isofs: 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_i_callback(struct rcu_head *head)
48 {
49         struct inode *inode = container_of(head, struct inode, i_rcu);
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
56 static void jffs2_destroy_inode(struct inode *inode)
57 {
58         call_rcu(&inode->i_rcu, jffs2_i_callback);
59 }
60
61 static void jffs2_i_init_once(void *foo)
62 {
63         struct jffs2_inode_info *f = foo;
64
65         mutex_init(&f->sem);
66         inode_init_once(&f->vfs_inode);
67 }
68
69 static const char *jffs2_compr_name(unsigned int compr)
70 {
71         switch (compr) {
72         case JFFS2_COMPR_MODE_NONE:
73                 return "none";
74 #ifdef CONFIG_JFFS2_LZO
75         case JFFS2_COMPR_MODE_FORCELZO:
76                 return "lzo";
77 #endif
78 #ifdef CONFIG_JFFS2_ZLIB
79         case JFFS2_COMPR_MODE_FORCEZLIB:
80                 return "zlib";
81 #endif
82         default:
83                 /* should never happen; programmer error */
84                 WARN_ON(1);
85                 return "";
86         }
87 }
88
89 static int jffs2_show_options(struct seq_file *s, struct dentry *root)
90 {
91         struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb);
92         struct jffs2_mount_opts *opts = &c->mount_opts;
93
94         if (opts->override_compr)
95                 seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr));
96         if (opts->rp_size)
97                 seq_printf(s, ",rp_size=%u", opts->rp_size / 1024);
98
99         return 0;
100 }
101
102 static int jffs2_sync_fs(struct super_block *sb, int wait)
103 {
104         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
105
106 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
107         if (jffs2_is_writebuffered(c))
108                 cancel_delayed_work_sync(&c->wbuf_dwork);
109 #endif
110
111         mutex_lock(&c->alloc_sem);
112         jffs2_flush_wbuf_pad(c);
113         mutex_unlock(&c->alloc_sem);
114         return 0;
115 }
116
117 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
118                                          uint32_t generation)
119 {
120         /* We don't care about i_generation. We'll destroy the flash
121            before we start re-using inode numbers anyway. And even
122            if that wasn't true, we'd have other problems...*/
123         return jffs2_iget(sb, ino);
124 }
125
126 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
127                                          int fh_len, int fh_type)
128 {
129         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
130                                     jffs2_nfs_get_inode);
131 }
132
133 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid,
134                                          int fh_len, int fh_type)
135 {
136         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
137                                     jffs2_nfs_get_inode);
138 }
139
140 static struct dentry *jffs2_get_parent(struct dentry *child)
141 {
142         struct jffs2_inode_info *f;
143         uint32_t pino;
144
145         BUG_ON(!d_is_dir(child));
146
147         f = JFFS2_INODE_INFO(d_inode(child));
148
149         pino = f->inocache->pino_nlink;
150
151         JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
152                     f->inocache->ino, pino);
153
154         return d_obtain_alias(jffs2_iget(child->d_sb, pino));
155 }
156
157 static const struct export_operations jffs2_export_ops = {
158         .get_parent = jffs2_get_parent,
159         .fh_to_dentry = jffs2_fh_to_dentry,
160         .fh_to_parent = jffs2_fh_to_parent,
161 };
162
163 /*
164  * JFFS2 mount options.
