1 /*
2 * GPL HEADER START
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
19 *
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
22 * have any questions.
23 *
24 * GPL HEADER END
25 */
26 /*
27 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
29 *
30 * Copyright (c) 2012, Intel Corporation.
31 */
32 /*
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
35 *
36 * libcfs/libcfs/tracefile.c
37 *
38 * Author: Zach Brown <zab@clusterfs.com>
39 * Author: Phil Schwan <phil@clusterfs.com>
40 */
41
42
43 #define DEBUG_SUBSYSTEM S_LNET
44 #define LUSTRE_TRACEFILE_PRIVATE
45 #include "tracefile.h"
46
47 #include "../../include/linux/libcfs/libcfs.h"
48
49 /* XXX move things up to the top, comment */
50 union cfs_trace_data_union (*cfs_trace_data[TCD_MAX_TYPES])[NR_CPUS] __cacheline_aligned;
51
52 char cfs_tracefile[TRACEFILE_NAME_SIZE];
53 long long cfs_tracefile_size = CFS_TRACEFILE_SIZE;
54 static struct tracefiled_ctl trace_tctl;
55 struct mutex cfs_trace_thread_mutex;
56 static int thread_running;
57
58 static atomic_t cfs_tage_allocated = ATOMIC_INIT(0);
59
60 static void put_pages_on_tcd_daemon_list(struct page_collection *pc,
61 struct cfs_trace_cpu_data *tcd);
62
63 static inline struct cfs_trace_page *
cfs_tage_from_list(struct list_head * list)64 cfs_tage_from_list(struct list_head *list)
65 {
66 return list_entry(list, struct cfs_trace_page, linkage);
67 }
68
cfs_tage_alloc(gfp_t gfp)69 static struct cfs_trace_page *cfs_tage_alloc(gfp_t gfp)
70 {
71 struct page *page;
72 struct cfs_trace_page *tage;
73
74 /* My caller is trying to free memory */
75 if (!in_interrupt() && memory_pressure_get())
76 return NULL;
77
78 /*
79 * Don't spam console with allocation failures: they will be reported
80 * by upper layer anyway.
81 */
82 gfp |= __GFP_NOWARN;
83 page = alloc_page(gfp);
84 if (page == NULL)
85 return NULL;
86
87 tage = kmalloc(sizeof(*tage), gfp);
88 if (tage == NULL) {
89 __free_page(page);
90 return NULL;
91 }
92
93 tage->page = page;
94 atomic_inc(&cfs_tage_allocated);
95 return tage;
96 }
97
cfs_tage_free(struct cfs_trace_page * tage)98 static void cfs_tage_free(struct cfs_trace_page *tage)
99 {
100 __LASSERT(tage != NULL);
101 __LASSERT(tage->page != NULL);
102
103 __free_page(tage->page);
104 kfree(tage);
105 atomic_dec(&cfs_tage_allocated);
106 }
107
cfs_tage_to_tail(struct cfs_trace_page * tage,struct list_head * queue)108 static void cfs_tage_to_tail(struct cfs_trace_page *tage,
109 struct list_head *queue)
110 {
111 __LASSERT(tage != NULL);
112 __LASSERT(queue != NULL);
113
114 list_move_tail(&tage->linkage, queue);
115 }
116
cfs_trace_refill_stock(struct cfs_trace_cpu_data * tcd,gfp_t gfp,struct list_head * stock)117 int cfs_trace_refill_stock(struct cfs_trace_cpu_data *tcd, gfp_t gfp,
118 struct list_head *stock)
119 {
120 int i;
121
122 /*
123 * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
124 * from here: this will lead to infinite recursion.
125 */
126
127 for (i = 0; i + tcd->tcd_cur_stock_pages < TCD_STOCK_PAGES ; ++ i) {
128 struct cfs_trace_page *tage;
129
130 tage = cfs_tage_alloc(gfp);
131 if (tage == NULL)
132 break;
133 list_add_tail(&tage->linkage, stock);
134 }
135 return i;
136 }
137
138 /* return a page that has 'len' bytes left at the end */
139 static struct cfs_trace_page *
cfs_trace_get_tage_try(struct cfs_trace_cpu_data * tcd,unsigned long len)140 cfs_trace_get_tage_try(struct cfs_trace_cpu_data *tcd, unsigned long len)
141 {
142 struct cfs_trace_page *tage;
143
144 if (tcd->tcd_cur_pages > 0) {
145 __LASSERT(!list_empty(&tcd->tcd_pages));
146 tage = cfs_tage_from_list(tcd->tcd_pages.prev);
147 if (tage->used + len <= PAGE_CACHE_SIZE)
148 return tage;
149 }
150
151 if (tcd->tcd_cur_pages < tcd->tcd_max_pages) {
152 if (tcd->tcd_cur_stock_pages > 0) {
153 tage = cfs_tage_from_list(tcd->tcd_stock_pages.prev);
154 --tcd->tcd_cur_stock_pages;
155 list_del_init(&tage->linkage);
156 } else {
157 tage = cfs_tage_alloc(GFP_ATOMIC);
158 if (unlikely(tage == NULL)) {
159 if ((!memory_pressure_get() ||
160 in_interrupt()) && printk_ratelimit())
161 printk(KERN_WARNING
162 "cannot allocate a tage (%ld)\n",
163 tcd->tcd_cur_pages);
164 return NULL;
165 }
166 }
167
168 tage->used = 0;
169 tage->cpu = smp_processor_id();
170 tage->type = tcd->tcd_type;
171 list_add_tail(&tage->linkage, &tcd->tcd_pages);
172 tcd->tcd_cur_pages++;
173
174 if (tcd->tcd_cur_pages > 8 && thread_running) {
175 struct tracefiled_ctl *tctl = &trace_tctl;
176 /*
177 * wake up tracefiled to process some pages.
