4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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.
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).
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.gnu.org/licenses/gpl-2.0.html
23 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
26 * Copyright (c) 2012, 2017, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
30 * Lustre is a trademark of Sun Microsystems, Inc.
32 * libcfs/libcfs/tracefile.c
34 * Author: Zach Brown <zab@clusterfs.com>
35 * Author: Phil Schwan <phil@clusterfs.com>
39 #define DEBUG_SUBSYSTEM S_LNET
40 #define LUSTRE_TRACEFILE_PRIVATE
41 #include "tracefile.h"
43 #include <linux/ctype.h>
45 #include <linux/kthread.h>
46 #include <linux/pagemap.h>
47 #include <linux/uaccess.h>
48 #include <libcfs/linux/linux-fs.h>
49 #include <libcfs/libcfs.h>
51 /* XXX move things up to the top, comment */
52 union cfs_trace_data_union (*cfs_trace_data[TCD_MAX_TYPES])[NR_CPUS] __cacheline_aligned;
54 char cfs_tracefile[TRACEFILE_NAME_SIZE];
55 long long cfs_tracefile_size = CFS_TRACEFILE_SIZE;
56 static struct tracefiled_ctl trace_tctl;
57 static DEFINE_MUTEX(cfs_trace_thread_mutex);
58 static int thread_running = 0;
60 static atomic_t cfs_tage_allocated = ATOMIC_INIT(0);
62 static void put_pages_on_tcd_daemon_list(struct page_collection *pc,
63 struct cfs_trace_cpu_data *tcd);
65 static inline struct cfs_trace_page *
66 cfs_tage_from_list(struct list_head *list)
68 return list_entry(list, struct cfs_trace_page, linkage);
71 static struct cfs_trace_page *cfs_tage_alloc(gfp_t gfp)
74 struct cfs_trace_page *tage;
76 /* My caller is trying to free memory */
77 if (!in_interrupt() && memory_pressure_get())
81 * Don't spam console with allocation failures: they will be reported
82 * by upper layer anyway.
85 page = alloc_page(gfp);
89 tage = kmalloc(sizeof(*tage), gfp);
96 atomic_inc(&cfs_tage_allocated);
100 static void cfs_tage_free(struct cfs_trace_page *tage)
102 __LASSERT(tage != NULL);
103 __LASSERT(tage->page != NULL);
105 __free_page(tage->page);
107 atomic_dec(&cfs_tage_allocated);
110 static void cfs_tage_to_tail(struct cfs_trace_page *tage,
111 struct list_head *queue)
113 __LASSERT(tage != NULL);
114 __LASSERT(queue != NULL);
116 list_move_tail(&tage->linkage, queue);
119 int cfs_trace_refill_stock(struct cfs_trace_cpu_data *tcd, gfp_t gfp,
120 struct list_head *stock)
125 * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
126 * from here: this will lead to infinite recursion.
129 for (i = 0; i + tcd->tcd_cur_stock_pages < TCD_STOCK_PAGES ; ++ i) {
130 struct cfs_trace_page *tage;
132 tage = cfs_tage_alloc(gfp);
135 list_add_tail(&tage->linkage, stock);
140 /* return a page that has 'len' bytes left at the end */
141 static struct cfs_trace_page *
142 cfs_trace_get_tage_try(struct cfs_trace_cpu_data *tcd, unsigned long len)
144 struct cfs_trace_page *tage;
146 if (tcd->tcd_cur_pages > 0) {
147 __LASSERT(!list_empty(&tcd->tcd_pages));
148 tage = cfs_tage_from_list(tcd->tcd_pages.prev);
149 if (tage->used + len <= PAGE_SIZE)
153 if (tcd->tcd_cur_pages < tcd->tcd_max_pages) {
154 if (tcd->tcd_cur_stock_pages > 0) {
155 tage = cfs_tage_from_list(tcd->tcd_stock_pages.prev);
156 --tcd->tcd_cur_stock_pages;
157 list_del_init(&tage->linkage);
159 tage = cfs_tage_alloc(GFP_ATOMIC);
160 if (unlikely(tage == NULL)) {
161 if ((!memory_pressure_get() ||
162 in_interrupt()) && printk_ratelimit())
164 "cannot allocate a tage (%ld)\n",
171 tage->cpu = smp_processor_id();
172 tage->type = tcd->tcd_type;
173 list_add_tail(&tage->linkage, &tcd->tcd_pages);
174 tcd->tcd_cur_pages++;
176 if (tcd->tcd_cur_pages > 8 && thread_running) {
177 struct tracefiled_ctl *tctl = &trace_tctl;
179 * wake up tracefiled to process some pages.
