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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/time.h>
27#include <linux/uaccess.h>
28
29#include <trace/events/block.h>
30
31#include "trace_output.h"
32
33#ifdef CONFIG_BLK_DEV_IO_TRACE
34
35static unsigned int blktrace_seq __read_mostly = 1;
36
37static struct trace_array *blk_tr;
38static bool blk_tracer_enabled __read_mostly;
39
40
41#define TRACE_BLK_OPT_CLASSIC 0x1
42
43static struct tracer_opt blk_tracer_opts[] = {
44
45 { TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) },
46 { }
47};
48
49static struct tracer_flags blk_tracer_flags = {
50 .val = 0,
51 .opts = blk_tracer_opts,
52};
53
54
55static atomic_t blk_probes_ref = ATOMIC_INIT(0);
56
57static void blk_register_tracepoints(void);
58static void blk_unregister_tracepoints(void);
59
60
61
62
63static void trace_note(struct blk_trace *bt, pid_t pid, int action,
64 const void *data, size_t len)
65{
66 struct blk_io_trace *t;
67 struct ring_buffer_event *event = NULL;
68 struct ring_buffer *buffer = NULL;
69 int pc = 0;
70 int cpu = smp_processor_id();
71 bool blk_tracer = blk_tracer_enabled;
72
73 if (blk_tracer) {
74 buffer = blk_tr->buffer;
75 pc = preempt_count();
76 event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
77 sizeof(*t) + len,
78 0, pc);
79 if (!event)
80 return;
81 t = ring_buffer_event_data(event);
82 goto record_it;
83 }
84
85 if (!bt->rchan)
86 return;
87
88 t = relay_reserve(bt->rchan, sizeof(*t) + len);
89 if (t) {
90 t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
91 t->time = ktime_to_ns(ktime_get());
92record_it:
93 t->device = bt->dev;
94 t->action = action;
95 t->pid = pid;
96 t->cpu = cpu;
97 t->pdu_len = len;
98 memcpy((void *) t + sizeof(*t), data, len);
99
100 if (blk_tracer)
101 trace_buffer_unlock_commit(buffer, event, 0, pc);
102 }
103}
104
105
106
107
108
109static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk)
110{
111 tsk->btrace_seq = blktrace_seq;
112 trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm, sizeof(tsk->comm));
113}
114
115static void trace_note_time(struct blk_trace *bt)
116{
117 struct timespec now;
118 unsigned long flags;
119 u32 words[2];
120
121 getnstimeofday(&now);
122 words[0] = now.tv_sec;
123 words[1] = now.tv_nsec;
124
125 local_irq_save(flags);
126 trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words));
127 local_irq_restore(flags);
128}
129
130void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
131{
132 int n;
133 va_list args;
134 unsigned long flags;
135 char *buf;
136
137 if (unlikely(bt->trace_state != Blktrace_running &&
138 !blk_tracer_enabled))
139 return;
140
141
142
143
144
145 if (!(bt->act_mask & BLK_TC_NOTIFY))
146 return;
147
148 local_irq_save(flags);
149 buf = per_cpu_ptr(bt->msg_data, smp_processor_id());
150 va_start(args, fmt);
151 n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
152 va_end(args);
153
154 trace_note(bt, 0, BLK_TN_MESSAGE, buf, n);
155 local_irq_restore(flags);
156}
157EXPORT_SYMBOL_GPL(__trace_note_message);
158
159static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
160 pid_t pid)
161{
162 if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0)
163 return 1;
164 if (sector && (sector < bt->start_lba || sector > bt->end_lba))
165 return 1;
166 if (bt->pid && pid != bt->pid)
167 return 1;
168
169 return 0;
170}
171
172
173
174
175static const u32 ddir_act[2] = { BLK_TC_ACT(BLK_TC_READ),
176 BLK_TC_ACT(BLK_TC_WRITE) };
177
178#define BLK_TC_RAHEAD BLK_TC_AHEAD
179
180
181#define MASK_TC_BIT(rw, __name) ((rw & REQ_ ## __name) << \
182 (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - __REQ_ ## __name))
183
184
185
186
187
188static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
189 int rw, u32 what, int error, int pdu_len, void *pdu_data)
190{
191 struct task_struct *tsk = current;
192 struct ring_buffer_event *event = NULL;
193 struct ring_buffer *buffer = NULL;
194 struct blk_io_trace *t;
195 unsigned long flags = 0;
196 unsigned long *sequence;
197 pid_t pid;
198 int cpu, pc = 0;
199 bool blk_tracer = blk_tracer_enabled;
200
201 if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer))
202 return;
203
204 what |= ddir_act[rw & WRITE];
205 what |= MASK_TC_BIT(rw, SYNC);
206 what |= MASK_TC_BIT(rw, RAHEAD);
207 what |= MASK_TC_BIT(rw, META);
208 what |= MASK_TC_BIT(rw, DISCARD);
209
210 pid = tsk->pid;
211 if (act_log_check(bt, what, sector, pid))
212 return;
213 cpu = raw_smp_processor_id();
214
215 if (blk_tracer) {
216 tracing_record_cmdline(current);
217
218 buffer = blk_tr->buffer;
219 pc = preempt_count();
220 event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
221 sizeof(*t) + pdu_len,
222 0, pc);
223 if (!event)
224 return;
225 t = ring_buffer_event_data(event);
226 goto record_it;
227 }
228
229
230
231
232
233
234 local_irq_save(flags);
235
236 if (unlikely(tsk->btrace_seq != blktrace_seq))
237 trace_note_tsk(bt, tsk);
238
239 t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len);
240 if (t) {
241 sequence = per_cpu_ptr(bt->sequence, cpu);
242
243 t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
244 t->sequence = ++(*sequence);
245 t->time = ktime_to_ns(ktime_get());
246record_it:
247
248
249
250
251
252
253 t->cpu = cpu;
254 t->pid = pid;
255
256 t->sector = sector;
257 t->bytes = bytes;
258 t->action = what;
259 t->device = bt->dev;
260 t->error = error;
261 t->pdu_len = pdu_len;
262
263 if (pdu_len)
264 memcpy((void *) t + sizeof(*t), pdu_data, pdu_len);
265
266 if (blk_tracer) {
267 trace_buffer_unlock_commit(buffer, event, 0, pc);
268 return;
269 }
270 }
271
272 local_irq_restore(flags);
