Commit | Line | Data |
---|---|---|
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) { | |
44 | d_instantiate(dentry, inode); | |
41080b5a | 45 | unlock_new_inode(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 | ||
58 | static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd) | |
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); |
4d6c13f8 BD |
70 | if (unlikely(IS_ERR(inode))) { |
71 | if (PTR_ERR(inode) == -ESTALE) { | |
72 | ext2_error(dir->i_sb, __func__, | |
73 | "deleted inode referenced: %lu", | |
a4255e4c | 74 | (unsigned long) ino); |
4d6c13f8 BD |
75 | return ERR_PTR(-EIO); |
76 | } else { | |
77 | return ERR_CAST(inode); | |
78 | } | |
79 | } | |
1da177e4 | 80 | } |
082a05c6 | 81 | return d_splice_alias(inode, dentry); |
1da177e4 LT |
82 | } |
83 | ||
84 | struct dentry *ext2_get_parent(struct dentry *child) | |
85 | { | |
a9885444 AV |
86 | struct qstr dotdot = {.name = "..", .len = 2}; |
87 | unsigned long ino = ext2_inode_by_name(child->d_inode, &dotdot); | |
1da177e4 LT |
88 | if (!ino) |
89 | return ERR_PTR(-ENOENT); | |
44003728 | 90 | return d_obtain_alias(ext2_iget(child->d_inode->i_sb, ino)); |
1da177e4 LT |
91 | } |
92 | ||
93 | /* | |
94 | * By the time this is called, we already have created | |
95 | * the directory cache entry for the new file, but it | |
96 | * is so far negative - it has no inode. | |
97 | * | |
98 | * If the create succeeds, we fill in the inode information | |
99 | * with d_instantiate(). | |
100 | */ | |
101 | static int ext2_create (struct inode * dir, struct dentry * dentry, int mode, struct nameidata *nd) | |
102 | { | |
907f4554 CH |
103 | struct inode *inode; |
104 | ||
871a2931 | 105 | dquot_initialize(dir); |
907f4554 CH |
106 | |
107 | inode = ext2_new_inode(dir, mode); | |
108 | if (IS_ERR(inode)) | |
109 | return PTR_ERR(inode); | |
110 | ||
111 | inode->i_op = &ext2_file_inode_operations; | |
112 | if (ext2_use_xip(inode->i_sb)) { | |
113 | inode->i_mapping->a_ops = &ext2_aops_xip; | |
114 | inode->i_fop = &ext2_xip_file_operations; | |
115 | } else if (test_opt(inode->i_sb, NOBH)) { | |
116 | inode->i_mapping->a_ops = &ext2_nobh_aops; | |
117 | inode->i_fop = &ext2_file_operations; | |
118 | } else { | |
119 | inode->i_mapping->a_ops = &ext2_aops; | |
120 | inode->i_fop = &ext2_file_operations; | |
1da177e4 | 121 | } |
907f4554 CH |
122 | mark_inode_dirty(inode); |
123 | return ext2_add_nondir(dentry, inode); | |
1da177e4 LT |
124 | } |
125 | ||
126 | static int ext2_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev) | |
127 | { | |
128 | struct inode * inode; | |
129 | int err; | |
130 | ||
131 | if (!new_valid_dev(rdev)) | |
132 | return -EINVAL; | |
133 | ||
871a2931 | 134 | dquot_initialize(dir); |
907f4554 | 135 | |
1da177e4 LT |
136 | inode = ext2_new_inode (dir, mode); |
137 | err = PTR_ERR(inode); | |
138 | if (!IS_ERR(inode)) { | |
139 | init_special_inode(inode, inode->i_mode, rdev); | |
140 | #ifdef CONFIG_EXT2_FS_XATTR | |
