[deliverable/linux.git] / fs / bfs / inode.c

/*
 *	fs/bfs/inode.c
 *	BFS superblock and inode operations.
 *	Copyright (C) 1999-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
 *	From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
 *
 *      Made endianness-clean by Andrew Stribblehill <ads@wompom.org>, 2005.
 */

#include <linux/module.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/vfs.h>
#include <linux/writeback.h>
#include <asm/uaccess.h>
#include "bfs.h"

MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
MODULE_LICENSE("GPL");

#undef DEBUG

#ifdef DEBUG
#define dprintf(x...)	printf(x)
#else
#define dprintf(x...)
#endif

void dump_imap(const char *prefix, struct super_block *s);

struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
{
	struct bfs_inode *di;
	struct inode *inode;
	struct buffer_head *bh;
	int block, off;

	inode = iget_locked(sb, ino);
	if (IS_ERR(inode))
		return ERR_PTR(-ENOMEM);
	if (!(inode->i_state & I_NEW))
		return inode;

	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
		printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
		goto error;
	}

	block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
	bh = sb_bread(inode->i_sb, block);
	if (!bh) {
		printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
									ino);
		goto error;
	}

	off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
	di = (struct bfs_inode *)bh->b_data + off;

	inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
	if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
		inode->i_mode |= S_IFDIR;
		inode->i_op = &bfs_dir_inops;
		inode->i_fop = &bfs_dir_operations;
	} else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
		inode->i_mode |= S_IFREG;
		inode->i_op = &bfs_file_inops;
		inode->i_fop = &bfs_file_operations;
		inode->i_mapping->a_ops = &bfs_aops;
	}

	BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
	BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
	BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
	inode->i_uid =  le32_to_cpu(di->i_uid);
	inode->i_gid =  le32_to_cpu(di->i_gid);
	set_nlink(inode, le32_to_cpu(di->i_nlink));
	inode->i_size = BFS_FILESIZE(di);
	inode->i_blocks = BFS_FILEBLOCKS(di);
	inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
	inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
	inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
	inode->i_atime.tv_nsec = 0;
	inode->i_mtime.tv_nsec = 0;
	inode->i_ctime.tv_nsec = 0;

	brelse(bh);
	unlock_new_inode(inode);
	return inode;

error:
	iget_failed(inode);
	return ERR_PTR(-EIO);
}

static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
{
	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
		printf("Bad inode number %s:%08x\n", sb->s_id, ino);
		return ERR_PTR(-EIO);
	}

	ino -= BFS_ROOT_INO;

	*p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
	if (!*p) {
		printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
		return ERR_PTR(-EIO);
	}

	return (struct bfs_inode *)(*p)->b_data +  ino % BFS_INODES_PER_BLOCK;
}

static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
{
	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
	unsigned int ino = (u16)inode->i_ino;
        unsigned long i_sblock;
	struct bfs_inode *di;
	struct buffer_head *bh;
	int err = 0;

        dprintf("ino=%08x\n", ino);

	di = find_inode(inode->i_sb, ino, &bh);
	if (IS_ERR(di))
		return PTR_ERR(di);

	mutex_lock(&info->bfs_lock);

	if (ino == BFS_ROOT_INO)
		di->i_vtype = cpu_to_le32(BFS_VDIR);
	else
		di->i_vtype = cpu_to_le32(BFS_VREG);

	di->i_ino = cpu_to_le16(ino);
	di->i_mode = cpu_to_le32(inode->i_mode);
	di->i_uid = cpu_to_le32(inode->i_uid);
	di->i_gid = cpu_to_le32(inode->i_gid);
	di->i_nlink = cpu_to_le32(inode->i_nlink);
	di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
	di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
	di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
        i_sblock = BFS_I(inode)->i_sblock;
	di->i_sblock = cpu_to_le32(i_sblock);
	di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
	di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);

	mark_buffer_dirty(bh);
	if (wbc->sync_mode == WB_SYNC_ALL) {
		sync_dirty_buffer(bh);
		if (buffer_req(bh) && !buffer_uptodate(bh))
			err = -EIO;
	}
	brelse(bh);
	mutex_unlock(&info->bfs_lock);
	return err;
}

