Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6-block.git] / fs / ext2 / namei.c
CommitLineData
b2441318 1// SPDX-License-Identifier: GPL-2.0
1da177e4
LT
2/*
3 * linux/fs/ext2/namei.c
4 *
5 * Rewrite to pagecache. Almost all code had been changed, so blame me
6 * if the things go wrong. Please, send bug reports to
7 * viro@parcelfarce.linux.theplanet.co.uk
8 *
9 * Stuff here is basically a glue between the VFS and generic UNIXish
10 * filesystem that keeps everything in pagecache. All knowledge of the
11 * directory layout is in fs/ext2/dir.c - it turned out to be easily separatable
12 * and it's easier to debug that way. In principle we might want to
13 * generalize that a bit and turn it into a library. Or not.
14 *
15 * The only non-static object here is ext2_dir_inode_operations.
16 *
17 * TODO: get rid of kmap() use, add readahead.
18 *
19 * Copyright (C) 1992, 1993, 1994, 1995
20 * Remy Card (card@masi.ibp.fr)
21 * Laboratoire MASI - Institut Blaise Pascal
22 * Universite Pierre et Marie Curie (Paris VI)
23 *
24 * from
25 *
26 * linux/fs/minix/namei.c
27 *
28 * Copyright (C) 1991, 1992 Linus Torvalds
29 *
30 * Big-endian to little-endian byte-swapping/bitmaps by
31 * David S. Miller (davem@caip.rutgers.edu), 1995
32 */
33
34#include <linux/pagemap.h>
907f4554 35#include <linux/quotaops.h>
1da177e4
LT
36#include "ext2.h"
37#include "xattr.h"
38#include "acl.h"
39
1da177e4
LT
40static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode)
41{
42 int err = ext2_add_link(dentry, inode);
43 if (!err) {
41080b5a 44 unlock_new_inode(inode);
8fc37ec5 45 d_instantiate(dentry, inode);
1da177e4
LT
46 return 0;
47 }
a513b035 48 inode_dec_link_count(inode);
41080b5a 49 unlock_new_inode(inode);
1da177e4
LT
50 iput(inode);
51 return err;
52}
53
54/*
55 * Methods themselves.
56 */
57
00cd8dd3 58static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
1da177e4
LT
59{
60 struct inode * inode;
61 ino_t ino;
62
63 if (dentry->d_name.len > EXT2_NAME_LEN)
64 return ERR_PTR(-ENAMETOOLONG);
65
a9885444 66 ino = ext2_inode_by_name(dir, &dentry->d_name);
1da177e4
LT
67 inode = NULL;
68 if (ino) {
52fcf703 69 inode = ext2_iget(dir->i_sb, ino);
a9049376
AV
70 if (inode == ERR_PTR(-ESTALE)) {
71 ext2_error(dir->i_sb, __func__,
72 "deleted inode referenced: %lu",
73 (unsigned long) ino);
74 return ERR_PTR(-EIO);
4d6c13f8 75 }
1da177e4 76 }
082a05c6 77 return d_splice_alias(inode, dentry);
1da177e4
LT
78}
79
80struct dentry *ext2_get_parent(struct dentry *child)
81{
26fe5750 82 struct qstr dotdot = QSTR_INIT("..", 2);
2b0143b5 83 unsigned long ino = ext2_inode_by_name(d_inode(child), &dotdot);
1da177e4
LT
84 if (!ino)
85 return ERR_PTR(-ENOENT);
fc64005c 86 return d_obtain_alias(ext2_iget(child->d_sb, ino));
1da177e4
LT
87}
88
89/*
90 * By the time this is called, we already have created
91 * the directory cache entry for the new file, but it
92 * is so far negative - it has no inode.
93 *
94 * If the create succeeds, we fill in the inode information
95 * with d_instantiate().
