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Commit | Line | Data |
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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> | |
11 | #include <linux/efs_fs.h> | |
12 | #include <linux/smp_lock.h> | |
13 | ||
14 | static efs_ino_t efs_find_entry(struct inode *inode, const char *name, int len) { | |
15 | struct buffer_head *bh; | |
16 | ||
17 | int slot, namelen; | |
18 | char *nameptr; | |
19 | struct efs_dir *dirblock; | |
20 | struct efs_dentry *dirslot; | |
21 | efs_ino_t inodenum; | |
22 | efs_block_t block; | |
23 | ||
24 | if (inode->i_size & (EFS_DIRBSIZE-1)) | |
25 | printk(KERN_WARNING "EFS: WARNING: find_entry(): directory size not a multiple of EFS_DIRBSIZE\n"); | |
26 | ||
27 | for(block = 0; block < inode->i_blocks; block++) { | |
28 | ||
29 | bh = sb_bread(inode->i_sb, efs_bmap(inode, block)); | |
30 | if (!bh) { | |
31 | printk(KERN_ERR "EFS: find_entry(): failed to read dir block %d\n", block); | |
32 | return 0; | |
33 | } | |
34 | ||
35 | dirblock = (struct efs_dir *) bh->b_data; | |
36 | ||
37 | if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) { | |
38 | printk(KERN_ERR "EFS: find_entry(): invalid directory block\n"); | |
39 | brelse(bh); | |
40 | return(0); | |
41 | } | |
42 | ||
43 | for(slot = 0; slot < dirblock->slots; slot++) { | |
44 | dirslot = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot)); | |
45 | ||
46 | namelen = dirslot->namelen; | |
47 | nameptr = dirslot->name; | |
48 | ||
49 | if ((namelen == len) && (!memcmp(name, nameptr, len))) { | |
50 | inodenum = be32_to_cpu(dirslot->inode); | |
51 | brelse(bh); | |
52 | return(inodenum); | |
53 | } | |
54 | } | |
55 | brelse(bh); | |
56 | } | |
57 | return(0); | |
58 | } | |
59 | ||
60 | struct dentry *efs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { | |
61 | efs_ino_t inodenum; | |
62 | struct inode * inode = NULL; | |
63 | ||
64 | lock_kernel(); | |
65 | inodenum = efs_find_entry(dir, dentry->d_name.name, dentry->d_name.len); | |
66 | if (inodenum) { | |
67 | if (!(inode = iget(dir->i_sb, inodenum))) { | |
68 | unlock_kernel(); | |
69 | return ERR_PTR(-EACCES); | |
70 | } | |
71 | } | |
72 | unlock_kernel(); | |
73 | ||
74 | d_add(dentry, inode); | |
75 | return NULL; | |
76 | } | |
77 | ||
78 | struct dentry *efs_get_parent(struct dentry *child) | |
79 | { | |
80 | struct dentry *parent; | |
81 | struct inode *inode; | |
82 | efs_ino_t ino; | |
83 | int error; | |
84 | ||
85 | lock_kernel(); | |
86 | ||
87 | error = -ENOENT; | |
88 | ino = efs_find_entry(child->d_inode, "..", 2); | |
89 | if (!ino) | |
90 | goto fail; | |
91 | ||
92 | error = -EACCES; | |
93 | inode = iget(child->d_inode->i_sb, ino); | |
94 | if (!inode) | |
95 | goto fail; | |
96 | ||
97 | error = -ENOMEM; | |
98 | parent = d_alloc_anon(inode); | |
99 | if (!parent) | |
100 | goto fail_iput; | |
101 | ||
102 | unlock_kernel(); | |
103 | return parent; | |
104 | ||
105 | fail_iput: | |
106 | iput(inode); | |
107 | fail: | |
108 | unlock_kernel(); | |
109 | return ERR_PTR(error); | |
110 | } |