1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | #include <linux/errno.h> |
3 | #include <linux/numa.h> |
4 | #include <linux/slab.h> |
5 | #include <linux/rculist.h> |
6 | #include <linux/threads.h> |
7 | #include <linux/preempt.h> |
8 | #include <linux/irqflags.h> |
9 | #include <linux/vmalloc.h> |
10 | #include <linux/mm.h> |
11 | #include <linux/module.h> |
12 | #include <linux/device-mapper.h> |
13 | |
14 | #include "dm-core.h" |
15 | #include "dm-stats.h" |
16 | |
17 | #define DM_MSG_PREFIX "stats" |
18 | |
19 | static int dm_stat_need_rcu_barrier; |
20 | |
21 | /* |
22 | * Using 64-bit values to avoid overflow (which is a |
23 | * problem that block/genhd.c's IO accounting has). |
24 | */ |
25 | struct dm_stat_percpu { |
26 | unsigned long long sectors[2]; |
27 | unsigned long long ios[2]; |
28 | unsigned long long merges[2]; |
29 | unsigned long long ticks[2]; |
30 | unsigned long long io_ticks[2]; |
31 | unsigned long long io_ticks_total; |
32 | unsigned long long time_in_queue; |
33 | unsigned long long *histogram; |
34 | }; |
35 | |
36 | struct dm_stat_shared { |
37 | atomic_t in_flight[2]; |
38 | unsigned long long stamp; |
39 | struct dm_stat_percpu tmp; |
40 | }; |
41 | |
42 | struct dm_stat { |
43 | struct list_head list_entry; |
44 | int id; |
45 | unsigned int stat_flags; |
46 | size_t n_entries; |
47 | sector_t start; |
48 | sector_t end; |
49 | sector_t step; |
50 | unsigned int n_histogram_entries; |
51 | unsigned long long *histogram_boundaries; |
52 | const char *program_id; |
53 | const char *aux_data; |
54 | struct rcu_head rcu_head; |
55 | size_t shared_alloc_size; |
56 | size_t percpu_alloc_size; |
57 | size_t histogram_alloc_size; |
58 | struct dm_stat_percpu *stat_percpu[NR_CPUS]; |
59 | struct dm_stat_shared stat_shared[] __counted_by(n_entries); |
60 | }; |
61 | |
62 | #define STAT_PRECISE_TIMESTAMPS 1 |
63 | |
64 | struct dm_stats_last_position { |
65 | sector_t last_sector; |
66 | unsigned int last_rw; |
67 | }; |
68 | |
69 | #define DM_STAT_MAX_ENTRIES 8388608 |
70 | #define DM_STAT_MAX_HISTOGRAM_ENTRIES 134217728 |
71 | |
72 | /* |
73 | * A typo on the command line could possibly make the kernel run out of memory |
74 | * and crash. To prevent the crash we account all used memory. We fail if we |
75 | * exhaust 1/4 of all memory or 1/2 of vmalloc space. |
76 | */ |
77 | #define DM_STATS_MEMORY_FACTOR 4 |
78 | #define DM_STATS_VMALLOC_FACTOR 2 |
79 | |
80 | static DEFINE_SPINLOCK(shared_memory_lock); |
81 | |
82 | static unsigned long shared_memory_amount; |
83 | |
84 | static bool __check_shared_memory(size_t alloc_size) |
85 | { |
86 | size_t a; |
87 | |
88 | a = shared_memory_amount + alloc_size; |
89 | if (a < shared_memory_amount) |
90 | return false; |
91 | if (a >> PAGE_SHIFT > totalram_pages() / DM_STATS_MEMORY_FACTOR) |
92 | return false; |
93 | #ifdef CONFIG_MMU |
94 | if (a > (VMALLOC_END - VMALLOC_START) / DM_STATS_VMALLOC_FACTOR) |
95 | return false; |
96 | #endif |
97 | return true; |
98 | } |
99 | |
100 | static bool check_shared_memory(size_t alloc_size) |
101 | { |
102 | bool ret; |
103 | |
104 | spin_lock_irq(lock: &shared_memory_lock); |
105 | |
106 | ret = __check_shared_memory(alloc_size); |
107 | |
108 | spin_unlock_irq(lock: &shared_memory_lock); |
109 | |
110 | return ret; |
111 | } |
112 | |
113 | static bool claim_shared_memory(size_t alloc_size) |
114 | { |
115 | spin_lock_irq(lock: &shared_memory_lock); |
116 | |
117 | if (!__check_shared_memory(alloc_size)) { |
118 | spin_unlock_irq(lock: &shared_memory_lock); |
119 | return false; |
120 | } |
121 | |
122 | shared_memory_amount += alloc_size; |
123 | |
124 | spin_unlock_irq(lock: &shared_memory_lock); |
125 | |
126 | return true; |
127 | } |
128 | |
129 | static void free_shared_memory(size_t alloc_size) |
130 | { |
131 | unsigned long flags; |
132 | |
133 | spin_lock_irqsave(&shared_memory_lock, flags); |
134 | |
135 | if (WARN_ON_ONCE(shared_memory_amount < alloc_size)) { |
136 | spin_unlock_irqrestore(lock: &shared_memory_lock, flags); |
137 | DMCRIT("Memory usage accounting bug." ); |
138 | return; |
139 | } |
140 | |
141 | shared_memory_amount -= alloc_size; |
142 | |
143 | spin_unlock_irqrestore(lock: &shared_memory_lock, flags); |
144 | } |
145 | |
146 | static void *dm_kvzalloc(size_t alloc_size, int node) |
147 | { |
148 | void *p; |
149 | |
150 | if (!claim_shared_memory(alloc_size)) |
151 | return NULL; |
152 | |
153 | p = kvzalloc_node(size: alloc_size, GFP_KERNEL | __GFP_NOMEMALLOC, node); |
154 | if (p) |
155 | return p; |
156 | |
157 | free_shared_memory(alloc_size); |
158 | |
159 | return NULL; |
160 | } |
161 | |
162 | static void dm_kvfree(void *ptr, size_t alloc_size) |
163 | { |
164 | if (!ptr) |
165 | return; |
166 | |
167 | free_shared_memory(alloc_size); |
168 | |
169 | kvfree(addr: ptr); |
170 | } |
171 | |
172 | static void dm_stat_free(struct rcu_head *head) |
173 | { |
174 | int cpu; |
175 | struct dm_stat *s = container_of(head, struct dm_stat, rcu_head); |
176 | |
