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Merge tag 'xfs-for-linus-4.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git...
[deliverable/linux.git] / drivers / staging / lustre / lustre / libcfs / tracefile.c
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 *
63 cfs_tage_from_list(struct list_head *list)
64 {
65 return list_entry(list, struct cfs_trace_page, linkage);
66 }
67
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
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
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
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 *
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
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
203 list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages, linkage) {
204 if (pgcount-- == 0)
205 break;
206
207 list_move_tail(&tage->linkage, &pc.pc_pages);
208 tcd->tcd_cur_pages--;
209 }
210 put_pages_on_tcd_daemon_list(&pc, tcd);
211 }
212
213 /* return a page that has 'len' bytes left at the end */
214 static struct cfs_trace_page *cfs_trace_get_tage(struct cfs_trace_cpu_data *tcd,
215 unsigned long len)
216 {
217 struct cfs_trace_page *tage;
218
219 /*
220 * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
221 * from here: this will lead to infinite recursion.
222 */
223
224 if (len > PAGE_CACHE_SIZE) {
225 pr_err("cowardly refusing to write %lu bytes in a page\n", len);
226 return NULL;
227 }
228
229 tage = cfs_trace_get_tage_try(tcd, len);
230 if (tage != NULL)
231 return tage;
232 if (thread_running)
233 cfs_tcd_shrink(tcd);
234 if (tcd->tcd_cur_pages > 0) {
235 tage = cfs_tage_from_list(tcd->tcd_pages.next);
236 tage->used = 0;
237 cfs_tage_to_tail(tage, &tcd->tcd_pages);
238 }
239 return tage;
240 }
241
242 int libcfs_debug_msg(struct libcfs_debug_msg_data *msgdata,
243 const char *format, ...)
244 {
245 va_list args;
246 int rc;
247
248 va_start(args, format);
249 rc = libcfs_debug_vmsg2(msgdata, format, args, NULL);
250 va_end(args);
251
252 return rc;
253 }
254 EXPORT_SYMBOL(libcfs_debug_msg);
255
256 int libcfs_debug_vmsg2(struct libcfs_debug_msg_data *msgdata,
257 const char *format1, va_list args,
258 const char *format2, ...)
259 {
260 struct cfs_trace_cpu_data *tcd = NULL;
261 struct ptldebug_header header = {0};
262 struct cfs_trace_page *tage;
263 /* string_buf is used only if tcd != NULL, and is always set then */
264 char *string_buf = NULL;
265 char *debug_buf;
266 int known_size;
267 int needed = 85; /* average message length */
268 int max_nob;
269 va_list ap;
270 int depth;
271 int i;
272 int remain;
273 int mask = msgdata->msg_mask;
274 const char *file = kbasename(msgdata->msg_file);
275 struct cfs_debug_limit_state *cdls = msgdata->msg_cdls;
276
277 tcd = cfs_trace_get_tcd();
278
279 /* cfs_trace_get_tcd() grabs a lock, which disables preemption and
280 * pins us to a particular CPU. This avoids an smp_processor_id()
281 * warning on Linux when debugging is enabled. */
282 cfs_set_ptldebug_header(&header, msgdata, CDEBUG_STACK());
283
284 if (tcd == NULL) /* arch may not log in IRQ context */
285 goto console;
286
287 if (tcd->tcd_cur_pages == 0)
288 header.ph_flags |= PH_FLAG_FIRST_RECORD;
289
290 if (tcd->tcd_shutting_down) {
291 cfs_trace_put_tcd(tcd);
292 tcd = NULL;
293 goto console;
294 }
295
296 depth = __current_nesting_level();
297 known_size = strlen(file) + 1 + depth;
298 if (msgdata->msg_fn)
299 known_size += strlen(msgdata->msg_fn) + 1;
300
301 if (libcfs_debug_binary)
302 known_size += sizeof(header);
303
304 /*/
305 * '2' used because vsnprintf return real size required for output
306 * _without_ terminating NULL.
307 * if needed is to small for this format.
