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Commit | Line | Data |
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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> |
2db270a8 | 28 | #include "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 */ | |
ef18012b | 36 | #define TRACE_BLK_OPT_CLASSIC 0x1 |
c71a8961 ACM |
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 | 167 | struct blk_io_trace *t; |
0a987751 | 168 | unsigned long flags = 0; |
2056a782 JA |
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 | 178 | what |= MASK_TC_BIT(rw, BARRIER); |
93dbb393 | 179 | what |= MASK_TC_BIT(rw, SYNCIO); |
35ba8f70 DW |
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) { | |
c71a8961 ACM |
190 | tracing_record_cmdline(current); |
191 | ||
51a763dd ACM |
192 | pc = preempt_count(); |
193 | event = trace_buffer_lock_reserve(blk_tr, TRACE_BLK, | |
194 | sizeof(*t) + pdu_len, | |
195 | 0, pc); | |
c71a8961 ACM |
196 | if (!event) |
197 | return; | |
51a763dd | 198 | t = ring_buffer_event_data(event); |
c71a8961 ACM |
199 | goto record_it; |
200 | } | |
2056a782 JA |
201 | |
202 | /* | |
203 | * A word about the locking here - we disable interrupts to reserve | |
204 | * some space in the relay per-cpu buffer, to prevent an irq | |
14a73f54 | 205 | * from coming in and stepping on our toes. |
2056a782 JA |
206 | */ |
207 | local_irq_save(flags); | |
208 | ||
209 | if (unlikely(tsk->btrace_seq != blktrace_seq)) | |
210 | trace_note_tsk(bt, tsk); | |
211 | ||
212 | t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len); | |
213 | if (t) { | |
2056a782 JA |
214 | sequence = per_cpu_ptr(bt->sequence, cpu); |
215 | ||
216 | t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; | |
217 | t->sequence = ++(*sequence); | |
2997c8c4 | 218 | t->time = ktime_to_ns(ktime_get()); |
c71a8961 | 219 | record_it: |
08a06b83 | 220 | /* |
939b3669 ACM |
221 | * These two are not needed in ftrace as they are in the |
222 | * generic trace_entry, filled by tracing_generic_entry_update, | |
223 | * but for the trace_event->bin() synthesizer benefit we do it | |
224 | * here too. | |
225 | */ | |
226 | t->cpu = cpu; | |
227 | t->pid = pid; | |
08a06b83 | 228 | |
2056a782 JA |
229 | t->sector = sector; |
230 | t->bytes = bytes; | |
231 | t->action = what; | |
2056a782 | 232 | t->device = bt->dev; |
2056a782 JA |
233 | t->error = error; |
234 | t->pdu_len = pdu_len; | |
235 | ||
236 | if (pdu_len) | |
237 | memcpy((void *) t + sizeof(*t), pdu_data, pdu_len); | |
c71a8961 ACM |
238 | |
239 | if (blk_tr) { | |
51a763dd | 240 | trace_buffer_unlock_commit(blk_tr, event, 0, pc); |
c71a8961 ACM |
241 | return; |
242 | } | |
2056a782 JA |
243 | } |
244 | ||
245 | local_irq_restore(flags); | |
246 | } | |
247 | ||
2056a782 | 248 | static struct dentry *blk_tree_root; |
11a57153 | 249 | static DEFINE_MUTEX(blk_tree_mutex); |
2056a782 JA |
250 | |
251 | static void blk_trace_cleanup(struct blk_trace *bt) | |
252 | { | |
02c62304 | 253 | debugfs_remove(bt->msg_file); |
2056a782 | 254 | debugfs_remove(bt->dropped_file); |
f48fc4d3 | 255 | relay_close(bt->rchan); |
2056a782 | 256 | free_percpu(bt->sequence); |
64565911 | 257 | free_percpu(bt->msg_data); |
2056a782 | 258 | kfree(bt); |
5f3ea37c ACM |
259 | mutex_lock(&blk_probe_mutex); |
260 | if (atomic_dec_and_test(&blk_probes_ref)) | |
261 | blk_unregister_tracepoints(); | |
262 | mutex_unlock(&blk_probe_mutex); | |
2056a782 JA |
263 | } |
264 | ||
6da127ad | 265 | int blk_trace_remove(struct request_queue *q) |
2056a782 JA |
266 | { |
267 | struct blk_trace *bt; | |
268 | ||
269 | bt = xchg(&q->blk_trace, NULL); | |
270 | if (!bt) | |
271 | return -EINVAL; | |
272 | ||
273 | if (bt->trace_state == Blktrace_setup || | |
274 | bt->trace_state == Blktrace_stopped) | |
275 | blk_trace_cleanup(bt); | |
276 | ||
277 | return 0; | |
278 | } | |
6da127ad | 279 | EXPORT_SYMBOL_GPL(blk_trace_remove); |
2056a782 JA |
280 | |
281 | static int blk_dropped_open(struct inode *inode, struct file *filp) | |
282 | { | |
8e18e294 | 283 | filp->private_data = inode->i_private; |
2056a782 JA |
284 | |
285 | return 0; | |
286 | } | |
287 | ||
288 | static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, | |
289 | size_t count, loff_t *ppos) | |
290 | { | |
291 | struct blk_trace *bt = filp->private_data; | |
292 | char buf[16]; | |
293 | ||
294 | snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped)); | |
295 | ||
296 | return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf)); | |
297 | } | |
298 | ||
2b8693c0 | 299 | static const struct file_operations blk_dropped_fops = { |
2056a782 JA |
300 | .owner = THIS_MODULE, |
301 | .open = blk_dropped_open, | |
302 | .read = blk_dropped_read, | |
303 | }; | |
304 | ||
02c62304 AB |
305 | static int blk_msg_open(struct inode *inode, struct file *filp) |
306 | { | |
307 | filp->private_data = inode->i_private; | |
308 | ||
309 | return 0; | |
310 | } | |
311 | ||
312 | static ssize_t blk_msg_write(struct file *filp, const char __user *buffer, | |
313 | size_t count, loff_t *ppos) | |
314 | { | |
315 | char *msg; | |
316 | struct blk_trace *bt; | |
317 | ||
318 | if (count > BLK_TN_MAX_MSG) | |
319 | return -EINVAL; | |
320 | ||
321 | msg = kmalloc(count, GFP_KERNEL); | |
322 | if (msg == NULL) | |
323 | return -ENOMEM; | |
324 | ||
325 | if (copy_from_user(msg, buffer, count)) { | |
326 | kfree(msg); | |
327 | return -EFAULT; | |
328 | } | |
329 | ||
330 | bt = filp->private_data; | |
331 | __trace_note_message(bt, "%s", msg); | |
332 | kfree(msg); | |
333 | ||
334 | return count; | |
335 | } | |
336 | ||
337 | static const struct file_operations blk_msg_fops = { | |
338 | .owner = THIS_MODULE, | |
339 | .open = blk_msg_open, | |
340 | .write = blk_msg_write, | |
341 | }; | |
342 | ||
2056a782 JA |
343 | /* |
344 | * Keep track of how many times we encountered a full subbuffer, to aid | |
345 | * the user space app in telling how many lost events there were. | |