165  *
166  * Opt_override_compr: override default compressor
167  * Opt_rp_size: size of reserved pool in KiB
168  * Opt_err: just end of array marker
169  */
170 enum {
171         Opt_override_compr,
172         Opt_rp_size,
173         Opt_err,
174 };
175
176 static const match_table_t tokens = {
177         {Opt_override_compr, "compr=%s"},
178         {Opt_rp_size, "rp_size=%u"},
179         {Opt_err, NULL},
180 };
181
182 static int jffs2_parse_options(struct jffs2_sb_info *c, char *data)
183 {
184         substring_t args[MAX_OPT_ARGS];
185         char *p, *name;
186         unsigned int opt;
187
188         if (!data)
189                 return 0;
190
191         while ((p = strsep(&data, ","))) {
192                 int token;
193
194                 if (!*p)
195                         continue;
196
197                 token = match_token(p, tokens, args);
198                 switch (token) {
199                 case Opt_override_compr:
200                         name = match_strdup(&args[0]);
201
202                         if (!name)
203                                 return -ENOMEM;
204                         if (!strcmp(name, "none"))
205                                 c->mount_opts.compr = JFFS2_COMPR_MODE_NONE;
206 #ifdef CONFIG_JFFS2_LZO
207                         else if (!strcmp(name, "lzo"))
208                                 c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO;
209 #endif
210 #ifdef CONFIG_JFFS2_ZLIB
211                         else if (!strcmp(name, "zlib"))
212                                 c->mount_opts.compr =
213                                                 JFFS2_COMPR_MODE_FORCEZLIB;
214 #endif
215                         else {
216                                 pr_err("Error: unknown compressor \"%s\"\n",
217                                        name);
218                                 kfree(name);
219                                 return -EINVAL;
220                         }
221                         kfree(name);
222                         c->mount_opts.override_compr = true;
223                         break;
224                 case Opt_rp_size:
225                         if (match_int(&args[0], &opt))
226                                 return -EINVAL;
227                         opt *= 1024;
228                         if (opt > c->mtd->size) {
229                                 pr_warn("Too large reserve pool specified, max "
230                                         "is %llu KB\n", c->mtd->size / 1024);
231                                 return -EINVAL;
232                         }
233                         c->mount_opts.rp_size = opt;
234                         break;
235                 default:
236                         pr_err("Error: unrecognized mount option '%s' or missing value\n",
237                                p);
238                         return -EINVAL;
239                 }
240         }
241
242         return 0;
243 }
244
245 static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data)
246 {
247         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
248         int err;
249
250         sync_filesystem(sb);
251         err = jffs2_parse_options(c, data);
252         if (err)
253                 return -EINVAL;
254
255         return jffs2_do_remount_fs(sb, flags, data);
256 }
257
258 static const struct super_operations jffs2_super_operations =
259 {
260         .alloc_inode =  jffs2_alloc_inode,
261         .destroy_inode =jffs2_destroy_inode,
262         .put_super =    jffs2_put_super,
263         .statfs =       jffs2_statfs,
264         .remount_fs =   jffs2_remount_fs,
265         .evict_inode =  jffs2_evict_inode,
266         .dirty_inode =  jffs2_dirty_inode,
267         .show_options = jffs2_show_options,
268         .sync_fs =      jffs2_sync_fs,
269 };
270
271 /*
272  * fill in the superblock
273  */
274 static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
275 {
276         struct jffs2_sb_info *c;
277         int ret;
278
279         jffs2_dbg(1, "jffs2_get_sb_mtd():"
280                   " New superblock for device %d (\"%s\")\n",
281                   sb->s_mtd->index, sb->s_mtd->name);
282
283         c = kzalloc(sizeof(*c), GFP_KERNEL);
284         if (!c)
285                 return -ENOMEM;
286
287         c->mtd = sb->s_mtd;
288         c->os_priv = sb;
289         sb->s_fs_info = c;
290
291         ret = jffs2_parse_options(c, data);
292         if (ret)
293                 return -EINVAL;
294
295         /* Initialize JFFS2 superblock locks, the further initialization will
296          * be done later */
297         mutex_init(&c->alloc_sem);
298         mutex_init(&c->erase_free_sem);
299         init_waitqueue_head(&c->erase_wait);
300         init_waitqueue_head(&c->inocache_wq);
301         spin_lock_init(&c->erase_completion_lock);
302         spin_lock_init(&c->inocache_lock);
303
304         sb->s_op = &jffs2_super_operations;
305         sb->s_export_op = &jffs2_export_ops;
306         sb->s_flags = sb->s_flags | SB_NOATIME;
307         sb->s_xattr = jffs2_xattr_handlers;
308 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
309         sb->s_flags |= SB_POSIXACL;
310 #endif
311         ret = jffs2_do_fill_super(sb, data, silent);
312         return ret;
313 }
314
315 static struct dentry *jffs2_mount(struct file_system_type *fs_type,
316                         int flags, const char *dev_name,
317                         void *data)
318 {
319         return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super);
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(&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(c->blocks);
337         jffs2_flash_cleanup(c);
338         kfree(c->inocache_list);
339         jffs2_clear_xattr_subsystem(c);
340         mtd_sync(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(c);
351 }
352
353 static struct file_system_type jffs2_fs_type = {
354         .owner =        THIS_MODULE,
355         .name =         "jffs2",
356         .mount =        jffs2_mount,
357         .kill_sb =      jffs2_kill_sb,
358 };
359 MODULE_ALIAS_FS("jffs2");
360
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
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.