blob: 791743deedf1b389177225a66d5a0967f2026b25 [file] [log] [blame]
Tony Luckca01d6d2010-12-28 14:25:21 -08001/*
2 * Persistent Storage - platform driver interface parts.
3 *
Anton Vorontsovf29e5952012-05-26 06:20:19 -07004 * Copyright (C) 2007-2008 Google, Inc.
Tony Luckca01d6d2010-12-28 14:25:21 -08005 * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
Fabian Frederickef748852014-06-06 14:37:31 -070021#define pr_fmt(fmt) "pstore: " fmt
22
Tony Luckca01d6d2010-12-28 14:25:21 -080023#include <linux/atomic.h>
24#include <linux/types.h>
25#include <linux/errno.h>
26#include <linux/init.h>
27#include <linux/kmsg_dump.h>
Anton Vorontsovf29e5952012-05-26 06:20:19 -070028#include <linux/console.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080029#include <linux/module.h>
30#include <linux/pstore.h>
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -070031#include <linux/zlib.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080032#include <linux/string.h>
Luck, Tony6dda9262011-08-11 15:14:39 -070033#include <linux/timer.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080034#include <linux/slab.h>
35#include <linux/uaccess.h>
Don Zickusabd4d552011-08-12 10:54:51 -070036#include <linux/hardirq.h>
Anton Vorontsova3f5f072012-05-26 06:20:28 -070037#include <linux/jiffies.h>
Luck, Tony6dda9262011-08-11 15:14:39 -070038#include <linux/workqueue.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080039
40#include "internal.h"
41
42/*
Luck, Tony6dda9262011-08-11 15:14:39 -070043 * We defer making "oops" entries appear in pstore - see
44 * whether the system is actually still running well enough
45 * to let someone see the entry
46 */
Anton Vorontsov521f72882012-05-26 06:20:29 -070047static int pstore_update_ms = -1;
Anton Vorontsova3f5f072012-05-26 06:20:28 -070048module_param_named(update_ms, pstore_update_ms, int, 0600);
49MODULE_PARM_DESC(update_ms, "milliseconds before pstore updates its content "
Anton Vorontsov521f72882012-05-26 06:20:29 -070050 "(default is -1, which means runtime updates are disabled; "
51 "enabling this option is not safe, it may lead to further "
52 "corruption on Oopses)");
Luck, Tony6dda9262011-08-11 15:14:39 -070053
54static int pstore_new_entry;
55
56static void pstore_timefunc(unsigned long);
57static DEFINE_TIMER(pstore_timer, pstore_timefunc, 0, 0);
58
59static void pstore_dowork(struct work_struct *);
60static DECLARE_WORK(pstore_work, pstore_dowork);
61
62/*
Tony Luckca01d6d2010-12-28 14:25:21 -080063 * pstore_lock just protects "psinfo" during
64 * calls to pstore_register()
65 */
66static DEFINE_SPINLOCK(pstore_lock);
Anton Vorontsov060287b2012-07-09 17:10:41 -070067struct pstore_info *psinfo;
Tony Luckca01d6d2010-12-28 14:25:21 -080068
Matthew Garrettdee28e72011-07-21 16:57:55 -040069static char *backend;
70
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -070071/* Compression parameters */
72#define COMPR_LEVEL 6
73#define WINDOW_BITS 12
74#define MEM_LEVEL 4
75static struct z_stream_s stream;
76
77static char *big_oops_buf;
78static size_t big_oops_buf_sz;
79
Luck, Tony366f7e72011-03-18 15:33:43 -070080/* How much of the console log to snapshot */
Tony Luckca01d6d2010-12-28 14:25:21 -080081static unsigned long kmsg_bytes = 10240;
82
Luck, Tony366f7e72011-03-18 15:33:43 -070083void pstore_set_kmsg_bytes(int bytes)
Tony Luckca01d6d2010-12-28 14:25:21 -080084{
Luck, Tony366f7e72011-03-18 15:33:43 -070085 kmsg_bytes = bytes;
Tony Luckca01d6d2010-12-28 14:25:21 -080086}
87
Tony Luckca01d6d2010-12-28 14:25:21 -080088/* Tag each group of saved records with a sequence number */
89static int oopscount;
90
Seiji Aguchi381b8722012-03-16 15:36:59 -070091static const char *get_reason_str(enum kmsg_dump_reason reason)
92{
93 switch (reason) {
94 case KMSG_DUMP_PANIC:
95 return "Panic";
96 case KMSG_DUMP_OOPS:
97 return "Oops";
98 case KMSG_DUMP_EMERG:
99 return "Emergency";
100 case KMSG_DUMP_RESTART:
101 return "Restart";
102 case KMSG_DUMP_HALT:
103 return "Halt";
104 case KMSG_DUMP_POWEROFF:
105 return "Poweroff";
106 default:
107 return "Unknown";
108 }
109}
Tony Luck9f6af272011-03-22 16:01:49 -0700110
Seiji Aguchi9f244e92013-01-11 18:09:41 +0000111bool pstore_cannot_block_path(enum kmsg_dump_reason reason)
112{
113 /*
114 * In case of NMI path, pstore shouldn't be blocked
115 * regardless of reason.
