mm: remove CONFIG_DISCONTIGMEM
[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) {
1e2e547a 44 d_instantiate_new(dentry, inode);
1da177e4
LT
45 return 0;
46 }
a513b035 47 inode_dec_link_count(inode);
2e5afe54 48 discard_new_inode(inode);
1da177e4
LT
49 return err;
50}
51
52/*
53 * Methods themselves.
54 */
55
00cd8dd3 56static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
1da177e4
LT
57{
58 struct inode * inode;
a43850a3 59 ino_t ino;
b4962091 60 int res;
1da177e4
LT
61
62 if (dentry->d_name.len > EXT2_NAME_LEN)
63 return ERR_PTR(-ENAMETOOLONG);
64
b4962091 65 res = ext2_inode_by_name(dir, &dentry->d_name, &ino);
a43850a3 66 if (res) {
67 if (res != -ENOENT)
68 return ERR_PTR(res);
69 inode = NULL;
70 } else {
52fcf703 71 inode = ext2_iget(dir->i_sb, ino);
a9049376
AV
72 if (inode == ERR_PTR(-ESTALE)) {
73 ext2_error(dir->i_sb, __func__,
74 "deleted inode referenced: %lu",
75 (unsigned long) ino);
76 return ERR_PTR(-EIO);
4d6c13f8 77 }
1da177e4 78 }
082a05c6 79 return d_splice_alias(inode, dentry);
1da177e4
LT
80}
81
82struct dentry *ext2_get_parent(struct dentry *child)
83{
a43850a3 84 ino_t ino;
b4962091 85 int res;
86
80e5d1ff 87 res = ext2_inode_by_name(d_inode(child), &dotdot_name, &ino);
b4962091 88 if (res)
89 return ERR_PTR(res);
a43850a3 90
fc64005c 91 return d_obtain_alias(ext2_iget(child->d_sb, ino));
1da177e4
LT
92}
93
94/*
95 * By the time this is called, we already have created
96 * the directory cache entry for the new file, but it
97 * is so far negative - it has no inode.
98 *
99 * If the create succeeds, we fill in the inode information
100 * with d_instantiate().
101 */
549c7297
CB
102static int ext2_create (struct user_namespace * mnt_userns,
103 struct inode * dir, struct dentry * dentry,
104 umode_t mode, bool excl)
1da177e4 105{
907f4554 106 struct inode *inode;
c2edb305 107 int err;
907f4554 108
c2edb305
JK
109 err = dquot_initialize(dir);
110 if (err)
111 return err;
907f4554 112
2a7dba39 113 inode = ext2_new_inode(dir, mode, &dentry->d_name);
907f4554
CH
114 if (IS_ERR(inode))
115 return PTR_ERR(inode);
116
fb094c90 117 ext2_set_file_ops(inode);
907f4554
CH
118 mark_inode_dirty(inode);
119 return ext2_add_nondir(dentry, inode);
1da177e4
LT
120}
121
549c7297
CB
122static int ext2_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
123 struct dentry *dentry, umode_t mode)
60545d0d
AV
124{
125 struct inode *inode = ext2_new_inode(dir, mode, NULL);
126 if (IS_ERR(inode))
127 return PTR_ERR(inode);
128
fb094c90 129 ext2_set_file_ops(inode);
60545d0d
AV
130 mark_inode_dirty(inode);
131 d_tmpfile(dentry, inode);
132 unlock_new_inode(inode);
133 return 0;
134}
135
549c7297
CB
136static int ext2_mknod (struct user_namespace * mnt_userns, struct inode * dir,
137 struct dentry *dentry, umode_t mode, dev_t rdev)
1da177e4
LT
138{
139 struct inode * inode;
140 int err;
141
c2edb305
JK
142 err = dquot_initialize(dir);
143 if (err)
144 return err;
907f4554 145
2a7dba39 146 inode = ext2_new_inode (dir, mode, &dentry->d_name);
1da177e4
LT
147 err = PTR_ERR(inode);
148 if (!IS_ERR(inode)) {
149 init_special_inode(inode, inode->i_mode, rdev);
1da177e4 150 inode->i_op = &ext2_special_inode_operations;
1da177e4
LT
151 mark_inode_dirty(inode);
152 err = ext2_add_nondir(dentry, inode);
153 }
154 return err;
155}
156
549c7297
CB
157static int ext2_symlink (struct user_namespace * mnt_userns, struct inode * dir,
158 struct dentry * dentry, const char * symname)
1da177e4
LT
159{
160 struct super_block * sb = dir->i_sb;
161 int err = -ENAMETOOLONG;
162 unsigned l = strlen(symname)+1;
163 struct inode * inode;
164
165 if (l > sb->s_blocksize)
166 goto out;
167
c2edb305
JK
168 err = dquot_initialize(dir);
169 if (err)
170 goto out;
907f4554 171
2a7dba39 172 inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO, &dentry->d_name);
