2 * JFFS2 -- Journalling Flash File System, Version 2.
4 * Copyright (C) 2001-2003 Red Hat, Inc.
6 * Created by David Woodhouse <dwmw2@redhat.com>
8 * For licensing information, see the file 'LICENCE' in this directory.
10 * $Id: super.c,v 1.90 2003/10/11 11:47:23 dwmw2 Exp $
14 #include <linux/config.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/init.h>
19 #include <linux/list.h>
21 #include <linux/mount.h>
22 #include <linux/jffs2.h>
23 #include <linux/pagemap.h>
24 #include <linux/mtd/mtd.h>
25 #include <linux/ctype.h>
26 #include <linux/namei.h>
29 static void jffs2_put_super(struct super_block *);
31 static kmem_cache_t *jffs2_inode_cachep;
33 static struct inode *jffs2_alloc_inode(struct super_block *sb)
35 struct jffs2_inode_info *ei;
36 ei = (struct jffs2_inode_info *)kmem_cache_alloc(jffs2_inode_cachep, SLAB_KERNEL);
39 return &ei->vfs_inode;
42 static void jffs2_destroy_inode(struct inode *inode)
44 kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
47 static void jffs2_i_init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
49 struct jffs2_inode_info *ei = (struct jffs2_inode_info *) foo;
51 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
52 SLAB_CTOR_CONSTRUCTOR) {
53 init_MUTEX_LOCKED(&ei->sem);
54 inode_init_once(&ei->vfs_inode);
58 static struct super_operations jffs2_super_operations =
60 .alloc_inode = jffs2_alloc_inode,
61 .destroy_inode =jffs2_destroy_inode,
62 .read_inode = jffs2_read_inode,
63 .put_super = jffs2_put_super,
64 .write_super = jffs2_write_super,
65 .statfs = jffs2_statfs,
66 .remount_fs = jffs2_remount_fs,
67 .clear_inode = jffs2_clear_inode,
68 .dirty_inode = jffs2_dirty_inode,
71 static int jffs2_sb_compare(struct super_block *sb, void *data)
73 struct jffs2_sb_info *p = data;
74 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
76 /* The superblocks are considered to be equivalent if the underlying MTD
77 device is the same one */
78 if (c->mtd == p->mtd) {
79 D1(printk(KERN_DEBUG "jffs2_sb_compare: match on device %d (\"%s\")\n", p->mtd->index, p->mtd->name));
82 D1(printk(KERN_DEBUG "jffs2_sb_compare: No match, device %d (\"%s\"), device %d (\"%s\")\n",
83 c->mtd->index, c->mtd->name, p->mtd->index, p->mtd->name));
88 static int jffs2_sb_set(struct super_block *sb, void *data)
90 struct jffs2_sb_info *p = data;
92 /* For persistence of NFS exports etc. we use the same s_dev
93 each time we mount the device, don't just use an anonymous
97 sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, p->mtd->index);
102 static struct super_block *jffs2_get_sb_mtd(struct file_system_type *fs_type,
103 int flags, const char *dev_name,
104 void *data, struct mtd_info *mtd)
106 struct super_block *sb;
107 struct jffs2_sb_info *c;
110 c = kmalloc(sizeof(*c), GFP_KERNEL);
112 return ERR_PTR(-ENOMEM);
113 memset(c, 0, sizeof(*c));
116 sb = sget(fs_type, jffs2_sb_compare, jffs2_sb_set, c);
122 /* New mountpoint for JFFS2 which is already mounted */
123 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): Device %d (\"%s\") is already mounted\n",
124 mtd->index, mtd->name));
128 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): New superblock for device %d (\"%s\")\n",
129 mtd->index, mtd->name));
131 sb->s_op = &jffs2_super_operations;
132 sb->s_flags |= MS_NOATIME;
134 ret = jffs2_do_fill_super(sb, data, (flags&MS_VERBOSE)?1:0);
137 /* Failure case... */
138 up_write(&sb->s_umount);
139 deactivate_super(sb);
143 sb->s_flags |= MS_ACTIVE;
153 static struct super_block *jffs2_get_sb_mtdnr(struct file_system_type *fs_type,
154 int flags, const char *dev_name,
155 void *data, int mtdnr)
157 struct mtd_info *mtd;
159 mtd = get_mtd_device(NULL, mtdnr);
161 D1(printk(KERN_DEBUG "jffs2: MTD device #%u doesn't appear to exist\n", mtdnr));
162 return ERR_PTR(-EINVAL);
165 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd);
168 static struct super_block *jffs2_get_sb(struct file_system_type *fs_type,
169 int flags, const char *dev_name,