273}
274
275static struct dentry *blk_tree_root;
276static DEFINE_MUTEX(blk_tree_mutex);
277
278static void blk_trace_free(struct blk_trace *bt)
279{
280 debugfs_remove(bt->msg_file);
281 debugfs_remove(bt->dropped_file);
282 relay_close(bt->rchan);
283 debugfs_remove(bt->dir);
284 free_percpu(bt->sequence);
285 free_percpu(bt->msg_data);
286 kfree(bt);
287}
288
289static void blk_trace_cleanup(struct blk_trace *bt)
290{
291 blk_trace_free(bt);
292 if (atomic_dec_and_test(&blk_probes_ref))
293 blk_unregister_tracepoints();
294}
295
296int blk_trace_remove(struct request_queue *q)
297{
298 struct blk_trace *bt;
299
300 bt = xchg(&q->blk_trace, NULL);
301 if (!bt)
302 return -EINVAL;
303
304 if (bt->trace_state != Blktrace_running)
305 blk_trace_cleanup(bt);
306
307 return 0;
308}
309EXPORT_SYMBOL_GPL(blk_trace_remove);
310
311static int blk_dropped_open(struct inode *inode, struct file *filp)
312{
313 filp->private_data = inode->i_private;
314
315 return 0;
316}
317
318static ssize_t blk_dropped_read(struct file *filp, char __user *buffer,
319 size_t count, loff_t *ppos)
320{
321 struct blk_trace *bt = filp->private_data;
322 char buf[16];
323
324 snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped));
325
326 return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf));
327}
328
329static const struct file_operations blk_dropped_fops = {
330 .owner = THIS_MODULE,
331 .open = blk_dropped_open,
332 .read = blk_dropped_read,
333 .llseek = default_llseek,
334};
335
336static int blk_msg_open(struct inode *inode, struct file *filp)
337{
338 filp->private_data = inode->i_private;
339
340 return 0;
341}
342
343static ssize_t blk_msg_write(struct file *filp, const char __user *buffer,
344 size_t count, loff_t *ppos)
345{
346 char *msg;
347 struct blk_trace *bt;
348
349 if (count >= BLK_TN_MAX_MSG)
350 return -EINVAL;
351
352 msg = kmalloc(count + 1, GFP_KERNEL);
353 if (msg == NULL)
354 return -ENOMEM;
355
356 if (copy_from_user(msg, buffer, count)) {
357 kfree(msg);
358 return -EFAULT;
359 }
360
361 msg[count] = '\0';
362 bt = filp->private_data;
363 __trace_note_message(bt, "%s", msg);
364 kfree(msg);
365
366 return count;
367}
368
369static const struct file_operations blk_msg_fops = {
370 .owner = THIS_MODULE,
371 .open = blk_msg_open,
372 .write = blk_msg_write,
373 .llseek = noop_llseek,
374};
375
376
377
378
379
380static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf,
381 void *prev_subbuf, size_t prev_padding)
382{
383 struct blk_trace *bt;
384
385 if (!relay_buf_full(buf))
386 return 1;
387
388 bt = buf->chan->private_data;
389 atomic_inc(&bt->dropped);
390 return 0;
391}
392
393static int blk_remove_buf_file_callback(struct dentry *dentry)
394{
395 debugfs_remove(dentry);
396
397 return 0;
398}
399
400static struct dentry *blk_create_buf_file_callback(const char *filename,
401 struct dentry *parent,
402 int mode,
403 struct rchan_buf *buf,
404 int *is_global)
405{
406 return debugfs_create_file(filename, mode, parent, buf,
407 &relay_file_operations);
408}
409
410static struct rchan_callbacks blk_relay_callbacks = {
411 .subbuf_start = blk_subbuf_start_callback,
412 .create_buf_file = blk_create_buf_file_callback,
413 .remove_buf_file = blk_remove_buf_file_callback,
414};
415
416static void blk_trace_setup_lba(struct blk_trace *bt,
417 struct block_device *bdev)
418{
419 struct hd_struct *part = NULL;
420
421 if (bdev)
422 part = bdev->bd_part;
423
424 if (part) {
425 bt->start_lba = part->start_sect;
426 bt->end_lba = part->start_sect + part->nr_sects;
427 } else {
428 bt->start_lba = 0;
429 bt->end_lba = -1ULL;
430 }
431}
432
433
434
435
436int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
437 struct block_device *bdev,
438 struct blk_user_trace_setup *buts)
439{
440 struct blk_trace *old_bt, *bt = NULL;
441 struct dentry *dir = NULL;
442 int ret, i;
443
444 if (!buts->buf_size || !buts->buf_nr)
445 return -EINVAL;
446
447 strncpy(buts->name, name, BLKTRACE_BDEV_SIZE);
448 buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0';
449
450
451
452
453
454 for (i = 0; i < strlen(buts->name); i++)
455 if (buts->name[i] == '/')
456 buts->name[i] = '_';
457
458 bt = kzalloc(sizeof(*bt), GFP_KERNEL);
459 if (!bt)
460 return -ENOMEM;
461
462 ret = -ENOMEM;
463 bt->sequence = alloc_percpu(unsigned long);
464 if (!bt->sequence)
465 goto err;
466
467 bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
468 if (!bt->msg_data)
469 goto err;
470
471 ret = -ENOENT;
472
473 mutex_lock(&blk_tree_mutex);
474 if (!blk_tree_root) {
475 blk_tree_root = debugfs_create_dir("block", NULL);
476 if (!blk_tree_root) {
477 mutex_unlock(&blk_tree_mutex);
478 goto err;
479 }
480 }
481 mutex_unlock(&blk_tree_mutex);
482
483 dir = debugfs_create_dir(buts->name, blk_tree_root);
484
485 if (!dir)
486 goto err;
487
488 bt->dir = dir;
489 bt->dev = dev;
490 atomic_set(&bt->dropped, 0);
491
492 ret = -EIO;
493 bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt,
494 &blk_dropped_fops);
495 if (!bt->dropped_file)
496 goto err;
497
498 bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops);
499 if (!bt->msg_file)
500 goto err;
501
502 bt->rchan = relay_open("trace", dir, buts->buf_size,
503 buts->buf_nr, &blk_relay_callbacks, bt);
504 if (!bt->rchan)
505 goto err;
506
507 bt->act_mask = buts->act_mask;
508 if (!bt->act_mask)
509 bt->act_mask = (u16) -1;
510
511 blk_trace_setup_lba(bt, bdev);
512
513
514 if (buts->start_lba)
515 bt->start_lba = buts->start_lba;
516 if (buts->end_lba)
517 bt->end_lba = buts->end_lba;
518
519 bt->pid = buts->pid;
520 bt->trace_state = Blktrace_setup;
521
