Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/minix/namei.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | #include "minix.h" | |
8 | ||
9 | static inline void inc_count(struct inode *inode) | |
10 | { | |
11 | inode->i_nlink++; | |
12 | mark_inode_dirty(inode); | |
13 | } | |
14 | ||
15 | static inline void dec_count(struct inode *inode) | |
16 | { | |
17 | inode->i_nlink--; | |
18 | mark_inode_dirty(inode); | |
19 | } | |
20 | ||
21 | static int add_nondir(struct dentry *dentry, struct inode *inode) | |
22 | { | |
23 | int err = minix_add_link(dentry, inode); | |
24 | if (!err) { | |
25 | d_instantiate(dentry, inode); | |
26 | return 0; | |
27 | } | |
28 | dec_count(inode); | |
29 | iput(inode); | |
30 | return err; | |
31 | } | |
32 | ||
33 | static int minix_hash(struct dentry *dentry, struct qstr *qstr) | |
34 | { | |
35 | unsigned long hash; | |
36 | int i; | |
37 | const unsigned char *name; | |
38 | ||
39 | i = minix_sb(dentry->d_inode->i_sb)->s_namelen; | |
40 | if (i >= qstr->len) | |
41 | return 0; | |
42 | /* Truncate the name in place, avoids having to define a compare | |
43 | function. */ | |
44 | qstr->len = i; | |
45 | name = qstr->name; | |
46 | hash = init_name_hash(); | |
47 | while (i--) | |
48 | hash = partial_name_hash(*name++, hash); | |
49 | qstr->hash = end_name_hash(hash); | |
50 | return 0; | |
51 | } | |
52 | ||
53 | struct dentry_operations minix_dentry_operations = { | |
54 | .d_hash = minix_hash, | |
55 | }; | |
56 | ||
57 | static struct dentry *minix_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd) | |
58 | { | |
59 | struct inode * inode = NULL; | |
60 | ino_t ino; | |
61 | ||
62 | dentry->d_op = dir->i_sb->s_root->d_op; | |
63 | ||
64 | if (dentry->d_name.len > minix_sb(dir->i_sb)->s_namelen) | |
65 | return ERR_PTR(-ENAMETOOLONG); | |
66 | ||
67 | ino = minix_inode_by_name(dentry); | |
68 | if (ino) { | |
69 | inode = iget(dir->i_sb, ino); | |
70 | ||
71 | if (!inode) | |
72 | return ERR_PTR(-EACCES); | |
73 | } | |
74 | d_add(dentry, inode); | |
75 | return NULL; | |
76 | } | |
77 | ||
78 | static int minix_mknod(struct inode * dir, struct dentry *dentry, int mode, dev_t rdev) | |
79 | { | |
80 | int error; | |
81 | struct inode *inode; | |
82 | ||
83 | if (!old_valid_dev(rdev)) | |
84 | return -EINVAL; | |
85 | ||
86 | inode = minix_new_inode(dir, &error); | |
87 | ||
88 | if (inode) { | |
89 | inode->i_mode = mode; | |
90 | minix_set_inode(inode, rdev); | |
91 | mark_inode_dirty(inode); | |
92 | error = add_nondir(dentry, inode); | |
93 | } | |
94 | return error; | |
95 | } | |
96 | ||
97 | static int minix_create(struct inode * dir, struct dentry *dentry, int mode, | |
98 | struct nameidata *nd) | |
99 | { | |
100 | return minix_mknod(dir, dentry, mode, 0); | |
101 | } | |
102 | ||
103 | static int minix_symlink(struct inode * dir, struct dentry *dentry, | |
104 | const char * symname) | |
105 | { | |
106 | int err = -ENAMETOOLONG; | |
107 | int i = strlen(symname)+1; | |
108 | struct inode * inode; | |
109 | ||
110 | if (i > dir->i_sb->s_blocksize) | |
111 | goto out; | |
112 | ||
113 | inode = minix_new_inode(dir, &err); | |
114 | if (!inode) | |
115 | goto out; | |
116 | ||
117 | inode->i_mode = S_IFLNK | 0777; | |
118 | minix_set_inode(inode, 0); | |
119 | err = page_symlink(inode, symname, i); | |
120 | if (err) | |
121 | goto out_fail; | |
122 | ||
123 | err = add_nondir(dentry, inode); | |
124 | out: | |
125 | return err; | |
126 | ||
127 | out_fail: | |
128 | dec_count(inode); | |
129 | iput(inode); | |
130 | goto out; | |
131 | } | |
132 | ||
133 | static int minix_link(struct dentry * old_dentry, struct inode * dir, | |
134 | struct dentry *dentry) | |
135 | { | |
136 | struct inode *inode = old_dentry->d_inode; | |
137 | ||
138 | if (inode->i_nlink >= minix_sb(inode->i_sb)->s_link_max) | |
139 | return -EMLINK; | |
140 | ||
141 | inode->i_ctime = CURRENT_TIME_SEC; | |
142 | inc_count(inode); | |
143 | atomic_inc(&inode->i_count); | |
144 | return add_nondir(dentry, inode); | |
145 | } | |
146 | ||
147 | static int minix_mkdir(struct inode * dir, struct dentry *dentry, int mode) | |
148 | { | |
149 | struct inode * inode; | |
150 | int err = -EMLINK; | |
151 | ||
152 | if (dir->i_nlink >= minix_sb(dir->i_sb)->s_link_max) | |
153 | goto out; | |
154 | ||
155 | inc_count(dir); | |
156 | ||
157 | inode = minix_new_inode(dir, &err); | |
158 | if (!inode) | |
159 | goto out_dir; | |
160 | ||
161 | inode->i_mode = S_IFDIR | mode; | |
