aboutsummaryrefslogtreecommitdiff
path: root/fs/jffs2/super.c
blob: e51164a8a8d45024cbc7068c37d92f9d01fe5f12 (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
/*
 * 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.
 *
 */

#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/jffs2.h>
#include <linux/pagemap.h>
#include <linux/mtd/mtd.h>
#include <linux/ctype.h>
#include <linux/namei.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 *ei;
	ei = (struct jffs2_inode_info *)kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
	if (!ei)
		return NULL;
	return &ei->vfs_inode;
}

static void jffs2_destroy_inode(struct inode *inode)
{
	kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
}

static void jffs2_i_init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
{
	struct jffs2_inode_info *ei = (struct jffs2_inode_info *) foo;

	if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
	    SLAB_CTOR_CONSTRUCTOR) {
		init_MUTEX(&ei->sem);
		inode_init_once(&ei->vfs_inode);
	}
}

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

	down(&c->alloc_sem);
	jffs2_flush_wbuf_pad(c);
	up(&c->alloc_sem);
	return 0;
}

static const struct super_operations jffs2_super_operations =
{
	.alloc_inode =	jffs2_alloc_inode,
	.destroy_inode =jffs2_destroy_inode,
	.read_inode =	jffs2_read_inode,
	.put_super =	jffs2_put_super,
	.write_super =	jffs2_write_super,
	.statfs =	jffs2_statfs,
	.remount_fs =	jffs2_remount_fs,
	.clear_inode =	jffs2_clear_inode,
	.dirty_inode =	jffs2_dirty_inode,
	.sync_fs =	jffs2_sync_fs,
};

static int jffs2_sb_compare(struct super_block *sb, void *data)
{
	struct jffs2_sb_info *p = data;
	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);

	/* The superblocks are considered to be equivalent if the underlying MTD
	   device is the same one */
	if (c->mtd == p->mtd) {
		D1(printk(KERN_DEBUG "jffs2_sb_compare: match on device %d (\"%s\")\n", p->mtd->index, p->mtd->name));
		return 1;
	} else {
		D1(printk(KERN_DEBUG "jffs2_sb_compare: No match, device %d (\"%s\"), device %d (\"%s\")\n",
			  c->mtd->index, c->mtd->name, p->mtd->index, p->mtd->name));
		return 0;
	}
}

static int jffs2_sb_set(struct super_block *sb, void *data)
{
	struct jffs2_sb_info *p = data;

	/* For persistence of NFS exports etc. we use the same s_dev
	   each time we mount the device, don't just use an anonymous
	   device */
	sb->s_fs_info = p;
	p->os_priv = sb;
	sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, p->mtd->index);

	return 0;
}

static int jffs2_get_sb_mtd(struct file_system_type *fs_type,
			    int flags, const char *dev_name,
			    void *data, struct mtd_info *mtd,
			    struct vfsmount *mnt)
{
	struct super_block *sb;
	struct jffs2_sb_info *c;
	int ret;

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

	sb = sget(fs_type, jffs2_sb_compare, jffs2_sb_set, c);

	if (IS_ERR(sb))
		goto out_error;

	if (sb->s_root) {
		/* New mountpoint for JFFS2 which is already mounted */
		D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): Device %d (\"%s\") is already mounted\n",
			  mtd->index, mtd->name));
		ret = simple_set_mnt(mnt, sb);
		goto out_put;
	}

	D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): New superblock for device %d (\"%s\")\n",
		  mtd->index, mtd->name));

	/* Initialize JFFS2 superblock locks, the further initialization will be
	 * done later */
	init_MUTEX(&c->alloc_sem);
	init_MUTEX(&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_flags = 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, flags & MS_SILENT ? 1 : 0);

	if (ret) {
		/* Failure case... */
		up_write(&sb->s_umount);
		deactivate_super(sb);
		return ret;
	}

	sb->s_flags |= MS_ACTIVE;
	return simple_set_mnt(mnt, sb);

out_error:
	ret = PTR_ERR(sb);
 out_put:
	kfree(c);
	put_mtd_device(mtd);

