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 #define DEBUG_SUBSYSTEM S_LNET
43 #define LUSTRE_TRACEFILE_PRIVATE
44 #include "tracefile.h"
45
46 #include "../../include/linux/libcfs/libcfs.h"
47
48 /* XXX move things up to the top, comment */
49 union cfs_trace_data_union (*cfs_trace_data[TCD_MAX_TYPES])[NR_CPUS] __cacheline_aligned;
50
51 char cfs_tracefile[TRACEFILE_NAME_SIZE];
52 long long cfs_tracefile_size = CFS_TRACEFILE_SIZE;
53 static struct tracefiled_ctl trace_tctl;
54 static DEFINE_MUTEX(cfs_trace_thread_mutex);
55 static int thread_running;
56
57 static atomic_t cfs_tage_allocated = ATOMIC_INIT(0);
58
59 static void put_pages_on_tcd_daemon_list(struct page_collection *pc,
60 struct cfs_trace_cpu_data *tcd);
61
62 static inline struct cfs_trace_page *
cfs_tage_from_list(struct list_head * list)63 cfs_tage_from_list(struct list_head *list)
64 {
65 return list_entry(list, struct cfs_trace_page, linkage);
66 }
67
cfs_tage_alloc(gfp_t gfp)68 static struct cfs_trace_page *cfs_tage_alloc(gfp_t gfp)
69 {
70 struct page *page;
71 struct cfs_trace_page *tage;
72
73 /* My caller is trying to free memory */
74 if (!in_interrupt() && memory_pressure_get())
75 return NULL;
76
77 /*
78 * Don't spam console with allocation failures: they will be reported
79 * by upper layer anyway.
80 */
81 gfp |= __GFP_NOWARN;
82 page = alloc_page(gfp);
83 if (page == NULL)
84 return NULL;
85
86 tage = kmalloc(sizeof(*tage), gfp);
87 if (tage == NULL) {
88 __free_page(page);
89 return NULL;
90 }
91
92 tage->page = page;
93 atomic_inc(&cfs_tage_allocated);
94 return tage;
95 }
96
cfs_tage_free(struct cfs_trace_page * tage)97 static void cfs_tage_free(struct cfs_trace_page *tage)
98 {
99 __LASSERT(tage != NULL);
100 __LASSERT(tage->page != NULL);
101
102 __free_page(tage->page);
103 kfree(tage);
104 atomic_dec(&cfs_tage_allocated);
105 }
106
cfs_tage_to_tail(struct cfs_trace_page * tage,struct list_head * queue)107 static void cfs_tage_to_tail(struct cfs_trace_page *tage,
108 struct list_head *queue)
109 {
110 __LASSERT(tage != NULL);
111 __LASSERT(queue != NULL);
112
113 list_move_tail(&tage->linkage, queue);
114 }
115
cfs_trace_refill_stock(struct cfs_trace_cpu_data * tcd,gfp_t gfp,struct list_head * stock)116 int cfs_trace_refill_stock(struct cfs_trace_cpu_data *tcd, gfp_t gfp,
117 struct list_head *stock)
118 {
119 int i;
120
121 /*
122 * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
123 * from here: this will lead to infinite recursion.
