[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/smp_lock.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);
	inode->i_nlink =  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);
	end_writeback(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;

	lock_kernel();

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

	unlock_kernel();
}

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_destroy_inode(struct inode *inode)
{
	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
}

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;

	lock_kernel();

	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (!info) {
		unlock_kernel();
		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_alloc_root(inode);
	if (!s->s_root) {
		iput(inode);
		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);
	unlock_kernel();
	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;
	unlock_kernel();
	return ret;
}

static int bfs_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
	return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
}

static struct file_system_type bfs_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "bfs",
	.get_sb		= bfs_get_sb,
	.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>
	15	#include <linux/smp_lock.h>
	16	#include <linux/buffer_head.h>
	17	#include <linux/vfs.h>
a9185b41	18	#include <linux/writeback.h>
1da177e4 LT	19	#include <asm/uaccess.h>
	20	#include "bfs.h"
	21
69688262	22	MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
1da177e4 LT	23	MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
	24	MODULE_LICENSE("GPL");
	25
	26	#undef DEBUG
	27
	28	#ifdef DEBUG
	29	#define dprintf(x...) printf(x)
	30	#else
	31	#define dprintf(x...)
	32	#endif
	33
f433dc56	34	void dump_imap(const char prefix, struct super_block s);
1da177e4	35
e33ab086	36	struct inode bfs_iget(struct super_block sb, unsigned long ino)
1da177e4	37	{
f433dc56	38	struct bfs_inode *di;
e33ab086	39	struct inode *inode;
f433dc56	40	struct buffer_head *bh;
1da177e4 LT	41	int block, off;
1da177e4 LT	42
e33ab086 DH	43	inode = iget_locked(sb, ino);
	44	if (IS_ERR(inode))
	45	return ERR_PTR(-ENOMEM);
	46	if (!(inode->i_state & I_NEW))
	47	return inode;
	48
f433dc56	49	if ((ino < BFS_ROOT_INO) \|\| (ino > BFS_SB(inode->i_sb)->si_lasti)) {
1da177e4	50	printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
e33ab086	51	goto error;
1da177e4 LT	52	}
1da177e4 LT	53
f433dc56	54	block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
1da177e4 LT	55	bh = sb_bread(inode->i_sb, block);
1da177e4 LT	56	if (!bh) {
f433dc56 DV	57	printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
f433dc56 DV	58	ino);
e33ab086	59	goto error;
1da177e4 LT	60	}
	61
	62	off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
	63	di = (struct bfs_inode *)bh->b_data + off;
	64
f433dc56	65	inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
fac92bec	66	if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
1da177e4 LT	67	inode->i_mode \|= S_IFDIR;
	68	inode->i_op = &bfs_dir_inops;
	69	inode->i_fop = &bfs_dir_operations;
fac92bec	70	} else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
1da177e4 LT	71	inode->i_mode \|= S_IFREG;
	72	inode->i_op = &bfs_file_inops;
	73	inode->i_fop = &bfs_file_operations;
	74	inode->i_mapping->a_ops = &bfs_aops;
	75	}
	76
fac92bec AS	77	BFS_I(inode)->i_sblock = le32_to_cpu(di->i_sblock);
