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Commit | Line | Data |
---|---|---|
2056a782 | 1 | /* |
0fe23479 | 2 | * Copyright (C) 2006 Jens Axboe <axboe@kernel.dk> |
2056a782 JA |
3 | * |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License | |
14 | * along with this program; if not, write to the Free Software | |
15 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
16 | * | |
17 | */ | |
2056a782 JA |
18 | #include <linux/kernel.h> |
19 | #include <linux/blkdev.h> | |
20 | #include <linux/blktrace_api.h> | |
21 | #include <linux/percpu.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/mutex.h> | |
24 | #include <linux/debugfs.h> | |
be1c6341 | 25 | #include <linux/time.h> |
5f3ea37c | 26 | #include <trace/block.h> |
2056a782 JA |
27 | #include <asm/uaccess.h> |
28 | ||
2056a782 JA |
29 | static unsigned int blktrace_seq __read_mostly = 1; |
30 | ||
5f3ea37c ACM |
31 | /* Global reference count of probes */ |
32 | static DEFINE_MUTEX(blk_probe_mutex); | |
33 | static atomic_t blk_probes_ref = ATOMIC_INIT(0); | |
34 | ||
35 | static int blk_register_tracepoints(void); | |
36 | static void blk_unregister_tracepoints(void); | |
37 | ||
be1c6341 OK |
38 | /* |
39 | * Send out a notify message. | |
40 | */ | |
a863055b JA |
41 | static void trace_note(struct blk_trace *bt, pid_t pid, int action, |
42 | const void *data, size_t len) | |
be1c6341 OK |
43 | { |
44 | struct blk_io_trace *t; | |
be1c6341 OK |
45 | |
46 | t = relay_reserve(bt->rchan, sizeof(*t) + len); | |
d3d9d2a5 JA |
47 | if (t) { |
48 | const int cpu = smp_processor_id(); | |
49 | ||
50 | t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; | |
2997c8c4 | 51 | t->time = ktime_to_ns(ktime_get()); |
d3d9d2a5 JA |
52 | t->device = bt->dev; |
53 | t->action = action; | |
54 | t->pid = pid; | |
55 | t->cpu = cpu; | |
56 | t->pdu_len = len; | |
57 | memcpy((void *) t + sizeof(*t), data, len); | |
58 | } | |
be1c6341 OK |
59 | } |
60 | ||
2056a782 JA |
61 | /* |
62 | * Send out a notify for this process, if we haven't done so since a trace | |
63 | * started | |
64 | */ | |
65 | static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk) | |
66 | { | |
a863055b JA |
67 | tsk->btrace_seq = blktrace_seq; |
68 | trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm, sizeof(tsk->comm)); | |
be1c6341 | 69 | } |
2056a782 | 70 | |
be1c6341 OK |
71 | static void trace_note_time(struct blk_trace *bt) |
72 | { | |
73 | struct timespec now; | |
74 | unsigned long flags; | |
75 | u32 words[2]; | |
76 | ||
77 | getnstimeofday(&now); | |
78 | words[0] = now.tv_sec; | |
79 | words[1] = now.tv_nsec; | |
80 | ||
81 | local_irq_save(flags); | |
82 | trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words)); | |
83 | local_irq_restore(flags); | |
2056a782 JA |
84 | } |
85 | ||
9d5f09a4 AB |
86 | void __trace_note_message(struct blk_trace *bt, const char *fmt, ...) |
87 | { | |
88 | int n; | |
89 | va_list args; | |
14a73f54 | 90 | unsigned long flags; |
64565911 | 91 | char *buf; |
9d5f09a4 | 92 | |
14a73f54 | 93 | local_irq_save(flags); |
64565911 | 94 | buf = per_cpu_ptr(bt->msg_data, smp_processor_id()); |
9d5f09a4 | 95 | va_start(args, fmt); |
64565911 | 96 | n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args); |
9d5f09a4 AB |
97 | va_end(args); |
98 | ||
64565911 | 99 | trace_note(bt, 0, BLK_TN_MESSAGE, buf, n); |
14a73f54 | 100 | local_irq_restore(flags); |
9d5f09a4 AB |
101 | } |
102 | EXPORT_SYMBOL_GPL(__trace_note_message); | |
103 | ||
2056a782 JA |
104 | static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector, |
105 | pid_t pid) | |
106 | { | |
107 | if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0) | |
108 | return 1; | |
109 | if (sector < bt->start_lba || sector > bt->end_lba) | |