177 | kfree(objp: s->histogram_boundaries); |
178 | kfree(objp: s->program_id); |
179 | kfree(objp: s->aux_data); |
180 | for_each_possible_cpu(cpu) { |
181 | dm_kvfree(ptr: s->stat_percpu[cpu][0].histogram, alloc_size: s->histogram_alloc_size); |
182 | dm_kvfree(ptr: s->stat_percpu[cpu], alloc_size: s->percpu_alloc_size); |
183 | } |
184 | dm_kvfree(ptr: s->stat_shared[0].tmp.histogram, alloc_size: s->histogram_alloc_size); |
185 | dm_kvfree(ptr: s, alloc_size: s->shared_alloc_size); |
186 | } |
187 | |
188 | static int dm_stat_in_flight(struct dm_stat_shared *shared) |
189 | { |
190 | return atomic_read(v: &shared->in_flight[READ]) + |
191 | atomic_read(v: &shared->in_flight[WRITE]); |
192 | } |
193 | |
194 | int 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(list: &stats->list); |
201 | stats->precise_timestamps = false; |
202 | stats->last = alloc_percpu(struct dm_stats_last_position); |
203 | if (!stats->last) |
204 | return -ENOMEM; |
205 | |
206 | for_each_possible_cpu(cpu) { |
207 | last = per_cpu_ptr(stats->last, cpu); |
208 | last->last_sector = (sector_t)ULLONG_MAX; |
209 | last->last_rw = UINT_MAX; |
210 | } |
211 | |
212 | return 0; |
213 | } |
214 | |
215 | void dm_stats_cleanup(struct dm_stats *stats) |
216 | { |
217 | size_t ni; |
218 | struct dm_stat *s; |
219 | struct dm_stat_shared *shared; |
220 | |
221 | while (!list_empty(head: &stats->list)) { |
222 | s = container_of(stats->list.next, struct dm_stat, list_entry); |
223 | list_del(entry: &s->list_entry); |
224 | for (ni = 0; ni < s->n_entries; ni++) { |
225 | shared = &s->stat_shared[ni]; |
226 | if (WARN_ON(dm_stat_in_flight(shared))) { |
227 | DMCRIT("leaked in-flight counter at index %lu " |
228 | "(start %llu, end %llu, step %llu): reads %d, writes %d" , |
229 | (unsigned long)ni, |
230 | (unsigned long long)s->start, |
231 | (unsigned long long)s->end, |
232 | (unsigned long long)s->step, |
233 | atomic_read(&shared->in_flight[READ]), |
234 | atomic_read(&shared->in_flight[WRITE])); |
235 | } |
236 | cond_resched(); |
237 | } |
238 | dm_stat_free(head: &s->rcu_head); |
239 | } |
240 | free_percpu(pdata: stats->last); |
241 | mutex_destroy(lock: &stats->mutex); |
242 | } |
243 | |
244 | static void dm_stats_recalc_precise_timestamps(struct dm_stats *stats) |
245 | { |
246 | struct list_head *l; |
247 | struct dm_stat *tmp_s; |
248 | bool precise_timestamps = false; |
249 | |
250 | list_for_each(l, &stats->list) { |
251 | tmp_s = container_of(l, struct dm_stat, list_entry); |
252 | if (tmp_s->stat_flags & STAT_PRECISE_TIMESTAMPS) { |
253 | precise_timestamps = true; |
254 | break; |
255 | } |
256 | } |
257 | stats->precise_timestamps = precise_timestamps; |
258 | } |
259 | |
260 | static int dm_stats_create(struct dm_stats *stats, sector_t start, sector_t end, |
261 | sector_t step, unsigned int stat_flags, |
262 | unsigned int n_histogram_entries, |
263 | unsigned long long *histogram_boundaries, |
264 | const char *program_id, const char *aux_data, |
265 | void (*suspend_callback)(struct mapped_device *), |
266 | void (*resume_callback)(struct mapped_device *), |
267 | struct mapped_device *md) |
268 | { |
269 | struct list_head *l; |
270 | struct dm_stat *s, *tmp_s; |
271 | sector_t n_entries; |
272 | size_t ni; |
273 | size_t shared_alloc_size; |
274 | size_t percpu_alloc_size; |
275 | size_t histogram_alloc_size; |
276 | struct dm_stat_percpu *p; |
277 | int cpu; |
278 | int ret_id; |
279 | int r; |
280 | |
281 | if (end < start || !step) |
282 | return -EINVAL; |
283 | |
284 | n_entries = end - start; |
285 | if (dm_sector_div64(n_entries, step)) |
286 | n_entries++; |
287 | |
288 | if (n_entries != (size_t)n_entries || !(size_t)(n_entries + 1)) |
289 | return -EOVERFLOW; |
290 | |
291 | if (n_entries > DM_STAT_MAX_ENTRIES) |
292 | return -EOVERFLOW; |
293 | |
294 | shared_alloc_size = struct_size(s, stat_shared, n_entries); |
295 | if ((shared_alloc_size - sizeof(struct dm_stat)) / sizeof(struct dm_stat_shared) != n_entries) |
296 | return -EOVERFLOW; |
297 | |
298 | percpu_alloc_size = (size_t)n_entries * sizeof(struct dm_stat_percpu); |
299 | if (percpu_alloc_size / sizeof(struct dm_stat_percpu) != n_entries) |
300 | return -EOVERFLOW; |
301 | |
302 | histogram_alloc_size = (n_histogram_entries + 1) * (size_t)n_entries * sizeof(unsigned long long); |
303 | if (histogram_alloc_size / (n_histogram_entries + 1) != (size_t)n_entries * sizeof(unsigned long long)) |
304 | return -EOVERFLOW; |
305 | |
306 | if ((n_histogram_entries + 1) * (size_t)n_entries > DM_STAT_MAX_HISTOGRAM_ENTRIES) |
307 | return -EOVERFLOW; |
308 | |
309 | if (!check_shared_memory(alloc_size: shared_alloc_size + histogram_alloc_size + |
310 | num_possible_cpus() * (percpu_alloc_size + histogram_alloc_size))) |
311 | return -ENOMEM; |
312 | |
313 | s = dm_kvzalloc(alloc_size: shared_alloc_size, NUMA_NO_NODE); |
314 | if (!s) |
315 | return -ENOMEM; |
316 | |
317 | s->stat_flags = stat_flags; |
318 | s->n_entries = n_entries; |
319 | s->start = start; |
