1 // SPDX-License-Identifier: GPL-2.0-only <<
2 /* 1 /*
3 * Persistent Storage - ramfs parts. 2 * Persistent Storage - ramfs parts.
4 * 3 *
5 * Copyright (C) 2010 Intel Corporation <tony. 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
6 */ 18 */
7 19
8 #include <linux/module.h> 20 #include <linux/module.h>
9 #include <linux/fs.h> 21 #include <linux/fs.h>
10 #include <linux/fsnotify.h> 22 #include <linux/fsnotify.h>
11 #include <linux/pagemap.h> 23 #include <linux/pagemap.h>
12 #include <linux/highmem.h> 24 #include <linux/highmem.h>
13 #include <linux/time.h> 25 #include <linux/time.h>
14 #include <linux/init.h> 26 #include <linux/init.h>
15 #include <linux/list.h> 27 #include <linux/list.h>
16 #include <linux/string.h> 28 #include <linux/string.h>
17 #include <linux/mount.h> 29 #include <linux/mount.h>
18 #include <linux/seq_file.h> 30 #include <linux/seq_file.h>
19 #include <linux/ramfs.h> 31 #include <linux/ramfs.h>
20 #include <linux/parser.h> 32 #include <linux/parser.h>
21 #include <linux/sched.h> 33 #include <linux/sched.h>
22 #include <linux/magic.h> 34 #include <linux/magic.h>
23 #include <linux/pstore.h> 35 #include <linux/pstore.h>
24 #include <linux/slab.h> 36 #include <linux/slab.h>
>> 37 #include <linux/spinlock.h>
25 #include <linux/uaccess.h> 38 #include <linux/uaccess.h>
26 #include <linux/cleanup.h> <<
27 39
28 #include "internal.h" 40 #include "internal.h"
29 41
30 #define PSTORE_NAMELEN 64 42 #define PSTORE_NAMELEN 64
31 43
32 static DEFINE_MUTEX(records_list_lock); !! 44 static DEFINE_SPINLOCK(allpstore_lock);
33 static LIST_HEAD(records_list); !! 45 static LIST_HEAD(allpstore);
34 <<
35 static DEFINE_MUTEX(pstore_sb_lock); <<
36 static struct super_block *pstore_sb; <<
37 <<
38 DEFINE_FREE(pstore_iput, struct inode *, if (_ <<
39 46
40 struct pstore_private { 47 struct pstore_private {
41 struct list_head list; 48 struct list_head list;
42 struct dentry *dentry; <<
43 struct pstore_record *record; 49 struct pstore_record *record;
44 size_t total_size; 50 size_t total_size;
45 }; 51 };
46 52
47 struct pstore_ftrace_seq_data { 53 struct pstore_ftrace_seq_data {
48 const void *ptr; 54 const void *ptr;
49 size_t off; 55 size_t off;
50 size_t size; 56 size_t size;
51 }; 57 };
52 58
53 #define REC_SIZE sizeof(struct pstore_ftrace_r 59 #define REC_SIZE sizeof(struct pstore_ftrace_record)
54 60
55 static void free_pstore_private(struct pstore_ 61 static void free_pstore_private(struct pstore_private *private)
56 { 62 {
57 if (!private) 63 if (!private)
58 return; 64 return;
59 if (private->record) { 65 if (private->record) {
60 kvfree(private->record->buf); !! 66 kfree(private->record->buf);
61 kfree(private->record->priv); <<
62 kfree(private->record); 67 kfree(private->record);
63 } 68 }
64 kfree(private); 69 kfree(private);
65 } 70 }
66 DEFINE_FREE(pstore_private, struct pstore_priv <<
67 71
68 static void *pstore_ftrace_seq_start(struct se 72 static void *pstore_ftrace_seq_start(struct seq_file *s, loff_t *pos)
69 { 73 {
