[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/smp_lock.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 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,
	.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>
405f5571	15	#include <linux/smp_lock.h>
1da177e4 LT	16	#include <linux/init.h>
	17	#include <linux/list.h>
	18	#include <linux/fs.h>
9c74034f	19	#include <linux/err.h>
1da177e4 LT	20	#include <linux/mount.h>
	21	#include <linux/jffs2.h>
	22	#include <linux/pagemap.h>
acaebfd8	23	#include <linux/mtd/super.h>
1da177e4 LT	24	#include <linux/ctype.h>
1da177e4 LT	25	#include <linux/namei.h>
5f556aab	26	#include <linux/exportfs.h>
1da177e4 LT	27	#include "compr.h"
	28	#include "nodelist.h"
	29
	30	static void jffs2_put_super(struct super_block *);
	31
e18b890b	32	static struct kmem_cache *jffs2_inode_cachep;
1da177e4 LT	33
	34	static struct inode jffs2_alloc_inode(struct super_block sb)
	35	{
4e571aba DW	36	struct jffs2_inode_info *f;
	37
	38	f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
	39	if (!f)
1da177e4	40	return NULL;
4e571aba	41	return &f->vfs_inode;
1da177e4 LT	42	}
	43
	44	static void jffs2_destroy_inode(struct inode *inode)
	45	{
	46	kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
	47	}
	48
51cc5068	49	static void jffs2_i_init_once(void *foo)
1da177e4	50	{
4e571aba	51	struct jffs2_inode_info *f = foo;
1da177e4	52
4e571aba DW	53	mutex_init(&f->sem);
4e571aba DW	54	inode_init_once(&f->vfs_inode);
1da177e4 LT	55	}
1da177e4 LT	56
01ba6875 CH	57	static void jffs2_write_super(struct super_block *sb)
	58	{
	59	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
ebc1ac16 CH	60
ebc1ac16 CH	61	lock_super(sb);
01ba6875 CH	62	sb->s_dirt = 0;
01ba6875 CH	63
ebc1ac16 CH	64	if (!(sb->s_flags & MS_RDONLY)) {
ebc1ac16 CH	65	D1(printk(KERN_DEBUG "jffs2_write_super()\n"));
ebc1ac16 CH	66	jffs2_flush_wbuf_gc(c, 0);
ebc1ac16 CH	67	}
01ba6875	68
ebc1ac16	69	unlock_super(sb);
01ba6875 CH	70	}
01ba6875 CH	71
1da177e4 LT	72	static int jffs2_sync_fs(struct super_block *sb, int wait)
	73	{
	74	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
	75
d579ed00 CH	76	jffs2_write_super(sb);
d579ed00 CH	77
ced22070	78	mutex_lock(&c->alloc_sem);
1da177e4	79	jffs2_flush_wbuf_pad(c);
ced22070	80	mutex_unlock(&c->alloc_sem);
1da177e4 LT	81	return 0;
	82	}
	83
5f556aab DW	84	static struct inode jffs2_nfs_get_inode(struct super_block sb, uint64_t ino,
	85	uint32_t generation)
	86	{
	87	/* We don't care about i_generation. We'll destroy the flash
	88	before we start re-using inode numbers anyway. And even
	89	if that wasn't true, we'd have other problems...*/
	90	return jffs2_iget(sb, ino);
	91	}
	92
	93	static struct dentry jffs2_fh_to_dentry(struct super_block sb, struct fid *fid,
	94	int fh_len, int fh_type)
	95	{
	96	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
	97	jffs2_nfs_get_inode);
	98	}
	99
	100	static struct dentry jffs2_fh_to_parent(struct super_block sb, struct fid *fid,
	101	int fh_len, int fh_type)
	102	{
	103	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
	104	jffs2_nfs_get_inode);
	105	}
	106
	107	static struct dentry jffs2_get_parent(struct dentry child)
	108	{
	109	struct jffs2_inode_info *f;
	110	uint32_t pino;
	111
	112	BUG_ON(!S_ISDIR(child->d_inode->i_mode));
	113
	114	f = JFFS2_INODE_INFO(child->d_inode);