320 | s->end = end; |
321 | s->step = step; |
322 | s->shared_alloc_size = shared_alloc_size; |
323 | s->percpu_alloc_size = percpu_alloc_size; |
324 | s->histogram_alloc_size = histogram_alloc_size; |
325 | |
326 | s->n_histogram_entries = n_histogram_entries; |
327 | s->histogram_boundaries = kmemdup(p: histogram_boundaries, |
328 | size: s->n_histogram_entries * sizeof(unsigned long long), GFP_KERNEL); |
329 | if (!s->histogram_boundaries) { |
330 | r = -ENOMEM; |
331 | goto out; |
332 | } |
333 | |
334 | s->program_id = kstrdup(s: program_id, GFP_KERNEL); |
335 | if (!s->program_id) { |
336 | r = -ENOMEM; |
337 | goto out; |
338 | } |
339 | s->aux_data = kstrdup(s: aux_data, GFP_KERNEL); |
340 | if (!s->aux_data) { |
341 | r = -ENOMEM; |
342 | goto out; |
343 | } |
344 | |
345 | for (ni = 0; ni < n_entries; ni++) { |
346 | atomic_set(v: &s->stat_shared[ni].in_flight[READ], i: 0); |
347 | atomic_set(v: &s->stat_shared[ni].in_flight[WRITE], i: 0); |
348 | cond_resched(); |
349 | } |
350 | |
351 | if (s->n_histogram_entries) { |
352 | unsigned long long *hi; |
353 | |
354 | hi = dm_kvzalloc(alloc_size: s->histogram_alloc_size, NUMA_NO_NODE); |
355 | if (!hi) { |
356 | r = -ENOMEM; |
357 | goto out; |
358 | } |
359 | for (ni = 0; ni < n_entries; ni++) { |
360 | s->stat_shared[ni].tmp.histogram = hi; |
361 | hi += s->n_histogram_entries + 1; |
362 | cond_resched(); |
363 | } |
364 | } |
365 | |
366 | for_each_possible_cpu(cpu) { |
367 | p = dm_kvzalloc(alloc_size: percpu_alloc_size, cpu_to_node(cpu)); |
368 | if (!p) { |
369 | r = -ENOMEM; |
370 | goto out; |
371 | } |
372 | s->stat_percpu[cpu] = p; |
373 | if (s->n_histogram_entries) { |
374 | unsigned long long *hi; |
375 | |
376 | hi = dm_kvzalloc(alloc_size: s->histogram_alloc_size, cpu_to_node(cpu)); |
377 | if (!hi) { |
378 | r = -ENOMEM; |
379 | goto out; |
380 | } |
381 | for (ni = 0; ni < n_entries; ni++) { |
382 | p[ni].histogram = hi; |
383 | hi += s->n_histogram_entries + 1; |
384 | cond_resched(); |
385 | } |
386 | } |
387 | } |
388 | |
389 | /* |
390 | * Suspend/resume to make sure there is no i/o in flight, |
391 | * so that newly created statistics will be exact. |
392 | * |
393 | * (note: we couldn't suspend earlier because we must not |
394 | * allocate memory while suspended) |
395 | */ |
396 | suspend_callback(md); |
397 | |
398 | mutex_lock(&stats->mutex); |
399 | s->id = 0; |
400 | list_for_each(l, &stats->list) { |
401 | tmp_s = container_of(l, struct dm_stat, list_entry); |
402 | if (WARN_ON(tmp_s->id < s->id)) { |
403 | r = -EINVAL; |
404 | goto out_unlock_resume; |
405 | } |
406 | if (tmp_s->id > s->id) |
407 | break; |
408 | if (unlikely(s->id == INT_MAX)) { |
409 | r = -ENFILE; |
410 | goto out_unlock_resume; |
411 | } |
412 | s->id++; |
413 | } |
414 | ret_id = s->id; |
415 | list_add_tail_rcu(new: &s->list_entry, head: l); |
416 | |
417 | dm_stats_recalc_precise_timestamps(stats); |
418 | |
419 | if (!static_key_enabled(&stats_enabled.key)) |
420 | static_branch_enable(&stats_enabled); |
421 | |
422 | mutex_unlock(lock: &stats->mutex); |
423 | |
424 | resume_callback(md); |
425 | |
426 | return ret_id; |
427 | |
428 | out_unlock_resume: |
429 | mutex_unlock(lock: &stats->mutex); |
430 | resume_callback(md); |
431 | out: |
432 | dm_stat_free(head: &s->rcu_head); |
433 | return r; |
434 | } |
435 | |
436 | static struct dm_stat *__dm_stats_find(struct dm_stats *stats, int id) |
437 | { |
438 | struct dm_stat *s; |
439 | |
440 | list_for_each_entry(s, &stats->list, list_entry) { |
441 | if (s->id > id) |
442 | break; |
443 | if (s->id == id) |
444 | return s; |
445 | } |
446 | |
447 | return NULL; |
448 | } |
449 | |
450 | static int dm_stats_delete(struct dm_stats *stats, int id) |
451 | { |
452 | struct dm_stat *s; |
453 | int cpu; |
454 | |
455 | mutex_lock(&stats->mutex); |
456 | |
457 | s = __dm_stats_find(stats, id); |
458 | if (!s) { |
459 | mutex_unlock(lock: &stats->mutex); |
460 | return -ENOENT; |
461 | } |
462 | |
463 | list_del_rcu(entry: &s->list_entry); |
464 | |
465 | dm_stats_recalc_precise_timestamps(stats); |
466 | |
467 | mutex_unlock(lock: &stats->mutex); |
468 | |
469 | /* |
470 | * vfree can't be called from RCU callback |
471 | */ |
472 | for_each_possible_cpu(cpu) |
473 | if (is_vmalloc_addr(x: s->stat_percpu) || |
474 | is_vmalloc_addr(x: s->stat_percpu[cpu][0].histogram)) |
475 | goto do_sync_free; |
476 | if (is_vmalloc_addr(x: s) || |
477 | is_vmalloc_addr(x: s->stat_shared[0].tmp.histogram)) { |
478 | do_sync_free: |
479 | synchronize_rcu_expedited(); |
480 | dm_stat_free(head: &s->rcu_head); |
481 | } else { |
482 | WRITE_ONCE(dm_stat_need_rcu_barrier, 1); |
483 | call_rcu(head: &s->rcu_head, func: dm_stat_free); |
484 | } |
485 | return 0; |
486 | } |
487 | |
488 | static int dm_stats_list(struct dm_stats *stats, const char *program, |
489 | char *result, unsigned int maxlen) |
490 | { |
491 | struct dm_stat *s; |
492 | sector_t len; |
493 | unsigned int sz = 0; |
494 | |
495 | /* |
496 | * Output format: |
