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> | |
34 | #include "ext2.h" | |
35 | #include "xattr.h" | |
36 | #include "acl.h" | |
6d79125b | 37 | #include "xip.h" |
1da177e4 | 38 | |
1da177e4 LT |
39 | static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode) |
40 | { | |
41 | int err = ext2_add_link(dentry, inode); | |
42 | if (!err) { | |
43 | d_instantiate(dentry, inode); | |
41080b5a | 44 | unlock_new_inode(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 | ||
57 | static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd) | |
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 DH |
68 | inode = ext2_iget(dir->i_sb, ino); |
69 | if (IS_ERR(inode)) | |
70 | return ERR_CAST(inode); | |
1da177e4 | 71 | } |
082a05c6 | 72 | return d_splice_alias(inode, dentry); |
1da177e4 LT |
73 | } |
74 | ||
75 | struct dentry *ext2_get_parent(struct dentry *child) | |
76 | { | |
a9885444 AV |
77 | struct qstr dotdot = {.name = "..", .len = 2}; |
78 | unsigned long ino = ext2_inode_by_name(child->d_inode, &dotdot); | |
1da177e4 LT |
79 | if (!ino) |
80 | return ERR_PTR(-ENOENT); | |
44003728 | 81 | return d_obtain_alias(ext2_iget(child->d_inode->i_sb, ino)); |
1da177e4 LT |
82 | } |
83 | ||
84 | /* | |
85 | * By the time this is called, we already have created | |
86 | * the directory cache entry for the new file, but it | |
87 | * is so far negative - it has no inode. | |
88 | * | |
89 | * If the create succeeds, we fill in the inode information | |
90 | * with d_instantiate(). | |
91 | */ | |
92 | static int ext2_create (struct inode * dir, struct dentry * dentry, int mode, struct nameidata *nd) | |
93 | { | |
94 | struct inode * inode = ext2_new_inode (dir, mode); | |
95 | int err = PTR_ERR(inode); | |
96 | if (!IS_ERR(inode)) { | |
97 | inode->i_op = &ext2_file_inode_operations; | |
6d79125b CO |
98 | if (ext2_use_xip(inode->i_sb)) { |
99 | inode->i_mapping->a_ops = &ext2_aops_xip; | |
100 | inode->i_fop = &ext2_xip_file_operations; | |
101 | } else if (test_opt(inode->i_sb, NOBH)) { | |
1da177e4 | 102 | inode->i_mapping->a_ops = &ext2_nobh_aops; |
6d79125b CO |
103 | inode->i_fop = &ext2_file_operations; |
104 | } else { | |
1da177e4 | 105 | inode->i_mapping->a_ops = &ext2_aops; |
6d79125b CO |
106 | inode->i_fop = &ext2_file_operations; |
107 | } | |
1da177e4 LT |
108 | mark_inode_dirty(inode); |
109 | err = ext2_add_nondir(dentry, inode); | |
110 | } | |
111 | return err; | |
112 | } | |
113 | ||
114 | static int ext2_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev) | |
115 | { | |
116 | struct inode * inode; | |
117 | int err; | |
118 | ||
119 | if (!new_valid_dev(rdev)) | |
120 | return -EINVAL; | |
121 | ||
122 | inode = ext2_new_inode (dir, mode); | |
123 | err = PTR_ERR(inode); | |
124 | if (!IS_ERR(inode)) { | |
125 | init_special_inode(inode, inode->i_mode, rdev); | |
126 | #ifdef CONFIG_EXT2_FS_XATTR | |
127 | inode->i_op = &ext2_special_inode_operations; | |
128 | #endif | |
129 | mark_inode_dirty(inode); | |
130 | err = ext2_add_nondir(dentry, inode); | |
131 | } | |
132 | return err; | |
133 | } | |
134 | ||
135 | static int ext2_symlink (struct inode * dir, struct dentry * dentry, | |
136 | const char * symname) | |
137 | { | |
138 | struct super_block * sb = dir->i_sb; | |
139 | int err = -ENAMETOOLONG; | |
140 | unsigned l = strlen(symname)+1; | |
141 | struct inode * inode; | |
142 | ||
143 | if (l > sb->s_blocksize) | |
144 | goto out; | |
145 | ||
146 | inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO); | |
147 | err = PTR_ERR(inode); | |
148 | if (IS_ERR(inode)) | |
149 | goto out; | |
150 | ||
151 | if (l > sizeof (EXT2_I(inode)->i_data)) { | |
152 | /* slow symlink */ | |
153 | inode->i_op = &ext2_symlink_inode_operations; | |
154 | if (test_opt(inode->i_sb, NOBH)) | |
155 | inode->i_mapping->a_ops = &ext2_nobh_aops; | |
156 | else | |
157 | inode->i_mapping->a_ops = &ext2_aops; | |
158 | err = page_symlink(inode, symname, l); | |