178 */
179 wake_up(&tctl->tctl_waitq);
180 }
181 return tage;
182 }
183 return NULL;
184 }
185
cfs_tcd_shrink(struct cfs_trace_cpu_data * tcd)186 static void cfs_tcd_shrink(struct cfs_trace_cpu_data *tcd)
187 {
188 int pgcount = tcd->tcd_cur_pages / 10;
189 struct page_collection pc;
190 struct cfs_trace_page *tage;
191 struct cfs_trace_page *tmp;
192
193 /*
194 * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
195 * from here: this will lead to infinite recursion.
196 */
197
198 if (printk_ratelimit())
199 printk(KERN_WARNING "debug daemon buffer overflowed; discarding 10%% of pages (%d of %ld)\n",
200 pgcount + 1, tcd->tcd_cur_pages);
201
202 INIT_LIST_HEAD(&pc.pc_pages);
203 spin_lock_init(&pc.pc_lock);
204
205 list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages, linkage) {
206 if (pgcount-- == 0)
207 break;
208
209 list_move_tail(&tage->linkage, &pc.pc_pages);
210 tcd->tcd_cur_pages--;
211 }
212 put_pages_on_tcd_daemon_list(&pc, tcd);
213 }
214
215 /* return a page that has 'len' bytes left at the end */
cfs_trace_get_tage(struct cfs_trace_cpu_data * tcd,unsigned long len)216 static struct cfs_trace_page *cfs_trace_get_tage(struct cfs_trace_cpu_data *tcd,
217 unsigned long len)
218 {
219 struct cfs_trace_page *tage;
220
221 /*
222 * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
223 * from here: this will lead to infinite recursion.
224 */
225
226 if (len > PAGE_CACHE_SIZE) {
227 pr_err("cowardly refusing to write %lu bytes in a page\n", len);
228 return NULL;
229 }
230
231 tage = cfs_trace_get_tage_try(tcd, len);
232 if (tage != NULL)
233 return tage;
234 if (thread_running)
235 cfs_tcd_shrink(tcd);
236 if (tcd->tcd_cur_pages > 0) {
237 tage = cfs_tage_from_list(tcd->tcd_pages.next);
238 tage->used = 0;
239 cfs_tage_to_tail(tage, &tcd->tcd_pages);
240 }
241 return tage;
242 }
243
libcfs_debug_msg(struct libcfs_debug_msg_data * msgdata,const char * format,...)244 int libcfs_debug_msg(struct libcfs_debug_msg_data *msgdata,
245 const char *format, ...)
246 {
247 va_list args;
248 int rc;
249
250 va_start(args, format);
251 rc = libcfs_debug_vmsg2(msgdata, format, args, NULL);
252 va_end(args);
253
254 return rc;
255 }
256 EXPORT_SYMBOL(libcfs_debug_msg);
257
libcfs_debug_vmsg2(struct libcfs_debug_msg_data * msgdata,const char * format1,va_list args,const char * format2,...)258 int libcfs_debug_vmsg2(struct libcfs_debug_msg_data *msgdata,
259 const char *format1, va_list args,
260 const char *format2, ...)
261 {
262 struct cfs_trace_cpu_data *tcd = NULL;
263 struct ptldebug_header header = {0};
264 struct cfs_trace_page *tage;
265 /* string_buf is used only if tcd != NULL, and is always set then */
266 char *string_buf = NULL;
267 char *debug_buf;
268 int known_size;
269 int needed = 85; /* average message length */
270 int max_nob;
271 va_list ap;
272 int depth;
273 int i;
274 int remain;
275 int mask = msgdata->msg_mask;
276 const char *file = kbasename(msgdata->msg_file);
277 struct cfs_debug_limit_state *cdls = msgdata->msg_cdls;
278
279 tcd = cfs_trace_get_tcd();
280
281 /* cfs_trace_get_tcd() grabs a lock, which disables preemption and
282 * pins us to a particular CPU. This avoids an smp_processor_id()
283 * warning on Linux when debugging is enabled. */
284 cfs_set_ptldebug_header(&header, msgdata, CDEBUG_STACK());
285
286 if (tcd == NULL) /* arch may not log in IRQ context */
287 goto console;
288
289 if (tcd->tcd_cur_pages == 0)
290 header.ph_flags |= PH_FLAG_FIRST_RECORD;
291
292 if (tcd->tcd_shutting_down) {
293 cfs_trace_put_tcd(tcd);
294 tcd = NULL;
295 goto console;
296 }
297
298 depth = __current_nesting_level();
299 known_size = strlen(file) + 1 + depth;
300 if (msgdata->msg_fn)
301 known_size += strlen(msgdata->msg_fn) + 1;
302
303 if (libcfs_debug_binary)
304 known_size += sizeof(header);
305
306 /*/
307 * '2' used because vsnprintf return real size required for output
308 * _without_ terminating NULL.
