blob: 71efb0e9a3f2ababa1ae74033e5caa73332fba61 [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>
Christoph Hellwig907f4552010-03-03 09:05:06 -050034#include <linux/quotaops.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include "ext2.h"
36#include "xattr.h"
37#include "acl.h"
Carsten Otte6d791252005-06-23 22:05:26 -070038#include "xip.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
Linus Torvalds1da177e2005-04-16 15:20:36 -070040static 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);
Al Viro41080b52008-12-30 01:52:35 -050045 unlock_new_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 return 0;
47 }
Alexey Dobriyana513b032006-03-23 03:00:53 -080048 inode_dec_link_count(inode);
Al Viro41080b52008-12-30 01:52:35 -050049 unlock_new_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 iput(inode);
51 return err;
52}
53
54/*
55 * Methods themselves.
56 */
57
58static 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
Al Viroa9885442008-08-24 07:28:39 -040066 ino = ext2_inode_by_name(dir, &dentry->d_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 inode = NULL;
68 if (ino) {
David Howells52fcf702008-02-07 00:15:35 -080069 inode = ext2_iget(dir->i_sb, ino);
Bryan Donlan4d6c13f2009-06-30 11:41:24 -070070 if (unlikely(IS_ERR(inode))) {
71 if (PTR_ERR(inode) == -ESTALE) {
72 ext2_error(dir->i_sb, __func__,
73 "deleted inode referenced: %lu",
Heiko Carstensa4255e42009-09-22 16:48:01 -070074 (unsigned long) ino);
Bryan Donlan4d6c13f2009-06-30 11:41:24 -070075 return ERR_PTR(-EIO);
76 } else {
77 return ERR_CAST(inode);
78 }
79 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 }
Pekka Enberg082a05c2006-01-14 13:21:07 -080081 return d_splice_alias(inode, dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082}
83
84struct dentry *ext2_get_parent(struct dentry *child)
85{
Al Viroa9885442008-08-24 07:28:39 -040086 struct qstr dotdot = {.name = "..", .len = 2};
87 unsigned long ino = ext2_inode_by_name(child->d_inode, &dotdot);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 if (!ino)
89 return ERR_PTR(-ENOENT);
Christoph Hellwig44003722008-08-11 15:49:04 +020090 return d_obtain_alias(ext2_iget(child->d_inode->i_sb, ino));
Linus Torvalds1da177e2005-04-16 15:20:36 -070091}
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 */
101static int ext2_create (struct inode * dir, struct dentry * dentry, int mode, struct nameidata *nd)
102{
Christoph Hellwig907f4552010-03-03 09:05:06 -0500103 struct inode *inode;
104
Christoph Hellwig871a2932010-03-03 09:05:07 -0500105 dquot_initialize(dir);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500106
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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 }
Christoph Hellwig907f4552010-03-03 09:05:06 -0500122 mark_inode_dirty(inode);
123 return ext2_add_nondir(dentry, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124}
125
126static 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
Christoph Hellwig871a2932010-03-03 09:05:07 -0500134 dquot_initialize(dir);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500135
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 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
149static 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
Christoph Hellwig871a2932010-03-03 09:05:07 -0500160 dquot_initialize(dir);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500161
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 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);
186out:
187 return err;
188
189out_fail:
Alexey Dobriyana513b032006-03-23 03:00:53 -0800190 inode_dec_link_count(inode);
Al Viro41080b52008-12-30 01:52:35 -0500191 unlock_new_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 iput (inode);
193 goto out;
194}
195
196static int ext2_link (struct dentry * old_dentry, struct inode * dir,
197 struct dentry *dentry)
198{
199 struct inode *inode = old_dentry->d_inode;
Al Viro41080b52008-12-30 01:52:35 -0500200 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201
202 if (inode->i_nlink >= EXT2_LINK_MAX)
203 return -EMLINK;
204
Christoph Hellwig871a2932010-03-03 09:05:07 -0500205 dquot_initialize(dir);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500206
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 inode->i_ctime = CURRENT_TIME_SEC;
Alexey Dobriyana513b032006-03-23 03:00:53 -0800208 inode_inc_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 atomic_inc(&inode->i_count);
210
Al Viro41080b52008-12-30 01:52:35 -0500211 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219}
220
221static 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
Christoph Hellwig871a2932010-03-03 09:05:07 -0500229 dquot_initialize(dir);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500230
Alexey Dobriyana513b032006-03-23 03:00:53 -0800231 inode_inc_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232
