blob: 299bb66e3bde55a880435c5dee0c315cfbdced0d [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/minix/namei.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7#include "minix.h"
8
Linus Torvalds1da177e2005-04-16 15:20:36 -07009static int add_nondir(struct dentry *dentry, struct inode *inode)
10{
11 int err = minix_add_link(dentry, inode);
12 if (!err) {
13 d_instantiate(dentry, inode);
14 return 0;
15 }
Alexey Dobriyan78ec7b62006-03-23 03:00:51 -080016 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 iput(inode);
18 return err;
19}
20
21static int minix_hash(struct dentry *dentry, struct qstr *qstr)
22{
23 unsigned long hash;
24 int i;
25 const unsigned char *name;
26
27 i = minix_sb(dentry->d_inode->i_sb)->s_namelen;
28 if (i >= qstr->len)
29 return 0;
30 /* Truncate the name in place, avoids having to define a compare
31 function. */
32 qstr->len = i;
33 name = qstr->name;
34 hash = init_name_hash();
35 while (i--)
36 hash = partial_name_hash(*name++, hash);
37 qstr->hash = end_name_hash(hash);
38 return 0;
39}
40
41struct dentry_operations minix_dentry_operations = {
42 .d_hash = minix_hash,
43};
44
45static struct dentry *minix_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
46{
47 struct inode * inode = NULL;
48 ino_t ino;
49
50 dentry->d_op = dir->i_sb->s_root->d_op;
51
52 if (dentry->d_name.len > minix_sb(dir->i_sb)->s_namelen)
53 return ERR_PTR(-ENAMETOOLONG);
54
55 ino = minix_inode_by_name(dentry);
56 if (ino) {
57 inode = iget(dir->i_sb, ino);
58
59 if (!inode)
60 return ERR_PTR(-EACCES);
61 }
62 d_add(dentry, inode);
63 return NULL;
64}
65
66static int minix_mknod(struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
67{
68 int error;
69 struct inode *inode;
70
71 if (!old_valid_dev(rdev))
72 return -EINVAL;
73
74 inode = minix_new_inode(dir, &error);
75
76 if (inode) {
77 inode->i_mode = mode;
78 minix_set_inode(inode, rdev);
79 mark_inode_dirty(inode);
80 error = add_nondir(dentry, inode);
81 }
82 return error;
83}
84
85static int minix_create(struct inode * dir, struct dentry *dentry, int mode,
86 struct nameidata *nd)
87{
88 return minix_mknod(dir, dentry, mode, 0);
89}
90
91static int minix_symlink(struct inode * dir, struct dentry *dentry,
92 const char * symname)
93{
94 int err = -ENAMETOOLONG;
95 int i = strlen(symname)+1;
96 struct inode * inode;
97
98 if (i > dir->i_sb->s_blocksize)
99 goto out;
100
101 inode = minix_new_inode(dir, &err);
102 if (!inode)
103 goto out;
104
105 inode->i_mode = S_IFLNK | 0777;
106 minix_set_inode(inode, 0);
107 err = page_symlink(inode, symname, i);
108 if (err)
109 goto out_fail;
110
111 err = add_nondir(dentry, inode);
112out:
113 return err;
114
115out_fail:
Alexey Dobriyan78ec7b62006-03-23 03:00:51 -0800116 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 iput(inode);
118 goto out;
119}
120
121static int minix_link(struct dentry * old_dentry, struct inode * dir,
122 struct dentry *dentry)
123{
124 struct inode *inode = old_dentry->d_inode;
125
126 if (inode->i_nlink >= minix_sb(inode->i_sb)->s_link_max)
127 return -EMLINK;
128
129 inode->i_ctime = CURRENT_TIME_SEC;
Alexey Dobriyan78ec7b62006-03-23 03:00:51 -0800130 inode_inc_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 atomic_inc(&inode->i_count);
132 return add_nondir(dentry, inode);
133}
134
135static int minix_mkdir(struct inode * dir, struct dentry *dentry, int mode)
136{
137 struct inode * inode;
138 int err = -EMLINK;
139
140 if (dir->i_nlink >= minix_sb(dir->i_sb)->s_link_max)
141 goto out;
142
Alexey Dobriyan78ec7b62006-03-23 03:00:51 -0800143 inode_inc_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
145 inode = minix_new_inode(dir, &err);
146 if (!inode)
147 goto out_dir;
148
149 inode->i_mode = S_IFDIR | mode;
150 if (dir->i_mode & S_ISGID)
151 inode->i_mode |= S_ISGID;
152 minix_set_inode(inode, 0);
153
Alexey Dobriyan78ec7b62006-03-23 03:00:51 -0800154 inode_inc_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
156 err = minix_make_empty(inode, dir);
157 if (err)
158 goto out_fail;
159
160 err = minix_add_link(dentry, inode);
161 if (err)
162 goto out_fail;
163
164 d_instantiate(dentry, inode);
165out:
166 return err;
167
168out_fail:
Alexey Dobriyan78ec7b62006-03-23 03:00:51 -0800169 inode_dec_link_count(inode);
