1 /*
2 * Copyright (C) 2005, 2006
3 * Avishay Traeger (avishay@gmail.com)
4 * Copyright (C) 2008, 2009
5 * Boaz Harrosh <bharrosh@panasas.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,struct nameidata * nd)48 static struct dentry *exofs_lookup(struct inode *dir, struct dentry *dentry,
49 struct nameidata *nd)
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,struct nameidata * nd)62 static int exofs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
63 struct nameidata *nd)
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 if (!new_valid_dev(rdev))
84 return -EINVAL;
85
86 inode = exofs_new_inode(dir, mode);
87 err = PTR_ERR(inode);
88 if (!IS_ERR(inode)) {
89 init_special_inode(inode, inode->i_mode, rdev);
90 mark_inode_dirty(inode);
91 err = exofs_add_nondir(dentry, inode);
92 }
93 return err;
94 }
95
exofs_symlink(struct inode * dir,struct dentry * dentry,const char * symname)96 static int exofs_symlink(struct inode *dir, struct dentry *dentry,
97 const char *symname)
98 {
99 struct super_block *sb = dir->i_sb;
100 int err = -ENAMETOOLONG;
101 unsigned l = strlen(symname)+1;
102 struct inode *inode;
103 struct exofs_i_info *oi;
104
105 if (l > sb->s_blocksize)
106 goto out;
107
108 inode = exofs_new_inode(dir, S_IFLNK | S_IRWXUGO);
109 err = PTR_ERR(inode);
110 if (IS_ERR(inode))
111 goto out;
112
113 oi = exofs_i(inode);
114 if (l > sizeof(oi->i_data)) {
115 /* slow symlink */
116 inode->i_op = &exofs_symlink_inode_operations;
117 inode->i_mapping->a_ops = &exofs_aops;
118 memset(oi->i_data, 0, sizeof(oi->i_data));
119
120 err = page_symlink(inode, symname, l);
121 if (err)
122 goto out_fail;
123 } else {
124 /* fast symlink */
125 inode->i_op = &exofs_fast_symlink_inode_operations;
126 memcpy(oi->i_data, symname, l);
127 inode->i_size = l-1;
128 }
129 mark_inode_dirty(inode);
130
131 err = exofs_add_nondir(dentry, inode);
132 out:
133 return err;
134
135 out_fail:
136 inode_dec_link_count(inode);
137 iput(inode);
138 goto out;
139 }
140
exofs_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)141 static int exofs_link(struct dentry *old_dentry, struct inode *dir,
142 struct dentry *dentry)
143 {
144 struct inode *inode = old_dentry->d_inode;
145
146 if (inode->i_nlink >= EXOFS_LINK_MAX)
147 return -EMLINK;
148
149 inode->i_ctime = CURRENT_TIME;
150 inode_inc_link_count(inode);
151 ihold(inode);
152
153 return exofs_add_nondir(dentry, inode);
154 }
155
exofs_mkdir(struct inode * dir,struct dentry * dentry,umode_t mode)156 static int exofs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
157 {
158 struct inode *inode;
159 int err = -EMLINK;
160
161 if (dir->i_nlink >= EXOFS_LINK_MAX)
162 goto out;
163
164 inode_inc_link_count(dir);
165
166 inode = exofs_new_inode(dir, S_IFDIR | mode);
167 err = PTR_ERR(inode);
168 if (IS_ERR(inode))
169 goto out_dir;
170
171 inode->i_op = &exofs_dir_inode_operations;
172 inode->i_fop = &exofs_dir_operations;
173 inode->i_mapping->a_ops = &exofs_aops;
174
175 inode_inc_link_count(inode);
176
177 err = exofs_make_empty(inode, dir);
178 if (err)
179 goto out_fail;
180
181 err = exofs_add_link(dentry, inode);
182 if (err)
183 goto out_fail;
184
185 d_instantiate(dentry, inode);
186 out:
187 return err;
188
189 out_fail:
190 inode_dec_link_count(inode);
191 inode_dec_link_count(inode);
192 iput(inode);
193 out_dir:
194 inode_dec_link_count(dir);
195 goto out;