70 struct pstore_private *ps = s->private 74 struct pstore_private *ps = s->private;
71 struct pstore_ftrace_seq_data *data __ !! 75 struct pstore_ftrace_seq_data *data;
72 76
73 data = kzalloc(sizeof(*data), GFP_KERN 77 data = kzalloc(sizeof(*data), GFP_KERNEL);
74 if (!data) 78 if (!data)
75 return NULL; 79 return NULL;
76 80
77 data->off = ps->total_size % REC_SIZE; 81 data->off = ps->total_size % REC_SIZE;
78 data->off += *pos * REC_SIZE; 82 data->off += *pos * REC_SIZE;
79 if (data->off + REC_SIZE > ps->total_s !! 83 if (data->off + REC_SIZE > ps->total_size) {
>> 84 kfree(data);
80 return NULL; 85 return NULL;
>> 86 }
>> 87
>> 88 return data;
81 89
82 return_ptr(data); <<
83 } 90 }
84 91
85 static void pstore_ftrace_seq_stop(struct seq_ 92 static void pstore_ftrace_seq_stop(struct seq_file *s, void *v)
86 { 93 {
87 kfree(v); 94 kfree(v);
88 } 95 }
89 96
90 static void *pstore_ftrace_seq_next(struct seq 97 static void *pstore_ftrace_seq_next(struct seq_file *s, void *v, loff_t *pos)
91 { 98 {
92 struct pstore_private *ps = s->private 99 struct pstore_private *ps = s->private;
93 struct pstore_ftrace_seq_data *data = 100 struct pstore_ftrace_seq_data *data = v;
94 101
95 (*pos)++; <<
96 data->off += REC_SIZE; 102 data->off += REC_SIZE;
97 if (data->off + REC_SIZE > ps->total_s 103 if (data->off + REC_SIZE > ps->total_size)
98 return NULL; 104 return NULL;
99 105
>> 106 (*pos)++;
100 return data; 107 return data;
101 } 108 }
102 109
103 static int pstore_ftrace_seq_show(struct seq_f 110 static int pstore_ftrace_seq_show(struct seq_file *s, void *v)
104 { 111 {
105 struct pstore_private *ps = s->private 112 struct pstore_private *ps = s->private;
106 struct pstore_ftrace_seq_data *data = 113 struct pstore_ftrace_seq_data *data = v;
107 struct pstore_ftrace_record *rec; 114 struct pstore_ftrace_record *rec;
108 115
109 if (!data) <<
110 return 0; <<
111 <<
112 rec = (struct pstore_ftrace_record *)( 116 rec = (struct pstore_ftrace_record *)(ps->record->buf + data->off);
113 117
114 seq_printf(s, "CPU:%d ts:%llu %08lx % !! 118 seq_printf(s, "CPU:%d ts:%llu %08lx %08lx %pf <- %pF\n",
115 pstore_ftrace_decode_cpu(re 119 pstore_ftrace_decode_cpu(rec),
116 pstore_ftrace_read_timestam 120 pstore_ftrace_read_timestamp(rec),
117 rec->ip, rec->parent_ip, (v 121 rec->ip, rec->parent_ip, (void *)rec->ip,
118 (void *)rec->parent_ip); 122 (void *)rec->parent_ip);
119 123
120 return 0; 124 return 0;
121 } 125 }
122 126
123 static const struct seq_operations pstore_ftra 127 static const struct seq_operations pstore_ftrace_seq_ops = {
124 .start = pstore_ftrace_seq_start, 128 .start = pstore_ftrace_seq_start,
125 .next = pstore_ftrace_seq_next, 129 .next = pstore_ftrace_seq_next,
126 .stop = pstore_ftrace_seq_stop, 130 .stop = pstore_ftrace_seq_stop,
127 .show = pstore_ftrace_seq_show, 131 .show = pstore_ftrace_seq_show,
128 }; 132 };
129 133
130 static ssize_t pstore_file_read(struct file *f 134 static ssize_t pstore_file_read(struct file *file, char __user *userbuf,
131 135 size_t count, loff_t *ppos)
