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blktrace: fix accounting of partially completed requests
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / trace / blktrace.c
1 /*
2 * Copyright (C) 2006 Jens Axboe <axboe@kernel.dk>
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 */
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/slab.h>
25 #include <linux/debugfs.h>
26 #include <linux/export.h>
27 #include <linux/time.h>
28 #include <linux/uaccess.h>
29
30 #include <trace/events/block.h>
31
32 #include "trace_output.h"
33
34 #ifdef CONFIG_BLK_DEV_IO_TRACE
35
36 static unsigned int blktrace_seq __read_mostly = 1;
37
38 static struct trace_array *blk_tr;
39 static bool blk_tracer_enabled __read_mostly;
40
41 /* Select an alternative, minimalistic output than the original one */
42 #define TRACE_BLK_OPT_CLASSIC 0x1
43
44 static struct tracer_opt blk_tracer_opts[] = {
45 /* Default disable the minimalistic output */
46 { TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) },
47 { }
48 };
49
50 static struct tracer_flags blk_tracer_flags = {
51 .val = 0,
52 .opts = blk_tracer_opts,
53 };
54
55 /* Global reference count of probes */
56 static atomic_t blk_probes_ref = ATOMIC_INIT(0);
57
58 static void blk_register_tracepoints(void);
59 static void blk_unregister_tracepoints(void);
60
61 /*
62 * Send out a notify message.
63 */
64 static void trace_note(struct blk_trace *bt, pid_t pid, int action,
65 const void *data, size_t len)
66 {
67 struct blk_io_trace *t;
68 struct ring_buffer_event *event = NULL;
69 struct ring_buffer *buffer = NULL;
70 int pc = 0;
71 int cpu = smp_processor_id();
72 bool blk_tracer = blk_tracer_enabled;
73
74 if (blk_tracer) {
75 buffer = blk_tr->trace_buffer.buffer;
76 pc = preempt_count();
77 event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
78 sizeof(*t) + len,
79 0, pc);
80 if (!event)
81 return;
82 t = ring_buffer_event_data(event);
83 goto record_it;
84 }
85
86 if (!bt->rchan)
87 return;
88
89 t = relay_reserve(bt->rchan, sizeof(*t) + len);
90 if (t) {
91 t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
92 t->time = ktime_to_ns(ktime_get());
93 record_it:
94 t->device = bt->dev;
95 t->action = action;
96 t->pid = pid;
97 t->cpu = cpu;
98 t->pdu_len = len;
99 memcpy((void *) t + sizeof(*t), data, len);
100
101 if (blk_tracer)
102 trace_buffer_unlock_commit(buffer, event, 0, pc);
103 }
104 }
105
106 /*
107 * Send out a notify for this process, if we haven't done so since a trace
108 * started
109 */
110 static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk)
111 {
112 tsk->btrace_seq = blktrace_seq;
113 trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm, sizeof(tsk->comm));
114 }
115
116 static void trace_note_time(struct blk_trace *bt)
117 {
118 struct timespec now;
119 unsigned long flags;
120 u32 words[2];
121
122 getnstimeofday(&now);
123 words[0] = now.tv_sec;
124 words[1] = now.tv_nsec;
125
126 local_irq_save(flags);
127 trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words));
128 local_irq_restore(flags);
129 }
130
131 void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
132 {
133 int n;
134 va_list args;
135 unsigned long flags;
136 char *buf;
137
138 if (unlikely(bt->trace_state != Blktrace_running &&
139 !blk_tracer_enabled))
140 return;
141
142 /*
143 * If the BLK_TC_NOTIFY action mask isn't set, don't send any note
144 * message to the trace.
145 */
146 if (!(bt->act_mask & BLK_TC_NOTIFY))
147 return;
148
149 local_irq_save(flags);
150 buf = this_cpu_ptr(bt->msg_data);
151 va_start(args, fmt);
152 n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
153 va_end(args);
154
155 trace_note(bt, 0, BLK_TN_MESSAGE, buf, n);
156 local_irq_restore(flags);
157 }
158 EXPORT_SYMBOL_GPL(__trace_note_message);
159
160 static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
161 pid_t pid)
162 {
163 if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0)
164 return 1;
165 if (sector && (sector < bt->start_lba || sector > bt->end_lba))
166 return 1;
167 if (bt->pid && pid != bt->pid)
168 return 1;
169
170 return 0;
171 }
172
173 /*
174 * Data direction bit lookup
175 */
176 static const u32 ddir_act[2] = { BLK_TC_ACT(BLK_TC_READ),
177 BLK_TC_ACT(BLK_TC_WRITE) };
178
179 #define BLK_TC_RAHEAD BLK_TC_AHEAD
180
181 /* The ilog2() calls fall out because they're constant */
182 #define MASK_TC_BIT(rw, __name) ((rw & REQ_ ## __name) << \
183 (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - __REQ_ ## __name))
184
185 /*
186 * The worker for the various blk_add_trace*() types. Fills out a
187 * blk_io_trace structure and places it in a per-cpu subbuffer.
188 */
189 static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
190 int rw, u32 what, int error, int pdu_len, void *pdu_data)
191 {
192 struct task_struct *tsk = current;
193 struct ring_buffer_event *event = NULL;
194 struct ring_buffer *buffer = NULL;
195 struct blk_io_trace *t;
196 unsigned long flags = 0;
197 unsigned long *sequence;
198 pid_t pid;
199 int cpu, pc = 0;
200 bool blk_tracer = blk_tracer_enabled;
201
202 if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer))
203 return;
204
205 what |= ddir_act[rw & WRITE];
206 what |= MASK_TC_BIT(rw, SYNC);
207 what |= MASK_TC_BIT(rw, RAHEAD);
208 what |= MASK_TC_BIT(rw, META);
209 what |= MASK_TC_BIT(rw, DISCARD);
210 what |= MASK_TC_BIT(rw, FLUSH);
211 what |= MASK_TC_BIT(rw, FUA);
212
213 pid = tsk->pid;
214 if (act_log_check(bt, what, sector, pid))
215 return;
216 cpu = raw_smp_processor_id();
217
218 if (blk_tracer) {
219 tracing_record_cmdline(current);
220
221 buffer = blk_tr->trace_buffer.buffer;
222 pc = preempt_count();
223 event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
224 sizeof(*t) + pdu_len,
225 0, pc);
226 if (!event)
227 return;
228 t = ring_buffer_event_data(event);
229 goto record_it;
230 }
231
232 /*
233 * A word about the locking here - we disable interrupts to reserve
234 * some space in the relay per-cpu buffer, to prevent an irq
235 * from coming in and stepping on our toes.
236 */
237 local_irq_save(flags);
238
239 if (unlikely(tsk->btrace_seq != blktrace_seq))
240 trace_note_tsk(bt, tsk);
241
242 t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len);
243 if (t) {
244 sequence = per_cpu_ptr(bt->sequence, cpu);
245
246 t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
247 t->sequence = ++(*sequence);
248 t->time = ktime_to_ns(ktime_get());
249 record_it:
250 /*
251 * These two are not needed in ftrace as they are in the
252 * generic trace_entry, filled by tracing_generic_entry_update,
253 * but for the trace_event->bin() synthesizer benefit we do it
254 * here too.