124 */
125
126 for (i = 0; i + tcd->tcd_cur_stock_pages < TCD_STOCK_PAGES ; ++i) {
127 struct cfs_trace_page *tage;
128
129 tage = cfs_tage_alloc(gfp);
130 if (tage == NULL)
131 break;
132 list_add_tail(&tage->linkage, stock);
133 }
134 return i;
135 }
136
137 /* return a page that has 'len' bytes left at the end */
138 static struct cfs_trace_page *
cfs_trace_get_tage_try(struct cfs_trace_cpu_data * tcd,unsigned long len)139 cfs_trace_get_tage_try(struct cfs_trace_cpu_data *tcd, unsigned long len)
140 {
141 struct cfs_trace_page *tage;
142
143 if (tcd->tcd_cur_pages > 0) {
144 __LASSERT(!list_empty(&tcd->tcd_pages));
145 tage = cfs_tage_from_list(tcd->tcd_pages.prev);
146 if (tage->used + len <= PAGE_CACHE_SIZE)
147 return tage;
148 }
149
150 if (tcd->tcd_cur_pages < tcd->tcd_max_pages) {
151 if (tcd->tcd_cur_stock_pages > 0) {
152 tage = cfs_tage_from_list(tcd->tcd_stock_pages.prev);
153 --tcd->tcd_cur_stock_pages;
154 list_del_init(&tage->linkage);
155 } else {
156 tage = cfs_tage_alloc(GFP_ATOMIC);
157 if (unlikely(tage == NULL)) {
158 if ((!memory_pressure_get() ||
159 in_interrupt()) && printk_ratelimit())
160 printk(KERN_WARNING
161 "cannot allocate a tage (%ld)\n",
162 tcd->tcd_cur_pages);
163 return NULL;
164 }
165 }
166
167 tage->used = 0;
168 tage->cpu = smp_processor_id();
169 tage->type = tcd->tcd_type;
170 list_add_tail(&tage->linkage, &tcd->tcd_pages);
171 tcd->tcd_cur_pages++;
172
173 if (tcd->tcd_cur_pages > 8 && thread_running) {
174 struct tracefiled_ctl *tctl = &trace_tctl;
175 /*
176 * wake up tracefiled to process some pages.
177 */
178 wake_up(&tctl->tctl_waitq);
179 }
180 return tage;
181 }
182 return NULL;
183 }
184
cfs_tcd_shrink(struct cfs_trace_cpu_data * tcd)185 static void cfs_tcd_shrink(struct cfs_trace_cpu_data *tcd)
186 {
187 int pgcount = tcd->tcd_cur_pages / 10;
188 struct page_collection pc;
189 struct cfs_trace_page *tage;
190 struct cfs_trace_page *tmp;
191
192 /*
193 * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
194 * from here: this will lead to infinite recursion.
195 */
196
197 if (printk_ratelimit())
198 printk(KERN_WARNING "debug daemon buffer overflowed; discarding 10%% of pages (%d of %ld)\n",
199 pgcount + 1, tcd->tcd_cur_pages);
200
201 INIT_LIST_HEAD(&pc.pc_pages);
202 spin_lock_init(&pc.pc_lock);
203
204 list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages, linkage) {
205 if (pgcount-- == 0)
206 break;
207
208 list_move_tail(&tage->linkage, &pc.pc_pages);
209 tcd->tcd_cur_pages--;
210 }
211 put_pages_on_tcd_daemon_list(&pc, tcd);
212 }
213
214 /* return a page that has 'len' bytes left at the end */
cfs_trace_get_tage(struct cfs_trace_cpu_data * tcd,unsigned long len)215 static struct cfs_trace_page *cfs_trace_get_tage(struct cfs_trace_cpu_data *tcd,
216 unsigned long len)
217 {
218 struct cfs_trace_page *tage;
219
220 /*
221 * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
222 * from here: this will lead to infinite recursion.
223 */
224
225 if (len > PAGE_CACHE_SIZE) {
226 pr_err("cowardly refusing to write %lu bytes in a page\n", len);
227 return NULL;
228 }
229
230 tage = cfs_trace_get_tage_try(tcd, len);
231 if (tage != NULL)
232 return tage;
233 if (thread_running)
234 cfs_tcd_shrink(tcd);
235 if (tcd->tcd_cur_pages > 0) {
236 tage = cfs_tage_from_list(tcd->tcd_pages.next);
237 tage->used = 0;
238 cfs_tage_to_tail(tage, &tcd->tcd_pages);
239 }
240 return tage;
241 }
242
libcfs_debug_msg(struct libcfs_debug_msg_data * msgdata,const char * format,...)243 int libcfs_debug_msg(struct libcfs_debug_msg_data *msgdata,
244 const char *format, ...)
