[net-next-2.6.git] / fs / qnx4 / inode.c

/*
 * QNX4 file system, Linux implementation.
 *
 * Version : 0.2.1
 *
 * Using parts of the xiafs filesystem.
 *
 * History :
 *
 * 01-06-1998 by Richard Frowijn : first release.
 * 20-06-1998 by Frank Denis : Linux 2.1.99+ support, boot signature, misc.
 * 30-06-1998 by Frank Denis : first step to write inodes.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/highuid.h>
#include <linux/smp_lock.h>
#include <linux/pagemap.h>
#include <linux/buffer_head.h>
#include <linux/writeback.h>
#include <linux/statfs.h>
#include "qnx4.h"

#define QNX4_VERSION  4
#define QNX4_BMNAME   ".bitmap"

static const struct super_operations qnx4_sops;

static void qnx4_put_super(struct super_block *sb);
static struct inode *qnx4_alloc_inode(struct super_block *sb);
static void qnx4_destroy_inode(struct inode *inode);
static int qnx4_remount(struct super_block *sb, int *flags, char *data);
static int qnx4_statfs(struct dentry *, struct kstatfs *);

static const struct super_operations qnx4_sops =
{
	.alloc_inode	= qnx4_alloc_inode,
	.destroy_inode	= qnx4_destroy_inode,
	.put_super	= qnx4_put_super,
	.statfs		= qnx4_statfs,
	.remount_fs	= qnx4_remount,
};

static int qnx4_remount(struct super_block *sb, int *flags, char *data)
{
	struct qnx4_sb_info *qs;

	qs = qnx4_sb(sb);
	qs->Version = QNX4_VERSION;
	*flags |= MS_RDONLY;
	return 0;
}

static struct buffer_head *qnx4_getblk(struct inode *inode, int nr,
				       int create)
{
	struct buffer_head *result = NULL;

	if ( nr >= 0 )
		nr = qnx4_block_map( inode, nr );
	if (nr) {
		result = sb_getblk(inode->i_sb, nr);
		return result;
	}
	return NULL;
}

struct buffer_head *qnx4_bread(struct inode *inode, int block, int create)
{
	struct buffer_head *bh;

	bh = qnx4_getblk(inode, block, create);
	if (!bh || buffer_uptodate(bh)) {
		return bh;
	}
	ll_rw_block(READ, 1, &bh);
	wait_on_buffer(bh);
	if (buffer_uptodate(bh)) {
		return bh;
	}
	brelse(bh);

	return NULL;
}

static int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create )
{
	unsigned long phys;

	QNX4DEBUG((KERN_INFO "qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));

	phys = qnx4_block_map( inode, iblock );
	if ( phys ) {
		// logical block is before EOF
		map_bh(bh, inode->i_sb, phys);
	}
	return 0;
}

unsigned long qnx4_block_map( struct inode *inode, long iblock )
{
	int ix;
	long offset, i_xblk;
	unsigned long block = 0;
	struct buffer_head *bh = NULL;
	struct qnx4_xblk *xblk = NULL;
	struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
	u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);

	if ( iblock < le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size) ) {
		// iblock is in the first extent. This is easy.
		block = le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_blk) + iblock - 1;
	} else {
		// iblock is beyond first extent. We have to follow the extent chain.
		i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
		offset = iblock - le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size);
		ix = 0;
		while ( --nxtnt > 0 ) {
			if ( ix == 0 ) {
				// read next xtnt block.
				bh = sb_bread(inode->i_sb, i_xblk - 1);
				if ( !bh ) {
					QNX4DEBUG((KERN_ERR "qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
					return -EIO;
				}
				xblk = (struct qnx4_xblk*)bh->b_data;
				if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
					QNX4DEBUG((KERN_ERR "qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
					return -EIO;
				}
			}
			if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) {
				// got it!
				block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1;
				break;
			}
			offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size);
			if ( ++ix >= xblk->xblk_num_xtnts ) {
				i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
				ix = 0;
				brelse( bh );
				bh = NULL;
			}
		}
		if ( bh )
			brelse( bh );
	}

