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 = 0;
57
58 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; "
200 "discarding 10%% of pages (%d of %ld)\n",
201 pgcount + 1, tcd->tcd_cur_pages);
202
203 INIT_LIST_HEAD(&pc.pc_pages);
204 spin_lock_init(&pc.pc_lock);
205
206 list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages, linkage) {
207 if (pgcount-- == 0)
208 break;
209
210 list_move_tail(&tage->linkage, &pc.pc_pages);
211 tcd->tcd_cur_pages--;
212 }
213 put_pages_on_tcd_daemon_list(&pc, tcd);
214 }
215
216 /* return a page that has 'len' bytes left at the end */
cfs_trace_get_tage(struct cfs_trace_cpu_data * tcd,unsigned long len)217 static struct cfs_trace_page *cfs_trace_get_tage(struct cfs_trace_cpu_data *tcd,
218 unsigned long len)
219 {
220 struct cfs_trace_page *tage;
221
222 /*
223 * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
224 * from here: this will lead to infinite recursion.
225 */
226
227 if (len > PAGE_CACHE_SIZE) {
228 printk(KERN_ERR
229 "cowardly refusing to write %lu bytes in a page\n", len);
230 return NULL;
231 }
232
233 tage = cfs_trace_get_tage_try(tcd, len);
234 if (tage != NULL)
235 return tage;
236 if (thread_running)
237 cfs_tcd_shrink(tcd);
238 if (tcd->tcd_cur_pages > 0) {
239 tage = cfs_tage_from_list(tcd->tcd_pages.next);
240 tage->used = 0;
241 cfs_tage_to_tail(tage, &tcd->tcd_pages);
242 }
243 return tage;
244 }
245
libcfs_debug_msg(struct libcfs_debug_msg_data * msgdata,const char * format,...)246 int libcfs_debug_msg(struct libcfs_debug_msg_data *msgdata,
247 const char *format, ...)
248 {
249 va_list args;
250 int rc;
251
252 va_start(args, format);
253 rc = libcfs_debug_vmsg2(msgdata, format, args, NULL);
254 va_end(args);
255
256 return rc;
257 }
258 EXPORT_SYMBOL(libcfs_debug_msg);
259
libcfs_debug_vmsg2(struct libcfs_debug_msg_data * msgdata,const char * format1,va_list args,const char * format2,...)260 int libcfs_debug_vmsg2(struct libcfs_debug_msg_data *msgdata,
261 const char *format1, va_list args,
262 const char *format2, ...)
263 {
264 struct cfs_trace_cpu_data *tcd = NULL;
265 struct ptldebug_header header = {0};
266 struct cfs_trace_page *tage;
267 /* string_buf is used only if tcd != NULL, and is always set then */
268 char *string_buf = NULL;
269 char *debug_buf;
270 int known_size;
271 int needed = 85; /* average message length */
272 int max_nob;
273 va_list ap;
274 int depth;
275 int i;
276 int remain;
277 int mask = msgdata->msg_mask;
278 const char *file = kbasename(msgdata->msg_file);
279 struct cfs_debug_limit_state *cdls = msgdata->msg_cdls;
280
281 tcd = cfs_trace_get_tcd();
282
283 /* cfs_trace_get_tcd() grabs a lock, which disables preemption and
284 * pins us to a particular CPU. This avoids an smp_processor_id()
285 * warning on Linux when debugging is enabled. */
286 cfs_set_ptldebug_header(&header, msgdata, CDEBUG_STACK());
287
288 if (tcd == NULL) /* arch may not log in IRQ context */
289 goto console;
290
291 if (tcd->tcd_cur_pages == 0)
292 header.ph_flags |= PH_FLAG_FIRST_RECORD;
293
294 if (tcd->tcd_shutting_down) {
295 cfs_trace_put_tcd(tcd);
296 tcd = NULL;
297 goto console;
298 }
299
300 depth = __current_nesting_level();
301 known_size = strlen(file) + 1 + depth;
302 if (msgdata->msg_fn)
303 known_size += strlen(msgdata->msg_fn) + 1;
304
305 if (libcfs_debug_binary)
306 known_size += sizeof(header);
307
308 /*/
309 * '2' used because vsnprintf return real size required for output
310 * _without_ terminating NULL.
311 * if needed is to small for this format.