245 {
246 va_list args;
247 int rc;
248
249 va_start(args, format);
250 rc = libcfs_debug_vmsg2(msgdata, format, args, NULL);
251 va_end(args);
252
253 return rc;
254 }
255 EXPORT_SYMBOL(libcfs_debug_msg);
256
libcfs_debug_vmsg2(struct libcfs_debug_msg_data * msgdata,const char * format1,va_list args,const char * format2,...)257 int libcfs_debug_vmsg2(struct libcfs_debug_msg_data *msgdata,
258 const char *format1, va_list args,
259 const char *format2, ...)
260 {
261 struct cfs_trace_cpu_data *tcd = NULL;
262 struct ptldebug_header header = {0};
263 struct cfs_trace_page *tage;
264 /* string_buf is used only if tcd != NULL, and is always set then */
265 char *string_buf = NULL;
266 char *debug_buf;
267 int known_size;
268 int needed = 85; /* average message length */
269 int max_nob;
270 va_list ap;
271 int depth;
272 int i;
273 int remain;
274 int mask = msgdata->msg_mask;
275 const char *file = kbasename(msgdata->msg_file);
276 struct cfs_debug_limit_state *cdls = msgdata->msg_cdls;
277
278 tcd = cfs_trace_get_tcd();
279
280 /* cfs_trace_get_tcd() grabs a lock, which disables preemption and
281 * pins us to a particular CPU. This avoids an smp_processor_id()
282 * warning on Linux when debugging is enabled. */
283 cfs_set_ptldebug_header(&header, msgdata, CDEBUG_STACK());
284
285 if (tcd == NULL) /* arch may not log in IRQ context */
286 goto console;
287
288 if (tcd->tcd_cur_pages == 0)
289 header.ph_flags |= PH_FLAG_FIRST_RECORD;
290
291 if (tcd->tcd_shutting_down) {
292 cfs_trace_put_tcd(tcd);
293 tcd = NULL;
294 goto console;
295 }
296
297 depth = __current_nesting_level();
298 known_size = strlen(file) + 1 + depth;
299 if (msgdata->msg_fn)
300 known_size += strlen(msgdata->msg_fn) + 1;
301
302 if (libcfs_debug_binary)
303 known_size += sizeof(header);
304
305 /*/
306 * '2' used because vsnprintf return real size required for output
307 * _without_ terminating NULL.
308 * if needed is to small for this format.
309 */
310 for (i = 0; i < 2; i++) {
311 tage = cfs_trace_get_tage(tcd, needed + known_size + 1);
312 if (tage == NULL) {
313 if (needed + known_size > PAGE_CACHE_SIZE)
314 mask |= D_ERROR;
315
316 cfs_trace_put_tcd(tcd);
317 tcd = NULL;
318 goto console;
319 }
320
321 string_buf = (char *)page_address(tage->page) +
322 tage->used + known_size;
323
324 max_nob = PAGE_CACHE_SIZE - tage->used - known_size;
325 if (max_nob <= 0) {
326 printk(KERN_EMERG "negative max_nob: %d\n",
327 max_nob);
328 mask |= D_ERROR;
329 cfs_trace_put_tcd(tcd);
330 tcd = NULL;
331 goto console;
332 }
333
334 needed = 0;
335 if (format1) {
336 va_copy(ap, args);
337 needed = vsnprintf(string_buf, max_nob, format1, ap);
338 va_end(ap);
339 }
340
341 if (format2) {
342 remain = max_nob - needed;
343 if (remain < 0)
344 remain = 0;
345
346 va_start(ap, format2);
347 needed += vsnprintf(string_buf + needed, remain,
348 format2, ap);
349 va_end(ap);
350 }
351
352 if (needed < max_nob) /* well. printing ok.. */
353 break;
354 }
355
