1/*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright © 2001-2007 Red Hat, Inc.
5 *
6 * Created by David Woodhouse <dwmw2@infradead.org>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
10 */
11
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/slab.h>
17#include <linux/init.h>
18#include <linux/list.h>
19#include <linux/fs.h>
20#include <linux/err.h>
21#include <linux/mount.h>
22#include <linux/parser.h>
23#include <linux/jffs2.h>
24#include <linux/pagemap.h>
25#include <linux/mtd/super.h>
26#include <linux/ctype.h>
27#include <linux/namei.h>
28#include <linux/seq_file.h>
29#include <linux/exportfs.h>
30#include "compr.h"
31#include "nodelist.h"
32
33static void jffs2_put_super(struct super_block *);
34
35static struct kmem_cache *jffs2_inode_cachep;
36
37static struct inode *jffs2_alloc_inode(struct super_block *sb)
38{
39	struct jffs2_inode_info *f;
40
41	f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
42	if (!f)
43		return NULL;
44	return &f->vfs_inode;
45}
46
47static void jffs2_i_callback(struct rcu_head *head)
48{
49	struct inode *inode = container_of(head, struct inode, i_rcu);
50	kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
51}
52
53static void jffs2_destroy_inode(struct inode *inode)
54{
55	call_rcu(&inode->i_rcu, jffs2_i_callback);
56}
57
58static void jffs2_i_init_once(void *foo)
59{
60	struct jffs2_inode_info *f = foo;
61
62	mutex_init(&f->sem);
63	inode_init_once(&f->vfs_inode);
64}
65
66static const char *jffs2_compr_name(unsigned int compr)
67{
68	switch (compr) {
69	case JFFS2_COMPR_MODE_NONE:
70		return "none";
71#ifdef CONFIG_JFFS2_LZO
72	case JFFS2_COMPR_MODE_FORCELZO:
73		return "lzo";
74#endif
75#ifdef CONFIG_JFFS2_ZLIB
76	case JFFS2_COMPR_MODE_FORCEZLIB:
77		return "zlib";
78#endif
79	default:
80		/* should never happen; programmer error */
81		WARN_ON(1);
82		return "";
83	}
84}
85
86static int jffs2_show_options(struct seq_file *s, struct dentry *root)
87{
88	struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb);
89	struct jffs2_mount_opts *opts = &c->mount_opts;
90
91	if (opts->override_compr)
92		seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr));
93	if (opts->rp_size)
94		seq_printf(s, ",rp_size=%u", opts->rp_size / 1024);
95
96	return 0;
97}
98
99static int jffs2_sync_fs(struct super_block *sb, int wait)
100{
101	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
102
103#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
104	cancel_delayed_work_sync(&c->wbuf_dwork);
105#endif
106
107	mutex_lock(&c->alloc_sem);
108	jffs2_flush_wbuf_pad(c);
109	mutex_unlock(&c->alloc_sem);
110	return 0;
111}
112
113static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
114					 uint32_t generation)
115{
116	/* We don't care about i_generation. We'll destroy the flash
117	   before we start re-using inode numbers anyway. And even
118	   if that wasn't true, we'd have other problems...*/
119	return jffs2_iget(sb, ino);
120}
121
122static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
123					 int fh_len, int fh_type)
124{
125        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
126                                    jffs2_nfs_get_inode);
127}
128
129static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid,
130					 int fh_len, int fh_type)
131{
132        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
133                                    jffs2_nfs_get_inode);
134}
135
136static struct dentry *jffs2_get_parent(struct dentry *child)
137{
138	struct jffs2_inode_info *f;
139	uint32_t pino;
140
141	BUG_ON(!S_ISDIR(child->d_inode->i_mode));
142
143	f = JFFS2_INODE_INFO(child->d_inode);
144
145	pino = f->inocache->pino_nlink;
146
147	JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
148		    f->inocache->ino, pino);
149
150	return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino));
151}
152
153static const struct export_operations jffs2_export_ops = {
154	.get_parent = jffs2_get_parent,
155	.fh_to_dentry = jffs2_fh_to_dentry,
156	.fh_to_parent = jffs2_fh_to_parent,
157};
158
159/*
160 * JFFS2 mount options.