177 return ERR_PTR(-EINVAL);
179 D1(printk(KERN_DEBUG "jffs2_get_sb(): dev_name \"%s\"\n", dev_name));
181 /* The preferred way of mounting in future; especially when
182 CONFIG_BLK_DEV is implemented - we specify the underlying
183 MTD device by number or by name, so that we don't require
184 block device support to be present in the kernel. */
186 /* FIXME: How to do the root fs this way? */
188 if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') {
189 /* Probably mounting without the blkdev crap */
190 if (dev_name[3] == ':') {
191 struct mtd_info *mtd;
193 /* Mount by MTD device name */
194 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd:%%s, name \"%s\"\n", dev_name+4));
195 for (mtdnr = 0; mtdnr < MAX_MTD_DEVICES; mtdnr++) {
196 mtd = get_mtd_device(NULL, mtdnr);
198 if (!strcmp(mtd->name, dev_name+4))
199 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd);
203 printk(KERN_NOTICE "jffs2_get_sb(): MTD device with name \"%s\" not found.\n", dev_name+4);
204 } else if (isdigit(dev_name[3])) {
205 /* Mount by MTD device number name */
208 mtdnr = simple_strtoul(dev_name+3, &endptr, 0);
210 /* It was a valid number */
211 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd%%d, mtdnr %d\n", mtdnr));
212 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr);
217 /* Try the old way - the hack where we allowed users to mount
218 /dev/mtdblock$(n) but didn't actually _use_ the blkdev */
220 err = path_lookup(dev_name, LOOKUP_FOLLOW, &nd);
222 D1(printk(KERN_DEBUG "jffs2_get_sb(): path_lookup() returned %d, inode %p\n",
223 err, nd.dentry->d_inode));
230 if (!S_ISBLK(nd.dentry->d_inode->i_mode))
233 if (nd.mnt->mnt_flags & MNT_NODEV) {
238 if (imajor(nd.dentry->d_inode) != MTD_BLOCK_MAJOR) {
239 if (!(flags & MS_VERBOSE)) /* Yes I mean this. Strangely */
240 printk(KERN_NOTICE "Attempt to mount non-MTD device \"%s\" as JFFS2\n",
245 mtdnr = iminor(nd.dentry->d_inode);
248 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr);
255 static void jffs2_put_super (struct super_block *sb)
257 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
259 D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));
261 if (!(sb->s_flags & MS_RDONLY))
262 jffs2_stop_garbage_collect_thread(c);
264 jffs2_flush_wbuf_pad(c);
266 jffs2_free_ino_caches(c);
267 jffs2_free_raw_node_refs(c);
269 jffs2_nand_flash_cleanup(c);
270 kfree(c->inocache_list);
272 c->mtd->sync(c->mtd);
274 D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
277 static void jffs2_kill_sb(struct super_block *sb)
279 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
280 generic_shutdown_super(sb);
281 put_mtd_device(c->mtd);
285 static struct file_system_type jffs2_fs_type = {
286 .owner = THIS_MODULE,
288 .get_sb = jffs2_get_sb,
289 .kill_sb = jffs2_kill_sb,
292 static int __init init_jffs2_fs(void)
296 printk(KERN_INFO "JFFS2 version 2.2."
297 #ifdef CONFIG_FS_JFFS2_NAND
300 " (C) 2001-2003 Red Hat, Inc.\n");
302 jffs2_inode_cachep = kmem_cache_create("jffs2_i",
303 sizeof(struct jffs2_inode_info),
304 0, SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT,
305 jffs2_i_init_once, NULL);
306 if (!jffs2_inode_cachep) {
307 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n");
310 ret = jffs2_zlib_init();
312 printk(KERN_ERR "JFFS2 error: Failed to initialise zlib workspaces\n");
315 ret = jffs2_create_slab_caches();
317 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
320 ret = register_filesystem(&jffs2_fs_type);
322 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n");
328 jffs2_destroy_slab_caches();
335 static void __exit exit_jffs2_fs(void)
337 unregister_filesystem(&jffs2_fs_type);
338 jffs2_destroy_slab_caches();
340 kmem_cache_destroy(jffs2_inode_cachep);
343 module_init(init_jffs2_fs);
344 module_exit(exit_jffs2_fs);
346 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
347 MODULE_AUTHOR("Red Hat, Inc.");
348 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
349 // the sake of this tag. It's Free Software.