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drm/vmwgfx: Initial DX support
[linux-2.6-block.git] / drivers / md / dm-stats.c
CommitLineData
fd2ed4d2
MP		 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.h"
14#include "dm-stats.h"
15
16#define DM_MSG_PREFIX "stats"
17
18static int dm_stat_need_rcu_barrier;
19
20/*
21 * Using 64-bit values to avoid overflow (which is a
22 * problem that block/genhd.c's IO accounting has).
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;
dfcfac3e 32 unsigned long long *histogram;
fd2ed4d2
MP		 33};
34
35struct dm_stat_shared {
36 atomic_t in_flight[2];
c96aec34 37 unsigned long long stamp;
fd2ed4d2
MP		 38 struct dm_stat_percpu tmp;
39};
40
41struct dm_stat {
42 struct list_head list_entry;
43 int id;
c96aec34 44 unsigned stat_flags;
fd2ed4d2
MP		 45 size_t n_entries;
46 sector_t start;
47 sector_t end;
48 sector_t step;
dfcfac3e
MP		 49 unsigned n_histogram_entries;
50 unsigned long long *histogram_boundaries;
fd2ed4d2
MP		 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;
dfcfac3e 56 size_t histogram_alloc_size;
fd2ed4d2
MP		 57 struct dm_stat_percpu *stat_percpu[NR_CPUS];
58 struct dm_stat_shared stat_shared[0];
59};
60
c96aec34
MP		 61#define STAT_PRECISE_TIMESTAMPS 1
62
fd2ed4d2
MP		 63struct dm_stats_last_position {
64 sector_t last_sector;
65 unsigned last_rw;
66};
67
68/*
69 * A typo on the command line could possibly make the kernel run out of memory
70 * and crash. To prevent the crash we account all used memory. We fail if we
71 * exhaust 1/4 of all memory or 1/2 of vmalloc space.
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
0f24b79b 170 kvfree(ptr);
fd2ed4d2
MP		 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);
dfcfac3e
MP		 180 for_each_possible_cpu(cpu) {
181 dm_kvfree(s->stat_percpu[cpu][0].histogram, s->histogram_alloc_size);
fd2ed4d2 182 dm_kvfree(s->stat_percpu[cpu], s->percpu_alloc_size);
dfcfac3e
MP		 183 }
184 dm_kvfree(s->stat_shared[0].tmp.histogram, s->histogram_alloc_size);
fd2ed4d2
MP		 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,
c96aec34 237 sector_t step, unsigned stat_flags,
dfcfac3e
MP		 238 unsigned n_histogram_entries,
239 unsigned long long *histogram_boundaries,
c96aec34 240 const char *program_id, const char *aux_data,
fd2ed4d2
MP		 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;
dfcfac3e 251 size_t histogram_alloc_size;
fd2ed4d2
MP		 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
dfcfac3e
MP		 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)))
fd2ed4d2
MP		 281 return -ENOMEM;
282
283 s = dm_kvzalloc(shared_alloc_size, NUMA_NO_NODE);
284 if (!s)
285 return -ENOMEM;
286
c96aec34 287 s->stat_flags = stat_flags;
fd2ed4d2
MP		 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;
dfcfac3e
MP		 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 }
fd2ed4d2
MP		 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
dfcfac3e
MP		 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
fd2ed4d2
MP		 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;
dfcfac3e
MP		 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 }
fd2ed4d2
MP		 352 }
353
354 /*
355 * Suspend/resume to make sure there is no i/o in flight,
356 * so that newly created statistics will be exact.
357 *
358 * (note: we couldn't suspend earlier because we must not
359 * allocate memory while suspended)
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 * vfree can't be called from RCU callback
427 */
428 for_each_possible_cpu(cpu)
dfcfac3e
MP		 429 if (is_vmalloc_addr(s->stat_percpu) ||
430 is_vmalloc_addr(s->stat_percpu[cpu][0].histogram))
fd2ed4d2 431 goto do_sync_free;
dfcfac3e
MP		 432 if (is_vmalloc_addr(s) ||
433 is_vmalloc_addr(s->stat_shared[0].tmp.histogram)) {
fd2ed4d2
MP		 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 * Output format:
453 * <region_id>: <start_sector>+<length> <step> <program_id> <aux_data>
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\n", 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 }
467 }
468 mutex_unlock(&stats->mutex);
469
470 return 1;
471}
472
c96aec34
MP		 473static void dm_stat_round(struct dm_stat *s, struct dm_stat_shared *shared,
474 struct dm_stat_percpu *p)
fd2ed4d2
MP		 475{
476 /*
477 * This is racy, but so is part_round_stats_single.