356 if (*(string_buf+needed-1) != '\n')
357 printk(KERN_INFO "format at %s:%d:%s doesn't end in newline\n",
358 file, msgdata->msg_line, msgdata->msg_fn);
359
360 header.ph_len = known_size + needed;
361 debug_buf = (char *)page_address(tage->page) + tage->used;
362
363 if (libcfs_debug_binary) {
364 memcpy(debug_buf, &header, sizeof(header));
365 tage->used += sizeof(header);
366 debug_buf += sizeof(header);
367 }
368
369 /* indent message according to the nesting level */
370 while (depth-- > 0) {
371 *(debug_buf++) = '.';
372 ++tage->used;
373 }
374
375 strcpy(debug_buf, file);
376 tage->used += strlen(file) + 1;
377 debug_buf += strlen(file) + 1;
378
379 if (msgdata->msg_fn) {
380 strcpy(debug_buf, msgdata->msg_fn);
381 tage->used += strlen(msgdata->msg_fn) + 1;
382 debug_buf += strlen(msgdata->msg_fn) + 1;
383 }
384
385 __LASSERT(debug_buf == string_buf);
386
387 tage->used += needed;
388 __LASSERT (tage->used <= PAGE_CACHE_SIZE);
389
390 console:
391 if ((mask & libcfs_printk) == 0) {
392 /* no console output requested */
393 if (tcd != NULL)
394 cfs_trace_put_tcd(tcd);
395 return 1;
396 }
397
398 if (cdls != NULL) {
399 if (libcfs_console_ratelimit &&
400 cdls->cdls_next != 0 && /* not first time ever */
401 !cfs_time_after(cfs_time_current(), cdls->cdls_next)) {
402 /* skipping a console message */
403 cdls->cdls_count++;
404 if (tcd != NULL)
405 cfs_trace_put_tcd(tcd);
406 return 1;
407 }
408
409 if (cfs_time_after(cfs_time_current(), cdls->cdls_next +
410 libcfs_console_max_delay
411 + cfs_time_seconds(10))) {
412 /* last timeout was a long time ago */
413 cdls->cdls_delay /= libcfs_console_backoff * 4;
414 } else {
415 cdls->cdls_delay *= libcfs_console_backoff;
416 }
417
418 if (cdls->cdls_delay < libcfs_console_min_delay)
419 cdls->cdls_delay = libcfs_console_min_delay;
420 else if (cdls->cdls_delay > libcfs_console_max_delay)
421 cdls->cdls_delay = libcfs_console_max_delay;
422
423 /* ensure cdls_next is never zero after it's been seen */
424 cdls->cdls_next = (cfs_time_current() + cdls->cdls_delay) | 1;
425 }
426
427 if (tcd != NULL) {
428 cfs_print_to_console(&header, mask, string_buf, needed, file,
429 msgdata->msg_fn);
430 cfs_trace_put_tcd(tcd);
431 } else {
432 string_buf = cfs_trace_get_console_buffer();
433
434 needed = 0;
435 if (format1 != NULL) {
436 va_copy(ap, args);
437 needed = vsnprintf(string_buf,
438 CFS_TRACE_CONSOLE_BUFFER_SIZE,
439 format1, ap);
440 va_end(ap);
441 }
442 if (format2 != NULL) {
443 remain = CFS_TRACE_CONSOLE_BUFFER_SIZE - needed;
444 if (remain > 0) {
445 va_start(ap, format2);
446 needed += vsnprintf(string_buf+needed, remain,
447 format2, ap);
448 va_end(ap);
449 }
450 }
451 cfs_print_to_console(&header, mask,
452 string_buf, needed, file, msgdata->msg_fn);
453
454 cfs_trace_put_console_buffer(string_buf);
455 }
456
457 if (cdls != NULL && cdls->cdls_count != 0) {
458 string_buf = cfs_trace_get_console_buffer();
459
460 needed = snprintf(string_buf, CFS_TRACE_CONSOLE_BUFFER_SIZE,
