Commit | Line | Data |
---|---|---|
ca01d6dd TL |
1 | /* |
2 | * Persistent Storage - platform driver interface parts. | |
3 | * | |
4 | * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com> | |
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 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | */ | |
19 | ||
20 | #include <linux/atomic.h> | |
21 | #include <linux/types.h> | |
22 | #include <linux/errno.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/kmsg_dump.h> | |
25 | #include <linux/module.h> | |
26 | #include <linux/pstore.h> | |
27 | #include <linux/string.h> | |
6dda9266 | 28 | #include <linux/timer.h> |
ca01d6dd TL |
29 | #include <linux/slab.h> |
30 | #include <linux/uaccess.h> | |
abd4d558 | 31 | #include <linux/hardirq.h> |
6dda9266 | 32 | #include <linux/workqueue.h> |
ca01d6dd TL |
33 | |
34 | #include "internal.h" | |
35 | ||
6dda9266 LT |
36 | /* |
37 | * We defer making "oops" entries appear in pstore - see | |
38 | * whether the system is actually still running well enough | |
39 | * to let someone see the entry | |
40 | */ | |
41 | #define PSTORE_INTERVAL (60 * HZ) | |
42 | ||
43 | static int pstore_new_entry; | |
44 | ||
45 | static void pstore_timefunc(unsigned long); | |
46 | static DEFINE_TIMER(pstore_timer, pstore_timefunc, 0, 0); | |
47 | ||
48 | static void pstore_dowork(struct work_struct *); | |
49 | static DECLARE_WORK(pstore_work, pstore_dowork); | |
50 | ||
ca01d6dd TL |
51 | /* |
52 | * pstore_lock just protects "psinfo" during | |
53 | * calls to pstore_register() | |
54 | */ | |
55 | static DEFINE_SPINLOCK(pstore_lock); | |
56 | static struct pstore_info *psinfo; | |
57 | ||
dee28e72 MG |
58 | static char *backend; |
59 | ||
366f7e7a | 60 | /* How much of the console log to snapshot */ |
ca01d6dd TL |
61 | static unsigned long kmsg_bytes = 10240; |
62 | ||
366f7e7a | 63 | void pstore_set_kmsg_bytes(int bytes) |
ca01d6dd | 64 | { |
366f7e7a | 65 | kmsg_bytes = bytes; |
ca01d6dd TL |
66 | } |
67 | ||
ca01d6dd TL |
68 | /* Tag each group of saved records with a sequence number */ |
69 | static int oopscount; | |
70 | ||
381b872c SA |
71 | static const char *get_reason_str(enum kmsg_dump_reason reason) |
72 | { | |
73 | switch (reason) { | |
74 | case KMSG_DUMP_PANIC: | |
75 | return "Panic"; | |
76 | case KMSG_DUMP_OOPS: | |
77 | return "Oops"; | |
78 | case KMSG_DUMP_EMERG: | |
79 | return "Emergency"; | |
80 | case KMSG_DUMP_RESTART: | |
81 | return "Restart"; | |
82 | case KMSG_DUMP_HALT: | |
83 | return "Halt"; | |
84 | case KMSG_DUMP_POWEROFF: | |
85 | return "Poweroff"; | |
86 | default: | |
87 | return "Unknown"; | |
88 | } | |
89 | } | |
9f6af27f | 90 | |
ca01d6dd TL |
91 | /* |
92 | * callback from kmsg_dump. (s2,l2) has the most recently | |
93 | * written bytes, older bytes are in (s1,l1). Save as much | |
94 | * as we can from the end of the buffer. | |
95 | */ | |
96 | static void pstore_dump(struct kmsg_dumper *dumper, | |
e2ae715d | 97 | enum kmsg_dump_reason reason) |
ca01d6dd | 98 | { |
e2ae715d | 99 | unsigned long total = 0; |
381b872c | 100 | const char *why; |
ca01d6dd | 101 | u64 id; |
b94fdd07 | 102 | unsigned int part = 1; |
abd4d558 DZ |
103 | unsigned long flags = 0; |
104 | int is_locked = 0; | |
e2ae715d | 105 | int ret; |
ca01d6dd | 106 | |
381b872c | 107 | why = get_reason_str(reason); |
9f6af27f | 108 | |
abd4d558 DZ |
109 | if (in_nmi()) { |
110 | is_locked = spin_trylock(&psinfo->buf_lock); | |
111 | if (!is_locked) | |
112 | pr_err("pstore dump routine blocked in NMI, may corrupt error record\n"); | |
113 | } else | |
114 | spin_lock_irqsave(&psinfo->buf_lock, flags); | |
ca01d6dd TL |
115 | oopscount++; |
116 | while (total < kmsg_bytes) { | |
e2ae715d KS |
117 | char *dst; |
118 | unsigned long size; | |
119 | int hsize; | |
120 | size_t len; | |
121 | ||
ca01d6dd | 122 | dst = psinfo->buf; |
56280682 | 123 | hsize = sprintf(dst, "%s#%d Part%d\n", why, oopscount, part); |
ca01d6dd TL |
124 | size = psinfo->bufsize - hsize; |
125 | dst += hsize; | |
126 | ||
e2ae715d | 127 | if (!kmsg_dump_get_buffer(dumper, true, dst, size, &len)) |
ca01d6dd TL |
128 | break; |
129 | ||
