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LU-6245 libcfs: cleanup libcfs lock handling
[fs/lustre-release.git] / libcfs / libcfs / tracefile.h
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, 2014, 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
37 #ifndef __LIBCFS_TRACEFILE_H__
38 #define __LIBCFS_TRACEFILE_H__
39
40 #include <libcfs/libcfs.h>
41
42 typedef enum {
43         CFS_TCD_TYPE_PROC = 0,
44         CFS_TCD_TYPE_SOFTIRQ,
45         CFS_TCD_TYPE_IRQ,
46         CFS_TCD_TYPE_MAX
47 } cfs_trace_buf_type_t;
48
49 /* trace file lock routines */
50
51 #define TRACEFILE_NAME_SIZE 1024
52 extern char      cfs_tracefile[TRACEFILE_NAME_SIZE];
53 extern long long cfs_tracefile_size;
54
55 extern char lnet_upcall[1024];
56 /**
57  * The path of debug log dump upcall script.
58  */
59 extern char lnet_debug_log_upcall[1024];
60
61 extern void libcfs_run_debug_log_upcall(char *file);
62
63 int  cfs_tracefile_init_arch(void);
64 void cfs_tracefile_fini_arch(void);
65
66 void cfs_tracefile_read_lock(void);
67 void cfs_tracefile_read_unlock(void);
68 void cfs_tracefile_write_lock(void);
69 void cfs_tracefile_write_unlock(void);
70
71 int cfs_tracefile_dump_all_pages(char *filename);
72 void cfs_trace_debug_print(void);
73 void cfs_trace_flush_pages(void);
74 int cfs_trace_start_thread(void);
75 void cfs_trace_stop_thread(void);
76 int cfs_tracefile_init(int max_pages);
77 void cfs_tracefile_exit(void);
78
79
80
81 int cfs_trace_copyin_string(char *knl_buffer, int knl_buffer_nob,
82                             const char __user *usr_buffer, int usr_buffer_nob);
83 int cfs_trace_copyout_string(char __user *usr_buffer, int usr_buffer_nob,
84                              const char *knl_str, char *append);
85 int cfs_trace_allocate_string_buffer(char **str, int nob);
86 void cfs_trace_free_string_buffer(char *str, int nob);
87 int cfs_trace_dump_debug_buffer_usrstr(void __user *usr_str, int usr_str_nob);
88 int cfs_trace_daemon_command(char *str);
89 int cfs_trace_daemon_command_usrstr(void __user *usr_str, int usr_str_nob);
90 int cfs_trace_set_debug_mb(int mb);
91 int cfs_trace_set_debug_mb_usrstr(void __user *usr_str, int usr_str_nob);
92 int cfs_trace_get_debug_mb(void);
93
94 extern void libcfs_debug_dumplog_internal(void *arg);
95 extern void libcfs_register_panic_notifier(void);
96 extern void libcfs_unregister_panic_notifier(void);
97 extern int  libcfs_panic_in_progress;
98 extern int  cfs_trace_max_debug_mb(void);
99
100 #define TCD_MAX_PAGES (5 << (20 - PAGE_CACHE_SHIFT))
101 #define TCD_STOCK_PAGES (TCD_MAX_PAGES)
102 #define CFS_TRACEFILE_SIZE (500 << 20)
103
104 #ifdef LUSTRE_TRACEFILE_PRIVATE
105
106 /*
107  * Private declare for tracefile
108  */
109 #define TCD_MAX_PAGES (5 << (20 - PAGE_CACHE_SHIFT))
110 #define TCD_STOCK_PAGES (TCD_MAX_PAGES)
111
112 #define CFS_TRACEFILE_SIZE (500 << 20)
113
114 /* Size of a buffer for sprinting console messages if we can't get a page
115  * from system */
116 #define CFS_TRACE_CONSOLE_BUFFER_SIZE   1024
117
118 union cfs_trace_data_union {
119         struct cfs_trace_cpu_data {
120                 /*
121                  * Even though this structure is meant to be per-CPU, locking
122                  * is needed because in some places the data may be accessed
123                  * from other CPUs. This lock is directly used in trace_get_tcd
124                  * and trace_put_tcd, which are called in libcfs_debug_vmsg2 and
125                  * tcd_for_each_type_lock
126                  */
127                 spinlock_t              tcd_lock;
128                 unsigned long           tcd_lock_flags;
129
130                 /*
131                  * pages with trace records not yet processed by tracefiled.
