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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> |
939b3669 | 27 | #include <linux/uaccess.h> |
c71a8961 | 28 | #include <../kernel/trace/trace_output.h> |
2056a782 | 29 | |
2056a782 JA |
30 | static unsigned int blktrace_seq __read_mostly = 1; |
31 | ||
c71a8961 ACM |
32 | static struct trace_array *blk_tr; |
33 | static int __read_mostly blk_tracer_enabled; | |
34 | ||
35 | /* Select an alternative, minimalistic output than the original one */ | |
36 | #define TRACE_BLK_OPT_CLASSIC 0x1 | |
37 | ||
38 | static struct tracer_opt blk_tracer_opts[] = { | |
39 | /* Default disable the minimalistic output */ | |
157f9c00 | 40 | { TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) }, |
c71a8961 ACM |
41 | { } |
42 | }; | |
43 | ||
44 | static struct tracer_flags blk_tracer_flags = { | |
45 | .val = 0, | |
46 | .opts = blk_tracer_opts, | |
47 | }; | |
48 | ||
5f3ea37c ACM |
49 | /* Global reference count of probes */ |
50 | static DEFINE_MUTEX(blk_probe_mutex); | |
51 | static atomic_t blk_probes_ref = ATOMIC_INIT(0); | |
52 | ||
53 | static int blk_register_tracepoints(void); | |
54 | static void blk_unregister_tracepoints(void); | |
55 | ||
be1c6341 OK |
56 | /* |
57 | * Send out a notify message. | |
58 | */ | |
a863055b JA |
59 | static void trace_note(struct blk_trace *bt, pid_t pid, int action, |
60 | const void *data, size_t len) | |
be1c6341 OK |
61 | { |
62 | struct blk_io_trace *t; | |
be1c6341 | 63 | |
c71a8961 ACM |
64 | if (!bt->rchan) |
65 | return; | |
66 | ||
be1c6341 | 67 | t = relay_reserve(bt->rchan, sizeof(*t) + len); |
d3d9d2a5 JA |
68 | if (t) { |
69 | const int cpu = smp_processor_id(); | |
70 | ||
71 | t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; | |
2997c8c4 | 72 | t->time = ktime_to_ns(ktime_get()); |
d3d9d2a5 JA |
73 | t->device = bt->dev; |
74 | t->action = action; | |
75 | t->pid = pid; | |
76 | t->cpu = cpu; | |
77 | t->pdu_len = len; | |
78 | memcpy((void *) t + sizeof(*t), data, len); | |
79 | } | |
be1c6341 OK |
80 | } |
81 | ||
2056a782 JA |
82 | /* |
83 | * Send out a notify for this process, if we haven't done so since a trace | |
84 | * started | |
85 | */ | |
86 | static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk) | |
87 | { | |
a863055b JA |
88 | tsk->btrace_seq = blktrace_seq; |
89 | trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm, sizeof(tsk->comm)); | |
be1c6341 | 90 | } |
2056a782 | 91 | |
be1c6341 OK |
92 | static void trace_note_time(struct blk_trace *bt) |
93 | { | |
94 | struct timespec now; | |
95 | unsigned long flags; | |
96 | u32 words[2]; | |
97 | ||
98 | getnstimeofday(&now); | |
99 | words[0] = now.tv_sec; | |
100 | words[1] = now.tv_nsec; | |
101 | ||
102 | local_irq_save(flags); | |
103 | trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words)); | |
104 | local_irq_restore(flags); | |
2056a782 JA |
105 | } |
106 | ||
9d5f09a4 AB |
107 | void __trace_note_message(struct blk_trace *bt, const char *fmt, ...) |
108 | { | |
109 | int n; | |
110 | va_list args; | |
14a73f54 | 111 | unsigned long flags; |
64565911 | 112 | char *buf; |
9d5f09a4 | 113 | |
c71a8961 ACM |
114 | if (blk_tr) { |
115 | va_start(args, fmt); | |
116 | ftrace_vprintk(fmt, args); | |
117 | va_end(args); | |
118 | return; | |
119 | } | |
120 | ||
121 | if (!bt->msg_data) | |
122 | return; | |
123 | ||
14a73f54 | 124 | local_irq_save(flags); |
64565911 | 125 | buf = per_cpu_ptr(bt->msg_data, smp_processor_id()); |
9d5f09a4 | 126 | va_start(args, fmt); |
64565911 | 127 | n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args); |
9d5f09a4 AB |
128 | va_end(args); |
129 | ||
64565911 | 130 | trace_note(bt, 0, BLK_TN_MESSAGE, buf, n); |
14a73f54 | 131 | local_irq_restore(flags); |
9d5f09a4 AB |
132 | } |
133 | EXPORT_SYMBOL_GPL(__trace_note_message); | |
134 | ||
2056a782 JA |
135 | static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector, |
136 | pid_t pid) | |
137 | { | |
138 | if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0) | |
139 | return 1; | |
140 | if (sector < bt->start_lba || sector > bt->end_lba) | |
141 | return 1; | |
142 | if (bt->pid && pid != bt->pid) | |
143 | return 1; | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
148 | /* | |
149 | * Data direction bit lookup | |
150 | */ | |
939b3669 ACM |
151 | static u32 ddir_act[2] __read_mostly = { BLK_TC_ACT(BLK_TC_READ), |
152 | BLK_TC_ACT(BLK_TC_WRITE) }; | |
2056a782 | 153 | |
35ba8f70 | 154 | /* The ilog2() calls fall out because they're constant */ |
939b3669 ACM |
155 | #define MASK_TC_BIT(rw, __name) ((rw & (1 << BIO_RW_ ## __name)) << \ |
156 | (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - BIO_RW_ ## __name)) | |
2056a782 JA |
157 | |
158 | /* | |
159 | * The worker for the various blk_add_trace*() types. Fills out a | |
160 | * blk_io_trace structure and places it in a per-cpu subbuffer. | |
161 | */ | |
5f3ea37c | 162 | static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, |
2056a782 JA |
163 | int rw, u32 what, int error, int pdu_len, void *pdu_data) |
164 | { | |
165 | struct task_struct *tsk = current; | |
c71a8961 | 166 | struct ring_buffer_event *event = NULL; |
2056a782 JA |
167 | struct blk_io_trace *t; |
168 | unsigned long flags; | |
169 | unsigned long *sequence; | |
170 | pid_t pid; | |
c71a8961 | 171 | int cpu, pc = 0; |
2056a782 | 172 | |
157f9c00 ACM |
173 | if (unlikely(bt->trace_state != Blktrace_running || |
174 | !blk_tracer_enabled)) | |
2056a782 JA |
175 | return; |
176 | ||
177 | what |= ddir_act[rw & WRITE]; | |
35ba8f70 DW |
178 | what |= MASK_TC_BIT(rw, BARRIER); |
179 | what |= MASK_TC_BIT(rw, SYNC); | |
180 | what |= MASK_TC_BIT(rw, AHEAD); | |
181 | what |= MASK_TC_BIT(rw, META); | |
182 | what |= MASK_TC_BIT(rw, DISCARD); | |
2056a782 JA |
183 | |
184 | pid = tsk->pid; | |
185 | if (unlikely(act_log_check(bt, what, sector, pid))) | |
186 | return; | |
c71a8961 ACM |
187 | cpu = raw_smp_processor_id(); |
188 | ||
189 | if (blk_tr) { | |
190 | struct trace_entry *ent; | |
191 | tracing_record_cmdline(current); | |
192 | ||
193 | event = ring_buffer_lock_reserve(blk_tr->buffer, | |
194 | sizeof(*t) + pdu_len, &flags); | |
195 | if (!event) | |
196 | return; | |
157f9c00 | 197 | |
c71a8961 ACM |
198 | ent = ring_buffer_event_data(event); |
199 | t = (struct blk_io_trace *)ent; | |
200 | pc = preempt_count(); | |
201 | tracing_generic_entry_update(ent, 0, pc); | |
202 | ent->type = TRACE_BLK; | |
203 | goto record_it; | |
204 | } | |
2056a782 JA |
205 | |
206 | /* | |
207 | * A word about the locking here - we disable interrupts to reserve | |
