1 // SPDX-License-Identifier: GPL-2.0
3 * linux/fs/ext2/namei.c
5 * Rewrite to pagecache. Almost all code had been changed, so blame me
6 * if the things go wrong. Please, send bug reports to
7 * viro@parcelfarce.linux.theplanet.co.uk
9 * Stuff here is basically a glue between the VFS and generic UNIXish
10 * filesystem that keeps everything in pagecache. All knowledge of the
11 * directory layout is in fs/ext2/dir.c - it turned out to be easily separatable
12 * and it's easier to debug that way. In principle we might want to
13 * generalize that a bit and turn it into a library. Or not.
15 * The only non-static object here is ext2_dir_inode_operations.
17 * TODO: get rid of kmap() use, add readahead.
19 * Copyright (C) 1992, 1993, 1994, 1995
20 * Remy Card (card@masi.ibp.fr)
21 * Laboratoire MASI - Institut Blaise Pascal
22 * Universite Pierre et Marie Curie (Paris VI)
26 * linux/fs/minix/namei.c
28 * Copyright (C) 1991, 1992 Linus Torvalds
30 * Big-endian to little-endian byte-swapping/bitmaps by
31 * David S. Miller (davem@caip.rutgers.edu), 1995
34 #include <linux/pagemap.h>
35 #include <linux/quotaops.h>
40 static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode)
42 int err = ext2_add_link(dentry, inode);
44 d_instantiate_new(dentry, inode);
47 inode_dec_link_count(inode);
48 discard_new_inode(inode);
56 static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
62 if (dentry->d_name.len > EXT2_NAME_LEN)
63 return ERR_PTR(-ENAMETOOLONG);
65 res = ext2_inode_by_name(dir, &dentry->d_name, &ino);
71 inode = ext2_iget(dir->i_sb, ino);
72 if (inode == ERR_PTR(-ESTALE)) {
73 ext2_error(dir->i_sb, __func__,
74 "deleted inode referenced: %lu",
79 return d_splice_alias(inode, dentry);
82 struct dentry *ext2_get_parent(struct dentry *child)
84 struct qstr dotdot = QSTR_INIT("..", 2);
88 res = ext2_inode_by_name(d_inode(child), &dotdot, &ino);
92 return d_obtain_alias(ext2_iget(child->d_sb, ino));
96 * By the time this is called, we already have created
97 * the directory cache entry for the new file, but it
98 * is so far negative - it has no inode.
100 * If the create succeeds, we fill in the inode information
101 * with d_instantiate().
103 static int ext2_create (struct user_namespace * mnt_userns,
104 struct inode * dir, struct dentry * dentry,
105 umode_t mode, bool excl)
110 err = dquot_initialize(dir);
114 inode = ext2_new_inode(dir, mode, &dentry->d_name);
116 return PTR_ERR(inode);
118 ext2_set_file_ops(inode);
119 mark_inode_dirty(inode);
120 return ext2_add_nondir(dentry, inode);
123 static int ext2_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
124 struct dentry *dentry, umode_t mode)
126 struct inode *inode = ext2_new_inode(dir, mode, NULL);
128 return PTR_ERR(inode);
130 ext2_set_file_ops(inode);
131 mark_inode_dirty(inode);
132 d_tmpfile(dentry, inode);
133 unlock_new_inode(inode);
137 static int ext2_mknod (struct user_namespace * mnt_userns, struct inode * dir,
138 struct dentry *dentry, umode_t mode, dev_t rdev)
140 struct inode * inode;
143 err = dquot_initialize(dir);
147 inode = ext2_new_inode (dir, mode, &dentry->d_name);
148 err = PTR_ERR(inode);
149 if (!IS_ERR(inode)) {
150 init_special_inode(inode, inode->i_mode, rdev);
151 inode->i_op = &ext2_special_inode_operations;
152 mark_inode_dirty(inode);
153 err = ext2_add_nondir(dentry, inode);
158 static int ext2_symlink (struct user_namespace * mnt_userns, struct inode * dir,
159 struct dentry * dentry, const char * symname)
161 struct super_block * sb = dir->i_sb;
162 int err = -ENAMETOOLONG;
163 unsigned l = strlen(symname)+1;
164 struct inode * inode;
166 if (l > sb->s_blocksize)
169 err = dquot_initialize(dir);
173 inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO, &dentry->d_name);
174 err = PTR_ERR(inode);
178 if (l > sizeof (EXT2_I(inode)->i_data)) {
180 inode->i_op = &ext2_symlink_inode_operations;
181 inode_nohighmem(inode);
182 if (test_opt(inode->i_sb, NOBH))
183 inode->i_mapping->a_ops = &ext2_nobh_aops;
185 inode->i_mapping->a_ops = &ext2_aops;
186 err = page_symlink(inode, symname, l);
191 inode->i_op = &ext2_fast_symlink_inode_operations;
192 inode->i_link = (char*)EXT2_I(inode)->i_data;
193 memcpy(inode->i_link, symname, l);
196 mark_inode_dirty(inode);
198 err = ext2_add_nondir(dentry, inode);
203 inode_dec_link_count(inode);
204 discard_new_inode(inode);