255 */
256 t->cpu = cpu;
257 t->pid = pid;
258
259 t->sector = sector;
260 t->bytes = bytes;
261 t->action = what;
262 t->device = bt->dev;
263 t->error = error;
264 t->pdu_len = pdu_len;
265
266 if (pdu_len)
267 memcpy((void *) t + sizeof(*t), pdu_data, pdu_len);
268
269 if (blk_tracer) {
270 trace_buffer_unlock_commit(buffer, event, 0, pc);
271 return;
272 }
273 }
274
275 local_irq_restore(flags);
276 }
277
278 static struct dentry *blk_tree_root;
279 static DEFINE_MUTEX(blk_tree_mutex);
280
281 static void blk_trace_free(struct blk_trace *bt)
282 {
283 debugfs_remove(bt->msg_file);
284 debugfs_remove(bt->dropped_file);
285 relay_close(bt->rchan);
286 debugfs_remove(bt->dir);
287 free_percpu(bt->sequence);
288 free_percpu(bt->msg_data);
289 kfree(bt);
290 }
291
292 static void blk_trace_cleanup(struct blk_trace *bt)
293 {
294 blk_trace_free(bt);
295 if (atomic_dec_and_test(&blk_probes_ref))
296 blk_unregister_tracepoints();
297 }
298
299 int blk_trace_remove(struct request_queue *q)
300 {
301 struct blk_trace *bt;
302
303 bt = xchg(&q->blk_trace, NULL);
304 if (!bt)
305 return -EINVAL;
306
307 if (bt->trace_state != Blktrace_running)
308 blk_trace_cleanup(bt);
309
310 return 0;
311 }
312 EXPORT_SYMBOL_GPL(blk_trace_remove);
313
314 static ssize_t blk_dropped_read(struct file *filp, char __user *buffer,
315 size_t count, loff_t *ppos)
316 {
317 struct blk_trace *bt = filp->private_data;
318 char buf[16];
319
320 snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped));
321
322 return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf));
323 }
324
325 static const struct file_operations blk_dropped_fops = {
326 .owner = THIS_MODULE,
327 .open = simple_open,
328 .read = blk_dropped_read,
329 .llseek = default_llseek,
330 };
331
332 static ssize_t blk_msg_write(struct file *filp, const char __user *buffer,
333 size_t count, loff_t *ppos)
334 {
335 char *msg;
336 struct blk_trace *bt;
337
338 if (count >= BLK_TN_MAX_MSG)
339 return -EINVAL;
340
341 msg = kmalloc(count + 1, GFP_KERNEL);
342 if (msg == NULL)
343 return -ENOMEM;
344
345 if (copy_from_user(msg, buffer, count)) {
346 kfree(msg);
347 return -EFAULT;
348 }
349
350 msg[count] = '\0';
351 bt = filp->private_data;
352 __trace_note_message(bt, "%s", msg);
353 kfree(msg);
354
355 return count;
356 }
357
358 static const struct file_operations blk_msg_fops = {
359 .owner = THIS_MODULE,
360 .open = simple_open,
361 .write = blk_msg_write,
362 .llseek = noop_llseek,
363 };
364
365 /*
366 * Keep track of how many times we encountered a full subbuffer, to aid
367 * the user space app in telling how many lost events there were.
368 */
369 static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf,
370 void *prev_subbuf, size_t prev_padding)
371 {
372 struct blk_trace *bt;
373
374 if (!relay_buf_full(buf))
375 return 1;
376
377 bt = buf->chan->private_data;
378 atomic_inc(&bt->dropped);
379 return 0;
380 }
381
382 static int blk_remove_buf_file_callback(struct dentry *dentry)
383 {
384 debugfs_remove(dentry);
385
386 return 0;
387 }
388
389 static struct dentry *blk_create_buf_file_callback(const char *filename,
390 struct dentry *parent,
391 umode_t mode,
392 struct rchan_buf *buf,
393 int *is_global)
394 {
395 return debugfs_create_file(filename, mode, parent, buf,
396 &relay_file_operations);
397 }
398
399 static struct rchan_callbacks blk_relay_callbacks = {
400 .subbuf_start = blk_subbuf_start_callback,
401 .create_buf_file = blk_create_buf_file_callback,
402 .remove_buf_file = blk_remove_buf_file_callback,
403 };
404
405 static void blk_trace_setup_lba(struct blk_trace *bt,
406 struct block_device *bdev)
407 {
408 struct hd_struct *part = NULL;
409
410 if (bdev)
411 part = bdev->bd_part;
412
413 if (part) {
414 bt->start_lba = part->start_sect;
415 bt->end_lba = part->start_sect + part->nr_sects;
416 } else {
417 bt->start_lba = 0;
418 bt->end_lba = -1ULL;
419 }
420 }
421
422 /*
423 * Setup everything required to start tracing
424 */
425 int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
426 struct block_device *bdev,
427 struct blk_user_trace_setup *buts)
428 {
429 struct blk_trace *old_bt, *bt = NULL;
430 struct dentry *dir = NULL;
431 int ret, i;
432
433 if (!buts->buf_size || !buts->buf_nr)
434 return -EINVAL;
435
436 strncpy(buts->name, name, BLKTRACE_BDEV_SIZE);
437 buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0';
438
439 /*
440 * some device names have larger paths - convert the slashes
441 * to underscores for this to work as expected
442 */
443 for (i = 0; i < strlen(buts->name); i++)
444 if (buts->name[i] == '/')
445 buts->name[i] = '_';
446
447 bt = kzalloc(sizeof(*bt), GFP_KERNEL);
448 if (!bt)
449 return -ENOMEM;
450
451 ret = -ENOMEM;
452 bt->sequence = alloc_percpu(unsigned long);
453 if (!bt->sequence)
454 goto err;
455
456 bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
457 if (!bt->msg_data)
458 goto err;
459
460 ret = -ENOENT;
461
462 mutex_lock(&blk_tree_mutex);
463 if (!blk_tree_root) {
464 blk_tree_root = debugfs_create_dir("block", NULL);
465 if (!blk_tree_root) {
466 mutex_unlock(&blk_tree_mutex);
467 goto err;
468 }
469 }
470 mutex_unlock(&blk_tree_mutex);
471
472 dir = debugfs_create_dir(buts->name, blk_tree_root);
473
474 if (!dir)
475 goto err;
476
477 bt->dir = dir;
478 bt->dev = dev;
479 atomic_set(&bt->dropped, 0);
480
481 ret = -EIO;
482 bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt,
483 &blk_dropped_fops);
484 if (!bt->dropped_file)
485 goto err;
486
487 bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops);
488 if (!bt->msg_file)
489 goto err;
490
491 bt->rchan = relay_open("trace", dir, buts->buf_size,
492 buts->buf_nr, &blk_relay_callbacks, bt);
493 if (!bt->rchan)
494 goto err;
495
496 bt->act_mask = buts->act_mask;
497 if (!bt->act_mask)
498 bt->act_mask = (u16) -1;
499
500 blk_trace_setup_lba(bt, bdev);
501
502 /* overwrite with user settings */
503 if (buts->start_lba)
504 bt->start_lba = buts->start_lba;
505 if (buts->end_lba)
506 bt->end_lba = buts->end_lba;
507
508 bt->pid = buts->pid;