159 | if (err) | |
160 | goto out_fail; | |
161 | } else { | |
162 | /* fast symlink */ | |
163 | inode->i_op = &ext2_fast_symlink_inode_operations; | |
164 | memcpy((char*)(EXT2_I(inode)->i_data),symname,l); | |
165 | inode->i_size = l-1; | |
166 | } | |
167 | mark_inode_dirty(inode); | |
168 | ||
169 | err = ext2_add_nondir(dentry, inode); | |
170 | out: | |
171 | return err; | |
172 | ||
173 | out_fail: | |
a513b035 | 174 | inode_dec_link_count(inode); |
41080b5a | 175 | unlock_new_inode(inode); |
1da177e4 LT |
176 | iput (inode); |
177 | goto out; | |
178 | } | |
179 | ||
180 | static int ext2_link (struct dentry * old_dentry, struct inode * dir, | |
181 | struct dentry *dentry) | |
182 | { | |
183 | struct inode *inode = old_dentry->d_inode; | |
41080b5a | 184 | int err; |
1da177e4 LT |
185 | |
186 | if (inode->i_nlink >= EXT2_LINK_MAX) | |
187 | return -EMLINK; | |
188 | ||
189 | inode->i_ctime = CURRENT_TIME_SEC; | |
a513b035 | 190 | inode_inc_link_count(inode); |
1da177e4 LT |
191 | atomic_inc(&inode->i_count); |
192 | ||
41080b5a AV |
193 | err = ext2_add_link(dentry, inode); |
194 | if (!err) { | |
195 | d_instantiate(dentry, inode); | |
196 | return 0; | |
197 | } | |
198 | inode_dec_link_count(inode); | |
199 | iput(inode); | |
200 | return err; | |
1da177e4 LT |
201 | } |
202 | ||
203 | static int ext2_mkdir(struct inode * dir, struct dentry * dentry, int mode) | |
204 | { | |
205 | struct inode * inode; | |
206 | int err = -EMLINK; | |
207 | ||
208 | if (dir->i_nlink >= EXT2_LINK_MAX) | |
209 | goto out; | |
210 | ||
a513b035 | 211 | inode_inc_link_count(dir); |
1da177e4 LT |
212 | |
213 | inode = ext2_new_inode (dir, S_IFDIR | mode); | |
214 | err = PTR_ERR(inode); | |
215 | if (IS_ERR(inode)) | |
216 | goto out_dir; | |
217 | ||
218 | inode->i_op = &ext2_dir_inode_operations; | |
219 | inode->i_fop = &ext2_dir_operations; | |
220 | if (test_opt(inode->i_sb, NOBH)) | |
221 | inode->i_mapping->a_ops = &ext2_nobh_aops; | |
222 | else | |
223 | inode->i_mapping->a_ops = &ext2_aops; | |
224 | ||
a513b035 | 225 | inode_inc_link_count(inode); |
1da177e4 LT |
226 | |
227 | err = ext2_make_empty(inode, dir); | |
228 | if (err) | |
229 | goto out_fail; | |
230 | ||
231 | err = ext2_add_link(dentry, inode); | |
232 | if (err) | |
233 | goto out_fail; | |
234 | ||
235 | d_instantiate(dentry, inode); | |
41080b5a | 236 | unlock_new_inode(inode); |
1da177e4 LT |
237 | out: |
238 | return err; | |
239 | ||
240 | out_fail: | |
a513b035 AD |
241 | inode_dec_link_count(inode); |
242 | inode_dec_link_count(inode); | |
41080b5a | 243 | unlock_new_inode(inode); |
1da177e4 LT |
244 | iput(inode); |
245 | out_dir: | |
a513b035 | 246 | inode_dec_link_count(dir); |
1da177e4 LT |
247 | goto out; |
248 | } | |
249 | ||
250 | static int ext2_unlink(struct inode * dir, struct dentry *dentry) | |
251 | { | |
252 | struct inode * inode = dentry->d_inode; | |
253 | struct ext2_dir_entry_2 * de; | |
254 | struct page * page; | |
255 | int err = -ENOENT; | |
256 | ||
a9885444 | 257 | de = ext2_find_entry (dir, &dentry->d_name, &page); |
1da177e4 LT |
258 | if (!de) |
259 | goto out; | |
260 | ||
261 | err = ext2_delete_entry (de, page); | |
262 | if (err) | |
263 | goto out; | |
264 | ||
265 | inode->i_ctime = dir->i_ctime; | |
a513b035 | 266 | inode_dec_link_count(inode); |
1da177e4 LT |
267 | err = 0; |
268 | out: | |
269 | return err; | |
270 | } | |
271 | ||
272 | static int ext2_rmdir (struct inode * dir, struct dentry *dentry) | |
273 | { | |
274 | struct inode * inode = dentry->d_inode; | |
275 | int err = -ENOTEMPTY; | |
276 | ||
277 | if (ext2_empty_dir(inode)) { | |
278 | err = ext2_unlink(dir, dentry); | |
279 | if (!err) { | |
280 | inode->i_size = 0; | |
a513b035 AD |
281 | inode_dec_link_count(inode); |
282 | inode_dec_link_count(dir); | |
1da177e4 LT |
283 | } |
284 | } | |
285 | return err; | |
286 | } | |
287 | ||
288 | static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry, | |