fac92bec AS	78	BFS_I(inode)->i_eblock = le32_to_cpu(di->i_eblock);
f433dc56	79	BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
fac92bec AS	80	inode->i_uid = le32_to_cpu(di->i_uid);
	81	inode->i_gid = le32_to_cpu(di->i_gid);
	82	inode->i_nlink = le32_to_cpu(di->i_nlink);
1da177e4 LT	83	inode->i_size = BFS_FILESIZE(di);
1da177e4 LT	84	inode->i_blocks = BFS_FILEBLOCKS(di);
fac92bec AS	85	inode->i_atime.tv_sec = le32_to_cpu(di->i_atime);
	86	inode->i_mtime.tv_sec = le32_to_cpu(di->i_mtime);
	87	inode->i_ctime.tv_sec = le32_to_cpu(di->i_ctime);
1da177e4 LT	88	inode->i_atime.tv_nsec = 0;
	89	inode->i_mtime.tv_nsec = 0;
	90	inode->i_ctime.tv_nsec = 0;
1da177e4 LT	91
1da177e4 LT	92	brelse(bh);
e33ab086 DH	93	unlock_new_inode(inode);
	94	return inode;
	95
	96	error:
	97	iget_failed(inode);
	98	return ERR_PTR(-EIO);
1da177e4 LT	99	}
1da177e4 LT	100
9df2f851 AV	101	static struct bfs_inode find_inode(struct super_block sb, u16 ino, struct buffer_head **p)
	102	{
	103	if ((ino < BFS_ROOT_INO) \|\| (ino > BFS_SB(sb)->si_lasti)) {
	104	printf("Bad inode number %s:%08x\n", sb->s_id, ino);
	105	return ERR_PTR(-EIO);
	106	}
	107
	108	ino -= BFS_ROOT_INO;
	109
	110	*p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
	111	if (!*p) {
	112	printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
	113	return ERR_PTR(-EIO);
	114	}
	115
	116	return (struct bfs_inode )(p)->b_data + ino % BFS_INODES_PER_BLOCK;
	117	}
	118
a9185b41	119	static int bfs_write_inode(struct inode inode, struct writeback_control wbc)
1da177e4	120	{
4427f0c3	121	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
fac92bec AS	122	unsigned int ino = (u16)inode->i_ino;
fac92bec AS	123	unsigned long i_sblock;
f433dc56 DV	124	struct bfs_inode *di;
f433dc56 DV	125	struct buffer_head *bh;
4427f0c3	126	int err = 0;
1da177e4	127
fac92bec AS	128	dprintf("ino=%08x\n", ino);
fac92bec AS	129
9df2f851 AV	130	di = find_inode(inode->i_sb, ino, &bh);
	131	if (IS_ERR(di))
	132	return PTR_ERR(di);
1da177e4	133
3f165e4c	134	mutex_lock(&info->bfs_lock);
1da177e4	135
fac92bec AS	136	if (ino == BFS_ROOT_INO)
fac92bec AS	137	di->i_vtype = cpu_to_le32(BFS_VDIR);
1da177e4	138	else
fac92bec AS	139	di->i_vtype = cpu_to_le32(BFS_VREG);
	140
	141	di->i_ino = cpu_to_le16(ino);
	142	di->i_mode = cpu_to_le32(inode->i_mode);
	143	di->i_uid = cpu_to_le32(inode->i_uid);
	144	di->i_gid = cpu_to_le32(inode->i_gid);
	145	di->i_nlink = cpu_to_le32(inode->i_nlink);
	146	di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
	147	di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
	148	di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
	149	i_sblock = BFS_I(inode)->i_sblock;
	150	di->i_sblock = cpu_to_le32(i_sblock);
	151	di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
	152	di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
1da177e4 LT	153
1da177e4 LT	154	mark_buffer_dirty(bh);
a9185b41	155	if (wbc->sync_mode == WB_SYNC_ALL) {
4427f0c3 AV	156	sync_dirty_buffer(bh);
	157	if (buffer_req(bh) && !buffer_uptodate(bh))
	158	err = -EIO;
	159	}
1da177e4	160	brelse(bh);
3f165e4c	161	mutex_unlock(&info->bfs_lock);
4427f0c3	162	return err;
1da177e4 LT	163	}
1da177e4 LT	164
9df2f851	165	static void bfs_evict_inode(struct inode *inode)
1da177e4 LT	166	{
1da177e4 LT	167	unsigned long ino = inode->i_ino;
f433dc56 DV	168	struct bfs_inode *di;
f433dc56 DV	169	struct buffer_head *bh;
