blob: d34843925b23f17485bb24114439b81164826122 [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"
38
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) {
Al Viro41080b52008-12-30 01:52:35 -050043 unlock_new_inode(inode);
Al Viro8fc37ec2012-07-19 09:18:15 +040044 d_instantiate(dentry, 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
Al Viro00cd8dd2012-06-10 17:13:09 -040057static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -070058{
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);
Al Viroa9049372011-07-08 21:20:11 -040069 if (inode == ERR_PTR(-ESTALE)) {
70 ext2_error(dir->i_sb, __func__,
71 "deleted inode referenced: %lu",
72 (unsigned long) ino);
73 return ERR_PTR(-EIO);
Bryan Donlan4d6c13f2009-06-30 11:41:24 -070074 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 }
Pekka Enberg082a05c2006-01-14 13:21:07 -080076 return d_splice_alias(inode, dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -070077}
78
79struct dentry *ext2_get_parent(struct dentry *child)
80{
Linus Torvalds26fe5752012-05-10 13:14:12 -070081 struct qstr dotdot = QSTR_INIT("..", 2);
David Howells2b0143b2015-03-17 22:25:59 +000082 unsigned long ino = ext2_inode_by_name(d_inode(child), &dotdot);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 if (!ino)
84 return ERR_PTR(-ENOENT);
David Howells2b0143b2015-03-17 22:25:59 +000085 return d_obtain_alias(ext2_iget(d_inode(child)->i_sb, ino));
Linus Torvalds1da177e2005-04-16 15:20:36 -070086}
87
88/*
89 * By the time this is called, we already have created
90 * the directory cache entry for the new file, but it
91 * is so far negative - it has no inode.
92 *
93 * If the create succeeds, we fill in the inode information
94 * with d_instantiate().
95 */
Al Viroebfc3b42012-06-10 18:05:36 -040096static int ext2_create (struct inode * dir, struct dentry * dentry, umode_t mode, bool excl)
Linus Torvalds1da177e2005-04-16 15:20:36 -070097{
Christoph Hellwig907f4552010-03-03 09:05:06 -050098 struct inode *inode;
Jan Karac2edb302015-06-29 16:08:45 +020099 int err;
Christoph Hellwig907f4552010-03-03 09:05:06 -0500100
Jan Karac2edb302015-06-29 16:08:45 +0200101 err = dquot_initialize(dir);
102 if (err)
103 return err;
Christoph Hellwig907f4552010-03-03 09:05:06 -0500104
Eric Paris2a7dba32011-02-01 11:05:39 -0500105 inode = ext2_new_inode(dir, mode, &dentry->d_name);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500106 if (IS_ERR(inode))
107 return PTR_ERR(inode);
108
109 inode->i_op = &ext2_file_inode_operations;
Boaz Harroshbe64f882015-04-15 16:15:17 -0700110 if (test_opt(inode->i_sb, NOBH)) {
Christoph Hellwig907f4552010-03-03 09:05:06 -0500111 inode->i_mapping->a_ops = &ext2_nobh_aops;
112 inode->i_fop = &ext2_file_operations;
113 } else {
114 inode->i_mapping->a_ops = &ext2_aops;
115 inode->i_fop = &ext2_file_operations;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 }
Christoph Hellwig907f4552010-03-03 09:05:06 -0500117 mark_inode_dirty(inode);
118 return ext2_add_nondir(dentry, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119}
120
Al Viro60545d02013-06-07 01:20:27 -0400121static int ext2_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
122{
123 struct inode *inode = ext2_new_inode(dir, mode, NULL);
124 if (IS_ERR(inode))
125 return PTR_ERR(inode);
126
127 inode->i_op = &ext2_file_inode_operations;
Boaz Harroshbe64f882015-04-15 16:15:17 -0700128 if (test_opt(inode->i_sb, NOBH)) {
Al Viro60545d02013-06-07 01:20:27 -0400129 inode->i_mapping->a_ops = &ext2_nobh_aops;
130 inode->i_fop = &ext2_file_operations;
131 } else {
132 inode->i_mapping->a_ops = &ext2_aops;
133 inode->i_fop = &ext2_file_operations;
134 }
135 mark_inode_dirty(inode);
136 d_tmpfile(dentry, inode);
137 unlock_new_inode(inode);
138 return 0;
139}
140
Al Viro1a67aaf2011-07-26 01:52:52 -0400141static int ext2_mknod (struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142{
143 struct inode * inode;
144 int err;
145