509 bt->trace_state = Blktrace_setup;
510
511 ret = -EBUSY;
512 old_bt = xchg(&q->blk_trace, bt);
513 if (old_bt) {
514 (void) xchg(&q->blk_trace, old_bt);
515 goto err;
516 }
517
518 if (atomic_inc_return(&blk_probes_ref) == 1)
519 blk_register_tracepoints();
520
521 return 0;
522 err:
523 blk_trace_free(bt);
524 return ret;
525 }
526
527 int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
528 struct block_device *bdev,
529 char __user *arg)
530 {
531 struct blk_user_trace_setup buts;
532 int ret;
533
534 ret = copy_from_user(&buts, arg, sizeof(buts));
535 if (ret)
536 return -EFAULT;
537
538 ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
539 if (ret)
540 return ret;
541
542 if (copy_to_user(arg, &buts, sizeof(buts))) {
543 blk_trace_remove(q);
544 return -EFAULT;
545 }
546 return 0;
547 }
548 EXPORT_SYMBOL_GPL(blk_trace_setup);
549
550 #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
551 static int compat_blk_trace_setup(struct request_queue *q, char *name,
552 dev_t dev, struct block_device *bdev,
553 char __user *arg)
554 {
555 struct blk_user_trace_setup buts;
556 struct compat_blk_user_trace_setup cbuts;
557 int ret;
558
559 if (copy_from_user(&cbuts, arg, sizeof(cbuts)))
560 return -EFAULT;
561
562 buts = (struct blk_user_trace_setup) {
563 .act_mask = cbuts.act_mask,
564 .buf_size = cbuts.buf_size,
565 .buf_nr = cbuts.buf_nr,
566 .start_lba = cbuts.start_lba,
567 .end_lba = cbuts.end_lba,
568 .pid = cbuts.pid,
569 };
570 memcpy(&buts.name, &cbuts.name, 32);
571
572 ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
573 if (ret)
574 return ret;
575
576 if (copy_to_user(arg, &buts.name, 32)) {
577 blk_trace_remove(q);
578 return -EFAULT;
579 }
580
581 return 0;
582 }
583 #endif
584
585 int blk_trace_startstop(struct request_queue *q, int start)
586 {
587 int ret;
588 struct blk_trace *bt = q->blk_trace;
589
590 if (bt == NULL)
591 return -EINVAL;
592
593 /*
594 * For starting a trace, we can transition from a setup or stopped
595 * trace. For stopping a trace, the state must be running
596 */
597 ret = -EINVAL;
598 if (start) {
599 if (bt->trace_state == Blktrace_setup ||
600 bt->trace_state == Blktrace_stopped) {
601 blktrace_seq++;
602 smp_mb();
603 bt->trace_state = Blktrace_running;
604
605 trace_note_time(bt);
606 ret = 0;
607 }
608 } else {
609 if (bt->trace_state == Blktrace_running) {
610 bt->trace_state = Blktrace_stopped;
611 relay_flush(bt->rchan);
612 ret = 0;
613 }
614 }
615
616 return ret;
617 }
618 EXPORT_SYMBOL_GPL(blk_trace_startstop);
619
620 /**
621 * blk_trace_ioctl: - handle the ioctls associated with tracing
622 * @bdev: the block device
623 * @cmd: the ioctl cmd
624 * @arg: the argument data, if any
625 *
626 **/
627 int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
628 {
629 struct request_queue *q;
630 int ret, start = 0;
631 char b[BDEVNAME_SIZE];
632
633 q = bdev_get_queue(bdev);
634 if (!q)
635 return -ENXIO;
636
637 mutex_lock(&bdev->bd_mutex);
638
639 switch (cmd) {
640 case BLKTRACESETUP:
641 bdevname(bdev, b);
642 ret = blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
643 break;
644 #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
645 case BLKTRACESETUP32:
646 bdevname(bdev, b);
647 ret = compat_blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
648 break;
649 #endif
650 case BLKTRACESTART:
651 start = 1;
652 case BLKTRACESTOP:
653 ret = blk_trace_startstop(q, start);
654 break;
655 case BLKTRACETEARDOWN:
656 ret = blk_trace_remove(q);
657 break;
658 default:
659 ret = -ENOTTY;
660 break;
661 }
662
663 mutex_unlock(&bdev->bd_mutex);
664 return ret;
665 }
666
667 /**
668 * blk_trace_shutdown: - stop and cleanup trace structures
669 * @q: the request queue associated with the device
670 *
671 **/
672 void blk_trace_shutdown(struct request_queue *q)
673 {
674 if (q->blk_trace) {
675 blk_trace_startstop(q, 0);
676 blk_trace_remove(q);
677 }
678 }
679
680 /*
681 * blktrace probes
682 */
683
684 /**
685 * blk_add_trace_rq - Add a trace for a request oriented action
686 * @q: queue the io is for
687 * @rq: the source request
688 * @nr_bytes: number of completed bytes
689 * @what: the action
690 *
691 * Description:
692 * Records an action against a request. Will log the bio offset + size.
693 *
694 **/
695 static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
696 unsigned int nr_bytes, u32 what)
697 {
698 struct blk_trace *bt = q->blk_trace;
699
700 if (likely(!bt))
701 return;
702
703 if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
704 what |= BLK_TC_ACT(BLK_TC_PC);
705 __blk_add_trace(bt, 0, nr_bytes, rq->cmd_flags,
706 what, rq->errors, rq->cmd_len, rq->cmd);
707 } else {
708 what |= BLK_TC_ACT(BLK_TC_FS);
709 __blk_add_trace(bt, blk_rq_pos(rq), nr_bytes,
710 rq->cmd_flags, what, rq->errors, 0, NULL);
711 }
712 }
713
714 static void blk_add_trace_rq_abort(void *ignore,
715 struct request_queue *q, struct request *rq)
716 {
717 blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_ABORT);
718 }
719
720 static void blk_add_trace_rq_insert(void *ignore,
721 struct request_queue *q, struct request *rq)
722 {
723 blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_INSERT);
724 }
725
726 static void blk_add_trace_rq_issue(void *ignore,
727 struct request_queue *q, struct request *rq)
728 {
729 blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_ISSUE);
730 }
731
732 static void blk_add_trace_rq_requeue(void *ignore,
733 struct request_queue *q,
734 struct request *rq)
735 {
736 blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_REQUEUE);
737 }
738
739 static void blk_add_trace_rq_complete(void *ignore,
740 struct request_queue *q,
741 struct request *rq,
742 unsigned int nr_bytes)
743 {
744 blk_add_trace_rq(q, rq, nr_bytes, BLK_TA_COMPLETE);
745 }
746
747 /**
748 * blk_add_trace_bio - Add a trace for a bio oriented action
749 * @q: queue the io is for
750 * @bio: the source bio
751 * @what: the action
752 * @error: error, if any
753 *
754 * Description:
755 * Records an action against a bio. Will log the bio offset + size.
