Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
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linux
1#ifndef BLKTRACE_H
2#define BLKTRACE_H
3
4#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 */
14 BLK_TC_SYNC = 1 << 3, /* sync IO */
15 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 BLK_TC_AHEAD = 1 << 11, /* readahead */
23 BLK_TC_META = 1 << 12, /* metadata */
24
25 BLK_TC_END = 1 << 15, /* only 16-bits, reminder */
26};
27
28#define BLK_TC_SHIFT (16)
29#define BLK_TC_ACT(act) ((act) << BLK_TC_SHIFT)
30
31/*
32 * Basic trace actions
33 */
34enum blktrace_act {
35 __BLK_TA_QUEUE = 1, /* queued */
36 __BLK_TA_BACKMERGE, /* back merged to existing rq */
37 __BLK_TA_FRONTMERGE, /* front merge to existing rq */
38 __BLK_TA_GETRQ, /* allocated new request */
39 __BLK_TA_SLEEPRQ, /* sleeping on rq allocation */
40 __BLK_TA_REQUEUE, /* request requeued */
41 __BLK_TA_ISSUE, /* sent to driver */
42 __BLK_TA_COMPLETE, /* completed by driver */
43 __BLK_TA_PLUG, /* queue was plugged */
44 __BLK_TA_UNPLUG_IO, /* queue was unplugged by io */
45 __BLK_TA_UNPLUG_TIMER, /* queue was unplugged by timer */
46 __BLK_TA_INSERT, /* insert request */
47 __BLK_TA_SPLIT, /* bio was split */
48 __BLK_TA_BOUNCE, /* bio was bounced */
49 __BLK_TA_REMAP, /* bio was remapped */
50};
51
52/*
53 * Notify events.
54 */
55enum blktrace_notify {
56 __BLK_TN_PROCESS = 0, /* establish pid/name mapping */
57 __BLK_TN_TIMESTAMP, /* include system clock */
58 __BLK_TN_MESSAGE, /* Character string message */
59};
60
61
62/*
63 * Trace actions in full. Additionally, read or write is masked
64 */
65#define BLK_TA_QUEUE (__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE))
66#define BLK_TA_BACKMERGE (__BLK_TA_BACKMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
67#define BLK_TA_FRONTMERGE (__BLK_TA_FRONTMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
68#define BLK_TA_GETRQ (__BLK_TA_GETRQ | BLK_TC_ACT(BLK_TC_QUEUE))
69#define BLK_TA_SLEEPRQ (__BLK_TA_SLEEPRQ | BLK_TC_ACT(BLK_TC_QUEUE))
70#define BLK_TA_REQUEUE (__BLK_TA_REQUEUE | BLK_TC_ACT(BLK_TC_REQUEUE))
71#define BLK_TA_ISSUE (__BLK_TA_ISSUE | BLK_TC_ACT(BLK_TC_ISSUE))
72#define BLK_TA_COMPLETE (__BLK_TA_COMPLETE| BLK_TC_ACT(BLK_TC_COMPLETE))
73#define BLK_TA_PLUG (__BLK_TA_PLUG | BLK_TC_ACT(BLK_TC_QUEUE))
74#define BLK_TA_UNPLUG_IO (__BLK_TA_UNPLUG_IO | BLK_TC_ACT(BLK_TC_QUEUE))
75#define BLK_TA_UNPLUG_TIMER (__BLK_TA_UNPLUG_TIMER | BLK_TC_ACT(BLK_TC_QUEUE))
76#define BLK_TA_INSERT (__BLK_TA_INSERT | BLK_TC_ACT(BLK_TC_QUEUE))
77#define BLK_TA_SPLIT (__BLK_TA_SPLIT)
78#define BLK_TA_BOUNCE (__BLK_TA_BOUNCE)
79#define BLK_TA_REMAP (__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE))
80
81#define BLK_TN_PROCESS (__BLK_TN_PROCESS | BLK_TC_ACT(BLK_TC_NOTIFY))
82#define BLK_TN_TIMESTAMP (__BLK_TN_TIMESTAMP | BLK_TC_ACT(BLK_TC_NOTIFY))
83#define BLK_TN_MESSAGE (__BLK_TN_MESSAGE | BLK_TC_ACT(BLK_TC_NOTIFY))
84
85#define BLK_IO_TRACE_MAGIC 0x65617400
86#define BLK_IO_TRACE_VERSION 0x07
87
88/*
89 * The trace itself
90 */
91struct blk_io_trace {
92 u32 magic; /* MAGIC << 8 | version */
93 u32 sequence; /* event number */
94 u64 time; /* in microseconds */
95 u64 sector; /* disk offset */
96 u32 bytes; /* transfer length */
