summaryrefslogtreecommitdiff
path: root/fs/jffs2/super.c
blob: 9fc297df8c758bc1868d696ab50c3c6f2bb7758a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2001-2007 Red Hat, Inc.
 *
 * Created by David Woodhouse <dwmw2@infradead.org>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/fs.h>
#include <linux/err.h>
#include <linux/mount.h>
#include <linux/parser.h>
#include <linux/jffs2.h>
#include <linux/pagemap.h>
#include <linux/mtd/super.h>
#include <linux/ctype.h>
#include <linux/namei.h>
#include <linux/seq_file.h>
#include <linux/exportfs.h>
#include "compr.h"
#include "nodelist.h"

static void jffs2_put_super(struct super_block *);

static struct kmem_cache *jffs2_inode_cachep;

static struct inode *jffs2_alloc_inode(struct super_block *sb)
{
	struct jffs2_inode_info *f;

	f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
	if (!f)
		return NULL;
	return &f->vfs_inode;
}

static void jffs2_i_callback(struct rcu_head *head)
{
	struct inode *inode = container_of(head, struct inode, i_rcu);
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);

	kfree(f->target);
	kmem_cache_free(jffs2_inode_cachep, f);
}

static void jffs2_destroy_inode(struct inode *inode)
{
	call_rcu(&inode->i_rcu, jffs2_i_callback);
}

static void jffs2_i_init_once(void *foo)
{
	struct jffs2_inode_info *f = foo;

	mutex_init(&f->sem);
	inode_init_once(&f->vfs_inode);
}

static const char *jffs2_compr_name(unsigned int compr)
{
	switch (compr) {
	case JFFS2_COMPR_MODE_NONE:
		return "none";
#ifdef CONFIG_JFFS2_LZO
	case JFFS2_COMPR_MODE_FORCELZO:
		return "lzo";
#endif
#ifdef CONFIG_JFFS2_ZLIB
	case JFFS2_COMPR_MODE_FORCEZLIB:
		return "zlib";
#endif
	default:
		/* should never happen; programmer error */
		WARN_ON(1);
		return "";
	}
}

static int jffs2_show_options(struct seq_file *s, struct dentry *root)
{
	struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb);
	struct jffs2_mount_opts *opts = &c->mount_opts;

	if (opts->override_compr)
		seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr));
	if (opts->rp_size)
		seq_printf(s, ",rp_size=%u", opts->rp_size / 1024);

	return 0;
}

static int jffs2_sync_fs(struct super_block *sb, int wait)
{
	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);

#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
	if (jffs2_is_writebuffered(c))
		cancel_delayed_work_sync(&c->wbuf_dwork);
#endif

	mutex_lock(&c->alloc_sem);
	jffs2_flush_wbuf_pad(c);
	mutex_unlock(&c->alloc_sem);
	return 0;
}

static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
					 uint32_t generation)
{
	/* We don't care about i_generation. We'll destroy the flash
	   before we start re-using inode numbers anyway. And even
	   if that wasn't true, we'd have other problems...*/
	return jffs2_iget(sb, ino);
}

static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
					 int fh_len, int fh_type)
{
        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
                                    jffs2_nfs_get_inode);
}

static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid,
					 int fh_len, int fh_type)
{
        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
                                    jffs2_nfs_get_inode);
}

static struct dentry *jffs2_get_parent(struct dentry *child)
{
	struct jffs2_inode_info *f;
	uint32_t pino;

	BUG_ON(!d_is_dir(child));

	f = JFFS2_INODE_INFO(d_inode(child));

	pino = f->inocache->pino_nlink;

	JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
		    f->inocache->ino, pino);

	return d_obtain_alias(jffs2_iget(d_inode(child)->i_sb, pino));
}

static const struct export_operations jffs2_export_ops = {
	.get_parent = jffs2_get_parent,
	.fh_to_dentry = jffs2_fh_to_dentry,
	.fh_to_parent = jffs2_fh_to_parent,
};