309 * if needed is to small for this format.
310 */
311 for (i = 0; i < 2; i++) {
312 tage = cfs_trace_get_tage(tcd, needed + known_size + 1);
313 if (tage == NULL) {
314 if (needed + known_size > PAGE_CACHE_SIZE)
315 mask |= D_ERROR;
316
317 cfs_trace_put_tcd(tcd);
318 tcd = NULL;
319 goto console;
320 }
321
322 string_buf = (char *)page_address(tage->page) +
323 tage->used + known_size;
324
325 max_nob = PAGE_CACHE_SIZE - tage->used - known_size;
326 if (max_nob <= 0) {
327 printk(KERN_EMERG "negative max_nob: %d\n",
328 max_nob);
329 mask |= D_ERROR;
330 cfs_trace_put_tcd(tcd);
331 tcd = NULL;
332 goto console;
333 }
334
335 needed = 0;
336 if (format1) {
337 va_copy(ap, args);
338 needed = vsnprintf(string_buf, max_nob, format1, ap);
339 va_end(ap);
340 }
341
342 if (format2) {
343 remain = max_nob - needed;
344 if (remain < 0)
345 remain = 0;
346
347 va_start(ap, format2);
348 needed += vsnprintf(string_buf + needed, remain,
349 format2, ap);
350 va_end(ap);
351 }
352
353 if (needed < max_nob) /* well. printing ok.. */
354 break;
355 }
356
357 if (*(string_buf+needed-1) != '\n')
358 printk(KERN_INFO "format at %s:%d:%s doesn't end in newline\n",
359 file, msgdata->msg_line, msgdata->msg_fn);
360
361 header.ph_len = known_size + needed;
362 debug_buf = (char *)page_address(tage->page) + tage->used;
363
364 if (libcfs_debug_binary) {
365 memcpy(debug_buf, &header, sizeof(header));
366 tage->used += sizeof(header);
367 debug_buf += sizeof(header);
368 }
369
370 /* indent message according to the nesting level */
371 while (depth-- > 0) {
372 *(debug_buf++) = '.';
373 ++ tage->used;
374 }
375
376 strcpy(debug_buf, file);
377 tage->used += strlen(file) + 1;
378 debug_buf += strlen(file) + 1;
379
380 if (msgdata->msg_fn) {
381 strcpy(debug_buf, msgdata->msg_fn);
382 tage->used += strlen(msgdata->msg_fn) + 1;
383 debug_buf += strlen(msgdata->msg_fn) + 1;
384 }
385
386 __LASSERT(debug_buf == string_buf);
387
388 tage->used += needed;
389 __LASSERT (tage->used <= PAGE_CACHE_SIZE);
390
391 console:
392 if ((mask & libcfs_printk) == 0) {
393 /* no console output requested */
394 if (tcd != NULL)
395 cfs_trace_put_tcd(tcd);
396 return 1;
397 }
398
399 if (cdls != NULL) {
400 if (libcfs_console_ratelimit &&
401 cdls->cdls_next != 0 && /* not first time ever */
402 !cfs_time_after(cfs_time_current(), cdls->cdls_next)) {
403 /* skipping a console message */
404 cdls->cdls_count++;
405 if (tcd != NULL)
406 cfs_trace_put_tcd(tcd);
407 return 1;
408 }
409
410 if (cfs_time_after(cfs_time_current(), cdls->cdls_next +
411 libcfs_console_max_delay
412 + cfs_time_seconds(10))) {
413 /* last timeout was a long time ago */
414 cdls->cdls_delay /= libcfs_console_backoff * 4;
415 } else {
416 cdls->cdls_delay *= libcfs_console_backoff;
417 }
418
419 if (cdls->cdls_delay < libcfs_console_min_delay)
420 cdls->cdls_delay = libcfs_console_min_delay;
421 else if (cdls->cdls_delay > libcfs_console_max_delay)
422 cdls->cdls_delay = libcfs_console_max_delay;
423
424 /* ensure cdls_next is never zero after it's been seen */
425 cdls->cdls_next = (cfs_time_current() + cdls->cdls_delay) | 1;
426 }
427
428 if (tcd != NULL) {
429 cfs_print_to_console(&header, mask, string_buf, needed, file,
430 msgdata->msg_fn);
431 cfs_trace_put_tcd(tcd);
432 } else {
433 string_buf = cfs_trace_get_console_buffer();
434
435 needed = 0;
436 if (format1 != NULL) {
437 va_copy(ap, args);
438 needed = vsnprintf(string_buf,
439 CFS_TRACE_CONSOLE_BUFFER_SIZE,
440 format1, ap);
441 va_end(ap);
442 }
443 if (format2 != NULL) {
444 remain = CFS_TRACE_CONSOLE_BUFFER_SIZE - needed;
445 if (remain > 0) {
446 va_start(ap, format2);
447 needed += vsnprintf(string_buf+needed, remain,
448 format2, ap);
449 va_end(ap);
450 }
451 }
452 cfs_print_to_console(&header, mask,
453 string_buf, needed, file, msgdata->msg_fn);
454
455 cfs_trace_put_console_buffer(string_buf);
456 }
457
458 if (cdls != NULL && cdls->cdls_count != 0) {