461 "Skipped %d previous similar message%s\n",
462 cdls->cdls_count,
463 (cdls->cdls_count > 1) ? "s" : "");
464
465 cfs_print_to_console(&header, mask,
466 string_buf, needed, file, msgdata->msg_fn);
467
468 cfs_trace_put_console_buffer(string_buf);
469 cdls->cdls_count = 0;
470 }
471
472 return 0;
473 }
474 EXPORT_SYMBOL(libcfs_debug_vmsg2);
475
476 void
cfs_trace_assertion_failed(const char * str,struct libcfs_debug_msg_data * msgdata)477 cfs_trace_assertion_failed(const char *str,
478 struct libcfs_debug_msg_data *msgdata)
479 {
480 struct ptldebug_header hdr;
481
482 libcfs_panic_in_progress = 1;
483 libcfs_catastrophe = 1;
484 mb();
485
486 cfs_set_ptldebug_header(&hdr, msgdata, CDEBUG_STACK());
487
488 cfs_print_to_console(&hdr, D_EMERG, str, strlen(str),
489 msgdata->msg_file, msgdata->msg_fn);
490
491 panic("Lustre debug assertion failure\n");
492
493 /* not reached */
494 }
495
496 static void
panic_collect_pages(struct page_collection * pc)497 panic_collect_pages(struct page_collection *pc)
498 {
499 /* Do the collect_pages job on a single CPU: assumes that all other
500 * CPUs have been stopped during a panic. If this isn't true for some
501 * arch, this will have to be implemented separately in each arch. */
502 int i;
503 int j;
504 struct cfs_trace_cpu_data *tcd;
505
506 INIT_LIST_HEAD(&pc->pc_pages);
507
508 cfs_tcd_for_each(tcd, i, j) {
509 list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
510 tcd->tcd_cur_pages = 0;
511
512 if (pc->pc_want_daemon_pages) {
513 list_splice_init(&tcd->tcd_daemon_pages,
514 &pc->pc_pages);
515 tcd->tcd_cur_daemon_pages = 0;
516 }
517 }
518 }
519
collect_pages_on_all_cpus(struct page_collection * pc)520 static void collect_pages_on_all_cpus(struct page_collection *pc)
521 {
522 struct cfs_trace_cpu_data *tcd;
523 int i, cpu;
524
525 spin_lock(&pc->pc_lock);
526 for_each_possible_cpu(cpu) {
527 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
528 list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
529 tcd->tcd_cur_pages = 0;
530 if (pc->pc_want_daemon_pages) {
531 list_splice_init(&tcd->tcd_daemon_pages,
532 &pc->pc_pages);
533 tcd->tcd_cur_daemon_pages = 0;
534 }
535 }
536 }
537 spin_unlock(&pc->pc_lock);
538 }
539
collect_pages(struct page_collection * pc)540 static void collect_pages(struct page_collection *pc)
541 {
542 INIT_LIST_HEAD(&pc->pc_pages);
543
544 if (libcfs_panic_in_progress)
545 panic_collect_pages(pc);
546 else
547 collect_pages_on_all_cpus(pc);
548 }
549
put_pages_back_on_all_cpus(struct page_collection * pc)550 static void put_pages_back_on_all_cpus(struct page_collection *pc)
551 {
552 struct cfs_trace_cpu_data *tcd;
553 struct list_head *cur_head;
554 struct cfs_trace_page *tage;
555 struct cfs_trace_page *tmp;
556 int i, cpu;
557
558 spin_lock(&pc->pc_lock);
559 for_each_possible_cpu(cpu) {
560 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
561 cur_head = tcd->tcd_pages.next;
562
563 list_for_each_entry_safe(tage, tmp, &pc->pc_pages,