522 ret = -EBUSY;
523 old_bt = xchg(&q->blk_trace, bt);
524 if (old_bt) {
525 (void) xchg(&q->blk_trace, old_bt);
526 goto err;
527 }
528
529 if (atomic_inc_return(&blk_probes_ref) == 1)
530 blk_register_tracepoints();
531
532 return 0;
533err:
534 blk_trace_free(bt);
535 return ret;
536}
537
538int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
539 struct block_device *bdev,
540 char __user *arg)
541{
542 struct blk_user_trace_setup buts;
543 int ret;
544
545 ret = copy_from_user(&buts, arg, sizeof(buts));
546 if (ret)
547 return -EFAULT;
548
549 ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
550 if (ret)
551 return ret;
552
553 if (copy_to_user(arg, &buts, sizeof(buts))) {
554 blk_trace_remove(q);
555 return -EFAULT;
556 }
557 return 0;
558}
559EXPORT_SYMBOL_GPL(blk_trace_setup);
560
561#if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
562static int compat_blk_trace_setup(struct request_queue *q, char *name,
563 dev_t dev, struct block_device *bdev,
564 char __user *arg)
565{
566 struct blk_user_trace_setup buts;
567 struct compat_blk_user_trace_setup cbuts;
568 int ret;
569
570 if (copy_from_user(&cbuts, arg, sizeof(cbuts)))
571 return -EFAULT;
572
573 buts = (struct blk_user_trace_setup) {
574 .act_mask = cbuts.act_mask,
575 .buf_size = cbuts.buf_size,
576 .buf_nr = cbuts.buf_nr,
577 .start_lba = cbuts.start_lba,
578 .end_lba = cbuts.end_lba,
579 .pid = cbuts.pid,
580 };
581 memcpy(&buts.name, &cbuts.name, 32);
582
583 ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
584 if (ret)
585 return ret;
586
587 if (copy_to_user(arg, &buts.name, 32)) {
588 blk_trace_remove(q);
589 return -EFAULT;
590 }
591
592 return 0;
593}
594#endif
595
596int blk_trace_startstop(struct request_queue *q, int start)
597{
598 int ret;
599 struct blk_trace *bt = q->blk_trace;
600
601 if (bt == NULL)
602 return -EINVAL;
603
604
605
606
607
608 ret = -EINVAL;
609 if (start) {
610 if (bt->trace_state == Blktrace_setup ||
611 bt->trace_state == Blktrace_stopped) {
612 blktrace_seq++;
613 smp_mb();
614 bt->trace_state = Blktrace_running;
615
616 trace_note_time(bt);
617 ret = 0;
618 }
619 } else {
620 if (bt->trace_state == Blktrace_running) {
621 bt->trace_state = Blktrace_stopped;
622 relay_flush(bt->rchan);
623 ret = 0;
624 }
625 }
626
627 return ret;
628}
629EXPORT_SYMBOL_GPL(blk_trace_startstop);
630
631
632
633
634
635
636
637
638int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
639{
640 struct request_queue *q;
641 int ret, start = 0;
642 char b[BDEVNAME_SIZE];
643
644 q = bdev_get_queue(bdev);
645 if (!q)
646 return -ENXIO;
647
648 mutex_lock(&bdev->bd_mutex);
649
650 switch (cmd) {
651 case BLKTRACESETUP:
652 bdevname(bdev, b);
653 ret = blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
654 break;
655#if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
656 case BLKTRACESETUP32:
657 bdevname(bdev, b);
658 ret = compat_blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
659 break;
660#endif
661 case BLKTRACESTART:
662 start = 1;
663 case BLKTRACESTOP:
664 ret = blk_trace_startstop(q, start);
665 break;
666 case BLKTRACETEARDOWN:
667 ret = blk_trace_remove(q);
668 break;
669 default:
670 ret = -ENOTTY;
671 break;
672 }
673
674 mutex_unlock(&bdev->bd_mutex);
675 return ret;
676}
677
678
679
680
681
682
683void blk_trace_shutdown(struct request_queue *q)
684{
685 if (q->blk_trace) {
686 blk_trace_startstop(q, 0);
687 blk_trace_remove(q);
688 }
689}
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
706 u32 what)
707{
708 struct blk_trace *bt = q->blk_trace;
709
710 if (likely(!bt))
711 return;
712
713 if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
714 what |= BLK_TC_ACT(BLK_TC_PC);
715 __blk_add_trace(bt, 0, blk_rq_bytes(rq), rq->cmd_flags,
716 what, rq->errors, rq->cmd_len, rq->cmd);
717 } else {
718 what |= BLK_TC_ACT(BLK_TC_FS);
719 __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
720 rq->cmd_flags, what, rq->errors, 0, NULL);
721 }
722}
723
724static void blk_add_trace_rq_abort(void *ignore,
725 struct request_queue *q, struct request *rq)
726{
727 blk_add_trace_rq(q, rq, BLK_TA_ABORT);
728}
729
730static void blk_add_trace_rq_insert(void *ignore,
731 struct request_queue *q, struct request *rq)
732{
733 blk_add_trace_rq(q, rq, BLK_TA_INSERT);
734}
735
736static void blk_add_trace_rq_issue(void *ignore,
737 struct request_queue *q, struct request *rq)
738{
739 blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
740}
741
742static void blk_add_trace_rq_requeue(void *ignore,
743 struct request_queue *q,
744 struct request *rq)
745{
746 blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
747}
748
749static void blk_add_trace_rq_complete(void *ignore,
750 struct request_queue *q,
751 struct request *rq)
752{
753 blk_add_trace_rq(q, rq, BLK_TA_COMPLETE);
754}
755
756
757
758
759
760
761
762
763
764
765
766
767static void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
768 u32 what, int error)
769{
770 struct blk_trace *bt = q->blk_trace;
771
772 if (likely(!bt))
773 return;
774
775 if (!error && !bio_flagged(bio, BIO_UPTODATE))
776 error = EIO;
777
778 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what,
779 error, 0, NULL);
780}
781
782static void blk_add_trace_bio_bounce(void *ignore,
783 struct request_queue *q, struct bio *bio)
784{
785 blk_add_trace_bio(q, bio, BLK_TA_BOUNCE, 0);
786}
787
788static void blk_add_trace_bio_complete(void *ignore,
789 struct request_queue *q, struct bio *bio,
790 int error)
791{
792 blk_add_trace_bio(q, bio, BLK_TA_COMPLETE, error);
793}
794
795static void blk_add_trace_bio_backmerge(void *ignore,
796 struct request_queue *q,
