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Commit | Line | Data |
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ca01d6dd TL |
1 | /* |
2 | * Persistent Storage - ramfs 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/module.h> | |
21 | #include <linux/fs.h> | |
22 | #include <linux/fsnotify.h> | |
23 | #include <linux/pagemap.h> | |
24 | #include <linux/highmem.h> | |
25 | #include <linux/time.h> | |
26 | #include <linux/init.h> | |
6dda9266 | 27 | #include <linux/list.h> |
ca01d6dd TL |
28 | #include <linux/string.h> |
29 | #include <linux/mount.h> | |
060287b8 | 30 | #include <linux/seq_file.h> |
ca01d6dd | 31 | #include <linux/ramfs.h> |
366f7e7a | 32 | #include <linux/parser.h> |
ca01d6dd TL |
33 | #include <linux/sched.h> |
34 | #include <linux/magic.h> | |
35 | #include <linux/pstore.h> | |
36 | #include <linux/slab.h> | |
6dda9266 | 37 | #include <linux/spinlock.h> |
ca01d6dd | 38 | #include <linux/uaccess.h> |
68c4a4f8 | 39 | #include <linux/syslog.h> |
ca01d6dd TL |
40 | |
41 | #include "internal.h" | |
42 | ||
43 | #define PSTORE_NAMELEN 64 | |
44 | ||
6dda9266 TL |
45 | static DEFINE_SPINLOCK(allpstore_lock); |
46 | static LIST_HEAD(allpstore); | |
47 | ||
ca01d6dd | 48 | struct pstore_private { |
6dda9266 | 49 | struct list_head list; |
83f70f07 KC |
50 | struct pstore_record *record; |
51 | size_t total_size; | |
ca01d6dd TL |
52 | }; |
53 | ||
060287b8 AV |
54 | struct pstore_ftrace_seq_data { |
55 | const void *ptr; | |
56 | size_t off; | |
57 | size_t size; | |
58 | }; | |
59 | ||
60 | #define REC_SIZE sizeof(struct pstore_ftrace_record) | |
61 | ||
1dfff7dd KC |
62 | static void free_pstore_private(struct pstore_private *private) |
63 | { | |
64 | if (!private) | |
65 | return; | |
83f70f07 KC |
66 | if (private->record) { |
67 | kfree(private->record->buf); | |
68 | kfree(private->record); | |
69 | } | |
1dfff7dd KC |
70 | kfree(private); |
71 | } | |
72 | ||
060287b8 AV |
73 | static void *pstore_ftrace_seq_start(struct seq_file *s, loff_t *pos) |
74 | { | |
75 | struct pstore_private *ps = s->private; | |
76 | struct pstore_ftrace_seq_data *data; | |
77 | ||
78 | data = kzalloc(sizeof(*data), GFP_KERNEL); | |
79 | if (!data) | |
80 | return NULL; | |
81 | ||
83f70f07 | 82 | data->off = ps->total_size % REC_SIZE; |
060287b8 | 83 | data->off += *pos * REC_SIZE; |
83f70f07 | 84 | if (data->off + REC_SIZE > ps->total_size) { |
060287b8 AV |
85 | kfree(data); |
86 | return NULL; | |
87 | } | |
88 | ||
89 | return data; | |
90 | ||
91 | } | |
92 | ||
93 | static void pstore_ftrace_seq_stop(struct seq_file *s, void *v) | |
94 | { | |
95 | kfree(v); | |
96 | } | |
97 | ||
98 | static void *pstore_ftrace_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
99 | { | |
100 | struct pstore_private *ps = s->private; | |
101 | struct pstore_ftrace_seq_data *data = v; | |
102 | ||
103 | data->off += REC_SIZE; | |
83f70f07 | 104 | if (data->off + REC_SIZE > ps->total_size) |
060287b8 AV |
105 | return NULL; |
106 | ||