346 | */ | |
347 | static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf, | |
348 | void *prev_subbuf, size_t prev_padding) | |
349 | { | |
350 | struct blk_trace *bt; | |
351 | ||
352 | if (!relay_buf_full(buf)) | |
353 | return 1; | |
354 | ||
355 | bt = buf->chan->private_data; | |
356 | atomic_inc(&bt->dropped); | |
357 | return 0; | |
358 | } | |
359 | ||
360 | static int blk_remove_buf_file_callback(struct dentry *dentry) | |
361 | { | |
f48fc4d3 | 362 | struct dentry *parent = dentry->d_parent; |
2056a782 | 363 | debugfs_remove(dentry); |
f48fc4d3 JA |
364 | |
365 | /* | |
366 | * this will fail for all but the last file, but that is ok. what we | |
367 | * care about is the top level buts->name directory going away, when | |
368 | * the last trace file is gone. Then we don't have to rmdir() that | |
369 | * manually on trace stop, so it nicely solves the issue with | |
370 | * force killing of running traces. | |
371 | */ | |
372 | ||
373 | debugfs_remove(parent); | |
2056a782 JA |
374 | return 0; |
375 | } | |
376 | ||
377 | static struct dentry *blk_create_buf_file_callback(const char *filename, | |
378 | struct dentry *parent, | |
379 | int mode, | |
380 | struct rchan_buf *buf, | |
381 | int *is_global) | |
382 | { | |
383 | return debugfs_create_file(filename, mode, parent, buf, | |
384 | &relay_file_operations); | |
385 | } | |
386 | ||
387 | static struct rchan_callbacks blk_relay_callbacks = { | |
388 | .subbuf_start = blk_subbuf_start_callback, | |
389 | .create_buf_file = blk_create_buf_file_callback, | |
390 | .remove_buf_file = blk_remove_buf_file_callback, | |
391 | }; | |
392 | ||
393 | /* | |
394 | * Setup everything required to start tracing | |
395 | */ | |
6da127ad | 396 | int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, |
171044d4 | 397 | struct blk_user_trace_setup *buts) |
2056a782 | 398 | { |
2056a782 JA |
399 | struct blk_trace *old_bt, *bt = NULL; |
400 | struct dentry *dir = NULL; | |
2056a782 JA |
401 | int ret, i; |
402 | ||
171044d4 | 403 | if (!buts->buf_size || !buts->buf_nr) |
2056a782 JA |
404 | return -EINVAL; |
405 | ||
0497b345 JA |
406 | strncpy(buts->name, name, BLKTRACE_BDEV_SIZE); |
407 | buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0'; | |
2056a782 JA |
408 | |
409 | /* | |
410 | * some device names have larger paths - convert the slashes | |
411 | * to underscores for this to work as expected | |
412 | */ | |
171044d4 AB |
413 | for (i = 0; i < strlen(buts->name); i++) |
414 | if (buts->name[i] == '/') | |
415 | buts->name[i] = '_'; | |
2056a782 JA |
416 | |
417 | ret = -ENOMEM; | |
418 | bt = kzalloc(sizeof(*bt), GFP_KERNEL); | |
419 | if (!bt) | |
420 | goto err; | |
421 | ||
422 | bt->sequence = alloc_percpu(unsigned long); | |
423 | if (!bt->sequence) | |
424 | goto err; | |
425 | ||
313e458f | 426 | bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char)); |
64565911 JA |
427 | if (!bt->msg_data) |
428 | goto err; | |
429 | ||
2056a782 | 430 | ret = -ENOENT; |
f48fc4d3 JA |
431 | |
432 | if (!blk_tree_root) { | |
433 | blk_tree_root = debugfs_create_dir("block", NULL); | |
434 | if (!blk_tree_root) | |
435 | return -ENOMEM; | |
436 | } | |
437 | ||
438 | dir = debugfs_create_dir(buts->name, blk_tree_root); | |
439 | ||
2056a782 JA |
440 | if (!dir) |
441 | goto err; | |
442 | ||
443 | bt->dir = dir; | |
6da127ad | 444 | bt->dev = dev; |
2056a782 JA |
445 | atomic_set(&bt->dropped, 0); |
446 | ||
447 | ret = -EIO; | |
939b3669 ACM |
448 | bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, |
449 | &blk_dropped_fops); | |
2056a782 JA |
450 | if (!bt->dropped_file) |
451 | goto err; | |
452 | ||
02c62304 AB |
453 | bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops); |
454 | if (!bt->msg_file) | |
455 | goto err; | |
456 | ||
171044d4 AB |
457 | bt->rchan = relay_open("trace", dir, buts->buf_size, |
458 | buts->buf_nr, &blk_relay_callbacks, bt); | |
2056a782 JA |
459 | if (!bt->rchan) |
460 | goto err; | |
2056a782 | 461 | |
171044d4 | 462 | bt->act_mask = buts->act_mask; |
2056a782 JA |
463 | if (!bt->act_mask) |
464 | bt->act_mask = (u16) -1; | |
465 | ||
171044d4 AB |
466 | bt->start_lba = buts->start_lba; |
467 | bt->end_lba = buts->end_lba; | |
2056a782 JA |
468 | if (!bt->end_lba) |
469 | bt->end_lba = -1ULL; | |
470 | ||
171044d4 | 471 | bt->pid = buts->pid; |
2056a782 JA |
472 | bt->trace_state = Blktrace_setup; |
473 | ||
5f3ea37c ACM |
474 | mutex_lock(&blk_probe_mutex); |
475 | if (atomic_add_return(1, &blk_probes_ref) == 1) { | |
476 | ret = blk_register_tracepoints(); | |
477 | if (ret) | |
478 | goto probe_err; | |
479 | } | |
480 | mutex_unlock(&blk_probe_mutex); | |
481 | ||
2056a782 JA |
482 | ret = -EBUSY; |
483 | old_bt = xchg(&q->blk_trace, bt); | |
484 | if (old_bt) { | |
485 | (void) xchg(&q->blk_trace, old_bt); | |
486 | goto err; | |
487 | } | |
488 | ||
489 | return 0; | |
5f3ea37c ACM |
490 | probe_err: |
491 | atomic_dec(&blk_probes_ref); | |
492 | mutex_unlock(&blk_probe_mutex); | |
2056a782 | 493 | err: |
2056a782 | 494 | if (bt) { |
02c62304 AB |
495 | if (bt->msg_file) |
496 | debugfs_remove(bt->msg_file); | |
2056a782 JA |
497 | if (bt->dropped_file) |
498 | debugfs_remove(bt->dropped_file); | |
a1205868 | 499 | free_percpu(bt->sequence); |
64565911 | 500 | free_percpu(bt->msg_data); |
2056a782 JA |
501 | if (bt->rchan) |
502 | relay_close(bt->rchan); | |
503 | kfree(bt); | |
504 | } | |
505 | return ret; | |
506 | } | |
171044d4 | 507 | |
6da127ad CS |
508 | int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, |
509 | char __user *arg) | |
171044d4 AB |
510 | { |
511 | struct blk_user_trace_setup buts; | |
512 | int ret; | |
513 | ||
514 | ret = copy_from_user(&buts, arg, sizeof(buts)); | |
515 | if (ret) | |
516 | return -EFAULT; | |
517 | ||
6da127ad | 518 | ret = do_blk_trace_setup(q, name, dev, &buts); |
171044d4 AB |
519 | if (ret) |
520 | return ret; | |
521 | ||
522 | if (copy_to_user(arg, &buts, sizeof(buts))) | |