116 */
117 if (in_nmi())
118 return true;
119
120 switch (reason) {
121 /* In panic case, other cpus are stopped by smp_send_stop(). */
122 case KMSG_DUMP_PANIC:
123 /* Emergency restart shouldn't be blocked by spin lock. */
124 case KMSG_DUMP_EMERG:
125 return true;
126 default:
127 return false;
128 }
129}
130EXPORT_SYMBOL_GPL(pstore_cannot_block_path);
131
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700132/* Derived from logfs_compress() */
133static int pstore_compress(const void *in, void *out, size_t inlen,
134 size_t outlen)
135{
136 int err, ret;
137
138 ret = -EIO;
139 err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
140 MEM_LEVEL, Z_DEFAULT_STRATEGY);
141 if (err != Z_OK)
142 goto error;
143
144 stream.next_in = in;
145 stream.avail_in = inlen;
146 stream.total_in = 0;
147 stream.next_out = out;
148 stream.avail_out = outlen;
149 stream.total_out = 0;
150
151 err = zlib_deflate(&stream, Z_FINISH);
152 if (err != Z_STREAM_END)
153 goto error;
154
155 err = zlib_deflateEnd(&stream);
156 if (err != Z_OK)
157 goto error;
158
159 if (stream.total_out >= stream.total_in)
160 goto error;
161
162 ret = stream.total_out;
163error:
164 return ret;
165}
166
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700167/* Derived from logfs_uncompress */
168static int pstore_decompress(void *in, void *out, size_t inlen, size_t outlen)
169{
170 int err, ret;
171
172 ret = -EIO;
Aruna Balakrishnaiahb61edf82013-09-11 10:58:03 -0700173 err = zlib_inflateInit2(&stream, WINDOW_BITS);
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700174 if (err != Z_OK)
175 goto error;
176
177 stream.next_in = in;
178 stream.avail_in = inlen;
179 stream.total_in = 0;
180 stream.next_out = out;
181 stream.avail_out = outlen;
182 stream.total_out = 0;
183
184 err = zlib_inflate(&stream, Z_FINISH);
185 if (err != Z_STREAM_END)
186 goto error;
187
188 err = zlib_inflateEnd(&stream);
189 if (err != Z_OK)
190 goto error;
191
192 ret = stream.total_out;
193error:
194 return ret;
195}
196
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700197static void allocate_buf_for_compression(void)
198{
199 size_t size;
Aruna Balakrishnaiah7de8fe22013-09-11 10:57:41 -0700200 size_t cmpr;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700201
Aruna Balakrishnaiah7de8fe22013-09-11 10:57:41 -0700202 switch (psinfo->bufsize) {
203 /* buffer range for efivars */
204 case 1000 ... 2000:
205 cmpr = 56;
206 break;
207 case 2001 ... 3000:
208 cmpr = 54;
209 break;
210 case 3001 ... 3999:
211 cmpr = 52;
212 break;
213 /* buffer range for nvram, erst */
214 case 4000 ... 10000:
215 cmpr = 45;
216 break;
217 default:
218 cmpr = 60;
219 break;
220 }
221
222 big_oops_buf_sz = (psinfo->bufsize * 100) / cmpr;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700223 big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
224 if (big_oops_buf) {
225 size = max(zlib_deflate_workspacesize(WINDOW_BITS, MEM_LEVEL),
226 zlib_inflate_workspacesize());
227 stream.workspace = kmalloc(size, GFP_KERNEL);
228 if (!stream.workspace) {
Fabian Frederickef748852014-06-06 14:37:31 -0700229 pr_err("No memory for compression workspace; skipping compression\n");
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700230 kfree(big_oops_buf);
231 big_oops_buf = NULL;
232 }
233 } else {
Fabian Frederickef748852014-06-06 14:37:31 -0700234 pr_err("No memory for uncompressed data; skipping compression\n");
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700235 stream.workspace = NULL;
236 }
237
238}
239
240/*
241 * Called when compression fails, since the printk buffer
242 * would be fetched for compression calling it again when
243 * compression fails would have moved the iterator of
244 * printk buffer which results in fetching old contents.