208 | * some space in the relay per-cpu buffer, to prevent an irq | |
14a73f54 | 209 | * from coming in and stepping on our toes. |
2056a782 JA |
210 | */ |
211 | local_irq_save(flags); | |
212 | ||
213 | if (unlikely(tsk->btrace_seq != blktrace_seq)) | |
214 | trace_note_tsk(bt, tsk); | |
215 | ||
216 | t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len); | |
217 | if (t) { | |
2056a782 JA |
218 | sequence = per_cpu_ptr(bt->sequence, cpu); |
219 | ||
220 | t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; | |
221 | t->sequence = ++(*sequence); | |
2997c8c4 | 222 | t->time = ktime_to_ns(ktime_get()); |
c71a8961 | 223 | record_it: |
08a06b83 | 224 | /* |
939b3669 ACM |
225 | * These two are not needed in ftrace as they are in the |
226 | * generic trace_entry, filled by tracing_generic_entry_update, | |
227 | * but for the trace_event->bin() synthesizer benefit we do it | |
228 | * here too. | |
229 | */ | |
230 | t->cpu = cpu; | |
231 | t->pid = pid; | |
08a06b83 | 232 | |
2056a782 JA |
233 | t->sector = sector; |
234 | t->bytes = bytes; | |
235 | t->action = what; | |
2056a782 | 236 | t->device = bt->dev; |
2056a782 JA |
237 | t->error = error; |
238 | t->pdu_len = pdu_len; | |
239 | ||
240 | if (pdu_len) | |
241 | memcpy((void *) t + sizeof(*t), pdu_data, pdu_len); | |
c71a8961 ACM |
242 | |
243 | if (blk_tr) { | |
244 | ring_buffer_unlock_commit(blk_tr->buffer, event, flags); | |
245 | if (pid != 0 && | |
157f9c00 | 246 | !(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC) && |
c71a8961 | 247 | (trace_flags & TRACE_ITER_STACKTRACE) != 0) |
7be42151 | 248 | __trace_stack(blk_tr, flags, 5, pc); |
c71a8961 ACM |
249 | trace_wake_up(); |
250 | return; | |
251 | } | |
2056a782 JA |
252 | } |
253 | ||
254 | local_irq_restore(flags); | |
255 | } | |
256 | ||
2056a782 | 257 | static struct dentry *blk_tree_root; |
11a57153 | 258 | static DEFINE_MUTEX(blk_tree_mutex); |
2056a782 JA |
259 | |
260 | static void blk_trace_cleanup(struct blk_trace *bt) | |
261 | { | |
02c62304 | 262 | debugfs_remove(bt->msg_file); |
2056a782 | 263 | debugfs_remove(bt->dropped_file); |
f48fc4d3 | 264 | relay_close(bt->rchan); |
2056a782 | 265 | free_percpu(bt->sequence); |
64565911 | 266 | free_percpu(bt->msg_data); |
2056a782 | 267 | kfree(bt); |
5f3ea37c ACM |
268 | mutex_lock(&blk_probe_mutex); |
269 | if (atomic_dec_and_test(&blk_probes_ref)) | |
270 | blk_unregister_tracepoints(); | |
271 | mutex_unlock(&blk_probe_mutex); | |
2056a782 JA |
272 | } |
273 | ||
6da127ad | 274 | int blk_trace_remove(struct request_queue *q) |
2056a782 JA |
275 | { |
276 | struct blk_trace *bt; | |
277 | ||
278 | bt = xchg(&q->blk_trace, NULL); | |
279 | if (!bt) | |
280 | return -EINVAL; | |
281 | ||
282 | if (bt->trace_state == Blktrace_setup || | |
283 | bt->trace_state == Blktrace_stopped) | |
284 | blk_trace_cleanup(bt); | |
285 | ||
286 | return 0; | |
287 | } | |
6da127ad | 288 | EXPORT_SYMBOL_GPL(blk_trace_remove); |
2056a782 JA |
289 | |
290 | static int blk_dropped_open(struct inode *inode, struct file *filp) | |
291 | { | |
8e18e294 | 292 | filp->private_data = inode->i_private; |
2056a782 JA |
293 | |
294 | return 0; | |
295 | } | |
296 | ||
297 | static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, | |
298 | size_t count, loff_t *ppos) | |
299 | { | |
300 | struct blk_trace *bt = filp->private_data; | |
301 | char buf[16]; | |
302 | ||
303 | snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped)); | |
304 | ||
305 | return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf)); | |
306 | } | |
307 | ||
2b8693c0 | 308 | static const struct file_operations blk_dropped_fops = { |
2056a782 JA |
309 | .owner = THIS_MODULE, |
310 | .open = blk_dropped_open, | |
311 | .read = blk_dropped_read, | |
312 | }; | |
313 | ||
02c62304 AB |
314 | static int blk_msg_open(struct inode *inode, struct file *filp) |
315 | { | |
316 | filp->private_data = inode->i_private; | |
317 | ||
318 | return 0; | |
319 | } | |
320 | ||
321 | static ssize_t blk_msg_write(struct file *filp, const char __user *buffer, | |
322 | size_t count, loff_t *ppos) | |
323 | { | |
324 | char *msg; | |
325 | struct blk_trace *bt; | |
326 | ||
327 | if (count > BLK_TN_MAX_MSG) | |
328 | return -EINVAL; | |
329 | ||
330 | msg = kmalloc(count, GFP_KERNEL); | |
331 | if (msg == NULL) | |
332 | return -ENOMEM; | |
333 | ||
334 | if (copy_from_user(msg, buffer, count)) { | |
335 | kfree(msg); | |
336 | return -EFAULT; | |
337 | } | |
338 | ||
339 | bt = filp->private_data; | |
340 | __trace_note_message(bt, "%s", msg); | |
341 | kfree(msg); | |
342 | ||
343 | return count; | |
344 | } | |
345 | ||
346 | static const struct file_operations blk_msg_fops = { | |
347 | .owner = THIS_MODULE, | |
348 | .open = blk_msg_open, | |
349 | .write = blk_msg_write, | |
350 | }; | |
351 | ||
2056a782 JA |
352 | /* |
353 | * Keep track of how many times we encountered a full subbuffer, to aid | |
354 | * the user space app in telling how many lost events there were. | |
355 | */ | |
356 | static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf, | |
357 | void *prev_subbuf, size_t prev_padding) | |
358 | { | |
359 | struct blk_trace *bt; | |
360 | ||
361 | if (!relay_buf_full(buf)) | |
362 | return 1; | |
363 | ||
364 | bt = buf->chan->private_data; | |
365 | atomic_inc(&bt->dropped); | |
366 | return 0; | |
367 | } | |
368 | ||
369 | static int blk_remove_buf_file_callback(struct dentry *dentry) | |
370 | { | |
f48fc4d3 | 371 | struct dentry *parent = dentry->d_parent; |
2056a782 | 372 | debugfs_remove(dentry); |
f48fc4d3 JA |
373 | |
374 | /* | |
375 | * this will fail for all but the last file, but that is ok. what we | |
376 | * care about is the top level buts->name directory going away, when | |
377 | * the last trace file is gone. Then we don't have to rmdir() that | |
378 | * manually on trace stop, so it nicely solves the issue with | |
379 | * force killing of running traces. | |
380 | */ | |
381 | ||
382 | debugfs_remove(parent); | |
2056a782 JA |
383 | return 0; |
384 | } | |
385 | ||
386 | static struct dentry *blk_create_buf_file_callback(const char *filename, | |
387 | struct dentry *parent, | |
388 | int mode, | |
389 | struct rchan_buf *buf, | |
390 | int *is_global) | |
391 | { | |
392 | return debugfs_create_file(filename, mode, parent, buf, | |
393 | &relay_file_operations); | |
394 | } | |
395 | ||
396 | static struct rchan_callbacks blk_relay_callbacks = { | |
397 | .subbuf_start = blk_subbuf_start_callback, | |
398 | .create_buf_file = blk_create_buf_file_callback, | |
399 | .remove_buf_file = blk_remove_buf_file_callback, | |
