xfs: validate acl count
[linux-2.6.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/jffs2.h>
21 #include <linux/pagemap.h>
22 #include <linux/mtd/super.h>
23 #include <linux/ctype.h>
24 #include <linux/namei.h>
25 #include <linux/exportfs.h>
26 #include "compr.h"
27 #include "nodelist.h"
28
29 static void jffs2_put_super(struct super_block *);
30
31 static struct kmem_cache *jffs2_inode_cachep;
32
33 static struct inode *jffs2_alloc_inode(struct super_block *sb)
34 {
35         struct jffs2_inode_info *f;
36
37         f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
38         if (!f)
39                 return NULL;
40         return &f->vfs_inode;
41 }
42
43 static void jffs2_i_callback(struct rcu_head *head)
44 {
45         struct inode *inode = container_of(head, struct inode, i_rcu);
46         INIT_LIST_HEAD(&inode->i_dentry);
47         kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
48 }
49
50 static void jffs2_destroy_inode(struct inode *inode)
51 {
52         call_rcu(&inode->i_rcu, jffs2_i_callback);
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 void jffs2_write_super(struct super_block *sb)
64 {
65         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
66
67         lock_super(sb);
68         sb->s_dirt = 0;
69
70         if (!(sb->s_flags & MS_RDONLY)) {
71                 D1(printk(KERN_DEBUG "jffs2_write_super()\n"));
72                 jffs2_flush_wbuf_gc(c, 0);
73         }
74
75         unlock_super(sb);
76 }
77
78 static int jffs2_sync_fs(struct super_block *sb, int wait)
79 {
80         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
81
82         jffs2_write_super(sb);
83
84         mutex_lock(&c->alloc_sem);
85         jffs2_flush_wbuf_pad(c);
86         mutex_unlock(&c->alloc_sem);
87         return 0;
88 }
89
90 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
91                                          uint32_t generation)
92 {
93         /* We don't care about i_generation. We'll destroy the flash
94            before we start re-using inode numbers anyway. And even
95            if that wasn't true, we'd have other problems...*/
96         return jffs2_iget(sb, ino);
97 }
98
99 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
100                                          int fh_len, int fh_type)
101 {
102         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
103                                     jffs2_nfs_get_inode);
104 }
105
106 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid,
107                                          int fh_len, int fh_type)
108 {
109         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
110                                     jffs2_nfs_get_inode);
111 }
112
113 static struct dentry *jffs2_get_parent(struct dentry *child)
114 {
115         struct jffs2_inode_info *f;
116         uint32_t pino;
117
118         BUG_ON(!S_ISDIR(child->d_inode->i_mode));
119
120         f = JFFS2_INODE_INFO(child->d_inode);
121
122         pino = f->inocache->pino_nlink;
123
124         JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
125                     f->inocache->ino, pino);
126
127         return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino));
128 }
129
130 static const struct export_operations jffs2_export_ops = {
131         .get_parent = jffs2_get_parent,
132         .fh_to_dentry = jffs2_fh_to_dentry,
133         .fh_to_parent = jffs2_fh_to_parent,
134 };
135
136 static const struct super_operations jffs2_super_operations =
137 {
138         .alloc_inode =  jffs2_alloc_inode,
139         .destroy_inode =jffs2_destroy_inode,
140         .put_super =    jffs2_put_super,
141         .write_super =  jffs2_write_super,
142         .statfs =       jffs2_statfs,
143         .remount_fs =   jffs2_remount_fs,
144         .evict_inode =  jffs2_evict_inode,
145         .dirty_inode =  jffs2_dirty_inode,
146         .sync_fs =      jffs2_sync_fs,
147 };
148
149 /*
150  * fill in the superblock
151  */
152 static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
153 {
154         struct jffs2_sb_info *c;
155         int ret;
156
157         D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():"
158                   " New superblock for device %d (\"%s\")\n",
159                   sb->s_mtd->index, sb->s_mtd->name));
160
161         c = kzalloc(sizeof(*c), GFP_KERNEL);
162         if (!c)
163                 return -ENOMEM;
164
165         c->mtd = sb->s_mtd;
166         c->os_priv = sb;
167         sb->s_fs_info = c;
168
169         /* Initialize JFFS2 superblock locks, the further initialization will
170          * be done later */
171         mutex_init(&c->alloc_sem);
172         mutex_init(&c->erase_free_sem);
173         init_waitqueue_head(&c->erase_wait);
174         init_waitqueue_head(&c->inocache_wq);
175         spin_lock_init(&c->erase_completion_lock);
176         spin_lock_init(&c->inocache_lock);
177
178         sb->s_op = &jffs2_super_operations;
179         sb->s_export_op = &jffs2_export_ops;
