[linux.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/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);

	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);

	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;

	if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/')
		return "no qnx4 filesystem (no root dir).";
	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.";
		rootdir = (struct qnx4_inode_entry *) bh->b_data;
		for (i = 0; i < QNX4_INODES_PER_BLOCK; i++, rootdir++) {
			QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname));
			if (strcmp(rootdir->di_fname, QNX4_BMNAME) != 0)
				continue;
			qnx4_sb(sb)->BitMap = kmemdup(rootdir,
						      sizeof(struct qnx4_inode_entry),
						      GFP_KERNEL);
			brelse(bh);
			if (!qnx4_sb(sb)->BitMap)
				return "not enough memory for bitmap inode";
			/* keep bitmap inode known */
			return NULL;
		}
		brelse(bh);
	}
	return "bitmap file not found.";
}

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 outb;
 	}

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

	brelse(bh);
	return 0;

      outi:
	iput(root);
      outb:
	kfree(qs->BitMap);
      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,
	.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);
	set_nlink(inode, 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_i_callback(struct rcu_head *head)
{
	struct inode *inode = container_of(head, struct inode, i_rcu);
	kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
}

static void qnx4_destroy_inode(struct inode *inode)
{
	call_rcu(&inode->i_rcu, qnx4_i_callback);
}

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 struct dentry *qnx4_mount(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data)
{
	return mount_bdev(fs_type, flags, dev_name, data, qnx4_fill_super);
}