312 */
313 for (i = 0; i < 2; i++) {
314 tage = cfs_trace_get_tage(tcd, needed + known_size + 1);
315 if (tage == NULL) {
316 if (needed + known_size > PAGE_CACHE_SIZE)
317 mask |= D_ERROR;
318
319 cfs_trace_put_tcd(tcd);
320 tcd = NULL;
321 goto console;
322 }
323
324 string_buf = (char *)page_address(tage->page) +
325 tage->used + known_size;
326
327 max_nob = PAGE_CACHE_SIZE - tage->used - known_size;
328 if (max_nob <= 0) {
329 printk(KERN_EMERG "negative max_nob: %d\n",
330 max_nob);
331 mask |= D_ERROR;
332 cfs_trace_put_tcd(tcd);
333 tcd = NULL;
334 goto console;
335 }
336
337 needed = 0;
338 if (format1) {
339 va_copy(ap, args);
340 needed = vsnprintf(string_buf, max_nob, format1, ap);
341 va_end(ap);
342 }
343
344 if (format2) {
345 remain = max_nob - needed;
346 if (remain < 0)
347 remain = 0;
348
349 va_start(ap, format2);
350 needed += vsnprintf(string_buf + needed, remain,
351 format2, ap);
352 va_end(ap);
353 }
354
355 if (needed < max_nob) /* well. printing ok.. */
356 break;
357 }
358
359 if (*(string_buf+needed-1) != '\n')
360 printk(KERN_INFO "format at %s:%d:%s doesn't end in "
361 "newline\n", file, msgdata->msg_line, msgdata->msg_fn);
362
363 header.ph_len = known_size + needed;
364 debug_buf = (char *)page_address(tage->page) + tage->used;
365
366 if (libcfs_debug_binary) {
367 memcpy(debug_buf, &header, sizeof(header));
368 tage->used += sizeof(header);
369 debug_buf += sizeof(header);
370 }
371
372 /* indent message according to the nesting level */
373 while (depth-- > 0) {
374 *(debug_buf++) = '.';
375 ++ tage->used;
376 }
377
378 strcpy(debug_buf, file);
379 tage->used += strlen(file) + 1;
380 debug_buf += strlen(file) + 1;
381
382 if (msgdata->msg_fn) {
383 strcpy(debug_buf, msgdata->msg_fn);
384 tage->used += strlen(msgdata->msg_fn) + 1;
385 debug_buf += strlen(msgdata->msg_fn) + 1;
386 }
387
388 __LASSERT(debug_buf == string_buf);
389
390 tage->used += needed;
391 __LASSERT (tage->used <= PAGE_CACHE_SIZE);
392
393 console:
394 if ((mask & libcfs_printk) == 0) {
395 /* no console output requested */
396 if (tcd != NULL)
397 cfs_trace_put_tcd(tcd);
398 return 1;
399 }
400
401 if (cdls != NULL) {
402 if (libcfs_console_ratelimit &&
403 cdls->cdls_next != 0 && /* not first time ever */
404 !cfs_time_after(cfs_time_current(), cdls->cdls_next)) {
405 /* skipping a console message */
406 cdls->cdls_count++;
407 if (tcd != NULL)
408 cfs_trace_put_tcd(tcd);
409 return 1;
410 }
411
412 if (cfs_time_after(cfs_time_current(), cdls->cdls_next +
413 libcfs_console_max_delay
414 + cfs_time_seconds(10))) {
415 /* last timeout was a long time ago */
416 cdls->cdls_delay /= libcfs_console_backoff * 4;
417 } else {
418 cdls->cdls_delay *= libcfs_console_backoff;
419 }
420
421 if (cdls->cdls_delay < libcfs_console_min_delay)
422 cdls->cdls_delay = libcfs_console_min_delay;
423 else if (cdls->cdls_delay > libcfs_console_max_delay)
424 cdls->cdls_delay = libcfs_console_max_delay;
425
426 /* ensure cdls_next is never zero after it's been seen */
427 cdls->cdls_next = (cfs_time_current() + cdls->cdls_delay) | 1;
428 }
429
430 if (tcd != NULL) {
431 cfs_print_to_console(&header, mask, string_buf, needed, file,
432 msgdata->msg_fn);
433 cfs_trace_put_tcd(tcd);
434 } else {
435 string_buf = cfs_trace_get_console_buffer();
436
437 needed = 0;
438 if (format1 != NULL) {
439 va_copy(ap, args);
440 needed = vsnprintf(string_buf,