181 wake_up(&tctl->tctl_waitq);
188 static void cfs_tcd_shrink(struct cfs_trace_cpu_data *tcd)
190 int pgcount = tcd->tcd_cur_pages / 10;
191 struct page_collection pc;
192 struct cfs_trace_page *tage;
193 struct cfs_trace_page *tmp;
196 * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
197 * from here: this will lead to infinite recursion.
200 if (printk_ratelimit())
201 printk(KERN_WARNING "debug daemon buffer overflowed; "
202 "discarding 10%% of pages (%d of %ld)\n",
203 pgcount + 1, tcd->tcd_cur_pages);
205 INIT_LIST_HEAD(&pc.pc_pages);
207 list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages, linkage) {
211 list_move_tail(&tage->linkage, &pc.pc_pages);
212 tcd->tcd_cur_pages--;
214 put_pages_on_tcd_daemon_list(&pc, tcd);
217 /* return a page that has 'len' bytes left at the end */
218 static struct cfs_trace_page *cfs_trace_get_tage(struct cfs_trace_cpu_data *tcd,
221 struct cfs_trace_page *tage;
224 * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
225 * from here: this will lead to infinite recursion.
228 if (len > PAGE_SIZE) {
230 "cowardly refusing to write %lu bytes in a page\n", len);
234 tage = cfs_trace_get_tage_try(tcd, len);
239 if (tcd->tcd_cur_pages > 0) {
240 tage = cfs_tage_from_list(tcd->tcd_pages.next);
242 cfs_tage_to_tail(tage, &tcd->tcd_pages);
247 int libcfs_debug_msg(struct libcfs_debug_msg_data *msgdata,
248 const char *format, ...)
253 va_start(args, format);
254 rc = libcfs_debug_vmsg2(msgdata, format, args, NULL);
259 EXPORT_SYMBOL(libcfs_debug_msg);
261 int libcfs_debug_vmsg2(struct libcfs_debug_msg_data *msgdata,
262 const char *format1, va_list args,
263 const char *format2, ...)
265 struct cfs_trace_cpu_data *tcd = NULL;
266 struct ptldebug_header header = {0};
267 struct cfs_trace_page *tage;
268 /* string_buf is used only if tcd != NULL, and is always set then */
269 char *string_buf = NULL;
272 int needed = 85; /* average message length */
277 int mask = msgdata->msg_mask;
278 char *file = (char *)msgdata->msg_file;
279 struct cfs_debug_limit_state *cdls = msgdata->msg_cdls;
281 if (strchr(file, '/'))
282 file = strrchr(file, '/') + 1;
284 tcd = cfs_trace_get_tcd();
286 /* cfs_trace_get_tcd() grabs a lock, which disables preemption and
287 * pins us to a particular CPU. This avoids an smp_processor_id()
288 * warning on Linux when debugging is enabled. */
289 cfs_set_ptldebug_header(&header, msgdata, CDEBUG_STACK());
291 if (tcd == NULL) /* arch may not log in IRQ context */
294 if (tcd->tcd_cur_pages == 0)
295 header.ph_flags |= PH_FLAG_FIRST_RECORD;
297 if (tcd->tcd_shutting_down) {
298 cfs_trace_put_tcd(tcd);
303 known_size = strlen(file) + 1;
305 known_size += strlen(msgdata->msg_fn) + 1;
307 if (libcfs_debug_binary)
308 known_size += sizeof(header);
311 * '2' used because vsnprintf return real size required for output
312 * _without_ terminating NULL.
313 * if needed is to small for this format.
