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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/fs/sysv/namei.c | |
4 | * | |
5 | * minix/namei.c | |
6 | * Copyright (C) 1991, 1992 Linus Torvalds | |
7 | * | |
8 | * coh/namei.c | |
9 | * Copyright (C) 1993 Pascal Haible, Bruno Haible | |
10 | * | |
11 | * sysv/namei.c | |
12 | * Copyright (C) 1993 Bruno Haible | |
13 | * Copyright (C) 1997, 1998 Krzysztof G. Baranowski | |
14 | */ | |
15 | ||
16 | #include <linux/pagemap.h> | |
1da177e4 LT |
17 | #include "sysv.h" |
18 | ||
1da177e4 LT |
19 | static int add_nondir(struct dentry *dentry, struct inode *inode) |
20 | { | |
21 | int err = sysv_add_link(dentry, inode); | |
22 | if (!err) { | |
23 | d_instantiate(dentry, inode); | |
24 | return 0; | |
25 | } | |
4e907c3d | 26 | inode_dec_link_count(inode); |
1da177e4 LT |
27 | iput(inode); |
28 | return err; | |
29 | } | |
30 | ||
00cd8dd3 | 31 | static struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags) |
1da177e4 LT |
32 | { |
33 | struct inode * inode = NULL; | |
34 | ino_t ino; | |
35 | ||
1da177e4 LT |
36 | if (dentry->d_name.len > SYSV_NAMELEN) |
37 | return ERR_PTR(-ENAMETOOLONG); | |
38 | ino = sysv_inode_by_name(dentry); | |
5bf35449 | 39 | if (ino) |
b8e1343f | 40 | inode = sysv_iget(dir->i_sb, ino); |
5bf35449 | 41 | return d_splice_alias(inode, dentry); |
1da177e4 LT |
42 | } |
43 | ||
549c7297 CB |
44 | static int sysv_mknod(struct user_namespace *mnt_userns, struct inode *dir, |
45 | struct dentry *dentry, umode_t mode, dev_t rdev) | |
1da177e4 LT |
46 | { |
47 | struct inode * inode; | |
48 | int err; | |
49 | ||
50 | if (!old_valid_dev(rdev)) | |
51 | return -EINVAL; | |
52 | ||
53 | inode = sysv_new_inode(dir, mode); | |
54 | err = PTR_ERR(inode); | |
55 | ||
56 | if (!IS_ERR(inode)) { | |
57 | sysv_set_inode(inode, rdev); | |
58 | mark_inode_dirty(inode); | |
59 | err = add_nondir(dentry, inode); | |
60 | } | |
61 | return err; | |
62 | } | |
63 | ||
549c7297 CB |
64 | static int sysv_create(struct user_namespace *mnt_userns, struct inode *dir, |
65 | struct dentry *dentry, umode_t mode, bool excl) | |
1da177e4 | 66 | { |
549c7297 | 67 | return sysv_mknod(&init_user_ns, dir, dentry, mode, 0); |
1da177e4 LT |
68 | } |
69 | ||
549c7297 CB |
70 | static int sysv_symlink(struct user_namespace *mnt_userns, struct inode *dir, |
71 | struct dentry *dentry, const char *symname) | |
1da177e4 LT |
72 | { |
73 | int err = -ENAMETOOLONG; | |
74 | int l = strlen(symname)+1; | |
75 | struct inode * inode; | |
76 | ||
77 | if (l > dir->i_sb->s_blocksize) | |
78 | goto out; | |
79 | ||
80 | inode = sysv_new_inode(dir, S_IFLNK|0777); | |
81 | err = PTR_ERR(inode); | |
82 | if (IS_ERR(inode)) | |
83 | goto out; | |
84 | ||
85 | sysv_set_inode(inode, 0); | |
86 | err = page_symlink(inode, symname, l); | |
87 | if (err) | |
88 | goto out_fail; | |
89 | ||
90 | mark_inode_dirty(inode); | |
91 | err = add_nondir(dentry, inode); | |
92 | out: | |