170 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 iput(inode);
172out_dir:
Alexey Dobriyan78ec7b62006-03-23 03:00:51 -0800173 inode_dec_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 goto out;
175}
176
177static int minix_unlink(struct inode * dir, struct dentry *dentry)
178{
179 int err = -ENOENT;
180 struct inode * inode = dentry->d_inode;
181 struct page * page;
182 struct minix_dir_entry * de;
183
184 de = minix_find_entry(dentry, &page);
185 if (!de)
186 goto end_unlink;
187
188 err = minix_delete_entry(de, page);
189 if (err)
190 goto end_unlink;
191
192 inode->i_ctime = dir->i_ctime;
Alexey Dobriyan78ec7b62006-03-23 03:00:51 -0800193 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194end_unlink:
195 return err;
196}
197
198static int minix_rmdir(struct inode * dir, struct dentry *dentry)
199{
200 struct inode * inode = dentry->d_inode;
201 int err = -ENOTEMPTY;
202
203 if (minix_empty_dir(inode)) {
204 err = minix_unlink(dir, dentry);
205 if (!err) {
Alexey Dobriyan78ec7b62006-03-23 03:00:51 -0800206 inode_dec_link_count(dir);
207 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 }
209 }
210 return err;
211}
212
213static int minix_rename(struct inode * old_dir, struct dentry *old_dentry,
214 struct inode * new_dir, struct dentry *new_dentry)
215{
216 struct minix_sb_info * info = minix_sb(old_dir->i_sb);
217 struct inode * old_inode = old_dentry->d_inode;
218 struct inode * new_inode = new_dentry->d_inode;
219 struct page * dir_page = NULL;
220 struct minix_dir_entry * dir_de = NULL;
221 struct page * old_page;
222 struct minix_dir_entry * old_de;
223 int err = -ENOENT;
224
225 old_de = minix_find_entry(old_dentry, &old_page);
226 if (!old_de)
227 goto out;
228
229 if (S_ISDIR(old_inode->i_mode)) {
230 err = -EIO;
231 dir_de = minix_dotdot(old_inode, &dir_page);
232 if (!dir_de)
233 goto out_old;
234 }
235
236 if (new_inode) {
237 struct page * new_page;
238 struct minix_dir_entry * new_de;
239
240 err = -ENOTEMPTY;
241 if (dir_de && !minix_empty_dir(new_inode))
242 goto out_dir;
243
244 err = -ENOENT;
245 new_de = minix_find_entry(new_dentry, &new_page);
246 if (!new_de)
247 goto out_dir;
Alexey Dobriyan78ec7b62006-03-23 03:00:51 -0800248 inode_inc_link_count(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 minix_set_link(new_de, new_page, old_inode);
250 new_inode->i_ctime = CURRENT_TIME_SEC;
251 if (dir_de)
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700252 drop_nlink(new_inode);
Alexey Dobriyan78ec7b62006-03-23 03:00:51 -0800253 inode_dec_link_count(new_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 } else {
255 if (dir_de) {
256 err = -EMLINK;
257 if (new_dir->i_nlink >= info->s_link_max)
258 goto out_dir;
259 }
Alexey Dobriyan78ec7b62006-03-23 03:00:51 -0800260 inode_inc_link_count(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 err = minix_add_link(new_dentry, old_inode);
262 if (err) {
Alexey Dobriyan78ec7b62006-03-23 03:00:51 -0800263 inode_dec_link_count(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 goto out_dir;
265 }
266 if (dir_de)
Alexey Dobriyan78ec7b62006-03-23 03:00:51 -0800267 inode_inc_link_count(new_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 }
269
270 minix_delete_entry(old_de, old_page);
Alexey Dobriyan78ec7b62006-03-23 03:00:51 -0800271 inode_dec_link_count(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272
273 if (dir_de) {
274 minix_set_link(dir_de, dir_page, new_dir);
Alexey Dobriyan78ec7b62006-03-23 03:00:51 -0800275 inode_dec_link_count(old_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 }
277 return 0;
278
279out_dir:
280 if (dir_de) {
281 kunmap(dir_page);
282 page_cache_release(dir_page);
283 }
284out_old:
285 kunmap(old_page);
286 page_cache_release(old_page);
287out:
288 return err;
289}
290
291/*
292 * directories can handle most operations...
293 */
294struct inode_operations minix_dir_inode_operations = {
295 .create = minix_create,
296 .lookup = minix_lookup,
297 .link = minix_link,
298 .unlink = minix_unlink,
299 .symlink = minix_symlink,
300 .mkdir = minix_mkdir,
301 .rmdir = minix_rmdir,
302 .mknod = minix_mknod,
303 .rename = minix_rename,
304 .getattr = minix_getattr,
305};