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v4.6
  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>
 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#include <linux/syslog.h>
 40
 41#include "internal.h"
 42
 43#define	PSTORE_NAMELEN	64
 44
 45static DEFINE_SPINLOCK(allpstore_lock);
 46static LIST_HEAD(allpstore);
 47
 48struct pstore_private {
 49	struct list_head list;
 50	struct pstore_info *psi;
 51	enum pstore_type_id type;
 52	u64	id;
 53	int	count;
 54	ssize_t	size;
 55	char	data[];
 56};
 57
 58struct 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
 66static 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
 86static void pstore_ftrace_seq_stop(struct seq_file *s, void *v)
 87{
 88	kfree(v);
 89}
 90
 91static 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
104static 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
110	seq_printf(s, "%d %08lx  %08lx  %pf <- %pF\n",
111		pstore_ftrace_decode_cpu(rec), rec->ip, rec->parent_ip,
112		(void *)rec->ip, (void *)rec->parent_ip);
113
114	return 0;
115}
116
117static const struct seq_operations pstore_ftrace_seq_ops = {
118	.start	= pstore_ftrace_seq_start,
119	.next	= pstore_ftrace_seq_next,
120	.stop	= pstore_ftrace_seq_stop,
121	.show	= pstore_ftrace_seq_show,
122};
123
124static int pstore_check_syslog_permissions(struct pstore_private *ps)
125{
126	switch (ps->type) {
127	case PSTORE_TYPE_DMESG:
128	case PSTORE_TYPE_CONSOLE:
129		return check_syslog_permissions(SYSLOG_ACTION_READ_ALL,
130			SYSLOG_FROM_READER);
131	default:
132		return 0;
133	}
134}
135
136static ssize_t pstore_file_read(struct file *file, char __user *userbuf,
137						size_t count, loff_t *ppos)
138{
139	struct seq_file *sf = file->private_data;
140	struct pstore_private *ps = sf->private;
141
142	if (ps->type == PSTORE_TYPE_FTRACE)
143		return seq_read(file, userbuf, count, ppos);
144	return simple_read_from_buffer(userbuf, count, ppos, ps->data, ps->size);
145}
146
147static int pstore_file_open(struct inode *inode, struct file *file)
148{
149	struct pstore_private *ps = inode->i_private;
150	struct seq_file *sf;
151	int err;
152	const struct seq_operations *sops = NULL;
153
154	err = pstore_check_syslog_permissions(ps);
155	if (err)
156		return err;
157
158	if (ps->type == PSTORE_TYPE_FTRACE)
159		sops = &pstore_ftrace_seq_ops;
160
161	err = seq_open(file, sops);
162	if (err < 0)
163		return err;
164
165	sf = file->private_data;
166	sf->private = ps;
167
168	return 0;
169}
170
171static loff_t pstore_file_llseek(struct file *file, loff_t off, int whence)
172{
173	struct seq_file *sf = file->private_data;
174
175	if (sf->op)
176		return seq_lseek(file, off, whence);
177	return default_llseek(file, off, whence);
178}
179
180static const struct file_operations pstore_file_operations = {
181	.owner		= THIS_MODULE,
182	.open		= pstore_file_open,
183	.read		= pstore_file_read,
184	.llseek		= pstore_file_llseek,
185	.release	= seq_release,
186};
187
188/*
189 * When a file is unlinked from our file system we call the
190 * platform driver to erase the record from persistent store.
191 */
192static int pstore_unlink(struct inode *dir, struct dentry *dentry)
193{
194	struct pstore_private *p = d_inode(dentry)->i_private;
195	int err;
196
197	err = pstore_check_syslog_permissions(p);
