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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; |
638c1fd3 | 50 | struct pstore_info *psi; |
56280682 MG |
51 | enum pstore_type_id type; |
52 | u64 id; | |
755d4fe4 | 53 | int count; |
fbe0aa1f TL |
54 | ssize_t size; |
55 | char data[]; | |
ca01d6dd TL |
56 | }; |
57 | ||
060287b8 AV |
58 | struct pstore_ftrace_seq_data { |
59 | const void *ptr; | |
60 | size_t off; | |
61 | size_t size; | |
62 | }; | |
63 | ||
64 | #define REC_SIZE sizeof(struct pstore_ftrace_record) | |
65 | ||
66 | static void *pstore_ftrace_seq_start(struct seq_file *s, loff_t *pos) | |
67 | { | |
68 | struct pstore_private *ps = s->private; | |
69 | struct pstore_ftrace_seq_data *data; | |
70 | ||
71 | data = kzalloc(sizeof(*data), GFP_KERNEL); | |
72 | if (!data) | |
73 | return NULL; | |
74 | ||
75 | data->off = ps->size % REC_SIZE; | |
76 | data->off += *pos * REC_SIZE; | |
77 | if (data->off + REC_SIZE > ps->size) { | |
78 | kfree(data); | |
79 | return NULL; | |
80 | } | |
81 | ||
82 | return data; | |
83 | ||
84 | } | |
85 | ||
86 | static void pstore_ftrace_seq_stop(struct seq_file *s, void *v) | |
87 | { | |
88 | kfree(v); | |
89 | } | |
90 | ||
91 | static void *pstore_ftrace_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
92 | { | |
93 | struct pstore_private *ps = s->private; | |
94 | struct pstore_ftrace_seq_data *data = v; | |
95 | ||
96 | data->off += REC_SIZE; | |
97 | if (data->off + REC_SIZE > ps->size) | |
98 | return NULL; | |
99 | ||
100 | (*pos)++; | |
101 | return data; | |
102 | } | |
103 | ||
104 | static int pstore_ftrace_seq_show(struct seq_file *s, void *v) | |
105 | { | |
106 | struct pstore_private *ps = s->private; | |
107 | struct pstore_ftrace_seq_data *data = v; | |
108 | struct pstore_ftrace_record *rec = (void *)(ps->data + data->off); | |
109 | ||
fbccdeb8 JF |
110 | seq_printf(s, "CPU:%d ts:%llu %08lx %08lx %pf <- %pF\n", |
111 | pstore_ftrace_decode_cpu(rec), | |
112 | pstore_ftrace_read_timestamp(rec), | |
113 | rec->ip, rec->parent_ip, (void *)rec->ip, | |
114 | (void *)rec->parent_ip); | |
060287b8 AV |
115 | |
116 | return 0; | |
117 | } | |
118 | ||
119 | static const struct seq_operations pstore_ftrace_seq_ops = { | |
120 | .start = pstore_ftrace_seq_start, | |
121 | .next = pstore_ftrace_seq_next, | |
122 | .stop = pstore_ftrace_seq_stop, | |
123 | .show = pstore_ftrace_seq_show, | |
124 | }; | |
125 | ||
68c4a4f8 SS |
126 | static int pstore_check_syslog_permissions(struct pstore_private *ps) |
127 | { | |
128 | switch (ps->type) { | |
129 | case PSTORE_TYPE_DMESG: | |
130 | case PSTORE_TYPE_CONSOLE: | |
131 | return check_syslog_permissions(SYSLOG_ACTION_READ_ALL, | |
132 | SYSLOG_FROM_READER); | |
133 | default: | |
134 | return 0; | |
135 | } | |
136 | } | |
137 | ||
fbe0aa1f TL |
138 | static ssize_t pstore_file_read(struct file *file, char __user *userbuf, |
139 | size_t count, loff_t *ppos) | |
140 | { | |
060287b8 AV |
141 | struct seq_file *sf = file->private_data; |
142 | struct pstore_private *ps = sf->private; | |
fbe0aa1f | 143 | |
