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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
18static 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
30static int sysv_hash(const struct dentry *dentry, const struct inode *inode,
31 struct qstr *qstr)
32{
33 /* Truncate the name in place, avoids having to define a compare
34 function. */
35 if (qstr->len > SYSV_NAMELEN) {
36 qstr->len = SYSV_NAMELEN;
37 qstr->hash = full_name_hash(qstr->name, qstr->len);
38 }
39 return 0;
40}
41
42const struct dentry_operations sysv_dentry_operations = {
43 .d_hash = sysv_hash,
44};
45
46static struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
47{
48 struct inode * inode = NULL;
49 ino_t ino;
50
51 if (dentry->d_name.len > SYSV_NAMELEN)
52 return ERR_PTR(-ENAMETOOLONG);
53 ino = sysv_inode_by_name(dentry);
54
55 if (ino) {
56 inode = sysv_iget(dir->i_sb, ino);
57 if (IS_ERR(inode))
58 return ERR_CAST(inode);
59 }
60 d_add(dentry, inode);
61 return NULL;
62}
63
64static int sysv_mknod(struct inode * dir, struct dentry * dentry, int mode, dev_t rdev)
65{
66 struct inode * inode;
67 int err;
68
69 if (!old_valid_dev(rdev))
70 return -EINVAL;
71
72 inode = sysv_new_inode(dir, mode);
73 err = PTR_ERR(inode);
74
75 if (!IS_ERR(inode)) {
76 sysv_set_inode(inode, rdev);
77 mark_inode_dirty(inode);
78 err = add_nondir(dentry, inode);
79 }
80 return err;
81}
82
83static int sysv_create(struct inode * dir, struct dentry * dentry, int mode, struct nameidata *nd)
84{
85 return sysv_mknod(dir, dentry, mode, 0);
86}
87
88static int sysv_symlink(struct inode * dir, struct dentry * dentry,
89 const char * symname)
90{
91 int err = -ENAMETOOLONG;
92 int l = strlen(symname)+1;
93 struct inode * inode;
94
95 if (l > dir->i_sb->s_blocksize)
96 goto out;
97
98 inode = sysv_new_inode(dir, S_IFLNK|0777);
99 err = PTR_ERR(inode);
100 if (IS_ERR(inode))
101 goto out;
102
103 sysv_set_inode(inode, 0);
104 err = page_symlink(inode, symname, l);
105 if (err)
106 goto out_fail;
107
108 mark_inode_dirty(inode);
109 err = add_nondir(dentry, inode);
110out:
111 return err;
112
113out_fail:
114 inode_dec_link_count(inode);
115 iput(inode);
116 goto out;
117}
118
119static int sysv_link(struct dentry * old_dentry, struct inode * dir,
120 struct dentry * dentry)
121{
122 struct inode *inode = old_dentry->d_inode;
123
124 if (inode->i_nlink >= SYSV_SB(inode->i_sb)->s_link_max)
125 return -EMLINK;
126
127 inode->i_ctime = CURRENT_TIME_SEC;
128 inode_inc_link_count(inode);
129 ihold(inode);
130
131 return add_nondir(dentry, inode);
132}
133
134static int sysv_mkdir(struct inode * dir, struct dentry *dentry, int mode)
135{
136 struct inode * inode;
137 int err = -EMLINK;
138
139 if (dir->i_nlink >= SYSV_SB(dir->i_sb)->s_link_max)
140 goto out;
141 inode_inc_link_count(dir);
142
143 inode = sysv_new_inode(dir, S_IFDIR|mode);
144 err = PTR_ERR(inode);
145 if (IS_ERR(inode))
146 goto out_dir;
147