110 | return 1; | |
111 | if (bt->pid && pid != bt->pid) | |
112 | return 1; | |
113 | ||
114 | return 0; | |
115 | } | |
116 | ||
117 | /* | |
118 | * Data direction bit lookup | |
119 | */ | |
120 | static u32 ddir_act[2] __read_mostly = { BLK_TC_ACT(BLK_TC_READ), BLK_TC_ACT(BLK_TC_WRITE) }; | |
121 | ||
35ba8f70 DW |
122 | /* The ilog2() calls fall out because they're constant */ |
123 | #define MASK_TC_BIT(rw, __name) ( (rw & (1 << BIO_RW_ ## __name)) << \ | |
124 | (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - BIO_RW_ ## __name) ) | |
2056a782 JA |
125 | |
126 | /* | |
127 | * The worker for the various blk_add_trace*() types. Fills out a | |
128 | * blk_io_trace structure and places it in a per-cpu subbuffer. | |
129 | */ | |
5f3ea37c | 130 | static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, |
2056a782 JA |
131 | int rw, u32 what, int error, int pdu_len, void *pdu_data) |
132 | { | |
133 | struct task_struct *tsk = current; | |
134 | struct blk_io_trace *t; | |
135 | unsigned long flags; | |
136 | unsigned long *sequence; | |
137 | pid_t pid; | |
138 | int cpu; | |
139 | ||
140 | if (unlikely(bt->trace_state != Blktrace_running)) | |
141 | return; | |
142 | ||
143 | what |= ddir_act[rw & WRITE]; | |
35ba8f70 DW |
144 | what |= MASK_TC_BIT(rw, BARRIER); |
145 | what |= MASK_TC_BIT(rw, SYNC); | |
146 | what |= MASK_TC_BIT(rw, AHEAD); | |
147 | what |= MASK_TC_BIT(rw, META); | |
148 | what |= MASK_TC_BIT(rw, DISCARD); | |
2056a782 JA |
149 | |
150 | pid = tsk->pid; | |
151 | if (unlikely(act_log_check(bt, what, sector, pid))) | |
152 | return; | |
153 | ||
154 | /* | |
155 | * A word about the locking here - we disable interrupts to reserve | |
156 | * some space in the relay per-cpu buffer, to prevent an irq | |
14a73f54 | 157 | * from coming in and stepping on our toes. |
2056a782 JA |
158 | */ |
159 | local_irq_save(flags); | |
160 | ||
161 | if (unlikely(tsk->btrace_seq != blktrace_seq)) | |
162 | trace_note_tsk(bt, tsk); | |
163 | ||
164 | t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len); | |
165 | if (t) { | |
166 | cpu = smp_processor_id(); | |
167 | sequence = per_cpu_ptr(bt->sequence, cpu); | |
168 | ||
169 | t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; | |
170 | t->sequence = ++(*sequence); | |
2997c8c4 | 171 | t->time = ktime_to_ns(ktime_get()); |
2056a782 JA |
172 | t->sector = sector; |
173 | t->bytes = bytes; | |
174 | t->action = what; | |
175 | t->pid = pid; | |
176 | t->device = bt->dev; | |
177 | t->cpu = cpu; | |
178 | t->error = error; | |
179 | t->pdu_len = pdu_len; | |
180 | ||
181 | if (pdu_len) | |
182 | memcpy((void *) t + sizeof(*t), pdu_data, pdu_len); | |
183 | } | |
184 | ||
185 | local_irq_restore(flags); | |
186 | } | |
187 | ||
2056a782 | 188 | static struct dentry *blk_tree_root; |
11a57153 | 189 | static DEFINE_MUTEX(blk_tree_mutex); |
2056a782 JA |
190 | static unsigned int root_users; |
191 | ||
192 | static inline void blk_remove_root(void) | |
193 | { | |
194 | if (blk_tree_root) { | |
195 | debugfs_remove(blk_tree_root); | |
196 | blk_tree_root = NULL; | |
197 | } | |
198 | } | |
199 | ||
200 | static void blk_remove_tree(struct dentry *dir) | |
201 | { | |
202 | mutex_lock(&blk_tree_mutex); | |
203 | debugfs_remove(dir); | |
204 | if (--root_users == 0) | |
205 | blk_remove_root(); | |
206 | mutex_unlock(&blk_tree_mutex); | |
207 | } | |
208 | ||
209 | static struct dentry *blk_create_tree(const char *blk_name) | |
210 | { | |
211 | struct dentry *dir = NULL; | |
35fc51e7 | 212 | int created = 0; |
2056a782 JA |
213 | |
214 | mutex_lock(&blk_tree_mutex); | |
215 | ||
216 | if (!blk_tree_root) { | |
217 | blk_tree_root = debugfs_create_dir("block", NULL); | |
218 | if (!blk_tree_root) | |