400 | }; | |
401 | ||
402 | /* | |
403 | * Setup everything required to start tracing | |
404 | */ | |
6da127ad | 405 | int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, |
171044d4 | 406 | struct blk_user_trace_setup *buts) |
2056a782 | 407 | { |
2056a782 JA |
408 | struct blk_trace *old_bt, *bt = NULL; |
409 | struct dentry *dir = NULL; | |
2056a782 JA |
410 | int ret, i; |
411 | ||
171044d4 | 412 | if (!buts->buf_size || !buts->buf_nr) |
2056a782 JA |
413 | return -EINVAL; |
414 | ||
0497b345 JA |
415 | strncpy(buts->name, name, BLKTRACE_BDEV_SIZE); |
416 | buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0'; | |
2056a782 JA |
417 | |
418 | /* | |
419 | * some device names have larger paths - convert the slashes | |
420 | * to underscores for this to work as expected | |
421 | */ | |
171044d4 AB |
422 | for (i = 0; i < strlen(buts->name); i++) |
423 | if (buts->name[i] == '/') | |
424 | buts->name[i] = '_'; | |
2056a782 JA |
425 | |
426 | ret = -ENOMEM; | |
427 | bt = kzalloc(sizeof(*bt), GFP_KERNEL); | |
428 | if (!bt) | |
429 | goto err; | |
430 | ||
431 | bt->sequence = alloc_percpu(unsigned long); | |
432 | if (!bt->sequence) | |
433 | goto err; | |
434 | ||
64565911 JA |
435 | bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG); |
436 | if (!bt->msg_data) | |
437 | goto err; | |
438 | ||
2056a782 | 439 | ret = -ENOENT; |
f48fc4d3 JA |
440 | |
441 | if (!blk_tree_root) { | |
442 | blk_tree_root = debugfs_create_dir("block", NULL); | |
443 | if (!blk_tree_root) | |
444 | return -ENOMEM; | |
445 | } | |
446 | ||
447 | dir = debugfs_create_dir(buts->name, blk_tree_root); | |
448 | ||
2056a782 JA |
449 | if (!dir) |
450 | goto err; | |
451 | ||
452 | bt->dir = dir; | |
6da127ad | 453 | bt->dev = dev; |
2056a782 JA |
454 | atomic_set(&bt->dropped, 0); |
455 | ||
456 | ret = -EIO; | |
939b3669 ACM |
457 | bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, |
458 | &blk_dropped_fops); | |
2056a782 JA |
459 | if (!bt->dropped_file) |
460 | goto err; | |
461 | ||
02c62304 AB |
462 | bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops); |
463 | if (!bt->msg_file) | |
464 | goto err; | |
465 | ||
171044d4 AB |
466 | bt->rchan = relay_open("trace", dir, buts->buf_size, |
467 | buts->buf_nr, &blk_relay_callbacks, bt); | |
2056a782 JA |
468 | if (!bt->rchan) |
469 | goto err; | |
2056a782 | 470 | |
171044d4 | 471 | bt->act_mask = buts->act_mask; |
2056a782 JA |
472 | if (!bt->act_mask) |
473 | bt->act_mask = (u16) -1; | |
474 | ||
171044d4 AB |
475 | bt->start_lba = buts->start_lba; |
476 | bt->end_lba = buts->end_lba; | |
2056a782 JA |
477 | if (!bt->end_lba) |
478 | bt->end_lba = -1ULL; | |
479 | ||
171044d4 | 480 | bt->pid = buts->pid; |
2056a782 JA |
481 | bt->trace_state = Blktrace_setup; |
482 | ||
5f3ea37c ACM |
483 | mutex_lock(&blk_probe_mutex); |
484 | if (atomic_add_return(1, &blk_probes_ref) == 1) { | |
485 | ret = blk_register_tracepoints(); | |
486 | if (ret) | |
487 | goto probe_err; | |
488 | } | |
489 | mutex_unlock(&blk_probe_mutex); | |
490 | ||
2056a782 JA |
491 | ret = -EBUSY; |
492 | old_bt = xchg(&q->blk_trace, bt); | |
493 | if (old_bt) { | |
494 | (void) xchg(&q->blk_trace, old_bt); | |
495 | goto err; | |
496 | } | |
497 | ||
498 | return 0; | |
5f3ea37c ACM |
499 | probe_err: |
500 | atomic_dec(&blk_probes_ref); | |
501 | mutex_unlock(&blk_probe_mutex); | |
2056a782 | 502 | err: |
2056a782 | 503 | if (bt) { |
02c62304 AB |
504 | if (bt->msg_file) |
505 | debugfs_remove(bt->msg_file); | |
2056a782 JA |
506 | if (bt->dropped_file) |
507 | debugfs_remove(bt->dropped_file); | |
a1205868 | 508 | free_percpu(bt->sequence); |
64565911 | 509 | free_percpu(bt->msg_data); |
2056a782 JA |
510 | if (bt->rchan) |
511 | relay_close(bt->rchan); | |
512 | kfree(bt); | |
513 | } | |
514 | return ret; | |
515 | } | |
171044d4 | 516 | |
6da127ad CS |
517 | int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, |
518 | char __user *arg) | |
171044d4 AB |
519 | { |
520 | struct blk_user_trace_setup buts; | |
521 | int ret; | |
522 | ||
523 | ret = copy_from_user(&buts, arg, sizeof(buts)); | |
524 | if (ret) | |
525 | return -EFAULT; | |
526 | ||
6da127ad | 527 | ret = do_blk_trace_setup(q, name, dev, &buts); |
171044d4 AB |
528 | if (ret) |
529 | return ret; | |
530 | ||
531 | if (copy_to_user(arg, &buts, sizeof(buts))) | |
532 | return -EFAULT; | |
533 | ||
534 | return 0; | |
535 | } | |
6da127ad | 536 | EXPORT_SYMBOL_GPL(blk_trace_setup); |
2056a782 | 537 | |
6da127ad | 538 | int blk_trace_startstop(struct request_queue *q, int start) |
2056a782 | 539 | { |
2056a782 | 540 | int ret; |
939b3669 | 541 | struct blk_trace *bt = q->blk_trace; |
2056a782 | 542 | |
939b3669 | 543 | if (bt == NULL) |
2056a782 JA |
544 | return -EINVAL; |
545 | ||
546 | /* | |
547 | * For starting a trace, we can transition from a setup or stopped | |
548 | * trace. For stopping a trace, the state must be running | |
549 | */ | |
550 | ret = -EINVAL; | |
551 | if (start) { | |
552 | if (bt->trace_state == Blktrace_setup || | |
553 | bt->trace_state == Blktrace_stopped) { | |
554 | blktrace_seq++; | |
555 | smp_mb(); | |
556 | bt->trace_state = Blktrace_running; | |
be1c6341 OK |
557 | |
558 | trace_note_time(bt); | |
2056a782 JA |
559 | ret = 0; |
560 | } | |
561 | } else { | |
562 | if (bt->trace_state == Blktrace_running) { | |
563 | bt->trace_state = Blktrace_stopped; | |
564 | relay_flush(bt->rchan); | |
565 | ret = 0; | |
566 | } | |
567 | } | |
568 | ||
569 | return ret; | |
570 | } | |
6da127ad | 571 | EXPORT_SYMBOL_GPL(blk_trace_startstop); |
2056a782 JA |
572 | |
573 | /** | |
574 | * blk_trace_ioctl: - handle the ioctls associated with tracing | |
575 | * @bdev: the block device | |
576 | * @cmd: the ioctl cmd | |
577 | * @arg: the argument data, if any | |
578 | * | |
579 | **/ | |
580 | int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) | |
581 | { | |
165125e1 | 582 | struct request_queue *q; |
2056a782 | 583 | int ret, start = 0; |
6da127ad | 584 | char b[BDEVNAME_SIZE]; |
2056a782 JA |
585 | |
586 | q = bdev_get_queue(bdev); | |
587 | if (!q) | |
588 | return -ENXIO; | |
589 | ||
590 | mutex_lock(&bdev->bd_mutex); | |
591 | ||
592 | switch (cmd) { | |
593 | case BLKTRACESETUP: | |
f36f21ec | 594 | bdevname(bdev, b); |
6da127ad | 595 | ret = blk_trace_setup(q, b, bdev->bd_dev, arg); |
2056a782 JA |
596 | break; |
597 | case BLKTRACESTART: | |
598 | start = 1; | |
599 | case BLKTRACESTOP: | |
600 | ret = blk_trace_startstop(q, start); | |
601 | break; | |
602 | case BLKTRACETEARDOWN: | |
603 | ret = blk_trace_remove(q); | |
604 | break; | |
605 | default: | |
