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Commit | Line | Data |
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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" | |
6d79125b | 38 | #include "xip.h" |
1da177e4 | 39 | |
1da177e4 LT |
40 | static 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 | 58 | static 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 | ||
80 | struct dentry *ext2_get_parent(struct dentry *child) | |
81 | { | |
26fe5750 | 82 | struct qstr dotdot = QSTR_INIT("..", 2); |
a9885444 | 83 | unsigned long ino = ext2_inode_by_name(child->d_inode, &dotdot); |
1da177e4 LT |
84 | if (!ino) |
85 | return ERR_PTR(-ENOENT); | |
44003728 | 86 | return d_obtain_alias(ext2_iget(child->d_inode->i_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 | 97 | static int ext2_create (struct inode * dir, struct dentry * dentry, umode_t mode, bool excl) |
1da177e4 | 98 | { |
907f4554 CH |
99 | struct inode *inode; |
100 | ||
871a2931 | 101 | dquot_initialize(dir); |
907f4554 | 102 | |
2a7dba39 | 103 | inode = ext2_new_inode(dir, mode, &dentry->d_name); |
907f4554 CH |
104 | if (IS_ERR(inode)) |
105 | return PTR_ERR(inode); | |
106 | ||
107 | inode->i_op = &ext2_file_inode_operations; | |
108 | if (ext2_use_xip(inode->i_sb)) { | |
109 | inode->i_mapping->a_ops = &ext2_aops_xip; | |
110 | inode->i_fop = &ext2_xip_file_operations; | |
111 | } else if (test_opt(inode->i_sb, NOBH)) { | |
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 |
122 | static 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; | |
129 | if (ext2_use_xip(inode->i_sb)) { | |
130 | inode->i_mapping->a_ops = &ext2_aops_xip; | |
131 | inode->i_fop = &ext2_xip_file_operations; | |
132 | } else if (test_opt(inode->i_sb, NOBH)) { | |
133 | inode->i_mapping->a_ops = &ext2_nobh_aops; | |
134 | inode->i_fop = &ext2_file_operations; | |
135 | } else { | |
136 | inode->i_mapping->a_ops = &ext2_aops; | |
137 | inode->i_fop = &ext2_file_operations; | |
138 | } | |
139 | mark_inode_dirty(inode); | |
140 | d_tmpfile(dentry, inode); | |
141 | unlock_new_inode(inode); | |
142 | return 0; | |
143 | } | |
144 | ||
1a67aafb | 145 | static int ext2_mknod (struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev) |
1da177e4 LT |
146 | { |
147 | struct inode * inode; | |
148 | int err; | |
149 | ||
150 | if (!new_valid_dev(rdev)) | |
151 | return -EINVAL; | |
152 | ||
871a2931 | 153 | dquot_initialize(dir); |
907f4554 | 154 | |
2a7dba39 | 155 | inode = ext2_new_inode (dir, mode, &dentry->d_name); |
1da177e4 LT |
156 | err = PTR_ERR(inode); |
157 | if (!IS_ERR(inode)) { | |
158 | init_special_inode(inode, inode->i_mode, rdev); | |
159 | #ifdef CONFIG_EXT2_FS_XATTR | |
160 | inode->i_op = &ext2_special_inode_operations; | |
161 | #endif | |
162 | mark_inode_dirty(inode); | |
163 | err = ext2_add_nondir(dentry, inode); | |
164 | } | |
165 | return err; | |
166 | } | |
167 | ||
168 | static int ext2_symlink (struct inode * dir, struct dentry * dentry, | |
169 | const char * symname) | |
170 | { | |
171 | struct super_block * sb = dir->i_sb; | |
172 | int err = -ENAMETOOLONG; | |
173 | unsigned l = strlen(symname)+1; | |
174 | struct inode * inode; | |
175 | ||
176 | if (l > sb->s_blocksize) | |
177 | goto out; | |
178 | ||
871a2931 | 179 | dquot_initialize(dir); |
907f4554 | 180 | |
2a7dba39 | 181 | inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO, &dentry->d_name); |
