jffs2: switch to ->free_inode()
[muen/linux.git] / fs / jffs2 / super.c
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/parser.h>
23 #include <linux/jffs2.h>
24 #include <linux/pagemap.h>
25 #include <linux/mtd/super.h>
26 #include <linux/ctype.h>
27 #include <linux/namei.h>
28 #include <linux/seq_file.h>
29 #include <linux/exportfs.h>
30 #include "compr.h"
31 #include "nodelist.h"
32
33 static void jffs2_put_super(struct super_block *);
34
35 static struct kmem_cache *jffs2_inode_cachep;
36
37 static struct inode *jffs2_alloc_inode(struct super_block *sb)
38 {
39         struct jffs2_inode_info *f;
40
41         f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
42         if (!f)
43                 return NULL;
44         return &f->vfs_inode;
45 }
46
47 static void jffs2_free_inode(struct inode *inode)
48 {
49         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
50
51         kfree(f->target);
52         kmem_cache_free(jffs2_inode_cachep, f);
53 }
54
55 static void jffs2_i_init_once(void *foo)
56 {
57         struct jffs2_inode_info *f = foo;
58
59         mutex_init(&f->sem);
60         inode_init_once(&f->vfs_inode);
61 }
62
63 static const char *jffs2_compr_name(unsigned int compr)
64 {
65         switch (compr) {
66         case JFFS2_COMPR_MODE_NONE:
67                 return "none";
68 #ifdef CONFIG_JFFS2_LZO
69         case JFFS2_COMPR_MODE_FORCELZO:
70                 return "lzo";
71 #endif
72 #ifdef CONFIG_JFFS2_ZLIB
73         case JFFS2_COMPR_MODE_FORCEZLIB:
74                 return "zlib";
75 #endif
76         default:
77                 /* should never happen; programmer error */
78                 WARN_ON(1);
79                 return "";
80         }
81 }
82
83 static int jffs2_show_options(struct seq_file *s, struct dentry *root)
84 {
85         struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb);
86         struct jffs2_mount_opts *opts = &c->mount_opts;
87
88         if (opts->override_compr)
89                 seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr));
90         if (opts->rp_size)
91                 seq_printf(s, ",rp_size=%u", opts->rp_size / 1024);
92
93         return 0;
94 }
95
96 static int jffs2_sync_fs(struct super_block *sb, int wait)
97 {
98         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
99
100 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
101         if (jffs2_is_writebuffered(c))
102                 cancel_delayed_work_sync(&c->wbuf_dwork);
103 #endif
104
105         mutex_lock(&c->alloc_sem);
106         jffs2_flush_wbuf_pad(c);
107         mutex_unlock(&c->alloc_sem);
108         return 0;
109 }
110
111 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
112                                          uint32_t generation)
113 {
114         /* We don't care about i_generation. We'll destroy the flash
115            before we start re-using inode numbers anyway. And even
116            if that wasn't true, we'd have other problems...*/
117         return jffs2_iget(sb, ino);
118 }
119
120 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
121                                          int fh_len, int fh_type)
122 {
123         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
124                                     jffs2_nfs_get_inode);
125 }
126
127 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid,
128                                          int fh_len, int fh_type)
129 {
130         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
131                                     jffs2_nfs_get_inode);
132 }
133
134 static struct dentry *jffs2_get_parent(struct dentry *child)
135 {
136         struct jffs2_inode_info *f;
137         uint32_t pino;
138
139         BUG_ON(!d_is_dir(child));
140
141         f = JFFS2_INODE_INFO(d_inode(child));
142
143         pino = f->inocache->pino_nlink;
144
145         JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
146                     f->inocache->ino, pino);
147
148         return d_obtain_alias(jffs2_iget(child->d_sb, pino));
149 }
150
151 static const struct export_operations jffs2_export_ops = {
152         .get_parent = jffs2_get_parent,
153         .fh_to_dentry = jffs2_fh_to_dentry,
154         .fh_to_parent = jffs2_fh_to_parent,
155 };
156
157 /*
158  * JFFS2 mount options.