441 CFS_TRACE_CONSOLE_BUFFER_SIZE,
442 format1, ap);
443 va_end(ap);
444 }
445 if (format2 != NULL) {
446 remain = CFS_TRACE_CONSOLE_BUFFER_SIZE - needed;
447 if (remain > 0) {
448 va_start(ap, format2);
449 needed += vsnprintf(string_buf+needed, remain,
450 format2, ap);
451 va_end(ap);
452 }
453 }
454 cfs_print_to_console(&header, mask,
455 string_buf, needed, file, msgdata->msg_fn);
456
457 cfs_trace_put_console_buffer(string_buf);
458 }
459
460 if (cdls != NULL && cdls->cdls_count != 0) {
461 string_buf = cfs_trace_get_console_buffer();
462
463 needed = snprintf(string_buf, CFS_TRACE_CONSOLE_BUFFER_SIZE,
464 "Skipped %d previous similar message%s\n",
465 cdls->cdls_count,
466 (cdls->cdls_count > 1) ? "s" : "");
467
468 cfs_print_to_console(&header, mask,
469 string_buf, needed, file, msgdata->msg_fn);
470
471 cfs_trace_put_console_buffer(string_buf);
472 cdls->cdls_count = 0;
473 }
474
475 return 0;
476 }
477 EXPORT_SYMBOL(libcfs_debug_vmsg2);
478
479 void
cfs_trace_assertion_failed(const char * str,struct libcfs_debug_msg_data * msgdata)480 cfs_trace_assertion_failed(const char *str,
481 struct libcfs_debug_msg_data *msgdata)
482 {
483 struct ptldebug_header hdr;
484
485 libcfs_panic_in_progress = 1;
486 libcfs_catastrophe = 1;
487 mb();
488
489 cfs_set_ptldebug_header(&hdr, msgdata, CDEBUG_STACK());
490
491 cfs_print_to_console(&hdr, D_EMERG, str, strlen(str),
492 msgdata->msg_file, msgdata->msg_fn);
493
494 panic("Lustre debug assertion failure\n");
495
496 /* not reached */
497 }
498
499 static void
panic_collect_pages(struct page_collection * pc)500 panic_collect_pages(struct page_collection *pc)
501 {
502 /* Do the collect_pages job on a single CPU: assumes that all other
503 * CPUs have been stopped during a panic. If this isn't true for some
504 * arch, this will have to be implemented separately in each arch. */
505 int i;
506 int j;
507 struct cfs_trace_cpu_data *tcd;
508
509 INIT_LIST_HEAD(&pc->pc_pages);
510
511 cfs_tcd_for_each(tcd, i, j) {
512 list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
513 tcd->tcd_cur_pages = 0;
514
515 if (pc->pc_want_daemon_pages) {
516 list_splice_init(&tcd->tcd_daemon_pages,
517 &pc->pc_pages);
518 tcd->tcd_cur_daemon_pages = 0;
519 }
520 }
521 }
522
collect_pages_on_all_cpus(struct page_collection * pc)523 static void collect_pages_on_all_cpus(struct page_collection *pc)
524 {
525 struct cfs_trace_cpu_data *tcd;
526 int i, cpu;
527
528 spin_lock(&pc->pc_lock);
529 for_each_possible_cpu(cpu) {
530 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
531 list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
532 tcd->tcd_cur_pages = 0;
533 if (pc->pc_want_daemon_pages) {
534 list_splice_init(&tcd->tcd_daemon_pages,
535 &pc->pc_pages);
536 tcd->tcd_cur_daemon_pages = 0;
537 }
538 }
539 }
540 spin_unlock(&pc->pc_lock);
541 }
542
collect_pages(struct page_collection * pc)543 static void collect_pages(struct page_collection *pc)
544 {
545 INIT_LIST_HEAD(&pc->pc_pages);
546
547 if (libcfs_panic_in_progress)
548 panic_collect_pages(pc);
549 else
550 collect_pages_on_all_cpus(pc);
551 }
552
put_pages_back_on_all_cpus(struct page_collection * pc)553 static void put_pages_back_on_all_cpus(struct page_collection *pc)
554 {
555 struct cfs_trace_cpu_data *tcd;
556 struct list_head *cur_head;
557 struct cfs_trace_page *tage;
558 struct cfs_trace_page *tmp;
559 int i, cpu;
560
561 spin_lock(&pc->pc_lock);