060287b8 AV |
144 | if (ps->type == PSTORE_TYPE_FTRACE) |
145 | return seq_read(file, userbuf, count, ppos); | |
fbe0aa1f TL |
146 | return simple_read_from_buffer(userbuf, count, ppos, ps->data, ps->size); |
147 | } | |
148 | ||
060287b8 AV |
149 | static int pstore_file_open(struct inode *inode, struct file *file) |
150 | { | |
151 | struct pstore_private *ps = inode->i_private; | |
152 | struct seq_file *sf; | |
153 | int err; | |
154 | const struct seq_operations *sops = NULL; | |
155 | ||
68c4a4f8 SS |
156 | err = pstore_check_syslog_permissions(ps); |
157 | if (err) | |
158 | return err; | |
159 | ||
060287b8 AV |
160 | if (ps->type == PSTORE_TYPE_FTRACE) |
161 | sops = &pstore_ftrace_seq_ops; | |
162 | ||
163 | err = seq_open(file, sops); | |
164 | if (err < 0) | |
165 | return err; | |
166 | ||
167 | sf = file->private_data; | |
168 | sf->private = ps; | |
169 | ||
170 | return 0; | |
171 | } | |
172 | ||
965c8e59 | 173 | static loff_t pstore_file_llseek(struct file *file, loff_t off, int whence) |
060287b8 AV |
174 | { |
175 | struct seq_file *sf = file->private_data; | |
176 | ||
177 | if (sf->op) | |
965c8e59 AM |
178 | return seq_lseek(file, off, whence); |
179 | return default_llseek(file, off, whence); | |
060287b8 AV |
180 | } |
181 | ||
fbe0aa1f | 182 | static const struct file_operations pstore_file_operations = { |
060287b8 AV |
183 | .open = pstore_file_open, |
184 | .read = pstore_file_read, | |
185 | .llseek = pstore_file_llseek, | |
186 | .release = seq_release, | |
fbe0aa1f | 187 | }; |
ca01d6dd TL |
188 | |
189 | /* | |
190 | * When a file is unlinked from our file system we call the | |
191 | * platform driver to erase the record from persistent store. | |
192 | */ | |
193 | static int pstore_unlink(struct inode *dir, struct dentry *dentry) | |
194 | { | |
2b0143b5 | 195 | struct pstore_private *p = d_inode(dentry)->i_private; |
68c4a4f8 SS |
196 | int err; |
197 | ||
198 | err = pstore_check_syslog_permissions(p); | |
199 | if (err) | |
200 | return err; | |
ca01d6dd | 201 | |
e9e360b0 NK |
202 | if (p->psi->erase) { |
203 | mutex_lock(&p->psi->read_mutex); | |
755d4fe4 | 204 | p->psi->erase(p->type, p->id, p->count, |
2b0143b5 | 205 | d_inode(dentry)->i_ctime, p->psi); |
e9e360b0 NK |
206 | mutex_unlock(&p->psi->read_mutex); |
207 | } else { | |
bf288333 | 208 | return -EPERM; |
e9e360b0 | 209 | } |
ca01d6dd TL |
210 | |
211 | return simple_unlink(dir, dentry); | |
212 | } | |
213 | ||
a872d510 TL |
214 | static void pstore_evict_inode(struct inode *inode) |
215 | { | |
6dda9266 TL |
216 | struct pstore_private *p = inode->i_private; |
217 | unsigned long flags; | |
218 | ||
dbd5768f | 219 | clear_inode(inode); |
6dda9266 TL |
220 | if (p) { |
221 | spin_lock_irqsave(&allpstore_lock, flags); | |
222 | list_del(&p->list); | |
223 | spin_unlock_irqrestore(&allpstore_lock, flags); | |
224 | kfree(p); | |
225 | } | |
a872d510 TL |
226 | } |
227 | ||
ca01d6dd TL |
228 | static const struct inode_operations pstore_dir_inode_operations = { |
229 | .lookup = simple_lookup, | |
230 | .unlink = pstore_unlink, | |
