Commit | Line | Data |
---|---|---|
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> | |
05da0804 CH |
13 | #include <linux/exportfs.h> |
14 | ||
1da177e4 LT |
15 | |
16 | static efs_ino_t efs_find_entry(struct inode *inode, const char *name, int len) { | |
17 | struct buffer_head *bh; | |
18 | ||
19 | int slot, namelen; | |
20 | char *nameptr; | |
21 | struct efs_dir *dirblock; | |
22 | struct efs_dentry *dirslot; | |
23 | efs_ino_t inodenum; | |
24 | efs_block_t block; | |
25 | ||
26 | if (inode->i_size & (EFS_DIRBSIZE-1)) | |
27 | printk(KERN_WARNING "EFS: WARNING: find_entry(): directory size not a multiple of EFS_DIRBSIZE\n"); | |
28 | ||
29 | for(block = 0; block < inode->i_blocks; block++) { | |
30 | ||
31 | bh = sb_bread(inode->i_sb, efs_bmap(inode, block)); | |
32 | if (!bh) { | |
33 | printk(KERN_ERR "EFS: find_entry(): failed to read dir block %d\n", block); | |
34 | return 0; | |
35 | } | |
36 | ||
37 | dirblock = (struct efs_dir *) bh->b_data; | |
38 | ||
39 | if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) { | |
40 | printk(KERN_ERR "EFS: find_entry(): invalid directory block\n"); | |
41 | brelse(bh); | |
42 | return(0); | |
43 | } | |
44 | ||
45 | for(slot = 0; slot < dirblock->slots; slot++) { | |
46 | dirslot = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot)); | |
47 | ||
48 | namelen = dirslot->namelen; | |
49 | nameptr = dirslot->name; | |
50 | ||
51 | if ((namelen == len) && (!memcmp(name, nameptr, len))) { | |
52 | inodenum = be32_to_cpu(dirslot->inode); | |
53 | brelse(bh); | |
54 | return(inodenum); | |
55 | } | |
56 | } | |
57 | brelse(bh); | |
58 | } | |
59 | return(0); | |
60 | } | |
61 | ||
62 | struct dentry *efs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { | |
63 | efs_ino_t inodenum; | |
64 | struct inode * inode = NULL; | |
65 | ||
66 | lock_kernel(); | |
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 | unlock_kernel(); | |
71 | return ERR_PTR(-EACCES); | |
72 | } | |
73 | } | |
74 | unlock_kernel(); | |
75 | ||
76 | d_add(dentry, inode); | |
77 | return NULL; | |
78 | } | |
79 | ||
05da0804 CH |
80 | static struct inode *efs_nfs_get_inode(struct super_block *sb, u64 ino, |
81 | u32 generation) | |
5ca29607 | 82 | { |
5ca29607 | 83 | struct inode *inode; |
5ca29607 CH |
84 | |
85 | if (ino == 0) | |
86 | return ERR_PTR(-ESTALE); | |
87 | inode = iget(sb, ino); | |
88 | if (inode == NULL) | |
89 | return ERR_PTR(-ENOMEM); | |
90 | ||
91 | if (is_bad_inode(inode) || | |
92 | (generation && inode->i_generation != generation)) { | |
05da0804 CH |
93 | iput(inode); |
94 | return ERR_PTR(-ESTALE); | |
5ca29607 CH |
95 | } |
96 | ||
05da0804 CH |
97 | return inode; |
98 | } | |
5ca29607 | 99 | |
05da0804 CH |
100 | struct dentry *efs_fh_to_dentry(struct super_block *sb, struct fid *fid, |
101 | int fh_len, int fh_type) | |
102 | { | |
103 | return generic_fh_to_dentry(sb, fid, fh_len, fh_type, | |
104 | efs_nfs_get_inode); | |
105 | } | |
106 | ||
107 | struct dentry *efs_fh_to_parent(struct super_block *sb, struct fid *fid, | |
108 | int fh_len, int fh_type) | |
109 | { | |
110 | return generic_fh_to_parent(sb, fid, fh_len, fh_type, | |
111 | efs_nfs_get_inode); | |
5ca29607 CH |
112 | } |
113 | ||
1da177e4 LT |
114 | struct dentry *efs_get_parent(struct dentry *child) |
115 | { | |
116 | struct dentry *parent; | |
117 | struct inode *inode; | |
118 | efs_ino_t ino; | |
119 | int error; | |
120 | ||
121 | lock_kernel(); | |
122 | ||
123 | error = -ENOENT; | |
124 | ino = efs_find_entry(child->d_inode, "..", 2); | |
125 | if (!ino) | |
126 | goto fail; | |
127 | ||
128 | error = -EACCES; | |
129 | inode = iget(child->d_inode->i_sb, ino); | |
130 | if (!inode) | |
131 | goto fail; | |
132 | ||
133 | error = -ENOMEM; | |
134 | parent = d_alloc_anon(inode); | |
135 | if (!parent) | |
136 | goto fail_iput; | |
137 | ||
138 | unlock_kernel(); | |
139 | return parent; | |
140 | ||
141 | fail_iput: | |
142 | iput(inode); | |
143 | fail: | |
144 | unlock_kernel(); | |
145 | return ERR_PTR(error); | |
146 | } |