1#include <linux/errno.h>
2#include <linux/numa.h>
3#include <linux/slab.h>
4#include <linux/rculist.h>
5#include <linux/threads.h>
6#include <linux/preempt.h>
7#include <linux/irqflags.h>
8#include <linux/vmalloc.h>
9#include <linux/mm.h>
10#include <linux/module.h>
11#include <linux/device-mapper.h>
12
13#include "dm-core.h"
14#include "dm-stats.h"
15
16#define DM_MSG_PREFIX "stats"
17
18static int dm_stat_need_rcu_barrier;
19
20
21
22
23
24struct dm_stat_percpu {
25 unsigned long long sectors[2];
26 unsigned long long ios[2];
27 unsigned long long merges[2];
28 unsigned long long ticks[2];
29 unsigned long long io_ticks[2];
30 unsigned long long io_ticks_total;
31 unsigned long long time_in_queue;
32 unsigned long long *histogram;
33};
34
35struct dm_stat_shared {
36 atomic_t in_flight[2];
37 unsigned long long stamp;
38 struct dm_stat_percpu tmp;
39};
40
41struct dm_stat {
42 struct list_head list_entry;
43 int id;
44 unsigned stat_flags;
45 size_t n_entries;
46 sector_t start;
47 sector_t end;
48 sector_t step;
49 unsigned n_histogram_entries;
50 unsigned long long *histogram_boundaries;
51 const char *program_id;
52 const char *aux_data;
53 struct rcu_head rcu_head;
54 size_t shared_alloc_size;
55 size_t percpu_alloc_size;
56 size_t histogram_alloc_size;
57 struct dm_stat_percpu *stat_percpu[NR_CPUS];
58 struct dm_stat_shared stat_shared[0];
59};
60
61#define STAT_PRECISE_TIMESTAMPS 1
62
63struct dm_stats_last_position {
64 sector_t last_sector;
65 unsigned last_rw;
66};
67
68
69
70
71
72
73#define DM_STATS_MEMORY_FACTOR 4
74#define DM_STATS_VMALLOC_FACTOR 2
75
76static DEFINE_SPINLOCK(shared_memory_lock);
77
78static unsigned long shared_memory_amount;
79
80static bool __check_shared_memory(size_t alloc_size)
81{
82 size_t a;
83
84 a = shared_memory_amount + alloc_size;
85 if (a < shared_memory_amount)
86 return false;
87 if (a >> PAGE_SHIFT > totalram_pages / DM_STATS_MEMORY_FACTOR)
88 return false;
89#ifdef CONFIG_MMU
90 if (a > (VMALLOC_END - VMALLOC_START) / DM_STATS_VMALLOC_FACTOR)
91 return false;
92#endif
93 return true;
94}
95
96static bool check_shared_memory(size_t alloc_size)
97{
98 bool ret;
99
100 spin_lock_irq(&shared_memory_lock);
101
102 ret = __check_shared_memory(alloc_size);
103
104 spin_unlock_irq(&shared_memory_lock);
105
106 return ret;
107}
108
109static bool claim_shared_memory(size_t alloc_size)
110{
111 spin_lock_irq(&shared_memory_lock);
112
113 if (!__check_shared_memory(alloc_size)) {
114 spin_unlock_irq(&shared_memory_lock);
115 return false;
116 }
117
118 shared_memory_amount += alloc_size;
119
120 spin_unlock_irq(&shared_memory_lock);
121
122 return true;
123}
124
125static void free_shared_memory(size_t alloc_size)
126{
127 unsigned long flags;
128
129 spin_lock_irqsave(&shared_memory_lock, flags);
130
131 if (WARN_ON_ONCE(shared_memory_amount < alloc_size)) {
132 spin_unlock_irqrestore(&shared_memory_lock, flags);
133 DMCRIT("Memory usage accounting bug.");
134 return;
135 }
136
137 shared_memory_amount -= alloc_size;
138
139 spin_unlock_irqrestore(&shared_memory_lock, flags);
140}
141
142static void *dm_kvzalloc(size_t alloc_size, int node)
143{
144 void *p;
145
146 if (!claim_shared_memory(alloc_size))
147 return NULL;
148
149 if (alloc_size <= KMALLOC_MAX_SIZE) {
150 p = kzalloc_node(alloc_size, GFP_KERNEL | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN, node);
151 if (p)
152 return p;
153 }
154 p = vzalloc_node(alloc_size, node);
155 if (p)
156 return p;
157
158 free_shared_memory(alloc_size);
159
160 return NULL;
161}
162
163static void dm_kvfree(void *ptr, size_t alloc_size)
164{
165 if (!ptr)
166 return;
167
168 free_shared_memory(alloc_size);
169
170 kvfree(ptr);
171}
172
173static void dm_stat_free(struct rcu_head *head)
174{
175 int cpu;
176 struct dm_stat *s = container_of(head, struct dm_stat, rcu_head);