231 | }; | |
232 | ||
22a71c30 | 233 | static struct inode *pstore_get_inode(struct super_block *sb) |
fbe0aa1f TL |
234 | { |
235 | struct inode *inode = new_inode(sb); | |
fbe0aa1f TL |
236 | if (inode) { |
237 | inode->i_ino = get_next_ino(); | |
078cd827 | 238 | inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); |
fbe0aa1f TL |
239 | } |
240 | return inode; | |
241 | } | |
242 | ||
366f7e7a TL |
243 | enum { |
244 | Opt_kmsg_bytes, Opt_err | |
245 | }; | |
246 | ||
247 | static const match_table_t tokens = { | |
248 | {Opt_kmsg_bytes, "kmsg_bytes=%u"}, | |
249 | {Opt_err, NULL} | |
250 | }; | |
251 | ||
252 | static void parse_options(char *options) | |
253 | { | |
254 | char *p; | |
255 | substring_t args[MAX_OPT_ARGS]; | |
256 | int option; | |
257 | ||
258 | if (!options) | |
259 | return; | |
260 | ||
261 | while ((p = strsep(&options, ",")) != NULL) { | |
262 | int token; | |
263 | ||
264 | if (!*p) | |
265 | continue; | |
266 | ||
267 | token = match_token(p, tokens, args); | |
268 | switch (token) { | |
269 | case Opt_kmsg_bytes: | |
270 | if (!match_int(&args[0], &option)) | |
271 | pstore_set_kmsg_bytes(option); | |
272 | break; | |
273 | } | |
274 | } | |
275 | } | |
276 | ||
277 | static int pstore_remount(struct super_block *sb, int *flags, char *data) | |
278 | { | |
02b9984d | 279 | sync_filesystem(sb); |
366f7e7a TL |
280 | parse_options(data); |
281 | ||
282 | return 0; | |
283 | } | |
284 | ||
ca01d6dd TL |
285 | static const struct super_operations pstore_ops = { |
286 | .statfs = simple_statfs, | |
287 | .drop_inode = generic_delete_inode, | |
a872d510 | 288 | .evict_inode = pstore_evict_inode, |
366f7e7a | 289 | .remount_fs = pstore_remount, |
ca01d6dd TL |
290 | .show_options = generic_show_options, |
291 | }; | |
292 | ||
293 | static struct super_block *pstore_sb; | |
ca01d6dd | 294 | |
7e26e9ff | 295 | bool pstore_is_mounted(void) |
ca01d6dd | 296 | { |
fbe0aa1f | 297 | return pstore_sb != NULL; |
ca01d6dd TL |
298 | } |
299 | ||
300 | /* | |
301 | * Make a regular file in the root directory of our file system. | |
302 | * Load it up with "size" bytes of data from "buf". | |
303 | * Set the mtime & ctime to the date that this record was originally stored. | |
304 | */ | |
755d4fe4 | 305 | int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count, |
9ad2cbe0 AB |
306 | char *data, bool compressed, size_t size, |
307 | struct timespec time, struct pstore_info *psi) | |
ca01d6dd TL |
308 | { |
309 | struct dentry *root = pstore_sb->s_root; | |
310 | struct dentry *dentry; | |
311 | struct inode *inode; | |
6dda9266 | 312 | int rc = 0; |
ca01d6dd | 313 | char name[PSTORE_NAMELEN]; |
6dda9266 TL |
314 | struct pstore_private *private, *pos; |
315 | unsigned long flags; | |
316 | ||
317 | spin_lock_irqsave(&allpstore_lock, flags); | |
318 | list_for_each_entry(pos, &allpstore, list) { | |
319 | if (pos->type == type && | |
320 | pos->id == id && | |
321 | pos->psi == psi) { | |
322 | rc = -EEXIST; | |
323 | break; | |
324 | } | |
325 | } | |
326 | spin_unlock_irqrestore(&allpstore_lock, flags); | |