308 */
309 for (i = 0; i < 2; i++) {
310 tage = cfs_trace_get_tage(tcd, needed + known_size + 1);
311 if (tage == NULL) {
312 if (needed + known_size > PAGE_CACHE_SIZE)
313 mask |= D_ERROR;
314
315 cfs_trace_put_tcd(tcd);
316 tcd = NULL;
317 goto console;
318 }
319
320 string_buf = (char *)page_address(tage->page) +
321 tage->used + known_size;
322
323 max_nob = PAGE_CACHE_SIZE - tage->used - known_size;
324 if (max_nob <= 0) {
325 printk(KERN_EMERG "negative max_nob: %d\n",
326 max_nob);
327 mask |= D_ERROR;
328 cfs_trace_put_tcd(tcd);
329 tcd = NULL;
330 goto console;
331 }
332
333 needed = 0;
334 if (format1) {
335 va_copy(ap, args);
336 needed = vsnprintf(string_buf, max_nob, format1, ap);
337 va_end(ap);
338 }
339
340 if (format2) {
341 remain = max_nob - needed;
342 if (remain < 0)
343 remain = 0;
344
345 va_start(ap, format2);
346 needed += vsnprintf(string_buf + needed, remain,
347 format2, ap);
348 va_end(ap);
349 }
350
351 if (needed < max_nob) /* well. printing ok.. */
352 break;
353 }
354
355 if (*(string_buf+needed-1) != '\n')
356 printk(KERN_INFO "format at %s:%d:%s doesn't end in newline\n",
357 file, msgdata->msg_line, msgdata->msg_fn);
358
359 header.ph_len = known_size + needed;
360 debug_buf = (char *)page_address(tage->page) + tage->used;
361
362 if (libcfs_debug_binary) {
363 memcpy(debug_buf, &header, sizeof(header));
364 tage->used += sizeof(header);
365 debug_buf += sizeof(header);
366 }
367
368 /* indent message according to the nesting level */
369 while (depth-- > 0) {
370 *(debug_buf++) = '.';
371 ++tage->used;
372 }
373
374 strcpy(debug_buf, file);
375 tage->used += strlen(file) + 1;
376 debug_buf += strlen(file) + 1;
377
378 if (msgdata->msg_fn) {
379 strcpy(debug_buf, msgdata->msg_fn);
380 tage->used += strlen(msgdata->msg_fn) + 1;
381 debug_buf += strlen(msgdata->msg_fn) + 1;
382 }
383
384 __LASSERT(debug_buf == string_buf);
385
386 tage->used += needed;
387 __LASSERT (tage->used <= PAGE_CACHE_SIZE);
388
389 console:
390 if ((mask & libcfs_printk) == 0) {
391 /* no console output requested */
392 if (tcd != NULL)
393 cfs_trace_put_tcd(tcd);
394 return 1;
395 }
396
397 if (cdls != NULL) {
398 if (libcfs_console_ratelimit &&
399 cdls->cdls_next != 0 && /* not first time ever */
400 !cfs_time_after(cfs_time_current(), cdls->cdls_next)) {
401 /* skipping a console message */
402 cdls->cdls_count++;
403 if (tcd != NULL)
404 cfs_trace_put_tcd(tcd);
405 return 1;
406 }
407
408 if (cfs_time_after(cfs_time_current(), cdls->cdls_next +
409 libcfs_console_max_delay
410 + cfs_time_seconds(10))) {
411 /* last timeout was a long time ago */
412 cdls->cdls_delay /= libcfs_console_backoff * 4;
413 } else {
414 cdls->cdls_delay *= libcfs_console_backoff;
415 }
416
417 if (cdls->cdls_delay < libcfs_console_min_delay)
418 cdls->cdls_delay = libcfs_console_min_delay;
419 else if (cdls->cdls_delay > libcfs_console_max_delay)
420 cdls->cdls_delay = libcfs_console_max_delay;
421
422 /* ensure cdls_next is never zero after it's been seen */
423 cdls->cdls_next = (cfs_time_current() + cdls->cdls_delay) | 1;