289 | struct inode * new_dir, struct dentry * new_dentry ) | |
290 | { | |
291 | struct inode * old_inode = old_dentry->d_inode; | |
292 | struct inode * new_inode = new_dentry->d_inode; | |
293 | struct page * dir_page = NULL; | |
294 | struct ext2_dir_entry_2 * dir_de = NULL; | |
295 | struct page * old_page; | |
296 | struct ext2_dir_entry_2 * old_de; | |
297 | int err = -ENOENT; | |
298 | ||
a9885444 | 299 | old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page); |
1da177e4 LT |
300 | if (!old_de) |
301 | goto out; | |
302 | ||
303 | if (S_ISDIR(old_inode->i_mode)) { | |
304 | err = -EIO; | |
305 | dir_de = ext2_dotdot(old_inode, &dir_page); | |
306 | if (!dir_de) | |
307 | goto out_old; | |
308 | } | |
309 | ||
310 | if (new_inode) { | |
311 | struct page *new_page; | |
312 | struct ext2_dir_entry_2 *new_de; | |
313 | ||
314 | err = -ENOTEMPTY; | |
315 | if (dir_de && !ext2_empty_dir (new_inode)) | |
316 | goto out_dir; | |
317 | ||
318 | err = -ENOENT; | |
a9885444 | 319 | new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page); |
1da177e4 LT |
320 | if (!new_de) |
321 | goto out_dir; | |
a513b035 | 322 | inode_inc_link_count(old_inode); |
39fe7557 | 323 | ext2_set_link(new_dir, new_de, new_page, old_inode, 1); |
1da177e4 LT |
324 | new_inode->i_ctime = CURRENT_TIME_SEC; |
325 | if (dir_de) | |
9a53c3a7 | 326 | drop_nlink(new_inode); |
a513b035 | 327 | inode_dec_link_count(new_inode); |
1da177e4 LT |
328 | } else { |
329 | if (dir_de) { | |
330 | err = -EMLINK; | |
331 | if (new_dir->i_nlink >= EXT2_LINK_MAX) | |
332 | goto out_dir; | |
333 | } | |
a513b035 | 334 | inode_inc_link_count(old_inode); |
1da177e4 LT |
335 | err = ext2_add_link(new_dentry, old_inode); |
336 | if (err) { | |
a513b035 | 337 | inode_dec_link_count(old_inode); |
1da177e4 LT |
338 | goto out_dir; |
339 | } | |
340 | if (dir_de) | |
a513b035 | 341 | inode_inc_link_count(new_dir); |
1da177e4 LT |
342 | } |
343 | ||
344 | /* | |
345 | * Like most other Unix systems, set the ctime for inodes on a | |
346 | * rename. | |
a513b035 | 347 | * inode_dec_link_count() will mark the inode dirty. |
1da177e4 LT |
348 | */ |
349 | old_inode->i_ctime = CURRENT_TIME_SEC; | |
350 | ||
351 | ext2_delete_entry (old_de, old_page); | |
a513b035 | 352 | inode_dec_link_count(old_inode); |
1da177e4 LT |
353 | |
354 | if (dir_de) { | |
39fe7557 JK |
355 | if (old_dir != new_dir) |
356 | ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0); | |
a513b035 | 357 | inode_dec_link_count(old_dir); |
1da177e4 LT |
358 | } |
359 | return 0; | |
360 | ||
361 | ||
362 | out_dir: | |
363 | if (dir_de) { | |
364 | kunmap(dir_page); | |
365 | page_cache_release(dir_page); | |
366 | } | |
367 | out_old: | |
368 | kunmap(old_page); | |
369 | page_cache_release(old_page); | |
370 | out: | |
371 | return err; | |
372 | } | |
373 | ||
754661f1 | 374 | const struct inode_operations ext2_dir_inode_operations = { |
1da177e4 LT |
375 | .create = ext2_create, |
376 | .lookup = ext2_lookup, | |
377 | .link = ext2_link, | |
378 | .unlink = ext2_unlink, | |
379 | .symlink = ext2_symlink, | |
380 | .mkdir = ext2_mkdir, | |
381 | .rmdir = ext2_rmdir, | |
382 | .mknod = ext2_mknod, | |
383 | .rename = ext2_rename, | |
384 | #ifdef CONFIG_EXT2_FS_XATTR | |
385 | .setxattr = generic_setxattr, | |
386 | .getxattr = generic_getxattr, | |
387 | .listxattr = ext2_listxattr, | |
388 | .removexattr = generic_removexattr, | |
389 | #endif | |
390 | .setattr = ext2_setattr, | |
391 | .permission = ext2_permission, | |
392 | }; | |
393 | ||
754661f1 | 394 | const struct inode_operations ext2_special_inode_operations = { |
1da177e4 LT |
395 | #ifdef CONFIG_EXT2_FS_XATTR |
396 | .setxattr = generic_setxattr, | |
397 | .getxattr = generic_getxattr, | |
398 | .listxattr = ext2_listxattr, | |
399 | .removexattr = generic_removexattr, | |
400 | #endif | |
401 | .setattr = ext2_setattr, | |
402 | .permission = ext2_permission, | |
403 | }; |