606 | ret = -ENOTTY; | |
607 | break; | |
608 | } | |
609 | ||
610 | mutex_unlock(&bdev->bd_mutex); | |
611 | return ret; | |
612 | } | |
613 | ||
614 | /** | |
615 | * blk_trace_shutdown: - stop and cleanup trace structures | |
616 | * @q: the request queue associated with the device | |
617 | * | |
618 | **/ | |
165125e1 | 619 | void blk_trace_shutdown(struct request_queue *q) |
2056a782 | 620 | { |
6c5c9341 AD |
621 | if (q->blk_trace) { |
622 | blk_trace_startstop(q, 0); | |
623 | blk_trace_remove(q); | |
624 | } | |
2056a782 | 625 | } |
5f3ea37c ACM |
626 | |
627 | /* | |
628 | * blktrace probes | |
629 | */ | |
630 | ||
631 | /** | |
632 | * blk_add_trace_rq - Add a trace for a request oriented action | |
633 | * @q: queue the io is for | |
634 | * @rq: the source request | |
635 | * @what: the action | |
636 | * | |
637 | * Description: | |
638 | * Records an action against a request. Will log the bio offset + size. | |
639 | * | |
640 | **/ | |
641 | static void blk_add_trace_rq(struct request_queue *q, struct request *rq, | |
642 | u32 what) | |
643 | { | |
644 | struct blk_trace *bt = q->blk_trace; | |
645 | int rw = rq->cmd_flags & 0x03; | |
646 | ||
647 | if (likely(!bt)) | |
648 | return; | |
649 | ||
650 | if (blk_discard_rq(rq)) | |
651 | rw |= (1 << BIO_RW_DISCARD); | |
652 | ||
653 | if (blk_pc_request(rq)) { | |
654 | what |= BLK_TC_ACT(BLK_TC_PC); | |
655 | __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, | |
656 | sizeof(rq->cmd), rq->cmd); | |
657 | } else { | |
658 | what |= BLK_TC_ACT(BLK_TC_FS); | |
659 | __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, | |
660 | rw, what, rq->errors, 0, NULL); | |
661 | } | |
662 | } | |
663 | ||
664 | static void blk_add_trace_rq_abort(struct request_queue *q, struct request *rq) | |
665 | { | |
666 | blk_add_trace_rq(q, rq, BLK_TA_ABORT); | |
667 | } | |
668 | ||
669 | static void blk_add_trace_rq_insert(struct request_queue *q, struct request *rq) | |
670 | { | |
671 | blk_add_trace_rq(q, rq, BLK_TA_INSERT); | |
672 | } | |
673 | ||
674 | static void blk_add_trace_rq_issue(struct request_queue *q, struct request *rq) | |
675 | { | |
676 | blk_add_trace_rq(q, rq, BLK_TA_ISSUE); | |
677 | } | |
678 | ||
939b3669 ACM |
679 | static void blk_add_trace_rq_requeue(struct request_queue *q, |
680 | struct request *rq) | |
5f3ea37c ACM |
681 | { |
682 | blk_add_trace_rq(q, rq, BLK_TA_REQUEUE); | |
683 | } | |
684 | ||
939b3669 ACM |
685 | static void blk_add_trace_rq_complete(struct request_queue *q, |
686 | struct request *rq) | |
5f3ea37c ACM |
687 | { |
688 | blk_add_trace_rq(q, rq, BLK_TA_COMPLETE); | |
689 | } | |
690 | ||
691 | /** | |
692 | * blk_add_trace_bio - Add a trace for a bio oriented action | |
693 | * @q: queue the io is for | |
694 | * @bio: the source bio | |
695 | * @what: the action | |
696 | * | |
697 | * Description: | |
698 | * Records an action against a bio. Will log the bio offset + size. | |
699 | * | |
700 | **/ | |
701 | static void blk_add_trace_bio(struct request_queue *q, struct bio *bio, | |
702 | u32 what) | |
703 | { | |
704 | struct blk_trace *bt = q->blk_trace; | |
705 | ||
706 | if (likely(!bt)) | |
707 | return; | |
708 | ||
709 | __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, | |
710 | !bio_flagged(bio, BIO_UPTODATE), 0, NULL); | |
711 | } | |
712 | ||
713 | static void blk_add_trace_bio_bounce(struct request_queue *q, struct bio *bio) | |
714 | { | |
715 | blk_add_trace_bio(q, bio, BLK_TA_BOUNCE); | |
716 | } | |
717 | ||
718 | static void blk_add_trace_bio_complete(struct request_queue *q, struct bio *bio) | |
719 | { | |
720 | blk_add_trace_bio(q, bio, BLK_TA_COMPLETE); | |
721 | } | |
722 | ||
939b3669 ACM |
723 | static void blk_add_trace_bio_backmerge(struct request_queue *q, |
724 | struct bio *bio) | |
5f3ea37c ACM |
725 | { |
726 | blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE); | |
727 | } | |
728 | ||
939b3669 ACM |
729 | static void blk_add_trace_bio_frontmerge(struct request_queue *q, |
730 | struct bio *bio) | |
5f3ea37c ACM |
731 | { |
732 | blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE); | |
733 | } | |
734 | ||
735 | static void blk_add_trace_bio_queue(struct request_queue *q, struct bio *bio) | |
736 | { | |
737 | blk_add_trace_bio(q, bio, BLK_TA_QUEUE); | |
738 | } | |
739 | ||
939b3669 ACM |
740 | static void blk_add_trace_getrq(struct request_queue *q, |
741 | struct bio *bio, int rw) | |
5f3ea37c ACM |
742 | { |
743 | if (bio) | |
744 | blk_add_trace_bio(q, bio, BLK_TA_GETRQ); | |
745 | else { | |
746 | struct blk_trace *bt = q->blk_trace; | |
747 | ||
748 | if (bt) | |
749 | __blk_add_trace(bt, 0, 0, rw, BLK_TA_GETRQ, 0, 0, NULL); | |
750 | } | |
751 | } | |
752 | ||
753 | ||
939b3669 ACM |
754 | static void blk_add_trace_sleeprq(struct request_queue *q, |
755 | struct bio *bio, int rw) | |
5f3ea37c ACM |
756 | { |
757 | if (bio) | |
758 | blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ); | |
759 | else { | |
760 | struct blk_trace *bt = q->blk_trace; | |
761 | ||
762 | if (bt) | |
939b3669 ACM |
763 | __blk_add_trace(bt, 0, 0, rw, BLK_TA_SLEEPRQ, |
764 | 0, 0, NULL); | |
5f3ea37c ACM |
765 | } |
766 | } | |
767 | ||
768 | static void blk_add_trace_plug(struct request_queue *q) | |
769 | { | |
770 | struct blk_trace *bt = q->blk_trace; | |
771 | ||
772 | if (bt) | |
773 | __blk_add_trace(bt, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL); | |
774 | } | |
775 | ||
776 | static void blk_add_trace_unplug_io(struct request_queue *q) | |
777 | { | |
778 | struct blk_trace *bt = q->blk_trace; | |
779 | ||
780 | if (bt) { | |
781 | unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE]; | |
782 | __be64 rpdu = cpu_to_be64(pdu); | |
783 | ||
784 | __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_IO, 0, | |
785 | sizeof(rpdu), &rpdu); | |
786 | } | |
787 | } | |
788 | ||
789 | static void blk_add_trace_unplug_timer(struct request_queue *q) | |
790 | { | |
791 | struct blk_trace *bt = q->blk_trace; | |
792 | ||
793 | if (bt) { | |
794 | unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE]; | |
795 | __be64 rpdu = cpu_to_be64(pdu); | |
796 | ||
797 | __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_TIMER, 0, | |
798 | sizeof(rpdu), &rpdu); | |
799 | } | |
800 | } | |
801 | ||
802 | static void blk_add_trace_split(struct request_queue *q, struct bio *bio, | |
803 | unsigned int pdu) | |
804 | { | |
805 | struct blk_trace *bt = q->blk_trace; | |
806 | ||
807 | if (bt) { | |
808 | __be64 rpdu = cpu_to_be64(pdu); | |
809 | ||
810 | __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, | |
