1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/ufs/namei.c
4 *
5 * Migration to usage of "page cache" on May 2006 by
6 * Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base.
7 *
8 * Copyright (C) 1998
9 * Daniel Pirkl <daniel.pirkl@email.cz>
10 * Charles University, Faculty of Mathematics and Physics
11 *
12 * from
13 *
14 * linux/fs/ext2/namei.c
15 *
16 * Copyright (C) 1992, 1993, 1994, 1995
17 * Remy Card (card@masi.ibp.fr)
18 * Laboratoire MASI - Institut Blaise Pascal
19 * Universite Pierre et Marie Curie (Paris VI)
20 *
21 * from
22 *
23 * linux/fs/minix/namei.c
24 *
25 * Copyright (C) 1991, 1992 Linus Torvalds
26 *
27 * Big-endian to little-endian byte-swapping/bitmaps by
28 * David S. Miller (davem@caip.rutgers.edu), 1995
29 */
30
31 #include <linux/time.h>
32 #include <linux/fs.h>
33
34 #include "ufs_fs.h"
35 #include "ufs.h"
36 #include "util.h"
37
38 static inline int ufs_add_nondir(struct dentry *dentry, struct inode *inode)
39 {
40 int err = ufs_add_link(dentry, inode);
41 if (!err) {
42 d_instantiate_new(dentry, inode);
43 return 0;
44 }
45 inode_dec_link_count(inode);
46 discard_new_inode(inode);
47 return err;
48 }
49
50 static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
51 {
52 struct inode * inode = NULL;
53 ino_t ino;
54
55 if (dentry->d_name.len > UFS_MAXNAMLEN)
56 return ERR_PTR(-ENAMETOOLONG);
57
58 ino = ufs_inode_by_name(dir, &dentry->d_name);
59 if (ino)
60 inode = ufs_iget(dir->i_sb, ino);
61 return d_splice_alias(inode, dentry);
62 }
63
64 /*
65 * By the time this is called, we already have created
66 * the directory cache entry for the new file, but it
67 * is so far negative - it has no inode.
68 *
69 * If the create succeeds, we fill in the inode information
70 * with d_instantiate().
71 */
72 static int ufs_create (struct mnt_idmap * idmap,
73 struct inode * dir, struct dentry * dentry, umode_t mode,
74 bool excl)
75 {
76 struct inode *inode;
77
78 inode = ufs_new_inode(dir, mode);
79 if (IS_ERR(inode))
80 return PTR_ERR(inode);
81
82 inode->i_op = &ufs_file_inode_operations;
83 inode->i_fop = &ufs_file_operations;
84 inode->i_mapping->a_ops = &ufs_aops;
85 mark_inode_dirty(inode);
86 return ufs_add_nondir(dentry, inode);
87 }
88
89 static int ufs_mknod(struct mnt_idmap *idmap, struct inode *dir,
90 struct dentry *dentry, umode_t mode, dev_t rdev)
91 {
92 struct inode *inode;
93 int err;
94
95 if (!old_valid_dev(rdev))
96 return -EINVAL;
97
98 inode = ufs_new_inode(dir, mode);
99 err = PTR_ERR(inode);
100 if (!IS_ERR(inode)) {
101 init_special_inode(inode, mode, rdev);
102 ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev);
103 mark_inode_dirty(inode);
104 err = ufs_add_nondir(dentry, inode);
105 }
106 return err;
107 }
108
109 static int ufs_symlink (struct mnt_idmap * idmap, struct inode * dir,
110 struct dentry * dentry, const char * symname)
111 {
112 struct super_block * sb = dir->i_sb;
113 int err;
114 unsigned l = strlen(symname)+1;
115 struct inode * inode;
116
117 if (l > sb->s_blocksize)
118 return -ENAMETOOLONG;
119
120 inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO);
121 err = PTR_ERR(inode);
122 if (IS_ERR(inode))
123 return err;
124
125 if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) {
126 /* slow symlink */
127 inode->i_op = &page_symlink_inode_operations;
128 inode_nohighmem(inode);
129 inode->i_mapping->a_ops = &ufs_aops;
130 err = page_symlink(inode, symname, l);
131 if (err)
132 goto out_fail;
133 } else {
134 /* fast symlink */
135 inode->i_op = &simple_symlink_inode_operations;
136 inode->i_link = (char *)UFS_I(inode)->i_u1.i_symlink;
137 memcpy(inode->i_link, symname, l);
138 inode->i_size = l-1;
139 }
140 mark_inode_dirty(inode);
141
142 return ufs_add_nondir(dentry, inode);
143
144 out_fail:
145 inode_dec_link_count(inode);
146 discard_new_inode(inode);
147 return err;
148 }
149
150 static int ufs_link (struct dentry * old_dentry, struct inode * dir,
151 struct dentry *dentry)
152 {
153 struct inode *inode = d_inode(old_dentry);
154 int error;
155
156 inode_set_ctime_current(inode);
157 inode_inc_link_count(inode);
158 ihold(inode);
159
160 error = ufs_add_link(dentry, inode);
161 if (error) {
162 inode_dec_link_count(inode);