	QNX4DEBUG((KERN_INFO "qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));
	return block;
}

static int qnx4_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	struct super_block *sb = dentry->d_sb;
	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);

	lock_kernel();

	buf->f_type    = sb->s_magic;
	buf->f_bsize   = sb->s_blocksize;
	buf->f_blocks  = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;
	buf->f_bfree   = qnx4_count_free_blocks(sb);
	buf->f_bavail  = buf->f_bfree;
	buf->f_namelen = QNX4_NAME_MAX;
	buf->f_fsid.val[0] = (u32)id;
	buf->f_fsid.val[1] = (u32)(id >> 32);

	unlock_kernel();

	return 0;
}

/*
 * Check the root directory of the filesystem to make sure
 * it really _is_ a qnx4 filesystem, and to check the size
 * of the directory entry.
 */
static const char *qnx4_checkroot(struct super_block *sb)
{
	struct buffer_head *bh;
	struct qnx4_inode_entry *rootdir;
	int rd, rl;
	int i, j;
	int found = 0;

	if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/') {
		return "no qnx4 filesystem (no root dir).";
	} else {
		QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id));
		rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1;
		rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size);
		for (j = 0; j < rl; j++) {
			bh = sb_bread(sb, rd + j);	/* root dir, first block */
			if (bh == NULL) {
				return "unable to read root entry.";
			}
			for (i = 0; i < QNX4_INODES_PER_BLOCK; i++) {
				rootdir = (struct qnx4_inode_entry *) (bh->b_data + i * QNX4_DIR_ENTRY_SIZE);
				if (rootdir->di_fname != NULL) {
					QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname));
					if (!strcmp(rootdir->di_fname,
						    QNX4_BMNAME)) {
						found = 1;
						qnx4_sb(sb)->BitMap = kmalloc( sizeof( struct qnx4_inode_entry ), GFP_KERNEL );
						if (!qnx4_sb(sb)->BitMap) {
							brelse (bh);
							return "not enough memory for bitmap inode";
						}
						memcpy( qnx4_sb(sb)->BitMap, rootdir, sizeof( struct qnx4_inode_entry ) );	/* keep bitmap inode known */
						break;
					}
				}
			}
			brelse(bh);
			if (found != 0) {
				break;
			}
		}
		if (found == 0) {
			return "bitmap file not found.";
		}
	}
	return NULL;
}

static int qnx4_fill_super(struct super_block *s, void *data, int silent)
{
	struct buffer_head *bh;
	struct inode *root;
	const char *errmsg;
	struct qnx4_sb_info *qs;
	int ret = -EINVAL;

	qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
	if (!qs)
		return -ENOMEM;
	s->s_fs_info = qs;

	sb_set_blocksize(s, QNX4_BLOCK_SIZE);

	/* Check the superblock signature. Since the qnx4 code is
	   dangerous, we should leave as quickly as possible
	   if we don't belong here... */
	bh = sb_bread(s, 1);
	if (!bh) {
		printk(KERN_ERR "qnx4: unable to read the superblock\n");
		goto outnobh;
	}
	if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) {
		if (!silent)
			printk(KERN_ERR "qnx4: wrong fsid in superblock.\n");
		goto out;
	}
	s->s_op = &qnx4_sops;
	s->s_magic = QNX4_SUPER_MAGIC;
	s->s_flags |= MS_RDONLY;	/* Yup, read-only yet */
	qnx4_sb(s)->sb_buf = bh;
	qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data;


 	/* check before allocating dentries, inodes, .. */
	errmsg = qnx4_checkroot(s);
	if (errmsg != NULL) {
 		if (!silent)
			printk(KERN_ERR "qnx4: %s\n", errmsg);
		goto out;
	}

 	/* does root not have inode number QNX4_ROOT_INO ?? */
	root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
	if (IS_ERR(root)) {
		printk(KERN_ERR "qnx4: get inode failed\n");
		ret = PTR_ERR(root);
 		goto out;
 	}

	ret = -ENOMEM;
 	s->s_root = d_alloc_root(root);
 	if (s->s_root == NULL)
 		goto outi;

	brelse(bh);

	return 0;

      outi:
	iput(root);
      out:
	brelse(bh);
      outnobh:
	kfree(qs);
	s->s_fs_info = NULL;
	return ret;
}

static void qnx4_put_super(struct super_block *sb)
{
	struct qnx4_sb_info *qs = qnx4_sb(sb);
	kfree( qs->BitMap );
	kfree( qs );
	sb->s_fs_info = NULL;
	return;
}

static int qnx4_writepage(struct page *page, struct writeback_control *wbc)
{
	return block_write_full_page(page,qnx4_get_block, wbc);
}

static int qnx4_readpage(struct file *file, struct page *page)
{
	return block_read_full_page(page,qnx4_get_block);
}

static int qnx4_write_begin(struct file *file, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned flags,
			struct page **pagep, void **fsdata)
{
	struct qnx4_inode_info *qnx4_inode = qnx4_i(mapping->host);
	int ret;

