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