148 sysv_set_inode(inode, 0);
149
150 inode_inc_link_count(inode);
151
152 err = sysv_make_empty(inode, dir);
153 if (err)
154 goto out_fail;
155
156 err = sysv_add_link(dentry, inode);
157 if (err)
158 goto out_fail;
159
160 d_instantiate(dentry, inode);
161out:
162 return err;
163
164out_fail:
165 inode_dec_link_count(inode);
166 inode_dec_link_count(inode);
167 iput(inode);
168out_dir:
169 inode_dec_link_count(dir);
170 goto out;
171}
172
173static int sysv_unlink(struct inode * dir, struct dentry * dentry)
174{
175 struct inode * inode = dentry->d_inode;
176 struct page * page;
177 struct sysv_dir_entry * de;
178 int err = -ENOENT;
179
180 de = sysv_find_entry(dentry, &page);
181 if (!de)
182 goto out;
183
184 err = sysv_delete_entry (de, page);
185 if (err)
186 goto out;
187
188 inode->i_ctime = dir->i_ctime;
189 inode_dec_link_count(inode);
190out:
191 return err;
192}
193
194static int sysv_rmdir(struct inode * dir, struct dentry * dentry)
195{
196 struct inode *inode = dentry->d_inode;
197 int err = -ENOTEMPTY;
198
199 if (sysv_empty_dir(inode)) {
200 err = sysv_unlink(dir, dentry);
201 if (!err) {
202 inode->i_size = 0;
203 inode_dec_link_count(inode);
204 inode_dec_link_count(dir);
205 }
206 }
207 return err;
208}
209
210/*
211 * Anybody can rename anything with this: the permission checks are left to the
212 * higher-level routines.
213 */
214static int sysv_rename(struct inode * old_dir, struct dentry * old_dentry,
215 struct inode * new_dir, struct dentry * new_dentry)
216{
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 sysv_dir_entry * dir_de = NULL;
221 struct page * old_page;
222 struct sysv_dir_entry * old_de;
223 int err = -ENOENT;
224
225 old_de = sysv_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 = sysv_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 sysv_dir_entry * new_de;
239
240 err = -ENOTEMPTY;
241 if (dir_de && !sysv_empty_dir(new_inode))
242 goto out_dir;
243
244 err = -ENOENT;
245 new_de = sysv_find_entry(new_dentry, &new_page);
246 if (!new_de)
247 goto out_dir;
248 sysv_set_link(new_de, new_page, old_inode);
249 new_inode->i_ctime = CURRENT_TIME_SEC;
250 if (dir_de)
251 drop_nlink(new_inode);
252 inode_dec_link_count(new_inode);
253 } else {
254 if (dir_de) {
255 err = -EMLINK;
256 if (new_dir->i_nlink >= SYSV_SB(new_dir->i_sb)->s_link_max)
257 goto out_dir;
258 }
259 err = sysv_add_link(new_dentry, old_inode);
260 if (err)
261 goto out_dir;
262 if (dir_de)
263 inode_inc_link_count(new_dir);
264 }
265
266 sysv_delete_entry(old_de, old_page);
267 mark_inode_dirty(old_inode);
268
269 if (dir_de) {
270 sysv_set_link(dir_de, dir_page, new_dir);
271 inode_dec_link_count(old_dir);
272 }
273 return 0;
274
275out_dir:
276 if (dir_de) {
277 kunmap(dir_page);
278 page_cache_release(dir_page);
279 }
280out_old:
281 kunmap(old_page);
282 page_cache_release(old_page);
283out:
284 return err;
285}
286
287/*
288 * directories can handle most operations...