93 | return err; | |
94 | ||
95 | out_fail: | |
4e907c3d | 96 | inode_dec_link_count(inode); |
1da177e4 LT |
97 | iput(inode); |
98 | goto out; | |
99 | } | |
100 | ||
101 | static int sysv_link(struct dentry * old_dentry, struct inode * dir, | |
102 | struct dentry * dentry) | |
103 | { | |
2b0143b5 | 104 | struct inode *inode = d_inode(old_dentry); |
1da177e4 | 105 | |
02027d42 | 106 | inode->i_ctime = current_time(inode); |
4e907c3d | 107 | inode_inc_link_count(inode); |
7de9c6ee | 108 | ihold(inode); |
1da177e4 LT |
109 | |
110 | return add_nondir(dentry, inode); | |
111 | } | |
112 | ||
549c7297 CB |
113 | static int sysv_mkdir(struct user_namespace *mnt_userns, struct inode *dir, |
114 | struct dentry *dentry, umode_t mode) | |
1da177e4 LT |
115 | { |
116 | struct inode * inode; | |
8de52778 | 117 | int err; |
1da177e4 | 118 | |
4e907c3d | 119 | inode_inc_link_count(dir); |
1da177e4 LT |
120 | |
121 | inode = sysv_new_inode(dir, S_IFDIR|mode); | |
122 | err = PTR_ERR(inode); | |
123 | if (IS_ERR(inode)) | |
124 | goto out_dir; | |
125 | ||
126 | sysv_set_inode(inode, 0); | |
127 | ||
4e907c3d | 128 | inode_inc_link_count(inode); |
1da177e4 LT |
129 | |
130 | err = sysv_make_empty(inode, dir); | |
131 | if (err) | |
132 | goto out_fail; | |
133 | ||
134 | err = sysv_add_link(dentry, inode); | |
135 | if (err) | |
136 | goto out_fail; | |
137 | ||
138 | d_instantiate(dentry, inode); | |
139 | out: | |
140 | return err; | |
141 | ||
142 | out_fail: | |
4e907c3d AD |
143 | inode_dec_link_count(inode); |
144 | inode_dec_link_count(inode); | |
1da177e4 LT |
145 | iput(inode); |
146 | out_dir: | |
4e907c3d | 147 | inode_dec_link_count(dir); |
1da177e4 LT |
148 | goto out; |
149 | } | |
150 | ||
151 | static int sysv_unlink(struct inode * dir, struct dentry * dentry) | |
152 | { | |
2b0143b5 | 153 | struct inode * inode = d_inode(dentry); |
1da177e4 LT |
154 | struct page * page; |
155 | struct sysv_dir_entry * de; | |
156 | int err = -ENOENT; | |
157 | ||
158 | de = sysv_find_entry(dentry, &page); | |
159 | if (!de) | |
160 | goto out; | |
161 | ||
162 | err = sysv_delete_entry (de, page); | |
163 | if (err) | |
164 | goto out; | |
165 | ||
166 | inode->i_ctime = dir->i_ctime; | |
4e907c3d | 167 | inode_dec_link_count(inode); |
1da177e4 LT |
168 | out: |
169 | return err; | |
170 | } | |
171 | ||
172 | static int sysv_rmdir(struct inode * dir, struct dentry * dentry) | |
173 | { | |
2b0143b5 | 174 | struct inode *inode = d_inode(dentry); |
1da177e4 LT |
175 | int err = -ENOTEMPTY; |
176 | ||
177 | if (sysv_empty_dir(inode)) { | |
178 | err = sysv_unlink(dir, dentry); | |
179 | if (!err) { | |
180 | inode->i_size = 0; | |
4e907c3d AD |
181 | inode_dec_link_count(inode); |
182 | inode_dec_link_count(dir); | |
1da177e4 LT |
183 | } |
184 | } | |
185 | return err; | |
186 | } | |
187 | ||
188 | /* | |
189 | * Anybody can rename anything with this: the permission checks are left to the | |
190 | * higher-level routines. | |