static struct file_system_type qnx4_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "qnx4",
	.mount		= qnx4_mount,
	.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	18	#include <linux/highuid.h>
1da177e4 LT	19	#include <linux/pagemap.h>
1da177e4 LT	20	#include <linux/buffer_head.h>
79d25767	21	#include <linux/writeback.h>
964f5369 AV	22	#include <linux/statfs.h>
964f5369 AV	23	#include "qnx4.h"
1da177e4 LT	24
	25	#define QNX4_VERSION 4
	26	#define QNX4_BMNAME ".bitmap"
	27
ee9b6d61	28	static const struct super_operations qnx4_sops;
1da177e4	29
1da177e4 LT	30	static void qnx4_put_super(struct super_block *sb);
	31	static struct inode qnx4_alloc_inode(struct super_block sb);
	32	static void qnx4_destroy_inode(struct inode *inode);
1da177e4	33	static int qnx4_remount(struct super_block sb, int flags, char *data);
726c3342	34	static int qnx4_statfs(struct dentry , struct kstatfs );
1da177e4	35
ee9b6d61	36	static const struct super_operations qnx4_sops =
1da177e4 LT	37	{
	38	.alloc_inode = qnx4_alloc_inode,
	39	.destroy_inode = qnx4_destroy_inode,
1da177e4 LT	40	.put_super = qnx4_put_super,
	41	.statfs = qnx4_statfs,
	42	.remount_fs = qnx4_remount,
1da177e4 LT	43	};
	44
	45	static int qnx4_remount(struct super_block sb, int flags, char *data)
	46	{
	47	struct qnx4_sb_info *qs;
	48
	49	qs = qnx4_sb(sb);
	50	qs->Version = QNX4_VERSION;
1da177e4	51	*flags \|= MS_RDONLY;
1da177e4 LT	52	return 0;
	53	}
	54
	55	static struct buffer_head qnx4_getblk(struct inode inode, int nr,
	56	int create)
	57	{
	58	struct buffer_head *result = NULL;
	59
	60	if ( nr >= 0 )
	61	nr = qnx4_block_map( inode, nr );
	62	if (nr) {
	63	result = sb_getblk(inode->i_sb, nr);
	64	return result;
	65	}
ca120b20	66	return NULL;
1da177e4 LT	67	}
	68
	69	struct buffer_head qnx4_bread(struct inode inode, int block, int create)
	70	{
	71	struct buffer_head *bh;
	72
	73	bh = qnx4_getblk(inode, block, create);
	74	if (!bh \|\| buffer_uptodate(bh)) {
	75	return bh;
	76	}
	77	ll_rw_block(READ, 1, &bh);
	78	wait_on_buffer(bh);
	79	if (buffer_uptodate(bh)) {
	80	return bh;
	81	}
	82	brelse(bh);
	83
	84	return NULL;
	85	}
	86
	87	static int qnx4_get_block( struct inode inode, sector_t iblock, struct buffer_head bh, int create )
	88	{
	89	unsigned long phys;
	90
891ddb95	91	QNX4DEBUG((KERN_INFO "qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));
1da177e4 LT	92
	93	phys = qnx4_block_map( inode, iblock );
	94	if ( phys ) {
	95	// logical block is before EOF
	96	map_bh(bh, inode->i_sb, phys);
1da177e4 LT	97	}
	98	return 0;
	99	}
	100
	101	unsigned long qnx4_block_map( struct inode *inode, long iblock )
	102	{
	103	int ix;
	104	long offset, i_xblk;
	105	unsigned long block = 0;
	106	struct buffer_head *bh = NULL;
	107	struct qnx4_xblk *xblk = NULL;
	108	struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
75043cb5	109	u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);
1da177e4 LT	110
	111	if ( iblock < le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size) ) {
	112	// iblock is in the first extent. This is easy.
	113	block = le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_blk) + iblock - 1;
	114	} else {
	115	// iblock is beyond first extent. We have to follow the extent chain.
	116	i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
	117	offset = iblock - le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size);
	118	ix = 0;
	119	while ( --nxtnt > 0 ) {
	120	if ( ix == 0 ) {
	121	// read next xtnt block.
	122	bh = sb_bread(inode->i_sb, i_xblk - 1);
	123	if ( !bh ) {
891ddb95	124	QNX4DEBUG((KERN_ERR "qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
1da177e4 LT	125	return -EIO;
	126	}
	127	xblk = (struct qnx4_xblk*)bh->b_data;
	128	if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
891ddb95	129	QNX4DEBUG((KERN_ERR "qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
1da177e4 LT	130	return -EIO;
	131	}
	132	}
	133	if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) {
