xref: /linux/fs/hfsplus/dir.c (revision 704bf317fd21683e5c71a542f5fb5f65271a1582)
1 /*
2  *  linux/fs/hfsplus/dir.c
3  *
4  * Copyright (C) 2001
5  * Brad Boyer (flar@allandria.com)
6  * (C) 2003 Ardis Technologies <roman@ardistech.com>
7  *
8  * Handling of directories
9  */
10 
11 #include <linux/errno.h>
12 #include <linux/fs.h>
13 #include <linux/slab.h>
14 #include <linux/random.h>
15 
16 #include "hfsplus_fs.h"
17 #include "hfsplus_raw.h"
18 
19 static inline void hfsplus_instantiate(struct dentry *dentry,
20 				       struct inode *inode, u32 cnid)
21 {
22 	dentry->d_fsdata = (void *)(unsigned long)cnid;
23 	d_instantiate(dentry, inode);
24 }
25 
26 /* Find the entry inside dir named dentry->d_name */
27 static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
28 				     struct nameidata *nd)
29 {
30 	struct inode *inode = NULL;
31 	struct hfs_find_data fd;
32 	struct super_block *sb;
33 	hfsplus_cat_entry entry;
34 	int err;
35 	u32 cnid, linkid = 0;
36 	u16 type;
37 
38 	sb = dir->i_sb;
39 
40 	d_set_d_op(dentry, &hfsplus_dentry_operations);
41 	dentry->d_fsdata = NULL;
42 	hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
43 	hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, &dentry->d_name);
44 again:
45 	err = hfs_brec_read(&fd, &entry, sizeof(entry));
46 	if (err) {
47 		if (err == -ENOENT) {
48 			hfs_find_exit(&fd);
49 			/* No such entry */
50 			inode = NULL;
51 			goto out;
52 		}
53 		goto fail;
54 	}
55 	type = be16_to_cpu(entry.type);
56 	if (type == HFSPLUS_FOLDER) {
57 		if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
58 			err = -EIO;
59 			goto fail;
60 		}
61 		cnid = be32_to_cpu(entry.folder.id);
62 		dentry->d_fsdata = (void *)(unsigned long)cnid;
63 	} else if (type == HFSPLUS_FILE) {
64 		if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
65 			err = -EIO;
66 			goto fail;
67 		}
68 		cnid = be32_to_cpu(entry.file.id);
69 		if (entry.file.user_info.fdType ==
70 				cpu_to_be32(HFSP_HARDLINK_TYPE) &&
71 				entry.file.user_info.fdCreator ==
72 				cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
73 				(entry.file.create_date ==
74 					HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
75 						create_date ||
76 				entry.file.create_date ==
77 					HFSPLUS_I(sb->s_root->d_inode)->
78 						create_date) &&
79 				HFSPLUS_SB(sb)->hidden_dir) {
80 			struct qstr str;
81 			char name[32];
82 
83 			if (dentry->d_fsdata) {
84 				/*
85 				 * We found a link pointing to another link,
86 				 * so ignore it and treat it as regular file.