497 | * <region_id>: <start_sector>+<length> <step> <program_id> <aux_data> |
498 | */ |
499 | |
500 | mutex_lock(&stats->mutex); |
501 | list_for_each_entry(s, &stats->list, list_entry) { |
502 | if (!program || !strcmp(program, s->program_id)) { |
503 | len = s->end - s->start; |
504 | DMEMIT("%d: %llu+%llu %llu %s %s" , s->id, |
505 | (unsigned long long)s->start, |
506 | (unsigned long long)len, |
507 | (unsigned long long)s->step, |
508 | s->program_id, |
509 | s->aux_data); |
510 | if (s->stat_flags & STAT_PRECISE_TIMESTAMPS) |
511 | DMEMIT(" precise_timestamps" ); |
512 | if (s->n_histogram_entries) { |
513 | unsigned int i; |
514 | |
515 | DMEMIT(" histogram:" ); |
516 | for (i = 0; i < s->n_histogram_entries; i++) { |
517 | if (i) |
518 | DMEMIT("," ); |
519 | DMEMIT("%llu" , s->histogram_boundaries[i]); |
520 | } |
521 | } |
522 | DMEMIT("\n" ); |
523 | } |
524 | cond_resched(); |
525 | } |
526 | mutex_unlock(lock: &stats->mutex); |
527 | |
528 | return 1; |
529 | } |
530 | |
531 | static void dm_stat_round(struct dm_stat *s, struct dm_stat_shared *shared, |
532 | struct dm_stat_percpu *p) |
533 | { |
534 | /* |
535 | * This is racy, but so is part_round_stats_single. |
536 | */ |
537 | unsigned long long now, difference; |
538 | unsigned int in_flight_read, in_flight_write; |
539 | |
540 | if (likely(!(s->stat_flags & STAT_PRECISE_TIMESTAMPS))) |
541 | now = jiffies; |
542 | else |
543 | now = ktime_to_ns(kt: ktime_get()); |
544 | |
545 | difference = now - shared->stamp; |
546 | if (!difference) |
547 | return; |
548 | |
549 | in_flight_read = (unsigned int)atomic_read(v: &shared->in_flight[READ]); |
550 | in_flight_write = (unsigned int)atomic_read(v: &shared->in_flight[WRITE]); |
551 | if (in_flight_read) |
552 | p->io_ticks[READ] += difference; |
553 | if (in_flight_write) |
554 | p->io_ticks[WRITE] += difference; |
555 | if (in_flight_read + in_flight_write) { |
556 | p->io_ticks_total += difference; |
557 | p->time_in_queue += (in_flight_read + in_flight_write) * difference; |
558 | } |
559 | shared->stamp = now; |
560 | } |
561 | |
562 | static void dm_stat_for_entry(struct dm_stat *s, size_t entry, |
563 | int idx, sector_t len, |
564 | struct dm_stats_aux *stats_aux, bool end, |
565 | unsigned long duration_jiffies) |
566 | { |
567 | struct dm_stat_shared *shared = &s->stat_shared[entry]; |
568 | struct dm_stat_percpu *p; |
569 | |
570 | /* |
571 | * For strict correctness we should use local_irq_save/restore |
572 | * instead of preempt_disable/enable. |
573 | * |
574 | * preempt_disable/enable is racy if the driver finishes bios |
575 | * from non-interrupt context as well as from interrupt context |
576 | * or from more different interrupts. |
577 | * |
578 | * On 64-bit architectures the race only results in not counting some |
579 | * events, so it is acceptable. On 32-bit architectures the race could |
580 | * cause the counter going off by 2^32, so we need to do proper locking |
581 | * there. |
582 | * |
583 | * part_stat_lock()/part_stat_unlock() have this race too. |
584 | */ |
585 | #if BITS_PER_LONG == 32 |
586 | unsigned long flags; |
587 | |
588 | local_irq_save(flags); |
589 | #else |
590 | preempt_disable(); |
591 | #endif |
592 | p = &s->stat_percpu[smp_processor_id()][entry]; |
593 | |
594 | if (!end) { |
595 | dm_stat_round(s, shared, p); |
596 | atomic_inc(v: &shared->in_flight[idx]); |
597 | } else { |
598 | unsigned long long duration; |
599 | |
600 | dm_stat_round(s, shared, p); |
601 | atomic_dec(v: &shared->in_flight[idx]); |
602 | p->sectors[idx] += len; |
603 | p->ios[idx] += 1; |
604 | p->merges[idx] += stats_aux->merged; |
605 | if (!(s->stat_flags & STAT_PRECISE_TIMESTAMPS)) { |
606 | p->ticks[idx] += duration_jiffies; |
607 | duration = jiffies_to_msecs(j: duration_jiffies); |
608 | } else { |
609 | p->ticks[idx] += stats_aux->duration_ns; |
610 | duration = stats_aux->duration_ns; |
611 | } |
612 | if (s->n_histogram_entries) { |
613 | unsigned int lo = 0, hi = s->n_histogram_entries + 1; |
614 | |
615 | while (lo + 1 < hi) { |
616 | unsigned int mid = (lo + hi) / 2; |
617 | |
618 | if (s->histogram_boundaries[mid - 1] > duration) |
619 | hi = mid; |
620 | else |
621 | lo = mid; |
622 | } |
623 | p->histogram[lo]++; |
624 | } |
625 | } |
626 | |
627 | #if BITS_PER_LONG == 32 |
628 | local_irq_restore(flags); |
629 | #else |
630 | preempt_enable(); |
631 | #endif |
632 | } |
633 | |
634 | static void __dm_stat_bio(struct dm_stat *s, int bi_rw, |
635 | sector_t bi_sector, sector_t end_sector, |
636 | bool end, unsigned long duration_jiffies, |
637 | struct dm_stats_aux *stats_aux) |
638 | { |
639 | sector_t rel_sector, offset, todo, fragment_len; |
640 | size_t entry; |
641 | |
642 | if (end_sector <= s->start || bi_sector >= s->end) |
643 | return; |
644 | if (unlikely(bi_sector < s->start)) { |
645 | rel_sector = 0; |
646 | todo = end_sector - s->start; |
647 | } else { |
648 | rel_sector = bi_sector - s->start; |
649 | todo = end_sector - bi_sector; |
