[linux.git] / fs / jffs2 / super.c

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2001-2007 Red Hat, Inc.
 *
 * Created by David Woodhouse <[email protected]>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/fs.h>
#include <linux/err.h>
#include <linux/mount.h>
#include <linux/jffs2.h>
#include <linux/pagemap.h>
#include <linux/mtd/super.h>
#include <linux/ctype.h>
#include <linux/namei.h>
#include <linux/exportfs.h>
#include "compr.h"
#include "nodelist.h"

static void jffs2_put_super(struct super_block *);

static struct kmem_cache *jffs2_inode_cachep;

static struct inode *jffs2_alloc_inode(struct super_block *sb)
{
	struct jffs2_inode_info *f;

	f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
	if (!f)
		return NULL;
	return &f->vfs_inode;
}

static void jffs2_i_callback(struct rcu_head *head)
{
	struct inode *inode = container_of(head, struct inode, i_rcu);
	INIT_LIST_HEAD(&inode->i_dentry);
	kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
}

static void jffs2_destroy_inode(struct inode *inode)
{
	call_rcu(&inode->i_rcu, jffs2_i_callback);
}

static void jffs2_i_init_once(void *foo)
{
	struct jffs2_inode_info *f = foo;

	mutex_init(&f->sem);
	inode_init_once(&f->vfs_inode);
}

static void jffs2_write_super(struct super_block *sb)
{
	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);

	lock_super(sb);
	sb->s_dirt = 0;

	if (!(sb->s_flags & MS_RDONLY)) {
		D1(printk(KERN_DEBUG "jffs2_write_super()\n"));
		jffs2_flush_wbuf_gc(c, 0);
	}

	unlock_super(sb);
}

static int jffs2_sync_fs(struct super_block *sb, int wait)
{
	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);

	jffs2_write_super(sb);

	mutex_lock(&c->alloc_sem);
	jffs2_flush_wbuf_pad(c);
	mutex_unlock(&c->alloc_sem);
	return 0;
}

static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
					 uint32_t generation)
{
	/* We don't care about i_generation. We'll destroy the flash
	   before we start re-using inode numbers anyway. And even
	   if that wasn't true, we'd have other problems...*/
	return jffs2_iget(sb, ino);
}

static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
					 int fh_len, int fh_type)
{
        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
                                    jffs2_nfs_get_inode);
}

static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid,
					 int fh_len, int fh_type)
{
        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
                                    jffs2_nfs_get_inode);
}

static struct dentry *jffs2_get_parent(struct dentry *child)
{
	struct jffs2_inode_info *f;
	uint32_t pino;

	BUG_ON(!S_ISDIR(child->d_inode->i_mode));

	f = JFFS2_INODE_INFO(child->d_inode);

	pino = f->inocache->pino_nlink;

	JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
		    f->inocache->ino, pino);

	return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino));
}

static const struct export_operations jffs2_export_ops = {
	.get_parent = jffs2_get_parent,
	.fh_to_dentry = jffs2_fh_to_dentry,
	.fh_to_parent = jffs2_fh_to_parent,
};

static const struct super_operations jffs2_super_operations =
{
	.alloc_inode =	jffs2_alloc_inode,
	.destroy_inode =jffs2_destroy_inode,
	.put_super =	jffs2_put_super,
	.write_super =	jffs2_write_super,
	.statfs =	jffs2_statfs,
	.remount_fs =	jffs2_remount_fs,
	.evict_inode =	jffs2_evict_inode,
	.dirty_inode =	jffs2_dirty_inode,
	.sync_fs =	jffs2_sync_fs,
};

/*
 * fill in the superblock
 */
static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
{
	struct jffs2_sb_info *c;
	int ret;

	D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():"
		  " New superblock for device %d (\"%s\")\n",
		  sb->s_mtd->index, sb->s_mtd->name));

	c = kzalloc(sizeof(*c), GFP_KERNEL);
	if (!c)
		return -ENOMEM;

	c->mtd = sb->s_mtd;
	c->os_priv = sb;
	sb->s_fs_info = c;

