[mirror_ubuntu-bionic-kernel.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/exportfs.h>
#include "efs.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, unsigned int flags)
{
	efs_ino_t inodenum;
	struct inode *inode = NULL;

	inodenum = efs_find_entry(dir, dentry->d_name.name, dentry->d_name.len);
	if (inodenum)
		inode = efs_iget(dir->i_sb, inodenum);

	return d_splice_alias(inode, dentry);
}

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 = efs_iget(sb, ino);
	if (IS_ERR(inode))
		return ERR_CAST(inode);

	if (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 = ERR_PTR(-ENOENT);
	efs_ino_t ino;

	ino = efs_find_entry(child->d_inode, "..", 2);
	if (ino)
		parent = d_obtain_alias(efs_iget(child->d_inode->i_sb, ino));

	return parent;
}
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>
05da0804	11	#include <linux/exportfs.h>
45254b4f	12	#include "efs.h"
05da0804	13
1da177e4 LT	14
	15	static efs_ino_t efs_find_entry(struct inode inode, const char name, int len) {
	16	struct buffer_head *bh;
	17
	18	int slot, namelen;
	19	char *nameptr;
	20	struct efs_dir *dirblock;
	21	struct efs_dentry *dirslot;
	22	efs_ino_t inodenum;
	23	efs_block_t block;
	24
	25	if (inode->i_size & (EFS_DIRBSIZE-1))
	26	printk(KERN_WARNING "EFS: WARNING: find_entry(): directory size not a multiple of EFS_DIRBSIZE\n");
	27
	28	for(block = 0; block < inode->i_blocks; block++) {
	29
	30	bh = sb_bread(inode->i_sb, efs_bmap(inode, block));
	31	if (!bh) {
	32	printk(KERN_ERR "EFS: find_entry(): failed to read dir block %d\n", block);
	33	return 0;
	34	}
	35
	36	dirblock = (struct efs_dir *) bh->b_data;
	37
	38	if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
	39	printk(KERN_ERR "EFS: find_entry(): invalid directory block\n");
	40	brelse(bh);
	41	return(0);
	42	}
	43
	44	for(slot = 0; slot < dirblock->slots; slot++) {
	45	dirslot = (struct efs_dentry ) (((char ) bh->b_data) + EFS_SLOTAT(dirblock, slot));
	46
	47	namelen = dirslot->namelen;
	48	nameptr = dirslot->name;
	49
	50	if ((namelen == len) && (!memcmp(name, nameptr, len))) {
	51	inodenum = be32_to_cpu(dirslot->inode);
	52	brelse(bh);
	53	return(inodenum);
	54	}
	55	}
	56	brelse(bh);
	57	}
	58	return(0);
	59	}
	60
00cd8dd3 AV	61	struct dentry efs_lookup(struct inode dir, struct dentry *dentry, unsigned int flags)
00cd8dd3 AV	62	{
1da177e4	63	efs_ino_t inodenum;
a9049376	64	struct inode *inode = NULL;
1da177e4	65
1da177e4	66	inodenum = efs_find_entry(dir, dentry->d_name.name, dentry->d_name.len);
a9049376	67	if (inodenum)
298384cd	68	inode = efs_iget(dir->i_sb, inodenum);
1da177e4	69
2d8a10cd	70	return d_splice_alias(inode, dentry);
1da177e4 LT	71	}
1da177e4 LT	72
05da0804 CH	73	static struct inode efs_nfs_get_inode(struct super_block sb, u64 ino,
05da0804 CH	74	u32 generation)
5ca29607	75	{
5ca29607	76	struct inode *inode;
5ca29607 CH	77
	78	if (ino == 0)
	79	return ERR_PTR(-ESTALE);
298384cd DH	80	inode = efs_iget(sb, ino);
	81	if (IS_ERR(inode))
	82	return ERR_CAST(inode);
5ca29607	83
298384cd	84	if (generation && inode->i_generation != generation) {
05da0804 CH	85	iput(inode);
05da0804 CH	86	return ERR_PTR(-ESTALE);
5ca29607 CH	87	}
5ca29607 CH	88
05da0804 CH	89	return inode;
05da0804 CH	90	}
5ca29607	91
05da0804 CH	92	struct dentry efs_fh_to_dentry(struct super_block sb, struct fid *fid,
	93	int fh_len, int fh_type)
	94	{
	95	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
	96	efs_nfs_get_inode);
	97	}
	98
	99	struct dentry efs_fh_to_parent(struct super_block sb, struct fid *fid,
	100	int fh_len, int fh_type)
	101	{
	102	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
	103	efs_nfs_get_inode);
5ca29607 CH	104	}
5ca29607 CH	105
1da177e4 LT	106	struct dentry efs_get_parent(struct dentry child)
1da177e4 LT	107	{
44003728	108	struct dentry *parent = ERR_PTR(-ENOENT);
1da177e4	109	efs_ino_t ino;
1da177e4	110
1da177e4	111	ino = efs_find_entry(child->d_inode, "..", 2);
44003728 CH	112	if (ino)
44003728 CH	113	parent = d_obtain_alias(efs_iget(child->d_inode->i_sb, ino));
1da177e4	114
44003728	115	return parent;
1da177e4	116	}