562 for_each_possible_cpu(cpu) {
563 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
564 cur_head = tcd->tcd_pages.next;
565
566 list_for_each_entry_safe(tage, tmp, &pc->pc_pages,
567 linkage) {
568
569 __LASSERT_TAGE_INVARIANT(tage);
570
571 if (tage->cpu != cpu || tage->type != i)
572 continue;
573
574 cfs_tage_to_tail(tage, cur_head);
575 tcd->tcd_cur_pages++;
576 }
577 }
578 }
579 spin_unlock(&pc->pc_lock);
580 }
581
put_pages_back(struct page_collection * pc)582 static void put_pages_back(struct page_collection *pc)
583 {
584 if (!libcfs_panic_in_progress)
585 put_pages_back_on_all_cpus(pc);
586 }
587
588 /* Add pages to a per-cpu debug daemon ringbuffer. This buffer makes sure that
589 * we have a good amount of data at all times for dumping during an LBUG, even
590 * if we have been steadily writing (and otherwise discarding) pages via the
591 * debug daemon. */
put_pages_on_tcd_daemon_list(struct page_collection * pc,struct cfs_trace_cpu_data * tcd)592 static void put_pages_on_tcd_daemon_list(struct page_collection *pc,
593 struct cfs_trace_cpu_data *tcd)
594 {
595 struct cfs_trace_page *tage;
596 struct cfs_trace_page *tmp;
597
598 spin_lock(&pc->pc_lock);
599 list_for_each_entry_safe(tage, tmp, &pc->pc_pages, linkage) {
600
601 __LASSERT_TAGE_INVARIANT(tage);
602
603 if (tage->cpu != tcd->tcd_cpu || tage->type != tcd->tcd_type)
604 continue;
605
606 cfs_tage_to_tail(tage, &tcd->tcd_daemon_pages);
607 tcd->tcd_cur_daemon_pages++;
608
609 if (tcd->tcd_cur_daemon_pages > tcd->tcd_max_pages) {
610 struct cfs_trace_page *victim;
611
612 __LASSERT(!list_empty(&tcd->tcd_daemon_pages));
613 victim = cfs_tage_from_list(tcd->tcd_daemon_pages.next);
614
615 __LASSERT_TAGE_INVARIANT(victim);
616
617 list_del(&victim->linkage);
618 cfs_tage_free(victim);
619 tcd->tcd_cur_daemon_pages--;
620 }
621 }
622 spin_unlock(&pc->pc_lock);
623 }
624
put_pages_on_daemon_list(struct page_collection * pc)625 static void put_pages_on_daemon_list(struct page_collection *pc)
626 {
627 struct cfs_trace_cpu_data *tcd;
628 int i, cpu;
629
630 for_each_possible_cpu(cpu) {
631 cfs_tcd_for_each_type_lock(tcd, i, cpu)
632 put_pages_on_tcd_daemon_list(pc, tcd);
633 }
634 }
635
cfs_trace_debug_print(void)636 void cfs_trace_debug_print(void)
637 {
638 struct page_collection pc;
639 struct cfs_trace_page *tage;
640 struct cfs_trace_page *tmp;
641
642 spin_lock_init(&pc.pc_lock);
643
644 pc.pc_want_daemon_pages = 1;
645 collect_pages(&pc);
646 list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
647 char *p, *file, *fn;
648 struct page *page;
649
650 __LASSERT_TAGE_INVARIANT(tage);
651
652 page = tage->page;
653 p = page_address(page);
654 while (p < ((char *)page_address(page) + tage->used)) {
655 struct ptldebug_header *hdr;
656 int len;
657 hdr = (void *)p;
658 p += sizeof(*hdr);
659 file = p;
660 p += strlen(file) + 1;
661 fn = p;
662 p += strlen(fn) + 1;
663 len = hdr->ph_len - (int)(p - (char *)hdr);
664
665 cfs_print_to_console(hdr, D_EMERG, p, len, file, fn);
666
667 p += len;
668 }
669
670 list_del(&tage->linkage);
671 cfs_tage_free(tage);
672 }
673 }
674
cfs_tracefile_dump_all_pages(char * filename)675 int cfs_tracefile_dump_all_pages(char *filename)
676 {
677 struct page_collection pc;
678 struct file *filp;
679 struct cfs_trace_page *tage;
680 struct cfs_trace_page *tmp;
681 char *buf;
682 int rc;
683
684 DECL_MMSPACE;
685