811 | BLK_TA_SPLIT, !bio_flagged(bio, BIO_UPTODATE), | |
812 | sizeof(rpdu), &rpdu); | |
813 | } | |
814 | } | |
815 | ||
816 | /** | |
817 | * blk_add_trace_remap - Add a trace for a remap operation | |
818 | * @q: queue the io is for | |
819 | * @bio: the source bio | |
820 | * @dev: target device | |
821 | * @from: source sector | |
822 | * @to: target sector | |
823 | * | |
824 | * Description: | |
825 | * Device mapper or raid target sometimes need to split a bio because | |
826 | * it spans a stripe (or similar). Add a trace for that action. | |
827 | * | |
828 | **/ | |
829 | static void blk_add_trace_remap(struct request_queue *q, struct bio *bio, | |
830 | dev_t dev, sector_t from, sector_t to) | |
831 | { | |
832 | struct blk_trace *bt = q->blk_trace; | |
833 | struct blk_io_trace_remap r; | |
834 | ||
835 | if (likely(!bt)) | |
836 | return; | |
837 | ||
838 | r.device = cpu_to_be32(dev); | |
839 | r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev); | |
840 | r.sector = cpu_to_be64(to); | |
841 | ||
842 | __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, | |
843 | !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r); | |
844 | } | |
845 | ||
846 | /** | |
847 | * blk_add_driver_data - Add binary message with driver-specific data | |
848 | * @q: queue the io is for | |
849 | * @rq: io request | |
850 | * @data: driver-specific data | |
851 | * @len: length of driver-specific data | |
852 | * | |
853 | * Description: | |
854 | * Some drivers might want to write driver-specific data per request. | |
855 | * | |
856 | **/ | |
857 | void blk_add_driver_data(struct request_queue *q, | |
858 | struct request *rq, | |
859 | void *data, size_t len) | |
860 | { | |
861 | struct blk_trace *bt = q->blk_trace; | |
862 | ||
863 | if (likely(!bt)) | |
864 | return; | |
865 | ||
866 | if (blk_pc_request(rq)) | |
867 | __blk_add_trace(bt, 0, rq->data_len, 0, BLK_TA_DRV_DATA, | |
868 | rq->errors, len, data); | |
869 | else | |
870 | __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, | |
871 | 0, BLK_TA_DRV_DATA, rq->errors, len, data); | |
872 | } | |
873 | EXPORT_SYMBOL_GPL(blk_add_driver_data); | |
874 | ||
875 | static int blk_register_tracepoints(void) | |
876 | { | |
877 | int ret; | |
878 | ||
879 | ret = register_trace_block_rq_abort(blk_add_trace_rq_abort); | |
880 | WARN_ON(ret); | |
881 | ret = register_trace_block_rq_insert(blk_add_trace_rq_insert); | |
882 | WARN_ON(ret); | |
883 | ret = register_trace_block_rq_issue(blk_add_trace_rq_issue); | |
884 | WARN_ON(ret); | |
885 | ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue); | |
886 | WARN_ON(ret); | |
887 | ret = register_trace_block_rq_complete(blk_add_trace_rq_complete); | |
888 | WARN_ON(ret); | |
889 | ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce); | |
890 | WARN_ON(ret); | |
891 | ret = register_trace_block_bio_complete(blk_add_trace_bio_complete); | |
892 | WARN_ON(ret); | |
893 | ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge); | |
894 | WARN_ON(ret); | |
895 | ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge); | |
896 | WARN_ON(ret); | |
897 | ret = register_trace_block_bio_queue(blk_add_trace_bio_queue); | |
898 | WARN_ON(ret); | |
899 | ret = register_trace_block_getrq(blk_add_trace_getrq); | |
900 | WARN_ON(ret); | |
901 | ret = register_trace_block_sleeprq(blk_add_trace_sleeprq); | |
902 | WARN_ON(ret); | |
903 | ret = register_trace_block_plug(blk_add_trace_plug); | |
904 | WARN_ON(ret); | |
905 | ret = register_trace_block_unplug_timer(blk_add_trace_unplug_timer); | |
906 | WARN_ON(ret); | |
907 | ret = register_trace_block_unplug_io(blk_add_trace_unplug_io); | |
908 | WARN_ON(ret); | |
909 | ret = register_trace_block_split(blk_add_trace_split); | |
910 | WARN_ON(ret); | |
911 | ret = register_trace_block_remap(blk_add_trace_remap); | |
912 | WARN_ON(ret); | |
913 | return 0; | |
914 | } | |
915 | ||
916 | static void blk_unregister_tracepoints(void) | |
917 | { | |
918 | unregister_trace_block_remap(blk_add_trace_remap); | |
919 | unregister_trace_block_split(blk_add_trace_split); | |
920 | unregister_trace_block_unplug_io(blk_add_trace_unplug_io); | |
921 | unregister_trace_block_unplug_timer(blk_add_trace_unplug_timer); | |
922 | unregister_trace_block_plug(blk_add_trace_plug); | |
923 | unregister_trace_block_sleeprq(blk_add_trace_sleeprq); | |
924 | unregister_trace_block_getrq(blk_add_trace_getrq); | |
925 | unregister_trace_block_bio_queue(blk_add_trace_bio_queue); | |
926 | unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge); | |
927 | unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge); | |
928 | unregister_trace_block_bio_complete(blk_add_trace_bio_complete); | |
929 | unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce); | |
930 | unregister_trace_block_rq_complete(blk_add_trace_rq_complete); | |
931 | unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue); | |
932 | unregister_trace_block_rq_issue(blk_add_trace_rq_issue); | |
933 | unregister_trace_block_rq_insert(blk_add_trace_rq_insert); | |
934 | unregister_trace_block_rq_abort(blk_add_trace_rq_abort); | |
935 | ||
936 | tracepoint_synchronize_unregister(); | |
937 | } | |
c71a8961 ACM |
938 | |
939 | /* | |
940 | * struct blk_io_tracer formatting routines | |
941 | */ | |
942 | ||
943 | static void fill_rwbs(char *rwbs, const struct blk_io_trace *t) | |
944 | { | |
157f9c00 ACM |
945 | int i = 0; |
946 | ||
947 | if (t->action & BLK_TC_DISCARD) | |
948 | rwbs[i++] = 'D'; | |
949 | else if (t->action & BLK_TC_WRITE) | |
950 | rwbs[i++] = 'W'; | |
951 | else if (t->bytes) | |
952 | rwbs[i++] = 'R'; | |
953 | else | |
954 | rwbs[i++] = 'N'; | |
955 | ||
956 | if (t->action & BLK_TC_AHEAD) | |
957 | rwbs[i++] = 'A'; | |
958 | if (t->action & BLK_TC_BARRIER) | |
959 | rwbs[i++] = 'B'; | |
960 | if (t->action & BLK_TC_SYNC) | |
961 | rwbs[i++] = 'S'; | |
962 | if (t->action & BLK_TC_META) | |
963 | rwbs[i++] = 'M'; | |
964 | ||
965 | rwbs[i] = '\0'; | |
c71a8961 ACM |
966 | } |
967 | ||
968 | static inline | |
969 | const struct blk_io_trace *te_blk_io_trace(const struct trace_entry *ent) | |
970 | { | |
971 | return (const struct blk_io_trace *)ent; | |
972 | } | |
973 | ||
974 | static inline const void *pdu_start(const struct trace_entry *ent) | |
975 | { | |
976 | return te_blk_io_trace(ent) + 1; | |
977 | } | |
978 | ||
979 | static inline u32 t_sec(const struct trace_entry *ent) | |
980 | { | |
981 | return te_blk_io_trace(ent)->bytes >> 9; | |
982 | } | |
983 | ||
984 | static inline unsigned long long t_sector(const struct trace_entry *ent) | |
985 | { | |
986 | return te_blk_io_trace(ent)->sector; | |
