Merge branch 'fix/hda' into for-linus
[linux-2.6] / 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_destroy_inode(struct inode *inode)
44 {
45         kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
46 }
47
48 static void jffs2_i_init_once(void *foo)
49 {
50         struct jffs2_inode_info *f = foo;
51
52         mutex_init(&f->sem);
53         inode_init_once(&f->vfs_inode);
54 }
55
56 static int jffs2_sync_fs(struct super_block *sb, int wait)
57 {
58         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
59
60         mutex_lock(&c->alloc_sem);
61         jffs2_flush_wbuf_pad(c);
62         mutex_unlock(&c->alloc_sem);
63         return 0;
64 }
65
66 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
67                                          uint32_t generation)
68 {
69         /* We don't care about i_generation. We'll destroy the flash
70            before we start re-using inode numbers anyway. And even
71            if that wasn't true, we'd have other problems...*/
72         return jffs2_iget(sb, ino);
73 }
74
75 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
76                                          int fh_len, int fh_type)
77 {
78         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
79                                     jffs2_nfs_get_inode);
80 }
81
82 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid,
83                                          int fh_len, int fh_type)
84 {
85         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
86                                     jffs2_nfs_get_inode);
87 }
88
89 static struct dentry *jffs2_get_parent(struct dentry *child)
90 {
91         struct jffs2_inode_info *f;
92         uint32_t pino;
93
94         BUG_ON(!S_ISDIR(child->d_inode->i_mode));
95
96         f = JFFS2_INODE_INFO(child->d_inode);
97
98         pino = f->inocache->pino_nlink;
99
100         JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
101                     f->inocache->ino, pino);
102
103         return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino));
104 }
105
106 static struct export_operations jffs2_export_ops = {
107         .get_parent = jffs2_get_parent,
108         .fh_to_dentry = jffs2_fh_to_dentry,
109         .fh_to_parent = jffs2_fh_to_parent,
110 };
111
112 static const struct super_operations jffs2_super_operations =
113 {
114         .alloc_inode =  jffs2_alloc_inode,
115         .destroy_inode =jffs2_destroy_inode,
116         .put_super =    jffs2_put_super,
117         .write_super =  jffs2_write_super,
118         .statfs =       jffs2_statfs,
119         .remount_fs =   jffs2_remount_fs,
120         .clear_inode =  jffs2_clear_inode,
121         .dirty_inode =  jffs2_dirty_inode,
122         .sync_fs =      jffs2_sync_fs,
123 };
124
125 /*
126  * fill in the superblock
127  */
128 static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
129 {
130         struct jffs2_sb_info *c;
131
132         D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():"
133                   " New superblock for device %d (\"%s\")\n",
134                   sb->s_mtd->index, sb->s_mtd->name));
135
136         c = kzalloc(sizeof(*c), GFP_KERNEL);
137         if (!c)
138                 return -ENOMEM;
139
140         c->mtd = sb->s_mtd;
141         c->os_priv = sb;
142         sb->s_fs_info = c;
143
144         /* Initialize JFFS2 superblock locks, the further initialization will
145          * be done later */
146         mutex_init(&c->alloc_sem);
147         mutex_init(&c->erase_free_sem);
148         init_waitqueue_head(&c->erase_wait);
149         init_waitqueue_head(&c->inocache_wq);
150         spin_lock_init(&c->erase_completion_lock);
151         spin_lock_init(&c->inocache_lock);
152
153         sb->s_op = &jffs2_super_operations;
154         sb->s_export_op = &jffs2_export_ops;
155         sb->s_flags = sb->s_flags | MS_NOATIME;
156         sb->s_xattr = jffs2_xattr_handlers;
157 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
158         sb->s_flags |= MS_POSIXACL;
159 #endif
160         return jffs2_do_fill_super(sb, data, silent);
161 }
162
163 static int jffs2_get_sb(struct file_system_type *fs_type,
164                         int flags, const char *dev_name,
165                         void *data, struct vfsmount *mnt)
166 {
167         return get_sb_mtd(fs_type, flags, dev_name, data, jffs2_fill_super,