107 | (*pos)++; | |
108 | return data; | |
109 | } | |
110 | ||
111 | static int pstore_ftrace_seq_show(struct seq_file *s, void *v) | |
112 | { | |
113 | struct pstore_private *ps = s->private; | |
114 | struct pstore_ftrace_seq_data *data = v; | |
83f70f07 KC |
115 | struct pstore_ftrace_record *rec; |
116 | ||
117 | rec = (struct pstore_ftrace_record *)(ps->record->buf + data->off); | |
060287b8 | 118 | |
fbccdeb8 JF |
119 | seq_printf(s, "CPU:%d ts:%llu %08lx %08lx %pf <- %pF\n", |
120 | pstore_ftrace_decode_cpu(rec), | |
121 | pstore_ftrace_read_timestamp(rec), | |
122 | rec->ip, rec->parent_ip, (void *)rec->ip, | |
123 | (void *)rec->parent_ip); | |
060287b8 AV |
124 | |
125 | return 0; | |
126 | } | |
127 | ||
128 | static const struct seq_operations pstore_ftrace_seq_ops = { | |
129 | .start = pstore_ftrace_seq_start, | |
130 | .next = pstore_ftrace_seq_next, | |
131 | .stop = pstore_ftrace_seq_stop, | |
132 | .show = pstore_ftrace_seq_show, | |
133 | }; | |
134 | ||
68c4a4f8 SS |
135 | static int pstore_check_syslog_permissions(struct pstore_private *ps) |
136 | { | |
83f70f07 | 137 | switch (ps->record->type) { |
68c4a4f8 SS |
138 | case PSTORE_TYPE_DMESG: |
139 | case PSTORE_TYPE_CONSOLE: | |
140 | return check_syslog_permissions(SYSLOG_ACTION_READ_ALL, | |
141 | SYSLOG_FROM_READER); | |
142 | default: | |
143 | return 0; | |
144 | } | |
145 | } | |
146 | ||
fbe0aa1f TL |
147 | static ssize_t pstore_file_read(struct file *file, char __user *userbuf, |
148 | size_t count, loff_t *ppos) | |
149 | { | |
060287b8 AV |
150 | struct seq_file *sf = file->private_data; |
151 | struct pstore_private *ps = sf->private; | |
fbe0aa1f | 152 | |
83f70f07 | 153 | if (ps->record->type == PSTORE_TYPE_FTRACE) |
060287b8 | 154 | return seq_read(file, userbuf, count, ppos); |
83f70f07 KC |
155 | return simple_read_from_buffer(userbuf, count, ppos, |
156 | ps->record->buf, ps->total_size); | |
fbe0aa1f TL |
157 | } |
158 | ||
060287b8 AV |
159 | static int pstore_file_open(struct inode *inode, struct file *file) |
160 | { | |
161 | struct pstore_private *ps = inode->i_private; | |
162 | struct seq_file *sf; | |
163 | int err; | |
164 | const struct seq_operations *sops = NULL; | |
165 | ||
68c4a4f8 SS |
166 | err = pstore_check_syslog_permissions(ps); |
167 | if (err) | |
168 | return err; | |
169 | ||
83f70f07 | 170 | if (ps->record->type == PSTORE_TYPE_FTRACE) |
060287b8 AV |
171 | sops = &pstore_ftrace_seq_ops; |
172 | ||
173 | err = seq_open(file, sops); | |
174 | if (err < 0) | |
175 | return err; | |
176 | ||
177 | sf = file->private_data; | |
178 | sf->private = ps; | |
179 | ||
180 | return 0; | |
181 | } | |
182 | ||
965c8e59 | 183 | static loff_t pstore_file_llseek(struct file *file, loff_t off, int whence) |
060287b8 AV |
184 | { |
185 | struct seq_file *sf = file->private_data; | |
186 | ||
187 | if (sf->op) | |
965c8e59 AM |
188 | return seq_lseek(file, off, whence); |
189 | return default_llseek(file, off, whence); | |
060287b8 AV |
190 | } |
