[linux-block.git] / fs / efs / namei.c

/*
 * namei.c
 *
 * Copyright (c) 1999 Al Smith
 *
 * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
 */

#include <linux/buffer_head.h>
#include <linux/string.h>
#include <linux/efs_fs.h>
#include <linux/smp_lock.h>
#include <linux/exportfs.h>


static efs_ino_t efs_find_entry(struct inode *inode, const char *name, int len) {
	struct buffer_head *bh;

	int			slot, namelen;
	char			*nameptr;
	struct efs_dir		*dirblock;
	struct efs_dentry	*dirslot;
	efs_ino_t		inodenum;
	efs_block_t		block;
 
	if (inode->i_size & (EFS_DIRBSIZE-1))
		printk(KERN_WARNING "EFS: WARNING: find_entry(): directory size not a multiple of EFS_DIRBSIZE\n");

	for(block = 0; block < inode->i_blocks; block++) {

		bh = sb_bread(inode->i_sb, efs_bmap(inode, block));
		if (!bh) {
			printk(KERN_ERR "EFS: find_entry(): failed to read dir block %d\n", block);
			return 0;
		}
    
		dirblock = (struct efs_dir *) bh->b_data;

		if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
			printk(KERN_ERR "EFS: find_entry(): invalid directory block\n");
			brelse(bh);
			return(0);
		}

		for(slot = 0; slot < dirblock->slots; slot++) {
			dirslot  = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot));

			namelen  = dirslot->namelen;
			nameptr  = dirslot->name;

			if ((namelen == len) && (!memcmp(name, nameptr, len))) {
				inodenum = be32_to_cpu(dirslot->inode);
				brelse(bh);
				return(inodenum);
			}
		}
		brelse(bh);
	}
	return(0);
}

struct dentry *efs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) {
	efs_ino_t inodenum;
	struct inode * inode = NULL;

	lock_kernel();
	inodenum = efs_find_entry(dir, dentry->d_name.name, dentry->d_name.len);
	if (inodenum) {
		if (!(inode = iget(dir->i_sb, inodenum))) {
			unlock_kernel();
			return ERR_PTR(-EACCES);
		}
	}
	unlock_kernel();

	d_add(dentry, inode);
	return NULL;
}

static struct inode *efs_nfs_get_inode(struct super_block *sb, u64 ino,
		u32 generation)
{
	struct inode *inode;

	if (ino == 0)
		return ERR_PTR(-ESTALE);
	inode = iget(sb, ino);
	if (inode == NULL)
		return ERR_PTR(-ENOMEM);

	if (is_bad_inode(inode) ||
	    (generation && inode->i_generation != generation)) {
		iput(inode);
		return ERR_PTR(-ESTALE);
	}

	return inode;
}

struct dentry *efs_fh_to_dentry(struct super_block *sb, struct fid *fid,
		int fh_len, int fh_type)
{
	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
				    efs_nfs_get_inode);
}

struct dentry *efs_fh_to_parent(struct super_block *sb, struct fid *fid,
		int fh_len, int fh_type)
{
	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
				    efs_nfs_get_inode);
}

struct dentry *efs_get_parent(struct dentry *child)
{
	struct dentry *parent;
	struct inode *inode;
	efs_ino_t ino;
	int error;

	lock_kernel();

	error = -ENOENT;
	ino = efs_find_entry(child->d_inode, "..", 2);
	if (!ino)
		goto fail;

	error = -EACCES;
	inode = iget(child->d_inode->i_sb, ino);
	if (!inode)
		goto fail;

	error = -ENOMEM;
	parent = d_alloc_anon(inode);
	if (!parent)
		goto fail_iput;

	unlock_kernel();
	return parent;