315 for (i = 0; i < 2; i++) {
316 tage = cfs_trace_get_tage(tcd, needed + known_size + 1);
318 if (needed + known_size > PAGE_SIZE)
321 cfs_trace_put_tcd(tcd);
326 string_buf = (char *)page_address(tage->page) +
327 tage->used + known_size;
329 max_nob = PAGE_SIZE - tage->used - known_size;
331 printk(KERN_EMERG "negative max_nob: %d\n",
334 cfs_trace_put_tcd(tcd);
342 needed = vsnprintf(string_buf, max_nob, format1, ap);
347 remain = max_nob - needed;
351 va_start(ap, format2);
352 needed += vsnprintf(string_buf + needed, remain,
357 if (needed < max_nob) /* well. printing ok.. */
361 if (*(string_buf + needed - 1) != '\n') {
362 printk(KERN_INFO "format at %s:%d:%s doesn't end in "
363 "newline\n", file, msgdata->msg_line, msgdata->msg_fn);
364 } else if (mask & D_TTY) {
365 /* TTY needs '\r\n' to move carriage to leftmost position */
366 if (needed < 2 || *(string_buf + needed - 2) != '\r')
367 printk(KERN_INFO "format at %s:%d:%s doesn't end in "
368 "'\\r\\n'\n", file, msgdata->msg_line,
372 header.ph_len = known_size + needed;
373 debug_buf = (char *)page_address(tage->page) + tage->used;
375 if (libcfs_debug_binary) {
376 memcpy(debug_buf, &header, sizeof(header));
377 tage->used += sizeof(header);
378 debug_buf += sizeof(header);
381 strcpy(debug_buf, file);
382 tage->used += strlen(file) + 1;
383 debug_buf += strlen(file) + 1;
385 if (msgdata->msg_fn) {
386 strcpy(debug_buf, msgdata->msg_fn);
387 tage->used += strlen(msgdata->msg_fn) + 1;
388 debug_buf += strlen(msgdata->msg_fn) + 1;
391 __LASSERT(debug_buf == string_buf);
393 tage->used += needed;
394 __LASSERT(tage->used <= PAGE_SIZE);
397 if ((mask & libcfs_printk) == 0) {
398 /* no console output requested */
400 cfs_trace_put_tcd(tcd);
405 if (libcfs_console_ratelimit &&
406 cdls->cdls_next != 0 && /* not first time ever */
407 time_before(jiffies, cdls->cdls_next)) {
408 /* skipping a console message */
411 cfs_trace_put_tcd(tcd);
415 if (time_after(jiffies, cdls->cdls_next +
416 libcfs_console_max_delay +
417 cfs_time_seconds(10))) {
418 /* last timeout was a long time ago */
419 cdls->cdls_delay /= libcfs_console_backoff * 4;
421 cdls->cdls_delay *= libcfs_console_backoff;
424 if (cdls->cdls_delay < libcfs_console_min_delay)
425 cdls->cdls_delay = libcfs_console_min_delay;
426 else if (cdls->cdls_delay > libcfs_console_max_delay)
427 cdls->cdls_delay = libcfs_console_max_delay;
429 /* ensure cdls_next is never zero after it's been seen */
430 cdls->cdls_next = (jiffies + cdls->cdls_delay) | 1;
434 cfs_print_to_console(&header, mask, string_buf, needed, file,
436 cfs_trace_put_tcd(tcd);
438 string_buf = cfs_trace_get_console_buffer();
441 if (format1 != NULL) {
443 needed = vsnprintf(string_buf,
444 CFS_TRACE_CONSOLE_BUFFER_SIZE,
448 if (format2 != NULL) {
449 remain = CFS_TRACE_CONSOLE_BUFFER_SIZE - needed;
451 va_start(ap, format2);
452 needed += vsnprintf(string_buf+needed, remain,
457 cfs_print_to_console(&header, mask,
458 string_buf, needed, file, msgdata->msg_fn);
463 if (cdls != NULL && cdls->cdls_count != 0) {
464 string_buf = cfs_trace_get_console_buffer();
466 needed = snprintf(string_buf, CFS_TRACE_CONSOLE_BUFFER_SIZE,
467 "Skipped %d previous similar message%s\n",
469 (cdls->cdls_count > 1) ? "s" : "");