219 | goto err; | |
35fc51e7 | 220 | created = 1; |
2056a782 JA |
221 | } |
222 | ||
223 | dir = debugfs_create_dir(blk_name, blk_tree_root); | |
224 | if (dir) | |
225 | root_users++; | |
35fc51e7 AK |
226 | else { |
227 | /* Delete root only if we created it */ | |
228 | if (created) | |
229 | blk_remove_root(); | |
230 | } | |
2056a782 JA |
231 | |
232 | err: | |
233 | mutex_unlock(&blk_tree_mutex); | |
234 | return dir; | |
235 | } | |
236 | ||
237 | static void blk_trace_cleanup(struct blk_trace *bt) | |
238 | { | |
239 | relay_close(bt->rchan); | |
02c62304 | 240 | debugfs_remove(bt->msg_file); |
2056a782 JA |
241 | debugfs_remove(bt->dropped_file); |
242 | blk_remove_tree(bt->dir); | |
243 | free_percpu(bt->sequence); | |
64565911 | 244 | free_percpu(bt->msg_data); |
2056a782 | 245 | kfree(bt); |
5f3ea37c ACM |
246 | mutex_lock(&blk_probe_mutex); |
247 | if (atomic_dec_and_test(&blk_probes_ref)) | |
248 | blk_unregister_tracepoints(); | |
249 | mutex_unlock(&blk_probe_mutex); | |
2056a782 JA |
250 | } |
251 | ||
6da127ad | 252 | int blk_trace_remove(struct request_queue *q) |
2056a782 JA |
253 | { |
254 | struct blk_trace *bt; | |
255 | ||
256 | bt = xchg(&q->blk_trace, NULL); | |
257 | if (!bt) | |
258 | return -EINVAL; | |
259 | ||
260 | if (bt->trace_state == Blktrace_setup || | |
261 | bt->trace_state == Blktrace_stopped) | |
262 | blk_trace_cleanup(bt); | |
263 | ||
264 | return 0; | |
265 | } | |
6da127ad | 266 | EXPORT_SYMBOL_GPL(blk_trace_remove); |
2056a782 JA |
267 | |
268 | static int blk_dropped_open(struct inode *inode, struct file *filp) | |
269 | { | |
8e18e294 | 270 | filp->private_data = inode->i_private; |
2056a782 JA |
271 | |
272 | return 0; | |
273 | } | |
274 | ||
275 | static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, | |
276 | size_t count, loff_t *ppos) | |
277 | { | |
278 | struct blk_trace *bt = filp->private_data; | |
279 | char buf[16]; | |
280 | ||
281 | snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped)); | |
282 | ||
283 | return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf)); | |
284 | } | |
285 | ||
2b8693c0 | 286 | static const struct file_operations blk_dropped_fops = { |
2056a782 JA |
287 | .owner = THIS_MODULE, |
288 | .open = blk_dropped_open, | |
289 | .read = blk_dropped_read, | |
290 | }; | |
291 | ||
02c62304 AB |
292 | static int blk_msg_open(struct inode *inode, struct file *filp) |
293 | { | |
294 | filp->private_data = inode->i_private; | |
295 | ||
296 | return 0; | |
297 | } | |
298 | ||
299 | static ssize_t blk_msg_write(struct file *filp, const char __user *buffer, | |
300 | size_t count, loff_t *ppos) | |
301 | { | |
302 | char *msg; | |
303 | struct blk_trace *bt; | |
304 | ||
305 | if (count > BLK_TN_MAX_MSG) | |
306 | return -EINVAL; | |
307 | ||
308 | msg = kmalloc(count, GFP_KERNEL); | |
309 | if (msg == NULL) | |
310 | return -ENOMEM; | |
311 | ||
312 | if (copy_from_user(msg, buffer, count)) { | |
313 | kfree(msg); | |
314 | return -EFAULT; | |
315 | } | |
316 | ||
317 | bt = filp->private_data; | |
318 | __trace_note_message(bt, "%s", msg); | |
319 | kfree(msg); | |
320 | ||
321 | return count; | |
322 | } | |
323 | ||
324 | static const struct file_operations blk_msg_fops = { | |
325 | .owner = THIS_MODULE, | |
326 | .open = blk_msg_open, | |
327 | .write = blk_msg_write, | |
328 | }; | |
329 | ||
2056a782 JA |
330 | /* |
331 | * Keep track of how many times we encountered a full subbuffer, to aid | |
332 | * the user space app in telling how many lost events there were. | |
333 | */ | |
334 | static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf, | |
335 | void *prev_subbuf, size_t prev_padding) | |
336 | { | |
337 | struct blk_trace *bt; | |
338 | ||
339 | if (!relay_buf_full(buf)) | |