756 *
757 **/
758 static void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
759 u32 what, int error)
760 {
761 struct blk_trace *bt = q->blk_trace;
762
763 if (likely(!bt))
764 return;
765
766 if (!error && !bio_flagged(bio, BIO_UPTODATE))
767 error = EIO;
768
769 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what,
770 error, 0, NULL);
771 }
772
773 static void blk_add_trace_bio_bounce(void *ignore,
774 struct request_queue *q, struct bio *bio)
775 {
776 blk_add_trace_bio(q, bio, BLK_TA_BOUNCE, 0);
777 }
778
779 static void blk_add_trace_bio_complete(void *ignore,
780 struct request_queue *q, struct bio *bio,
781 int error)
782 {
783 blk_add_trace_bio(q, bio, BLK_TA_COMPLETE, error);
784 }
785
786 static void blk_add_trace_bio_backmerge(void *ignore,
787 struct request_queue *q,
788 struct request *rq,
789 struct bio *bio)
790 {
791 blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE, 0);
792 }
793
794 static void blk_add_trace_bio_frontmerge(void *ignore,
795 struct request_queue *q,
796 struct request *rq,
797 struct bio *bio)
798 {
799 blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE, 0);
800 }
801
802 static void blk_add_trace_bio_queue(void *ignore,
803 struct request_queue *q, struct bio *bio)
804 {
805 blk_add_trace_bio(q, bio, BLK_TA_QUEUE, 0);
806 }
807
808 static void blk_add_trace_getrq(void *ignore,
809 struct request_queue *q,
810 struct bio *bio, int rw)
811 {
812 if (bio)
813 blk_add_trace_bio(q, bio, BLK_TA_GETRQ, 0);
814 else {
815 struct blk_trace *bt = q->blk_trace;
816
817 if (bt)
818 __blk_add_trace(bt, 0, 0, rw, BLK_TA_GETRQ, 0, 0, NULL);
819 }
820 }
821
822
823 static void blk_add_trace_sleeprq(void *ignore,
824 struct request_queue *q,
825 struct bio *bio, int rw)
826 {
827 if (bio)
828 blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ, 0);
829 else {
830 struct blk_trace *bt = q->blk_trace;
831
832 if (bt)
833 __blk_add_trace(bt, 0, 0, rw, BLK_TA_SLEEPRQ,
834 0, 0, NULL);
835 }
836 }
837
838 static void blk_add_trace_plug(void *ignore, struct request_queue *q)
839 {
840 struct blk_trace *bt = q->blk_trace;
841
842 if (bt)
843 __blk_add_trace(bt, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL);
844 }
845
846 static void blk_add_trace_unplug(void *ignore, struct request_queue *q,
847 unsigned int depth, bool explicit)
848 {
849 struct blk_trace *bt = q->blk_trace;
850
851 if (bt) {
852 __be64 rpdu = cpu_to_be64(depth);
853 u32 what;
854
855 if (explicit)
856 what = BLK_TA_UNPLUG_IO;
857 else
858 what = BLK_TA_UNPLUG_TIMER;
859
860 __blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu);
861 }
862 }
863
864 static void blk_add_trace_split(void *ignore,
865 struct request_queue *q, struct bio *bio,
866 unsigned int pdu)
867 {
868 struct blk_trace *bt = q->blk_trace;
869
870 if (bt) {
871 __be64 rpdu = cpu_to_be64(pdu);
872
873 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw,
874 BLK_TA_SPLIT, !bio_flagged(bio, BIO_UPTODATE),
875 sizeof(rpdu), &rpdu);
876 }
877 }
878
879 /**
880 * blk_add_trace_bio_remap - Add a trace for a bio-remap operation
881 * @ignore: trace callback data parameter (not used)
882 * @q: queue the io is for
883 * @bio: the source bio
884 * @dev: target device
885 * @from: source sector
886 *
887 * Description:
888 * Device mapper or raid target sometimes need to split a bio because
889 * it spans a stripe (or similar). Add a trace for that action.
890 *
891 **/
892 static void blk_add_trace_bio_remap(void *ignore,
893 struct request_queue *q, struct bio *bio,
894 dev_t dev, sector_t from)
895 {
896 struct blk_trace *bt = q->blk_trace;
897 struct blk_io_trace_remap r;
898
899 if (likely(!bt))
900 return;
901
902 r.device_from = cpu_to_be32(dev);
903 r.device_to = cpu_to_be32(bio->bi_bdev->bd_dev);
904 r.sector_from = cpu_to_be64(from);
905
906 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw,
907 BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE),
908 sizeof(r), &r);
909 }
910
911 /**
912 * blk_add_trace_rq_remap - Add a trace for a request-remap operation
913 * @ignore: trace callback data parameter (not used)
914 * @q: queue the io is for
915 * @rq: the source request
916 * @dev: target device
917 * @from: source sector
918 *
919 * Description:
920 * Device mapper remaps request to other devices.
921 * Add a trace for that action.
922 *
923 **/
924 static void blk_add_trace_rq_remap(void *ignore,
925 struct request_queue *q,
926 struct request *rq, dev_t dev,
927 sector_t from)
928 {
929 struct blk_trace *bt = q->blk_trace;
930 struct blk_io_trace_remap r;
931
932 if (likely(!bt))
933 return;
934
935 r.device_from = cpu_to_be32(dev);
936 r.device_to = cpu_to_be32(disk_devt(rq->rq_disk));
937 r.sector_from = cpu_to_be64(from);
938
939 __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
940 rq_data_dir(rq), BLK_TA_REMAP, !!rq->errors,
941 sizeof(r), &r);
942 }
943
944 /**
945 * blk_add_driver_data - Add binary message with driver-specific data
946 * @q: queue the io is for
947 * @rq: io request
948 * @data: driver-specific data
949 * @len: length of driver-specific data
950 *
951 * Description:
952 * Some drivers might want to write driver-specific data per request.