96 */
ebfc3b49 97static int ext2_create (struct inode * dir, struct dentry * dentry, umode_t mode, bool excl)
1da177e4 98{
907f4554 99 struct inode *inode;
c2edb305 100 int err;
907f4554 101
c2edb305
JK
102 err = dquot_initialize(dir);
103 if (err)
104 return err;
907f4554 105
2a7dba39 106 inode = ext2_new_inode(dir, mode, &dentry->d_name);
907f4554
CH
107 if (IS_ERR(inode))
108 return PTR_ERR(inode);
109
110 inode->i_op = &ext2_file_inode_operations;
be64f884 111 if (test_opt(inode->i_sb, NOBH)) {
907f4554
CH
112 inode->i_mapping->a_ops = &ext2_nobh_aops;
113 inode->i_fop = &ext2_file_operations;
114 } else {
115 inode->i_mapping->a_ops = &ext2_aops;
116 inode->i_fop = &ext2_file_operations;
1da177e4 117 }
907f4554
CH
118 mark_inode_dirty(inode);
119 return ext2_add_nondir(dentry, inode);
1da177e4
LT
120}
121
60545d0d
AV
122static int ext2_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
123{
124 struct inode *inode = ext2_new_inode(dir, mode, NULL);
125 if (IS_ERR(inode))
126 return PTR_ERR(inode);
127
128 inode->i_op = &ext2_file_inode_operations;
be64f884 129 if (test_opt(inode->i_sb, NOBH)) {
60545d0d
AV
130 inode->i_mapping->a_ops = &ext2_nobh_aops;
131 inode->i_fop = &ext2_file_operations;
132 } else {
133 inode->i_mapping->a_ops = &ext2_aops;
134 inode->i_fop = &ext2_file_operations;
135 }
136 mark_inode_dirty(inode);
137 d_tmpfile(dentry, inode);
138 unlock_new_inode(inode);
139 return 0;
140}
141
1a67aafb 142static int ext2_mknod (struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1da177e4
LT
143{
144 struct inode * inode;
145 int err;
146
c2edb305
JK
147 err = dquot_initialize(dir);
148 if (err)
149 return err;
907f4554 150
2a7dba39 151 inode = ext2_new_inode (dir, mode, &dentry->d_name);
1da177e4
LT
152 err = PTR_ERR(inode);
153 if (!IS_ERR(inode)) {
154 init_special_inode(inode, inode->i_mode, rdev);
155#ifdef CONFIG_EXT2_FS_XATTR
156 inode->i_op = &ext2_special_inode_operations;
157#endif
158 mark_inode_dirty(inode);
159 err = ext2_add_nondir(dentry, inode);
160 }
161 return err;
162}
163
164static int ext2_symlink (struct inode * dir, struct dentry * dentry,
165 const char * symname)
166{
167 struct super_block * sb = dir->i_sb;
168 int err = -ENAMETOOLONG;
169 unsigned l = strlen(symname)+1;
170 struct inode * inode;
171
172 if (l > sb->s_blocksize)
173 goto out;
174
c2edb305
JK
175 err = dquot_initialize(dir);
176 if (err)
177 goto out;
907f4554 178
2a7dba39 179 inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO, &dentry->d_name);
1da177e4
LT
180 err = PTR_ERR(inode);
181 if (IS_ERR(inode))
182 goto out;
183
184 if (l > sizeof (EXT2_I(inode)->i_data)) {
185 /* slow symlink */
186 inode->i_op = &ext2_symlink_inode_operations;
21fc61c7 187 inode_nohighmem(inode);
1da177e4
LT
188 if (test_opt(inode->i_sb, NOBH))
189 inode->i_mapping->a_ops = &ext2_nobh_aops;
190 else
191 inode->i_mapping->a_ops = &ext2_aops;
192 err = page_symlink(inode, symname, l);
193 if (err)
194 goto out_fail;
195 } else {
196 /* fast symlink */
197 inode->i_op = &ext2_fast_symlink_inode_operations;
cbe0fa38
AV
198 inode->i_link = (char*)EXT2_I(inode)->i_data;
199 memcpy(inode->i_link, symname, l);
1da177e4
LT
200 inode->i_size = l-1;
201 }
202 mark_inode_dirty(inode);
203
204 err = ext2_add_nondir(dentry, inode);
205out:
206 return err;