196 }
197
exofs_unlink(struct inode * dir,struct dentry * dentry)198 static int exofs_unlink(struct inode *dir, struct dentry *dentry)
199 {
200 struct inode *inode = dentry->d_inode;
201 struct exofs_dir_entry *de;
202 struct page *page;
203 int err = -ENOENT;
204
205 de = exofs_find_entry(dir, dentry, &page);
206 if (!de)
207 goto out;
208
209 err = exofs_delete_entry(de, page);
210 if (err)
211 goto out;
212
213 inode->i_ctime = dir->i_ctime;
214 inode_dec_link_count(inode);
215 err = 0;
216 out:
217 return err;
218 }
219
exofs_rmdir(struct inode * dir,struct dentry * dentry)220 static int exofs_rmdir(struct inode *dir, struct dentry *dentry)
221 {
222 struct inode *inode = dentry->d_inode;
223 int err = -ENOTEMPTY;
224
225 if (exofs_empty_dir(inode)) {
226 err = exofs_unlink(dir, dentry);
227 if (!err) {
228 inode->i_size = 0;
229 inode_dec_link_count(inode);
230 inode_dec_link_count(dir);
231 }
232 }
233 return err;
234 }
235
exofs_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry)236 static int exofs_rename(struct inode *old_dir, struct dentry *old_dentry,
237 struct inode *new_dir, struct dentry *new_dentry)
238 {
239 struct inode *old_inode = old_dentry->d_inode;
240 struct inode *new_inode = new_dentry->d_inode;
241 struct page *dir_page = NULL;
242 struct exofs_dir_entry *dir_de = NULL;
243 struct page *old_page;
244 struct exofs_dir_entry *old_de;
245 int err = -ENOENT;
246
247 old_de = exofs_find_entry(old_dir, old_dentry, &old_page);
248 if (!old_de)
249 goto out;
250
251 if (S_ISDIR(old_inode->i_mode)) {
252 err = -EIO;
253 dir_de = exofs_dotdot(old_inode, &dir_page);
254 if (!dir_de)
255 goto out_old;
256 }
257
258 if (new_inode) {
259 struct page *new_page;
260 struct exofs_dir_entry *new_de;
261
262 err = -ENOTEMPTY;
263 if (dir_de && !exofs_empty_dir(new_inode))
264 goto out_dir;
265
266 err = -ENOENT;
267 new_de = exofs_find_entry(new_dir, new_dentry, &new_page);
268 if (!new_de)
269 goto out_dir;
270 err = exofs_set_link(new_dir, new_de, new_page, old_inode);
271 new_inode->i_ctime = CURRENT_TIME;
272 if (dir_de)
273 drop_nlink(new_inode);
274 inode_dec_link_count(new_inode);
275 if (err)
276 goto out_dir;
277 } else {
278 if (dir_de) {
279 err = -EMLINK;
280 if (new_dir->i_nlink >= EXOFS_LINK_MAX)
281 goto out_dir;
282 }
283 err = exofs_add_link(new_dentry, old_inode);
284 if (err)
285 goto out_dir;
286 if (dir_de)
287 inode_inc_link_count(new_dir);
288 }
289
290 old_inode->i_ctime = CURRENT_TIME;
291
292 exofs_delete_entry(old_de, old_page);
293 mark_inode_dirty(old_inode);
294
295 if (dir_de) {
296 err = exofs_set_link(old_inode, dir_de, dir_page, new_dir);
297 inode_dec_link_count(old_dir);
298 if (err)
299 goto out_dir;
300 }
301 return 0;
302
303
304 out_dir:
305 if (dir_de) {
306 kunmap(dir_page);
307 page_cache_release(dir_page);
308 }
309 out_old:
310 kunmap(old_page);
311 page_cache_release(old_page);
312 out:
313 return err;
314 }
315
316 const struct inode_operations exofs_dir_inode_operations = {
317 .create = exofs_create,
318 .lookup = exofs_lookup,
319 .link = exofs_link,
320 .unlink = exofs_unlink,
321 .symlink = exofs_symlink,
322 .mkdir = exofs_mkdir,
323 .rmdir = exofs_rmdir,
324 .mknod = exofs_mknod,
325 .rename = exofs_rename,
326 .setattr = exofs_setattr,
327 };
328
329 const struct inode_operations exofs_special_inode_operations = {
330 .setattr = exofs_setattr,
331 };
332