340 | return 1; | |
341 | ||
342 | bt = buf->chan->private_data; | |
343 | atomic_inc(&bt->dropped); | |
344 | return 0; | |
345 | } | |
346 | ||
347 | static int blk_remove_buf_file_callback(struct dentry *dentry) | |
348 | { | |
349 | debugfs_remove(dentry); | |
350 | return 0; | |
351 | } | |
352 | ||
353 | static struct dentry *blk_create_buf_file_callback(const char *filename, | |
354 | struct dentry *parent, | |
355 | int mode, | |
356 | struct rchan_buf *buf, | |
357 | int *is_global) | |
358 | { | |
359 | return debugfs_create_file(filename, mode, parent, buf, | |
360 | &relay_file_operations); | |
361 | } | |
362 | ||
363 | static struct rchan_callbacks blk_relay_callbacks = { | |
364 | .subbuf_start = blk_subbuf_start_callback, | |
365 | .create_buf_file = blk_create_buf_file_callback, | |
366 | .remove_buf_file = blk_remove_buf_file_callback, | |
367 | }; | |
368 | ||
369 | /* | |
370 | * Setup everything required to start tracing | |
371 | */ | |
6da127ad | 372 | int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, |
171044d4 | 373 | struct blk_user_trace_setup *buts) |
2056a782 | 374 | { |
2056a782 JA |
375 | struct blk_trace *old_bt, *bt = NULL; |
376 | struct dentry *dir = NULL; | |
2056a782 JA |
377 | int ret, i; |
378 | ||
171044d4 | 379 | if (!buts->buf_size || !buts->buf_nr) |
2056a782 JA |
380 | return -EINVAL; |
381 | ||
0497b345 JA |
382 | strncpy(buts->name, name, BLKTRACE_BDEV_SIZE); |
383 | buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0'; | |
2056a782 JA |
384 | |
385 | /* | |
386 | * some device names have larger paths - convert the slashes | |
387 | * to underscores for this to work as expected | |
388 | */ | |
171044d4 AB |
389 | for (i = 0; i < strlen(buts->name); i++) |
390 | if (buts->name[i] == '/') | |
391 | buts->name[i] = '_'; | |
2056a782 JA |
392 | |
393 | ret = -ENOMEM; | |
394 | bt = kzalloc(sizeof(*bt), GFP_KERNEL); | |
395 | if (!bt) | |
396 | goto err; | |
397 | ||
398 | bt->sequence = alloc_percpu(unsigned long); | |
399 | if (!bt->sequence) | |
400 | goto err; | |
401 | ||
64565911 JA |
402 | bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG); |
403 | if (!bt->msg_data) | |
404 | goto err; | |
405 | ||
2056a782 | 406 | ret = -ENOENT; |
171044d4 | 407 | dir = blk_create_tree(buts->name); |
2056a782 JA |
408 | if (!dir) |
409 | goto err; | |
410 | ||
411 | bt->dir = dir; | |
6da127ad | 412 | bt->dev = dev; |
2056a782 JA |
413 | atomic_set(&bt->dropped, 0); |
414 | ||
415 | ret = -EIO; | |
416 | bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, &blk_dropped_fops); | |
417 | if (!bt->dropped_file) | |
418 | goto err; | |
419 | ||
02c62304 AB |
420 | bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops); |
421 | if (!bt->msg_file) | |
422 | goto err; | |
423 | ||
171044d4 AB |
424 | bt->rchan = relay_open("trace", dir, buts->buf_size, |
425 | buts->buf_nr, &blk_relay_callbacks, bt); | |
2056a782 JA |
426 | if (!bt->rchan) |
427 | goto err; | |
2056a782 | 428 | |
171044d4 | 429 | bt->act_mask = buts->act_mask; |
2056a782 JA |
430 | if (!bt->act_mask) |
431 | bt->act_mask = (u16) -1; | |
432 | ||
171044d4 AB |
433 | bt->start_lba = buts->start_lba; |
434 | bt->end_lba = buts->end_lba; | |
2056a782 JA |
435 | if (!bt->end_lba) |
436 | bt->end_lba = -1ULL; | |
437 | ||
171044d4 | 438 | bt->pid = buts->pid; |
2056a782 JA |
439 | bt->trace_state = Blktrace_setup; |
440 | ||
5f3ea37c ACM |
441 | mutex_lock(&blk_probe_mutex); |
442 | if (atomic_add_return(1, &blk_probes_ref) == 1) { | |
443 | ret = blk_register_tracepoints(); | |
444 | if (ret) | |
445 | goto probe_err; | |
446 | } | |
447 | mutex_unlock(&blk_probe_mutex); | |
448 | ||
2056a782 JA |
449 | ret = -EBUSY; |
450 | old_bt = xchg(&q->blk_trace, bt); | |