289 */
290const struct inode_operations sysv_dir_inode_operations = {
291 .create = sysv_create,
292 .lookup = sysv_lookup,
293 .link = sysv_link,
294 .unlink = sysv_unlink,
295 .symlink = sysv_symlink,
296 .mkdir = sysv_mkdir,
297 .rmdir = sysv_rmdir,
298 .mknod = sysv_mknod,
299 .rename = sysv_rename,
300 .getattr = sysv_getattr,
301};
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/sysv/namei.c
4 *
5 * minix/namei.c
6 * Copyright (C) 1991, 1992 Linus Torvalds
7 *
8 * coh/namei.c
9 * Copyright (C) 1993 Pascal Haible, Bruno Haible
10 *
11 * sysv/namei.c
12 * Copyright (C) 1993 Bruno Haible
13 * Copyright (C) 1997, 1998 Krzysztof G. Baranowski
14 */
15
16#include <linux/pagemap.h>
17#include "sysv.h"
18
19static int add_nondir(struct dentry *dentry, struct inode *inode)
20{
21 int err = sysv_add_link(dentry, inode);
22 if (!err) {
23 d_instantiate(dentry, inode);
24 return 0;
25 }
26 inode_dec_link_count(inode);
27 iput(inode);
28 return err;
29}
30
31static struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags)
32{
33 struct inode * inode = NULL;
34 ino_t ino;
35
36 if (dentry->d_name.len > SYSV_NAMELEN)
37 return ERR_PTR(-ENAMETOOLONG);
38 ino = sysv_inode_by_name(dentry);
39 if (ino)
40 inode = sysv_iget(dir->i_sb, ino);
41 return d_splice_alias(inode, dentry);
42}
43
44static int sysv_mknod(struct mnt_idmap *idmap, struct inode *dir,
45 struct dentry *dentry, umode_t mode, dev_t rdev)
46{
47 struct inode * inode;
48 int err;
49
50 if (!old_valid_dev(rdev))
51 return -EINVAL;
52
53 inode = sysv_new_inode(dir, mode);
54 err = PTR_ERR(inode);
55
56 if (!IS_ERR(inode)) {
57 sysv_set_inode(inode, rdev);
58 mark_inode_dirty(inode);
59 err = add_nondir(dentry, inode);
60 }
61 return err;
62}
63
64static int sysv_create(struct mnt_idmap *idmap, struct inode *dir,
65 struct dentry *dentry, umode_t mode, bool excl)
66{
67 return sysv_mknod(&nop_mnt_idmap, dir, dentry, mode, 0);
68}
69
70static int sysv_symlink(struct mnt_idmap *idmap, struct inode *dir,
71 struct dentry *dentry, const char *symname)
72{
73 int err = -ENAMETOOLONG;
74 int l = strlen(symname)+1;
75 struct inode * inode;
76
77 if (l > dir->i_sb->s_blocksize)
78 goto out;
79
80 inode = sysv_new_inode(dir, S_IFLNK|0777);
81 err = PTR_ERR(inode);
82 if (IS_ERR(inode))
83 goto out;
84
85 sysv_set_inode(inode, 0);
86 err = page_symlink(inode, symname, l);
87 if (err)
88 goto out_fail;
89
90 mark_inode_dirty(inode);
91 err = add_nondir(dentry, inode);
92out:
93 return err;
94
95out_fail:
96 inode_dec_link_count(inode);
97 iput(inode);
98 goto out;
99}
100
101static int sysv_link(struct dentry * old_dentry, struct inode * dir,
102 struct dentry * dentry)
103{
104 struct inode *inode = d_inode(old_dentry);
105
106 inode_set_ctime_current(inode);
107 inode_inc_link_count(inode);
108 ihold(inode);
109
110 return add_nondir(dentry, inode);
111}
112
113static int sysv_mkdir(struct mnt_idmap *idmap, struct inode *dir,
114 struct dentry *dentry, umode_t mode)
115{
116 struct inode * inode;
117 int err;
118
119 inode_inc_link_count(dir);
120
121 inode = sysv_new_inode(dir, S_IFDIR|mode);
122 err = PTR_ERR(inode);
123 if (IS_ERR(inode))
124 goto out_dir;
125
126 sysv_set_inode(inode, 0);
127
128 inode_inc_link_count(inode);
129
130 err = sysv_make_empty(inode, dir);
131 if (err)
132 goto out_fail;
133
134 err = sysv_add_link(dentry, inode);
135 if (err)
136 goto out_fail;
137
138 d_instantiate(dentry, inode);
139out:
140 return err;
141
142out_fail:
143 inode_dec_link_count(inode);
144 inode_dec_link_count(inode);
145 iput(inode);
146out_dir:
147 inode_dec_link_count(dir);
148 goto out;
149}
150
151static int sysv_unlink(struct inode * dir, struct dentry * dentry)
152{
153 struct inode * inode = d_inode(dentry);
154 struct page * page;
155 struct sysv_dir_entry * de;
156 int err;
157
158 de = sysv_find_entry(dentry, &page);
159 if (!de)
160 return -ENOENT;
161
162 err = sysv_delete_entry(de, page);
163 if (!err) {
164 inode_set_ctime_to_ts(inode, inode_get_ctime(dir));
165 inode_dec_link_count(inode);
166 }
167 unmap_and_put_page(page, de);
168 return err;
169}
170
171static int sysv_rmdir(struct inode * dir, struct dentry * dentry)
172{
173 struct inode *inode = d_inode(dentry);
174 int err = -ENOTEMPTY;
175
176 if (sysv_empty_dir(inode)) {
177 err = sysv_unlink(dir, dentry);
178 if (!err) {
179 inode->i_size = 0;
180 inode_dec_link_count(inode);
181 inode_dec_link_count(dir);
182 }
183 }
184 return err;
185}
186
187/*
188 * Anybody can rename anything with this: the permission checks are left to the
189 * higher-level routines.