686 cfs_tracefile_write_lock();
687
688 filp = filp_open(filename, O_CREAT|O_EXCL|O_WRONLY|O_LARGEFILE, 0600);
689 if (IS_ERR(filp)) {
690 rc = PTR_ERR(filp);
691 filp = NULL;
692 printk(KERN_ERR "LustreError: can't open %s for dump: rc %d\n",
693 filename, rc);
694 goto out;
695 }
696
697 spin_lock_init(&pc.pc_lock);
698 pc.pc_want_daemon_pages = 1;
699 collect_pages(&pc);
700 if (list_empty(&pc.pc_pages)) {
701 rc = 0;
702 goto close;
703 }
704
705 /* ok, for now, just write the pages. in the future we'll be building
706 * iobufs with the pages and calling generic_direct_IO */
707 MMSPACE_OPEN;
708 list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
709
710 __LASSERT_TAGE_INVARIANT(tage);
711
712 buf = kmap(tage->page);
713 rc = vfs_write(filp, (__force const char __user *)buf,
714 tage->used, &filp->f_pos);
715 kunmap(tage->page);
716
717 if (rc != (int)tage->used) {
718 printk(KERN_WARNING "wanted to write %u but wrote "
719 "%d\n", tage->used, rc);
720 put_pages_back(&pc);
721 __LASSERT(list_empty(&pc.pc_pages));
722 break;
723 }
724 list_del(&tage->linkage);
725 cfs_tage_free(tage);
726 }
727 MMSPACE_CLOSE;
728 rc = vfs_fsync(filp, 1);
729 if (rc)
730 printk(KERN_ERR "sync returns %d\n", rc);
731 close:
732 filp_close(filp, NULL);
733 out:
734 cfs_tracefile_write_unlock();
735 return rc;
736 }
737
cfs_trace_flush_pages(void)738 void cfs_trace_flush_pages(void)
739 {
740 struct page_collection pc;
741 struct cfs_trace_page *tage;
742 struct cfs_trace_page *tmp;
743
744 spin_lock_init(&pc.pc_lock);
745
746 pc.pc_want_daemon_pages = 1;
747 collect_pages(&pc);
748 list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
749
750 __LASSERT_TAGE_INVARIANT(tage);
751
752 list_del(&tage->linkage);
753 cfs_tage_free(tage);
754 }
755 }
756
cfs_trace_copyin_string(char * knl_buffer,int knl_buffer_nob,const char __user * usr_buffer,int usr_buffer_nob)757 int cfs_trace_copyin_string(char *knl_buffer, int knl_buffer_nob,
758 const char __user *usr_buffer, int usr_buffer_nob)
759 {
760 int nob;
761
762 if (usr_buffer_nob > knl_buffer_nob)
763 return -EOVERFLOW;
764
765 if (copy_from_user((void *)knl_buffer,
766 usr_buffer, usr_buffer_nob))
767 return -EFAULT;
768
769 nob = strnlen(knl_buffer, usr_buffer_nob);
770 while (nob-- >= 0) /* strip trailing whitespace */
771 if (!isspace(knl_buffer[nob]))
772 break;
773
774 if (nob < 0) /* empty string */
775 return -EINVAL;
776
777 if (nob == knl_buffer_nob) /* no space to terminate */
778 return -EOVERFLOW;
779
780 knl_buffer[nob + 1] = 0; /* terminate */
781 return 0;
782 }
783 EXPORT_SYMBOL(cfs_trace_copyin_string);
784
cfs_trace_copyout_string(char __user * usr_buffer,int usr_buffer_nob,const char * knl_buffer,char * append)785 int cfs_trace_copyout_string(char __user *usr_buffer, int usr_buffer_nob,
786 const char *knl_buffer, char *append)
787 {
788 /* NB if 'append' != NULL, it's a single character to append to the
789 * copied out string - usually "\n", for /proc entries and "" (i.e. a
790 * terminating zero byte) for sysctl entries */
791 int nob = strlen(knl_buffer);
792
793 if (nob > usr_buffer_nob)
794 nob = usr_buffer_nob;
795
796 if (copy_to_user(usr_buffer, knl_buffer, nob))
797 return -EFAULT;
798
799 if (append != NULL && nob < usr_buffer_nob) {
800 if (copy_to_user(usr_buffer + nob, append, 1))
801 return -EFAULT;
802
803 nob++;
804 }
805
806 return nob;
807 }
808 EXPORT_SYMBOL(cfs_trace_copyout_string);
