]> git.openfabrics.org - ~shefty/rdma-dev.git/blob - fs/jffs2/super.c
Merge tag 'for-linus-3.3' of git://git.infradead.org/mtd-2.6
[~shefty/rdma-dev.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 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include <linux/init.h>
16 #include <linux/list.h>
17 #include <linux/fs.h>
18 #include <linux/err.h>
19 #include <linux/mount.h>
20 #include <linux/parser.h>
21 #include <linux/jffs2.h>
22 #include <linux/pagemap.h>
23 #include <linux/mtd/super.h>
24 #include <linux/ctype.h>
25 #include <linux/namei.h>
26 #include <linux/seq_file.h>
27 #include <linux/exportfs.h>
28 #include "compr.h"
29 #include "nodelist.h"
30
31 static void jffs2_put_super(struct super_block *);
32
33 static struct kmem_cache *jffs2_inode_cachep;
34
35 static struct inode *jffs2_alloc_inode(struct super_block *sb)
36 {
37         struct jffs2_inode_info *f;
38
39         f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
40         if (!f)
41                 return NULL;
42         return &f->vfs_inode;
43 }
44
45 static void jffs2_i_callback(struct rcu_head *head)
46 {
47         struct inode *inode = container_of(head, struct inode, i_rcu);
48         kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
49 }
50
51 static void jffs2_destroy_inode(struct inode *inode)
52 {
53         call_rcu(&inode->i_rcu, jffs2_i_callback);
54 }
55
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
64 static void jffs2_write_super(struct super_block *sb)
65 {
66         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
67
68         lock_super(sb);
69         sb->s_dirt = 0;
70
71         if (!(sb->s_flags & MS_RDONLY)) {
72                 D1(printk(KERN_DEBUG "jffs2_write_super()\n"));
73                 jffs2_flush_wbuf_gc(c, 0);
74         }
75
76         unlock_super(sb);
77 }
78
79 static const char *jffs2_compr_name(unsigned int compr)
80 {
81         switch (compr) {
82         case JFFS2_COMPR_MODE_NONE:
83                 return "none";
84 #ifdef CONFIG_JFFS2_LZO
85         case JFFS2_COMPR_MODE_FORCELZO:
86                 return "lzo";
87 #endif
88 #ifdef CONFIG_JFFS2_ZLIB
89         case JFFS2_COMPR_MODE_FORCEZLIB:
90                 return "zlib";
91 #endif
92         default:
93                 /* should never happen; programmer error */
94                 WARN_ON(1);
95                 return "";
96         }
97 }
98
99 static int jffs2_show_options(struct seq_file *s, struct dentry *root)
100 {
101         struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb);
102         struct jffs2_mount_opts *opts = &c->mount_opts;
103
104         if (opts->override_compr)
105                 seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr));
106
107         return 0;
108 }
109
110 static int jffs2_sync_fs(struct super_block *sb, int wait)
111 {
112         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
113
114         jffs2_write_super(sb);
115
116         mutex_lock(&c->alloc_sem);
117         jffs2_flush_wbuf_pad(c);
118         mutex_unlock(&c->alloc_sem);
119         return 0;
120 }
121
122 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
123                                          uint32_t generation)
124 {
125         /* We don't care about i_generation. We'll destroy the flash
126            before we start re-using inode numbers anyway. And even
127            if that wasn't true, we'd have other problems...*/
128         return jffs2_iget(sb, ino);
129 }
130
131 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
132                                          int fh_len, int fh_type)
133 {
134         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
135                                     jffs2_nfs_get_inode);
136 }
137
138 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid,
139                                          int fh_len, int fh_type)
140 {
141         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
142                                     jffs2_nfs_get_inode);
143 }
144
145 static struct dentry *jffs2_get_parent(struct dentry *child)
146 {
147         struct jffs2_inode_info *f;
148         uint32_t pino;
149
150         BUG_ON(!S_ISDIR(child->d_inode->i_mode));
151
152         f = JFFS2_INODE_INFO(child->d_inode);
153
154         pino = f->inocache->pino_nlink;
155
156         JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
157                     f->inocache->ino, pino);
158
159         return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino));
160 }
161
162 static const struct export_operations jffs2_export_ops = {
163         .get_parent = jffs2_get_parent,
164         .fh_to_dentry = jffs2_fh_to_dentry,
165         .fh_to_parent = jffs2_fh_to_parent,
166 };
167
168 /*
169  * JFFS2 mount options.