3d6d8d20 | 130 | ret = psinfo->write(PSTORE_TYPE_DMESG, reason, &id, part, |
e2ae715d | 131 | hsize + len, psinfo); |
b238b8fa | 132 | if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted()) |
6dda9266 | 133 | pstore_new_entry = 1; |
e2ae715d KS |
134 | |
135 | total += hsize + len; | |
56280682 | 136 | part++; |
ca01d6dd | 137 | } |
abd4d558 DZ |
138 | if (in_nmi()) { |
139 | if (is_locked) | |
140 | spin_unlock(&psinfo->buf_lock); | |
141 | } else | |
142 | spin_unlock_irqrestore(&psinfo->buf_lock, flags); | |
ca01d6dd TL |
143 | } |
144 | ||
145 | static struct kmsg_dumper pstore_dumper = { | |
146 | .dump = pstore_dump, | |
147 | }; | |
148 | ||
149 | /* | |
150 | * platform specific persistent storage driver registers with | |
151 | * us here. If pstore is already mounted, call the platform | |
152 | * read function right away to populate the file system. If not | |
153 | * then the pstore mount code will call us later to fill out | |
154 | * the file system. | |
155 | * | |
156 | * Register with kmsg_dump to save last part of console log on panic. | |
157 | */ | |
158 | int pstore_register(struct pstore_info *psi) | |
159 | { | |
160 | struct module *owner = psi->owner; | |
161 | ||
162 | spin_lock(&pstore_lock); | |
163 | if (psinfo) { | |
164 | spin_unlock(&pstore_lock); | |
165 | return -EBUSY; | |
166 | } | |
dee28e72 MG |
167 | |
168 | if (backend && strcmp(backend, psi->name)) { | |
169 | spin_unlock(&pstore_lock); | |
170 | return -EINVAL; | |
171 | } | |
172 | ||
ca01d6dd | 173 | psinfo = psi; |
f6f82851 | 174 | mutex_init(&psinfo->read_mutex); |
ca01d6dd TL |
175 | spin_unlock(&pstore_lock); |
176 | ||
177 | if (owner && !try_module_get(owner)) { | |
178 | psinfo = NULL; | |
179 | return -EINVAL; | |
180 | } | |
181 | ||
182 | if (pstore_is_mounted()) | |
6dda9266 | 183 | pstore_get_records(0); |
ca01d6dd TL |
184 | |
185 | kmsg_dump_register(&pstore_dumper); | |
186 | ||
6dda9266 LT |
187 | pstore_timer.expires = jiffies + PSTORE_INTERVAL; |
188 | add_timer(&pstore_timer); | |
189 | ||
ca01d6dd TL |
190 | return 0; |
191 | } | |
192 | EXPORT_SYMBOL_GPL(pstore_register); | |
193 | ||
194 | /* | |
6dda9266 LT |
195 | * Read all the records from the persistent store. Create |
196 | * files in our filesystem. Don't warn about -EEXIST errors | |
197 | * when we are re-scanning the backing store looking to add new | |
198 | * error records. | |
ca01d6dd | 199 | */ |
6dda9266 | 200 | void pstore_get_records(int quiet) |
ca01d6dd TL |
201 | { |
202 | struct pstore_info *psi = psinfo; | |
f6f82851 | 203 | char *buf = NULL; |
8d38d74b | 204 | ssize_t size; |
ca01d6dd TL |
205 | u64 id; |
206 | enum pstore_type_id type; | |
207 | struct timespec time; | |
06cf91b4 | 208 | int failed = 0, rc; |
ca01d6dd TL |
209 | |
210 | if (!psi) | |
211 | return; | |
212 | ||
f6f82851 | 213 | mutex_lock(&psi->read_mutex); |
2174f6df | 214 | if (psi->open && psi->open(psi)) |
06cf91b4 CG |
215 | goto out; |
216 | ||
f6f82851 KC |
217 | while ((size = psi->read(&id, &type, &time, &buf, psi)) > 0) { |
218 | rc = pstore_mkfile(type, psi->name, id, buf, (size_t)size, | |
6dda9266 | 219 | time, psi); |
f6f82851 KC |
220 | kfree(buf); |
221 | buf = NULL; | |
6dda9266 | 222 | if (rc && (rc != -EEXIST || !quiet)) |
ca01d6dd TL |
223 | failed++; |
224 | } | |
2174f6df KC |
225 | if (psi->close) |
226 | psi->close(psi); | |
06cf91b4 | 227 | out: |
f6f82851 | 228 | mutex_unlock(&psi->read_mutex); |
ca01d6dd TL |
229 | |
230 | if (failed) | |
231 | printk(KERN_WARNING "pstore: failed to load %d record(s) from '%s'\n", | |
232 | failed, psi->name); | |
233 | } | |
234 | ||
6dda9266 LT |
235 | static void pstore_dowork(struct work_struct *work) |
236 | { | |
237 | pstore_get_records(1); | |
238 | } | |
239 | ||
240 | static void pstore_timefunc(unsigned long dummy) | |
241 | { | |
242 | if (pstore_new_entry) { | |
243 | pstore_new_entry = 0; | |
244 | schedule_work(&pstore_work); | |
245 | } | |
246 | ||
247 | mod_timer(&pstore_timer, jiffies + PSTORE_INTERVAL); | |
248 | } | |
249 | ||
dee28e72 MG |
250 | module_param(backend, charp, 0444); |
251 | MODULE_PARM_DESC(backend, "Pstore backend to use"); |