478 */
c96aec34
MP		 479 unsigned long long now, difference;
480 unsigned in_flight_read, in_flight_write;
481
482 if (likely(!(s->stat_flags & STAT_PRECISE_TIMESTAMPS)))
483 now = jiffies;
484 else
485 now = ktime_to_ns(ktime_get());
fd2ed4d2 486
c96aec34 487 difference = now - shared->stamp;
fd2ed4d2
MP		 488 if (!difference)
489 return;
c96aec34 490
fd2ed4d2
MP		 491 in_flight_read = (unsigned)atomic_read(&shared->in_flight[READ]);
492 in_flight_write = (unsigned)atomic_read(&shared->in_flight[WRITE]);
493 if (in_flight_read)
494 p->io_ticks[READ] += difference;
495 if (in_flight_write)
496 p->io_ticks[WRITE] += difference;
497 if (in_flight_read + in_flight_write) {
498 p->io_ticks_total += difference;
499 p->time_in_queue += (in_flight_read + in_flight_write) * difference;
500 }
501 shared->stamp = now;
502}
503
504static void dm_stat_for_entry(struct dm_stat *s, size_t entry,
c96aec34
MP		 505 unsigned long bi_rw, sector_t len,
506 struct dm_stats_aux *stats_aux, bool end,
507 unsigned long duration_jiffies)
fd2ed4d2
MP		 508{
509 unsigned long idx = bi_rw & REQ_WRITE;
510 struct dm_stat_shared *shared = &s->stat_shared[entry];
511 struct dm_stat_percpu *p;
512
513 /*
bbf3f8cb 514 * For strict correctness we should use local_irq_save/restore
fd2ed4d2
MP		 515 * instead of preempt_disable/enable.
516 *
bbf3f8cb
MP		 517 * preempt_disable/enable is racy if the driver finishes bios
518 * from non-interrupt context as well as from interrupt context
519 * or from more different interrupts.
fd2ed4d2 520 *
bbf3f8cb
MP		 521 * On 64-bit architectures the race only results in not counting some
522 * events, so it is acceptable. On 32-bit architectures the race could
523 * cause the counter going off by 2^32, so we need to do proper locking
524 * there.
fd2ed4d2
MP		 525 *
526 * part_stat_lock()/part_stat_unlock() have this race too.
527 */
bbf3f8cb
MP		 528#if BITS_PER_LONG == 32
529 unsigned long flags;
530 local_irq_save(flags);
531#else
fd2ed4d2 532 preempt_disable();
bbf3f8cb 533#endif
fd2ed4d2
MP		 534 p = &s->stat_percpu[smp_processor_id()][entry];
535
536 if (!end) {
c96aec34 537 dm_stat_round(s, shared, p);
fd2ed4d2
MP		 538 atomic_inc(&shared->in_flight[idx]);
539 } else {
dfcfac3e 540 unsigned long long duration;
c96aec34 541 dm_stat_round(s, shared, p);
fd2ed4d2
MP		 542 atomic_dec(&shared->in_flight[idx]);
543 p->sectors[idx] += len;
544 p->ios[idx] += 1;
c96aec34 545 p->merges[idx] += stats_aux->merged;
dfcfac3e 546 if (!(s->stat_flags & STAT_PRECISE_TIMESTAMPS)) {
c96aec34 547 p->ticks[idx] += duration_jiffies;
dfcfac3e
MP		 548 duration = jiffies_to_msecs(duration_jiffies);
549 } else {
c96aec34 550 p->ticks[idx] += stats_aux->duration_ns;
dfcfac3e
MP		 551 duration = stats_aux->duration_ns;
552 }
553 if (s->n_histogram_entries) {
554 unsigned lo = 0, hi = s->n_histogram_entries + 1;
555 while (lo + 1 < hi) {
556 unsigned mid = (lo + hi) / 2;
557 if (s->histogram_boundaries[mid - 1] > duration) {
558 hi = mid;
559 } else {
560 lo = mid;
561 }
562
563 }
564 p->histogram[lo]++;
565 }
fd2ed4d2
MP		 566 }
567
bbf3f8cb
MP		 568#if BITS_PER_LONG == 32
569 local_irq_restore(flags);
570#else
fd2ed4d2 571 preempt_enable();
bbf3f8cb 572#endif
fd2ed4d2