523 | return -EFAULT; | |
524 | ||
525 | return 0; | |
526 | } | |
6da127ad | 527 | EXPORT_SYMBOL_GPL(blk_trace_setup); |
2056a782 | 528 | |
6da127ad | 529 | int blk_trace_startstop(struct request_queue *q, int start) |
2056a782 | 530 | { |
2056a782 | 531 | int ret; |
939b3669 | 532 | struct blk_trace *bt = q->blk_trace; |
2056a782 | 533 | |
939b3669 | 534 | if (bt == NULL) |
2056a782 JA |
535 | return -EINVAL; |
536 | ||
537 | /* | |
538 | * For starting a trace, we can transition from a setup or stopped | |
539 | * trace. For stopping a trace, the state must be running | |
540 | */ | |
541 | ret = -EINVAL; | |
542 | if (start) { | |
543 | if (bt->trace_state == Blktrace_setup || | |
544 | bt->trace_state == Blktrace_stopped) { | |
545 | blktrace_seq++; | |
546 | smp_mb(); | |
547 | bt->trace_state = Blktrace_running; | |
be1c6341 OK |
548 | |
549 | trace_note_time(bt); | |
2056a782 JA |
550 | ret = 0; |
551 | } | |
552 | } else { | |
553 | if (bt->trace_state == Blktrace_running) { | |
554 | bt->trace_state = Blktrace_stopped; | |
555 | relay_flush(bt->rchan); | |
556 | ret = 0; | |
557 | } | |
558 | } | |
559 | ||
560 | return ret; | |
561 | } | |
6da127ad | 562 | EXPORT_SYMBOL_GPL(blk_trace_startstop); |
2056a782 JA |
563 | |
564 | /** | |
565 | * blk_trace_ioctl: - handle the ioctls associated with tracing | |
566 | * @bdev: the block device | |
ef18012b | 567 | * @cmd: the ioctl cmd |
2056a782 JA |
568 | * @arg: the argument data, if any |
569 | * | |
570 | **/ | |
571 | int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) | |
572 | { | |
165125e1 | 573 | struct request_queue *q; |
2056a782 | 574 | int ret, start = 0; |
6da127ad | 575 | char b[BDEVNAME_SIZE]; |
2056a782 JA |
576 | |
577 | q = bdev_get_queue(bdev); | |
578 | if (!q) | |
579 | return -ENXIO; | |
580 | ||
581 | mutex_lock(&bdev->bd_mutex); | |
582 | ||
583 | switch (cmd) { | |
584 | case BLKTRACESETUP: | |
f36f21ec | 585 | bdevname(bdev, b); |
6da127ad | 586 | ret = blk_trace_setup(q, b, bdev->bd_dev, arg); |
2056a782 JA |
587 | break; |
588 | case BLKTRACESTART: | |
589 | start = 1; | |
590 | case BLKTRACESTOP: | |
591 | ret = blk_trace_startstop(q, start); | |
592 | break; | |
593 | case BLKTRACETEARDOWN: | |
594 | ret = blk_trace_remove(q); | |
595 | break; | |
596 | default: | |
597 | ret = -ENOTTY; | |
598 | break; | |
599 | } | |
600 | ||
601 | mutex_unlock(&bdev->bd_mutex); | |
602 | return ret; | |
603 | } | |
604 | ||
605 | /** | |
606 | * blk_trace_shutdown: - stop and cleanup trace structures | |
607 | * @q: the request queue associated with the device | |
608 | * | |
609 | **/ | |
165125e1 | 610 | void blk_trace_shutdown(struct request_queue *q) |
2056a782 | 611 | { |
6c5c9341 AD |
612 | if (q->blk_trace) { |
613 | blk_trace_startstop(q, 0); | |
614 | blk_trace_remove(q); | |
615 | } | |
2056a782 | 616 | } |
5f3ea37c ACM |
617 | |
618 | /* | |
619 | * blktrace probes | |
620 | */ | |
621 | ||
622 | /** | |
623 | * blk_add_trace_rq - Add a trace for a request oriented action | |
624 | * @q: queue the io is for | |
625 | * @rq: the source request | |
626 | * @what: the action | |
627 | * | |
628 | * Description: | |
629 | * Records an action against a request. Will log the bio offset + size. | |
630 | * | |
631 | **/ | |
632 | static void blk_add_trace_rq(struct request_queue *q, struct request *rq, | |
633 | u32 what) | |
634 | { | |
635 | struct blk_trace *bt = q->blk_trace; | |
636 | int rw = rq->cmd_flags & 0x03; | |
637 | ||
638 | if (likely(!bt)) | |
639 | return; | |
640 | ||
641 | if (blk_discard_rq(rq)) | |
642 | rw |= (1 << BIO_RW_DISCARD); | |
643 | ||
644 | if (blk_pc_request(rq)) { | |
645 | what |= BLK_TC_ACT(BLK_TC_PC); | |
646 | __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, | |
647 | sizeof(rq->cmd), rq->cmd); | |
648 | } else { | |
649 | what |= BLK_TC_ACT(BLK_TC_FS); | |
650 | __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, | |
651 | rw, what, rq->errors, 0, NULL); | |
652 | } | |
653 | } | |
654 | ||
655 | static void blk_add_trace_rq_abort(struct request_queue *q, struct request *rq) | |
656 | { | |
657 | blk_add_trace_rq(q, rq, BLK_TA_ABORT); | |
658 | } | |
659 | ||
660 | static void blk_add_trace_rq_insert(struct request_queue *q, struct request *rq) | |
661 | { | |
662 | blk_add_trace_rq(q, rq, BLK_TA_INSERT); | |
663 | } | |
664 | ||
665 | static void blk_add_trace_rq_issue(struct request_queue *q, struct request *rq) | |
666 | { | |
667 | blk_add_trace_rq(q, rq, BLK_TA_ISSUE); | |
668 | } | |
669 | ||
939b3669 ACM |
670 | static void blk_add_trace_rq_requeue(struct request_queue *q, |
671 | struct request *rq) | |
5f3ea37c ACM |
672 | { |
673 | blk_add_trace_rq(q, rq, BLK_TA_REQUEUE); | |
674 | } | |
675 | ||
939b3669 ACM |
676 | static void blk_add_trace_rq_complete(struct request_queue *q, |
677 | struct request *rq) | |
5f3ea37c ACM |
678 | { |
679 | blk_add_trace_rq(q, rq, BLK_TA_COMPLETE); | |
680 | } | |
681 | ||
682 | /** | |
683 | * blk_add_trace_bio - Add a trace for a bio oriented action | |
684 | * @q: queue the io is for | |
685 | * @bio: the source bio | |
686 | * @what: the action | |
687 | * | |
688 | * Description: | |
689 | * Records an action against a bio. Will log the bio offset + size. | |
690 | * | |
691 | **/ | |
692 | static void blk_add_trace_bio(struct request_queue *q, struct bio *bio, | |
693 | u32 what) | |
694 | { | |
695 | struct blk_trace *bt = q->blk_trace; | |
696 | ||
697 | if (likely(!bt)) | |
698 | return; | |
699 | ||
700 | __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, | |
701 | !bio_flagged(bio, BIO_UPTODATE), 0, NULL); | |
702 | } | |
703 | ||
704 | static void blk_add_trace_bio_bounce(struct request_queue *q, struct bio *bio) | |
705 | { | |
706 | blk_add_trace_bio(q, bio, BLK_TA_BOUNCE); | |
707 | } | |
708 | ||
709 | static void blk_add_trace_bio_complete(struct request_queue *q, struct bio *bio) | |
710 | { | |