953 *
954 **/
955 void blk_add_driver_data(struct request_queue *q,
956 struct request *rq,
957 void *data, size_t len)
958 {
959 struct blk_trace *bt = q->blk_trace;
960
961 if (likely(!bt))
962 return;
963
964 if (rq->cmd_type == REQ_TYPE_BLOCK_PC)
965 __blk_add_trace(bt, 0, blk_rq_bytes(rq), 0,
966 BLK_TA_DRV_DATA, rq->errors, len, data);
967 else
968 __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq), 0,
969 BLK_TA_DRV_DATA, rq->errors, len, data);
970 }
971 EXPORT_SYMBOL_GPL(blk_add_driver_data);
972
973 static void blk_register_tracepoints(void)
974 {
975 int ret;
976
977 ret = register_trace_block_rq_abort(blk_add_trace_rq_abort, NULL);
978 WARN_ON(ret);
979 ret = register_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
980 WARN_ON(ret);
981 ret = register_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
982 WARN_ON(ret);
983 ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
984 WARN_ON(ret);
985 ret = register_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
986 WARN_ON(ret);
987 ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL);
988 WARN_ON(ret);
989 ret = register_trace_block_bio_complete(blk_add_trace_bio_complete, NULL);
990 WARN_ON(ret);
991 ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL);
992 WARN_ON(ret);
993 ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
994 WARN_ON(ret);
995 ret = register_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
996 WARN_ON(ret);
997 ret = register_trace_block_getrq(blk_add_trace_getrq, NULL);
998 WARN_ON(ret);
999 ret = register_trace_block_sleeprq(blk_add_trace_sleeprq, NULL);
1000 WARN_ON(ret);
1001 ret = register_trace_block_plug(blk_add_trace_plug, NULL);
1002 WARN_ON(ret);
1003 ret = register_trace_block_unplug(blk_add_trace_unplug, NULL);
1004 WARN_ON(ret);
1005 ret = register_trace_block_split(blk_add_trace_split, NULL);
1006 WARN_ON(ret);
1007 ret = register_trace_block_bio_remap(blk_add_trace_bio_remap, NULL);
1008 WARN_ON(ret);
1009 ret = register_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);
1010 WARN_ON(ret);
1011 }
1012
1013 static void blk_unregister_tracepoints(void)
1014 {
1015 unregister_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);
1016 unregister_trace_block_bio_remap(blk_add_trace_bio_remap, NULL);
1017 unregister_trace_block_split(blk_add_trace_split, NULL);
1018 unregister_trace_block_unplug(blk_add_trace_unplug, NULL);
1019 unregister_trace_block_plug(blk_add_trace_plug, NULL);
1020 unregister_trace_block_sleeprq(blk_add_trace_sleeprq, NULL);
1021 unregister_trace_block_getrq(blk_add_trace_getrq, NULL);
1022 unregister_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
1023 unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
1024 unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL);
1025 unregister_trace_block_bio_complete(blk_add_trace_bio_complete, NULL);
1026 unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL);
1027 unregister_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
1028 unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
1029 unregister_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
1030 unregister_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
1031 unregister_trace_block_rq_abort(blk_add_trace_rq_abort, NULL);
1032
1033 tracepoint_synchronize_unregister();
1034 }
1035
1036 /*
1037 * struct blk_io_tracer formatting routines
1038 */
1039
1040 static void fill_rwbs(char *rwbs, const struct blk_io_trace *t)
1041 {
1042 int i = 0;
1043 int tc = t->action >> BLK_TC_SHIFT;
1044
1045 if (t->action == BLK_TN_MESSAGE) {
1046 rwbs[i++] = 'N';
1047 goto out;
1048 }
1049
1050 if (tc & BLK_TC_FLUSH)
1051 rwbs[i++] = 'F';
1052
1053 if (tc & BLK_TC_DISCARD)
1054 rwbs[i++] = 'D';
1055 else if (tc & BLK_TC_WRITE)
1056 rwbs[i++] = 'W';
1057 else if (t->bytes)
1058 rwbs[i++] = 'R';
1059 else
1060 rwbs[i++] = 'N';
1061
1062 if (tc & BLK_TC_FUA)
1063 rwbs[i++] = 'F';
1064 if (tc & BLK_TC_AHEAD)
1065 rwbs[i++] = 'A';
1066 if (tc & BLK_TC_SYNC)
1067 rwbs[i++] = 'S';
1068 if (tc & BLK_TC_META)
1069 rwbs[i++] = 'M';
1070 out:
1071 rwbs[i] = '\0';
1072 }
1073
1074 static inline
1075 const struct blk_io_trace *te_blk_io_trace(const struct trace_entry *ent)
1076 {
1077 return (const struct blk_io_trace *)ent;
1078 }
1079
1080 static inline const void *pdu_start(const struct trace_entry *ent)
1081 {
1082 return te_blk_io_trace(ent) + 1;
1083 }
1084
1085 static inline u32 t_action(const struct trace_entry *ent)
1086 {
1087 return te_blk_io_trace(ent)->action;
1088 }
1089
1090 static inline u32 t_bytes(const struct trace_entry *ent)
1091 {
1092 return te_blk_io_trace(ent)->bytes;
1093 }
1094
1095 static inline u32 t_sec(const struct trace_entry *ent)
1096 {
1097 return te_blk_io_trace(ent)->bytes >> 9;
1098 }
1099
1100 static inline unsigned long long t_sector(const struct trace_entry *ent)
1101 {
1102 return te_blk_io_trace(ent)->sector;
1103 }
1104
1105 static inline __u16 t_error(const struct trace_entry *ent)
1106 {
1107 return te_blk_io_trace(ent)->error;
1108 }
1109
1110 static __u64 get_pdu_int(const struct trace_entry *ent)
1111 {
1112 const __u64 *val = pdu_start(ent);
1113 return be64_to_cpu(*val);
1114 }
1115
1116 static void get_pdu_remap(const struct trace_entry *ent,
1117 struct blk_io_trace_remap *r)
1118 {
1119 const struct blk_io_trace_remap *__r = pdu_start(ent);
1120 __u64 sector_from = __r->sector_from;
1121
1122 r->device_from = be32_to_cpu(__r->device_from);
1123 r->device_to = be32_to_cpu(__r->device_to);
1124 r->sector_from = be64_to_cpu(sector_from);
1125 }
1126
1127 typedef int (blk_log_action_t) (struct trace_iterator *iter, const char *act);
1128
1129 static int blk_log_action_classic(struct trace_iterator *iter, const char *act)
1130 {
1131 char rwbs[RWBS_LEN];
1132 unsigned long long ts = iter->ts;
1133 unsigned long nsec_rem = do_div(ts, NSEC_PER_SEC);
1134 unsigned secs = (unsigned long)ts;
1135 const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
1136
1137 fill_rwbs(rwbs, t);
1138
1139 return trace_seq_printf(&iter->seq,
1140 "%3d,%-3d %2d %5d.%09lu %5u %2s %3s ",
1141 MAJOR(t->device), MINOR(t->device), iter->cpu,
1142 secs, nsec_rem, iter->ent->pid, act, rwbs);
1143 }
1144
1145 static int blk_log_action(struct trace_iterator *iter, const char *act)
1146 {
1147 char rwbs[RWBS_LEN];
1148 const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
1149
1150 fill_rwbs(rwbs, t);
1151 return trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ",
1152 MAJOR(t->device), MINOR(t->device), act, rwbs);
1153 }
1154
1155 static int blk_log_dump_pdu(struct trace_seq *s, const struct trace_entry *ent)
1156 {
1157 const unsigned char *pdu_buf;
1158 int pdu_len;
1159 int i, end, ret;
1160
1161 pdu_buf = pdu_start(ent);
1162 pdu_len = te_blk_io_trace(ent)->pdu_len;
1163
1164 if (!pdu_len)
1165 return 1;
1166
1167 /* find the last zero that needs to be printed */
1168 for (end = pdu_len - 1; end >= 0; end--)
