xref: /openbmc/linux/fs/ufs/namei.c (revision b6dcefde)
1 /*
2  * linux/fs/ufs/namei.c
3  *
4  * Migration to usage of "page cache" on May 2006 by
5  * Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base.
6  *
7  * Copyright (C) 1998
8  * Daniel Pirkl <daniel.pirkl@email.cz>
9  * Charles University, Faculty of Mathematics and Physics
10  *
11  *  from
12  *
13  *  linux/fs/ext2/namei.c
14  *
15  * Copyright (C) 1992, 1993, 1994, 1995
16  * Remy Card (card@masi.ibp.fr)
17  * Laboratoire MASI - Institut Blaise Pascal
18  * Universite Pierre et Marie Curie (Paris VI)
19  *
20  *  from
21  *
22  *  linux/fs/minix/namei.c
23  *
24  *  Copyright (C) 1991, 1992  Linus Torvalds
25  *
26  *  Big-endian to little-endian byte-swapping/bitmaps by
27  *        David S. Miller (davem@caip.rutgers.edu), 1995
28  */
29 
30 #include <linux/time.h>
31 #include <linux/fs.h>
32 #include <linux/smp_lock.h>
33 
34 #include "ufs_fs.h"
35 #include "ufs.h"
36 #include "util.h"
37 
38 static inline int ufs_add_nondir(struct dentry *dentry, struct inode *inode)
39 {
40 	int err = ufs_add_link(dentry, inode);
41 	if (!err) {
42 		d_instantiate(dentry, inode);
43 		return 0;
44 	}
45 	inode_dec_link_count(inode);
46 	iput(inode);
47 	return err;
48 }
49 
50 static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
51 {
52 	struct inode * inode = NULL;
53 	ino_t ino;
54 
55 	if (dentry->d_name.len > UFS_MAXNAMLEN)
56 		return ERR_PTR(-ENAMETOOLONG);
57 
58 	lock_kernel();
59 	ino = ufs_inode_by_name(dir, &dentry->d_name);
60 	if (ino) {
61 		inode = ufs_iget(dir->i_sb, ino);
62 		if (IS_ERR(inode)) {
63 			unlock_kernel();
64 			return ERR_CAST(inode);
65 		}
66 	}
67 	unlock_kernel();
68 	d_add(dentry, inode);
69 	return NULL;
70 }
71 
72 /*
73  * By the time this is called, we already have created
74  * the directory cache entry for the new file, but it
75  * is so far negative - it has no inode.
76  *
77  * If the create succeeds, we fill in the inode information
78  * with d_instantiate().
79  */
80 static int ufs_create (struct inode * dir, struct dentry * dentry, int mode,
81 		struct nameidata *nd)
82 {
83 	struct inode *inode;
84 	int err;
85 
86 	UFSD("BEGIN\n");
87 	inode = ufs_new_inode(dir, mode);
88 	err = PTR_ERR(inode);
89 
90 	if (!IS_ERR(inode)) {
91 		inode->i_op = &ufs_file_inode_operations;
92 		inode->i_fop = &ufs_file_operations;
93 		inode->i_mapping->a_ops = &ufs_aops;
94 		mark_inode_dirty(inode);
95 		lock_kernel();
96 		err = ufs_add_nondir(dentry, inode);
97 		unlock_kernel();
98 	}
99 	UFSD("END: err=%d\n", err);
100 	return err;
101 }
102 
103 static int ufs_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
104 {
105 	struct inode *inode;
106 	int err;
107 
108 	if (!old_valid_dev(rdev))
109 		return -EINVAL;
110 	inode = ufs_new_inode(dir, mode);
111 	err = PTR_ERR(inode);
112 	if (!IS_ERR(inode)) {
113 		init_special_inode(inode, mode, rdev);
114 		ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev);
115 		mark_inode_dirty(inode);
116 		lock_kernel();
117 		err = ufs_add_nondir(dentry, inode);
118 		unlock_kernel();
