Merge branch 'for-linus' of git://git.kernel.dk/linux-block
[deliverable/linux.git] / fs / ext2 / namei.c
CommitLineData
1da177e4
LT
1/*
2 * linux/fs/ext2/namei.c
3 *
4 * Rewrite to pagecache. Almost all code had been changed, so blame me
5 * if the things go wrong. Please, send bug reports to
6 * viro@parcelfarce.linux.theplanet.co.uk
7 *
8 * Stuff here is basically a glue between the VFS and generic UNIXish
9 * filesystem that keeps everything in pagecache. All knowledge of the
10 * directory layout is in fs/ext2/dir.c - it turned out to be easily separatable
11 * and it's easier to debug that way. In principle we might want to
12 * generalize that a bit and turn it into a library. Or not.
13 *
14 * The only non-static object here is ext2_dir_inode_operations.
15 *
16 * TODO: get rid of kmap() use, add readahead.
17 *
18 * Copyright (C) 1992, 1993, 1994, 1995
19 * Remy Card (card@masi.ibp.fr)
20 * Laboratoire MASI - Institut Blaise Pascal
21 * Universite Pierre et Marie Curie (Paris VI)
22 *
23 * from
24 *
25 * linux/fs/minix/namei.c
26 *
27 * Copyright (C) 1991, 1992 Linus Torvalds
28 *
29 * Big-endian to little-endian byte-swapping/bitmaps by
30 * David S. Miller (davem@caip.rutgers.edu), 1995
31 */
32
33#include <linux/pagemap.h>
907f4554 34#include <linux/quotaops.h>
1da177e4
LT
35#include "ext2.h"
36#include "xattr.h"
37#include "acl.h"
38
1da177e4
LT
39static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode)
40{
41 int err = ext2_add_link(dentry, inode);
42 if (!err) {
41080b5a 43 unlock_new_inode(inode);
8fc37ec5 44 d_instantiate(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);
2b0143b5 85 return d_obtain_alias(ext2_iget(d_inode(child)->i_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
CH
98 struct inode *inode;
99
871a2931 100 dquot_initialize(dir);
907f4554 101
2a7dba39 102 inode = ext2_new_inode(dir, mode, &dentry->d_name);
907f4554
CH
103 if (IS_ERR(inode))
104 return PTR_ERR(inode);
105
106 inode->i_op = &ext2_file_inode_operations;
be64f884 107 if (test_opt(inode->i_sb, NOBH)) {
907f4554
CH
108 inode->i_mapping->a_ops = &ext2_nobh_aops;
109 inode->i_fop = &ext2_file_operations;
110 } else {
111 inode->i_mapping->a_ops = &ext2_aops;
112 inode->i_fop = &ext2_file_operations;
1da177e4 113 }
907f4554
CH
114 mark_inode_dirty(inode);
115 return ext2_add_nondir(dentry, inode);
1da177e4
LT
116}
117
60545d0d
AV
118static int ext2_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
119{
120 struct inode *inode = ext2_new_inode(dir, mode, NULL);
121 if (IS_ERR(inode))
122 return PTR_ERR(inode);
123
124 inode->i_op = &ext2_file_inode_operations;
be64f884 125 if (test_opt(inode->i_sb, NOBH)) {
60545d0d
AV
126 inode->i_mapping->a_ops = &ext2_nobh_aops;
127 inode->i_fop = &ext2_file_operations;
128 } else {
129 inode->i_mapping->a_ops = &ext2_aops;
130 inode->i_fop = &ext2_file_operations;
131 }
132 mark_inode_dirty(inode);
133 d_tmpfile(dentry, inode);
134 unlock_new_inode(inode);
135 return 0;
136}
137
1a67aafb 138static int ext2_mknod (struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1da177e4
LT
139{
140 struct inode * inode;
141 int err;
142
143 if (!new_valid_dev(rdev))
144 return -EINVAL;
145
871a2931 146 dquot_initialize(dir);
907f4554 147
2a7dba39 148 inode = ext2_new_inode (dir, mode, &dentry->d_name);
1da177e4
LT
149 err = PTR_ERR(inode);
150 if (!IS_ERR(inode)) {
151 init_special_inode(inode, inode->i_mode, rdev);
152#ifdef CONFIG_EXT2_FS_XATTR
153 inode->i_op = &ext2_special_inode_operations;
154#endif
155 mark_inode_dirty(inode);
156 err = ext2_add_nondir(dentry, inode);
157 }
158 return err;
159}
160
