blob: 192297b0090da25026bb5ee9b8033b48ccca927e [file] [log] [blame]
Tony Luckca01d6d2010-12-28 14:25:21 -08001/*
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>
Luck, Tony6dda9262011-08-11 15:14:39 -070027#include <linux/list.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080028#include <linux/string.h>
29#include <linux/mount.h>
Anton Vorontsov060287b2012-07-09 17:10:41 -070030#include <linux/seq_file.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080031#include <linux/ramfs.h>
Luck, Tony366f7e72011-03-18 15:33:43 -070032#include <linux/parser.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080033#include <linux/sched.h>
34#include <linux/magic.h>
35#include <linux/pstore.h>
36#include <linux/slab.h>
Luck, Tony6dda9262011-08-11 15:14:39 -070037#include <linux/spinlock.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080038#include <linux/uaccess.h>
39
40#include "internal.h"
41
42#define PSTORE_NAMELEN 64
43
Luck, Tony6dda9262011-08-11 15:14:39 -070044static DEFINE_SPINLOCK(allpstore_lock);
45static LIST_HEAD(allpstore);
46
Tony Luckca01d6d2010-12-28 14:25:21 -080047struct pstore_private {
Luck, Tony6dda9262011-08-11 15:14:39 -070048 struct list_head list;
Matthew Garrett638c1fd2011-07-21 16:57:52 -040049 struct pstore_info *psi;
Matthew Garrett56280682011-07-21 16:57:53 -040050 enum pstore_type_id type;
51 u64 id;
Seiji Aguchi755d4fe2012-11-26 16:07:44 -080052 int count;
Tony Luckfbe0aa12011-03-17 16:29:15 -070053 ssize_t size;
54 char data[];
Tony Luckca01d6d2010-12-28 14:25:21 -080055};
56
Anton Vorontsov060287b2012-07-09 17:10:41 -070057struct pstore_ftrace_seq_data {
58 const void *ptr;
59 size_t off;
60 size_t size;
61};
62
63#define REC_SIZE sizeof(struct pstore_ftrace_record)
64
65static void *pstore_ftrace_seq_start(struct seq_file *s, loff_t *pos)
66{
67 struct pstore_private *ps = s->private;
68 struct pstore_ftrace_seq_data *data;
69
70 data = kzalloc(sizeof(*data), GFP_KERNEL);
71 if (!data)
72 return NULL;
73
74 data->off = ps->size % REC_SIZE;
75 data->off += *pos * REC_SIZE;
76 if (data->off + REC_SIZE > ps->size) {
77 kfree(data);
78 return NULL;
79 }
80
81 return data;
82
83}
84
85static void pstore_ftrace_seq_stop(struct seq_file *s, void *v)
86{
87 kfree(v);
88}
89
90static void *pstore_ftrace_seq_next(struct seq_file *s, void *v, loff_t *pos)
91{
92 struct pstore_private *ps = s->private;
93 struct pstore_ftrace_seq_data *data = v;
94
95 data->off += REC_SIZE;
96 if (data->off + REC_SIZE > ps->size)
97 return NULL;
98
99 (*pos)++;
100 return data;
101}
102
103static int pstore_ftrace_seq_show(struct seq_file *s, void *v)
104{
105 struct pstore_private *ps = s->private;
106 struct pstore_ftrace_seq_data *data = v;
107 struct pstore_ftrace_record *rec = (void *)(ps->data + data->off);
108
109 seq_printf(s, "%d %08lx %08lx %pf <- %pF\n",
110 pstore_ftrace_decode_cpu(rec), rec->ip, rec->parent_ip,
111 (void *)rec->ip, (void *)rec->parent_ip);
112
113 return 0;
114}
115
116static const struct seq_operations pstore_ftrace_seq_ops = {
117 .start = pstore_ftrace_seq_start,
118 .next = pstore_ftrace_seq_next,
119 .stop = pstore_ftrace_seq_stop,