797 struct bio *bio)
798{
799 blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE, 0);
800}
801
802static void blk_add_trace_bio_frontmerge(void *ignore,
803 struct request_queue *q,
804 struct bio *bio)
805{
806 blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE, 0);
807}
808
809static void blk_add_trace_bio_queue(void *ignore,
810 struct request_queue *q, struct bio *bio)
811{
812 blk_add_trace_bio(q, bio, BLK_TA_QUEUE, 0);
813}
814
815static void blk_add_trace_getrq(void *ignore,
816 struct request_queue *q,
817 struct bio *bio, int rw)
818{
819 if (bio)
820 blk_add_trace_bio(q, bio, BLK_TA_GETRQ, 0);
821 else {
822 struct blk_trace *bt = q->blk_trace;
823
824 if (bt)
825 __blk_add_trace(bt, 0, 0, rw, BLK_TA_GETRQ, 0, 0, NULL);
826 }
827}
828
829
830static void blk_add_trace_sleeprq(void *ignore,
831 struct request_queue *q,
832 struct bio *bio, int rw)
833{
834 if (bio)
835 blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ, 0);
836 else {
837 struct blk_trace *bt = q->blk_trace;
838
839 if (bt)
840 __blk_add_trace(bt, 0, 0, rw, BLK_TA_SLEEPRQ,
841 0, 0, NULL);
842 }
843}
844
845static void blk_add_trace_plug(void *ignore, struct request_queue *q)
846{
847 struct blk_trace *bt = q->blk_trace;
848
849 if (bt)
850 __blk_add_trace(bt, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL);
851}
852
853static void blk_add_trace_unplug(void *ignore, struct request_queue *q,
854 unsigned int depth, bool explicit)
855{
856 struct blk_trace *bt = q->blk_trace;
857
858 if (bt) {
859 __be64 rpdu = cpu_to_be64(depth);
860 u32 what;
861
862 if (explicit)
863 what = BLK_TA_UNPLUG_IO;
864 else
865 what = BLK_TA_UNPLUG_TIMER;
866
867 __blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu);
868 }
869}
870
871static void blk_add_trace_split(void *ignore,
872 struct request_queue *q, struct bio *bio,
873 unsigned int pdu)
874{
875 struct blk_trace *bt = q->blk_trace;
876
877 if (bt) {
878 __be64 rpdu = cpu_to_be64(pdu);
879
880 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw,
881 BLK_TA_SPLIT, !bio_flagged(bio, BIO_UPTODATE),
882 sizeof(rpdu), &rpdu);
883 }
884}
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899static void blk_add_trace_bio_remap(void *ignore,
900 struct request_queue *q, struct bio *bio,
901 dev_t dev, sector_t from)
902{
903 struct blk_trace *bt = q->blk_trace;
904 struct blk_io_trace_remap r;
905
906 if (likely(!bt))
907 return;
908
909 r.device_from = cpu_to_be32(dev);
910 r.device_to = cpu_to_be32(bio->bi_bdev->bd_dev);
911 r.sector_from = cpu_to_be64(from);
912
913 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw,
914 BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE),
915 sizeof(r), &r);
916}
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931static void blk_add_trace_rq_remap(void *ignore,
932 struct request_queue *q,
933 struct request *rq, dev_t dev,
934 sector_t from)
935{
936 struct blk_trace *bt = q->blk_trace;
937 struct blk_io_trace_remap r;
938
939 if (likely(!bt))
940 return;
941
942 r.device_from = cpu_to_be32(dev);
943 r.device_to = cpu_to_be32(disk_devt(rq->rq_disk));
944 r.sector_from = cpu_to_be64(from);
945
946 __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
947 rq_data_dir(rq), BLK_TA_REMAP, !!rq->errors,
948 sizeof(r), &r);
949}
950
951
952
953
954
955
956
957
958
959
960
961
962void blk_add_driver_data(struct request_queue *q,
963 struct request *rq,
964 void *data, size_t len)
965{
966 struct blk_trace *bt = q->blk_trace;
967
968 if (likely(!bt))
969 return;
970
971 if (rq->cmd_type == REQ_TYPE_BLOCK_PC)
972 __blk_add_trace(bt, 0, blk_rq_bytes(rq), 0,
973 BLK_TA_DRV_DATA, rq->errors, len, data);
974 else
975 __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq), 0,
976 BLK_TA_DRV_DATA, rq->errors, len, data);
977}
978EXPORT_SYMBOL_GPL(blk_add_driver_data);
979
980static void blk_register_tracepoints(void)
981{
982 int ret;
983
984 ret = register_trace_block_rq_abort(blk_add_trace_rq_abort, NULL);
985 WARN_ON(ret);
986 ret = register_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
987 WARN_ON(ret);
988 ret = register_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
989 WARN_ON(ret);
990 ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
991 WARN_ON(ret);
992 ret = register_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
993 WARN_ON(ret);
994 ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL);
995 WARN_ON(ret);
996 ret = register_trace_block_bio_complete(blk_add_trace_bio_complete, NULL);
997 WARN_ON(ret);
998 ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL);
999 WARN_ON(ret);
1000 ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
1001 WARN_ON(ret);
1002 ret = register_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
1003 WARN_ON(ret);
1004 ret = register_trace_block_getrq(blk_add_trace_getrq, NULL);
1005 WARN_ON(ret);
1006 ret = register_trace_block_sleeprq(blk_add_trace_sleeprq, NULL);
1007 WARN_ON(ret);
1008 ret = register_trace_block_plug(blk_add_trace_plug, NULL);
1009 WARN_ON(ret);
1010 ret = register_trace_block_unplug(blk_add_trace_unplug, NULL);
1011 WARN_ON(ret);
1012 ret = register_trace_block_split(blk_add_trace_split, NULL);
1013 WARN_ON(ret);
1014 ret = register_trace_block_bio_remap(blk_add_trace_bio_remap, NULL);
1015 WARN_ON(ret);
1016 ret = register_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);
1017 WARN_ON(ret);
1018}
1019
1020static void blk_unregister_tracepoints(void)
1021{
1022 unregister_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);
1023 unregister_trace_block_bio_remap(blk_add_trace_bio_remap, NULL);
