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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>
27#include <linux/list.h>
28#include <linux/string.h>
29#include <linux/mount.h>
30#include <linux/seq_file.h>
31#include <linux/ramfs.h>
32#include <linux/parser.h>
33#include <linux/sched.h>
34#include <linux/magic.h>
35#include <linux/pstore.h>
36#include <linux/slab.h>
37#include <linux/spinlock.h>
38#include <linux/uaccess.h>
39
40#include "internal.h"
41
42#define PSTORE_NAMELEN 64
43
44static DEFINE_SPINLOCK(allpstore_lock);
45static LIST_HEAD(allpstore);
46
47struct pstore_private {
48 struct list_head list;
49 struct pstore_info *psi;
50 enum pstore_type_id type;
51 u64 id;
52 int count;
53 ssize_t size;
54 char data[];
55};
56
57struct 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
123static ssize_t pstore_file_read(struct file *file, char __user *userbuf,
124 size_t count, loff_t *ppos)
125{
126 struct seq_file *sf = file->private_data;
127 struct pstore_private *ps = sf->private;
128
129 if (ps->type == PSTORE_TYPE_FTRACE)
130 return seq_read(file, userbuf, count, ppos);
131 return simple_read_from_buffer(userbuf, count, ppos, ps->data, ps->size);
132}
133
134static 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
154static loff_t pstore_file_llseek(struct file *file, loff_t off, int whence)
155{
156 struct seq_file *sf = file->private_data;
157
158 if (sf->op)
159 return seq_lseek(file, off, whence);
160 return default_llseek(file, off, whence);
161}
162
163static const struct file_operations pstore_file_operations = {
164 .open = pstore_file_open,
165 .read = pstore_file_read,
166 .llseek = pstore_file_llseek,
167 .release = seq_release,
168};
169
170
171
172
173
174static int pstore_unlink(struct inode *dir, struct dentry *dentry)
175{
176 struct pstore_private *p = dentry->d_inode->i_private;
177
178 if (p->psi->erase)
179 p->psi->erase(p->type, p->id, p->count,
180 dentry->d_inode->i_ctime, p->psi);
181 else
182 return -EPERM;
183
184 return simple_unlink(dir, dentry);
185}
186
187static void pstore_evict_inode(struct inode *inode)
188{
189 struct pstore_private *p = inode->i_private;
190 unsigned long flags;
191
192 clear_inode(inode);
193 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 }
199}
200
201static const struct inode_operations pstore_dir_inode_operations = {
202 .lookup = simple_lookup,
203 .unlink = pstore_unlink,
204};
205
206static struct inode *pstore_get_inode(struct super_block *sb)
207{
208 struct inode *inode = new_inode(sb);
209 if (inode) {
210 inode->i_ino = get_next_ino();
211 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
212 }
213 return inode;
214}
215
216enum {
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{
252 parse_options(data);
253
254 return 0;
255}
256
257static const struct super_operations pstore_ops = {
258 .statfs = simple_statfs,
259 .drop_inode = generic_delete_inode,
260 .evict_inode = pstore_evict_inode,
261 .remount_fs = pstore_remount,
262 .show_options = generic_show_options,
263};
264
265static struct super_block *pstore_sb;
266
267int pstore_is_mounted(void)
268{
269 return pstore_sb != NULL;
270}
271
272
273
274
275
276
277int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
278 char *data, size_t size, struct timespec time,
279 struct pstore_info *psi)
280{
281 struct dentry *root = pstore_sb->s_root;
282 struct dentry *dentry;
283 struct inode *inode;
284 int rc = 0;
285 char name[PSTORE_NAMELEN];
286 struct pstore_private *private, *pos;
287 unsigned long flags;
288
289 spin_lock_irqsave(&allpstore_lock, flags);
290 list_for_each_entry(pos, &allpstore, list) {
291 if (pos->type == type &&
292 pos->id == id &&
293 pos->psi == psi) {
294 rc = -EEXIST;
295 break;
296 }
297 }