	return ret;
}

static int jffs2_get_sb_mtdnr(struct file_system_type *fs_type,
			      int flags, const char *dev_name,
			      void *data, int mtdnr,
			      struct vfsmount *mnt)
{
	struct mtd_info *mtd;

	mtd = get_mtd_device(NULL, mtdnr);
	if (IS_ERR(mtd)) {
		D1(printk(KERN_DEBUG "jffs2: MTD device #%u doesn't appear to exist\n", mtdnr));
		return PTR_ERR(mtd);
	}

	return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd, mnt);
}

static int jffs2_get_sb(struct file_system_type *fs_type,
			int flags, const char *dev_name,
			void *data, struct vfsmount *mnt)
{
	int err;
	struct nameidata nd;
	int mtdnr;

	if (!dev_name)
		return -EINVAL;

	D1(printk(KERN_DEBUG "jffs2_get_sb(): dev_name \"%s\"\n", dev_name));

	/* The preferred way of mounting in future; especially when
	   CONFIG_BLK_DEV is implemented - we specify the underlying
	   MTD device by number or by name, so that we don't require
	   block device support to be present in the kernel. */

	/* FIXME: How to do the root fs this way? */

	if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') {
		/* Probably mounting without the blkdev crap */
		if (dev_name[3] == ':') {
			struct mtd_info *mtd;

			/* Mount by MTD device name */
			D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd:%%s, name \"%s\"\n", dev_name+4));
			for (mtdnr = 0; mtdnr < MAX_MTD_DEVICES; mtdnr++) {
				mtd = get_mtd_device(NULL, mtdnr);
				if (!IS_ERR(mtd)) {
					if (!strcmp(mtd->name, dev_name+4))
						return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd, mnt);
					put_mtd_device(mtd);
				}
			}
			printk(KERN_NOTICE "jffs2_get_sb(): MTD device with name \"%s\" not found.\n", dev_name+4);
		} else if (isdigit(dev_name[3])) {
			/* Mount by MTD device number name */
			char *endptr;

			mtdnr = simple_strtoul(dev_name+3, &endptr, 0);
			if (!*endptr) {
				/* It was a valid number */
				D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd%%d, mtdnr %d\n", mtdnr));
				return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr, mnt);
			}
		}
	}

	/* Try the old way - the hack where we allowed users to mount
	   /dev/mtdblock$(n) but didn't actually _use_ the blkdev */

	err = path_lookup(dev_name, LOOKUP_FOLLOW, &nd);

	D1(printk(KERN_DEBUG "jffs2_get_sb(): path_lookup() returned %d, inode %p\n",
		  err, nd.dentry->d_inode));

	if (err)
		return err;

	err = -EINVAL;

	if (!S_ISBLK(nd.dentry->d_inode->i_mode))
		goto out;

	if (nd.mnt->mnt_flags & MNT_NODEV) {
		err = -EACCES;
		goto out;
	}

	if (imajor(nd.dentry->d_inode) != MTD_BLOCK_MAJOR) {
		if (!(flags & MS_SILENT))
			printk(KERN_NOTICE "Attempt to mount non-MTD device \"%s\" as JFFS2\n",
			       dev_name);
		goto out;
	}

	mtdnr = iminor(nd.dentry->d_inode);
	path_release(&nd);

	return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr, mnt);

out:
	path_release(&nd);
	return err;
}

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

	D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));

	down(&c->alloc_sem);
	jffs2_flush_wbuf_pad(c);
	up(&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);
	if (c->mtd->sync)
		c->mtd->sync(c->mtd);

	D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
}

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

static struct file_system_type jffs2_fs_type = {
	.owner =	THIS_MODULE,
	.name =		"jffs2",
	.get_sb =	jffs2_get_sb,
	.kill_sb =	jffs2_kill_sb,
};

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);

	printk(KERN_INFO "JFFS2 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, NULL);
	if (!jffs2_inode_cachep) {
		printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n");
		return -ENOMEM;
	}
	ret = jffs2_compressors_init();
	if (ret) {
		printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n");
		goto out;
	}
	ret = jffs2_create_slab_caches();
	if (ret) {
		printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
		goto out_compressors;
	}
	ret = register_filesystem(&jffs2_fs_type);
	if (ret) {
		printk(KERN_ERR "JFFS2 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();
	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.