191 | ||
fbe0aa1f | 192 | static const struct file_operations pstore_file_operations = { |
060287b8 AV |
193 | .open = pstore_file_open, |
194 | .read = pstore_file_read, | |
195 | .llseek = pstore_file_llseek, | |
196 | .release = seq_release, | |
fbe0aa1f | 197 | }; |
ca01d6dd TL |
198 | |
199 | /* | |
200 | * When a file is unlinked from our file system we call the | |
201 | * platform driver to erase the record from persistent store. | |
202 | */ | |
203 | static int pstore_unlink(struct inode *dir, struct dentry *dentry) | |
204 | { | |
2b0143b5 | 205 | struct pstore_private *p = d_inode(dentry)->i_private; |
83f70f07 | 206 | struct pstore_record *record = p->record; |
68c4a4f8 SS |
207 | int err; |
208 | ||
209 | err = pstore_check_syslog_permissions(p); | |
210 | if (err) | |
211 | return err; | |
ca01d6dd | 212 | |
a61072aa | 213 | if (!record->psi->erase) |
bf288333 | 214 | return -EPERM; |
a61072aa KC |
215 | |
216 | mutex_lock(&record->psi->read_mutex); | |
217 | record->psi->erase(record); | |
218 | mutex_unlock(&record->psi->read_mutex); | |
ca01d6dd TL |
219 | |
220 | return simple_unlink(dir, dentry); | |
221 | } | |
222 | ||
a872d510 TL |
223 | static void pstore_evict_inode(struct inode *inode) |
224 | { | |
6dda9266 TL |
225 | struct pstore_private *p = inode->i_private; |
226 | unsigned long flags; | |
227 | ||
dbd5768f | 228 | clear_inode(inode); |
6dda9266 TL |
229 | if (p) { |
230 | spin_lock_irqsave(&allpstore_lock, flags); | |
231 | list_del(&p->list); | |
232 | spin_unlock_irqrestore(&allpstore_lock, flags); | |
1dfff7dd | 233 | free_pstore_private(p); |
6dda9266 | 234 | } |
a872d510 TL |
235 | } |
236 | ||
ca01d6dd TL |
237 | static const struct inode_operations pstore_dir_inode_operations = { |
238 | .lookup = simple_lookup, | |
239 | .unlink = pstore_unlink, | |
240 | }; | |
241 | ||
22a71c30 | 242 | static struct inode *pstore_get_inode(struct super_block *sb) |
fbe0aa1f TL |
243 | { |
244 | struct inode *inode = new_inode(sb); | |
fbe0aa1f TL |
245 | if (inode) { |
246 | inode->i_ino = get_next_ino(); | |
078cd827 | 247 | inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); |
fbe0aa1f TL |
248 | } |
249 | return inode; | |
250 | } | |
251 | ||
366f7e7a TL |
252 | enum { |
253 | Opt_kmsg_bytes, Opt_err | |
254 | }; | |
255 | ||
256 | static const match_table_t tokens = { | |
257 | {Opt_kmsg_bytes, "kmsg_bytes=%u"}, | |
258 | {Opt_err, NULL} | |
259 | }; | |
260 | ||
261 | static void parse_options(char *options) | |
262 | { | |
263 | char *p; | |
264 | substring_t args[MAX_OPT_ARGS]; | |
265 | int option; | |
266 | ||
267 | if (!options) | |
268 | return; | |
269 | ||
270 | while ((p = strsep(&options, ",")) != NULL) { | |
271 | int token; | |
272 | ||
273 | if (!*p) | |
274 | continue; | |
275 | ||
276 | token = match_token(p, tokens, args); | |
277 | switch (token) { | |
278 | case Opt_kmsg_bytes: | |
279 | if (!match_int(&args[0], &option)) | |
280 | pstore_set_kmsg_bytes(option); | |
281 | break; | |