424 }
425
426 if (tcd != NULL) {
427 cfs_print_to_console(&header, mask, string_buf, needed, file,
428 msgdata->msg_fn);
429 cfs_trace_put_tcd(tcd);
430 } else {
431 string_buf = cfs_trace_get_console_buffer();
432
433 needed = 0;
434 if (format1 != NULL) {
435 va_copy(ap, args);
436 needed = vsnprintf(string_buf,
437 CFS_TRACE_CONSOLE_BUFFER_SIZE,
438 format1, ap);
439 va_end(ap);
440 }
441 if (format2 != NULL) {
442 remain = CFS_TRACE_CONSOLE_BUFFER_SIZE - needed;
443 if (remain > 0) {
444 va_start(ap, format2);
445 needed += vsnprintf(string_buf+needed, remain,
446 format2, ap);
447 va_end(ap);
448 }
449 }
450 cfs_print_to_console(&header, mask,
451 string_buf, needed, file, msgdata->msg_fn);
452
453 put_cpu();
454 }
455
456 if (cdls != NULL && cdls->cdls_count != 0) {
457 string_buf = cfs_trace_get_console_buffer();
458
459 needed = snprintf(string_buf, CFS_TRACE_CONSOLE_BUFFER_SIZE,
460 "Skipped %d previous similar message%s\n",
461 cdls->cdls_count,
462 (cdls->cdls_count > 1) ? "s" : "");
463
464 cfs_print_to_console(&header, mask,
465 string_buf, needed, file, msgdata->msg_fn);
466
467 put_cpu();
468 cdls->cdls_count = 0;
469 }
470
471 return 0;
472 }
473 EXPORT_SYMBOL(libcfs_debug_vmsg2);
474
475 void
476 cfs_trace_assertion_failed(const char *str,
477 struct libcfs_debug_msg_data *msgdata)
478 {
479 struct ptldebug_header hdr;
480
481 libcfs_panic_in_progress = 1;
482 libcfs_catastrophe = 1;
483 mb();
484
485 cfs_set_ptldebug_header(&hdr, msgdata, CDEBUG_STACK());
486
487 cfs_print_to_console(&hdr, D_EMERG, str, strlen(str),
488 msgdata->msg_file, msgdata->msg_fn);
489
490 panic("Lustre debug assertion failure\n");
491
492 /* not reached */
493 }
494
495 static void
496 panic_collect_pages(struct page_collection *pc)
497 {
498 /* Do the collect_pages job on a single CPU: assumes that all other
499 * CPUs have been stopped during a panic. If this isn't true for some
500 * arch, this will have to be implemented separately in each arch. */
501 int i;
502 int j;
503 struct cfs_trace_cpu_data *tcd;
504
505 INIT_LIST_HEAD(&pc->pc_pages);
506
507 cfs_tcd_for_each(tcd, i, j) {
508 list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
509 tcd->tcd_cur_pages = 0;
510
511 if (pc->pc_want_daemon_pages) {
512 list_splice_init(&tcd->tcd_daemon_pages,
513 &pc->pc_pages);
514 tcd->tcd_cur_daemon_pages = 0;
515 }
516 }
517 }
518
519 static void collect_pages_on_all_cpus(struct page_collection *pc)
520 {
521 struct cfs_trace_cpu_data *tcd;
522 int i, cpu;
523
524 for_each_possible_cpu(cpu) {
525 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
526 list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
527 tcd->tcd_cur_pages = 0;
528 if (pc->pc_want_daemon_pages) {
529 list_splice_init(&tcd->tcd_daemon_pages,
530 &pc->pc_pages);
531 tcd->tcd_cur_daemon_pages = 0;
532 }
533 }
534 }
535 }
536
537 static void collect_pages(struct page_collection *pc)
538 {
539 INIT_LIST_HEAD(&pc->pc_pages);
540
541 if (libcfs_panic_in_progress)
542 panic_collect_pages(pc);
543 else
544 collect_pages_on_all_cpus(pc);
545 }
