be2b70c2ec1653890df1c08aae864293e47a6b50
[linux-3.10.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 "compr.h"
26 #include "nodelist.h"
27
28 static void jffs2_put_super(struct super_block *);
29
30 static struct kmem_cache *jffs2_inode_cachep;
31
32 static struct inode *jffs2_alloc_inode(struct super_block *sb)
33 {
34         struct jffs2_inode_info *ei;
35         ei = (struct jffs2_inode_info *)kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
36         if (!ei)
37                 return NULL;
38         return &ei->vfs_inode;
39 }
40
41 static void jffs2_destroy_inode(struct inode *inode)
42 {
43         kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
44 }
45
46 static void jffs2_i_init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
47 {
48         struct jffs2_inode_info *ei = (struct jffs2_inode_info *) foo;
49
50         init_MUTEX(&ei->sem);
51         inode_init_once(&ei->vfs_inode);
52 }
53
54 static int jffs2_sync_fs(struct super_block *sb, int wait)
55 {
56         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
57
58         down(&c->alloc_sem);
59         jffs2_flush_wbuf_pad(c);
60         up(&c->alloc_sem);
61         return 0;
62 }
63
64 static const struct super_operations jffs2_super_operations =
65 {
66         .alloc_inode =  jffs2_alloc_inode,
67         .destroy_inode =jffs2_destroy_inode,
68         .read_inode =   jffs2_read_inode,
69         .put_super =    jffs2_put_super,
70         .write_super =  jffs2_write_super,
71         .statfs =       jffs2_statfs,
72         .remount_fs =   jffs2_remount_fs,
73         .clear_inode =  jffs2_clear_inode,
74         .dirty_inode =  jffs2_dirty_inode,
75         .sync_fs =      jffs2_sync_fs,
76 };
77
78 /*
79  * fill in the superblock
80  */
81 static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
82 {
83         struct jffs2_sb_info *c;
84
85         D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():"
86                   " New superblock for device %d (\"%s\")\n",
87                   sb->s_mtd->index, sb->s_mtd->name));
88
89         c = kzalloc(sizeof(*c), GFP_KERNEL);
90         if (!c)
91                 return -ENOMEM;
92
93         c->mtd = sb->s_mtd;
94         c->os_priv = sb;
95         sb->s_fs_info = c;
96
97         /* Initialize JFFS2 superblock locks, the further initialization will
98          * be done later */
99         init_MUTEX(&c->alloc_sem);
100         init_MUTEX(&c->erase_free_sem);
101         init_waitqueue_head(&c->erase_wait);
102         init_waitqueue_head(&c->inocache_wq);
103         spin_lock_init(&c->erase_completion_lock);
104         spin_lock_init(&c->inocache_lock);
105
106         sb->s_op = &jffs2_super_operations;
107         sb->s_flags = sb->s_flags | MS_NOATIME;
108         sb->s_xattr = jffs2_xattr_handlers;
109 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
110         sb->s_flags |= MS_POSIXACL;
111 #endif
112         return jffs2_do_fill_super(sb, data, silent);
113 }
114
115 static int jffs2_get_sb(struct file_system_type *fs_type,
116                         int flags, const char *dev_name,
117                         void *data, struct vfsmount *mnt)
118 {
119         return get_sb_mtd(fs_type, flags, dev_name, data, jffs2_fill_super,
120                           mnt);
121 }
122
123 static void jffs2_put_super (struct super_block *sb)
124 {
125         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
126
127         D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));
128
129         down(&c->alloc_sem);
130         jffs2_flush_wbuf_pad(c);
131         up(&c->alloc_sem);
132
133         jffs2_sum_exit(c);
134
135         jffs2_free_ino_caches(c);
136         jffs2_free_raw_node_refs(c);
137         if (jffs2_blocks_use_vmalloc(c))
138                 vfree(c->blocks);
139         else
140                 kfree(c->blocks);
141         jffs2_flash_cleanup(c);
142         kfree(c->inocache_list);
143         jffs2_clear_xattr_subsystem(c);
144         if (c->mtd->sync)
145                 c->mtd->sync(c->mtd);
146
147         D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
148 }
149
150 static void jffs2_kill_sb(struct super_block *sb)
151 {
152         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
153         if (!(sb->s_flags & MS_RDONLY))
154                 jffs2_stop_garbage_collect_thread(c);
155         kill_mtd_super(sb);
156         kfree(c);
157 }
158
159 static struct file_system_type jffs2_fs_type = {
160         .owner =        THIS_MODULE,
161         .name =         "jffs2",
162         .get_sb =       jffs2_get_sb,
163         .kill_sb =      jffs2_kill_sb,
164 };
165
166 static int __init init_jffs2_fs(void)
167 {
168         int ret;
169
170         /* Paranoia checks for on-medium structures. If we ask GCC
171            to pack them with __attribute__((packed)) then it _also_
172            assumes that they're not aligned -- so it emits crappy
173            code on some architectures. Ideally we want an attribute
174            which means just 'no padding', without the alignment
175            thing. But GCC doesn't have that -- we have to just
176            hope the structs are the right sizes, instead. */
177         BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
178         BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
179         BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
180         BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
181
182         printk(KERN_INFO "JFFS2 version 2.2."
183 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
184                " (NAND)"
185 #endif
186 #ifdef CONFIG_JFFS2_SUMMARY
187                " (SUMMARY) "
188 #endif
189                " © 2001-2006 Red Hat, Inc.\n");
190
191         jffs2_inode_cachep = kmem_cache_create("jffs2_i",
192                                              sizeof(struct jffs2_inode_info),
193                                              0, (SLAB_RECLAIM_ACCOUNT|
194                                                 SLAB_MEM_SPREAD),
195                                              jffs2_i_init_once);
196         if (!jffs2_inode_cachep) {
197                 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n");
198                 return -ENOMEM;
199         }
200         ret = jffs2_compressors_init();
201         if (ret) {
202                 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n");
203                 goto out;
204         }
205         ret = jffs2_create_slab_caches();
206         if (ret) {
207                 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
208                 goto out_compressors;
209         }
210         ret = register_filesystem(&jffs2_fs_type);
211         if (ret) {
212                 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n");
213                 goto out_slab;
214         }
215         return 0;
216
217  out_slab:
218         jffs2_destroy_slab_caches();
219  out_compressors:
220         jffs2_compressors_exit();
221  out:
222         kmem_cache_destroy(jffs2_inode_cachep);
223         return ret;
224 }
225
226 static void __exit exit_jffs2_fs(void)
227 {
228         unregister_filesystem(&jffs2_fs_type);
229         jffs2_destroy_slab_caches();
230         jffs2_compressors_exit();
231         kmem_cache_destroy(jffs2_inode_cachep);
232 }
233
234 module_init(init_jffs2_fs);
235 module_exit(exit_jffs2_fs);
236
237 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
238 MODULE_AUTHOR("Red Hat, Inc.");
239 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
240                        // the sake of this tag. It's Free Software.