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
34 static void jffs2_put_super(struct super_block *);
35
36 static struct kmem_cache *jffs2_inode_cachep;
37
38 static 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
48 static 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
56 static void jffs2_i_init_once(void *foo)
57 {
58 struct jffs2_inode_info *f = foo;
59
60 mutex_init(&f->sem);
61 f->target = NULL;
62 inode_init_once(&f->vfs_inode);
63 }
64
65 static const char *jffs2_compr_name(unsigned int compr)
66 {
67 switch (compr) {
68 case JFFS2_COMPR_MODE_NONE:
69 return "none";
70 #ifdef CONFIG_JFFS2_LZO
71 case JFFS2_COMPR_MODE_FORCELZO:
72 return "lzo";
73 #endif
74 #ifdef CONFIG_JFFS2_ZLIB
75 case JFFS2_COMPR_MODE_FORCEZLIB:
76 return "zlib";
77 #endif
78 default:
79 /* should never happen; programmer error */
80 WARN_ON(1);
81 return "";
82 }
83 }
84
85 static int jffs2_show_options(struct seq_file *s, struct dentry *root)
86 {
87 struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb);
88 struct jffs2_mount_opts *opts = &c->mount_opts;
89
90 if (opts->override_compr)
91 seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr));
92 if (opts->set_rp_size)
93 seq_printf(s, ",rp_size=%u", opts->rp_size / 1024);
94
95 return 0;
96 }
97
98 static int jffs2_sync_fs(struct super_block *sb, int wait)
99 {
100 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
101
102 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
103 if (jffs2_is_writebuffered(c))
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
113 static 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
122 static 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
129 static 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
136 static struct dentry *jffs2_get_parent(struct dentry *child)
137 {
138 struct jffs2_inode_info *f;
139 uint32_t pino;
140
141 BUG_ON(!d_is_dir(child));
142
143 f = JFFS2_INODE_INFO(d_inode(child));
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_sb, pino));
151 }
152
153 static const struct export_operations jffs2_export_ops = {
154 .encode_fh = generic_encode_ino32_fh,
155 .get_parent = jffs2_get_parent,
156 .fh_to_dentry = jffs2_fh_to_dentry,
157 .fh_to_parent = jffs2_fh_to_parent,
158 };
159
160 /*
161 * JFFS2 mount options.
162 *
163 * Opt_source: The source device
164 * Opt_override_compr: override default compressor
165 * Opt_rp_size: size of reserved pool in KiB
166 */
167 enum {
168 Opt_override_compr,
169 Opt_rp_size,
170 };
171
172 static const struct constant_table jffs2_param_compr[] = {
173 {"none", JFFS2_COMPR_MODE_NONE },
174 #ifdef CONFIG_JFFS2_LZO
175 {"lzo", JFFS2_COMPR_MODE_FORCELZO },
176 #endif
177 #ifdef CONFIG_JFFS2_ZLIB
178 {"zlib", JFFS2_COMPR_MODE_FORCEZLIB },
179 #endif
180 {}
181 };
182
183 static const struct fs_parameter_spec jffs2_fs_parameters[] = {
184 fsparam_enum ("compr", Opt_override_compr, jffs2_param_compr),
185 fsparam_u32 ("rp_size", Opt_rp_size),
186 {}
187 };
188
189 static int jffs2_parse_param(struct fs_context *fc, struct fs_parameter *param)
190 {
191 struct fs_parse_result result;
192 struct jffs2_sb_info *c = fc->s_fs_info;
193 int opt;
194
195 opt = fs_parse(fc, jffs2_fs_parameters, param, &result);
196 if (opt < 0)
197 return opt;
198
199 switch (opt) {
200 case Opt_override_compr:
201 c->mount_opts.compr = result.uint_32;
202 c->mount_opts.override_compr = true;