f433dc56 DV	170	struct super_block *s = inode->i_sb;
	171	struct bfs_sb_info *info = BFS_SB(s);
	172	struct bfs_inode_info *bi = BFS_I(inode);
1da177e4	173
fac92bec	174	dprintf("ino=%08lx\n", ino);
1da177e4	175
fef26658	176	truncate_inode_pages(&inode->i_data, 0);
9df2f851 AV	177	invalidate_inode_buffers(inode);
9df2f851 AV	178	end_writeback(inode);
fef26658	179
9df2f851	180	if (inode->i_nlink)
1da177e4	181	return;
f433dc56	182
9df2f851 AV	183	di = find_inode(s, inode->i_ino, &bh);
9df2f851 AV	184	if (IS_ERR(di))
1da177e4	185	return;
9df2f851 AV	186
	187	mutex_lock(&info->bfs_lock);
	188	/* clear on-disk inode */
	189	memset(di, 0, sizeof(struct bfs_inode));
f433dc56 DV	190	mark_buffer_dirty(bh);
	191	brelse(bh);
	192
fac92bec	193	if (bi->i_dsk_ino) {
7e46aa5c AV	194	if (bi->i_sblock)
7e46aa5c AV	195	info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
1da177e4	196	info->si_freei++;
fac92bec	197	clear_bit(ino, info->si_imap);
1da177e4	198	dump_imap("delete_inode", s);
fac92bec	199	}
1da177e4	200
f433dc56 DV	201	/*
	202	* If this was the last file, make the previous block
	203	* "last block of the last file" even if there is no
	204	* real file there, saves us 1 gap.
	205	*/
4e29d50a	206	if (info->si_lf_eblk == bi->i_eblock)
f433dc56	207	info->si_lf_eblk = bi->i_sblock - 1;
3f165e4c	208	mutex_unlock(&info->bfs_lock);
1da177e4 LT	209	}
	210
	211	static void bfs_put_super(struct super_block *s)
	212	{
	213	struct bfs_sb_info *info = BFS_SB(s);
3f165e4c	214
e1f89ec9 ES	215	if (!info)
	216	return;
	217
6cfd0148 CH	218	lock_kernel();
6cfd0148 CH	219
3f165e4c	220	mutex_destroy(&info->bfs_lock);
1da177e4 LT	221	kfree(info->si_imap);
	222	kfree(info);
	223	s->s_fs_info = NULL;
6cfd0148 CH	224
6cfd0148 CH	225	unlock_kernel();
1da177e4 LT	226	}
1da177e4 LT	227
726c3342	228	static int bfs_statfs(struct dentry dentry, struct kstatfs buf)
1da177e4	229	{
726c3342	230	struct super_block *s = dentry->d_sb;
1da177e4 LT	231	struct bfs_sb_info *info = BFS_SB(s);
	232	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
	233	buf->f_type = BFS_MAGIC;
	234	buf->f_bsize = s->s_blocksize;
	235	buf->f_blocks = info->si_blocks;
	236	buf->f_bfree = buf->f_bavail = info->si_freeb;
	237	buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
	238	buf->f_ffree = info->si_freei;
	239	buf->f_fsid.val[0] = (u32)id;
	240	buf->f_fsid.val[1] = (u32)(id >> 32);
	241	buf->f_namelen = BFS_NAMELEN;
	242	return 0;
	243	}
	244
f433dc56	245	static struct kmem_cache *bfs_inode_cachep;
1da177e4 LT	246
	247	static struct inode bfs_alloc_inode(struct super_block sb)
	248	{
	249	struct bfs_inode_info *bi;
e94b1766	250	bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
1da177e4 LT	251	if (!bi)
	252	return NULL;
	253	return &bi->vfs_inode;
	254	}
	255
	256	static void bfs_destroy_inode(struct inode *inode)
	257	{
	258	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
	259	}
	260
51cc5068	261	static void init_once(void *foo)
1da177e4 LT	262	{
	263	struct bfs_inode_info *bi = foo;
	264
a35afb83	265	inode_init_once(&bi->vfs_inode);
1da177e4	266	}
20c2df83	267
1da177e4 LT	268	static int init_inodecache(void)
	269	{
	270	bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
	271	sizeof(struct bfs_inode_info),
fffb60f9 PJ	272	0, (SLAB_RECLAIM_ACCOUNT\|
fffb60f9 PJ	273	SLAB_MEM_SPREAD),
20c2df83	274	init_once);
1da177e4 LT	275	if (bfs_inode_cachep == NULL)