static void bfs_evict_inode(struct inode *inode)
{
	unsigned long ino = inode->i_ino;
	struct bfs_inode *di;
	struct buffer_head *bh;
	struct super_block *s = inode->i_sb;
	struct bfs_sb_info *info = BFS_SB(s);
	struct bfs_inode_info *bi = BFS_I(inode);

	dprintf("ino=%08lx\n", ino);

	truncate_inode_pages(&inode->i_data, 0);
	invalidate_inode_buffers(inode);
	clear_inode(inode);

	if (inode->i_nlink)
		return;

	di = find_inode(s, inode->i_ino, &bh);
	if (IS_ERR(di))
		return;

	mutex_lock(&info->bfs_lock);
	/* clear on-disk inode */
	memset(di, 0, sizeof(struct bfs_inode));
	mark_buffer_dirty(bh);
	brelse(bh);

        if (bi->i_dsk_ino) {
		if (bi->i_sblock)
			info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
		info->si_freei++;
		clear_bit(ino, info->si_imap);
		dump_imap("delete_inode", s);
        }

	/*
	 * If this was the last file, make the previous block
	 * "last block of the last file" even if there is no
	 * real file there, saves us 1 gap.
	 */
	if (info->si_lf_eblk == bi->i_eblock)
		info->si_lf_eblk = bi->i_sblock - 1;
	mutex_unlock(&info->bfs_lock);
}

static void bfs_put_super(struct super_block *s)
{
	struct bfs_sb_info *info = BFS_SB(s);

	if (!info)
		return;

	mutex_destroy(&info->bfs_lock);
	kfree(info->si_imap);
	kfree(info);
	s->s_fs_info = NULL;
}

static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	struct super_block *s = dentry->d_sb;
	struct bfs_sb_info *info = BFS_SB(s);
	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
	buf->f_type = BFS_MAGIC;
	buf->f_bsize = s->s_blocksize;
	buf->f_blocks = info->si_blocks;
	buf->f_bfree = buf->f_bavail = info->si_freeb;
	buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
	buf->f_ffree = info->si_freei;
	buf->f_fsid.val[0] = (u32)id;
	buf->f_fsid.val[1] = (u32)(id >> 32);
	buf->f_namelen = BFS_NAMELEN;
	return 0;
}

static struct kmem_cache *bfs_inode_cachep;

static struct inode *bfs_alloc_inode(struct super_block *sb)
{
	struct bfs_inode_info *bi;
	bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
	if (!bi)
		return NULL;
	return &bi->vfs_inode;
}

static void bfs_i_callback(struct rcu_head *head)
{
	struct inode *inode = container_of(head, struct inode, i_rcu);
	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
}

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

static void init_once(void *foo)
{
	struct bfs_inode_info *bi = foo;

	inode_init_once(&bi->vfs_inode);
}

static int init_inodecache(void)
{
	bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
					     sizeof(struct bfs_inode_info),
					     0, (SLAB_RECLAIM_ACCOUNT|
						SLAB_MEM_SPREAD),
					     init_once);
	if (bfs_inode_cachep == NULL)
		return -ENOMEM;
	return 0;
}

static void destroy_inodecache(void)
{
	kmem_cache_destroy(bfs_inode_cachep);
}

static const struct super_operations bfs_sops = {
	.alloc_inode	= bfs_alloc_inode,
	.destroy_inode	= bfs_destroy_inode,
	.write_inode	= bfs_write_inode,
	.evict_inode	= bfs_evict_inode,
	.put_super	= bfs_put_super,
	.statfs		= bfs_statfs,
};

void dump_imap(const char *prefix, struct super_block *s)
{
#ifdef DEBUG
	int i;
	char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);

	if (!tmpbuf)
		return;
	for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
		if (i > PAGE_SIZE - 100) break;
		if (test_bit(i, BFS_SB(s)->si_imap))
			strcat(tmpbuf, "1");
		else
			strcat(tmpbuf, "0");
	}
	printf("BFS-fs: %s: lasti=%08lx <%s>\n",
				prefix, BFS_SB(s)->si_lasti, tmpbuf);
	free_page((unsigned long)tmpbuf);
#endif
}

static int bfs_fill_super(struct super_block *s, void *data, int silent)
{
	struct buffer_head *bh, *sbh;
	struct bfs_super_block *bfs_sb;
	struct inode *inode;
	unsigned i, imap_len;
	struct bfs_sb_info *info;
	int ret = -EINVAL;
	unsigned long i_sblock, i_eblock, i_eoff, s_size;