207
208out_fail:
a513b035 209 inode_dec_link_count(inode);
41080b5a 210 unlock_new_inode(inode);
1da177e4
LT
211 iput (inode);
212 goto out;
213}
214
215static int ext2_link (struct dentry * old_dentry, struct inode * dir,
216 struct dentry *dentry)
217{
2b0143b5 218 struct inode *inode = d_inode(old_dentry);
41080b5a 219 int err;
1da177e4 220
c2edb305
JK
221 err = dquot_initialize(dir);
222 if (err)
223 return err;
907f4554 224
02027d42 225 inode->i_ctime = current_time(inode);
a513b035 226 inode_inc_link_count(inode);
7de9c6ee 227 ihold(inode);
1da177e4 228
41080b5a
AV
229 err = ext2_add_link(dentry, inode);
230 if (!err) {
231 d_instantiate(dentry, inode);
232 return 0;
233 }
234 inode_dec_link_count(inode);
235 iput(inode);
236 return err;
1da177e4
LT
237}
238
18bb1db3 239static int ext2_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
1da177e4
LT
240{
241 struct inode * inode;
8de52778 242 int err;
1da177e4 243
c2edb305
JK
244 err = dquot_initialize(dir);
245 if (err)
246 return err;
907f4554 247
a513b035 248 inode_inc_link_count(dir);
1da177e4 249
2a7dba39 250 inode = ext2_new_inode(dir, S_IFDIR | mode, &dentry->d_name);
1da177e4
LT
251 err = PTR_ERR(inode);
252 if (IS_ERR(inode))
253 goto out_dir;
254
255 inode->i_op = &ext2_dir_inode_operations;
256 inode->i_fop = &ext2_dir_operations;
257 if (test_opt(inode->i_sb, NOBH))
258 inode->i_mapping->a_ops = &ext2_nobh_aops;
259 else
260 inode->i_mapping->a_ops = &ext2_aops;
261
a513b035 262 inode_inc_link_count(inode);
1da177e4
LT
263
264 err = ext2_make_empty(inode, dir);
265 if (err)
266 goto out_fail;
267
268 err = ext2_add_link(dentry, inode);
269 if (err)
270 goto out_fail;
271
41080b5a 272 unlock_new_inode(inode);
8fc37ec5 273 d_instantiate(dentry, inode);
1da177e4
LT
274out:
275 return err;
276
277out_fail:
a513b035
AD
278 inode_dec_link_count(inode);
279 inode_dec_link_count(inode);
41080b5a 280 unlock_new_inode(inode);
1da177e4
LT
281 iput(inode);
282out_dir:
a513b035 283 inode_dec_link_count(dir);
1da177e4
LT
284 goto out;
285}
286
287static int ext2_unlink(struct inode * dir, struct dentry *dentry)
288{
2b0143b5 289 struct inode * inode = d_inode(dentry);
1da177e4
LT
290 struct ext2_dir_entry_2 * de;
291 struct page * page;
c2edb305 292 int err;
1da177e4 293
c2edb305
JK
294 err = dquot_initialize(dir);
295 if (err)
296 goto out;
907f4554 297
a9885444 298 de = ext2_find_entry (dir, &dentry->d_name, &page);
c2edb305
JK
299 if (!de) {
300 err = -ENOENT;
1da177e4 301 goto out;
c2edb305 302 }
1da177e4
LT
303
304 err = ext2_delete_entry (de, page);
305 if (err)
306 goto out;
307
308 inode->i_ctime = dir->i_ctime;
a513b035 309 inode_dec_link_count(inode);
1da177e4
LT
310 err = 0;
311out:
312 return err;
313}
314
315static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
316{
2b0143b5 317 struct inode * inode = d_inode(dentry);
1da177e4
LT
318 int err = -ENOTEMPTY;
319
320 if (ext2_empty_dir(inode)) {
321 err = ext2_unlink(dir, dentry);
322 if (!err) {
323 inode->i_size = 0;
a513b035
AD
324 inode_dec_link_count(inode);
325 inode_dec_link_count(dir);
1da177e4
LT
326 }
327 }
328 return err;
329}
330
331static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
f03b8ad8
MS
332 struct inode * new_dir, struct dentry * new_dentry,
333 unsigned int flags)
1da177e4 334{