170  *
171  * Opt_override_compr: override default compressor
172  * Opt_err: just end of array marker
173  */
174 enum {
175         Opt_override_compr,
176         Opt_err,
177 };
178
179 static const match_table_t tokens = {
180         {Opt_override_compr, "compr=%s"},
181         {Opt_err, NULL},
182 };
183
184 static int jffs2_parse_options(struct jffs2_sb_info *c, char *data)
185 {
186         substring_t args[MAX_OPT_ARGS];
187         char *p, *name;
188
189         if (!data)
190                 return 0;
191
192         while ((p = strsep(&data, ","))) {
193                 int token;
194
195                 if (!*p)
196                         continue;
197
198                 token = match_token(p, tokens, args);
199                 switch (token) {
200                 case Opt_override_compr:
201                         name = match_strdup(&args[0]);
202
203                         if (!name)
204                                 return -ENOMEM;
205                         if (!strcmp(name, "none"))
206                                 c->mount_opts.compr = JFFS2_COMPR_MODE_NONE;
207 #ifdef CONFIG_JFFS2_LZO
208                         else if (!strcmp(name, "lzo"))
209                                 c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO;
210 #endif
211 #ifdef CONFIG_JFFS2_ZLIB
212                         else if (!strcmp(name, "zlib"))
213                                 c->mount_opts.compr =
214                                                 JFFS2_COMPR_MODE_FORCEZLIB;
215 #endif
216                         else {
217                                 printk(KERN_ERR "JFFS2 Error: unknown compressor \"%s\"",
218                                                 name);
219                                 kfree(name);
220                                 return -EINVAL;
221                         }
222                         kfree(name);
223                         c->mount_opts.override_compr = true;
224                         break;
225                 default:
226                         printk(KERN_ERR "JFFS2 Error: unrecognized mount option '%s' or missing value\n",
227                                         p);
228                         return -EINVAL;
229                 }
230         }
231
232         return 0;
233 }
234
235 static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data)
236 {
237         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
238         int err;
239
240         err = jffs2_parse_options(c, data);
241         if (err)
242                 return -EINVAL;
243
244         return jffs2_do_remount_fs(sb, flags, data);
245 }
246
247 static const struct super_operations jffs2_super_operations =
248 {
249         .alloc_inode =  jffs2_alloc_inode,
250         .destroy_inode =jffs2_destroy_inode,
251         .put_super =    jffs2_put_super,
252         .write_super =  jffs2_write_super,
253         .statfs =       jffs2_statfs,
254         .remount_fs =   jffs2_remount_fs,
255         .evict_inode =  jffs2_evict_inode,
256         .dirty_inode =  jffs2_dirty_inode,
257         .show_options = jffs2_show_options,
258         .sync_fs =      jffs2_sync_fs,
259 };
260
261 /*
262  * fill in the superblock
263  */
264 static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
265 {
266         struct jffs2_sb_info *c;
267         int ret;
268
269         D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():"
270                   " New superblock for device %d (\"%s\")\n",
271                   sb->s_mtd->index, sb->s_mtd->name));
272
273         c = kzalloc(sizeof(*c), GFP_KERNEL);
274         if (!c)
275                 return -ENOMEM;
276
277         c->mtd = sb->s_mtd;
278         c->os_priv = sb;
279         sb->s_fs_info = c;
280
281         ret = jffs2_parse_options(c, data);
282         if (ret) {
283                 kfree(c);
284                 return -EINVAL;
285         }
286
287         /* Initialize JFFS2 superblock locks, the further initialization will
288          * be done later */
289         mutex_init(&c->alloc_sem);
290         mutex_init(&c->erase_free_sem);
291         init_waitqueue_head(&c->erase_wait);
292         init_waitqueue_head(&c->inocache_wq);
293         spin_lock_init(&c->erase_completion_lock);
294         spin_lock_init(&c->inocache_lock);
295
296         sb->s_op = &jffs2_super_operations;
297         sb->s_export_op = &jffs2_export_ops;
298         sb->s_flags = sb->s_flags | MS_NOATIME;
299         sb->s_xattr = jffs2_xattr_handlers;
300 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
301         sb->s_flags |= MS_POSIXACL;
302 #endif
303         ret = jffs2_do_fill_super(sb, data, silent);
