1 /*
2 * linux/fs/sysv/namei.c
3 *
4 * minix/namei.c
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * coh/namei.c
8 * Copyright (C) 1993 Pascal Haible, Bruno Haible
9 *
10 * sysv/namei.c
11 * Copyright (C) 1993 Bruno Haible
12 * Copyright (C) 1997, 1998 Krzysztof G. Baranowski
13 */
14
15 #include <linux/pagemap.h>
16 #include <linux/smp_lock.h>
17 #include "sysv.h"
18
19 static inline void inc_count(struct inode *inode)
20 {
21 inode->i_nlink++;
22 mark_inode_dirty(inode);
23 }
24
25 static inline void dec_count(struct inode *inode)
26 {
27 inode->i_nlink--;
28 mark_inode_dirty(inode);
29 }
30
31 static int add_nondir(struct dentry *dentry, struct inode *inode)
32 {
33 int err = sysv_add_link(dentry, inode);
34 if (!err) {
35 d_instantiate(dentry, inode);
36 return 0;
37 }
38 dec_count(inode);
39 iput(inode);
40 return err;
41 }
42
43 static int sysv_hash(struct dentry *dentry, struct qstr *qstr)
44 {
45 /* Truncate the name in place, avoids having to define a compare
46 function. */
47 if (qstr->len > SYSV_NAMELEN) {
48 qstr->len = SYSV_NAMELEN;
49 qstr->hash = full_name_hash(qstr->name, qstr->len);
50 }
51 return 0;
52 }
53
54 struct dentry_operations sysv_dentry_operations = {
55 .d_hash = sysv_hash,
56 };
57
58 static struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
59 {
60 struct inode * inode = NULL;
61 ino_t ino;
62
63 dentry->d_op = dir->i_sb->s_root->d_op;
64 if (dentry->d_name.len > SYSV_NAMELEN)
65 return ERR_PTR(-ENAMETOOLONG);
66 ino = sysv_inode_by_name(dentry);
67
68 if (ino) {
69 inode = iget(dir->i_sb, ino);
70 if (!inode)
71 return ERR_PTR(-EACCES);
72 }
73 d_add(dentry, inode);
74 return NULL;
75 }
76
77 static int sysv_mknod(struct inode * dir, struct dentry * dentry, int mode, dev_t rdev)
78 {
79 struct inode * inode;
80 int err;
81
82 if (!old_valid_dev(rdev))
83 return -EINVAL;
84
85 inode = sysv_new_inode(dir, mode);
86 err = PTR_ERR(inode);
87
88 if (!IS_ERR(inode)) {
89 sysv_set_inode(inode, rdev);
90 mark_inode_dirty(inode);
91 err = add_nondir(dentry, inode);
92 }
93 return err;
94 }
95
96 static int sysv_create(struct inode * dir, struct dentry * dentry, int mode, struct nameidata *nd)
97 {
98 return sysv_mknod(dir, dentry, mode, 0);
99 }
100
101 static int sysv_symlink(struct inode * dir, struct dentry * dentry,
102 const char * symname)
103 {
104 int err = -ENAMETOOLONG;
105 int l = strlen(symname)+1;
106 struct inode * inode;
107
108 if (l > dir->i_sb->s_blocksize)
109 goto out;
110
111 inode = sysv_new_inode(dir, S_IFLNK|0777);
112 err = PTR_ERR(inode);
113 if (IS_ERR(inode))
114 goto out;
115
116 sysv_set_inode(inode, 0);
117 err = page_symlink(inode, symname, l);
118 if (err)
119 goto out_fail;
120
121 mark_inode_dirty(inode);
122 err = add_nondir(dentry, inode);
123 out:
124 return err;
125
126 out_fail:
127 dec_count(inode);
128 iput(inode);
129 goto out;
130 }
131
132 static int sysv_link(struct dentry * old_dentry, struct inode * dir,
133 struct dentry * dentry)
134 {
135 struct inode *inode = old_dentry->d_inode;
136
137 if (inode->i_nlink >= SYSV_SB(inode->i_sb)->s_link_max)
138 return -EMLINK;
139
140 inode->i_ctime = CURRENT_TIME_SEC;
141 inc_count(inode);
142 atomic_inc(&inode->i_count);
143
144 return add_nondir(dentry, inode);
145 }
146
147 static int sysv_mkdir(struct inode * dir, struct dentry *dentry, int mode)
148 {
149 struct inode * inode;
150 int err = -EMLINK;
151
152 if (dir->i_nlink >= SYSV_SB(dir->i_sb)->s_link_max)
153 goto out;
154 inc_count(dir);
155
156 inode = sysv_new_inode(dir, S_IFDIR|mode);
157 err = PTR_ERR(inode);
158 if (IS_ERR(inode))
159 goto out_dir;