177
178 kfree(s->program_id);
179 kfree(s->aux_data);
180 for_each_possible_cpu(cpu) {
181 dm_kvfree(s->stat_percpu[cpu][0].histogram, s->histogram_alloc_size);
182 dm_kvfree(s->stat_percpu[cpu], s->percpu_alloc_size);
183 }
184 dm_kvfree(s->stat_shared[0].tmp.histogram, s->histogram_alloc_size);
185 dm_kvfree(s, s->shared_alloc_size);
186}
187
188static int dm_stat_in_flight(struct dm_stat_shared *shared)
189{
190 return atomic_read(&shared->in_flight[READ]) +
191 atomic_read(&shared->in_flight[WRITE]);
192}
193
194void dm_stats_init(struct dm_stats *stats)
195{
196 int cpu;
197 struct dm_stats_last_position *last;
198
199 mutex_init(&stats->mutex);
200 INIT_LIST_HEAD(&stats->list);
201 stats->last = alloc_percpu(struct dm_stats_last_position);
202 for_each_possible_cpu(cpu) {
203 last = per_cpu_ptr(stats->last, cpu);
204 last->last_sector = (sector_t)ULLONG_MAX;
205 last->last_rw = UINT_MAX;
206 }
207}
208
209void dm_stats_cleanup(struct dm_stats *stats)
210{
211 size_t ni;
212 struct dm_stat *s;
213 struct dm_stat_shared *shared;
214
215 while (!list_empty(&stats->list)) {
216 s = container_of(stats->list.next, struct dm_stat, list_entry);
217 list_del(&s->list_entry);
218 for (ni = 0; ni < s->n_entries; ni++) {
219 shared = &s->stat_shared[ni];
220 if (WARN_ON(dm_stat_in_flight(shared))) {
221 DMCRIT("leaked in-flight counter at index %lu "
222 "(start %llu, end %llu, step %llu): reads %d, writes %d",
223 (unsigned long)ni,
224 (unsigned long long)s->start,
225 (unsigned long long)s->end,
226 (unsigned long long)s->step,
227 atomic_read(&shared->in_flight[READ]),
228 atomic_read(&shared->in_flight[WRITE]));
229 }
230 }
231 dm_stat_free(&s->rcu_head);
232 }
233 free_percpu(stats->last);
234}
235
236static int dm_stats_create(struct dm_stats *stats, sector_t start, sector_t end,
237 sector_t step, unsigned stat_flags,
238 unsigned n_histogram_entries,
239 unsigned long long *histogram_boundaries,
240 const char *program_id, const char *aux_data,
241 void (*suspend_callback)(struct mapped_device *),
242 void (*resume_callback)(struct mapped_device *),
243 struct mapped_device *md)
244{
245 struct list_head *l;
246 struct dm_stat *s, *tmp_s;
247 sector_t n_entries;
248 size_t ni;
249 size_t shared_alloc_size;
250 size_t percpu_alloc_size;
251 size_t histogram_alloc_size;
252 struct dm_stat_percpu *p;
253 int cpu;
254 int ret_id;
255 int r;
256
257 if (end < start || !step)
258 return -EINVAL;
259
260 n_entries = end - start;
261 if (dm_sector_div64(n_entries, step))
262 n_entries++;
263
264 if (n_entries != (size_t)n_entries || !(size_t)(n_entries + 1))
265 return -EOVERFLOW;
266
267 shared_alloc_size = sizeof(struct dm_stat) + (size_t)n_entries * sizeof(struct dm_stat_shared);
268 if ((shared_alloc_size - sizeof(struct dm_stat)) / sizeof(struct dm_stat_shared) != n_entries)
269 return -EOVERFLOW;
270
271 percpu_alloc_size = (size_t)n_entries * sizeof(struct dm_stat_percpu);
272 if (percpu_alloc_size / sizeof(struct dm_stat_percpu) != n_entries)
273 return -EOVERFLOW;
274
275 histogram_alloc_size = (n_histogram_entries + 1) * (size_t)n_entries * sizeof(unsigned long long);
276 if (histogram_alloc_size / (n_histogram_entries + 1) != (size_t)n_entries * sizeof(unsigned long long))
277 return -EOVERFLOW;
278
279 if (!check_shared_memory(shared_alloc_size + histogram_alloc_size +
280 num_possible_cpus() * (percpu_alloc_size + histogram_alloc_size)))
281 return -ENOMEM;
282
283 s = dm_kvzalloc(shared_alloc_size, NUMA_NO_NODE);
284 if (!s)
285 return -ENOMEM;
286
287 s->stat_flags = stat_flags;
288 s->n_entries = n_entries;
289 s->start = start;
290 s->end = end;
291 s->step = step;
292 s->shared_alloc_size = shared_alloc_size;
293 s->percpu_alloc_size = percpu_alloc_size;
294 s->histogram_alloc_size = histogram_alloc_size;
295
296 s->n_histogram_entries = n_histogram_entries;