MP		 573}
574
575static void __dm_stat_bio(struct dm_stat *s, unsigned long bi_rw,
576 sector_t bi_sector, sector_t end_sector,
c96aec34 577 bool end, unsigned long duration_jiffies,
fd2ed4d2
MP		 578 struct dm_stats_aux *stats_aux)
579{
580 sector_t rel_sector, offset, todo, fragment_len;
581 size_t entry;
582
583 if (end_sector <= s->start || bi_sector >= s->end)
584 return;
585 if (unlikely(bi_sector < s->start)) {
586 rel_sector = 0;
587 todo = end_sector - s->start;
588 } else {
589 rel_sector = bi_sector - s->start;
590 todo = end_sector - bi_sector;
591 }
592 if (unlikely(end_sector > s->end))
593 todo -= (end_sector - s->end);
594
595 offset = dm_sector_div64(rel_sector, s->step);
596 entry = rel_sector;
597 do {
598 if (WARN_ON_ONCE(entry >= s->n_entries)) {
599 DMCRIT("Invalid area access in region id %d", s->id);
600 return;
601 }
602 fragment_len = todo;
603 if (fragment_len > s->step - offset)
604 fragment_len = s->step - offset;
605 dm_stat_for_entry(s, entry, bi_rw, fragment_len,
c96aec34 606 stats_aux, end, duration_jiffies);
fd2ed4d2
MP		 607 todo -= fragment_len;
608 entry++;
609 offset = 0;
610 } while (unlikely(todo != 0));
611}
612
613void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw,
614 sector_t bi_sector, unsigned bi_sectors, bool end,
c96aec34
MP		 615 unsigned long duration_jiffies,
616 struct dm_stats_aux *stats_aux)
fd2ed4d2
MP		 617{
618 struct dm_stat *s;
619 sector_t end_sector;
620 struct dm_stats_last_position *last;
c96aec34 621 bool got_precise_time;
fd2ed4d2
MP		 622
623 if (unlikely(!bi_sectors))
624 return;
625
626 end_sector = bi_sector + bi_sectors;
627
628 if (!end) {
629 /*
630 * A race condition can at worst result in the merged flag being
631 * misrepresented, so we don't have to disable preemption here.
632 */
1f125e76 633 last = raw_cpu_ptr(stats->last);
fd2ed4d2
MP		 634 stats_aux->merged =
635 (bi_sector == (ACCESS_ONCE(last->last_sector) &&
636 ((bi_rw & (REQ_WRITE | REQ_DISCARD)) ==
637 (ACCESS_ONCE(last->last_rw) & (REQ_WRITE | REQ_DISCARD)))
638 ));
639 ACCESS_ONCE(last->last_sector) = end_sector;
640 ACCESS_ONCE(last->last_rw) = bi_rw;
641 }
642
643 rcu_read_lock();
644
c96aec34
MP		 645 got_precise_time = false;
646 list_for_each_entry_rcu(s, &stats->list, list_entry) {
647 if (s->stat_flags & STAT_PRECISE_TIMESTAMPS && !got_precise_time) {
648 if (!end)
649 stats_aux->duration_ns = ktime_to_ns(ktime_get());
650 else
651 stats_aux->duration_ns = ktime_to_ns(ktime_get()) - stats_aux->duration_ns;
652 got_precise_time = true;
653 }
654 __dm_stat_bio(s, bi_rw, bi_sector, end_sector, end, duration_jiffies, stats_aux);
655 }
fd2ed4d2
MP		 656
657 rcu_read_unlock();
658}
659
660static void __dm_stat_init_temporary_percpu_totals(struct dm_stat_shared *shared,
661 struct dm_stat *s, size_t x)
662{
663 int cpu;
664 struct dm_stat_percpu *p;
665
666 local_irq_disable();
667 p = &s->stat_percpu[smp_processor_id()][x];
c96aec34 668 dm_stat_round(s, shared, p);
fd2ed4d2
MP		 669 local_irq_enable();
670
dfcfac3e
MP		 671 shared->tmp.sectors[READ] = 0;
672 shared->tmp.sectors[WRITE] = 0;
673 shared->tmp.ios[READ] = 0;
674 shared->tmp.ios[WRITE] = 0;
675 shared->tmp.merges[READ] = 0;
676 shared->tmp.merges[WRITE] = 0;