471 /* Do not allow print this to TTY */
472 cfs_print_to_console(&header, mask & ~D_TTY, string_buf,
473 needed, file, msgdata->msg_fn);
476 cdls->cdls_count = 0;
481 EXPORT_SYMBOL(libcfs_debug_vmsg2);
484 cfs_trace_assertion_failed(const char *str,
485 struct libcfs_debug_msg_data *msgdata)
487 struct ptldebug_header hdr;
489 libcfs_panic_in_progress = 1;
490 libcfs_catastrophe = 1;
493 cfs_set_ptldebug_header(&hdr, msgdata, CDEBUG_STACK());
495 cfs_print_to_console(&hdr, D_EMERG, str, strlen(str),
496 msgdata->msg_file, msgdata->msg_fn);
498 panic("Lustre debug assertion failure\n");
504 panic_collect_pages(struct page_collection *pc)
506 /* Do the collect_pages job on a single CPU: assumes that all other
507 * CPUs have been stopped during a panic. If this isn't true for some
508 * arch, this will have to be implemented separately in each arch. */
511 struct cfs_trace_cpu_data *tcd;
513 INIT_LIST_HEAD(&pc->pc_pages);
515 cfs_tcd_for_each(tcd, i, j) {
516 list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
517 tcd->tcd_cur_pages = 0;
519 if (pc->pc_want_daemon_pages) {
520 list_splice_init(&tcd->tcd_daemon_pages,
522 tcd->tcd_cur_daemon_pages = 0;
527 static void collect_pages_on_all_cpus(struct page_collection *pc)
529 struct cfs_trace_cpu_data *tcd;
532 for_each_possible_cpu(cpu) {
533 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
534 list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
535 tcd->tcd_cur_pages = 0;
536 if (pc->pc_want_daemon_pages) {
537 list_splice_init(&tcd->tcd_daemon_pages,
539 tcd->tcd_cur_daemon_pages = 0;
545 static void collect_pages(struct page_collection *pc)
547 INIT_LIST_HEAD(&pc->pc_pages);
549 if (libcfs_panic_in_progress)
550 panic_collect_pages(pc);
552 collect_pages_on_all_cpus(pc);
555 static void put_pages_back_on_all_cpus(struct page_collection *pc)
557 struct cfs_trace_cpu_data *tcd;
558 struct list_head *cur_head;
559 struct cfs_trace_page *tage;
560 struct cfs_trace_page *tmp;
563 for_each_possible_cpu(cpu) {
564 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
565 cur_head = tcd->tcd_pages.next;
567 list_for_each_entry_safe(tage, tmp, &pc->pc_pages,
570 __LASSERT_TAGE_INVARIANT(tage);
572 if (tage->cpu != cpu || tage->type != i)
575 cfs_tage_to_tail(tage, cur_head);
576 tcd->tcd_cur_pages++;
582 static void put_pages_back(struct page_collection *pc)
584 if (!libcfs_panic_in_progress)
585 put_pages_back_on_all_cpus(pc);
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
592 static void put_pages_on_tcd_daemon_list(struct page_collection *pc,
593 struct cfs_trace_cpu_data *tcd)
595 struct cfs_trace_page *tage;
596 struct cfs_trace_page *tmp;
598 list_for_each_entry_safe(tage, tmp, &pc->pc_pages, linkage) {
599 __LASSERT_TAGE_INVARIANT(tage);
601 if (tage->cpu != tcd->tcd_cpu || tage->type != tcd->tcd_type)
604 cfs_tage_to_tail(tage, &tcd->tcd_daemon_pages);
605 tcd->tcd_cur_daemon_pages++;
607 if (tcd->tcd_cur_daemon_pages > tcd->tcd_max_pages) {
608 struct cfs_trace_page *victim;
610 __LASSERT(!list_empty(&tcd->tcd_daemon_pages));
611 victim = cfs_tage_from_list(tcd->tcd_daemon_pages.next);
613 __LASSERT_TAGE_INVARIANT(victim);
615 list_del(&victim->linkage);
616 cfs_tage_free(victim);