1024 unregister_trace_block_split(blk_add_trace_split, NULL);
1025 unregister_trace_block_unplug(blk_add_trace_unplug, NULL);
1026 unregister_trace_block_plug(blk_add_trace_plug, NULL);
1027 unregister_trace_block_sleeprq(blk_add_trace_sleeprq, NULL);
1028 unregister_trace_block_getrq(blk_add_trace_getrq, NULL);
1029 unregister_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
1030 unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
1031 unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL);
1032 unregister_trace_block_bio_complete(blk_add_trace_bio_complete, NULL);
1033 unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL);
1034 unregister_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
1035 unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
1036 unregister_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
1037 unregister_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
1038 unregister_trace_block_rq_abort(blk_add_trace_rq_abort, NULL);
1039
1040 tracepoint_synchronize_unregister();
1041}
1042
1043
1044
1045
1046
1047static void fill_rwbs(char *rwbs, const struct blk_io_trace *t)
1048{
1049 int i = 0;
1050 int tc = t->action >> BLK_TC_SHIFT;
1051
1052 if (t->action == BLK_TN_MESSAGE) {
1053 rwbs[i++] = 'N';
1054 goto out;
1055 }
1056
1057 if (tc & BLK_TC_DISCARD)
1058 rwbs[i++] = 'D';
1059 else if (tc & BLK_TC_WRITE)
1060 rwbs[i++] = 'W';
1061 else if (t->bytes)
1062 rwbs[i++] = 'R';
1063 else
1064 rwbs[i++] = 'N';
1065
1066 if (tc & BLK_TC_AHEAD)
1067 rwbs[i++] = 'A';
1068 if (tc & BLK_TC_BARRIER)
1069 rwbs[i++] = 'B';
1070 if (tc & BLK_TC_SYNC)
1071 rwbs[i++] = 'S';
1072 if (tc & BLK_TC_META)
1073 rwbs[i++] = 'M';
1074out:
1075 rwbs[i] = '\0';
1076}
1077
1078static inline
1079const struct blk_io_trace *te_blk_io_trace(const struct trace_entry *ent)
1080{
1081 return (const struct blk_io_trace *)ent;
1082}
1083
1084static inline const void *pdu_start(const struct trace_entry *ent)
1085{
1086 return te_blk_io_trace(ent) + 1;
1087}
1088
1089static inline u32 t_action(const struct trace_entry *ent)
1090{
1091 return te_blk_io_trace(ent)->action;
1092}
1093
1094static inline u32 t_bytes(const struct trace_entry *ent)
1095{
1096 return te_blk_io_trace(ent)->bytes;
1097}
1098
1099static inline u32 t_sec(const struct trace_entry *ent)
1100{
1101 return te_blk_io_trace(ent)->bytes >> 9;
1102}
1103
1104static inline unsigned long long t_sector(const struct trace_entry *ent)
1105{
1106 return te_blk_io_trace(ent)->sector;
1107}
1108
1109static inline __u16 t_error(const struct trace_entry *ent)
1110{
1111 return te_blk_io_trace(ent)->error;
1112}
1113
1114static __u64 get_pdu_int(const struct trace_entry *ent)
1115{
1116 const __u64 *val = pdu_start(ent);
1117 return be64_to_cpu(*val);
1118}
1119
1120static void get_pdu_remap(const struct trace_entry *ent,
1121 struct blk_io_trace_remap *r)
1122{
1123 const struct blk_io_trace_remap *__r = pdu_start(ent);
1124 __u64 sector_from = __r->sector_from;
1125
1126 r->device_from = be32_to_cpu(__r->device_from);
1127 r->device_to = be32_to_cpu(__r->device_to);
1128 r->sector_from = be64_to_cpu(sector_from);
1129}
1130
1131typedef int (blk_log_action_t) (struct trace_iterator *iter, const char *act);
1132
1133static int blk_log_action_classic(struct trace_iterator *iter, const char *act)
1134{
1135 char rwbs[6];
1136 unsigned long long ts = iter->ts;
1137 unsigned long nsec_rem = do_div(ts, NSEC_PER_SEC);
1138 unsigned secs = (unsigned long)ts;
1139 const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
1140
1141 fill_rwbs(rwbs, t);
1142
1143 return trace_seq_printf(&iter->seq,
1144 "%3d,%-3d %2d %5d.%09lu %5u %2s %3s ",
1145 MAJOR(t->device), MINOR(t->device), iter->cpu,
1146 secs, nsec_rem, iter->ent->pid, act, rwbs);
1147}
1148
1149static int blk_log_action(struct trace_iterator *iter, const char *act)
1150{
1151 char rwbs[6];
1152 const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
1153
1154 fill_rwbs(rwbs, t);
1155 return trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ",
1156 MAJOR(t->device), MINOR(t->device), act, rwbs);
1157}
1158
1159static int blk_log_dump_pdu(struct trace_seq *s, const struct trace_entry *ent)
1160{
1161 const unsigned char *pdu_buf;
1162 int pdu_len;
1163 int i, end, ret;
1164
1165 pdu_buf = pdu_start(ent);
1166 pdu_len = te_blk_io_trace(ent)->pdu_len;
1167
1168 if (!pdu_len)
1169 return 1;
1170
1171
1172 for (end = pdu_len - 1; end >= 0; end--)
1173 if (pdu_buf[end])
1174 break;
1175 end++;
1176
1177 if (!trace_seq_putc(s, '('))
1178 return 0;
1179
1180 for (i = 0; i < pdu_len; i++) {
1181
1182 ret = trace_seq_printf(s, "%s%02x",
1183 i == 0 ? "" : " ", pdu_buf[i]);
1184 if (!ret)
1185 return ret;
1186
1187
1188
1189
1190
1191 if (i == end && end != pdu_len - 1)
1192 return trace_seq_puts(s, " ..) ");
1193 }
1194
1195 return trace_seq_puts(s, ") ");
1196}
1197
1198static int blk_log_generic(struct trace_seq *s, const struct trace_entry *ent)
1199{
1200 char cmd[TASK_COMM_LEN];
1201
1202 trace_find_cmdline(ent->pid, cmd);
1203
1204 if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
1205 int ret;
1206
1207 ret = trace_seq_printf(s, "%u ", t_bytes(ent));
1208 if (!ret)
1209 return 0;
1210 ret = blk_log_dump_pdu(s, ent);
1211 if (!ret)
1212 return 0;
1213 return trace_seq_printf(s, "[%s]\n", cmd);
1214 } else {
1215 if (t_sec(ent))
1216 return trace_seq_printf(s, "%llu + %u [%s]\n",
1217 t_sector(ent), t_sec(ent), cmd);
1218 return trace_seq_printf(s, "[%s]\n", cmd);
1219 }
1220}
1221
1222static int blk_log_with_error(struct trace_seq *s,
1223 const struct trace_entry *ent)
1224{
