usb: gadget: udc: reduce indentation
[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;
59 ino_t ino;
60
61 if (dentry->d_name.len > EXT2_NAME_LEN)
62 return ERR_PTR(-ENAMETOOLONG);
63
a9885444 64 ino = ext2_inode_by_name(dir, &dentry->d_name);
1da177e4
LT
65 inode = NULL;
66 if (ino) {
52fcf703 67 inode = ext2_iget(dir->i_sb, ino);
a9049376
AV
68 if (inode == ERR_PTR(-ESTALE)) {
69 ext2_error(dir->i_sb, __func__,
70 "deleted inode referenced: %lu",
71 (unsigned long) ino);
72 return ERR_PTR(-EIO);
4d6c13f8 73 }
1da177e4 74 }
082a05c6 75 return d_splice_alias(inode, dentry);
1da177e4
LT
76}
77
78struct dentry *ext2_get_parent(struct dentry *child)
79{
26fe5750 80 struct qstr dotdot = QSTR_INIT("..", 2);
2b0143b5 81 unsigned long ino = ext2_inode_by_name(d_inode(child), &dotdot);
1da177e4
LT
82 if (!ino)
83 return ERR_PTR(-ENOENT);
fc64005c 84 return d_obtain_alias(ext2_iget(child->d_sb, ino));
1da177e4
LT
85}
86
87/*
88 * By the time this is called, we already have created
89 * the directory cache entry for the new file, but it
90 * is so far negative - it has no inode.
91 *
92 * If the create succeeds, we fill in the inode information
93 * with d_instantiate().
94 */
ebfc3b49 95static int ext2_create (struct inode * dir, struct dentry * dentry, umode_t mode, bool excl)
1da177e4 96{
907f4554 97 struct inode *inode;
c2edb305 98 int err;
907f4554 99
c2edb305
JK
100 err = dquot_initialize(dir);
101 if (err)
102 return err;
907f4554 103
2a7dba39 104 inode = ext2_new_inode(dir, mode, &dentry->d_name);
907f4554
CH
105 if (IS_ERR(inode))
106 return PTR_ERR(inode);
107
fb094c90 108 ext2_set_file_ops(inode);
907f4554
CH
109 mark_inode_dirty(inode);
110 return ext2_add_nondir(dentry, inode);
1da177e4
LT
111}
112
60545d0d
AV
113static int ext2_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
114{
115 struct inode *inode = ext2_new_inode(dir, mode, NULL);
116 if (IS_ERR(inode))
117 return PTR_ERR(inode);
118
fb094c90 119 ext2_set_file_ops(inode);
60545d0d
AV
120 mark_inode_dirty(inode);
121 d_tmpfile(dentry, inode);
122 unlock_new_inode(inode);
123 return 0;
124}
125
1a67aafb 126static int ext2_mknod (struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1da177e4
LT
127{
128 struct inode * inode;
129 int err;
130
c2edb305
JK
131 err = dquot_initialize(dir);
132 if (err)
133 return err;
907f4554 134
2a7dba39 135 inode = ext2_new_inode (dir, mode, &dentry->d_name);
1da177e4
LT
136 err = PTR_ERR(inode);
137 if (!IS_ERR(inode)) {
138 init_special_inode(inode, inode->i_mode, rdev);
139#ifdef CONFIG_EXT2_FS_XATTR
140 inode->i_op = &ext2_special_inode_operations;
141#endif
142 mark_inode_dirty(inode);
143 err = ext2_add_nondir(dentry, inode);
144 }
145 return err;
146}
147
148static int ext2_symlink (struct inode * dir, struct dentry * dentry,
149 const char * symname)
150{
151 struct super_block * sb = dir->i_sb;
152 int err = -ENAMETOOLONG;
153 unsigned l = strlen(symname)+1;
154 struct inode * inode;
155
156 if (l > sb->s_blocksize)
157 goto out;
158
c2edb305
JK
159 err = dquot_initialize(dir);
160 if (err)
161 goto out;
907f4554 162
2a7dba39 163 inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO, &dentry->d_name);
1da177e4
LT
164 err = PTR_ERR(inode);
165 if (IS_ERR(inode))
166 goto out;
167
168 if (l > sizeof (EXT2_I(inode)->i_data)) {
169 /* slow symlink */
170 inode->i_op = &ext2_symlink_inode_operations;
21fc61c7 171 inode_nohighmem(inode);
1da177e4
LT
172 if (test_opt(inode->i_sb, NOBH))
173 inode->i_mapping->a_ops = &ext2_nobh_aops;