	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (!info)
		return -ENOMEM;
	mutex_init(&info->bfs_lock);
	s->s_fs_info = info;

	sb_set_blocksize(s, BFS_BSIZE);

	sbh = sb_bread(s, 0);
	if (!sbh)
		goto out;
	bfs_sb = (struct bfs_super_block *)sbh->b_data;
	if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
		if (!silent)
			printf("No BFS filesystem on %s (magic=%08x)\n", 
				s->s_id,  le32_to_cpu(bfs_sb->s_magic));
		goto out1;
	}
	if (BFS_UNCLEAN(bfs_sb, s) && !silent)
		printf("%s is unclean, continuing\n", s->s_id);

	s->s_magic = BFS_MAGIC;

	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
		printf("Superblock is corrupted\n");
		goto out1;
	}

	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
					sizeof(struct bfs_inode)
					+ BFS_ROOT_INO - 1;
	imap_len = (info->si_lasti / 8) + 1;
	info->si_imap = kzalloc(imap_len, GFP_KERNEL);
	if (!info->si_imap)
		goto out1;
	for (i = 0; i < BFS_ROOT_INO; i++)
		set_bit(i, info->si_imap);

	s->s_op = &bfs_sops;
	inode = bfs_iget(s, BFS_ROOT_INO);
	if (IS_ERR(inode)) {
		ret = PTR_ERR(inode);
		goto out2;
	}
	s->s_root = d_make_root(inode);
	if (!s->s_root) {
		ret = -ENOMEM;
		goto out2;
	}

	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
			- le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
	info->si_freei = 0;
	info->si_lf_eblk = 0;

	/* can we read the last block? */
	bh = sb_bread(s, info->si_blocks - 1);
	if (!bh) {
		printf("Last block not available: %lu\n", info->si_blocks - 1);
		ret = -EIO;
		goto out3;
	}
	brelse(bh);

	bh = NULL;
	for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
		struct bfs_inode *di;
		int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
		int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
		unsigned long eblock;

		if (!off) {
			brelse(bh);
			bh = sb_bread(s, block);
		}

		if (!bh)
			continue;

		di = (struct bfs_inode *)bh->b_data + off;

		/* test if filesystem is not corrupted */

		i_eoff = le32_to_cpu(di->i_eoffset);
		i_sblock = le32_to_cpu(di->i_sblock);
		i_eblock = le32_to_cpu(di->i_eblock);
		s_size = le32_to_cpu(bfs_sb->s_end);

		if (i_sblock > info->si_blocks ||
			i_eblock > info->si_blocks ||
			i_sblock > i_eblock ||
			i_eoff > s_size ||
			i_sblock * BFS_BSIZE > i_eoff) {

			printf("Inode 0x%08x corrupted\n", i);

			brelse(bh);
			ret = -EIO;
			goto out3;
		}

		if (!di->i_ino) {
			info->si_freei++;
			continue;
		}
		set_bit(i, info->si_imap);
		info->si_freeb -= BFS_FILEBLOCKS(di);

		eblock =  le32_to_cpu(di->i_eblock);
		if (eblock > info->si_lf_eblk)
			info->si_lf_eblk = eblock;
	}
	brelse(bh);
	brelse(sbh);
	dump_imap("read_super", s);
	return 0;

out3:
	dput(s->s_root);
	s->s_root = NULL;
out2:
	kfree(info->si_imap);
out1:
	brelse(sbh);
out:
	mutex_destroy(&info->bfs_lock);
	kfree(info);
	s->s_fs_info = NULL;
	return ret;
}

static struct dentry *bfs_mount(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data)
{
	return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
}

static struct file_system_type bfs_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "bfs",
	.mount		= bfs_mount,
	.kill_sb	= kill_block_super,
	.fs_flags	= FS_REQUIRES_DEV,
};

static int __init init_bfs_fs(void)
{
	int err = init_inodecache();
	if (err)
		goto out1;
        err = register_filesystem(&bfs_fs_type);
	if (err)
		goto out;
	return 0;
out:
	destroy_inodecache();
out1:
	return err;
}

static void __exit exit_bfs_fs(void)
{
	unregister_filesystem(&bfs_fs_type);
	destroy_inodecache();
}