	*pagep = NULL;
	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
				qnx4_get_block,
				&qnx4_inode->mmu_private);
	if (unlikely(ret)) {
		loff_t isize = mapping->host->i_size;
		if (pos + len > isize)
			vmtruncate(mapping->host, isize);
	}

	return ret;
}
static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
{
	return generic_block_bmap(mapping,block,qnx4_get_block);
}
static const struct address_space_operations qnx4_aops = {
	.readpage	= qnx4_readpage,
	.writepage	= qnx4_writepage,
	.sync_page	= block_sync_page,
	.write_begin	= qnx4_write_begin,
	.write_end	= generic_write_end,
	.bmap		= qnx4_bmap
};

struct inode *qnx4_iget(struct super_block *sb, unsigned long ino)
{
	struct buffer_head *bh;
	struct qnx4_inode_entry *raw_inode;
	int block;
	struct qnx4_inode_entry *qnx4_inode;
	struct inode *inode;

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

	qnx4_inode = qnx4_raw_inode(inode);
	inode->i_mode = 0;

	QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino));
	if (!ino) {
		printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is "
				"out of range\n",
		       sb->s_id, ino);
		iget_failed(inode);
		return ERR_PTR(-EIO);
	}
	block = ino / QNX4_INODES_PER_BLOCK;

	if (!(bh = sb_bread(sb, block))) {
		printk(KERN_ERR "qnx4: major problem: unable to read inode from dev "
		       "%s\n", sb->s_id);
		iget_failed(inode);
		return ERR_PTR(-EIO);
	}
	raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
	    (ino % QNX4_INODES_PER_BLOCK);

	inode->i_mode    = le16_to_cpu(raw_inode->di_mode);
	inode->i_uid     = (uid_t)le16_to_cpu(raw_inode->di_uid);
	inode->i_gid     = (gid_t)le16_to_cpu(raw_inode->di_gid);
	inode->i_nlink   = le16_to_cpu(raw_inode->di_nlink);
	inode->i_size    = le32_to_cpu(raw_inode->di_size);
	inode->i_mtime.tv_sec   = le32_to_cpu(raw_inode->di_mtime);
	inode->i_mtime.tv_nsec = 0;
	inode->i_atime.tv_sec   = le32_to_cpu(raw_inode->di_atime);
	inode->i_atime.tv_nsec = 0;
	inode->i_ctime.tv_sec   = le32_to_cpu(raw_inode->di_ctime);
	inode->i_ctime.tv_nsec = 0;
	inode->i_blocks  = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);

	memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
	if (S_ISREG(inode->i_mode)) {
		inode->i_fop = &generic_ro_fops;
		inode->i_mapping->a_ops = &qnx4_aops;
		qnx4_i(inode)->mmu_private = inode->i_size;
	} else if (S_ISDIR(inode->i_mode)) {
		inode->i_op = &qnx4_dir_inode_operations;
		inode->i_fop = &qnx4_dir_operations;
	} else if (S_ISLNK(inode->i_mode)) {
		inode->i_op = &page_symlink_inode_operations;
		inode->i_mapping->a_ops = &qnx4_aops;
		qnx4_i(inode)->mmu_private = inode->i_size;
	} else {
		printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n",
			ino, sb->s_id);
		iget_failed(inode);
		brelse(bh);
		return ERR_PTR(-EIO);
	}
	brelse(bh);
	unlock_new_inode(inode);
	return inode;
}

static struct kmem_cache *qnx4_inode_cachep;

static struct inode *qnx4_alloc_inode(struct super_block *sb)
{
	struct qnx4_inode_info *ei;
	ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL);
	if (!ei)
		return NULL;
	return &ei->vfs_inode;
}

static void qnx4_destroy_inode(struct inode *inode)
{
	kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
}