168                           mnt);
169 }
170
171 static void jffs2_put_super (struct super_block *sb)
172 {
173         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
174
175         D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));
176
177         mutex_lock(&c->alloc_sem);
178         jffs2_flush_wbuf_pad(c);
179         mutex_unlock(&c->alloc_sem);
180
181         jffs2_sum_exit(c);
182
183         jffs2_free_ino_caches(c);
184         jffs2_free_raw_node_refs(c);
185         if (jffs2_blocks_use_vmalloc(c))
186                 vfree(c->blocks);
187         else
188                 kfree(c->blocks);
189         jffs2_flash_cleanup(c);
190         kfree(c->inocache_list);
191         jffs2_clear_xattr_subsystem(c);
192         if (c->mtd->sync)
193                 c->mtd->sync(c->mtd);
194
195         D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
196 }
197
198 static void jffs2_kill_sb(struct super_block *sb)
199 {
200         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
201         if (!(sb->s_flags & MS_RDONLY))
202                 jffs2_stop_garbage_collect_thread(c);
203         kill_mtd_super(sb);
204         kfree(c);
205 }
206
207 static struct file_system_type jffs2_fs_type = {
208         .owner =        THIS_MODULE,
209         .name =         "jffs2",
210         .get_sb =       jffs2_get_sb,
211         .kill_sb =      jffs2_kill_sb,
212 };
213
214 static int __init init_jffs2_fs(void)
215 {
216         int ret;
217
218         /* Paranoia checks for on-medium structures. If we ask GCC
219            to pack them with __attribute__((packed)) then it _also_
220            assumes that they're not aligned -- so it emits crappy
221            code on some architectures. Ideally we want an attribute
222            which means just 'no padding', without the alignment
223            thing. But GCC doesn't have that -- we have to just
224            hope the structs are the right sizes, instead. */
225         BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
226         BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
227         BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
228         BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
229
230         printk(KERN_INFO "JFFS2 version 2.2."
231 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
232                " (NAND)"
233 #endif
234 #ifdef CONFIG_JFFS2_SUMMARY
235                " (SUMMARY) "
236 #endif
237                " © 2001-2006 Red Hat, Inc.\n");
238
239         jffs2_inode_cachep = kmem_cache_create("jffs2_i",
240                                              sizeof(struct jffs2_inode_info),
241                                              0, (SLAB_RECLAIM_ACCOUNT|
242                                                 SLAB_MEM_SPREAD),
243                                              jffs2_i_init_once);
244         if (!jffs2_inode_cachep) {
245                 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n");
246                 return -ENOMEM;
247         }
248         ret = jffs2_compressors_init();
249         if (ret) {
250                 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n");
251                 goto out;
252         }
253         ret = jffs2_create_slab_caches();
254         if (ret) {
255                 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
256                 goto out_compressors;
257         }
258         ret = register_filesystem(&jffs2_fs_type);
259         if (ret) {
260                 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n");
261                 goto out_slab;
262         }
263         return 0;
264
265  out_slab:
266         jffs2_destroy_slab_caches();
267  out_compressors:
268         jffs2_compressors_exit();
269  out:
270         kmem_cache_destroy(jffs2_inode_cachep);
271         return ret;
272 }
273
274 static void __exit exit_jffs2_fs(void)
275 {
276         unregister_filesystem(&jffs2_fs_type);
277         jffs2_destroy_slab_caches();
278         jffs2_compressors_exit();
279         kmem_cache_destroy(jffs2_inode_cachep);
280 }
281
282 module_init(init_jffs2_fs);
283 module_exit(exit_jffs2_fs);
284
285 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
286 MODULE_AUTHOR("Red Hat, Inc.");
287 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
288                        // the sake of this tag. It's Free Software.