module_init(init_bfs_fs)
module_exit(exit_bfs_fs)
Commit	Line	Data
1da177e4 LT	1	/*
	2	* fs/bfs/inode.c
	3	* BFS superblock and inode operations.
69688262	4	* Copyright (C) 1999-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
1da177e4	5	* From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
fac92bec AS	6	*
fac92bec AS	7	* Made endianness-clean by Andrew Stribblehill <ads@wompom.org>, 2005.
1da177e4 LT	8	*/
	9
	10	#include <linux/module.h>
	11	#include <linux/mm.h>
	12	#include <linux/slab.h>
	13	#include <linux/init.h>
	14	#include <linux/fs.h>
1da177e4 LT	15	#include <linux/buffer_head.h>
1da177e4 LT	16	#include <linux/vfs.h>
a9185b41	17	#include <linux/writeback.h>
1da177e4 LT	18	#include <asm/uaccess.h>
	19	#include "bfs.h"
	20
69688262	21	MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
1da177e4 LT	22	MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
	23	MODULE_LICENSE("GPL");
	24
	25	#undef DEBUG
	26
	27	#ifdef DEBUG
	28	#define dprintf(x...) printf(x)
	29	#else
	30	#define dprintf(x...)
	31	#endif
	32
f433dc56	33	void dump_imap(const char prefix, struct super_block s);
1da177e4	34
e33ab086	35	struct inode bfs_iget(struct super_block sb, unsigned long ino)
1da177e4	36	{
f433dc56	37	struct bfs_inode *di;
e33ab086	38	struct inode *inode;
f433dc56	39	struct buffer_head *bh;
1da177e4 LT	40	int block, off;
1da177e4 LT	41
e33ab086 DH	42	inode = iget_locked(sb, ino);
	43	if (IS_ERR(inode))
	44	return ERR_PTR(-ENOMEM);
	45	if (!(inode->i_state & I_NEW))
	46	return inode;
	47
f433dc56	48	if ((ino < BFS_ROOT_INO) \|\| (ino > BFS_SB(inode->i_sb)->si_lasti)) {
1da177e4	49	printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
e33ab086	50	goto error;
1da177e4 LT	51	}
1da177e4 LT	52
f433dc56	53	block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
1da177e4 LT	54	bh = sb_bread(inode->i_sb, block);
1da177e4 LT	55	if (!bh) {
f433dc56 DV	56	printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
f433dc56 DV	57	ino);
e33ab086	58	goto error;
1da177e4 LT	59	}
	60
	61	off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
	62	di = (struct bfs_inode *)bh->b_data + off;
	63
f433dc56	64	inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
fac92bec	65	if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
1da177e4 LT	66	inode->i_mode \|= S_IFDIR;
	67	inode->i_op = &bfs_dir_inops;
	68	inode->i_fop = &bfs_dir_operations;
fac92bec	69	} else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
1da177e4 LT	70	inode->i_mode \|= S_IFREG;
	71	inode->i_op = &bfs_file_inops;
	72	inode->i_fop = &bfs_file_operations;
	73	inode->i_mapping->a_ops = &bfs_aops;
	74	}
	75
fac92bec AS	76	BFS_I(inode)->i_sblock = le32_to_cpu(di->i_sblock);
fac92bec AS	77	BFS_I(inode)->i_eblock = le32_to_cpu(di->i_eblock);
f433dc56	78	BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
fac92bec AS	79	inode->i_uid = le32_to_cpu(di->i_uid);
fac92bec AS	80	inode->i_gid = le32_to_cpu(di->i_gid);
bfe86848	81	set_nlink(inode, le32_to_cpu(di->i_nlink));
1da177e4 LT	82	inode->i_size = BFS_FILESIZE(di);
1da177e4 LT	83	inode->i_blocks = BFS_FILEBLOCKS(di);
fac92bec AS	84	inode->i_atime.tv_sec = le32_to_cpu(di->i_atime);
	85	inode->i_mtime.tv_sec = le32_to_cpu(di->i_mtime);