617 tcd->tcd_cur_daemon_pages--;
622 static void put_pages_on_daemon_list(struct page_collection *pc)
624 struct cfs_trace_cpu_data *tcd;
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);
633 void cfs_trace_debug_print(void)
635 struct page_collection pc;
636 struct cfs_trace_page *tage;
637 struct cfs_trace_page *tmp;
639 pc.pc_want_daemon_pages = 1;
641 list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
645 __LASSERT_TAGE_INVARIANT(tage);
648 p = page_address(page);
649 while (p < ((char *)page_address(page) + tage->used)) {
650 struct ptldebug_header *hdr;
655 p += strlen(file) + 1;
658 len = hdr->ph_len - (int)(p - (char *)hdr);
660 cfs_print_to_console(hdr, D_EMERG, p, len, file, fn);
665 list_del(&tage->linkage);
670 int cfs_tracefile_dump_all_pages(char *filename)
672 struct page_collection pc;
674 struct cfs_trace_page *tage;
675 struct cfs_trace_page *tmp;
679 cfs_tracefile_write_lock();
681 filp = filp_open(filename, O_CREAT|O_EXCL|O_WRONLY|O_LARGEFILE, 0600);
685 printk(KERN_ERR "LustreError: can't open %s for dump: rc %d\n",
690 pc.pc_want_daemon_pages = 1;
692 if (list_empty(&pc.pc_pages)) {
697 /* ok, for now, just write the pages. in the future we'll be building
698 * iobufs with the pages and calling generic_direct_IO */
699 list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
701 __LASSERT_TAGE_INVARIANT(tage);
703 buf = kmap(tage->page);
704 rc = cfs_kernel_write(filp, buf, tage->used, &filp->f_pos);
706 if (rc != (int)tage->used) {
707 printk(KERN_WARNING "wanted to write %u but wrote "
708 "%d\n", tage->used, rc);
710 __LASSERT(list_empty(&pc.pc_pages));
713 list_del(&tage->linkage);
717 rc = ll_vfs_fsync_range(filp, 0, LLONG_MAX, 1);
719 printk(KERN_ERR "sync returns %d\n", rc);
721 filp_close(filp, NULL);
723 cfs_tracefile_write_unlock();
727 void cfs_trace_flush_pages(void)
729 struct page_collection pc;
730 struct cfs_trace_page *tage;
731 struct cfs_trace_page *tmp;
733 pc.pc_want_daemon_pages = 1;
735 list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
737 __LASSERT_TAGE_INVARIANT(tage);
739 list_del(&tage->linkage);
744 int cfs_trace_copyin_string(char *knl_buffer, int knl_buffer_nob,
745 const char __user *usr_buffer, int usr_buffer_nob)
749 if (usr_buffer_nob > knl_buffer_nob)
752 if (copy_from_user(knl_buffer, usr_buffer, usr_buffer_nob))
755 nob = strnlen(knl_buffer, usr_buffer_nob);
756 while (nob-- >= 0) /* strip trailing whitespace */
757 if (!isspace(knl_buffer[nob]))
760 if (nob < 0) /* empty string */
763 if (nob == knl_buffer_nob) /* no space to terminate */
766 knl_buffer[nob + 1] = 0; /* terminate */
769 EXPORT_SYMBOL(cfs_trace_copyin_string);
771 int cfs_trace_copyout_string(char __user *usr_buffer, int usr_buffer_nob,
772 const char *knl_buffer, char *append)
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);
779 if (nob > usr_buffer_nob)
780 nob = usr_buffer_nob;
782 if (copy_to_user(usr_buffer, knl_buffer, nob))
785 if (append != NULL && nob < usr_buffer_nob) {
786 if (copy_to_user(usr_buffer + nob, append, 1))
794 EXPORT_SYMBOL(cfs_trace_copyout_string);
796 int cfs_trace_allocate_string_buffer(char **str, int nob)
798 if (nob > 2 * PAGE_SIZE) /* string must be "sensible" */
801 *str = kmalloc(nob, GFP_KERNEL | __GFP_ZERO);