static void init_once(void *foo)
{
	struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;

	inode_init_once(&ei->vfs_inode);
}

static int init_inodecache(void)
{
	qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
					     sizeof(struct qnx4_inode_info),
					     0, (SLAB_RECLAIM_ACCOUNT|
						SLAB_MEM_SPREAD),
					     init_once);
	if (qnx4_inode_cachep == NULL)
		return -ENOMEM;
	return 0;
}

static void destroy_inodecache(void)
{
	kmem_cache_destroy(qnx4_inode_cachep);
}

static int qnx4_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, qnx4_fill_super,
			   mnt);
}

static struct file_system_type qnx4_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "qnx4",
	.get_sb		= qnx4_get_sb,
	.kill_sb	= kill_block_super,
	.fs_flags	= FS_REQUIRES_DEV,
};

static int __init init_qnx4_fs(void)
{
	int err;

	err = init_inodecache();
	if (err)
		return err;

	err = register_filesystem(&qnx4_fs_type);
	if (err) {
		destroy_inodecache();
		return err;
	}

	printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n");
	return 0;
}

static void __exit exit_qnx4_fs(void)
{
	unregister_filesystem(&qnx4_fs_type);
	destroy_inodecache();
}

module_init(init_qnx4_fs)
module_exit(exit_qnx4_fs)
MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* QNX4 file system, Linux implementation.
	3	*
	4	* Version : 0.2.1
	5	*
	6	* Using parts of the xiafs filesystem.
	7	*
	8	* History :
	9	*
	10	* 01-06-1998 by Richard Frowijn : first release.
	11	* 20-06-1998 by Frank Denis : Linux 2.1.99+ support, boot signature, misc.
	12	* 30-06-1998 by Frank Denis : first step to write inodes.
	13	*/
	14
1da177e4	15	#include <linux/module.h>
1da177e4	16	#include <linux/init.h>
964f5369	17	#include <linux/slab.h>
1da177e4 LT	18	#include <linux/highuid.h>
	19	#include <linux/smp_lock.h>
	20	#include <linux/pagemap.h>
	21	#include <linux/buffer_head.h>
79d25767	22	#include <linux/writeback.h>
964f5369 AV	23	#include <linux/statfs.h>
964f5369 AV	24	#include "qnx4.h"
1da177e4 LT	25
	26	#define QNX4_VERSION 4
	27	#define QNX4_BMNAME ".bitmap"
	28
ee9b6d61	29	static const struct super_operations qnx4_sops;
1da177e4	30
1da177e4 LT	31	static void qnx4_put_super(struct super_block *sb);
	32	static struct inode qnx4_alloc_inode(struct super_block sb);
	33	static void qnx4_destroy_inode(struct inode *inode);
1da177e4	34	static int qnx4_remount(struct super_block sb, int flags, char *data);
726c3342	35	static int qnx4_statfs(struct dentry , struct kstatfs );
1da177e4	36
ee9b6d61	37	static const struct super_operations qnx4_sops =
1da177e4 LT	38	{
	39	.alloc_inode = qnx4_alloc_inode,
	40	.destroy_inode = qnx4_destroy_inode,
1da177e4 LT	41	.put_super = qnx4_put_super,
	42	.statfs = qnx4_statfs,
	43	.remount_fs = qnx4_remount,
1da177e4 LT	44	};
	45
	46	static int qnx4_remount(struct super_block sb, int flags, char *data)
	47	{
	48	struct qnx4_sb_info *qs;
	49
	50	qs = qnx4_sb(sb);
	51	qs->Version = QNX4_VERSION;
1da177e4	52	*flags \|= MS_RDONLY;
1da177e4 LT	53	return 0;
	54	}
	55
	56	static struct buffer_head qnx4_getblk(struct inode inode, int nr,
	57	int create)
	58	{
	59	struct buffer_head *result = NULL;
	60
	61	if ( nr >= 0 )
	62	nr = qnx4_block_map( inode, nr );
	63	if (nr) {
	64	result = sb_getblk(inode->i_sb, nr);
	65	return result;
	66	}
ca120b20	67	return NULL;
1da177e4 LT	68	}
	69
	70	struct buffer_head qnx4_bread(struct inode inode, int block, int create)
	71	{
	72	struct buffer_head *bh;
	73
