1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/minix/namei.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8 #include "minix.h"
9
add_nondir(struct dentry * dentry,struct inode * inode)10 static int add_nondir(struct dentry *dentry, struct inode *inode)
11 {
12 int err = minix_add_link(dentry, inode);
13 if (!err) {
14 d_instantiate(dentry, inode);
15 return 0;
16 }
17 inode_dec_link_count(inode);
18 iput(inode);
19 return err;
20 }
21
minix_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)22 static struct dentry *minix_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
23 {
24 struct inode * inode = NULL;
25 ino_t ino;
26
27 if (dentry->d_name.len > minix_sb(dir->i_sb)->s_namelen)
28 return ERR_PTR(-ENAMETOOLONG);
29
30 ino = minix_inode_by_name(dentry);
31 if (ino)
32 inode = minix_iget(dir->i_sb, ino);
33 return d_splice_alias(inode, dentry);
34 }
35
minix_mknod(struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)36 static int minix_mknod(struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev)
37 {
38 int error;
39 struct inode *inode;
40
41 if (!old_valid_dev(rdev))
42 return -EINVAL;
43
44 inode = minix_new_inode(dir, mode, &error);
45
46 if (inode) {
47 minix_set_inode(inode, rdev);
48 mark_inode_dirty(inode);
49 error = add_nondir(dentry, inode);
50 }
51 return error;
52 }
53
minix_tmpfile(struct inode * dir,struct dentry * dentry,umode_t mode)54 static int minix_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
55 {
56 int error;
57 struct inode *inode = minix_new_inode(dir, mode, &error);
58 if (inode) {
59 minix_set_inode(inode, 0);
60 mark_inode_dirty(inode);
61 d_tmpfile(dentry, inode);
62 }
63 return error;
64 }
65
minix_create(struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)66 static int minix_create(struct inode *dir, struct dentry *dentry, umode_t mode,
67 bool excl)
68 {
69 return minix_mknod(dir, dentry, mode, 0);
70 }
71
minix_symlink(struct inode * dir,struct dentry * dentry,const char * symname)72 static int minix_symlink(struct inode * dir, struct dentry *dentry,
73 const char * symname)
74 {
75 int err = -ENAMETOOLONG;
76 int i = strlen(symname)+1;
77 struct inode * inode;
78
79 if (i > dir->i_sb->s_blocksize)
80 goto out;
81
82 inode = minix_new_inode(dir, S_IFLNK | 0777, &err);
83 if (!inode)
84 goto out;
85
86 minix_set_inode(inode, 0);
87 err = page_symlink(inode, symname, i);
88 if (err)
89 goto out_fail;
90
91 err = add_nondir(dentry, inode);
92 out:
93 return err;
94
95 out_fail:
96 inode_dec_link_count(inode);
97 iput(inode);
98 goto out;
99 }
100
minix_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)101 static int minix_link(struct dentry * old_dentry, struct inode * dir,
102 struct dentry *dentry)
103 {
104 struct inode *inode = d_inode(old_dentry);
105
106 inode->i_ctime = current_time(inode);
107 inode_inc_link_count(inode);
108 ihold(inode);
109 return add_nondir(dentry, inode);
110 }
111
minix_mkdir(struct inode * dir,struct dentry * dentry,umode_t mode)112 static int minix_mkdir(struct inode * dir, struct dentry *dentry, umode_t mode)
113 {
114 struct inode * inode;
115 int err;
116
117 inode_inc_link_count(dir);
118
119 inode = minix_new_inode(dir, S_IFDIR | mode, &err);
120 if (!inode)
121 goto out_dir;
122
123 minix_set_inode(inode, 0);
124
125 inode_inc_link_count(inode);
126
127 err = minix_make_empty(inode, dir);
128 if (err)
129 goto out_fail;
130
131 err = minix_add_link(dentry, inode);