120 .show = pstore_ftrace_seq_show,
121};
122
Tony Luckfbe0aa12011-03-17 16:29:15 -0700123static ssize_t pstore_file_read(struct file *file, char __user *userbuf,
124 size_t count, loff_t *ppos)
125{
Anton Vorontsov060287b2012-07-09 17:10:41 -0700126 struct seq_file *sf = file->private_data;
127 struct pstore_private *ps = sf->private;
Tony Luckfbe0aa12011-03-17 16:29:15 -0700128
Anton Vorontsov060287b2012-07-09 17:10:41 -0700129 if (ps->type == PSTORE_TYPE_FTRACE)
130 return seq_read(file, userbuf, count, ppos);
Tony Luckfbe0aa12011-03-17 16:29:15 -0700131 return simple_read_from_buffer(userbuf, count, ppos, ps->data, ps->size);
132}
133
Anton Vorontsov060287b2012-07-09 17:10:41 -0700134static int pstore_file_open(struct inode *inode, struct file *file)
135{
136 struct pstore_private *ps = inode->i_private;
137 struct seq_file *sf;
138 int err;
139 const struct seq_operations *sops = NULL;
140
141 if (ps->type == PSTORE_TYPE_FTRACE)
142 sops = &pstore_ftrace_seq_ops;
143
144 err = seq_open(file, sops);
145 if (err < 0)
146 return err;
147
148 sf = file->private_data;
149 sf->private = ps;
150
151 return 0;
152}
153
Andrew Morton965c8e52012-12-17 15:59:39 -0800154static loff_t pstore_file_llseek(struct file *file, loff_t off, int whence)
Anton Vorontsov060287b2012-07-09 17:10:41 -0700155{
156 struct seq_file *sf = file->private_data;
157
158 if (sf->op)
Andrew Morton965c8e52012-12-17 15:59:39 -0800159 return seq_lseek(file, off, whence);
160 return default_llseek(file, off, whence);
Anton Vorontsov060287b2012-07-09 17:10:41 -0700161}
162
Tony Luckfbe0aa12011-03-17 16:29:15 -0700163static const struct file_operations pstore_file_operations = {
Anton Vorontsov060287b2012-07-09 17:10:41 -0700164 .open = pstore_file_open,
165 .read = pstore_file_read,
166 .llseek = pstore_file_llseek,
167 .release = seq_release,
Tony Luckfbe0aa12011-03-17 16:29:15 -0700168};
Tony Luckca01d6d2010-12-28 14:25:21 -0800169
170/*
171 * When a file is unlinked from our file system we call the
172 * platform driver to erase the record from persistent store.
173 */
174static int pstore_unlink(struct inode *dir, struct dentry *dentry)
175{
176 struct pstore_private *p = dentry->d_inode->i_private;
177
Kees Cook2174f6d2011-11-18 13:49:00 -0800178 if (p->psi->erase)
Seiji Aguchi755d4fe2012-11-26 16:07:44 -0800179 p->psi->erase(p->type, p->id, p->count,
180 dentry->d_inode->i_ctime, p->psi);
Aruna Balakrishnaiahbf288332013-06-25 14:33:56 +0530181 else
182 return -EPERM;
Tony Luckca01d6d2010-12-28 14:25:21 -0800183
184 return simple_unlink(dir, dentry);
185}
186
Tony Lucka872d512011-03-18 11:44:48 -0700187static void pstore_evict_inode(struct inode *inode)
188{
Luck, Tony6dda9262011-08-11 15:14:39 -0700189 struct pstore_private *p = inode->i_private;
190 unsigned long flags;
191
Jan Karadbd57682012-05-03 14:48:02 +0200192 clear_inode(inode);
Luck, Tony6dda9262011-08-11 15:14:39 -0700193 if (p) {
194 spin_lock_irqsave(&allpstore_lock, flags);
195 list_del(&p->list);
196 spin_unlock_irqrestore(&allpstore_lock, flags);
197 kfree(p);
198 }
Tony Lucka872d512011-03-18 11:44:48 -0700199}
200
Tony Luckca01d6d2010-12-28 14:25:21 -0800201static const struct inode_operations pstore_dir_inode_operations = {