297 s->histogram_boundaries = kmemdup(histogram_boundaries,
298 s->n_histogram_entries * sizeof(unsigned long long), GFP_KERNEL);
299 if (!s->histogram_boundaries) {
300 r = -ENOMEM;
301 goto out;
302 }
303
304 s->program_id = kstrdup(program_id, GFP_KERNEL);
305 if (!s->program_id) {
306 r = -ENOMEM;
307 goto out;
308 }
309 s->aux_data = kstrdup(aux_data, GFP_KERNEL);
310 if (!s->aux_data) {
311 r = -ENOMEM;
312 goto out;
313 }
314
315 for (ni = 0; ni < n_entries; ni++) {
316 atomic_set(&s->stat_shared[ni].in_flight[READ], 0);
317 atomic_set(&s->stat_shared[ni].in_flight[WRITE], 0);
318 }
319
320 if (s->n_histogram_entries) {
321 unsigned long long *hi;
322 hi = dm_kvzalloc(s->histogram_alloc_size, NUMA_NO_NODE);
323 if (!hi) {
324 r = -ENOMEM;
325 goto out;
326 }
327 for (ni = 0; ni < n_entries; ni++) {
328 s->stat_shared[ni].tmp.histogram = hi;
329 hi += s->n_histogram_entries + 1;
330 }
331 }
332
333 for_each_possible_cpu(cpu) {
334 p = dm_kvzalloc(percpu_alloc_size, cpu_to_node(cpu));
335 if (!p) {
336 r = -ENOMEM;
337 goto out;
338 }
339 s->stat_percpu[cpu] = p;
340 if (s->n_histogram_entries) {
341 unsigned long long *hi;
342 hi = dm_kvzalloc(s->histogram_alloc_size, cpu_to_node(cpu));
343 if (!hi) {
344 r = -ENOMEM;
345 goto out;
346 }
347 for (ni = 0; ni < n_entries; ni++) {
348 p[ni].histogram = hi;
349 hi += s->n_histogram_entries + 1;
350 }
351 }
352 }
353
354
355
356
357
358
359
360
361 suspend_callback(md);
362
363 mutex_lock(&stats->mutex);
364 s->id = 0;
365 list_for_each(l, &stats->list) {
366 tmp_s = container_of(l, struct dm_stat, list_entry);
367 if (WARN_ON(tmp_s->id < s->id)) {
368 r = -EINVAL;
369 goto out_unlock_resume;
370 }
371 if (tmp_s->id > s->id)
372 break;
373 if (unlikely(s->id == INT_MAX)) {
374 r = -ENFILE;
375 goto out_unlock_resume;
376 }
377 s->id++;
378 }
379 ret_id = s->id;
380 list_add_tail_rcu(&s->list_entry, l);
381 mutex_unlock(&stats->mutex);
382
383 resume_callback(md);
384
385 return ret_id;
386
387out_unlock_resume:
388 mutex_unlock(&stats->mutex);
389 resume_callback(md);
390out:
391 dm_stat_free(&s->rcu_head);
392 return r;
393}
394
395static struct dm_stat *__dm_stats_find(struct dm_stats *stats, int id)
396{
397 struct dm_stat *s;
398
399 list_for_each_entry(s, &stats->list, list_entry) {
400 if (s->id > id)
401 break;
402 if (s->id == id)
403 return s;
404 }
405
406 return NULL;
407}
408
409static int dm_stats_delete(struct dm_stats *stats, int id)
410{
411 struct dm_stat *s;
412 int cpu;
413
414 mutex_lock(&stats->mutex);
415
416 s = __dm_stats_find(stats, id);
417 if (!s) {
418 mutex_unlock(&stats->mutex);
419 return -ENOENT;
420 }
421
422 list_del_rcu(&s->list_entry);
423 mutex_unlock(&stats->mutex);
424
425
426
427
428 for_each_possible_cpu(cpu)
429 if (is_vmalloc_addr(s->stat_percpu) ||
430 is_vmalloc_addr(s->stat_percpu[cpu][0].histogram))
431 goto do_sync_free;
432 if (is_vmalloc_addr(s) ||
433 is_vmalloc_addr(s->stat_shared[0].tmp.histogram)) {
434do_sync_free:
435 synchronize_rcu_expedited();
436 dm_stat_free(&s->rcu_head);
437 } else {
438 ACCESS_ONCE(dm_stat_need_rcu_barrier) = 1;
439 call_rcu(&s->rcu_head, dm_stat_free);
440 }
441 return 0;
442}
443
444static int dm_stats_list(struct dm_stats *stats, const char *program,
445 char *result, unsigned maxlen)
446{
447 struct dm_stat *s;
448 sector_t len;
449 unsigned sz = 0;
450
451
452
453
454
455
456 mutex_lock(&stats->mutex);
457 list_for_each_entry(s, &stats->list, list_entry) {
458 if (!program || !strcmp(program, s->program_id)) {
459 len = s->end - s->start;
460 DMEMIT("%d: %llu+%llu %llu %s %s", s->id,
461 (unsigned long long)s->start,
462 (unsigned long long)len,
463 (unsigned long long)s->step,
464 s->program_id,
465 s->aux_data);
466 if (s->stat_flags & STAT_PRECISE_TIMESTAMPS)
467 DMEMIT(" precise_timestamps");
468 if (s->n_histogram_entries) {