161 *
162 * Opt_override_compr: override default compressor
163 * Opt_rp_size: size of reserved pool in KiB
164 * Opt_err: just end of array marker
165 */
166enum {
167	Opt_override_compr,
168	Opt_rp_size,
169	Opt_err,
170};
171
172static const match_table_t tokens = {
173	{Opt_override_compr, "compr=%s"},
174	{Opt_rp_size, "rp_size=%u"},
175	{Opt_err, NULL},
176};
177
178static int jffs2_parse_options(struct jffs2_sb_info *c, char *data)
179{
180	substring_t args[MAX_OPT_ARGS];
181	char *p, *name;
182	unsigned int opt;
183
184	if (!data)
185		return 0;
186
187	while ((p = strsep(&data, ","))) {
188		int token;
189
190		if (!*p)
191			continue;
192
193		token = match_token(p, tokens, args);
194		switch (token) {
195		case Opt_override_compr:
196			name = match_strdup(&args[0]);
197
198			if (!name)
199				return -ENOMEM;
200			if (!strcmp(name, "none"))
201				c->mount_opts.compr = JFFS2_COMPR_MODE_NONE;
202#ifdef CONFIG_JFFS2_LZO
203			else if (!strcmp(name, "lzo"))
204				c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO;
205#endif
206#ifdef CONFIG_JFFS2_ZLIB
207			else if (!strcmp(name, "zlib"))
208				c->mount_opts.compr =
209						JFFS2_COMPR_MODE_FORCEZLIB;
210#endif
211			else {
212				pr_err("Error: unknown compressor \"%s\"\n",
213				       name);
214				kfree(name);
215				return -EINVAL;
216			}
217			kfree(name);
218			c->mount_opts.override_compr = true;
219			break;
220		case Opt_rp_size:
221			if (match_int(&args[0], &opt))
222				return -EINVAL;
223			opt *= 1024;
224			if (opt > c->mtd->size) {
225				pr_warn("Too large reserve pool specified, max "
226					"is %llu KB\n", c->mtd->size / 1024);
227				return -EINVAL;
228			}
229			c->mount_opts.rp_size = opt;
230			break;
231		default:
232			pr_err("Error: unrecognized mount option '%s' or missing value\n",
233			       p);
234			return -EINVAL;
235		}
236	}
237
238	return 0;
239}
240
241static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data)
242{
243	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
244	int err;
245
246	sync_filesystem(sb);
247	err = jffs2_parse_options(c, data);
248	if (err)
249		return -EINVAL;
250
251	return jffs2_do_remount_fs(sb, flags, data);
252}
253
254static const struct super_operations jffs2_super_operations =
255{
256	.alloc_inode =	jffs2_alloc_inode,
257	.destroy_inode =jffs2_destroy_inode,
258	.put_super =	jffs2_put_super,
259	.statfs =	jffs2_statfs,
260	.remount_fs =	jffs2_remount_fs,
261	.evict_inode =	jffs2_evict_inode,
262	.dirty_inode =	jffs2_dirty_inode,
263	.show_options =	jffs2_show_options,
264	.sync_fs =	jffs2_sync_fs,
265};
266
267/*
268 * fill in the superblock
269 */
270static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
271{
272	struct jffs2_sb_info *c;
273	int ret;
274
275	jffs2_dbg(1, "jffs2_get_sb_mtd():"
276		  " New superblock for device %d (\"%s\")\n",
277		  sb->s_mtd->index, sb->s_mtd->name);
278
279	c = kzalloc(sizeof(*c), GFP_KERNEL);
280	if (!c)
281		return -ENOMEM;
282
283	c->mtd = sb->s_mtd;
284	c->os_priv = sb;
285	sb->s_fs_info = c;
286
287	ret = jffs2_parse_options(c, data);
288	if (ret) {
289		kfree(c);
290		return -EINVAL;
291	}
292
293	/* Initialize JFFS2 superblock locks, the further initialization will
294	 * be done later */
295	mutex_init(&c->alloc_sem);
296	mutex_init(&c->erase_free_sem);
297	init_waitqueue_head(&c->erase_wait);
298	init_waitqueue_head(&c->inocache_wq);
299	spin_lock_init(&c->erase_completion_lock);
300	spin_lock_init(&c->inocache_lock);
301
302	sb->s_op = &jffs2_super_operations;
303	sb->s_export_op = &jffs2_export_ops;
304	sb->s_flags = sb->s_flags | MS_NOATIME;
305	sb->s_xattr = jffs2_xattr_handlers;
306#ifdef CONFIG_JFFS2_FS_POSIX_ACL
307	sb->s_flags |= MS_POSIXACL;
308#endif
309	ret = jffs2_do_fill_super(sb, data, silent);
310	return ret;