677 shared->tmp.ticks[READ] = 0;
678 shared->tmp.ticks[WRITE] = 0;
679 shared->tmp.io_ticks[READ] = 0;
680 shared->tmp.io_ticks[WRITE] = 0;
681 shared->tmp.io_ticks_total = 0;
682 shared->tmp.time_in_queue = 0;
683
684 if (s->n_histogram_entries)
685 memset(shared->tmp.histogram, 0, (s->n_histogram_entries + 1) * sizeof(unsigned long long));
686
fd2ed4d2
MP		 687 for_each_possible_cpu(cpu) {
688 p = &s->stat_percpu[cpu][x];
689 shared->tmp.sectors[READ] += ACCESS_ONCE(p->sectors[READ]);
690 shared->tmp.sectors[WRITE] += ACCESS_ONCE(p->sectors[WRITE]);
691 shared->tmp.ios[READ] += ACCESS_ONCE(p->ios[READ]);
692 shared->tmp.ios[WRITE] += ACCESS_ONCE(p->ios[WRITE]);
693 shared->tmp.merges[READ] += ACCESS_ONCE(p->merges[READ]);
694 shared->tmp.merges[WRITE] += ACCESS_ONCE(p->merges[WRITE]);
695 shared->tmp.ticks[READ] += ACCESS_ONCE(p->ticks[READ]);
696 shared->tmp.ticks[WRITE] += ACCESS_ONCE(p->ticks[WRITE]);
697 shared->tmp.io_ticks[READ] += ACCESS_ONCE(p->io_ticks[READ]);
698 shared->tmp.io_ticks[WRITE] += ACCESS_ONCE(p->io_ticks[WRITE]);
699 shared->tmp.io_ticks_total += ACCESS_ONCE(p->io_ticks_total);
700 shared->tmp.time_in_queue += ACCESS_ONCE(p->time_in_queue);
dfcfac3e
MP		 701 if (s->n_histogram_entries) {
702 unsigned i;
703 for (i = 0; i < s->n_histogram_entries + 1; i++)
704 shared->tmp.histogram[i] += ACCESS_ONCE(p->histogram[i]);
705 }
fd2ed4d2
MP		 706 }
707}
708
709static void __dm_stat_clear(struct dm_stat *s, size_t idx_start, size_t idx_end,
710 bool init_tmp_percpu_totals)
711{
712 size_t x;
713 struct dm_stat_shared *shared;
714 struct dm_stat_percpu *p;
715
716 for (x = idx_start; x < idx_end; x++) {
717 shared = &s->stat_shared[x];
718 if (init_tmp_percpu_totals)
719 __dm_stat_init_temporary_percpu_totals(shared, s, x);
720 local_irq_disable();
721 p = &s->stat_percpu[smp_processor_id()][x];
722 p->sectors[READ] -= shared->tmp.sectors[READ];
723 p->sectors[WRITE] -= shared->tmp.sectors[WRITE];
724 p->ios[READ] -= shared->tmp.ios[READ];
725 p->ios[WRITE] -= shared->tmp.ios[WRITE];
726 p->merges[READ] -= shared->tmp.merges[READ];
727 p->merges[WRITE] -= shared->tmp.merges[WRITE];
728 p->ticks[READ] -= shared->tmp.ticks[READ];
729 p->ticks[WRITE] -= shared->tmp.ticks[WRITE];
730 p->io_ticks[READ] -= shared->tmp.io_ticks[READ];
731 p->io_ticks[WRITE] -= shared->tmp.io_ticks[WRITE];
732 p->io_ticks_total -= shared->tmp.io_ticks_total;
733 p->time_in_queue -= shared->tmp.time_in_queue;
734 local_irq_enable();
dfcfac3e
MP		 735 if (s->n_histogram_entries) {
736 unsigned i;
737 for (i = 0; i < s->n_histogram_entries + 1; i++) {
738 local_irq_disable();
739 p = &s->stat_percpu[smp_processor_id()][x];
740 p->histogram[i] -= shared->tmp.histogram[i];
741 local_irq_enable();
742 }
743 }
fd2ed4d2
MP		 744 }
745}
746
747static int dm_stats_clear(struct dm_stats *stats, int id)
748{
749 struct dm_stat *s;
750
751 mutex_lock(&stats->mutex);
752
753 s = __dm_stats_find(stats, id);
754 if (!s) {
755 mutex_unlock(&stats->mutex);
756 return -ENOENT;
757 }
758
759 __dm_stat_clear(s, 0, s->n_entries, true);
760
761 mutex_unlock(&stats->mutex);
762
763 return 1;
764}
765
766/*
767 * This is like jiffies_to_msec, but works for 64-bit values.
