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); | |
44 | return 0; | |
45 | } | |
a513b035 | 46 | inode_dec_link_count(inode); |
1da177e4 LT |
47 | iput(inode); |
48 | return err; | |
49 | } | |
50 | ||
51 | /* | |
52 | * Methods themselves. | |
53 | */ | |
54 | ||
55 | static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd) | |
56 | { | |
57 | struct inode * inode; | |
58 | ino_t ino; | |
59 | ||
60 | if (dentry->d_name.len > EXT2_NAME_LEN) | |
61 | return ERR_PTR(-ENAMETOOLONG); | |
62 | ||
a9885444 | 63 | ino = ext2_inode_by_name(dir, &dentry->d_name); |
1da177e4 LT |
64 | inode = NULL; |
65 | if (ino) { | |
52fcf703 DH |
66 | inode = ext2_iget(dir->i_sb, ino); |
67 | if (IS_ERR(inode)) | |
68 | return ERR_CAST(inode); | |
1da177e4 | 69 | } |
082a05c6 | 70 | return d_splice_alias(inode, dentry); |
1da177e4 LT |
71 | } |
72 | ||
73 | struct dentry *ext2_get_parent(struct dentry *child) | |
74 | { | |
a9885444 AV |
75 | struct qstr dotdot = {.name = "..", .len = 2}; |
76 | unsigned long ino = ext2_inode_by_name(child->d_inode, &dotdot); | |
1da177e4 LT |
77 | if (!ino) |
78 | return ERR_PTR(-ENOENT); | |
44003728 | 79 | return d_obtain_alias(ext2_iget(child->d_inode->i_sb, ino)); |
1da177e4 LT |
80 | } |
81 | ||
82 | /* | |
83 | * By the time this is called, we already have created | |
84 | * the directory cache entry for the new file, but it | |
85 | * is so far negative - it has no inode. | |
86 | * | |
87 | * If the create succeeds, we fill in the inode information | |
88 | * with d_instantiate(). | |
89 | */ | |
90 | static int ext2_create (struct inode * dir, struct dentry * dentry, int mode, struct nameidata *nd) | |
91 | { | |
92 | struct inode * inode = ext2_new_inode (dir, mode); | |
93 | int err = PTR_ERR(inode); | |
94 | if (!IS_ERR(inode)) { | |
95 | inode->i_op = &ext2_file_inode_operations; | |
6d79125b CO |
96 | if (ext2_use_xip(inode->i_sb)) { |
97 | inode->i_mapping->a_ops = &ext2_aops_xip; | |
98 | inode->i_fop = &ext2_xip_file_operations; | |
99 | } else if (test_opt(inode->i_sb, NOBH)) { | |
1da177e4 | 100 | inode->i_mapping->a_ops = &ext2_nobh_aops; |
6d79125b CO |
101 | inode->i_fop = &ext2_file_operations; |
102 | } else { | |
1da177e4 | 103 | inode->i_mapping->a_ops = &ext2_aops; |
6d79125b CO |
104 | inode->i_fop = &ext2_file_operations; |
105 | } | |
1da177e4 LT |
106 | mark_inode_dirty(inode); |
107 | err = ext2_add_nondir(dentry, inode); | |
108 | } | |
109 | return err; | |
110 | } | |
111 | ||
112 | static int ext2_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev) | |
113 | { | |
114 | struct inode * inode; | |
115 | int err; | |
116 | ||
117 | if (!new_valid_dev(rdev)) | |
118 | return -EINVAL; | |
119 | ||
120 | inode = ext2_new_inode (dir, mode); | |
121 | err = PTR_ERR(inode); | |
122 | if (!IS_ERR(inode)) { | |
123 | init_special_inode(inode, inode->i_mode, rdev); | |
124 | #ifdef CONFIG_EXT2_FS_XATTR | |
125 | inode->i_op = &ext2_special_inode_operations; | |
126 | #endif | |
127 | mark_inode_dirty(inode); | |
128 | err = ext2_add_nondir(dentry, inode); | |
129 | } | |
130 | return err; | |
131 | } | |
132 | ||
133 | static int ext2_symlink (struct inode * dir, struct dentry * dentry, | |
134 | const char * symname) | |
135 | { | |
136 | struct super_block * sb = dir->i_sb; | |
137 | int err = -ENAMETOOLONG; | |
138 | unsigned l = strlen(symname)+1; | |
139 | struct inode * inode; | |
140 | ||
141 | if (l > sb->s_blocksize) | |
142 | goto out; | |
143 | ||
144 | inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO); | |
145 | err = PTR_ERR(inode); | |
146 | if (IS_ERR(inode)) | |
147 | goto out; | |
148 | ||
149 | if (l > sizeof (EXT2_I(inode)->i_data)) { | |
150 | /* slow symlink */ | |
151 | inode->i_op = &ext2_symlink_inode_operations; | |
152 | if (test_opt(inode->i_sb, NOBH)) | |
