[linux-block.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 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,
	.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 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;
}

static inline u32 try_extent(qnx4_xtnt_t *extent, u32 *offset)
{
	u32 size = le32_to_cpu(extent->xtnt_size);
	if (*offset < size)
		return le32_to_cpu(extent->xtnt_blk) + *offset - 1;
	*offset -= size;
	return 0;
}

unsigned long qnx4_block_map( struct inode *inode, long iblock )
{
	int ix;
	long i_xblk;
	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);
	u32 offset = iblock;
	u32 block = try_extent(&qnx4_inode->di_first_xtnt, &offset);

	if (block) {
		// iblock is in the first extent. This is easy.
	} else {
		// iblock is beyond first extent. We have to follow the extent chain.
		i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
		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;
				}
			}
			block = try_extent(&xblk->xblk_xtnts[ix], &offset);
			if (block) {
				// got it!
				break;
			}
			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 qnx4_super_block *s)
{
	struct buffer_head *bh;
	struct qnx4_inode_entry *rootdir;
	int rd, rl;
	int i, j;

	if (s->RootDir.di_fname[0] != '/' || s->RootDir.di_fname[1] != '\0')
		return "no qnx4 filesystem (no root dir).";
	QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id));
	rd = le32_to_cpu(s->RootDir.di_first_xtnt.xtnt_blk) - 1;
	rl = le32_to_cpu(s->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;

	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);

	s->s_op = &qnx4_sops;
	s->s_magic = QNX4_SUPER_MAGIC;
	s->s_flags |= MS_RDONLY;	/* Yup, read-only yet */

	/* 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");
		return -EINVAL;
	}

 	/* check before allocating dentries, inodes, .. */
	errmsg = qnx4_checkroot(s, (struct qnx4_super_block *) bh->b_data);
	brelse(bh);
	if (errmsg != NULL) {
 		if (!silent)
			printk(KERN_ERR "qnx4: %s\n", errmsg);
		return -EINVAL;
	}

 	/* 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");
		return PTR_ERR(root);
 	}

 	s->s_root = d_make_root(root);
 	if (s->s_root == NULL)
 		return -ENOMEM;

	return 0;
}

static void qnx4_kill_sb(struct super_block *sb)
{
	struct qnx4_sb_info *qs = qnx4_sb(sb);
	kill_block_super(sb);
	if (qs) {
		kfree(qs->BitMap);
		kfree(qs);
	}
}

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

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,
	.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);
	i_uid_write(inode, (uid_t)le16_to_cpu(raw_inode->di_uid));
	i_gid_write(inode, (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)
{
	/*
	 * Make sure all delayed rcu free inodes are flushed before we
	 * destroy cache.
	 */
	rcu_barrier();
	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	= qnx4_kill_sb,
	.fs_flags	= FS_REQUIRES_DEV,
};
MODULE_ALIAS_FS("qnx4");

