blob: 4e48abbd2b5de63ff1e93f7c5599a9b917f18e43 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070019static int add_nondir(struct dentry *dentry, struct inode *inode)
20{
21 int err = sysv_add_link(dentry, inode);
22 if (!err) {
23 d_instantiate(dentry, inode);
24 return 0;
25 }
Alexey Dobriyan4e907c32006-03-23 03:00:52 -080026 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -070027 iput(inode);
28 return err;
29}
30
31static int sysv_hash(struct dentry *dentry, struct qstr *qstr)
32{
33 /* Truncate the name in place, avoids having to define a compare
34 function. */
35 if (qstr->len > SYSV_NAMELEN) {
36 qstr->len = SYSV_NAMELEN;
37 qstr->hash = full_name_hash(qstr->name, qstr->len);
38 }
39 return 0;
40}
41
42struct dentry_operations sysv_dentry_operations = {
43 .d_hash = sysv_hash,
44};
45
46static struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
47{
48 struct inode * inode = NULL;
49 ino_t ino;
50
51 dentry->d_op = dir->i_sb->s_root->d_op;
52 if (dentry->d_name.len > SYSV_NAMELEN)
53 return ERR_PTR(-ENAMETOOLONG);
54 ino = sysv_inode_by_name(dentry);
55
56 if (ino) {
57 inode = iget(dir->i_sb, ino);
58 if (!inode)
59 return ERR_PTR(-EACCES);
60 }
61 d_add(dentry, inode);
62 return NULL;
63}
64
65static int sysv_mknod(struct inode * dir, struct dentry * dentry, int mode, dev_t rdev)
66{
67 struct inode * inode;
68 int err;
69
70 if (!old_valid_dev(rdev))
71 return -EINVAL;
72
73 inode = sysv_new_inode(dir, mode);
74 err = PTR_ERR(inode);
75
76 if (!IS_ERR(inode)) {
77 sysv_set_inode(inode, rdev);
78 mark_inode_dirty(inode);
79 err = add_nondir(dentry, inode);
80 }
81 return err;
82}
83
84static int sysv_create(struct inode * dir, struct dentry * dentry, int mode, struct nameidata *nd)
85{
86 return sysv_mknod(dir, dentry, mode, 0);
87}
88
89static int sysv_symlink(struct inode * dir, struct dentry * dentry,
90 const char * symname)
91{
92 int err = -ENAMETOOLONG;
93 int l = strlen(symname)+1;
94 struct inode * inode;
95
96 if (l > dir->i_sb->s_blocksize)
97 goto out;
98
99 inode = sysv_new_inode(dir, S_IFLNK|0777);
100 err = PTR_ERR(inode);
101 if (IS_ERR(inode))
102 goto out;
103
104 sysv_set_inode(inode, 0);
105 err = page_symlink(inode, symname, l);
106 if (err)
107 goto out_fail;
108
109 mark_inode_dirty(inode);
110 err = add_nondir(dentry, inode);
111out:
112 return err;
113
114out_fail:
Alexey Dobriyan4e907c32006-03-23 03:00:52 -0800115 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 iput(inode);
117 goto out;
118}
119
120static int sysv_link(struct dentry * old_dentry, struct inode * dir,
121 struct dentry * dentry)
122{
123 struct inode *inode = old_dentry->d_inode;
124
125 if (inode->i_nlink >= SYSV_SB(inode->i_sb)->s_link_max)
126 return -EMLINK;
127
128 inode->i_ctime = CURRENT_TIME_SEC;
Alexey Dobriyan4e907c32006-03-23 03:00:52 -0800129 inode_inc_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 atomic_inc(&inode->i_count);
131
132 return add_nondir(dentry, inode);
133}
134
135static int sysv_mkdir(struct inode * dir, struct dentry *dentry, int mode)
136{
137 struct inode * inode;
138 int err = -EMLINK;
139
140 if (dir->i_nlink >= SYSV_SB(dir->i_sb)->s_link_max)
141 goto out;
Alexey Dobriyan4e907c32006-03-23 03:00:52 -0800142 inode_inc_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
144 inode = sysv_new_inode(dir, S_IFDIR|mode);
145 err = PTR_ERR(inode);
146 if (IS_ERR(inode))
147 goto out_dir;
148
149 sysv_set_inode(inode, 0);
150
Alexey Dobriyan4e907c32006-03-23 03:00:52 -0800151 inode_inc_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
153 err = sysv_make_empty(inode, dir);
154 if (err)
155 goto out_fail;
156
157 err = sysv_add_link(dentry, inode);
158 if (err)
159 goto out_fail;
160
161 d_instantiate(dentry, inode);
162out:
163 return err;
164
165out_fail:
Alexey Dobriyan4e907c32006-03-23 03:00:52 -0800166 inode_dec_link_count(inode);
167 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 iput(inode);
169out_dir:
Alexey Dobriyan4e907c32006-03-23 03:00:52 -0800170 inode_dec_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 goto out;
172}
173
174static int sysv_unlink(struct inode * dir, struct dentry * dentry)
175{
176 struct inode * inode = dentry->d_inode;
177 struct page * page;
178 struct sysv_dir_entry * de;
179 int err = -ENOENT;
180
181 de = sysv_find_entry(dentry, &page);
182 if (!de)
183 goto out;
184
185 err = sysv_delete_entry (de, page);
186 if (err)
187 goto out;
188
189 inode->i_ctime = dir->i_ctime;
Alexey Dobriyan4e907c32006-03-23 03:00:52 -0800190 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191out:
192 return err;
193}
194
195static int sysv_rmdir(struct inode * dir, struct dentry * dentry)
196{
197 struct inode *inode = dentry->d_inode;
198 int err = -ENOTEMPTY;
199
200 if (sysv_empty_dir(inode)) {
201 err = sysv_unlink(dir, dentry);
202 if (!err) {
203 inode->i_size = 0;
Alexey Dobriyan4e907c32006-03-23 03:00:52 -0800204 inode_dec_link_count(inode);
205 inode_dec_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 }
207 }
208 return err;
209}
210
211/*
212 * Anybody can rename anything with this: the permission checks are left to the
213 * higher-level routines.