987 | } | |
988 | ||
989 | static inline __u16 t_error(const struct trace_entry *ent) | |
990 | { | |
991 | return te_blk_io_trace(ent)->sector; | |
992 | } | |
993 | ||
994 | static __u64 get_pdu_int(const struct trace_entry *ent) | |
995 | { | |
996 | const __u64 *val = pdu_start(ent); | |
997 | return be64_to_cpu(*val); | |
998 | } | |
999 | ||
1000 | static void get_pdu_remap(const struct trace_entry *ent, | |
1001 | struct blk_io_trace_remap *r) | |
1002 | { | |
1003 | const struct blk_io_trace_remap *__r = pdu_start(ent); | |
1004 | __u64 sector = __r->sector; | |
1005 | ||
1006 | r->device = be32_to_cpu(__r->device); | |
1007 | r->device_from = be32_to_cpu(__r->device_from); | |
1008 | r->sector = be64_to_cpu(sector); | |
1009 | } | |
1010 | ||
1011 | static int blk_log_action_iter(struct trace_iterator *iter, const char *act) | |
1012 | { | |
1013 | char rwbs[6]; | |
1014 | unsigned long long ts = ns2usecs(iter->ts); | |
1015 | unsigned long usec_rem = do_div(ts, USEC_PER_SEC); | |
1016 | unsigned secs = (unsigned long)ts; | |
1017 | const struct trace_entry *ent = iter->ent; | |
1018 | const struct blk_io_trace *t = (const struct blk_io_trace *)ent; | |
1019 | ||
1020 | fill_rwbs(rwbs, t); | |
1021 | ||
1022 | return trace_seq_printf(&iter->seq, | |
1023 | "%3d,%-3d %2d %5d.%06lu %5u %2s %3s ", | |
1024 | MAJOR(t->device), MINOR(t->device), iter->cpu, | |
1025 | secs, usec_rem, ent->pid, act, rwbs); | |
1026 | } | |
1027 | ||
1028 | static int blk_log_action_seq(struct trace_seq *s, const struct blk_io_trace *t, | |
1029 | const char *act) | |
1030 | { | |
1031 | char rwbs[6]; | |
1032 | fill_rwbs(rwbs, t); | |
1033 | return trace_seq_printf(s, "%3d,%-3d %2s %3s ", | |
1034 | MAJOR(t->device), MINOR(t->device), act, rwbs); | |
1035 | } | |
1036 | ||
1037 | static int blk_log_generic(struct trace_seq *s, const struct trace_entry *ent) | |
1038 | { | |
1039 | const char *cmd = trace_find_cmdline(ent->pid); | |
1040 | ||
1041 | if (t_sec(ent)) | |
1042 | return trace_seq_printf(s, "%llu + %u [%s]\n", | |
1043 | t_sector(ent), t_sec(ent), cmd); | |
1044 | return trace_seq_printf(s, "[%s]\n", cmd); | |
1045 | } | |
1046 | ||
157f9c00 ACM |
1047 | static int blk_log_with_error(struct trace_seq *s, |
1048 | const struct trace_entry *ent) | |
c71a8961 ACM |
1049 | { |
1050 | if (t_sec(ent)) | |
1051 | return trace_seq_printf(s, "%llu + %u [%d]\n", t_sector(ent), | |
1052 | t_sec(ent), t_error(ent)); | |
1053 | return trace_seq_printf(s, "%llu [%d]\n", t_sector(ent), t_error(ent)); | |
1054 | } | |
1055 | ||
1056 | static int blk_log_remap(struct trace_seq *s, const struct trace_entry *ent) | |
1057 | { | |
1058 | struct blk_io_trace_remap r = { .device = 0, }; | |
1059 | ||
1060 | get_pdu_remap(ent, &r); | |
1061 | return trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n", | |
1062 | t_sector(ent), | |
1063 | t_sec(ent), MAJOR(r.device), MINOR(r.device), | |
1064 | (unsigned long long)r.sector); | |
1065 | } | |
1066 | ||
1067 | static int blk_log_plug(struct trace_seq *s, const struct trace_entry *ent) | |
1068 | { | |
1069 | return trace_seq_printf(s, "[%s]\n", trace_find_cmdline(ent->pid)); | |
1070 | } | |
1071 | ||
1072 | static int blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent) | |
1073 | { | |
1074 | return trace_seq_printf(s, "[%s] %llu\n", trace_find_cmdline(ent->pid), | |
1075 | get_pdu_int(ent)); | |
1076 | } | |
1077 | ||
1078 | static int blk_log_split(struct trace_seq *s, const struct trace_entry *ent) | |
1079 | { | |
1080 | return trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent), | |
1081 | get_pdu_int(ent), trace_find_cmdline(ent->pid)); | |
1082 | } | |
1083 | ||
1084 | /* | |
1085 | * struct tracer operations | |
1086 | */ | |
1087 | ||
1088 | static void blk_tracer_print_header(struct seq_file *m) | |
1089 | { | |
1090 | if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC)) | |
1091 | return; | |
1092 | seq_puts(m, "# DEV CPU TIMESTAMP PID ACT FLG\n" | |
1093 | "# | | | | | |\n"); | |
1094 | } | |
1095 | ||
1096 | static void blk_tracer_start(struct trace_array *tr) | |
1097 | { | |
700a3dcb | 1098 | tracing_reset_online_cpus(tr); |
c71a8961 ACM |
1099 | |
1100 | mutex_lock(&blk_probe_mutex); | |
1101 | if (atomic_add_return(1, &blk_probes_ref) == 1) | |
1102 | if (blk_register_tracepoints()) | |
1103 | atomic_dec(&blk_probes_ref); | |
1104 | mutex_unlock(&blk_probe_mutex); | |
08a06b83 | 1105 | trace_flags &= ~TRACE_ITER_CONTEXT_INFO; |
c71a8961 ACM |
1106 | } |
1107 | ||
1108 | static int blk_tracer_init(struct trace_array *tr) | |
1109 | { | |
1110 | blk_tr = tr; | |
1111 | blk_tracer_start(tr); | |
1112 | mutex_lock(&blk_probe_mutex); | |
1113 | blk_tracer_enabled++; | |
1114 | mutex_unlock(&blk_probe_mutex); | |
1115 | return 0; | |
1116 | } | |
1117 | ||
1118 | static void blk_tracer_stop(struct trace_array *tr) | |
1119 | { | |
08a06b83 | 1120 | trace_flags |= TRACE_ITER_CONTEXT_INFO; |
c71a8961 ACM |
1121 | mutex_lock(&blk_probe_mutex); |
1122 | if (atomic_dec_and_test(&blk_probes_ref)) | |
1123 | blk_unregister_tracepoints(); | |
1124 | mutex_unlock(&blk_probe_mutex); | |
1125 | } | |
1126 | ||
1127 | static void blk_tracer_reset(struct trace_array *tr) | |
1128 | { | |
1129 | if (!atomic_read(&blk_probes_ref)) | |
1130 | return; | |
1131 | ||
1132 | mutex_lock(&blk_probe_mutex); | |
1133 | blk_tracer_enabled--; | |
1134 | WARN_ON(blk_tracer_enabled < 0); | |
1135 | mutex_unlock(&blk_probe_mutex); | |
1136 | ||
1137 | blk_tracer_stop(tr); | |
1138 | } | |
1139 | ||
1140 | static struct { | |
1141 | const char *act[2]; | |
1142 | int (*print)(struct trace_seq *s, const struct trace_entry *ent); | |
1143 | } what2act[] __read_mostly = { | |
1144 | [__BLK_TA_QUEUE] = {{ "Q", "queue" }, blk_log_generic }, | |
1145 | [__BLK_TA_BACKMERGE] = {{ "M", "backmerge" }, blk_log_generic }, | |
1146 | [__BLK_TA_FRONTMERGE] = {{ "F", "frontmerge" }, blk_log_generic }, | |
1147 | [__BLK_TA_GETRQ] = {{ "G", "getrq" }, blk_log_generic }, | |
1148 | [__BLK_TA_SLEEPRQ] = {{ "S", "sleeprq" }, blk_log_generic }, | |
1149 | [__BLK_TA_REQUEUE] = {{ "R", "requeue" }, blk_log_with_error }, | |
1150 | [__BLK_TA_ISSUE] = {{ "D", "issue" }, blk_log_generic }, | |
1151 | [__BLK_TA_COMPLETE] = {{ "C", "complete" }, blk_log_with_error }, | |
1152 | [__BLK_TA_PLUG] = {{ "P", "plug" }, blk_log_plug }, | |
1153 | [__BLK_TA_UNPLUG_IO] = {{ "U", "unplug_io" }, blk_log_unplug }, | |
1154 | [__BLK_TA_UNPLUG_TIMER] = {{ "UT", "unplug_timer" }, blk_log_unplug }, | |
1155 | [__BLK_TA_INSERT] = {{ "I", "insert" }, blk_log_generic }, | |
