2 * linux/fs/ext2/namei.c
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
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.
14 * The only non-static object here is ext2_dir_inode_operations.
16 * TODO: get rid of kmap() use, add readahead.
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)
25 * linux/fs/minix/namei.c
27 * Copyright (C) 1991, 1992 Linus Torvalds
29 * Big-endian to little-endian byte-swapping/bitmaps by
30 * David S. Miller (davem@caip.rutgers.edu), 1995
33 #include <linux/pagemap.h>
39 static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode)
41 int err = ext2_add_link(dentry, inode);
43 d_instantiate(dentry, inode);
46 inode_dec_link_count(inode);
55 static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
60 if (dentry->d_name.len > EXT2_NAME_LEN)
61 return ERR_PTR(-ENAMETOOLONG);
63 ino = ext2_inode_by_name(dir, dentry);
66 inode = ext2_iget(dir->i_sb, ino);
68 return ERR_CAST(inode);
70 return d_splice_alias(inode, dentry);
73 struct dentry *ext2_get_parent(struct dentry *child)
78 dotdot.d_name.name = "..";
79 dotdot.d_name.len = 2;
81 ino = ext2_inode_by_name(child->d_inode, &dotdot);
83 return ERR_PTR(-ENOENT);
84 return d_obtain_alias(ext2_iget(child->d_inode->i_sb, ino));
88 * By the time this is called, we already have created
89 * the directory cache entry for the new file, but it
90 * is so far negative - it has no inode.
92 * If the create succeeds, we fill in the inode information
93 * with d_instantiate().
95 static int ext2_create (struct inode * dir, struct dentry * dentry, int mode, struct nameidata *nd)
97 struct inode * inode = ext2_new_inode (dir, mode);
98 int err = PTR_ERR(inode);
100 inode->i_op = &ext2_file_inode_operations;
101 if (ext2_use_xip(inode->i_sb)) {
102 inode->i_mapping->a_ops = &ext2_aops_xip;
103 inode->i_fop = &ext2_xip_file_operations;
104 } else if (test_opt(inode->i_sb, NOBH)) {
105 inode->i_mapping->a_ops = &ext2_nobh_aops;
106 inode->i_fop = &ext2_file_operations;
108 inode->i_mapping->a_ops = &ext2_aops;
109 inode->i_fop = &ext2_file_operations;
111 mark_inode_dirty(inode);
112 err = ext2_add_nondir(dentry, inode);
117 static int ext2_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
119 struct inode * inode;
122 if (!new_valid_dev(rdev))
125 inode = ext2_new_inode (dir, mode);
126 err = PTR_ERR(inode);
127 if (!IS_ERR(inode)) {
128 init_special_inode(inode, inode->i_mode, rdev);
129 #ifdef CONFIG_EXT2_FS_XATTR
130 inode->i_op = &ext2_special_inode_operations;
132 mark_inode_dirty(inode);
133 err = ext2_add_nondir(dentry, inode);
138 static int ext2_symlink (struct inode * dir, struct dentry * dentry,
139 const char * symname)
141 struct super_block * sb = dir->i_sb;
142 int err = -ENAMETOOLONG;
143 unsigned l = strlen(symname)+1;
144 struct inode * inode;
146 if (l > sb->s_blocksize)
149 inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO);
150 err = PTR_ERR(inode);
154 if (l > sizeof (EXT2_I(inode)->i_data)) {
156 inode->i_op = &ext2_symlink_inode_operations;
157 if (test_opt(inode->i_sb, NOBH))
158 inode->i_mapping->a_ops = &ext2_nobh_aops;
160 inode->i_mapping->a_ops = &ext2_aops;
161 err = page_symlink(inode, symname, l);
166 inode->i_op = &ext2_fast_symlink_inode_operations;
167 memcpy((char*)(EXT2_I(inode)->i_data),symname,l);
170 mark_inode_dirty(inode);
172 err = ext2_add_nondir(dentry, inode);
177 inode_dec_link_count(inode);
182 static int ext2_link (struct dentry * old_dentry, struct inode * dir,
183 struct dentry *dentry)
185 struct inode *inode = old_dentry->d_inode;
187 if (inode->i_nlink >= EXT2_LINK_MAX)
190 inode->i_ctime = CURRENT_TIME_SEC;