245 * Copy the recent messages from big_oops_buf to psinfo->buf
246 */
247static size_t copy_kmsg_to_buffer(int hsize, size_t len)
248{
249 size_t total_len;
250 size_t diff;
251
252 total_len = hsize + len;
253
254 if (total_len > psinfo->bufsize) {
255 diff = total_len - psinfo->bufsize + hsize;
256 memcpy(psinfo->buf, big_oops_buf, hsize);
257 memcpy(psinfo->buf + hsize, big_oops_buf + diff,
258 psinfo->bufsize - hsize);
259 total_len = psinfo->bufsize;
260 } else
261 memcpy(psinfo->buf, big_oops_buf, total_len);
262
263 return total_len;
264}
265
Tony Luckca01d6d2010-12-28 14:25:21 -0800266/*
267 * callback from kmsg_dump. (s2,l2) has the most recently
268 * written bytes, older bytes are in (s1,l1). Save as much
269 * as we can from the end of the buffer.
270 */
271static void pstore_dump(struct kmsg_dumper *dumper,
Kay Sieverse2ae7152012-06-15 14:07:51 +0200272 enum kmsg_dump_reason reason)
Tony Luckca01d6d2010-12-28 14:25:21 -0800273{
Kay Sieverse2ae7152012-06-15 14:07:51 +0200274 unsigned long total = 0;
Seiji Aguchi381b8722012-03-16 15:36:59 -0700275 const char *why;
Tony Luckca01d6d2010-12-28 14:25:21 -0800276 u64 id;
Matthew Garrettb94fdd02011-07-21 16:57:54 -0400277 unsigned int part = 1;
Don Zickusabd4d552011-08-12 10:54:51 -0700278 unsigned long flags = 0;
279 int is_locked = 0;
Kay Sieverse2ae7152012-06-15 14:07:51 +0200280 int ret;
Tony Luckca01d6d2010-12-28 14:25:21 -0800281
Seiji Aguchi381b8722012-03-16 15:36:59 -0700282 why = get_reason_str(reason);
Tony Luck9f6af272011-03-22 16:01:49 -0700283
Seiji Aguchi9f244e92013-01-11 18:09:41 +0000284 if (pstore_cannot_block_path(reason)) {
285 is_locked = spin_trylock_irqsave(&psinfo->buf_lock, flags);
286 if (!is_locked) {
287 pr_err("pstore dump routine blocked in %s path, may corrupt error record\n"
288 , in_nmi() ? "NMI" : why);
289 }
Don Zickusabd4d552011-08-12 10:54:51 -0700290 } else
291 spin_lock_irqsave(&psinfo->buf_lock, flags);
Tony Luckca01d6d2010-12-28 14:25:21 -0800292 oopscount++;
293 while (total < kmsg_bytes) {
Kay Sieverse2ae7152012-06-15 14:07:51 +0200294 char *dst;
295 unsigned long size;
296 int hsize;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700297 int zipped_len = -1;
Kay Sieverse2ae7152012-06-15 14:07:51 +0200298 size_t len;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700299 bool compressed;
300 size_t total_len;
Kay Sieverse2ae7152012-06-15 14:07:51 +0200301
Konstantin Khlebnikovf0e2efc2015-05-21 09:26:19 -0700302 if (big_oops_buf && is_locked) {
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700303 dst = big_oops_buf;
alex chena6b89782015-01-16 15:52:03 -0800304 hsize = sprintf(dst, "%s#%d Part%u\n", why,
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700305 oopscount, part);
306 size = big_oops_buf_sz - hsize;
Tony Luckca01d6d2010-12-28 14:25:21 -0800307
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700308 if (!kmsg_dump_get_buffer(dumper, true, dst + hsize,
309 size, &len))
310 break;
311
312 zipped_len = pstore_compress(dst, psinfo->buf,
313 hsize + len, psinfo->bufsize);
314
315 if (zipped_len > 0) {
316 compressed = true;
317 total_len = zipped_len;
318 } else {
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700319 compressed = false;
320 total_len = copy_kmsg_to_buffer(hsize, len);
321 }
322 } else {
323 dst = psinfo->buf;
alex chena6b89782015-01-16 15:52:03 -0800324 hsize = sprintf(dst, "%s#%d Part%u\n", why, oopscount,
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700325 part);
326 size = psinfo->bufsize - hsize;
327 dst += hsize;
328
329 if (!kmsg_dump_get_buffer(dumper, true, dst,
330 size, &len))
