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9#include <linux/buffer_head.h>
10#include <linux/string.h>
11#include <linux/efs_fs.h>
12#include <linux/smp_lock.h>
13#include <linux/exportfs.h>
14
15
16static 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
62struct 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
80static struct inode *efs_nfs_get_inode(struct super_block *sb, u64 ino,
81 u32 generation)
82{
83 struct inode *inode;
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)) {
93 iput(inode);
94 return ERR_PTR(-ESTALE);
95 }
96
97 return inode;
98}
99
100struct 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
107struct 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);
112}
113
114struct 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}
147