282 | } | |
283 | } | |
284 | } | |
285 | ||
286 | static int pstore_remount(struct super_block *sb, int *flags, char *data) | |
287 | { | |
02b9984d | 288 | sync_filesystem(sb); |
366f7e7a TL |
289 | parse_options(data); |
290 | ||
291 | return 0; | |
292 | } | |
293 | ||
ca01d6dd TL |
294 | static const struct super_operations pstore_ops = { |
295 | .statfs = simple_statfs, | |
296 | .drop_inode = generic_delete_inode, | |
a872d510 | 297 | .evict_inode = pstore_evict_inode, |
366f7e7a | 298 | .remount_fs = pstore_remount, |
ca01d6dd TL |
299 | .show_options = generic_show_options, |
300 | }; | |
301 | ||
302 | static struct super_block *pstore_sb; | |
ca01d6dd | 303 | |
7e26e9ff | 304 | bool pstore_is_mounted(void) |
ca01d6dd | 305 | { |
fbe0aa1f | 306 | return pstore_sb != NULL; |
ca01d6dd TL |
307 | } |
308 | ||
309 | /* | |
310 | * Make a regular file in the root directory of our file system. | |
311 | * Load it up with "size" bytes of data from "buf". | |
312 | * Set the mtime & ctime to the date that this record was originally stored. | |
313 | */ | |
3a7d2fd1 | 314 | int pstore_mkfile(struct dentry *root, struct pstore_record *record) |
ca01d6dd | 315 | { |
ca01d6dd TL |
316 | struct dentry *dentry; |
317 | struct inode *inode; | |
6dda9266 | 318 | int rc = 0; |
ca01d6dd | 319 | char name[PSTORE_NAMELEN]; |
6dda9266 TL |
320 | struct pstore_private *private, *pos; |
321 | unsigned long flags; | |
1edd1aa3 | 322 | size_t size = record->size + record->ecc_notice_size; |
6dda9266 | 323 | |
3a7d2fd1 KC |
324 | WARN_ON(!inode_is_locked(d_inode(root))); |
325 | ||
6dda9266 TL |
326 | spin_lock_irqsave(&allpstore_lock, flags); |
327 | list_for_each_entry(pos, &allpstore, list) { | |
83f70f07 KC |
328 | if (pos->record->type == record->type && |
329 | pos->record->id == record->id && | |
330 | pos->record->psi == record->psi) { | |
6dda9266 TL |
331 | rc = -EEXIST; |
332 | break; | |
333 | } | |
334 | } | |
335 | spin_unlock_irqrestore(&allpstore_lock, flags); | |
336 | if (rc) | |
337 | return rc; | |
ca01d6dd TL |
338 | |
339 | rc = -ENOMEM; | |
3a7d2fd1 | 340 | inode = pstore_get_inode(root->d_sb); |
ca01d6dd TL |
341 | if (!inode) |
342 | goto fail; | |
22a71c30 AV |
343 | inode->i_mode = S_IFREG | 0444; |
344 | inode->i_fop = &pstore_file_operations; | |
1dfff7dd | 345 | private = kzalloc(sizeof(*private), GFP_KERNEL); |
ca01d6dd TL |
346 | if (!private) |
347 | goto fail_alloc; | |
83f70f07 | 348 | private->record = record; |
ca01d6dd | 349 | |
1edd1aa3 | 350 | switch (record->type) { |
ca01d6dd | 351 | case PSTORE_TYPE_DMESG: |
dbaffde7 | 352 | scnprintf(name, sizeof(name), "dmesg-%s-%lld%s", |
1edd1aa3 KC |
353 | record->psi->name, record->id, |
354 | record->compressed ? ".enc.z" : ""); | |
ca01d6dd | 355 | break; |
f29e5956 | 356 | case PSTORE_TYPE_CONSOLE: |
1edd1aa3 KC |
357 | scnprintf(name, sizeof(name), "console-%s-%lld", |
358 | record->psi->name, record->id); | |
f29e5956 | 359 | break; |
060287b8 | 360 | case PSTORE_TYPE_FTRACE: |