311}
312
313static struct dentry *jffs2_mount(struct file_system_type *fs_type,
314			int flags, const char *dev_name,
315			void *data)
316{
317	return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super);
318}
319
320static void jffs2_put_super (struct super_block *sb)
321{
322	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
323
324	jffs2_dbg(2, "%s()\n", __func__);
325
326	mutex_lock(&c->alloc_sem);
327	jffs2_flush_wbuf_pad(c);
328	mutex_unlock(&c->alloc_sem);
329
330	jffs2_sum_exit(c);
331
332	jffs2_free_ino_caches(c);
333	jffs2_free_raw_node_refs(c);
334	if (jffs2_blocks_use_vmalloc(c))
335		vfree(c->blocks);
336	else
337		kfree(c->blocks);
338	jffs2_flash_cleanup(c);
339	kfree(c->inocache_list);
340	jffs2_clear_xattr_subsystem(c);
341	mtd_sync(c->mtd);
342	jffs2_dbg(1, "%s(): returning\n", __func__);
343}
344
345static void jffs2_kill_sb(struct super_block *sb)
346{
347	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
348	if (!(sb->s_flags & MS_RDONLY))
349		jffs2_stop_garbage_collect_thread(c);
350	kill_mtd_super(sb);
351	kfree(c);
352}
353
354static struct file_system_type jffs2_fs_type = {
355	.owner =	THIS_MODULE,
356	.name =		"jffs2",
357	.mount =	jffs2_mount,
358	.kill_sb =	jffs2_kill_sb,
359};
360MODULE_ALIAS_FS("jffs2");
361
362static int __init init_jffs2_fs(void)
363{
364	int ret;
365
366	/* Paranoia checks for on-medium structures. If we ask GCC
367	   to pack them with __attribute__((packed)) then it _also_
368	   assumes that they're not aligned -- so it emits crappy
369	   code on some architectures. Ideally we want an attribute
370	   which means just 'no padding', without the alignment
371	   thing. But GCC doesn't have that -- we have to just
372	   hope the structs are the right sizes, instead. */
373	BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
374	BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
375	BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
376	BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
377
378	pr_info("version 2.2."
379#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
380	       " (NAND)"
381#endif
382#ifdef CONFIG_JFFS2_SUMMARY
383	       " (SUMMARY) "
384#endif
385	       " © 2001-2006 Red Hat, Inc.\n");
386
387	jffs2_inode_cachep = kmem_cache_create("jffs2_i",
388					     sizeof(struct jffs2_inode_info),
389					     0, (SLAB_RECLAIM_ACCOUNT|
390						SLAB_MEM_SPREAD),
391					     jffs2_i_init_once);
392	if (!jffs2_inode_cachep) {
393		pr_err("error: Failed to initialise inode cache\n");
394		return -ENOMEM;
395	}
396	ret = jffs2_compressors_init();
397	if (ret) {
398		pr_err("error: Failed to initialise compressors\n");
399		goto out;
400	}
401	ret = jffs2_create_slab_caches();
402	if (ret) {
403		pr_err("error: Failed to initialise slab caches\n");
404		goto out_compressors;
405	}
406	ret = register_filesystem(&jffs2_fs_type);
407	if (ret) {
408		pr_err("error: Failed to register filesystem\n");
409		goto out_slab;
410	}
411	return 0;
412
413 out_slab:
414	jffs2_destroy_slab_caches();
415 out_compressors:
416	jffs2_compressors_exit();
417 out:
418	kmem_cache_destroy(jffs2_inode_cachep);
419	return ret;
420}
421
422static void __exit exit_jffs2_fs(void)
423{
424	unregister_filesystem(&jffs2_fs_type);
425	jffs2_destroy_slab_caches();
426	jffs2_compressors_exit();
427
428	/*
429	 * Make sure all delayed rcu free inodes are flushed before we
430	 * destroy cache.
431	 */
432	rcu_barrier();
433	kmem_cache_destroy(jffs2_inode_cachep);
434}
435
436module_init(init_jffs2_fs);
437module_exit(exit_jffs2_fs);
438
439MODULE_DESCRIPTION("The Journalling Flash File System, v2");
440MODULE_AUTHOR("Red Hat, Inc.");
441MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
442		       // the sake of this tag. It's Free Software.
443