459 string_buf = cfs_trace_get_console_buffer();
460
461 needed = snprintf(string_buf, CFS_TRACE_CONSOLE_BUFFER_SIZE,
462 "Skipped %d previous similar message%s\n",
463 cdls->cdls_count,
464 (cdls->cdls_count > 1) ? "s" : "");
465
466 cfs_print_to_console(&header, mask,
467 string_buf, needed, file, msgdata->msg_fn);
468
469 cfs_trace_put_console_buffer(string_buf);
470 cdls->cdls_count = 0;
471 }
472
473 return 0;
474 }
475 EXPORT_SYMBOL(libcfs_debug_vmsg2);
476
477 void
cfs_trace_assertion_failed(const char * str,struct libcfs_debug_msg_data * msgdata)478 cfs_trace_assertion_failed(const char *str,
479 struct libcfs_debug_msg_data *msgdata)
480 {
481 struct ptldebug_header hdr;
482
483 libcfs_panic_in_progress = 1;
484 libcfs_catastrophe = 1;
485 mb();
486
487 cfs_set_ptldebug_header(&hdr, msgdata, CDEBUG_STACK());
488
489 cfs_print_to_console(&hdr, D_EMERG, str, strlen(str),
490 msgdata->msg_file, msgdata->msg_fn);
491
492 panic("Lustre debug assertion failure\n");
493
494 /* not reached */
495 }
496
497 static void
panic_collect_pages(struct page_collection * pc)498 panic_collect_pages(struct page_collection *pc)
499 {
500 /* Do the collect_pages job on a single CPU: assumes that all other
501 * CPUs have been stopped during a panic. If this isn't true for some
502 * arch, this will have to be implemented separately in each arch. */
503 int i;
504 int j;
505 struct cfs_trace_cpu_data *tcd;
506
507 INIT_LIST_HEAD(&pc->pc_pages);
508
509 cfs_tcd_for_each(tcd, i, j) {
510 list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
511 tcd->tcd_cur_pages = 0;
512
513 if (pc->pc_want_daemon_pages) {
514 list_splice_init(&tcd->tcd_daemon_pages,
515 &pc->pc_pages);
516 tcd->tcd_cur_daemon_pages = 0;
517 }
518 }
519 }
520
collect_pages_on_all_cpus(struct page_collection * pc)521 static void collect_pages_on_all_cpus(struct page_collection *pc)
522 {
523 struct cfs_trace_cpu_data *tcd;
524 int i, cpu;
525
526 spin_lock(&pc->pc_lock);
527 for_each_possible_cpu(cpu) {
528 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
529 list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
530 tcd->tcd_cur_pages = 0;
531 if (pc->pc_want_daemon_pages) {
532 list_splice_init(&tcd->tcd_daemon_pages,
533 &pc->pc_pages);
534 tcd->tcd_cur_daemon_pages = 0;
535 }
536 }
537 }
538 spin_unlock(&pc->pc_lock);
539 }
540
collect_pages(struct page_collection * pc)541 static void collect_pages(struct page_collection *pc)
542 {
543 INIT_LIST_HEAD(&pc->pc_pages);
544
545 if (libcfs_panic_in_progress)
546 panic_collect_pages(pc);
547 else
548 collect_pages_on_all_cpus(pc);
549 }
550
put_pages_back_on_all_cpus(struct page_collection * pc)551 static void put_pages_back_on_all_cpus(struct page_collection *pc)
552 {
553 struct cfs_trace_cpu_data *tcd;
554 struct list_head *cur_head;
555 struct cfs_trace_page *tage;
556 struct cfs_trace_page *tmp;
557 int i, cpu;
558
559 spin_lock(&pc->pc_lock);
560 for_each_possible_cpu(cpu) {
561 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
562 cur_head = tcd->tcd_pages.next;
563
564 list_for_each_entry_safe(tage, tmp, &pc->pc_pages,
565 linkage) {
566
567 __LASSERT_TAGE_INVARIANT(tage);
568
569 if (tage->cpu != cpu || tage->type != i)
570 continue;
571
572 cfs_tage_to_tail(tage, cur_head);
573 tcd->tcd_cur_pages++;
574 }
575 }
576 }
577 spin_unlock(&pc->pc_lock);
578 }
579
put_pages_back(struct page_collection * pc)580 static void put_pages_back(struct page_collection *pc)
581 {
582 if (!libcfs_panic_in_progress)
583 put_pages_back_on_all_cpus(pc);
584 }
585
586 /* Add pages to a per-cpu debug daemon ringbuffer. This buffer makes sure that
587 * we have a good amount of data at all times for dumping during an LBUG, even
588 * if we have been steadily writing (and otherwise discarding) pages via the
589 * debug daemon. */
put_pages_on_tcd_daemon_list(struct page_collection * pc,struct cfs_trace_cpu_data * tcd)590 static void put_pages_on_tcd_daemon_list(struct page_collection *pc,