	74	bh = qnx4_getblk(inode, block, create);
	75	if (!bh \|\| buffer_uptodate(bh)) {
	76	return bh;
	77	}
	78	ll_rw_block(READ, 1, &bh);
	79	wait_on_buffer(bh);
	80	if (buffer_uptodate(bh)) {
	81	return bh;
	82	}
	83	brelse(bh);
	84
	85	return NULL;
	86	}
	87
	88	static int qnx4_get_block( struct inode inode, sector_t iblock, struct buffer_head bh, int create )
	89	{
	90	unsigned long phys;
	91
891ddb95	92	QNX4DEBUG((KERN_INFO "qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));
1da177e4 LT	93
	94	phys = qnx4_block_map( inode, iblock );
	95	if ( phys ) {
	96	// logical block is before EOF
	97	map_bh(bh, inode->i_sb, phys);
1da177e4 LT	98	}
	99	return 0;
	100	}
	101
	102	unsigned long qnx4_block_map( struct inode *inode, long iblock )
	103	{
	104	int ix;
	105	long offset, i_xblk;
	106	unsigned long block = 0;
	107	struct buffer_head *bh = NULL;
	108	struct qnx4_xblk *xblk = NULL;
	109	struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
75043cb5	110	u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);
1da177e4 LT	111
	112	if ( iblock < le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size) ) {
	113	// iblock is in the first extent. This is easy.
	114	block = le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_blk) + iblock - 1;
	115	} else {
	116	// iblock is beyond first extent. We have to follow the extent chain.
	117	i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
	118	offset = iblock - le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size);
	119	ix = 0;
	120	while ( --nxtnt > 0 ) {
	121	if ( ix == 0 ) {
	122	// read next xtnt block.
	123	bh = sb_bread(inode->i_sb, i_xblk - 1);
	124	if ( !bh ) {
891ddb95	125	QNX4DEBUG((KERN_ERR "qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
1da177e4 LT	126	return -EIO;
	127	}
	128	xblk = (struct qnx4_xblk*)bh->b_data;
	129	if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
891ddb95	130	QNX4DEBUG((KERN_ERR "qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
1da177e4 LT	131	return -EIO;
	132	}
	133	}
	134	if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) {
	135	// got it!
	136	block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1;
	137	break;
	138	}
	139	offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size);
	140	if ( ++ix >= xblk->xblk_num_xtnts ) {
	141	i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
	142	ix = 0;
	143	brelse( bh );
	144	bh = NULL;
	145	}
	146	}
	147	if ( bh )
	148	brelse( bh );
	149	}
	150
891ddb95	151	QNX4DEBUG((KERN_INFO "qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));
1da177e4 LT	152	return block;
	153	}
	154
726c3342	155	static int qnx4_statfs(struct dentry dentry, struct kstatfs buf)
1da177e4	156	{
726c3342	157	struct super_block *sb = dentry->d_sb;
5b76dc06	158	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
726c3342	159
1da177e4 LT	160	lock_kernel();
	161
	162	buf->f_type = sb->s_magic;
	163	buf->f_bsize = sb->s_blocksize;
	164	buf->f_blocks = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;
	165	buf->f_bfree = qnx4_count_free_blocks(sb);
	166	buf->f_bavail = buf->f_bfree;
	167	buf->f_namelen = QNX4_NAME_MAX;
5b76dc06 CL	168	buf->f_fsid.val[0] = (u32)id;
5b76dc06 CL	169	buf->f_fsid.val[1] = (u32)(id >> 32);
1da177e4 LT	170
	171	unlock_kernel();
	172
	173	return 0;
	174	}
	175
	176	/*
	177	* Check the root directory of the filesystem to make sure
	178	* it really _is_ a qnx4 filesystem, and to check the size
	179	* of the directory entry.