546
547 static void put_pages_back_on_all_cpus(struct page_collection *pc)
548 {
549 struct cfs_trace_cpu_data *tcd;
550 struct list_head *cur_head;
551 struct cfs_trace_page *tage;
552 struct cfs_trace_page *tmp;
553 int i, cpu;
554
555 for_each_possible_cpu(cpu) {
556 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
557 cur_head = tcd->tcd_pages.next;
558
559 list_for_each_entry_safe(tage, tmp, &pc->pc_pages,
560 linkage) {
561
562 __LASSERT_TAGE_INVARIANT(tage);
563
564 if (tage->cpu != cpu || tage->type != i)
565 continue;
566
567 cfs_tage_to_tail(tage, cur_head);
568 tcd->tcd_cur_pages++;
569 }
570 }
571 }
572 }
573
574 static void put_pages_back(struct page_collection *pc)
575 {
576 if (!libcfs_panic_in_progress)
577 put_pages_back_on_all_cpus(pc);
578 }
579
580 /* Add pages to a per-cpu debug daemon ringbuffer. This buffer makes sure that
581 * we have a good amount of data at all times for dumping during an LBUG, even
582 * if we have been steadily writing (and otherwise discarding) pages via the
583 * debug daemon. */
584 static void put_pages_on_tcd_daemon_list(struct page_collection *pc,
585 struct cfs_trace_cpu_data *tcd)
586 {
587 struct cfs_trace_page *tage;
588 struct cfs_trace_page *tmp;
589
590 list_for_each_entry_safe(tage, tmp, &pc->pc_pages, linkage) {
591
592 __LASSERT_TAGE_INVARIANT(tage);
593
594 if (tage->cpu != tcd->tcd_cpu || tage->type != tcd->tcd_type)
595 continue;
596
597 cfs_tage_to_tail(tage, &tcd->tcd_daemon_pages);
598 tcd->tcd_cur_daemon_pages++;
599
600 if (tcd->tcd_cur_daemon_pages > tcd->tcd_max_pages) {
601 struct cfs_trace_page *victim;
602
603 __LASSERT(!list_empty(&tcd->tcd_daemon_pages));
604 victim = cfs_tage_from_list(tcd->tcd_daemon_pages.next);
605
606 __LASSERT_TAGE_INVARIANT(victim);
607
608 list_del(&victim->linkage);
609 cfs_tage_free(victim);
610 tcd->tcd_cur_daemon_pages--;
611 }
612 }
613 }
614
615 static void put_pages_on_daemon_list(struct page_collection *pc)
616 {
617 struct cfs_trace_cpu_data *tcd;
618 int i, cpu;
619
620 for_each_possible_cpu(cpu) {
621 cfs_tcd_for_each_type_lock(tcd, i, cpu)
622 put_pages_on_tcd_daemon_list(pc, tcd);
623 }
624 }
625
626 void cfs_trace_debug_print(void)
627 {
628 struct page_collection pc;
629 struct cfs_trace_page *tage;
630 struct cfs_trace_page *tmp;
631
632 pc.pc_want_daemon_pages = 1;
633 collect_pages(&pc);
634 list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
635 char *p, *file, *fn;
636 struct page *page;
637
638 __LASSERT_TAGE_INVARIANT(tage);
639
640 page = tage->page;
641 p = page_address(page);
642 while (p < ((char *)page_address(page) + tage->used)) {
643 struct ptldebug_header *hdr;
644 int len;
645
646 hdr = (void *)p;
647 p += sizeof(*hdr);
648 file = p;
649 p += strlen(file) + 1;
650 fn = p;
651 p += strlen(fn) + 1;
652 len = hdr->ph_len - (int)(p - (char *)hdr);
653
654 cfs_print_to_console(hdr, D_EMERG, p, len, file, fn);
655
656 p += len;
657 }
658
659 list_del(&tage->linkage);
660 cfs_tage_free(tage);
661 }
662 }
663
664 int cfs_tracefile_dump_all_pages(char *filename)
665 {