180         sb->s_flags = sb->s_flags | MS_NOATIME;
181         sb->s_xattr = jffs2_xattr_handlers;
182 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
183         sb->s_flags |= MS_POSIXACL;
184 #endif
185         ret = jffs2_do_fill_super(sb, data, silent);
186         return ret;
187 }
188
189 static struct dentry *jffs2_mount(struct file_system_type *fs_type,
190                         int flags, const char *dev_name,
191                         void *data)
192 {
193         return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super);
194 }
195
196 static void jffs2_put_super (struct super_block *sb)
197 {
198         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
199
200         D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));
201
202         if (sb->s_dirt)
203                 jffs2_write_super(sb);
204
205         mutex_lock(&c->alloc_sem);
206         jffs2_flush_wbuf_pad(c);
207         mutex_unlock(&c->alloc_sem);
208
209         jffs2_sum_exit(c);
210
211         jffs2_free_ino_caches(c);
212         jffs2_free_raw_node_refs(c);
213         if (jffs2_blocks_use_vmalloc(c))
214                 vfree(c->blocks);
215         else
216                 kfree(c->blocks);
217         jffs2_flash_cleanup(c);
218         kfree(c->inocache_list);
219         jffs2_clear_xattr_subsystem(c);
220         if (c->mtd->sync)
221                 c->mtd->sync(c->mtd);
222
223         D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
224 }
225
226 static void jffs2_kill_sb(struct super_block *sb)
227 {
228         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
229         if (!(sb->s_flags & MS_RDONLY))
230                 jffs2_stop_garbage_collect_thread(c);
231         kill_mtd_super(sb);
232         kfree(c);
233 }
234
235 static struct file_system_type jffs2_fs_type = {
236         .owner =        THIS_MODULE,
237         .name =         "jffs2",
238         .mount =        jffs2_mount,
239         .kill_sb =      jffs2_kill_sb,
240 };
241
242 static int __init init_jffs2_fs(void)
243 {
244         int ret;
245
246         /* Paranoia checks for on-medium structures. If we ask GCC
247            to pack them with __attribute__((packed)) then it _also_
248            assumes that they're not aligned -- so it emits crappy
249            code on some architectures. Ideally we want an attribute
250            which means just 'no padding', without the alignment
251            thing. But GCC doesn't have that -- we have to just
252            hope the structs are the right sizes, instead. */
253         BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
254         BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
255         BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
256         BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
257
258         printk(KERN_INFO "JFFS2 version 2.2."
259 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
260                " (NAND)"
261 #endif
262 #ifdef CONFIG_JFFS2_SUMMARY
263                " (SUMMARY) "
264 #endif
265                " © 2001-2006 Red Hat, Inc.\n");
266
267         jffs2_inode_cachep = kmem_cache_create("jffs2_i",
268                                              sizeof(struct jffs2_inode_info),
269                                              0, (SLAB_RECLAIM_ACCOUNT|
270                                                 SLAB_MEM_SPREAD),
271                                              jffs2_i_init_once);
272         if (!jffs2_inode_cachep) {
273                 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n");
274                 return -ENOMEM;
275         }
276         ret = jffs2_compressors_init();
277         if (ret) {
278                 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n");
279                 goto out;
280         }
281         ret = jffs2_create_slab_caches();
282         if (ret) {
283                 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
284                 goto out_compressors;
285         }
286         ret = register_filesystem(&jffs2_fs_type);
287         if (ret) {
288                 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n");
289                 goto out_slab;
290         }
291         return 0;
292
293  out_slab:
294         jffs2_destroy_slab_caches();
295  out_compressors:
296         jffs2_compressors_exit();
297  out:
298         kmem_cache_destroy(jffs2_inode_cachep);
299         return ret;
300 }
301
302 static void __exit exit_jffs2_fs(void)
303 {
304         unregister_filesystem(&jffs2_fs_type);
305         jffs2_destroy_slab_caches();
306         jffs2_compressors_exit();
307         kmem_cache_destroy(jffs2_inode_cachep);
308 }
309
310 module_init(init_jffs2_fs);
311 module_exit(exit_jffs2_fs);
312
313 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
314 MODULE_AUTHOR("Red Hat, Inc.");
315 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
316                        // the sake of this tag. It's Free Software.