	115
	116	pino = f->inocache->pino_nlink;
	117
	118	JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
	119	f->inocache->ino, pino);
	120
	121	return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino));
	122	}
	123
ac4cfdd6	124	static const struct export_operations jffs2_export_ops = {
5f556aab DW	125	.get_parent = jffs2_get_parent,
	126	.fh_to_dentry = jffs2_fh_to_dentry,
	127	.fh_to_parent = jffs2_fh_to_parent,
	128	};
	129
ee9b6d61	130	static const struct super_operations jffs2_super_operations =
1da177e4 LT	131	{
	132	.alloc_inode = jffs2_alloc_inode,
	133	.destroy_inode =jffs2_destroy_inode,
1da177e4 LT	134	.put_super = jffs2_put_super,
	135	.write_super = jffs2_write_super,
	136	.statfs = jffs2_statfs,
	137	.remount_fs = jffs2_remount_fs,
	138	.clear_inode = jffs2_clear_inode,
	139	.dirty_inode = jffs2_dirty_inode,
	140	.sync_fs = jffs2_sync_fs,
	141	};
	142
acaebfd8 DH	143	/*
	144	* fill in the superblock
	145	*/
	146	static int jffs2_fill_super(struct super_block sb, void data, int silent)
1da177e4	147	{
1da177e4	148	struct jffs2_sb_info *c;
acaebfd8 DH	149
	150	D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():"
	151	" New superblock for device %d (\"%s\")\n",
	152	sb->s_mtd->index, sb->s_mtd->name));
1da177e4	153
f8314dc6	154	c = kzalloc(sizeof(*c), GFP_KERNEL);
1da177e4	155	if (!c)
454e2398	156	return -ENOMEM;
1da177e4	157
acaebfd8 DH	158	c->mtd = sb->s_mtd;
	159	c->os_priv = sb;
	160	sb->s_fs_info = c;
1da177e4	161
acaebfd8 DH	162	/* Initialize JFFS2 superblock locks, the further initialization will
acaebfd8 DH	163	* be done later */
ced22070 DW	164	mutex_init(&c->alloc_sem);
ced22070 DW	165	mutex_init(&c->erase_free_sem);
b6220598 AB	166	init_waitqueue_head(&c->erase_wait);
	167	init_waitqueue_head(&c->inocache_wq);
	168	spin_lock_init(&c->erase_completion_lock);
	169	spin_lock_init(&c->inocache_lock);
	170
1da177e4	171	sb->s_op = &jffs2_super_operations;
5f556aab	172	sb->s_export_op = &jffs2_export_ops;
acaebfd8	173	sb->s_flags = sb->s_flags \| MS_NOATIME;
aa98d7cf KK	174	sb->s_xattr = jffs2_xattr_handlers;
	175	#ifdef CONFIG_JFFS2_FS_POSIX_ACL
	176	sb->s_flags \|= MS_POSIXACL;
	177	#endif
acaebfd8	178	return jffs2_do_fill_super(sb, data, silent);
1da177e4 LT	179	}
1da177e4 LT	180
454e2398 DH	181	static int jffs2_get_sb(struct file_system_type *fs_type,
	182	int flags, const char *dev_name,
	183	void data, struct vfsmount mnt)
1da177e4	184	{
acaebfd8 DH	185	return get_sb_mtd(fs_type, flags, dev_name, data, jffs2_fill_super,
acaebfd8 DH	186	mnt);
1da177e4 LT	187	}
	188
	189	static void jffs2_put_super (struct super_block *sb)
	190	{
	191	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
	192
	193	D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));
	194
6cfd0148 CH	195	lock_kernel();
6cfd0148 CH	196
8c85e125 CH	197	if (sb->s_dirt)
	198	jffs2_write_super(sb);
	199
ced22070	200	mutex_lock(&c->alloc_sem);
1da177e4	201	jffs2_flush_wbuf_pad(c);
ced22070	202	mutex_unlock(&c->alloc_sem);
e631ddba FH	203
	204	jffs2_sum_exit(c);
	205
1da177e4 LT	206	jffs2_free_ino_caches(c);
1da177e4 LT	207	jffs2_free_raw_node_refs(c);
4ce1f562	208	if (jffs2_blocks_use_vmalloc(c))
1da177e4 LT	209	vfree(c->blocks);
	210	else
	211	kfree(c->blocks);
	212	jffs2_flash_cleanup(c);
	213	kfree(c->inocache_list);