	276	return -ENOMEM;
	277	return 0;
	278	}
	279
	280	static void destroy_inodecache(void)
	281	{
1a1d92c1	282	kmem_cache_destroy(bfs_inode_cachep);
1da177e4 LT	283	}
1da177e4 LT	284
ee9b6d61	285	static const struct super_operations bfs_sops = {
1da177e4 LT	286	.alloc_inode = bfs_alloc_inode,
1da177e4 LT	287	.destroy_inode = bfs_destroy_inode,
1da177e4	288	.write_inode = bfs_write_inode,
9df2f851	289	.evict_inode = bfs_evict_inode,
1da177e4	290	.put_super = bfs_put_super,
1da177e4 LT	291	.statfs = bfs_statfs,
	292	};
	293
f433dc56	294	void dump_imap(const char prefix, struct super_block s)
1da177e4	295	{
fac92bec	296	#ifdef DEBUG
1da177e4 LT	297	int i;
	298	char tmpbuf = (char )get_zeroed_page(GFP_KERNEL);
	299
	300	if (!tmpbuf)
	301	return;
f433dc56 DV	302	for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
f433dc56 DV	303	if (i > PAGE_SIZE - 100) break;
1da177e4 LT	304	if (test_bit(i, BFS_SB(s)->si_imap))
	305	strcat(tmpbuf, "1");
	306	else
	307	strcat(tmpbuf, "0");
	308	}
f433dc56 DV	309	printf("BFS-fs: %s: lasti=%08lx <%s>\n",
f433dc56 DV	310	prefix, BFS_SB(s)->si_lasti, tmpbuf);
1da177e4 LT	311	free_page((unsigned long)tmpbuf);
	312	#endif
	313	}
	314
	315	static int bfs_fill_super(struct super_block s, void data, int silent)
	316	{
4e29d50a	317	struct buffer_head bh, sbh;
f433dc56 DV	318	struct bfs_super_block *bfs_sb;
f433dc56 DV	319	struct inode *inode;
fac92bec	320	unsigned i, imap_len;
f433dc56	321	struct bfs_sb_info *info;
5998649f	322	int ret = -EINVAL;
e1f89ec9	323	unsigned long i_sblock, i_eblock, i_eoff, s_size;
1da177e4	324
db719222 JB	325	lock_kernel();
db719222 JB	326
f8314dc6	327	info = kzalloc(sizeof(*info), GFP_KERNEL);
db719222 JB	328	if (!info) {
db719222 JB	329	unlock_kernel();
1da177e4	330	return -ENOMEM;
db719222	331	}
5998649f	332	mutex_init(&info->bfs_lock);
1da177e4	333	s->s_fs_info = info;
1da177e4 LT	334
	335	sb_set_blocksize(s, BFS_BSIZE);
	336
4e29d50a AB	337	sbh = sb_bread(s, 0);
4e29d50a AB	338	if (!sbh)
1da177e4	339	goto out;
4e29d50a	340	bfs_sb = (struct bfs_super_block *)sbh->b_data;
fac92bec	341	if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
1da177e4 LT	342	if (!silent)
1da177e4 LT	343	printf("No BFS filesystem on %s (magic=%08x)\n",
fac92bec	344	s->s_id, le32_to_cpu(bfs_sb->s_magic));
5998649f	345	goto out1;
1da177e4 LT	346	}
	347	if (BFS_UNCLEAN(bfs_sb, s) && !silent)
	348	printf("%s is unclean, continuing\n", s->s_id);
	349
	350	s->s_magic = BFS_MAGIC;
e1f89ec9 ES	351
	352	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
	353	printf("Superblock is corrupted\n");
5998649f	354	goto out1;
e1f89ec9 ES	355	}
e1f89ec9 ES	356
f433dc56 DV	357	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
	358	sizeof(struct bfs_inode)
	359	+ BFS_ROOT_INO - 1;
	360	imap_len = (info->si_lasti / 8) + 1;
f8314dc6	361	info->si_imap = kzalloc(imap_len, GFP_KERNEL);
1da177e4	362	if (!info->si_imap)
5998649f	363	goto out1;
f433dc56	364	for (i = 0; i < BFS_ROOT_INO; i++)
1da177e4 LT	365	set_bit(i, info->si_imap);
	366
	367	s->s_op = &bfs_sops;
e33ab086 DH	368	inode = bfs_iget(s, BFS_ROOT_INO);
	369	if (IS_ERR(inode)) {
	370	ret = PTR_ERR(inode);
5998649f	371	goto out2;
1da177e4 LT	372	}
	373	s->s_root = d_alloc_root(inode);
	374	if (!s->s_root) {
	375	iput(inode);
e33ab086	376	ret = -ENOMEM;
5998649f	377	goto out2;
1da177e4 LT	378	}
1da177e4 LT	379