591 struct cfs_trace_cpu_data *tcd)
592 {
593 struct cfs_trace_page *tage;
594 struct cfs_trace_page *tmp;
595
596 spin_lock(&pc->pc_lock);
597 list_for_each_entry_safe(tage, tmp, &pc->pc_pages, linkage) {
598
599 __LASSERT_TAGE_INVARIANT(tage);
600
601 if (tage->cpu != tcd->tcd_cpu || tage->type != tcd->tcd_type)
602 continue;
603
604 cfs_tage_to_tail(tage, &tcd->tcd_daemon_pages);
605 tcd->tcd_cur_daemon_pages++;
606
607 if (tcd->tcd_cur_daemon_pages > tcd->tcd_max_pages) {
608 struct cfs_trace_page *victim;
609
610 __LASSERT(!list_empty(&tcd->tcd_daemon_pages));
611 victim = cfs_tage_from_list(tcd->tcd_daemon_pages.next);
612
613 __LASSERT_TAGE_INVARIANT(victim);
614
615 list_del(&victim->linkage);
616 cfs_tage_free(victim);
617 tcd->tcd_cur_daemon_pages--;
618 }
619 }
620 spin_unlock(&pc->pc_lock);
621 }
622
put_pages_on_daemon_list(struct page_collection * pc)623 static void put_pages_on_daemon_list(struct page_collection *pc)
624 {
625 struct cfs_trace_cpu_data *tcd;
626 int i, cpu;
627
628 for_each_possible_cpu(cpu) {
629 cfs_tcd_for_each_type_lock(tcd, i, cpu)
630 put_pages_on_tcd_daemon_list(pc, tcd);
631 }
632 }
633
cfs_trace_debug_print(void)634 void cfs_trace_debug_print(void)
635 {
636 struct page_collection pc;
637 struct cfs_trace_page *tage;
638 struct cfs_trace_page *tmp;
639
640 spin_lock_init(&pc.pc_lock);
641
642 pc.pc_want_daemon_pages = 1;
643 collect_pages(&pc);
644 list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
645 char *p, *file, *fn;
646 struct page *page;
647
648 __LASSERT_TAGE_INVARIANT(tage);
649
650 page = tage->page;
651 p = page_address(page);
652 while (p < ((char *)page_address(page) + tage->used)) {
653 struct ptldebug_header *hdr;
654 int len;
655 hdr = (void *)p;
656 p += sizeof(*hdr);
657 file = p;
658 p += strlen(file) + 1;
659 fn = p;
660 p += strlen(fn) + 1;
661 len = hdr->ph_len - (int)(p - (char *)hdr);
662
663 cfs_print_to_console(hdr, D_EMERG, p, len, file, fn);
664
665 p += len;
666 }
667
668 list_del(&tage->linkage);
669 cfs_tage_free(tage);
670 }
671 }
672
cfs_tracefile_dump_all_pages(char * filename)673 int cfs_tracefile_dump_all_pages(char *filename)
674 {
675 struct page_collection pc;
676 struct file *filp;
677 struct cfs_trace_page *tage;
678 struct cfs_trace_page *tmp;
679 char *buf;
680 int rc;
681
682 DECL_MMSPACE;
683
684 cfs_tracefile_write_lock();
685
686 filp = filp_open(filename, O_CREAT|O_EXCL|O_WRONLY|O_LARGEFILE, 0600);
687 if (IS_ERR(filp)) {
688 rc = PTR_ERR(filp);
689 filp = NULL;
690 pr_err("LustreError: can't open %s for dump: rc %d\n",
691 filename, rc);
692 goto out;
693 }
694
695 spin_lock_init(&pc.pc_lock);
696 pc.pc_want_daemon_pages = 1;
697 collect_pages(&pc);
698 if (list_empty(&pc.pc_pages)) {
699 rc = 0;
700 goto close;
701 }
702
703 /* ok, for now, just write the pages. in the future we'll be building
704 * iobufs with the pages and calling generic_direct_IO */
705 MMSPACE_OPEN;
706 list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
707
708 __LASSERT_TAGE_INVARIANT(tage);
709
710 buf = kmap(tage->page);
711 rc = vfs_write(filp, (__force const char __user *)buf,
712 tage->used, &filp->f_pos);
713 kunmap(tage->page);
714
715 if (rc != (int)tage->used) {
716 printk(KERN_WARNING "wanted to write %u but wrote %d\n",
717 tage->used, rc);
718 put_pages_back(&pc);
719 __LASSERT(list_empty(&pc.pc_pages));
720 break;
721 }
722 list_del(&tage->linkage);
723 cfs_tage_free(tage);
724 }
725 MMSPACE_CLOSE;
726 rc = vfs_fsync(filp, 1);
727 if (rc)
728 pr_err("sync returns %d\n", rc);
729 close:
730 filp_close(filp, NULL);
731 out:
732 cfs_tracefile_write_unlock();
733 return rc;
734 }
735
cfs_trace_flush_pages(void)736 void cfs_trace_flush_pages(void)
737 {
738 struct page_collection pc;
739 struct cfs_trace_page *tage;
740 struct cfs_trace_page *tmp;
741
742 spin_lock_init(&pc.pc_lock);
743
744 pc.pc_want_daemon_pages = 1;
745 collect_pages(&pc);
746 list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