aa98d7cf	214	jffs2_clear_xattr_subsystem(c);
1da177e4 LT	215	if (c->mtd->sync)
	216	c->mtd->sync(c->mtd);
	217
6cfd0148 CH	218	unlock_kernel();
6cfd0148 CH	219
1da177e4 LT	220	D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
	221	}
	222
	223	static void jffs2_kill_sb(struct super_block *sb)
	224	{
	225	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
a69dde91 AB	226	if (!(sb->s_flags & MS_RDONLY))
a69dde91 AB	227	jffs2_stop_garbage_collect_thread(c);
acaebfd8	228	kill_mtd_super(sb);
1da177e4 LT	229	kfree(c);
	230	}
	231
	232	static struct file_system_type jffs2_fs_type = {
	233	.owner = THIS_MODULE,
	234	.name = "jffs2",
	235	.get_sb = jffs2_get_sb,
	236	.kill_sb = jffs2_kill_sb,
	237	};
	238
	239	static int __init init_jffs2_fs(void)
	240	{
	241	int ret;
	242
3e68fbb5 DW	243	/* Paranoia checks for on-medium structures. If we ask GCC
	244	to pack them with __attribute__((packed)) then it _also_
	245	assumes that they're not aligned -- so it emits crappy
	246	code on some architectures. Ideally we want an attribute
	247	which means just 'no padding', without the alignment
	248	thing. But GCC doesn't have that -- we have to just
	249	hope the structs are the right sizes, instead. */
2ecd05ae AD	250	BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
	251	BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
	252	BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
	253	BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
3e68fbb5	254
1da177e4	255	printk(KERN_INFO "JFFS2 version 2.2."
2f82ce1e	256	#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
1da177e4	257	" (NAND)"
e631ddba FH	258	#endif
	259	#ifdef CONFIG_JFFS2_SUMMARY
	260	" (SUMMARY) "
1da177e4	261	#endif
c00c310e	262	" © 2001-2006 Red Hat, Inc.\n");
1da177e4 LT	263
	264	jffs2_inode_cachep = kmem_cache_create("jffs2_i",
	265	sizeof(struct jffs2_inode_info),
fffb60f9 PJ	266	0, (SLAB_RECLAIM_ACCOUNT\|
fffb60f9 PJ	267	SLAB_MEM_SPREAD),
20c2df83	268	jffs2_i_init_once);
1da177e4 LT	269	if (!jffs2_inode_cachep) {
	270	printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n");
	271	return -ENOMEM;
	272	}
	273	ret = jffs2_compressors_init();
	274	if (ret) {
	275	printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n");
	276	goto out;
	277	}
	278	ret = jffs2_create_slab_caches();
	279	if (ret) {
	280	printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
	281	goto out_compressors;
	282	}
	283	ret = register_filesystem(&jffs2_fs_type);
	284	if (ret) {
	285	printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n");
	286	goto out_slab;
	287	}
	288	return 0;
	289
	290	out_slab:
	291	jffs2_destroy_slab_caches();
	292	out_compressors:
	293	jffs2_compressors_exit();
	294	out:
	295	kmem_cache_destroy(jffs2_inode_cachep);
	296	return ret;
	297	}
	298
	299	static void __exit exit_jffs2_fs(void)
	300	{
	301	unregister_filesystem(&jffs2_fs_type);
	302	jffs2_destroy_slab_caches();
	303	jffs2_compressors_exit();
	304	kmem_cache_destroy(jffs2_inode_cachep);
	305	}
	306
	307	module_init(init_jffs2_fs);
	308	module_exit(exit_jffs2_fs);
	309
	310	MODULE_DESCRIPTION("The Journalling Flash File System, v2");
	311	MODULE_AUTHOR("Red Hat, Inc.");
182ec4ee	312	MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
1da177e4	313	// the sake of this tag. It's Free Software.