198	if (err)
199		return err;
200
201	if (p->psi->erase)
202		p->psi->erase(p->type, p->id, p->count,
203			      d_inode(dentry)->i_ctime, p->psi);
204	else
205		return -EPERM;
206
207	return simple_unlink(dir, dentry);
208}
209
210static void pstore_evict_inode(struct inode *inode)
211{
212	struct pstore_private	*p = inode->i_private;
213	unsigned long		flags;
214
215	clear_inode(inode);
216	if (p) {
217		spin_lock_irqsave(&allpstore_lock, flags);
218		list_del(&p->list);
219		spin_unlock_irqrestore(&allpstore_lock, flags);
220		kfree(p);
221	}
222}
223
224static const struct inode_operations pstore_dir_inode_operations = {
225	.lookup		= simple_lookup,
226	.unlink		= pstore_unlink,
227};
228
229static struct inode *pstore_get_inode(struct super_block *sb)
230{
231	struct inode *inode = new_inode(sb);
232	if (inode) {
233		inode->i_ino = get_next_ino();
234		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
235	}
236	return inode;
237}
238
239enum {
240	Opt_kmsg_bytes, Opt_err
241};
242
243static const match_table_t tokens = {
244	{Opt_kmsg_bytes, "kmsg_bytes=%u"},
245	{Opt_err, NULL}
246};
247
248static void parse_options(char *options)
249{
250	char		*p;
251	substring_t	args[MAX_OPT_ARGS];
252	int		option;
253
254	if (!options)
255		return;
256
257	while ((p = strsep(&options, ",")) != NULL) {
258		int token;
259
260		if (!*p)
261			continue;
262
263		token = match_token(p, tokens, args);
264		switch (token) {
265		case Opt_kmsg_bytes:
266			if (!match_int(&args[0], &option))
267				pstore_set_kmsg_bytes(option);
268			break;
269		}
270	}
271}
272
273static int pstore_remount(struct super_block *sb, int *flags, char *data)
274{
275	sync_filesystem(sb);
276	parse_options(data);
277
278	return 0;
279}
280
281static const struct super_operations pstore_ops = {
282	.statfs		= simple_statfs,
283	.drop_inode	= generic_delete_inode,
284	.evict_inode	= pstore_evict_inode,
285	.remount_fs	= pstore_remount,
286	.show_options	= generic_show_options,
287};
288
289static struct super_block *pstore_sb;
290
291bool pstore_is_mounted(void)
292{
293	return pstore_sb != NULL;
294}
295
296/*
297 * Make a regular file in the root directory of our file system.
298 * Load it up with "size" bytes of data from "buf".
299 * Set the mtime & ctime to the date that this record was originally stored.
300 */
301int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
302		  char *data, bool compressed, size_t size,
303		  struct timespec time, struct pstore_info *psi)
304{
305	struct dentry		*root = pstore_sb->s_root;
306	struct dentry		*dentry;
307	struct inode		*inode;
308	int			rc = 0;
309	char			name[PSTORE_NAMELEN];
310	struct pstore_private	*private, *pos;
311	unsigned long		flags;
312
313	spin_lock_irqsave(&allpstore_lock, flags);
314	list_for_each_entry(pos, &allpstore, list) {
315		if (pos->type == type &&
316		    pos->id == id &&
317		    pos->psi == psi) {
318			rc = -EEXIST;
319			break;
320		}
321	}
322	spin_unlock_irqrestore(&allpstore_lock, flags);
323	if (rc)
324		return rc;
325
326	rc = -ENOMEM;
327	inode = pstore_get_inode(pstore_sb);
328	if (!inode)
329		goto fail;
330	inode->i_mode = S_IFREG | 0444;
331	inode->i_fop = &pstore_file_operations;
332	private = kmalloc(sizeof *private + size, GFP_KERNEL);
333	if (!private)
334		goto fail_alloc;