711 | blk_add_trace_bio(q, bio, BLK_TA_COMPLETE); | |
712 | } | |
713 | ||
939b3669 ACM |
714 | static void blk_add_trace_bio_backmerge(struct request_queue *q, |
715 | struct bio *bio) | |
5f3ea37c ACM |
716 | { |
717 | blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE); | |
718 | } | |
719 | ||
939b3669 ACM |
720 | static void blk_add_trace_bio_frontmerge(struct request_queue *q, |
721 | struct bio *bio) | |
5f3ea37c ACM |
722 | { |
723 | blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE); | |
724 | } | |
725 | ||
726 | static void blk_add_trace_bio_queue(struct request_queue *q, struct bio *bio) | |
727 | { | |
728 | blk_add_trace_bio(q, bio, BLK_TA_QUEUE); | |
729 | } | |
730 | ||
939b3669 ACM |
731 | static void blk_add_trace_getrq(struct request_queue *q, |
732 | struct bio *bio, int rw) | |
5f3ea37c ACM |
733 | { |
734 | if (bio) | |
735 | blk_add_trace_bio(q, bio, BLK_TA_GETRQ); | |
736 | else { | |
737 | struct blk_trace *bt = q->blk_trace; | |
738 | ||
739 | if (bt) | |
740 | __blk_add_trace(bt, 0, 0, rw, BLK_TA_GETRQ, 0, 0, NULL); | |
741 | } | |
742 | } | |
743 | ||
744 | ||
939b3669 ACM |
745 | static void blk_add_trace_sleeprq(struct request_queue *q, |
746 | struct bio *bio, int rw) | |
5f3ea37c ACM |
747 | { |
748 | if (bio) | |
749 | blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ); | |
750 | else { | |
751 | struct blk_trace *bt = q->blk_trace; | |
752 | ||
753 | if (bt) | |
939b3669 ACM |
754 | __blk_add_trace(bt, 0, 0, rw, BLK_TA_SLEEPRQ, |
755 | 0, 0, NULL); | |
5f3ea37c ACM |
756 | } |
757 | } | |
758 | ||
759 | static void blk_add_trace_plug(struct request_queue *q) | |
760 | { | |
761 | struct blk_trace *bt = q->blk_trace; | |
762 | ||
763 | if (bt) | |
764 | __blk_add_trace(bt, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL); | |
765 | } | |
766 | ||
767 | static void blk_add_trace_unplug_io(struct request_queue *q) | |
768 | { | |
769 | struct blk_trace *bt = q->blk_trace; | |
770 | ||
771 | if (bt) { | |
772 | unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE]; | |
773 | __be64 rpdu = cpu_to_be64(pdu); | |
774 | ||
775 | __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_IO, 0, | |
776 | sizeof(rpdu), &rpdu); | |
777 | } | |
778 | } | |
779 | ||
780 | static void blk_add_trace_unplug_timer(struct request_queue *q) | |
781 | { | |
782 | struct blk_trace *bt = q->blk_trace; | |
783 | ||
784 | if (bt) { | |
785 | unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE]; | |
786 | __be64 rpdu = cpu_to_be64(pdu); | |
787 | ||
788 | __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_TIMER, 0, | |
789 | sizeof(rpdu), &rpdu); | |
790 | } | |
791 | } | |
792 | ||
793 | static void blk_add_trace_split(struct request_queue *q, struct bio *bio, | |
794 | unsigned int pdu) | |
795 | { | |
796 | struct blk_trace *bt = q->blk_trace; | |
797 | ||
798 | if (bt) { | |
799 | __be64 rpdu = cpu_to_be64(pdu); | |
800 | ||
801 | __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, | |
802 | BLK_TA_SPLIT, !bio_flagged(bio, BIO_UPTODATE), | |
803 | sizeof(rpdu), &rpdu); | |
804 | } | |
805 | } | |
806 | ||
807 | /** | |
808 | * blk_add_trace_remap - Add a trace for a remap operation | |
809 | * @q: queue the io is for | |
810 | * @bio: the source bio | |
811 | * @dev: target device | |
812 | * @from: source sector | |
813 | * @to: target sector | |
814 | * | |
815 | * Description: | |
816 | * Device mapper or raid target sometimes need to split a bio because | |
817 | * it spans a stripe (or similar). Add a trace for that action. | |
818 | * | |
819 | **/ | |
820 | static void blk_add_trace_remap(struct request_queue *q, struct bio *bio, | |
821 | dev_t dev, sector_t from, sector_t to) | |
822 | { | |
823 | struct blk_trace *bt = q->blk_trace; | |
824 | struct blk_io_trace_remap r; | |
825 | ||
826 | if (likely(!bt)) | |
827 | return; | |
828 | ||
829 | r.device = cpu_to_be32(dev); | |
830 | r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev); | |
831 | r.sector = cpu_to_be64(to); | |
832 | ||
833 | __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, | |
834 | !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r); | |
835 | } | |
836 | ||
837 | /** | |
838 | * blk_add_driver_data - Add binary message with driver-specific data | |
839 | * @q: queue the io is for | |
840 | * @rq: io request | |
841 | * @data: driver-specific data | |
842 | * @len: length of driver-specific data | |
843 | * | |
844 | * Description: | |
845 | * Some drivers might want to write driver-specific data per request. | |
846 | * | |
847 | **/ | |
848 | void blk_add_driver_data(struct request_queue *q, | |
849 | struct request *rq, | |
850 | void *data, size_t len) | |
851 | { | |
852 | struct blk_trace *bt = q->blk_trace; | |
853 | ||
854 | if (likely(!bt)) | |
855 | return; | |
856 | ||
857 | if (blk_pc_request(rq)) | |
858 | __blk_add_trace(bt, 0, rq->data_len, 0, BLK_TA_DRV_DATA, | |
859 | rq->errors, len, data); | |
860 | else | |
861 | __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, | |
862 | 0, BLK_TA_DRV_DATA, rq->errors, len, data); | |
863 | } | |
864 | EXPORT_SYMBOL_GPL(blk_add_driver_data); | |
865 | ||
866 | static int blk_register_tracepoints(void) | |
867 | { | |
868 | int ret; | |
869 | ||
870 | ret = register_trace_block_rq_abort(blk_add_trace_rq_abort); | |
871 | WARN_ON(ret); | |
872 | ret = register_trace_block_rq_insert(blk_add_trace_rq_insert); | |
873 | WARN_ON(ret); | |
874 | ret = register_trace_block_rq_issue(blk_add_trace_rq_issue); | |
875 | WARN_ON(ret); | |
876 | ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue); | |
877 | WARN_ON(ret); | |
878 | ret = register_trace_block_rq_complete(blk_add_trace_rq_complete); | |
879 | WARN_ON(ret); | |
880 | ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce); | |
881 | WARN_ON(ret); | |
882 | ret = register_trace_block_bio_complete(blk_add_trace_bio_complete); | |
883 | WARN_ON(ret); | |
884 | ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge); | |