87 				 */
88 				cnid = (unsigned long)dentry->d_fsdata;
89 				linkid = 0;
90 			} else {
91 				dentry->d_fsdata = (void *)(unsigned long)cnid;
92 				linkid =
93 					be32_to_cpu(entry.file.permissions.dev);
94 				str.len = sprintf(name, "iNode%d", linkid);
95 				str.name = name;
96 				hfsplus_cat_build_key(sb, fd.search_key,
97 					HFSPLUS_SB(sb)->hidden_dir->i_ino,
98 					&str);
99 				goto again;
100 			}
101 		} else if (!dentry->d_fsdata)
102 			dentry->d_fsdata = (void *)(unsigned long)cnid;
103 	} else {
104 		printk(KERN_ERR "hfs: invalid catalog entry type in lookup\n");
105 		err = -EIO;
106 		goto fail;
107 	}
108 	hfs_find_exit(&fd);
109 	inode = hfsplus_iget(dir->i_sb, cnid);
110 	if (IS_ERR(inode))
111 		return ERR_CAST(inode);
112 	if (S_ISREG(inode->i_mode))
113 		HFSPLUS_I(inode)->linkid = linkid;
114 out:
115 	d_add(dentry, inode);
116 	return NULL;
117 fail:
118 	hfs_find_exit(&fd);
119 	return ERR_PTR(err);
120 }
121 
122 static int hfsplus_readdir(struct file *filp, void *dirent, filldir_t filldir)
123 {
124 	struct inode *inode = filp->f_path.dentry->d_inode;
125 	struct super_block *sb = inode->i_sb;
126 	int len, err;
127 	char strbuf[HFSPLUS_MAX_STRLEN + 1];
128 	hfsplus_cat_entry entry;
129 	struct hfs_find_data fd;
130 	struct hfsplus_readdir_data *rd;
131 	u16 type;
132 
133 	if (filp->f_pos >= inode->i_size)
134 		return 0;
135 
136 	hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
137 	hfsplus_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
138 	err = hfs_brec_find(&fd);
139 	if (err)
140 		goto out;
141 
142 	switch ((u32)filp->f_pos) {
143 	case 0:
144 		/* This is completely artificial... */
145 		if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR))
146 			goto out;
147 		filp->f_pos++;
148 		/* fall through */
149 	case 1:
150 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
151 			fd.entrylength);
152 		if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
153 			printk(KERN_ERR "hfs: bad catalog folder thread\n");
154 			err = -EIO;
155 			goto out;
156 		}
157 		if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
158 			printk(KERN_ERR "hfs: truncated catalog thread\n");
159 			err = -EIO;
160 			goto out;
161 		}
162 		if (filldir(dirent, "..", 2, 1,
163 			    be32_to_cpu(entry.thread.parentID), DT_DIR))
164 			goto out;
165 		filp->f_pos++;
166 		/* fall through */
167 	default:
168 		if (filp->f_pos >= inode->i_size)
169 			goto out;
170 		err = hfs_brec_goto(&fd, filp->f_pos - 1);
171 		if (err)
172 			goto out;
173 	}
174 
175 	for (;;) {
176 		if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
177 			printk(KERN_ERR "hfs: walked past end of dir\n");
178 			err = -EIO;
179 			goto out;
180 		}
181 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
182 			fd.entrylength);
183 		type = be16_to_cpu(entry.type);
184 		len = HFSPLUS_MAX_STRLEN;
185 		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
186 		if (err)
187 			goto out;
188 		if (type == HFSPLUS_FOLDER) {
189 			if (fd.entrylength <
190 					sizeof(struct hfsplus_cat_folder)) {
191 				printk(KERN_ERR "hfs: small dir entry\n");
192 				err = -EIO;
193 				goto out;
194 			}
195 			if (HFSPLUS_SB(sb)->hidden_dir &&
196 			    HFSPLUS_SB(sb)->hidden_dir->i_ino ==
197 					be32_to_cpu(entry.folder.id))
198 				goto next;
199 			if (filldir(dirent, strbuf, len, filp->f_pos,
200 				    be32_to_cpu(entry.folder.id), DT_DIR))
201 				break;
202 		} else if (type == HFSPLUS_FILE) {
203 			if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
204 				printk(KERN_ERR "hfs: small file entry\n");
205 				err = -EIO;
206 				goto out;
207 			}
208 			if (filldir(dirent, strbuf, len, filp->f_pos,
209 				    be32_to_cpu(entry.file.id), DT_REG))
210 				break;
211 		} else {
212 			printk(KERN_ERR "hfs: bad catalog entry type\n");
213 			err = -EIO;
214 			goto out;
215 		}
216 next:
217 		filp->f_pos++;
