blob: 761fde807fc910f7961d494db363c341fa5f2baf [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);
Al Viroa9049372011-07-08 21:20:11 -040070 if (inode == ERR_PTR(-ESTALE)) {
71 ext2_error(dir->i_sb, __func__,
72 "deleted inode referenced: %lu",
73 (unsigned long) ino);
74 return ERR_PTR(-EIO);
Bryan Donlan4d6c13f2009-06-30 11:41:24 -070075 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 }
Pekka Enberg082a05c2006-01-14 13:21:07 -080077 return d_splice_alias(inode, dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -070078}
79
80struct dentry *ext2_get_parent(struct dentry *child)
81{
Al Viroa9885442008-08-24 07:28:39 -040082 struct qstr dotdot = {.name = "..", .len = 2};
83 unsigned long ino = ext2_inode_by_name(child->d_inode, &dotdot);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 if (!ino)
85 return ERR_PTR(-ENOENT);
Christoph Hellwig44003722008-08-11 15:49:04 +020086 return d_obtain_alias(ext2_iget(child->d_inode->i_sb, ino));
Linus Torvalds1da177e2005-04-16 15:20:36 -070087}
88
89/*
90 * By the time this is called, we already have created
91 * the directory cache entry for the new file, but it
92 * is so far negative - it has no inode.
93 *
94 * If the create succeeds, we fill in the inode information
95 * with d_instantiate().
96 */
97static int ext2_create (struct inode * dir, struct dentry * dentry, int mode, struct nameidata *nd)
98{
Christoph Hellwig907f4552010-03-03 09:05:06 -050099 struct inode *inode;
100
Christoph Hellwig871a2932010-03-03 09:05:07 -0500101 dquot_initialize(dir);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500102
Eric Paris2a7dba32011-02-01 11:05:39 -0500103 inode = ext2_new_inode(dir, mode, &dentry->d_name);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500104 if (IS_ERR(inode))
105 return PTR_ERR(inode);
106
107 inode->i_op = &ext2_file_inode_operations;
108 if (ext2_use_xip(inode->i_sb)) {
109 inode->i_mapping->a_ops = &ext2_aops_xip;
110 inode->i_fop = &ext2_xip_file_operations;
111 } else if (test_opt(inode->i_sb, NOBH)) {
112 inode->i_mapping->a_ops = &ext2_nobh_aops;
113 inode->i_fop = &ext2_file_operations;
114 } else {
115 inode->i_mapping->a_ops = &ext2_aops;
116 inode->i_fop = &ext2_file_operations;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 }
Christoph Hellwig907f4552010-03-03 09:05:06 -0500118 mark_inode_dirty(inode);
119 return ext2_add_nondir(dentry, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120}
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
Christoph Hellwig871a2932010-03-03 09:05:07 -0500130 dquot_initialize(dir);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500131
Eric Paris2a7dba32011-02-01 11:05:39 -0500132 inode = ext2_new_inode (dir, mode, &dentry->d_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 err = PTR_ERR(inode);
134 if (!IS_ERR(inode)) {
135 init_special_inode(inode, inode->i_mode, rdev);
136#ifdef CONFIG_EXT2_FS_XATTR
137 inode->i_op = &ext2_special_inode_operations;
138#endif
139 mark_inode_dirty(inode);
140 err = ext2_add_nondir(dentry, inode);
141 }
142 return err;
143}
144
145static int ext2_symlink (struct inode * dir, struct dentry * dentry,
146 const char * symname)
147{
148 struct super_block * sb = dir->i_sb;
149 int err = -ENAMETOOLONG;
150 unsigned l = strlen(symname)+1;
151 struct inode * inode;
152
153 if (l > sb->s_blocksize)
154 goto out;
155
Christoph Hellwig871a2932010-03-03 09:05:07 -0500156 dquot_initialize(dir);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500157
Eric Paris2a7dba32011-02-01 11:05:39 -0500158 inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO, &dentry->d_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 err = PTR_ERR(inode);
160 if (IS_ERR(inode))
161 goto out;
162
163 if (l > sizeof (EXT2_I(inode)->i_data)) {
164 /* slow symlink */
165 inode->i_op = &ext2_symlink_inode_operations;
166 if (test_opt(inode->i_sb, NOBH))
167 inode->i_mapping->a_ops = &ext2_nobh_aops;
168 else
169 inode->i_mapping->a_ops = &ext2_aops;
170 err = page_symlink(inode, symname, l);
171 if (err)
172 goto out_fail;
173 } else {
174 /* fast symlink */
175 inode->i_op = &ext2_fast_symlink_inode_operations;
176 memcpy((char*)(EXT2_I(inode)->i_data),symname,l);
177 inode->i_size = l-1;
178 }
179 mark_inode_dirty(inode);
180
