xref: /linux/fs/hfsplus/dir.c (revision d614267329f2bee7a082ed8781c581c0f3aaa808) 
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 #include "xattr.h"
19 
20 static inline void hfsplus_instantiate(struct dentry *dentry,
21 				       struct inode *inode, u32 cnid)
22 {
23 	dentry->d_fsdata = (void *)(unsigned long)cnid;
24 	d_instantiate(dentry, inode);
25 }
26 
27 /* Find the entry inside dir named dentry->d_name */
28 static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
29 				     unsigned int flags)
30 {
31 	struct inode *inode = NULL;
32 	struct hfs_find_data fd;
33 	struct super_block *sb;
34 	hfsplus_cat_entry entry;
35 	int err;
36 	u32 cnid, linkid = 0;
37 	u16 type;
38 
39 	sb = dir->i_sb;
40 
41 	dentry->d_fsdata = NULL;
42 	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
43 	if (err)
44 		return ERR_PTR(err);
45 	hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, &dentry->d_name);
46 again:
47 	err = hfs_brec_read(&fd, &entry, sizeof(entry));
48 	if (err) {
49 		if (err == -ENOENT) {
50 			hfs_find_exit(&fd);
51 			/* No such entry */
52 			inode = NULL;
53 			goto out;
54 		}
55 		goto fail;
56 	}
57 	type = be16_to_cpu(entry.type);
58 	if (type == HFSPLUS_FOLDER) {
59 		if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
60 			err = -EIO;
61 			goto fail;
62 		}
63 		cnid = be32_to_cpu(entry.folder.id);
64 		dentry->d_fsdata = (void *)(unsigned long)cnid;
65 	} else if (type == HFSPLUS_FILE) {
66 		if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
67 			err = -EIO;
68 			goto fail;
69 		}
70 		cnid = be32_to_cpu(entry.file.id);
71 		if (entry.file.user_info.fdType ==
72 				cpu_to_be32(HFSP_HARDLINK_TYPE) &&
73 				entry.file.user_info.fdCreator ==
74 				cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
75 				(entry.file.create_date ==
76 					HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
77 						create_date ||
78 				entry.file.create_date ==
79 					HFSPLUS_I(sb->s_root->d_inode)->
80 						create_date) &&
81 				HFSPLUS_SB(sb)->hidden_dir) {
82 			struct qstr str;
83 			char name[32];
84 
85 			if (dentry->d_fsdata) {
86 				/*
87 				 * We found a link pointing to another link,
88 				 * so ignore it and treat it as regular file.
89 				 */
90 				cnid = (unsigned long)dentry->d_fsdata;
91 				linkid = 0;
92 			} else {
93 				dentry->d_fsdata = (void *)(unsigned long)cnid;
94 				linkid =
95 					be32_to_cpu(entry.file.permissions.dev);
96 				str.len = sprintf(name, "iNode%d", linkid);
97 				str.name = name;
98 				hfsplus_cat_build_key(sb, fd.search_key,
99 					HFSPLUS_SB(sb)->hidden_dir->i_ino,
100 					&str);
101 				goto again;
102 			}
103 		} else if (!dentry->d_fsdata)
104 			dentry->d_fsdata = (void *)(unsigned long)cnid;
105 	} else {
106 		pr_err("invalid catalog entry type in lookup\n");
107 		err = -EIO;
108 		goto fail;
109 	}
110 	hfs_find_exit(&fd);
111 	inode = hfsplus_iget(dir->i_sb, cnid);
112 	if (IS_ERR(inode))
113 		return ERR_CAST(inode);
114 	if (S_ISREG(inode->i_mode))
115 		HFSPLUS_I(inode)->linkid = linkid;
116 out:
117 	d_add(dentry, inode);
118 	return NULL;
119 fail:
120 	hfs_find_exit(&fd);
121 	return ERR_PTR(err);
122 }
123 
124 static int hfsplus_readdir(struct file *filp, void *dirent, filldir_t filldir)
125 {
126 	struct inode *inode = file_inode(filp);
127 	struct super_block *sb = inode->i_sb;
128 	int len, err;
