xref: /linux/fs/hfs/dir.c (revision d29fd593e6836c96c6fd6df2b0cc6a47dda21b74)
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  */
20 static 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  */
48 static 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 	rd = file->private_data;
101 	if (rd && rd->pos == ctx->pos) {
102 		memcpy(fd.search_key, &rd->key, sizeof(struct hfs_cat_key));
103 		err = hfs_brec_find(&fd);
104 		if (err == -ENOENT)
105 			err = hfs_brec_goto(&fd, 1);
106 	} else {
107 		err = hfs_brec_goto(&fd, ctx->pos - 1);
108 	}
109 	if (err)
110 		goto out;
111 
112 	for (;;) {
113 		if (be32_to_cpu(fd.key->cat.ParID) != inode->i_ino) {
114 			pr_err("walked past end of dir\n");
115 			err = -EIO;
116 			goto out;
117 		}
118 
119 		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
120 			err = -EIO;
121 			goto out;
122 		}
123 
124 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
125 		type = entry.type;
126 		len = hfs_mac2asc(sb, strbuf, &fd.key->cat.CName);
127 		if (type == HFS_CDR_DIR) {
128 			if (fd.entrylength < sizeof(struct hfs_cat_dir)) {
129 				pr_err("small dir entry\n");
130 				err = -EIO;
131 				goto out;
132 			}
133 			if (!dir_emit(ctx, strbuf, len,
134 				    be32_to_cpu(entry.dir.DirID), DT_DIR))
135 				break;
136 		} else if (type == HFS_CDR_FIL) {
137 			if (fd.entrylength < sizeof(struct hfs_cat_file)) {
138 				pr_err("small file entry\n");
139 				err = -EIO;
140 				goto out;
141 			}
142 			if (!dir_emit(ctx, strbuf, len,
143 				    be32_to_cpu(entry.file.FlNum), DT_REG))
144 				break;
145 		} else {
146 			pr_err("bad catalog entry type %d\n", type);
147 			err = -EIO;
148 			goto out;
149 		}
150 		ctx->pos++;
151 		if (ctx->pos >= inode->i_size)
152 			goto out;
153 		err = hfs_brec_goto(&fd, 1);
154 		if (err)
155 			goto out;
156 	}
157 	if (!rd) {
158 		rd = kmalloc_obj(struct hfs_readdir_data);
159 		if (!rd) {
160 			err = -ENOMEM;
161 			goto out;
162 		}
163 		file->private_data = rd;
164 	}
165 	rd->pos = ctx->pos;
166 	memcpy(&rd->key, &fd.key->cat, sizeof(struct hfs_cat_key));
167 out:
168 	hfs_find_exit(&fd);
169 	return err;
170 }
171 
172 static int hfs_dir_release(struct inode *inode, struct file *file)
173 {
174 	kfree(file->private_data);
175 	return 0;
176 }
177 
178 /*
179  * hfs_create()
180  *
181  * This is the create() entry in the inode_operations structure for
182  * regular HFS directories.  The purpose is to create a new file in
183  * a directory and return a corresponding inode, given the inode for
184  * the directory and the name (and its length) of the new file.
185  */
186 static int hfs_create(struct mnt_idmap *idmap, struct inode *dir,
187 		      struct dentry *dentry, umode_t mode, bool excl)
188 {
189 	struct inode *inode;
190 	int res;
191 
192 	inode = hfs_new_inode(dir, &dentry->d_name, mode);
193 	if (IS_ERR(inode))
194 		return PTR_ERR(inode);
195 
196 	res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
197 	if (res) {
198 		clear_nlink(inode);
199 		hfs_delete_inode(inode);
200 		iput(inode);
201 		return res;
202 	}
203 	d_instantiate(dentry, inode);
204 	mark_inode_dirty(inode);
205 	return 0;
206 }
207 
208 /*
209  * hfs_mkdir()
210  *
211  * This is the mkdir() entry in the inode_operations structure for
212  * regular HFS directories.  The purpose is to create a new directory
213  * in a directory, given the inode for the parent directory and the
214  * name (and its length) of the new directory.