768 */
c96aec34 769static unsigned long long dm_jiffies_to_msec64(struct dm_stat *s, unsigned long long j)
fd2ed4d2 770{
c96aec34 771 unsigned long long result;
fd2ed4d2
MP		 772 unsigned mult;
773
c96aec34
MP		 774 if (s->stat_flags & STAT_PRECISE_TIMESTAMPS)
775 return j;
776
777 result = 0;
fd2ed4d2
MP		 778 if (j)
779 result = jiffies_to_msecs(j & 0x3fffff);
780 if (j >= 1 << 22) {
781 mult = jiffies_to_msecs(1 << 22);
782 result += (unsigned long long)mult * (unsigned long long)jiffies_to_msecs((j >> 22) & 0x3fffff);
783 }
784 if (j >= 1ULL << 44)
785 result += (unsigned long long)mult * (unsigned long long)mult * (unsigned long long)jiffies_to_msecs(j >> 44);
786
787 return result;
788}
789
790static int dm_stats_print(struct dm_stats *stats, int id,
791 size_t idx_start, size_t idx_len,
792 bool clear, char *result, unsigned maxlen)
793{
794 unsigned sz = 0;
795 struct dm_stat *s;
796 size_t x;
797 sector_t start, end, step;
798 size_t idx_end;
799 struct dm_stat_shared *shared;
800
801 /*
802 * Output format:
803 * <start_sector>+<length> counters
804 */
805
806 mutex_lock(&stats->mutex);
807
808 s = __dm_stats_find(stats, id);
809 if (!s) {
810 mutex_unlock(&stats->mutex);
811 return -ENOENT;
812 }
813
814 idx_end = idx_start + idx_len;
815 if (idx_end < idx_start ||
816 idx_end > s->n_entries)
817 idx_end = s->n_entries;
818
819 if (idx_start > idx_end)
820 idx_start = idx_end;
821
822 step = s->step;
823 start = s->start + (step * idx_start);
824
825 for (x = idx_start; x < idx_end; x++, start = end) {
826 shared = &s->stat_shared[x];
827 end = start + step;
828 if (unlikely(end > s->end))
829 end = s->end;
830
831 __dm_stat_init_temporary_percpu_totals(shared, s, x);
832
dfcfac3e 833 DMEMIT("%llu+%llu %llu %llu %llu %llu %llu %llu %llu %llu %d %llu %llu %llu %llu",
fd2ed4d2
MP		 834 (unsigned long long)start,
835 (unsigned long long)step,
836 shared->tmp.ios[READ],
837 shared->tmp.merges[READ],
838 shared->tmp.sectors[READ],
c96aec34 839 dm_jiffies_to_msec64(s, shared->tmp.ticks[READ]),
fd2ed4d2
MP		 840 shared->tmp.ios[WRITE],
841 shared->tmp.merges[WRITE],
842 shared->tmp.sectors[WRITE],
c96aec34 843 dm_jiffies_to_msec64(s, shared->tmp.ticks[WRITE]),
fd2ed4d2 844 dm_stat_in_flight(shared),
c96aec34
MP		 845 dm_jiffies_to_msec64(s, shared->tmp.io_ticks_total),
846 dm_jiffies_to_msec64(s, shared->tmp.time_in_queue),
847 dm_jiffies_to_msec64(s, shared->tmp.io_ticks[READ]),
848 dm_jiffies_to_msec64(s, shared->tmp.io_ticks[WRITE]));
dfcfac3e
MP		 849 if (s->n_histogram_entries) {
850 unsigned i;
851 for (i = 0; i < s->n_histogram_entries + 1; i++) {
852 DMEMIT("%s%llu", !i ? " " : ":", shared->tmp.histogram[i]);
853 }
854 }
855 DMEMIT("\n");
fd2ed4d2
MP		 856
857 if (unlikely(sz + 1 >= maxlen))
858 goto buffer_overflow;
859 }
860
861 if (clear)
862 __dm_stat_clear(s, idx_start, idx_end, false);
863
864buffer_overflow:
865 mutex_unlock(&stats->mutex);
866
867 return 1;
868}
869
870static int dm_stats_set_aux(struct dm_stats *stats, int id, const char *aux_data)