161static int ext2_symlink (struct inode * dir, struct dentry * dentry,
162 const char * symname)
163{
164 struct super_block * sb = dir->i_sb;
165 int err = -ENAMETOOLONG;
166 unsigned l = strlen(symname)+1;
167 struct inode * inode;
168
169 if (l > sb->s_blocksize)
170 goto out;
171
871a2931 172 dquot_initialize(dir);
907f4554 173
2a7dba39 174 inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO, &dentry->d_name);
1da177e4
LT
175 err = PTR_ERR(inode);
176 if (IS_ERR(inode))
177 goto out;
178
179 if (l > sizeof (EXT2_I(inode)->i_data)) {
180 /* slow symlink */
181 inode->i_op = &ext2_symlink_inode_operations;
182 if (test_opt(inode->i_sb, NOBH))
183 inode->i_mapping->a_ops = &ext2_nobh_aops;
184 else
185 inode->i_mapping->a_ops = &ext2_aops;
186 err = page_symlink(inode, symname, l);
187 if (err)
188 goto out_fail;
189 } else {
190 /* fast symlink */
191 inode->i_op = &ext2_fast_symlink_inode_operations;
192 memcpy((char*)(EXT2_I(inode)->i_data),symname,l);
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);
41080b5a 203 unlock_new_inode(inode);
1da177e4
LT
204 iput (inode);
205 goto out;
206}
207
208static int ext2_link (struct dentry * old_dentry, struct inode * dir,
209 struct dentry *dentry)
210{
2b0143b5 211 struct inode *inode = d_inode(old_dentry);
41080b5a 212 int err;
1da177e4 213
871a2931 214 dquot_initialize(dir);
907f4554 215
1da177e4 216 inode->i_ctime = CURRENT_TIME_SEC;
a513b035 217 inode_inc_link_count(inode);
7de9c6ee 218 ihold(inode);
1da177e4 219
41080b5a
AV
220 err = ext2_add_link(dentry, inode);
221 if (!err) {
222 d_instantiate(dentry, inode);
223 return 0;
224 }
225 inode_dec_link_count(inode);
226 iput(inode);
227 return err;
1da177e4
LT
228}
229
18bb1db3 230static int ext2_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
1da177e4
LT
231{
232 struct inode * inode;
8de52778 233 int err;
1da177e4 234
871a2931 235 dquot_initialize(dir);
907f4554 236
a513b035 237 inode_inc_link_count(dir);
1da177e4 238
2a7dba39 239 inode = ext2_new_inode(dir, S_IFDIR | mode, &dentry->d_name);
1da177e4
LT
240 err = PTR_ERR(inode);
241 if (IS_ERR(inode))
242 goto out_dir;
243
244 inode->i_op = &ext2_dir_inode_operations;
245 inode->i_fop = &ext2_dir_operations;
246 if (test_opt(inode->i_sb, NOBH))
247 inode->i_mapping->a_ops = &ext2_nobh_aops;
248 else
249 inode->i_mapping->a_ops = &ext2_aops;
250
a513b035 251 inode_inc_link_count(inode);
1da177e4
LT
252
253 err = ext2_make_empty(inode, dir);
254 if (err)
255 goto out_fail;
256
257 err = ext2_add_link(dentry, inode);
258 if (err)
259 goto out_fail;
260
41080b5a 261 unlock_new_inode(inode);
8fc37ec5 262 d_instantiate(dentry, inode);
1da177e4
LT
263out:
264 return err;
265
266out_fail:
a513b035
AD
267 inode_dec_link_count(inode);
268 inode_dec_link_count(inode);
41080b5a 269 unlock_new_inode(inode);
1da177e4
LT
270 iput(inode);
271out_dir:
a513b035 272 inode_dec_link_count(dir);
1da177e4
LT
273 goto out;
274}
275
276static int ext2_unlink(struct inode * dir, struct dentry *dentry)
277{
2b0143b5 278 struct inode * inode = d_inode(dentry);
1da177e4
LT
279 struct ext2_dir_entry_2 * de;
280 struct page * page;
281 int err = -ENOENT;
282
871a2931 283 dquot_initialize(dir);
907f4554 284
a9885444 285 de = ext2_find_entry (dir, &dentry->d_name, &page);
1da177e4
LT
286 if (!de)
287 goto out;
288
289 err = ext2_delete_entry (de, page);
290 if (err)
291 goto out;
292
293 inode->i_ctime = dir->i_ctime;
a513b035 294 inode_dec_link_count(inode);
1da177e4
LT
295 err = 0;
296out:
297 return err;
298}
299
300static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
301{
2b0143b5 302 struct inode * inode = d_inode(dentry);
1da177e4
LT
