blob: 1511bf9e5f80b524117dac9870c99a60ba9a72e4 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Christoph Hellwig05da0802007-10-21 16:42:09 -070011#include <linux/exportfs.h>
Christoph Hellwig45254b42008-02-23 15:23:51 -080012#include "efs.h"
Christoph Hellwig05da0802007-10-21 16:42:09 -070013
Linus Torvalds1da177e2005-04-16 15:20:36 -070014
15static 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
61struct dentry *efs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) {
62 efs_ino_t inodenum;
63 struct inode * inode = NULL;
64
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 inodenum = efs_find_entry(dir, dentry->d_name.name, dentry->d_name.len);
66 if (inodenum) {
David Howells298384c2008-02-07 00:15:34 -080067 inode = efs_iget(dir->i_sb, inodenum);
Al Viroe7ec9522009-06-16 23:35:46 -040068 if (IS_ERR(inode))
David Howells298384c2008-02-07 00:15:34 -080069 return ERR_CAST(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
Al Viro2d8a10c2008-08-11 11:33:57 -040072 return d_splice_alias(inode, dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -070073}
74
Christoph Hellwig05da0802007-10-21 16:42:09 -070075static struct inode *efs_nfs_get_inode(struct super_block *sb, u64 ino,
76 u32 generation)
Christoph Hellwig5ca29602007-07-17 04:04:29 -070077{
Christoph Hellwig5ca29602007-07-17 04:04:29 -070078 struct inode *inode;
Christoph Hellwig5ca29602007-07-17 04:04:29 -070079
80 if (ino == 0)
81 return ERR_PTR(-ESTALE);
David Howells298384c2008-02-07 00:15:34 -080082 inode = efs_iget(sb, ino);
83 if (IS_ERR(inode))
84 return ERR_CAST(inode);
Christoph Hellwig5ca29602007-07-17 04:04:29 -070085
David Howells298384c2008-02-07 00:15:34 -080086 if (generation && inode->i_generation != generation) {
Christoph Hellwig05da0802007-10-21 16:42:09 -070087 iput(inode);
88 return ERR_PTR(-ESTALE);
Christoph Hellwig5ca29602007-07-17 04:04:29 -070089 }
90
Christoph Hellwig05da0802007-10-21 16:42:09 -070091 return inode;
92}
Christoph Hellwig5ca29602007-07-17 04:04:29 -070093
Christoph Hellwig05da0802007-10-21 16:42:09 -070094struct dentry *efs_fh_to_dentry(struct super_block *sb, struct fid *fid,
95 int fh_len, int fh_type)
96{
97 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
98 efs_nfs_get_inode);
99}
100
101struct dentry *efs_fh_to_parent(struct super_block *sb, struct fid *fid,
102 int fh_len, int fh_type)
103{
104 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
105 efs_nfs_get_inode);
Christoph Hellwig5ca29602007-07-17 04:04:29 -0700106}
107
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108struct dentry *efs_get_parent(struct dentry *child)
109{
Christoph Hellwig44003722008-08-11 15:49:04 +0200110 struct dentry *parent = ERR_PTR(-ENOENT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 efs_ino_t ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 ino = efs_find_entry(child->d_inode, "..", 2);
Christoph Hellwig44003722008-08-11 15:49:04 +0200114 if (ino)
115 parent = d_obtain_alias(efs_iget(child->d_inode->i_sb, ino));
Christoph Hellwig44003722008-08-11 15:49:04 +0200116
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 return parent;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118}