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, cache: 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(objp: f->target); |
53 | kmem_cache_free(s: jffs2_inode_cachep, objp: 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 | inode_init_once(&f->vfs_inode); |
62 | } |
63 | |
64 | static 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 | |
84 | static 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(m: s, fmt: ",compr=%s" , jffs2_compr_name(compr: opts->compr)); |
91 | if (opts->set_rp_size) |
92 | seq_printf(m: s, fmt: ",rp_size=%u" , opts->rp_size / 1024); |
93 | |
94 | return 0; |
95 | } |
96 | |
97 | static 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(dwork: &c->wbuf_dwork); |
104 | #endif |
105 | |
106 | mutex_lock(&c->alloc_sem); |
107 | jffs2_flush_wbuf_pad(c); |
108 | mutex_unlock(lock: &c->alloc_sem); |
109 | return 0; |
110 | } |
111 | |
112 | static 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 | |
121 | static 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 | get_inode: jffs2_nfs_get_inode); |
126 | } |
127 | |
128 | static 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 | get_inode: jffs2_nfs_get_inode); |
133 | } |
134 | |
135 | static 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 | |
152 | static 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 | */ |
166 | enum { |
167 | Opt_override_compr, |
168 | Opt_rp_size, |
169 | }; |
170 | |
171 | static 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 | |
182 | static 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 | |
188 | static 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, desc: jffs2_fs_parameters, param, result: &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 | |
216 | static 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(lock: &c->alloc_sem); |
231 | } |
232 | |
233 | static 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 | |
243 | static 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 | */ |
258 | static 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 | |
292 | static int jffs2_get_tree(struct fs_context *fc) |
293 | { |
294 | return get_tree_mtd(fc, fill_super: jffs2_fill_super); |
295 | } |
296 | |
297 | static void jffs2_free_fc(struct fs_context *fc) |
298 | { |
299 | kfree(objp: fc->s_fs_info); |
300 | } |
301 | |
302 | static 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 | |
309 | static int jffs2_init_fs_context(struct fs_context *fc) |
310 | { |
311 | struct jffs2_sb_info *ctx; |
312 | |
313 | ctx = kzalloc(size: 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 | |
322 | static 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(lock: &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(addr: c->blocks); |
337 | jffs2_flash_cleanup(c); |
338 | kfree(objp: c->inocache_list); |
339 | jffs2_clear_xattr_subsystem(c); |
340 | mtd_sync(mtd: c->mtd); |
341 | jffs2_dbg(1, "%s(): returning\n" , __func__); |
342 | } |
343 | |
344 | static 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(objp: c); |
351 | } |
352 | |
353 | static 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 | }; |
360 | MODULE_ALIAS_FS("jffs2" ); |
361 | |
362 | static 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(name: "jffs2_i" , |
388 | size: sizeof(struct jffs2_inode_info), |
389 | align: 0, flags: (SLAB_RECLAIM_ACCOUNT| |
390 | SLAB_ACCOUNT), |
391 | ctor: 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(s: jffs2_inode_cachep); |
419 | return ret; |
420 | } |
421 | |
422 | static 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(s: jffs2_inode_cachep); |
434 | } |
435 | |
436 | module_init(init_jffs2_fs); |
437 | module_exit(exit_jffs2_fs); |
438 | |
439 | MODULE_DESCRIPTION("The Journalling Flash File System, v2" ); |
440 | MODULE_AUTHOR("Red Hat, Inc." ); |
441 | MODULE_LICENSE("GPL" ); // Actually dual-licensed, but it doesn't matter for |
442 | // the sake of this tag. It's Free Software. |
443 | |