1/*
2 *  linux/fs/hfs/dir.c
3 *
4 * Copyright (C) 1995-1997  Paul H. Hargrove
5 * (C) 2003 Ardis Technologies <roman@ardistech.com>
6 * This file may be distributed under the terms of the GNU General Public License.
7 *
8 * This file contains directory-related functions independent of which
9 * scheme is being used to represent forks.
10 *
11 * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
12 */
13
14#include "hfs_fs.h"
15#include "btree.h"
16
17/*
18 * hfs_lookup()
19 */
20static struct dentry *hfs_lookup(struct inode *dir, struct dentry *dentry,
21				 unsigned int flags)
22{
23	hfs_cat_rec rec;
24	struct hfs_find_data fd;
25	struct inode *inode = NULL;
26	int res;
27
28	res = hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
29	if (res)
30		return ERR_PTR(res);
31	hfs_cat_build_key(dir->i_sb, fd.search_key, dir->i_ino, &dentry->d_name);
32	res = hfs_brec_read(&fd, &rec, sizeof(rec));
33	if (res) {
34		if (res != -ENOENT)
35			inode = ERR_PTR(res);
36	} else {
37		inode = hfs_iget(dir->i_sb, &fd.search_key->cat, &rec);
38		if (!inode)
39			inode = ERR_PTR(-EACCES);
40	}
41	hfs_find_exit(&fd);
42	return d_splice_alias(inode, dentry);
43}
44
45/*
46 * hfs_readdir
47 */
48static int hfs_readdir(struct file *file, struct dir_context *ctx)
49{
50	struct inode *inode = file_inode(file);
51	struct super_block *sb = inode->i_sb;
52	int len, err;
53	char strbuf[HFS_MAX_NAMELEN];
54	union hfs_cat_rec entry;
55	struct hfs_find_data fd;
56	struct hfs_readdir_data *rd;
57	u16 type;
58
59	if (ctx->pos >= inode->i_size)
60		return 0;
61
62	err = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
63	if (err)
64		return err;
65	hfs_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
66	err = hfs_brec_find(&fd);
67	if (err)
68		goto out;
69
70	if (ctx->pos == 0) {
71		/* This is completely artificial... */
72		if (!dir_emit_dot(file, ctx))
73			goto out;
74		ctx->pos = 1;
75	}
76	if (ctx->pos == 1) {
77		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
78			err = -EIO;
79			goto out;
80		}
81
82		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
83		if (entry.type != HFS_CDR_THD) {
84			pr_err("bad catalog folder thread\n");
85			err = -EIO;
86			goto out;
87		}
88		//if (fd.entrylength < HFS_MIN_THREAD_SZ) {
89		//	pr_err("truncated catalog thread\n");
90		//	err = -EIO;
91		//	goto out;
92		//}
93		if (!dir_emit(ctx, "..", 2,
94			    be32_to_cpu(entry.thread.ParID), DT_DIR))
95			goto out;
96		ctx->pos = 2;
97	}
98	if (ctx->pos >= inode->i_size)
99		goto out;
100	err = hfs_brec_goto(&fd, ctx->pos - 1);
101	if (err)
102		goto out;
103
104	for (;;) {
105		if (be32_to_cpu(fd.key->cat.ParID) != inode->i_ino) {
106			pr_err("walked past end of dir\n");
107			err = -EIO;
108			goto out;
109		}
110
111		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
112			err = -EIO;
113			goto out;
114		}
115
116		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
117		type = entry.type;
118		len = hfs_mac2asc(sb, strbuf, &fd.key->cat.CName);
119		if (type == HFS_CDR_DIR) {
120			if (fd.entrylength < sizeof(struct hfs_cat_dir)) {
121				pr_err("small dir entry\n");
122				err = -EIO;
123				goto out;
124			}
125			if (!dir_emit(ctx, strbuf, len,
126				    be32_to_cpu(entry.dir.DirID), DT_DIR))
127				break;
128		} else if (type == HFS_CDR_FIL) {
129			if (fd.entrylength < sizeof(struct hfs_cat_file)) {
130				pr_err("small file entry\n");
131				err = -EIO;
132				goto out;
133			}
134			if (!dir_emit(ctx, strbuf, len,
135				    be32_to_cpu(entry.file.FlNum), DT_REG))
136				break;
137		} else {
138			pr_err("bad catalog entry type %d\n", type);
139			err = -EIO;
140			goto out;
141		}
142		ctx->pos++;
143		if (ctx->pos >= inode->i_size)
144			goto out;
145		err = hfs_brec_goto(&fd, 1);
146		if (err)
147			goto out;
148	}
149	rd = file->private_data;
150	if (!rd) {
151		rd = kmalloc(sizeof(struct hfs_readdir_data), GFP_KERNEL);
152		if (!rd) {
153			err = -ENOMEM;
154			goto out;
155		}
156		file->private_data = rd;
157		rd->file = file;
158		spin_lock(&HFS_I(inode)->open_dir_lock);
159		list_add(&rd->list, &HFS_I(inode)->open_dir_list);
160		spin_unlock(&HFS_I(inode)->open_dir_lock);
161	}
162	/*
163	 * Can be done after the list insertion; exclusion with
164	 * hfs_delete_cat() is provided by directory lock.