885 | WARN_ON(ret); | |
886 | ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge); | |
887 | WARN_ON(ret); | |
888 | ret = register_trace_block_bio_queue(blk_add_trace_bio_queue); | |
889 | WARN_ON(ret); | |
890 | ret = register_trace_block_getrq(blk_add_trace_getrq); | |
891 | WARN_ON(ret); | |
892 | ret = register_trace_block_sleeprq(blk_add_trace_sleeprq); | |
893 | WARN_ON(ret); | |
894 | ret = register_trace_block_plug(blk_add_trace_plug); | |
895 | WARN_ON(ret); | |
896 | ret = register_trace_block_unplug_timer(blk_add_trace_unplug_timer); | |
897 | WARN_ON(ret); | |
898 | ret = register_trace_block_unplug_io(blk_add_trace_unplug_io); | |
899 | WARN_ON(ret); | |
900 | ret = register_trace_block_split(blk_add_trace_split); | |
901 | WARN_ON(ret); | |
902 | ret = register_trace_block_remap(blk_add_trace_remap); | |
903 | WARN_ON(ret); | |
904 | return 0; | |
905 | } | |
906 | ||
907 | static void blk_unregister_tracepoints(void) | |
908 | { | |
909 | unregister_trace_block_remap(blk_add_trace_remap); | |
910 | unregister_trace_block_split(blk_add_trace_split); | |
911 | unregister_trace_block_unplug_io(blk_add_trace_unplug_io); | |
912 | unregister_trace_block_unplug_timer(blk_add_trace_unplug_timer); | |
913 | unregister_trace_block_plug(blk_add_trace_plug); | |
914 | unregister_trace_block_sleeprq(blk_add_trace_sleeprq); | |
915 | unregister_trace_block_getrq(blk_add_trace_getrq); | |
916 | unregister_trace_block_bio_queue(blk_add_trace_bio_queue); | |
917 | unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge); | |
918 | unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge); | |
919 | unregister_trace_block_bio_complete(blk_add_trace_bio_complete); | |
920 | unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce); | |
921 | unregister_trace_block_rq_complete(blk_add_trace_rq_complete); | |
922 | unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue); | |
923 | unregister_trace_block_rq_issue(blk_add_trace_rq_issue); | |
924 | unregister_trace_block_rq_insert(blk_add_trace_rq_insert); | |
925 | unregister_trace_block_rq_abort(blk_add_trace_rq_abort); | |
926 | ||
927 | tracepoint_synchronize_unregister(); | |
928 | } | |
c71a8961 ACM |
929 | |
930 | /* | |
931 | * struct blk_io_tracer formatting routines | |
932 | */ | |
933 | ||
934 | static void fill_rwbs(char *rwbs, const struct blk_io_trace *t) | |
935 | { | |
157f9c00 ACM |
936 | int i = 0; |
937 | ||
938 | if (t->action & BLK_TC_DISCARD) | |
939 | rwbs[i++] = 'D'; | |
940 | else if (t->action & BLK_TC_WRITE) | |
941 | rwbs[i++] = 'W'; | |
942 | else if (t->bytes) | |
943 | rwbs[i++] = 'R'; | |
944 | else | |
945 | rwbs[i++] = 'N'; | |
946 | ||
947 | if (t->action & BLK_TC_AHEAD) | |
948 | rwbs[i++] = 'A'; | |
949 | if (t->action & BLK_TC_BARRIER) | |
950 | rwbs[i++] = 'B'; | |
951 | if (t->action & BLK_TC_SYNC) | |
952 | rwbs[i++] = 'S'; | |
953 | if (t->action & BLK_TC_META) | |
954 | rwbs[i++] = 'M'; | |
955 | ||
956 | rwbs[i] = '\0'; | |
c71a8961 ACM |
957 | } |
958 | ||
959 | static inline | |
960 | const struct blk_io_trace *te_blk_io_trace(const struct trace_entry *ent) | |
961 | { | |
962 | return (const struct blk_io_trace *)ent; | |
963 | } | |
964 | ||
965 | static inline const void *pdu_start(const struct trace_entry *ent) | |
966 | { | |
967 | return te_blk_io_trace(ent) + 1; | |
968 | } | |
969 | ||
970 | static inline u32 t_sec(const struct trace_entry *ent) | |
971 | { | |
972 | return te_blk_io_trace(ent)->bytes >> 9; | |
973 | } | |
974 | ||
975 | static inline unsigned long long t_sector(const struct trace_entry *ent) | |
976 | { | |
977 | return te_blk_io_trace(ent)->sector; | |
978 | } | |
979 | ||
980 | static inline __u16 t_error(const struct trace_entry *ent) | |
981 | { | |
982 | return te_blk_io_trace(ent)->sector; | |
983 | } | |
984 | ||
985 | static __u64 get_pdu_int(const struct trace_entry *ent) | |
986 | { | |
987 | const __u64 *val = pdu_start(ent); | |
988 | return be64_to_cpu(*val); | |
989 | } | |
990 | ||
991 | static void get_pdu_remap(const struct trace_entry *ent, | |
992 | struct blk_io_trace_remap *r) | |
993 | { | |
994 | const struct blk_io_trace_remap *__r = pdu_start(ent); | |
995 | __u64 sector = __r->sector; | |
996 | ||
997 | r->device = be32_to_cpu(__r->device); | |
998 | r->device_from = be32_to_cpu(__r->device_from); | |
999 | r->sector = be64_to_cpu(sector); | |
1000 | } | |
1001 | ||
1002 | static int blk_log_action_iter(struct trace_iterator *iter, const char *act) | |
1003 | { | |
1004 | char rwbs[6]; | |
1005 | unsigned long long ts = ns2usecs(iter->ts); | |
1006 | unsigned long usec_rem = do_div(ts, USEC_PER_SEC); | |
1007 | unsigned secs = (unsigned long)ts; | |
1008 | const struct trace_entry *ent = iter->ent; | |
1009 | const struct blk_io_trace *t = (const struct blk_io_trace *)ent; | |
1010 | ||
1011 | fill_rwbs(rwbs, t); | |
1012 | ||
1013 | return trace_seq_printf(&iter->seq, | |
1014 | "%3d,%-3d %2d %5d.%06lu %5u %2s %3s ", | |
1015 | MAJOR(t->device), MINOR(t->device), iter->cpu, | |
1016 | secs, usec_rem, ent->pid, act, rwbs); | |
1017 | } | |
1018 | ||
1019 | static int blk_log_action_seq(struct trace_seq *s, const struct blk_io_trace *t, | |
1020 | const char *act) | |
1021 | { | |
1022 | char rwbs[6]; | |
1023 | fill_rwbs(rwbs, t); | |
1024 | return trace_seq_printf(s, "%3d,%-3d %2s %3s ", | |
1025 | MAJOR(t->device), MINOR(t->device), act, rwbs); | |
1026 | } | |
1027 | ||
1028 | static int blk_log_generic(struct trace_seq *s, const struct trace_entry *ent) | |
1029 | { | |
4ca53085 SR |
1030 | char cmd[TASK_COMM_LEN]; |
1031 | ||
1032 | trace_find_cmdline(ent->pid, cmd); | |
c71a8961 ACM |
1033 | |
1034 | if (t_sec(ent)) | |
1035 | return trace_seq_printf(s, "%llu + %u [%s]\n", | |
1036 | t_sector(ent), t_sec(ent), cmd); | |
1037 | return trace_seq_printf(s, "[%s]\n", cmd); | |
1038 | } | |
1039 | ||
157f9c00 ACM |
1040 | static int blk_log_with_error(struct trace_seq *s, |