1156 | [__BLK_TA_SPLIT] = {{ "X", "split" }, blk_log_split }, | |
1157 | [__BLK_TA_BOUNCE] = {{ "B", "bounce" }, blk_log_generic }, | |
1158 | [__BLK_TA_REMAP] = {{ "A", "remap" }, blk_log_remap }, | |
1159 | }; | |
1160 | ||
ae7462b4 ACM |
1161 | static enum print_line_t blk_trace_event_print(struct trace_iterator *iter, |
1162 | int flags) | |
c71a8961 | 1163 | { |
2c9b238e ACM |
1164 | struct trace_seq *s = &iter->seq; |
1165 | const struct blk_io_trace *t = (struct blk_io_trace *)iter->ent; | |
c71a8961 ACM |
1166 | const u16 what = t->action & ((1 << BLK_TC_SHIFT) - 1); |
1167 | int ret; | |
1168 | ||
d9793bd8 | 1169 | if (!trace_print_context(iter)) |
08a06b83 ACM |
1170 | return TRACE_TYPE_PARTIAL_LINE; |
1171 | ||
c71a8961 ACM |
1172 | if (unlikely(what == 0 || what > ARRAY_SIZE(what2act))) |
1173 | ret = trace_seq_printf(s, "Bad pc action %x\n", what); | |
1174 | else { | |
1175 | const bool long_act = !!(trace_flags & TRACE_ITER_VERBOSE); | |
1176 | ret = blk_log_action_seq(s, t, what2act[what].act[long_act]); | |
1177 | if (ret) | |
2c9b238e | 1178 | ret = what2act[what].print(s, iter->ent); |
c71a8961 ACM |
1179 | } |
1180 | ||
1181 | return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; | |
1182 | } | |
1183 | ||
08a06b83 ACM |
1184 | static int blk_trace_synthesize_old_trace(struct trace_iterator *iter) |
1185 | { | |
1186 | struct trace_seq *s = &iter->seq; | |
1187 | struct blk_io_trace *t = (struct blk_io_trace *)iter->ent; | |
1188 | const int offset = offsetof(struct blk_io_trace, sector); | |
1189 | struct blk_io_trace old = { | |
1190 | .magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION, | |
1191 | .time = ns2usecs(iter->ts), | |
1192 | }; | |
1193 | ||
1194 | if (!trace_seq_putmem(s, &old, offset)) | |
1195 | return 0; | |
1196 | return trace_seq_putmem(s, &t->sector, | |
1197 | sizeof(old) - offset + t->pdu_len); | |
1198 | } | |
1199 | ||
ae7462b4 ACM |
1200 | static enum print_line_t |
1201 | blk_trace_event_print_binary(struct trace_iterator *iter, int flags) | |
08a06b83 ACM |
1202 | { |
1203 | return blk_trace_synthesize_old_trace(iter) ? | |
1204 | TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; | |
1205 | } | |
1206 | ||
c71a8961 ACM |
1207 | static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter) |
1208 | { | |
1209 | const struct blk_io_trace *t; | |
1210 | u16 what; | |
1211 | int ret; | |
1212 | ||
1213 | if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC)) | |
1214 | return TRACE_TYPE_UNHANDLED; | |
1215 | ||
1216 | t = (const struct blk_io_trace *)iter->ent; | |
1217 | what = t->action & ((1 << BLK_TC_SHIFT) - 1); | |
1218 | ||
1219 | if (unlikely(what == 0 || what > ARRAY_SIZE(what2act))) | |
1220 | ret = trace_seq_printf(&iter->seq, "Bad pc action %x\n", what); | |
1221 | else { | |
1222 | const bool long_act = !!(trace_flags & TRACE_ITER_VERBOSE); | |
1223 | ret = blk_log_action_iter(iter, what2act[what].act[long_act]); | |
1224 | if (ret) | |
1225 | ret = what2act[what].print(&iter->seq, iter->ent); | |
1226 | } | |
1227 | ||
1228 | return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; | |
1229 | } | |
1230 | ||
1231 | static struct tracer blk_tracer __read_mostly = { | |
1232 | .name = "blk", | |
1233 | .init = blk_tracer_init, | |
1234 | .reset = blk_tracer_reset, | |
1235 | .start = blk_tracer_start, | |
1236 | .stop = blk_tracer_stop, | |
1237 | .print_header = blk_tracer_print_header, | |
1238 | .print_line = blk_tracer_print_line, | |
1239 | .flags = &blk_tracer_flags, | |
1240 | }; | |
1241 | ||
1242 | static struct trace_event trace_blk_event = { | |
1243 | .type = TRACE_BLK, | |
1244 | .trace = blk_trace_event_print, | |
1245 | .latency_trace = blk_trace_event_print, | |
08a06b83 | 1246 | .binary = blk_trace_event_print_binary, |
c71a8961 ACM |
1247 | }; |
1248 | ||
1249 | static int __init init_blk_tracer(void) | |
1250 | { | |
1251 | if (!register_ftrace_event(&trace_blk_event)) { | |
1252 | pr_warning("Warning: could not register block events\n"); | |
1253 | return 1; | |
1254 | } | |
1255 | ||
1256 | if (register_tracer(&blk_tracer) != 0) { | |
1257 | pr_warning("Warning: could not register the block tracer\n"); | |
1258 | unregister_ftrace_event(&trace_blk_event); | |
1259 | return 1; | |
1260 | } | |
1261 | ||
1262 | return 0; | |
1263 | } | |
1264 | ||
1265 | device_initcall(init_blk_tracer); | |
1266 | ||
1267 | static int blk_trace_remove_queue(struct request_queue *q) | |
1268 | { | |
1269 | struct blk_trace *bt; | |
1270 | ||
1271 | bt = xchg(&q->blk_trace, NULL); | |
1272 | if (bt == NULL) | |
1273 | return -EINVAL; | |
1274 | ||
1275 | kfree(bt); | |
1276 | return 0; | |
1277 | } | |
1278 | ||
1279 | /* | |
1280 | * Setup everything required to start tracing | |
1281 | */ | |
1282 | static int blk_trace_setup_queue(struct request_queue *q, dev_t dev) | |
1283 | { | |
1284 | struct blk_trace *old_bt, *bt = NULL; | |
1285 | int ret; | |
1286 | ||
1287 | ret = -ENOMEM; | |
1288 | bt = kzalloc(sizeof(*bt), GFP_KERNEL); | |
1289 | if (!bt) | |
1290 | goto err; | |
1291 | ||
1292 | bt->dev = dev; | |
1293 | bt->act_mask = (u16)-1; | |
1294 | bt->end_lba = -1ULL; | |
1295 | bt->trace_state = Blktrace_running; | |
1296 | ||
1297 | old_bt = xchg(&q->blk_trace, bt); | |
1298 | if (old_bt != NULL) { | |
1299 | (void)xchg(&q->blk_trace, old_bt); | |
1300 | kfree(bt); | |
1301 | ret = -EBUSY; | |
1302 | } | |
1303 | return 0; | |
1304 | err: | |
1305 | return ret; | |
1306 | } | |
1307 | ||
1308 | /* | |
1309 | * sysfs interface to enable and configure tracing | |
1310 | */ | |
1311 | ||
1312 | static ssize_t sysfs_blk_trace_enable_show(struct device *dev, | |
1313 | struct device_attribute *attr, | |
1314 | char *buf) | |
1315 | { | |
1316 | struct hd_struct *p = dev_to_part(dev); | |
1317 | struct block_device *bdev; | |
1318 | ssize_t ret = -ENXIO; | |
1319 | ||
1320 | lock_kernel(); | |
1321 | bdev = bdget(part_devt(p)); | |
1322 | if (bdev != NULL) { | |
1323 | struct request_queue *q = bdev_get_queue(bdev); | |
1324 | ||
1325 | if (q != NULL) { | |
1326 | mutex_lock(&bdev->bd_mutex); | |
1327 | ret = sprintf(buf, "%u\n", !!q->blk_trace); | |
1328 | mutex_unlock(&bdev->bd_mutex); | |
1329 | } | |
1330 | ||
1331 | bdput(bdev); | |
1332 | } | |
1333 | ||
1334 | unlock_kernel(); | |
1335 | return ret; | |
1336 | } | |
1337 | ||
1338 | static ssize_t sysfs_blk_trace_enable_store(struct device *dev, | |
1339 | struct device_attribute *attr, | |
1340 | const char *buf, size_t count) | |
1341 | { | |
1342 | struct block_device *bdev; | |
1343 | struct request_queue *q; | |
1344 | struct hd_struct *p; | |
