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 fs_parameter_spec jffs2_param_specs[] = {
171 fsparam_enum ("compr", Opt_override_compr),
172 fsparam_u32 ("rp_size", Opt_rp_size),
173 {}
174 };
175
176 static const struct fs_parameter_enum jffs2_param_enums[] = {
177 { Opt_override_compr, "none", JFFS2_COMPR_MODE_NONE },
178 #ifdef CONFIG_JFFS2_LZO
179 { Opt_override_compr, "lzo", JFFS2_COMPR_MODE_FORCELZO },
180 #endif
181 #ifdef CONFIG_JFFS2_ZLIB
182 { Opt_override_compr, "zlib", JFFS2_COMPR_MODE_FORCEZLIB },
183 #endif
184 {}
185 };
186
187 const struct fs_parameter_description jffs2_fs_parameters = {
188 .name = "jffs2",
189 .specs = jffs2_param_specs,
190 .enums = jffs2_param_enums,
191 };
192
jffs2_parse_param(struct fs_context * fc,struct fs_parameter * param)193 static int jffs2_parse_param(struct fs_context *fc, struct fs_parameter *param)
194 {
195 struct fs_parse_result result;
196 struct jffs2_sb_info *c = fc->s_fs_info;
197 int opt;
198
199 opt = fs_parse(fc, &jffs2_fs_parameters, param, &result);
200 if (opt < 0)
201 return opt;
202
203 switch (opt) {
204 case Opt_override_compr:
205 c->mount_opts.compr = result.uint_32;
206 c->mount_opts.override_compr = true;
207 break;
208 case Opt_rp_size:
209 if (result.uint_32 > UINT_MAX / 1024)
210 return invalf(fc, "jffs2: rp_size unrepresentable");
211 c->mount_opts.rp_size = result.uint_32 * 1024;
212 c->mount_opts.set_rp_size = true;
213 break;
214 default:
215 return -EINVAL;
216 }
217
218 return 0;
219 }
220
jffs2_update_mount_opts(struct fs_context * fc)221 static inline void jffs2_update_mount_opts(struct fs_context *fc)
222 {
223 struct jffs2_sb_info *new_c = fc->s_fs_info;
224 struct jffs2_sb_info *c = JFFS2_SB_INFO(fc->root->d_sb);
225
226 mutex_lock(&c->alloc_sem);
227 if (new_c->mount_opts.override_compr) {
228 c->mount_opts.override_compr = new_c->mount_opts.override_compr;
229 c->mount_opts.compr = new_c->mount_opts.compr;
230 }
231 if (new_c->mount_opts.set_rp_size) {
232 c->mount_opts.set_rp_size = new_c->mount_opts.set_rp_size;
233 c->mount_opts.rp_size = new_c->mount_opts.rp_size;
234 }
235 mutex_unlock(&c->alloc_sem);
236 }
237
jffs2_reconfigure(struct fs_context * fc)238 static int jffs2_reconfigure(struct fs_context *fc)
239 {
240 struct super_block *sb = fc->root->d_sb;
241
242 sync_filesystem(sb);
243 jffs2_update_mount_opts(fc);
244
245 return jffs2_do_remount_fs(sb, fc);
246 }
247
248 static const struct super_operations jffs2_super_operations =
249 {
250 .alloc_inode = jffs2_alloc_inode,
251 .free_inode = jffs2_free_inode,
252 .put_super = jffs2_put_super,
253 .statfs = jffs2_statfs,
254 .evict_inode = jffs2_evict_inode,
255 .dirty_inode = jffs2_dirty_inode,
256 .show_options = jffs2_show_options,
257 .sync_fs = jffs2_sync_fs,
258 };
259
260 /*
261 * fill in the superblock
262 */
jffs2_fill_super(struct super_block * sb,struct fs_context * fc)263 static int jffs2_fill_super(struct super_block *sb, struct fs_context *fc)
264 {
265 struct jffs2_sb_info *c = sb->s_fs_info;
266
267 jffs2_dbg(1, "jffs2_get_sb_mtd():"
268 " New superblock for device %d (\"%s\")\n",
269 sb->s_mtd->index, sb->s_mtd->name);
270
271 c->mtd = sb->s_mtd;
272 c->os_priv = sb;
273
274 if (c->mount_opts.rp_size > c->mtd->size)
275 return invalf(fc, "jffs2: Too large reserve pool specified, max is %llu KB",
276 c->mtd->size / 1024);
277
278 /* Initialize JFFS2 superblock locks, the further initialization will
279 * be done later */
280 mutex_init(&c->alloc_sem);
281 mutex_init(&c->erase_free_sem);
282 init_waitqueue_head(&c->erase_wait);
283 init_waitqueue_head(&c->inocache_wq);
284 spin_lock_init(&c->erase_completion_lock);
285 spin_lock_init(&c->inocache_lock);
286
287 sb->s_op = &jffs2_super_operations;
288 sb->s_export_op = &jffs2_export_ops;
289 sb->s_flags = sb->s_flags | SB_NOATIME;
290 sb->s_xattr = jffs2_xattr_handlers;
291 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
292 sb->s_flags |= SB_POSIXACL;
293 #endif
294 return jffs2_do_fill_super(sb, fc);
295 }
296
jffs2_get_tree(struct fs_context * fc)297 static int jffs2_get_tree(struct fs_context *fc)
298 {
299 return get_tree_mtd(fc, jffs2_fill_super);
300 }
301
jffs2_free_fc(struct fs_context * fc)302 static void jffs2_free_fc(struct fs_context *fc)