666 struct page_collection pc;
667 struct file *filp;
668 struct cfs_trace_page *tage;
669 struct cfs_trace_page *tmp;
670 char *buf;
671 int rc;
672
673 DECL_MMSPACE;
674
675 cfs_tracefile_write_lock();
676
677 filp = filp_open(filename, O_CREAT|O_EXCL|O_WRONLY|O_LARGEFILE, 0600);
678 if (IS_ERR(filp)) {
679 rc = PTR_ERR(filp);
680 filp = NULL;
681 pr_err("LustreError: can't open %s for dump: rc %d\n",
682 filename, rc);
683 goto out;
684 }
685
686 pc.pc_want_daemon_pages = 1;
687 collect_pages(&pc);
688 if (list_empty(&pc.pc_pages)) {
689 rc = 0;
690 goto close;
691 }
692
693 /* ok, for now, just write the pages. in the future we'll be building
694 * iobufs with the pages and calling generic_direct_IO */
695 MMSPACE_OPEN;
696 list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
697
698 __LASSERT_TAGE_INVARIANT(tage);
699
700 buf = kmap(tage->page);
701 rc = vfs_write(filp, (__force const char __user *)buf,
702 tage->used, &filp->f_pos);
703 kunmap(tage->page);
704
705 if (rc != (int)tage->used) {
706 printk(KERN_WARNING "wanted to write %u but wrote %d\n",
707 tage->used, rc);
708 put_pages_back(&pc);
709 __LASSERT(list_empty(&pc.pc_pages));
710 break;
711 }
712 list_del(&tage->linkage);
713 cfs_tage_free(tage);
714 }
715 MMSPACE_CLOSE;
716 rc = vfs_fsync(filp, 1);
717 if (rc)
718 pr_err("sync returns %d\n", rc);
719 close:
720 filp_close(filp, NULL);
721 out:
722 cfs_tracefile_write_unlock();
723 return rc;
724 }
725
726 void cfs_trace_flush_pages(void)
727 {
728 struct page_collection pc;
729 struct cfs_trace_page *tage;
730 struct cfs_trace_page *tmp;
731
732 pc.pc_want_daemon_pages = 1;
733 collect_pages(&pc);
734 list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
735
736 __LASSERT_TAGE_INVARIANT(tage);
737
738 list_del(&tage->linkage);
739 cfs_tage_free(tage);
740 }
741 }
742
743 int cfs_trace_copyin_string(char *knl_buffer, int knl_buffer_nob,
744 const char __user *usr_buffer, int usr_buffer_nob)
745 {
746 int nob;
747
748 if (usr_buffer_nob > knl_buffer_nob)
749 return -EOVERFLOW;
750
751 if (copy_from_user((void *)knl_buffer,
752 usr_buffer, usr_buffer_nob))
753 return -EFAULT;
754
755 nob = strnlen(knl_buffer, usr_buffer_nob);
756 while (nob-- >= 0) /* strip trailing whitespace */
757 if (!isspace(knl_buffer[nob]))
758 break;
759
760 if (nob < 0) /* empty string */
761 return -EINVAL;
762
763 if (nob == knl_buffer_nob) /* no space to terminate */
764 return -EOVERFLOW;
765
766 knl_buffer[nob + 1] = 0; /* terminate */
767 return 0;
768 }
769 EXPORT_SYMBOL(cfs_trace_copyin_string);
770
771 int cfs_trace_copyout_string(char __user *usr_buffer, int usr_buffer_nob,
772 const char *knl_buffer, char *append)
773 {
774 /* NB if 'append' != NULL, it's a single character to append to the
775 * copied out string - usually "\n", for /proc entries and "" (i.e. a
776 * terminating zero byte) for sysctl entries */
777 int nob = strlen(knl_buffer);
778
779 if (nob > usr_buffer_nob)
780 nob = usr_buffer_nob;
781
782 if (copy_to_user(usr_buffer, knl_buffer, nob))
783 return -EFAULT;
784
