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// SPDX-License-Identifier: GPL-2.0
/*
* 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))
pr_warn("%s(): directory size not a multiple of EFS_DIRBSIZE\n",
__func__);
for(block = 0; block < inode->i_blocks; block++) {
bh = sb_bread(inode->i_sb, efs_bmap(inode, block));
if (!bh) {
pr_err("%s(): failed to read dir block %d\n",
__func__, block);
return 0;
}
dirblock = (struct efs_dir *) bh->b_data;
if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
pr_err("%s(): invalid directory block\n", __func__);
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(d_inode(child), "..", 2);
if (ino)
parent = d_obtain_alias(efs_iget(child->d_sb, ino));
return parent;
}
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