469 unsigned i;
470 DMEMIT(" histogram:");
471 for (i = 0; i < s->n_histogram_entries; i++) {
472 if (i)
473 DMEMIT(",");
474 DMEMIT("%llu", s->histogram_boundaries[i]);
475 }
476 }
477 DMEMIT("\n");
478 }
479 }
480 mutex_unlock(&stats->mutex);
481
482 return 1;
483}
484
485static void dm_stat_round(struct dm_stat *s, struct dm_stat_shared *shared,
486 struct dm_stat_percpu *p)
487{
488
489
490
491 unsigned long long now, difference;
492 unsigned in_flight_read, in_flight_write;
493
494 if (likely(!(s->stat_flags & STAT_PRECISE_TIMESTAMPS)))
495 now = jiffies;
496 else
497 now = ktime_to_ns(ktime_get());
498
499 difference = now - shared->stamp;
500 if (!difference)
501 return;
502
503 in_flight_read = (unsigned)atomic_read(&shared->in_flight[READ]);
504 in_flight_write = (unsigned)atomic_read(&shared->in_flight[WRITE]);
505 if (in_flight_read)
506 p->io_ticks[READ] += difference;
507 if (in_flight_write)
508 p->io_ticks[WRITE] += difference;
509 if (in_flight_read + in_flight_write) {
510 p->io_ticks_total += difference;
511 p->time_in_queue += (in_flight_read + in_flight_write) * difference;
512 }
513 shared->stamp = now;
514}
515
516static void dm_stat_for_entry(struct dm_stat *s, size_t entry,
517 int idx, sector_t len,
518 struct dm_stats_aux *stats_aux, bool end,
519 unsigned long duration_jiffies)
520{
521 struct dm_stat_shared *shared = &s->stat_shared[entry];
522 struct dm_stat_percpu *p;
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539#if BITS_PER_LONG == 32
540 unsigned long flags;
541 local_irq_save(flags);
542#else
543 preempt_disable();
544#endif
545 p = &s->stat_percpu[smp_processor_id()][entry];
546
547 if (!end) {
548 dm_stat_round(s, shared, p);
549 atomic_inc(&shared->in_flight[idx]);
550 } else {
551 unsigned long long duration;
552 dm_stat_round(s, shared, p);
553 atomic_dec(&shared->in_flight[idx]);
554 p->sectors[idx] += len;
555 p->ios[idx] += 1;
556 p->merges[idx] += stats_aux->merged;
557 if (!(s->stat_flags & STAT_PRECISE_TIMESTAMPS)) {
558 p->ticks[idx] += duration_jiffies;
559 duration = jiffies_to_msecs(duration_jiffies);
560 } else {
561 p->ticks[idx] += stats_aux->duration_ns;
562 duration = stats_aux->duration_ns;
563 }
564 if (s->n_histogram_entries) {
565 unsigned lo = 0, hi = s->n_histogram_entries + 1;
566 while (lo + 1 < hi) {
567 unsigned mid = (lo + hi) / 2;
568 if (s->histogram_boundaries[mid - 1] > duration) {
569 hi = mid;
570 } else {
571 lo = mid;
572 }
573
574 }
575 p->histogram[lo]++;
576 }
577 }
578
579#if BITS_PER_LONG == 32
580 local_irq_restore(flags);
581#else
582 preempt_enable();
583#endif
584}
585
586static void __dm_stat_bio(struct dm_stat *s, int bi_rw,
587 sector_t bi_sector, sector_t end_sector,
588 bool end, unsigned long duration_jiffies,
589 struct dm_stats_aux *stats_aux)
590{
591 sector_t rel_sector, offset, todo, fragment_len;
592 size_t entry;
593
594 if (end_sector <= s->start || bi_sector >= s->end)
595 return;
596 if (unlikely(bi_sector < s->start)) {
597 rel_sector = 0;
598 todo = end_sector - s->start;
599 } else {
600 rel_sector = bi_sector - s->start;
601 todo = end_sector - bi_sector;
602 }
603 if (unlikely(end_sector > s->end))
604 todo -= (end_sector - s->end);
605
606 offset = dm_sector_div64(rel_sector, s->step);
607 entry = rel_sector;
608 do {
609 if (WARN_ON_ONCE(entry >= s->n_entries)) {
610 DMCRIT("Invalid area access in region id %d", s->id);
611 return;
612 }
613 fragment_len = todo;
614 if (fragment_len > s->step - offset)
615 fragment_len = s->step - offset;
616 dm_stat_for_entry(s, entry, bi_rw, fragment_len,
617 stats_aux, end, duration_jiffies);
618 todo -= fragment_len;
619 entry++;
620 offset = 0;
621 } while (unlikely(todo != 0));
622}
623
624void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw,
625 sector_t bi_sector, unsigned bi_sectors, bool end,