	134	// got it!
	135	block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1;
	136	break;
	137	}
	138	offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size);
	139	if ( ++ix >= xblk->xblk_num_xtnts ) {
	140	i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
	141	ix = 0;
	142	brelse( bh );
	143	bh = NULL;
	144	}
	145	}
	146	if ( bh )
	147	brelse( bh );
	148	}
	149
891ddb95	150	QNX4DEBUG((KERN_INFO "qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));
1da177e4 LT	151	return block;
	152	}
	153
726c3342	154	static int qnx4_statfs(struct dentry dentry, struct kstatfs buf)
1da177e4	155	{
726c3342	156	struct super_block *sb = dentry->d_sb;
5b76dc06	157	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
726c3342	158
1da177e4 LT	159	buf->f_type = sb->s_magic;
	160	buf->f_bsize = sb->s_blocksize;
	161	buf->f_blocks = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;
	162	buf->f_bfree = qnx4_count_free_blocks(sb);
	163	buf->f_bavail = buf->f_bfree;
	164	buf->f_namelen = QNX4_NAME_MAX;
5b76dc06 CL	165	buf->f_fsid.val[0] = (u32)id;
5b76dc06 CL	166	buf->f_fsid.val[1] = (u32)(id >> 32);
1da177e4	167
1da177e4 LT	168	return 0;
	169	}
	170
	171	/*
	172	* Check the root directory of the filesystem to make sure
	173	* it really _is_ a qnx4 filesystem, and to check the size
	174	* of the directory entry.
	175	*/
	176	static const char qnx4_checkroot(struct super_block sb)
	177	{
	178	struct buffer_head *bh;
	179	struct qnx4_inode_entry *rootdir;
	180	int rd, rl;
	181	int i, j;
1da177e4	182
4134bf81	183	if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/')
1da177e4	184	return "no qnx4 filesystem (no root dir).";
4134bf81 AV	185	QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id));
	186	rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1;
	187	rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size);
	188	for (j = 0; j < rl; j++) {
	189	bh = sb_bread(sb, rd + j); /* root dir, first block */
	190	if (bh == NULL)
	191	return "unable to read root entry.";
	192	rootdir = (struct qnx4_inode_entry *) bh->b_data;
	193	for (i = 0; i < QNX4_INODES_PER_BLOCK; i++, rootdir++) {
	194	QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname));
	195	if (strcmp(rootdir->di_fname, QNX4_BMNAME) != 0)
	196	continue;
	197	qnx4_sb(sb)->BitMap = kmemdup(rootdir,
	198	sizeof(struct qnx4_inode_entry),
	199	GFP_KERNEL);
1da177e4	200	brelse(bh);
4134bf81 AV	201	if (!qnx4_sb(sb)->BitMap)
	202	return "not enough memory for bitmap inode";
	203	/* keep bitmap inode known */
	204	return NULL;
1da177e4	205	}
4134bf81	206	brelse(bh);
1da177e4	207	}
4134bf81	208	return "bitmap file not found.";
1da177e4 LT	209	}
	210
	211	static int qnx4_fill_super(struct super_block s, void data, int silent)
	212	{
	213	struct buffer_head *bh;
	214	struct inode *root;
	215	const char *errmsg;
	216	struct qnx4_sb_info *qs;
2b7e5bcb	217	int ret = -EINVAL;
1da177e4	218
f8314dc6	219	qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
073c2141	220	if (!qs)
1da177e4 LT	221	return -ENOMEM;
1da177e4 LT	222	s->s_fs_info = qs;
1da177e4 LT	223
	224	sb_set_blocksize(s, QNX4_BLOCK_SIZE);
	225
	226	/* Check the superblock signature. Since the qnx4 code is
	227	dangerous, we should leave as quickly as possible
	228	if we don't belong here... */
	229	bh = sb_bread(s, 1);
	230	if (!bh) {
891ddb95	231	printk(KERN_ERR "qnx4: unable to read the superblock\n");
1da177e4 LT	232	goto outnobh;
1da177e4 LT	233	}
75043cb5	234	if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) {
1da177e4	235	if (!silent)
891ddb95	236	printk(KERN_ERR "qnx4: wrong fsid in superblock.\n");
1da177e4 LT	237	goto out;
	238	}
	239	s->s_op = &qnx4_sops;
	240	s->s_magic = QNX4_SUPER_MAGIC;
1da177e4	241	s->s_flags \|= MS_RDONLY; /* Yup, read-only yet */
1da177e4 LT	242	qnx4_sb(s)->sb_buf = bh;
	243	qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data;
	244
	245