191 inode_inc_link_count(inode);
192 atomic_inc(&inode->i_count);
194 return ext2_add_nondir(dentry, inode);
197 static int ext2_mkdir(struct inode * dir, struct dentry * dentry, int mode)
199 struct inode * inode;
202 if (dir->i_nlink >= EXT2_LINK_MAX)
205 inode_inc_link_count(dir);
207 inode = ext2_new_inode (dir, S_IFDIR | mode);
208 err = PTR_ERR(inode);
212 inode->i_op = &ext2_dir_inode_operations;
213 inode->i_fop = &ext2_dir_operations;
214 if (test_opt(inode->i_sb, NOBH))
215 inode->i_mapping->a_ops = &ext2_nobh_aops;
217 inode->i_mapping->a_ops = &ext2_aops;
219 inode_inc_link_count(inode);
221 err = ext2_make_empty(inode, dir);
225 err = ext2_add_link(dentry, inode);
229 d_instantiate(dentry, inode);
234 inode_dec_link_count(inode);
235 inode_dec_link_count(inode);
238 inode_dec_link_count(dir);
242 static int ext2_unlink(struct inode * dir, struct dentry *dentry)
244 struct inode * inode = dentry->d_inode;
245 struct ext2_dir_entry_2 * de;
249 de = ext2_find_entry (dir, dentry, &page);
253 err = ext2_delete_entry (de, page);
257 inode->i_ctime = dir->i_ctime;
258 inode_dec_link_count(inode);
264 static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
266 struct inode * inode = dentry->d_inode;
267 int err = -ENOTEMPTY;
269 if (ext2_empty_dir(inode)) {
270 err = ext2_unlink(dir, dentry);
273 inode_dec_link_count(inode);
274 inode_dec_link_count(dir);
280 static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
281 struct inode * new_dir, struct dentry * new_dentry )
283 struct inode * old_inode = old_dentry->d_inode;
284 struct inode * new_inode = new_dentry->d_inode;
285 struct page * dir_page = NULL;
286 struct ext2_dir_entry_2 * dir_de = NULL;
287 struct page * old_page;
288 struct ext2_dir_entry_2 * old_de;
291 old_de = ext2_find_entry (old_dir, old_dentry, &old_page);
295 if (S_ISDIR(old_inode->i_mode)) {
297 dir_de = ext2_dotdot(old_inode, &dir_page);
303 struct page *new_page;
304 struct ext2_dir_entry_2 *new_de;
307 if (dir_de && !ext2_empty_dir (new_inode))
311 new_de = ext2_find_entry (new_dir, new_dentry, &new_page);
314 inode_inc_link_count(old_inode);
315 ext2_set_link(new_dir, new_de, new_page, old_inode);
316 new_inode->i_ctime = CURRENT_TIME_SEC;
318 drop_nlink(new_inode);
319 inode_dec_link_count(new_inode);
323 if (new_dir->i_nlink >= EXT2_LINK_MAX)
326 inode_inc_link_count(old_inode);
327 err = ext2_add_link(new_dentry, old_inode);
329 inode_dec_link_count(old_inode);
333 inode_inc_link_count(new_dir);
337 * Like most other Unix systems, set the ctime for inodes on a
339 * inode_dec_link_count() will mark the inode dirty.
341 old_inode->i_ctime = CURRENT_TIME_SEC;
343 ext2_delete_entry (old_de, old_page);
344 inode_dec_link_count(old_inode);
347 ext2_set_link(old_inode, dir_de, dir_page, new_dir);
348 inode_dec_link_count(old_dir);
356 page_cache_release(dir_page);
360 page_cache_release(old_page);
365 const struct inode_operations ext2_dir_inode_operations = {
366 .create = ext2_create,
367 .lookup = ext2_lookup,
369 .unlink = ext2_unlink,
370 .symlink = ext2_symlink,
374 .rename = ext2_rename,
375 #ifdef CONFIG_EXT2_FS_XATTR
376 .setxattr = generic_setxattr,
377 .getxattr = generic_getxattr,
378 .listxattr = ext2_listxattr,
379 .removexattr = generic_removexattr,
381 .setattr = ext2_setattr,
382 .permission = ext2_permission,
385 const struct inode_operations ext2_special_inode_operations = {
386 #ifdef CONFIG_EXT2_FS_XATTR
387 .setxattr = generic_setxattr,
388 .getxattr = generic_getxattr,
389 .listxattr = ext2_listxattr,
390 .removexattr = generic_removexattr,
392 .setattr = ext2_setattr,
393 .permission = ext2_permission,