202 .lookup = simple_lookup,
203 .unlink = pstore_unlink,
204};
205
Al Viro22a71c32012-03-22 12:26:35 -0400206static struct inode *pstore_get_inode(struct super_block *sb)
Tony Luckfbe0aa12011-03-17 16:29:15 -0700207{
208 struct inode *inode = new_inode(sb);
Tony Luckfbe0aa12011-03-17 16:29:15 -0700209 if (inode) {
210 inode->i_ino = get_next_ino();
Tony Luckfbe0aa12011-03-17 16:29:15 -0700211 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
Tony Luckfbe0aa12011-03-17 16:29:15 -0700212 }
213 return inode;
214}
215
Luck, Tony366f7e72011-03-18 15:33:43 -0700216enum {
217 Opt_kmsg_bytes, Opt_err
218};
219
220static const match_table_t tokens = {
221 {Opt_kmsg_bytes, "kmsg_bytes=%u"},
222 {Opt_err, NULL}
223};
224
225static void parse_options(char *options)
226{
227 char *p;
228 substring_t args[MAX_OPT_ARGS];
229 int option;
230
231 if (!options)
232 return;
233
234 while ((p = strsep(&options, ",")) != NULL) {
235 int token;
236
237 if (!*p)
238 continue;
239
240 token = match_token(p, tokens, args);
241 switch (token) {
242 case Opt_kmsg_bytes:
243 if (!match_int(&args[0], &option))
244 pstore_set_kmsg_bytes(option);
245 break;
246 }
247 }
248}
249
250static int pstore_remount(struct super_block *sb, int *flags, char *data)
251{
Theodore Ts'o02b99842014-03-13 10:14:33 -0400252 sync_filesystem(sb);
Luck, Tony366f7e72011-03-18 15:33:43 -0700253 parse_options(data);
254
255 return 0;
256}
257
Tony Luckca01d6d2010-12-28 14:25:21 -0800258static const struct super_operations pstore_ops = {
259 .statfs = simple_statfs,
260 .drop_inode = generic_delete_inode,
Tony Lucka872d512011-03-18 11:44:48 -0700261 .evict_inode = pstore_evict_inode,
Luck, Tony366f7e72011-03-18 15:33:43 -0700262 .remount_fs = pstore_remount,
Tony Luckca01d6d2010-12-28 14:25:21 -0800263 .show_options = generic_show_options,
264};
265
266static struct super_block *pstore_sb;
Tony Luckca01d6d2010-12-28 14:25:21 -0800267
268int pstore_is_mounted(void)
269{
Tony Luckfbe0aa12011-03-17 16:29:15 -0700270 return pstore_sb != NULL;
Tony Luckca01d6d2010-12-28 14:25:21 -0800271}
272
273/*
274 * Make a regular file in the root directory of our file system.
275 * Load it up with "size" bytes of data from "buf".
276 * Set the mtime & ctime to the date that this record was originally stored.
277 */
Seiji Aguchi755d4fe2012-11-26 16:07:44 -0800278int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
Aruna Balakrishnaiah9ad2cbe2013-08-16 13:53:39 -0700279 char *data, bool compressed, size_t size,
280 struct timespec time, struct pstore_info *psi)
Tony Luckca01d6d2010-12-28 14:25:21 -0800281{
282 struct dentry *root = pstore_sb->s_root;
283 struct dentry *dentry;
284 struct inode *inode;
Luck, Tony6dda9262011-08-11 15:14:39 -0700285 int rc = 0;
Tony Luckca01d6d2010-12-28 14:25:21 -0800286 char name[PSTORE_NAMELEN];
Luck, Tony6dda9262011-08-11 15:14:39 -0700287 struct pstore_private *private, *pos;
288 unsigned long flags;
289
290 spin_lock_irqsave(&allpstore_lock, flags);
291 list_for_each_entry(pos, &allpstore, list) {
292 if (pos->type == type &&
293 pos->id == id &&
294 pos->psi == psi) {