129 	char strbuf[HFSPLUS_MAX_STRLEN + 1];
130 	hfsplus_cat_entry entry;
131 	struct hfs_find_data fd;
132 	struct hfsplus_readdir_data *rd;
133 	u16 type;
134 
135 	if (filp->f_pos >= inode->i_size)
136 		return 0;
137 
138 	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
139 	if (err)
140 		return err;
141 	hfsplus_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
142 	err = hfs_brec_find(&fd, hfs_find_rec_by_key);
143 	if (err)
144 		goto out;
145 
146 	switch ((u32)filp->f_pos) {
147 	case 0:
148 		/* This is completely artificial... */
149 		if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR))
150 			goto out;
151 		filp->f_pos++;
152 		/* fall through */
153 	case 1:
154 		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
155 			err = -EIO;
156 			goto out;
157 		}
158 
159 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
160 			fd.entrylength);
161 		if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
162 			pr_err("bad catalog folder thread\n");
163 			err = -EIO;
164 			goto out;
165 		}
166 		if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
167 			pr_err("truncated catalog thread\n");
168 			err = -EIO;
169 			goto out;
170 		}
171 		if (filldir(dirent, "..", 2, 1,
172 			    be32_to_cpu(entry.thread.parentID), DT_DIR))
173 			goto out;
174 		filp->f_pos++;
175 		/* fall through */
176 	default:
177 		if (filp->f_pos >= inode->i_size)
178 			goto out;
179 		err = hfs_brec_goto(&fd, filp->f_pos - 1);
180 		if (err)
181 			goto out;
182 	}
183 
184 	for (;;) {
185 		if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
186 			pr_err("walked past end of dir\n");
187 			err = -EIO;
188 			goto out;
189 		}
190 
191 		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
192 			err = -EIO;
193 			goto out;
194 		}
195 
196 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
197 			fd.entrylength);
198 		type = be16_to_cpu(entry.type);
199 		len = HFSPLUS_MAX_STRLEN;
200 		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
201 		if (err)
202 			goto out;
203 		if (type == HFSPLUS_FOLDER) {
204 			if (fd.entrylength <
205 					sizeof(struct hfsplus_cat_folder)) {
206 				pr_err("small dir entry\n");
207 				err = -EIO;
208 				goto out;
209 			}
210 			if (HFSPLUS_SB(sb)->hidden_dir &&
211 			    HFSPLUS_SB(sb)->hidden_dir->i_ino ==
212 					be32_to_cpu(entry.folder.id))
213 				goto next;
214 			if (filldir(dirent, strbuf, len, filp->f_pos,
215 				    be32_to_cpu(entry.folder.id), DT_DIR))
216 				break;
217 		} else if (type == HFSPLUS_FILE) {
218 			if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
219 				pr_err("small file entry\n");
220 				err = -EIO;
221 				goto out;
222 			}
223 			if (filldir(dirent, strbuf, len, filp->f_pos,
224 				    be32_to_cpu(entry.file.id), DT_REG))
225 				break;
226 		} else {
227 			pr_err("bad catalog entry type\n");
228 			err = -EIO;
229 			goto out;
230 		}
231 next:
232 		filp->f_pos++;
233 		if (filp->f_pos >= inode->i_size)
234 			goto out;
235 		err = hfs_brec_goto(&fd, 1);
236 		if (err)
237 			goto out;
238 	}
239 	rd = filp->private_data;
240 	if (!rd) {
241 		rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
242 		if (!rd) {
243 			err = -ENOMEM;
244 			goto out;
245 		}
246 		filp->private_data = rd;
247 		rd->file = filp;
248 		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
249 	}
250 	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
