1 /*
2 * Copyright (C) 2005, 2006
3 * Avishay Traeger (avishay@gmail.com)
4 * Copyright (C) 2008, 2009
5 * Boaz Harrosh <ooo@electrozaur.com>
6 *
7 * Copyrights for code taken from ext2:
8 * Copyright (C) 1992, 1993, 1994, 1995
9 * Remy Card (card@masi.ibp.fr)
10 * Laboratoire MASI - Institut Blaise Pascal
11 * Universite Pierre et Marie Curie (Paris VI)
12 * from
13 * linux/fs/minix/inode.c
14 * Copyright (C) 1991, 1992 Linus Torvalds
15 *
16 * This file is part of exofs.
17 *
18 * exofs is free software; you can redistribute it and/or modify
19 * it under the terms of the GNU General Public License as published by
20 * the Free Software Foundation. Since it is based on ext2, and the only
21 * valid version of GPL for the Linux kernel is version 2, the only valid
22 * version of GPL for exofs is version 2.
23 *
24 * exofs is distributed in the hope that it will be useful,
25 * but WITHOUT ANY WARRANTY; without even the implied warranty of
26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
27 * GNU General Public License for more details.
28 *
29 * You should have received a copy of the GNU General Public License
30 * along with exofs; if not, write to the Free Software
31 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
32 */
33
34 #include "exofs.h"
35
exofs_add_nondir(struct dentry * dentry,struct inode * inode)36 static inline int exofs_add_nondir(struct dentry *dentry, struct inode *inode)
37 {
38 int err = exofs_add_link(dentry, inode);
39 if (!err) {
40 d_instantiate(dentry, inode);
41 return 0;
42 }
43 inode_dec_link_count(inode);
44 iput(inode);
45 return err;
46 }
47
exofs_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)48 static struct dentry *exofs_lookup(struct inode *dir, struct dentry *dentry,
49 unsigned int flags)
50 {
51 struct inode *inode;
52 ino_t ino;
53
54 if (dentry->d_name.len > EXOFS_NAME_LEN)
55 return ERR_PTR(-ENAMETOOLONG);
56
57 ino = exofs_inode_by_name(dir, dentry);
58 inode = ino ? exofs_iget(dir->i_sb, ino) : NULL;
59 return d_splice_alias(inode, dentry);
60 }
61
exofs_create(struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)62 static int exofs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
63 bool excl)
64 {
65 struct inode *inode = exofs_new_inode(dir, mode);
66 int err = PTR_ERR(inode);
67 if (!IS_ERR(inode)) {
68 inode->i_op = &exofs_file_inode_operations;
69 inode->i_fop = &exofs_file_operations;
70 inode->i_mapping->a_ops = &exofs_aops;
71 mark_inode_dirty(inode);
72 err = exofs_add_nondir(dentry, inode);
73 }
74 return err;
75 }
76
exofs_mknod(struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)77 static int exofs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode,
78 dev_t rdev)
79 {
80 struct inode *inode;
81 int err;
82
83 inode = exofs_new_inode(dir, mode);
84 err = PTR_ERR(inode);
85 if (!IS_ERR(inode)) {
86 init_special_inode(inode, inode->i_mode, rdev);
87 mark_inode_dirty(inode);
88 err = exofs_add_nondir(dentry, inode);
89 }
90 return err;
91 }
92
exofs_symlink(struct inode * dir,struct dentry * dentry,const char * symname)93 static int exofs_symlink(struct inode *dir, struct dentry *dentry,
94 const char *symname)
95 {
96 struct super_block *sb = dir->i_sb;
97 int err = -ENAMETOOLONG;
98 unsigned l = strlen(symname)+1;
99 struct inode *inode;
100 struct exofs_i_info *oi;
101
102 if (l > sb->s_blocksize)
103 goto out;
104
105 inode = exofs_new_inode(dir, S_IFLNK | S_IRWXUGO);
106 err = PTR_ERR(inode);
107 if (IS_ERR(inode))
108 goto out;
109
110 oi = exofs_i(inode);
111 if (l > sizeof(oi->i_data)) {
112 /* slow symlink */
113 inode->i_op = &page_symlink_inode_operations;
114 inode->i_mapping->a_ops = &exofs_aops;
115 memset(oi->i_data, 0, sizeof(oi->i_data));
116
117 err = page_symlink(inode, symname, l);
118 if (err)
119 goto out_fail;
120 } else {
121 /* fast symlink */
122 inode->i_op = &simple_symlink_inode_operations;
123 inode->i_link = (char *)oi->i_data;
124 memcpy(oi->i_data, symname, l);
125 inode->i_size = l-1;
126 }
127 mark_inode_dirty(inode);
128
129 err = exofs_add_nondir(dentry, inode);
130 out:
131 return err;
132
133 out_fail:
134 inode_dec_link_count(inode);
135 iput(inode);
136 goto out;
137 }
138
exofs_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)139 static int exofs_link(struct dentry *old_dentry, struct inode *dir,