	86	inode->i_ctime.tv_sec = le32_to_cpu(di->i_ctime);
1da177e4 LT	87	inode->i_atime.tv_nsec = 0;
	88	inode->i_mtime.tv_nsec = 0;
	89	inode->i_ctime.tv_nsec = 0;
1da177e4 LT	90
1da177e4 LT	91	brelse(bh);
e33ab086 DH	92	unlock_new_inode(inode);
	93	return inode;
	94
	95	error:
	96	iget_failed(inode);
	97	return ERR_PTR(-EIO);
1da177e4 LT	98	}
1da177e4 LT	99
9df2f851 AV	100	static struct bfs_inode find_inode(struct super_block sb, u16 ino, struct buffer_head **p)
	101	{
	102	if ((ino < BFS_ROOT_INO) \|\| (ino > BFS_SB(sb)->si_lasti)) {
	103	printf("Bad inode number %s:%08x\n", sb->s_id, ino);
	104	return ERR_PTR(-EIO);
	105	}
	106
	107	ino -= BFS_ROOT_INO;
	108
	109	*p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
	110	if (!*p) {
	111	printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
	112	return ERR_PTR(-EIO);
	113	}
	114
	115	return (struct bfs_inode )(p)->b_data + ino % BFS_INODES_PER_BLOCK;
	116	}
	117
a9185b41	118	static int bfs_write_inode(struct inode inode, struct writeback_control wbc)
1da177e4	119	{
4427f0c3	120	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
fac92bec AS	121	unsigned int ino = (u16)inode->i_ino;
fac92bec AS	122	unsigned long i_sblock;
f433dc56 DV	123	struct bfs_inode *di;
f433dc56 DV	124	struct buffer_head *bh;
4427f0c3	125	int err = 0;
1da177e4	126
fac92bec AS	127	dprintf("ino=%08x\n", ino);
fac92bec AS	128
9df2f851 AV	129	di = find_inode(inode->i_sb, ino, &bh);
	130	if (IS_ERR(di))
	131	return PTR_ERR(di);
1da177e4	132
3f165e4c	133	mutex_lock(&info->bfs_lock);
1da177e4	134
fac92bec AS	135	if (ino == BFS_ROOT_INO)
fac92bec AS	136	di->i_vtype = cpu_to_le32(BFS_VDIR);
1da177e4	137	else
fac92bec AS	138	di->i_vtype = cpu_to_le32(BFS_VREG);
	139
	140	di->i_ino = cpu_to_le16(ino);
	141	di->i_mode = cpu_to_le32(inode->i_mode);
	142	di->i_uid = cpu_to_le32(inode->i_uid);
	143	di->i_gid = cpu_to_le32(inode->i_gid);
	144	di->i_nlink = cpu_to_le32(inode->i_nlink);
	145	di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
	146	di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
	147	di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
	148	i_sblock = BFS_I(inode)->i_sblock;
	149	di->i_sblock = cpu_to_le32(i_sblock);
	150	di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
	151	di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
1da177e4 LT	152
1da177e4 LT	153	mark_buffer_dirty(bh);
a9185b41	154	if (wbc->sync_mode == WB_SYNC_ALL) {
4427f0c3 AV	155	sync_dirty_buffer(bh);
	156	if (buffer_req(bh) && !buffer_uptodate(bh))
	157	err = -EIO;
	158	}
1da177e4	159	brelse(bh);
3f165e4c	160	mutex_unlock(&info->bfs_lock);
4427f0c3	161	return err;
1da177e4 LT	162	}
1da177e4 LT	163
9df2f851	164	static void bfs_evict_inode(struct inode *inode)
1da177e4 LT	165	{
1da177e4 LT	166	unsigned long ino = inode->i_ino;
f433dc56 DV	167	struct bfs_inode *di;
f433dc56 DV	168	struct buffer_head *bh;
f433dc56 DV	169	struct super_block *s = inode->i_sb;
	170	struct bfs_sb_info *info = BFS_SB(s);
	171	struct bfs_inode_info *bi = BFS_I(inode);
1da177e4	172
fac92bec	173	dprintf("ino=%08lx\n", ino);
1da177e4	174
fef26658	175	truncate_inode_pages(&inode->i_data, 0);
9df2f851	176	invalidate_inode_buffers(inode);
dbd5768f	177	clear_inode(inode);
fef26658	178