Jan Karac2edb302015-06-29 16:08:45 +0200146 err = dquot_initialize(dir);
147 if (err)
148 return err;
Christoph Hellwig907f4552010-03-03 09:05:06 -0500149
Eric Paris2a7dba32011-02-01 11:05:39 -0500150 inode = ext2_new_inode (dir, mode, &dentry->d_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 err = PTR_ERR(inode);
152 if (!IS_ERR(inode)) {
153 init_special_inode(inode, inode->i_mode, rdev);
154#ifdef CONFIG_EXT2_FS_XATTR
155 inode->i_op = &ext2_special_inode_operations;
156#endif
157 mark_inode_dirty(inode);
158 err = ext2_add_nondir(dentry, inode);
159 }
160 return err;
161}
162
163static int ext2_symlink (struct inode * dir, struct dentry * dentry,
164 const char * symname)
165{
166 struct super_block * sb = dir->i_sb;
167 int err = -ENAMETOOLONG;
168 unsigned l = strlen(symname)+1;
169 struct inode * inode;
170
171 if (l > sb->s_blocksize)
172 goto out;
173
Jan Karac2edb302015-06-29 16:08:45 +0200174 err = dquot_initialize(dir);
175 if (err)
176 goto out;
Christoph Hellwig907f4552010-03-03 09:05:06 -0500177
Eric Paris2a7dba32011-02-01 11:05:39 -0500178 inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO, &dentry->d_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 err = PTR_ERR(inode);
180 if (IS_ERR(inode))
181 goto out;
182
183 if (l > sizeof (EXT2_I(inode)->i_data)) {
184 /* slow symlink */
185 inode->i_op = &ext2_symlink_inode_operations;
Al Viro21fc61c2015-11-17 01:07:57 -0500186 inode_nohighmem(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 if (test_opt(inode->i_sb, NOBH))
188 inode->i_mapping->a_ops = &ext2_nobh_aops;
189 else
190 inode->i_mapping->a_ops = &ext2_aops;
191 err = page_symlink(inode, symname, l);
192 if (err)
193 goto out_fail;
194 } else {
195 /* fast symlink */
196 inode->i_op = &ext2_fast_symlink_inode_operations;
Al Virocbe0fa32015-05-02 10:02:46 -0400197 inode->i_link = (char*)EXT2_I(inode)->i_data;
198 memcpy(inode->i_link, symname, l);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 inode->i_size = l-1;
200 }
201 mark_inode_dirty(inode);
202
203 err = ext2_add_nondir(dentry, inode);
204out:
205 return err;
206
207out_fail:
Alexey Dobriyana513b032006-03-23 03:00:53 -0800208 inode_dec_link_count(inode);
Al Viro41080b52008-12-30 01:52:35 -0500209 unlock_new_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 iput (inode);
211 goto out;
212}
213
214static int ext2_link (struct dentry * old_dentry, struct inode * dir,
215 struct dentry *dentry)
216{
David Howells2b0143b2015-03-17 22:25:59 +0000217 struct inode *inode = d_inode(old_dentry);
Al Viro41080b52008-12-30 01:52:35 -0500218 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
Jan Karac2edb302015-06-29 16:08:45 +0200220 err = dquot_initialize(dir);
221 if (err)
222 return err;
Christoph Hellwig907f4552010-03-03 09:05:06 -0500223
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 inode->i_ctime = CURRENT_TIME_SEC;
Alexey Dobriyana513b032006-03-23 03:00:53 -0800225 inode_inc_link_count(inode);
Al Viro7de9c6ee2010-10-23 11:11:40 -0400226 ihold(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227
Al Viro41080b52008-12-30 01:52:35 -0500228 err = ext2_add_link(dentry, inode);
229 if (!err) {
230 d_instantiate(dentry, inode);
231 return 0;
232 }
233 inode_dec_link_count(inode);
234 iput(inode);
235 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236}
237
Al Viro18bb1db2011-07-26 01:41:39 -0400238static int ext2_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239{
240 struct inode * inode;
Al Viro8de52772012-02-06 12:45:27 -0500241 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242
Jan Karac2edb302015-06-29 16:08:45 +0200243 err = dquot_initialize(dir);
244 if (err)
245 return err;
Christoph Hellwig907f4552010-03-03 09:05:06 -0500246
Alexey Dobriyana513b032006-03-23 03:00:53 -0800247 inode_inc_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248
Eric Paris2a7dba32011-02-01 11:05:39 -0500249 inode = ext2_new_inode(dir, S_IFDIR | mode, &dentry->d_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 err = PTR_ERR(inode);