	246	/* check before allocating dentries, inodes, .. */
	247	errmsg = qnx4_checkroot(s);
	248	if (errmsg != NULL) {
	249	if (!silent)
891ddb95	250	printk(KERN_ERR "qnx4: %s\n", errmsg);
1da177e4 LT	251	goto out;
	252	}
	253
	254	/* does root not have inode number QNX4_ROOT_INO ?? */
2b7e5bcb DH	255	root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
2b7e5bcb DH	256	if (IS_ERR(root)) {
891ddb95	257	printk(KERN_ERR "qnx4: get inode failed\n");
2b7e5bcb	258	ret = PTR_ERR(root);
8bc5191b	259	goto outb;
1da177e4 LT	260	}
1da177e4 LT	261
2b7e5bcb	262	ret = -ENOMEM;
1da177e4 LT	263	s->s_root = d_alloc_root(root);
	264	if (s->s_root == NULL)
	265	goto outi;
	266
	267	brelse(bh);
1da177e4 LT	268	return 0;
	269
	270	outi:
	271	iput(root);
8bc5191b AV	272	outb:
8bc5191b AV	273	kfree(qs->BitMap);
1da177e4 LT	274	out:
	275	brelse(bh);
	276	outnobh:
	277	kfree(qs);
	278	s->s_fs_info = NULL;
2b7e5bcb	279	return ret;
1da177e4 LT	280	}
	281
	282	static void qnx4_put_super(struct super_block *sb)
	283	{
	284	struct qnx4_sb_info *qs = qnx4_sb(sb);
	285	kfree( qs->BitMap );
	286	kfree( qs );
	287	sb->s_fs_info = NULL;
	288	return;
	289	}
	290
	291	static int qnx4_writepage(struct page page, struct writeback_control wbc)
	292	{
	293	return block_write_full_page(page,qnx4_get_block, wbc);
	294	}
f8706184	295
1da177e4 LT	296	static int qnx4_readpage(struct file file, struct page page)
	297	{
	298	return block_read_full_page(page,qnx4_get_block);
	299	}
f8706184 NP	300
	301	static int qnx4_write_begin(struct file file, struct address_space mapping,
	302	loff_t pos, unsigned len, unsigned flags,
	303	struct page pagep, void fsdata)
1da177e4	304	{
f8706184	305	struct qnx4_inode_info *qnx4_inode = qnx4_i(mapping->host);
282dc178 CH	306	int ret;
282dc178 CH	307
f8706184	308	*pagep = NULL;
282dc178	309	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
f8706184 NP	310	qnx4_get_block,
f8706184 NP	311	&qnx4_inode->mmu_private);
282dc178 CH	312	if (unlikely(ret)) {
	313	loff_t isize = mapping->host->i_size;
	314	if (pos + len > isize)
	315	vmtruncate(mapping->host, isize);
	316	}
	317
	318	return ret;
1da177e4 LT	319	}
	320	static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
	321	{
	322	return generic_block_bmap(mapping,block,qnx4_get_block);
	323	}
f5e54d6e	324	static const struct address_space_operations qnx4_aops = {
1da177e4 LT	325	.readpage = qnx4_readpage,
1da177e4 LT	326	.writepage = qnx4_writepage,
f8706184 NP	327	.write_begin = qnx4_write_begin,
f8706184 NP	328	.write_end = generic_write_end,
1da177e4 LT	329	.bmap = qnx4_bmap
	330	};
	331
2b7e5bcb	332	struct inode qnx4_iget(struct super_block sb, unsigned long ino)
1da177e4 LT	333	{
	334	struct buffer_head *bh;
	335	struct qnx4_inode_entry *raw_inode;
2b7e5bcb DH	336	int block;
	337	struct qnx4_inode_entry *qnx4_inode;
	338	struct inode *inode;
1da177e4	339
2b7e5bcb DH	340	inode = iget_locked(sb, ino);
	341	if (!inode)
	342	return ERR_PTR(-ENOMEM);
	343	if (!(inode->i_state & I_NEW))
	344	return inode;
	345
	346	qnx4_inode = qnx4_raw_inode(inode);
1da177e4 LT	347	inode->i_mode = 0;
1da177e4 LT	348
891ddb95	349	QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino));
1da177e4	350	if (!ino) {
2b7e5bcb DH	351	printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is "
2b7e5bcb DH	352	"out of range\n",
1da177e4	353	sb->s_id, ino);
2b7e5bcb DH	354	iget_failed(inode);
2b7e5bcb DH	355	return ERR_PTR(-EIO);
1da177e4 LT	356	}
	357	block = ino / QNX4_INODES_PER_BLOCK;
	358
	359	if (!(bh = sb_bread(sb, block))) {
891ddb95	360	printk(KERN_ERR "qnx4: major problem: unable to read inode from dev "
1da177e4	361	"%s\n", sb->s_id);
2b7e5bcb DH	362	iget_failed(inode);
2b7e5bcb DH	363	return ERR_PTR(-EIO);
1da177e4 LT	364	}
	365	raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
	366	(ino % QNX4_INODES_PER_BLOCK);
	367
	368	inode->i_mode = le16_to_cpu(raw_inode->di_mode);
	369	inode->i_uid = (uid_t)le16_to_cpu(raw_inode->di_uid);
