blob: 23701f289e985b94e9a9d4024b70a361917d3b25 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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"
Carsten Otte6d791252005-06-23 22:05:26 -070037#include "xip.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
Linus Torvalds1da177e2005-04-16 15:20:36 -070039static 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);
Al Viro41080b52008-12-30 01:52:35 -050044 unlock_new_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 return 0;
46 }
Alexey Dobriyana513b032006-03-23 03:00:53 -080047 inode_dec_link_count(inode);
Al Viro41080b52008-12-30 01:52:35 -050048 unlock_new_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -070049 iput(inode);
50 return err;
51}
52
53/*
54 * Methods themselves.
55 */
56
57static 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
Al Viroa9885442008-08-24 07:28:39 -040065 ino = ext2_inode_by_name(dir, &dentry->d_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 inode = NULL;
67 if (ino) {
David Howells52fcf702008-02-07 00:15:35 -080068 inode = ext2_iget(dir->i_sb, ino);
Bryan Donlan4d6c13f2009-06-30 11:41:24 -070069 if (unlikely(IS_ERR(inode))) {
70 if (PTR_ERR(inode) == -ESTALE) {
71 ext2_error(dir->i_sb, __func__,
72 "deleted inode referenced: %lu",
73 ino);
74 return ERR_PTR(-EIO);
75 } else {
76 return ERR_CAST(inode);
77 }
78 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 }
Pekka Enberg082a05c2006-01-14 13:21:07 -080080 return d_splice_alias(inode, dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081}
82
83struct dentry *ext2_get_parent(struct dentry *child)
84{
Al Viroa9885442008-08-24 07:28:39 -040085 struct qstr dotdot = {.name = "..", .len = 2};
86 unsigned long ino = ext2_inode_by_name(child->d_inode, &dotdot);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 if (!ino)
88 return ERR_PTR(-ENOENT);
Christoph Hellwig44003722008-08-11 15:49:04 +020089 return d_obtain_alias(ext2_iget(child->d_inode->i_sb, ino));
Linus Torvalds1da177e2005-04-16 15:20:36 -070090}
91
92/*
93 * By the time this is called, we already have created
94 * the directory cache entry for the new file, but it
95 * is so far negative - it has no inode.
96 *
97 * If the create succeeds, we fill in the inode information
98 * with d_instantiate().
99 */
100static int ext2_create (struct inode * dir, struct dentry * dentry, int mode, struct nameidata *nd)
101{
102 struct inode * inode = ext2_new_inode (dir, mode);
103 int err = PTR_ERR(inode);
104 if (!IS_ERR(inode)) {
105 inode->i_op = &ext2_file_inode_operations;
Carsten Otte6d791252005-06-23 22:05:26 -0700106 if (ext2_use_xip(inode->i_sb)) {
107 inode->i_mapping->a_ops = &ext2_aops_xip;
108 inode->i_fop = &ext2_xip_file_operations;
109 } else if (test_opt(inode->i_sb, NOBH)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 inode->i_mapping->a_ops = &ext2_nobh_aops;
Carsten Otte6d791252005-06-23 22:05:26 -0700111 inode->i_fop = &ext2_file_operations;
112 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 inode->i_mapping->a_ops = &ext2_aops;
Carsten Otte6d791252005-06-23 22:05:26 -0700114 inode->i_fop = &ext2_file_operations;
115 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 mark_inode_dirty(inode);
117 err = ext2_add_nondir(dentry, inode);
118 }
119 return err;
120}
121
122static int ext2_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
123{
124 struct inode * inode;
125 int err;
126
127 if (!new_valid_dev(rdev))
128 return -EINVAL;
129
130 inode = ext2_new_inode (dir, mode);
131 err = PTR_ERR(inode);
132 if (!IS_ERR(inode)) {
133 init_special_inode(inode, inode->i_mode, rdev);
134#ifdef CONFIG_EXT2_FS_XATTR
135 inode->i_op = &ext2_special_inode_operations;
136#endif
137 mark_inode_dirty(inode);
138 err = ext2_add_nondir(dentry, inode);
139 }
140 return err;
141}
142
143static int ext2_symlink (struct inode * dir, struct dentry * dentry,
144 const char * symname)
145{
146 struct super_block * sb = dir->i_sb;
147 int err = -ENAMETOOLONG;
148 unsigned l = strlen(symname)+1;
149 struct inode * inode;
150
151 if (l > sb->s_blocksize)
152 goto out;
153
154 inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO);
155 err = PTR_ERR(inode);
156 if (IS_ERR(inode))
157 goto out;
158
159 if (l > sizeof (EXT2_I(inode)->i_data)) {