1edd1aa3 KC |
361 | scnprintf(name, sizeof(name), "ftrace-%s-%lld", |
362 | record->psi->name, record->id); | |
060287b8 | 363 | break; |
ca01d6dd | 364 | case PSTORE_TYPE_MCE: |
1edd1aa3 KC |
365 | scnprintf(name, sizeof(name), "mce-%s-%lld", |
366 | record->psi->name, record->id); | |
ca01d6dd | 367 | break; |
69020eea | 368 | case PSTORE_TYPE_PPC_RTAS: |
1edd1aa3 KC |
369 | scnprintf(name, sizeof(name), "rtas-%s-%lld", |
370 | record->psi->name, record->id); | |
69020eea | 371 | break; |
f33f748c | 372 | case PSTORE_TYPE_PPC_OF: |
dbaffde7 | 373 | scnprintf(name, sizeof(name), "powerpc-ofw-%s-%lld", |
1edd1aa3 | 374 | record->psi->name, record->id); |
f33f748c | 375 | break; |
a5e4797b | 376 | case PSTORE_TYPE_PPC_COMMON: |
dbaffde7 | 377 | scnprintf(name, sizeof(name), "powerpc-common-%s-%lld", |
1edd1aa3 | 378 | record->psi->name, record->id); |
a5e4797b | 379 | break; |
9d5438f4 | 380 | case PSTORE_TYPE_PMSG: |
1edd1aa3 KC |
381 | scnprintf(name, sizeof(name), "pmsg-%s-%lld", |
382 | record->psi->name, record->id); | |
9d5438f4 | 383 | break; |
ae011d2e | 384 | case PSTORE_TYPE_PPC_OPAL: |
1edd1aa3 KC |
385 | scnprintf(name, sizeof(name), "powerpc-opal-%s-%lld", |
386 | record->psi->name, record->id); | |
ae011d2e | 387 | break; |
ca01d6dd | 388 | case PSTORE_TYPE_UNKNOWN: |
1edd1aa3 KC |
389 | scnprintf(name, sizeof(name), "unknown-%s-%lld", |
390 | record->psi->name, record->id); | |
ca01d6dd TL |
391 | break; |
392 | default: | |
dbaffde7 | 393 | scnprintf(name, sizeof(name), "type%d-%s-%lld", |
1edd1aa3 | 394 | record->type, record->psi->name, record->id); |
ca01d6dd TL |
395 | break; |
396 | } | |
397 | ||
ca01d6dd | 398 | dentry = d_alloc_name(root, name); |
c39524e6 | 399 | if (!dentry) |
3a7d2fd1 | 400 | goto fail_private; |
ca01d6dd | 401 | |
83f70f07 | 402 | inode->i_size = private->total_size = size; |
ca01d6dd TL |
403 | |
404 | inode->i_private = private; | |
405 | ||
1edd1aa3 KC |
406 | if (record->time.tv_sec) |
407 | inode->i_mtime = inode->i_ctime = record->time; | |
ca01d6dd | 408 | |
fbe0aa1f | 409 | d_add(dentry, inode); |
ca01d6dd | 410 | |
6dda9266 TL |
411 | spin_lock_irqsave(&allpstore_lock, flags); |
412 | list_add(&private->list, &allpstore); | |
413 | spin_unlock_irqrestore(&allpstore_lock, flags); | |
414 | ||
fbe0aa1f | 415 | return 0; |
ca01d6dd | 416 | |
3a7d2fd1 | 417 | fail_private: |
1dfff7dd | 418 | free_pstore_private(private); |
ca01d6dd TL |
419 | fail_alloc: |
420 | iput(inode); | |
421 | ||
422 | fail: | |
423 | return rc; | |
424 | } | |
425 | ||
3a7d2fd1 KC |
426 | /* |
427 | * Read all the records from the persistent store. Create | |
428 | * files in our filesystem. Don't warn about -EEXIST errors | |
429 | * when we are re-scanning the backing store looking to add new | |
430 | * error records. | |
431 | */ | |
432 | void pstore_get_records(int quiet) | |
433 | { | |
434 | struct pstore_info *psi = psinfo; | |
435 | struct dentry *root; | |
436 | ||
437 | if (!psi || !pstore_sb) | |
