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/exportfs.h>
12 #include "efs.h"
13
14
efs_find_entry(struct inode * inode,const char * name,int len)15 static efs_ino_t efs_find_entry(struct inode *inode, const char *name, int len) {
16 struct buffer_head *bh;
17
18 int slot, namelen;
19 char *nameptr;
20 struct efs_dir *dirblock;
21 struct efs_dentry *dirslot;
22 efs_ino_t inodenum;
23 efs_block_t block;
24
25 if (inode->i_size & (EFS_DIRBSIZE-1))
26 printk(KERN_WARNING "EFS: WARNING: find_entry(): directory size not a multiple of EFS_DIRBSIZE\n");
27
28 for(block = 0; block < inode->i_blocks; block++) {
29
30 bh = sb_bread(inode->i_sb, efs_bmap(inode, block));
31 if (!bh) {
32 printk(KERN_ERR "EFS: find_entry(): failed to read dir block %d\n", block);
33 return 0;
34 }
35
36 dirblock = (struct efs_dir *) bh->b_data;
37
38 if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
39 printk(KERN_ERR "EFS: find_entry(): invalid directory block\n");
40 brelse(bh);
41 return(0);
42 }
43
44 for(slot = 0; slot < dirblock->slots; slot++) {
45 dirslot = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot));
46
47 namelen = dirslot->namelen;
48 nameptr = dirslot->name;
49
50 if ((namelen == len) && (!memcmp(name, nameptr, len))) {
51 inodenum = be32_to_cpu(dirslot->inode);
52 brelse(bh);
53 return(inodenum);
54 }
55 }
56 brelse(bh);
57 }
58 return(0);
59 }
60
efs_lookup(struct inode * dir,struct dentry * dentry,struct nameidata * nd)61 struct dentry *efs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) {
62 efs_ino_t inodenum;
63 struct inode *inode = NULL;
64
65 inodenum = efs_find_entry(dir, dentry->d_name.name, dentry->d_name.len);
66 if (inodenum)
67 inode = efs_iget(dir->i_sb, inodenum);
68
69 return d_splice_alias(inode, dentry);
70 }
71
efs_nfs_get_inode(struct super_block * sb,u64 ino,u32 generation)72 static struct inode *efs_nfs_get_inode(struct super_block *sb, u64 ino,
73 u32 generation)
74 {
75 struct inode *inode;
76
77 if (ino == 0)
78 return ERR_PTR(-ESTALE);
79 inode = efs_iget(sb, ino);
80 if (IS_ERR(inode))
81 return ERR_CAST(inode);
82
83 if (generation && inode->i_generation != generation) {
84 iput(inode);
85 return ERR_PTR(-ESTALE);
86 }
87
88 return inode;
89 }
90
efs_fh_to_dentry(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)91 struct dentry *efs_fh_to_dentry(struct super_block *sb, struct fid *fid,
92 int fh_len, int fh_type)
93 {
94 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
95 efs_nfs_get_inode);
96 }
97
efs_fh_to_parent(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)98 struct dentry *efs_fh_to_parent(struct super_block *sb, struct fid *fid,
99 int fh_len, int fh_type)
100 {
101 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
102 efs_nfs_get_inode);
103 }
104
efs_get_parent(struct dentry * child)105 struct dentry *efs_get_parent(struct dentry *child)
106 {
107 struct dentry *parent = ERR_PTR(-ENOENT);
108 efs_ino_t ino;
109
110 ino = efs_find_entry(child->d_inode, "..", 2);
111 if (ino)
112 parent = d_obtain_alias(efs_iget(child->d_inode->i_sb, ino));
113
114 return parent;
115 }
116