809
cfs_trace_allocate_string_buffer(char ** str,int nob)810 int cfs_trace_allocate_string_buffer(char **str, int nob)
811 {
812 if (nob > 2 * PAGE_CACHE_SIZE) /* string must be "sensible" */
813 return -EINVAL;
814
815 *str = kmalloc(nob, GFP_IOFS | __GFP_ZERO);
816 if (*str == NULL)
817 return -ENOMEM;
818
819 return 0;
820 }
821
cfs_trace_free_string_buffer(char * str,int nob)822 void cfs_trace_free_string_buffer(char *str, int nob)
823 {
824 kfree(str);
825 }
826
cfs_trace_dump_debug_buffer_usrstr(void __user * usr_str,int usr_str_nob)827 int cfs_trace_dump_debug_buffer_usrstr(void __user *usr_str, int usr_str_nob)
828 {
829 char *str;
830 int rc;
831
832 rc = cfs_trace_allocate_string_buffer(&str, usr_str_nob + 1);
833 if (rc != 0)
834 return rc;
835
836 rc = cfs_trace_copyin_string(str, usr_str_nob + 1,
837 usr_str, usr_str_nob);
838 if (rc != 0)
839 goto out;
840
841 if (str[0] != '/') {
842 rc = -EINVAL;
843 goto out;
844 }
845 rc = cfs_tracefile_dump_all_pages(str);
846 out:
847 cfs_trace_free_string_buffer(str, usr_str_nob + 1);
848 return rc;
849 }
850
cfs_trace_daemon_command(char * str)851 int cfs_trace_daemon_command(char *str)
852 {
853 int rc = 0;
854
855 cfs_tracefile_write_lock();
856
857 if (strcmp(str, "stop") == 0) {
858 cfs_tracefile_write_unlock();
859 cfs_trace_stop_thread();
860 cfs_tracefile_write_lock();
861 memset(cfs_tracefile, 0, sizeof(cfs_tracefile));
862
863 } else if (strncmp(str, "size=", 5) == 0) {
864 cfs_tracefile_size = simple_strtoul(str + 5, NULL, 0);
865 if (cfs_tracefile_size < 10 || cfs_tracefile_size > 20480)
866 cfs_tracefile_size = CFS_TRACEFILE_SIZE;
867 else
868 cfs_tracefile_size <<= 20;
869
870 } else if (strlen(str) >= sizeof(cfs_tracefile)) {
871 rc = -ENAMETOOLONG;
872 } else if (str[0] != '/') {
873 rc = -EINVAL;
874 } else {
875 strcpy(cfs_tracefile, str);
876
877 printk(KERN_INFO
878 "Lustre: debug daemon will attempt to start writing "
879 "to %s (%lukB max)\n", cfs_tracefile,
880 (long)(cfs_tracefile_size >> 10));
881
882 cfs_trace_start_thread();
883 }
884
885 cfs_tracefile_write_unlock();
886 return rc;
887 }
888
cfs_trace_daemon_command_usrstr(void __user * usr_str,int usr_str_nob)889 int cfs_trace_daemon_command_usrstr(void __user *usr_str, int usr_str_nob)
890 {
891 char *str;
892 int rc;
893
894 rc = cfs_trace_allocate_string_buffer(&str, usr_str_nob + 1);
895 if (rc != 0)
896 return rc;
897
898 rc = cfs_trace_copyin_string(str, usr_str_nob + 1,
899 usr_str, usr_str_nob);
900 if (rc == 0)
901 rc = cfs_trace_daemon_command(str);
902
903 cfs_trace_free_string_buffer(str, usr_str_nob + 1);
904 return rc;
905 }
906
cfs_trace_set_debug_mb(int mb)907 int cfs_trace_set_debug_mb(int mb)
908 {
909 int i;
910 int j;
911 int pages;
912 int limit = cfs_trace_max_debug_mb();
913 struct cfs_trace_cpu_data *tcd;
914
915 if (mb < num_possible_cpus()) {
916 printk(KERN_WARNING
917 "Lustre: %d MB is too small for debug buffer size, "
918 "setting it to %d MB.\n", mb, num_possible_cpus());
919 mb = num_possible_cpus();
920 }
921
922 if (mb > limit) {
923 printk(KERN_WARNING
924 "Lustre: %d MB is too large for debug buffer size, "
925 "setting it to %d MB.\n", mb, limit);
926 mb = limit;
927 }
928
929 mb /= num_possible_cpus();
930 pages = mb << (20 - PAGE_CACHE_SHIFT);
931
932 cfs_tracefile_write_lock();
933
934 cfs_tcd_for_each(tcd, i, j)