451 | if (old_bt) { | |
452 | (void) xchg(&q->blk_trace, old_bt); | |
453 | goto err; | |
454 | } | |
455 | ||
456 | return 0; | |
5f3ea37c ACM |
457 | probe_err: |
458 | atomic_dec(&blk_probes_ref); | |
459 | mutex_unlock(&blk_probe_mutex); | |
2056a782 JA |
460 | err: |
461 | if (dir) | |
462 | blk_remove_tree(dir); | |
463 | if (bt) { | |
02c62304 AB |
464 | if (bt->msg_file) |
465 | debugfs_remove(bt->msg_file); | |
2056a782 JA |
466 | if (bt->dropped_file) |
467 | debugfs_remove(bt->dropped_file); | |
a1205868 | 468 | free_percpu(bt->sequence); |
64565911 | 469 | free_percpu(bt->msg_data); |
2056a782 JA |
470 | if (bt->rchan) |
471 | relay_close(bt->rchan); | |
472 | kfree(bt); | |
473 | } | |
474 | return ret; | |
475 | } | |
171044d4 | 476 | |
6da127ad CS |
477 | int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, |
478 | char __user *arg) | |
171044d4 AB |
479 | { |
480 | struct blk_user_trace_setup buts; | |
481 | int ret; | |
482 | ||
483 | ret = copy_from_user(&buts, arg, sizeof(buts)); | |
484 | if (ret) | |
485 | return -EFAULT; | |
486 | ||
6da127ad | 487 | ret = do_blk_trace_setup(q, name, dev, &buts); |
171044d4 AB |
488 | if (ret) |
489 | return ret; | |
490 | ||
491 | if (copy_to_user(arg, &buts, sizeof(buts))) | |
492 | return -EFAULT; | |
493 | ||
494 | return 0; | |
495 | } | |
6da127ad | 496 | EXPORT_SYMBOL_GPL(blk_trace_setup); |
2056a782 | 497 | |
6da127ad | 498 | int blk_trace_startstop(struct request_queue *q, int start) |
2056a782 JA |
499 | { |
500 | struct blk_trace *bt; | |
501 | int ret; | |
502 | ||
503 | if ((bt = q->blk_trace) == NULL) | |
504 | return -EINVAL; | |
505 | ||
506 | /* | |
507 | * For starting a trace, we can transition from a setup or stopped | |
508 | * trace. For stopping a trace, the state must be running | |
509 | */ | |
510 | ret = -EINVAL; | |
511 | if (start) { | |
512 | if (bt->trace_state == Blktrace_setup || | |
513 | bt->trace_state == Blktrace_stopped) { | |
514 | blktrace_seq++; | |
515 | smp_mb(); | |
516 | bt->trace_state = Blktrace_running; | |
be1c6341 OK |
517 | |
518 | trace_note_time(bt); | |
2056a782 JA |
519 | ret = 0; |
520 | } | |
521 | } else { | |
522 | if (bt->trace_state == Blktrace_running) { | |
523 | bt->trace_state = Blktrace_stopped; | |
524 | relay_flush(bt->rchan); | |
525 | ret = 0; | |
526 | } | |
527 | } | |
528 | ||
529 | return ret; | |
530 | } | |
6da127ad | 531 | EXPORT_SYMBOL_GPL(blk_trace_startstop); |
2056a782 JA |
532 | |
533 | /** | |
534 | * blk_trace_ioctl: - handle the ioctls associated with tracing | |
535 | * @bdev: the block device | |
536 | * @cmd: the ioctl cmd | |
537 | * @arg: the argument data, if any | |
538 | * | |
539 | **/ | |
540 | int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) | |
541 | { | |
165125e1 | 542 | struct request_queue *q; |
2056a782 | 543 | int ret, start = 0; |
6da127ad | 544 | char b[BDEVNAME_SIZE]; |
2056a782 JA |
545 | |
546 | q = bdev_get_queue(bdev); | |
547 | if (!q) | |
548 | return -ENXIO; | |
549 | ||
550 | mutex_lock(&bdev->bd_mutex); | |
551 | ||
552 | switch (cmd) { | |
553 | case BLKTRACESETUP: | |
f36f21ec | 554 | bdevname(bdev, b); |
6da127ad | 555 | ret = blk_trace_setup(q, b, bdev->bd_dev, arg); |
2056a782 JA |
556 | break; |
557 | case BLKTRACESTART: | |
558 | start = 1; | |
559 | case BLKTRACESTOP: | |
560 | ret = blk_trace_startstop(q, start); | |
561 | break; | |
562 | case BLKTRACETEARDOWN: | |
563 | ret = blk_trace_remove(q); | |
564 | break; | |
565 | default: | |
566 | ret = -ENOTTY; | |
567 | break; | |
568 | } | |
569 | ||
570 | mutex_unlock(&bdev->bd_mutex); | |
571 | return ret; | |
572 | } | |
573 | ||
574 | /** | |
575 | * blk_trace_shutdown: - stop and cleanup trace structures | |
576 | * @q: the request queue associated with the device | |