650 | } |
651 | if (unlikely(end_sector > s->end)) |
652 | todo -= (end_sector - s->end); |
653 | |
654 | offset = dm_sector_div64(rel_sector, s->step); |
655 | entry = rel_sector; |
656 | do { |
657 | if (WARN_ON_ONCE(entry >= s->n_entries)) { |
658 | DMCRIT("Invalid area access in region id %d" , s->id); |
659 | return; |
660 | } |
661 | fragment_len = todo; |
662 | if (fragment_len > s->step - offset) |
663 | fragment_len = s->step - offset; |
664 | dm_stat_for_entry(s, entry, idx: bi_rw, len: fragment_len, |
665 | stats_aux, end, duration_jiffies); |
666 | todo -= fragment_len; |
667 | entry++; |
668 | offset = 0; |
669 | } while (unlikely(todo != 0)); |
670 | } |
671 | |
672 | void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw, |
673 | sector_t bi_sector, unsigned int bi_sectors, bool end, |
674 | unsigned long start_time, |
675 | struct dm_stats_aux *stats_aux) |
676 | { |
677 | struct dm_stat *s; |
678 | sector_t end_sector; |
679 | struct dm_stats_last_position *last; |
680 | bool got_precise_time; |
681 | unsigned long duration_jiffies = 0; |
682 | |
683 | if (unlikely(!bi_sectors)) |
684 | return; |
685 | |
686 | end_sector = bi_sector + bi_sectors; |
687 | |
688 | if (!end) { |
689 | /* |
690 | * A race condition can at worst result in the merged flag being |
691 | * misrepresented, so we don't have to disable preemption here. |
692 | */ |
693 | last = raw_cpu_ptr(stats->last); |
694 | stats_aux->merged = |
695 | (bi_sector == (READ_ONCE(last->last_sector) && |
696 | ((bi_rw == WRITE) == |
697 | (READ_ONCE(last->last_rw) == WRITE)) |
698 | )); |
699 | WRITE_ONCE(last->last_sector, end_sector); |
700 | WRITE_ONCE(last->last_rw, bi_rw); |
701 | } else |
702 | duration_jiffies = jiffies - start_time; |
703 | |
704 | rcu_read_lock(); |
705 | |
706 | got_precise_time = false; |
707 | list_for_each_entry_rcu(s, &stats->list, list_entry) { |
708 | if (s->stat_flags & STAT_PRECISE_TIMESTAMPS && !got_precise_time) { |
709 | /* start (!end) duration_ns is set by DM core's alloc_io() */ |
710 | if (end) |
711 | stats_aux->duration_ns = ktime_to_ns(kt: ktime_get()) - stats_aux->duration_ns; |
712 | got_precise_time = true; |
713 | } |
714 | __dm_stat_bio(s, bi_rw, bi_sector, end_sector, end, duration_jiffies, stats_aux); |
715 | } |
716 | |
717 | rcu_read_unlock(); |
718 | } |
719 | |
720 | static void __dm_stat_init_temporary_percpu_totals(struct dm_stat_shared *shared, |
721 | struct dm_stat *s, size_t x) |
722 | { |
723 | int cpu; |
724 | struct dm_stat_percpu *p; |
725 | |
726 | local_irq_disable(); |
727 | p = &s->stat_percpu[smp_processor_id()][x]; |
728 | dm_stat_round(s, shared, p); |
729 | local_irq_enable(); |
730 | |
731 | shared->tmp.sectors[READ] = 0; |
732 | shared->tmp.sectors[WRITE] = 0; |
733 | shared->tmp.ios[READ] = 0; |
734 | shared->tmp.ios[WRITE] = 0; |
735 | shared->tmp.merges[READ] = 0; |
736 | shared->tmp.merges[WRITE] = 0; |
737 | shared->tmp.ticks[READ] = 0; |
738 | shared->tmp.ticks[WRITE] = 0; |
739 | shared->tmp.io_ticks[READ] = 0; |
740 | shared->tmp.io_ticks[WRITE] = 0; |
741 | shared->tmp.io_ticks_total = 0; |
742 | shared->tmp.time_in_queue = 0; |
743 | |
744 | if (s->n_histogram_entries) |
745 | memset(shared->tmp.histogram, 0, (s->n_histogram_entries + 1) * sizeof(unsigned long long)); |
746 | |
747 | for_each_possible_cpu(cpu) { |
748 | p = &s->stat_percpu[cpu][x]; |
749 | shared->tmp.sectors[READ] += READ_ONCE(p->sectors[READ]); |
750 | shared->tmp.sectors[WRITE] += READ_ONCE(p->sectors[WRITE]); |
751 | shared->tmp.ios[READ] += READ_ONCE(p->ios[READ]); |
752 | shared->tmp.ios[WRITE] += READ_ONCE(p->ios[WRITE]); |
753 | shared->tmp.merges[READ] += READ_ONCE(p->merges[READ]); |
754 | shared->tmp.merges[WRITE] += READ_ONCE(p->merges[WRITE]); |
755 | shared->tmp.ticks[READ] += READ_ONCE(p->ticks[READ]); |
756 | shared->tmp.ticks[WRITE] += READ_ONCE(p->ticks[WRITE]); |
757 | shared->tmp.io_ticks[READ] += READ_ONCE(p->io_ticks[READ]); |
758 | shared->tmp.io_ticks[WRITE] += READ_ONCE(p->io_ticks[WRITE]); |
759 | shared->tmp.io_ticks_total += READ_ONCE(p->io_ticks_total); |
760 | shared->tmp.time_in_queue += READ_ONCE(p->time_in_queue); |
761 | if (s->n_histogram_entries) { |
762 | unsigned int i; |
763 | |
764 | for (i = 0; i < s->n_histogram_entries + 1; i++) |
765 | shared->tmp.histogram[i] += READ_ONCE(p->histogram[i]); |
766 | } |
767 | } |
768 | } |
769 | |
770 | static void __dm_stat_clear(struct dm_stat *s, size_t idx_start, size_t idx_end, |
771 | bool init_tmp_percpu_totals) |
772 | { |
773 | size_t x; |
774 | struct dm_stat_shared *shared; |
775 | struct dm_stat_percpu *p; |
776 | |
777 | for (x = idx_start; x < idx_end; x++) { |
778 | shared = &s->stat_shared[x]; |
779 | if (init_tmp_percpu_totals) |
780 | __dm_stat_init_temporary_percpu_totals(shared, s, x); |
781 | local_irq_disable(); |
782 | p = &s->stat_percpu[smp_processor_id()][x]; |
783 | p->sectors[READ] -= shared->tmp.sectors[READ]; |
784 | p->sectors[WRITE] -= shared->tmp.sectors[WRITE]; |