141 | inode->i_op = &ext2_special_inode_operations; | |
142 | #endif | |
143 | mark_inode_dirty(inode); | |
144 | err = ext2_add_nondir(dentry, inode); | |
145 | } | |
146 | return err; | |
147 | } | |
148 | ||
149 | static int ext2_symlink (struct inode * dir, struct dentry * dentry, | |
150 | const char * symname) | |
151 | { | |
152 | struct super_block * sb = dir->i_sb; | |
153 | int err = -ENAMETOOLONG; | |
154 | unsigned l = strlen(symname)+1; | |
155 | struct inode * inode; | |
156 | ||
157 | if (l > sb->s_blocksize) | |
158 | goto out; | |
159 | ||
871a2931 | 160 | dquot_initialize(dir); |
907f4554 | 161 | |
1da177e4 LT |
162 | inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO); |
163 | err = PTR_ERR(inode); | |
164 | if (IS_ERR(inode)) | |
165 | goto out; | |
166 | ||
167 | if (l > sizeof (EXT2_I(inode)->i_data)) { | |
168 | /* slow symlink */ | |
169 | inode->i_op = &ext2_symlink_inode_operations; | |
170 | if (test_opt(inode->i_sb, NOBH)) | |
171 | inode->i_mapping->a_ops = &ext2_nobh_aops; | |
172 | else | |
173 | inode->i_mapping->a_ops = &ext2_aops; | |
174 | err = page_symlink(inode, symname, l); | |
175 | if (err) | |
176 | goto out_fail; | |
177 | } else { | |
178 | /* fast symlink */ | |
179 | inode->i_op = &ext2_fast_symlink_inode_operations; | |
180 | memcpy((char*)(EXT2_I(inode)->i_data),symname,l); | |
181 | inode->i_size = l-1; | |
182 | } | |
183 | mark_inode_dirty(inode); | |
184 | ||
185 | err = ext2_add_nondir(dentry, inode); | |
186 | out: | |
187 | return err; | |
188 | ||
189 | out_fail: | |
a513b035 | 190 | inode_dec_link_count(inode); |
41080b5a | 191 | unlock_new_inode(inode); |
1da177e4 LT |
192 | iput (inode); |
193 | goto out; | |
194 | } | |
195 | ||
196 | static int ext2_link (struct dentry * old_dentry, struct inode * dir, | |
197 | struct dentry *dentry) | |
198 | { | |
199 | struct inode *inode = old_dentry->d_inode; | |
41080b5a | 200 | int err; |
1da177e4 LT |
201 | |
202 | if (inode->i_nlink >= EXT2_LINK_MAX) | |
203 | return -EMLINK; | |
204 | ||
871a2931 | 205 | dquot_initialize(dir); |
907f4554 | 206 | |
1da177e4 | 207 | inode->i_ctime = CURRENT_TIME_SEC; |
a513b035 | 208 | inode_inc_link_count(inode); |
1da177e4 LT |
209 | atomic_inc(&inode->i_count); |
210 | ||
41080b5a AV |
211 | err = ext2_add_link(dentry, inode); |
212 | if (!err) { | |
213 | d_instantiate(dentry, inode); | |
214 | return 0; | |
215 | } | |
216 | inode_dec_link_count(inode); | |
217 | iput(inode); | |
218 | return err; | |
1da177e4 LT |
219 | } |
220 | ||
221 | static int ext2_mkdir(struct inode * dir, struct dentry * dentry, int mode) | |
222 | { | |
223 | struct inode * inode; | |
224 | int err = -EMLINK; | |
225 | ||
226 | if (dir->i_nlink >= EXT2_LINK_MAX) | |
227 | goto out; | |
228 | ||
871a2931 | 229 | dquot_initialize(dir); |
907f4554 | 230 | |
a513b035 | 231 | inode_inc_link_count(dir); |
1da177e4 LT |
232 | |
233 | inode = ext2_new_inode (dir, S_IFDIR | mode); | |
