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, cache: 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(objp: f->target);
53 kmem_cache_free(s: jffs2_inode_cachep, objp: 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(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
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(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
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 get_inode: 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 get_inode: 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, 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
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(lock: &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, fill_super: jffs2_fill_super);
295}
296
297static void jffs2_free_fc(struct fs_context *fc)
298{
299 kfree(objp: 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(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
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(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
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(objp: 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(name: "jffs2_i",
388 size: sizeof(struct jffs2_inode_info),
389 align: 0, flags: (SLAB_RECLAIM_ACCOUNT|
390 SLAB_MEM_SPREAD|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
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(s: 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

source code of linux/fs/jffs2/super.c