438 | return; | |
439 | ||
440 | root = pstore_sb->s_root; | |
441 | ||
442 | inode_lock(d_inode(root)); | |
443 | pstore_get_backend_records(psi, root, quiet); | |
444 | inode_unlock(d_inode(root)); | |
445 | } | |
446 | ||
364ed2f4 | 447 | static int pstore_fill_super(struct super_block *sb, void *data, int silent) |
ca01d6dd | 448 | { |
318ceed0 | 449 | struct inode *inode; |
ca01d6dd TL |
450 | |
451 | save_mount_options(sb, data); | |
452 | ||
453 | pstore_sb = sb; | |
454 | ||
455 | sb->s_maxbytes = MAX_LFS_FILESIZE; | |
09cbfeaf KS |
456 | sb->s_blocksize = PAGE_SIZE; |
457 | sb->s_blocksize_bits = PAGE_SHIFT; | |
ca01d6dd TL |
458 | sb->s_magic = PSTOREFS_MAGIC; |
459 | sb->s_op = &pstore_ops; | |
460 | sb->s_time_gran = 1; | |
461 | ||
366f7e7a TL |
462 | parse_options(data); |
463 | ||
22a71c30 | 464 | inode = pstore_get_inode(sb); |
318ceed0 | 465 | if (inode) { |
22a71c30 | 466 | inode->i_mode = S_IFDIR | 0755; |
318ceed0 | 467 | inode->i_op = &pstore_dir_inode_operations; |
22a71c30 AV |
468 | inode->i_fop = &simple_dir_operations; |
469 | inc_nlink(inode); | |
ca01d6dd | 470 | } |
318ceed0 AV |
471 | sb->s_root = d_make_root(inode); |
472 | if (!sb->s_root) | |
473 | return -ENOMEM; | |
ca01d6dd | 474 | |
6dda9266 | 475 | pstore_get_records(0); |
ca01d6dd TL |
476 | |
477 | return 0; | |
ca01d6dd TL |
478 | } |
479 | ||
fbe0aa1f TL |
480 | static struct dentry *pstore_mount(struct file_system_type *fs_type, |
481 | int flags, const char *dev_name, void *data) | |
ca01d6dd | 482 | { |
fbe0aa1f | 483 | return mount_single(fs_type, flags, data, pstore_fill_super); |
ca01d6dd TL |
484 | } |
485 | ||
486 | static void pstore_kill_sb(struct super_block *sb) | |
487 | { | |
488 | kill_litter_super(sb); | |
489 | pstore_sb = NULL; | |
ca01d6dd TL |
490 | } |
491 | ||
492 | static struct file_system_type pstore_fs_type = { | |
ee1d2674 | 493 | .owner = THIS_MODULE, |
ca01d6dd | 494 | .name = "pstore", |
fbe0aa1f | 495 | .mount = pstore_mount, |
ca01d6dd TL |
496 | .kill_sb = pstore_kill_sb, |
497 | }; | |
498 | ||
499 | static int __init init_pstore_fs(void) | |
500 | { | |
f9bb4882 | 501 | int err; |
fb0af3f2 JB |
502 | |
503 | /* Create a convenient mount point for people to access pstore */ | |
f9bb4882 EB |
504 | err = sysfs_create_mount_point(fs_kobj, "pstore"); |
505 | if (err) | |
fb0af3f2 | 506 | goto out; |
fb0af3f2 JB |
507 | |
508 | err = register_filesystem(&pstore_fs_type); | |
509 | if (err < 0) | |
f9bb4882 | 510 | sysfs_remove_mount_point(fs_kobj, "pstore"); |
fb0af3f2 JB |
511 | |
512 | out: | |
513 | return err; | |
ca01d6dd TL |
514 | } |
515 | module_init(init_pstore_fs) | |
516 | ||
ee1d2674 GT |
517 | static void __exit exit_pstore_fs(void) |
518 | { | |
519 | unregister_filesystem(&pstore_fs_type); | |
520 | sysfs_remove_mount_point(fs_kobj, "pstore"); | |
521 | } | |
522 | module_exit(exit_pstore_fs) | |
523 | ||
ca01d6dd TL |
524 | MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>"); |
525 | MODULE_LICENSE("GPL"); |