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 | ||
255 | d_instantiate(dentry, inode); | |
41080b5a | 256 | unlock_new_inode(inode); |
1da177e4 LT |
257 | out: |
258 | return err; | |
259 | ||
260 | out_fail: | |
a513b035 AD |
261 | inode_dec_link_count(inode); |
262 | inode_dec_link_count(inode); | |
41080b5a | 263 | unlock_new_inode(inode); |
1da177e4 LT |
264 | iput(inode); |
265 | out_dir: | |
a513b035 | 266 | inode_dec_link_count(dir); |
1da177e4 LT |
267 | goto out; |
268 | } | |
269 | ||
270 | static int ext2_unlink(struct inode * dir, struct dentry *dentry) | |
271 | { | |
272 | struct inode * inode = dentry->d_inode; | |
273 | struct ext2_dir_entry_2 * de; | |
274 | struct page * page; | |
275 | int err = -ENOENT; | |
276 | ||
871a2931 | 277 | dquot_initialize(dir); |
907f4554 | 278 | |
a9885444 | 279 | de = ext2_find_entry (dir, &dentry->d_name, &page); |
1da177e4 LT |
280 | if (!de) |
281 | goto out; | |
282 | ||
283 | err = ext2_delete_entry (de, page); | |
284 | if (err) | |
285 | goto out; | |
286 | ||
287 | inode->i_ctime = dir->i_ctime; | |
a513b035 | 288 | inode_dec_link_count(inode); |
1da177e4 LT |
289 | err = 0; |
290 | out: | |
291 | return err; | |
292 | } | |
293 | ||
294 | static int ext2_rmdir (struct inode * dir, struct dentry *dentry) | |
295 | { | |
296 | struct inode * inode = dentry->d_inode; | |
297 | int err = -ENOTEMPTY; | |
298 | ||
299 | if (ext2_empty_dir(inode)) { | |
300 | err = ext2_unlink(dir, dentry); | |
301 | if (!err) { | |
302 | inode->i_size = 0; | |
a513b035 AD |
303 | inode_dec_link_count(inode); |
304 | inode_dec_link_count(dir); | |
1da177e4 LT |
305 | } |
306 | } | |
307 | return err; | |
308 | } | |
309 | ||
310 | static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry, | |
311 | struct inode * new_dir, struct dentry * new_dentry ) | |
312 | { | |
313 | struct inode * old_inode = old_dentry->d_inode; | |
314 | struct inode * new_inode = new_dentry->d_inode; | |
315 | struct page * dir_page = NULL; | |
316 | struct ext2_dir_entry_2 * dir_de = NULL; | |
317 | struct page * old_page; | |
318 | struct ext2_dir_entry_2 * old_de; | |
319 | int err = -ENOENT; | |
320 | ||
871a2931 CH |
321 | dquot_initialize(old_dir); |
322 | dquot_initialize(new_dir); | |
907f4554 | 323 | |
a9885444 | 324 | old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page); |
1da177e4 LT |
325 | if (!old_de) |
326 | goto out; | |
327 | ||
328 | if (S_ISDIR(old_inode->i_mode)) { | |
329 | err = -EIO; | |
330 | dir_de = ext2_dotdot(old_inode, &dir_page); | |
331 | if (!dir_de) | |
332 | goto out_old; | |
333 | } | |
334 | ||
335 | if (new_inode) { | |
336 | struct page *new_page; | |
337 | struct ext2_dir_entry_2 *new_de; | |
338 | ||
339 | err = -ENOTEMPTY; | |
340 | if (dir_de && !ext2_empty_dir (new_inode)) | |
341 | goto out_dir; | |
342 | ||
343 | err = -ENOENT; | |
a9885444 | 344 | new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page); |
1da177e4 LT |
345 | if (!new_de) |