935 tcd->tcd_max_pages = (pages * tcd->tcd_pages_factor) / 100;
936
937 cfs_tracefile_write_unlock();
938
939 return 0;
940 }
941
cfs_trace_set_debug_mb_usrstr(void __user * usr_str,int usr_str_nob)942 int cfs_trace_set_debug_mb_usrstr(void __user *usr_str, int usr_str_nob)
943 {
944 char str[32];
945 int rc;
946
947 rc = cfs_trace_copyin_string(str, sizeof(str), usr_str, usr_str_nob);
948 if (rc < 0)
949 return rc;
950
951 return cfs_trace_set_debug_mb(simple_strtoul(str, NULL, 0));
952 }
953
cfs_trace_get_debug_mb(void)954 int cfs_trace_get_debug_mb(void)
955 {
956 int i;
957 int j;
958 struct cfs_trace_cpu_data *tcd;
959 int total_pages = 0;
960
961 cfs_tracefile_read_lock();
962
963 cfs_tcd_for_each(tcd, i, j)
964 total_pages += tcd->tcd_max_pages;
965
966 cfs_tracefile_read_unlock();
967
968 return (total_pages >> (20 - PAGE_CACHE_SHIFT)) + 1;
969 }
970
tracefiled(void * arg)971 static int tracefiled(void *arg)
972 {
973 struct page_collection pc;
974 struct tracefiled_ctl *tctl = arg;
975 struct cfs_trace_page *tage;
976 struct cfs_trace_page *tmp;
977 struct file *filp;
978 char *buf;
979 int last_loop = 0;
980 int rc;
981
982 DECL_MMSPACE;
983
984 /* we're started late enough that we pick up init's fs context */
985 /* this is so broken in uml? what on earth is going on? */
986
987 spin_lock_init(&pc.pc_lock);
988 complete(&tctl->tctl_start);
989
990 while (1) {
991 wait_queue_t __wait;
992
993 pc.pc_want_daemon_pages = 0;
994 collect_pages(&pc);
995 if (list_empty(&pc.pc_pages))
996 goto end_loop;
997
998 filp = NULL;
999 cfs_tracefile_read_lock();
1000 if (cfs_tracefile[0] != 0) {
1001 filp = filp_open(cfs_tracefile,
1002 O_CREAT | O_RDWR | O_LARGEFILE,
1003 0600);
1004 if (IS_ERR(filp)) {
1005 rc = PTR_ERR(filp);
1006 filp = NULL;
1007 printk(KERN_WARNING "couldn't open %s: "
1008 "%d\n", cfs_tracefile, rc);
1009 }
1010 }
1011 cfs_tracefile_read_unlock();
1012 if (filp == NULL) {
1013 put_pages_on_daemon_list(&pc);
1014 __LASSERT(list_empty(&pc.pc_pages));
1015 goto end_loop;
1016 }
1017
1018 MMSPACE_OPEN;
1019
1020 list_for_each_entry_safe(tage, tmp, &pc.pc_pages,
1021 linkage) {
1022 static loff_t f_pos;
1023
1024 __LASSERT_TAGE_INVARIANT(tage);
1025
1026 if (f_pos >= (off_t)cfs_tracefile_size)
1027 f_pos = 0;
1028 else if (f_pos > i_size_read(filp->f_dentry->d_inode))
1029 f_pos = i_size_read(filp->f_dentry->d_inode);
1030
1031 buf = kmap(tage->page);
1032 rc = vfs_write(filp, (__force const char __user *)buf,
1033 tage->used, &f_pos);
1034 kunmap(tage->page);
1035
1036 if (rc != (int)tage->used) {
1037 printk(KERN_WARNING "wanted to write %u "
1038 "but wrote %d\n", tage->used, rc);
1039 put_pages_back(&pc);
1040 __LASSERT(list_empty(&pc.pc_pages));
1041 }
1042 }
1043 MMSPACE_CLOSE;
1044
1045 filp_close(filp, NULL);
1046 put_pages_on_daemon_list(&pc);
1047 if (!list_empty(&pc.pc_pages)) {
1048 int i;
1049
1050 printk(KERN_ALERT "Lustre: trace pages aren't "
1051 " empty\n");
1052 printk(KERN_ERR "total cpus(%d): ",
1053 num_possible_cpus());
1054 for (i = 0; i < num_possible_cpus(); i++)
1055 if (cpu_online(i))
1056 printk(KERN_ERR "%d(on) ", i);
1057 else
1058 printk(KERN_ERR "%d(off) ", i);
1059 printk(KERN_ERR "\n");
1060
1061 i = 0;
1062 list_for_each_entry_safe(tage, tmp, &pc.pc_pages,
1063 linkage)
1064 printk(KERN_ERR "page %d belongs to cpu "
1065 "%d\n", ++i, tage->cpu);
1066 printk(KERN_ERR "There are %d pages unwritten\n",
1067 i);
1068 }