119 	}
120 	return err;
121 }
122 
123 static int ufs_symlink (struct inode * dir, struct dentry * dentry,
124 	const char * symname)
125 {
126 	struct super_block * sb = dir->i_sb;
127 	int err = -ENAMETOOLONG;
128 	unsigned l = strlen(symname)+1;
129 	struct inode * inode;
130 
131 	if (l > sb->s_blocksize)
132 		goto out_notlocked;
133 
134 	lock_kernel();
135 	inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO);
136 	err = PTR_ERR(inode);
137 	if (IS_ERR(inode))
138 		goto out;
139 
140 	if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) {
141 		/* slow symlink */
142 		inode->i_op = &page_symlink_inode_operations;
143 		inode->i_mapping->a_ops = &ufs_aops;
144 		err = page_symlink(inode, symname, l);
145 		if (err)
146 			goto out_fail;
147 	} else {
148 		/* fast symlink */
149 		inode->i_op = &ufs_fast_symlink_inode_operations;
150 		memcpy(UFS_I(inode)->i_u1.i_symlink, symname, l);
151 		inode->i_size = l-1;
152 	}
153 	mark_inode_dirty(inode);
154 
155 	err = ufs_add_nondir(dentry, inode);
156 out:
157 	unlock_kernel();
158 out_notlocked:
159 	return err;
160 
161 out_fail:
162 	inode_dec_link_count(inode);
163 	iput(inode);
164 	goto out;
165 }
166 
167 static int ufs_link (struct dentry * old_dentry, struct inode * dir,
168 	struct dentry *dentry)
169 {
170 	struct inode *inode = old_dentry->d_inode;
171 	int error;
172 
173 	lock_kernel();
174 	if (inode->i_nlink >= UFS_LINK_MAX) {
175 		unlock_kernel();
176 		return -EMLINK;
177 	}
178 
179 	inode->i_ctime = CURRENT_TIME_SEC;
180 	inode_inc_link_count(inode);
181 	atomic_inc(&inode->i_count);
182 
183 	error = ufs_add_nondir(dentry, inode);
184 	unlock_kernel();
185 	return error;
186 }
187 
188 static int ufs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
189 {
190 	struct inode * inode;
191 	int err = -EMLINK;
192 
193 	if (dir->i_nlink >= UFS_LINK_MAX)
194 		goto out;
195 
196 	lock_kernel();
197 	inode_inc_link_count(dir);
198 
199 	inode = ufs_new_inode(dir, S_IFDIR|mode);
200 	err = PTR_ERR(inode);
201 	if (IS_ERR(inode))
202 		goto out_dir;
203 
204 	inode->i_op = &ufs_dir_inode_operations;
205 	inode->i_fop = &ufs_dir_operations;
206 	inode->i_mapping->a_ops = &ufs_aops;
207 
208 	inode_inc_link_count(inode);
209 
210 	err = ufs_make_empty(inode, dir);
211 	if (err)
212 		goto out_fail;
213 
214 	err = ufs_add_link(dentry, inode);
215 	if (err)
216 		goto out_fail;
217 	unlock_kernel();
218 
219 	d_instantiate(dentry, inode);
220 out:
221 	return err;
222 
223 out_fail:
224 	inode_dec_link_count(inode);
225 	inode_dec_link_count(inode);
226 	iput (inode);
227 out_dir:
228 	inode_dec_link_count(dir);
229 	unlock_kernel();
230 	goto out;
231 }
232 
233 static int ufs_unlink(struct inode *dir, struct dentry *dentry)
234 {
235 	struct inode * inode = dentry->d_inode;
236 	struct ufs_dir_entry *de;
237 	struct page *page;
238 	int err = -ENOENT;
239 
240 	de = ufs_find_entry(dir, &dentry->d_name, &page);
241 	if (!de)
242 		goto out;
243 
244 	err = ufs_delete_entry(dir, de, page);
245 	if (err)
246 		goto out;
247 
248 	inode->i_ctime = dir->i_ctime;