1225 if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
1226 int ret;
1227
1228 ret = blk_log_dump_pdu(s, ent);
1229 if (ret)
1230 return trace_seq_printf(s, "[%d]\n", t_error(ent));
1231 return 0;
1232 } else {
1233 if (t_sec(ent))
1234 return trace_seq_printf(s, "%llu + %u [%d]\n",
1235 t_sector(ent),
1236 t_sec(ent), t_error(ent));
1237 return trace_seq_printf(s, "%llu [%d]\n",
1238 t_sector(ent), t_error(ent));
1239 }
1240}
1241
1242static int blk_log_remap(struct trace_seq *s, const struct trace_entry *ent)
1243{
1244 struct blk_io_trace_remap r = { .device_from = 0, };
1245
1246 get_pdu_remap(ent, &r);
1247 return trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n",
1248 t_sector(ent), t_sec(ent),
1249 MAJOR(r.device_from), MINOR(r.device_from),
1250 (unsigned long long)r.sector_from);
1251}
1252
1253static int blk_log_plug(struct trace_seq *s, const struct trace_entry *ent)
1254{
1255 char cmd[TASK_COMM_LEN];
1256
1257 trace_find_cmdline(ent->pid, cmd);
1258
1259 return trace_seq_printf(s, "[%s]\n", cmd);
1260}
1261
1262static int blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent)
1263{
1264 char cmd[TASK_COMM_LEN];
1265
1266 trace_find_cmdline(ent->pid, cmd);
1267
1268 return trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent));
1269}
1270
1271static int blk_log_split(struct trace_seq *s, const struct trace_entry *ent)
1272{
1273 char cmd[TASK_COMM_LEN];
1274
1275 trace_find_cmdline(ent->pid, cmd);
1276
1277 return trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent),
1278 get_pdu_int(ent), cmd);
1279}
1280
1281static int blk_log_msg(struct trace_seq *s, const struct trace_entry *ent)
1282{
1283 int ret;
1284 const struct blk_io_trace *t = te_blk_io_trace(ent);
1285
1286 ret = trace_seq_putmem(s, t + 1, t->pdu_len);
1287 if (ret)
1288 return trace_seq_putc(s, '\n');
1289 return ret;
1290}
1291
1292
1293
1294
1295
1296static void blk_tracer_print_header(struct seq_file *m)
1297{
1298 if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
1299 return;
1300 seq_puts(m, "# DEV CPU TIMESTAMP PID ACT FLG\n"
1301 "# | | | | | |\n");
1302}
1303
1304static void blk_tracer_start(struct trace_array *tr)
1305{
1306 blk_tracer_enabled = true;
1307}
1308
1309static int blk_tracer_init(struct trace_array *tr)
1310{
1311 blk_tr = tr;
1312 blk_tracer_start(tr);
1313 return 0;
1314}
1315
1316static void blk_tracer_stop(struct trace_array *tr)
1317{
1318 blk_tracer_enabled = false;
1319}
1320
1321static void blk_tracer_reset(struct trace_array *tr)
1322{
1323 blk_tracer_stop(tr);
1324}
1325
1326static const struct {
1327 const char *act[2];
1328 int (*print)(struct trace_seq *s, const struct trace_entry *ent);
1329} what2act[] = {
1330 [__BLK_TA_QUEUE] = {{ "Q", "queue" }, blk_log_generic },
1331 [__BLK_TA_BACKMERGE] = {{ "M", "backmerge" }, blk_log_generic },
1332 [__BLK_TA_FRONTMERGE] = {{ "F", "frontmerge" }, blk_log_generic },
1333 [__BLK_TA_GETRQ] = {{ "G", "getrq" }, blk_log_generic },
1334 [__BLK_TA_SLEEPRQ] = {{ "S", "sleeprq" }, blk_log_generic },
1335 [__BLK_TA_REQUEUE] = {{ "R", "requeue" }, blk_log_with_error },
1336 [__BLK_TA_ISSUE] = {{ "D", "issue" }, blk_log_generic },
1337 [__BLK_TA_COMPLETE] = {{ "C", "complete" }, blk_log_with_error },
1338 [__BLK_TA_PLUG] = {{ "P", "plug" }, blk_log_plug },
1339 [__BLK_TA_UNPLUG_IO] = {{ "U", "unplug_io" }, blk_log_unplug },
1340 [__BLK_TA_UNPLUG_TIMER] = {{ "UT", "unplug_timer" }, blk_log_unplug },
1341 [__BLK_TA_INSERT] = {{ "I", "insert" }, blk_log_generic },
1342 [__BLK_TA_SPLIT] = {{ "X", "split" }, blk_log_split },
1343 [__BLK_TA_BOUNCE] = {{ "B", "bounce" }, blk_log_generic },
1344 [__BLK_TA_REMAP] = {{ "A", "remap" }, blk_log_remap },
1345};
1346
1347static enum print_line_t print_one_line(struct trace_iterator *iter,
1348 bool classic)
1349{
1350 struct trace_seq *s = &iter->seq;
1351 const struct blk_io_trace *t;
1352 u16 what;
1353 int ret;
1354 bool long_act;
1355 blk_log_action_t *log_action;
1356
1357 t = te_blk_io_trace(iter->ent);
1358 what = t->action & ((1 << BLK_TC_SHIFT) - 1);
1359 long_act = !!(trace_flags & TRACE_ITER_VERBOSE);
1360 log_action = classic ? &blk_log_action_classic : &blk_log_action;
1361
1362 if (t->action == BLK_TN_MESSAGE) {
1363 ret = log_action(iter, long_act ? "message" : "m");
1364 if (ret)
1365 ret = blk_log_msg(s, iter->ent);
1366 goto out;
1367 }
1368
1369 if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act)))
1370 ret = trace_seq_printf(s, "Unknown action %x\n", what);
1371 else {
1372 ret = log_action(iter, what2act[what].act[long_act]);
1373 if (ret)
1374 ret = what2act[what].print(s, iter->ent);
1375 }
1376out:
1377 return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
1378}
1379
1380static enum print_line_t blk_trace_event_print(struct trace_iterator *iter,
1381 int flags, struct trace_event *event)
1382{
1383 return print_one_line(iter, false);
1384}
1385
1386static int blk_trace_synthesize_old_trace(struct trace_iterator *iter)
1387{
1388 struct trace_seq *s = &iter->seq;
1389 struct blk_io_trace *t = (struct blk_io_trace *)iter->ent;
1390 const int offset = offsetof(struct blk_io_trace, sector);
1391 struct blk_io_trace old = {
1392 .magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION,
1393 .time = iter->ts,
1394 };
1395
1396 if (!trace_seq_putmem(s, &old, offset))
1397 return 0;
1398 return trace_seq_putmem(s, &t->sector,
1399 sizeof(old) - offset + t->pdu_len);
1400}
1401
1402static enum print_line_t
1403blk_trace_event_print_binary(struct trace_iterator *iter, int flags,
1404 struct trace_event *event)
1405{
1406 return blk_trace_synthesize_old_trace(iter) ?
