[net-next-2.6.git] / fs / jffs2 / super.c

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2001-2007 Red Hat, Inc.
 *
 * Created by David Woodhouse <dwmw2@infradead.org>
 *
 * 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_destroy_inode(struct inode *inode)
{
	kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
}

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 int jffs2_sync_fs(struct super_block *sb, int wait)
{
	struct jffs2_sb_info *c = JFFS2_SB_INFO(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 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,
	.clear_inode =	jffs2_clear_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;

	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
	return jffs2_do_fill_super(sb, data, silent);
}

static int jffs2_get_sb(struct file_system_type *fs_type,
			int flags, const char *dev_name,
			void *data, struct vfsmount *mnt)
{
	return get_sb_mtd(fs_type, flags, dev_name, data, jffs2_fill_super,
			  mnt);
}

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"));

	lock_kernel();

	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);

	unlock_kernel();

	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",
	.get_sb =	jffs2_get_sb,
	.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 <dwmw2@infradead.org>
	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	}
	42
	43	static void jffs2_destroy_inode(struct inode *inode)
	44	{
	45	kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
	46	}
	47
51cc5068	48	static void jffs2_i_init_once(void *foo)
1da177e4	49	{
4e571aba	50	struct jffs2_inode_info *f = foo;
1da177e4	51
4e571aba DW	52	mutex_init(&f->sem);
4e571aba DW	53	inode_init_once(&f->vfs_inode);
1da177e4 LT	54	}
	55
	56	static int jffs2_sync_fs(struct super_block *sb, int wait)
	57	{
	58	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
	59
ced22070	60	mutex_lock(&c->alloc_sem);
1da177e4	61	jffs2_flush_wbuf_pad(c);
ced22070	62	mutex_unlock(&c->alloc_sem);
1da177e4 LT	63	return 0;
	64	}
	65
5f556aab DW	66	static struct inode jffs2_nfs_get_inode(struct super_block sb, uint64_t ino,
	67	uint32_t generation)
	68	{
	69	/* We don't care about i_generation. We'll destroy the flash
	70	before we start re-using inode numbers anyway. And even
	71	if that wasn't true, we'd have other problems...*/
	72	return jffs2_iget(sb, ino);
	73	}
	74
	75	static struct dentry jffs2_fh_to_dentry(struct super_block sb, struct fid *fid,
	76	int fh_len, int fh_type)
	77	{
	78	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
	79	jffs2_nfs_get_inode);
	80	}
	81
	82	static struct dentry jffs2_fh_to_parent(struct super_block sb, struct fid *fid,
	83	int fh_len, int fh_type)
	84	{
	85	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
	86	jffs2_nfs_get_inode);
	87	}
	88
	89	static struct dentry jffs2_get_parent(struct dentry child)
	90	{
	91	struct jffs2_inode_info *f;
	92	uint32_t pino;
	93
	94	BUG_ON(!S_ISDIR(child->d_inode->i_mode));
	95
	96	f = JFFS2_INODE_INFO(child->d_inode);
	97
	98	pino = f->inocache->pino_nlink;
	99
	100	JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
	101	f->inocache->ino, pino);
	102
	103	return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino));
	104	}
	105
	106	static struct export_operations jffs2_export_ops = {
	107	.get_parent = jffs2_get_parent,
	108	.fh_to_dentry = jffs2_fh_to_dentry,
	109	.fh_to_parent = jffs2_fh_to_parent,
	110	};
	111
ee9b6d61	112	static const struct super_operations jffs2_super_operations =
1da177e4 LT	113	{
	114	.alloc_inode = jffs2_alloc_inode,
	115	.destroy_inode =jffs2_destroy_inode,
1da177e4 LT	116	.put_super = jffs2_put_super,
	117	.write_super = jffs2_write_super,
	118	.statfs = jffs2_statfs,
	119	.remount_fs = jffs2_remount_fs,
	120	.clear_inode = jffs2_clear_inode,
	121	.dirty_inode = jffs2_dirty_inode,
	122	.sync_fs = jffs2_sync_fs,
	123	};
	124
acaebfd8 DH	125	/*
	126	* fill in the superblock
	127	*/
	128	static int jffs2_fill_super(struct super_block sb, void data, int silent)
1da177e4	129	{
1da177e4	130	struct jffs2_sb_info *c;
acaebfd8 DH	131
	132	D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():"
	133	" New superblock for device %d (\"%s\")\n",
	134	sb->s_mtd->index, sb->s_mtd->name));
1da177e4	135
f8314dc6	136	c = kzalloc(sizeof(*c), GFP_KERNEL);
1da177e4	137	if (!c)
454e2398	138	return -ENOMEM;
1da177e4	139
acaebfd8 DH	140	c->mtd = sb->s_mtd;
	141	c->os_priv = sb;
	142	sb->s_fs_info = c;
1da177e4	143
acaebfd8 DH	144	/* Initialize JFFS2 superblock locks, the further initialization will
acaebfd8 DH	145	* be done later */
ced22070 DW	146	mutex_init(&c->alloc_sem);
ced22070 DW	147	mutex_init(&c->erase_free_sem);
b6220598 AB	148	init_waitqueue_head(&c->erase_wait);
	149	init_waitqueue_head(&c->inocache_wq);