249 	inode_dec_link_count(inode);
250 	err = 0;
251 out:
252 	return err;
253 }
254 
255 static int ufs_rmdir (struct inode * dir, struct dentry *dentry)
256 {
257 	struct inode * inode = dentry->d_inode;
258 	int err= -ENOTEMPTY;
259 
260 	lock_kernel();
261 	if (ufs_empty_dir (inode)) {
262 		err = ufs_unlink(dir, dentry);
263 		if (!err) {
264 			inode->i_size = 0;
265 			inode_dec_link_count(inode);
266 			inode_dec_link_count(dir);
267 		}
268 	}
269 	unlock_kernel();
270 	return err;
271 }
272 
273 static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
274 		      struct inode *new_dir, struct dentry *new_dentry)
275 {
276 	struct inode *old_inode = old_dentry->d_inode;
277 	struct inode *new_inode = new_dentry->d_inode;
278 	struct page *dir_page = NULL;
279 	struct ufs_dir_entry * dir_de = NULL;
280 	struct page *old_page;
281 	struct ufs_dir_entry *old_de;
282 	int err = -ENOENT;
283 
284 	old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_page);
285 	if (!old_de)
286 		goto out;
287 
288 	if (S_ISDIR(old_inode->i_mode)) {
289 		err = -EIO;
290 		dir_de = ufs_dotdot(old_inode, &dir_page);
291 		if (!dir_de)
292 			goto out_old;
293 	}
294 
295 	if (new_inode) {
296 		struct page *new_page;
297 		struct ufs_dir_entry *new_de;
298 
299 		err = -ENOTEMPTY;
300 		if (dir_de && !ufs_empty_dir(new_inode))
301 			goto out_dir;
302 
303 		err = -ENOENT;
304 		new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page);
305 		if (!new_de)
306 			goto out_dir;
307 		inode_inc_link_count(old_inode);
308 		ufs_set_link(new_dir, new_de, new_page, old_inode);
309 		new_inode->i_ctime = CURRENT_TIME_SEC;
310 		if (dir_de)
311 			drop_nlink(new_inode);
312 		inode_dec_link_count(new_inode);
313 	} else {
314 		if (dir_de) {
315 			err = -EMLINK;
316 			if (new_dir->i_nlink >= UFS_LINK_MAX)
317 				goto out_dir;
318 		}
319 		inode_inc_link_count(old_inode);
320 		err = ufs_add_link(new_dentry, old_inode);
321 		if (err) {
322 			inode_dec_link_count(old_inode);
323 			goto out_dir;
324 		}
325 		if (dir_de)
326 			inode_inc_link_count(new_dir);
327 	}
328 
329 	/*
330 	 * Like most other Unix systems, set the ctime for inodes on a
331  	 * rename.
332 	 * inode_dec_link_count() will mark the inode dirty.
333 	 */
334 	old_inode->i_ctime = CURRENT_TIME_SEC;
335 
336 	ufs_delete_entry(old_dir, old_de, old_page);
337 	inode_dec_link_count(old_inode);
338 
339 	if (dir_de) {
340 		ufs_set_link(old_inode, dir_de, dir_page, new_dir);
341 		inode_dec_link_count(old_dir);
342 	}
343 	return 0;
344 
345 
346 out_dir:
347 	if (dir_de) {
348 		kunmap(dir_page);
349 		page_cache_release(dir_page);
350 	}
351 out_old:
352 	kunmap(old_page);
353 	page_cache_release(old_page);
354 out:
355 	return err;
356 }
357 
358 const struct inode_operations ufs_dir_inode_operations = {
359 	.create		= ufs_create,
360 	.lookup		= ufs_lookup,
361 	.link		= ufs_link,
362 	.unlink		= ufs_unlink,
363 	.symlink	= ufs_symlink,
364 	.mkdir		= ufs_mkdir,
365 	.rmdir		= ufs_rmdir,
366 	.mknod		= ufs_mknod,
367 	.rename		= ufs_rename,
368 };
369