871{
872 struct dm_stat *s;
873 const char *new_aux_data;
874
875 mutex_lock(&stats->mutex);
876
877 s = __dm_stats_find(stats, id);
878 if (!s) {
879 mutex_unlock(&stats->mutex);
880 return -ENOENT;
881 }
882
883 new_aux_data = kstrdup(aux_data, GFP_KERNEL);
884 if (!new_aux_data) {
885 mutex_unlock(&stats->mutex);
886 return -ENOMEM;
887 }
888
889 kfree(s->aux_data);
890 s->aux_data = new_aux_data;
891
892 mutex_unlock(&stats->mutex);
893
894 return 0;
895}
896
dfcfac3e
MP		 897static int parse_histogram(const char *h, unsigned *n_histogram_entries,
898 unsigned long long **histogram_boundaries)
899{
900 const char *q;
901 unsigned n;
902 unsigned long long last;
903
904 *n_histogram_entries = 1;
905 for (q = h; *q; q++)
906 if (*q == ',')
907 (*n_histogram_entries)++;
908
909 *histogram_boundaries = kmalloc(*n_histogram_entries * sizeof(unsigned long long), GFP_KERNEL);
910 if (!*histogram_boundaries)
911 return -ENOMEM;
912
913 n = 0;
914 last = 0;
915 while (1) {
916 unsigned long long hi;
917 int s;
918 char ch;
919 s = sscanf(h, "%llu%c", &hi, &ch);
920 if (!s || (s == 2 && ch != ','))
921 return -EINVAL;
922 if (hi <= last)
923 return -EINVAL;
924 last = hi;
925 (*histogram_boundaries)[n] = hi;
926 if (s == 1)
927 return 0;
928 h = strchr(h, ',') + 1;
929 n++;
930 }
931}
932
fd2ed4d2
MP		 933static int message_stats_create(struct mapped_device *md,
934 unsigned argc, char **argv,
935 char *result, unsigned maxlen)
936{
dfcfac3e 937 int r;
fd2ed4d2
MP		 938 int id;
939 char dummy;
940 unsigned long long start, end, len, step;
941 unsigned divisor;
942 const char *program_id, *aux_data;
c96aec34
MP		 943 unsigned stat_flags = 0;
944
dfcfac3e
MP		 945 unsigned n_histogram_entries = 0;
946 unsigned long long *histogram_boundaries = NULL;
947
c96aec34
MP		 948 struct dm_arg_set as, as_backup;
949 const char *a;
950 unsigned feature_args;
fd2ed4d2
MP		 951
952 /*
953 * Input format:
c96aec34 954 * <range> <step> [<extra_parameters> <parameters>] [<program_id> [<aux_data>]]
fd2ed4d2
MP		 955 */
956
c96aec34 957 if (argc < 3)
dfcfac3e 958 goto ret_einval;
fd2ed4d2 959
c96aec34
MP		 960 as.argc = argc;
961 as.argv = argv;
962 dm_consume_args(&as, 1);
963
964 a = dm_shift_arg(&as);
965 if (!strcmp(a, "-")) {
fd2ed4d2
MP		 966 start = 0;
967 len = dm_get_size(md);
968 if (!len)
969 len = 1;
c96aec34 970 } else if (sscanf(a, "%llu+%llu%c", &start, &len, &dummy) != 2 ||
fd2ed4d2 971 start != (sector_t)start || len != (sector_t)len)
dfcfac3e 972 goto ret_einval;
fd2ed4d2
MP		 973
974 end = start + len;
975 if (start >= end)
dfcfac3e 976 goto ret_einval;
fd2ed4d2 977
c96aec34
MP		 978 a = dm_shift_arg(&as);
979 if (sscanf(a, "/%u%c", &divisor, &dummy) == 1) {
dd4c1b7d
MP		 980 if (!divisor)
981 return -EINVAL;
fd2ed4d2
MP		 982 step = end - start;
983 if (do_div(step, divisor))
984 step++;
985 if (!step)
986 step = 1;
c96aec34 987 } else if (sscanf(a, "%llu%c", &step, &dummy) != 1 ||
