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
jffs2_alloc_inode(struct super_block * sb)38 static struct inode *jffs2_alloc_inode(struct super_block *sb)
39 {
40 struct jffs2_inode_info *f;
41
42 f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
43 if (!f)
44 return NULL;
45 return &f->vfs_inode;
46 }
47
jffs2_free_inode(struct inode * inode)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
jffs2_i_init_once(void * foo)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
jffs2_compr_name(unsigned int compr)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
jffs2_show_options(struct seq_file * s,struct dentry * root)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(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
jffs2_sync_fs(struct super_block * sb,int wait)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(&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
jffs2_nfs_get_inode(struct super_block * sb,uint64_t ino,uint32_t generation)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
jffs2_fh_to_dentry(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)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 jffs2_nfs_get_inode);
126 }
127
jffs2_fh_to_parent(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)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 jffs2_nfs_get_inode);
133 }
134
jffs2_get_parent(struct dentry * child)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 .get_parent = jffs2_get_parent,
154 .fh_to_dentry = jffs2_fh_to_dentry,
155 .fh_to_parent = jffs2_fh_to_parent,
156 };
157
158 /*
159 * JFFS2 mount options.
160 *
161 * Opt_source: The source device
162 * Opt_override_compr: override default compressor
163 * Opt_rp_size: size of reserved pool in KiB
164 */
165 enum {
166 Opt_override_compr,
167 Opt_rp_size,
168 };
169
170 static const struct constant_table jffs2_param_compr[] = {
171 {"none", JFFS2_COMPR_MODE_NONE },
172 #ifdef CONFIG_JFFS2_LZO
173 {"lzo", JFFS2_COMPR_MODE_FORCELZO },
174 #endif
175 #ifdef CONFIG_JFFS2_ZLIB
176 {"zlib", JFFS2_COMPR_MODE_FORCEZLIB },
177 #endif
178 {}
179 };
180
181 static const struct fs_parameter_spec jffs2_fs_parameters[] = {
182 fsparam_enum ("compr", Opt_override_compr, jffs2_param_compr),
183 fsparam_u32 ("rp_size", Opt_rp_size),
184 {}
185 };
186
jffs2_parse_param(struct fs_context * fc,struct fs_parameter * param)187 static int jffs2_parse_param(struct fs_context *fc, struct fs_parameter *param)
188 {
189 struct fs_parse_result result;
190 struct jffs2_sb_info *c = fc->s_fs_info;
191 int opt;
192
193 opt = fs_parse(fc, jffs2_fs_parameters, param, &result);
194 if (opt < 0)
195 return opt;
196
197 switch (opt) {
198 case Opt_override_compr:
199 c->mount_opts.compr = result.uint_32;
200 c->mount_opts.override_compr = true;
201 break;
202 case Opt_rp_size:
203 if (result.uint_32 > UINT_MAX / 1024)
204 return invalf(fc, "jffs2: rp_size unrepresentable");
205 c->mount_opts.rp_size = result.uint_32 * 1024;
206 c->mount_opts.set_rp_size = true;
207 break;
208 default:
209 return -EINVAL;
210 }
211
212 return 0;
213 }
214
jffs2_update_mount_opts(struct fs_context * fc)215 static inline void jffs2_update_mount_opts(struct fs_context *fc)
216 {
217 struct jffs2_sb_info *new_c = fc->s_fs_info;
218 struct jffs2_sb_info *c = JFFS2_SB_INFO(fc->root->d_sb);
219
220 mutex_lock(&c->alloc_sem);