785 if (append != NULL && nob < usr_buffer_nob) {
786 if (copy_to_user(usr_buffer + nob, append, 1))
787 return -EFAULT;
788
789 nob++;
790 }
791
792 return nob;
793 }
794 EXPORT_SYMBOL(cfs_trace_copyout_string);
795
796 int cfs_trace_allocate_string_buffer(char **str, int nob)
797 {
798 if (nob > 2 * PAGE_CACHE_SIZE) /* string must be "sensible" */
799 return -EINVAL;
800
801 *str = kmalloc(nob, GFP_KERNEL | __GFP_ZERO);
802 if (*str == NULL)
803 return -ENOMEM;
804
805 return 0;
806 }
807
808 int cfs_trace_dump_debug_buffer_usrstr(void __user *usr_str, int usr_str_nob)
809 {
810 char *str;
811 int rc;
812
813 rc = cfs_trace_allocate_string_buffer(&str, usr_str_nob + 1);
814 if (rc != 0)
815 return rc;
816
817 rc = cfs_trace_copyin_string(str, usr_str_nob + 1,
818 usr_str, usr_str_nob);
819 if (rc != 0)
820 goto out;
821
822 if (str[0] != '/') {
823 rc = -EINVAL;
824 goto out;
825 }
826 rc = cfs_tracefile_dump_all_pages(str);
827 out:
828 kfree(str);
829 return rc;
830 }
831
832 int cfs_trace_daemon_command(char *str)
833 {
834 int rc = 0;
835
836 cfs_tracefile_write_lock();
837
838 if (strcmp(str, "stop") == 0) {
839 cfs_tracefile_write_unlock();
840 cfs_trace_stop_thread();
841 cfs_tracefile_write_lock();
842 memset(cfs_tracefile, 0, sizeof(cfs_tracefile));
843
844 } else if (strncmp(str, "size=", 5) == 0) {
845 cfs_tracefile_size = simple_strtoul(str + 5, NULL, 0);
846 if (cfs_tracefile_size < 10 || cfs_tracefile_size > 20480)
847 cfs_tracefile_size = CFS_TRACEFILE_SIZE;
848 else
849 cfs_tracefile_size <<= 20;
850
851 } else if (strlen(str) >= sizeof(cfs_tracefile)) {
852 rc = -ENAMETOOLONG;
853 } else if (str[0] != '/') {
854 rc = -EINVAL;
855 } else {
856 strcpy(cfs_tracefile, str);
857
858 printk(KERN_INFO
859 "Lustre: debug daemon will attempt to start writing to %s (%lukB max)\n",
860 cfs_tracefile,
861 (long)(cfs_tracefile_size >> 10));
862
863 cfs_trace_start_thread();
864 }
865
866 cfs_tracefile_write_unlock();
867 return rc;
868 }
869
870 int cfs_trace_daemon_command_usrstr(void __user *usr_str, int usr_str_nob)
871 {
872 char *str;
873 int rc;
874
875 rc = cfs_trace_allocate_string_buffer(&str, usr_str_nob + 1);
876 if (rc != 0)
877 return rc;
878
879 rc = cfs_trace_copyin_string(str, usr_str_nob + 1,
880 usr_str, usr_str_nob);
881 if (rc == 0)
882 rc = cfs_trace_daemon_command(str);
883
884 kfree(str);
885 return rc;
886 }
887
888 int cfs_trace_set_debug_mb(int mb)
889 {
890 int i;
891 int j;
892 int pages;
893 int limit = cfs_trace_max_debug_mb();
894 struct cfs_trace_cpu_data *tcd;
895
896 if (mb < num_possible_cpus()) {
897 printk(KERN_WARNING
898 "Lustre: %d MB is too small for debug buffer size, setting it to %d MB.\n",
899 mb, num_possible_cpus());
900 mb = num_possible_cpus();
901 }
902
903 if (mb > limit) {
904 printk(KERN_WARNING
905 "Lustre: %d MB is too large for debug buffer size, setting it to %d MB.\n",
906 mb, limit);
907 mb = limit;
908 }
909
910 mb /= num_possible_cpus();
911 pages = mb << (20 - PAGE_CACHE_SHIFT);
912
913 cfs_tracefile_write_lock();
914
915 cfs_tcd_for_each(tcd, i, j)