304         return ret;
305 }
306
307 static struct dentry *jffs2_mount(struct file_system_type *fs_type,
308                         int flags, const char *dev_name,
309                         void *data)
310 {
311         return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super);
312 }
313
314 static void jffs2_put_super (struct super_block *sb)
315 {
316         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
317
318         D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));
319
320         if (sb->s_dirt)
321                 jffs2_write_super(sb);
322
323         mutex_lock(&c->alloc_sem);
324         jffs2_flush_wbuf_pad(c);
325         mutex_unlock(&c->alloc_sem);
326
327         jffs2_sum_exit(c);
328
329         jffs2_free_ino_caches(c);
330         jffs2_free_raw_node_refs(c);
331         if (jffs2_blocks_use_vmalloc(c))
332                 vfree(c->blocks);
333         else
334                 kfree(c->blocks);
335         jffs2_flash_cleanup(c);
336         kfree(c->inocache_list);
337         jffs2_clear_xattr_subsystem(c);
338         mtd_sync(c->mtd);
339         D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
340 }
341
342 static void jffs2_kill_sb(struct super_block *sb)
343 {
344         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
345         if (!(sb->s_flags & MS_RDONLY))
346                 jffs2_stop_garbage_collect_thread(c);
347         kill_mtd_super(sb);
348         kfree(c);
349 }
350
351 static struct file_system_type jffs2_fs_type = {
352         .owner =        THIS_MODULE,
353         .name =         "jffs2",
354         .mount =        jffs2_mount,
355         .kill_sb =      jffs2_kill_sb,
356 };
357
358 static int __init init_jffs2_fs(void)
359 {
360         int ret;
361
362         /* Paranoia checks for on-medium structures. If we ask GCC
363            to pack them with __attribute__((packed)) then it _also_
364            assumes that they're not aligned -- so it emits crappy
365            code on some architectures. Ideally we want an attribute
366            which means just 'no padding', without the alignment
367            thing. But GCC doesn't have that -- we have to just
368            hope the structs are the right sizes, instead. */
369         BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
370         BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
371         BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
372         BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
373
374         printk(KERN_INFO "JFFS2 version 2.2."
375 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
376                " (NAND)"
377 #endif
378 #ifdef CONFIG_JFFS2_SUMMARY
379                " (SUMMARY) "
380 #endif
381                " © 2001-2006 Red Hat, Inc.\n");
382
383         jffs2_inode_cachep = kmem_cache_create("jffs2_i",
384                                              sizeof(struct jffs2_inode_info),
385                                              0, (SLAB_RECLAIM_ACCOUNT|
386                                                 SLAB_MEM_SPREAD),
387                                              jffs2_i_init_once);
388         if (!jffs2_inode_cachep) {
389                 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n");
390                 return -ENOMEM;
391         }
392         ret = jffs2_compressors_init();
393         if (ret) {
394                 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n");
395                 goto out;
396         }
397         ret = jffs2_create_slab_caches();
398         if (ret) {
399                 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
400                 goto out_compressors;
401         }
402         ret = register_filesystem(&jffs2_fs_type);
403         if (ret) {
404                 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n");
405                 goto out_slab;
406         }
407         return 0;
408
409  out_slab:
410         jffs2_destroy_slab_caches();
411  out_compressors:
412         jffs2_compressors_exit();
413  out:
414         kmem_cache_destroy(jffs2_inode_cachep);
415         return ret;
416 }
417
418 static void __exit exit_jffs2_fs(void)
419 {
420         unregister_filesystem(&jffs2_fs_type);
421         jffs2_destroy_slab_caches();
422         jffs2_compressors_exit();
423         kmem_cache_destroy(jffs2_inode_cachep);
424 }
425
426 module_init(init_jffs2_fs);
427 module_exit(exit_jffs2_fs);
428
429 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
430 MODULE_AUTHOR("Red Hat, Inc.");
431 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
432                        // the sake of this tag. It's Free Software.