1da177e4 LT |
182 | err = PTR_ERR(inode); |
183 | if (IS_ERR(inode)) | |
184 | goto out; | |
185 | ||
186 | if (l > sizeof (EXT2_I(inode)->i_data)) { | |
187 | /* slow symlink */ | |
188 | inode->i_op = &ext2_symlink_inode_operations; | |
189 | if (test_opt(inode->i_sb, NOBH)) | |
190 | inode->i_mapping->a_ops = &ext2_nobh_aops; | |
191 | else | |
192 | inode->i_mapping->a_ops = &ext2_aops; | |
193 | err = page_symlink(inode, symname, l); | |
194 | if (err) | |
195 | goto out_fail; | |
196 | } else { | |
197 | /* fast symlink */ | |
198 | inode->i_op = &ext2_fast_symlink_inode_operations; | |
199 | memcpy((char*)(EXT2_I(inode)->i_data),symname,l); | |
200 | inode->i_size = l-1; | |
201 | } | |
202 | mark_inode_dirty(inode); | |
203 | ||
204 | err = ext2_add_nondir(dentry, inode); | |
205 | out: | |
206 | return err; | |
207 | ||
208 | out_fail: | |
a513b035 | 209 | inode_dec_link_count(inode); |
41080b5a | 210 | unlock_new_inode(inode); |
1da177e4 LT |
211 | iput (inode); |
212 | goto out; | |
213 | } | |
214 | ||
215 | static int ext2_link (struct dentry * old_dentry, struct inode * dir, | |
216 | struct dentry *dentry) | |
217 | { | |
218 | struct inode *inode = old_dentry->d_inode; | |
41080b5a | 219 | int err; |
1da177e4 | 220 | |
871a2931 | 221 | dquot_initialize(dir); |
907f4554 | 222 | |
1da177e4 | 223 | inode->i_ctime = CURRENT_TIME_SEC; |
a513b035 | 224 | inode_inc_link_count(inode); |
7de9c6ee | 225 | ihold(inode); |
1da177e4 | 226 | |
41080b5a AV |
227 | err = ext2_add_link(dentry, inode); |
228 | if (!err) { | |
229 | d_instantiate(dentry, inode); | |
230 | return 0; | |
231 | } | |
232 | inode_dec_link_count(inode); | |
233 | iput(inode); | |
234 | return err; | |
1da177e4 LT |
235 | } |
236 | ||
18bb1db3 | 237 | static int ext2_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode) |
1da177e4 LT |
238 | { |
239 | struct inode * inode; | |
8de52778 | 240 | int err; |
1da177e4 | 241 | |
871a2931 | 242 | dquot_initialize(dir); |
907f4554 | 243 | |
a513b035 | 244 | inode_inc_link_count(dir); |
1da177e4 | 245 | |
2a7dba39 | 246 | inode = ext2_new_inode(dir, S_IFDIR | mode, &dentry->d_name); |
1da177e4 LT |
247 | err = PTR_ERR(inode); |
248 | if (IS_ERR(inode)) | |
249 | goto out_dir; | |
250 | ||
251 | inode->i_op = &ext2_dir_inode_operations; | |
252 | inode->i_fop = &ext2_dir_operations; | |
253 | if (test_opt(inode->i_sb, NOBH)) | |
254 | inode->i_mapping->a_ops = &ext2_nobh_aops; | |
255 | else | |
256 | inode->i_mapping->a_ops = &ext2_aops; | |
257 | ||
a513b035 | 258 | inode_inc_link_count(inode); |
1da177e4 LT |
259 | |
260 | err = ext2_make_empty(inode, dir); | |
261 | if (err) | |
262 | goto out_fail; | |
263 | ||
264 | err = ext2_add_link(dentry, inode); | |
265 | if (err) | |
266 | goto out_fail; | |
267 | ||
41080b5a | 268 | unlock_new_inode(inode); |
8fc37ec5 | 269 | d_instantiate(dentry, inode); |
1da177e4 LT |
270 | out: |
271 | return err; | |
272 | ||
273 | out_fail: | |
a513b035 AD |
274 | inode_dec_link_count(inode); |
275 | inode_dec_link_count(inode); | |
41080b5a | 276 | unlock_new_inode(inode); |
1da177e4 LT |
277 | iput(inode); |
278 | out_dir: | |
a513b035 | 279 | inode_dec_link_count(dir); |
1da177e4 LT |
280 | goto out; |
281 | } | |
282 | ||
283 | static int ext2_unlink(struct inode * dir, struct dentry *dentry) | |
284 | { | |