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 struct inode qnx4_alloc_inode(struct super_block sb);
1da177e4 LT	31	static void qnx4_destroy_inode(struct inode *inode);
1da177e4	32	static int qnx4_remount(struct super_block sb, int flags, char *data);
726c3342	33	static int qnx4_statfs(struct dentry , struct kstatfs );
1da177e4	34
ee9b6d61	35	static const struct super_operations qnx4_sops =
1da177e4 LT	36	{
	37	.alloc_inode = qnx4_alloc_inode,
	38	.destroy_inode = qnx4_destroy_inode,
1da177e4 LT	39	.statfs = qnx4_statfs,
1da177e4 LT	40	.remount_fs = qnx4_remount,
1da177e4 LT	41	};
	42
	43	static int qnx4_remount(struct super_block sb, int flags, char *data)
	44	{
	45	struct qnx4_sb_info *qs;
	46
	47	qs = qnx4_sb(sb);
	48	qs->Version = QNX4_VERSION;
1da177e4	49	*flags \|= MS_RDONLY;
1da177e4 LT	50	return 0;
	51	}
	52
1da177e4 LT	53	static int qnx4_get_block( struct inode inode, sector_t iblock, struct buffer_head bh, int create )
	54	{
	55	unsigned long phys;
	56
891ddb95	57	QNX4DEBUG((KERN_INFO "qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));
1da177e4 LT	58
	59	phys = qnx4_block_map( inode, iblock );
	60	if ( phys ) {
	61	// logical block is before EOF
	62	map_bh(bh, inode->i_sb, phys);
1da177e4 LT	63	}
	64	return 0;
	65	}
	66
7cd916f6 AV	67	static inline u32 try_extent(qnx4_xtnt_t extent, u32 offset)
	68	{
	69	u32 size = le32_to_cpu(extent->xtnt_size);
	70	if (*offset < size)
	71	return le32_to_cpu(extent->xtnt_blk) + *offset - 1;
	72	*offset -= size;
	73	return 0;
	74	}
	75
1da177e4 LT	76	unsigned long qnx4_block_map( struct inode *inode, long iblock )
	77	{
	78	int ix;
7cd916f6	79	long i_xblk;
1da177e4 LT	80	struct buffer_head *bh = NULL;
	81	struct qnx4_xblk *xblk = NULL;
	82	struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
75043cb5	83	u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);
7cd916f6 AV	84	u32 offset = iblock;
7cd916f6 AV	85	u32 block = try_extent(&qnx4_inode->di_first_xtnt, &offset);
1da177e4	86
7cd916f6	87	if (block) {
1da177e4	88	// iblock is in the first extent. This is easy.
1da177e4 LT	89	} else {
	90	// iblock is beyond first extent. We have to follow the extent chain.
	91	i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
1da177e4 LT	92	ix = 0;
	93	while ( --nxtnt > 0 ) {
	94	if ( ix == 0 ) {
	95	// read next xtnt block.
	96	bh = sb_bread(inode->i_sb, i_xblk - 1);
	97	if ( !bh ) {
891ddb95	98	QNX4DEBUG((KERN_ERR "qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
1da177e4 LT	99	return -EIO;
	100	}
	101	xblk = (struct qnx4_xblk*)bh->b_data;
	102	if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
891ddb95	103	QNX4DEBUG((KERN_ERR "qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
1da177e4 LT	104	return -EIO;
	105	}
	106	}
7cd916f6 AV	107	block = try_extent(&xblk->xblk_xtnts[ix], &offset);
7cd916f6 AV	108	if (block) {
1da177e4	109	// got it!
1da177e4 LT	110	break;
1da177e4 LT	111	}
1da177e4 LT	112	if ( ++ix >= xblk->xblk_num_xtnts ) {
	113	i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
	114	ix = 0;
	115	brelse( bh );
	116	bh = NULL;
	117	}
	118	}
	119	if ( bh )
	120	brelse( bh );
	121	}
	122
891ddb95	123	QNX4DEBUG((KERN_INFO "qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));
1da177e4 LT	124	return block;
	125	}
	126
726c3342	127	static int qnx4_statfs(struct dentry dentry, struct kstatfs buf)
1da177e4	128	{
