xref: /openbmc/linux/fs/hfs/dir.c (revision de3a9980)
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 	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));
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 	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  */
192 static int hfs_create(struct user_namespace *mnt_userns, 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  */
222 static int hfs_mkdir(struct user_namespace *mnt_userns, 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  */
255 static 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->i_ctime = current_time(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  */
283 static int hfs_rename(struct user_namespace *mnt_userns, 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 
309 const 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 
316 const 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