132 if (err)
133 goto out_fail;
134
135 d_instantiate(dentry, inode);
136 out:
137 return err;
138
139 out_fail:
140 inode_dec_link_count(inode);
141 inode_dec_link_count(inode);
142 iput(inode);
143 out_dir:
144 inode_dec_link_count(dir);
145 goto out;
146 }
147
minix_unlink(struct inode * dir,struct dentry * dentry)148 static int minix_unlink(struct inode * dir, struct dentry *dentry)
149 {
150 int err = -ENOENT;
151 struct inode * inode = d_inode(dentry);
152 struct page * page;
153 struct minix_dir_entry * de;
154
155 de = minix_find_entry(dentry, &page);
156 if (!de)
157 goto end_unlink;
158
159 err = minix_delete_entry(de, page);
160 if (err)
161 goto end_unlink;
162
163 inode->i_ctime = dir->i_ctime;
164 inode_dec_link_count(inode);
165 end_unlink:
166 return err;
167 }
168
minix_rmdir(struct inode * dir,struct dentry * dentry)169 static int minix_rmdir(struct inode * dir, struct dentry *dentry)
170 {
171 struct inode * inode = d_inode(dentry);
172 int err = -ENOTEMPTY;
173
174 if (minix_empty_dir(inode)) {
175 err = minix_unlink(dir, dentry);
176 if (!err) {
177 inode_dec_link_count(dir);
178 inode_dec_link_count(inode);
179 }
180 }
181 return err;
182 }
183
minix_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)184 static int minix_rename(struct inode * old_dir, struct dentry *old_dentry,
185 struct inode * new_dir, struct dentry *new_dentry,
186 unsigned int flags)
187 {
188 struct inode * old_inode = d_inode(old_dentry);
189 struct inode * new_inode = d_inode(new_dentry);
190 struct page * dir_page = NULL;
191 struct minix_dir_entry * dir_de = NULL;
192 struct page * old_page;
193 struct minix_dir_entry * old_de;
194 int err = -ENOENT;
195
196 if (flags & ~RENAME_NOREPLACE)
197 return -EINVAL;
198
199 old_de = minix_find_entry(old_dentry, &old_page);
200 if (!old_de)
201 goto out;
202
203 if (S_ISDIR(old_inode->i_mode)) {
204 err = -EIO;
205 dir_de = minix_dotdot(old_inode, &dir_page);
206 if (!dir_de)
207 goto out_old;
208 }
209
210 if (new_inode) {
211 struct page * new_page;
212 struct minix_dir_entry * new_de;
213
214 err = -ENOTEMPTY;
215 if (dir_de && !minix_empty_dir(new_inode))
216 goto out_dir;
217
218 err = -ENOENT;
219 new_de = minix_find_entry(new_dentry, &new_page);
220 if (!new_de)
221 goto out_dir;
222 minix_set_link(new_de, new_page, old_inode);
223 new_inode->i_ctime = current_time(new_inode);
224 if (dir_de)
225 drop_nlink(new_inode);
226 inode_dec_link_count(new_inode);
227 } else {
228 err = minix_add_link(new_dentry, old_inode);
229 if (err)
230 goto out_dir;
231 if (dir_de)
232 inode_inc_link_count(new_dir);
233 }
234
235 minix_delete_entry(old_de, old_page);
236 mark_inode_dirty(old_inode);
237
238 if (dir_de) {
239 minix_set_link(dir_de, dir_page, new_dir);
240 inode_dec_link_count(old_dir);
241 }
242 return 0;
243
244 out_dir:
245 if (dir_de) {
246 kunmap(dir_page);
247 put_page(dir_page);
248 }
249 out_old:
250 kunmap(old_page);
251 put_page(old_page);
252 out:
253 return err;
254 }
255
256 /*
257 * directories can handle most operations...
258 */
259 const struct inode_operations minix_dir_inode_operations = {
260 .create = minix_create,
261 .lookup = minix_lookup,
262 .link = minix_link,
263 .unlink = minix_unlink,
264 .symlink = minix_symlink,
265 .mkdir = minix_mkdir,
266 .rmdir = minix_rmdir,
267 .mknod = minix_mknod,
268 .rename = minix_rename,
269 .getattr = minix_getattr,
270 .tmpfile = minix_tmpfile,
271 };
272