726c3342	129	struct super_block *sb = dentry->d_sb;
5b76dc06	130	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
726c3342	131
1da177e4 LT	132	buf->f_type = sb->s_magic;
	133	buf->f_bsize = sb->s_blocksize;
	134	buf->f_blocks = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;
	135	buf->f_bfree = qnx4_count_free_blocks(sb);
	136	buf->f_bavail = buf->f_bfree;
	137	buf->f_namelen = QNX4_NAME_MAX;
5b76dc06 CL	138	buf->f_fsid.val[0] = (u32)id;
5b76dc06 CL	139	buf->f_fsid.val[1] = (u32)(id >> 32);
1da177e4	140
1da177e4 LT	141	return 0;
	142	}
	143
	144	/*
	145	* Check the root directory of the filesystem to make sure
	146	* it really _is_ a qnx4 filesystem, and to check the size
	147	* of the directory entry.
	148	*/
208adb64 AV	149	static const char qnx4_checkroot(struct super_block sb,
208adb64 AV	150	struct qnx4_super_block *s)
1da177e4 LT	151	{
	152	struct buffer_head *bh;
	153	struct qnx4_inode_entry *rootdir;
	154	int rd, rl;
	155	int i, j;
1da177e4	156
208adb64	157	if (s->RootDir.di_fname[0] != '/' \|\| s->RootDir.di_fname[1] != '\0')
1da177e4	158	return "no qnx4 filesystem (no root dir).";
4134bf81	159	QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id));
208adb64 AV	160	rd = le32_to_cpu(s->RootDir.di_first_xtnt.xtnt_blk) - 1;
208adb64 AV	161	rl = le32_to_cpu(s->RootDir.di_first_xtnt.xtnt_size);
4134bf81 AV	162	for (j = 0; j < rl; j++) {
	163	bh = sb_bread(sb, rd + j); /* root dir, first block */
	164	if (bh == NULL)
	165	return "unable to read root entry.";
	166	rootdir = (struct qnx4_inode_entry *) bh->b_data;
	167	for (i = 0; i < QNX4_INODES_PER_BLOCK; i++, rootdir++) {
	168	QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname));
	169	if (strcmp(rootdir->di_fname, QNX4_BMNAME) != 0)
	170	continue;
	171	qnx4_sb(sb)->BitMap = kmemdup(rootdir,
	172	sizeof(struct qnx4_inode_entry),
	173	GFP_KERNEL);
1da177e4	174	brelse(bh);
4134bf81 AV	175	if (!qnx4_sb(sb)->BitMap)
	176	return "not enough memory for bitmap inode";
	177	/* keep bitmap inode known */
	178	return NULL;
1da177e4	179	}
4134bf81	180	brelse(bh);
1da177e4	181	}
4134bf81	182	return "bitmap file not found.";
1da177e4 LT	183	}
	184
	185	static int qnx4_fill_super(struct super_block s, void data, int silent)
	186	{
	187	struct buffer_head *bh;
	188	struct inode *root;
	189	const char *errmsg;
	190	struct qnx4_sb_info *qs;
	191
f8314dc6	192	qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
073c2141	193	if (!qs)
1da177e4 LT	194	return -ENOMEM;
1da177e4 LT	195	s->s_fs_info = qs;
1da177e4 LT	196
	197	sb_set_blocksize(s, QNX4_BLOCK_SIZE);
	198
208adb64 AV	199	s->s_op = &qnx4_sops;
	200	s->s_magic = QNX4_SUPER_MAGIC;
	201	s->s_flags \|= MS_RDONLY; /* Yup, read-only yet */
	202
1da177e4 LT	203	/* Check the superblock signature. Since the qnx4 code is
	204	dangerous, we should leave as quickly as possible
	205	if we don't belong here... */
	206	bh = sb_bread(s, 1);
	207	if (!bh) {
891ddb95	208	printk(KERN_ERR "qnx4: unable to read the superblock\n");
208adb64	209	return -EINVAL;
1da177e4	210	}
1da177e4 LT	211
1da177e4 LT	212	/* check before allocating dentries, inodes, .. */
208adb64 AV	213	errmsg = qnx4_checkroot(s, (struct qnx4_super_block *) bh->b_data);
208adb64 AV	214	brelse(bh);
1da177e4 LT	215	if (errmsg != NULL) {
1da177e4 LT	216	if (!silent)
891ddb95	217	printk(KERN_ERR "qnx4: %s\n", errmsg);
208adb64	218	return -EINVAL;
1da177e4 LT	219	}