331 break;
332
333 compressed = false;
334 total_len = hsize + len;
335 }
Tony Luckca01d6d2010-12-28 14:25:21 -0800336
Kees Cook3d6d8d22011-11-17 13:13:29 -0800337 ret = psinfo->write(PSTORE_TYPE_DMESG, reason, &id, part,
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700338 oopscount, compressed, total_len, psinfo);
Chen Gongb238b8f2011-10-12 09:17:24 -0700339 if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted())
Luck, Tony6dda9262011-08-11 15:14:39 -0700340 pstore_new_entry = 1;
Kay Sieverse2ae7152012-06-15 14:07:51 +0200341
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700342 total += total_len;
Matthew Garrett56280682011-07-21 16:57:53 -0400343 part++;
Tony Luckca01d6d2010-12-28 14:25:21 -0800344 }
Seiji Aguchi9f244e92013-01-11 18:09:41 +0000345 if (pstore_cannot_block_path(reason)) {
Don Zickusabd4d552011-08-12 10:54:51 -0700346 if (is_locked)
Seiji Aguchi9f244e92013-01-11 18:09:41 +0000347 spin_unlock_irqrestore(&psinfo->buf_lock, flags);
Don Zickusabd4d552011-08-12 10:54:51 -0700348 } else
349 spin_unlock_irqrestore(&psinfo->buf_lock, flags);
Tony Luckca01d6d2010-12-28 14:25:21 -0800350}
351
352static struct kmsg_dumper pstore_dumper = {
353 .dump = pstore_dump,
354};
355
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700356#ifdef CONFIG_PSTORE_CONSOLE
357static void pstore_console_write(struct console *con, const char *s, unsigned c)
358{
359 const char *e = s + c;
360
361 while (s < e) {
362 unsigned long flags;
Colin Ian King70a6f462012-11-14 11:49:53 +0000363 u64 id;
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700364
365 if (c > psinfo->bufsize)
366 c = psinfo->bufsize;
Chuansheng Liu80c9d032012-09-18 01:43:44 +0800367
368 if (oops_in_progress) {
369 if (!spin_trylock_irqsave(&psinfo->buf_lock, flags))
370 break;
371 } else {
372 spin_lock_irqsave(&psinfo->buf_lock, flags);
373 }
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700374 memcpy(psinfo->buf, s, c);
Aruna Balakrishnaiah6bbbca72013-06-27 14:02:56 +0530375 psinfo->write(PSTORE_TYPE_CONSOLE, 0, &id, 0, 0, 0, c, psinfo);
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700376 spin_unlock_irqrestore(&psinfo->buf_lock, flags);
377 s += c;
378 c = e - s;
379 }
380}
381
382static struct console pstore_console = {
383 .name = "pstore",
384 .write = pstore_console_write,
385 .flags = CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME,
386 .index = -1,
387};
388
389static void pstore_register_console(void)
390{
391 register_console(&pstore_console);
392}
393#else
394static void pstore_register_console(void) {}
395#endif
396
Anton Vorontsov897dba02012-07-09 17:10:40 -0700397static int pstore_write_compat(enum pstore_type_id type,
398 enum kmsg_dump_reason reason,
Seiji Aguchi755d4fe2012-11-26 16:07:44 -0800399 u64 *id, unsigned int part, int count,
Aruna Balakrishnaiahb3b515b2013-08-16 13:52:47 -0700400 bool compressed, size_t size,
Aruna Balakrishnaiah6bbbca72013-06-27 14:02:56 +0530401 struct pstore_info *psi)
Anton Vorontsov897dba02012-07-09 17:10:40 -0700402{
Aruna Balakrishnaiahb3b515b2013-08-16 13:52:47 -0700403 return psi->write_buf(type, reason, id, part, psinfo->buf, compressed,
Aruna Balakrishnaiah6bbbca72013-06-27 14:02:56 +0530404 size, psi);
Anton Vorontsov897dba02012-07-09 17:10:40 -0700405}
406
Tony Luckca01d6d2010-12-28 14:25:21 -0800407/*
408 * platform specific persistent storage driver registers with
409 * us here. If pstore is already mounted, call the platform
410 * read function right away to populate the file system. If not
411 * then the pstore mount code will call us later to fill out
412 * the file system.