626 unsigned long duration_jiffies,
627 struct dm_stats_aux *stats_aux)
628{
629 struct dm_stat *s;
630 sector_t end_sector;
631 struct dm_stats_last_position *last;
632 bool got_precise_time;
633
634 if (unlikely(!bi_sectors))
635 return;
636
637 end_sector = bi_sector + bi_sectors;
638
639 if (!end) {
640
641
642
643
644 last = raw_cpu_ptr(stats->last);
645 stats_aux->merged =
646 (bi_sector == (ACCESS_ONCE(last->last_sector) &&
647 ((bi_rw == WRITE) ==
648 (ACCESS_ONCE(last->last_rw) == WRITE))
649 ));
650 ACCESS_ONCE(last->last_sector) = end_sector;
651 ACCESS_ONCE(last->last_rw) = bi_rw;
652 }
653
654 rcu_read_lock();
655
656 got_precise_time = false;
657 list_for_each_entry_rcu(s, &stats->list, list_entry) {
658 if (s->stat_flags & STAT_PRECISE_TIMESTAMPS && !got_precise_time) {
659 if (!end)
660 stats_aux->duration_ns = ktime_to_ns(ktime_get());
661 else
662 stats_aux->duration_ns = ktime_to_ns(ktime_get()) - stats_aux->duration_ns;
663 got_precise_time = true;
664 }
665 __dm_stat_bio(s, bi_rw, bi_sector, end_sector, end, duration_jiffies, stats_aux);
666 }
667
668 rcu_read_unlock();
669}
670
671static void __dm_stat_init_temporary_percpu_totals(struct dm_stat_shared *shared,
672 struct dm_stat *s, size_t x)
673{
674 int cpu;
675 struct dm_stat_percpu *p;
676
677 local_irq_disable();
678 p = &s->stat_percpu[smp_processor_id()][x];
679 dm_stat_round(s, shared, p);
680 local_irq_enable();
681
682 shared->tmp.sectors[READ] = 0;
683 shared->tmp.sectors[WRITE] = 0;
684 shared->tmp.ios[READ] = 0;
685 shared->tmp.ios[WRITE] = 0;
686 shared->tmp.merges[READ] = 0;
687 shared->tmp.merges[WRITE] = 0;
688 shared->tmp.ticks[READ] = 0;
689 shared->tmp.ticks[WRITE] = 0;
690 shared->tmp.io_ticks[READ] = 0;
691 shared->tmp.io_ticks[WRITE] = 0;
692 shared->tmp.io_ticks_total = 0;
693 shared->tmp.time_in_queue = 0;
694
695 if (s->n_histogram_entries)
696 memset(shared->tmp.histogram, 0, (s->n_histogram_entries + 1) * sizeof(unsigned long long));
697
698 for_each_possible_cpu(cpu) {
699 p = &s->stat_percpu[cpu][x];
700 shared->tmp.sectors[READ] += ACCESS_ONCE(p->sectors[READ]);
701 shared->tmp.sectors[WRITE] += ACCESS_ONCE(p->sectors[WRITE]);
702 shared->tmp.ios[READ] += ACCESS_ONCE(p->ios[READ]);
703 shared->tmp.ios[WRITE] += ACCESS_ONCE(p->ios[WRITE]);
704 shared->tmp.merges[READ] += ACCESS_ONCE(p->merges[READ]);
705 shared->tmp.merges[WRITE] += ACCESS_ONCE(p->merges[WRITE]);
706 shared->tmp.ticks[READ] += ACCESS_ONCE(p->ticks[READ]);
707 shared->tmp.ticks[WRITE] += ACCESS_ONCE(p->ticks[WRITE]);
708 shared->tmp.io_ticks[READ] += ACCESS_ONCE(p->io_ticks[READ]);
709 shared->tmp.io_ticks[WRITE] += ACCESS_ONCE(p->io_ticks[WRITE]);
710 shared->tmp.io_ticks_total += ACCESS_ONCE(p->io_ticks_total);
711 shared->tmp.time_in_queue += ACCESS_ONCE(p->time_in_queue);
712 if (s->n_histogram_entries) {
713 unsigned i;
714 for (i = 0; i < s->n_histogram_entries + 1; i++)
715 shared->tmp.histogram[i] += ACCESS_ONCE(p->histogram[i]);
716 }
717 }
718}
719
720static void __dm_stat_clear(struct dm_stat *s, size_t idx_start, size_t idx_end,
721 bool init_tmp_percpu_totals)
722{
723 size_t x;
724 struct dm_stat_shared *shared;
725 struct dm_stat_percpu *p;
726
727 for (x = idx_start; x < idx_end; x++) {
728 shared = &s->stat_shared[x];
729 if (init_tmp_percpu_totals)
730 __dm_stat_init_temporary_percpu_totals(shared, s, x);
731 local_irq_disable();
732 p = &s->stat_percpu[smp_processor_id()][x];
733 p->sectors[READ] -= shared->tmp.sectors[READ];
734 p->sectors[WRITE] -= shared->tmp.sectors[WRITE];
735 p->ios[READ] -= shared->tmp.ios[READ];
736 p->ios[WRITE] -= shared->tmp.ios[WRITE];
737 p->merges[READ] -= shared->tmp.merges[READ];
738 p->merges[WRITE] -= shared->tmp.merges[WRITE];
739 p->ticks[READ] -= shared->tmp.ticks[READ];
740 p->ticks[WRITE] -= shared->tmp.ticks[WRITE];