	180	*/
	181	static const char qnx4_checkroot(struct super_block sb)
	182	{
	183	struct buffer_head *bh;
	184	struct qnx4_inode_entry *rootdir;
	185	int rd, rl;
	186	int i, j;
	187	int found = 0;
	188
	189	if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/') {
	190	return "no qnx4 filesystem (no root dir).";
	191	} else {
891ddb95	192	QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id));
1da177e4 LT	193	rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1;
	194	rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size);
	195	for (j = 0; j < rl; j++) {
	196	bh = sb_bread(sb, rd + j); /* root dir, first block */
	197	if (bh == NULL) {
	198	return "unable to read root entry.";
	199	}
	200	for (i = 0; i < QNX4_INODES_PER_BLOCK; i++) {
	201	rootdir = (struct qnx4_inode_entry ) (bh->b_data + i QNX4_DIR_ENTRY_SIZE);
	202	if (rootdir->di_fname != NULL) {
891ddb95	203	QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname));
7e2a1083 JL	204	if (!strcmp(rootdir->di_fname,
7e2a1083 JL	205	QNX4_BMNAME)) {
1da177e4 LT	206	found = 1;
	207	qnx4_sb(sb)->BitMap = kmalloc( sizeof( struct qnx4_inode_entry ), GFP_KERNEL );
	208	if (!qnx4_sb(sb)->BitMap) {
	209	brelse (bh);
	210	return "not enough memory for bitmap inode";
	211	}
	212	memcpy( qnx4_sb(sb)->BitMap, rootdir, sizeof( struct qnx4_inode_entry ) ); /* keep bitmap inode known */
	213	break;
	214	}
	215	}
	216	}
	217	brelse(bh);
	218	if (found != 0) {
	219	break;
	220	}
	221	}
	222	if (found == 0) {
	223	return "bitmap file not found.";
	224	}
	225	}
	226	return NULL;
	227	}
	228
	229	static int qnx4_fill_super(struct super_block s, void data, int silent)
	230	{
	231	struct buffer_head *bh;
	232	struct inode *root;
	233	const char *errmsg;
	234	struct qnx4_sb_info *qs;
2b7e5bcb	235	int ret = -EINVAL;
1da177e4	236
f8314dc6	237	qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
1da177e4 LT	238	if (!qs)
	239	return -ENOMEM;
	240	s->s_fs_info = qs;
1da177e4 LT	241
	242	sb_set_blocksize(s, QNX4_BLOCK_SIZE);
	243
	244	/* Check the superblock signature. Since the qnx4 code is
	245	dangerous, we should leave as quickly as possible
	246	if we don't belong here... */
	247	bh = sb_bread(s, 1);
	248	if (!bh) {
891ddb95	249	printk(KERN_ERR "qnx4: unable to read the superblock\n");
1da177e4 LT	250	goto outnobh;
1da177e4 LT	251	}
75043cb5	252	if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) {
1da177e4	253	if (!silent)
891ddb95	254	printk(KERN_ERR "qnx4: wrong fsid in superblock.\n");
1da177e4 LT	255	goto out;
	256	}
	257	s->s_op = &qnx4_sops;
	258	s->s_magic = QNX4_SUPER_MAGIC;
1da177e4	259	s->s_flags \|= MS_RDONLY; /* Yup, read-only yet */
1da177e4 LT	260	qnx4_sb(s)->sb_buf = bh;
	261	qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data;
	262
	263
	264	/* check before allocating dentries, inodes, .. */
	265	errmsg = qnx4_checkroot(s);
	266	if (errmsg != NULL) {
	267	if (!silent)
891ddb95	268	printk(KERN_ERR "qnx4: %s\n", errmsg);
1da177e4 LT	269	goto out;
	270	}
	271
	272	/* does root not have inode number QNX4_ROOT_INO ?? */
2b7e5bcb DH	273	root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
2b7e5bcb DH	274	if (IS_ERR(root)) {
891ddb95	275	printk(KERN_ERR "qnx4: get inode failed\n");
2b7e5bcb	276	ret = PTR_ERR(root);
1da177e4 LT	277	goto out;
	278	}
	279
2b7e5bcb	280	ret = -ENOMEM;
1da177e4 LT	281	s->s_root = d_alloc_root(root);
	282	if (s->s_root == NULL)
	283	goto outi;
	284
	285	brelse(bh);
	286
