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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_nohighmem(inode);
115 		inode->i_mapping->a_ops = &exofs_aops;
116 		memset(oi->i_data, 0, sizeof(oi->i_data));
117 
118 		err = page_symlink(inode, symname, l);
119 		if (err)
120 			goto out_fail;
121 	} else {
122 		/* fast symlink */
123 		inode->i_op = &simple_symlink_inode_operations;
124 		inode->i_link = (char *)oi->i_data;
125 		memcpy(oi->i_data, symname, l);
126 		inode->i_size = l-1;
127 	}
128 	mark_inode_dirty(inode);
129 
130 	err = exofs_add_nondir(dentry, inode);
131 out:
132 	return err;
133 
134 out_fail:
135 	inode_dec_link_count(inode);
136 	iput(inode);
137 	goto out;
138 }
139 
exofs_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)140 static int exofs_link(struct dentry *old_dentry, struct inode *dir,
141 		struct dentry *dentry)
142 {
143 	struct inode *inode = d_inode(old_dentry);
144 
145 	inode->i_ctime = current_time(inode);
146 	inode_inc_link_count(inode);
147 	ihold(inode);
148 
149 	return exofs_add_nondir(dentry, inode);
150 }
151 
exofs_mkdir(struct inode * dir,struct dentry * dentry,umode_t mode)152 static int exofs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
153 {
154 	struct inode *inode;
155 	int err;
156 
157 	inode_inc_link_count(dir);
158 
159 	inode = exofs_new_inode(dir, S_IFDIR | mode);
160 	err = PTR_ERR(inode);
161 	if (IS_ERR(inode))
162 		goto out_dir;
163 
164 	inode->i_op = &exofs_dir_inode_operations;
165 	inode->i_fop = &exofs_dir_operations;
166 	inode->i_mapping->a_ops = &exofs_aops;
167 
168 	inode_inc_link_count(inode);
169 
170 	err = exofs_make_empty(inode, dir);
171 	if (err)
172 		goto out_fail;
173 
174 	err = exofs_add_link(dentry, inode);
175 	if (err)
176 		goto out_fail;
177 
178 	d_instantiate(dentry, inode);
179 out:
180 	return err;
181 
182 out_fail:
183 	inode_dec_link_count(inode);
184 	inode_dec_link_count(inode);
185 	iput(inode);
186 out_dir:
187 	inode_dec_link_count(dir);
188 	goto out;
189 }
190 
exofs_unlink(struct inode * dir,struct dentry * dentry)191 static int exofs_unlink(struct inode *dir, struct dentry *dentry)
192 {
193 	struct inode *inode = d_inode(dentry);
194 	struct exofs_dir_entry *de;
195 	struct page *page;
196 	int err = -ENOENT;
197 
198 	de = exofs_find_entry(dir, dentry, &page);
199 	if (!de)
200 		goto out;
201 
202 	err = exofs_delete_entry(de, page);
203 	if (err)
204 		goto out;
205 
206 	inode->i_ctime = dir->i_ctime;
207 	inode_dec_link_count(inode);
208 	err = 0;
209 out:
210 	return err;
211 }
212 
exofs_rmdir(struct inode * dir,struct dentry * dentry)213 static int exofs_rmdir(struct inode *dir, struct dentry *dentry)
214 {
215 	struct inode *inode = d_inode(dentry);
216 	int err = -ENOTEMPTY;
217 
218 	if (exofs_empty_dir(inode)) {
219 		err = exofs_unlink(dir, dentry);
220 		if (!err) {
221 			inode->i_size = 0;
222 			inode_dec_link_count(inode);
223 			inode_dec_link_count(dir);
224 		}
225 	}
226 	return err;
227 }
228 
exofs_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)229 static int exofs_rename(struct inode *old_dir, struct dentry *old_dentry,
230 			struct inode *new_dir, struct dentry *new_dentry,
231 			unsigned int flags)
232 {
233 	struct inode *old_inode = d_inode(old_dentry);
234 	struct inode *new_inode = d_inode(new_dentry);
235 	struct page *dir_page = NULL;
236 	struct exofs_dir_entry *dir_de = NULL;
237 	struct page *old_page;
238 	struct exofs_dir_entry *old_de;
239 	int err = -ENOENT;
240 
241 	if (flags & ~RENAME_NOREPLACE)
242 		return -EINVAL;
243 
244 	old_de = exofs_find_entry(old_dir, old_dentry, &old_page);
245 	if (!old_de)
246 		goto out;
247 
248 	if (S_ISDIR(old_inode->i_mode)) {
249 		err = -EIO;
250 		dir_de = exofs_dotdot(old_inode, &dir_page);
251 		if (!dir_de)
252 			goto out_old;
253 	}
254 
255 	if (new_inode) {
256 		struct page *new_page;
257 		struct exofs_dir_entry *new_de;
258 
259 		err = -ENOTEMPTY;
260 		if (dir_de && !exofs_empty_dir(new_inode))
261 			goto out_dir;
262 
263 		err = -ENOENT;
264 		new_de = exofs_find_entry(new_dir, new_dentry, &new_page);
265 		if (!new_de)
266 			goto out_dir;
267 		err = exofs_set_link(new_dir, new_de, new_page, old_inode);
268 		new_inode->i_ctime = current_time(new_inode);
269 		if (dir_de)
270 			drop_nlink(new_inode);
271 		inode_dec_link_count(new_inode);
272 		if (err)
273 			goto out_dir;
274 	} else {
275 		err = exofs_add_link(new_dentry, old_inode);
276 		if (err)
277 			goto out_dir;
278 		if (dir_de)
279 			inode_inc_link_count(new_dir);
280 	}
281 
282 	old_inode->i_ctime = current_time(old_inode);
283 
284 	exofs_delete_entry(old_de, old_page);
285 	mark_inode_dirty(old_inode);
286 
287 	if (dir_de) {
288 		err = exofs_set_link(old_inode, dir_de, dir_page, new_dir);
289 		inode_dec_link_count(old_dir);
290 		if (err)
291 			goto out_dir;
292 	}
293 	return 0;
294 
295 
296 out_dir:
297 	if (dir_de) {
298 		kunmap(dir_page);
299 		put_page(dir_page);
300 	}
301 out_old:
302 	kunmap(old_page);
303 	put_page(old_page);
304 out:
305 	return err;
306 }
307 
308 const struct inode_operations exofs_dir_inode_operations = {
309 	.create 	= exofs_create,
310 	.lookup 	= exofs_lookup,
311 	.link   	= exofs_link,
312 	.unlink 	= exofs_unlink,
313 	.symlink	= exofs_symlink,
314 	.mkdir  	= exofs_mkdir,
315 	.rmdir  	= exofs_rmdir,
316 	.mknod  	= exofs_mknod,
317 	.rename		= exofs_rename,
318 	.setattr	= exofs_setattr,
319 };
320 
321 const struct inode_operations exofs_special_inode_operations = {
322 	.setattr	= exofs_setattr,
323 };
324