747
748 __LASSERT_TAGE_INVARIANT(tage);
749
750 list_del(&tage->linkage);
751 cfs_tage_free(tage);
752 }
753 }
754
cfs_trace_copyin_string(char * knl_buffer,int knl_buffer_nob,const char __user * usr_buffer,int usr_buffer_nob)755 int cfs_trace_copyin_string(char *knl_buffer, int knl_buffer_nob,
756 const char __user *usr_buffer, int usr_buffer_nob)
757 {
758 int nob;
759
760 if (usr_buffer_nob > knl_buffer_nob)
761 return -EOVERFLOW;
762
763 if (copy_from_user((void *)knl_buffer,
764 usr_buffer, usr_buffer_nob))
765 return -EFAULT;
766
767 nob = strnlen(knl_buffer, usr_buffer_nob);
768 while (nob-- >= 0) /* strip trailing whitespace */
769 if (!isspace(knl_buffer[nob]))
770 break;
771
772 if (nob < 0) /* empty string */
773 return -EINVAL;
774
775 if (nob == knl_buffer_nob) /* no space to terminate */
776 return -EOVERFLOW;
777
778 knl_buffer[nob + 1] = 0; /* terminate */
779 return 0;
780 }
781 EXPORT_SYMBOL(cfs_trace_copyin_string);
782
cfs_trace_copyout_string(char __user * usr_buffer,int usr_buffer_nob,const char * knl_buffer,char * append)783 int cfs_trace_copyout_string(char __user *usr_buffer, int usr_buffer_nob,
784 const char *knl_buffer, char *append)
785 {
786 /* NB if 'append' != NULL, it's a single character to append to the
787 * copied out string - usually "\n", for /proc entries and "" (i.e. a
788 * terminating zero byte) for sysctl entries */
789 int nob = strlen(knl_buffer);
790
791 if (nob > usr_buffer_nob)
792 nob = usr_buffer_nob;
793
794 if (copy_to_user(usr_buffer, knl_buffer, nob))
795 return -EFAULT;
796
797 if (append != NULL && nob < usr_buffer_nob) {
798 if (copy_to_user(usr_buffer + nob, append, 1))
799 return -EFAULT;
800
801 nob++;
802 }
803
804 return nob;
805 }
806 EXPORT_SYMBOL(cfs_trace_copyout_string);
807
cfs_trace_allocate_string_buffer(char ** str,int nob)808 int cfs_trace_allocate_string_buffer(char **str, int nob)
809 {
810 if (nob > 2 * PAGE_CACHE_SIZE) /* string must be "sensible" */
811 return -EINVAL;
812
813 *str = kmalloc(nob, GFP_IOFS | __GFP_ZERO);
814 if (*str == NULL)
815 return -ENOMEM;
816
817 return 0;
818 }
819
cfs_trace_free_string_buffer(char * str,int nob)820 void cfs_trace_free_string_buffer(char *str, int nob)
821 {
822 kfree(str);
823 }
824
cfs_trace_dump_debug_buffer_usrstr(void __user * usr_str,int usr_str_nob)825 int cfs_trace_dump_debug_buffer_usrstr(void __user *usr_str, int usr_str_nob)
826 {
827 char *str;
828 int rc;
829
830 rc = cfs_trace_allocate_string_buffer(&str, usr_str_nob + 1);
831 if (rc != 0)
832 return rc;
833
834 rc = cfs_trace_copyin_string(str, usr_str_nob + 1,
835 usr_str, usr_str_nob);
836 if (rc != 0)
837 goto out;
838
839 if (str[0] != '/') {
840 rc = -EINVAL;
841 goto out;
842 }
843 rc = cfs_tracefile_dump_all_pages(str);
844 out:
845 cfs_trace_free_string_buffer(str, usr_str_nob + 1);
846 return rc;
847 }
848
cfs_trace_daemon_command(char * str)849 int cfs_trace_daemon_command(char *str)
850 {
851 int rc = 0;
852
853 cfs_tracefile_write_lock();
854
855 if (strcmp(str, "stop") == 0) {
856 cfs_tracefile_write_unlock();
857 cfs_trace_stop_thread();
858 cfs_tracefile_write_lock();
859 memset(cfs_tracefile, 0, sizeof(cfs_tracefile));
860
861 } else if (strncmp(str, "size=", 5) == 0) {
862 cfs_tracefile_size = simple_strtoul(str + 5, NULL, 0);
863 if (cfs_tracefile_size < 10 || cfs_tracefile_size > 20480)
864 cfs_tracefile_size = CFS_TRACEFILE_SIZE;
865 else
866 cfs_tracefile_size <<= 20;
867
868 } else if (strlen(str) >= sizeof(cfs_tracefile)) {
869 rc = -ENAMETOOLONG;
870 } else if (str[0] != '/') {
871 rc = -EINVAL;
872 } else {
873 strcpy(cfs_tracefile, str);
874
875 printk(KERN_INFO
876 "Lustre: debug daemon will attempt to start writing to %s (%lukB max)\n",
877 cfs_tracefile,
878 (long)(cfs_tracefile_size >> 10));
879
880 cfs_trace_start_thread();
881 }
882
883 cfs_tracefile_write_unlock();
884 return rc;
885 }
886