	287	return 0;
	288
	289	outi:
	290	iput(root);
	291	out:
	292	brelse(bh);
	293	outnobh:
	294	kfree(qs);
	295	s->s_fs_info = NULL;
2b7e5bcb	296	return ret;
1da177e4 LT	297	}
	298
	299	static void qnx4_put_super(struct super_block *sb)
	300	{
	301	struct qnx4_sb_info *qs = qnx4_sb(sb);
	302	kfree( qs->BitMap );
	303	kfree( qs );
	304	sb->s_fs_info = NULL;
	305	return;
	306	}
	307
	308	static int qnx4_writepage(struct page page, struct writeback_control wbc)
	309	{
	310	return block_write_full_page(page,qnx4_get_block, wbc);
	311	}
f8706184	312
1da177e4 LT	313	static int qnx4_readpage(struct file file, struct page page)
	314	{
	315	return block_read_full_page(page,qnx4_get_block);
	316	}
f8706184 NP	317
	318	static int qnx4_write_begin(struct file file, struct address_space mapping,
	319	loff_t pos, unsigned len, unsigned flags,
	320	struct page pagep, void fsdata)
1da177e4	321	{
f8706184	322	struct qnx4_inode_info *qnx4_inode = qnx4_i(mapping->host);
282dc178 CH	323	int ret;
282dc178 CH	324
f8706184	325	*pagep = NULL;
282dc178	326	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
f8706184 NP	327	qnx4_get_block,
f8706184 NP	328	&qnx4_inode->mmu_private);
282dc178 CH	329	if (unlikely(ret)) {
	330	loff_t isize = mapping->host->i_size;
	331	if (pos + len > isize)
	332	vmtruncate(mapping->host, isize);
	333	}
	334
	335	return ret;
1da177e4 LT	336	}
	337	static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
	338	{
	339	return generic_block_bmap(mapping,block,qnx4_get_block);
	340	}
f5e54d6e	341	static const struct address_space_operations qnx4_aops = {
1da177e4 LT	342	.readpage = qnx4_readpage,
	343	.writepage = qnx4_writepage,
	344	.sync_page = block_sync_page,
f8706184 NP	345	.write_begin = qnx4_write_begin,
f8706184 NP	346	.write_end = generic_write_end,
1da177e4 LT	347	.bmap = qnx4_bmap
	348	};
	349
2b7e5bcb	350	struct inode qnx4_iget(struct super_block sb, unsigned long ino)
1da177e4 LT	351	{
	352	struct buffer_head *bh;
	353	struct qnx4_inode_entry *raw_inode;
2b7e5bcb DH	354	int block;
	355	struct qnx4_inode_entry *qnx4_inode;
	356	struct inode *inode;
1da177e4	357
2b7e5bcb DH	358	inode = iget_locked(sb, ino);
	359	if (!inode)
	360	return ERR_PTR(-ENOMEM);
	361	if (!(inode->i_state & I_NEW))
	362	return inode;
	363
	364	qnx4_inode = qnx4_raw_inode(inode);
1da177e4 LT	365	inode->i_mode = 0;
1da177e4 LT	366
891ddb95	367	QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino));
1da177e4	368	if (!ino) {
2b7e5bcb DH	369	printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is "
2b7e5bcb DH	370	"out of range\n",
1da177e4	371	sb->s_id, ino);
2b7e5bcb DH	372	iget_failed(inode);
2b7e5bcb DH	373	return ERR_PTR(-EIO);
1da177e4 LT	374	}
	375	block = ino / QNX4_INODES_PER_BLOCK;
	376
	377	if (!(bh = sb_bread(sb, block))) {
891ddb95	378	printk(KERN_ERR "qnx4: major problem: unable to read inode from dev "
1da177e4	379	"%s\n", sb->s_id);
2b7e5bcb DH	380	iget_failed(inode);
2b7e5bcb DH	381	return ERR_PTR(-EIO);
1da177e4 LT	382	}
	383	raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
	384	(ino % QNX4_INODES_PER_BLOCK);
	385
	386	inode->i_mode = le16_to_cpu(raw_inode->di_mode);
	387	inode->i_uid = (uid_t)le16_to_cpu(raw_inode->di_uid);
	388	inode->i_gid = (gid_t)le16_to_cpu(raw_inode->di_gid);
	389	inode->i_nlink = le16_to_cpu(raw_inode->di_nlink);
	390	inode->i_size = le32_to_cpu(raw_inode->di_size);
	391	inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->di_mtime);