203 break;
204 case Opt_rp_size:
205 if (result.uint_32 > UINT_MAX / 1024)
206 return invalf(fc, "jffs2: rp_size unrepresentable");
207 c->mount_opts.rp_size = result.uint_32 * 1024;
208 c->mount_opts.set_rp_size = true;
209 break;
210 default:
211 return -EINVAL;
212 }
213
214 return 0;
215 }
216
217 static inline void jffs2_update_mount_opts(struct fs_context *fc)
218 {
219 struct jffs2_sb_info *new_c = fc->s_fs_info;
220 struct jffs2_sb_info *c = JFFS2_SB_INFO(fc->root->d_sb);
221
222 mutex_lock(&c->alloc_sem);
223 if (new_c->mount_opts.override_compr) {
224 c->mount_opts.override_compr = new_c->mount_opts.override_compr;
225 c->mount_opts.compr = new_c->mount_opts.compr;
226 }
227 if (new_c->mount_opts.set_rp_size) {
228 c->mount_opts.set_rp_size = new_c->mount_opts.set_rp_size;
229 c->mount_opts.rp_size = new_c->mount_opts.rp_size;
230 }
231 mutex_unlock(&c->alloc_sem);
232 }
233
234 static int jffs2_reconfigure(struct fs_context *fc)
235 {
236 struct super_block *sb = fc->root->d_sb;
237
238 sync_filesystem(sb);
239 jffs2_update_mount_opts(fc);
240
241 return jffs2_do_remount_fs(sb, fc);
242 }
243
244 static const struct super_operations jffs2_super_operations =
245 {
246 .alloc_inode = jffs2_alloc_inode,
247 .free_inode = jffs2_free_inode,
248 .put_super = jffs2_put_super,
249 .statfs = jffs2_statfs,
250 .evict_inode = jffs2_evict_inode,
251 .dirty_inode = jffs2_dirty_inode,
252 .show_options = jffs2_show_options,
253 .sync_fs = jffs2_sync_fs,
254 };
255
256 /*
257 * fill in the superblock
258 */
259 static int jffs2_fill_super(struct super_block *sb, struct fs_context *fc)
260 {
261 struct jffs2_sb_info *c = sb->s_fs_info;
262
263 jffs2_dbg(1, "jffs2_get_sb_mtd():"
264 " New superblock for device %d (\"%s\")\n",
265 sb->s_mtd->index, sb->s_mtd->name);
266
267 c->mtd = sb->s_mtd;
268 c->os_priv = sb;
269
270 if (c->mount_opts.rp_size > c->mtd->size)
271 return invalf(fc, "jffs2: Too large reserve pool specified, max is %llu KB",
272 c->mtd->size / 1024);
273
274 /* Initialize JFFS2 superblock locks, the further initialization will
275 * be done later */
276 mutex_init(&c->alloc_sem);
277 mutex_init(&c->erase_free_sem);
278 init_waitqueue_head(&c->erase_wait);
279 init_waitqueue_head(&c->inocache_wq);
280 spin_lock_init(&c->erase_completion_lock);
281 spin_lock_init(&c->inocache_lock);
282
283 sb->s_op = &jffs2_super_operations;
284 sb->s_export_op = &jffs2_export_ops;
285 sb->s_flags = sb->s_flags | SB_NOATIME;
286 sb->s_xattr = jffs2_xattr_handlers;
287 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
288 sb->s_flags |= SB_POSIXACL;
289 #endif
290 return jffs2_do_fill_super(sb, fc);
291 }
292
293 static int jffs2_get_tree(struct fs_context *fc)
294 {
295 return get_tree_mtd(fc, jffs2_fill_super);
296 }
297
298 static void jffs2_free_fc(struct fs_context *fc)
299 {
300 kfree(fc->s_fs_info);
301 }
302
303 static const struct fs_context_operations jffs2_context_ops = {
304 .free = jffs2_free_fc,
305 .parse_param = jffs2_parse_param,
306 .get_tree = jffs2_get_tree,
307 .reconfigure = jffs2_reconfigure,
308 };
309
310 static int jffs2_init_fs_context(struct fs_context *fc)
311 {
312 struct jffs2_sb_info *ctx;
313
314 ctx = kzalloc(sizeof(struct jffs2_sb_info), GFP_KERNEL);
315 if (!ctx)
316 return -ENOMEM;
317
318 fc->s_fs_info = ctx;
319 fc->ops = &jffs2_context_ops;
320 return 0;
321 }
322
