]> git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - fs/sysv/namei.c
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
[mirror_ubuntu-zesty-kernel.git] / fs / sysv / namei.c
1 /*
2 * linux/fs/sysv/namei.c
3 *
4 * minix/namei.c
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * coh/namei.c
8 * Copyright (C) 1993 Pascal Haible, Bruno Haible
9 *
10 * sysv/namei.c
11 * Copyright (C) 1993 Bruno Haible
12 * Copyright (C) 1997, 1998 Krzysztof G. Baranowski
13 */
14
15 #include <linux/pagemap.h>
16 #include "sysv.h"
17
18 static int add_nondir(struct dentry *dentry, struct inode *inode)
19 {
20 int err = sysv_add_link(dentry, inode);
21 if (!err) {
22 d_instantiate(dentry, inode);
23 return 0;
24 }
25 inode_dec_link_count(inode);
26 iput(inode);
27 return err;
28 }
29
30 static int sysv_hash(const struct dentry *dentry, struct qstr *qstr)
31 {
32 /* Truncate the name in place, avoids having to define a compare
33 function. */
34 if (qstr->len > SYSV_NAMELEN) {
35 qstr->len = SYSV_NAMELEN;
36 qstr->hash = full_name_hash(dentry, qstr->name, qstr->len);
37 }
38 return 0;
39 }
40
41 const struct dentry_operations sysv_dentry_operations = {
42 .d_hash = sysv_hash,
43 };
44
45 static struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags)
46 {
47 struct inode * inode = NULL;
48 ino_t ino;
49
50 if (dentry->d_name.len > SYSV_NAMELEN)
51 return ERR_PTR(-ENAMETOOLONG);
52 ino = sysv_inode_by_name(dentry);
53
54 if (ino) {
55 inode = sysv_iget(dir->i_sb, ino);
56 if (IS_ERR(inode))
57 return ERR_CAST(inode);
58 }
59 d_add(dentry, inode);
60 return NULL;
61 }
62
63 static int sysv_mknod(struct inode * dir, struct dentry * dentry, umode_t mode, dev_t rdev)
64 {
65 struct inode * inode;
66 int err;
67
68 if (!old_valid_dev(rdev))
69 return -EINVAL;
70
71 inode = sysv_new_inode(dir, mode);
72 err = PTR_ERR(inode);
73
74 if (!IS_ERR(inode)) {
75 sysv_set_inode(inode, rdev);
76 mark_inode_dirty(inode);
77 err = add_nondir(dentry, inode);
78 }
79 return err;
80 }
81
82 static int sysv_create(struct inode * dir, struct dentry * dentry, umode_t mode, bool excl)
83 {
84 return sysv_mknod(dir, dentry, mode, 0);
85 }
86
87 static int sysv_symlink(struct inode * dir, struct dentry * dentry,
88 const char * symname)
89 {
90 int err = -ENAMETOOLONG;
91 int l = strlen(symname)+1;
92 struct inode * inode;
93
94 if (l > dir->i_sb->s_blocksize)
95 goto out;
96
97 inode = sysv_new_inode(dir, S_IFLNK|0777);
98 err = PTR_ERR(inode);
99 if (IS_ERR(inode))
100 goto out;
101
102 sysv_set_inode(inode, 0);
103 err = page_symlink(inode, symname, l);
104 if (err)
105 goto out_fail;
106
107 mark_inode_dirty(inode);
108 err = add_nondir(dentry, inode);
109 out:
110 return err;
111
112 out_fail:
113 inode_dec_link_count(inode);
114 iput(inode);
115 goto out;
116 }
117
118 static int sysv_link(struct dentry * old_dentry, struct inode * dir,
119 struct dentry * dentry)
120 {
121 struct inode *inode = d_inode(old_dentry);
122
123 inode->i_ctime = current_time(inode);
124 inode_inc_link_count(inode);
125 ihold(inode);
126
127 return add_nondir(dentry, inode);
128 }
129
130 static int sysv_mkdir(struct inode * dir, struct dentry *dentry, umode_t mode)
131 {
132 struct inode * inode;
133 int err;
134
135 inode_inc_link_count(dir);
136
137 inode = sysv_new_inode(dir, S_IFDIR|mode);
138 err = PTR_ERR(inode);
139 if (IS_ERR(inode))
140 goto out_dir;
141
142 sysv_set_inode(inode, 0);
143
144 inode_inc_link_count(inode);