132                  */
133                 struct list_head        tcd_pages;
134                 /* number of pages on ->tcd_pages */
135                 unsigned long           tcd_cur_pages;
136
137                 /*
138                  * pages with trace records already processed by
139                  * tracefiled. These pages are kept in memory, so that some
140                  * portion of log can be written in the event of LBUG. This
141                  * list is maintained in LRU order.
142                  *
143                  * Pages are moved to ->tcd_daemon_pages by tracefiled()
144                  * (put_pages_on_daemon_list()). LRU pages from this list are
145                  * discarded when list grows too large.
146                  */
147                 struct list_head        tcd_daemon_pages;
148                 /* number of pages on ->tcd_daemon_pages */
149                 unsigned long           tcd_cur_daemon_pages;
150
151                 /*
152                  * Maximal number of pages allowed on ->tcd_pages and
153                  * ->tcd_daemon_pages each.
154                  * Always TCD_MAX_PAGES * tcd_pages_factor / 100 in current
155                  * implementation.
156                  */
157                 unsigned long           tcd_max_pages;
158
159                 /*
160                  * preallocated pages to write trace records into. Pages from
161                  * ->tcd_stock_pages are moved to ->tcd_pages by
162                  * portals_debug_msg().
163                  *
164                  * This list is necessary, because on some platforms it's
165                  * impossible to perform efficient atomic page allocation in a
166                  * non-blockable context.
167                  *
168                  * Such platforms fill ->tcd_stock_pages "on occasion", when
169                  * tracing code is entered in blockable context.
170                  *
171                  * trace_get_tage_try() tries to get a page from
172                  * ->tcd_stock_pages first and resorts to atomic page
173                  * allocation only if this queue is empty. ->tcd_stock_pages
174                  * is replenished when tracing code is entered in blocking
175                  * context (darwin-tracefile.c:trace_get_tcd()). We try to
176                  * maintain TCD_STOCK_PAGES (40 by default) pages in this
177                  * queue. Atomic allocation is only required if more than
178                  * TCD_STOCK_PAGES pagesful are consumed by trace records all
179                  * emitted in non-blocking contexts. Which is quite unlikely.
180                  */
181                 struct list_head        tcd_stock_pages;
182                 /* number of pages on ->tcd_stock_pages */
183                 unsigned long           tcd_cur_stock_pages;
184
185                 unsigned short          tcd_shutting_down;
186                 unsigned short          tcd_cpu;
187                 unsigned short          tcd_type;
188                 /* The factors to share debug memory. */
189                 unsigned short          tcd_pages_factor;
190         } tcd;
191         char __pad[L1_CACHE_ALIGN(sizeof(struct cfs_trace_cpu_data))];
192 };
193
194 #define TCD_MAX_TYPES      8
195 extern union cfs_trace_data_union (*cfs_trace_data[TCD_MAX_TYPES])[NR_CPUS];
196
197 #define cfs_tcd_for_each(tcd, i, j)                                       \
198     for (i = 0; cfs_trace_data[i] != NULL; i++)                           \
199         for (j = 0, ((tcd) = &(*cfs_trace_data[i])[j].tcd);               \
200              j < num_possible_cpus();                                     \
201              j++, (tcd) = &(*cfs_trace_data[i])[j].tcd)
202
203 #define cfs_tcd_for_each_type_lock(tcd, i, cpu)                           \
204     for (i = 0; cfs_trace_data[i] &&                                      \
205          (tcd = &(*cfs_trace_data[i])[cpu].tcd) &&                        \
206          cfs_trace_lock_tcd(tcd, 1); cfs_trace_unlock_tcd(tcd, 1), i++)
207
208 /* XXX nikita: this declaration is internal to tracefile.c and should probably
209  * be moved there */
210 struct page_collection {
211         struct list_head        pc_pages;
212         /*
213          * if this flag is set, collect_pages() will spill both
214          * ->tcd_daemon_pages and ->tcd_pages to the ->pc_pages. Otherwise,
215          * only ->tcd_pages are spilled.