285 | struct inode * inode = dentry->d_inode; | |
286 | struct ext2_dir_entry_2 * de; | |
287 | struct page * page; | |
288 | int err = -ENOENT; | |
289 | ||
871a2931 | 290 | dquot_initialize(dir); |
907f4554 | 291 | |
a9885444 | 292 | de = ext2_find_entry (dir, &dentry->d_name, &page); |
1da177e4 LT |
293 | if (!de) |
294 | goto out; | |
295 | ||
296 | err = ext2_delete_entry (de, page); | |
297 | if (err) | |
298 | goto out; | |
299 | ||
300 | inode->i_ctime = dir->i_ctime; | |
a513b035 | 301 | inode_dec_link_count(inode); |
1da177e4 LT |
302 | err = 0; |
303 | out: | |
304 | return err; | |
305 | } | |
306 | ||
307 | static int ext2_rmdir (struct inode * dir, struct dentry *dentry) | |
308 | { | |
309 | struct inode * inode = dentry->d_inode; | |
310 | int err = -ENOTEMPTY; | |
311 | ||
312 | if (ext2_empty_dir(inode)) { | |
313 | err = ext2_unlink(dir, dentry); | |
314 | if (!err) { | |
315 | inode->i_size = 0; | |
a513b035 AD |
316 | inode_dec_link_count(inode); |
317 | inode_dec_link_count(dir); | |
1da177e4 LT |
318 | } |
319 | } | |
320 | return err; | |
321 | } | |
322 | ||
323 | static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry, | |
324 | struct inode * new_dir, struct dentry * new_dentry ) | |
325 | { | |
326 | struct inode * old_inode = old_dentry->d_inode; | |
327 | struct inode * new_inode = new_dentry->d_inode; | |
328 | struct page * dir_page = NULL; | |
329 | struct ext2_dir_entry_2 * dir_de = NULL; | |
330 | struct page * old_page; | |
331 | struct ext2_dir_entry_2 * old_de; | |
332 | int err = -ENOENT; | |
333 | ||
871a2931 CH |
334 | dquot_initialize(old_dir); |
335 | dquot_initialize(new_dir); | |
907f4554 | 336 | |
a9885444 | 337 | old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page); |
1da177e4 LT |
338 | if (!old_de) |
339 | goto out; | |
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); |
1da177e4 LT |
361 | new_inode->i_ctime = CURRENT_TIME_SEC; |
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 LT |
376 | */ |
377 | old_inode->i_ctime = CURRENT_TIME_SEC; | |
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); | |
387 | page_cache_release(dir_page); | |
388 | } | |
a513b035 | 389 | inode_dec_link_count(old_dir); |
1da177e4 LT |
390 | } |
391 | return 0; | |
392 | ||
393 | ||
394 | out_dir: | |
395 | if (dir_de) { | |
396 | kunmap(dir_page); | |
397 | page_cache_release(dir_page); | |
398 | } | |
399 | out_old: | |
400 | kunmap(old_page); | |
401 | page_cache_release(old_page); | |
402 | out: | |
403 | return err; | |
404 | } | |
405 | ||
754661f1 | 406 | const 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 | |
417 | .setxattr = generic_setxattr, | |
418 | .getxattr = generic_getxattr, | |
419 | .listxattr = ext2_listxattr, | |
420 | .removexattr = generic_removexattr, | |
421 | #endif | |
422 | .setattr = ext2_setattr, | |
4e34e719 | 423 | .get_acl = ext2_get_acl, |
60545d0d | 424 | .tmpfile = ext2_tmpfile, |
1da177e4 LT |
425 | }; |
426 | ||
754661f1 | 427 | const struct inode_operations ext2_special_inode_operations = { |
1da177e4 LT |
428 | #ifdef CONFIG_EXT2_FS_XATTR |
429 | .setxattr = generic_setxattr, | |
430 | .getxattr = generic_getxattr, | |
431 | .listxattr = ext2_listxattr, | |
432 | .removexattr = generic_removexattr, | |
433 | #endif | |
434 | .setattr = ext2_setattr, | |
4e34e719 | 435 | .get_acl = ext2_get_acl, |
1da177e4 | 436 | }; |