218 		if (filp->f_pos >= inode->i_size)
219 			goto out;
220 		err = hfs_brec_goto(&fd, 1);
221 		if (err)
222 			goto out;
223 	}
224 	rd = filp->private_data;
225 	if (!rd) {
226 		rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
227 		if (!rd) {
228 			err = -ENOMEM;
229 			goto out;
230 		}
231 		filp->private_data = rd;
232 		rd->file = filp;
233 		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
234 	}
235 	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
236 out:
237 	hfs_find_exit(&fd);
238 	return err;
239 }
240 
241 static int hfsplus_dir_release(struct inode *inode, struct file *file)
242 {
243 	struct hfsplus_readdir_data *rd = file->private_data;
244 	if (rd) {
245 		mutex_lock(&inode->i_mutex);
246 		list_del(&rd->list);
247 		mutex_unlock(&inode->i_mutex);
248 		kfree(rd);
249 	}
250 	return 0;
251 }
252 
253 static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
254 			struct dentry *dst_dentry)
255 {
256 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
257 	struct inode *inode = src_dentry->d_inode;
258 	struct inode *src_dir = src_dentry->d_parent->d_inode;
259 	struct qstr str;
260 	char name[32];
261 	u32 cnid, id;
262 	int res;
263 
264 	if (HFSPLUS_IS_RSRC(inode))
265 		return -EPERM;
266 	if (!S_ISREG(inode->i_mode))
267 		return -EPERM;
268 
269 	mutex_lock(&sbi->vh_mutex);
270 	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
271 		for (;;) {
272 			get_random_bytes(&id, sizeof(cnid));
273 			id &= 0x3fffffff;
274 			str.name = name;
275 			str.len = sprintf(name, "iNode%d", id);
276 			res = hfsplus_rename_cat(inode->i_ino,
277 						 src_dir, &src_dentry->d_name,
278 						 sbi->hidden_dir, &str);
279 			if (!res)
280 				break;
281 			if (res != -EEXIST)
282 				goto out;
283 		}
284 		HFSPLUS_I(inode)->linkid = id;
285 		cnid = sbi->next_cnid++;
286 		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
287 		res = hfsplus_create_cat(cnid, src_dir,
288 			&src_dentry->d_name, inode);
289 		if (res)
290 			/* panic? */
291 			goto out;
292 		sbi->file_count++;
293 	}
294 	cnid = sbi->next_cnid++;
295 	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
296 	if (res)
297 		goto out;
298 
299 	inc_nlink(inode);
300 	hfsplus_instantiate(dst_dentry, inode, cnid);
301 	ihold(inode);
302 	inode->i_ctime = CURRENT_TIME_SEC;
303 	mark_inode_dirty(inode);
304 	sbi->file_count++;
305 	dst_dir->i_sb->s_dirt = 1;
306 out:
307 	mutex_unlock(&sbi->vh_mutex);
308 	return res;
309 }
310 
311 static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
312 {
313 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
314 	struct inode *inode = dentry->d_inode;
315 	struct qstr str;
316 	char name[32];
317 	u32 cnid;
318 	int res;
319 
320 	if (HFSPLUS_IS_RSRC(inode))
321 		return -EPERM;
322 
323 	mutex_lock(&sbi->vh_mutex);
324 	cnid = (u32)(unsigned long)dentry->d_fsdata;
325 	if (inode->i_ino == cnid &&
326 	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
327 		str.name = name;
328 		str.len = sprintf(name, "temp%lu", inode->i_ino);
329 		res = hfsplus_rename_cat(inode->i_ino,
330 					 dir, &dentry->d_name,
331 					 sbi->hidden_dir, &str);
332 		if (!res) {
333 			inode->i_flags |= S_DEAD;
334 			drop_nlink(inode);
335 		}
336 		goto out;
337 	}
338 	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
339 	if (res)
340 		goto out;
341 
342 	if (inode->i_nlink > 0)
343 		drop_nlink(inode);
344 	if (inode->i_ino == cnid)
345 		clear_nlink(inode);
346 	if (!inode->i_nlink) {
347 		if (inode->i_ino != cnid) {
348 			sbi->file_count--;
349 			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
350 				res = hfsplus_delete_cat(inode->i_ino,
351 							 sbi->hidden_dir,
352 							 NULL);
353 				if (!res)
354 					hfsplus_delete_inode(inode);
355 			} else
356 				inode->i_flags |= S_DEAD;
357 		} else
358 			hfsplus_delete_inode(inode);
359 	} else
360 		sbi->file_count--;
361 	inode->i_ctime = CURRENT_TIME_SEC;