916 tcd->tcd_max_pages = (pages * tcd->tcd_pages_factor) / 100;
917
918 cfs_tracefile_write_unlock();
919
920 return 0;
921 }
922
923 int cfs_trace_get_debug_mb(void)
924 {
925 int i;
926 int j;
927 struct cfs_trace_cpu_data *tcd;
928 int total_pages = 0;
929
930 cfs_tracefile_read_lock();
931
932 cfs_tcd_for_each(tcd, i, j)
933 total_pages += tcd->tcd_max_pages;
934
935 cfs_tracefile_read_unlock();
936
937 return (total_pages >> (20 - PAGE_CACHE_SHIFT)) + 1;
938 }
939
940 static int tracefiled(void *arg)
941 {
942 struct page_collection pc;
943 struct tracefiled_ctl *tctl = arg;
944 struct cfs_trace_page *tage;
945 struct cfs_trace_page *tmp;
946 struct file *filp;
947 char *buf;
948 int last_loop = 0;
949 int rc;
950
951 DECL_MMSPACE;
952
953 /* we're started late enough that we pick up init's fs context */
954 /* this is so broken in uml? what on earth is going on? */
955
956 complete(&tctl->tctl_start);
957
958 while (1) {
959 wait_queue_t __wait;
960
961 pc.pc_want_daemon_pages = 0;
962 collect_pages(&pc);
963 if (list_empty(&pc.pc_pages))
964 goto end_loop;
965
966 filp = NULL;
967 cfs_tracefile_read_lock();
968 if (cfs_tracefile[0] != 0) {
969 filp = filp_open(cfs_tracefile,
970 O_CREAT | O_RDWR | O_LARGEFILE,
971 0600);
972 if (IS_ERR(filp)) {
973 rc = PTR_ERR(filp);
974 filp = NULL;
975 printk(KERN_WARNING "couldn't open %s: %d\n",
976 cfs_tracefile, rc);
977 }
978 }
979 cfs_tracefile_read_unlock();
980 if (filp == NULL) {
981 put_pages_on_daemon_list(&pc);
982 __LASSERT(list_empty(&pc.pc_pages));
983 goto end_loop;
984 }
985
986 MMSPACE_OPEN;
987
988 list_for_each_entry_safe(tage, tmp, &pc.pc_pages,
989 linkage) {
990 static loff_t f_pos;
991
992 __LASSERT_TAGE_INVARIANT(tage);
993
994 if (f_pos >= (off_t)cfs_tracefile_size)
995 f_pos = 0;
996 else if (f_pos > i_size_read(file_inode(filp)))
997 f_pos = i_size_read(file_inode(filp));
998
999 buf = kmap(tage->page);
1000 rc = vfs_write(filp, (__force const char __user *)buf,
1001 tage->used, &f_pos);
1002 kunmap(tage->page);
1003
1004 if (rc != (int)tage->used) {
1005 printk(KERN_WARNING "wanted to write %u but wrote %d\n",
1006 tage->used, rc);
1007 put_pages_back(&pc);
1008 __LASSERT(list_empty(&pc.pc_pages));
1009 break;
1010 }
1011 }
1012 MMSPACE_CLOSE;
1013
1014 filp_close(filp, NULL);
1015 put_pages_on_daemon_list(&pc);
1016 if (!list_empty(&pc.pc_pages)) {
1017 int i;
1018
1019 printk(KERN_ALERT "Lustre: trace pages aren't empty\n");
1020 pr_err("total cpus(%d): ",
1021 num_possible_cpus());
1022 for (i = 0; i < num_possible_cpus(); i++)
1023 if (cpu_online(i))
1024 pr_cont("%d(on) ", i);
1025 else
1026 pr_cont("%d(off) ", i);
1027 pr_cont("\n");
1028
1029 i = 0;
1030 list_for_each_entry_safe(tage, tmp, &pc.pc_pages,
1031 linkage)
1032 pr_err("page %d belongs to cpu %d\n",
1033 ++i, tage->cpu);
1034 pr_err("There are %d pages unwritten\n", i);
1035 }
1036 __LASSERT(list_empty(&pc.pc_pages));
1037 end_loop:
1038 if (atomic_read(&tctl->tctl_shutdown)) {
1039 if (last_loop == 0) {
1040 last_loop = 1;
1041 continue;
1042 } else {
1043 break;
1044 }
1045 }
