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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) {
00d2f2d5 44 d_instantiate_new(dentry, inode);
1da177e4
LT
45 return 0;
46 }
a513b035 47 inode_dec_link_count(inode);
41080b5a 48 unlock_new_inode(inode);
1da177e4
LT
49 iput(inode);
50 return err;
51}
52
53/*
54 * Methods themselves.
55 */
56
00cd8dd3 57static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
1da177e4
LT
58{
59 struct inode * inode;
60 ino_t ino;
61
62 if (dentry->d_name.len > EXT2_NAME_LEN)
63 return ERR_PTR(-ENAMETOOLONG);
64
a9885444 65 ino = ext2_inode_by_name(dir, &dentry->d_name);
1da177e4
LT
66 inode = NULL;
67 if (ino) {
52fcf703 68 inode = ext2_iget(dir->i_sb, ino);
a9049376
AV
69 if (inode == ERR_PTR(-ESTALE)) {
70 ext2_error(dir->i_sb, __func__,
71 "deleted inode referenced: %lu",
72 (unsigned long) ino);
73 return ERR_PTR(-EIO);
4d6c13f8 74 }
1da177e4 75 }
082a05c6 76 return d_splice_alias(inode, dentry);
1da177e4
LT
77}
78
79struct dentry *ext2_get_parent(struct dentry *child)
80{
26fe5750 81 struct qstr dotdot = QSTR_INIT("..", 2);
2b0143b5 82 unsigned long ino = ext2_inode_by_name(d_inode(child), &dotdot);
1da177e4
LT
83 if (!ino)
84 return ERR_PTR(-ENOENT);
fc64005c 85 return d_obtain_alias(ext2_iget(child->d_sb, ino));
1da177e4
LT
86}
87
88/*
89 * By the time this is called, we already have created
90 * the directory cache entry for the new file, but it
91 * is so far negative - it has no inode.
92 *
93 * If the create succeeds, we fill in the inode information
94 * with d_instantiate().
95 */
ebfc3b49 96static int ext2_create (struct inode * dir, struct dentry * dentry, umode_t mode, bool excl)
1da177e4 97{
907f4554 98 struct inode *inode;
c2edb305 99 int err;
907f4554 100
c2edb305
JK
101 err = dquot_initialize(dir);
102 if (err)
103 return err;
907f4554 104
2a7dba39 105 inode = ext2_new_inode(dir, mode, &dentry->d_name);
907f4554
CH
106 if (IS_ERR(inode))
107 return PTR_ERR(inode);
108
109 inode->i_op = &ext2_file_inode_operations;
be64f884 110 if (test_opt(inode->i_sb, NOBH)) {
907f4554
CH
111 inode->i_mapping->a_ops = &ext2_nobh_aops;
112 inode->i_fop = &ext2_file_operations;
113 } else {
114 inode->i_mapping->a_ops = &ext2_aops;
115 inode->i_fop = &ext2_file_operations;
1da177e4 116 }
907f4554
CH
117 mark_inode_dirty(inode);
118 return ext2_add_nondir(dentry, inode);
1da177e4
LT
119}
120
60545d0d
AV
121static int ext2_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
122{
123 struct inode *inode = ext2_new_inode(dir, mode, NULL);
124 if (IS_ERR(inode))
125 return PTR_ERR(inode);
126
127 inode->i_op = &ext2_file_inode_operations;
be64f884 128 if (test_opt(inode->i_sb, NOBH)) {
60545d0d
AV
129 inode->i_mapping->a_ops = &ext2_nobh_aops;
130 inode->i_fop = &ext2_file_operations;
131 } else {
132 inode->i_mapping->a_ops = &ext2_aops;
133 inode->i_fop = &ext2_file_operations;
134 }
135 mark_inode_dirty(inode);
136 d_tmpfile(dentry, inode);
137 unlock_new_inode(inode);
138 return 0;
139}
140
1a67aafb 141static int ext2_mknod (struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1da177e4
LT
142{
143 struct inode * inode;
144 int err;
145
c2edb305
JK
146 err = dquot_initialize(dir);
147 if (err)
148 return err;
907f4554 149
2a7dba39 150 inode = ext2_new_inode (dir, mode, &dentry->d_name);
1da177e4
LT
151 err = PTR_ERR(inode);
152 if (!IS_ERR(inode)) {
153 init_special_inode(inode, inode->i_mode, rdev);
154#ifdef CONFIG_EXT2_FS_XATTR
155 inode->i_op = &ext2_special_inode_operations;
156#endif
157 mark_inode_dirty(inode);
158 err = ext2_add_nondir(dentry, inode);
159 }
160 return err;
161}
162
163static int ext2_symlink (struct inode * dir, struct dentry * dentry,
164 const char * symname)
165{
166 struct super_block * sb = dir->i_sb;
167 int err = -ENAMETOOLONG;
168 unsigned l = strlen(symname)+1;