327 | if (rc) | |
328 | return rc; | |
ca01d6dd TL |
329 | |
330 | rc = -ENOMEM; | |
22a71c30 | 331 | inode = pstore_get_inode(pstore_sb); |
ca01d6dd TL |
332 | if (!inode) |
333 | goto fail; | |
22a71c30 AV |
334 | inode->i_mode = S_IFREG | 0444; |
335 | inode->i_fop = &pstore_file_operations; | |
fbe0aa1f | 336 | private = kmalloc(sizeof *private + size, GFP_KERNEL); |
ca01d6dd TL |
337 | if (!private) |
338 | goto fail_alloc; | |
56280682 | 339 | private->type = type; |
ca01d6dd | 340 | private->id = id; |
755d4fe4 | 341 | private->count = count; |
638c1fd3 | 342 | private->psi = psi; |
ca01d6dd TL |
343 | |
344 | switch (type) { | |
345 | case PSTORE_TYPE_DMESG: | |
dbaffde7 MS |
346 | scnprintf(name, sizeof(name), "dmesg-%s-%lld%s", |
347 | psname, id, compressed ? ".enc.z" : ""); | |
ca01d6dd | 348 | break; |
f29e5956 | 349 | case PSTORE_TYPE_CONSOLE: |
dbaffde7 | 350 | scnprintf(name, sizeof(name), "console-%s-%lld", psname, id); |
f29e5956 | 351 | break; |
060287b8 | 352 | case PSTORE_TYPE_FTRACE: |
dbaffde7 | 353 | scnprintf(name, sizeof(name), "ftrace-%s-%lld", psname, id); |
060287b8 | 354 | break; |
ca01d6dd | 355 | case PSTORE_TYPE_MCE: |
dbaffde7 | 356 | scnprintf(name, sizeof(name), "mce-%s-%lld", psname, id); |
ca01d6dd | 357 | break; |
69020eea | 358 | case PSTORE_TYPE_PPC_RTAS: |
dbaffde7 | 359 | scnprintf(name, sizeof(name), "rtas-%s-%lld", psname, id); |
69020eea | 360 | break; |
f33f748c | 361 | case PSTORE_TYPE_PPC_OF: |
dbaffde7 MS |
362 | scnprintf(name, sizeof(name), "powerpc-ofw-%s-%lld", |
363 | psname, id); | |
f33f748c | 364 | break; |
a5e4797b | 365 | case PSTORE_TYPE_PPC_COMMON: |
dbaffde7 MS |
366 | scnprintf(name, sizeof(name), "powerpc-common-%s-%lld", |
367 | psname, id); | |
a5e4797b | 368 | break; |
9d5438f4 MS |
369 | case PSTORE_TYPE_PMSG: |
370 | scnprintf(name, sizeof(name), "pmsg-%s-%lld", psname, id); | |
371 | break; | |
ae011d2e HB |
372 | case PSTORE_TYPE_PPC_OPAL: |
373 | sprintf(name, "powerpc-opal-%s-%lld", psname, id); | |
374 | break; | |
ca01d6dd | 375 | case PSTORE_TYPE_UNKNOWN: |
dbaffde7 | 376 | scnprintf(name, sizeof(name), "unknown-%s-%lld", psname, id); |
ca01d6dd TL |
377 | break; |
378 | default: | |
dbaffde7 MS |
379 | scnprintf(name, sizeof(name), "type%d-%s-%lld", |
380 | type, psname, id); | |
ca01d6dd TL |
381 | break; |
382 | } | |
383 | ||
5955102c | 384 | inode_lock(d_inode(root)); |
ca01d6dd | 385 | |
ca01d6dd | 386 | dentry = d_alloc_name(root, name); |
c39524e6 | 387 | if (!dentry) |
ca01d6dd TL |
388 | goto fail_lockedalloc; |
389 | ||
fbe0aa1f TL |
390 | memcpy(private->data, data, size); |
391 | inode->i_size = private->size = size; | |
ca01d6dd TL |
392 | |
393 | inode->i_private = private; | |
394 | ||
395 | if (time.tv_sec) | |
396 | inode->i_mtime = inode->i_ctime = time; | |
397 | ||
fbe0aa1f | 398 | d_add(dentry, inode); |
ca01d6dd | 399 | |
6dda9266 TL |
400 | spin_lock_irqsave(&allpstore_lock, flags); |
401 | list_add(&private->list, &allpstore); | |
402 | spin_unlock_irqrestore(&allpstore_lock, flags); | |
403 | ||
5955102c | 404 | inode_unlock(d_inode(root)); |