295 rc = -EEXIST;
296 break;
297 }
298 }
299 spin_unlock_irqrestore(&allpstore_lock, flags);
300 if (rc)
301 return rc;
Tony Luckca01d6d2010-12-28 14:25:21 -0800302
303 rc = -ENOMEM;
Al Viro22a71c32012-03-22 12:26:35 -0400304 inode = pstore_get_inode(pstore_sb);
Tony Luckca01d6d2010-12-28 14:25:21 -0800305 if (!inode)
306 goto fail;
Al Viro22a71c32012-03-22 12:26:35 -0400307 inode->i_mode = S_IFREG | 0444;
308 inode->i_fop = &pstore_file_operations;
Tony Luckfbe0aa12011-03-17 16:29:15 -0700309 private = kmalloc(sizeof *private + size, GFP_KERNEL);
Tony Luckca01d6d2010-12-28 14:25:21 -0800310 if (!private)
311 goto fail_alloc;
Matthew Garrett56280682011-07-21 16:57:53 -0400312 private->type = type;
Tony Luckca01d6d2010-12-28 14:25:21 -0800313 private->id = id;
Seiji Aguchi755d4fe2012-11-26 16:07:44 -0800314 private->count = count;
Matthew Garrett638c1fd2011-07-21 16:57:52 -0400315 private->psi = psi;
Tony Luckca01d6d2010-12-28 14:25:21 -0800316
317 switch (type) {
318 case PSTORE_TYPE_DMESG:
Aruna Balakrishnaiah9ad2cbe2013-08-16 13:53:39 -0700319 sprintf(name, "dmesg-%s-%lld%s", psname, id,
320 compressed ? ".enc.z" : "");
Tony Luckca01d6d2010-12-28 14:25:21 -0800321 break;
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700322 case PSTORE_TYPE_CONSOLE:
323 sprintf(name, "console-%s", psname);
324 break;
Anton Vorontsov060287b2012-07-09 17:10:41 -0700325 case PSTORE_TYPE_FTRACE:
326 sprintf(name, "ftrace-%s", psname);
327 break;
Tony Luckca01d6d2010-12-28 14:25:21 -0800328 case PSTORE_TYPE_MCE:
329 sprintf(name, "mce-%s-%lld", psname, id);
330 break;
Aruna Balakrishnaiah69020ee2013-06-06 00:21:44 +0530331 case PSTORE_TYPE_PPC_RTAS:
332 sprintf(name, "rtas-%s-%lld", psname, id);
333 break;
Aruna Balakrishnaiahf33f7482013-06-06 00:22:10 +0530334 case PSTORE_TYPE_PPC_OF:
335 sprintf(name, "powerpc-ofw-%s-%lld", psname, id);
336 break;
Aruna Balakrishnaiaha5e47972013-06-06 00:22:20 +0530337 case PSTORE_TYPE_PPC_COMMON:
338 sprintf(name, "powerpc-common-%s-%lld", psname, id);
339 break;
Tony Luckca01d6d2010-12-28 14:25:21 -0800340 case PSTORE_TYPE_UNKNOWN:
341 sprintf(name, "unknown-%s-%lld", psname, id);
342 break;
343 default:
344 sprintf(name, "type%d-%s-%lld", type, psname, id);
345 break;
346 }
347
348 mutex_lock(&root->d_inode->i_mutex);
349
Tony Luckca01d6d2010-12-28 14:25:21 -0800350 dentry = d_alloc_name(root, name);
Dan Carpenterc39524e2013-08-14 10:55:49 -0700351 if (!dentry)
Tony Luckca01d6d2010-12-28 14:25:21 -0800352 goto fail_lockedalloc;
353
Tony Luckfbe0aa12011-03-17 16:29:15 -0700354 memcpy(private->data, data, size);
355 inode->i_size = private->size = size;
Tony Luckca01d6d2010-12-28 14:25:21 -0800356
357 inode->i_private = private;
358
359 if (time.tv_sec)
360 inode->i_mtime = inode->i_ctime = time;
361
Tony Luckfbe0aa12011-03-17 16:29:15 -0700362 d_add(dentry, inode);
Tony Luckca01d6d2010-12-28 14:25:21 -0800363
Luck, Tony6dda9262011-08-11 15:14:39 -0700364 spin_lock_irqsave(&allpstore_lock, flags);
365 list_add(&private->list, &allpstore);
366 spin_unlock_irqrestore(&allpstore_lock, flags);
367
Tony Luckca01d6d2010-12-28 14:25:21 -0800368 mutex_unlock(&root->d_inode->i_mutex);