190 */
191static int sysv_rename(struct mnt_idmap *idmap, struct inode *old_dir,
192 struct dentry *old_dentry, struct inode *new_dir,
193 struct dentry *new_dentry, unsigned int flags)
194{
195 struct inode * old_inode = d_inode(old_dentry);
196 struct inode * new_inode = d_inode(new_dentry);
197 struct page * dir_page = NULL;
198 struct sysv_dir_entry * dir_de = NULL;
199 struct page * old_page;
200 struct sysv_dir_entry * old_de;
201 int err = -ENOENT;
202
203 if (flags & ~RENAME_NOREPLACE)
204 return -EINVAL;
205
206 old_de = sysv_find_entry(old_dentry, &old_page);
207 if (!old_de)
208 goto out;
209
210 if (S_ISDIR(old_inode->i_mode)) {
211 err = -EIO;
212 dir_de = sysv_dotdot(old_inode, &dir_page);
213 if (!dir_de)
214 goto out_old;
215 }
216
217 if (new_inode) {
218 struct page * new_page;
219 struct sysv_dir_entry * new_de;
220
221 err = -ENOTEMPTY;
222 if (dir_de && !sysv_empty_dir(new_inode))
223 goto out_dir;
224
225 err = -ENOENT;
226 new_de = sysv_find_entry(new_dentry, &new_page);
227 if (!new_de)
228 goto out_dir;
229 err = sysv_set_link(new_de, new_page, old_inode);
230 unmap_and_put_page(new_page, new_de);
231 if (err)
232 goto out_dir;
233 inode_set_ctime_current(new_inode);
234 if (dir_de)
235 drop_nlink(new_inode);
236 inode_dec_link_count(new_inode);
237 } else {
238 err = sysv_add_link(new_dentry, old_inode);
239 if (err)
240 goto out_dir;
241 if (dir_de)
242 inode_inc_link_count(new_dir);
243 }
244
245 err = sysv_delete_entry(old_de, old_page);
246 if (err)
247 goto out_dir;
248
249 mark_inode_dirty(old_inode);
250
251 if (dir_de) {
252 err = sysv_set_link(dir_de, dir_page, new_dir);
253 if (!err)
254 inode_dec_link_count(old_dir);
255 }
256
257out_dir:
258 if (dir_de)
259 unmap_and_put_page(dir_page, dir_de);
260out_old:
261 unmap_and_put_page(old_page, old_de);
262out:
263 return err;
264}
265
266/*
267 * directories can handle most operations...
268 */
269const struct inode_operations sysv_dir_inode_operations = {
270 .create = sysv_create,
271 .lookup = sysv_lookup,
272 .link = sysv_link,
273 .unlink = sysv_unlink,
274 .symlink = sysv_symlink,
275 .mkdir = sysv_mkdir,
276 .rmdir = sysv_rmdir,
277 .mknod = sysv_mknod,
278 .rename = sysv_rename,
279 .getattr = sysv_getattr,
280};