808 int cfs_trace_dump_debug_buffer_usrstr(void __user *usr_str, int usr_str_nob)
813 rc = cfs_trace_allocate_string_buffer(&str, usr_str_nob + 1);
817 rc = cfs_trace_copyin_string(str, usr_str_nob + 1,
818 usr_str, usr_str_nob);
826 rc = cfs_tracefile_dump_all_pages(str);
832 int cfs_trace_daemon_command(char *str)
836 cfs_tracefile_write_lock();
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));
844 } else if (strncmp(str, "size=", 5) == 0) {
847 rc = kstrtoul(str + 5, 10, &tmp);
849 if (tmp < 10 || tmp > 20480)
850 cfs_tracefile_size = CFS_TRACEFILE_SIZE;
852 cfs_tracefile_size = tmp << 20;
854 } else if (strlen(str) >= sizeof(cfs_tracefile)) {
856 } else if (str[0] != '/') {
859 strcpy(cfs_tracefile, str);
862 "Lustre: debug daemon will attempt to start writing "
863 "to %s (%lukB max)\n", cfs_tracefile,
864 (long)(cfs_tracefile_size >> 10));
866 cfs_trace_start_thread();
869 cfs_tracefile_write_unlock();
873 int cfs_trace_daemon_command_usrstr(void __user *usr_str, int usr_str_nob)
878 rc = cfs_trace_allocate_string_buffer(&str, usr_str_nob + 1);
882 rc = cfs_trace_copyin_string(str, usr_str_nob + 1,
883 usr_str, usr_str_nob);
885 rc = cfs_trace_daemon_command(str);
891 int cfs_trace_set_debug_mb(int mb)
896 int limit = cfs_trace_max_debug_mb();
897 struct cfs_trace_cpu_data *tcd;
899 if (mb < num_possible_cpus()) {
901 "Lustre: %d MB is too small for debug buffer size, "
902 "setting it to %d MB.\n", mb, num_possible_cpus());
903 mb = num_possible_cpus();
908 "Lustre: %d MB is too large for debug buffer size, "
909 "setting it to %d MB.\n", mb, limit);
913 mb /= num_possible_cpus();
914 pages = mb << (20 - PAGE_SHIFT);
916 cfs_tracefile_write_lock();
918 cfs_tcd_for_each(tcd, i, j)
919 tcd->tcd_max_pages = (pages * tcd->tcd_pages_factor) / 100;
921 cfs_tracefile_write_unlock();
926 int cfs_trace_get_debug_mb(void)
930 struct cfs_trace_cpu_data *tcd;
933 cfs_tracefile_read_lock();
935 cfs_tcd_for_each(tcd, i, j)
936 total_pages += tcd->tcd_max_pages;
938 cfs_tracefile_read_unlock();
940 return (total_pages >> (20 - PAGE_SHIFT)) + 1;
943 static int tracefiled(void *arg)
945 struct page_collection pc;
946 struct tracefiled_ctl *tctl = arg;
947 struct cfs_trace_page *tage;
948 struct cfs_trace_page *tmp;
954 /* we're started late enough that we pick up init's fs context */
955 /* this is so broken in uml? what on earth is going on? */
957 complete(&tctl->tctl_start);
960 wait_queue_entry_t __wait;
962 pc.pc_want_daemon_pages = 0;
964 if (list_empty(&pc.pc_pages))
968 cfs_tracefile_read_lock();
969 if (cfs_tracefile[0] != 0) {
970 filp = filp_open(cfs_tracefile,
971 O_CREAT | O_RDWR | O_LARGEFILE,
976 printk(KERN_WARNING "couldn't open %s: "
977 "%d\n", cfs_tracefile, rc);
980 cfs_tracefile_read_unlock();
982 put_pages_on_daemon_list(&pc);
983 __LASSERT(list_empty(&pc.pc_pages));
987 list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
988 struct dentry *de = file_dentry(filp);
991 __LASSERT_TAGE_INVARIANT(tage);
993 if (f_pos >= (off_t)cfs_tracefile_size)
995 else if (f_pos > i_size_read(de->d_inode))
996 f_pos = i_size_read(de->d_inode);
998 buf = kmap(tage->page);
999 rc = cfs_kernel_write(filp, buf, tage->used, &f_pos);
1001 if (rc != (int)tage->used) {