215  */
216 static struct dentry *hfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
217 				struct dentry *dentry, umode_t mode)
218 {
219 	struct inode *inode;
220 	int res;
221 
222 	inode = hfs_new_inode(dir, &dentry->d_name, S_IFDIR | mode);
223 	if (IS_ERR(inode))
224 		return ERR_CAST(inode);
225 
226 	res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
227 	if (res) {
228 		clear_nlink(inode);
229 		hfs_delete_inode(inode);
230 		iput(inode);
231 		return ERR_PTR(res);
232 	}
233 	d_instantiate(dentry, inode);
234 	mark_inode_dirty(inode);
235 	return NULL;
236 }
237 
238 /*
239  * hfs_remove()
240  *
241  * This serves as both unlink() and rmdir() in the inode_operations
242  * structure for regular HFS directories.  The purpose is to delete
243  * an existing child, given the inode for the parent directory and
244  * the name (and its length) of the existing directory.
245  *
246  * HFS does not have hardlinks, so both rmdir and unlink set the
247  * link count to 0.  The only difference is the emptiness check.
248  */
249 static int hfs_remove(struct inode *dir, struct dentry *dentry)
250 {
251 	struct super_block *sb = dir->i_sb;
252 	struct inode *inode = d_inode(dentry);
253 	int res;
254 
255 	if (S_ISDIR(inode->i_mode) && inode->i_size != 2)
256 		return -ENOTEMPTY;
257 
258 	if (unlikely(!is_hfs_cnid_counts_valid(sb))) {
259 	    pr_err("cannot remove file/folder\n");
260 	    return -ERANGE;
261 	}
262 
263 	res = hfs_cat_delete(inode->i_ino, dir, &dentry->d_name);
264 	if (res)
265 		return res;
266 	clear_nlink(inode);
267 	inode_set_ctime_current(inode);
268 	hfs_delete_inode(inode);
269 	mark_inode_dirty(inode);
270 	return 0;
271 }
272 
273 /*
274  * hfs_rename()
275  *
276  * This is the rename() entry in the inode_operations structure for
277  * regular HFS directories.  The purpose is to rename an existing
278  * file or directory, given the inode for the current directory and
279  * the name (and its length) of the existing file/directory and the
280  * inode for the new directory and the name (and its length) of the
281  * new file/directory.
282  * XXX: how do you handle must_be dir?
283  */
284 static int hfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
285 		      struct dentry *old_dentry, struct inode *new_dir,
286 		      struct dentry *new_dentry, unsigned int flags)
287 {
288 	int res;
289 
290 	if (flags & ~RENAME_NOREPLACE)
291 		return -EINVAL;
292 
293 	/* Unlink destination if it already exists */
294 	if (d_really_is_positive(new_dentry)) {
295 		res = hfs_remove(new_dir, new_dentry);
296 		if (res)
297 			return res;
298 	}
299 
300 	res = hfs_cat_move(d_inode(old_dentry)->i_ino,
301 			   old_dir, &old_dentry->d_name,
302 			   new_dir, &new_dentry->d_name);
303 	if (!res) {
304 		struct inode *inode = d_inode(old_dentry);
305 
306 		hfs_cat_build_key(old_dir->i_sb,
307 				  (btree_key *)&HFS_I(inode)->cat_key,
308 				  new_dir->i_ino, &new_dentry->d_name);
309 		inode_set_ctime_current(inode);
310 		mark_inode_dirty(inode);
311 	}
312 	return res;
313 }
314 
315 const struct file_operations hfs_dir_operations = {
316 	.read		= generic_read_dir,
317 	.iterate_shared	= hfs_readdir,
318 	.llseek		= generic_file_llseek,
319 	.release	= hfs_dir_release,
320 };
321 
322 const struct inode_operations hfs_dir_inode_operations = {
323 	.create		= hfs_create,
324 	.lookup		= hfs_lookup,
325 	.unlink		= hfs_remove,
326 	.mkdir		= hfs_mkdir,
327 	.rmdir		= hfs_remove,
328 	.rename		= hfs_rename,
329 	.setattr	= hfs_inode_setattr,
330 	.fileattr_get	= hfs_fileattr_get,
331 };
332