cfs_trace_daemon_command_usrstr(void __user * usr_str,int usr_str_nob)887 int cfs_trace_daemon_command_usrstr(void __user *usr_str, int usr_str_nob)
888 {
889 char *str;
890 int rc;
891
892 rc = cfs_trace_allocate_string_buffer(&str, usr_str_nob + 1);
893 if (rc != 0)
894 return rc;
895
896 rc = cfs_trace_copyin_string(str, usr_str_nob + 1,
897 usr_str, usr_str_nob);
898 if (rc == 0)
899 rc = cfs_trace_daemon_command(str);
900
901 cfs_trace_free_string_buffer(str, usr_str_nob + 1);
902 return rc;
903 }
904
cfs_trace_set_debug_mb(int mb)905 int cfs_trace_set_debug_mb(int mb)
906 {
907 int i;
908 int j;
909 int pages;
910 int limit = cfs_trace_max_debug_mb();
911 struct cfs_trace_cpu_data *tcd;
912
913 if (mb < num_possible_cpus()) {
914 printk(KERN_WARNING
915 "Lustre: %d MB is too small for debug buffer size, setting it to %d MB.\n",
916 mb, num_possible_cpus());
917 mb = num_possible_cpus();
918 }
919
920 if (mb > limit) {
921 printk(KERN_WARNING
922 "Lustre: %d MB is too large for debug buffer size, setting it to %d MB.\n",
923 mb, limit);
924 mb = limit;
925 }
926
927 mb /= num_possible_cpus();
928 pages = mb << (20 - PAGE_CACHE_SHIFT);
929
930 cfs_tracefile_write_lock();
931
932 cfs_tcd_for_each(tcd, i, j)
933 tcd->tcd_max_pages = (pages * tcd->tcd_pages_factor) / 100;
934
935 cfs_tracefile_write_unlock();
936
937 return 0;
938 }
939
cfs_trace_set_debug_mb_usrstr(void __user * usr_str,int usr_str_nob)940 int cfs_trace_set_debug_mb_usrstr(void __user *usr_str, int usr_str_nob)
941 {
942 char str[32];
943 int rc;
944
945 rc = cfs_trace_copyin_string(str, sizeof(str), usr_str, usr_str_nob);
946 if (rc < 0)
947 return rc;
948
949 return cfs_trace_set_debug_mb(simple_strtoul(str, NULL, 0));
950 }
951
cfs_trace_get_debug_mb(void)952 int cfs_trace_get_debug_mb(void)
953 {
954 int i;
955 int j;
956 struct cfs_trace_cpu_data *tcd;
957 int total_pages = 0;
958
959 cfs_tracefile_read_lock();
960
961 cfs_tcd_for_each(tcd, i, j)
962 total_pages += tcd->tcd_max_pages;
963
964 cfs_tracefile_read_unlock();
965
966 return (total_pages >> (20 - PAGE_CACHE_SHIFT)) + 1;
967 }
968
tracefiled(void * arg)969 static int tracefiled(void *arg)
970 {
971 struct page_collection pc;
972 struct tracefiled_ctl *tctl = arg;
973 struct cfs_trace_page *tage;
974 struct cfs_trace_page *tmp;
975 struct file *filp;
976 char *buf;
977 int last_loop = 0;
978 int rc;
979
980 DECL_MMSPACE;
981
982 /* we're started late enough that we pick up init's fs context */
983 /* this is so broken in uml? what on earth is going on? */
984
985 spin_lock_init(&pc.pc_lock);
986 complete(&tctl->tctl_start);
987
988 while (1) {
989 wait_queue_t __wait;
990
991 pc.pc_want_daemon_pages = 0;
992 collect_pages(&pc);
993 if (list_empty(&pc.pc_pages))
994 goto end_loop;
995
996 filp = NULL;
997 cfs_tracefile_read_lock();
998 if (cfs_tracefile[0] != 0) {
999 filp = filp_open(cfs_tracefile,
1000 O_CREAT | O_RDWR | O_LARGEFILE,
1001 0600);
1002 if (IS_ERR(filp)) {
1003 rc = PTR_ERR(filp);
1004 filp = NULL;
1005 printk(KERN_WARNING "couldn't open %s: %d\n",
1006 cfs_tracefile, rc);
1007 }
1008 }
1009 cfs_tracefile_read_unlock();
1010 if (filp == NULL) {
1011 put_pages_on_daemon_list(&pc);
1012 __LASSERT(list_empty(&pc.pc_pages));
1013 goto end_loop;
1014 }
1015
1016 MMSPACE_OPEN;
1017
1018 list_for_each_entry_safe(tage, tmp, &pc.pc_pages,
1019 linkage) {
1020 static loff_t f_pos;
1021
1022 __LASSERT_TAGE_INVARIANT(tage);
1023
1024 if (f_pos >= (off_t)cfs_tracefile_size)
1025 f_pos = 0;
1026 else if (f_pos > i_size_read(file_inode(filp)))
1027 f_pos = i_size_read(file_inode(filp));
1028
1029 buf = kmap(tage->page);
1030 rc = vfs_write(filp, (__force const char __user *)buf,
1031 tage->used, &f_pos);
1032 kunmap(tage->page);
1033
1034 if (rc != (int)tage->used) {
1035 printk(KERN_WARNING "wanted to write %u but wrote %d\n",
1036 tage->used, rc);
1037 put_pages_back(&pc);
1038 __LASSERT(list_empty(&pc.pc_pages));
1039 break;
1040 }
1041 }
1042 MMSPACE_CLOSE;
1043
1044 filp_close(filp, NULL);
1045 put_pages_on_daemon_list(&pc);