169 struct inode * inode;
170
171 if (l > sb->s_blocksize)
172 goto out;
173
c2edb305
JK
174 err = dquot_initialize(dir);
175 if (err)
176 goto out;
907f4554 177
2a7dba39 178 inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO, &dentry->d_name);
1da177e4
LT
179 err = PTR_ERR(inode);
180 if (IS_ERR(inode))
181 goto out;
182
183 if (l > sizeof (EXT2_I(inode)->i_data)) {
184 /* slow symlink */
185 inode->i_op = &ext2_symlink_inode_operations;
21fc61c7 186 inode_nohighmem(inode);
1da177e4
LT
187 if (test_opt(inode->i_sb, NOBH))
188 inode->i_mapping->a_ops = &ext2_nobh_aops;
189 else
190 inode->i_mapping->a_ops = &ext2_aops;
191 err = page_symlink(inode, symname, l);
192 if (err)
193 goto out_fail;
194 } else {
195 /* fast symlink */
196 inode->i_op = &ext2_fast_symlink_inode_operations;
cbe0fa38
AV
197 inode->i_link = (char*)EXT2_I(inode)->i_data;
198 memcpy(inode->i_link, symname, l);
1da177e4
LT
199 inode->i_size = l-1;
200 }
201 mark_inode_dirty(inode);
202
203 err = ext2_add_nondir(dentry, inode);
204out:
205 return err;
206
207out_fail:
a513b035 208 inode_dec_link_count(inode);
41080b5a 209 unlock_new_inode(inode);
1da177e4
LT
210 iput (inode);
211 goto out;
212}
213
214static int ext2_link (struct dentry * old_dentry, struct inode * dir,
215 struct dentry *dentry)
216{
2b0143b5 217 struct inode *inode = d_inode(old_dentry);
41080b5a 218 int err;
1da177e4 219
c2edb305
JK
220 err = dquot_initialize(dir);
221 if (err)
222 return err;
907f4554 223
02027d42 224 inode->i_ctime = current_time(inode);
a513b035 225 inode_inc_link_count(inode);
7de9c6ee 226 ihold(inode);
1da177e4 227
41080b5a
AV
228 err = ext2_add_link(dentry, inode);
229 if (!err) {
230 d_instantiate(dentry, inode);
231 return 0;
232 }
233 inode_dec_link_count(inode);
234 iput(inode);
235 return err;
1da177e4
LT
236}
237
18bb1db3 238static int ext2_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
1da177e4
LT
239{
240 struct inode * inode;
8de52778 241 int err;
1da177e4 242
c2edb305
JK
243 err = dquot_initialize(dir);
244 if (err)
245 return err;
907f4554 246
a513b035 247 inode_inc_link_count(dir);
1da177e4 248
2a7dba39 249 inode = ext2_new_inode(dir, S_IFDIR | mode, &dentry->d_name);
1da177e4
LT
250 err = PTR_ERR(inode);
251 if (IS_ERR(inode))
252 goto out_dir;
253
254 inode->i_op = &ext2_dir_inode_operations;
255 inode->i_fop = &ext2_dir_operations;
256 if (test_opt(inode->i_sb, NOBH))
257 inode->i_mapping->a_ops = &ext2_nobh_aops;
258 else
259 inode->i_mapping->a_ops = &ext2_aops;
260
a513b035 261 inode_inc_link_count(inode);
1da177e4
LT
262
263 err = ext2_make_empty(inode, dir);
264 if (err)
265 goto out_fail;
266
267 err = ext2_add_link(dentry, inode);
268 if (err)
269 goto out_fail;
270
00d2f2d5 271 d_instantiate_new(dentry, inode);
1da177e4
LT
272out:
273 return err;
274
275out_fail:
a513b035
AD
276 inode_dec_link_count(inode);
277 inode_dec_link_count(inode);
41080b5a 278 unlock_new_inode(inode);
1da177e4
LT
279 iput(inode);
280out_dir:
a513b035 281 inode_dec_link_count(dir);
1da177e4
LT
282 goto out;
283}
284
285static int ext2_unlink(struct inode * dir, struct dentry *dentry)
286{
2b0143b5 287 struct inode * inode = d_inode(dentry);
1da177e4
LT
288 struct ext2_dir_entry_2 * de;
289 struct page * page;
c2edb305 290 int err;
1da177e4 291
c2edb305
JK
292 err = dquot_initialize(dir);
293 if (err)
294 goto out;
907f4554 295
a9885444 296 de = ext2_find_entry (dir, &dentry->d_name, &page);
c2edb305
JK
297 if (!de) {
298 err = -ENOENT;
1da177e4 299 goto out;
c2edb305 300 }
1da177e4
LT
301
302 err = ext2_delete_entry (de, page);
303 if (err)
304 goto out;
305
306 inode->i_ctime = dir->i_ctime;
a513b035 307 inode_dec_link_count(inode);
1da177e4
LT
308 err = 0;
309out:
310 return err;
311}
312
313static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