1169 if (pdu_buf[end])
1170 break;
1171 end++;
1172
1173 if (!trace_seq_putc(s, '('))
1174 return 0;
1175
1176 for (i = 0; i < pdu_len; i++) {
1177
1178 ret = trace_seq_printf(s, "%s%02x",
1179 i == 0 ? "" : " ", pdu_buf[i]);
1180 if (!ret)
1181 return ret;
1182
1183 /*
1184 * stop when the rest is just zeroes and indicate so
1185 * with a ".." appended
1186 */
1187 if (i == end && end != pdu_len - 1)
1188 return trace_seq_puts(s, " ..) ");
1189 }
1190
1191 return trace_seq_puts(s, ") ");
1192 }
1193
1194 static int blk_log_generic(struct trace_seq *s, const struct trace_entry *ent)
1195 {
1196 char cmd[TASK_COMM_LEN];
1197
1198 trace_find_cmdline(ent->pid, cmd);
1199
1200 if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
1201 int ret;
1202
1203 ret = trace_seq_printf(s, "%u ", t_bytes(ent));
1204 if (!ret)
1205 return 0;
1206 ret = blk_log_dump_pdu(s, ent);
1207 if (!ret)
1208 return 0;
1209 return trace_seq_printf(s, "[%s]\n", cmd);
1210 } else {
1211 if (t_sec(ent))
1212 return trace_seq_printf(s, "%llu + %u [%s]\n",
1213 t_sector(ent), t_sec(ent), cmd);
1214 return trace_seq_printf(s, "[%s]\n", cmd);
1215 }
1216 }
1217
1218 static int blk_log_with_error(struct trace_seq *s,
1219 const struct trace_entry *ent)
1220 {
1221 if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
1222 int ret;
1223
1224 ret = blk_log_dump_pdu(s, ent);
1225 if (ret)
1226 return trace_seq_printf(s, "[%d]\n", t_error(ent));
1227 return 0;
1228 } else {
1229 if (t_sec(ent))
1230 return trace_seq_printf(s, "%llu + %u [%d]\n",
1231 t_sector(ent),
1232 t_sec(ent), t_error(ent));
1233 return trace_seq_printf(s, "%llu [%d]\n",
1234 t_sector(ent), t_error(ent));
1235 }
1236 }
1237
1238 static int blk_log_remap(struct trace_seq *s, const struct trace_entry *ent)
1239 {
1240 struct blk_io_trace_remap r = { .device_from = 0, };
1241
1242 get_pdu_remap(ent, &r);
1243 return trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n",
1244 t_sector(ent), t_sec(ent),
1245 MAJOR(r.device_from), MINOR(r.device_from),
1246 (unsigned long long)r.sector_from);
1247 }
1248
1249 static int blk_log_plug(struct trace_seq *s, const struct trace_entry *ent)
1250 {
1251 char cmd[TASK_COMM_LEN];
1252
1253 trace_find_cmdline(ent->pid, cmd);
1254
1255 return trace_seq_printf(s, "[%s]\n", cmd);
1256 }
1257
1258 static int blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent)
1259 {
1260 char cmd[TASK_COMM_LEN];
1261
1262 trace_find_cmdline(ent->pid, cmd);
1263
1264 return trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent));
1265 }
1266
1267 static int blk_log_split(struct trace_seq *s, const struct trace_entry *ent)
1268 {
1269 char cmd[TASK_COMM_LEN];
1270
1271 trace_find_cmdline(ent->pid, cmd);
1272
1273 return trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent),
1274 get_pdu_int(ent), cmd);
1275 }
1276
1277 static int blk_log_msg(struct trace_seq *s, const struct trace_entry *ent)
1278 {
1279 int ret;
1280 const struct blk_io_trace *t = te_blk_io_trace(ent);
1281
1282 ret = trace_seq_putmem(s, t + 1, t->pdu_len);
1283 if (ret)
1284 return trace_seq_putc(s, '\n');
1285 return ret;
1286 }
1287
1288 /*
1289 * struct tracer operations
1290 */
1291
1292 static void blk_tracer_print_header(struct seq_file *m)
1293 {
1294 if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
1295 return;
1296 seq_puts(m, "# DEV CPU TIMESTAMP PID ACT FLG\n"
1297 "# | | | | | |\n");
1298 }
1299
1300 static void blk_tracer_start(struct trace_array *tr)
1301 {
1302 blk_tracer_enabled = true;
1303 }
1304
1305 static int blk_tracer_init(struct trace_array *tr)
1306 {
1307 blk_tr = tr;
1308 blk_tracer_start(tr);
1309 return 0;
1310 }
1311
1312 static void blk_tracer_stop(struct trace_array *tr)
1313 {
1314 blk_tracer_enabled = false;
1315 }
1316
1317 static void blk_tracer_reset(struct trace_array *tr)
1318 {
1319 blk_tracer_stop(tr);
1320 }
1321
1322 static const struct {
1323 const char *act[2];
1324 int (*print)(struct trace_seq *s, const struct trace_entry *ent);
1325 } what2act[] = {
1326 [__BLK_TA_QUEUE] = {{ "Q", "queue" }, blk_log_generic },
1327 [__BLK_TA_BACKMERGE] = {{ "M", "backmerge" }, blk_log_generic },
1328 [__BLK_TA_FRONTMERGE] = {{ "F", "frontmerge" }, blk_log_generic },
1329 [__BLK_TA_GETRQ] = {{ "G", "getrq" }, blk_log_generic },
1330 [__BLK_TA_SLEEPRQ] = {{ "S", "sleeprq" }, blk_log_generic },
1331 [__BLK_TA_REQUEUE] = {{ "R", "requeue" }, blk_log_with_error },
1332 [__BLK_TA_ISSUE] = {{ "D", "issue" }, blk_log_generic },
1333 [__BLK_TA_COMPLETE] = {{ "C", "complete" }, blk_log_with_error },
1334 [__BLK_TA_PLUG] = {{ "P", "plug" }, blk_log_plug },
1335 [__BLK_TA_UNPLUG_IO] = {{ "U", "unplug_io" }, blk_log_unplug },
1336 [__BLK_TA_UNPLUG_TIMER] = {{ "UT", "unplug_timer" }, blk_log_unplug },
1337 [__BLK_TA_INSERT] = {{ "I", "insert" }, blk_log_generic },
1338 [__BLK_TA_SPLIT] = {{ "X", "split" }, blk_log_split },
1339 [__BLK_TA_BOUNCE] = {{ "B", "bounce" }, blk_log_generic },
1340 [__BLK_TA_REMAP] = {{ "A", "remap" }, blk_log_remap },
1341 };
1342
1343 static enum print_line_t print_one_line(struct trace_iterator *iter,
1344 bool classic)
1345 {
1346 struct trace_seq *s = &iter->seq;
1347 const struct blk_io_trace *t;
1348 u16 what;
1349 int ret;
1350 bool long_act;
1351 blk_log_action_t *log_action;
1352
1353 t = te_blk_io_trace(iter->ent);
1354 what = t->action & ((1 << BLK_TC_SHIFT) - 1);
1355 long_act = !!(trace_flags & TRACE_ITER_VERBOSE);
1356 log_action = classic ? &blk_log_action_classic : &blk_log_action;
1357
1358 if (t->action == BLK_TN_MESSAGE) {
1359 ret = log_action(iter, long_act ? "message" : "m");
1360 if (ret)
1361 ret = blk_log_msg(s, iter->ent);
1362 goto out;
1363 }
1364
1365 if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act)))
1366 ret = trace_seq_printf(s, "Unknown action %x\n", what);
1367 else {
1368 ret = log_action(iter, what2act[what].act[long_act]);
1369 if (ret)
1370 ret = what2act[what].print(s, iter->ent);
1371 }
1372 out:
1373 return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
1374 }
1375
1376 static enum print_line_t blk_trace_event_print(struct trace_iterator *iter,
1377 int flags, struct trace_event *event)
1378 {
1379 return print_one_line(iter, false);
1380 }
1381
1382 static int blk_trace_synthesize_old_trace(struct trace_iterator *iter)
1383 {
1384 struct trace_seq *s = &iter->seq;
1385 struct blk_io_trace *t = (struct blk_io_trace *)iter->ent;
1386 const int offset = offsetof(struct blk_io_trace, sector);
1387 struct blk_io_trace old = {
1388 .magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION,
1389 .time = iter->ts,
1390 };
1391
1392 if (!trace_seq_putmem(s, &old, offset))
1393 return 0;
1394 return trace_seq_putmem(s, &t->sector,
1395 sizeof(old) - offset + t->pdu_len);
1396 }
1397
1398 static enum print_line_t
1399 blk_trace_event_print_binary(struct trace_iterator *iter, int flags,
1400 struct trace_event *event)
1401 {
1402 return blk_trace_synthesize_old_trace(iter) ?
