BLK_TA_BACKMERGE (__BLK_TA_BACKMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
55#define BLK_TA_FRONTMERGE (__BLK_TA_FRONTMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
56#define BLK_TA_GETRQ (__BLK_TA_GETRQ | BLK_TC_ACT(BLK_TC_QUEUE))
57#define BLK_TA_SLEEPRQ (__BLK_TA_SLEEPRQ | BLK_TC_ACT(BLK_TC_QUEUE))
58#define BLK_TA_REQUEUE (__BLK_TA_REQUEUE | BLK_TC_ACT(BLK_TC_REQUEUE))
59#define BLK_TA_ISSUE (__BLK_TA_ISSUE | BLK_TC_ACT(BLK_TC_ISSUE))
60#define BLK_TA_COMPLETE (__BLK_TA_COMPLETE| BLK_TC_ACT(BLK_TC_COMPLETE))
61#define BLK_TA_PLUG (__BLK_TA_PLUG | BLK_TC_ACT(BLK_TC_QUEUE))
62#define BLK_TA_UNPLUG_IO (__BLK_TA_UNPLUG_IO | BLK_TC_ACT(BLK_TC_QUEUE))
63#define BLK_TA_UNPLUG_TIMER (__BLK_TA_UNPLUG_TIMER | BLK_TC_ACT(BLK_TC_QUEUE))
64#define BLK_TA_INSERT (__BLK_TA_INSERT | BLK_TC_ACT(BLK_TC_QUEUE))
65#define BLK_TA_SPLIT (__BLK_TA_SPLIT)
66#define BLK_TA_BOUNCE (__BLK_TA_BOUNCE)
67#define BLK_TA_REMAP (__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE))
68
69#define BLK_IO_TRACE_MAGIC 0x65617400
70#define BLK_IO_TRACE_VERSION 0x07
71
72/*
73 * The trace itself
74 */
75struct blk_io_trace {
76 u32 magic; /* MAGIC << 8 | version */
77 u32 sequence; /* event number */
78 u64 time; /* in microseconds */
79 u64 sector; /* disk offset */
80 u32 bytes; /* transfer length */
81 u32 action; /* what happened */
82 u32 pid; /* who did it */
83 u32 device; /* device number */
84 u32 cpu; /* on what cpu did it happen */
85 u16 error; /* completion error */
86 u16 pdu_len; /* length of data after this trace */
87};
88
89/*
90 * The remap event
91 */
92struct blk_io_trace_remap {
Alexey Dobriyanfda151d2006-06-05 12:09:50 +020093 __be32 device;
Jens Axboe2056a782006-03-23 20:00:26 +010094 u32 __pad;
Alexey Dobriyanfda151d2006-06-05 12:09:50 +020095 __be64 sector;
Jens Axboe2056a782006-03-23 20:00:26 +010096};
97
98enum {
99 Blktrace_setup = 1,
100 Blktrace_running,
101 Blktrace_stopped,
102};
103
104struct blk_trace {
105 int trace_state;
106 struct rchan *rchan;
107 unsigned long *sequence;
108 u16 act_mask;
109 u64 start_lba;
110 u64 end_lba;
111 u32 pid;
112 u32 dev;
113 struct dentry *dir;
114 struct dentry *dropped_file;
115 atomic_t dropped;
116};
117
118/*
119 * User setup structure passed with BLKTRACESTART
120 */
121struct blk_user_trace_setup {
122 char name[BDEVNAME_SIZE]; /* output */
123 u16 act_mask; /* input */
124 u32 buf_size; /* input */
125 u32 buf_nr; /* input */
126 u64 start_lba;
127 u64 end_lba;
128 u32 pid;
129};
130
131#if defined(CONFIG_BLK_DEV_IO_TRACE)
132extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
133extern void blk_trace_shutdown(request_queue_t *);
134extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
135
136/**
137 * blk_add_trace_rq - Add a trace for a request oriented action
138 * @q: queue the io is for
139 * @rq: the source request
140 * @what: the action
141 *
142 * Description:
143 * Records an action against a request. Will log the bio offset + size.