1da177e4
LT
173 err = PTR_ERR(inode);
174 if (IS_ERR(inode))
175 goto out;
176
177 if (l > sizeof (EXT2_I(inode)->i_data)) {
178 /* slow symlink */
179 inode->i_op = &ext2_symlink_inode_operations;
21fc61c7 180 inode_nohighmem(inode);
1da177e4
LT
181 if (test_opt(inode->i_sb, NOBH))
182 inode->i_mapping->a_ops = &ext2_nobh_aops;
183 else
184 inode->i_mapping->a_ops = &ext2_aops;
185 err = page_symlink(inode, symname, l);
186 if (err)
187 goto out_fail;
188 } else {
189 /* fast symlink */
190 inode->i_op = &ext2_fast_symlink_inode_operations;
cbe0fa38
AV
191 inode->i_link = (char*)EXT2_I(inode)->i_data;
192 memcpy(inode->i_link, symname, l);
1da177e4
LT
193 inode->i_size = l-1;
194 }
195 mark_inode_dirty(inode);
196
197 err = ext2_add_nondir(dentry, inode);
198out:
199 return err;
200
201out_fail:
a513b035 202 inode_dec_link_count(inode);
2e5afe54 203 discard_new_inode(inode);
1da177e4
LT
204 goto out;
205}
206
207static int ext2_link (struct dentry * old_dentry, struct inode * dir,
208 struct dentry *dentry)
209{
2b0143b5 210 struct inode *inode = d_inode(old_dentry);
41080b5a 211 int err;
1da177e4 212
c2edb305
JK
213 err = dquot_initialize(dir);
214 if (err)
215 return err;
907f4554 216
02027d42 217 inode->i_ctime = current_time(inode);
a513b035 218 inode_inc_link_count(inode);
7de9c6ee 219 ihold(inode);
1da177e4 220
41080b5a
AV
221 err = ext2_add_link(dentry, inode);
222 if (!err) {
223 d_instantiate(dentry, inode);
224 return 0;
225 }
226 inode_dec_link_count(inode);
227 iput(inode);
228 return err;
1da177e4
LT
229}
230
549c7297
CB
231static int ext2_mkdir(struct user_namespace * mnt_userns,
232 struct inode * dir, struct dentry * dentry, umode_t mode)
1da177e4
LT
233{
234 struct inode * inode;
8de52778 235 int err;
1da177e4 236
c2edb305
JK
237 err = dquot_initialize(dir);
238 if (err)
239 return err;
907f4554 240
a513b035 241 inode_inc_link_count(dir);
1da177e4 242
2a7dba39 243 inode = ext2_new_inode(dir, S_IFDIR | mode, &dentry->d_name);
1da177e4
LT
244 err = PTR_ERR(inode);
245 if (IS_ERR(inode))
246 goto out_dir;
247
248 inode->i_op = &ext2_dir_inode_operations;
249 inode->i_fop = &ext2_dir_operations;
250 if (test_opt(inode->i_sb, NOBH))
251 inode->i_mapping->a_ops = &ext2_nobh_aops;
252 else
253 inode->i_mapping->a_ops = &ext2_aops;
254
a513b035 255 inode_inc_link_count(inode);
1da177e4
LT
256
257 err = ext2_make_empty(inode, dir);
258 if (err)
259 goto out_fail;
260
261 err = ext2_add_link(dentry, inode);
262 if (err)
263 goto out_fail;
264
1e2e547a 265 d_instantiate_new(dentry, inode);
1da177e4
LT
266out:
267 return err;
268
269out_fail:
a513b035
AD
270 inode_dec_link_count(inode);
271 inode_dec_link_count(inode);
2e5afe54 272 discard_new_inode(inode);
1da177e4 273out_dir:
a513b035 274 inode_dec_link_count(dir);
1da177e4
LT
275 goto out;
276}
277
278static int ext2_unlink(struct inode * dir, struct dentry *dentry)
279{
2b0143b5 280 struct inode * inode = d_inode(dentry);
1da177e4
LT
281 struct ext2_dir_entry_2 * de;
282 struct page * page;
782b76d7 283 void *page_addr;
c2edb305 284 int err;
1da177e4 285
c2edb305
JK
286 err = dquot_initialize(dir);
287 if (err)
288 goto out;
907f4554 289
782b76d7 290 de = ext2_find_entry(dir, &dentry->d_name, &page, &page_addr);
b4962091 291 if (IS_ERR(de)) {
292 err = PTR_ERR(de);
293 goto out;
294 }
1da177e4
LT
295
296 err = ext2_delete_entry (de, page);
782b76d7 297 ext2_put_page(page, page_addr);
1da177e4
LT
298 if (err)
299 goto out;
300
301 inode->i_ctime = dir->i_ctime;
a513b035 302 inode_dec_link_count(inode);
1da177e4
LT
303 err = 0;
304out:
305 return err;
306}
307
308static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
309{
2b0143b5 310 struct inode * inode = d_inode(dentry);
1da177e4
LT
311 int err = -ENOTEMPTY;
312