f433dc56 DV	380	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
	381	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
	382	- le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
1da177e4 LT	383	info->si_freei = 0;
1da177e4 LT	384	info->si_lf_eblk = 0;
50682bb4 ES	385
	386	/* can we read the last block? */
	387	bh = sb_bread(s, info->si_blocks - 1);
	388	if (!bh) {
	389	printf("Last block not available: %lu\n", info->si_blocks - 1);
50682bb4	390	ret = -EIO;
5998649f	391	goto out3;
50682bb4 ES	392	}
	393	brelse(bh);
	394
c2b513df	395	bh = NULL;
f433dc56	396	for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
c2b513df	397	struct bfs_inode *di;
f433dc56	398	int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
c2b513df	399	int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
75b25b4c	400	unsigned long eblock;
c2b513df AV	401
	402	if (!off) {
	403	brelse(bh);
	404	bh = sb_bread(s, block);
	405	}
	406
	407	if (!bh)
	408	continue;
	409
	410	di = (struct bfs_inode *)bh->b_data + off;
	411
e1f89ec9 ES	412	/* test if filesystem is not corrupted */
	413
	414	i_eoff = le32_to_cpu(di->i_eoffset);
	415	i_sblock = le32_to_cpu(di->i_sblock);
	416	i_eblock = le32_to_cpu(di->i_eblock);
	417	s_size = le32_to_cpu(bfs_sb->s_end);
	418
	419	if (i_sblock > info->si_blocks \|\|
	420	i_eblock > info->si_blocks \|\|
	421	i_sblock > i_eblock \|\|
	422	i_eoff > s_size \|\|
	423	i_sblock * BFS_BSIZE > i_eoff) {
	424
	425	printf("Inode 0x%08x corrupted\n", i);
	426
	427	brelse(bh);
5998649f AV	428	ret = -EIO;
5998649f AV	429	goto out3;
e1f89ec9 ES	430	}
e1f89ec9 ES	431
c2b513df	432	if (!di->i_ino) {
1da177e4	433	info->si_freei++;
c2b513df AV	434	continue;
	435	}
	436	set_bit(i, info->si_imap);
	437	info->si_freeb -= BFS_FILEBLOCKS(di);
	438
c2b513df	439	eblock = le32_to_cpu(di->i_eblock);
f433dc56	440	if (eblock > info->si_lf_eblk)
c2b513df	441	info->si_lf_eblk = eblock;
1da177e4	442	}
c2b513df	443	brelse(bh);
4e29d50a	444	brelse(sbh);
1da177e4	445	dump_imap("read_super", s);
db719222	446	unlock_kernel();
1da177e4 LT	447	return 0;
1da177e4 LT	448
5998649f AV	449	out3:
	450	dput(s->s_root);
	451	s->s_root = NULL;
	452	out2:
	453	kfree(info->si_imap);
	454	out1:
4e29d50a	455	brelse(sbh);
1da177e4	456	out:
5998649f	457	mutex_destroy(&info->bfs_lock);
1da177e4 LT	458	kfree(info);
1da177e4 LT	459	s->s_fs_info = NULL;
db719222	460	unlock_kernel();
e33ab086	461	return ret;
1da177e4 LT	462	}
1da177e4 LT	463
454e2398 DH	464	static int bfs_get_sb(struct file_system_type *fs_type,
454e2398 DH	465	int flags, const char dev_name, void data, struct vfsmount *mnt)
1da177e4	466	{
454e2398	467	return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
1da177e4 LT	468	}
	469
	470	static struct file_system_type bfs_fs_type = {
	471	.owner = THIS_MODULE,
	472	.name = "bfs",
	473	.get_sb = bfs_get_sb,
	474	.kill_sb = kill_block_super,
	475	.fs_flags = FS_REQUIRES_DEV,
	476	};
	477
	478	static int __init init_bfs_fs(void)
	479	{
	480	int err = init_inodecache();
	481	if (err)
	482	goto out1;
	483	err = register_filesystem(&bfs_fs_type);
	484	if (err)
	485	goto out;
	486	return 0;
	487	out:
	488	destroy_inodecache();
	489	out1:
	490	return err;
	491	}
	492
	493	static void __exit exit_bfs_fs(void)
	494	{
	495	unregister_filesystem(&bfs_fs_type);
	496	destroy_inodecache();
	497	}
	498
	499	module_init(init_bfs_fs)
	500	module_exit(exit_bfs_fs)