1041 | const struct trace_entry *ent) | |
c71a8961 ACM |
1042 | { |
1043 | if (t_sec(ent)) | |
1044 | return trace_seq_printf(s, "%llu + %u [%d]\n", t_sector(ent), | |
1045 | t_sec(ent), t_error(ent)); | |
1046 | return trace_seq_printf(s, "%llu [%d]\n", t_sector(ent), t_error(ent)); | |
1047 | } | |
1048 | ||
1049 | static int blk_log_remap(struct trace_seq *s, const struct trace_entry *ent) | |
1050 | { | |
1051 | struct blk_io_trace_remap r = { .device = 0, }; | |
1052 | ||
1053 | get_pdu_remap(ent, &r); | |
1054 | return trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n", | |
1055 | t_sector(ent), | |
1056 | t_sec(ent), MAJOR(r.device), MINOR(r.device), | |
1057 | (unsigned long long)r.sector); | |
1058 | } | |
1059 | ||
1060 | static int blk_log_plug(struct trace_seq *s, const struct trace_entry *ent) | |
1061 | { | |
4ca53085 SR |
1062 | char cmd[TASK_COMM_LEN]; |
1063 | ||
1064 | trace_find_cmdline(ent->pid, cmd); | |
1065 | ||
1066 | return trace_seq_printf(s, "[%s]\n", cmd); | |
c71a8961 ACM |
1067 | } |
1068 | ||
1069 | static int blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent) | |
1070 | { | |
4ca53085 SR |
1071 | char cmd[TASK_COMM_LEN]; |
1072 | ||
1073 | trace_find_cmdline(ent->pid, cmd); | |
1074 | ||
1075 | return trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent)); | |
c71a8961 ACM |
1076 | } |
1077 | ||
1078 | static int blk_log_split(struct trace_seq *s, const struct trace_entry *ent) | |
1079 | { | |
4ca53085 SR |
1080 | char cmd[TASK_COMM_LEN]; |
1081 | ||
1082 | trace_find_cmdline(ent->pid, cmd); | |
1083 | ||
c71a8961 | 1084 | return trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent), |
4ca53085 | 1085 | get_pdu_int(ent), cmd); |
c71a8961 ACM |
1086 | } |
1087 | ||
1088 | /* | |
1089 | * struct tracer operations | |
1090 | */ | |
1091 | ||
1092 | static void blk_tracer_print_header(struct seq_file *m) | |
1093 | { | |
1094 | if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC)) | |
1095 | return; | |
1096 | seq_puts(m, "# DEV CPU TIMESTAMP PID ACT FLG\n" | |
1097 | "# | | | | | |\n"); | |
1098 | } | |
1099 | ||
1100 | static void blk_tracer_start(struct trace_array *tr) | |
1101 | { | |
c71a8961 ACM |
1102 | mutex_lock(&blk_probe_mutex); |
1103 | if (atomic_add_return(1, &blk_probes_ref) == 1) | |
1104 | if (blk_register_tracepoints()) | |
1105 | atomic_dec(&blk_probes_ref); | |
1106 | mutex_unlock(&blk_probe_mutex); | |
08a06b83 | 1107 | trace_flags &= ~TRACE_ITER_CONTEXT_INFO; |
c71a8961 ACM |
1108 | } |
1109 | ||
1110 | static int blk_tracer_init(struct trace_array *tr) | |
1111 | { | |
1112 | blk_tr = tr; | |
1113 | blk_tracer_start(tr); | |
1114 | mutex_lock(&blk_probe_mutex); | |
1115 | blk_tracer_enabled++; | |
1116 | mutex_unlock(&blk_probe_mutex); | |
1117 | return 0; | |
1118 | } | |
1119 | ||
1120 | static void blk_tracer_stop(struct trace_array *tr) | |
1121 | { | |
08a06b83 | 1122 | trace_flags |= TRACE_ITER_CONTEXT_INFO; |
c71a8961 ACM |
1123 | mutex_lock(&blk_probe_mutex); |
1124 | if (atomic_dec_and_test(&blk_probes_ref)) | |
1125 | blk_unregister_tracepoints(); | |
1126 | mutex_unlock(&blk_probe_mutex); | |
1127 | } | |
1128 | ||
1129 | static void blk_tracer_reset(struct trace_array *tr) | |
1130 | { | |
1131 | if (!atomic_read(&blk_probes_ref)) | |
1132 | return; | |
1133 | ||
1134 | mutex_lock(&blk_probe_mutex); | |
1135 | blk_tracer_enabled--; | |
1136 | WARN_ON(blk_tracer_enabled < 0); | |
1137 | mutex_unlock(&blk_probe_mutex); | |
1138 | ||
1139 | blk_tracer_stop(tr); | |
1140 | } | |
1141 | ||
1142 | static struct { | |
1143 | const char *act[2]; | |
ef18012b | 1144 | int (*print)(struct trace_seq *s, const struct trace_entry *ent); |
c71a8961 | 1145 | } what2act[] __read_mostly = { |
ef18012b | 1146 | [__BLK_TA_QUEUE] = {{ "Q", "queue" }, blk_log_generic }, |
c71a8961 ACM |
1147 | [__BLK_TA_BACKMERGE] = {{ "M", "backmerge" }, blk_log_generic }, |
1148 | [__BLK_TA_FRONTMERGE] = {{ "F", "frontmerge" }, blk_log_generic }, | |
1149 | [__BLK_TA_GETRQ] = {{ "G", "getrq" }, blk_log_generic }, | |
1150 | [__BLK_TA_SLEEPRQ] = {{ "S", "sleeprq" }, blk_log_generic }, | |
1151 | [__BLK_TA_REQUEUE] = {{ "R", "requeue" }, blk_log_with_error }, | |
1152 | [__BLK_TA_ISSUE] = {{ "D", "issue" }, blk_log_generic }, | |
1153 | [__BLK_TA_COMPLETE] = {{ "C", "complete" }, blk_log_with_error }, | |
1154 | [__BLK_TA_PLUG] = {{ "P", "plug" }, blk_log_plug }, | |
1155 | [__BLK_TA_UNPLUG_IO] = {{ "U", "unplug_io" }, blk_log_unplug }, | |
1156 | [__BLK_TA_UNPLUG_TIMER] = {{ "UT", "unplug_timer" }, blk_log_unplug }, | |
1157 | [__BLK_TA_INSERT] = {{ "I", "insert" }, blk_log_generic }, | |
1158 | [__BLK_TA_SPLIT] = {{ "X", "split" }, blk_log_split }, | |
1159 | [__BLK_TA_BOUNCE] = {{ "B", "bounce" }, blk_log_generic }, | |
1160 | [__BLK_TA_REMAP] = {{ "A", "remap" }, blk_log_remap }, | |
1161 | }; | |
1162 | ||
ae7462b4 ACM |
1163 | static enum print_line_t blk_trace_event_print(struct trace_iterator *iter, |
1164 | int flags) | |
c71a8961 | 1165 | { |
2c9b238e ACM |
1166 | struct trace_seq *s = &iter->seq; |
1167 | const struct blk_io_trace *t = (struct blk_io_trace *)iter->ent; | |
c71a8961 ACM |
1168 | const u16 what = t->action & ((1 << BLK_TC_SHIFT) - 1); |
1169 | int ret; | |
1170 | ||
d9793bd8 | 1171 | if (!trace_print_context(iter)) |
08a06b83 ACM |
1172 | return TRACE_TYPE_PARTIAL_LINE; |
1173 | ||
c71a8961 ACM |
1174 | if (unlikely(what == 0 || what > ARRAY_SIZE(what2act))) |
1175 | ret = trace_seq_printf(s, "Bad pc action %x\n", what); | |
1176 | else { | |
1177 | const bool long_act = !!(trace_flags & TRACE_ITER_VERBOSE); | |
1178 | ret = blk_log_action_seq(s, t, what2act[what].act[long_act]); | |
1179 | if (ret) | |
2c9b238e | 1180 | ret = what2act[what].print(s, iter->ent); |
c71a8961 ACM |
1181 | } |
1182 | ||
1183 | return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; | |
1184 | } | |
1185 | ||
08a06b83 ACM |