9df2f851	179	if (inode->i_nlink)
1da177e4	180	return;
f433dc56	181
9df2f851 AV	182	di = find_inode(s, inode->i_ino, &bh);
9df2f851 AV	183	if (IS_ERR(di))
1da177e4	184	return;
9df2f851 AV	185
	186	mutex_lock(&info->bfs_lock);
	187	/* clear on-disk inode */
	188	memset(di, 0, sizeof(struct bfs_inode));
f433dc56 DV	189	mark_buffer_dirty(bh);
	190	brelse(bh);
	191
fac92bec	192	if (bi->i_dsk_ino) {
7e46aa5c AV	193	if (bi->i_sblock)
7e46aa5c AV	194	info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
1da177e4	195	info->si_freei++;
fac92bec	196	clear_bit(ino, info->si_imap);
1da177e4	197	dump_imap("delete_inode", s);
fac92bec	198	}
1da177e4	199
f433dc56 DV	200	/*
	201	* If this was the last file, make the previous block
	202	* "last block of the last file" even if there is no
	203	* real file there, saves us 1 gap.
	204	*/
4e29d50a	205	if (info->si_lf_eblk == bi->i_eblock)
f433dc56	206	info->si_lf_eblk = bi->i_sblock - 1;
3f165e4c	207	mutex_unlock(&info->bfs_lock);
1da177e4 LT	208	}
	209
	210	static void bfs_put_super(struct super_block *s)
	211	{
	212	struct bfs_sb_info *info = BFS_SB(s);
3f165e4c	213
e1f89ec9 ES	214	if (!info)
	215	return;
	216
3f165e4c	217	mutex_destroy(&info->bfs_lock);
1da177e4 LT	218	kfree(info->si_imap);
	219	kfree(info);
	220	s->s_fs_info = NULL;
	221	}
	222
726c3342	223	static int bfs_statfs(struct dentry dentry, struct kstatfs buf)
1da177e4	224	{
726c3342	225	struct super_block *s = dentry->d_sb;
1da177e4 LT	226	struct bfs_sb_info *info = BFS_SB(s);
	227	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
	228	buf->f_type = BFS_MAGIC;
	229	buf->f_bsize = s->s_blocksize;
	230	buf->f_blocks = info->si_blocks;
	231	buf->f_bfree = buf->f_bavail = info->si_freeb;
	232	buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
	233	buf->f_ffree = info->si_freei;
	234	buf->f_fsid.val[0] = (u32)id;
	235	buf->f_fsid.val[1] = (u32)(id >> 32);
	236	buf->f_namelen = BFS_NAMELEN;
	237	return 0;
	238	}
	239
f433dc56	240	static struct kmem_cache *bfs_inode_cachep;
1da177e4 LT	241
	242	static struct inode bfs_alloc_inode(struct super_block sb)
	243	{
	244	struct bfs_inode_info *bi;
e94b1766	245	bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
1da177e4 LT	246	if (!bi)
	247	return NULL;
	248	return &bi->vfs_inode;
	249	}
	250
fa0d7e3d	251	static void bfs_i_callback(struct rcu_head *head)
1da177e4	252	{
fa0d7e3d	253	struct inode *inode = container_of(head, struct inode, i_rcu);
1da177e4 LT	254	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
	255	}
	256
fa0d7e3d NP	257	static void bfs_destroy_inode(struct inode *inode)
	258	{
	259	call_rcu(&inode->i_rcu, bfs_i_callback);
	260	}
	261
51cc5068	262	static void init_once(void *foo)
1da177e4 LT	263	{
	264	struct bfs_inode_info *bi = foo;
	265
a35afb83	266	inode_init_once(&bi->vfs_inode);
1da177e4	267	}
20c2df83	268
1da177e4 LT	269	static int init_inodecache(void)
	270	{
	271	bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
	272	sizeof(struct bfs_inode_info),
fffb60f9 PJ	273	0, (SLAB_RECLAIM_ACCOUNT\|
fffb60f9 PJ	274	SLAB_MEM_SPREAD),
20c2df83	275	init_once);
1da177e4 LT	276	if (bfs_inode_cachep == NULL)
	277	return -ENOMEM;
	278	return 0;
	279	}
	280
	281	static void destroy_inodecache(void)
	282	{