323 static void jffs2_put_super (struct super_block *sb)
324 {
325 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
326
327 jffs2_dbg(2, "%s()\n", __func__);
328
329 mutex_lock(&c->alloc_sem);
330 jffs2_flush_wbuf_pad(c);
331 mutex_unlock(&c->alloc_sem);
332
333 jffs2_sum_exit(c);
334
335 jffs2_free_ino_caches(c);
336 jffs2_free_raw_node_refs(c);
337 kvfree(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
345 static void jffs2_kill_sb(struct super_block *sb)
346 {
347 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
348 if (c && !sb_rdonly(sb))
349 jffs2_stop_garbage_collect_thread(c);
350 kill_mtd_super(sb);
351 kfree(c);
352 }
353
354 static struct file_system_type jffs2_fs_type = {
355 .owner = THIS_MODULE,
356 .name = "jffs2",
357 .init_fs_context = jffs2_init_fs_context,
358 .parameters = jffs2_fs_parameters,
359 .kill_sb = jffs2_kill_sb,
360 };
361 MODULE_ALIAS_FS("jffs2");
362
363 static int __init init_jffs2_fs(void)
364 {
365 int ret;
366
367 /* Paranoia checks for on-medium structures. If we ask GCC
368 to pack them with __attribute__((packed)) then it _also_
369 assumes that they're not aligned -- so it emits crappy
370 code on some architectures. Ideally we want an attribute
371 which means just 'no padding', without the alignment
372 thing. But GCC doesn't have that -- we have to just
373 hope the structs are the right sizes, instead. */
374 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
375 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
376 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
377 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
378
379 pr_info("version 2.2."
380 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
381 " (NAND)"
382 #endif
383 #ifdef CONFIG_JFFS2_SUMMARY
384 " (SUMMARY) "
385 #endif
386 " © 2001-2006 Red Hat, Inc.\n");
387
388 jffs2_inode_cachep = kmem_cache_create("jffs2_i",
389 sizeof(struct jffs2_inode_info),
390 0, (SLAB_RECLAIM_ACCOUNT|
391 SLAB_ACCOUNT),
392 jffs2_i_init_once);
393 if (!jffs2_inode_cachep) {
394 pr_err("error: Failed to initialise inode cache\n");
395 return -ENOMEM;
396 }
397 ret = jffs2_compressors_init();
398 if (ret) {
399 pr_err("error: Failed to initialise compressors\n");
400 goto out;
401 }
402 ret = jffs2_create_slab_caches();
403 if (ret) {
404 pr_err("error: Failed to initialise slab caches\n");
405 goto out_compressors;
406 }
407 ret = register_filesystem(&jffs2_fs_type);
408 if (ret) {
409 pr_err("error: Failed to register filesystem\n");
410 goto out_slab;
411 }
412 return 0;
413
414 out_slab:
415 jffs2_destroy_slab_caches();
416 out_compressors:
417 jffs2_compressors_exit();
418 out:
419 kmem_cache_destroy(jffs2_inode_cachep);
420 return ret;
421 }
422
423 static void __exit exit_jffs2_fs(void)
424 {
425 unregister_filesystem(&jffs2_fs_type);
426 jffs2_destroy_slab_caches();
427 jffs2_compressors_exit();
428
429 /*
430 * Make sure all delayed rcu free inodes are flushed before we
431 * destroy cache.
432 */
433 rcu_barrier();
434 kmem_cache_destroy(jffs2_inode_cachep);
435 }
436
437 module_init(init_jffs2_fs);
438 module_exit(exit_jffs2_fs);
439
440 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
441 MODULE_AUTHOR("Red Hat, Inc.");
442 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
443 // the sake of this tag. It's Free Software.
444
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