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/fs_context.h>
23#include <linux/fs_parser.h>
24#include <linux/jffs2.h>
25#include <linux/pagemap.h>
26#include <linux/mtd/super.h>
27#include <linux/ctype.h>
28#include <linux/namei.h>
29#include <linux/seq_file.h>
30#include <linux/exportfs.h>
31#include "compr.h"
32#include "nodelist.h"
33
34static void jffs2_put_super(struct super_block *);
35
36static struct kmem_cache *jffs2_inode_cachep;
37
38static struct inode *jffs2_alloc_inode(struct super_block *sb)
39{
40	struct jffs2_inode_info *f;
41
42	f = alloc_inode_sb(sb, jffs2_inode_cachep, GFP_KERNEL);
43	if (!f)
44		return NULL;
45	return &f->vfs_inode;
46}
47
48static void jffs2_free_inode(struct inode *inode)
49{
50	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
51
52	kfree(f->target);
53	kmem_cache_free(jffs2_inode_cachep, f);
54}
55
56static void jffs2_i_init_once(void *foo)
57{
58	struct jffs2_inode_info *f = foo;
59
60	mutex_init(&f->sem);
61	inode_init_once(&f->vfs_inode);
62}
63
64static const char *jffs2_compr_name(unsigned int compr)
65{
66	switch (compr) {
67	case JFFS2_COMPR_MODE_NONE:
68		return "none";
69#ifdef CONFIG_JFFS2_LZO
70	case JFFS2_COMPR_MODE_FORCELZO:
71		return "lzo";
72#endif
73#ifdef CONFIG_JFFS2_ZLIB
74	case JFFS2_COMPR_MODE_FORCEZLIB:
75		return "zlib";
76#endif
77	default:
78		/* should never happen; programmer error */
79		WARN_ON(1);
80		return "";
81	}
82}
83
84static int jffs2_show_options(struct seq_file *s, struct dentry *root)
85{
86	struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb);
87	struct jffs2_mount_opts *opts = &c->mount_opts;
88
89	if (opts->override_compr)
90		seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr));
91	if (opts->set_rp_size)
92		seq_printf(s, ",rp_size=%u", opts->rp_size / 1024);
93
94	return 0;
95}
96
97static int jffs2_sync_fs(struct super_block *sb, int wait)
98{
99	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
100
101#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
102	if (jffs2_is_writebuffered(c))
103		cancel_delayed_work_sync(&c->wbuf_dwork);
104#endif
105
106	mutex_lock(&c->alloc_sem);
107	jffs2_flush_wbuf_pad(c);
108	mutex_unlock(&c->alloc_sem);
109	return 0;
110}
111
112static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
113					 uint32_t generation)
114{
115	/* We don't care about i_generation. We'll destroy the flash
116	   before we start re-using inode numbers anyway. And even
117	   if that wasn't true, we'd have other problems...*/
118	return jffs2_iget(sb, ino);
119}
120
121static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
122					 int fh_len, int fh_type)
123{
124        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
125                                    jffs2_nfs_get_inode);
126}
127
128static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid,
129					 int fh_len, int fh_type)
130{
131        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
132                                    jffs2_nfs_get_inode);
133}
134
135static struct dentry *jffs2_get_parent(struct dentry *child)
136{
137	struct jffs2_inode_info *f;
138	uint32_t pino;
139
140	BUG_ON(!d_is_dir(child));
141
142	f = JFFS2_INODE_INFO(d_inode(child));
143
144	pino = f->inocache->pino_nlink;
145
146	JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
147		    f->inocache->ino, pino);
148
149	return d_obtain_alias(jffs2_iget(child->d_sb, pino));
150}
151
152static const struct export_operations jffs2_export_ops = {
153	.encode_fh = generic_encode_ino32_fh,
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_source: The source device
163 * Opt_override_compr: override default compressor
164 * Opt_rp_size: size of reserved pool in KiB
165 */
166enum {
167	Opt_override_compr,
168	Opt_rp_size,
169};
170
171static const struct constant_table jffs2_param_compr[] = {
172	{"none",	JFFS2_COMPR_MODE_NONE },
173#ifdef CONFIG_JFFS2_LZO
174	{"lzo",		JFFS2_COMPR_MODE_FORCELZO },
175#endif
176#ifdef CONFIG_JFFS2_ZLIB
177	{"zlib",	JFFS2_COMPR_MODE_FORCEZLIB },
178#endif
179	{}
180};
181
182static const struct fs_parameter_spec jffs2_fs_parameters[] = {
183	fsparam_enum	("compr",	Opt_override_compr, jffs2_param_compr),
184	fsparam_u32	("rp_size",	Opt_rp_size),
185	{}
186};
187
188static int jffs2_parse_param(struct fs_context *fc, struct fs_parameter *param)
189{
190	struct fs_parse_result result;
191	struct jffs2_sb_info *c = fc->s_fs_info;
192	int opt;
193
194	opt = fs_parse(fc, jffs2_fs_parameters, param, &result);
195	if (opt < 0)
196		return opt;
197
198	switch (opt) {