	150	spin_lock_init(&c->erase_completion_lock);
	151	spin_lock_init(&c->inocache_lock);
	152
1da177e4	153	sb->s_op = &jffs2_super_operations;
5f556aab	154	sb->s_export_op = &jffs2_export_ops;
acaebfd8	155	sb->s_flags = sb->s_flags \| MS_NOATIME;
aa98d7cf KK	156	sb->s_xattr = jffs2_xattr_handlers;
	157	#ifdef CONFIG_JFFS2_FS_POSIX_ACL
	158	sb->s_flags \|= MS_POSIXACL;
	159	#endif
acaebfd8	160	return jffs2_do_fill_super(sb, data, silent);
1da177e4 LT	161	}
1da177e4 LT	162
454e2398 DH	163	static int jffs2_get_sb(struct file_system_type *fs_type,
	164	int flags, const char *dev_name,
	165	void data, struct vfsmount mnt)
1da177e4	166	{
acaebfd8 DH	167	return get_sb_mtd(fs_type, flags, dev_name, data, jffs2_fill_super,
acaebfd8 DH	168	mnt);
1da177e4 LT	169	}
	170
	171	static void jffs2_put_super (struct super_block *sb)
	172	{
	173	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
	174
	175	D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));
	176
6cfd0148 CH	177	lock_kernel();
6cfd0148 CH	178
8c85e125 CH	179	if (sb->s_dirt)
	180	jffs2_write_super(sb);
	181
ced22070	182	mutex_lock(&c->alloc_sem);
1da177e4	183	jffs2_flush_wbuf_pad(c);
ced22070	184	mutex_unlock(&c->alloc_sem);
e631ddba FH	185
	186	jffs2_sum_exit(c);
	187
1da177e4 LT	188	jffs2_free_ino_caches(c);
1da177e4 LT	189	jffs2_free_raw_node_refs(c);
4ce1f562	190	if (jffs2_blocks_use_vmalloc(c))
1da177e4 LT	191	vfree(c->blocks);
	192	else
	193	kfree(c->blocks);
	194	jffs2_flash_cleanup(c);
	195	kfree(c->inocache_list);
aa98d7cf	196	jffs2_clear_xattr_subsystem(c);
1da177e4 LT	197	if (c->mtd->sync)
	198	c->mtd->sync(c->mtd);
	199
6cfd0148 CH	200	unlock_kernel();
6cfd0148 CH	201
1da177e4 LT	202	D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
	203	}
	204
	205	static void jffs2_kill_sb(struct super_block *sb)
	206	{
	207	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
a69dde91 AB	208	if (!(sb->s_flags & MS_RDONLY))
a69dde91 AB	209	jffs2_stop_garbage_collect_thread(c);
acaebfd8	210	kill_mtd_super(sb);
1da177e4 LT	211	kfree(c);
	212	}
	213
	214	static struct file_system_type jffs2_fs_type = {
	215	.owner = THIS_MODULE,
	216	.name = "jffs2",
	217	.get_sb = jffs2_get_sb,
	218	.kill_sb = jffs2_kill_sb,
	219	};
	220
	221	static int __init init_jffs2_fs(void)
	222	{
	223	int ret;
	224
3e68fbb5 DW	225	/* Paranoia checks for on-medium structures. If we ask GCC
	226	to pack them with __attribute__((packed)) then it _also_
	227	assumes that they're not aligned -- so it emits crappy
	228	code on some architectures. Ideally we want an attribute
	229	which means just 'no padding', without the alignment
	230	thing. But GCC doesn't have that -- we have to just
	231	hope the structs are the right sizes, instead. */
2ecd05ae AD	232	BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
	233	BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
	234	BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
	235	BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
3e68fbb5	236
1da177e4	237	printk(KERN_INFO "JFFS2 version 2.2."
2f82ce1e	238	#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
1da177e4	239	" (NAND)"
e631ddba FH	240	#endif
	241	#ifdef CONFIG_JFFS2_SUMMARY
	242	" (SUMMARY) "
1da177e4	243	#endif
c00c310e	244	" © 2001-2006 Red Hat, Inc.\n");
1da177e4 LT	245
	246	jffs2_inode_cachep = kmem_cache_create("jffs2_i",
	247	sizeof(struct jffs2_inode_info),
fffb60f9 PJ	248	0, (SLAB_RECLAIM_ACCOUNT\|
fffb60f9 PJ	249	SLAB_MEM_SPREAD),
20c2df83	250	jffs2_i_init_once);
1da177e4 LT	251	if (!jffs2_inode_cachep) {
	252	printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n");
	253	return -ENOMEM;
	254	}
	255	ret = jffs2_compressors_init();
	256	if (ret) {
	257	printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n");
	258	goto out;
	259	}
	260	ret = jffs2_create_slab_caches();
	261	if (ret) {
	262	printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
	263	goto out_compressors;
	264	}
	265	ret = register_filesystem(&jffs2_fs_type);
	266	if (ret) {
	267	printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n");
	268	goto out_slab;
	269	}
	270	return 0;
	271
	272	out_slab:
	273	jffs2_destroy_slab_caches();
	274	out_compressors:
	275	jffs2_compressors_exit();
	276	out:
	277	kmem_cache_destroy(jffs2_inode_cachep);
	278	return ret;
	279	}
	280
	281	static void __exit exit_jffs2_fs(void)
	282	{
	283	unregister_filesystem(&jffs2_fs_type);
	284	jffs2_destroy_slab_caches();
	285	jffs2_compressors_exit();
	286	kmem_cache_destroy(jffs2_inode_cachep);
	287	}
	288
	289	module_init(init_jffs2_fs);
	290	module_exit(exit_jffs2_fs);
	291
	292	MODULE_DESCRIPTION("The Journalling Flash File System, v2");
	293	MODULE_AUTHOR("Red Hat, Inc.");
182ec4ee	294	MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
1da177e4	295	// the sake of this tag. It's Free Software.