	/* Initialize JFFS2 superblock locks, the further initialization will
	 * be done later */
	mutex_init(&c->alloc_sem);
	mutex_init(&c->erase_free_sem);
	init_waitqueue_head(&c->erase_wait);
	init_waitqueue_head(&c->inocache_wq);
	spin_lock_init(&c->erase_completion_lock);
	spin_lock_init(&c->inocache_lock);

	sb->s_op = &jffs2_super_operations;
	sb->s_export_op = &jffs2_export_ops;
	sb->s_flags = sb->s_flags | MS_NOATIME;
	sb->s_xattr = jffs2_xattr_handlers;
#ifdef CONFIG_JFFS2_FS_POSIX_ACL
	sb->s_flags |= MS_POSIXACL;
#endif
	ret = jffs2_do_fill_super(sb, data, silent);
	return ret;
}

static struct dentry *jffs2_mount(struct file_system_type *fs_type,
			int flags, const char *dev_name,
			void *data)
{
	return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super);
}

static void jffs2_put_super (struct super_block *sb)
{
	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);

	D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));

	if (sb->s_dirt)
		jffs2_write_super(sb);

	mutex_lock(&c->alloc_sem);
	jffs2_flush_wbuf_pad(c);
	mutex_unlock(&c->alloc_sem);

	jffs2_sum_exit(c);

	jffs2_free_ino_caches(c);
	jffs2_free_raw_node_refs(c);
	if (jffs2_blocks_use_vmalloc(c))
		vfree(c->blocks);
	else
		kfree(c->blocks);
	jffs2_flash_cleanup(c);
	kfree(c->inocache_list);
	jffs2_clear_xattr_subsystem(c);
	if (c->mtd->sync)
		c->mtd->sync(c->mtd);

	D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
}

static void jffs2_kill_sb(struct super_block *sb)
{
	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
	if (!(sb->s_flags & MS_RDONLY))
		jffs2_stop_garbage_collect_thread(c);
	kill_mtd_super(sb);
	kfree(c);
}

static struct file_system_type jffs2_fs_type = {
	.owner =	THIS_MODULE,
	.name =		"jffs2",
	.mount =	jffs2_mount,
	.kill_sb =	jffs2_kill_sb,
};

static int __init init_jffs2_fs(void)
{
	int ret;

	/* Paranoia checks for on-medium structures. If we ask GCC
	   to pack them with __attribute__((packed)) then it _also_
	   assumes that they're not aligned -- so it emits crappy
	   code on some architectures. Ideally we want an attribute
	   which means just 'no padding', without the alignment
	   thing. But GCC doesn't have that -- we have to just
	   hope the structs are the right sizes, instead. */
	BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
	BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
	BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
	BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);

	printk(KERN_INFO "JFFS2 version 2.2."
#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
	       " (NAND)"
#endif
#ifdef CONFIG_JFFS2_SUMMARY
	       " (SUMMARY) "
#endif
	       " © 2001-2006 Red Hat, Inc.\n");

	jffs2_inode_cachep = kmem_cache_create("jffs2_i",
					     sizeof(struct jffs2_inode_info),
					     0, (SLAB_RECLAIM_ACCOUNT|
						SLAB_MEM_SPREAD),
					     jffs2_i_init_once);
	if (!jffs2_inode_cachep) {
		printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n");
		return -ENOMEM;
	}
	ret = jffs2_compressors_init();
	if (ret) {
		printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n");
		goto out;
	}
	ret = jffs2_create_slab_caches();
	if (ret) {
		printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
		goto out_compressors;
	}
	ret = register_filesystem(&jffs2_fs_type);
	if (ret) {
		printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n");
		goto out_slab;
	}
	return 0;

 out_slab:
	jffs2_destroy_slab_caches();
 out_compressors:
	jffs2_compressors_exit();
 out:
	kmem_cache_destroy(jffs2_inode_cachep);
	return ret;
}

static void __exit exit_jffs2_fs(void)
{
	unregister_filesystem(&jffs2_fs_type);
	jffs2_destroy_slab_caches();
	jffs2_compressors_exit();
	kmem_cache_destroy(jffs2_inode_cachep);
}

module_init(init_jffs2_fs);
module_exit(exit_jffs2_fs);