174 else
175 inode->i_mapping->a_ops = &ext2_aops;
176 err = page_symlink(inode, symname, l);
177 if (err)
178 goto out_fail;
179 } else {
180 /* fast symlink */
181 inode->i_op = &ext2_fast_symlink_inode_operations;
cbe0fa38
AV
182 inode->i_link = (char*)EXT2_I(inode)->i_data;
183 memcpy(inode->i_link, symname, l);
1da177e4
LT
184 inode->i_size = l-1;
185 }
186 mark_inode_dirty(inode);
187
188 err = ext2_add_nondir(dentry, inode);
189out:
190 return err;
191
192out_fail:
a513b035 193 inode_dec_link_count(inode);
2e5afe54 194 discard_new_inode(inode);
1da177e4
LT
195 goto out;
196}
197
198static int ext2_link (struct dentry * old_dentry, struct inode * dir,
199 struct dentry *dentry)
200{
2b0143b5 201 struct inode *inode = d_inode(old_dentry);
41080b5a 202 int err;
1da177e4 203
c2edb305
JK
204 err = dquot_initialize(dir);
205 if (err)
206 return err;
907f4554 207
02027d42 208 inode->i_ctime = current_time(inode);
a513b035 209 inode_inc_link_count(inode);
7de9c6ee 210 ihold(inode);
1da177e4 211
41080b5a
AV
212 err = ext2_add_link(dentry, inode);
213 if (!err) {
214 d_instantiate(dentry, inode);
215 return 0;
216 }
217 inode_dec_link_count(inode);
218 iput(inode);
219 return err;
1da177e4
LT
220}
221
18bb1db3 222static int ext2_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
1da177e4
LT
223{
224 struct inode * inode;
8de52778 225 int err;
1da177e4 226
c2edb305
JK
227 err = dquot_initialize(dir);
228 if (err)
229 return err;
907f4554 230
a513b035 231 inode_inc_link_count(dir);
1da177e4 232
2a7dba39 233 inode = ext2_new_inode(dir, S_IFDIR | mode, &dentry->d_name);
1da177e4
LT
234 err = PTR_ERR(inode);
235 if (IS_ERR(inode))
236 goto out_dir;
237
238 inode->i_op = &ext2_dir_inode_operations;
239 inode->i_fop = &ext2_dir_operations;
240 if (test_opt(inode->i_sb, NOBH))
241 inode->i_mapping->a_ops = &ext2_nobh_aops;
242 else
243 inode->i_mapping->a_ops = &ext2_aops;
244
a513b035 245 inode_inc_link_count(inode);
1da177e4
LT
246
247 err = ext2_make_empty(inode, dir);
248 if (err)
249 goto out_fail;
250
251 err = ext2_add_link(dentry, inode);
252 if (err)
253 goto out_fail;
254
1e2e547a 255 d_instantiate_new(dentry, inode);
1da177e4
LT
256out:
257 return err;
258
259out_fail:
a513b035
AD
260 inode_dec_link_count(inode);
261 inode_dec_link_count(inode);
2e5afe54 262 discard_new_inode(inode);
1da177e4 263out_dir:
a513b035 264 inode_dec_link_count(dir);
1da177e4
LT
265 goto out;
266}
267
268static int ext2_unlink(struct inode * dir, struct dentry *dentry)
269{
2b0143b5 270 struct inode * inode = d_inode(dentry);
1da177e4
LT
271 struct ext2_dir_entry_2 * de;
272 struct page * page;
c2edb305 273 int err;
1da177e4 274
c2edb305
JK
275 err = dquot_initialize(dir);
276 if (err)
277 goto out;
907f4554 278
a9885444 279 de = ext2_find_entry (dir, &dentry->d_name, &page);
c2edb305
JK
280 if (!de) {
281 err = -ENOENT;
1da177e4 282 goto out;
c2edb305 283 }
1da177e4
LT
284
285 err = ext2_delete_entry (de, page);
286 if (err)
287 goto out;
288
289 inode->i_ctime = dir->i_ctime;
a513b035 290 inode_dec_link_count(inode);
1da177e4
LT
291 err = 0;
292out:
293 return err;
294}
295
296static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
297{
2b0143b5 298 struct inode * inode = d_inode(dentry);
1da177e4
LT
299 int err = -ENOTEMPTY;
300
301 if (ext2_empty_dir(inode)) {
302 err = ext2_unlink(dir, dentry);
303 if (!err) {
304 inode->i_size = 0;
a513b035
AD
305 inode_dec_link_count(inode);
306 inode_dec_link_count(dir);
1da177e4
LT
307 }