577 | * | |
578 | **/ | |
165125e1 | 579 | void blk_trace_shutdown(struct request_queue *q) |
2056a782 | 580 | { |
6c5c9341 AD |
581 | if (q->blk_trace) { |
582 | blk_trace_startstop(q, 0); | |
583 | blk_trace_remove(q); | |
584 | } | |
2056a782 | 585 | } |
5f3ea37c ACM |
586 | |
587 | /* | |
588 | * blktrace probes | |
589 | */ | |
590 | ||
591 | /** | |
592 | * blk_add_trace_rq - Add a trace for a request oriented action | |
593 | * @q: queue the io is for | |
594 | * @rq: the source request | |
595 | * @what: the action | |
596 | * | |
597 | * Description: | |
598 | * Records an action against a request. Will log the bio offset + size. | |
599 | * | |
600 | **/ | |
601 | static void blk_add_trace_rq(struct request_queue *q, struct request *rq, | |
602 | u32 what) | |
603 | { | |
604 | struct blk_trace *bt = q->blk_trace; | |
605 | int rw = rq->cmd_flags & 0x03; | |
606 | ||
607 | if (likely(!bt)) | |
608 | return; | |
609 | ||
610 | if (blk_discard_rq(rq)) | |
611 | rw |= (1 << BIO_RW_DISCARD); | |
612 | ||
613 | if (blk_pc_request(rq)) { | |
614 | what |= BLK_TC_ACT(BLK_TC_PC); | |
615 | __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, | |
616 | sizeof(rq->cmd), rq->cmd); | |
617 | } else { | |
618 | what |= BLK_TC_ACT(BLK_TC_FS); | |
619 | __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, | |
620 | rw, what, rq->errors, 0, NULL); | |
621 | } | |
622 | } | |
623 | ||
624 | static void blk_add_trace_rq_abort(struct request_queue *q, struct request *rq) | |
625 | { | |
626 | blk_add_trace_rq(q, rq, BLK_TA_ABORT); | |
627 | } | |
628 | ||
629 | static void blk_add_trace_rq_insert(struct request_queue *q, struct request *rq) | |
630 | { | |
631 | blk_add_trace_rq(q, rq, BLK_TA_INSERT); | |
632 | } | |
633 | ||
634 | static void blk_add_trace_rq_issue(struct request_queue *q, struct request *rq) | |
635 | { | |
636 | blk_add_trace_rq(q, rq, BLK_TA_ISSUE); | |
637 | } | |
638 | ||
639 | static void blk_add_trace_rq_requeue(struct request_queue *q, struct request *rq) | |
640 | { | |
641 | blk_add_trace_rq(q, rq, BLK_TA_REQUEUE); | |
642 | } | |
643 | ||
644 | static void blk_add_trace_rq_complete(struct request_queue *q, struct request *rq) | |
645 | { | |
646 | blk_add_trace_rq(q, rq, BLK_TA_COMPLETE); | |
647 | } | |
648 | ||
649 | /** | |
650 | * blk_add_trace_bio - Add a trace for a bio oriented action | |
651 | * @q: queue the io is for | |
652 | * @bio: the source bio | |
653 | * @what: the action | |
654 | * | |
655 | * Description: | |
656 | * Records an action against a bio. Will log the bio offset + size. | |
657 | * | |
658 | **/ | |
659 | static void blk_add_trace_bio(struct request_queue *q, struct bio *bio, | |
660 | u32 what) | |
661 | { | |
662 | struct blk_trace *bt = q->blk_trace; | |
663 | ||
664 | if (likely(!bt)) | |
665 | return; | |
666 | ||
667 | __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, | |
668 | !bio_flagged(bio, BIO_UPTODATE), 0, NULL); | |
669 | } | |
670 | ||
671 | static void blk_add_trace_bio_bounce(struct request_queue *q, struct bio *bio) | |
672 | { | |
673 | blk_add_trace_bio(q, bio, BLK_TA_BOUNCE); | |
674 | } | |
675 | ||
676 | static void blk_add_trace_bio_complete(struct request_queue *q, struct bio *bio) | |
677 | { | |
678 | blk_add_trace_bio(q, bio, BLK_TA_COMPLETE); | |
679 | } | |
680 | ||
681 | static void blk_add_trace_bio_backmerge(struct request_queue *q, struct bio *bio) | |
682 | { | |
683 | blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE); | |
684 | } | |
685 | ||
686 | static void blk_add_trace_bio_frontmerge(struct request_queue *q, struct bio *bio) | |
687 | { | |
688 | blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE); | |
689 | } | |
690 | ||