199	case Opt_override_compr:
200		c->mount_opts.compr = result.uint_32;
201		c->mount_opts.override_compr = true;
202		break;
203	case Opt_rp_size:
204		if (result.uint_32 > UINT_MAX / 1024)
205			return invalf(fc, "jffs2: rp_size unrepresentable");
206		c->mount_opts.rp_size = result.uint_32 * 1024;
207		c->mount_opts.set_rp_size = true;
208		break;
209	default:
210		return -EINVAL;
211	}
212
213	return 0;
214}
215
216static inline void jffs2_update_mount_opts(struct fs_context *fc)
217{
218	struct jffs2_sb_info *new_c = fc->s_fs_info;
219	struct jffs2_sb_info *c = JFFS2_SB_INFO(fc->root->d_sb);
220
221	mutex_lock(&c->alloc_sem);
222	if (new_c->mount_opts.override_compr) {
223		c->mount_opts.override_compr = new_c->mount_opts.override_compr;
224		c->mount_opts.compr = new_c->mount_opts.compr;
225	}
226	if (new_c->mount_opts.set_rp_size) {
227		c->mount_opts.set_rp_size = new_c->mount_opts.set_rp_size;
228		c->mount_opts.rp_size = new_c->mount_opts.rp_size;
229	}
230	mutex_unlock(&c->alloc_sem);
231}
232
233static int jffs2_reconfigure(struct fs_context *fc)
234{
235	struct super_block *sb = fc->root->d_sb;
236
237	sync_filesystem(sb);
238	jffs2_update_mount_opts(fc);
239
240	return jffs2_do_remount_fs(sb, fc);
241}
242
243static const struct super_operations jffs2_super_operations =
244{
245	.alloc_inode =	jffs2_alloc_inode,
246	.free_inode =	jffs2_free_inode,
247	.put_super =	jffs2_put_super,
248	.statfs =	jffs2_statfs,
249	.evict_inode =	jffs2_evict_inode,
250	.dirty_inode =	jffs2_dirty_inode,
251	.show_options =	jffs2_show_options,
252	.sync_fs =	jffs2_sync_fs,
253};
254
255/*
256 * fill in the superblock
257 */
258static int jffs2_fill_super(struct super_block *sb, struct fs_context *fc)
259{
260	struct jffs2_sb_info *c = sb->s_fs_info;
261
262	jffs2_dbg(1, "jffs2_get_sb_mtd():"
263		  " New superblock for device %d (\"%s\")\n",
264		  sb->s_mtd->index, sb->s_mtd->name);
265
266	c->mtd = sb->s_mtd;
267	c->os_priv = sb;
268
269	if (c->mount_opts.rp_size > c->mtd->size)
270		return invalf(fc, "jffs2: Too large reserve pool specified, max is %llu KB",
271			      c->mtd->size / 1024);
272
273	/* Initialize JFFS2 superblock locks, the further initialization will
274	 * be done later */
275	mutex_init(&c->alloc_sem);
276	mutex_init(&c->erase_free_sem);
277	init_waitqueue_head(&c->erase_wait);
278	init_waitqueue_head(&c->inocache_wq);
279	spin_lock_init(&c->erase_completion_lock);
280	spin_lock_init(&c->inocache_lock);
281
282	sb->s_op = &jffs2_super_operations;
283	sb->s_export_op = &jffs2_export_ops;
284	sb->s_flags = sb->s_flags | SB_NOATIME;
285	sb->s_xattr = jffs2_xattr_handlers;
286#ifdef CONFIG_JFFS2_FS_POSIX_ACL
287	sb->s_flags |= SB_POSIXACL;
288#endif
289	return jffs2_do_fill_super(sb, fc);
290}
291
292static int jffs2_get_tree(struct fs_context *fc)
293{
294	return get_tree_mtd(fc, jffs2_fill_super);
295}
296
297static void jffs2_free_fc(struct fs_context *fc)
298{
299	kfree(fc->s_fs_info);
300}
301
302static const struct fs_context_operations jffs2_context_ops = {
303	.free		= jffs2_free_fc,
304	.parse_param	= jffs2_parse_param,
305	.get_tree	= jffs2_get_tree,
306	.reconfigure	= jffs2_reconfigure,
307};
308
309static int jffs2_init_fs_context(struct fs_context *fc)
310{
311	struct jffs2_sb_info *ctx;
312
313	ctx = kzalloc(sizeof(struct jffs2_sb_info), GFP_KERNEL);
314	if (!ctx)
315		return -ENOMEM;
316
317	fc->s_fs_info = ctx;
318	fc->ops = &jffs2_context_ops;
319	return 0;
320}
321
322static void jffs2_put_super (struct super_block *sb)
323{
324	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
325
326	jffs2_dbg(2, "%s()\n", __func__);
327
328	mutex_lock(&c->alloc_sem);
329	jffs2_flush_wbuf_pad(c);
330	mutex_unlock(&c->alloc_sem);
331
332	jffs2_sum_exit(c);
333
334	jffs2_free_ino_caches(c);
335	jffs2_free_raw_node_refs(c);
336	kvfree(c->blocks);
337	jffs2_flash_cleanup(c);
338	kfree(c->inocache_list);
339	jffs2_clear_xattr_subsystem(c);
340	mtd_sync(c->mtd);
341	jffs2_dbg(1, "%s(): returning\n", __func__);
342}
343
344static void jffs2_kill_sb(struct super_block *sb)
345{
346	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
347	if (c && !sb_rdonly(sb))
348		jffs2_stop_garbage_collect_thread(c);
349	kill_mtd_super(sb);
350	kfree(c);
351}
352
353static struct file_system_type jffs2_fs_type = {
354	.owner =	THIS_MODULE,
355	.name =		"jffs2",
356	.init_fs_context = jffs2_init_fs_context,
357	.parameters =	jffs2_fs_parameters,
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_ACCOUNT),
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