160 /* slow symlink */
161 inode->i_op = &ext2_symlink_inode_operations;
162 if (test_opt(inode->i_sb, NOBH))
163 inode->i_mapping->a_ops = &ext2_nobh_aops;
164 else
165 inode->i_mapping->a_ops = &ext2_aops;
166 err = page_symlink(inode, symname, l);
167 if (err)
168 goto out_fail;
169 } else {
170 /* fast symlink */
171 inode->i_op = &ext2_fast_symlink_inode_operations;
172 memcpy((char*)(EXT2_I(inode)->i_data),symname,l);
173 inode->i_size = l-1;
174 }
175 mark_inode_dirty(inode);
176
177 err = ext2_add_nondir(dentry, inode);
178out:
179 return err;
180
181out_fail:
Alexey Dobriyana513b032006-03-23 03:00:53 -0800182 inode_dec_link_count(inode);
Al Viro41080b52008-12-30 01:52:35 -0500183 unlock_new_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 iput (inode);
185 goto out;
186}
187
188static int ext2_link (struct dentry * old_dentry, struct inode * dir,
189 struct dentry *dentry)
190{
191 struct inode *inode = old_dentry->d_inode;
Al Viro41080b52008-12-30 01:52:35 -0500192 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193
194 if (inode->i_nlink >= EXT2_LINK_MAX)
195 return -EMLINK;
196
197 inode->i_ctime = CURRENT_TIME_SEC;
Alexey Dobriyana513b032006-03-23 03:00:53 -0800198 inode_inc_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 atomic_inc(&inode->i_count);
200
Al Viro41080b52008-12-30 01:52:35 -0500201 err = ext2_add_link(dentry, inode);
202 if (!err) {
203 d_instantiate(dentry, inode);
204 return 0;
205 }
206 inode_dec_link_count(inode);
207 iput(inode);
208 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209}
210
211static int ext2_mkdir(struct inode * dir, struct dentry * dentry, int mode)
212{
213 struct inode * inode;
214 int err = -EMLINK;
215
216 if (dir->i_nlink >= EXT2_LINK_MAX)
217 goto out;
218
Alexey Dobriyana513b032006-03-23 03:00:53 -0800219 inode_inc_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220
221 inode = ext2_new_inode (dir, S_IFDIR | mode);
222 err = PTR_ERR(inode);
223 if (IS_ERR(inode))
224 goto out_dir;
225
226 inode->i_op = &ext2_dir_inode_operations;
227 inode->i_fop = &ext2_dir_operations;
228 if (test_opt(inode->i_sb, NOBH))
229 inode->i_mapping->a_ops = &ext2_nobh_aops;
230 else
231 inode->i_mapping->a_ops = &ext2_aops;
232
Alexey Dobriyana513b032006-03-23 03:00:53 -0800233 inode_inc_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
235 err = ext2_make_empty(inode, dir);
236 if (err)
237 goto out_fail;
238
239 err = ext2_add_link(dentry, inode);
240 if (err)
241 goto out_fail;
242
243 d_instantiate(dentry, inode);
Al Viro41080b52008-12-30 01:52:35 -0500244 unlock_new_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245out:
246 return err;
247
248out_fail:
Alexey Dobriyana513b032006-03-23 03:00:53 -0800249 inode_dec_link_count(inode);
250 inode_dec_link_count(inode);
Al Viro41080b52008-12-30 01:52:35 -0500251 unlock_new_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 iput(inode);
253out_dir:
Alexey Dobriyana513b032006-03-23 03:00:53 -0800254 inode_dec_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 goto out;
256}
257
258static int ext2_unlink(struct inode * dir, struct dentry *dentry)
259{
260 struct inode * inode = dentry->d_inode;
261 struct ext2_dir_entry_2 * de;
262 struct page * page;
263 int err = -ENOENT;
264
Al Viroa9885442008-08-24 07:28:39 -0400265 de = ext2_find_entry (dir, &dentry->d_name, &page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 if (!de)
267 goto out;
268
269 err = ext2_delete_entry (de, page);
270 if (err)
271 goto out;
272
273 inode->i_ctime = dir->i_ctime;
Alexey Dobriyana513b032006-03-23 03:00:53 -0800274 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 err = 0;
276out:
277 return err;
278}
279
280static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
281{
282 struct inode * inode = dentry->d_inode;
283 int err = -ENOTEMPTY;
284
285 if (ext2_empty_dir(inode)) {
286 err = ext2_unlink(dir, dentry);
287 if (!err) {
288 inode->i_size = 0;
Alexey Dobriyana513b032006-03-23 03:00:53 -0800289 inode_dec_link_count(inode);
290 inode_dec_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 }
292 }
293 return err;
294}
295
296static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
297 struct inode * new_dir, struct dentry * new_dentry )