	220
	221	/* does root not have inode number QNX4_ROOT_INO ?? */
2b7e5bcb DH	222	root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
2b7e5bcb DH	223	if (IS_ERR(root)) {
891ddb95	224	printk(KERN_ERR "qnx4: get inode failed\n");
208adb64	225	return PTR_ERR(root);
1da177e4 LT	226	}
1da177e4 LT	227
48fde701	228	s->s_root = d_make_root(root);
1da177e4	229	if (s->s_root == NULL)
208adb64	230	return -ENOMEM;
1da177e4	231
1da177e4	232	return 0;
1da177e4 LT	233	}
1da177e4 LT	234
208adb64	235	static void qnx4_kill_sb(struct super_block *sb)
1da177e4 LT	236	{
1da177e4 LT	237	struct qnx4_sb_info *qs = qnx4_sb(sb);
208adb64 AV	238	kill_block_super(sb);
	239	if (qs) {
	240	kfree(qs->BitMap);
	241	kfree(qs);
	242	}
1da177e4 LT	243	}
1da177e4 LT	244
1da177e4 LT	245	static int qnx4_readpage(struct file file, struct page page)
	246	{
	247	return block_read_full_page(page,qnx4_get_block);
	248	}
f8706184	249
1da177e4 LT	250	static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
	251	{
	252	return generic_block_bmap(mapping,block,qnx4_get_block);
	253	}
f5e54d6e	254	static const struct address_space_operations qnx4_aops = {
1da177e4	255	.readpage = qnx4_readpage,
1da177e4 LT	256	.bmap = qnx4_bmap
	257	};
	258
2b7e5bcb	259	struct inode qnx4_iget(struct super_block sb, unsigned long ino)
1da177e4 LT	260	{
	261	struct buffer_head *bh;
	262	struct qnx4_inode_entry *raw_inode;
2b7e5bcb DH	263	int block;
	264	struct qnx4_inode_entry *qnx4_inode;
	265	struct inode *inode;
1da177e4	266
2b7e5bcb DH	267	inode = iget_locked(sb, ino);
	268	if (!inode)
	269	return ERR_PTR(-ENOMEM);
	270	if (!(inode->i_state & I_NEW))
	271	return inode;
	272
	273	qnx4_inode = qnx4_raw_inode(inode);
1da177e4 LT	274	inode->i_mode = 0;
1da177e4 LT	275
891ddb95	276	QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino));
1da177e4	277	if (!ino) {
2b7e5bcb DH	278	printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is "
2b7e5bcb DH	279	"out of range\n",
1da177e4	280	sb->s_id, ino);
2b7e5bcb DH	281	iget_failed(inode);
2b7e5bcb DH	282	return ERR_PTR(-EIO);
1da177e4 LT	283	}
	284	block = ino / QNX4_INODES_PER_BLOCK;
	285
	286	if (!(bh = sb_bread(sb, block))) {
891ddb95	287	printk(KERN_ERR "qnx4: major problem: unable to read inode from dev "
1da177e4	288	"%s\n", sb->s_id);
2b7e5bcb DH	289	iget_failed(inode);
2b7e5bcb DH	290	return ERR_PTR(-EIO);
1da177e4 LT	291	}
	292	raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
	293	(ino % QNX4_INODES_PER_BLOCK);
	294
	295	inode->i_mode = le16_to_cpu(raw_inode->di_mode);
511728d7 EB	296	i_uid_write(inode, (uid_t)le16_to_cpu(raw_inode->di_uid));
511728d7 EB	297	i_gid_write(inode, (gid_t)le16_to_cpu(raw_inode->di_gid));
bfe86848	298	set_nlink(inode, le16_to_cpu(raw_inode->di_nlink));
1da177e4 LT	299	inode->i_size = le32_to_cpu(raw_inode->di_size);
	300	inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->di_mtime);
	301	inode->i_mtime.tv_nsec = 0;
	302	inode->i_atime.tv_sec = le32_to_cpu(raw_inode->di_atime);
	303	inode->i_atime.tv_nsec = 0;
	304	inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->di_ctime);
	305	inode->i_ctime.tv_nsec = 0;
	306	inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);
1da177e4 LT	307
	308	memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
	309	if (S_ISREG(inode->i_mode)) {
945ffe54	310	inode->i_fop = &generic_ro_fops;
1da177e4 LT	311	inode->i_mapping->a_ops = &qnx4_aops;