564 linkage) {
565
566 __LASSERT_TAGE_INVARIANT(tage);
567
568 if (tage->cpu != cpu || tage->type != i)
569 continue;
570
571 cfs_tage_to_tail(tage, cur_head);
572 tcd->tcd_cur_pages++;
573 }
574 }
575 }
576 spin_unlock(&pc->pc_lock);
577 }
578
put_pages_back(struct page_collection * pc)579 static void put_pages_back(struct page_collection *pc)
580 {
581 if (!libcfs_panic_in_progress)
582 put_pages_back_on_all_cpus(pc);
583 }
584
585 /* Add pages to a per-cpu debug daemon ringbuffer. This buffer makes sure that
586 * we have a good amount of data at all times for dumping during an LBUG, even
587 * if we have been steadily writing (and otherwise discarding) pages via the
588 * debug daemon. */
put_pages_on_tcd_daemon_list(struct page_collection * pc,struct cfs_trace_cpu_data * tcd)589 static void put_pages_on_tcd_daemon_list(struct page_collection *pc,
590 struct cfs_trace_cpu_data *tcd)
591 {
592 struct cfs_trace_page *tage;
593 struct cfs_trace_page *tmp;
594
595 spin_lock(&pc->pc_lock);
596 list_for_each_entry_safe(tage, tmp, &pc->pc_pages, linkage) {
597
598 __LASSERT_TAGE_INVARIANT(tage);
599
600 if (tage->cpu != tcd->tcd_cpu || tage->type != tcd->tcd_type)
601 continue;
602
603 cfs_tage_to_tail(tage, &tcd->tcd_daemon_pages);
604 tcd->tcd_cur_daemon_pages++;
605
606 if (tcd->tcd_cur_daemon_pages > tcd->tcd_max_pages) {
607 struct cfs_trace_page *victim;
608
609 __LASSERT(!list_empty(&tcd->tcd_daemon_pages));
610 victim = cfs_tage_from_list(tcd->tcd_daemon_pages.next);
611
612 __LASSERT_TAGE_INVARIANT(victim);
613
614 list_del(&victim->linkage);
615 cfs_tage_free(victim);
616 tcd->tcd_cur_daemon_pages--;
617 }
618 }
619 spin_unlock(&pc->pc_lock);
620 }
621
put_pages_on_daemon_list(struct page_collection * pc)622 static void put_pages_on_daemon_list(struct page_collection *pc)
623 {
624 struct cfs_trace_cpu_data *tcd;
625 int i, cpu;
626
627 for_each_possible_cpu(cpu) {
628 cfs_tcd_for_each_type_lock(tcd, i, cpu)
629 put_pages_on_tcd_daemon_list(pc, tcd);
630 }
631 }
632
cfs_trace_debug_print(void)633 void cfs_trace_debug_print(void)
634 {
635 struct page_collection pc;
636 struct cfs_trace_page *tage;
637 struct cfs_trace_page *tmp;
638
639 spin_lock_init(&pc.pc_lock);
640
641 pc.pc_want_daemon_pages = 1;
642 collect_pages(&pc);
643 list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
644 char *p, *file, *fn;
645 struct page *page;
646
647 __LASSERT_TAGE_INVARIANT(tage);
648
649 page = tage->page;
650 p = page_address(page);
651 while (p < ((char *)page_address(page) + tage->used)) {
652 struct ptldebug_header *hdr;
653 int len;
654
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_KERNEL | __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_get_debug_mb(void)940 int cfs_trace_get_debug_mb(void)
941 {
942 int i;
943 int j;
944 struct cfs_trace_cpu_data *tcd;
945 int total_pages = 0;
946
947 cfs_tracefile_read_lock();
948
949 cfs_tcd_for_each(tcd, i, j)
950 total_pages += tcd->tcd_max_pages;
951