308 }
309 return err;
310}
311
312static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
f03b8ad8
MS
313 struct inode * new_dir, struct dentry * new_dentry,
314 unsigned int flags)
1da177e4 315{
2b0143b5
DH
316 struct inode * old_inode = d_inode(old_dentry);
317 struct inode * new_inode = d_inode(new_dentry);
1da177e4
LT
318 struct page * dir_page = NULL;
319 struct ext2_dir_entry_2 * dir_de = NULL;
320 struct page * old_page;
321 struct ext2_dir_entry_2 * old_de;
c2edb305 322 int err;
1da177e4 323
f03b8ad8
MS
324 if (flags & ~RENAME_NOREPLACE)
325 return -EINVAL;
326
c2edb305
JK
327 err = dquot_initialize(old_dir);
328 if (err)
329 goto out;
330
331 err = dquot_initialize(new_dir);
332 if (err)
333 goto out;
907f4554 334
a9885444 335 old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
c2edb305
JK
336 if (!old_de) {
337 err = -ENOENT;
1da177e4 338 goto out;
c2edb305 339 }
1da177e4
LT
340
341 if (S_ISDIR(old_inode->i_mode)) {
342 err = -EIO;
343 dir_de = ext2_dotdot(old_inode, &dir_page);
344 if (!dir_de)
345 goto out_old;
346 }
347
348 if (new_inode) {
349 struct page *new_page;
350 struct ext2_dir_entry_2 *new_de;
351
352 err = -ENOTEMPTY;
353 if (dir_de && !ext2_empty_dir (new_inode))
354 goto out_dir;
355
356 err = -ENOENT;
a9885444 357 new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
1da177e4
LT
358 if (!new_de)
359 goto out_dir;
39fe7557 360 ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
02027d42 361 new_inode->i_ctime = current_time(new_inode);
1da177e4 362 if (dir_de)
9a53c3a7 363 drop_nlink(new_inode);
a513b035 364 inode_dec_link_count(new_inode);
1da177e4 365 } else {
1da177e4 366 err = ext2_add_link(new_dentry, old_inode);
e8a80c6f 367 if (err)
1da177e4 368 goto out_dir;
1da177e4 369 if (dir_de)
a513b035 370 inode_inc_link_count(new_dir);
1da177e4
LT
371 }
372
373 /*
374 * Like most other Unix systems, set the ctime for inodes on a
375 * rename.
1da177e4 376 */
02027d42 377 old_inode->i_ctime = current_time(old_inode);
e8a80c6f 378 mark_inode_dirty(old_inode);
1da177e4
LT
379
380 ext2_delete_entry (old_de, old_page);
1da177e4
LT
381
382 if (dir_de) {
39fe7557
JK
383 if (old_dir != new_dir)
384 ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
9de6886e
NP
385 else {
386 kunmap(dir_page);
09cbfeaf 387 put_page(dir_page);
9de6886e 388 }
a513b035 389 inode_dec_link_count(old_dir);
1da177e4
LT
390 }
391 return 0;
392
393
394out_dir:
395 if (dir_de) {
396 kunmap(dir_page);
09cbfeaf 397 put_page(dir_page);
1da177e4
LT
398 }
399out_old:
400 kunmap(old_page);
09cbfeaf 401 put_page(old_page);
1da177e4
LT
402out:
403 return err;
404}
405
754661f1 406const struct inode_operations ext2_dir_inode_operations = {
1da177e4
LT
407 .create = ext2_create,
408 .lookup = ext2_lookup,
409 .link = ext2_link,
410 .unlink = ext2_unlink,
411 .symlink = ext2_symlink,
412 .mkdir = ext2_mkdir,
413 .rmdir = ext2_rmdir,
414 .mknod = ext2_mknod,
415 .rename = ext2_rename,
416#ifdef CONFIG_EXT2_FS_XATTR
1da177e4 417 .listxattr = ext2_listxattr,
1da177e4
LT
418#endif
419 .setattr = ext2_setattr,
4e34e719 420 .get_acl = ext2_get_acl,
64e178a7 421 .set_acl = ext2_set_acl,
60545d0d 422 .tmpfile = ext2_tmpfile,
1da177e4
LT
423};
424
754661f1 425const struct inode_operations ext2_special_inode_operations = {
1da177e4 426#ifdef CONFIG_EXT2_FS_XATTR
1da177e4 427 .listxattr = ext2_listxattr,
1da177e4
LT
428#endif
429 .setattr = ext2_setattr,
4e34e719 430 .get_acl = ext2_get_acl,
64e178a7 431 .set_acl = ext2_set_acl,
1da177e4 432};