97 u32 action; /* what happened */
98 u32 pid; /* who did it */
99 u32 device; /* device number */
100 u32 cpu; /* on what cpu did it happen */
101 u16 error; /* completion error */
102 u16 pdu_len; /* length of data after this trace */
103};
104
105/*
106 * The remap event
107 */
108struct blk_io_trace_remap {
109 __be32 device;
110 __be32 device_from;
111 __be64 sector;
112};
113
114enum {
115 Blktrace_setup = 1,
116 Blktrace_running,
117 Blktrace_stopped,
118};
119
120struct blk_trace {
121 int trace_state;
122 struct rchan *rchan;
123 unsigned long *sequence;
124 unsigned char *msg_data;
125 u16 act_mask;
126 u64 start_lba;
127 u64 end_lba;
128 u32 pid;
129 u32 dev;
130 struct dentry *dir;
131 struct dentry *dropped_file;
132 struct dentry *msg_file;
133 atomic_t dropped;
134};
135
136/*
137 * User setup structure passed with BLKTRACESTART
138 */
139struct blk_user_trace_setup {
140 char name[BDEVNAME_SIZE]; /* output */
141 u16 act_mask; /* input */
142 u32 buf_size; /* input */
143 u32 buf_nr; /* input */
144 u64 start_lba;
145 u64 end_lba;
146 u32 pid;
147};
148
149#ifdef __KERNEL__
150#if defined(CONFIG_BLK_DEV_IO_TRACE)
151extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
152extern void blk_trace_shutdown(struct request_queue *);
153extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
154extern int do_blk_trace_setup(struct request_queue *q,
155 char *name, dev_t dev, struct blk_user_trace_setup *buts);
156extern void __trace_note_message(struct blk_trace *, const char *fmt, ...);
157
158/**
159 * blk_add_trace_msg - Add a (simple) message to the blktrace stream
160 * @q: queue the io is for
161 * @fmt: format to print message in
162 * args... Variable argument list for format
163 *
164 * Description:
165 * Records a (simple) message onto the blktrace stream.
166 *
167 * NOTE: BLK_TN_MAX_MSG characters are output at most.
168 * NOTE: Can not use 'static inline' due to presence of var args...
169 *
170 **/
171#define blk_add_trace_msg(q, fmt, ...) \
172 do { \
173 struct blk_trace *bt = (q)->blk_trace; \
174 if (unlikely(bt)) \
175 __trace_note_message(bt, fmt, ##__VA_ARGS__); \
176 } while (0)
177#define BLK_TN_MAX_MSG 128
178
179/**
180 * blk_add_trace_rq - Add a trace for a request oriented action
181 * @q: queue the io is for
182 * @rq: the source request
183 * @what: the action
184 *
185 * Description:
186 * Records an action against a request. Will log the bio offset + size.
187 *
188 **/
189static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
190 u32 what)
191{
192 struct blk_trace *bt = q->blk_trace;
193 int rw = rq->cmd_flags & 0x03;
194
195 if (likely(!bt))
196 return;
197
198 if (blk_pc_request(rq)) {
199 what |= BLK_TC_ACT(BLK_TC_PC);
200 __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, sizeof(rq->cmd), rq->cmd);
201 } else {
202 what |= BLK_TC_ACT(BLK_TC_FS);
203 __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, rw, what, rq->errors, 0, NULL);
204 }
205}
206
207/**
208 * blk_add_trace_bio - Add a trace for a bio oriented action
209 * @q: queue the io is for
210 * @bio: the source bio
211 * @what: the action
212 *
213 * Description:
214 * Records an action against a bio. Will log the bio offset + size.