159  *
160  * Opt_override_compr: override default compressor
161  * Opt_rp_size: size of reserved pool in KiB
162  * Opt_err: just end of array marker
163  */
164 enum {
165         Opt_override_compr,
166         Opt_rp_size,
167         Opt_err,
168 };
169
170 static const match_table_t tokens = {
171         {Opt_override_compr, "compr=%s"},
172         {Opt_rp_size, "rp_size=%u"},
173         {Opt_err, NULL},
174 };
175
176 static int jffs2_parse_options(struct jffs2_sb_info *c, char *data)
177 {
178         substring_t args[MAX_OPT_ARGS];
179         char *p, *name;
180         unsigned int opt;
181
182         if (!data)
183                 return 0;
184
185         while ((p = strsep(&data, ","))) {
186                 int token;
187
188                 if (!*p)
189                         continue;
190
191                 token = match_token(p, tokens, args);
192                 switch (token) {
193                 case Opt_override_compr:
194                         name = match_strdup(&args[0]);
195
196                         if (!name)
197                                 return -ENOMEM;
198                         if (!strcmp(name, "none"))
199                                 c->mount_opts.compr = JFFS2_COMPR_MODE_NONE;
200 #ifdef CONFIG_JFFS2_LZO
201                         else if (!strcmp(name, "lzo"))
202                                 c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO;
203 #endif
204 #ifdef CONFIG_JFFS2_ZLIB
205                         else if (!strcmp(name, "zlib"))
206                                 c->mount_opts.compr =
207                                                 JFFS2_COMPR_MODE_FORCEZLIB;
208 #endif
209                         else {
210                                 pr_err("Error: unknown compressor \"%s\"\n",
211                                        name);
212                                 kfree(name);
213                                 return -EINVAL;
214                         }
215                         kfree(name);
216                         c->mount_opts.override_compr = true;
217                         break;
218                 case Opt_rp_size:
219                         if (match_int(&args[0], &opt))
220                                 return -EINVAL;
221                         opt *= 1024;
222                         if (opt > c->mtd->size) {
223                                 pr_warn("Too large reserve pool specified, max "
224                                         "is %llu KB\n", c->mtd->size / 1024);
225                                 return -EINVAL;
226                         }
227                         c->mount_opts.rp_size = opt;
228                         break;
229                 default:
230                         pr_err("Error: unrecognized mount option '%s' or missing value\n",
231                                p);
232                         return -EINVAL;
233                 }
234         }
235
236         return 0;
237 }
238
239 static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data)
240 {
241         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
242         int err;
243
244         sync_filesystem(sb);
245         err = jffs2_parse_options(c, data);
246         if (err)
247                 return -EINVAL;
248
249         return jffs2_do_remount_fs(sb, flags, data);
250 }
251
252 static const struct super_operations jffs2_super_operations =
253 {
254         .alloc_inode =  jffs2_alloc_inode,
255         .free_inode =   jffs2_free_inode,
256         .put_super =    jffs2_put_super,
257         .statfs =       jffs2_statfs,
258         .remount_fs =   jffs2_remount_fs,
259         .evict_inode =  jffs2_evict_inode,
260         .dirty_inode =  jffs2_dirty_inode,
261         .show_options = jffs2_show_options,
262         .sync_fs =      jffs2_sync_fs,
263 };
264
265 /*
266  * fill in the superblock
267  */
268 static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
269 {
270         struct jffs2_sb_info *c;
271         int ret;
272
273         jffs2_dbg(1, "jffs2_get_sb_mtd():"
274                   " New superblock for device %d (\"%s\")\n",
275                   sb->s_mtd->index, sb->s_mtd->name);
276
277         c = kzalloc(sizeof(*c), GFP_KERNEL);
278         if (!c)
279                 return -ENOMEM;
280
281         c->mtd = sb->s_mtd;
282         c->os_priv = sb;
283         sb->s_fs_info = c;
284
285         ret = jffs2_parse_options(c, data);
286         if (ret)
287                 return -EINVAL;
288
289         /* Initialize JFFS2 superblock locks, the further initialization will
290          * be done later */
291         mutex_init(&c->alloc_sem);
292         mutex_init(&c->erase_free_sem);
293         init_waitqueue_head(&c->erase_wait);
294         init_waitqueue_head(&c->inocache_wq);
295         spin_lock_init(&c->erase_completion_lock);
296         spin_lock_init(&c->inocache_lock);
297
298         sb->s_op = &jffs2_super_operations;