1186 | static int blk_trace_synthesize_old_trace(struct trace_iterator *iter) |
1187 | { | |
1188 | struct trace_seq *s = &iter->seq; | |
1189 | struct blk_io_trace *t = (struct blk_io_trace *)iter->ent; | |
1190 | const int offset = offsetof(struct blk_io_trace, sector); | |
1191 | struct blk_io_trace old = { | |
1192 | .magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION, | |
1193 | .time = ns2usecs(iter->ts), | |
1194 | }; | |
1195 | ||
1196 | if (!trace_seq_putmem(s, &old, offset)) | |
1197 | return 0; | |
1198 | return trace_seq_putmem(s, &t->sector, | |
1199 | sizeof(old) - offset + t->pdu_len); | |
1200 | } | |
1201 | ||
ae7462b4 ACM |
1202 | static enum print_line_t |
1203 | blk_trace_event_print_binary(struct trace_iterator *iter, int flags) | |
08a06b83 ACM |
1204 | { |
1205 | return blk_trace_synthesize_old_trace(iter) ? | |
1206 | TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; | |
1207 | } | |
1208 | ||
c71a8961 ACM |
1209 | static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter) |
1210 | { | |
1211 | const struct blk_io_trace *t; | |
1212 | u16 what; | |
1213 | int ret; | |
1214 | ||
1215 | if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC)) | |
1216 | return TRACE_TYPE_UNHANDLED; | |
1217 | ||
1218 | t = (const struct blk_io_trace *)iter->ent; | |
1219 | what = t->action & ((1 << BLK_TC_SHIFT) - 1); | |
1220 | ||
1221 | if (unlikely(what == 0 || what > ARRAY_SIZE(what2act))) | |
1222 | ret = trace_seq_printf(&iter->seq, "Bad pc action %x\n", what); | |
1223 | else { | |
1224 | const bool long_act = !!(trace_flags & TRACE_ITER_VERBOSE); | |
1225 | ret = blk_log_action_iter(iter, what2act[what].act[long_act]); | |
1226 | if (ret) | |
1227 | ret = what2act[what].print(&iter->seq, iter->ent); | |
1228 | } | |
1229 | ||
1230 | return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; | |
1231 | } | |
1232 | ||
1233 | static struct tracer blk_tracer __read_mostly = { | |
1234 | .name = "blk", | |
1235 | .init = blk_tracer_init, | |
1236 | .reset = blk_tracer_reset, | |
1237 | .start = blk_tracer_start, | |
1238 | .stop = blk_tracer_stop, | |
1239 | .print_header = blk_tracer_print_header, | |
1240 | .print_line = blk_tracer_print_line, | |
1241 | .flags = &blk_tracer_flags, | |
1242 | }; | |
1243 | ||
1244 | static struct trace_event trace_blk_event = { | |
ef18012b | 1245 | .type = TRACE_BLK, |
c71a8961 | 1246 | .trace = blk_trace_event_print, |
08a06b83 | 1247 | .binary = blk_trace_event_print_binary, |
c71a8961 ACM |
1248 | }; |
1249 | ||
1250 | static int __init init_blk_tracer(void) | |
1251 | { | |
1252 | if (!register_ftrace_event(&trace_blk_event)) { | |
1253 | pr_warning("Warning: could not register block events\n"); | |
1254 | return 1; | |
1255 | } | |
1256 | ||
1257 | if (register_tracer(&blk_tracer) != 0) { | |
1258 | pr_warning("Warning: could not register the block tracer\n"); | |
1259 | unregister_ftrace_event(&trace_blk_event); | |
1260 | return 1; | |
1261 | } | |
1262 | ||
1263 | return 0; | |
1264 | } | |
1265 | ||
1266 | device_initcall(init_blk_tracer); | |
1267 | ||
1268 | static int blk_trace_remove_queue(struct request_queue *q) | |
1269 | { | |
1270 | struct blk_trace *bt; | |
1271 | ||
1272 | bt = xchg(&q->blk_trace, NULL); | |
1273 | if (bt == NULL) | |
1274 | return -EINVAL; | |
1275 | ||
1276 | kfree(bt); | |
1277 | return 0; | |
1278 | } | |
1279 | ||
1280 | /* | |
1281 | * Setup everything required to start tracing | |
1282 | */ | |
1283 | static int blk_trace_setup_queue(struct request_queue *q, dev_t dev) | |
1284 | { | |
1285 | struct blk_trace *old_bt, *bt = NULL; | |
1286 | int ret; | |
1287 | ||
1288 | ret = -ENOMEM; | |
1289 | bt = kzalloc(sizeof(*bt), GFP_KERNEL); | |
1290 | if (!bt) | |
1291 | goto err; | |
1292 | ||
1293 | bt->dev = dev; | |
1294 | bt->act_mask = (u16)-1; | |
1295 | bt->end_lba = -1ULL; | |
1296 | bt->trace_state = Blktrace_running; | |
1297 | ||
1298 | old_bt = xchg(&q->blk_trace, bt); | |
1299 | if (old_bt != NULL) { | |
1300 | (void)xchg(&q->blk_trace, old_bt); | |
1301 | kfree(bt); | |
1302 | ret = -EBUSY; | |
1303 | } | |
1304 | return 0; | |
1305 | err: | |
1306 | return ret; | |
1307 | } | |
1308 | ||
1309 | /* | |
1310 | * sysfs interface to enable and configure tracing | |
1311 | */ | |
1312 | ||
1313 | static ssize_t sysfs_blk_trace_enable_show(struct device *dev, | |
1314 | struct device_attribute *attr, | |
1315 | char *buf) | |
1316 | { | |
1317 | struct hd_struct *p = dev_to_part(dev); | |
1318 | struct block_device *bdev; | |
1319 | ssize_t ret = -ENXIO; | |
1320 | ||
1321 | lock_kernel(); | |
1322 | bdev = bdget(part_devt(p)); | |
1323 | if (bdev != NULL) { | |
1324 | struct request_queue *q = bdev_get_queue(bdev); | |
1325 | ||
1326 | if (q != NULL) { | |
1327 | mutex_lock(&bdev->bd_mutex); | |
1328 | ret = sprintf(buf, "%u\n", !!q->blk_trace); | |
1329 | mutex_unlock(&bdev->bd_mutex); | |
1330 | } | |
1331 | ||
1332 | bdput(bdev); | |
1333 | } | |
1334 | ||
1335 | unlock_kernel(); | |
1336 | return ret; | |
1337 | } | |
1338 | ||
1339 | static ssize_t sysfs_blk_trace_enable_store(struct device *dev, | |
1340 | struct device_attribute *attr, | |
1341 | const char *buf, size_t count) | |
1342 | { | |
1343 | struct block_device *bdev; | |
1344 | struct request_queue *q; | |
1345 | struct hd_struct *p; | |
1346 | int value; | |
1347 | ssize_t ret = -ENXIO; | |
1348 | ||
1349 | if (count == 0 || sscanf(buf, "%d", &value) != 1) | |
1350 | goto out; | |
1351 | ||
1352 | lock_kernel(); | |
1353 | p = dev_to_part(dev); | |
1354 | bdev = bdget(part_devt(p)); | |
1355 | if (bdev == NULL) | |
1356 | goto out_unlock_kernel; | |
1357 | ||
1358 | q = bdev_get_queue(bdev); | |
1359 | if (q == NULL) | |
1360 | goto out_bdput; | |
1361 | ||
1362 | mutex_lock(&bdev->bd_mutex); | |
1363 | if (value) | |
1364 | ret = blk_trace_setup_queue(q, bdev->bd_dev); | |
1365 | else | |
1366 | ret = blk_trace_remove_queue(q); | |
1367 | mutex_unlock(&bdev->bd_mutex); | |
1368 | ||