140 struct dentry *dentry)
141 {
142 struct inode *inode = d_inode(old_dentry);
143
144 inode->i_ctime = CURRENT_TIME;
145 inode_inc_link_count(inode);
146 ihold(inode);
147
148 return exofs_add_nondir(dentry, inode);
149 }
150
exofs_mkdir(struct inode * dir,struct dentry * dentry,umode_t mode)151 static int exofs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
152 {
153 struct inode *inode;
154 int err;
155
156 inode_inc_link_count(dir);
157
158 inode = exofs_new_inode(dir, S_IFDIR | mode);
159 err = PTR_ERR(inode);
160 if (IS_ERR(inode))
161 goto out_dir;
162
163 inode->i_op = &exofs_dir_inode_operations;
164 inode->i_fop = &exofs_dir_operations;
165 inode->i_mapping->a_ops = &exofs_aops;
166
167 inode_inc_link_count(inode);
168
169 err = exofs_make_empty(inode, dir);
170 if (err)
171 goto out_fail;
172
173 err = exofs_add_link(dentry, inode);
174 if (err)
175 goto out_fail;
176
177 d_instantiate(dentry, inode);
178 out:
179 return err;
180
181 out_fail:
182 inode_dec_link_count(inode);
183 inode_dec_link_count(inode);
184 iput(inode);
185 out_dir:
186 inode_dec_link_count(dir);
187 goto out;
188 }
189
exofs_unlink(struct inode * dir,struct dentry * dentry)190 static int exofs_unlink(struct inode *dir, struct dentry *dentry)
191 {
192 struct inode *inode = d_inode(dentry);
193 struct exofs_dir_entry *de;
194 struct page *page;
195 int err = -ENOENT;
196
197 de = exofs_find_entry(dir, dentry, &page);
198 if (!de)
199 goto out;
200
201 err = exofs_delete_entry(de, page);
202 if (err)
203 goto out;
204
205 inode->i_ctime = dir->i_ctime;
206 inode_dec_link_count(inode);
207 err = 0;
208 out:
209 return err;
210 }
211
exofs_rmdir(struct inode * dir,struct dentry * dentry)212 static int exofs_rmdir(struct inode *dir, struct dentry *dentry)
213 {
214 struct inode *inode = d_inode(dentry);
215 int err = -ENOTEMPTY;
216
217 if (exofs_empty_dir(inode)) {
218 err = exofs_unlink(dir, dentry);
219 if (!err) {
220 inode->i_size = 0;
221 inode_dec_link_count(inode);
222 inode_dec_link_count(dir);
223 }
224 }
225 return err;
226 }
227
exofs_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry)228 static int exofs_rename(struct inode *old_dir, struct dentry *old_dentry,
229 struct inode *new_dir, struct dentry *new_dentry)
230 {
231 struct inode *old_inode = d_inode(old_dentry);
232 struct inode *new_inode = d_inode(new_dentry);
233 struct page *dir_page = NULL;
234 struct exofs_dir_entry *dir_de = NULL;
235 struct page *old_page;
236 struct exofs_dir_entry *old_de;
237 int err = -ENOENT;
238
239 old_de = exofs_find_entry(old_dir, old_dentry, &old_page);
240 if (!old_de)
241 goto out;
242
243 if (S_ISDIR(old_inode->i_mode)) {
244 err = -EIO;
245 dir_de = exofs_dotdot(old_inode, &dir_page);
246 if (!dir_de)
247 goto out_old;
248 }
249
250 if (new_inode) {
251 struct page *new_page;
252 struct exofs_dir_entry *new_de;
253
254 err = -ENOTEMPTY;
255 if (dir_de && !exofs_empty_dir(new_inode))
256 goto out_dir;
257
258 err = -ENOENT;
259 new_de = exofs_find_entry(new_dir, new_dentry, &new_page);
260 if (!new_de)
261 goto out_dir;
262 err = exofs_set_link(new_dir, new_de, new_page, old_inode);
263 new_inode->i_ctime = CURRENT_TIME;
264 if (dir_de)
265 drop_nlink(new_inode);
266 inode_dec_link_count(new_inode);
267 if (err)
268 goto out_dir;
269 } else {
270 err = exofs_add_link(new_dentry, old_inode);
271 if (err)
272 goto out_dir;
273 if (dir_de)
274 inode_inc_link_count(new_dir);
275 }
276
277 old_inode->i_ctime = CURRENT_TIME;
278
279 exofs_delete_entry(old_de, old_page);
280 mark_inode_dirty(old_inode);
281
282 if (dir_de) {
283 err = exofs_set_link(old_inode, dir_de, dir_page, new_dir);
284 inode_dec_link_count(old_dir);
285 if (err)
286 goto out_dir;
287 }
288 return 0;
289
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 const struct inode_operations exofs_dir_inode_operations = {
304 .create = exofs_create,
305 .lookup = exofs_lookup,
306 .link = exofs_link,
307 .unlink = exofs_unlink,
308 .symlink = exofs_symlink,
309 .mkdir = exofs_mkdir,
310 .rmdir = exofs_rmdir,
311 .mknod = exofs_mknod,
312 .rename = exofs_rename,
313 .setattr = exofs_setattr,
314 };
315
316 const struct inode_operations exofs_special_inode_operations = {
317 .setattr = exofs_setattr,
318 };
319