181 err = ext2_add_nondir(dentry, inode);
182out:
183 return err;
184
185out_fail:
Alexey Dobriyana513b032006-03-23 03:00:53 -0800186 inode_dec_link_count(inode);
Al Viro41080b52008-12-30 01:52:35 -0500187 unlock_new_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 iput (inode);
189 goto out;
190}
191
192static int ext2_link (struct dentry * old_dentry, struct inode * dir,
193 struct dentry *dentry)
194{
195 struct inode *inode = old_dentry->d_inode;
Al Viro41080b52008-12-30 01:52:35 -0500196 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197
198 if (inode->i_nlink >= EXT2_LINK_MAX)
199 return -EMLINK;
200
Christoph Hellwig871a2932010-03-03 09:05:07 -0500201 dquot_initialize(dir);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500202
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 inode->i_ctime = CURRENT_TIME_SEC;
Alexey Dobriyana513b032006-03-23 03:00:53 -0800204 inode_inc_link_count(inode);
Al Viro7de9c6ee2010-10-23 11:11:40 -0400205 ihold(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206
Al Viro41080b52008-12-30 01:52:35 -0500207 err = ext2_add_link(dentry, inode);
208 if (!err) {
209 d_instantiate(dentry, inode);
210 return 0;
211 }
212 inode_dec_link_count(inode);
213 iput(inode);
214 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215}
216
217static int ext2_mkdir(struct inode * dir, struct dentry * dentry, int mode)
218{
219 struct inode * inode;
220 int err = -EMLINK;
221
222 if (dir->i_nlink >= EXT2_LINK_MAX)
223 goto out;
224
Christoph Hellwig871a2932010-03-03 09:05:07 -0500225 dquot_initialize(dir);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500226
Alexey Dobriyana513b032006-03-23 03:00:53 -0800227 inode_inc_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228
Eric Paris2a7dba32011-02-01 11:05:39 -0500229 inode = ext2_new_inode(dir, S_IFDIR | mode, &dentry->d_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 err = PTR_ERR(inode);
231 if (IS_ERR(inode))
232 goto out_dir;
233
234 inode->i_op = &ext2_dir_inode_operations;
235 inode->i_fop = &ext2_dir_operations;
236 if (test_opt(inode->i_sb, NOBH))
237 inode->i_mapping->a_ops = &ext2_nobh_aops;
238 else
239 inode->i_mapping->a_ops = &ext2_aops;
240
Alexey Dobriyana513b032006-03-23 03:00:53 -0800241 inode_inc_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242
243 err = ext2_make_empty(inode, dir);
244 if (err)
245 goto out_fail;
246
247 err = ext2_add_link(dentry, inode);
248 if (err)
249 goto out_fail;
250
251 d_instantiate(dentry, inode);
Al Viro41080b52008-12-30 01:52:35 -0500252 unlock_new_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253out:
254 return err;
255
256out_fail:
Alexey Dobriyana513b032006-03-23 03:00:53 -0800257 inode_dec_link_count(inode);
258 inode_dec_link_count(inode);
Al Viro41080b52008-12-30 01:52:35 -0500259 unlock_new_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 iput(inode);
261out_dir:
Alexey Dobriyana513b032006-03-23 03:00:53 -0800262 inode_dec_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 goto out;
264}
265
266static int ext2_unlink(struct inode * dir, struct dentry *dentry)
267{
268 struct inode * inode = dentry->d_inode;
269 struct ext2_dir_entry_2 * de;
270 struct page * page;
271 int err = -ENOENT;
272
Christoph Hellwig871a2932010-03-03 09:05:07 -0500273 dquot_initialize(dir);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500274
Al Viroa9885442008-08-24 07:28:39 -0400275 de = ext2_find_entry (dir, &dentry->d_name, &page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 if (!de)
277 goto out;
278
279 err = ext2_delete_entry (de, page);
280 if (err)
281 goto out;
282
283 inode->i_ctime = dir->i_ctime;
Alexey Dobriyana513b032006-03-23 03:00:53 -0800284 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 err = 0;
286out:
287 return err;
288}
289
290static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
291{
292 struct inode * inode = dentry->d_inode;
293 int err = -ENOTEMPTY;
294
295 if (ext2_empty_dir(inode)) {
296 err = ext2_unlink(dir, dentry);
297 if (!err) {
298 inode->i_size = 0;
Alexey Dobriyana513b032006-03-23 03:00:53 -0800299 inode_dec_link_count(inode);
300 inode_dec_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 }
302 }
303 return err;
304}
305
306static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