335	private->type = type;
336	private->id = id;
337	private->count = count;
338	private->psi = psi;
339
340	switch (type) {
341	case PSTORE_TYPE_DMESG:
342		scnprintf(name, sizeof(name), "dmesg-%s-%lld%s",
343			  psname, id, compressed ? ".enc.z" : "");
344		break;
345	case PSTORE_TYPE_CONSOLE:
346		scnprintf(name, sizeof(name), "console-%s-%lld", psname, id);
347		break;
348	case PSTORE_TYPE_FTRACE:
349		scnprintf(name, sizeof(name), "ftrace-%s-%lld", psname, id);
350		break;
351	case PSTORE_TYPE_MCE:
352		scnprintf(name, sizeof(name), "mce-%s-%lld", psname, id);
353		break;
354	case PSTORE_TYPE_PPC_RTAS:
355		scnprintf(name, sizeof(name), "rtas-%s-%lld", psname, id);
356		break;
357	case PSTORE_TYPE_PPC_OF:
358		scnprintf(name, sizeof(name), "powerpc-ofw-%s-%lld",
359			  psname, id);
360		break;
361	case PSTORE_TYPE_PPC_COMMON:
362		scnprintf(name, sizeof(name), "powerpc-common-%s-%lld",
363			  psname, id);
364		break;
365	case PSTORE_TYPE_PMSG:
366		scnprintf(name, sizeof(name), "pmsg-%s-%lld", psname, id);
367		break;
368	case PSTORE_TYPE_PPC_OPAL:
369		sprintf(name, "powerpc-opal-%s-%lld", psname, id);
370		break;
371	case PSTORE_TYPE_UNKNOWN:
372		scnprintf(name, sizeof(name), "unknown-%s-%lld", psname, id);
373		break;
374	default:
375		scnprintf(name, sizeof(name), "type%d-%s-%lld",
376			  type, psname, id);
377		break;
378	}
379
380	inode_lock(d_inode(root));
381
382	dentry = d_alloc_name(root, name);
383	if (!dentry)
384		goto fail_lockedalloc;
385
386	memcpy(private->data, data, size);
387	inode->i_size = private->size = size;
388
389	inode->i_private = private;
390
391	if (time.tv_sec)
392		inode->i_mtime = inode->i_ctime = time;
393
394	d_add(dentry, inode);
395
396	spin_lock_irqsave(&allpstore_lock, flags);
397	list_add(&private->list, &allpstore);
398	spin_unlock_irqrestore(&allpstore_lock, flags);
399
400	inode_unlock(d_inode(root));
401
402	return 0;
403
404fail_lockedalloc:
405	inode_unlock(d_inode(root));
406	kfree(private);
407fail_alloc:
408	iput(inode);
409
410fail:
411	return rc;
412}
413
414static int pstore_fill_super(struct super_block *sb, void *data, int silent)
415{
416	struct inode *inode;
417
418	save_mount_options(sb, data);
419
420	pstore_sb = sb;
421
422	sb->s_maxbytes		= MAX_LFS_FILESIZE;
423	sb->s_blocksize		= PAGE_SIZE;
424	sb->s_blocksize_bits	= PAGE_SHIFT;
425	sb->s_magic		= PSTOREFS_MAGIC;
426	sb->s_op		= &pstore_ops;
427	sb->s_time_gran		= 1;
428
429	parse_options(data);
430
431	inode = pstore_get_inode(sb);
432	if (inode) {
433		inode->i_mode = S_IFDIR | 0755;
434		inode->i_op = &pstore_dir_inode_operations;
435		inode->i_fop = &simple_dir_operations;
436		inc_nlink(inode);
437	}
438	sb->s_root = d_make_root(inode);
439	if (!sb->s_root)
440		return -ENOMEM;
441
442	pstore_get_records(0);
443
444	return 0;
445}
446
447static struct dentry *pstore_mount(struct file_system_type *fs_type,
448	int flags, const char *dev_name, void *data)
449{
450	return mount_single(fs_type, flags, data, pstore_fill_super);
451}
452
453static void pstore_kill_sb(struct super_block *sb)
454{
455	kill_litter_super(sb);
456	pstore_sb = NULL;
457}
458
459static struct file_system_type pstore_fs_type = {
460	.owner          = THIS_MODULE,
461	.name		= "pstore",
462	.mount		= pstore_mount,
463	.kill_sb	= pstore_kill_sb,
464};
465
 