/*
 * JFFS2 mount options.
 *
 * Opt_override_compr: override default compressor
 * Opt_rp_size: size of reserved pool in KiB
 * Opt_err: just end of array marker
 */
enum {
	Opt_override_compr,
	Opt_rp_size,
	Opt_err,
};

static const match_table_t tokens = {
	{Opt_override_compr, "compr=%s"},
	{Opt_rp_size, "rp_size=%u"},
	{Opt_err, NULL},
};

static int jffs2_parse_options(struct jffs2_sb_info *c, char *data)
{
	substring_t args[MAX_OPT_ARGS];
	char *p, *name;
	unsigned int opt;

	if (!data)
		return 0;

	while ((p = strsep(&data, ","))) {
		int token;

		if (!*p)
			continue;

		token = match_token(p, tokens, args);
		switch (token) {
		case Opt_override_compr:
			name = match_strdup(&args[0]);

			if (!name)
				return -ENOMEM;
			if (!strcmp(name, "none"))
				c->mount_opts.compr = JFFS2_COMPR_MODE_NONE;
#ifdef CONFIG_JFFS2_LZO
			else if (!strcmp(name, "lzo"))
				c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO;
#endif
#ifdef CONFIG_JFFS2_ZLIB
			else if (!strcmp(name, "zlib"))
				c->mount_opts.compr =
						JFFS2_COMPR_MODE_FORCEZLIB;
#endif
			else {
				pr_err("Error: unknown compressor \"%s\"\n",
				       name);
				kfree(name);
				return -EINVAL;
			}
			kfree(name);
			c->mount_opts.override_compr = true;
			break;
		case Opt_rp_size:
			if (match_int(&args[0], &opt))
				return -EINVAL;
			opt *= 1024;
			if (opt > c->mtd->size) {
				pr_warn("Too large reserve pool specified, max "
					"is %llu KB\n", c->mtd->size / 1024);
				return -EINVAL;
			}
			c->mount_opts.rp_size = opt;
			break;
		default:
			pr_err("Error: unrecognized mount option '%s' or missing value\n",
			       p);
			return -EINVAL;
		}
	}

	return 0;
}

static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data)
{
	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
	int err;

	sync_filesystem(sb);
	err = jffs2_parse_options(c, data);
	if (err)
		return -EINVAL;

	return jffs2_do_remount_fs(sb, flags, data);
}

static const struct super_operations jffs2_super_operations =
{
	.alloc_inode =	jffs2_alloc_inode,
	.destroy_inode =jffs2_destroy_inode,
	.put_super =	jffs2_put_super,
	.statfs =	jffs2_statfs,
	.remount_fs =	jffs2_remount_fs,
	.evict_inode =	jffs2_evict_inode,
	.dirty_inode =	jffs2_dirty_inode,
	.show_options =	jffs2_show_options,
	.sync_fs =	jffs2_sync_fs,
};

/*
 * fill in the superblock
 */
static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
{
	struct jffs2_sb_info *c;
	int ret;

	jffs2_dbg(1, "jffs2_get_sb_mtd():"
		  " New superblock for device %d (\"%s\")\n",
		  sb->s_mtd->index, sb->s_mtd->name);

	c = kzalloc(sizeof(*c), GFP_KERNEL);
	if (!c)
		return -ENOMEM;

	c->mtd = sb->s_mtd;
	c->os_priv = sb;
	sb->s_fs_info = c;

	ret = jffs2_parse_options(c, data);
	if (ret)
		return -EINVAL;

	/* Initialize JFFS2 superblock locks, the further initialization will
	 * be done later */
	mutex_init(&c->alloc_sem);
	mutex_init(&c->erase_free_sem);
	init_waitqueue_head(&c->erase_wait);
	init_waitqueue_head(&c->inocache_wq);
	spin_lock_init(&c->erase_completion_lock);
	spin_lock_init(&c->inocache_lock);

	sb->s_op = &jffs2_super_operations;
	sb->s_export_op = &jffs2_export_ops;
	sb->s_flags = sb->s_flags | MS_NOATIME;
	sb->s_xattr = jffs2_xattr_handlers;
#ifdef CONFIG_JFFS2_FS_POSIX_ACL
	sb->s_flags |= MS_POSIXACL;
#endif
	ret = jffs2_do_fill_super(sb, data, silent);
	return ret;
}