1345 | int value; | |
1346 | ssize_t ret = -ENXIO; | |
1347 | ||
1348 | if (count == 0 || sscanf(buf, "%d", &value) != 1) | |
1349 | goto out; | |
1350 | ||
1351 | lock_kernel(); | |
1352 | p = dev_to_part(dev); | |
1353 | bdev = bdget(part_devt(p)); | |
1354 | if (bdev == NULL) | |
1355 | goto out_unlock_kernel; | |
1356 | ||
1357 | q = bdev_get_queue(bdev); | |
1358 | if (q == NULL) | |
1359 | goto out_bdput; | |
1360 | ||
1361 | mutex_lock(&bdev->bd_mutex); | |
1362 | if (value) | |
1363 | ret = blk_trace_setup_queue(q, bdev->bd_dev); | |
1364 | else | |
1365 | ret = blk_trace_remove_queue(q); | |
1366 | mutex_unlock(&bdev->bd_mutex); | |
1367 | ||
1368 | if (ret == 0) | |
1369 | ret = count; | |
1370 | out_bdput: | |
1371 | bdput(bdev); | |
1372 | out_unlock_kernel: | |
1373 | unlock_kernel(); | |
1374 | out: | |
1375 | return ret; | |
1376 | } | |
1377 | ||
1378 | static ssize_t sysfs_blk_trace_attr_show(struct device *dev, | |
1379 | struct device_attribute *attr, | |
1380 | char *buf); | |
1381 | static ssize_t sysfs_blk_trace_attr_store(struct device *dev, | |
1382 | struct device_attribute *attr, | |
1383 | const char *buf, size_t count); | |
1384 | #define BLK_TRACE_DEVICE_ATTR(_name) \ | |
1385 | DEVICE_ATTR(_name, S_IRUGO | S_IWUSR, \ | |
1386 | sysfs_blk_trace_attr_show, \ | |
1387 | sysfs_blk_trace_attr_store) | |
1388 | ||
1389 | static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, | |
1390 | sysfs_blk_trace_enable_show, sysfs_blk_trace_enable_store); | |
1391 | static BLK_TRACE_DEVICE_ATTR(act_mask); | |
1392 | static BLK_TRACE_DEVICE_ATTR(pid); | |
1393 | static BLK_TRACE_DEVICE_ATTR(start_lba); | |
1394 | static BLK_TRACE_DEVICE_ATTR(end_lba); | |
1395 | ||
1396 | static struct attribute *blk_trace_attrs[] = { | |
1397 | &dev_attr_enable.attr, | |
1398 | &dev_attr_act_mask.attr, | |
1399 | &dev_attr_pid.attr, | |
1400 | &dev_attr_start_lba.attr, | |
1401 | &dev_attr_end_lba.attr, | |
1402 | NULL | |
1403 | }; | |
1404 | ||
1405 | struct attribute_group blk_trace_attr_group = { | |
1406 | .name = "trace", | |
1407 | .attrs = blk_trace_attrs, | |
1408 | }; | |
1409 | ||
1410 | static int blk_str2act_mask(const char *str) | |
1411 | { | |
1412 | int mask = 0; | |
1413 | char *copy = kstrdup(str, GFP_KERNEL), *s; | |
1414 | ||
1415 | if (copy == NULL) | |
1416 | return -ENOMEM; | |
1417 | ||
1418 | s = strstrip(copy); | |
1419 | ||
1420 | while (1) { | |
1421 | char *sep = strchr(s, ','); | |
1422 | ||
1423 | if (sep != NULL) | |
1424 | *sep = '\0'; | |
1425 | ||
1426 | if (strcasecmp(s, "barrier") == 0) | |
1427 | mask |= BLK_TC_BARRIER; | |
1428 | else if (strcasecmp(s, "complete") == 0) | |
1429 | mask |= BLK_TC_COMPLETE; | |
1430 | else if (strcasecmp(s, "fs") == 0) | |
1431 | mask |= BLK_TC_FS; | |
1432 | else if (strcasecmp(s, "issue") == 0) | |
1433 | mask |= BLK_TC_ISSUE; | |
1434 | else if (strcasecmp(s, "pc") == 0) | |
1435 | mask |= BLK_TC_PC; | |
1436 | else if (strcasecmp(s, "queue") == 0) | |
1437 | mask |= BLK_TC_QUEUE; | |
1438 | else if (strcasecmp(s, "read") == 0) | |
1439 | mask |= BLK_TC_READ; | |
1440 | else if (strcasecmp(s, "requeue") == 0) | |
1441 | mask |= BLK_TC_REQUEUE; | |
1442 | else if (strcasecmp(s, "sync") == 0) | |
1443 | mask |= BLK_TC_SYNC; | |
1444 | else if (strcasecmp(s, "write") == 0) | |
1445 | mask |= BLK_TC_WRITE; | |
1446 | ||
1447 | if (sep == NULL) | |
1448 | break; | |
1449 | ||
1450 | s = sep + 1; | |
1451 | } | |
1452 | kfree(copy); | |
1453 | ||
1454 | return mask; | |
1455 | } | |
1456 | ||
1457 | static ssize_t sysfs_blk_trace_attr_show(struct device *dev, | |
1458 | struct device_attribute *attr, | |
1459 | char *buf) | |
1460 | { | |
1461 | struct hd_struct *p = dev_to_part(dev); | |
1462 | struct request_queue *q; | |
1463 | struct block_device *bdev; | |
1464 | ssize_t ret = -ENXIO; | |
1465 | ||
1466 | lock_kernel(); | |
1467 | bdev = bdget(part_devt(p)); | |
1468 | if (bdev == NULL) | |
1469 | goto out_unlock_kernel; | |
1470 | ||
1471 | q = bdev_get_queue(bdev); | |
1472 | if (q == NULL) | |
1473 | goto out_bdput; | |
1474 | mutex_lock(&bdev->bd_mutex); | |
1475 | if (q->blk_trace == NULL) | |
1476 | ret = sprintf(buf, "disabled\n"); | |
1477 | else if (attr == &dev_attr_act_mask) | |
1478 | ret = sprintf(buf, "%#x\n", q->blk_trace->act_mask); | |
1479 | else if (attr == &dev_attr_pid) | |
1480 | ret = sprintf(buf, "%u\n", q->blk_trace->pid); | |
1481 | else if (attr == &dev_attr_start_lba) | |
1482 | ret = sprintf(buf, "%llu\n", q->blk_trace->start_lba); | |
1483 | else if (attr == &dev_attr_end_lba) | |
1484 | ret = sprintf(buf, "%llu\n", q->blk_trace->end_lba); | |
1485 | mutex_unlock(&bdev->bd_mutex); | |
1486 | out_bdput: | |
1487 | bdput(bdev); | |
1488 | out_unlock_kernel: | |
1489 | unlock_kernel(); | |
1490 | return ret; | |
1491 | } | |
1492 | ||
1493 | static ssize_t sysfs_blk_trace_attr_store(struct device *dev, | |
1494 | struct device_attribute *attr, | |
1495 | const char *buf, size_t count) | |
1496 | { | |
1497 | struct block_device *bdev; | |
1498 | struct request_queue *q; | |
1499 | struct hd_struct *p; | |
1500 | u64 value; | |
1501 | ssize_t ret = -ENXIO; | |
1502 | ||
1503 | if (count == 0) | |
1504 | goto out; | |
1505 | ||
1506 | if (attr == &dev_attr_act_mask) { | |
1507 | if (sscanf(buf, "%llx", &value) != 1) { | |
1508 | /* Assume it is a list of trace category names */ | |
1509 | value = blk_str2act_mask(buf); | |
1510 | if (value < 0) | |
1511 | goto out; | |
1512 | } | |
1513 | } else if (sscanf(buf, "%llu", &value) != 1) | |
1514 | goto out; | |
1515 | ||
1516 | lock_kernel(); | |
1517 | p = dev_to_part(dev); | |
1518 | bdev = bdget(part_devt(p)); | |
1519 | if (bdev == NULL) | |
1520 | goto out_unlock_kernel; | |
1521 | ||
1522 | q = bdev_get_queue(bdev); | |
1523 | if (q == NULL) | |
1524 | goto out_bdput; | |
1525 | ||
1526 | mutex_lock(&bdev->bd_mutex); | |
1527 | ret = 0; | |
1528 | if (q->blk_trace == NULL) | |
1529 | ret = blk_trace_setup_queue(q, bdev->bd_dev); | |
1530 | ||
1531 | if (ret == 0) { | |
1532 | if (attr == &dev_attr_act_mask) | |
1533 | q->blk_trace->act_mask = value; | |
1534 | else if (attr == &dev_attr_pid) | |
1535 | q->blk_trace->pid = value; | |
1536 | else if (attr == &dev_attr_start_lba) | |
1537 | q->blk_trace->start_lba = value; | |
1538 | else if (attr == &dev_attr_end_lba) | |
1539 | q->blk_trace->end_lba = value; | |
1540 | ret = count; | |
1541 | } | |
1542 | mutex_unlock(&bdev->bd_mutex); | |
1543 | out_bdput: | |
1544 | bdput(bdev); | |
1545 | out_unlock_kernel: | |
1546 | unlock_kernel(); | |
1547 | out: | |
1548 | return ret; | |
1549 | } |