299         sb->s_export_op = &jffs2_export_ops;
300         sb->s_flags = sb->s_flags | SB_NOATIME;
301         sb->s_xattr = jffs2_xattr_handlers;
302 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
303         sb->s_flags |= SB_POSIXACL;
304 #endif
305         ret = jffs2_do_fill_super(sb, data, silent);
306         return ret;
307 }
308
309 static struct dentry *jffs2_mount(struct file_system_type *fs_type,
310                         int flags, const char *dev_name,
311                         void *data)
312 {
313         return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super);
314 }
315
316 static void jffs2_put_super (struct super_block *sb)
317 {
318         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
319
320         jffs2_dbg(2, "%s()\n", __func__);
321
322         mutex_lock(&c->alloc_sem);
323         jffs2_flush_wbuf_pad(c);
324         mutex_unlock(&c->alloc_sem);
325
326         jffs2_sum_exit(c);
327
328         jffs2_free_ino_caches(c);
329         jffs2_free_raw_node_refs(c);
330         kvfree(c->blocks);
331         jffs2_flash_cleanup(c);
332         kfree(c->inocache_list);
333         jffs2_clear_xattr_subsystem(c);
334         mtd_sync(c->mtd);
335         jffs2_dbg(1, "%s(): returning\n", __func__);
336 }
337
338 static void jffs2_kill_sb(struct super_block *sb)
339 {
340         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
341         if (c && !sb_rdonly(sb))
342                 jffs2_stop_garbage_collect_thread(c);
343         kill_mtd_super(sb);
344         kfree(c);
345 }
346
347 static struct file_system_type jffs2_fs_type = {
348         .owner =        THIS_MODULE,
349         .name =         "jffs2",
350         .mount =        jffs2_mount,
351         .kill_sb =      jffs2_kill_sb,
352 };
353 MODULE_ALIAS_FS("jffs2");
354
355 static int __init init_jffs2_fs(void)
356 {
357         int ret;
358
359         /* Paranoia checks for on-medium structures. If we ask GCC
360            to pack them with __attribute__((packed)) then it _also_
361            assumes that they're not aligned -- so it emits crappy
362            code on some architectures. Ideally we want an attribute
363            which means just 'no padding', without the alignment
364            thing. But GCC doesn't have that -- we have to just
365            hope the structs are the right sizes, instead. */
366         BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
367         BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
368         BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
369         BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
370
371         pr_info("version 2.2."
372 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
373                " (NAND)"
374 #endif
375 #ifdef CONFIG_JFFS2_SUMMARY
376                " (SUMMARY) "
377 #endif
378                " © 2001-2006 Red Hat, Inc.\n");
379
380         jffs2_inode_cachep = kmem_cache_create("jffs2_i",
381                                              sizeof(struct jffs2_inode_info),
382                                              0, (SLAB_RECLAIM_ACCOUNT|
383                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
384                                              jffs2_i_init_once);
385         if (!jffs2_inode_cachep) {
386                 pr_err("error: Failed to initialise inode cache\n");
387                 return -ENOMEM;
388         }
389         ret = jffs2_compressors_init();
390         if (ret) {
391                 pr_err("error: Failed to initialise compressors\n");
392                 goto out;
393         }
394         ret = jffs2_create_slab_caches();
395         if (ret) {
396                 pr_err("error: Failed to initialise slab caches\n");
397                 goto out_compressors;
398         }
399         ret = register_filesystem(&jffs2_fs_type);
400         if (ret) {
401                 pr_err("error: Failed to register filesystem\n");
402                 goto out_slab;
403         }
404         return 0;
405
406  out_slab:
407         jffs2_destroy_slab_caches();
408  out_compressors:
409         jffs2_compressors_exit();
410  out:
411         kmem_cache_destroy(jffs2_inode_cachep);
412         return ret;
413 }
414
415 static void __exit exit_jffs2_fs(void)
416 {
417         unregister_filesystem(&jffs2_fs_type);
418         jffs2_destroy_slab_caches();
419         jffs2_compressors_exit();
420
421         /*
422          * Make sure all delayed rcu free inodes are flushed before we
423          * destroy cache.
424          */
425         rcu_barrier();
426         kmem_cache_destroy(jffs2_inode_cachep);
427 }
428
429 module_init(init_jffs2_fs);
430 module_exit(exit_jffs2_fs);
431
432 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
433 MODULE_AUTHOR("Red Hat, Inc.");
434 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
435                        // the sake of this tag. It's Free Software.