MODULE_DESCRIPTION("The Journalling Flash File System, v2");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
		       // the sake of this tag. It's Free Software.
Commit	Line	Data
1da177e4 LT	1	/*
	2	* JFFS2 -- Journalling Flash File System, Version 2.
	3	*
c00c310e	4	* Copyright © 2001-2007 Red Hat, Inc.
1da177e4 LT	5	*
	6	* Created by David Woodhouse <[email protected]>
	7	*
	8	* For licensing information, see the file 'LICENCE' in this directory.
	9	*
1da177e4 LT	10	*/
1da177e4 LT	11
1da177e4 LT	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>
9c74034f	18	#include <linux/err.h>
1da177e4 LT	19	#include <linux/mount.h>
	20	#include <linux/jffs2.h>
	21	#include <linux/pagemap.h>
acaebfd8	22	#include <linux/mtd/super.h>
1da177e4 LT	23	#include <linux/ctype.h>
1da177e4 LT	24	#include <linux/namei.h>
5f556aab	25	#include <linux/exportfs.h>
1da177e4 LT	26	#include "compr.h"
	27	#include "nodelist.h"
	28
	29	static void jffs2_put_super(struct super_block *);
	30
e18b890b	31	static struct kmem_cache *jffs2_inode_cachep;
1da177e4 LT	32
	33	static struct inode jffs2_alloc_inode(struct super_block sb)
	34	{
4e571aba DW	35	struct jffs2_inode_info *f;
	36
	37	f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
	38	if (!f)
1da177e4	39	return NULL;
4e571aba	40	return &f->vfs_inode;
1da177e4 LT	41	}
1da177e4 LT	42
fa0d7e3d	43	static void jffs2_i_callback(struct rcu_head *head)
1da177e4	44	{
fa0d7e3d NP	45	struct inode *inode = container_of(head, struct inode, i_rcu);
fa0d7e3d NP	46	INIT_LIST_HEAD(&inode->i_dentry);
1da177e4 LT	47	kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
	48	}
	49
fa0d7e3d NP	50	static void jffs2_destroy_inode(struct inode *inode)
	51	{
	52	call_rcu(&inode->i_rcu, jffs2_i_callback);
	53	}
	54
51cc5068	55	static void jffs2_i_init_once(void *foo)
1da177e4	56	{
4e571aba	57	struct jffs2_inode_info *f = foo;
1da177e4	58
4e571aba DW	59	mutex_init(&f->sem);
4e571aba DW	60	inode_init_once(&f->vfs_inode);
1da177e4 LT	61	}
1da177e4 LT	62
01ba6875 CH	63	static void jffs2_write_super(struct super_block *sb)
	64	{
	65	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
ebc1ac16 CH	66
ebc1ac16 CH	67	lock_super(sb);
01ba6875 CH	68	sb->s_dirt = 0;
01ba6875 CH	69
ebc1ac16 CH	70	if (!(sb->s_flags & MS_RDONLY)) {
ebc1ac16 CH	71	D1(printk(KERN_DEBUG "jffs2_write_super()\n"));
ebc1ac16 CH	72	jffs2_flush_wbuf_gc(c, 0);
ebc1ac16 CH	73	}
01ba6875	74
ebc1ac16	75	unlock_super(sb);
01ba6875 CH	76	}
01ba6875 CH	77
1da177e4 LT	78	static int jffs2_sync_fs(struct super_block *sb, int wait)
	79	{
	80	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
	81
d579ed00 CH	82	jffs2_write_super(sb);
d579ed00 CH	83
ced22070	84	mutex_lock(&c->alloc_sem);
1da177e4	85	jffs2_flush_wbuf_pad(c);
ced22070	86	mutex_unlock(&c->alloc_sem);
1da177e4 LT	87	return 0;
	88	}
	89
5f556aab DW	90	static struct inode jffs2_nfs_get_inode(struct super_block sb, uint64_t ino,
	91	uint32_t generation)
	92	{
	93	/* We don't care about i_generation. We'll destroy the flash
	94	before we start re-using inode numbers anyway. And even
	95	if that wasn't true, we'd have other problems...*/
	96	return jffs2_iget(sb, ino);
	97	}
	98
	99	static struct dentry jffs2_fh_to_dentry(struct super_block sb, struct fid *fid,
	100	int fh_len, int fh_type)
	101	{
	102	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
	103	jffs2_nfs_get_inode);
	104	}
	105
	106	static struct dentry jffs2_fh_to_parent(struct super_block sb, struct fid *fid,
