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gerrit-public.fairphone.software / kernel / msm-4.9 / cf17df223c8cd56a92f34162f2a362eec9f4b157 / . / fs / efs / namei.c
blob: 5276b19423c1abeda0ccd20cc0b0f0f99fc0d1eb [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]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
14static 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
60struct 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
Christoph Hellwig5ca29602007-07-17 04:04:29 -0700[diff] [blame]78struct dentry *efs_get_dentry(struct super_block *sb, void *vobjp)
79{
80 __u32 *objp = vobjp;
81 unsigned long ino = objp[0];
82 __u32 generation = objp[1];
83 struct inode *inode;
84 struct dentry *result;
85
86 if (ino == 0)
87 return ERR_PTR(-ESTALE);
88 inode = iget(sb, ino);
89 if (inode == NULL)
90 return ERR_PTR(-ENOMEM);
91
92 if (is_bad_inode(inode) ||
93 (generation && inode->i_generation != generation)) {
94 result = ERR_PTR(-ESTALE);
95 goto out_iput;
96 }
97
98 result = d_alloc_anon(inode);
99 if (!result) {
100 result = ERR_PTR(-ENOMEM);
101 goto out_iput;
102 }
103 return result;
104
105 out_iput:
106 iput(inode);
107 return result;
108}
109
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]110struct dentry *efs_get_parent(struct dentry *child)
111{
112 struct dentry *parent;
113 struct inode *inode;
114 efs_ino_t ino;
115 int error;
116
117 lock_kernel();
118
119 error = -ENOENT;
120 ino = efs_find_entry(child->d_inode, "..", 2);
121 if (!ino)
122 goto fail;
123
124 error = -EACCES;
125 inode = iget(child->d_inode->i_sb, ino);
126 if (!inode)
127 goto fail;
128
129 error = -ENOMEM;
130 parent = d_alloc_anon(inode);
131 if (!parent)
132 goto fail_iput;
133
134 unlock_kernel();
135 return parent;
136
137 fail_iput:
138 iput(inode);
139 fail:
140 unlock_kernel();
141 return ERR_PTR(error);
142}