162 | if (dir->i_mode & S_ISGID) | |
163 | inode->i_mode |= S_ISGID; | |
164 | minix_set_inode(inode, 0); | |
165 | ||
166 | inc_count(inode); | |
167 | ||
168 | err = minix_make_empty(inode, dir); | |
169 | if (err) | |
170 | goto out_fail; | |
171 | ||
172 | err = minix_add_link(dentry, inode); | |
173 | if (err) | |
174 | goto out_fail; | |
175 | ||
176 | d_instantiate(dentry, inode); | |
177 | out: | |
178 | return err; | |
179 | ||
180 | out_fail: | |
181 | dec_count(inode); | |
182 | dec_count(inode); | |
183 | iput(inode); | |
184 | out_dir: | |
185 | dec_count(dir); | |
186 | goto out; | |
187 | } | |
188 | ||
189 | static int minix_unlink(struct inode * dir, struct dentry *dentry) | |
190 | { | |
191 | int err = -ENOENT; | |
192 | struct inode * inode = dentry->d_inode; | |
193 | struct page * page; | |
194 | struct minix_dir_entry * de; | |
195 | ||
196 | de = minix_find_entry(dentry, &page); | |
197 | if (!de) | |
198 | goto end_unlink; | |
199 | ||
200 | err = minix_delete_entry(de, page); | |
201 | if (err) | |
202 | goto end_unlink; | |
203 | ||
204 | inode->i_ctime = dir->i_ctime; | |
205 | dec_count(inode); | |
206 | end_unlink: | |
207 | return err; | |
208 | } | |
209 | ||
210 | static int minix_rmdir(struct inode * dir, struct dentry *dentry) | |
211 | { | |
212 | struct inode * inode = dentry->d_inode; | |
213 | int err = -ENOTEMPTY; | |
214 | ||
215 | if (minix_empty_dir(inode)) { | |
216 | err = minix_unlink(dir, dentry); | |
217 | if (!err) { | |
218 | dec_count(dir); | |
219 | dec_count(inode); | |
220 | } | |
221 | } | |
222 | return err; | |
223 | } | |
224 | ||
225 | static int minix_rename(struct inode * old_dir, struct dentry *old_dentry, | |
226 | struct inode * new_dir, struct dentry *new_dentry) | |
227 | { | |
228 | struct minix_sb_info * info = minix_sb(old_dir->i_sb); | |
229 | struct inode * old_inode = old_dentry->d_inode; | |
230 | struct inode * new_inode = new_dentry->d_inode; | |
231 | struct page * dir_page = NULL; | |
232 | struct minix_dir_entry * dir_de = NULL; | |
233 | struct page * old_page; | |
234 | struct minix_dir_entry * old_de; | |
235 | int err = -ENOENT; | |
236 | ||
237 | old_de = minix_find_entry(old_dentry, &old_page); | |
238 | if (!old_de) | |
239 | goto out; | |
240 | ||
241 | if (S_ISDIR(old_inode->i_mode)) { | |
242 | err = -EIO; | |
243 | dir_de = minix_dotdot(old_inode, &dir_page); | |
244 | if (!dir_de) | |
245 | goto out_old; | |
246 | } | |
247 | ||
248 | if (new_inode) { | |
249 | struct page * new_page; | |
250 | struct minix_dir_entry * new_de; | |
251 | ||
252 | err = -ENOTEMPTY; | |
253 | if (dir_de && !minix_empty_dir(new_inode)) | |
254 | goto out_dir; | |
255 | ||
256 | err = -ENOENT; | |
257 | new_de = minix_find_entry(new_dentry, &new_page); | |
258 | if (!new_de) | |
259 | goto out_dir; | |
260 | inc_count(old_inode); | |
261 | minix_set_link(new_de, new_page, old_inode); | |
262 | new_inode->i_ctime = CURRENT_TIME_SEC; | |
263 | if (dir_de) | |
264 | new_inode->i_nlink--; | |
265 | dec_count(new_inode); | |
266 | } else { | |
267 | if (dir_de) { | |
268 | err = -EMLINK; | |
269 | if (new_dir->i_nlink >= info->s_link_max) | |
270 | goto out_dir; | |
271 | } | |
272 | inc_count(old_inode); | |
273 | err = minix_add_link(new_dentry, old_inode); | |
274 | if (err) { | |
275 | dec_count(old_inode); | |
276 | goto out_dir; | |
277 | } | |
278 | if (dir_de) | |
279 | inc_count(new_dir); | |
280 | } | |
281 | ||
282 | minix_delete_entry(old_de, old_page); | |
283 | dec_count(old_inode); | |
284 | ||
285 | if (dir_de) { | |
286 | minix_set_link(dir_de, dir_page, new_dir); | |
287 | dec_count(old_dir); | |
288 | } | |
289 | return 0; | |
290 | ||
291 | out_dir: | |
292 | if (dir_de) { | |
293 | kunmap(dir_page); | |
294 | page_cache_release(dir_page); | |
295 | } | |
296 | out_old: | |
297 | kunmap(old_page); | |
298 | page_cache_release(old_page); | |
299 | out: | |
300 | return err; | |
301 | } | |
302 | ||
303 | /* | |
304 | * directories can handle most operations... | |
305 | */ | |
306 | struct inode_operations minix_dir_inode_operations = { | |
307 | .create = minix_create, | |
308 | .lookup = minix_lookup, | |
309 | .link = minix_link, | |
310 | .unlink = minix_unlink, | |
311 | .symlink = minix_symlink, | |
312 | .mkdir = minix_mkdir, | |
313 | .rmdir = minix_rmdir, | |
314 | .mknod = minix_mknod, | |
315 | .rename = minix_rename, | |
316 | .getattr = minix_getattr, | |
317 | }; |