214 */
215static int sysv_rename(struct inode * old_dir, struct dentry * old_dentry,
216 struct inode * new_dir, struct dentry * new_dentry)
217{
218 struct inode * old_inode = old_dentry->d_inode;
219 struct inode * new_inode = new_dentry->d_inode;
220 struct page * dir_page = NULL;
221 struct sysv_dir_entry * dir_de = NULL;
222 struct page * old_page;
223 struct sysv_dir_entry * old_de;
224 int err = -ENOENT;
225
226 old_de = sysv_find_entry(old_dentry, &old_page);
227 if (!old_de)
228 goto out;
229
230 if (S_ISDIR(old_inode->i_mode)) {
231 err = -EIO;
232 dir_de = sysv_dotdot(old_inode, &dir_page);
233 if (!dir_de)
234 goto out_old;
235 }
236
237 if (new_inode) {
238 struct page * new_page;
239 struct sysv_dir_entry * new_de;
240
241 err = -ENOTEMPTY;
242 if (dir_de && !sysv_empty_dir(new_inode))
243 goto out_dir;
244
245 err = -ENOENT;
246 new_de = sysv_find_entry(new_dentry, &new_page);
247 if (!new_de)
248 goto out_dir;
Alexey Dobriyan4e907c32006-03-23 03:00:52 -0800249 inode_inc_link_count(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 sysv_set_link(new_de, new_page, old_inode);
251 new_inode->i_ctime = CURRENT_TIME_SEC;
252 if (dir_de)
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700253 drop_nlink(new_inode);
Alexey Dobriyan4e907c32006-03-23 03:00:52 -0800254 inode_dec_link_count(new_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 } else {
256 if (dir_de) {
257 err = -EMLINK;
258 if (new_dir->i_nlink >= SYSV_SB(new_dir->i_sb)->s_link_max)
259 goto out_dir;
260 }
Alexey Dobriyan4e907c32006-03-23 03:00:52 -0800261 inode_inc_link_count(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 err = sysv_add_link(new_dentry, old_inode);
263 if (err) {
Alexey Dobriyan4e907c32006-03-23 03:00:52 -0800264 inode_dec_link_count(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 goto out_dir;
266 }
267 if (dir_de)
Alexey Dobriyan4e907c32006-03-23 03:00:52 -0800268 inode_inc_link_count(new_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 }
270
271 sysv_delete_entry(old_de, old_page);
Alexey Dobriyan4e907c32006-03-23 03:00:52 -0800272 inode_dec_link_count(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273
274 if (dir_de) {
275 sysv_set_link(dir_de, dir_page, new_dir);
Alexey Dobriyan4e907c32006-03-23 03:00:52 -0800276 inode_dec_link_count(old_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 }
278 return 0;
279
280out_dir:
281 if (dir_de) {
282 kunmap(dir_page);
283 page_cache_release(dir_page);
284 }
285out_old:
286 kunmap(old_page);
287 page_cache_release(old_page);
288out:
289 return err;
290}
291
292/*
293 * directories can handle most operations...
294 */
Arjan van de Venc5ef1c42007-02-12 00:55:40 -0800295const struct inode_operations sysv_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 .create = sysv_create,
297 .lookup = sysv_lookup,
298 .link = sysv_link,
299 .unlink = sysv_unlink,
300 .symlink = sysv_symlink,
301 .mkdir = sysv_mkdir,
302 .rmdir = sysv_rmdir,
303 .mknod = sysv_mknod,
304 .rename = sysv_rename,
305 .getattr = sysv_getattr,
306};