1403 TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
1404 }
1405
1406 static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter)
1407 {
1408 if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
1409 return TRACE_TYPE_UNHANDLED;
1410
1411 return print_one_line(iter, true);
1412 }
1413
1414 static int blk_tracer_set_flag(u32 old_flags, u32 bit, int set)
1415 {
1416 /* don't output context-info for blk_classic output */
1417 if (bit == TRACE_BLK_OPT_CLASSIC) {
1418 if (set)
1419 trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
1420 else
1421 trace_flags |= TRACE_ITER_CONTEXT_INFO;
1422 }
1423 return 0;
1424 }
1425
1426 static struct tracer blk_tracer __read_mostly = {
1427 .name = "blk",
1428 .init = blk_tracer_init,
1429 .reset = blk_tracer_reset,
1430 .start = blk_tracer_start,
1431 .stop = blk_tracer_stop,
1432 .print_header = blk_tracer_print_header,
1433 .print_line = blk_tracer_print_line,
1434 .flags = &blk_tracer_flags,
1435 .set_flag = blk_tracer_set_flag,
1436 };
1437
1438 static struct trace_event_functions trace_blk_event_funcs = {
1439 .trace = blk_trace_event_print,
1440 .binary = blk_trace_event_print_binary,
1441 };
1442
1443 static struct trace_event trace_blk_event = {
1444 .type = TRACE_BLK,
1445 .funcs = &trace_blk_event_funcs,
1446 };
1447
1448 static int __init init_blk_tracer(void)
1449 {
1450 if (!register_ftrace_event(&trace_blk_event)) {
1451 pr_warning("Warning: could not register block events\n");
1452 return 1;
1453 }
1454
1455 if (register_tracer(&blk_tracer) != 0) {
1456 pr_warning("Warning: could not register the block tracer\n");
1457 unregister_ftrace_event(&trace_blk_event);
1458 return 1;
1459 }
1460
1461 return 0;
1462 }
1463
1464 device_initcall(init_blk_tracer);
1465
1466 static int blk_trace_remove_queue(struct request_queue *q)
1467 {
1468 struct blk_trace *bt;
1469
1470 bt = xchg(&q->blk_trace, NULL);
1471 if (bt == NULL)
1472 return -EINVAL;
1473
1474 if (atomic_dec_and_test(&blk_probes_ref))
1475 blk_unregister_tracepoints();
1476
1477 blk_trace_free(bt);
1478 return 0;
1479 }
1480
1481 /*
1482 * Setup everything required to start tracing
1483 */
1484 static int blk_trace_setup_queue(struct request_queue *q,
1485 struct block_device *bdev)
1486 {
1487 struct blk_trace *old_bt, *bt = NULL;
1488 int ret = -ENOMEM;
1489
1490 bt = kzalloc(sizeof(*bt), GFP_KERNEL);
1491 if (!bt)
1492 return -ENOMEM;
1493
1494 bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
1495 if (!bt->msg_data)
1496 goto free_bt;
1497
1498 bt->dev = bdev->bd_dev;
1499 bt->act_mask = (u16)-1;
1500
1501 blk_trace_setup_lba(bt, bdev);
1502
1503 old_bt = xchg(&q->blk_trace, bt);
1504 if (old_bt != NULL) {
1505 (void)xchg(&q->blk_trace, old_bt);
1506 ret = -EBUSY;
1507 goto free_bt;
1508 }
1509
1510 if (atomic_inc_return(&blk_probes_ref) == 1)
1511 blk_register_tracepoints();
1512 return 0;
1513
1514 free_bt:
1515 blk_trace_free(bt);
1516 return ret;
1517 }
1518
1519 /*
1520 * sysfs interface to enable and configure tracing
1521 */
1522
1523 static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
1524 struct device_attribute *attr,
1525 char *buf);
1526 static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
1527 struct device_attribute *attr,
1528 const char *buf, size_t count);
1529 #define BLK_TRACE_DEVICE_ATTR(_name) \
1530 DEVICE_ATTR(_name, S_IRUGO | S_IWUSR, \
1531 sysfs_blk_trace_attr_show, \
1532 sysfs_blk_trace_attr_store)
1533
1534 static BLK_TRACE_DEVICE_ATTR(enable);
1535 static BLK_TRACE_DEVICE_ATTR(act_mask);
1536 static BLK_TRACE_DEVICE_ATTR(pid);
1537 static BLK_TRACE_DEVICE_ATTR(start_lba);
1538 static BLK_TRACE_DEVICE_ATTR(end_lba);
1539
1540 static struct attribute *blk_trace_attrs[] = {
1541 &dev_attr_enable.attr,
1542 &dev_attr_act_mask.attr,
1543 &dev_attr_pid.attr,
1544 &dev_attr_start_lba.attr,
1545 &dev_attr_end_lba.attr,
1546 NULL
1547 };
1548
1549 struct attribute_group blk_trace_attr_group = {
1550 .name = "trace",
1551 .attrs = blk_trace_attrs,
1552 };
1553
1554 static const struct {
1555 int mask;
1556 const char *str;
1557 } mask_maps[] = {
1558 { BLK_TC_READ, "read" },
1559 { BLK_TC_WRITE, "write" },
1560 { BLK_TC_FLUSH, "flush" },
1561 { BLK_TC_SYNC, "sync" },
1562 { BLK_TC_QUEUE, "queue" },
1563 { BLK_TC_REQUEUE, "requeue" },
1564 { BLK_TC_ISSUE, "issue" },
1565 { BLK_TC_COMPLETE, "complete" },
1566 { BLK_TC_FS, "fs" },
1567 { BLK_TC_PC, "pc" },
1568 { BLK_TC_AHEAD, "ahead" },
1569 { BLK_TC_META, "meta" },
1570 { BLK_TC_DISCARD, "discard" },
1571 { BLK_TC_DRV_DATA, "drv_data" },
1572 { BLK_TC_FUA, "fua" },
1573 };
1574
1575 static int blk_trace_str2mask(const char *str)
1576 {
1577 int i;
1578 int mask = 0;
1579 char *buf, *s, *token;
1580
1581 buf = kstrdup(str, GFP_KERNEL);
1582 if (buf == NULL)
1583 return -ENOMEM;
1584 s = strstrip(buf);
1585
1586 while (1) {
1587 token = strsep(&s, ",");
1588 if (token == NULL)
1589 break;
1590
1591 if (*token == '\0')
1592 continue;
1593
1594 for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
1595 if (strcasecmp(token, mask_maps[i].str) == 0) {
1596 mask |= mask_maps[i].mask;
1597 break;