952 cfs_tracefile_read_unlock();
953
954 return (total_pages >> (20 - PAGE_CACHE_SHIFT)) + 1;
955 }
956
tracefiled(void * arg)957 static int tracefiled(void *arg)
958 {
959 struct page_collection pc;
960 struct tracefiled_ctl *tctl = arg;
961 struct cfs_trace_page *tage;
962 struct cfs_trace_page *tmp;
963 struct file *filp;
964 char *buf;
965 int last_loop = 0;
966 int rc;
967
968 DECL_MMSPACE;
969
970 /* we're started late enough that we pick up init's fs context */
971 /* this is so broken in uml? what on earth is going on? */
972
973 spin_lock_init(&pc.pc_lock);
974 complete(&tctl->tctl_start);
975
976 while (1) {
977 wait_queue_t __wait;
978
979 pc.pc_want_daemon_pages = 0;
980 collect_pages(&pc);
981 if (list_empty(&pc.pc_pages))
982 goto end_loop;
983
984 filp = NULL;
985 cfs_tracefile_read_lock();
986 if (cfs_tracefile[0] != 0) {
987 filp = filp_open(cfs_tracefile,
988 O_CREAT | O_RDWR | O_LARGEFILE,
989 0600);
990 if (IS_ERR(filp)) {
991 rc = PTR_ERR(filp);
992 filp = NULL;
993 printk(KERN_WARNING "couldn't open %s: %d\n",
994 cfs_tracefile, rc);
995 }
996 }
997 cfs_tracefile_read_unlock();
998 if (filp == NULL) {
999 put_pages_on_daemon_list(&pc);
1000 __LASSERT(list_empty(&pc.pc_pages));
1001 goto end_loop;
1002 }
1003
1004 MMSPACE_OPEN;
1005
1006 list_for_each_entry_safe(tage, tmp, &pc.pc_pages,
1007 linkage) {
1008 static loff_t f_pos;
1009
1010 __LASSERT_TAGE_INVARIANT(tage);
1011
1012 if (f_pos >= (off_t)cfs_tracefile_size)
1013 f_pos = 0;
1014 else if (f_pos > i_size_read(file_inode(filp)))
1015 f_pos = i_size_read(file_inode(filp));
1016
1017 buf = kmap(tage->page);
1018 rc = vfs_write(filp, (__force const char __user *)buf,
1019 tage->used, &f_pos);
1020 kunmap(tage->page);
1021
1022 if (rc != (int)tage->used) {
1023 printk(KERN_WARNING "wanted to write %u but wrote %d\n",
1024 tage->used, rc);
1025 put_pages_back(&pc);
1026 __LASSERT(list_empty(&pc.pc_pages));
1027 break;
1028 }
1029 }
1030 MMSPACE_CLOSE;
1031
1032 filp_close(filp, NULL);
1033 put_pages_on_daemon_list(&pc);
1034 if (!list_empty(&pc.pc_pages)) {
1035 int i;
1036
1037 printk(KERN_ALERT "Lustre: trace pages aren't empty\n");
1038 pr_err("total cpus(%d): ",
1039 num_possible_cpus());
1040 for (i = 0; i < num_possible_cpus(); i++)
1041 if (cpu_online(i))
1042 pr_cont("%d(on) ", i);
1043 else
1044 pr_cont("%d(off) ", i);
1045 pr_cont("\n");
1046
1047 i = 0;
1048 list_for_each_entry_safe(tage, tmp, &pc.pc_pages,
1049 linkage)
1050 pr_err("page %d belongs to cpu %d\n",
1051 ++i, tage->cpu);
1052 pr_err("There are %d pages unwritten\n", i);
1053 }
1054 __LASSERT(list_empty(&pc.pc_pages));
1055 end_loop:
1056 if (atomic_read(&tctl->tctl_shutdown)) {
1057 if (last_loop == 0) {
1058 last_loop = 1;
1059 continue;
1060 } else {
1061 break;
1062 }
1063 }
1064 init_waitqueue_entry(&__wait, current);
1065 add_wait_queue(&tctl->tctl_waitq, &__wait);
1066 set_current_state(TASK_INTERRUPTIBLE);
1067 schedule_timeout(cfs_time_seconds(1));
1068 remove_wait_queue(&tctl->tctl_waitq, &__wait);