191 | */ | |
549c7297 CB |
192 | static int sysv_rename(struct user_namespace *mnt_userns, struct inode *old_dir, |
193 | struct dentry *old_dentry, struct inode *new_dir, | |
194 | struct dentry *new_dentry, unsigned int flags) | |
1da177e4 | 195 | { |
2b0143b5 DH |
196 | struct inode * old_inode = d_inode(old_dentry); |
197 | struct inode * new_inode = d_inode(new_dentry); | |
1da177e4 LT |
198 | struct page * dir_page = NULL; |
199 | struct sysv_dir_entry * dir_de = NULL; | |
200 | struct page * old_page; | |
201 | struct sysv_dir_entry * old_de; | |
202 | int err = -ENOENT; | |
203 | ||
f03b8ad8 MS |
204 | if (flags & ~RENAME_NOREPLACE) |
205 | return -EINVAL; | |
206 | ||
1da177e4 LT |
207 | old_de = sysv_find_entry(old_dentry, &old_page); |
208 | if (!old_de) | |
209 | goto out; | |
210 | ||
211 | if (S_ISDIR(old_inode->i_mode)) { | |
212 | err = -EIO; | |
213 | dir_de = sysv_dotdot(old_inode, &dir_page); | |
214 | if (!dir_de) | |
215 | goto out_old; | |
216 | } | |
217 | ||
218 | if (new_inode) { | |
219 | struct page * new_page; | |
220 | struct sysv_dir_entry * new_de; | |
221 | ||
222 | err = -ENOTEMPTY; | |
223 | if (dir_de && !sysv_empty_dir(new_inode)) | |
224 | goto out_dir; | |
225 | ||
226 | err = -ENOENT; | |
227 | new_de = sysv_find_entry(new_dentry, &new_page); | |
228 | if (!new_de) | |
229 | goto out_dir; | |
1da177e4 | 230 | sysv_set_link(new_de, new_page, old_inode); |
02027d42 | 231 | new_inode->i_ctime = current_time(new_inode); |
1da177e4 | 232 | if (dir_de) |
9a53c3a7 | 233 | drop_nlink(new_inode); |
4e907c3d | 234 | inode_dec_link_count(new_inode); |
1da177e4 | 235 | } else { |
1da177e4 | 236 | err = sysv_add_link(new_dentry, old_inode); |
4787d45f | 237 | if (err) |
1da177e4 | 238 | goto out_dir; |
1da177e4 | 239 | if (dir_de) |
4e907c3d | 240 | inode_inc_link_count(new_dir); |
1da177e4 LT |
241 | } |
242 | ||
243 | sysv_delete_entry(old_de, old_page); | |
4787d45f | 244 | mark_inode_dirty(old_inode); |
1da177e4 LT |
245 | |
246 | if (dir_de) { | |
247 | sysv_set_link(dir_de, dir_page, new_dir); | |
4e907c3d | 248 | inode_dec_link_count(old_dir); |
1da177e4 LT |
249 | } |
250 | return 0; | |
251 | ||
252 | out_dir: | |
253 | if (dir_de) { | |
254 | kunmap(dir_page); | |
09cbfeaf | 255 | put_page(dir_page); |
1da177e4 LT |
256 | } |
257 | out_old: | |
258 | kunmap(old_page); | |
09cbfeaf | 259 | put_page(old_page); |
1da177e4 LT |
260 | out: |
261 | return err; | |
262 | } | |
263 | ||
264 | /* | |
265 | * directories can handle most operations... | |
266 | */ | |
c5ef1c42 | 267 | const struct inode_operations sysv_dir_inode_operations = { |
1da177e4 LT |
268 | .create = sysv_create, |
269 | .lookup = sysv_lookup, | |
270 | .link = sysv_link, | |
271 | .unlink = sysv_unlink, | |
272 | .symlink = sysv_symlink, | |
273 | .mkdir = sysv_mkdir, | |
274 | .rmdir = sysv_rmdir, | |
275 | .mknod = sysv_mknod, | |
276 | .rename = sysv_rename, | |
277 | .getattr = sysv_getattr, | |
278 | }; |