	312	qnx4_i(inode)->mmu_private = inode->i_size;
	313	} else if (S_ISDIR(inode->i_mode)) {
	314	inode->i_op = &qnx4_dir_inode_operations;
	315	inode->i_fop = &qnx4_dir_operations;
	316	} else if (S_ISLNK(inode->i_mode)) {
	317	inode->i_op = &page_symlink_inode_operations;
	318	inode->i_mapping->a_ops = &qnx4_aops;
	319	qnx4_i(inode)->mmu_private = inode->i_size;
2b7e5bcb DH	320	} else {
	321	printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n",
	322	ino, sb->s_id);
	323	iget_failed(inode);
	324	brelse(bh);
	325	return ERR_PTR(-EIO);
	326	}
1da177e4	327	brelse(bh);
2b7e5bcb DH	328	unlock_new_inode(inode);
2b7e5bcb DH	329	return inode;
1da177e4 LT	330	}
1da177e4 LT	331
e18b890b	332	static struct kmem_cache *qnx4_inode_cachep;
1da177e4 LT	333
	334	static struct inode qnx4_alloc_inode(struct super_block sb)
	335	{
	336	struct qnx4_inode_info *ei;
e94b1766	337	ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL);
1da177e4 LT	338	if (!ei)
	339	return NULL;
	340	return &ei->vfs_inode;
	341	}
	342
fa0d7e3d	343	static void qnx4_i_callback(struct rcu_head *head)
1da177e4	344	{
fa0d7e3d	345	struct inode *inode = container_of(head, struct inode, i_rcu);
1da177e4 LT	346	kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
	347	}
	348
fa0d7e3d NP	349	static void qnx4_destroy_inode(struct inode *inode)
	350	{
	351	call_rcu(&inode->i_rcu, qnx4_i_callback);
	352	}
	353
51cc5068	354	static void init_once(void *foo)
1da177e4 LT	355	{
	356	struct qnx4_inode_info ei = (struct qnx4_inode_info ) foo;
	357
a35afb83	358	inode_init_once(&ei->vfs_inode);
1da177e4 LT	359	}
	360
	361	static int init_inodecache(void)
	362	{
	363	qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
	364	sizeof(struct qnx4_inode_info),
fffb60f9 PJ	365	0, (SLAB_RECLAIM_ACCOUNT\|
fffb60f9 PJ	366	SLAB_MEM_SPREAD),
20c2df83	367	init_once);
1da177e4 LT	368	if (qnx4_inode_cachep == NULL)
	369	return -ENOMEM;
	370	return 0;
	371	}
	372
	373	static void destroy_inodecache(void)
	374	{
8c0a8537 KS	375	/*
	376	* Make sure all delayed rcu free inodes are flushed before we
	377	* destroy cache.
	378	*/
	379	rcu_barrier();
1a1d92c1	380	kmem_cache_destroy(qnx4_inode_cachep);
1da177e4 LT	381	}
1da177e4 LT	382
152a0836 AV	383	static struct dentry qnx4_mount(struct file_system_type fs_type,
152a0836 AV	384	int flags, const char dev_name, void data)
1da177e4	385	{
152a0836	386	return mount_bdev(fs_type, flags, dev_name, data, qnx4_fill_super);
1da177e4 LT	387	}
	388
	389	static struct file_system_type qnx4_fs_type = {
	390	.owner = THIS_MODULE,
	391	.name = "qnx4",
152a0836	392	.mount = qnx4_mount,
208adb64	393	.kill_sb = qnx4_kill_sb,
1da177e4 LT	394	.fs_flags = FS_REQUIRES_DEV,
1da177e4 LT	395	};
7f78e035	396	MODULE_ALIAS_FS("qnx4");
1da177e4 LT	397
	398	static int __init init_qnx4_fs(void)
	399	{
	400	int err;
	401
	402	err = init_inodecache();
	403	if (err)
	404	return err;
	405
	406	err = register_filesystem(&qnx4_fs_type);
	407	if (err) {
	408	destroy_inodecache();
	409	return err;
	410	}
	411
891ddb95	412	printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n");
1da177e4 LT	413	return 0;
	414	}
	415
	416	static void __exit exit_qnx4_fs(void)
	417	{
	418	unregister_filesystem(&qnx4_fs_type);
	419	destroy_inodecache();
	420	}
	421
	422	module_init(init_qnx4_fs)
	423	module_exit(exit_qnx4_fs)
	424	MODULE_LICENSE("GPL");
	425