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
ufs_add_nondir(struct dentry * dentry,struct inode * inode)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
ufs_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)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 */
ufs_create(struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)72 static int ufs_create (struct inode * dir, struct dentry * dentry, umode_t mode,
73 bool excl)
74 {
75 struct inode *inode;
76
77 inode = ufs_new_inode(dir, mode);
78 if (IS_ERR(inode))
79 return PTR_ERR(inode);
80
81 inode->i_op = &ufs_file_inode_operations;
82 inode->i_fop = &ufs_file_operations;
83 inode->i_mapping->a_ops = &ufs_aops;
84 mark_inode_dirty(inode);
85 return ufs_add_nondir(dentry, inode);
86 }
87
ufs_mknod(struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)88 static int ufs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
89 {
90 struct inode *inode;
91 int err;
92
93 if (!old_valid_dev(rdev))
94 return -EINVAL;
95
96 inode = ufs_new_inode(dir, mode);
97 err = PTR_ERR(inode);
98 if (!IS_ERR(inode)) {
99 init_special_inode(inode, mode, rdev);
100 ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev);
101 mark_inode_dirty(inode);
102 err = ufs_add_nondir(dentry, inode);
103 }
104 return err;
105 }
106
ufs_symlink(struct inode * dir,struct dentry * dentry,const char * symname)107 static int ufs_symlink (struct inode * dir, struct dentry * dentry,
108 const char * symname)
109 {
110 struct super_block * sb = dir->i_sb;
111 int err;
112 unsigned l = strlen(symname)+1;
113 struct inode * inode;
114
115 if (l > sb->s_blocksize)
116 return -ENAMETOOLONG;
117
118 inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO);
119 err = PTR_ERR(inode);
120 if (IS_ERR(inode))
121 return err;
122
123 if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) {
124 /* slow symlink */
125 inode->i_op = &page_symlink_inode_operations;
126 inode_nohighmem(inode);
127 inode->i_mapping->a_ops = &ufs_aops;
128 err = page_symlink(inode, symname, l);
129 if (err)
130 goto out_fail;
131 } else {
132 /* fast symlink */
133 inode->i_op = &simple_symlink_inode_operations;
134 inode->i_link = (char *)UFS_I(inode)->i_u1.i_symlink;
135 memcpy(inode->i_link, symname, l);
136 inode->i_size = l-1;
137 }
138 mark_inode_dirty(inode);
139
140 return ufs_add_nondir(dentry, inode);
141
142 out_fail:
143 inode_dec_link_count(inode);
144 discard_new_inode(inode);
145 return err;
146 }
147
ufs_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)148 static int ufs_link (struct dentry * old_dentry, struct inode * dir,
149 struct dentry *dentry)
150 {
151 struct inode *inode = d_inode(old_dentry);
152 int error;
153
154 inode->i_ctime = current_time(inode);
155 inode_inc_link_count(inode);
156 ihold(inode);
157
158 error = ufs_add_link(dentry, inode);
159 if (error) {
160 inode_dec_link_count(inode);
161 iput(inode);
162 } else
163 d_instantiate(dentry, inode);
164 return error;
165 }
166
ufs_mkdir(struct inode * dir,struct dentry * dentry,umode_t mode)167 static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
168 {
169 struct inode * inode;
170 int err;
171
172 inode_inc_link_count(dir);
173
174 inode = ufs_new_inode(dir, S_IFDIR|mode);
175 err = PTR_ERR(inode);
176 if (IS_ERR(inode))
177 goto out_dir;
178
179 inode->i_op = &ufs_dir_inode_operations;
180 inode->i_fop = &ufs_dir_operations;
181 inode->i_mapping->a_ops = &ufs_aops;
182
183 inode_inc_link_count(inode);
184
185 err = ufs_make_empty(inode, dir);
186 if (err)
187 goto out_fail;
188
189 err = ufs_add_link(dentry, inode);