	107	int fh_len, int fh_type)
	108	{
	109	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
	110	jffs2_nfs_get_inode);
	111	}
	112
	113	static struct dentry jffs2_get_parent(struct dentry child)
	114	{
	115	struct jffs2_inode_info *f;
	116	uint32_t pino;
	117
	118	BUG_ON(!S_ISDIR(child->d_inode->i_mode));
	119
	120	f = JFFS2_INODE_INFO(child->d_inode);
	121
	122	pino = f->inocache->pino_nlink;
	123
	124	JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
	125	f->inocache->ino, pino);
	126
	127	return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino));
	128	}
	129
ac4cfdd6	130	static const struct export_operations jffs2_export_ops = {
5f556aab DW	131	.get_parent = jffs2_get_parent,
	132	.fh_to_dentry = jffs2_fh_to_dentry,
	133	.fh_to_parent = jffs2_fh_to_parent,
	134	};
	135
ee9b6d61	136	static const struct super_operations jffs2_super_operations =
1da177e4 LT	137	{
	138	.alloc_inode = jffs2_alloc_inode,
	139	.destroy_inode =jffs2_destroy_inode,
1da177e4 LT	140	.put_super = jffs2_put_super,
	141	.write_super = jffs2_write_super,
	142	.statfs = jffs2_statfs,
	143	.remount_fs = jffs2_remount_fs,
b57922d9	144	.evict_inode = jffs2_evict_inode,
1da177e4 LT	145	.dirty_inode = jffs2_dirty_inode,
	146	.sync_fs = jffs2_sync_fs,
	147	};
	148
acaebfd8 DH	149	/*
	150	* fill in the superblock
	151	*/
	152	static int jffs2_fill_super(struct super_block sb, void data, int silent)
1da177e4	153	{
1da177e4	154	struct jffs2_sb_info *c;
db719222 JB	155	int ret;
db719222 JB	156
acaebfd8 DH	157	D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():"
	158	" New superblock for device %d (\"%s\")\n",
	159	sb->s_mtd->index, sb->s_mtd->name));
1da177e4	160
f8314dc6	161	c = kzalloc(sizeof(*c), GFP_KERNEL);
1a028dd2	162	if (!c)
454e2398	163	return -ENOMEM;
1da177e4	164
acaebfd8 DH	165	c->mtd = sb->s_mtd;
	166	c->os_priv = sb;
	167	sb->s_fs_info = c;
1da177e4	168
acaebfd8 DH	169	/* Initialize JFFS2 superblock locks, the further initialization will
acaebfd8 DH	170	* be done later */
ced22070 DW	171	mutex_init(&c->alloc_sem);
ced22070 DW	172	mutex_init(&c->erase_free_sem);
b6220598 AB	173	init_waitqueue_head(&c->erase_wait);
	174	init_waitqueue_head(&c->inocache_wq);
	175	spin_lock_init(&c->erase_completion_lock);
	176	spin_lock_init(&c->inocache_lock);
	177
1da177e4	178	sb->s_op = &jffs2_super_operations;
5f556aab	179	sb->s_export_op = &jffs2_export_ops;
acaebfd8	180	sb->s_flags = sb->s_flags \| MS_NOATIME;
aa98d7cf KK	181	sb->s_xattr = jffs2_xattr_handlers;
	182	#ifdef CONFIG_JFFS2_FS_POSIX_ACL
	183	sb->s_flags \|= MS_POSIXACL;
	184	#endif
db719222	185	ret = jffs2_do_fill_super(sb, data, silent);
db719222	186	return ret;
1da177e4 LT	187	}
1da177e4 LT	188
848b83a5	189	static struct dentry jffs2_mount(struct file_system_type fs_type,
454e2398	190	int flags, const char *dev_name,
848b83a5	191	void *data)
1da177e4	192	{
848b83a5	193	return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super);
1da177e4 LT	194	}
	195
	196	static void jffs2_put_super (struct super_block *sb)
	197	{
	198	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
	199
	200	D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));
	201
8c85e125 CH	202	if (sb->s_dirt)
	203	jffs2_write_super(sb);
	204
ced22070	205	mutex_lock(&c->alloc_sem);
1da177e4	206	jffs2_flush_wbuf_pad(c);
ced22070	207	mutex_unlock(&c->alloc_sem);
e631ddba FH	208
	209	jffs2_sum_exit(c);
	210
1da177e4 LT	211	jffs2_free_ino_caches(c);