145
146 err = sysv_make_empty(inode, dir);
147 if (err)
148 goto out_fail;
149
150 err = sysv_add_link(dentry, inode);
151 if (err)
152 goto out_fail;
153
154 d_instantiate(dentry, inode);
155 out:
156 return err;
157
158 out_fail:
159 inode_dec_link_count(inode);
160 inode_dec_link_count(inode);
161 iput(inode);
162 out_dir:
163 inode_dec_link_count(dir);
164 goto out;
165 }
166
167 static int sysv_unlink(struct inode * dir, struct dentry * dentry)
168 {
169 struct inode * inode = d_inode(dentry);
170 struct page * page;
171 struct sysv_dir_entry * de;
172 int err = -ENOENT;
173
174 de = sysv_find_entry(dentry, &page);
175 if (!de)
176 goto out;
177
178 err = sysv_delete_entry (de, page);
179 if (err)
180 goto out;
181
182 inode->i_ctime = dir->i_ctime;
183 inode_dec_link_count(inode);
184 out:
185 return err;
186 }
187
188 static int sysv_rmdir(struct inode * dir, struct dentry * dentry)
189 {
190 struct inode *inode = d_inode(dentry);
191 int err = -ENOTEMPTY;
192
193 if (sysv_empty_dir(inode)) {
194 err = sysv_unlink(dir, dentry);
195 if (!err) {
196 inode->i_size = 0;
197 inode_dec_link_count(inode);
198 inode_dec_link_count(dir);
199 }
200 }
201 return err;
202 }
203
204 /*
205 * Anybody can rename anything with this: the permission checks are left to the
206 * higher-level routines.
207 */
208 static int sysv_rename(struct inode * old_dir, struct dentry * old_dentry,
209 struct inode * new_dir, struct dentry * new_dentry,
210 unsigned int flags)
211 {
212 struct inode * old_inode = d_inode(old_dentry);
213 struct inode * new_inode = d_inode(new_dentry);
214 struct page * dir_page = NULL;
215 struct sysv_dir_entry * dir_de = NULL;
216 struct page * old_page;
217 struct sysv_dir_entry * old_de;
218 int err = -ENOENT;
219
220 if (flags & ~RENAME_NOREPLACE)
221 return -EINVAL;
222
223 old_de = sysv_find_entry(old_dentry, &old_page);
224 if (!old_de)
225 goto out;
226
227 if (S_ISDIR(old_inode->i_mode)) {
228 err = -EIO;
229 dir_de = sysv_dotdot(old_inode, &dir_page);
230 if (!dir_de)
231 goto out_old;
232 }
233
234 if (new_inode) {
235 struct page * new_page;
236 struct sysv_dir_entry * new_de;
237
238 err = -ENOTEMPTY;
239 if (dir_de && !sysv_empty_dir(new_inode))
240 goto out_dir;
241
242 err = -ENOENT;
243 new_de = sysv_find_entry(new_dentry, &new_page);
244 if (!new_de)
245 goto out_dir;
246 sysv_set_link(new_de, new_page, old_inode);
247 new_inode->i_ctime = current_time(new_inode);
248 if (dir_de)
249 drop_nlink(new_inode);
250 inode_dec_link_count(new_inode);
251 } else {
252 err = sysv_add_link(new_dentry, old_inode);
253 if (err)
254 goto out_dir;
255 if (dir_de)
256 inode_inc_link_count(new_dir);
257 }
258
259 sysv_delete_entry(old_de, old_page);
260 mark_inode_dirty(old_inode);
261
262 if (dir_de) {
263 sysv_set_link(dir_de, dir_page, new_dir);
264 inode_dec_link_count(old_dir);
265 }
266 return 0;
267
268 out_dir:
269 if (dir_de) {
270 kunmap(dir_page);
271 put_page(dir_page);
272 }
273 out_old:
274 kunmap(old_page);
275 put_page(old_page);
276 out:
277 return err;
278 }
279
280 /*
281 * directories can handle most operations...
282 */
283 const struct inode_operations sysv_dir_inode_operations = {
284 .create = sysv_create,
285 .lookup = sysv_lookup,
286 .link = sysv_link,
287 .unlink = sysv_unlink,
288 .symlink = sysv_symlink,
289 .mkdir = sysv_mkdir,
290 .rmdir = sysv_rmdir,
291 .mknod = sysv_mknod,
292 .rename = sysv_rename,
293 .getattr = sysv_getattr,
294 };