785 | p->ios[READ] -= shared->tmp.ios[READ]; |
786 | p->ios[WRITE] -= shared->tmp.ios[WRITE]; |
787 | p->merges[READ] -= shared->tmp.merges[READ]; |
788 | p->merges[WRITE] -= shared->tmp.merges[WRITE]; |
789 | p->ticks[READ] -= shared->tmp.ticks[READ]; |
790 | p->ticks[WRITE] -= shared->tmp.ticks[WRITE]; |
791 | p->io_ticks[READ] -= shared->tmp.io_ticks[READ]; |
792 | p->io_ticks[WRITE] -= shared->tmp.io_ticks[WRITE]; |
793 | p->io_ticks_total -= shared->tmp.io_ticks_total; |
794 | p->time_in_queue -= shared->tmp.time_in_queue; |
795 | local_irq_enable(); |
796 | if (s->n_histogram_entries) { |
797 | unsigned int i; |
798 | |
799 | for (i = 0; i < s->n_histogram_entries + 1; i++) { |
800 | local_irq_disable(); |
801 | p = &s->stat_percpu[smp_processor_id()][x]; |
802 | p->histogram[i] -= shared->tmp.histogram[i]; |
803 | local_irq_enable(); |
804 | } |
805 | } |
806 | cond_resched(); |
807 | } |
808 | } |
809 | |
810 | static int dm_stats_clear(struct dm_stats *stats, int id) |
811 | { |
812 | struct dm_stat *s; |
813 | |
814 | mutex_lock(&stats->mutex); |
815 | |
816 | s = __dm_stats_find(stats, id); |
817 | if (!s) { |
818 | mutex_unlock(lock: &stats->mutex); |
819 | return -ENOENT; |
820 | } |
821 | |
822 | __dm_stat_clear(s, idx_start: 0, idx_end: s->n_entries, init_tmp_percpu_totals: true); |
823 | |
824 | mutex_unlock(lock: &stats->mutex); |
825 | |
826 | return 1; |
827 | } |
828 | |
829 | /* |
830 | * This is like jiffies_to_msec, but works for 64-bit values. |
831 | */ |
832 | static unsigned long long dm_jiffies_to_msec64(struct dm_stat *s, unsigned long long j) |
833 | { |
834 | unsigned long long result; |
835 | unsigned int mult; |
836 | |
837 | if (s->stat_flags & STAT_PRECISE_TIMESTAMPS) |
838 | return j; |
839 | |
840 | result = 0; |
841 | if (j) |
842 | result = jiffies_to_msecs(j: j & 0x3fffff); |
843 | if (j >= 1 << 22) { |
844 | mult = jiffies_to_msecs(j: 1 << 22); |
845 | result += (unsigned long long)mult * (unsigned long long)jiffies_to_msecs(j: (j >> 22) & 0x3fffff); |
846 | } |
847 | if (j >= 1ULL << 44) |
848 | result += (unsigned long long)mult * (unsigned long long)mult * (unsigned long long)jiffies_to_msecs(j: j >> 44); |
849 | |
850 | return result; |
851 | } |
852 | |
853 | static int dm_stats_print(struct dm_stats *stats, int id, |
854 | size_t idx_start, size_t idx_len, |
855 | bool clear, char *result, unsigned int maxlen) |
856 | { |
857 | unsigned int sz = 0; |
858 | struct dm_stat *s; |
859 | size_t x; |
860 | sector_t start, end, step; |
861 | size_t idx_end; |
862 | struct dm_stat_shared *shared; |
863 | |
864 | /* |
865 | * Output format: |
866 | * <start_sector>+<length> counters |
867 | */ |
868 | |
869 | mutex_lock(&stats->mutex); |
870 | |
871 | s = __dm_stats_find(stats, id); |
872 | if (!s) { |
873 | mutex_unlock(lock: &stats->mutex); |
874 | return -ENOENT; |
875 | } |
876 | |
877 | idx_end = idx_start + idx_len; |
878 | if (idx_end < idx_start || |
879 | idx_end > s->n_entries) |
880 | idx_end = s->n_entries; |
881 | |
882 | if (idx_start > idx_end) |
883 | idx_start = idx_end; |
884 | |
885 | step = s->step; |
886 | start = s->start + (step * idx_start); |
887 | |
888 | for (x = idx_start; x < idx_end; x++, start = end) { |
889 | shared = &s->stat_shared[x]; |
890 | end = start + step; |
891 | if (unlikely(end > s->end)) |
892 | end = s->end; |
893 | |
894 | __dm_stat_init_temporary_percpu_totals(shared, s, x); |
895 | |
896 | DMEMIT("%llu+%llu %llu %llu %llu %llu %llu %llu %llu %llu %d %llu %llu %llu %llu" , |
897 | (unsigned long long)start, |
898 | (unsigned long long)step, |
899 | shared->tmp.ios[READ], |
900 | shared->tmp.merges[READ], |
901 | shared->tmp.sectors[READ], |
902 | dm_jiffies_to_msec64(s, shared->tmp.ticks[READ]), |
903 | shared->tmp.ios[WRITE], |
904 | shared->tmp.merges[WRITE], |
905 | shared->tmp.sectors[WRITE], |
906 | dm_jiffies_to_msec64(s, shared->tmp.ticks[WRITE]), |
907 | dm_stat_in_flight(shared), |
908 | dm_jiffies_to_msec64(s, shared->tmp.io_ticks_total), |
909 | dm_jiffies_to_msec64(s, shared->tmp.time_in_queue), |
910 | dm_jiffies_to_msec64(s, shared->tmp.io_ticks[READ]), |
911 | dm_jiffies_to_msec64(s, shared->tmp.io_ticks[WRITE])); |
912 | if (s->n_histogram_entries) { |
913 | unsigned int i; |
914 | |
915 | for (i = 0; i < s->n_histogram_entries + 1; i++) |
916 | DMEMIT("%s%llu" , !i ? " " : ":" , shared->tmp.histogram[i]); |
917 | } |
918 | DMEMIT("\n" ); |
919 | |
920 | if (unlikely(sz + 1 >= maxlen)) |
921 | goto buffer_overflow; |
922 | |
923 | cond_resched(); |
924 | } |
925 | |
926 | if (clear) |
927 | __dm_stat_clear(s, idx_start, idx_end, init_tmp_percpu_totals: false); |
928 | |
929 | buffer_overflow: |
930 | mutex_unlock(lock: &stats->mutex); |
931 | |
932 | return 1; |
933 | } |
934 | |
935 | static int dm_stats_set_aux(struct dm_stats *stats, int id, const char *aux_data) |
936 | { |
937 | struct dm_stat *s; |
938 | const char *new_aux_data; |
939 | |
940 | mutex_lock(&stats->mutex); |
941 | |
942 | s = __dm_stats_find(stats, id); |