741 p->io_ticks[READ] -= shared->tmp.io_ticks[READ];
742 p->io_ticks[WRITE] -= shared->tmp.io_ticks[WRITE];
743 p->io_ticks_total -= shared->tmp.io_ticks_total;
744 p->time_in_queue -= shared->tmp.time_in_queue;
745 local_irq_enable();
746 if (s->n_histogram_entries) {
747 unsigned i;
748 for (i = 0; i < s->n_histogram_entries + 1; i++) {
749 local_irq_disable();
750 p = &s->stat_percpu[smp_processor_id()][x];
751 p->histogram[i] -= shared->tmp.histogram[i];
752 local_irq_enable();
753 }
754 }
755 }
756}
757
758static int dm_stats_clear(struct dm_stats *stats, int id)
759{
760 struct dm_stat *s;
761
762 mutex_lock(&stats->mutex);
763
764 s = __dm_stats_find(stats, id);
765 if (!s) {
766 mutex_unlock(&stats->mutex);
767 return -ENOENT;
768 }
769
770 __dm_stat_clear(s, 0, s->n_entries, true);
771
772 mutex_unlock(&stats->mutex);
773
774 return 1;
775}
776
777
778
779
780static unsigned long long dm_jiffies_to_msec64(struct dm_stat *s, unsigned long long j)
781{
782 unsigned long long result;
783 unsigned mult;
784
785 if (s->stat_flags & STAT_PRECISE_TIMESTAMPS)
786 return j;
787
788 result = 0;
789 if (j)
790 result = jiffies_to_msecs(j & 0x3fffff);
791 if (j >= 1 << 22) {
792 mult = jiffies_to_msecs(1 << 22);
793 result += (unsigned long long)mult * (unsigned long long)jiffies_to_msecs((j >> 22) & 0x3fffff);
794 }
795 if (j >= 1ULL << 44)
796 result += (unsigned long long)mult * (unsigned long long)mult * (unsigned long long)jiffies_to_msecs(j >> 44);
797
798 return result;
799}
800
801static int dm_stats_print(struct dm_stats *stats, int id,
802 size_t idx_start, size_t idx_len,
803 bool clear, char *result, unsigned maxlen)
804{
805 unsigned sz = 0;
806 struct dm_stat *s;
807 size_t x;
808 sector_t start, end, step;
809 size_t idx_end;
810 struct dm_stat_shared *shared;
811
812
813
814
815
816
817 mutex_lock(&stats->mutex);
818
819 s = __dm_stats_find(stats, id);
820 if (!s) {
821 mutex_unlock(&stats->mutex);
822 return -ENOENT;
823 }
824
825 idx_end = idx_start + idx_len;
826 if (idx_end < idx_start ||
827 idx_end > s->n_entries)
828 idx_end = s->n_entries;
829
830 if (idx_start > idx_end)
831 idx_start = idx_end;
832
833 step = s->step;
834 start = s->start + (step * idx_start);
835
836 for (x = idx_start; x < idx_end; x++, start = end) {
837 shared = &s->stat_shared[x];
838 end = start + step;
839 if (unlikely(end > s->end))
840 end = s->end;
841
842 __dm_stat_init_temporary_percpu_totals(shared, s, x);
843
844 DMEMIT("%llu+%llu %llu %llu %llu %llu %llu %llu %llu %llu %d %llu %llu %llu %llu",
845 (unsigned long long)start,
846 (unsigned long long)step,
847 shared->tmp.ios[READ],
848 shared->tmp.merges[READ],
849 shared->tmp.sectors[READ],
850 dm_jiffies_to_msec64(s, shared->tmp.ticks[READ]),
851 shared->tmp.ios[WRITE],
852 shared->tmp.merges[WRITE],
853 shared->tmp.sectors[WRITE],
854 dm_jiffies_to_msec64(s, shared->tmp.ticks[WRITE]),
855 dm_stat_in_flight(shared),
856 dm_jiffies_to_msec64(s, shared->tmp.io_ticks_total),
857 dm_jiffies_to_msec64(s, shared->tmp.time_in_queue),
858 dm_jiffies_to_msec64(s, shared->tmp.io_ticks[READ]),
859 dm_jiffies_to_msec64(s, shared->tmp.io_ticks[WRITE]));
860 if (s->n_histogram_entries) {
861 unsigned i;
862 for (i = 0; i < s->n_histogram_entries + 1; i++) {
863 DMEMIT("%s%llu", !i ? " " : ":", shared->tmp.histogram[i]);
864 }
865 }
866 DMEMIT("\n");
867
868 if (unlikely(sz + 1 >= maxlen))
869 goto buffer_overflow;
870 }
871
872 if (clear)
873 __dm_stat_clear(s, idx_start, idx_end, false);
874
875buffer_overflow:
876 mutex_unlock(&stats->mutex);
877
878 return 1;
879}
880
881static int dm_stats_set_aux(struct dm_stats *stats, int id, const char *aux_data)
882{
883 struct dm_stat *s;
884 const char *new_aux_data;
885
886 mutex_lock(&stats->mutex);
887
888 s = __dm_stats_find(stats, id);
889 if (!s) {
890 mutex_unlock(&stats->mutex);
891 return -ENOENT;