691 | static void blk_add_trace_bio_queue(struct request_queue *q, struct bio *bio) | |
692 | { | |
693 | blk_add_trace_bio(q, bio, BLK_TA_QUEUE); | |
694 | } | |
695 | ||
696 | static void blk_add_trace_getrq(struct request_queue *q, struct bio *bio, int rw) | |
697 | { | |
698 | if (bio) | |
699 | blk_add_trace_bio(q, bio, BLK_TA_GETRQ); | |
700 | else { | |
701 | struct blk_trace *bt = q->blk_trace; | |
702 | ||
703 | if (bt) | |
704 | __blk_add_trace(bt, 0, 0, rw, BLK_TA_GETRQ, 0, 0, NULL); | |
705 | } | |
706 | } | |
707 | ||
708 | ||
709 | static void blk_add_trace_sleeprq(struct request_queue *q, struct bio *bio, int rw) | |
710 | { | |
711 | if (bio) | |
712 | blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ); | |
713 | else { | |
714 | struct blk_trace *bt = q->blk_trace; | |
715 | ||
716 | if (bt) | |
717 | __blk_add_trace(bt, 0, 0, rw, BLK_TA_SLEEPRQ, 0, 0, NULL); | |
718 | } | |
719 | } | |
720 | ||
721 | static void blk_add_trace_plug(struct request_queue *q) | |
722 | { | |
723 | struct blk_trace *bt = q->blk_trace; | |
724 | ||
725 | if (bt) | |
726 | __blk_add_trace(bt, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL); | |
727 | } | |
728 | ||
729 | static void blk_add_trace_unplug_io(struct request_queue *q) | |
730 | { | |
731 | struct blk_trace *bt = q->blk_trace; | |
732 | ||
733 | if (bt) { | |
734 | unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE]; | |
735 | __be64 rpdu = cpu_to_be64(pdu); | |
736 | ||
737 | __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_IO, 0, | |
738 | sizeof(rpdu), &rpdu); | |
739 | } | |
740 | } | |
741 | ||
742 | static void blk_add_trace_unplug_timer(struct request_queue *q) | |
743 | { | |
744 | struct blk_trace *bt = q->blk_trace; | |
745 | ||
746 | if (bt) { | |
747 | unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE]; | |
748 | __be64 rpdu = cpu_to_be64(pdu); | |
749 | ||
750 | __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_TIMER, 0, | |
751 | sizeof(rpdu), &rpdu); | |
752 | } | |
753 | } | |
754 | ||
755 | static void blk_add_trace_split(struct request_queue *q, struct bio *bio, | |
756 | unsigned int pdu) | |
757 | { | |
758 | struct blk_trace *bt = q->blk_trace; | |
759 | ||
760 | if (bt) { | |
761 | __be64 rpdu = cpu_to_be64(pdu); | |
762 | ||
763 | __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, | |
764 | BLK_TA_SPLIT, !bio_flagged(bio, BIO_UPTODATE), | |
765 | sizeof(rpdu), &rpdu); | |
766 | } | |
767 | } | |
768 | ||
769 | /** | |
770 | * blk_add_trace_remap - Add a trace for a remap operation | |
771 | * @q: queue the io is for | |
772 | * @bio: the source bio | |
773 | * @dev: target device | |
774 | * @from: source sector | |
775 | * @to: target sector | |
776 | * | |
777 | * Description: | |
778 | * Device mapper or raid target sometimes need to split a bio because | |
779 | * it spans a stripe (or similar). Add a trace for that action. | |
780 | * | |
781 | **/ | |
782 | static void blk_add_trace_remap(struct request_queue *q, struct bio *bio, | |
783 | dev_t dev, sector_t from, sector_t to) | |
784 | { | |
785 | struct blk_trace *bt = q->blk_trace; | |
786 | struct blk_io_trace_remap r; | |
787 | ||
788 | if (likely(!bt)) | |
789 | return; | |
790 | ||
791 | r.device = cpu_to_be32(dev); | |
792 | r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev); | |
793 | r.sector = cpu_to_be64(to); | |
794 | ||
795 | __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, | |
796 | !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r); | |
797 | } | |
798 | ||
799 | /** | |
800 | * blk_add_driver_data - Add binary message with driver-specific data | |
801 | * @q: queue the io is for | |
802 | * @rq: io request | |
803 | * @data: driver-specific data | |
804 | * @len: length of driver-specific data | |