215 *
216 **/
217static inline void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
218 u32 what)
219{
220 struct blk_trace *bt = q->blk_trace;
221
222 if (likely(!bt))
223 return;
224
225 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
226}
227
228/**
229 * blk_add_trace_generic - Add a trace for a generic action
230 * @q: queue the io is for
231 * @bio: the source bio
232 * @rw: the data direction
233 * @what: the action
234 *
235 * Description:
236 * Records a simple trace
237 *
238 **/
239static inline void blk_add_trace_generic(struct request_queue *q,
240 struct bio *bio, int rw, u32 what)
241{
242 struct blk_trace *bt = q->blk_trace;
243
244 if (likely(!bt))
245 return;
246
247 if (bio)
248 blk_add_trace_bio(q, bio, what);
249 else
250 __blk_add_trace(bt, 0, 0, rw, what, 0, 0, NULL);
251}
252
253/**
254 * blk_add_trace_pdu_int - Add a trace for a bio with an integer payload
255 * @q: queue the io is for
256 * @what: the action
257 * @bio: the source bio
258 * @pdu: the integer payload
259 *
260 * Description:
261 * Adds a trace with some integer payload. This might be an unplug
262 * option given as the action, with the depth at unplug time given
263 * as the payload
264 *
265 **/
266static inline void blk_add_trace_pdu_int(struct request_queue *q, u32 what,
267 struct bio *bio, unsigned int pdu)
268{
269 struct blk_trace *bt = q->blk_trace;
270 __be64 rpdu = cpu_to_be64(pdu);
271
272 if (likely(!bt))
273 return;
274
275 if (bio)
276 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), sizeof(rpdu), &rpdu);
277 else
278 __blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu);
279}
280
281/**
282 * blk_add_trace_remap - Add a trace for a remap operation
283 * @q: queue the io is for
284 * @bio: the source bio
285 * @dev: target device
286 * @from: source sector
287 * @to: target sector
288 *
289 * Description:
290 * Device mapper or raid target sometimes need to split a bio because
291 * it spans a stripe (or similar). Add a trace for that action.
292 *
293 **/
294static inline void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
295 dev_t dev, sector_t from, sector_t to)
296{
297 struct blk_trace *bt = q->blk_trace;
298 struct blk_io_trace_remap r;
299
300 if (likely(!bt))
301 return;
302
303 r.device = cpu_to_be32(dev);
304 r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev);
305 r.sector = cpu_to_be64(to);
306
307 __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
308}
309
310extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
311 char __user *arg);
312extern int blk_trace_startstop(struct request_queue *q, int start);
313extern int blk_trace_remove(struct request_queue *q);
314
315#else /* !CONFIG_BLK_DEV_IO_TRACE */
316#define blk_trace_ioctl(bdev, cmd, arg) (-ENOTTY)
317#define blk_trace_shutdown(q) do { } while (0)
318#define blk_add_trace_rq(q, rq, what) do { } while (0)
319#define blk_add_trace_bio(q, rq, what) do { } while (0)
320#define blk_add_trace_generic(q, rq, rw, what) do { } while (0)
321#define blk_add_trace_pdu_int(q, what, bio, pdu) do { } while (0)
322#define blk_add_trace_remap(q, bio, dev, f, t) do {} while (0)
323#define do_blk_trace_setup(q, name, dev, buts) (-ENOTTY)
324#define blk_trace_setup(q, name, dev, arg) (-ENOTTY)
325#define blk_trace_startstop(q, start) (-ENOTTY)
326#define blk_trace_remove(q) (-ENOTTY)
327#define blk_add_trace_msg(q, fmt, ...) do { } while (0)
328
329#endif /* CONFIG_BLK_DEV_IO_TRACE */
330#endif /* __KERNEL__ */
331#endif