943 | if (!s) { |
944 | mutex_unlock(lock: &stats->mutex); |
945 | return -ENOENT; |
946 | } |
947 | |
948 | new_aux_data = kstrdup(s: aux_data, GFP_KERNEL); |
949 | if (!new_aux_data) { |
950 | mutex_unlock(lock: &stats->mutex); |
951 | return -ENOMEM; |
952 | } |
953 | |
954 | kfree(objp: s->aux_data); |
955 | s->aux_data = new_aux_data; |
956 | |
957 | mutex_unlock(lock: &stats->mutex); |
958 | |
959 | return 0; |
960 | } |
961 | |
962 | static int parse_histogram(const char *h, unsigned int *n_histogram_entries, |
963 | unsigned long long **histogram_boundaries) |
964 | { |
965 | const char *q; |
966 | unsigned int n; |
967 | unsigned long long last; |
968 | |
969 | *n_histogram_entries = 1; |
970 | for (q = h; *q; q++) |
971 | if (*q == ',') |
972 | (*n_histogram_entries)++; |
973 | |
974 | *histogram_boundaries = kmalloc_array(n: *n_histogram_entries, |
975 | size: sizeof(unsigned long long), |
976 | GFP_KERNEL); |
977 | if (!*histogram_boundaries) |
978 | return -ENOMEM; |
979 | |
980 | n = 0; |
981 | last = 0; |
982 | while (1) { |
983 | unsigned long long hi; |
984 | int s; |
985 | char ch; |
986 | |
987 | s = sscanf(h, "%llu%c" , &hi, &ch); |
988 | if (!s || (s == 2 && ch != ',')) |
989 | return -EINVAL; |
990 | if (hi <= last) |
991 | return -EINVAL; |
992 | last = hi; |
993 | (*histogram_boundaries)[n] = hi; |
994 | if (s == 1) |
995 | return 0; |
996 | h = strchr(h, ',') + 1; |
997 | n++; |
998 | } |
999 | } |
1000 | |
1001 | static int message_stats_create(struct mapped_device *md, |
1002 | unsigned int argc, char **argv, |
1003 | char *result, unsigned int maxlen) |
1004 | { |
1005 | int r; |
1006 | int id; |
1007 | char dummy; |
1008 | unsigned long long start, end, len, step; |
1009 | unsigned int divisor; |
1010 | const char *program_id, *aux_data; |
1011 | unsigned int stat_flags = 0; |
1012 | unsigned int n_histogram_entries = 0; |
1013 | unsigned long long *histogram_boundaries = NULL; |
1014 | struct dm_arg_set as, as_backup; |
1015 | const char *a; |
1016 | unsigned int feature_args; |
1017 | |
1018 | /* |
1019 | * Input format: |
1020 | * <range> <step> [<extra_parameters> <parameters>] [<program_id> [<aux_data>]] |
1021 | */ |
1022 | |
1023 | if (argc < 3) |
1024 | goto ret_einval; |
1025 | |
1026 | as.argc = argc; |
1027 | as.argv = argv; |
1028 | dm_consume_args(as: &as, num_args: 1); |
1029 | |
1030 | a = dm_shift_arg(as: &as); |
1031 | if (!strcmp(a, "-" )) { |
1032 | start = 0; |
1033 | len = dm_get_size(md); |
1034 | if (!len) |
1035 | len = 1; |
1036 | } else if (sscanf(a, "%llu+%llu%c" , &start, &len, &dummy) != 2 || |
1037 | start != (sector_t)start || len != (sector_t)len) |
1038 | goto ret_einval; |
1039 | |
1040 | end = start + len; |
1041 | if (start >= end) |
1042 | goto ret_einval; |
1043 | |
1044 | a = dm_shift_arg(as: &as); |
1045 | if (sscanf(a, "/%u%c" , &divisor, &dummy) == 1) { |
1046 | if (!divisor) |
1047 | return -EINVAL; |
1048 | step = end - start; |
1049 | if (do_div(step, divisor)) |
1050 | step++; |
1051 | if (!step) |
1052 | step = 1; |
1053 | } else if (sscanf(a, "%llu%c" , &step, &dummy) != 1 || |
1054 | step != (sector_t)step || !step) |
1055 | goto ret_einval; |
1056 | |
1057 | as_backup = as; |
1058 | a = dm_shift_arg(as: &as); |
1059 | if (a && sscanf(a, "%u%c" , &feature_args, &dummy) == 1) { |
1060 | while (feature_args--) { |
1061 | a = dm_shift_arg(as: &as); |
1062 | if (!a) |
1063 | goto ret_einval; |
1064 | if (!strcasecmp(s1: a, s2: "precise_timestamps" )) |
1065 | stat_flags |= STAT_PRECISE_TIMESTAMPS; |
1066 | else if (!strncasecmp(s1: a, s2: "histogram:" , n: 10)) { |
1067 | if (n_histogram_entries) |
1068 | goto ret_einval; |
1069 | r = parse_histogram(h: a + 10, n_histogram_entries: &n_histogram_entries, histogram_boundaries: &histogram_boundaries); |
1070 | if (r) |
1071 | goto ret; |
1072 | } else |
1073 | goto ret_einval; |
1074 | } |
1075 | } else { |
1076 | as = as_backup; |
1077 | } |
1078 | |
1079 | program_id = "-" ; |
1080 | aux_data = "-" ; |
1081 | |
1082 | a = dm_shift_arg(as: &as); |
1083 | if (a) |
1084 | program_id = a; |
1085 | |
1086 | a = dm_shift_arg(as: &as); |
1087 | if (a) |
1088 | aux_data = a; |
1089 | |
1090 | if (as.argc) |
1091 | goto ret_einval; |
1092 | |
1093 | /* |
1094 | * If a buffer overflow happens after we created the region, |
1095 | * it's too late (the userspace would retry with a larger |
1096 | * buffer, but the region id that caused the overflow is already |
1097 | * leaked). So we must detect buffer overflow in advance. |
1098 | */ |
1099 | snprintf(buf: result, size: maxlen, fmt: "%d" , INT_MAX); |
1100 | if (dm_message_test_buffer_overflow(result, maxlen)) { |
1101 | r = 1; |
1102 | goto ret; |
1103 | } |
1104 | |
1105 | id = dm_stats_create(stats: dm_get_stats(md), start, end, step, stat_flags, |
1106 | n_histogram_entries, histogram_boundaries, program_id, aux_data, |
1107 | suspend_callback: dm_internal_suspend_fast, resume_callback: dm_internal_resume_fast, md); |
1108 | if (id < 0) { |