1069 __LASSERT(list_empty(&pc.pc_pages));
1070 end_loop:
1071 if (atomic_read(&tctl->tctl_shutdown)) {
1072 if (last_loop == 0) {
1073 last_loop = 1;
1074 continue;
1075 } else {
1076 break;
1077 }
1078 }
1079 init_waitqueue_entry(&__wait, current);
1080 add_wait_queue(&tctl->tctl_waitq, &__wait);
1081 set_current_state(TASK_INTERRUPTIBLE);
1082 schedule_timeout(cfs_time_seconds(1));
1083 remove_wait_queue(&tctl->tctl_waitq, &__wait);
1084 }
1085 complete(&tctl->tctl_stop);
1086 return 0;
1087 }
1088
cfs_trace_start_thread(void)1089 int cfs_trace_start_thread(void)
1090 {
1091 struct tracefiled_ctl *tctl = &trace_tctl;
1092 int rc = 0;
1093
1094 mutex_lock(&cfs_trace_thread_mutex);
1095 if (thread_running)
1096 goto out;
1097
1098 init_completion(&tctl->tctl_start);
1099 init_completion(&tctl->tctl_stop);
1100 init_waitqueue_head(&tctl->tctl_waitq);
1101 atomic_set(&tctl->tctl_shutdown, 0);
1102
1103 if (IS_ERR(kthread_run(tracefiled, tctl, "ktracefiled"))) {
1104 rc = -ECHILD;
1105 goto out;
1106 }
1107
1108 wait_for_completion(&tctl->tctl_start);
1109 thread_running = 1;
1110 out:
1111 mutex_unlock(&cfs_trace_thread_mutex);
1112 return rc;
1113 }
1114
cfs_trace_stop_thread(void)1115 void cfs_trace_stop_thread(void)
1116 {
1117 struct tracefiled_ctl *tctl = &trace_tctl;
1118
1119 mutex_lock(&cfs_trace_thread_mutex);
1120 if (thread_running) {
1121 printk(KERN_INFO
1122 "Lustre: shutting down debug daemon thread...\n");
1123 atomic_set(&tctl->tctl_shutdown, 1);
1124 wait_for_completion(&tctl->tctl_stop);
1125 thread_running = 0;
1126 }
1127 mutex_unlock(&cfs_trace_thread_mutex);
1128 }
1129
cfs_tracefile_init(int max_pages)1130 int cfs_tracefile_init(int max_pages)
1131 {
1132 struct cfs_trace_cpu_data *tcd;
1133 int i;
1134 int j;
1135 int rc;
1136 int factor;
1137
1138 rc = cfs_tracefile_init_arch();
1139 if (rc != 0)
1140 return rc;
1141
1142 cfs_tcd_for_each(tcd, i, j) {
1143 /* tcd_pages_factor is initialized int tracefile_init_arch. */
1144 factor = tcd->tcd_pages_factor;
1145 INIT_LIST_HEAD(&tcd->tcd_pages);
1146 INIT_LIST_HEAD(&tcd->tcd_stock_pages);
1147 INIT_LIST_HEAD(&tcd->tcd_daemon_pages);
1148 tcd->tcd_cur_pages = 0;
1149 tcd->tcd_cur_stock_pages = 0;
1150 tcd->tcd_cur_daemon_pages = 0;
1151 tcd->tcd_max_pages = (max_pages * factor) / 100;
1152 LASSERT(tcd->tcd_max_pages > 0);
1153 tcd->tcd_shutting_down = 0;
1154 }
1155
1156 return 0;
1157 }
1158
trace_cleanup_on_all_cpus(void)1159 static void trace_cleanup_on_all_cpus(void)
1160 {
1161 struct cfs_trace_cpu_data *tcd;
1162 struct cfs_trace_page *tage;
1163 struct cfs_trace_page *tmp;
1164 int i, cpu;
1165
1166 for_each_possible_cpu(cpu) {
1167 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
1168 tcd->tcd_shutting_down = 1;
1169
1170 list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages,
1171 linkage) {
1172 __LASSERT_TAGE_INVARIANT(tage);
1173
1174 list_del(&tage->linkage);
1175 cfs_tage_free(tage);
1176 }
1177
1178 tcd->tcd_cur_pages = 0;
1179 }
1180 }
1181 }
1182
cfs_trace_cleanup(void)1183 static void cfs_trace_cleanup(void)
1184 {
1185 struct page_collection pc;
1186
1187 INIT_LIST_HEAD(&pc.pc_pages);
1188 spin_lock_init(&pc.pc_lock);
1189
1190 trace_cleanup_on_all_cpus();
1191
1192 cfs_tracefile_fini_arch();
1193 }
1194
cfs_tracefile_exit(void)1195 void cfs_tracefile_exit(void)
1196 {
1197 cfs_trace_stop_thread();
1198 cfs_trace_cleanup();
1199 }
1200