153 | inode->i_mapping->a_ops = &ext2_nobh_aops; | |
154 | else | |
155 | inode->i_mapping->a_ops = &ext2_aops; | |
156 | err = page_symlink(inode, symname, l); | |
157 | if (err) | |
158 | goto out_fail; | |
159 | } else { | |
160 | /* fast symlink */ | |
161 | inode->i_op = &ext2_fast_symlink_inode_operations; | |
162 | memcpy((char*)(EXT2_I(inode)->i_data),symname,l); | |
163 | inode->i_size = l-1; | |
164 | } | |
165 | mark_inode_dirty(inode); | |
166 | ||
167 | err = ext2_add_nondir(dentry, inode); | |
168 | out: | |
169 | return err; | |
170 | ||
171 | out_fail: | |
a513b035 | 172 | inode_dec_link_count(inode); |
1da177e4 LT |
173 | iput (inode); |
174 | goto out; | |
175 | } | |
176 | ||
177 | static int ext2_link (struct dentry * old_dentry, struct inode * dir, | |
178 | struct dentry *dentry) | |
179 | { | |
180 | struct inode *inode = old_dentry->d_inode; | |
181 | ||
182 | if (inode->i_nlink >= EXT2_LINK_MAX) | |
183 | return -EMLINK; | |
184 | ||
185 | inode->i_ctime = CURRENT_TIME_SEC; | |
a513b035 | 186 | inode_inc_link_count(inode); |
1da177e4 LT |
187 | atomic_inc(&inode->i_count); |
188 | ||
189 | return ext2_add_nondir(dentry, inode); | |
190 | } | |
191 | ||
192 | static int ext2_mkdir(struct inode * dir, struct dentry * dentry, int mode) | |
193 | { | |
194 | struct inode * inode; | |
195 | int err = -EMLINK; | |
196 | ||
197 | if (dir->i_nlink >= EXT2_LINK_MAX) | |
198 | goto out; | |
199 | ||
a513b035 | 200 | inode_inc_link_count(dir); |
1da177e4 LT |
201 | |
202 | inode = ext2_new_inode (dir, S_IFDIR | mode); | |
203 | err = PTR_ERR(inode); | |
204 | if (IS_ERR(inode)) | |
205 | goto out_dir; | |
206 | ||
207 | inode->i_op = &ext2_dir_inode_operations; | |
208 | inode->i_fop = &ext2_dir_operations; | |
209 | if (test_opt(inode->i_sb, NOBH)) | |
210 | inode->i_mapping->a_ops = &ext2_nobh_aops; | |
211 | else | |
212 | inode->i_mapping->a_ops = &ext2_aops; | |
213 | ||
a513b035 | 214 | inode_inc_link_count(inode); |
1da177e4 LT |
215 | |
216 | err = ext2_make_empty(inode, dir); | |
217 | if (err) | |
218 | goto out_fail; | |
219 | ||
220 | err = ext2_add_link(dentry, inode); | |
221 | if (err) | |
222 | goto out_fail; | |
223 | ||
224 | d_instantiate(dentry, inode); | |
225 | out: | |
226 | return err; | |
227 | ||
228 | out_fail: | |
a513b035 AD |
229 | inode_dec_link_count(inode); |
230 | inode_dec_link_count(inode); | |
1da177e4 LT |
231 | iput(inode); |
232 | out_dir: | |
a513b035 | 233 | inode_dec_link_count(dir); |
1da177e4 LT |
234 | goto out; |
235 | } | |
236 | ||
237 | static int ext2_unlink(struct inode * dir, struct dentry *dentry) | |
238 | { | |
239 | struct inode * inode = dentry->d_inode; | |
240 | struct ext2_dir_entry_2 * de; | |
241 | struct page * page; | |
242 | int err = -ENOENT; | |
243 | ||
a9885444 | 244 | de = ext2_find_entry (dir, &dentry->d_name, &page); |
1da177e4 LT |
245 | if (!de) |
246 | goto out; | |
247 | ||
248 | err = ext2_delete_entry (de, page); | |
249 | if (err) | |
250 | goto out; | |
251 | ||
252 | inode->i_ctime = dir->i_ctime; | |
a513b035 | 253 | inode_dec_link_count(inode); |
1da177e4 LT |
254 | err = 0; |
255 | out: | |
256 | return err; | |
257 | } | |
258 | ||
259 | static int ext2_rmdir (struct inode * dir, struct dentry *dentry) | |
260 | { | |
261 | struct inode * inode = dentry->d_inode; | |
262 | int err = -ENOTEMPTY; | |
263 | ||
264 | if (ext2_empty_dir(inode)) { | |
265 | err = ext2_unlink(dir, dentry); | |
266 | if (!err) { | |
267 | inode->i_size = 0; | |
a513b035 AD |
268 | inode_dec_link_count(inode); |
269 | inode_dec_link_count(dir); | |
1da177e4 LT |
270 | } |
271 | } | |
272 | return err; | |
273 | } | |
274 | ||
275 | static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry, | |
276 | struct inode * new_dir, struct dentry * new_dentry ) | |