190 if (err)
191 goto out_fail;
192
193 d_instantiate_new(dentry, inode);
194 return 0;
195
196 out_fail:
197 inode_dec_link_count(inode);
198 inode_dec_link_count(inode);
199 discard_new_inode(inode);
200 out_dir:
201 inode_dec_link_count(dir);
202 return err;
203 }
204
ufs_unlink(struct inode * dir,struct dentry * dentry)205 static int ufs_unlink(struct inode *dir, struct dentry *dentry)
206 {
207 struct inode * inode = d_inode(dentry);
208 struct ufs_dir_entry *de;
209 struct page *page;
210 int err = -ENOENT;
211
212 de = ufs_find_entry(dir, &dentry->d_name, &page);
213 if (!de)
214 goto out;
215
216 err = ufs_delete_entry(dir, de, page);
217 if (err)
218 goto out;
219
220 inode->i_ctime = dir->i_ctime;
221 inode_dec_link_count(inode);
222 err = 0;
223 out:
224 return err;
225 }
226
ufs_rmdir(struct inode * dir,struct dentry * dentry)227 static int ufs_rmdir (struct inode * dir, struct dentry *dentry)
228 {
229 struct inode * inode = d_inode(dentry);
230 int err= -ENOTEMPTY;
231
232 if (ufs_empty_dir (inode)) {
233 err = ufs_unlink(dir, dentry);
234 if (!err) {
235 inode->i_size = 0;
236 inode_dec_link_count(inode);
237 inode_dec_link_count(dir);
238 }
239 }
240 return err;
241 }
242
ufs_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)243 static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
244 struct inode *new_dir, struct dentry *new_dentry,
245 unsigned int flags)
246 {
247 struct inode *old_inode = d_inode(old_dentry);
248 struct inode *new_inode = d_inode(new_dentry);
249 struct page *dir_page = NULL;
250 struct ufs_dir_entry * dir_de = NULL;
251 struct page *old_page;
252 struct ufs_dir_entry *old_de;
253 int err = -ENOENT;
254
255 if (flags & ~RENAME_NOREPLACE)
256 return -EINVAL;
257
258 old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_page);
259 if (!old_de)
260 goto out;
261
262 if (S_ISDIR(old_inode->i_mode)) {
263 err = -EIO;
264 dir_de = ufs_dotdot(old_inode, &dir_page);
265 if (!dir_de)
266 goto out_old;
267 }
268
269 if (new_inode) {
270 struct page *new_page;
271 struct ufs_dir_entry *new_de;
272
273 err = -ENOTEMPTY;
274 if (dir_de && !ufs_empty_dir(new_inode))
275 goto out_dir;
276
277 err = -ENOENT;
278 new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page);
279 if (!new_de)
280 goto out_dir;
281 ufs_set_link(new_dir, new_de, new_page, old_inode, 1);
282 new_inode->i_ctime = current_time(new_inode);
283 if (dir_de)
284 drop_nlink(new_inode);
285 inode_dec_link_count(new_inode);
286 } else {
287 err = ufs_add_link(new_dentry, old_inode);
288 if (err)
289 goto out_dir;
290 if (dir_de)
291 inode_inc_link_count(new_dir);
292 }
293
294 /*
295 * Like most other Unix systems, set the ctime for inodes on a
296 * rename.
297 */
298 old_inode->i_ctime = current_time(old_inode);
299
300 ufs_delete_entry(old_dir, old_de, old_page);
301 mark_inode_dirty(old_inode);
302
303 if (dir_de) {
304 if (old_dir != new_dir)
305 ufs_set_link(old_inode, dir_de, dir_page, new_dir, 0);
306 else {
307 kunmap(dir_page);
308 put_page(dir_page);
309 }
310 inode_dec_link_count(old_dir);
311 }
312 return 0;
313
314
315 out_dir:
316 if (dir_de) {
317 kunmap(dir_page);
318 put_page(dir_page);
319 }
320 out_old:
321 kunmap(old_page);
322 put_page(old_page);
323 out:
324 return err;
325 }
326
327 const struct inode_operations ufs_dir_inode_operations = {
328 .create = ufs_create,
329 .lookup = ufs_lookup,
330 .link = ufs_link,
331 .unlink = ufs_unlink,
332 .symlink = ufs_symlink,
333 .mkdir = ufs_mkdir,
334 .rmdir = ufs_rmdir,
335 .mknod = ufs_mknod,
336 .rename = ufs_rename,
337 };
338