1a1d92c1	283	kmem_cache_destroy(bfs_inode_cachep);
1da177e4 LT	284	}
1da177e4 LT	285
ee9b6d61	286	static const struct super_operations bfs_sops = {
1da177e4 LT	287	.alloc_inode = bfs_alloc_inode,
1da177e4 LT	288	.destroy_inode = bfs_destroy_inode,
1da177e4	289	.write_inode = bfs_write_inode,
9df2f851	290	.evict_inode = bfs_evict_inode,
1da177e4	291	.put_super = bfs_put_super,
1da177e4 LT	292	.statfs = bfs_statfs,
	293	};
	294
f433dc56	295	void dump_imap(const char prefix, struct super_block s)
1da177e4	296	{
fac92bec	297	#ifdef DEBUG
1da177e4 LT	298	int i;
	299	char tmpbuf = (char )get_zeroed_page(GFP_KERNEL);
	300
	301	if (!tmpbuf)
	302	return;
f433dc56 DV	303	for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
f433dc56 DV	304	if (i > PAGE_SIZE - 100) break;
1da177e4 LT	305	if (test_bit(i, BFS_SB(s)->si_imap))
	306	strcat(tmpbuf, "1");
	307	else
	308	strcat(tmpbuf, "0");
	309	}
f433dc56 DV	310	printf("BFS-fs: %s: lasti=%08lx <%s>\n",
f433dc56 DV	311	prefix, BFS_SB(s)->si_lasti, tmpbuf);
1da177e4 LT	312	free_page((unsigned long)tmpbuf);
	313	#endif
	314	}
	315
	316	static int bfs_fill_super(struct super_block s, void data, int silent)
	317	{
4e29d50a	318	struct buffer_head bh, sbh;
f433dc56 DV	319	struct bfs_super_block *bfs_sb;
f433dc56 DV	320	struct inode *inode;
fac92bec	321	unsigned i, imap_len;
f433dc56	322	struct bfs_sb_info *info;
5998649f	323	int ret = -EINVAL;
e1f89ec9	324	unsigned long i_sblock, i_eblock, i_eoff, s_size;
1da177e4	325
f8314dc6	326	info = kzalloc(sizeof(*info), GFP_KERNEL);
ba13d597	327	if (!info)
1da177e4	328	return -ENOMEM;
5998649f	329	mutex_init(&info->bfs_lock);
1da177e4	330	s->s_fs_info = info;
1da177e4 LT	331
	332	sb_set_blocksize(s, BFS_BSIZE);
	333
4e29d50a AB	334	sbh = sb_bread(s, 0);
4e29d50a AB	335	if (!sbh)
1da177e4	336	goto out;
4e29d50a	337	bfs_sb = (struct bfs_super_block *)sbh->b_data;
fac92bec	338	if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
1da177e4 LT	339	if (!silent)
1da177e4 LT	340	printf("No BFS filesystem on %s (magic=%08x)\n",
fac92bec	341	s->s_id, le32_to_cpu(bfs_sb->s_magic));
5998649f	342	goto out1;
1da177e4 LT	343	}
	344	if (BFS_UNCLEAN(bfs_sb, s) && !silent)
	345	printf("%s is unclean, continuing\n", s->s_id);
	346
	347	s->s_magic = BFS_MAGIC;
e1f89ec9 ES	348
	349	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
	350	printf("Superblock is corrupted\n");
5998649f	351	goto out1;
e1f89ec9 ES	352	}
e1f89ec9 ES	353
f433dc56 DV	354	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
	355	sizeof(struct bfs_inode)
	356	+ BFS_ROOT_INO - 1;
	357	imap_len = (info->si_lasti / 8) + 1;
f8314dc6	358	info->si_imap = kzalloc(imap_len, GFP_KERNEL);
1da177e4	359	if (!info->si_imap)
5998649f	360	goto out1;
f433dc56	361	for (i = 0; i < BFS_ROOT_INO; i++)
1da177e4 LT	362	set_bit(i, info->si_imap);
	363
	364	s->s_op = &bfs_sops;
e33ab086 DH	365	inode = bfs_iget(s, BFS_ROOT_INO);
	366	if (IS_ERR(inode)) {
	367	ret = PTR_ERR(inode);
5998649f	368	goto out2;
1da177e4	369	}
48fde701	370	s->s_root = d_make_root(inode);
1da177e4	371	if (!s->s_root) {
e33ab086	372	ret = -ENOMEM;
5998649f	373	goto out2;
1da177e4 LT	374	}
1da177e4 LT	375
f433dc56 DV	376	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
