xref: /openbmc/linux/fs/jffs2/super.c (revision 545e4006)
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 *f;
35 
36 	f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
37 	if (!f)
38 		return NULL;
39 	return &f->vfs_inode;
40 }
41 
42 static void jffs2_destroy_inode(struct inode *inode)
43 {
44 	kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
45 }
46 
47 static void jffs2_i_init_once(struct kmem_cache *cachep, void *foo)
48 {
49 	struct jffs2_inode_info *f = foo;
50 
51 	mutex_init(&f->sem);
52 	inode_init_once(&f->vfs_inode);
53 }
54 
55 static int jffs2_sync_fs(struct super_block *sb, int wait)
56 {
57 	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
58 
59 	mutex_lock(&c->alloc_sem);
60 	jffs2_flush_wbuf_pad(c);
61 	mutex_unlock(&c->alloc_sem);
62 	return 0;
63 }
64 
65 static const struct super_operations jffs2_super_operations =
66 {
67 	.alloc_inode =	jffs2_alloc_inode,
68 	.destroy_inode =jffs2_destroy_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 	mutex_init(&c->alloc_sem);
100 	mutex_init(&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 	mutex_lock(&c->alloc_sem);
130 	jffs2_flush_wbuf_pad(c);
131 	mutex_unlock(&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.
241