216          */
217         int                     pc_want_daemon_pages;
218 };
219
220 /* XXX nikita: this declaration is internal to tracefile.c and should probably
221  * be moved there */
222 struct tracefiled_ctl {
223         struct completion       tctl_start;
224         struct completion       tctl_stop;
225         wait_queue_head_t       tctl_waitq;
226         pid_t                   tctl_pid;
227         atomic_t                tctl_shutdown;
228 };
229
230 /*
231  * small data-structure for each page owned by tracefiled.
232  */
233 /* XXX nikita: this declaration is internal to tracefile.c and should probably
234  * be moved there */
235 struct cfs_trace_page {
236         /*
237          * page itself
238          */
239         struct page             *page;
240         /*
241          * linkage into one of the lists in trace_data_union or
242          * page_collection
243          */
244         struct list_head        linkage;
245         /*
246          * number of bytes used within this page
247          */
248         unsigned int            used;
249         /*
250          * cpu that owns this page
251          */
252         unsigned short          cpu;
253         /*
254          * type(context) of this page
255          */
256         unsigned short          type;
257 };
258
259 extern void cfs_set_ptldebug_header(struct ptldebug_header *header,
260                                     struct libcfs_debug_msg_data *m,
261                                     unsigned long stack);
262 extern void cfs_print_to_console(struct ptldebug_header *hdr, int mask,
263                                  const char *buf, int len, const char *file,
264                                  const char *fn);
265
266 extern int cfs_trace_lock_tcd(struct cfs_trace_cpu_data *tcd, int walking);
267 extern void cfs_trace_unlock_tcd(struct cfs_trace_cpu_data *tcd, int walking);
268
269 extern char *cfs_trace_console_buffers[NR_CPUS][CFS_TCD_TYPE_MAX];
270 extern cfs_trace_buf_type_t cfs_trace_buf_idx_get(void);
271
272 static inline char *cfs_trace_get_console_buffer(void)
273 {
274         unsigned int i = get_cpu();
275         unsigned int j = cfs_trace_buf_idx_get();
276
277         return cfs_trace_console_buffers[i][j];
278 }
279
280 static inline void
281 cfs_trace_put_console_buffer(char *buffer)
282 {
283         put_cpu();
284 }
285
286 static inline struct cfs_trace_cpu_data *cfs_trace_get_tcd(void)
287 {
288         struct cfs_trace_cpu_data *tcd =
289                 &(*cfs_trace_data[cfs_trace_buf_idx_get()])[get_cpu()].tcd;
290
291         cfs_trace_lock_tcd(tcd, 0);
292
293         return tcd;
294 }
295
296 static inline void cfs_trace_put_tcd(struct cfs_trace_cpu_data *tcd)
297 {
298         cfs_trace_unlock_tcd(tcd, 0);
299         put_cpu();
300 }
301
302 int cfs_trace_refill_stock(struct cfs_trace_cpu_data *tcd, gfp_t gfp,
303                                 struct list_head *stock);
304
305
306 int cfs_tcd_owns_tage(struct cfs_trace_cpu_data *tcd,
307                       struct cfs_trace_page *tage);
308
309 extern void cfs_trace_assertion_failed(const char *str,
310                                        struct libcfs_debug_msg_data *m);
311
312 /* ASSERTION that is safe to use within the debug system */
313 #define __LASSERT(cond)                                                 \
314 do {                                                                    \
315         if (unlikely(!(cond))) {                                        \
316                 LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, D_EMERG, NULL);     \
317                 cfs_trace_assertion_failed("ASSERTION("#cond") failed", \
318                                            &msgdata);                   \
319         }                                                               \
320 } while (0)
321
322 #define __LASSERT_TAGE_INVARIANT(tage)                                  \
323 do {                                                                    \
324         __LASSERT(tage != NULL);                                        \
325         __LASSERT(tage->page != NULL);                                  \
326         __LASSERT(tage->used <= PAGE_CACHE_SIZE);                         \
327         __LASSERT(page_count(tage->page) > 0);                      \
328 } while (0)
329
330 #endif  /* LUSTRE_TRACEFILE_PRIVATE */
331
332 #endif /* __LIBCFS_TRACEFILE_H__ */