1109 | r = id; |
1110 | goto ret; |
1111 | } |
1112 | |
1113 | snprintf(buf: result, size: maxlen, fmt: "%d" , id); |
1114 | |
1115 | r = 1; |
1116 | goto ret; |
1117 | |
1118 | ret_einval: |
1119 | r = -EINVAL; |
1120 | ret: |
1121 | kfree(objp: histogram_boundaries); |
1122 | return r; |
1123 | } |
1124 | |
1125 | static int message_stats_delete(struct mapped_device *md, |
1126 | unsigned int argc, char **argv) |
1127 | { |
1128 | int id; |
1129 | char dummy; |
1130 | |
1131 | if (argc != 2) |
1132 | return -EINVAL; |
1133 | |
1134 | if (sscanf(argv[1], "%d%c" , &id, &dummy) != 1 || id < 0) |
1135 | return -EINVAL; |
1136 | |
1137 | return dm_stats_delete(stats: dm_get_stats(md), id); |
1138 | } |
1139 | |
1140 | static int message_stats_clear(struct mapped_device *md, |
1141 | unsigned int argc, char **argv) |
1142 | { |
1143 | int id; |
1144 | char dummy; |
1145 | |
1146 | if (argc != 2) |
1147 | return -EINVAL; |
1148 | |
1149 | if (sscanf(argv[1], "%d%c" , &id, &dummy) != 1 || id < 0) |
1150 | return -EINVAL; |
1151 | |
1152 | return dm_stats_clear(stats: dm_get_stats(md), id); |
1153 | } |
1154 | |
1155 | static int message_stats_list(struct mapped_device *md, |
1156 | unsigned int argc, char **argv, |
1157 | char *result, unsigned int maxlen) |
1158 | { |
1159 | int r; |
1160 | const char *program = NULL; |
1161 | |
1162 | if (argc < 1 || argc > 2) |
1163 | return -EINVAL; |
1164 | |
1165 | if (argc > 1) { |
1166 | program = kstrdup(s: argv[1], GFP_KERNEL); |
1167 | if (!program) |
1168 | return -ENOMEM; |
1169 | } |
1170 | |
1171 | r = dm_stats_list(stats: dm_get_stats(md), program, result, maxlen); |
1172 | |
1173 | kfree(objp: program); |
1174 | |
1175 | return r; |
1176 | } |
1177 | |
1178 | static int message_stats_print(struct mapped_device *md, |
1179 | unsigned int argc, char **argv, bool clear, |
1180 | char *result, unsigned int maxlen) |
1181 | { |
1182 | int id; |
1183 | char dummy; |
1184 | unsigned long idx_start = 0, idx_len = ULONG_MAX; |
1185 | |
1186 | if (argc != 2 && argc != 4) |
1187 | return -EINVAL; |
1188 | |
1189 | if (sscanf(argv[1], "%d%c" , &id, &dummy) != 1 || id < 0) |
1190 | return -EINVAL; |
1191 | |
1192 | if (argc > 3) { |
1193 | if (strcmp(argv[2], "-" ) && |
1194 | sscanf(argv[2], "%lu%c" , &idx_start, &dummy) != 1) |
1195 | return -EINVAL; |
1196 | if (strcmp(argv[3], "-" ) && |
1197 | sscanf(argv[3], "%lu%c" , &idx_len, &dummy) != 1) |
1198 | return -EINVAL; |
1199 | } |
1200 | |
1201 | return dm_stats_print(stats: dm_get_stats(md), id, idx_start, idx_len, clear, |
1202 | result, maxlen); |
1203 | } |
1204 | |
1205 | static int message_stats_set_aux(struct mapped_device *md, |
1206 | unsigned int argc, char **argv) |
1207 | { |
1208 | int id; |
1209 | char dummy; |
1210 | |
1211 | if (argc != 3) |
1212 | return -EINVAL; |
1213 | |
1214 | if (sscanf(argv[1], "%d%c" , &id, &dummy) != 1 || id < 0) |
1215 | return -EINVAL; |
1216 | |
1217 | return dm_stats_set_aux(stats: dm_get_stats(md), id, aux_data: argv[2]); |
1218 | } |
1219 | |
1220 | int dm_stats_message(struct mapped_device *md, unsigned int argc, char **argv, |
1221 | char *result, unsigned int maxlen) |
1222 | { |
1223 | int r; |
1224 | |
1225 | /* All messages here must start with '@' */ |
1226 | if (!strcasecmp(s1: argv[0], s2: "@stats_create" )) |
1227 | r = message_stats_create(md, argc, argv, result, maxlen); |
1228 | else if (!strcasecmp(s1: argv[0], s2: "@stats_delete" )) |
1229 | r = message_stats_delete(md, argc, argv); |
1230 | else if (!strcasecmp(s1: argv[0], s2: "@stats_clear" )) |
1231 | r = message_stats_clear(md, argc, argv); |
1232 | else if (!strcasecmp(s1: argv[0], s2: "@stats_list" )) |
1233 | r = message_stats_list(md, argc, argv, result, maxlen); |
1234 | else if (!strcasecmp(s1: argv[0], s2: "@stats_print" )) |
1235 | r = message_stats_print(md, argc, argv, clear: false, result, maxlen); |
1236 | else if (!strcasecmp(s1: argv[0], s2: "@stats_print_clear" )) |
1237 | r = message_stats_print(md, argc, argv, clear: true, result, maxlen); |
1238 | else if (!strcasecmp(s1: argv[0], s2: "@stats_set_aux" )) |
1239 | r = message_stats_set_aux(md, argc, argv); |
1240 | else |
1241 | return 2; /* this wasn't a stats message */ |
1242 | |
1243 | if (r == -EINVAL) |
1244 | DMCRIT("Invalid parameters for message %s" , argv[0]); |
1245 | |
1246 | return r; |
1247 | } |
1248 | |
1249 | int __init dm_statistics_init(void) |
1250 | { |
1251 | shared_memory_amount = 0; |
1252 | dm_stat_need_rcu_barrier = 0; |
1253 | return 0; |
1254 | } |
1255 | |
1256 | void dm_statistics_exit(void) |
1257 | { |
1258 | if (dm_stat_need_rcu_barrier) |
1259 | rcu_barrier(); |
1260 | if (WARN_ON(shared_memory_amount)) |
1261 | DMCRIT("shared_memory_amount leaked: %lu" , shared_memory_amount); |
1262 | } |
1263 | |
1264 | module_param_named(stats_current_allocated_bytes, shared_memory_amount, ulong, 0444); |
1265 | MODULE_PARM_DESC(stats_current_allocated_bytes, "Memory currently used by statistics" ); |
1266 | |