	370	inode->i_gid = (gid_t)le16_to_cpu(raw_inode->di_gid);
bfe86848	371	set_nlink(inode, le16_to_cpu(raw_inode->di_nlink));
1da177e4 LT	372	inode->i_size = le32_to_cpu(raw_inode->di_size);
	373	inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->di_mtime);
	374	inode->i_mtime.tv_nsec = 0;
	375	inode->i_atime.tv_sec = le32_to_cpu(raw_inode->di_atime);
	376	inode->i_atime.tv_nsec = 0;
	377	inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->di_ctime);
	378	inode->i_ctime.tv_nsec = 0;
	379	inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);
1da177e4 LT	380
	381	memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
	382	if (S_ISREG(inode->i_mode)) {
945ffe54	383	inode->i_fop = &generic_ro_fops;
1da177e4 LT	384	inode->i_mapping->a_ops = &qnx4_aops;
	385	qnx4_i(inode)->mmu_private = inode->i_size;
	386	} else if (S_ISDIR(inode->i_mode)) {
	387	inode->i_op = &qnx4_dir_inode_operations;
	388	inode->i_fop = &qnx4_dir_operations;
	389	} else if (S_ISLNK(inode->i_mode)) {
	390	inode->i_op = &page_symlink_inode_operations;
	391	inode->i_mapping->a_ops = &qnx4_aops;
	392	qnx4_i(inode)->mmu_private = inode->i_size;
2b7e5bcb DH	393	} else {
	394	printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n",
	395	ino, sb->s_id);
	396	iget_failed(inode);
	397	brelse(bh);
	398	return ERR_PTR(-EIO);
	399	}
1da177e4	400	brelse(bh);
2b7e5bcb DH	401	unlock_new_inode(inode);
2b7e5bcb DH	402	return inode;
1da177e4 LT	403	}
1da177e4 LT	404
e18b890b	405	static struct kmem_cache *qnx4_inode_cachep;
1da177e4 LT	406
	407	static struct inode qnx4_alloc_inode(struct super_block sb)
	408	{
	409	struct qnx4_inode_info *ei;
e94b1766	410	ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL);
1da177e4 LT	411	if (!ei)
	412	return NULL;
	413	return &ei->vfs_inode;
	414	}
	415
fa0d7e3d	416	static void qnx4_i_callback(struct rcu_head *head)
1da177e4	417	{
fa0d7e3d	418	struct inode *inode = container_of(head, struct inode, i_rcu);
1da177e4 LT	419	kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
	420	}
	421
fa0d7e3d NP	422	static void qnx4_destroy_inode(struct inode *inode)
	423	{
	424	call_rcu(&inode->i_rcu, qnx4_i_callback);
	425	}
	426
51cc5068	427	static void init_once(void *foo)
1da177e4 LT	428	{
	429	struct qnx4_inode_info ei = (struct qnx4_inode_info ) foo;
	430
a35afb83	431	inode_init_once(&ei->vfs_inode);
1da177e4 LT	432	}
	433
	434	static int init_inodecache(void)
	435	{
	436	qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
	437	sizeof(struct qnx4_inode_info),
fffb60f9 PJ	438	0, (SLAB_RECLAIM_ACCOUNT\|
fffb60f9 PJ	439	SLAB_MEM_SPREAD),
20c2df83	440	init_once);
1da177e4 LT	441	if (qnx4_inode_cachep == NULL)
	442	return -ENOMEM;
	443	return 0;
	444	}
	445
	446	static void destroy_inodecache(void)
	447	{
1a1d92c1	448	kmem_cache_destroy(qnx4_inode_cachep);
1da177e4 LT	449	}
1da177e4 LT	450
152a0836 AV	451	static struct dentry qnx4_mount(struct file_system_type fs_type,
152a0836 AV	452	int flags, const char dev_name, void data)
1da177e4	453	{
152a0836	454	return mount_bdev(fs_type, flags, dev_name, data, qnx4_fill_super);
1da177e4 LT	455	}
	456
	457	static struct file_system_type qnx4_fs_type = {
	458	.owner = THIS_MODULE,
	459	.name = "qnx4",
152a0836	460	.mount = qnx4_mount,
1da177e4 LT	461	.kill_sb = kill_block_super,
	462	.fs_flags = FS_REQUIRES_DEV,
	463	};
	464
	465	static int __init init_qnx4_fs(void)
	466	{
	467	int err;
	468
	469	err = init_inodecache();
	470	if (err)
	471	return err;
	472
	473	err = register_filesystem(&qnx4_fs_type);
	474	if (err) {
	475	destroy_inodecache();
	476	return err;
	477	}
	478
891ddb95	479	printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n");
1da177e4 LT	480	return 0;
	481	}
	482
	483	static void __exit exit_qnx4_fs(void)
	484	{
	485	unregister_filesystem(&qnx4_fs_type);
	486	destroy_inodecache();
	487	}
	488
	489	module_init(init_qnx4_fs)
	490	module_exit(exit_qnx4_fs)
	491	MODULE_LICENSE("GPL");
	492