346 | goto out_dir; | |
a513b035 | 347 | inode_inc_link_count(old_inode); |
39fe7557 | 348 | ext2_set_link(new_dir, new_de, new_page, old_inode, 1); |
1da177e4 LT |
349 | new_inode->i_ctime = CURRENT_TIME_SEC; |
350 | if (dir_de) | |
9a53c3a7 | 351 | drop_nlink(new_inode); |
a513b035 | 352 | inode_dec_link_count(new_inode); |
1da177e4 LT |
353 | } else { |
354 | if (dir_de) { | |
355 | err = -EMLINK; | |
356 | if (new_dir->i_nlink >= EXT2_LINK_MAX) | |
357 | goto out_dir; | |
358 | } | |
a513b035 | 359 | inode_inc_link_count(old_inode); |
1da177e4 LT |
360 | err = ext2_add_link(new_dentry, old_inode); |
361 | if (err) { | |
a513b035 | 362 | inode_dec_link_count(old_inode); |
1da177e4 LT |
363 | goto out_dir; |
364 | } | |
365 | if (dir_de) | |
a513b035 | 366 | inode_inc_link_count(new_dir); |
1da177e4 LT |
367 | } |
368 | ||
369 | /* | |
370 | * Like most other Unix systems, set the ctime for inodes on a | |
371 | * rename. | |
a513b035 | 372 | * inode_dec_link_count() will mark the inode dirty. |
1da177e4 LT |
373 | */ |
374 | old_inode->i_ctime = CURRENT_TIME_SEC; | |
375 | ||
376 | ext2_delete_entry (old_de, old_page); | |
a513b035 | 377 | inode_dec_link_count(old_inode); |
1da177e4 LT |
378 | |
379 | if (dir_de) { | |
39fe7557 JK |
380 | if (old_dir != new_dir) |
381 | ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0); | |
9de6886e NP |
382 | else { |
383 | kunmap(dir_page); | |
384 | page_cache_release(dir_page); | |
385 | } | |
a513b035 | 386 | inode_dec_link_count(old_dir); |
1da177e4 LT |
387 | } |
388 | return 0; | |
389 | ||
390 | ||
391 | out_dir: | |
392 | if (dir_de) { | |
393 | kunmap(dir_page); | |
394 | page_cache_release(dir_page); | |
395 | } | |
396 | out_old: | |
397 | kunmap(old_page); | |
398 | page_cache_release(old_page); | |
399 | out: | |
400 | return err; | |
401 | } | |
402 | ||
754661f1 | 403 | const struct inode_operations ext2_dir_inode_operations = { |
1da177e4 LT |
404 | .create = ext2_create, |
405 | .lookup = ext2_lookup, | |
406 | .link = ext2_link, | |
407 | .unlink = ext2_unlink, | |
408 | .symlink = ext2_symlink, | |
409 | .mkdir = ext2_mkdir, | |
410 | .rmdir = ext2_rmdir, | |
411 | .mknod = ext2_mknod, | |
412 | .rename = ext2_rename, | |
413 | #ifdef CONFIG_EXT2_FS_XATTR | |
414 | .setxattr = generic_setxattr, | |
415 | .getxattr = generic_getxattr, | |
416 | .listxattr = ext2_listxattr, | |
417 | .removexattr = generic_removexattr, | |
418 | #endif | |
419 | .setattr = ext2_setattr, | |
1d5ccd1c | 420 | .check_acl = ext2_check_acl, |
1da177e4 LT |
421 | }; |
422 | ||
754661f1 | 423 | const struct inode_operations ext2_special_inode_operations = { |
1da177e4 LT |
424 | #ifdef CONFIG_EXT2_FS_XATTR |
425 | .setxattr = generic_setxattr, | |
426 | .getxattr = generic_getxattr, | |
427 | .listxattr = ext2_listxattr, | |
428 | .removexattr = generic_removexattr, | |
429 | #endif | |
430 | .setattr = ext2_setattr, | |
1d5ccd1c | 431 | .check_acl = ext2_check_acl, |
1da177e4 | 432 | }; |