1da177e4 LT	212	jffs2_free_raw_node_refs(c);
4ce1f562	213	if (jffs2_blocks_use_vmalloc(c))
1da177e4 LT	214	vfree(c->blocks);
	215	else
	216	kfree(c->blocks);
	217	jffs2_flash_cleanup(c);
	218	kfree(c->inocache_list);
aa98d7cf	219	jffs2_clear_xattr_subsystem(c);
1da177e4 LT	220	if (c->mtd->sync)
	221	c->mtd->sync(c->mtd);
	222
	223	D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
	224	}
	225
	226	static void jffs2_kill_sb(struct super_block *sb)
	227	{
	228	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
a69dde91 AB	229	if (!(sb->s_flags & MS_RDONLY))
a69dde91 AB	230	jffs2_stop_garbage_collect_thread(c);
acaebfd8	231	kill_mtd_super(sb);
1da177e4 LT	232	kfree(c);
	233	}
	234
	235	static struct file_system_type jffs2_fs_type = {
	236	.owner = THIS_MODULE,
	237	.name = "jffs2",
848b83a5	238	.mount = jffs2_mount,
1da177e4 LT	239	.kill_sb = jffs2_kill_sb,
	240	};
	241
	242	static int __init init_jffs2_fs(void)
	243	{
	244	int ret;
	245
3e68fbb5 DW	246	/* Paranoia checks for on-medium structures. If we ask GCC
	247	to pack them with __attribute__((packed)) then it _also_
	248	assumes that they're not aligned -- so it emits crappy
	249	code on some architectures. Ideally we want an attribute
	250	which means just 'no padding', without the alignment
	251	thing. But GCC doesn't have that -- we have to just
	252	hope the structs are the right sizes, instead. */
2ecd05ae AD	253	BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
	254	BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
	255	BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
	256	BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
3e68fbb5	257
1da177e4	258	printk(KERN_INFO "JFFS2 version 2.2."
2f82ce1e	259	#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
1da177e4	260	" (NAND)"
e631ddba FH	261	#endif
	262	#ifdef CONFIG_JFFS2_SUMMARY
	263	" (SUMMARY) "
1da177e4	264	#endif
c00c310e	265	" © 2001-2006 Red Hat, Inc.\n");
1da177e4 LT	266
	267	jffs2_inode_cachep = kmem_cache_create("jffs2_i",
	268	sizeof(struct jffs2_inode_info),
fffb60f9 PJ	269	0, (SLAB_RECLAIM_ACCOUNT\|
fffb60f9 PJ	270	SLAB_MEM_SPREAD),
20c2df83	271	jffs2_i_init_once);
1da177e4 LT	272	if (!jffs2_inode_cachep) {
	273	printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n");
	274	return -ENOMEM;
	275	}
	276	ret = jffs2_compressors_init();
	277	if (ret) {
	278	printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n");
	279	goto out;
	280	}
	281	ret = jffs2_create_slab_caches();
	282	if (ret) {
	283	printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
	284	goto out_compressors;
	285	}
	286	ret = register_filesystem(&jffs2_fs_type);
	287	if (ret) {
	288	printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n");
	289	goto out_slab;
	290	}
	291	return 0;
	292
	293	out_slab:
	294	jffs2_destroy_slab_caches();
	295	out_compressors:
	296	jffs2_compressors_exit();
	297	out:
	298	kmem_cache_destroy(jffs2_inode_cachep);
	299	return ret;
	300	}
	301
	302	static void __exit exit_jffs2_fs(void)
	303	{
	304	unregister_filesystem(&jffs2_fs_type);
	305	jffs2_destroy_slab_caches();
	306	jffs2_compressors_exit();
	307	kmem_cache_destroy(jffs2_inode_cachep);
	308	}
	309
	310	module_init(init_jffs2_fs);
	311	module_exit(exit_jffs2_fs);
	312
	313	MODULE_DESCRIPTION("The Journalling Flash File System, v2");
	314	MODULE_AUTHOR("Red Hat, Inc.");
182ec4ee	315	MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
1da177e4	316	// the sake of this tag. It's Free Software.