	392	inode->i_mtime.tv_nsec = 0;
	393	inode->i_atime.tv_sec = le32_to_cpu(raw_inode->di_atime);
	394	inode->i_atime.tv_nsec = 0;
	395	inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->di_ctime);
	396	inode->i_ctime.tv_nsec = 0;
	397	inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);
1da177e4 LT	398
	399	memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
	400	if (S_ISREG(inode->i_mode)) {
945ffe54	401	inode->i_fop = &generic_ro_fops;
1da177e4 LT	402	inode->i_mapping->a_ops = &qnx4_aops;
	403	qnx4_i(inode)->mmu_private = inode->i_size;
	404	} else if (S_ISDIR(inode->i_mode)) {
	405	inode->i_op = &qnx4_dir_inode_operations;
	406	inode->i_fop = &qnx4_dir_operations;
	407	} else if (S_ISLNK(inode->i_mode)) {
	408	inode->i_op = &page_symlink_inode_operations;
	409	inode->i_mapping->a_ops = &qnx4_aops;
	410	qnx4_i(inode)->mmu_private = inode->i_size;
2b7e5bcb DH	411	} else {
	412	printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n",
	413	ino, sb->s_id);
	414	iget_failed(inode);
	415	brelse(bh);
	416	return ERR_PTR(-EIO);
	417	}
1da177e4	418	brelse(bh);
2b7e5bcb DH	419	unlock_new_inode(inode);
2b7e5bcb DH	420	return inode;
1da177e4 LT	421	}
1da177e4 LT	422
e18b890b	423	static struct kmem_cache *qnx4_inode_cachep;
1da177e4 LT	424
	425	static struct inode qnx4_alloc_inode(struct super_block sb)
	426	{
	427	struct qnx4_inode_info *ei;
e94b1766	428	ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL);
1da177e4 LT	429	if (!ei)
	430	return NULL;
	431	return &ei->vfs_inode;
	432	}
	433
	434	static void qnx4_destroy_inode(struct inode *inode)
	435	{
	436	kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
	437	}
	438
51cc5068	439	static void init_once(void *foo)
1da177e4 LT	440	{
	441	struct qnx4_inode_info ei = (struct qnx4_inode_info ) foo;
	442
a35afb83	443	inode_init_once(&ei->vfs_inode);
1da177e4 LT	444	}
	445
	446	static int init_inodecache(void)
	447	{
	448	qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
	449	sizeof(struct qnx4_inode_info),
fffb60f9 PJ	450	0, (SLAB_RECLAIM_ACCOUNT\|
fffb60f9 PJ	451	SLAB_MEM_SPREAD),
20c2df83	452	init_once);
1da177e4 LT	453	if (qnx4_inode_cachep == NULL)
	454	return -ENOMEM;
	455	return 0;
	456	}
	457
	458	static void destroy_inodecache(void)
	459	{
1a1d92c1	460	kmem_cache_destroy(qnx4_inode_cachep);
1da177e4 LT	461	}
1da177e4 LT	462
454e2398 DH	463	static int qnx4_get_sb(struct file_system_type *fs_type,
454e2398 DH	464	int flags, const char dev_name, void data, struct vfsmount *mnt)
1da177e4	465	{
454e2398 DH	466	return get_sb_bdev(fs_type, flags, dev_name, data, qnx4_fill_super,
454e2398 DH	467	mnt);
1da177e4 LT	468	}
	469
	470	static struct file_system_type qnx4_fs_type = {
	471	.owner = THIS_MODULE,
	472	.name = "qnx4",
	473	.get_sb = qnx4_get_sb,
	474	.kill_sb = kill_block_super,
	475	.fs_flags = FS_REQUIRES_DEV,
	476	};
	477
	478	static int __init init_qnx4_fs(void)
	479	{
	480	int err;
	481
	482	err = init_inodecache();
	483	if (err)
	484	return err;
	485
	486	err = register_filesystem(&qnx4_fs_type);
	487	if (err) {
	488	destroy_inodecache();
	489	return err;
	490	}
	491
891ddb95	492	printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n");
1da177e4 LT	493	return 0;
	494	}
	495
	496	static void __exit exit_qnx4_fs(void)
	497	{
	498	unregister_filesystem(&qnx4_fs_type);
	499	destroy_inodecache();
	500	}
	501
	502	module_init(init_qnx4_fs)
	503	module_exit(exit_qnx4_fs)
	504	MODULE_LICENSE("GPL");
	505