1069 }
1070 complete(&tctl->tctl_stop);
1071 return 0;
1072 }
1073
cfs_trace_start_thread(void)1074 int cfs_trace_start_thread(void)
1075 {
1076 struct tracefiled_ctl *tctl = &trace_tctl;
1077 int rc = 0;
1078
1079 mutex_lock(&cfs_trace_thread_mutex);
1080 if (thread_running)
1081 goto out;
1082
1083 init_completion(&tctl->tctl_start);
1084 init_completion(&tctl->tctl_stop);
1085 init_waitqueue_head(&tctl->tctl_waitq);
1086 atomic_set(&tctl->tctl_shutdown, 0);
1087
1088 if (IS_ERR(kthread_run(tracefiled, tctl, "ktracefiled"))) {
1089 rc = -ECHILD;
1090 goto out;
1091 }
1092
1093 wait_for_completion(&tctl->tctl_start);
1094 thread_running = 1;
1095 out:
1096 mutex_unlock(&cfs_trace_thread_mutex);
1097 return rc;
1098 }
1099
cfs_trace_stop_thread(void)1100 void cfs_trace_stop_thread(void)
1101 {
1102 struct tracefiled_ctl *tctl = &trace_tctl;
1103
1104 mutex_lock(&cfs_trace_thread_mutex);
1105 if (thread_running) {
1106 printk(KERN_INFO
1107 "Lustre: shutting down debug daemon thread...\n");
1108 atomic_set(&tctl->tctl_shutdown, 1);
1109 wait_for_completion(&tctl->tctl_stop);
1110 thread_running = 0;
1111 }
1112 mutex_unlock(&cfs_trace_thread_mutex);
1113 }
1114
cfs_tracefile_init(int max_pages)1115 int cfs_tracefile_init(int max_pages)
1116 {
1117 struct cfs_trace_cpu_data *tcd;
1118 int i;
1119 int j;
1120 int rc;
1121 int factor;
1122
1123 rc = cfs_tracefile_init_arch();
1124 if (rc != 0)
1125 return rc;
1126
1127 cfs_tcd_for_each(tcd, i, j) {
1128 /* tcd_pages_factor is initialized int tracefile_init_arch. */
1129 factor = tcd->tcd_pages_factor;
1130 INIT_LIST_HEAD(&tcd->tcd_pages);
1131 INIT_LIST_HEAD(&tcd->tcd_stock_pages);
1132 INIT_LIST_HEAD(&tcd->tcd_daemon_pages);
1133 tcd->tcd_cur_pages = 0;
1134 tcd->tcd_cur_stock_pages = 0;
1135 tcd->tcd_cur_daemon_pages = 0;
1136 tcd->tcd_max_pages = (max_pages * factor) / 100;
1137 LASSERT(tcd->tcd_max_pages > 0);
1138 tcd->tcd_shutting_down = 0;
1139 }
1140
1141 return 0;
1142 }
1143
trace_cleanup_on_all_cpus(void)1144 static void trace_cleanup_on_all_cpus(void)
1145 {
1146 struct cfs_trace_cpu_data *tcd;
1147 struct cfs_trace_page *tage;
1148 struct cfs_trace_page *tmp;
1149 int i, cpu;
1150
1151 for_each_possible_cpu(cpu) {
1152 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
1153 tcd->tcd_shutting_down = 1;
1154
1155 list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages,
1156 linkage) {
1157 __LASSERT_TAGE_INVARIANT(tage);
1158
1159 list_del(&tage->linkage);
1160 cfs_tage_free(tage);
1161 }
1162
1163 tcd->tcd_cur_pages = 0;
1164 }
1165 }
1166 }
1167
cfs_trace_cleanup(void)1168 static void cfs_trace_cleanup(void)
1169 {
1170 struct page_collection pc;
1171
1172 INIT_LIST_HEAD(&pc.pc_pages);
1173 spin_lock_init(&pc.pc_lock);
1174
1175 trace_cleanup_on_all_cpus();
1176
1177 cfs_tracefile_fini_arch();
1178 }
1179
cfs_tracefile_exit(void)1180 void cfs_tracefile_exit(void)
1181 {
1182 cfs_trace_stop_thread();
1183 cfs_trace_cleanup();
1184 }
1185