xref: /openbmc/linux/fs/jffs2/super.c (revision a1e58bbd)
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(struct kmem_cache *cachep, void *foo)
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 	.put_super =	jffs2_put_super,
69 	.write_super =	jffs2_write_super,
70 	.statfs =	jffs2_statfs,
71 	.remount_fs =	jffs2_remount_fs,
72 	.clear_inode =	jffs2_clear_inode,
73 	.dirty_inode =	jffs2_dirty_inode,
74 	.sync_fs =	jffs2_sync_fs,
75 };
76 
77 /*
78  * fill in the superblock
79  */
80 static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
81 {
82 	struct jffs2_sb_info *c;
83 
84 	D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():"
85 		  " New superblock for device %d (\"%s\")\n",
86 		  sb->s_mtd->index, sb->s_mtd->name));
87 
88 	c = kzalloc(sizeof(*c), GFP_KERNEL);
89 	if (!c)
90 		return -ENOMEM;
91 
92 	c->mtd = sb->s_mtd;
93 	c->os_priv = sb;
94 	sb->s_fs_info = c;
95 
96 	/* Initialize JFFS2 superblock locks, the further initialization will
97 	 * be done later */
98 	init_MUTEX(&c->alloc_sem);
99 	init_MUTEX(&c->erase_free_sem);
100 	init_waitqueue_head(&c->erase_wait);
101 	init_waitqueue_head(&c->inocache_wq);
102 	spin_lock_init(&c->erase_completion_lock);
103 	spin_lock_init(&c->inocache_lock);
104 
105 	sb->s_op = &jffs2_super_operations;
106 	sb->s_flags = sb->s_flags | MS_NOATIME;
107 	sb->s_xattr = jffs2_xattr_handlers;
108 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
109 	sb->s_flags |= MS_POSIXACL;
110 #endif
111 	return jffs2_do_fill_super(sb, data, silent);
112 }
113 
114 static int jffs2_get_sb(struct file_system_type *fs_type,
115 			int flags, const char *dev_name,
116 			void *data, struct vfsmount *mnt)
117 {
118 	return get_sb_mtd(fs_type, flags, dev_name, data, jffs2_fill_super,
119 			  mnt);
120 }
121 
122 static void jffs2_put_super (struct super_block *sb)
123 {
124 	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
125 
126 	D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));
127 
128 	down(&c->alloc_sem);
129 	jffs2_flush_wbuf_pad(c);
130 	up(&c->alloc_sem);
131 
132 	jffs2_sum_exit(c);
133 
134 	jffs2_free_ino_caches(c);
135 	jffs2_free_raw_node_refs(c);
136 	if (jffs2_blocks_use_vmalloc(c))
137 		vfree(c->blocks);
138 	else
139 		kfree(c->blocks);
140 	jffs2_flash_cleanup(c);
141 	kfree(c->inocache_list);
142 	jffs2_clear_xattr_subsystem(c);
143 	if (c->mtd->sync)
144 		c->mtd->sync(c->mtd);
145 
146 	D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
147 }
148 
149 static void jffs2_kill_sb(struct super_block *sb)
150 {
151 	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
152 	if (!(sb->s_flags & MS_RDONLY))
153 		jffs2_stop_garbage_collect_thread(c);
154 	kill_mtd_super(sb);
155 	kfree(c);
156 }
157 
158 static struct file_system_type jffs2_fs_type = {
159 	.owner =	THIS_MODULE,
160 	.name =		"jffs2",
161 	.get_sb =	jffs2_get_sb,
162 	.kill_sb =	jffs2_kill_sb,
163 };
164 
165 static int __init init_jffs2_fs(void)
166 {
167 	int ret;
168 
169 	/* Paranoia checks for on-medium structures. If we ask GCC
170 	   to pack them with __attribute__((packed)) then it _also_
171 	   assumes that they're not aligned -- so it emits crappy
172 	   code on some architectures. Ideally we want an attribute
173 	   which means just 'no padding', without the alignment
174 	   thing. But GCC doesn't have that -- we have to just
175 	   hope the structs are the right sizes, instead. */
176 	BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
177 	BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
178 	BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
179 	BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
180 
181 	printk(KERN_INFO "JFFS2 version 2.2."
182 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
183 	       " (NAND)"
184 #endif
185 #ifdef CONFIG_JFFS2_SUMMARY
186 	       " (SUMMARY) "
187 #endif
188 	       " © 2001-2006 Red Hat, Inc.\n");
189 
190 	jffs2_inode_cachep = kmem_cache_create("jffs2_i",
191 					     sizeof(struct jffs2_inode_info),
192 					     0, (SLAB_RECLAIM_ACCOUNT|
193 						SLAB_MEM_SPREAD),
194 					     jffs2_i_init_once);
195 	if (!jffs2_inode_cachep) {
196 		printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n");
197 		return -ENOMEM;
198 	}
199 	ret = jffs2_compressors_init();
200 	if (ret) {
201 		printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n");
202 		goto out;
203 	}
204 	ret = jffs2_create_slab_caches();
205 	if (ret) {
206 		printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
207 		goto out_compressors;
208 	}
209 	ret = register_filesystem(&jffs2_fs_type);
210 	if (ret) {
211 		printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n");
212 		goto out_slab;
213 	}
214 	return 0;
215 
216  out_slab:
217 	jffs2_destroy_slab_caches();
218  out_compressors:
219 	jffs2_compressors_exit();
220  out:
221 	kmem_cache_destroy(jffs2_inode_cachep);
222 	return ret;
223 }
224 
225 static void __exit exit_jffs2_fs(void)
226 {
227 	unregister_filesystem(&jffs2_fs_type);
228 	jffs2_destroy_slab_caches();
229 	jffs2_compressors_exit();
230 	kmem_cache_destroy(jffs2_inode_cachep);
231 }
232 
233 module_init(init_jffs2_fs);
234 module_exit(exit_jffs2_fs);
235 
236 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
237 MODULE_AUTHOR("Red Hat, Inc.");
238 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
239 		       // the sake of this tag. It's Free Software.
240