static struct dentry *jffs2_mount(struct file_system_type *fs_type,
			int flags, const char *dev_name,
			void *data)
{
	return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super);
}

static void jffs2_put_super (struct super_block *sb)
{
	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);

	jffs2_dbg(2, "%s()\n", __func__);

	mutex_lock(&c->alloc_sem);
	jffs2_flush_wbuf_pad(c);
	mutex_unlock(&c->alloc_sem);

	jffs2_sum_exit(c);

	jffs2_free_ino_caches(c);
	jffs2_free_raw_node_refs(c);
	if (jffs2_blocks_use_vmalloc(c))
		vfree(c->blocks);
	else
		kfree(c->blocks);
	jffs2_flash_cleanup(c);
	kfree(c->inocache_list);
	jffs2_clear_xattr_subsystem(c);
	mtd_sync(c->mtd);
	jffs2_dbg(1, "%s(): returning\n", __func__);
}

static void jffs2_kill_sb(struct super_block *sb)
{
	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
	if (c && !(sb->s_flags & MS_RDONLY))
		jffs2_stop_garbage_collect_thread(c);
	kill_mtd_super(sb);
	kfree(c);
}

static struct file_system_type jffs2_fs_type = {
	.owner =	THIS_MODULE,
	.name =		"jffs2",
	.mount =	jffs2_mount,
	.kill_sb =	jffs2_kill_sb,
};
MODULE_ALIAS_FS("jffs2");

static int __init init_jffs2_fs(void)
{
	int ret;

	/* Paranoia checks for on-medium structures. If we ask GCC
	   to pack them with __attribute__((packed)) then it _also_
	   assumes that they're not aligned -- so it emits crappy
	   code on some architectures. Ideally we want an attribute
	   which means just 'no padding', without the alignment
	   thing. But GCC doesn't have that -- we have to just
	   hope the structs are the right sizes, instead. */
	BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
	BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
	BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
	BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);

	pr_info("version 2.2."
#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
	       " (NAND)"
#endif
#ifdef CONFIG_JFFS2_SUMMARY
	       " (SUMMARY) "
#endif
	       " © 2001-2006 Red Hat, Inc.\n");

	jffs2_inode_cachep = kmem_cache_create("jffs2_i",
					     sizeof(struct jffs2_inode_info),
					     0, (SLAB_RECLAIM_ACCOUNT|
						SLAB_MEM_SPREAD),
					     jffs2_i_init_once);
	if (!jffs2_inode_cachep) {
		pr_err("error: Failed to initialise inode cache\n");
		return -ENOMEM;
	}
	ret = jffs2_compressors_init();
	if (ret) {
		pr_err("error: Failed to initialise compressors\n");
		goto out;
	}
	ret = jffs2_create_slab_caches();
	if (ret) {
		pr_err("error: Failed to initialise slab caches\n");
		goto out_compressors;
	}
	ret = register_filesystem(&jffs2_fs_type);
	if (ret) {
		pr_err("error: Failed to register filesystem\n");
		goto out_slab;
	}
	return 0;

 out_slab:
	jffs2_destroy_slab_caches();
 out_compressors:
	jffs2_compressors_exit();
 out:
	kmem_cache_destroy(jffs2_inode_cachep);
	return ret;
}

static void __exit exit_jffs2_fs(void)
{
	unregister_filesystem(&jffs2_fs_type);
	jffs2_destroy_slab_caches();
	jffs2_compressors_exit();

	/*
	 * Make sure all delayed rcu free inodes are flushed before we
	 * destroy cache.
	 */
	rcu_barrier();
	kmem_cache_destroy(jffs2_inode_cachep);
}

module_init(init_jffs2_fs);
module_exit(exit_jffs2_fs);

MODULE_DESCRIPTION("The Journalling Flash File System, v2");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
		       // the sake of this tag. It's Free Software.