fbe0aa1f TL |
405 | |
406 | return 0; | |
ca01d6dd TL |
407 | |
408 | fail_lockedalloc: | |
5955102c | 409 | inode_unlock(d_inode(root)); |
ca01d6dd TL |
410 | kfree(private); |
411 | fail_alloc: | |
412 | iput(inode); | |
413 | ||
414 | fail: | |
415 | return rc; | |
416 | } | |
417 | ||
364ed2f4 | 418 | static int pstore_fill_super(struct super_block *sb, void *data, int silent) |
ca01d6dd | 419 | { |
318ceed0 | 420 | struct inode *inode; |
ca01d6dd TL |
421 | |
422 | save_mount_options(sb, data); | |
423 | ||
424 | pstore_sb = sb; | |
425 | ||
426 | sb->s_maxbytes = MAX_LFS_FILESIZE; | |
09cbfeaf KS |
427 | sb->s_blocksize = PAGE_SIZE; |
428 | sb->s_blocksize_bits = PAGE_SHIFT; | |
ca01d6dd TL |
429 | sb->s_magic = PSTOREFS_MAGIC; |
430 | sb->s_op = &pstore_ops; | |
431 | sb->s_time_gran = 1; | |
432 | ||
366f7e7a TL |
433 | parse_options(data); |
434 | ||
22a71c30 | 435 | inode = pstore_get_inode(sb); |
318ceed0 | 436 | if (inode) { |
22a71c30 | 437 | inode->i_mode = S_IFDIR | 0755; |
318ceed0 | 438 | inode->i_op = &pstore_dir_inode_operations; |
22a71c30 AV |
439 | inode->i_fop = &simple_dir_operations; |
440 | inc_nlink(inode); | |
ca01d6dd | 441 | } |
318ceed0 AV |
442 | sb->s_root = d_make_root(inode); |
443 | if (!sb->s_root) | |
444 | return -ENOMEM; | |
ca01d6dd | 445 | |
6dda9266 | 446 | pstore_get_records(0); |
ca01d6dd TL |
447 | |
448 | return 0; | |
ca01d6dd TL |
449 | } |
450 | ||
fbe0aa1f TL |
451 | static struct dentry *pstore_mount(struct file_system_type *fs_type, |
452 | int flags, const char *dev_name, void *data) | |
ca01d6dd | 453 | { |
fbe0aa1f | 454 | return mount_single(fs_type, flags, data, pstore_fill_super); |
ca01d6dd TL |
455 | } |
456 | ||
457 | static void pstore_kill_sb(struct super_block *sb) | |
458 | { | |
459 | kill_litter_super(sb); | |
460 | pstore_sb = NULL; | |
ca01d6dd TL |
461 | } |
462 | ||
463 | static struct file_system_type pstore_fs_type = { | |
ee1d2674 | 464 | .owner = THIS_MODULE, |
ca01d6dd | 465 | .name = "pstore", |
fbe0aa1f | 466 | .mount = pstore_mount, |
ca01d6dd TL |
467 | .kill_sb = pstore_kill_sb, |
468 | }; | |
469 | ||
470 | static int __init init_pstore_fs(void) | |
471 | { | |
f9bb4882 | 472 | int err; |
fb0af3f2 JB |
473 | |
474 | /* Create a convenient mount point for people to access pstore */ | |
f9bb4882 EB |
475 | err = sysfs_create_mount_point(fs_kobj, "pstore"); |
476 | if (err) | |
fb0af3f2 | 477 | goto out; |
fb0af3f2 JB |
478 | |
479 | err = register_filesystem(&pstore_fs_type); | |
480 | if (err < 0) | |
f9bb4882 | 481 | sysfs_remove_mount_point(fs_kobj, "pstore"); |
fb0af3f2 JB |
482 | |
483 | out: | |
484 | return err; | |
ca01d6dd TL |
485 | } |
486 | module_init(init_pstore_fs) | |
487 | ||
ee1d2674 GT |
488 | static void __exit exit_pstore_fs(void) |
489 | { | |
490 | unregister_filesystem(&pstore_fs_type); | |
491 | sysfs_remove_mount_point(fs_kobj, "pstore"); | |
492 | } | |
493 | module_exit(exit_pstore_fs) | |
494 | ||
ca01d6dd TL |
495 | MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>"); |
496 | MODULE_LICENSE("GPL"); |