fd2ed4d2 988 step != (sector_t)step || !step)
dfcfac3e 989 goto ret_einval;
fd2ed4d2 990
c96aec34
MP		 991 as_backup = as;
992 a = dm_shift_arg(&as);
993 if (a && sscanf(a, "%u%c", &feature_args, &dummy) == 1) {
994 while (feature_args--) {
995 a = dm_shift_arg(&as);
996 if (!a)
dfcfac3e 997 goto ret_einval;
c96aec34
MP		 998 if (!strcasecmp(a, "precise_timestamps"))
999 stat_flags |= STAT_PRECISE_TIMESTAMPS;
dfcfac3e
MP		 1000 else if (!strncasecmp(a, "histogram:", 10)) {
1001 if (n_histogram_entries)
1002 goto ret_einval;
1003 if ((r = parse_histogram(a + 10, &n_histogram_entries, &histogram_boundaries)))
1004 goto ret;
1005 } else
1006 goto ret_einval;
c96aec34
MP		 1007 }
1008 } else {
1009 as = as_backup;
1010 }
1011
fd2ed4d2
MP		 1012 program_id = "-";
1013 aux_data = "-";
1014
c96aec34
MP		 1015 a = dm_shift_arg(&as);
1016 if (a)
1017 program_id = a;
1018
1019 a = dm_shift_arg(&as);
1020 if (a)
1021 aux_data = a;
fd2ed4d2 1022
c96aec34 1023 if (as.argc)
dfcfac3e 1024 goto ret_einval;
fd2ed4d2
MP		 1025
1026 /*
1027 * If a buffer overflow happens after we created the region,
1028 * it's too late (the userspace would retry with a larger
1029 * buffer, but the region id that caused the overflow is already
1030 * leaked). So we must detect buffer overflow in advance.
1031 */
1032 snprintf(result, maxlen, "%d", INT_MAX);
dfcfac3e
MP		 1033 if (dm_message_test_buffer_overflow(result, maxlen)) {
1034 r = 1;
1035 goto ret;
1036 }
fd2ed4d2 1037
dfcfac3e
MP		 1038 id = dm_stats_create(dm_get_stats(md), start, end, step, stat_flags,
1039 n_histogram_entries, histogram_boundaries, program_id, aux_data,
ffcc3936 1040 dm_internal_suspend_fast, dm_internal_resume_fast, md);
dfcfac3e
MP		 1041 if (id < 0) {
1042 r = id;
1043 goto ret;
1044 }
fd2ed4d2
MP		 1045
1046 snprintf(result, maxlen, "%d", id);
1047
dfcfac3e
MP		 1048 r = 1;
1049 goto ret;
1050
1051ret_einval:
1052 r = -EINVAL;
1053ret:
1054 kfree(histogram_boundaries);
1055 return r;
fd2ed4d2
MP		 1056}
1057
1058static int message_stats_delete(struct mapped_device *md,
1059 unsigned argc, char **argv)
1060{
1061 int id;
1062 char dummy;
1063
1064 if (argc != 2)
1065 return -EINVAL;
1066
1067 if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
1068 return -EINVAL;
1069
1070 return dm_stats_delete(dm_get_stats(md), id);
1071}
1072
1073static int message_stats_clear(struct mapped_device *md,
1074 unsigned argc, char **argv)
1075{
1076 int id;
1077 char dummy;
1078
1079 if (argc != 2)
1080 return -EINVAL;
1081
1082 if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
1083 return -EINVAL;
1084
1085 return dm_stats_clear(dm_get_stats(md), id);
1086}
1087
1088static int message_stats_list(struct mapped_device *md,
1089 unsigned argc, char **argv,
1090 char *result, unsigned maxlen)
1091{
1092 int r;
1093 const char *program = NULL;
1094
1095 if (argc < 1 || argc > 2)
1096 return -EINVAL;
1097
1098 if (argc > 1) {
1099 program = kstrdup(argv[1], GFP_KERNEL);
1100 if (!program)
1101 return -ENOMEM;
