1 /*
2 * 2007+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
3 * All rights reserved.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16 #include <linux/module.h>
17 #include <linux/fs.h>
18 #include <linux/ktime.h>
19 #include <linux/fs_struct.h>
20 #include <linux/pagemap.h>
21 #include <linux/writeback.h>
22 #include <linux/mount.h>
23 #include <linux/mm.h>
24
25 #include "netfs.h"
26
27 #define UNHASHED_OBSCURE_STRING_SIZE sizeof(" (deleted)")
28
29 /*
30 * Create path from root for given inode.
31 * Path is formed as set of stuctures, containing name of the object
32 * and its inode data (mode, permissions and so on).
33 */
pohmelfs_construct_path_string(struct pohmelfs_inode * pi,void * data,int len)34 int pohmelfs_construct_path_string(struct pohmelfs_inode *pi, void *data, int len)
35 {
36 struct path path;
37 struct dentry *d;
38 char *ptr;
39 int err = 0, strlen, reduce = 0;
40
41 d = d_find_alias(&pi->vfs_inode);
42 if (!d) {
43 printk("%s: no alias, list_empty: %d.\n", __func__, list_empty(&pi->vfs_inode.i_dentry));
44 return -ENOENT;
45 }
46
47 spin_lock(¤t->fs->lock);
48 path.mnt = mntget(current->fs->root.mnt);
49 spin_unlock(¤t->fs->lock);
50
51 path.dentry = d;
52
53 if (!IS_ROOT(d) && d_unhashed(d))
54 reduce = 1;
55
56 ptr = d_path(&path, data, len);
57 if (IS_ERR(ptr)) {
58 err = PTR_ERR(ptr);
59 goto out;
60 }
61
62 if (reduce && len >= UNHASHED_OBSCURE_STRING_SIZE) {
63 char *end = data + len - UNHASHED_OBSCURE_STRING_SIZE;
64 *end = '\0';
65 }
66
67 strlen = len - (ptr - (char *)data);
68 memmove(data, ptr, strlen);
69 ptr = data;
70
71 err = strlen;
72
73 dprintk("%s: dname: '%s', len: %u, maxlen: %u, name: '%s', strlen: %d.\n",
74 __func__, d->d_name.name, d->d_name.len, len, ptr, strlen);
75
76 out:
77 dput(d);
78 mntput(path.mnt);
79
80 return err;
81 }
82
pohmelfs_path_length(struct pohmelfs_inode * pi)83 int pohmelfs_path_length(struct pohmelfs_inode *pi)
84 {
85 struct dentry *d, *root, *first;
86 int len;
87 unsigned seq;
88
89 first = d_find_alias(&pi->vfs_inode);
90 if (!first) {
91 dprintk("%s: ino: %llu, mode: %o.\n", __func__, pi->ino, pi->vfs_inode.i_mode);
92 return -ENOENT;
93 }
94
95 spin_lock(¤t->fs->lock);
96 root = dget(current->fs->root.dentry);
97 spin_unlock(¤t->fs->lock);
98
99 rename_retry:
100 len = 1; /* Root slash */
101 d = first;
102 seq = read_seqbegin(&rename_lock);
103 rcu_read_lock();
104
105 if (!IS_ROOT(d) && d_unhashed(d))
106 len += UNHASHED_OBSCURE_STRING_SIZE; /* Obscure " (deleted)" string */
107
108 while (d && d != root && !IS_ROOT(d)) {
109 len += d->d_name.len + 1; /* Plus slash */
110 d = d->d_parent;
111 }
112 rcu_read_unlock();
113 if (read_seqretry(&rename_lock, seq))
114 goto rename_retry;
115
116 dput(root);
117 dput(first);
118
119 return len + 1; /* Including zero-byte */
120 }
121