892 }
893
894 new_aux_data = kstrdup(aux_data, GFP_KERNEL);
895 if (!new_aux_data) {
896 mutex_unlock(&stats->mutex);
897 return -ENOMEM;
898 }
899
900 kfree(s->aux_data);
901 s->aux_data = new_aux_data;
902
903 mutex_unlock(&stats->mutex);
904
905 return 0;
906}
907
908static int parse_histogram(const char *h, unsigned *n_histogram_entries,
909 unsigned long long **histogram_boundaries)
910{
911 const char *q;
912 unsigned n;
913 unsigned long long last;
914
915 *n_histogram_entries = 1;
916 for (q = h; *q; q++)
917 if (*q == ',')
918 (*n_histogram_entries)++;
919
920 *histogram_boundaries = kmalloc(*n_histogram_entries * sizeof(unsigned long long), GFP_KERNEL);
921 if (!*histogram_boundaries)
922 return -ENOMEM;
923
924 n = 0;
925 last = 0;
926 while (1) {
927 unsigned long long hi;
928 int s;
929 char ch;
930 s = sscanf(h, "%llu%c", &hi, &ch);
931 if (!s || (s == 2 && ch != ','))
932 return -EINVAL;
933 if (hi <= last)
934 return -EINVAL;
935 last = hi;
936 (*histogram_boundaries)[n] = hi;
937 if (s == 1)
938 return 0;
939 h = strchr(h, ',') + 1;
940 n++;
941 }
942}
943
944static int message_stats_create(struct mapped_device *md,
945 unsigned argc, char **argv,
946 char *result, unsigned maxlen)
947{
948 int r;
949 int id;
950 char dummy;
951 unsigned long long start, end, len, step;
952 unsigned divisor;
953 const char *program_id, *aux_data;
954 unsigned stat_flags = 0;
955
956 unsigned n_histogram_entries = 0;
957 unsigned long long *histogram_boundaries = NULL;
958
959 struct dm_arg_set as, as_backup;
960 const char *a;
961 unsigned feature_args;
962
963
964
965
966
967
968 if (argc < 3)
969 goto ret_einval;
970
971 as.argc = argc;
972 as.argv = argv;
973 dm_consume_args(&as, 1);
974
975 a = dm_shift_arg(&as);
976 if (!strcmp(a, "-")) {
977 start = 0;
978 len = dm_get_size(md);
979 if (!len)
980 len = 1;
981 } else if (sscanf(a, "%llu+%llu%c", &start, &len, &dummy) != 2 ||
982 start != (sector_t)start || len != (sector_t)len)
983 goto ret_einval;
984
985 end = start + len;
986 if (start >= end)
987 goto ret_einval;
988
989 a = dm_shift_arg(&as);
990 if (sscanf(a, "/%u%c", &divisor, &dummy) == 1) {
991 if (!divisor)
992 return -EINVAL;
993 step = end - start;
994 if (do_div(step, divisor))
995 step++;
996 if (!step)
997 step = 1;
998 } else if (sscanf(a, "%llu%c", &step, &dummy) != 1 ||
999 step != (sector_t)step || !step)
1000 goto ret_einval;
1001
1002 as_backup = as;
1003 a = dm_shift_arg(&as);
1004 if (a && sscanf(a, "%u%c", &feature_args, &dummy) == 1) {
1005 while (feature_args--) {
1006 a = dm_shift_arg(&as);
1007 if (!a)
1008 goto ret_einval;
1009 if (!strcasecmp(a, "precise_timestamps"))
1010 stat_flags |= STAT_PRECISE_TIMESTAMPS;
1011 else if (!strncasecmp(a, "histogram:", 10)) {
1012 if (n_histogram_entries)
1013 goto ret_einval;
1014 if ((r = parse_histogram(a + 10, &n_histogram_entries, &histogram_boundaries)))
1015 goto ret;
1016 } else
1017 goto ret_einval;
1018 }
1019 } else {
1020 as = as_backup;
1021 }
1022
1023 program_id = "-";
1024 aux_data = "-";
1025
1026 a = dm_shift_arg(&as);
1027 if (a)
1028 program_id = a;
1029
1030 a = dm_shift_arg(&as);
1031 if (a)
1032 aux_data = a;
1033
1034 if (as.argc)
1035 goto ret_einval;
1036
1037
1038
1039
1040
1041
1042
1043 snprintf(result, maxlen, "%d", INT_MAX);
1044 if (dm_message_test_buffer_overflow(result, maxlen)) {
1045 r = 1;
1046 goto ret;
1047 }
1048
1049 id = dm_stats_create(dm_get_stats(md), start, end, step, stat_flags,
1050 n_histogram_entries, histogram_boundaries, program_id, aux_data,
1051 dm_internal_suspend_fast, dm_internal_resume_fast, md);
1052 if (id < 0) {
1053 r = id;
1054 goto ret;
1055 }
1056
1057 snprintf(result, maxlen, "%d", id);
1058
1059 r = 1;
1060 goto ret;
1061
1062ret_einval:
1063 r = -EINVAL;
1064ret:
1065 kfree(histogram_boundaries);
1066 return r;
1067}