362 	mark_inode_dirty(inode);
363 out:
364 	mutex_unlock(&sbi->vh_mutex);
365 	return res;
366 }
367 
368 static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
369 {
370 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
371 	struct inode *inode = dentry->d_inode;
372 	int res;
373 
374 	if (inode->i_size != 2)
375 		return -ENOTEMPTY;
376 
377 	mutex_lock(&sbi->vh_mutex);
378 	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
379 	if (res)
380 		goto out;
381 	clear_nlink(inode);
382 	inode->i_ctime = CURRENT_TIME_SEC;
383 	hfsplus_delete_inode(inode);
384 	mark_inode_dirty(inode);
385 out:
386 	mutex_unlock(&sbi->vh_mutex);
387 	return res;
388 }
389 
390 static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
391 			   const char *symname)
392 {
393 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
394 	struct inode *inode;
395 	int res = -ENOSPC;
396 
397 	mutex_lock(&sbi->vh_mutex);
398 	inode = hfsplus_new_inode(dir->i_sb, S_IFLNK | S_IRWXUGO);
399 	if (!inode)
400 		goto out;
401 
402 	res = page_symlink(inode, symname, strlen(symname) + 1);
403 	if (res)
404 		goto out_err;
405 
406 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
407 	if (res)
408 		goto out_err;
409 
410 	hfsplus_instantiate(dentry, inode, inode->i_ino);
411 	mark_inode_dirty(inode);
412 	goto out;
413 
414 out_err:
415 	inode->i_nlink = 0;
416 	hfsplus_delete_inode(inode);
417 	iput(inode);
418 out:
419 	mutex_unlock(&sbi->vh_mutex);
420 	return res;
421 }
422 
423 static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
424 			 int mode, dev_t rdev)
425 {
426 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
427 	struct inode *inode;
428 	int res = -ENOSPC;
429 
430 	mutex_lock(&sbi->vh_mutex);
431 	inode = hfsplus_new_inode(dir->i_sb, mode);
432 	if (!inode)
433 		goto out;
434 
435 	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
436 		init_special_inode(inode, mode, rdev);
437 
438 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
439 	if (res) {
440 		inode->i_nlink = 0;
441 		hfsplus_delete_inode(inode);
442 		iput(inode);
443 		goto out;
444 	}
445 
446 	hfsplus_instantiate(dentry, inode, inode->i_ino);
447 	mark_inode_dirty(inode);
448 out:
449 	mutex_unlock(&sbi->vh_mutex);
450 	return res;
451 }
452 
453 static int hfsplus_create(struct inode *dir, struct dentry *dentry, int mode,
454 			  struct nameidata *nd)
455 {
456 	return hfsplus_mknod(dir, dentry, mode, 0);
457 }
458 
459 static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, int mode)
460 {
461 	return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
462 }
463 
464 static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
465 			  struct inode *new_dir, struct dentry *new_dentry)
466 {
467 	int res;
468 
469 	/* Unlink destination if it already exists */
470 	if (new_dentry->d_inode) {
471 		if (S_ISDIR(new_dentry->d_inode->i_mode))
472 			res = hfsplus_rmdir(new_dir, new_dentry);
473 		else
474 			res = hfsplus_unlink(new_dir, new_dentry);
475 		if (res)
476 			return res;
477 	}
478 
479 	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
480 				 old_dir, &old_dentry->d_name,
481 				 new_dir, &new_dentry->d_name);
482 	if (!res)
483 		new_dentry->d_fsdata = old_dentry->d_fsdata;
484 	return res;
485 }
486 
487 const struct inode_operations hfsplus_dir_inode_operations = {
488 	.lookup		= hfsplus_lookup,
489 	.create		= hfsplus_create,
490 	.link		= hfsplus_link,
491 	.unlink		= hfsplus_unlink,
492 	.mkdir		= hfsplus_mkdir,
493 	.rmdir		= hfsplus_rmdir,
494 	.symlink	= hfsplus_symlink,
495 	.mknod		= hfsplus_mknod,
496 	.rename		= hfsplus_rename,
497 };
498 
499 const struct file_operations hfsplus_dir_operations = {
500 	.fsync		= hfsplus_file_fsync,
501 	.read		= generic_read_dir,
502 	.readdir	= hfsplus_readdir,
503 	.unlocked_ioctl = hfsplus_ioctl,
504 	.llseek		= generic_file_llseek,
505 	.release	= hfsplus_dir_release,
506 };
507