Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: ea2414b385ecf8c8bdb7bf8312c0cfb5b33c9b71 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/sysv/namei.c
 *
 *  minix/namei.c
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  coh/namei.c
 *  Copyright (C) 1993  Pascal Haible, Bruno Haible
 *
 *  sysv/namei.c
 *  Copyright (C) 1993  Bruno Haible
 *  Copyright (C) 1997, 1998  Krzysztof G. Baranowski
 */

#include <linux/pagemap.h>
#include "sysv.h"

static int add_nondir(struct dentry *dentry, struct inode *inode)
{
	int err = sysv_add_link(dentry, inode);
	if (!err) {
		d_instantiate(dentry, inode);
		return 0;
	}
	inode_dec_link_count(inode);
	iput(inode);
	return err;
}

static struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags)
{
	struct inode * inode = NULL;
	ino_t ino;

	if (dentry->d_name.len > SYSV_NAMELEN)
		return ERR_PTR(-ENAMETOOLONG);
	ino = sysv_inode_by_name(dentry);
	if (ino)
		inode = sysv_iget(dir->i_sb, ino);
	return d_splice_alias(inode, dentry);
}

static int sysv_mknod(struct inode * dir, struct dentry * dentry, umode_t mode, dev_t rdev)
{
	struct inode * inode;
	int err;

	if (!old_valid_dev(rdev))
		return -EINVAL;

	inode = sysv_new_inode(dir, mode);
	err = PTR_ERR(inode);

	if (!IS_ERR(inode)) {
		sysv_set_inode(inode, rdev);
		mark_inode_dirty(inode);
		err = add_nondir(dentry, inode);
	}
	return err;
}

static int sysv_create(struct inode * dir, struct dentry * dentry, umode_t mode, bool excl)
{
	return sysv_mknod(dir, dentry, mode, 0);
}

static int sysv_symlink(struct inode * dir, struct dentry * dentry, 
	const char * symname)
{
	int err = -ENAMETOOLONG;
	int l = strlen(symname)+1;
	struct inode * inode;

	if (l > dir->i_sb->s_blocksize)
		goto out;

	inode = sysv_new_inode(dir, S_IFLNK|0777);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out;
	
	sysv_set_inode(inode, 0);
	err = page_symlink(inode, symname, l);
	if (err)
		goto out_fail;

	mark_inode_dirty(inode);
	err = add_nondir(dentry, inode);
out:
	return err;

out_fail:
	inode_dec_link_count(inode);
	iput(inode);
	goto out;
}

static int sysv_link(struct dentry * old_dentry, struct inode * dir, 
	struct dentry * dentry)
{
	struct inode *inode = d_inode(old_dentry);

	inode->i_ctime = current_time(inode);
	inode_inc_link_count(inode);
	ihold(inode);

	return add_nondir(dentry, inode);
}

static int sysv_mkdir(struct inode * dir, struct dentry *dentry, umode_t mode)
{
	struct inode * inode;
	int err;

	inode_inc_link_count(dir);

	inode = sysv_new_inode(dir, S_IFDIR|mode);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_dir;

	sysv_set_inode(inode, 0);

	inode_inc_link_count(inode);

	err = sysv_make_empty(inode, dir);
	if (err)
		goto out_fail;

	err = sysv_add_link(dentry, inode);
	if (err)
		goto out_fail;

        d_instantiate(dentry, inode);
out:
	return err;

out_fail:
	inode_dec_link_count(inode);
	inode_dec_link_count(inode);
	iput(inode);
out_dir:
	inode_dec_link_count(dir);
	goto out;
}

static int sysv_unlink(struct inode * dir, struct dentry * dentry)
{
	struct inode * inode = d_inode(dentry);
	struct page * page;
	struct sysv_dir_entry * de;
	int err = -ENOENT;

	de = sysv_find_entry(dentry, &page);
	if (!de)
		goto out;

	err = sysv_delete_entry (de, page);
	if (err)
		goto out;

	inode->i_ctime = dir->i_ctime;
	inode_dec_link_count(inode);
out:
	return err;
}

static int sysv_rmdir(struct inode * dir, struct dentry * dentry)
{
	struct inode *inode = d_inode(dentry);
	int err = -ENOTEMPTY;

	if (sysv_empty_dir(inode)) {
		err = sysv_unlink(dir, dentry);
		if (!err) {
			inode->i_size = 0;
			inode_dec_link_count(inode);
			inode_dec_link_count(dir);
		}
	}
	return err;
}

/*
 * Anybody can rename anything with this: the permission checks are left to the
 * higher-level routines.
 */
static int sysv_rename(struct inode * old_dir, struct dentry * old_dentry,
		       struct inode * new_dir, struct dentry * new_dentry,
		       unsigned int flags)
{
	struct inode * old_inode = d_inode(old_dentry);
	struct inode * new_inode = d_inode(new_dentry);
	struct page * dir_page = NULL;
	struct sysv_dir_entry * dir_de = NULL;
	struct page * old_page;
	struct sysv_dir_entry * old_de;
	int err = -ENOENT;

	if (flags & ~RENAME_NOREPLACE)
		return -EINVAL;

	old_de = sysv_find_entry(old_dentry, &old_page);
	if (!old_de)
		goto out;

	if (S_ISDIR(old_inode->i_mode)) {
		err = -EIO;
		dir_de = sysv_dotdot(old_inode, &dir_page);
		if (!dir_de)
			goto out_old;
	}

	if (new_inode) {
		struct page * new_page;
		struct sysv_dir_entry * new_de;

		err = -ENOTEMPTY;
		if (dir_de && !sysv_empty_dir(new_inode))
			goto out_dir;

		err = -ENOENT;
		new_de = sysv_find_entry(new_dentry, &new_page);
		if (!new_de)
			goto out_dir;
		sysv_set_link(new_de, new_page, old_inode);
		new_inode->i_ctime = current_time(new_inode);
		if (dir_de)
			drop_nlink(new_inode);
		inode_dec_link_count(new_inode);
	} else {
		err = sysv_add_link(new_dentry, old_inode);
		if (err)
			goto out_dir;
		if (dir_de)
			inode_inc_link_count(new_dir);
	}

	sysv_delete_entry(old_de, old_page);
	mark_inode_dirty(old_inode);

	if (dir_de) {
		sysv_set_link(dir_de, dir_page, new_dir);
		inode_dec_link_count(old_dir);
	}
	return 0;

out_dir:
	if (dir_de) {
		kunmap(dir_page);
		put_page(dir_page);
	}
out_old:
	kunmap(old_page);
	put_page(old_page);
out:
	return err;
}

/*
 * directories can handle most operations...
 */
const struct inode_operations sysv_dir_inode_operations = {
	.create		= sysv_create,
	.lookup		= sysv_lookup,
	.link		= sysv_link,
	.unlink		= sysv_unlink,
	.symlink	= sysv_symlink,
	.mkdir		= sysv_mkdir,
	.rmdir		= sysv_rmdir,
	.mknod		= sysv_mknod,
	.rename		= sysv_rename,
	.getattr	= sysv_getattr,
};