160
161 sysv_set_inode(inode, 0);
162
163 inc_count(inode);
164
165 err = sysv_make_empty(inode, dir);
166 if (err)
167 goto out_fail;
168
169 err = sysv_add_link(dentry, inode);
170 if (err)
171 goto out_fail;
172
173 d_instantiate(dentry, inode);
174 out:
175 return err;
176
177 out_fail:
178 dec_count(inode);
179 dec_count(inode);
180 iput(inode);
181 out_dir:
182 dec_count(dir);
183 goto out;
184 }
185
186 static int sysv_unlink(struct inode * dir, struct dentry * dentry)
187 {
188 struct inode * inode = dentry->d_inode;
189 struct page * page;
190 struct sysv_dir_entry * de;
191 int err = -ENOENT;
192
193 de = sysv_find_entry(dentry, &page);
194 if (!de)
195 goto out;
196
197 err = sysv_delete_entry (de, page);
198 if (err)
199 goto out;
200
201 inode->i_ctime = dir->i_ctime;
202 dec_count(inode);
203 out:
204 return err;
205 }
206
207 static int sysv_rmdir(struct inode * dir, struct dentry * dentry)
208 {
209 struct inode *inode = dentry->d_inode;
210 int err = -ENOTEMPTY;
211
212 if (sysv_empty_dir(inode)) {
213 err = sysv_unlink(dir, dentry);
214 if (!err) {
215 inode->i_size = 0;
216 dec_count(inode);
217 dec_count(dir);
218 }
219 }
220 return err;
221 }
222
223 /*
224 * Anybody can rename anything with this: the permission checks are left to the
225 * higher-level routines.
226 */
227 static int sysv_rename(struct inode * old_dir, struct dentry * old_dentry,
228 struct inode * new_dir, struct dentry * new_dentry)
229 {
230 struct inode * old_inode = old_dentry->d_inode;
231 struct inode * new_inode = new_dentry->d_inode;
232 struct page * dir_page = NULL;
233 struct sysv_dir_entry * dir_de = NULL;
234 struct page * old_page;
235 struct sysv_dir_entry * old_de;
236 int err = -ENOENT;
237
238 old_de = sysv_find_entry(old_dentry, &old_page);
239 if (!old_de)
240 goto out;
241
242 if (S_ISDIR(old_inode->i_mode)) {
243 err = -EIO;
244 dir_de = sysv_dotdot(old_inode, &dir_page);
245 if (!dir_de)
246 goto out_old;
247 }
248
249 if (new_inode) {
250 struct page * new_page;
251 struct sysv_dir_entry * new_de;
252
253 err = -ENOTEMPTY;
254 if (dir_de && !sysv_empty_dir(new_inode))
255 goto out_dir;
256
257 err = -ENOENT;
258 new_de = sysv_find_entry(new_dentry, &new_page);
259 if (!new_de)
260 goto out_dir;
261 inc_count(old_inode);
262 sysv_set_link(new_de, new_page, old_inode);
263 new_inode->i_ctime = CURRENT_TIME_SEC;
264 if (dir_de)
265 new_inode->i_nlink--;
266 dec_count(new_inode);
267 } else {
268 if (dir_de) {
269 err = -EMLINK;
270 if (new_dir->i_nlink >= SYSV_SB(new_dir->i_sb)->s_link_max)
271 goto out_dir;
272 }
273 inc_count(old_inode);
274 err = sysv_add_link(new_dentry, old_inode);
275 if (err) {
276 dec_count(old_inode);
277 goto out_dir;
278 }
279 if (dir_de)
280 inc_count(new_dir);
281 }
282
283 sysv_delete_entry(old_de, old_page);
284 dec_count(old_inode);
285
286 if (dir_de) {
287 sysv_set_link(dir_de, dir_page, new_dir);
288 dec_count(old_dir);
289 }
290 return 0;
291
292 out_dir:
293 if (dir_de) {
294 kunmap(dir_page);
295 page_cache_release(dir_page);
296 }
297 out_old:
298 kunmap(old_page);
299 page_cache_release(old_page);
300 out:
301 return err;
302 }
303
304 /*
305 * directories can handle most operations...
306 */
307 struct inode_operations sysv_dir_inode_operations = {
308 .create = sysv_create,
309 .lookup = sysv_lookup,
310 .link = sysv_link,
311 .unlink = sysv_unlink,
312 .symlink = sysv_symlink,
313 .mkdir = sysv_mkdir,
314 .rmdir = sysv_rmdir,
315 .mknod = sysv_mknod,
316 .rename = sysv_rename,
317 .getattr = sysv_getattr,
318 };
319
|
This page was automatically generated by the
LXR engine.
|