144 *
145 **/
146static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
147 u32 what)
148{
149 struct blk_trace *bt = q->blk_trace;
150 int rw = rq->flags & 0x07;
151
152 if (likely(!bt))
153 return;
154
155 if (blk_pc_request(rq)) {
156 what |= BLK_TC_ACT(BLK_TC_PC);
157 __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, sizeof(rq->cmd), rq->cmd);
158 } else {
159 what |= BLK_TC_ACT(BLK_TC_FS);
160 __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, rw, what, rq->errors, 0, NULL);
161 }
162}
163
164/**
165 * blk_add_trace_bio - Add a trace for a bio oriented action
166 * @q: queue the io is for
167 * @bio: the source bio
168 * @what: the action
169 *
170 * Description:
171 * Records an action against a bio. Will log the bio offset + size.
172 *
173 **/
174static inline void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
175 u32 what)
176{
177 struct blk_trace *bt = q->blk_trace;
178
179 if (likely(!bt))
180 return;
181
182 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
183}
184
185/**
186 * blk_add_trace_generic - Add a trace for a generic action
187 * @q: queue the io is for
188 * @bio: the source bio
189 * @rw: the data direction
190 * @what: the action
191 *
192 * Description:
193 * Records a simple trace
194 *
195 **/
196static inline void blk_add_trace_generic(struct request_queue *q,
197 struct bio *bio, int rw, u32 what)
198{
199 struct blk_trace *bt = q->blk_trace;
200
201 if (likely(!bt))
202 return;
203
204 if (bio)
205 blk_add_trace_bio(q, bio, what);
206 else
207 __blk_add_trace(bt, 0, 0, rw, what, 0, 0, NULL);
208}
209
210/**
211 * blk_add_trace_pdu_int - Add a trace for a bio with an integer payload
212 * @q: queue the io is for
213 * @what: the action
214 * @bio: the source bio
215 * @pdu: the integer payload
216 *
217 * Description:
218 * Adds a trace with some integer payload. This might be an unplug
219 * option given as the action, with the depth at unplug time given
220 * as the payload
221 *
222 **/
223static inline void blk_add_trace_pdu_int(struct request_queue *q, u32 what,
224 struct bio *bio, unsigned int pdu)
225{
226 struct blk_trace *bt = q->blk_trace;
Alexey Dobriyanfda151d2006-06-05 12:09:50 +0200227 __be64 rpdu = cpu_to_be64(pdu);
Jens Axboe2056a782006-03-23 20:00:26 +0100228
229 if (likely(!bt))
230 return;
231
232 if (bio)
233 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), sizeof(rpdu), &rpdu);
234 else
235 __blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu);
236}
237
238/**
239 * blk_add_trace_remap - Add a trace for a remap operation
240 * @q: queue the io is for
241 * @bio: the source bio
242 * @dev: target device
243 * @from: source sector
244 * @to: target sector
245 *
246 * Description:
247 * Device mapper or raid target sometimes need to split a bio because
248 * it spans a stripe (or similar). Add a trace for that action.
249 *
250 **/
251static inline void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
252 dev_t dev, sector_t from, sector_t to)
253{
254 struct blk_trace *bt = q->blk_trace;
255 struct blk_io_trace_remap r;
256
257 if (likely(!bt))
258 return;
259
260 r.device = cpu_to_be32(dev);
261 r.sector = cpu_to_be64(to);
262
263 __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
264}
265
266#else /* !CONFIG_BLK_DEV_IO_TRACE */
267#define blk_trace_ioctl(bdev, cmd, arg) (-ENOTTY)
268#define blk_trace_shutdown(q) do { } while (0)
269#define blk_add_trace_rq(q, rq, what) do { } while (0)
270#define blk_add_trace_bio(q, rq, what) do { } while (0)
271#define blk_add_trace_generic(q, rq, rw, what) do { } while (0)
272#define blk_add_trace_pdu_int(q, what, bio, pdu) do { } while (0)
273#define blk_add_trace_remap(q, bio, dev, f, t) do {} while (0)
274#endif /* CONFIG_BLK_DEV_IO_TRACE */
275
276#endif