132 { 136 {
133 struct seq_file *sf = file->private_da 137 struct seq_file *sf = file->private_data;
134 struct pstore_private *ps = sf->privat 138 struct pstore_private *ps = sf->private;
135 139
136 if (ps->record->type == PSTORE_TYPE_FT 140 if (ps->record->type == PSTORE_TYPE_FTRACE)
137 return seq_read(file, userbuf, 141 return seq_read(file, userbuf, count, ppos);
138 return simple_read_from_buffer(userbuf 142 return simple_read_from_buffer(userbuf, count, ppos,
139 ps->rec 143 ps->record->buf, ps->total_size);
140 } 144 }
141 145
142 static int pstore_file_open(struct inode *inod 146 static int pstore_file_open(struct inode *inode, struct file *file)
143 { 147 {
144 struct pstore_private *ps = inode->i_p 148 struct pstore_private *ps = inode->i_private;
145 struct seq_file *sf; 149 struct seq_file *sf;
146 int err; 150 int err;
147 const struct seq_operations *sops = NU 151 const struct seq_operations *sops = NULL;
148 152
149 if (ps->record->type == PSTORE_TYPE_FT 153 if (ps->record->type == PSTORE_TYPE_FTRACE)
150 sops = &pstore_ftrace_seq_ops; 154 sops = &pstore_ftrace_seq_ops;
151 155
152 err = seq_open(file, sops); 156 err = seq_open(file, sops);
153 if (err < 0) 157 if (err < 0)
154 return err; 158 return err;
155 159
156 sf = file->private_data; 160 sf = file->private_data;
157 sf->private = ps; 161 sf->private = ps;
158 162
159 return 0; 163 return 0;
160 } 164 }
161 165
162 static loff_t pstore_file_llseek(struct file * 166 static loff_t pstore_file_llseek(struct file *file, loff_t off, int whence)
163 { 167 {
164 struct seq_file *sf = file->private_da 168 struct seq_file *sf = file->private_data;
165 169
166 if (sf->op) 170 if (sf->op)
167 return seq_lseek(file, off, wh 171 return seq_lseek(file, off, whence);
168 return default_llseek(file, off, whenc 172 return default_llseek(file, off, whence);
169 } 173 }
170 174
171 static const struct file_operations pstore_fil 175 static const struct file_operations pstore_file_operations = {
172 .open = pstore_file_open, 176 .open = pstore_file_open,
173 .read = pstore_file_read, 177 .read = pstore_file_read,
174 .llseek = pstore_file_llseek, 178 .llseek = pstore_file_llseek,
175 .release = seq_release, 179 .release = seq_release,
176 }; 180 };
177 181
178 /* 182 /*
179 * When a file is unlinked from our file syste 183 * When a file is unlinked from our file system we call the
180 * platform driver to erase the record from pe 184 * platform driver to erase the record from persistent store.
181 */ 185 */
182 static int pstore_unlink(struct inode *dir, st 186 static int pstore_unlink(struct inode *dir, struct dentry *dentry)
183 { 187 {
184 struct pstore_private *p = d_inode(den 188 struct pstore_private *p = d_inode(dentry)->i_private;
185 struct pstore_record *record = p->reco 189 struct pstore_record *record = p->record;
186 190
187 if (!record->psi->erase) 191 if (!record->psi->erase)
188 return -EPERM; 192 return -EPERM;
189 193
190 /* Make sure we can't race while remov !! 194 mutex_lock(&record->psi->read_mutex);