313 if (ext2_empty_dir(inode)) {
314 err = ext2_unlink(dir, dentry);
315 if (!err) {
316 inode->i_size = 0;
a513b035
AD
317 inode_dec_link_count(inode);
318 inode_dec_link_count(dir);
1da177e4
LT
319 }
320 }
321 return err;
322}
323
549c7297
CB
324static int ext2_rename (struct user_namespace * mnt_userns,
325 struct inode * old_dir, struct dentry * old_dentry,
326 struct inode * new_dir, struct dentry * new_dentry,
f03b8ad8 327 unsigned int flags)
1da177e4 328{
2b0143b5
DH
329 struct inode * old_inode = d_inode(old_dentry);
330 struct inode * new_inode = d_inode(new_dentry);
1da177e4 331 struct page * dir_page = NULL;
782b76d7 332 void *dir_page_addr;
1da177e4
LT
333 struct ext2_dir_entry_2 * dir_de = NULL;
334 struct page * old_page;
782b76d7 335 void *old_page_addr;
1da177e4 336 struct ext2_dir_entry_2 * old_de;
c2edb305 337 int err;
1da177e4 338
f03b8ad8
MS
339 if (flags & ~RENAME_NOREPLACE)
340 return -EINVAL;
341
c2edb305
JK
342 err = dquot_initialize(old_dir);
343 if (err)
344 goto out;
345
346 err = dquot_initialize(new_dir);
347 if (err)
348 goto out;
907f4554 349
782b76d7
IW
350 old_de = ext2_find_entry(old_dir, &old_dentry->d_name, &old_page,
351 &old_page_addr);
b4962091 352 if (IS_ERR(old_de)) {
353 err = PTR_ERR(old_de);
354 goto out;
355 }
1da177e4
LT
356
357 if (S_ISDIR(old_inode->i_mode)) {
358 err = -EIO;
782b76d7 359 dir_de = ext2_dotdot(old_inode, &dir_page, &dir_page_addr);
1da177e4
LT
360 if (!dir_de)
361 goto out_old;
362 }
363
364 if (new_inode) {
782b76d7 365 void *page_addr;
1da177e4
LT
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
782b76d7
IW
373 new_de = ext2_find_entry(new_dir, &new_dentry->d_name,
374 &new_page, &page_addr);
b4962091 375 if (IS_ERR(new_de)) {
376 err = PTR_ERR(new_de);
377 goto out_dir;
378 }
782b76d7
IW
379 ext2_set_link(new_dir, new_de, new_page, page_addr, old_inode, 1);
380 ext2_put_page(new_page, page_addr);
02027d42 381 new_inode->i_ctime = current_time(new_inode);
1da177e4 382 if (dir_de)
9a53c3a7 383 drop_nlink(new_inode);
a513b035 384 inode_dec_link_count(new_inode);
1da177e4 385 } else {
1da177e4 386 err = ext2_add_link(new_dentry, old_inode);
e8a80c6f 387 if (err)
1da177e4 388 goto out_dir;
1da177e4 389 if (dir_de)
a513b035 390 inode_inc_link_count(new_dir);
1da177e4
LT
391 }
392
393 /*
394 * Like most other Unix systems, set the ctime for inodes on a
395 * rename.
1da177e4 396 */
02027d42 397 old_inode->i_ctime = current_time(old_inode);
e8a80c6f 398 mark_inode_dirty(old_inode);
1da177e4 399
782b76d7 400 ext2_delete_entry(old_de, old_page);
1da177e4
LT
401
402 if (dir_de) {
39fe7557 403 if (old_dir != new_dir)
782b76d7
IW
404 ext2_set_link(old_inode, dir_de, dir_page,
405 dir_page_addr, new_dir, 0);
e2ebb123 406
782b76d7 407 ext2_put_page(dir_page, dir_page_addr);
a513b035 408 inode_dec_link_count(old_dir);
1da177e4 409 }
1da177e4 410
782b76d7
IW
411 ext2_put_page(old_page, old_page_addr);
412 return 0;
1da177e4
LT
413
414out_dir:
a6fbd0ab 415 if (dir_de)
782b76d7 416 ext2_put_page(dir_page, dir_page_addr);
1da177e4 417out_old:
782b76d7 418 ext2_put_page(old_page, old_page_addr);
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,
1da177e4 433 .listxattr = ext2_listxattr,
93bc420e 434 .getattr = ext2_getattr,
1da177e4 435 .setattr = ext2_setattr,
4e34e719 436 .get_acl = ext2_get_acl,
64e178a7 437 .set_acl = ext2_set_acl,
60545d0d 438 .tmpfile = ext2_tmpfile,
aba405e3
MS
439 .fileattr_get = ext2_fileattr_get,
440 .fileattr_set = ext2_fileattr_set,
1da177e4
LT
441};
442
754661f1 443const struct inode_operations ext2_special_inode_operations = {
1da177e4 444 .listxattr = ext2_listxattr,
93bc420e 445 .getattr = ext2_getattr,
1da177e4 446 .setattr = ext2_setattr,
4e34e719 447 .get_acl = ext2_get_acl,
64e178a7 448 .set_acl = ext2_set_acl,
1da177e4 449};