/*
* 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>
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;
}
struct dentry *efs_get_dentry(struct super_block *sb, void *vobjp)
{
__u32 *objp = vobjp;
unsigned long ino = objp[0];
__u32 generation = objp[1];
struct inode *inode;
struct dentry *result;
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)) {
result = ERR_PTR(-ESTALE);
goto out_iput;
}
result = d_alloc_anon(inode);
if (!result) {
result = ERR_PTR(-ENOMEM);
goto out_iput;
}
return result;
out_iput:
iput(inode);
return result;
}
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);
}