1369 | if (ret == 0) | |
1370 | ret = count; | |
1371 | out_bdput: | |
1372 | bdput(bdev); | |
1373 | out_unlock_kernel: | |
1374 | unlock_kernel(); | |
1375 | out: | |
1376 | return ret; | |
1377 | } | |
1378 | ||
1379 | static ssize_t sysfs_blk_trace_attr_show(struct device *dev, | |
1380 | struct device_attribute *attr, | |
1381 | char *buf); | |
1382 | static ssize_t sysfs_blk_trace_attr_store(struct device *dev, | |
1383 | struct device_attribute *attr, | |
1384 | const char *buf, size_t count); | |
1385 | #define BLK_TRACE_DEVICE_ATTR(_name) \ | |
1386 | DEVICE_ATTR(_name, S_IRUGO | S_IWUSR, \ | |
1387 | sysfs_blk_trace_attr_show, \ | |
1388 | sysfs_blk_trace_attr_store) | |
1389 | ||
1390 | static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, | |
1391 | sysfs_blk_trace_enable_show, sysfs_blk_trace_enable_store); | |
1392 | static BLK_TRACE_DEVICE_ATTR(act_mask); | |
1393 | static BLK_TRACE_DEVICE_ATTR(pid); | |
1394 | static BLK_TRACE_DEVICE_ATTR(start_lba); | |
1395 | static BLK_TRACE_DEVICE_ATTR(end_lba); | |
1396 | ||
1397 | static struct attribute *blk_trace_attrs[] = { | |
1398 | &dev_attr_enable.attr, | |
1399 | &dev_attr_act_mask.attr, | |
1400 | &dev_attr_pid.attr, | |
1401 | &dev_attr_start_lba.attr, | |
1402 | &dev_attr_end_lba.attr, | |
1403 | NULL | |
1404 | }; | |
1405 | ||
1406 | struct attribute_group blk_trace_attr_group = { | |
1407 | .name = "trace", | |
1408 | .attrs = blk_trace_attrs, | |
1409 | }; | |
1410 | ||
1411 | static int blk_str2act_mask(const char *str) | |
1412 | { | |
1413 | int mask = 0; | |
1414 | char *copy = kstrdup(str, GFP_KERNEL), *s; | |
1415 | ||
1416 | if (copy == NULL) | |
1417 | return -ENOMEM; | |
1418 | ||
1419 | s = strstrip(copy); | |
1420 | ||
1421 | while (1) { | |
1422 | char *sep = strchr(s, ','); | |
1423 | ||
1424 | if (sep != NULL) | |
1425 | *sep = '\0'; | |
1426 | ||
1427 | if (strcasecmp(s, "barrier") == 0) | |
1428 | mask |= BLK_TC_BARRIER; | |
1429 | else if (strcasecmp(s, "complete") == 0) | |
1430 | mask |= BLK_TC_COMPLETE; | |
1431 | else if (strcasecmp(s, "fs") == 0) | |
1432 | mask |= BLK_TC_FS; | |
1433 | else if (strcasecmp(s, "issue") == 0) | |
1434 | mask |= BLK_TC_ISSUE; | |
1435 | else if (strcasecmp(s, "pc") == 0) | |
1436 | mask |= BLK_TC_PC; | |
1437 | else if (strcasecmp(s, "queue") == 0) | |
1438 | mask |= BLK_TC_QUEUE; | |
1439 | else if (strcasecmp(s, "read") == 0) | |
1440 | mask |= BLK_TC_READ; | |
1441 | else if (strcasecmp(s, "requeue") == 0) | |
1442 | mask |= BLK_TC_REQUEUE; | |
1443 | else if (strcasecmp(s, "sync") == 0) | |
1444 | mask |= BLK_TC_SYNC; | |
1445 | else if (strcasecmp(s, "write") == 0) | |
1446 | mask |= BLK_TC_WRITE; | |
1447 | ||
1448 | if (sep == NULL) | |
1449 | break; | |
1450 | ||
1451 | s = sep + 1; | |
1452 | } | |
1453 | kfree(copy); | |
1454 | ||
1455 | return mask; | |
1456 | } | |
1457 | ||
1458 | static ssize_t sysfs_blk_trace_attr_show(struct device *dev, | |
1459 | struct device_attribute *attr, | |
1460 | char *buf) | |
1461 | { | |
1462 | struct hd_struct *p = dev_to_part(dev); | |
1463 | struct request_queue *q; | |
1464 | struct block_device *bdev; | |
1465 | ssize_t ret = -ENXIO; | |
1466 | ||
1467 | lock_kernel(); | |
1468 | bdev = bdget(part_devt(p)); | |
1469 | if (bdev == NULL) | |
1470 | goto out_unlock_kernel; | |
1471 | ||
1472 | q = bdev_get_queue(bdev); | |
1473 | if (q == NULL) | |
1474 | goto out_bdput; | |
1475 | mutex_lock(&bdev->bd_mutex); | |
1476 | if (q->blk_trace == NULL) | |
1477 | ret = sprintf(buf, "disabled\n"); | |
1478 | else if (attr == &dev_attr_act_mask) | |
1479 | ret = sprintf(buf, "%#x\n", q->blk_trace->act_mask); | |
1480 | else if (attr == &dev_attr_pid) | |
1481 | ret = sprintf(buf, "%u\n", q->blk_trace->pid); | |
1482 | else if (attr == &dev_attr_start_lba) | |
1483 | ret = sprintf(buf, "%llu\n", q->blk_trace->start_lba); | |
1484 | else if (attr == &dev_attr_end_lba) | |
1485 | ret = sprintf(buf, "%llu\n", q->blk_trace->end_lba); | |
1486 | mutex_unlock(&bdev->bd_mutex); | |
1487 | out_bdput: | |
1488 | bdput(bdev); | |
1489 | out_unlock_kernel: | |
1490 | unlock_kernel(); | |
1491 | return ret; | |
1492 | } | |
1493 | ||
1494 | static ssize_t sysfs_blk_trace_attr_store(struct device *dev, | |
1495 | struct device_attribute *attr, | |
1496 | const char *buf, size_t count) | |
1497 | { | |
1498 | struct block_device *bdev; | |
1499 | struct request_queue *q; | |
1500 | struct hd_struct *p; | |
1501 | u64 value; | |
1502 | ssize_t ret = -ENXIO; | |
1503 | ||
1504 | if (count == 0) | |
1505 | goto out; | |
1506 | ||
1507 | if (attr == &dev_attr_act_mask) { | |
1508 | if (sscanf(buf, "%llx", &value) != 1) { | |
1509 | /* Assume it is a list of trace category names */ | |
1510 | value = blk_str2act_mask(buf); | |
1511 | if (value < 0) | |
1512 | goto out; | |
1513 | } | |
1514 | } else if (sscanf(buf, "%llu", &value) != 1) | |
1515 | goto out; | |
1516 | ||
1517 | lock_kernel(); | |
1518 | p = dev_to_part(dev); | |
1519 | bdev = bdget(part_devt(p)); | |
1520 | if (bdev == NULL) | |
1521 | goto out_unlock_kernel; | |
1522 | ||
1523 | q = bdev_get_queue(bdev); | |
1524 | if (q == NULL) | |
1525 | goto out_bdput; | |
1526 | ||
1527 | mutex_lock(&bdev->bd_mutex); | |
1528 | ret = 0; | |
1529 | if (q->blk_trace == NULL) | |
1530 | ret = blk_trace_setup_queue(q, bdev->bd_dev); | |
1531 | ||
1532 | if (ret == 0) { | |
1533 | if (attr == &dev_attr_act_mask) | |
1534 | q->blk_trace->act_mask = value; | |
1535 | else if (attr == &dev_attr_pid) | |
1536 | q->blk_trace->pid = value; | |
1537 | else if (attr == &dev_attr_start_lba) | |
1538 | q->blk_trace->start_lba = value; | |
1539 | else if (attr == &dev_attr_end_lba) | |
1540 | q->blk_trace->end_lba = value; | |
1541 | ret = count; | |
1542 | } | |
1543 | mutex_unlock(&bdev->bd_mutex); | |
1544 | out_bdput: | |
1545 | bdput(bdev); | |
1546 | out_unlock_kernel: | |
1547 | unlock_kernel(); | |
1548 | out: | |
1549 | return ret; | |
1550 | } |