805 | * | |
806 | * Description: | |
807 | * Some drivers might want to write driver-specific data per request. | |
808 | * | |
809 | **/ | |
810 | void blk_add_driver_data(struct request_queue *q, | |
811 | struct request *rq, | |
812 | void *data, size_t len) | |
813 | { | |
814 | struct blk_trace *bt = q->blk_trace; | |
815 | ||
816 | if (likely(!bt)) | |
817 | return; | |
818 | ||
819 | if (blk_pc_request(rq)) | |
820 | __blk_add_trace(bt, 0, rq->data_len, 0, BLK_TA_DRV_DATA, | |
821 | rq->errors, len, data); | |
822 | else | |
823 | __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, | |
824 | 0, BLK_TA_DRV_DATA, rq->errors, len, data); | |
825 | } | |
826 | EXPORT_SYMBOL_GPL(blk_add_driver_data); | |
827 | ||
828 | static int blk_register_tracepoints(void) | |
829 | { | |
830 | int ret; | |
831 | ||
832 | ret = register_trace_block_rq_abort(blk_add_trace_rq_abort); | |
833 | WARN_ON(ret); | |
834 | ret = register_trace_block_rq_insert(blk_add_trace_rq_insert); | |
835 | WARN_ON(ret); | |
836 | ret = register_trace_block_rq_issue(blk_add_trace_rq_issue); | |
837 | WARN_ON(ret); | |
838 | ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue); | |
839 | WARN_ON(ret); | |
840 | ret = register_trace_block_rq_complete(blk_add_trace_rq_complete); | |
841 | WARN_ON(ret); | |
842 | ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce); | |
843 | WARN_ON(ret); | |
844 | ret = register_trace_block_bio_complete(blk_add_trace_bio_complete); | |
845 | WARN_ON(ret); | |
846 | ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge); | |
847 | WARN_ON(ret); | |
848 | ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge); | |
849 | WARN_ON(ret); | |
850 | ret = register_trace_block_bio_queue(blk_add_trace_bio_queue); | |
851 | WARN_ON(ret); | |
852 | ret = register_trace_block_getrq(blk_add_trace_getrq); | |
853 | WARN_ON(ret); | |
854 | ret = register_trace_block_sleeprq(blk_add_trace_sleeprq); | |
855 | WARN_ON(ret); | |
856 | ret = register_trace_block_plug(blk_add_trace_plug); | |
857 | WARN_ON(ret); | |
858 | ret = register_trace_block_unplug_timer(blk_add_trace_unplug_timer); | |
859 | WARN_ON(ret); | |
860 | ret = register_trace_block_unplug_io(blk_add_trace_unplug_io); | |
861 | WARN_ON(ret); | |
862 | ret = register_trace_block_split(blk_add_trace_split); | |
863 | WARN_ON(ret); | |
864 | ret = register_trace_block_remap(blk_add_trace_remap); | |
865 | WARN_ON(ret); | |
866 | return 0; | |
867 | } | |
868 | ||
869 | static void blk_unregister_tracepoints(void) | |
870 | { | |
871 | unregister_trace_block_remap(blk_add_trace_remap); | |
872 | unregister_trace_block_split(blk_add_trace_split); | |
873 | unregister_trace_block_unplug_io(blk_add_trace_unplug_io); | |
874 | unregister_trace_block_unplug_timer(blk_add_trace_unplug_timer); | |
875 | unregister_trace_block_plug(blk_add_trace_plug); | |
876 | unregister_trace_block_sleeprq(blk_add_trace_sleeprq); | |
877 | unregister_trace_block_getrq(blk_add_trace_getrq); | |
878 | unregister_trace_block_bio_queue(blk_add_trace_bio_queue); | |
879 | unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge); | |
880 | unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge); | |
881 | unregister_trace_block_bio_complete(blk_add_trace_bio_complete); | |
882 | unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce); | |
883 | unregister_trace_block_rq_complete(blk_add_trace_rq_complete); | |
884 | unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue); | |
885 | unregister_trace_block_rq_issue(blk_add_trace_rq_issue); | |
886 | unregister_trace_block_rq_insert(blk_add_trace_rq_insert); | |
887 | unregister_trace_block_rq_abort(blk_add_trace_rq_abort); | |
888 | ||
889 | tracepoint_synchronize_unregister(); | |
890 | } |