2b0143b5
DH
335 struct inode * old_inode = d_inode(old_dentry);
336 struct inode * new_inode = d_inode(new_dentry);
1da177e4
LT
337 struct page * dir_page = NULL;
338 struct ext2_dir_entry_2 * dir_de = NULL;
339 struct page * old_page;
340 struct ext2_dir_entry_2 * old_de;
c2edb305 341 int err;
1da177e4 342
f03b8ad8
MS
343 if (flags & ~RENAME_NOREPLACE)
344 return -EINVAL;
345
c2edb305
JK
346 err = dquot_initialize(old_dir);
347 if (err)
348 goto out;
349
350 err = dquot_initialize(new_dir);
351 if (err)
352 goto out;
907f4554 353
a9885444 354 old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
c2edb305
JK
355 if (!old_de) {
356 err = -ENOENT;
1da177e4 357 goto out;
c2edb305 358 }
1da177e4
LT
359
360 if (S_ISDIR(old_inode->i_mode)) {
361 err = -EIO;
362 dir_de = ext2_dotdot(old_inode, &dir_page);
363 if (!dir_de)
364 goto out_old;
365 }
366
367 if (new_inode) {
368 struct page *new_page;
369 struct ext2_dir_entry_2 *new_de;
370
371 err = -ENOTEMPTY;
372 if (dir_de && !ext2_empty_dir (new_inode))
373 goto out_dir;
374
375 err = -ENOENT;
a9885444 376 new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
1da177e4
LT
377 if (!new_de)
378 goto out_dir;
39fe7557 379 ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
02027d42 380 new_inode->i_ctime = current_time(new_inode);
1da177e4 381 if (dir_de)
9a53c3a7 382 drop_nlink(new_inode);
a513b035 383 inode_dec_link_count(new_inode);
1da177e4 384 } else {
1da177e4 385 err = ext2_add_link(new_dentry, old_inode);
e8a80c6f 386 if (err)
1da177e4 387 goto out_dir;
1da177e4 388 if (dir_de)
a513b035 389 inode_inc_link_count(new_dir);
1da177e4
LT
390 }
391
392 /*
393 * Like most other Unix systems, set the ctime for inodes on a
394 * rename.
1da177e4 395 */
02027d42 396 old_inode->i_ctime = current_time(old_inode);
e8a80c6f 397 mark_inode_dirty(old_inode);
1da177e4
LT
398
399 ext2_delete_entry (old_de, old_page);
1da177e4
LT
400
401 if (dir_de) {
39fe7557
JK
402 if (old_dir != new_dir)
403 ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
9de6886e
NP
404 else {
405 kunmap(dir_page);
09cbfeaf 406 put_page(dir_page);
9de6886e 407 }
a513b035 408 inode_dec_link_count(old_dir);
1da177e4
LT
409 }
410 return 0;
411
412
413out_dir:
414 if (dir_de) {
415 kunmap(dir_page);
09cbfeaf 416 put_page(dir_page);
1da177e4
LT
417 }
418out_old:
419 kunmap(old_page);
09cbfeaf 420 put_page(old_page);
1da177e4
LT
421out:
422 return err;
423}
424
754661f1 425const struct inode_operations ext2_dir_inode_operations = {
1da177e4
LT
426 .create = ext2_create,
427 .lookup = ext2_lookup,
428 .link = ext2_link,
429 .unlink = ext2_unlink,
430 .symlink = ext2_symlink,
431 .mkdir = ext2_mkdir,
432 .rmdir = ext2_rmdir,
433 .mknod = ext2_mknod,
434 .rename = ext2_rename,
435#ifdef CONFIG_EXT2_FS_XATTR
1da177e4 436 .listxattr = ext2_listxattr,
1da177e4
LT
437#endif
438 .setattr = ext2_setattr,
4e34e719 439 .get_acl = ext2_get_acl,
64e178a7 440 .set_acl = ext2_set_acl,
60545d0d 441 .tmpfile = ext2_tmpfile,
1da177e4
LT
442};
443
754661f1 444const struct inode_operations ext2_special_inode_operations = {
1da177e4 445#ifdef CONFIG_EXT2_FS_XATTR
1da177e4 446 .listxattr = ext2_listxattr,
1da177e4
LT
447#endif
448 .setattr = ext2_setattr,
4e34e719 449 .get_acl = ext2_get_acl,
64e178a7 450 .set_acl = ext2_set_acl,
1da177e4 451};