303 {
304 kfree(fc->s_fs_info);
305 }
306
307 static const struct fs_context_operations jffs2_context_ops = {
308 .free = jffs2_free_fc,
309 .parse_param = jffs2_parse_param,
310 .get_tree = jffs2_get_tree,
311 .reconfigure = jffs2_reconfigure,
312 };
313
jffs2_init_fs_context(struct fs_context * fc)314 static int jffs2_init_fs_context(struct fs_context *fc)
315 {
316 struct jffs2_sb_info *ctx;
317
318 ctx = kzalloc(sizeof(struct jffs2_sb_info), GFP_KERNEL);
319 if (!ctx)
320 return -ENOMEM;
321
322 fc->s_fs_info = ctx;
323 fc->ops = &jffs2_context_ops;
324 return 0;
325 }
326
jffs2_put_super(struct super_block * sb)327 static void jffs2_put_super (struct super_block *sb)
328 {
329 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
330
331 jffs2_dbg(2, "%s()\n", __func__);
332
333 mutex_lock(&c->alloc_sem);
334 jffs2_flush_wbuf_pad(c);
335 mutex_unlock(&c->alloc_sem);
336
337 jffs2_sum_exit(c);
338
339 jffs2_free_ino_caches(c);
340 jffs2_free_raw_node_refs(c);
341 kvfree(c->blocks);
342 jffs2_flash_cleanup(c);
343 kfree(c->inocache_list);
344 jffs2_clear_xattr_subsystem(c);
345 mtd_sync(c->mtd);
346 jffs2_dbg(1, "%s(): returning\n", __func__);
347 }
348
jffs2_kill_sb(struct super_block * sb)349 static void jffs2_kill_sb(struct super_block *sb)
350 {
351 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
352 if (c && !sb_rdonly(sb))
353 jffs2_stop_garbage_collect_thread(c);
354 kill_mtd_super(sb);
355 kfree(c);
356 }
357
358 static struct file_system_type jffs2_fs_type = {
359 .owner = THIS_MODULE,
360 .name = "jffs2",
361 .init_fs_context = jffs2_init_fs_context,
362 .parameters = &jffs2_fs_parameters,
363 .kill_sb = jffs2_kill_sb,
364 };
365 MODULE_ALIAS_FS("jffs2");
366
init_jffs2_fs(void)367 static int __init init_jffs2_fs(void)
368 {
369 int ret;
370
371 /* Paranoia checks for on-medium structures. If we ask GCC
372 to pack them with __attribute__((packed)) then it _also_
373 assumes that they're not aligned -- so it emits crappy
374 code on some architectures. Ideally we want an attribute
375 which means just 'no padding', without the alignment
376 thing. But GCC doesn't have that -- we have to just
377 hope the structs are the right sizes, instead. */
378 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
379 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
380 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
381 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
382
383 pr_info("version 2.2."
384 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
385 " (NAND)"
386 #endif
387 #ifdef CONFIG_JFFS2_SUMMARY
388 " (SUMMARY) "
389 #endif
390 " © 2001-2006 Red Hat, Inc.\n");
391
392 jffs2_inode_cachep = kmem_cache_create("jffs2_i",
393 sizeof(struct jffs2_inode_info),
394 0, (SLAB_RECLAIM_ACCOUNT|
395 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
396 jffs2_i_init_once);
397 if (!jffs2_inode_cachep) {
398 pr_err("error: Failed to initialise inode cache\n");
399 return -ENOMEM;
400 }
401 ret = jffs2_compressors_init();
402 if (ret) {
403 pr_err("error: Failed to initialise compressors\n");
404 goto out;
405 }
406 ret = jffs2_create_slab_caches();
407 if (ret) {
408 pr_err("error: Failed to initialise slab caches\n");
409 goto out_compressors;
410 }
411 ret = register_filesystem(&jffs2_fs_type);
412 if (ret) {
413 pr_err("error: Failed to register filesystem\n");
414 goto out_slab;
415 }
416 return 0;
417
418 out_slab:
419 jffs2_destroy_slab_caches();
420 out_compressors:
421 jffs2_compressors_exit();
422 out:
423 kmem_cache_destroy(jffs2_inode_cachep);
424 return ret;
425 }
426
exit_jffs2_fs(void)427 static void __exit exit_jffs2_fs(void)
428 {
429 unregister_filesystem(&jffs2_fs_type);
430 jffs2_destroy_slab_caches();
431 jffs2_compressors_exit();
432
433 /*
434 * Make sure all delayed rcu free inodes are flushed before we
435 * destroy cache.
436 */
437 rcu_barrier();
438 kmem_cache_destroy(jffs2_inode_cachep);
439 }
440
441 module_init(init_jffs2_fs);
442 module_exit(exit_jffs2_fs);
443
444 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
445 MODULE_AUTHOR("Red Hat, Inc.");
446 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
447 // the sake of this tag. It's Free Software.
448