221 if (new_c->mount_opts.override_compr) {
222 c->mount_opts.override_compr = new_c->mount_opts.override_compr;
223 c->mount_opts.compr = new_c->mount_opts.compr;
224 }
225 if (new_c->mount_opts.set_rp_size) {
226 c->mount_opts.set_rp_size = new_c->mount_opts.set_rp_size;
227 c->mount_opts.rp_size = new_c->mount_opts.rp_size;
228 }
229 mutex_unlock(&c->alloc_sem);
230 }
231
jffs2_reconfigure(struct fs_context * fc)232 static int jffs2_reconfigure(struct fs_context *fc)
233 {
234 struct super_block *sb = fc->root->d_sb;
235
236 sync_filesystem(sb);
237 jffs2_update_mount_opts(fc);
238
239 return jffs2_do_remount_fs(sb, fc);
240 }
241
242 static const struct super_operations jffs2_super_operations =
243 {
244 .alloc_inode = jffs2_alloc_inode,
245 .free_inode = jffs2_free_inode,
246 .put_super = jffs2_put_super,
247 .statfs = jffs2_statfs,
248 .evict_inode = jffs2_evict_inode,
249 .dirty_inode = jffs2_dirty_inode,
250 .show_options = jffs2_show_options,
251 .sync_fs = jffs2_sync_fs,
252 };
253
254 /*
255 * fill in the superblock
256 */
jffs2_fill_super(struct super_block * sb,struct fs_context * fc)257 static int jffs2_fill_super(struct super_block *sb, struct fs_context *fc)
258 {
259 struct jffs2_sb_info *c = sb->s_fs_info;
260
261 jffs2_dbg(1, "jffs2_get_sb_mtd():"
262 " New superblock for device %d (\"%s\")\n",
263 sb->s_mtd->index, sb->s_mtd->name);
264
265 c->mtd = sb->s_mtd;
266 c->os_priv = sb;
267
268 if (c->mount_opts.rp_size > c->mtd->size)
269 return invalf(fc, "jffs2: Too large reserve pool specified, max is %llu KB",
270 c->mtd->size / 1024);
271
272 /* Initialize JFFS2 superblock locks, the further initialization will
273 * be done later */
274 mutex_init(&c->alloc_sem);
275 mutex_init(&c->erase_free_sem);
276 init_waitqueue_head(&c->erase_wait);
277 init_waitqueue_head(&c->inocache_wq);
278 spin_lock_init(&c->erase_completion_lock);
279 spin_lock_init(&c->inocache_lock);
280
281 sb->s_op = &jffs2_super_operations;
282 sb->s_export_op = &jffs2_export_ops;
283 sb->s_flags = sb->s_flags | SB_NOATIME;
284 sb->s_xattr = jffs2_xattr_handlers;
285 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
286 sb->s_flags |= SB_POSIXACL;
287 #endif
288 return jffs2_do_fill_super(sb, fc);
289 }
290
jffs2_get_tree(struct fs_context * fc)291 static int jffs2_get_tree(struct fs_context *fc)
292 {
293 return get_tree_mtd(fc, jffs2_fill_super);
294 }
295
jffs2_free_fc(struct fs_context * fc)296 static void jffs2_free_fc(struct fs_context *fc)
297 {
298 kfree(fc->s_fs_info);
299 }
300
301 static const struct fs_context_operations jffs2_context_ops = {
302 .free = jffs2_free_fc,
303 .parse_param = jffs2_parse_param,
304 .get_tree = jffs2_get_tree,
305 .reconfigure = jffs2_reconfigure,
306 };
307
jffs2_init_fs_context(struct fs_context * fc)308 static int jffs2_init_fs_context(struct fs_context *fc)
309 {
310 struct jffs2_sb_info *ctx;
311
312 ctx = kzalloc(sizeof(struct jffs2_sb_info), GFP_KERNEL);
313 if (!ctx)
314 return -ENOMEM;
315
316 fc->s_fs_info = ctx;
317 fc->ops = &jffs2_context_ops;
318 return 0;
319 }
320
jffs2_put_super(struct super_block * sb)321 static void jffs2_put_super (struct super_block *sb)
322 {
323 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
324
325 jffs2_dbg(2, "%s()\n", __func__);
326
327 mutex_lock(&c->alloc_sem);
328 jffs2_flush_wbuf_pad(c);
329 mutex_unlock(&c->alloc_sem);
330