 fail_iput:
	iput(inode);
 fail:
	unlock_kernel();
	return ERR_PTR(error);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* namei.c
	3	*
	4	* Copyright (c) 1999 Al Smith
	5	*
	6	* Portions derived from work (c) 1995,1996 Christian Vogelgsang.
	7	*/
	8
	9	#include <linux/buffer_head.h>
	10	#include <linux/string.h>
	11	#include <linux/efs_fs.h>
	12	#include <linux/smp_lock.h>
05da0804 CH	13	#include <linux/exportfs.h>
05da0804 CH	14
1da177e4 LT	15
	16	static efs_ino_t efs_find_entry(struct inode inode, const char name, int len) {
	17	struct buffer_head *bh;
	18
	19	int slot, namelen;
	20	char *nameptr;
	21	struct efs_dir *dirblock;
	22	struct efs_dentry *dirslot;
	23	efs_ino_t inodenum;
	24	efs_block_t block;
	25
	26	if (inode->i_size & (EFS_DIRBSIZE-1))
	27	printk(KERN_WARNING "EFS: WARNING: find_entry(): directory size not a multiple of EFS_DIRBSIZE\n");
	28
	29	for(block = 0; block < inode->i_blocks; block++) {
	30
	31	bh = sb_bread(inode->i_sb, efs_bmap(inode, block));
	32	if (!bh) {
	33	printk(KERN_ERR "EFS: find_entry(): failed to read dir block %d\n", block);
	34	return 0;
	35	}
	36
	37	dirblock = (struct efs_dir *) bh->b_data;
	38
	39	if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
	40	printk(KERN_ERR "EFS: find_entry(): invalid directory block\n");
	41	brelse(bh);
	42	return(0);
	43	}
	44
	45	for(slot = 0; slot < dirblock->slots; slot++) {
	46	dirslot = (struct efs_dentry ) (((char ) bh->b_data) + EFS_SLOTAT(dirblock, slot));
	47
	48	namelen = dirslot->namelen;
	49	nameptr = dirslot->name;
	50
	51	if ((namelen == len) && (!memcmp(name, nameptr, len))) {
	52	inodenum = be32_to_cpu(dirslot->inode);
	53	brelse(bh);
	54	return(inodenum);
	55	}
	56	}
	57	brelse(bh);
	58	}
	59	return(0);
	60	}
	61
	62	struct dentry efs_lookup(struct inode dir, struct dentry dentry, struct nameidata nd) {
	63	efs_ino_t inodenum;
	64	struct inode * inode = NULL;
	65
	66	lock_kernel();
	67	inodenum = efs_find_entry(dir, dentry->d_name.name, dentry->d_name.len);
	68	if (inodenum) {
	69	if (!(inode = iget(dir->i_sb, inodenum))) {
	70	unlock_kernel();
	71	return ERR_PTR(-EACCES);
	72	}
	73	}
	74	unlock_kernel();
	75
	76	d_add(dentry, inode);
	77	return NULL;
	78	}
79
05da0804 CH	80	static struct inode efs_nfs_get_inode(struct super_block sb, u64 ino,
05da0804 CH	81	u32 generation)
5ca29607	82	{
5ca29607	83	struct inode *inode;
5ca29607 CH	84
	85	if (ino == 0)
	86	return ERR_PTR(-ESTALE);
	87	inode = iget(sb, ino);
	88	if (inode == NULL)
	89	return ERR_PTR(-ENOMEM);
	90
	91	if (is_bad_inode(inode) \|\|
	92	(generation && inode->i_generation != generation)) {
05da0804 CH	93	iput(inode);
05da0804 CH	94	return ERR_PTR(-ESTALE);
5ca29607 CH	95	}
5ca29607 CH	96
05da0804 CH	97	return inode;
05da0804 CH	98	}
5ca29607	99
05da0804 CH	100	struct dentry efs_fh_to_dentry(struct super_block sb, struct fid *fid,
	101	int fh_len, int fh_type)
	102	{
	103	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
	104	efs_nfs_get_inode);
	105	}
	106
	107	struct dentry efs_fh_to_parent(struct super_block sb, struct fid *fid,
	108	int fh_len, int fh_type)
	109	{
	110	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
	111	efs_nfs_get_inode);
5ca29607 CH	112	}
5ca29607 CH	113
1da177e4 LT	114	struct dentry efs_get_parent(struct dentry child)
	115	{
	116	struct dentry *parent;
	117	struct inode *inode;
	118	efs_ino_t ino;
	119	int error;
	120
	121	lock_kernel();
	122
	123	error = -ENOENT;
	124	ino = efs_find_entry(child->d_inode, "..", 2);
	125	if (!ino)
	126	goto fail;
	127
	128	error = -EACCES;
	129	inode = iget(child->d_inode->i_sb, ino);
	130	if (!inode)
	131	goto fail;
	132
	133	error = -ENOMEM;
	134	parent = d_alloc_anon(inode);
	135	if (!parent)
	136	goto fail_iput;
	137
	138	unlock_kernel();
	139	return parent;
	140
	141	fail_iput:
	142	iput(inode);
	143	fail:
	144	unlock_kernel();
	145	return ERR_PTR(error);
	146	}