1407 TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
1408}
1409
1410static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter)
1411{
1412 if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
1413 return TRACE_TYPE_UNHANDLED;
1414
1415 return print_one_line(iter, true);
1416}
1417
1418static int blk_tracer_set_flag(u32 old_flags, u32 bit, int set)
1419{
1420
1421 if (bit == TRACE_BLK_OPT_CLASSIC) {
1422 if (set)
1423 trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
1424 else
1425 trace_flags |= TRACE_ITER_CONTEXT_INFO;
1426 }
1427 return 0;
1428}
1429
1430static struct tracer blk_tracer __read_mostly = {
1431 .name = "blk",
1432 .init = blk_tracer_init,
1433 .reset = blk_tracer_reset,
1434 .start = blk_tracer_start,
1435 .stop = blk_tracer_stop,
1436 .print_header = blk_tracer_print_header,
1437 .print_line = blk_tracer_print_line,
1438 .flags = &blk_tracer_flags,
1439 .set_flag = blk_tracer_set_flag,
1440};
1441
1442static struct trace_event_functions trace_blk_event_funcs = {
1443 .trace = blk_trace_event_print,
1444 .binary = blk_trace_event_print_binary,
1445};
1446
1447static struct trace_event trace_blk_event = {
1448 .type = TRACE_BLK,
1449 .funcs = &trace_blk_event_funcs,
1450};
1451
1452static int __init init_blk_tracer(void)
1453{
1454 if (!register_ftrace_event(&trace_blk_event)) {
1455 pr_warning("Warning: could not register block events\n");
1456 return 1;
1457 }
1458
1459 if (register_tracer(&blk_tracer) != 0) {
1460 pr_warning("Warning: could not register the block tracer\n");
1461 unregister_ftrace_event(&trace_blk_event);
1462 return 1;
1463 }
1464
1465 return 0;
1466}
1467
1468device_initcall(init_blk_tracer);
1469
1470static int blk_trace_remove_queue(struct request_queue *q)
1471{
1472 struct blk_trace *bt;
1473
1474 bt = xchg(&q->blk_trace, NULL);
1475 if (bt == NULL)
1476 return -EINVAL;
1477
1478 if (atomic_dec_and_test(&blk_probes_ref))
1479 blk_unregister_tracepoints();
1480
1481 blk_trace_free(bt);
1482 return 0;
1483}
1484
1485
1486
1487
1488static int blk_trace_setup_queue(struct request_queue *q,
1489 struct block_device *bdev)
1490{
1491 struct blk_trace *old_bt, *bt = NULL;
1492 int ret = -ENOMEM;
1493
1494 bt = kzalloc(sizeof(*bt), GFP_KERNEL);
1495 if (!bt)
1496 return -ENOMEM;
1497
1498 bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
1499 if (!bt->msg_data)
1500 goto free_bt;
1501
1502 bt->dev = bdev->bd_dev;
1503 bt->act_mask = (u16)-1;
1504
1505 blk_trace_setup_lba(bt, bdev);
1506
1507 old_bt = xchg(&q->blk_trace, bt);
1508 if (old_bt != NULL) {
1509 (void)xchg(&q->blk_trace, old_bt);
1510 ret = -EBUSY;
1511 goto free_bt;
1512 }
1513
1514 if (atomic_inc_return(&blk_probes_ref) == 1)
1515 blk_register_tracepoints();
1516 return 0;
1517
1518free_bt:
1519 blk_trace_free(bt);
1520 return ret;
1521}
1522
1523
1524
1525
1526
1527static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
1528 struct device_attribute *attr,
1529 char *buf);
1530static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
1531 struct device_attribute *attr,
1532 const char *buf, size_t count);
1533#define BLK_TRACE_DEVICE_ATTR(_name) \
1534 DEVICE_ATTR(_name, S_IRUGO | S_IWUSR, \
1535 sysfs_blk_trace_attr_show, \
1536 sysfs_blk_trace_attr_store)
1537
1538static BLK_TRACE_DEVICE_ATTR(enable);
1539static BLK_TRACE_DEVICE_ATTR(act_mask);
1540static BLK_TRACE_DEVICE_ATTR(pid);
1541static BLK_TRACE_DEVICE_ATTR(start_lba);
1542static BLK_TRACE_DEVICE_ATTR(end_lba);
1543
1544static struct attribute *blk_trace_attrs[] = {
1545 &dev_attr_enable.attr,
1546 &dev_attr_act_mask.attr,
1547 &dev_attr_pid.attr,
1548 &dev_attr_start_lba.attr,
1549 &dev_attr_end_lba.attr,
1550 NULL
1551};
1552
1553struct attribute_group blk_trace_attr_group = {
1554 .name = "trace",
1555 .attrs = blk_trace_attrs,
1556};
1557
1558static const struct {
1559 int mask;
1560 const char *str;
1561} mask_maps[] = {
1562 { BLK_TC_READ, "read" },
1563 { BLK_TC_WRITE, "write" },
1564 { BLK_TC_BARRIER, "barrier" },
1565 { BLK_TC_SYNC, "sync" },
1566 { BLK_TC_QUEUE, "queue" },
1567 { BLK_TC_REQUEUE, "requeue" },
1568 { BLK_TC_ISSUE, "issue" },
1569 { BLK_TC_COMPLETE, "complete" },
1570 { BLK_TC_FS, "fs" },
1571 { BLK_TC_PC, "pc" },
1572 { BLK_TC_AHEAD, "ahead" },
1573 { BLK_TC_META, "meta" },
1574 { BLK_TC_DISCARD, "discard" },
1575 { BLK_TC_DRV_DATA, "drv_data" },
1576};
1577
1578static int blk_trace_str2mask(const char *str)
1579{
1580 int i;
1581 int mask = 0;
1582 char *buf, *s, *token;
1583
1584 buf = kstrdup(str, GFP_KERNEL);
1585 if (buf == NULL)
1586 return -ENOMEM;
1587 s = strstrip(buf);
1588
1589 while (1) {
1590 token = strsep(&s, ",");
1591 if (token == NULL)
1592 break;
1593
1594 if (*token == '\0')
1595 continue;
1596
1597 for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