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
Alexey Dobriyana513b032006-03-23 03:00:53 -0800245 inode_inc_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
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);
Al Viro41080b52008-12-30 01:52:35 -0500256 unlock_new_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257out:
258 return err;
259
260out_fail:
Alexey Dobriyana513b032006-03-23 03:00:53 -0800261 inode_dec_link_count(inode);
262 inode_dec_link_count(inode);
Al Viro41080b52008-12-30 01:52:35 -0500263 unlock_new_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 iput(inode);
265out_dir:
Alexey Dobriyana513b032006-03-23 03:00:53 -0800266 inode_dec_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 goto out;
268}
269
270static 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
Christoph Hellwig871a2932010-03-03 09:05:07 -0500277 dquot_initialize(dir);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500278
Al Viroa9885442008-08-24 07:28:39 -0400279 de = ext2_find_entry (dir, &dentry->d_name, &page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 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;
Alexey Dobriyana513b032006-03-23 03:00:53 -0800288 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 err = 0;
290out:
291 return err;
292}
293
294static 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;
Alexey Dobriyana513b032006-03-23 03:00:53 -0800303 inode_dec_link_count(inode);
304 inode_dec_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 }
306 }
307 return err;
308}
309
310static 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
Christoph Hellwig871a2932010-03-03 09:05:07 -0500321 dquot_initialize(old_dir);
322 dquot_initialize(new_dir);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500323
Al Viroa9885442008-08-24 07:28:39 -0400324 old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 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;
Al Viroa9885442008-08-24 07:28:39 -0400344 new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 if (!new_de)
346 goto out_dir;
Alexey Dobriyana513b032006-03-23 03:00:53 -0800347 inode_inc_link_count(old_inode);
Jan Kara39fe7552009-06-17 16:26:20 -0700348 ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 new_inode->i_ctime = CURRENT_TIME_SEC;
350 if (dir_de)
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700351 drop_nlink(new_inode);
Alexey Dobriyana513b032006-03-23 03:00:53 -0800352 inode_dec_link_count(new_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 } else {
354 if (dir_de) {
355 err = -EMLINK;
356 if (new_dir->i_nlink >= EXT2_LINK_MAX)
357 goto out_dir;
358 }
Alexey Dobriyana513b032006-03-23 03:00:53 -0800359 inode_inc_link_count(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 err = ext2_add_link(new_dentry, old_inode);
361 if (err) {
Alexey Dobriyana513b032006-03-23 03:00:53 -0800362 inode_dec_link_count(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 goto out_dir;
364 }
365 if (dir_de)
Alexey Dobriyana513b032006-03-23 03:00:53 -0800366 inode_inc_link_count(new_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 }
368
369 /*
370 * Like most other Unix systems, set the ctime for inodes on a
371 * rename.
Alexey Dobriyana513b032006-03-23 03:00:53 -0800372 * inode_dec_link_count() will mark the inode dirty.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 */
374 old_inode->i_ctime = CURRENT_TIME_SEC;
375
376 ext2_delete_entry (old_de, old_page);
Alexey Dobriyana513b032006-03-23 03:00:53 -0800377 inode_dec_link_count(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378
379 if (dir_de) {
Jan Kara39fe7552009-06-17 16:26:20 -0700380 if (old_dir != new_dir)
381 ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
Nicolas Pitre9de68862009-09-05 00:25:37 -0400382 else {
383 kunmap(dir_page);
384 page_cache_release(dir_page);
385 }
Alexey Dobriyana513b032006-03-23 03:00:53 -0800386 inode_dec_link_count(old_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 }
388 return 0;
389
390
391out_dir:
392 if (dir_de) {
393 kunmap(dir_page);
394 page_cache_release(dir_page);
395 }
396out_old:
397 kunmap(old_page);
398 page_cache_release(old_page);
399out:
400 return err;
401}
402
Arjan van de Ven754661f2007-02-12 00:55:38 -0800403const struct inode_operations ext2_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 .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,
Linus Torvalds1d5ccd12009-08-28 12:12:24 -0700420 .check_acl = ext2_check_acl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421};
422
Arjan van de Ven754661f2007-02-12 00:55:38 -0800423const struct inode_operations ext2_special_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424#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,
Linus Torvalds1d5ccd12009-08-28 12:12:24 -0700431 .check_acl = ext2_check_acl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432};