208 static int ext2_link (struct dentry * old_dentry, struct inode * dir,
209 struct dentry *dentry)
211 struct inode *inode = d_inode(old_dentry);
214 err = dquot_initialize(dir);
218 inode->i_ctime = current_time(inode);
219 inode_inc_link_count(inode);
222 err = ext2_add_link(dentry, inode);
224 d_instantiate(dentry, inode);
227 inode_dec_link_count(inode);
232 static int ext2_mkdir(struct user_namespace * mnt_userns,
233 struct inode * dir, struct dentry * dentry, umode_t mode)
235 struct inode * inode;
238 err = dquot_initialize(dir);
242 inode_inc_link_count(dir);
244 inode = ext2_new_inode(dir, S_IFDIR | mode, &dentry->d_name);
245 err = PTR_ERR(inode);
249 inode->i_op = &ext2_dir_inode_operations;
250 inode->i_fop = &ext2_dir_operations;
251 if (test_opt(inode->i_sb, NOBH))
252 inode->i_mapping->a_ops = &ext2_nobh_aops;
254 inode->i_mapping->a_ops = &ext2_aops;
256 inode_inc_link_count(inode);
258 err = ext2_make_empty(inode, dir);
262 err = ext2_add_link(dentry, inode);
266 d_instantiate_new(dentry, inode);
271 inode_dec_link_count(inode);
272 inode_dec_link_count(inode);
273 discard_new_inode(inode);
275 inode_dec_link_count(dir);
279 static int ext2_unlink(struct inode * dir, struct dentry *dentry)
281 struct inode * inode = d_inode(dentry);
282 struct ext2_dir_entry_2 * de;
287 err = dquot_initialize(dir);
291 de = ext2_find_entry(dir, &dentry->d_name, &page, &page_addr);
297 err = ext2_delete_entry (de, page);
298 ext2_put_page(page, page_addr);
302 inode->i_ctime = dir->i_ctime;
303 inode_dec_link_count(inode);
309 static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
311 struct inode * inode = d_inode(dentry);
312 int err = -ENOTEMPTY;
314 if (ext2_empty_dir(inode)) {
315 err = ext2_unlink(dir, dentry);
318 inode_dec_link_count(inode);
319 inode_dec_link_count(dir);
325 static int ext2_rename (struct user_namespace * mnt_userns,
326 struct inode * old_dir, struct dentry * old_dentry,
327 struct inode * new_dir, struct dentry * new_dentry,
330 struct inode * old_inode = d_inode(old_dentry);
331 struct inode * new_inode = d_inode(new_dentry);
332 struct page * dir_page = NULL;
334 struct ext2_dir_entry_2 * dir_de = NULL;
335 struct page * old_page;
337 struct ext2_dir_entry_2 * old_de;
340 if (flags & ~RENAME_NOREPLACE)
343 err = dquot_initialize(old_dir);
347 err = dquot_initialize(new_dir);
351 old_de = ext2_find_entry(old_dir, &old_dentry->d_name, &old_page,
353 if (IS_ERR(old_de)) {
354 err = PTR_ERR(old_de);
358 if (S_ISDIR(old_inode->i_mode)) {
360 dir_de = ext2_dotdot(old_inode, &dir_page, &dir_page_addr);
367 struct page *new_page;
368 struct ext2_dir_entry_2 *new_de;
371 if (dir_de && !ext2_empty_dir (new_inode))
374 new_de = ext2_find_entry(new_dir, &new_dentry->d_name,
375 &new_page, &page_addr);
376 if (IS_ERR(new_de)) {
377 err = PTR_ERR(new_de);
380 ext2_set_link(new_dir, new_de, new_page, page_addr, old_inode, 1);
381 ext2_put_page(new_page, page_addr);
382 new_inode->i_ctime = current_time(new_inode);
384 drop_nlink(new_inode);
385 inode_dec_link_count(new_inode);
387 err = ext2_add_link(new_dentry, old_inode);
391 inode_inc_link_count(new_dir);
395 * Like most other Unix systems, set the ctime for inodes on a
398 old_inode->i_ctime = current_time(old_inode);
399 mark_inode_dirty(old_inode);
401 ext2_delete_entry(old_de, old_page);
404 if (old_dir != new_dir)
405 ext2_set_link(old_inode, dir_de, dir_page,
406 dir_page_addr, new_dir, 0);
408 ext2_put_page(dir_page, dir_page_addr);
409 inode_dec_link_count(old_dir);
412 ext2_put_page(old_page, old_page_addr);
417 ext2_put_page(dir_page, dir_page_addr);
419 ext2_put_page(old_page, old_page_addr);
424 const struct inode_operations ext2_dir_inode_operations = {
425 .create = ext2_create,
426 .lookup = ext2_lookup,
428 .unlink = ext2_unlink,
429 .symlink = ext2_symlink,
433 .rename = ext2_rename,
434 .listxattr = ext2_listxattr,
435 .getattr = ext2_getattr,
436 .setattr = ext2_setattr,
437 .get_acl = ext2_get_acl,
438 .set_acl = ext2_set_acl,
439 .tmpfile = ext2_tmpfile,
440 .fileattr_get = ext2_fileattr_get,
441 .fileattr_set = ext2_fileattr_set,
444 const struct inode_operations ext2_special_inode_operations = {
445 .listxattr = ext2_listxattr,
446 .getattr = ext2_getattr,
447 .setattr = ext2_setattr,
448 .get_acl = ext2_get_acl,
449 .set_acl = ext2_set_acl,