331 jffs2_sum_exit(c);
332
333 jffs2_free_ino_caches(c);
334 jffs2_free_raw_node_refs(c);
335 kvfree(c->blocks);
336 jffs2_flash_cleanup(c);
337 kfree(c->inocache_list);
338 jffs2_clear_xattr_subsystem(c);
339 mtd_sync(c->mtd);
340 jffs2_dbg(1, "%s(): returning\n", __func__);
341 }
342
jffs2_kill_sb(struct super_block * sb)343 static void jffs2_kill_sb(struct super_block *sb)
344 {
345 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
346 if (c && !sb_rdonly(sb))
347 jffs2_stop_garbage_collect_thread(c);
348 kill_mtd_super(sb);
349 kfree(c);
350 }
351
352 static struct file_system_type jffs2_fs_type = {
353 .owner = THIS_MODULE,
354 .name = "jffs2",
355 .init_fs_context = jffs2_init_fs_context,
356 .parameters = jffs2_fs_parameters,
357 .kill_sb = jffs2_kill_sb,
358 };
359 MODULE_ALIAS_FS("jffs2");
360
init_jffs2_fs(void)361 static int __init init_jffs2_fs(void)
362 {
363 int ret;
364
365 /* Paranoia checks for on-medium structures. If we ask GCC
366 to pack them with __attribute__((packed)) then it _also_
367 assumes that they're not aligned -- so it emits crappy
368 code on some architectures. Ideally we want an attribute
369 which means just 'no padding', without the alignment
370 thing. But GCC doesn't have that -- we have to just
371 hope the structs are the right sizes, instead. */
372 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
373 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
374 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
375 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
376
377 pr_info("version 2.2."
378 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
379 " (NAND)"
380 #endif
381 #ifdef CONFIG_JFFS2_SUMMARY
382 " (SUMMARY) "
383 #endif
384 " © 2001-2006 Red Hat, Inc.\n");
385
386 jffs2_inode_cachep = kmem_cache_create("jffs2_i",
387 sizeof(struct jffs2_inode_info),
388 0, (SLAB_RECLAIM_ACCOUNT|
389 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
390 jffs2_i_init_once);
391 if (!jffs2_inode_cachep) {
392 pr_err("error: Failed to initialise inode cache\n");
393 return -ENOMEM;
394 }
395 ret = jffs2_compressors_init();
396 if (ret) {
397 pr_err("error: Failed to initialise compressors\n");
398 goto out;
399 }
400 ret = jffs2_create_slab_caches();
401 if (ret) {
402 pr_err("error: Failed to initialise slab caches\n");
403 goto out_compressors;
404 }
405 ret = register_filesystem(&jffs2_fs_type);
406 if (ret) {
407 pr_err("error: Failed to register filesystem\n");
408 goto out_slab;
409 }
410 return 0;
411
412 out_slab:
413 jffs2_destroy_slab_caches();
414 out_compressors:
415 jffs2_compressors_exit();
416 out:
417 kmem_cache_destroy(jffs2_inode_cachep);
418 return ret;
419 }
420
exit_jffs2_fs(void)421 static void __exit exit_jffs2_fs(void)
422 {
423 unregister_filesystem(&jffs2_fs_type);
424 jffs2_destroy_slab_caches();
425 jffs2_compressors_exit();
426
427 /*
428 * Make sure all delayed rcu free inodes are flushed before we
429 * destroy cache.
430 */
431 rcu_barrier();
432 kmem_cache_destroy(jffs2_inode_cachep);
433 }
434
435 module_init(init_jffs2_fs);
436 module_exit(exit_jffs2_fs);
437
438 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
439 MODULE_AUTHOR("Red Hat, Inc.");
440 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
441 // the sake of this tag. It's Free Software.
442 MODULE_IMPORT_NS(ANDROID_GKI_VFS_EXPORT_ONLY);
443