277 | { | |
278 | struct inode * old_inode = old_dentry->d_inode; | |
279 | struct inode * new_inode = new_dentry->d_inode; | |
280 | struct page * dir_page = NULL; | |
281 | struct ext2_dir_entry_2 * dir_de = NULL; | |
282 | struct page * old_page; | |
283 | struct ext2_dir_entry_2 * old_de; | |
284 | int err = -ENOENT; | |
285 | ||
a9885444 | 286 | old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page); |
1da177e4 LT |
287 | if (!old_de) |
288 | goto out; | |
289 | ||
290 | if (S_ISDIR(old_inode->i_mode)) { | |
291 | err = -EIO; | |
292 | dir_de = ext2_dotdot(old_inode, &dir_page); | |
293 | if (!dir_de) | |
294 | goto out_old; | |
295 | } | |
296 | ||
297 | if (new_inode) { | |
298 | struct page *new_page; | |
299 | struct ext2_dir_entry_2 *new_de; | |
300 | ||
301 | err = -ENOTEMPTY; | |
302 | if (dir_de && !ext2_empty_dir (new_inode)) | |
303 | goto out_dir; | |
304 | ||
305 | err = -ENOENT; | |
a9885444 | 306 | new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page); |
1da177e4 LT |
307 | if (!new_de) |
308 | goto out_dir; | |
a513b035 | 309 | inode_inc_link_count(old_inode); |
1da177e4 LT |
310 | ext2_set_link(new_dir, new_de, new_page, old_inode); |
311 | new_inode->i_ctime = CURRENT_TIME_SEC; | |
312 | if (dir_de) | |
9a53c3a7 | 313 | drop_nlink(new_inode); |
a513b035 | 314 | inode_dec_link_count(new_inode); |
1da177e4 LT |
315 | } else { |
316 | if (dir_de) { | |
317 | err = -EMLINK; | |
318 | if (new_dir->i_nlink >= EXT2_LINK_MAX) | |
319 | goto out_dir; | |
320 | } | |
a513b035 | 321 | inode_inc_link_count(old_inode); |
1da177e4 LT |
322 | err = ext2_add_link(new_dentry, old_inode); |
323 | if (err) { | |
a513b035 | 324 | inode_dec_link_count(old_inode); |
1da177e4 LT |
325 | goto out_dir; |
326 | } | |
327 | if (dir_de) | |
a513b035 | 328 | inode_inc_link_count(new_dir); |
1da177e4 LT |
329 | } |
330 | ||
331 | /* | |
332 | * Like most other Unix systems, set the ctime for inodes on a | |
333 | * rename. | |
a513b035 | 334 | * inode_dec_link_count() will mark the inode dirty. |
1da177e4 LT |
335 | */ |
336 | old_inode->i_ctime = CURRENT_TIME_SEC; | |
337 | ||
338 | ext2_delete_entry (old_de, old_page); | |
a513b035 | 339 | inode_dec_link_count(old_inode); |
1da177e4 LT |
340 | |
341 | if (dir_de) { | |
342 | ext2_set_link(old_inode, dir_de, dir_page, new_dir); | |
a513b035 | 343 | inode_dec_link_count(old_dir); |
1da177e4 LT |
344 | } |
345 | return 0; | |
346 | ||
347 | ||
348 | out_dir: | |
349 | if (dir_de) { | |
350 | kunmap(dir_page); | |
351 | page_cache_release(dir_page); | |
352 | } | |
353 | out_old: | |
354 | kunmap(old_page); | |
355 | page_cache_release(old_page); | |
356 | out: | |
357 | return err; | |
358 | } | |
359 | ||
754661f1 | 360 | const struct inode_operations ext2_dir_inode_operations = { |
1da177e4 LT |
361 | .create = ext2_create, |
362 | .lookup = ext2_lookup, | |
363 | .link = ext2_link, | |
364 | .unlink = ext2_unlink, | |
365 | .symlink = ext2_symlink, | |
366 | .mkdir = ext2_mkdir, | |
367 | .rmdir = ext2_rmdir, | |
368 | .mknod = ext2_mknod, | |
369 | .rename = ext2_rename, | |
370 | #ifdef CONFIG_EXT2_FS_XATTR | |
371 | .setxattr = generic_setxattr, | |
372 | .getxattr = generic_getxattr, | |
373 | .listxattr = ext2_listxattr, | |
374 | .removexattr = generic_removexattr, | |
375 | #endif | |
376 | .setattr = ext2_setattr, | |
377 | .permission = ext2_permission, | |
378 | }; | |
379 | ||
754661f1 | 380 | const struct inode_operations ext2_special_inode_operations = { |
1da177e4 LT |
381 | #ifdef CONFIG_EXT2_FS_XATTR |
382 | .setxattr = generic_setxattr, | |
383 | .getxattr = generic_getxattr, | |
384 | .listxattr = ext2_listxattr, | |
385 | .removexattr = generic_removexattr, | |
386 | #endif | |
387 | .setattr = ext2_setattr, | |
388 | .permission = ext2_permission, | |
389 | }; |