1598 if (strcasecmp(token, mask_maps[i].str) == 0) {
1599 mask |= mask_maps[i].mask;
1600 break;
1601 }
1602 }
1603 if (i == ARRAY_SIZE(mask_maps)) {
1604 mask = -EINVAL;
1605 break;
1606 }
1607 }
1608 kfree(buf);
1609
1610 return mask;
1611}
1612
1613static ssize_t blk_trace_mask2str(char *buf, int mask)
1614{
1615 int i;
1616 char *p = buf;
1617
1618 for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
1619 if (mask & mask_maps[i].mask) {
1620 p += sprintf(p, "%s%s",
1621 (p == buf) ? "" : ",", mask_maps[i].str);
1622 }
1623 }
1624 *p++ = '\n';
1625
1626 return p - buf;
1627}
1628
1629static struct request_queue *blk_trace_get_queue(struct block_device *bdev)
1630{
1631 if (bdev->bd_disk == NULL)
1632 return NULL;
1633
1634 return bdev_get_queue(bdev);
1635}
1636
1637static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
1638 struct device_attribute *attr,
1639 char *buf)
1640{
1641 struct hd_struct *p = dev_to_part(dev);
1642 struct request_queue *q;
1643 struct block_device *bdev;
1644 ssize_t ret = -ENXIO;
1645
1646 bdev = bdget(part_devt(p));
1647 if (bdev == NULL)
1648 goto out;
1649
1650 q = blk_trace_get_queue(bdev);
1651 if (q == NULL)
1652 goto out_bdput;
1653
1654 mutex_lock(&bdev->bd_mutex);
1655
1656 if (attr == &dev_attr_enable) {
1657 ret = sprintf(buf, "%u\n", !!q->blk_trace);
1658 goto out_unlock_bdev;
1659 }
1660
1661 if (q->blk_trace == NULL)
1662 ret = sprintf(buf, "disabled\n");
1663 else if (attr == &dev_attr_act_mask)
1664 ret = blk_trace_mask2str(buf, q->blk_trace->act_mask);
1665 else if (attr == &dev_attr_pid)
1666 ret = sprintf(buf, "%u\n", q->blk_trace->pid);
1667 else if (attr == &dev_attr_start_lba)
1668 ret = sprintf(buf, "%llu\n", q->blk_trace->start_lba);
1669 else if (attr == &dev_attr_end_lba)
1670 ret = sprintf(buf, "%llu\n", q->blk_trace->end_lba);
1671
1672out_unlock_bdev:
1673 mutex_unlock(&bdev->bd_mutex);
1674out_bdput:
1675 bdput(bdev);
1676out:
1677 return ret;
1678}
1679
1680static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
1681 struct device_attribute *attr,
1682 const char *buf, size_t count)
1683{
1684 struct block_device *bdev;
1685 struct request_queue *q;
1686 struct hd_struct *p;
1687 u64 value;
1688 ssize_t ret = -EINVAL;
1689
1690 if (count == 0)
1691 goto out;
1692
1693 if (attr == &dev_attr_act_mask) {
1694 if (sscanf(buf, "%llx", &value) != 1) {
1695
1696 ret = blk_trace_str2mask(buf);
1697 if (ret < 0)
1698 goto out;
1699 value = ret;
1700 }
1701 } else if (sscanf(buf, "%llu", &value) != 1)
1702 goto out;
1703
1704 ret = -ENXIO;
1705
1706 p = dev_to_part(dev);
1707 bdev = bdget(part_devt(p));
1708 if (bdev == NULL)
1709 goto out;
1710
1711 q = blk_trace_get_queue(bdev);
1712 if (q == NULL)
1713 goto out_bdput;
1714
1715 mutex_lock(&bdev->bd_mutex);
1716
1717 if (attr == &dev_attr_enable) {
1718 if (value)
1719 ret = blk_trace_setup_queue(q, bdev);
1720 else
1721 ret = blk_trace_remove_queue(q);
1722 goto out_unlock_bdev;
1723 }
1724
1725 ret = 0;
1726 if (q->blk_trace == NULL)
1727 ret = blk_trace_setup_queue(q, bdev);
1728
1729 if (ret == 0) {
1730 if (attr == &dev_attr_act_mask)
1731 q->blk_trace->act_mask = value;
1732 else if (attr == &dev_attr_pid)
1733 q->blk_trace->pid = value;
1734 else if (attr == &dev_attr_start_lba)
1735 q->blk_trace->start_lba = value;
1736 else if (attr == &dev_attr_end_lba)
1737 q->blk_trace->end_lba = value;
1738 }
1739
1740out_unlock_bdev:
1741 mutex_unlock(&bdev->bd_mutex);
1742out_bdput:
1743 bdput(bdev);
1744out:
1745 return ret ? ret : count;
1746}
1747
1748int blk_trace_init_sysfs(struct device *dev)
1749{
1750 return sysfs_create_group(&dev->kobj, &blk_trace_attr_group);
1751}
1752
1753void blk_trace_remove_sysfs(struct device *dev)
1754{
1755 sysfs_remove_group(&dev->kobj, &blk_trace_attr_group);
1756}
1757
1758#endif
1759
1760#ifdef CONFIG_EVENT_TRACING
1761
1762void blk_dump_cmd(char *buf, struct request *rq)
1763{
1764 int i, end;
1765 int len = rq->cmd_len;
1766 unsigned char *cmd = rq->cmd;
1767
1768 if (rq->cmd_type != REQ_TYPE_BLOCK_PC) {
1769 buf[0] = '\0';
1770 return;
1771 }
1772
1773 for (end = len - 1; end >= 0; end--)
1774 if (cmd[end])
1775 break;
1776 end++;
1777
1778 for (i = 0; i < len; i++) {
1779 buf += sprintf(buf, "%s%02x", i == 0 ? "" : " ", cmd[i]);
1780 if (i == end && end != len - 1) {
1781 sprintf(buf, " ..");
1782 break;
1783 }
1784 }
1785}
1786
1787void blk_fill_rwbs(char *rwbs, u32 rw, int bytes)
1788{
1789 int i = 0;
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_RAHEAD)
1801 rwbs[i++] = 'A';
1802 if (rw & REQ_SYNC)
1803 rwbs[i++] = 'S';
1804 if (rw & REQ_META)
1805 rwbs[i++] = 'M';
1806 if (rw & REQ_SECURE)
1807 rwbs[i++] = 'E';
1808
1809 rwbs[i] = '\0';
1810}
1811
1812#endif
1813
1814
