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/string.h>
10 #include <linux/efs_fs.h>
11
efs_find_entry(struct inode * inode,const char * name,int len)12 static efs_ino_t efs_find_entry(struct inode *inode, const char *name, int len) {
13 struct buffer_head *bh;
14
15 int slot, namelen;
16 char *nameptr;
17 struct efs_dir *dirblock;
18 struct efs_dentry *dirslot;
19 efs_ino_t inodenum;
20 efs_block_t block;
21
22 if (inode->i_size & (EFS_DIRBSIZE-1))
23 printk(KERN_WARNING "EFS: WARNING: find_entry(): directory size not a multiple of EFS_DIRBSIZE\n");
24
25 for(block = 0; block < inode->i_blocks; block++) {
26
27 bh = sb_bread(inode->i_sb, efs_bmap(inode, block));
28 if (!bh) {
29 printk(KERN_ERR "EFS: find_entry(): failed to read dir block %d\n", block);
30 return 0;
31 }
32
33 dirblock = (struct efs_dir *) bh->b_data;
34
35 if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
36 printk(KERN_ERR "EFS: find_entry(): invalid directory block\n");
37 brelse(bh);
38 return(0);
39 }
40
41 for(slot = 0; slot < dirblock->slots; slot++) {
42 dirslot = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot));
43
44 namelen = dirslot->namelen;
45 nameptr = dirslot->name;
46
47 if ((namelen == len) && (!memcmp(name, nameptr, len))) {
48 inodenum = be32_to_cpu(dirslot->inode);
49 brelse(bh);
50 return(inodenum);
51 }
52 }
53 brelse(bh);
54 }
55 return(0);
56 }
57
efs_lookup(struct inode * dir,struct dentry * dentry)58 struct dentry *efs_lookup(struct inode *dir, struct dentry *dentry) {
59 efs_ino_t inodenum;
60 struct inode * inode;
61
62 if (!dir || !S_ISDIR(dir->i_mode))
63 return ERR_PTR(-ENOENT);
64
65 inode = NULL;
66
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 return ERR_PTR(-EACCES);
71 }
72
73 d_add(dentry, inode);
74 return NULL;
75 }
76
77