298 spin_unlock_irqrestore(&allpstore_lock, flags);
299 if (rc)
300 return rc;
301
302 rc = -ENOMEM;
303 inode = pstore_get_inode(pstore_sb);
304 if (!inode)
305 goto fail;
306 inode->i_mode = S_IFREG | 0444;
307 inode->i_fop = &pstore_file_operations;
308 private = kmalloc(sizeof *private + size, GFP_KERNEL);
309 if (!private)
310 goto fail_alloc;
311 private->type = type;
312 private->id = id;
313 private->count = count;
314 private->psi = psi;
315
316 switch (type) {
317 case PSTORE_TYPE_DMESG:
318 sprintf(name, "dmesg-%s-%lld", psname, id);
319 break;
320 case PSTORE_TYPE_CONSOLE:
321 sprintf(name, "console-%s", psname);
322 break;
323 case PSTORE_TYPE_FTRACE:
324 sprintf(name, "ftrace-%s", psname);
325 break;
326 case PSTORE_TYPE_MCE:
327 sprintf(name, "mce-%s-%lld", psname, id);
328 break;
329 case PSTORE_TYPE_PPC_RTAS:
330 sprintf(name, "rtas-%s-%lld", psname, id);
331 break;
332 case PSTORE_TYPE_PPC_OF:
333 sprintf(name, "powerpc-ofw-%s-%lld", psname, id);
334 break;
335 case PSTORE_TYPE_PPC_COMMON:
336 sprintf(name, "powerpc-common-%s-%lld", psname, id);
337 break;
338 case PSTORE_TYPE_UNKNOWN:
339 sprintf(name, "unknown-%s-%lld", psname, id);
340 break;
341 default:
342 sprintf(name, "type%d-%s-%lld", type, psname, id);
343 break;
344 }
345
346 mutex_lock(&root->d_inode->i_mutex);
347
348 rc = -ENOSPC;
349 dentry = d_alloc_name(root, name);
350 if (IS_ERR(dentry))
351 goto fail_lockedalloc;
352
353 memcpy(private->data, data, size);
354 inode->i_size = private->size = size;
355
356 inode->i_private = private;
357
358 if (time.tv_sec)
359 inode->i_mtime = inode->i_ctime = time;
360
361 d_add(dentry, inode);
362
363 spin_lock_irqsave(&allpstore_lock, flags);
364 list_add(&private->list, &allpstore);
365 spin_unlock_irqrestore(&allpstore_lock, flags);
366
367 mutex_unlock(&root->d_inode->i_mutex);
368
369 return 0;
370
371fail_lockedalloc:
372 mutex_unlock(&root->d_inode->i_mutex);
373 kfree(private);
374fail_alloc:
375 iput(inode);
376
377fail:
378 return rc;
379}
380
381static int pstore_fill_super(struct super_block *sb, void *data, int silent)
382{
383 struct inode *inode;
384
385 save_mount_options(sb, data);
386
387 pstore_sb = sb;
388
389 sb->s_maxbytes = MAX_LFS_FILESIZE;
390 sb->s_blocksize = PAGE_CACHE_SIZE;
391 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
392 sb->s_magic = PSTOREFS_MAGIC;
393 sb->s_op = &pstore_ops;
394 sb->s_time_gran = 1;
395
396 parse_options(data);
397
398 inode = pstore_get_inode(sb);
399 if (inode) {
400 inode->i_mode = S_IFDIR | 0755;
401 inode->i_op = &pstore_dir_inode_operations;
402 inode->i_fop = &simple_dir_operations;
403 inc_nlink(inode);
404 }
405 sb->s_root = d_make_root(inode);
406 if (!sb->s_root)
407 return -ENOMEM;
408
409 pstore_get_records(0);
410
411 return 0;
412}
413
414static struct dentry *pstore_mount(struct file_system_type *fs_type,
415 int flags, const char *dev_name, void *data)
416{
417 return mount_single(fs_type, flags, data, pstore_fill_super);
418}
419
420static void pstore_kill_sb(struct super_block *sb)
421{
422 kill_litter_super(sb);
423 pstore_sb = NULL;
424}
425
426static struct file_system_type pstore_fs_type = {
427 .name = "pstore",
428 .mount = pstore_mount,
429 .kill_sb = pstore_kill_sb,
430};
431
432static struct kobject *pstore_kobj;
433
434static int __init init_pstore_fs(void)
435{
436 int err = 0;
437
438
439 pstore_kobj = kobject_create_and_add("pstore", fs_kobj);
440 if (!pstore_kobj) {
441 err = -ENOMEM;
442 goto out;
443 }
444
445 err = register_filesystem(&pstore_fs_type);
446 if (err < 0)
447 kobject_put(pstore_kobj);
448
449out:
450 return err;
451}
452module_init(init_pstore_fs)
453
454MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>");
455MODULE_LICENSE("GPL");
456