1046 init_waitqueue_entry(&__wait, current);
1047 add_wait_queue(&tctl->tctl_waitq, &__wait);
1048 set_current_state(TASK_INTERRUPTIBLE);
1049 schedule_timeout(cfs_time_seconds(1));
1050 remove_wait_queue(&tctl->tctl_waitq, &__wait);
1051 }
1052 complete(&tctl->tctl_stop);
1053 return 0;
1054 }
1055
1056 int cfs_trace_start_thread(void)
1057 {
1058 struct tracefiled_ctl *tctl = &trace_tctl;
1059 int rc = 0;
1060
1061 mutex_lock(&cfs_trace_thread_mutex);
1062 if (thread_running)
1063 goto out;
1064
1065 init_completion(&tctl->tctl_start);
1066 init_completion(&tctl->tctl_stop);
1067 init_waitqueue_head(&tctl->tctl_waitq);
1068 atomic_set(&tctl->tctl_shutdown, 0);
1069
1070 if (IS_ERR(kthread_run(tracefiled, tctl, "ktracefiled"))) {
1071 rc = -ECHILD;
1072 goto out;
1073 }
1074
1075 wait_for_completion(&tctl->tctl_start);
1076 thread_running = 1;
1077 out:
1078 mutex_unlock(&cfs_trace_thread_mutex);
1079 return rc;
1080 }
1081
1082 void cfs_trace_stop_thread(void)
1083 {
1084 struct tracefiled_ctl *tctl = &trace_tctl;
1085
1086 mutex_lock(&cfs_trace_thread_mutex);
1087 if (thread_running) {
1088 printk(KERN_INFO
1089 "Lustre: shutting down debug daemon thread...\n");
1090 atomic_set(&tctl->tctl_shutdown, 1);
1091 wait_for_completion(&tctl->tctl_stop);
1092 thread_running = 0;
1093 }
1094 mutex_unlock(&cfs_trace_thread_mutex);
1095 }
1096
1097 int cfs_tracefile_init(int max_pages)
1098 {
1099 struct cfs_trace_cpu_data *tcd;
1100 int i;
1101 int j;
1102 int rc;
1103 int factor;
1104
1105 rc = cfs_tracefile_init_arch();
1106 if (rc != 0)
1107 return rc;
1108
1109 cfs_tcd_for_each(tcd, i, j) {
1110 /* tcd_pages_factor is initialized int tracefile_init_arch. */
1111 factor = tcd->tcd_pages_factor;
1112 INIT_LIST_HEAD(&tcd->tcd_pages);
1113 INIT_LIST_HEAD(&tcd->tcd_stock_pages);
1114 INIT_LIST_HEAD(&tcd->tcd_daemon_pages);
1115 tcd->tcd_cur_pages = 0;
1116 tcd->tcd_cur_stock_pages = 0;
1117 tcd->tcd_cur_daemon_pages = 0;
1118 tcd->tcd_max_pages = (max_pages * factor) / 100;
1119 LASSERT(tcd->tcd_max_pages > 0);
1120 tcd->tcd_shutting_down = 0;
1121 }
1122
1123 return 0;
1124 }
1125
1126 static void trace_cleanup_on_all_cpus(void)
1127 {
1128 struct cfs_trace_cpu_data *tcd;
1129 struct cfs_trace_page *tage;
1130 struct cfs_trace_page *tmp;
1131 int i, cpu;
1132
1133 for_each_possible_cpu(cpu) {
1134 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
1135 tcd->tcd_shutting_down = 1;
1136
1137 list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages,
1138 linkage) {
1139 __LASSERT_TAGE_INVARIANT(tage);
1140
1141 list_del(&tage->linkage);
1142 cfs_tage_free(tage);
1143 }
1144
1145 tcd->tcd_cur_pages = 0;
1146 }
1147 }
1148 }
1149
1150 static void cfs_trace_cleanup(void)
1151 {
1152 struct page_collection pc;
1153
1154 INIT_LIST_HEAD(&pc.pc_pages);
1155
1156 trace_cleanup_on_all_cpus();
1157
1158 cfs_tracefile_fini_arch();
1159 }
1160
1161 void cfs_tracefile_exit(void)
1162 {
1163 cfs_trace_stop_thread();
1164 cfs_trace_cleanup();
1165 }
Linux kernel - Deliverables
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