251 if (IS_ERR(inode))
252 goto out_dir;
253
254 inode->i_op = &ext2_dir_inode_operations;
255 inode->i_fop = &ext2_dir_operations;
256 if (test_opt(inode->i_sb, NOBH))
257 inode->i_mapping->a_ops = &ext2_nobh_aops;
258 else
259 inode->i_mapping->a_ops = &ext2_aops;
260
Alexey Dobriyana513b032006-03-23 03:00:53 -0800261 inode_inc_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
263 err = ext2_make_empty(inode, dir);
264 if (err)
265 goto out_fail;
266
267 err = ext2_add_link(dentry, inode);
268 if (err)
269 goto out_fail;
270
Al Viro41080b52008-12-30 01:52:35 -0500271 unlock_new_inode(inode);
Al Viro8fc37ec2012-07-19 09:18:15 +0400272 d_instantiate(dentry, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273out:
274 return err;
275
276out_fail:
Alexey Dobriyana513b032006-03-23 03:00:53 -0800277 inode_dec_link_count(inode);
278 inode_dec_link_count(inode);
Al Viro41080b52008-12-30 01:52:35 -0500279 unlock_new_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 iput(inode);
281out_dir:
Alexey Dobriyana513b032006-03-23 03:00:53 -0800282 inode_dec_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 goto out;
284}
285
286static int ext2_unlink(struct inode * dir, struct dentry *dentry)
287{
David Howells2b0143b2015-03-17 22:25:59 +0000288 struct inode * inode = d_inode(dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 struct ext2_dir_entry_2 * de;
290 struct page * page;
Jan Karac2edb302015-06-29 16:08:45 +0200291 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292
Jan Karac2edb302015-06-29 16:08:45 +0200293 err = dquot_initialize(dir);
294 if (err)
295 goto out;
Christoph Hellwig907f4552010-03-03 09:05:06 -0500296
Al Viroa9885442008-08-24 07:28:39 -0400297 de = ext2_find_entry (dir, &dentry->d_name, &page);
Jan Karac2edb302015-06-29 16:08:45 +0200298 if (!de) {
299 err = -ENOENT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 goto out;
Jan Karac2edb302015-06-29 16:08:45 +0200301 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302
303 err = ext2_delete_entry (de, page);
304 if (err)
305 goto out;
306
307 inode->i_ctime = dir->i_ctime;
Alexey Dobriyana513b032006-03-23 03:00:53 -0800308 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 err = 0;
310out:
311 return err;
312}
313
314static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
315{
David Howells2b0143b2015-03-17 22:25:59 +0000316 struct inode * inode = d_inode(dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 int err = -ENOTEMPTY;
318
319 if (ext2_empty_dir(inode)) {
320 err = ext2_unlink(dir, dentry);
321 if (!err) {
322 inode->i_size = 0;
Alexey Dobriyana513b032006-03-23 03:00:53 -0800323 inode_dec_link_count(inode);
324 inode_dec_link_count(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 }
326 }
327 return err;
328}
329
330static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
331 struct inode * new_dir, struct dentry * new_dentry )
332{
David Howells2b0143b2015-03-17 22:25:59 +0000333 struct inode * old_inode = d_inode(old_dentry);
334 struct inode * new_inode = d_inode(new_dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 struct page * dir_page = NULL;
336 struct ext2_dir_entry_2 * dir_de = NULL;
337 struct page * old_page;
338 struct ext2_dir_entry_2 * old_de;
Jan Karac2edb302015-06-29 16:08:45 +0200339 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340
Jan Karac2edb302015-06-29 16:08:45 +0200341 err = dquot_initialize(old_dir);
342 if (err)
343 goto out;
344
345 err = dquot_initialize(new_dir);
346 if (err)
347 goto out;
Christoph Hellwig907f4552010-03-03 09:05:06 -0500348
Al Viroa9885442008-08-24 07:28:39 -0400349 old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
Jan Karac2edb302015-06-29 16:08:45 +0200350 if (!old_de) {
351 err = -ENOENT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 goto out;
Jan Karac2edb302015-06-29 16:08:45 +0200353 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354