191 scoped_guard(mutex, &records_list_lock !! 195 record->psi->erase(record);
192 if (!list_empty(&p->list)) !! 196 mutex_unlock(&record->psi->read_mutex);
193 list_del_init(&p->list <<
194 else <<
195 return -ENOENT; <<
196 p->dentry = NULL; <<
197 } <<
198 <<
199 scoped_guard(mutex, &record->psi->read <<
200 record->psi->erase(record); <<
201 197
202 return simple_unlink(dir, dentry); 198 return simple_unlink(dir, dentry);
203 } 199 }
204 200
205 static void pstore_evict_inode(struct inode *i 201 static void pstore_evict_inode(struct inode *inode)
206 { 202 {
207 struct pstore_private *p = inode->i_ 203 struct pstore_private *p = inode->i_private;
>> 204 unsigned long flags;
208 205
209 clear_inode(inode); 206 clear_inode(inode);
210 free_pstore_private(p); !! 207 if (p) {
>> 208 spin_lock_irqsave(&allpstore_lock, flags);
>> 209 list_del(&p->list);
>> 210 spin_unlock_irqrestore(&allpstore_lock, flags);
>> 211 free_pstore_private(p);
>> 212 }
211 } 213 }
212 214
213 static const struct inode_operations pstore_di 215 static const struct inode_operations pstore_dir_inode_operations = {
214 .lookup = simple_lookup, 216 .lookup = simple_lookup,
215 .unlink = pstore_unlink, 217 .unlink = pstore_unlink,
216 }; 218 };
217 219
218 static struct inode *pstore_get_inode(struct s 220 static struct inode *pstore_get_inode(struct super_block *sb)
219 { 221 {
220 struct inode *inode = new_inode(sb); 222 struct inode *inode = new_inode(sb);
221 if (inode) { 223 if (inode) {
222 inode->i_ino = get_next_ino(); 224 inode->i_ino = get_next_ino();
223 simple_inode_init_ts(inode); !! 225 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
224 } 226 }
225 return inode; 227 return inode;
226 } 228 }
227 229
228 enum { 230 enum {
229 Opt_kmsg_bytes, Opt_err 231 Opt_kmsg_bytes, Opt_err
230 }; 232 };
231 233
232 static const match_table_t tokens = { 234 static const match_table_t tokens = {
233 {Opt_kmsg_bytes, "kmsg_bytes=%u"}, 235 {Opt_kmsg_bytes, "kmsg_bytes=%u"},
234 {Opt_err, NULL} 236 {Opt_err, NULL}
235 }; 237 };
236 238
237 static void parse_options(char *options) 239 static void parse_options(char *options)
238 { 240 {
239 char *p; 241 char *p;
240 substring_t args[MAX_OPT_ARGS]; 242 substring_t args[MAX_OPT_ARGS];
241 int option; 243 int option;
242 244
243 if (!options) 245 if (!options)
244 return; 246 return;
245 247
246 while ((p = strsep(&options, ",")) != 248 while ((p = strsep(&options, ",")) != NULL) {
247 int token; 249 int token;
248 250
249 if (!*p) 251 if (!*p)
250 continue; 252 continue;
251 253
252 token = match_token(p, tokens, 254 token = match_token(p, tokens, args);
253 switch (token) { 255 switch (token) {
254 case Opt_kmsg_bytes: 256 case Opt_kmsg_bytes:
255 if (!match_int(&args[0 257 if (!match_int(&args[0], &option))
256 pstore_set_kms 258 pstore_set_kmsg_bytes(option);
257 break; 259 break;
258 } 260 }
259 } 261 }
260 } 262 }
261 263
262 /* 264 /*
263 * Display the mount options in /proc/mounts. 265 * Display the mount options in /proc/mounts.