314{
2b0143b5 315 struct inode * inode = d_inode(dentry);
1da177e4
LT
316 int err = -ENOTEMPTY;
317
318 if (ext2_empty_dir(inode)) {
319 err = ext2_unlink(dir, dentry);
320 if (!err) {
321 inode->i_size = 0;
a513b035
AD
322 inode_dec_link_count(inode);
323 inode_dec_link_count(dir);
1da177e4
LT
324 }
325 }
326 return err;
327}
328
329static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
f03b8ad8
MS
330 struct inode * new_dir, struct dentry * new_dentry,
331 unsigned int flags)
1da177e4 332{
2b0143b5
DH
333 struct inode * old_inode = d_inode(old_dentry);
334 struct inode * new_inode = d_inode(new_dentry);
1da177e4
LT
335 struct page * dir_page = NULL;
336 struct ext2_dir_entry_2 * dir_de = NULL;
337 struct page * old_page;
338 struct ext2_dir_entry_2 * old_de;
c2edb305 339 int err;
1da177e4 340
f03b8ad8
MS
341 if (flags & ~RENAME_NOREPLACE)
342 return -EINVAL;
343
c2edb305
JK
344 err = dquot_initialize(old_dir);
345 if (err)
346 goto out;
347
348 err = dquot_initialize(new_dir);
349 if (err)
350 goto out;
907f4554 351
a9885444 352 old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
c2edb305
JK
353 if (!old_de) {
354 err = -ENOENT;
1da177e4 355 goto out;
c2edb305 356 }
1da177e4
LT
357
358 if (S_ISDIR(old_inode->i_mode)) {
359 err = -EIO;
360 dir_de = ext2_dotdot(old_inode, &dir_page);
361 if (!dir_de)
362 goto out_old;
363 }
364
365 if (new_inode) {
366 struct page *new_page;
367 struct ext2_dir_entry_2 *new_de;
368
369 err = -ENOTEMPTY;
370 if (dir_de && !ext2_empty_dir (new_inode))
371 goto out_dir;
372
373 err = -ENOENT;
a9885444 374 new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
1da177e4
LT
375 if (!new_de)
376 goto out_dir;
39fe7557 377 ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
02027d42 378 new_inode->i_ctime = current_time(new_inode);
1da177e4 379 if (dir_de)
9a53c3a7 380 drop_nlink(new_inode);
a513b035 381 inode_dec_link_count(new_inode);
1da177e4 382 } else {
1da177e4 383 err = ext2_add_link(new_dentry, old_inode);
e8a80c6f 384 if (err)
1da177e4 385 goto out_dir;
1da177e4 386 if (dir_de)
a513b035 387 inode_inc_link_count(new_dir);
1da177e4
LT
388 }
389
390 /*
391 * Like most other Unix systems, set the ctime for inodes on a
392 * rename.
1da177e4 393 */
02027d42 394 old_inode->i_ctime = current_time(old_inode);
e8a80c6f 395 mark_inode_dirty(old_inode);
1da177e4
LT
396
397 ext2_delete_entry (old_de, old_page);
1da177e4
LT
398
399 if (dir_de) {
39fe7557
JK
400 if (old_dir != new_dir)
401 ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
9de6886e
NP
402 else {
403 kunmap(dir_page);
09cbfeaf 404 put_page(dir_page);
9de6886e 405 }
a513b035 406 inode_dec_link_count(old_dir);
1da177e4
LT
407 }
408 return 0;
409
410
411out_dir:
412 if (dir_de) {
413 kunmap(dir_page);
09cbfeaf 414 put_page(dir_page);
1da177e4
LT
415 }
416out_old:
417 kunmap(old_page);
09cbfeaf 418 put_page(old_page);
1da177e4
LT
419out:
420 return err;
421}
422
754661f1 423const struct inode_operations ext2_dir_inode_operations = {
1da177e4
LT
424 .create = ext2_create,
425 .lookup = ext2_lookup,
426 .link = ext2_link,
427 .unlink = ext2_unlink,
428 .symlink = ext2_symlink,
429 .mkdir = ext2_mkdir,
430 .rmdir = ext2_rmdir,
431 .mknod = ext2_mknod,
432 .rename = ext2_rename,
433#ifdef CONFIG_EXT2_FS_XATTR
1da177e4 434 .listxattr = ext2_listxattr,
1da177e4
LT
435#endif
436 .setattr = ext2_setattr,
4e34e719 437 .get_acl = ext2_get_acl,
64e178a7 438 .set_acl = ext2_set_acl,
60545d0d 439 .tmpfile = ext2_tmpfile,
1da177e4
LT
440};
441
754661f1 442const struct inode_operations ext2_special_inode_operations = {
1da177e4 443#ifdef CONFIG_EXT2_FS_XATTR
1da177e4 444 .listxattr = ext2_listxattr,
1da177e4
LT
445#endif
446 .setattr = ext2_setattr,
4e34e719 447 .get_acl = ext2_get_acl,
64e178a7 448 .set_acl = ext2_set_acl,
1da177e4 449};