1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
|
/*
* namei.c
*
* Copyright (c) 1999 Al Smith
*
* Portions derived from work (c) 1995,1996 Christian Vogelgsang.
*/
#include <linux/string.h>
#include <linux/efs_fs.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 = bread(inode->i_dev, efs_bmap(inode, block), EFS_DIRBSIZE);
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) {
efs_ino_t inodenum;
struct inode * inode;
if (!dir || !S_ISDIR(dir->i_mode))
return ERR_PTR(-ENOENT);
inode = NULL;
inodenum = efs_find_entry(dir, dentry->d_name.name, dentry->d_name.len);
if (inodenum) {
if (!(inode = iget(dir->i_sb, inodenum)))
return ERR_PTR(-EACCES);
}
d_add(dentry, inode);
return NULL;
}
|