1598 }
1599 }
1600 if (i == ARRAY_SIZE(mask_maps)) {
1601 mask = -EINVAL;
1602 break;
1603 }
1604 }
1605 kfree(buf);
1606
1607 return mask;
1608 }
1609
1610 static ssize_t blk_trace_mask2str(char *buf, int mask)
1611 {
1612 int i;
1613 char *p = buf;
1614
1615 for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
1616 if (mask & mask_maps[i].mask) {
1617 p += sprintf(p, "%s%s",
1618 (p == buf) ? "" : ",", mask_maps[i].str);
1619 }
1620 }
1621 *p++ = '\n';
1622
1623 return p - buf;
1624 }
1625
1626 static struct request_queue *blk_trace_get_queue(struct block_device *bdev)
1627 {
1628 if (bdev->bd_disk == NULL)
1629 return NULL;
1630
1631 return bdev_get_queue(bdev);
1632 }
1633
1634 static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
1635 struct device_attribute *attr,
1636 char *buf)
1637 {
1638 struct hd_struct *p = dev_to_part(dev);
1639 struct request_queue *q;
1640 struct block_device *bdev;
1641 ssize_t ret = -ENXIO;
1642
1643 bdev = bdget(part_devt(p));
1644 if (bdev == NULL)
1645 goto out;
1646
1647 q = blk_trace_get_queue(bdev);
1648 if (q == NULL)
1649 goto out_bdput;
1650
1651 mutex_lock(&bdev->bd_mutex);
1652
1653 if (attr == &dev_attr_enable) {
1654 ret = sprintf(buf, "%u\n", !!q->blk_trace);
1655 goto out_unlock_bdev;
1656 }
1657
1658 if (q->blk_trace == NULL)
1659 ret = sprintf(buf, "disabled\n");
1660 else if (attr == &dev_attr_act_mask)
1661 ret = blk_trace_mask2str(buf, q->blk_trace->act_mask);
1662 else if (attr == &dev_attr_pid)
1663 ret = sprintf(buf, "%u\n", q->blk_trace->pid);
1664 else if (attr == &dev_attr_start_lba)
1665 ret = sprintf(buf, "%llu\n", q->blk_trace->start_lba);
1666 else if (attr == &dev_attr_end_lba)
1667 ret = sprintf(buf, "%llu\n", q->blk_trace->end_lba);
1668
1669 out_unlock_bdev:
1670 mutex_unlock(&bdev->bd_mutex);
1671 out_bdput:
1672 bdput(bdev);
1673 out:
1674 return ret;
1675 }
1676
1677 static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
1678 struct device_attribute *attr,
1679 const char *buf, size_t count)
1680 {
1681 struct block_device *bdev;
1682 struct request_queue *q;
1683 struct hd_struct *p;
1684 u64 value;
1685 ssize_t ret = -EINVAL;
1686
1687 if (count == 0)
1688 goto out;
1689
1690 if (attr == &dev_attr_act_mask) {
1691 if (sscanf(buf, "%llx", &value) != 1) {
1692 /* Assume it is a list of trace category names */
1693 ret = blk_trace_str2mask(buf);
1694 if (ret < 0)
1695 goto out;
1696 value = ret;
1697 }
1698 } else if (sscanf(buf, "%llu", &value) != 1)
1699 goto out;
1700
1701 ret = -ENXIO;
1702
1703 p = dev_to_part(dev);
1704 bdev = bdget(part_devt(p));
1705 if (bdev == NULL)
1706 goto out;
1707
1708 q = blk_trace_get_queue(bdev);
1709 if (q == NULL)
1710 goto out_bdput;
1711
1712 mutex_lock(&bdev->bd_mutex);
1713
1714 if (attr == &dev_attr_enable) {
1715 if (value)
1716 ret = blk_trace_setup_queue(q, bdev);
1717 else
1718 ret = blk_trace_remove_queue(q);
1719 goto out_unlock_bdev;
1720 }
1721
1722 ret = 0;
1723 if (q->blk_trace == NULL)
1724 ret = blk_trace_setup_queue(q, bdev);
1725
1726 if (ret == 0) {
1727 if (attr == &dev_attr_act_mask)
1728 q->blk_trace->act_mask = value;
1729 else if (attr == &dev_attr_pid)
1730 q->blk_trace->pid = value;
1731 else if (attr == &dev_attr_start_lba)
1732 q->blk_trace->start_lba = value;
1733 else if (attr == &dev_attr_end_lba)
1734 q->blk_trace->end_lba = value;
1735 }
1736
1737 out_unlock_bdev:
1738 mutex_unlock(&bdev->bd_mutex);
1739 out_bdput:
1740 bdput(bdev);
1741 out:
1742 return ret ? ret : count;
1743 }
1744
1745 int blk_trace_init_sysfs(struct device *dev)
1746 {
1747 return sysfs_create_group(&dev->kobj, &blk_trace_attr_group);
1748 }
1749
1750 void blk_trace_remove_sysfs(struct device *dev)
1751 {
1752 sysfs_remove_group(&dev->kobj, &blk_trace_attr_group);
1753 }
1754
1755 #endif /* CONFIG_BLK_DEV_IO_TRACE */
1756
1757 #ifdef CONFIG_EVENT_TRACING
1758
1759 void blk_dump_cmd(char *buf, struct request *rq)
1760 {
1761 int i, end;
1762 int len = rq->cmd_len;
1763 unsigned char *cmd = rq->cmd;
1764
1765 if (rq->cmd_type != REQ_TYPE_BLOCK_PC) {
1766 buf[0] = '\0';
1767 return;
1768 }
1769
1770 for (end = len - 1; end >= 0; end--)
1771 if (cmd[end])
1772 break;
1773 end++;
1774
1775 for (i = 0; i < len; i++) {
1776 buf += sprintf(buf, "%s%02x", i == 0 ? "" : " ", cmd[i]);
1777 if (i == end && end != len - 1) {
1778 sprintf(buf, " ..");
1779 break;
1780 }
1781 }
1782 }
1783
1784 void blk_fill_rwbs(char *rwbs, u32 rw, int bytes)
1785 {
1786 int i = 0;
1787
1788 if (rw & REQ_FLUSH)
1789 rwbs[i++] = 'F';
1790
1791 if (rw & WRITE)
1792 rwbs[i++] = 'W';
1793 else if (rw & REQ_DISCARD)
1794 rwbs[i++] = 'D';
1795 else if (bytes)
1796 rwbs[i++] = 'R';
1797 else
1798 rwbs[i++] = 'N';
1799
1800 if (rw & REQ_FUA)
1801 rwbs[i++] = 'F';
1802 if (rw & REQ_RAHEAD)
1803 rwbs[i++] = 'A';
1804 if (rw & REQ_SYNC)
1805 rwbs[i++] = 'S';
1806 if (rw & REQ_META)
1807 rwbs[i++] = 'M';
1808 if (rw & REQ_SECURE)
1809 rwbs[i++] = 'E';
1810
1811 rwbs[i] = '\0';
1812 }
1813 EXPORT_SYMBOL_GPL(blk_fill_rwbs);
1814
1815 #endif /* CONFIG_EVENT_TRACING */
1816
kernel source for telekom puls (alcatel/mediatek)