	377	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
	378	- le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
1da177e4 LT	379	info->si_freei = 0;
1da177e4 LT	380	info->si_lf_eblk = 0;
50682bb4 ES	381
	382	/* can we read the last block? */
	383	bh = sb_bread(s, info->si_blocks - 1);
	384	if (!bh) {
	385	printf("Last block not available: %lu\n", info->si_blocks - 1);
50682bb4	386	ret = -EIO;
5998649f	387	goto out3;
50682bb4 ES	388	}
	389	brelse(bh);
	390
c2b513df	391	bh = NULL;
f433dc56	392	for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
c2b513df	393	struct bfs_inode *di;
f433dc56	394	int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
c2b513df	395	int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
75b25b4c	396	unsigned long eblock;
c2b513df AV	397
	398	if (!off) {
	399	brelse(bh);
	400	bh = sb_bread(s, block);
	401	}
	402
	403	if (!bh)
	404	continue;
	405
	406	di = (struct bfs_inode *)bh->b_data + off;
	407
e1f89ec9 ES	408	/* test if filesystem is not corrupted */
	409
	410	i_eoff = le32_to_cpu(di->i_eoffset);
	411	i_sblock = le32_to_cpu(di->i_sblock);
	412	i_eblock = le32_to_cpu(di->i_eblock);
	413	s_size = le32_to_cpu(bfs_sb->s_end);
	414
	415	if (i_sblock > info->si_blocks \|\|
	416	i_eblock > info->si_blocks \|\|
	417	i_sblock > i_eblock \|\|
	418	i_eoff > s_size \|\|
	419	i_sblock * BFS_BSIZE > i_eoff) {
	420
	421	printf("Inode 0x%08x corrupted\n", i);
	422
	423	brelse(bh);
5998649f AV	424	ret = -EIO;
5998649f AV	425	goto out3;
e1f89ec9 ES	426	}
e1f89ec9 ES	427
c2b513df	428	if (!di->i_ino) {
1da177e4	429	info->si_freei++;
c2b513df AV	430	continue;
	431	}
	432	set_bit(i, info->si_imap);
	433	info->si_freeb -= BFS_FILEBLOCKS(di);
	434
c2b513df	435	eblock = le32_to_cpu(di->i_eblock);
f433dc56	436	if (eblock > info->si_lf_eblk)
c2b513df	437	info->si_lf_eblk = eblock;
1da177e4	438	}
c2b513df	439	brelse(bh);
4e29d50a	440	brelse(sbh);
1da177e4 LT	441	dump_imap("read_super", s);
	442	return 0;
	443
5998649f AV	444	out3:
	445	dput(s->s_root);
	446	s->s_root = NULL;
	447	out2:
	448	kfree(info->si_imap);
	449	out1:
4e29d50a	450	brelse(sbh);
1da177e4	451	out:
5998649f	452	mutex_destroy(&info->bfs_lock);
1da177e4 LT	453	kfree(info);
1da177e4 LT	454	s->s_fs_info = NULL;
e33ab086	455	return ret;
1da177e4 LT	456	}
1da177e4 LT	457
152a0836 AV	458	static struct dentry bfs_mount(struct file_system_type fs_type,
152a0836 AV	459	int flags, const char dev_name, void data)
1da177e4	460	{
152a0836	461	return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
1da177e4 LT	462	}
	463
	464	static struct file_system_type bfs_fs_type = {
	465	.owner = THIS_MODULE,
	466	.name = "bfs",
152a0836	467	.mount = bfs_mount,
1da177e4 LT	468	.kill_sb = kill_block_super,
	469	.fs_flags = FS_REQUIRES_DEV,
	470	};
	471
	472	static int __init init_bfs_fs(void)
	473	{
	474	int err = init_inodecache();
	475	if (err)
	476	goto out1;
	477	err = register_filesystem(&bfs_fs_type);
	478	if (err)
	479	goto out;
	480	return 0;
	481	out:
	482	destroy_inodecache();
	483	out1:
	484	return err;
	485	}
	486
	487	static void __exit exit_bfs_fs(void)
	488	{
	489	unregister_filesystem(&bfs_fs_type);
	490	destroy_inodecache();
	491	}
	492
	493	module_init(init_bfs_fs)
	494	module_exit(exit_bfs_fs)