264 */ 266 */
265 static int pstore_show_options(struct seq_file 267 static int pstore_show_options(struct seq_file *m, struct dentry *root)
266 { 268 {
267 if (kmsg_bytes != CONFIG_PSTORE_DEFAUL !! 269 if (kmsg_bytes != PSTORE_DEFAULT_KMSG_BYTES)
268 seq_printf(m, ",kmsg_bytes=%lu 270 seq_printf(m, ",kmsg_bytes=%lu", kmsg_bytes);
269 return 0; 271 return 0;
270 } 272 }
271 273
272 static int pstore_remount(struct super_block * 274 static int pstore_remount(struct super_block *sb, int *flags, char *data)
273 { 275 {
274 sync_filesystem(sb); 276 sync_filesystem(sb);
275 parse_options(data); 277 parse_options(data);
276 278
277 return 0; 279 return 0;
278 } 280 }
279 281
280 static const struct super_operations pstore_op 282 static const struct super_operations pstore_ops = {
281 .statfs = simple_statfs, 283 .statfs = simple_statfs,
282 .drop_inode = generic_delete_inode 284 .drop_inode = generic_delete_inode,
283 .evict_inode = pstore_evict_inode, 285 .evict_inode = pstore_evict_inode,
284 .remount_fs = pstore_remount, 286 .remount_fs = pstore_remount,
285 .show_options = pstore_show_options, 287 .show_options = pstore_show_options,
286 }; 288 };
287 289
288 static struct dentry *psinfo_lock_root(void) !! 290 static struct super_block *pstore_sb;
289 { <<
290 struct dentry *root; <<
291 <<
292 guard(mutex)(&pstore_sb_lock); <<
293 /* <<
294 * Having no backend is fine -- no rec <<
295 * Not being mounted is fine -- nothin <<
296 */ <<
297 if (!psinfo || !pstore_sb) <<
298 return NULL; <<
299 <<
300 root = pstore_sb->s_root; <<
301 inode_lock(d_inode(root)); <<
302 <<
303 return root; <<
304 } <<
305 291
306 int pstore_put_backend_records(struct pstore_i !! 292 bool pstore_is_mounted(void)
307 { 293 {
308 struct pstore_private *pos, *tmp; !! 294 return pstore_sb != NULL;
309 struct dentry *root; <<
310 <<
311 root = psinfo_lock_root(); <<
312 if (!root) <<
313 return 0; <<
314 <<
315 scoped_guard(mutex, &records_list_lock <<
316 list_for_each_entry_safe(pos, <<
317 if (pos->record->psi = <<
318 list_del_init( <<
319 d_invalidate(p <<
320 simple_unlink( <<
321 pos->dentry = <<
322 } <<
323 } <<
324 } <<
325 <<
326 inode_unlock(d_inode(root)); <<
327 <<
328 return 0; <<
329 } 295 }
330 296
331 /* 297 /*
332 * Make a regular file in the root directory o 298 * Make a regular file in the root directory of our file system.
333 * Load it up with "size" bytes of data from " 299 * Load it up with "size" bytes of data from "buf".
334 * Set the mtime & ctime to the date that this 300 * Set the mtime & ctime to the date that this record was originally stored.
335 */ 301 */
336 int pstore_mkfile(struct dentry *root, struct 302 int pstore_mkfile(struct dentry *root, struct pstore_record *record)
337 { 303 {
338 struct dentry *dentry; 304 struct dentry *dentry;
339 struct inode *inode __free( !! 305 struct inode *inode;
>> 306 int rc = 0;
340 char name[PSTORE_NA 307 char name[PSTORE_NAMELEN];
341 struct pstore_private *private __fre !! 308 struct pstore_private *private, *pos;
>> 309 unsigned long flags;
342 size_t size = record- 310 size_t size = record->size + record->ecc_notice_size;
343 311
344 if (WARN_ON(!inode_is_locked(d_inode(r !! 312 WARN_ON(!inode_is_locked(d_inode(root)));
345 return -EINVAL; <<
346 <<
347 guard(mutex)(&records_list_lock); <<
348 313
349 /* Skip records that are already prese !! 314 spin_lock_irqsave(&allpstore_lock, flags);