413 *
414 * Register with kmsg_dump to save last part of console log on panic.
415 */
416int pstore_register(struct pstore_info *psi)
417{
418 struct module *owner = psi->owner;
419
Lenny Szubowicz8e48b1a2013-06-28 17:11:33 -0400420 if (backend && strcmp(backend, psi->name))
421 return -EPERM;
422
Tony Luckca01d6d2010-12-28 14:25:21 -0800423 spin_lock(&pstore_lock);
424 if (psinfo) {
425 spin_unlock(&pstore_lock);
426 return -EBUSY;
427 }
Matthew Garrettdee28e72011-07-21 16:57:55 -0400428
Anton Vorontsov897dba02012-07-09 17:10:40 -0700429 if (!psi->write)
430 psi->write = pstore_write_compat;
Tony Luckca01d6d2010-12-28 14:25:21 -0800431 psinfo = psi;
Kees Cookf6f82852011-11-17 12:58:07 -0800432 mutex_init(&psinfo->read_mutex);
Tony Luckca01d6d2010-12-28 14:25:21 -0800433 spin_unlock(&pstore_lock);
434
435 if (owner && !try_module_get(owner)) {
436 psinfo = NULL;
437 return -EINVAL;
438 }
439
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700440 allocate_buf_for_compression();
441
Tony Luckca01d6d2010-12-28 14:25:21 -0800442 if (pstore_is_mounted())
Luck, Tony6dda9262011-08-11 15:14:39 -0700443 pstore_get_records(0);
Tony Luckca01d6d2010-12-28 14:25:21 -0800444
445 kmsg_dump_register(&pstore_dumper);
Luck, Tonydf36ac12013-12-18 15:17:10 -0800446
447 if ((psi->flags & PSTORE_FLAGS_FRAGILE) == 0) {
448 pstore_register_console();
449 pstore_register_ftrace();
Mark Salyzyn9d5438f2015-01-16 16:01:10 -0800450 pstore_register_pmsg();
Luck, Tonydf36ac12013-12-18 15:17:10 -0800451 }
Tony Luckca01d6d2010-12-28 14:25:21 -0800452
Anton Vorontsova3f5f072012-05-26 06:20:28 -0700453 if (pstore_update_ms >= 0) {
454 pstore_timer.expires = jiffies +
455 msecs_to_jiffies(pstore_update_ms);
456 add_timer(&pstore_timer);
457 }
Luck, Tony6dda9262011-08-11 15:14:39 -0700458
Wang Long42222c22015-05-21 09:34:22 -0700459 /*
460 * Update the module parameter backend, so it is visible
461 * through /sys/module/pstore/parameters/backend
462 */
463 backend = psi->name;
464
Fabian Frederickef748852014-06-06 14:37:31 -0700465 pr_info("Registered %s as persistent store backend\n", psi->name);
Lenny Szubowicz8e48b1a2013-06-28 17:11:33 -0400466
Tony Luckca01d6d2010-12-28 14:25:21 -0800467 return 0;
468}
469EXPORT_SYMBOL_GPL(pstore_register);
470
471/*
Luck, Tony6dda9262011-08-11 15:14:39 -0700472 * Read all the records from the persistent store. Create
473 * files in our filesystem. Don't warn about -EEXIST errors
474 * when we are re-scanning the backing store looking to add new
475 * error records.