165	 */
166	memcpy(&rd->key, &fd.key->cat, sizeof(struct hfs_cat_key));
167out:
168	hfs_find_exit(&fd);
169	return err;
170}
171
172static int hfs_dir_release(struct inode *inode, struct file *file)
173{
174	struct hfs_readdir_data *rd = file->private_data;
175	if (rd) {
176		spin_lock(&HFS_I(inode)->open_dir_lock);
177		list_del(&rd->list);
178		spin_unlock(&HFS_I(inode)->open_dir_lock);
179		kfree(rd);
180	}
181	return 0;
182}
183
184/*
185 * hfs_create()
186 *
187 * This is the create() entry in the inode_operations structure for
188 * regular HFS directories.  The purpose is to create a new file in
189 * a directory and return a corresponding inode, given the inode for
190 * the directory and the name (and its length) of the new file.
191 */
192static int hfs_create(struct mnt_idmap *idmap, struct inode *dir,
193		      struct dentry *dentry, umode_t mode, bool excl)
194{
195	struct inode *inode;
196	int res;
197
198	inode = hfs_new_inode(dir, &dentry->d_name, mode);
199	if (!inode)
200		return -ENOMEM;
201
202	res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
203	if (res) {
204		clear_nlink(inode);
205		hfs_delete_inode(inode);
206		iput(inode);
207		return res;
208	}
209	d_instantiate(dentry, inode);
210	mark_inode_dirty(inode);
211	return 0;
212}
213
214/*
215 * hfs_mkdir()
216 *
217 * This is the mkdir() entry in the inode_operations structure for
218 * regular HFS directories.  The purpose is to create a new directory
219 * in a directory, given the inode for the parent directory and the
220 * name (and its length) of the new directory.
221 */
222static int hfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
223		     struct dentry *dentry, umode_t mode)
224{
225	struct inode *inode;
226	int res;
227
228	inode = hfs_new_inode(dir, &dentry->d_name, S_IFDIR | mode);
229	if (!inode)
230		return -ENOMEM;
231
232	res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
233	if (res) {
234		clear_nlink(inode);
235		hfs_delete_inode(inode);
236		iput(inode);
237		return res;
238	}
239	d_instantiate(dentry, inode);
240	mark_inode_dirty(inode);
241	return 0;
242}
243
244/*
245 * hfs_remove()
246 *
247 * This serves as both unlink() and rmdir() in the inode_operations
248 * structure for regular HFS directories.  The purpose is to delete
249 * an existing child, given the inode for the parent directory and
250 * the name (and its length) of the existing directory.
251 *
252 * HFS does not have hardlinks, so both rmdir and unlink set the
253 * link count to 0.  The only difference is the emptiness check.
254 */
255static int hfs_remove(struct inode *dir, struct dentry *dentry)
256{
257	struct inode *inode = d_inode(dentry);
258	int res;
259
260	if (S_ISDIR(inode->i_mode) && inode->i_size != 2)
261		return -ENOTEMPTY;
262	res = hfs_cat_delete(inode->i_ino, dir, &dentry->d_name);
263	if (res)
264		return res;
265	clear_nlink(inode);
266	inode_set_ctime_current(inode);
267	hfs_delete_inode(inode);
268	mark_inode_dirty(inode);
269	return 0;
270}
271
272/*
273 * hfs_rename()
274 *
275 * This is the rename() entry in the inode_operations structure for
276 * regular HFS directories.  The purpose is to rename an existing
277 * file or directory, given the inode for the current directory and
278 * the name (and its length) of the existing file/directory and the
279 * inode for the new directory and the name (and its length) of the
280 * new file/directory.
281 * XXX: how do you handle must_be dir?
282 */
283static int hfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
284		      struct dentry *old_dentry, struct inode *new_dir,
285		      struct dentry *new_dentry, unsigned int flags)
286{
287	int res;
288
289	if (flags & ~RENAME_NOREPLACE)
290		return -EINVAL;
291
292	/* Unlink destination if it already exists */
293	if (d_really_is_positive(new_dentry)) {
294		res = hfs_remove(new_dir, new_dentry);
295		if (res)
296			return res;
297	}
298
299	res = hfs_cat_move(d_inode(old_dentry)->i_ino,
300			   old_dir, &old_dentry->d_name,
301			   new_dir, &new_dentry->d_name);
302	if (!res)
303		hfs_cat_build_key(old_dir->i_sb,
304				  (btree_key *)&HFS_I(d_inode(old_dentry))->cat_key,
305				  new_dir->i_ino, &new_dentry->d_name);
306	return res;
307}
308
309const struct file_operations hfs_dir_operations = {
310	.read		= generic_read_dir,
311	.iterate_shared	= hfs_readdir,
312	.llseek		= generic_file_llseek,
313	.release	= hfs_dir_release,
314};
315
316const struct inode_operations hfs_dir_inode_operations = {
317	.create		= hfs_create,
318	.lookup		= hfs_lookup,
319	.unlink		= hfs_remove,
320	.mkdir		= hfs_mkdir,
321	.rmdir		= hfs_remove,
322	.rename		= hfs_rename,
323	.setattr	= hfs_inode_setattr,
324};
325