350 list_for_each_entry(pos, &records_list !! 315 list_for_each_entry(pos, &allpstore, list) {
351 if (pos->record->type == recor 316 if (pos->record->type == record->type &&
352 pos->record->id == record- 317 pos->record->id == record->id &&
353 pos->record->psi == record !! 318 pos->record->psi == record->psi) {
354 return -EEXIST; !! 319 rc = -EEXIST;
>> 320 break;
>> 321 }
355 } 322 }
>> 323 spin_unlock_irqrestore(&allpstore_lock, flags);
>> 324 if (rc)
>> 325 return rc;
356 326
>> 327 rc = -ENOMEM;
357 inode = pstore_get_inode(root->d_sb); 328 inode = pstore_get_inode(root->d_sb);
358 if (!inode) 329 if (!inode)
359 return -ENOMEM; !! 330 goto fail;
360 inode->i_mode = S_IFREG | 0444; 331 inode->i_mode = S_IFREG | 0444;
361 inode->i_fop = &pstore_file_operations 332 inode->i_fop = &pstore_file_operations;
>> 333 private = kzalloc(sizeof(*private), GFP_KERNEL);
>> 334 if (!private)
>> 335 goto fail_alloc;
>> 336 private->record = record;
>> 337
362 scnprintf(name, sizeof(name), "%s-%s-% 338 scnprintf(name, sizeof(name), "%s-%s-%llu%s",
363 pstore_type_to_name(re 339 pstore_type_to_name(record->type),
364 record->psi->name, rec 340 record->psi->name, record->id,
365 record->compressed ? " 341 record->compressed ? ".enc.z" : "");
366 342
367 private = kzalloc(sizeof(*private), GF <<
368 if (!private) <<
369 return -ENOMEM; <<
370 <<
371 dentry = d_alloc_name(root, name); 343 dentry = d_alloc_name(root, name);
372 if (!dentry) 344 if (!dentry)
373 return -ENOMEM; !! 345 goto fail_private;
374 346
375 private->dentry = dentry; <<
376 private->record = record; <<
377 inode->i_size = private->total_size = 347 inode->i_size = private->total_size = size;
>> 348
378 inode->i_private = private; 349 inode->i_private = private;
379 350
380 if (record->time.tv_sec) 351 if (record->time.tv_sec)
381 inode_set_mtime_to_ts(inode, !! 352 inode->i_mtime = inode->i_ctime = record->time;
382 inode_se <<
383 353
384 d_add(dentry, no_free_ptr(inode)); !! 354 d_add(dentry, inode);
385 355
386 list_add(&(no_free_ptr(private))->list !! 356 spin_lock_irqsave(&allpstore_lock, flags);
>> 357 list_add(&private->list, &allpstore);
>> 358 spin_unlock_irqrestore(&allpstore_lock, flags);
387 359
388 return 0; 360 return 0;
>> 361
>> 362 fail_private:
>> 363 free_pstore_private(private);
>> 364 fail_alloc:
>> 365 iput(inode);
>> 366
>> 367 fail:
>> 368 return rc;
389 } 369 }
390 370
391 /* 371 /*
392 * Read all the records from the persistent st 372 * Read all the records from the persistent store. Create
393 * files in our filesystem. Don't warn about 373 * files in our filesystem. Don't warn about -EEXIST errors
394 * when we are re-scanning the backing store l 374 * when we are re-scanning the backing store looking to add new
395 * error records. 375 * error records.
396 */ 376 */
397 void pstore_get_records(int quiet) 377 void pstore_get_records(int quiet)
398 { 378 {
>> 379 struct pstore_info *psi = psinfo;
399 struct dentry *root; 380 struct dentry *root;
400 381
401 root = psinfo_lock_root(); !! 382 if (!psi || !pstore_sb)
402 if (!root) <<
403 return; 383 return;
404 384
405 pstore_get_backend_records(psinfo, roo !! 385 root = pstore_sb->s_root;
>> 386
>> 387 inode_lock(d_inode(root));
>> 388 pstore_get_backend_records(psi, root, quiet);
406 inode_unlock(d_inode(root)); 389 inode_unlock(d_inode(root));
407 } 390 }
408 391
409 static int pstore_fill_super(struct super_bloc 392 static int pstore_fill_super(struct super_block *sb, void *data, int silent)