1002 printk(KERN_WARNING "wanted to write %u "
1003 "but wrote %d\n", tage->used, rc);
1004 put_pages_back(&pc);
1005 __LASSERT(list_empty(&pc.pc_pages));
1010 filp_close(filp, NULL);
1011 put_pages_on_daemon_list(&pc);
1012 if (!list_empty(&pc.pc_pages)) {
1015 printk(KERN_ALERT "Lustre: trace pages aren't "
1017 printk(KERN_ERR "total cpus(%d): ",
1018 num_possible_cpus());
1019 for (i = 0; i < num_possible_cpus(); i++)
1021 printk(KERN_ERR "%d(on) ", i);
1023 printk(KERN_ERR "%d(off) ", i);
1024 printk(KERN_ERR "\n");
1027 list_for_each_entry_safe(tage, tmp, &pc.pc_pages,
1029 printk(KERN_ERR "page %d belongs to cpu "
1030 "%d\n", ++i, tage->cpu);
1031 printk(KERN_ERR "There are %d pages unwritten\n",
1034 __LASSERT(list_empty(&pc.pc_pages));
1036 if (atomic_read(&tctl->tctl_shutdown)) {
1037 if (last_loop == 0) {
1044 init_waitqueue_entry(&__wait, current);
1045 add_wait_queue(&tctl->tctl_waitq, &__wait);
1046 set_current_state(TASK_INTERRUPTIBLE);
1047 schedule_timeout(cfs_time_seconds(1));
1048 remove_wait_queue(&tctl->tctl_waitq, &__wait);
1050 complete(&tctl->tctl_stop);
1054 int cfs_trace_start_thread(void)
1056 struct tracefiled_ctl *tctl = &trace_tctl;
1059 mutex_lock(&cfs_trace_thread_mutex);
1063 init_completion(&tctl->tctl_start);
1064 init_completion(&tctl->tctl_stop);
1065 init_waitqueue_head(&tctl->tctl_waitq);
1066 atomic_set(&tctl->tctl_shutdown, 0);
1068 if (IS_ERR(kthread_run(tracefiled, tctl, "ktracefiled"))) {
1073 wait_for_completion(&tctl->tctl_start);
1076 mutex_unlock(&cfs_trace_thread_mutex);
1080 void cfs_trace_stop_thread(void)
1082 struct tracefiled_ctl *tctl = &trace_tctl;
1084 mutex_lock(&cfs_trace_thread_mutex);
1085 if (thread_running) {
1087 "Lustre: shutting down debug daemon thread...\n");
1088 atomic_set(&tctl->tctl_shutdown, 1);
1089 wait_for_completion(&tctl->tctl_stop);
1092 mutex_unlock(&cfs_trace_thread_mutex);
1095 int cfs_tracefile_init(int max_pages)
1097 struct cfs_trace_cpu_data *tcd;
1103 rc = cfs_tracefile_init_arch();
1107 cfs_tcd_for_each(tcd, i, j) {
1108 /* tcd_pages_factor is initialized int tracefile_init_arch. */
1109 factor = tcd->tcd_pages_factor;
1110 INIT_LIST_HEAD(&tcd->tcd_pages);
1111 INIT_LIST_HEAD(&tcd->tcd_stock_pages);
1112 INIT_LIST_HEAD(&tcd->tcd_daemon_pages);
1113 tcd->tcd_cur_pages = 0;
1114 tcd->tcd_cur_stock_pages = 0;
1115 tcd->tcd_cur_daemon_pages = 0;
1116 tcd->tcd_max_pages = (max_pages * factor) / 100;
1117 LASSERT(tcd->tcd_max_pages > 0);
1118 tcd->tcd_shutting_down = 0;
1123 static void trace_cleanup_on_all_cpus(void)
1125 struct cfs_trace_cpu_data *tcd;
1126 struct cfs_trace_page *tage;
1127 struct cfs_trace_page *tmp;
1130 for_each_possible_cpu(cpu) {
1131 cfs_tcd_for_each_type_lock(tcd, i, cpu) {
1132 tcd->tcd_shutting_down = 1;
1134 list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages, linkage) {
1135 __LASSERT_TAGE_INVARIANT(tage);
1137 list_del(&tage->linkage);
1138 cfs_tage_free(tage);
1140 tcd->tcd_cur_pages = 0;
1145 static void cfs_trace_cleanup(void)
1147 struct page_collection pc;
1149 INIT_LIST_HEAD(&pc.pc_pages);
1151 trace_cleanup_on_all_cpus();
1153 cfs_tracefile_fini_arch();
1156 void cfs_tracefile_exit(void)
1158 cfs_trace_stop_thread();
1159 cfs_trace_cleanup();