1102 }
1103
1104 r = dm_stats_list(dm_get_stats(md), program, result, maxlen);
1105
1106 kfree(program);
1107
1108 return r;
1109}
1110
1111static int message_stats_print(struct mapped_device *md,
1112 unsigned argc, char **argv, bool clear,
1113 char *result, unsigned maxlen)
1114{
1115 int id;
1116 char dummy;
1117 unsigned long idx_start = 0, idx_len = ULONG_MAX;
1118
1119 if (argc != 2 && argc != 4)
1120 return -EINVAL;
1121
1122 if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
1123 return -EINVAL;
1124
1125 if (argc > 3) {
1126 if (strcmp(argv[2], "-") &&
1127 sscanf(argv[2], "%lu%c", &idx_start, &dummy) != 1)
1128 return -EINVAL;
1129 if (strcmp(argv[3], "-") &&
1130 sscanf(argv[3], "%lu%c", &idx_len, &dummy) != 1)
1131 return -EINVAL;
1132 }
1133
1134 return dm_stats_print(dm_get_stats(md), id, idx_start, idx_len, clear,
1135 result, maxlen);
1136}
1137
1138static int message_stats_set_aux(struct mapped_device *md,
1139 unsigned argc, char **argv)
1140{
1141 int id;
1142 char dummy;
1143
1144 if (argc != 3)
1145 return -EINVAL;
1146
1147 if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
1148 return -EINVAL;
1149
1150 return dm_stats_set_aux(dm_get_stats(md), id, argv[2]);
1151}
1152
1153int dm_stats_message(struct mapped_device *md, unsigned argc, char **argv,
1154 char *result, unsigned maxlen)
1155{
1156 int r;
1157
fd2ed4d2
MP		 1158 /* All messages here must start with '@' */
1159 if (!strcasecmp(argv[0], "@stats_create"))
1160 r = message_stats_create(md, argc, argv, result, maxlen);
1161 else if (!strcasecmp(argv[0], "@stats_delete"))
1162 r = message_stats_delete(md, argc, argv);
1163 else if (!strcasecmp(argv[0], "@stats_clear"))
1164 r = message_stats_clear(md, argc, argv);
1165 else if (!strcasecmp(argv[0], "@stats_list"))
1166 r = message_stats_list(md, argc, argv, result, maxlen);
1167 else if (!strcasecmp(argv[0], "@stats_print"))
1168 r = message_stats_print(md, argc, argv, false, result, maxlen);
1169 else if (!strcasecmp(argv[0], "@stats_print_clear"))
1170 r = message_stats_print(md, argc, argv, true, result, maxlen);
1171 else if (!strcasecmp(argv[0], "@stats_set_aux"))
1172 r = message_stats_set_aux(md, argc, argv);
1173 else
1174 return 2; /* this wasn't a stats message */
1175
1176 if (r == -EINVAL)
1177 DMWARN("Invalid parameters for message %s", argv[0]);
1178
1179 return r;
1180}
1181
1182int __init dm_statistics_init(void)
1183{
76f5bee5 1184 shared_memory_amount = 0;
fd2ed4d2
MP		 1185 dm_stat_need_rcu_barrier = 0;
1186 return 0;
1187}
1188
1189void dm_statistics_exit(void)
1190{
1191 if (dm_stat_need_rcu_barrier)
1192 rcu_barrier();
1193 if (WARN_ON(shared_memory_amount))
1194 DMCRIT("shared_memory_amount leaked: %lu", shared_memory_amount);
1195}
1196
1197module_param_named(stats_current_allocated_bytes, shared_memory_amount, ulong, S_IRUGO);
1198MODULE_PARM_DESC(stats_current_allocated_bytes, "Memory currently used by statistics");
Linux 6.x block layer and io_uring tree(s)