 
466static int __init init_pstore_fs(void)
467{
468	int err;
469
470	/* Create a convenient mount point for people to access pstore */
471	err = sysfs_create_mount_point(fs_kobj, "pstore");
472	if (err)
 
473		goto out;
 
474
475	err = register_filesystem(&pstore_fs_type);
476	if (err < 0)
477		sysfs_remove_mount_point(fs_kobj, "pstore");
478
479out:
480	return err;
481}
482module_init(init_pstore_fs)
483
484static void __exit exit_pstore_fs(void)
485{
486	unregister_filesystem(&pstore_fs_type);
487	sysfs_remove_mount_point(fs_kobj, "pstore");
488}
489module_exit(exit_pstore_fs)
490
491MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>");
492MODULE_LICENSE("GPL");
v3.15
  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>
 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 * 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
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	sync_filesystem(sb);
253	parse_options(data);
254
255	return 0;
256}
257
258static const struct super_operations pstore_ops = {
259	.statfs		= simple_statfs,
260	.drop_inode	= generic_delete_inode,
261	.evict_inode	= pstore_evict_inode,
262	.remount_fs	= pstore_remount,
263	.show_options	= generic_show_options,
264};
265
266static struct super_block *pstore_sb;
267
268int pstore_is_mounted(void)
269{
270	return pstore_sb != NULL;
271}
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 */
278int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
279		  char *data, bool compressed, size_t size,
280		  struct timespec time, struct pstore_info *psi)
281{
282	struct dentry		*root = pstore_sb->s_root;
283	struct dentry		*dentry;
284	struct inode		*inode;
285	int			rc = 0;
286	char			name[PSTORE_NAMELEN];
287	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;
302
303	rc = -ENOMEM;
304	inode = pstore_get_inode(pstore_sb);
305	if (!inode)
306		goto fail;
307	inode->i_mode = S_IFREG | 0444;
308	inode->i_fop = &pstore_file_operations;
309	private = kmalloc(sizeof *private + size, GFP_KERNEL);
310	if (!private)
311		goto fail_alloc;
312	private->type = type;
313	private->id = id;
314	private->count = count;
315	private->psi = psi;
316
317	switch (type) {
318	case PSTORE_TYPE_DMESG:
319		sprintf(name, "dmesg-%s-%lld%s", psname, id,
320						compressed ? ".enc.z" : "");
321		break;
322	case PSTORE_TYPE_CONSOLE:
323		sprintf(name, "console-%s", psname);
324		break;
325	case PSTORE_TYPE_FTRACE:
326		sprintf(name, "ftrace-%s", psname);
327		break;
328	case PSTORE_TYPE_MCE:
329		sprintf(name, "mce-%s-%lld", psname, id);
330		break;
331	case PSTORE_TYPE_PPC_RTAS:
332		sprintf(name, "rtas-%s-%lld", psname, id);
333		break;
334	case PSTORE_TYPE_PPC_OF:
335		sprintf(name, "powerpc-ofw-%s-%lld", psname, id);
 
336		break;
337	case PSTORE_TYPE_PPC_COMMON:
338		sprintf(name, "powerpc-common-%s-%lld", psname, id);
 
 
 
 
 
 
 
339		break;
340	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
350	dentry = d_alloc_name(root, name);
351	if (!dentry)
352		goto fail_lockedalloc;
353
354	memcpy(private->data, data, size);
355	inode->i_size = private->size = size;
356
357	inode->i_private = private;
358
359	if (time.tv_sec)
360		inode->i_mtime = inode->i_ctime = time;
361
362	d_add(dentry, inode);
363
364	spin_lock_irqsave(&allpstore_lock, flags);
365	list_add(&private->list, &allpstore);
366	spin_unlock_irqrestore(&allpstore_lock, flags);
367
368	mutex_unlock(&root->d_inode->i_mutex);
369
370	return 0;
371
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
382static int pstore_fill_super(struct super_block *sb, void *data, int silent)
383{
384	struct inode *inode;
385
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
397	parse_options(data);
398
399	inode = pstore_get_inode(sb);
400	if (inode) {
401		inode->i_mode = S_IFDIR | 0755;
402		inode->i_op = &pstore_dir_inode_operations;
403		inode->i_fop = &simple_dir_operations;
404		inc_nlink(inode);
405	}
406	sb->s_root = d_make_root(inode);
407	if (!sb->s_root)
408		return -ENOMEM;
409
410	pstore_get_records(0);
411
412	return 0;
413}
414
415static struct dentry *pstore_mount(struct file_system_type *fs_type,
416	int flags, const char *dev_name, void *data)
417{
418	return mount_single(fs_type, flags, data, pstore_fill_super);
419}
420
421static void pstore_kill_sb(struct super_block *sb)
422{
423	kill_litter_super(sb);
424	pstore_sb = NULL;
425}
426
427static struct file_system_type pstore_fs_type = {
 
428	.name		= "pstore",
429	.mount		= pstore_mount,
430	.kill_sb	= pstore_kill_sb,
431};
432
433static struct kobject *pstore_kobj;
434
435static int __init init_pstore_fs(void)
436{
437	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;
452}
453module_init(init_pstore_fs)
 
 
 
 
 
 
 
454
455MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>");
456MODULE_LICENSE("GPL");