298{
299 struct inode * old_inode = old_dentry->d_inode;
300 struct inode * new_inode = new_dentry->d_inode;
301 struct page * dir_page = NULL;
302 struct ext2_dir_entry_2 * dir_de = NULL;
303 struct page * old_page;
304 struct ext2_dir_entry_2 * old_de;
305 int err = -ENOENT;
306
Al Viroa9885442008-08-24 07:28:39 -0400307 old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 if (!old_de)
309 goto out;
310
311 if (S_ISDIR(old_inode->i_mode)) {
312 err = -EIO;
313 dir_de = ext2_dotdot(old_inode, &dir_page);
314 if (!dir_de)
315 goto out_old;
316 }
317
318 if (new_inode) {
319 struct page *new_page;
320 struct ext2_dir_entry_2 *new_de;
321
322 err = -ENOTEMPTY;
323 if (dir_de && !ext2_empty_dir (new_inode))
324 goto out_dir;
325
326 err = -ENOENT;
Al Viroa9885442008-08-24 07:28:39 -0400327 new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 if (!new_de)
329 goto out_dir;
Alexey Dobriyana513b032006-03-23 03:00:53 -0800330 inode_inc_link_count(old_inode);
Jan Kara39fe7552009-06-17 16:26:20 -0700331 ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 new_inode->i_ctime = CURRENT_TIME_SEC;
333 if (dir_de)
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700334 drop_nlink(new_inode);
Alexey Dobriyana513b032006-03-23 03:00:53 -0800335 inode_dec_link_count(new_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 } else {
337 if (dir_de) {
338 err = -EMLINK;
339 if (new_dir->i_nlink >= EXT2_LINK_MAX)
340 goto out_dir;
341 }
Alexey Dobriyana513b032006-03-23 03:00:53 -0800342 inode_inc_link_count(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 err = ext2_add_link(new_dentry, old_inode);
344 if (err) {
Alexey Dobriyana513b032006-03-23 03:00:53 -0800345 inode_dec_link_count(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 goto out_dir;
347 }
348 if (dir_de)
Alexey Dobriyana513b032006-03-23 03:00:53 -0800349 inode_inc_link_count(new_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 }
351
352 /*
353 * Like most other Unix systems, set the ctime for inodes on a
354 * rename.
Alexey Dobriyana513b032006-03-23 03:00:53 -0800355 * inode_dec_link_count() will mark the inode dirty.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 */
357 old_inode->i_ctime = CURRENT_TIME_SEC;
358
359 ext2_delete_entry (old_de, old_page);
Alexey Dobriyana513b032006-03-23 03:00:53 -0800360 inode_dec_link_count(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361
362 if (dir_de) {
Jan Kara39fe7552009-06-17 16:26:20 -0700363 if (old_dir != new_dir)
364 ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
Nicolas Pitre9de68862009-09-05 00:25:37 -0400365 else {
366 kunmap(dir_page);
367 page_cache_release(dir_page);
368 }
Alexey Dobriyana513b032006-03-23 03:00:53 -0800369 inode_dec_link_count(old_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 }
371 return 0;
372
373
374out_dir:
375 if (dir_de) {
376 kunmap(dir_page);
377 page_cache_release(dir_page);
378 }
379out_old:
380 kunmap(old_page);
381 page_cache_release(old_page);
382out:
383 return err;
384}
385
Arjan van de Ven754661f2007-02-12 00:55:38 -0800386const struct inode_operations ext2_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 .create = ext2_create,
388 .lookup = ext2_lookup,
389 .link = ext2_link,
390 .unlink = ext2_unlink,
391 .symlink = ext2_symlink,
392 .mkdir = ext2_mkdir,
393 .rmdir = ext2_rmdir,
394 .mknod = ext2_mknod,
395 .rename = ext2_rename,
396#ifdef CONFIG_EXT2_FS_XATTR
397 .setxattr = generic_setxattr,
398 .getxattr = generic_getxattr,
399 .listxattr = ext2_listxattr,
400 .removexattr = generic_removexattr,
401#endif
402 .setattr = ext2_setattr,
Linus Torvalds1d5ccd12009-08-28 12:12:24 -0700403 .check_acl = ext2_check_acl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404};
405
Arjan van de Ven754661f2007-02-12 00:55:38 -0800406const struct inode_operations ext2_special_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407#ifdef CONFIG_EXT2_FS_XATTR
408 .setxattr = generic_setxattr,
409 .getxattr = generic_getxattr,
410 .listxattr = ext2_listxattr,
411 .removexattr = generic_removexattr,
412#endif
413 .setattr = ext2_setattr,
Linus Torvalds1d5ccd12009-08-28 12:12:24 -0700414 .check_acl = ext2_check_acl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415};