Tony Luckfbe0aa12011-03-17 16:29:15 -0700369
370 return 0;
Tony Luckca01d6d2010-12-28 14:25:21 -0800371
372fail_lockedalloc:
373 mutex_unlock(&root->d_inode->i_mutex);
374 kfree(private);
375fail_alloc:
376 iput(inode);
377
378fail:
379 return rc;
380}
381
Anton Vorontsov364ed2f2012-05-26 06:07:53 -0700382static int pstore_fill_super(struct super_block *sb, void *data, int silent)
Tony Luckca01d6d2010-12-28 14:25:21 -0800383{
Al Viro318ceed2012-02-12 22:08:01 -0500384 struct inode *inode;
Tony Luckca01d6d2010-12-28 14:25:21 -0800385
386 save_mount_options(sb, data);
387
388 pstore_sb = sb;
389
390 sb->s_maxbytes = MAX_LFS_FILESIZE;
391 sb->s_blocksize = PAGE_CACHE_SIZE;
392 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
393 sb->s_magic = PSTOREFS_MAGIC;
394 sb->s_op = &pstore_ops;
395 sb->s_time_gran = 1;
396
Luck, Tony366f7e72011-03-18 15:33:43 -0700397 parse_options(data);
398
Al Viro22a71c32012-03-22 12:26:35 -0400399 inode = pstore_get_inode(sb);
Al Viro318ceed2012-02-12 22:08:01 -0500400 if (inode) {
Al Viro22a71c32012-03-22 12:26:35 -0400401 inode->i_mode = S_IFDIR | 0755;
Al Viro318ceed2012-02-12 22:08:01 -0500402 inode->i_op = &pstore_dir_inode_operations;
Al Viro22a71c32012-03-22 12:26:35 -0400403 inode->i_fop = &simple_dir_operations;
404 inc_nlink(inode);
Tony Luckca01d6d2010-12-28 14:25:21 -0800405 }
Al Viro318ceed2012-02-12 22:08:01 -0500406 sb->s_root = d_make_root(inode);
407 if (!sb->s_root)
408 return -ENOMEM;
Tony Luckca01d6d2010-12-28 14:25:21 -0800409
Luck, Tony6dda9262011-08-11 15:14:39 -0700410 pstore_get_records(0);
Tony Luckca01d6d2010-12-28 14:25:21 -0800411
412 return 0;
Tony Luckca01d6d2010-12-28 14:25:21 -0800413}
414
Tony Luckfbe0aa12011-03-17 16:29:15 -0700415static struct dentry *pstore_mount(struct file_system_type *fs_type,
416 int flags, const char *dev_name, void *data)
Tony Luckca01d6d2010-12-28 14:25:21 -0800417{
Tony Luckfbe0aa12011-03-17 16:29:15 -0700418 return mount_single(fs_type, flags, data, pstore_fill_super);
Tony Luckca01d6d2010-12-28 14:25:21 -0800419}
420
421static void pstore_kill_sb(struct super_block *sb)
422{
423 kill_litter_super(sb);
424 pstore_sb = NULL;
Tony Luckca01d6d2010-12-28 14:25:21 -0800425}
426
427static struct file_system_type pstore_fs_type = {
428 .name = "pstore",
Tony Luckfbe0aa12011-03-17 16:29:15 -0700429 .mount = pstore_mount,
Tony Luckca01d6d2010-12-28 14:25:21 -0800430 .kill_sb = pstore_kill_sb,
431};
432
Josh Boyerfb0af3f2013-02-12 13:07:22 -0800433static struct kobject *pstore_kobj;
434
Tony Luckca01d6d2010-12-28 14:25:21 -0800435static int __init init_pstore_fs(void)
436{
Josh Boyerfb0af3f2013-02-12 13:07:22 -0800437 int err = 0;
438
439 /* Create a convenient mount point for people to access pstore */
440 pstore_kobj = kobject_create_and_add("pstore", fs_kobj);
441 if (!pstore_kobj) {
442 err = -ENOMEM;
443 goto out;
444 }
445
446 err = register_filesystem(&pstore_fs_type);
447 if (err < 0)
448 kobject_put(pstore_kobj);
449
450out:
451 return err;
Tony Luckca01d6d2010-12-28 14:25:21 -0800452}
453module_init(init_pstore_fs)
454
455MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>");
456MODULE_LICENSE("GPL");