Tony Luckca01d6d2010-12-28 14:25:21 -0800476 */
Luck, Tony6dda9262011-08-11 15:14:39 -0700477void pstore_get_records(int quiet)
Tony Luckca01d6d2010-12-28 14:25:21 -0800478{
479 struct pstore_info *psi = psinfo;
Kees Cookf6f82852011-11-17 12:58:07 -0800480 char *buf = NULL;
Chen Gong8d38d742011-05-16 10:58:57 -0700481 ssize_t size;
Tony Luckca01d6d2010-12-28 14:25:21 -0800482 u64 id;
Seiji Aguchi755d4fe2012-11-26 16:07:44 -0800483 int count;
Tony Luckca01d6d2010-12-28 14:25:21 -0800484 enum pstore_type_id type;
485 struct timespec time;
Chen Gong06cf91b2011-05-16 11:00:27 -0700486 int failed = 0, rc;
Aruna Balakrishnaiah9a4e1392013-08-16 13:53:19 -0700487 bool compressed;
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700488 int unzipped_len = -1;
Tony Luckca01d6d2010-12-28 14:25:21 -0800489
490 if (!psi)
491 return;
492
Kees Cookf6f82852011-11-17 12:58:07 -0800493 mutex_lock(&psi->read_mutex);
Kees Cook2174f6d2011-11-18 13:49:00 -0800494 if (psi->open && psi->open(psi))
Chen Gong06cf91b2011-05-16 11:00:27 -0700495 goto out;
496
Aruna Balakrishnaiah9a4e1392013-08-16 13:53:19 -0700497 while ((size = psi->read(&id, &type, &count, &time, &buf, &compressed,
498 psi)) > 0) {
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700499 if (compressed && (type == PSTORE_TYPE_DMESG)) {
500 if (big_oops_buf)
501 unzipped_len = pstore_decompress(buf,
502 big_oops_buf, size,
503 big_oops_buf_sz);
504
505 if (unzipped_len > 0) {
Liu ShuoXe32634f2014-03-12 21:34:06 +0800506 kfree(buf);
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700507 buf = big_oops_buf;
508 size = unzipped_len;
Aruna Balakrishnaiah9ad2cbe2013-08-16 13:53:39 -0700509 compressed = false;
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700510 } else {
Fabian Frederickef748852014-06-06 14:37:31 -0700511 pr_err("decompression failed;returned %d\n",
512 unzipped_len);
Aruna Balakrishnaiah9ad2cbe2013-08-16 13:53:39 -0700513 compressed = true;
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700514 }
515 }
Seiji Aguchi755d4fe2012-11-26 16:07:44 -0800516 rc = pstore_mkfile(type, psi->name, id, count, buf,
Aruna Balakrishnaiah9ad2cbe2013-08-16 13:53:39 -0700517 compressed, (size_t)size, time, psi);
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700518 if (unzipped_len < 0) {
519 /* Free buffer other than big oops */
520 kfree(buf);
521 buf = NULL;
522 } else
523 unzipped_len = -1;
Luck, Tony6dda9262011-08-11 15:14:39 -0700524 if (rc && (rc != -EEXIST || !quiet))
Tony Luckca01d6d2010-12-28 14:25:21 -0800525 failed++;
526 }
Kees Cook2174f6d2011-11-18 13:49:00 -0800527 if (psi->close)
528 psi->close(psi);
Chen Gong06cf91b2011-05-16 11:00:27 -0700529out:
Kees Cookf6f82852011-11-17 12:58:07 -0800530 mutex_unlock(&psi->read_mutex);
Tony Luckca01d6d2010-12-28 14:25:21 -0800531
532 if (failed)
Fabian Frederickef748852014-06-06 14:37:31 -0700533 pr_warn("failed to load %d record(s) from '%s'\n",
534 failed, psi->name);
Tony Luckca01d6d2010-12-28 14:25:21 -0800535}
536
Luck, Tony6dda9262011-08-11 15:14:39 -0700537static void pstore_dowork(struct work_struct *work)
538{
539 pstore_get_records(1);
540}
541
542static void pstore_timefunc(unsigned long dummy)
543{
544 if (pstore_new_entry) {
545 pstore_new_entry = 0;
546 schedule_work(&pstore_work);
547 }
548
Anton Vorontsova3f5f072012-05-26 06:20:28 -0700549 mod_timer(&pstore_timer, jiffies + msecs_to_jiffies(pstore_update_ms));
Luck, Tony6dda9262011-08-11 15:14:39 -0700550}
551
Matthew Garrettdee28e72011-07-21 16:57:55 -0400552module_param(backend, charp, 0444);
553MODULE_PARM_DESC(backend, "Pstore backend to use");