303 int err = -ENOTEMPTY;
304
305 if (ext2_empty_dir(inode)) {
306 err = ext2_unlink(dir, dentry);
307 if (!err) {
308 inode->i_size = 0;
a513b035
AD
309 inode_dec_link_count(inode);
310 inode_dec_link_count(dir);
1da177e4
LT
311 }
312 }
313 return err;
314}
315
316static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
317 struct inode * new_dir, struct dentry * new_dentry )
318{
2b0143b5
DH
319 struct inode * old_inode = d_inode(old_dentry);
320 struct inode * new_inode = d_inode(new_dentry);
1da177e4
LT
321 struct page * dir_page = NULL;
322 struct ext2_dir_entry_2 * dir_de = NULL;
323 struct page * old_page;
324 struct ext2_dir_entry_2 * old_de;
325 int err = -ENOENT;
326
871a2931
CH
327 dquot_initialize(old_dir);
328 dquot_initialize(new_dir);
907f4554 329
a9885444 330 old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
1da177e4
LT
331 if (!old_de)
332 goto out;
333
334 if (S_ISDIR(old_inode->i_mode)) {
335 err = -EIO;
336 dir_de = ext2_dotdot(old_inode, &dir_page);
337 if (!dir_de)
338 goto out_old;
339 }
340
341 if (new_inode) {
342 struct page *new_page;
343 struct ext2_dir_entry_2 *new_de;
344
345 err = -ENOTEMPTY;
346 if (dir_de && !ext2_empty_dir (new_inode))
347 goto out_dir;
348
349 err = -ENOENT;
a9885444 350 new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
1da177e4
LT
351 if (!new_de)
352 goto out_dir;
39fe7557 353 ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
1da177e4
LT
354 new_inode->i_ctime = CURRENT_TIME_SEC;
355 if (dir_de)
9a53c3a7 356 drop_nlink(new_inode);
a513b035 357 inode_dec_link_count(new_inode);
1da177e4 358 } else {
1da177e4 359 err = ext2_add_link(new_dentry, old_inode);
e8a80c6f 360 if (err)
1da177e4 361 goto out_dir;
1da177e4 362 if (dir_de)
a513b035 363 inode_inc_link_count(new_dir);
1da177e4
LT
364 }
365
366 /*
367 * Like most other Unix systems, set the ctime for inodes on a
368 * rename.
1da177e4
LT
369 */
370 old_inode->i_ctime = CURRENT_TIME_SEC;
e8a80c6f 371 mark_inode_dirty(old_inode);
1da177e4
LT
372
373 ext2_delete_entry (old_de, old_page);
1da177e4
LT
374
375 if (dir_de) {
39fe7557
JK
376 if (old_dir != new_dir)
377 ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
9de6886e
NP
378 else {
379 kunmap(dir_page);
380 page_cache_release(dir_page);
381 }
a513b035 382 inode_dec_link_count(old_dir);
1da177e4
LT
383 }
384 return 0;
385
386
387out_dir:
388 if (dir_de) {
389 kunmap(dir_page);
390 page_cache_release(dir_page);
391 }
392out_old:
393 kunmap(old_page);
394 page_cache_release(old_page);
395out:
396 return err;
397}
398
754661f1 399const struct inode_operations ext2_dir_inode_operations = {
1da177e4
LT
400 .create = ext2_create,
401 .lookup = ext2_lookup,
402 .link = ext2_link,
403 .unlink = ext2_unlink,
404 .symlink = ext2_symlink,
405 .mkdir = ext2_mkdir,
406 .rmdir = ext2_rmdir,
407 .mknod = ext2_mknod,
408 .rename = ext2_rename,
409#ifdef CONFIG_EXT2_FS_XATTR
410 .setxattr = generic_setxattr,
411 .getxattr = generic_getxattr,
412 .listxattr = ext2_listxattr,
413 .removexattr = generic_removexattr,
414#endif
415 .setattr = ext2_setattr,
4e34e719 416 .get_acl = ext2_get_acl,
64e178a7 417 .set_acl = ext2_set_acl,
60545d0d 418 .tmpfile = ext2_tmpfile,
1da177e4
LT
419};
420
754661f1 421const struct inode_operations ext2_special_inode_operations = {
1da177e4
LT
422#ifdef CONFIG_EXT2_FS_XATTR
423 .setxattr = generic_setxattr,
424 .getxattr = generic_getxattr,
425 .listxattr = ext2_listxattr,
426 .removexattr = generic_removexattr,
427#endif
428 .setattr = ext2_setattr,
4e34e719 429 .get_acl = ext2_get_acl,
64e178a7 430 .set_acl = ext2_set_acl,
1da177e4 431};
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