355 if (S_ISDIR(old_inode->i_mode)) {
356 err = -EIO;
357 dir_de = ext2_dotdot(old_inode, &dir_page);
358 if (!dir_de)
359 goto out_old;
360 }
361
362 if (new_inode) {
363 struct page *new_page;
364 struct ext2_dir_entry_2 *new_de;
365
366 err = -ENOTEMPTY;
367 if (dir_de && !ext2_empty_dir (new_inode))
368 goto out_dir;
369
370 err = -ENOENT;
Al Viroa9885442008-08-24 07:28:39 -0400371 new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 if (!new_de)
373 goto out_dir;
Jan Kara39fe7552009-06-17 16:26:20 -0700374 ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 new_inode->i_ctime = CURRENT_TIME_SEC;
376 if (dir_de)
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700377 drop_nlink(new_inode);
Alexey Dobriyana513b032006-03-23 03:00:53 -0800378 inode_dec_link_count(new_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 err = ext2_add_link(new_dentry, old_inode);
Josh Hunte8a80c62011-02-24 11:48:22 +0100381 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 goto out_dir;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 if (dir_de)
Alexey Dobriyana513b032006-03-23 03:00:53 -0800384 inode_inc_link_count(new_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 }
386
387 /*
388 * Like most other Unix systems, set the ctime for inodes on a
389 * rename.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 */
391 old_inode->i_ctime = CURRENT_TIME_SEC;
Josh Hunte8a80c62011-02-24 11:48:22 +0100392 mark_inode_dirty(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393
394 ext2_delete_entry (old_de, old_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395
396 if (dir_de) {
Jan Kara39fe7552009-06-17 16:26:20 -0700397 if (old_dir != new_dir)
398 ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
Nicolas Pitre9de68862009-09-05 00:25:37 -0400399 else {
400 kunmap(dir_page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300401 put_page(dir_page);
Nicolas Pitre9de68862009-09-05 00:25:37 -0400402 }
Alexey Dobriyana513b032006-03-23 03:00:53 -0800403 inode_dec_link_count(old_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 }
405 return 0;
406
407
408out_dir:
409 if (dir_de) {
410 kunmap(dir_page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300411 put_page(dir_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 }
413out_old:
414 kunmap(old_page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300415 put_page(old_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416out:
417 return err;
418}
419
Arjan van de Ven754661f2007-02-12 00:55:38 -0800420const struct inode_operations ext2_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 .create = ext2_create,
422 .lookup = ext2_lookup,
423 .link = ext2_link,
424 .unlink = ext2_unlink,
425 .symlink = ext2_symlink,
426 .mkdir = ext2_mkdir,
427 .rmdir = ext2_rmdir,
428 .mknod = ext2_mknod,
429 .rename = ext2_rename,
430#ifdef CONFIG_EXT2_FS_XATTR
431 .setxattr = generic_setxattr,
432 .getxattr = generic_getxattr,
433 .listxattr = ext2_listxattr,
434 .removexattr = generic_removexattr,
435#endif
436 .setattr = ext2_setattr,
Christoph Hellwig4e34e712011-07-23 17:37:31 +0200437 .get_acl = ext2_get_acl,
Christoph Hellwig64e178a2013-12-20 05:16:44 -0800438 .set_acl = ext2_set_acl,
Al Viro60545d02013-06-07 01:20:27 -0400439 .tmpfile = ext2_tmpfile,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440};
441
Arjan van de Ven754661f2007-02-12 00:55:38 -0800442const struct inode_operations ext2_special_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443#ifdef CONFIG_EXT2_FS_XATTR
444 .setxattr = generic_setxattr,
445 .getxattr = generic_getxattr,
446 .listxattr = ext2_listxattr,
447 .removexattr = generic_removexattr,
448#endif
449 .setattr = ext2_setattr,
Christoph Hellwig4e34e712011-07-23 17:37:31 +0200450 .get_acl = ext2_get_acl,
Christoph Hellwig64e178a2013-12-20 05:16:44 -0800451 .set_acl = ext2_set_acl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452};