1068
1069static int message_stats_delete(struct mapped_device *md,
1070 unsigned argc, char **argv)
1071{
1072 int id;
1073 char dummy;
1074
1075 if (argc != 2)
1076 return -EINVAL;
1077
1078 if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
1079 return -EINVAL;
1080
1081 return dm_stats_delete(dm_get_stats(md), id);
1082}
1083
1084static int message_stats_clear(struct mapped_device *md,
1085 unsigned argc, char **argv)
1086{
1087 int id;
1088 char dummy;
1089
1090 if (argc != 2)
1091 return -EINVAL;
1092
1093 if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
1094 return -EINVAL;
1095
1096 return dm_stats_clear(dm_get_stats(md), id);
1097}
1098
1099static int message_stats_list(struct mapped_device *md,
1100 unsigned argc, char **argv,
1101 char *result, unsigned maxlen)
1102{
1103 int r;
1104 const char *program = NULL;
1105
1106 if (argc < 1 || argc > 2)
1107 return -EINVAL;
1108
1109 if (argc > 1) {
1110 program = kstrdup(argv[1], GFP_KERNEL);
1111 if (!program)
1112 return -ENOMEM;
1113 }
1114
1115 r = dm_stats_list(dm_get_stats(md), program, result, maxlen);
1116
1117 kfree(program);
1118
1119 return r;
1120}
1121
1122static int message_stats_print(struct mapped_device *md,
1123 unsigned argc, char **argv, bool clear,
1124 char *result, unsigned maxlen)
1125{
1126 int id;
1127 char dummy;
1128 unsigned long idx_start = 0, idx_len = ULONG_MAX;
1129
1130 if (argc != 2 && argc != 4)
1131 return -EINVAL;
1132
1133 if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
1134 return -EINVAL;
1135
1136 if (argc > 3) {
1137 if (strcmp(argv[2], "-") &&
1138 sscanf(argv[2], "%lu%c", &idx_start, &dummy) != 1)
1139 return -EINVAL;
1140 if (strcmp(argv[3], "-") &&
1141 sscanf(argv[3], "%lu%c", &idx_len, &dummy) != 1)
1142 return -EINVAL;
1143 }
1144
1145 return dm_stats_print(dm_get_stats(md), id, idx_start, idx_len, clear,
1146 result, maxlen);
1147}
1148
1149static int message_stats_set_aux(struct mapped_device *md,
1150 unsigned argc, char **argv)
1151{
1152 int id;
1153 char dummy;
1154
1155 if (argc != 3)
1156 return -EINVAL;
1157
1158 if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
1159 return -EINVAL;
1160
1161 return dm_stats_set_aux(dm_get_stats(md), id, argv[2]);
1162}
1163
1164int dm_stats_message(struct mapped_device *md, unsigned argc, char **argv,
1165 char *result, unsigned maxlen)
1166{
1167 int r;
1168
1169
1170 if (!strcasecmp(argv[0], "@stats_create"))
1171 r = message_stats_create(md, argc, argv, result, maxlen);
1172 else if (!strcasecmp(argv[0], "@stats_delete"))
1173 r = message_stats_delete(md, argc, argv);
1174 else if (!strcasecmp(argv[0], "@stats_clear"))
1175 r = message_stats_clear(md, argc, argv);
1176 else if (!strcasecmp(argv[0], "@stats_list"))
1177 r = message_stats_list(md, argc, argv, result, maxlen);
1178 else if (!strcasecmp(argv[0], "@stats_print"))
1179 r = message_stats_print(md, argc, argv, false, result, maxlen);
1180 else if (!strcasecmp(argv[0], "@stats_print_clear"))
1181 r = message_stats_print(md, argc, argv, true, result, maxlen);
1182 else if (!strcasecmp(argv[0], "@stats_set_aux"))
1183 r = message_stats_set_aux(md, argc, argv);
1184 else
1185 return 2;
1186
1187 if (r == -EINVAL)
1188 DMWARN("Invalid parameters for message %s", argv[0]);
1189
1190 return r;
1191}
1192
1193int __init dm_statistics_init(void)
1194{
1195 shared_memory_amount = 0;
1196 dm_stat_need_rcu_barrier = 0;
1197 return 0;
1198}
1199
1200void dm_statistics_exit(void)
1201{
1202 if (dm_stat_need_rcu_barrier)
1203 rcu_barrier();
1204 if (WARN_ON(shared_memory_amount))
1205 DMCRIT("shared_memory_amount leaked: %lu", shared_memory_amount);
1206}
1207
1208module_param_named(stats_current_allocated_bytes, shared_memory_amount, ulong, S_IRUGO);
1209MODULE_PARM_DESC(stats_current_allocated_bytes, "Memory currently used by statistics");
1210