163 iput(inode);
164 } else
165 d_instantiate(dentry, inode);
166 return error;
167 }
168
169 static int ufs_mkdir(struct mnt_idmap * idmap, struct inode * dir,
170 struct dentry * dentry, umode_t mode)
171 {
172 struct inode * inode;
173 int err;
174
175 inode_inc_link_count(dir);
176
177 inode = ufs_new_inode(dir, S_IFDIR|mode);
178 err = PTR_ERR(inode);
179 if (IS_ERR(inode))
180 goto out_dir;
181
182 inode->i_op = &ufs_dir_inode_operations;
183 inode->i_fop = &ufs_dir_operations;
184 inode->i_mapping->a_ops = &ufs_aops;
185
186 inode_inc_link_count(inode);
187
188 err = ufs_make_empty(inode, dir);
189 if (err)
190 goto out_fail;
191
192 err = ufs_add_link(dentry, inode);
193 if (err)
194 goto out_fail;
195
196 d_instantiate_new(dentry, inode);
197 return 0;
198
199 out_fail:
200 inode_dec_link_count(inode);
201 inode_dec_link_count(inode);
202 discard_new_inode(inode);
203 out_dir:
204 inode_dec_link_count(dir);
205 return err;
206 }
207
208 static int ufs_unlink(struct inode *dir, struct dentry *dentry)
209 {
210 struct inode * inode = d_inode(dentry);
211 struct ufs_dir_entry *de;
212 struct page *page;
213 int err = -ENOENT;
214
215 de = ufs_find_entry(dir, &dentry->d_name, &page);
216 if (!de)
217 goto out;
218
219 err = ufs_delete_entry(dir, de, page);
220 if (err)
221 goto out;
222
223 inode_set_ctime_to_ts(inode, inode_get_ctime(dir));
224 inode_dec_link_count(inode);
225 err = 0;
226 out:
227 return err;
228 }
229
230 static int ufs_rmdir (struct inode * dir, struct dentry *dentry)
231 {
232 struct inode * inode = d_inode(dentry);
233 int err= -ENOTEMPTY;
234
235 if (ufs_empty_dir (inode)) {
236 err = ufs_unlink(dir, dentry);
237 if (!err) {
238 inode->i_size = 0;
239 inode_dec_link_count(inode);
240 inode_dec_link_count(dir);
241 }
242 }
243 return err;
244 }
245
246 static int ufs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
247 struct dentry *old_dentry, struct inode *new_dir,
248 struct dentry *new_dentry, unsigned int flags)
249 {
250 struct inode *old_inode = d_inode(old_dentry);
251 struct inode *new_inode = d_inode(new_dentry);
252 struct page *dir_page = NULL;
253 struct ufs_dir_entry * dir_de = NULL;
254 struct page *old_page;
255 struct ufs_dir_entry *old_de;
256 int err = -ENOENT;
257
258 if (flags & ~RENAME_NOREPLACE)
259 return -EINVAL;
260
261 old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_page);
262 if (!old_de)
263 goto out;
264
265 if (S_ISDIR(old_inode->i_mode)) {
266 err = -EIO;
267 dir_de = ufs_dotdot(old_inode, &dir_page);
268 if (!dir_de)
269 goto out_old;
270 }
271
272 if (new_inode) {
273 struct page *new_page;
274 struct ufs_dir_entry *new_de;
275
276 err = -ENOTEMPTY;
277 if (dir_de && !ufs_empty_dir(new_inode))
278 goto out_dir;
279
280 err = -ENOENT;
281 new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page);
282 if (!new_de)
283 goto out_dir;
284 ufs_set_link(new_dir, new_de, new_page, old_inode, 1);
285 inode_set_ctime_current(new_inode);
286 if (dir_de)
287 drop_nlink(new_inode);
288 inode_dec_link_count(new_inode);
289 } else {
290 err = ufs_add_link(new_dentry, old_inode);
291 if (err)
292 goto out_dir;
293 if (dir_de)
294 inode_inc_link_count(new_dir);
295 }
296
297 /*
298 * Like most other Unix systems, set the ctime for inodes on a
299 * rename.
300 */
301 inode_set_ctime_current(old_inode);
302
303 ufs_delete_entry(old_dir, old_de, old_page);
304 mark_inode_dirty(old_inode);
305
306 if (dir_de) {
307 if (old_dir != new_dir)
308 ufs_set_link(old_inode, dir_de, dir_page, new_dir, 0);
309 else {
310 kunmap(dir_page);
311 put_page(dir_page);
312 }
313 inode_dec_link_count(old_dir);
314 }
315 return 0;
316
317
318 out_dir:
319 if (dir_de) {
320 kunmap(dir_page);
321 put_page(dir_page);
322 }
323 out_old:
324 kunmap(old_page);
325 put_page(old_page);
326 out:
327 return err;
328 }
329
330 const struct inode_operations ufs_dir_inode_operations = {
331 .create = ufs_create,
332 .lookup = ufs_lookup,
333 .link = ufs_link,
334 .unlink = ufs_unlink,
335 .symlink = ufs_symlink,
336 .mkdir = ufs_mkdir,
337 .rmdir = ufs_rmdir,
338 .mknod = ufs_mknod,
339 .rename = ufs_rename,
340 };
341
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