1046 if (!list_empty(&pc.pc_pages)) {
1047 int i;
1048
1049 printk(KERN_ALERT "Lustre: trace pages aren't empty\n");
1050 pr_err("total cpus(%d): ",
1051 num_possible_cpus());
1052 for (i = 0; i < num_possible_cpus(); i++)
1053 if (cpu_online(i))
1054 pr_cont("%d(on) ", i);
1055 else
1056 pr_cont("%d(off) ", i);
1057 pr_cont("\n");
1058
1059 i = 0;
1060 list_for_each_entry_safe(tage, tmp, &pc.pc_pages,
1061 linkage)
1062 pr_err("page %d belongs to cpu %d\n",
1063 ++i, tage->cpu);
1064 pr_err("There are %d pages unwritten\n", i);
1065 }
1066 __LASSERT(list_empty(&pc.pc_pages));
1067 end_loop:
1068 if (atomic_read(&tctl->tctl_shutdown)) {
1069 if (last_loop == 0) {
1070 last_loop = 1;
1071 continue;
1072 } else {
1073 break;
1074 }
1075 }
1076 init_waitqueue_entry(&__wait, current);
1077 add_wait_queue(&tctl->tctl_waitq, &__wait);
1078 set_current_state(TASK_INTERRUPTIBLE);
1079 schedule_timeout(cfs_time_seconds(1));
1080 remove_wait_queue(&tctl->tctl_waitq, &__wait);
1081 }
1082 complete(&tctl->tctl_stop);
1083 return 0;
1084 }
1085
cfs_trace_start_thread(void)1086 int cfs_trace_start_thread(void)
1087 {
1088 struct tracefiled_ctl *tctl = &trace_tctl;
1089 int rc = 0;
1090
1091 mutex_lock(&cfs_trace_thread_mutex);
1092 if (thread_running)
1093 goto out;
1094
1095 init_completion(&tctl->tctl_start);
1096 init_completion(&tctl->tctl_stop);
1097 init_waitqueue_head(&tctl->tctl_waitq);
1098 atomic_set(&tctl->tctl_shutdown, 0);
1099
1100 if (IS_ERR(kthread_run(tracefiled, tctl, "ktracefiled"))) {
1101 rc = -ECHILD;
1102 goto out;
1103 }
1104
1105 wait_for_completion(&tctl->tctl_start);
1106 thread_running = 1;
1107 out:
1108 mutex_unlock(&cfs_trace_thread_mutex);
1109 return rc;
1110 }
1111
cfs_trace_stop_thread(void)1112 void cfs_trace_stop_thread(void)
1113 {
1114 struct tracefiled_ctl *tctl = &trace_tctl;
1115
1116 mutex_lock(&cfs_trace_thread_mutex);
1117 if (thread_running) {
1118 printk(KERN_INFO
1119 "Lustre: shutting down debug daemon thread...\n");
1120 atomic_set(&tctl->tctl_shutdown, 1);
1121 wait_for_completion(&tctl->tctl_stop);
1122 thread_running = 0;
1123 }
1124 mutex_unlock(&cfs_trace_thread_mutex);
1125 }
1126
cfs_tracefile_init(int max_pages)1127 int cfs_tracefile_init(int max_pages)
1128 {
1129 struct cfs_trace_cpu_data *tcd;
1130 int i;
1131 int j;
1132 int rc;
1133 int factor;
1134
1135 rc = cfs_tracefile_init_arch();
1136 if (rc != 0)
1137 return rc;
1138
1139 cfs_tcd_for_each(tcd, i, j) {
1140 /* tcd_pages_factor is initialized int tracefile_init_arch. */
1141 factor = tcd->tcd_pages_factor;
1142 INIT_LIST_HEAD(&tcd->tcd_pages);
1143 INIT_LIST_HEAD(&tcd->tcd_stock_pages);
1144 INIT_LIST_HEAD(&tcd->tcd_daemon_pages);
1145 tcd->tcd_cur_pages = 0;
1146 tcd->tcd_cur_stock_pages = 0;
1147 tcd->tcd_cur_daemon_pages = 0;
1148 tcd->tcd_max_pages = (max_pages * factor) / 100;
1149 LASSERT(tcd->tcd_max_pages > 0);
1150 tcd->tcd_shutting_down = 0;
1151 }
1152
1153 return 0;
1154 }
1155
trace_cleanup_on_all_cpus(void)1156 static void trace_cleanup_on_all_cpus(void)
1157 {
1158 struct cfs_trace_cpu_data *tcd;
1159 struct cfs_trace_page *tage;
1160 struct cfs_trace_page *tmp;
1161 int i, cpu;
1162
1163 for_each_possible_cpu(cpu) {
1164 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
1165 tcd->tcd_shutting_down = 1;
1166
1167 list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages,
1168 linkage) {
1169 __LASSERT_TAGE_INVARIANT(tage);
1170
1171 list_del(&tage->linkage);
1172 cfs_tage_free(tage);
1173 }
1174
1175 tcd->tcd_cur_pages = 0;
1176 }
1177 }
1178 }
1179
cfs_trace_cleanup(void)1180 static void cfs_trace_cleanup(void)
1181 {
1182 struct page_collection pc;
1183
1184 INIT_LIST_HEAD(&pc.pc_pages);
1185 spin_lock_init(&pc.pc_lock);
1186
1187 trace_cleanup_on_all_cpus();
1188
1189 cfs_tracefile_fini_arch();
1190 }
1191
cfs_tracefile_exit(void)1192 void cfs_tracefile_exit(void)
1193 {
1194 cfs_trace_stop_thread();
1195 cfs_trace_cleanup();
1196 }
1197