307 struct inode * new_dir, struct dentry * new_dentry )
308{
309 struct inode * old_inode = old_dentry->d_inode;
310 struct inode * new_inode = new_dentry->d_inode;
311 struct page * dir_page = NULL;
312 struct ext2_dir_entry_2 * dir_de = NULL;
313 struct page * old_page;
314 struct ext2_dir_entry_2 * old_de;
315 int err = -ENOENT;
316
Christoph Hellwig871a2932010-03-03 09:05:07 -0500317 dquot_initialize(old_dir);
318 dquot_initialize(new_dir);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500319
Al Viroa9885442008-08-24 07:28:39 -0400320 old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 if (!old_de)
322 goto out;
323
324 if (S_ISDIR(old_inode->i_mode)) {
325 err = -EIO;
326 dir_de = ext2_dotdot(old_inode, &dir_page);
327 if (!dir_de)
328 goto out_old;
329 }
330
331 if (new_inode) {
332 struct page *new_page;
333 struct ext2_dir_entry_2 *new_de;
334
335 err = -ENOTEMPTY;
336 if (dir_de && !ext2_empty_dir (new_inode))
337 goto out_dir;
338
339 err = -ENOENT;
Al Viroa9885442008-08-24 07:28:39 -0400340 new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 if (!new_de)
342 goto out_dir;
Jan Kara39fe7552009-06-17 16:26:20 -0700343 ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 new_inode->i_ctime = CURRENT_TIME_SEC;
345 if (dir_de)
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700346 drop_nlink(new_inode);
Alexey Dobriyana513b032006-03-23 03:00:53 -0800347 inode_dec_link_count(new_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 } else {
349 if (dir_de) {
350 err = -EMLINK;
351 if (new_dir->i_nlink >= EXT2_LINK_MAX)
352 goto out_dir;
353 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 err = ext2_add_link(new_dentry, old_inode);
Josh Hunte8a80c62011-02-24 11:48:22 +0100355 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 goto out_dir;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 if (dir_de)
Alexey Dobriyana513b032006-03-23 03:00:53 -0800358 inode_inc_link_count(new_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 }
360
361 /*
362 * Like most other Unix systems, set the ctime for inodes on a
363 * rename.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 */
365 old_inode->i_ctime = CURRENT_TIME_SEC;
Josh Hunte8a80c62011-02-24 11:48:22 +0100366 mark_inode_dirty(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367
368 ext2_delete_entry (old_de, old_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369
370 if (dir_de) {
Jan Kara39fe7552009-06-17 16:26:20 -0700371 if (old_dir != new_dir)
372 ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
Nicolas Pitre9de68862009-09-05 00:25:37 -0400373 else {
374 kunmap(dir_page);
375 page_cache_release(dir_page);
376 }
Alexey Dobriyana513b032006-03-23 03:00:53 -0800377 inode_dec_link_count(old_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 }
379 return 0;
380
381
382out_dir:
383 if (dir_de) {
384 kunmap(dir_page);
385 page_cache_release(dir_page);
386 }
387out_old:
388 kunmap(old_page);
389 page_cache_release(old_page);
390out:
391 return err;
392}
393
Arjan van de Ven754661f2007-02-12 00:55:38 -0800394const struct inode_operations ext2_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 .create = ext2_create,
396 .lookup = ext2_lookup,
397 .link = ext2_link,
398 .unlink = ext2_unlink,
399 .symlink = ext2_symlink,
400 .mkdir = ext2_mkdir,
401 .rmdir = ext2_rmdir,
402 .mknod = ext2_mknod,
403 .rename = ext2_rename,
404#ifdef CONFIG_EXT2_FS_XATTR
405 .setxattr = generic_setxattr,
406 .getxattr = generic_getxattr,
407 .listxattr = ext2_listxattr,
408 .removexattr = generic_removexattr,
409#endif
410 .setattr = ext2_setattr,
Christoph Hellwig4e34e712011-07-23 17:37:31 +0200411 .get_acl = ext2_get_acl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412};
413
Arjan van de Ven754661f2007-02-12 00:55:38 -0800414const struct inode_operations ext2_special_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415#ifdef CONFIG_EXT2_FS_XATTR
416 .setxattr = generic_setxattr,
417 .getxattr = generic_getxattr,
418 .listxattr = ext2_listxattr,
419 .removexattr = generic_removexattr,
420#endif
421 .setattr = ext2_setattr,
Christoph Hellwig4e34e712011-07-23 17:37:31 +0200422 .get_acl = ext2_get_acl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423};