410 { 393 {
411 struct inode *inode; 394 struct inode *inode;
412 395
>> 396 pstore_sb = sb;
>> 397
413 sb->s_maxbytes = MAX_LFS_FILE 398 sb->s_maxbytes = MAX_LFS_FILESIZE;
414 sb->s_blocksize = PAGE_SIZE; 399 sb->s_blocksize = PAGE_SIZE;
415 sb->s_blocksize_bits = PAGE_SHIFT; 400 sb->s_blocksize_bits = PAGE_SHIFT;
416 sb->s_magic = PSTOREFS_MAG 401 sb->s_magic = PSTOREFS_MAGIC;
417 sb->s_op = &pstore_ops; 402 sb->s_op = &pstore_ops;
418 sb->s_time_gran = 1; 403 sb->s_time_gran = 1;
419 404
420 parse_options(data); 405 parse_options(data);
421 406
422 inode = pstore_get_inode(sb); 407 inode = pstore_get_inode(sb);
423 if (inode) { 408 if (inode) {
424 inode->i_mode = S_IFDIR | 0750 409 inode->i_mode = S_IFDIR | 0750;
425 inode->i_op = &pstore_dir_inod 410 inode->i_op = &pstore_dir_inode_operations;
426 inode->i_fop = &simple_dir_ope 411 inode->i_fop = &simple_dir_operations;
427 inc_nlink(inode); 412 inc_nlink(inode);
428 } 413 }
429 sb->s_root = d_make_root(inode); 414 sb->s_root = d_make_root(inode);
430 if (!sb->s_root) 415 if (!sb->s_root)
431 return -ENOMEM; 416 return -ENOMEM;
432 417
433 scoped_guard(mutex, &pstore_sb_lock) <<
434 pstore_sb = sb; <<
435 <<
436 pstore_get_records(0); 418 pstore_get_records(0);
437 419
438 return 0; 420 return 0;
439 } 421 }
440 422
441 static struct dentry *pstore_mount(struct file 423 static struct dentry *pstore_mount(struct file_system_type *fs_type,
442 int flags, const char *dev_name, void 424 int flags, const char *dev_name, void *data)
443 { 425 {
444 return mount_single(fs_type, flags, da 426 return mount_single(fs_type, flags, data, pstore_fill_super);
445 } 427 }
446 428
447 static void pstore_kill_sb(struct super_block 429 static void pstore_kill_sb(struct super_block *sb)
448 { 430 {
449 guard(mutex)(&pstore_sb_lock); <<
450 WARN_ON(pstore_sb && pstore_sb != sb); <<
451 <<
452 kill_litter_super(sb); 431 kill_litter_super(sb);
453 pstore_sb = NULL; 432 pstore_sb = NULL;
454 <<
455 guard(mutex)(&records_list_lock); <<
456 INIT_LIST_HEAD(&records_list); <<
457 } 433 }
458 434
459 static struct file_system_type pstore_fs_type 435 static struct file_system_type pstore_fs_type = {
460 .owner = THIS_MODULE, 436 .owner = THIS_MODULE,
461 .name = "pstore", 437 .name = "pstore",
462 .mount = pstore_mount, 438 .mount = pstore_mount,
463 .kill_sb = pstore_kill_sb, 439 .kill_sb = pstore_kill_sb,
464 }; 440 };
465 441
466 int __init pstore_init_fs(void) 442 int __init pstore_init_fs(void)
467 { 443 {
468 int err; 444 int err;
469 445
470 /* Create a convenient mount point for 446 /* Create a convenient mount point for people to access pstore */
471 err = sysfs_create_mount_point(fs_kobj 447 err = sysfs_create_mount_point(fs_kobj, "pstore");
472 if (err) 448 if (err)
473 goto out; 449 goto out;
474 450
475 err = register_filesystem(&pstore_fs_t 451 err = register_filesystem(&pstore_fs_type);
476 if (err < 0) 452 if (err < 0)
477 sysfs_remove_mount_point(fs_ko 453 sysfs_remove_mount_point(fs_kobj, "pstore");
478 454
479 out: 455 out:
480 return err; 456 return err;
481 } 457 }
482 458
483 void __exit pstore_exit_fs(void) 459 void __exit pstore_exit_fs(void)
484 { 460 {
485 unregister_filesystem(&pstore_fs_type) 461 unregister_filesystem(&pstore_fs_type);
486 sysfs_remove_mount_point(fs_kobj, "pst 462 sysfs_remove_mount_point(fs_kobj, "pstore");
487 } 463 }
488 464
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