251 out:
252 	hfs_find_exit(&fd);
253 	return err;
254 }
255 
256 static int hfsplus_dir_release(struct inode *inode, struct file *file)
257 {
258 	struct hfsplus_readdir_data *rd = file->private_data;
259 	if (rd) {
260 		mutex_lock(&inode->i_mutex);
261 		list_del(&rd->list);
262 		mutex_unlock(&inode->i_mutex);
263 		kfree(rd);
264 	}
265 	return 0;
266 }
267 
268 static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
269 			struct dentry *dst_dentry)
270 {
271 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
272 	struct inode *inode = src_dentry->d_inode;
273 	struct inode *src_dir = src_dentry->d_parent->d_inode;
274 	struct qstr str;
275 	char name[32];
276 	u32 cnid, id;
277 	int res;
278 
279 	if (HFSPLUS_IS_RSRC(inode))
280 		return -EPERM;
281 	if (!S_ISREG(inode->i_mode))
282 		return -EPERM;
283 
284 	mutex_lock(&sbi->vh_mutex);
285 	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
286 		for (;;) {
287 			get_random_bytes(&id, sizeof(cnid));
288 			id &= 0x3fffffff;
289 			str.name = name;
290 			str.len = sprintf(name, "iNode%d", id);
291 			res = hfsplus_rename_cat(inode->i_ino,
292 						 src_dir, &src_dentry->d_name,
293 						 sbi->hidden_dir, &str);
294 			if (!res)
295 				break;
296 			if (res != -EEXIST)
297 				goto out;
298 		}
299 		HFSPLUS_I(inode)->linkid = id;
300 		cnid = sbi->next_cnid++;
301 		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
302 		res = hfsplus_create_cat(cnid, src_dir,
303 			&src_dentry->d_name, inode);
304 		if (res)
305 			/* panic? */
306 			goto out;
307 		sbi->file_count++;
308 	}
309 	cnid = sbi->next_cnid++;
310 	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
311 	if (res)
312 		goto out;
313 
314 	inc_nlink(inode);
315 	hfsplus_instantiate(dst_dentry, inode, cnid);
316 	ihold(inode);
317 	inode->i_ctime = CURRENT_TIME_SEC;
318 	mark_inode_dirty(inode);
319 	sbi->file_count++;
320 	hfsplus_mark_mdb_dirty(dst_dir->i_sb);
321 out:
322 	mutex_unlock(&sbi->vh_mutex);
323 	return res;
324 }
325 
326 static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
327 {
328 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
329 	struct inode *inode = dentry->d_inode;
330 	struct qstr str;
331 	char name[32];
332 	u32 cnid;
333 	int res;
334 
335 	if (HFSPLUS_IS_RSRC(inode))
336 		return -EPERM;
337 
338 	mutex_lock(&sbi->vh_mutex);
339 	cnid = (u32)(unsigned long)dentry->d_fsdata;
340 	if (inode->i_ino == cnid &&
341 	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
342 		str.name = name;
343 		str.len = sprintf(name, "temp%lu", inode->i_ino);
344 		res = hfsplus_rename_cat(inode->i_ino,
345 					 dir, &dentry->d_name,
346 					 sbi->hidden_dir, &str);
347 		if (!res) {
348 			inode->i_flags |= S_DEAD;
349 			drop_nlink(inode);
350 		}
351 		goto out;
352 	}
353 	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
354 	if (res)
355 		goto out;
356 
357 	if (inode->i_nlink > 0)
358 		drop_nlink(inode);
359 	if (inode->i_ino == cnid)
360 		clear_nlink(inode);
361 	if (!inode->i_nlink) {
362 		if (inode->i_ino != cnid) {
363 			sbi->file_count--;
364 			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
365 				res = hfsplus_delete_cat(inode->i_ino,
366 							 sbi->hidden_dir,
367 							 NULL);
368 				if (!res)
369 					hfsplus_delete_inode(inode);
370 			} else
371 				inode->i_flags |= S_DEAD;
372 		} else
373 			hfsplus_delete_inode(inode);
374 	} else
375 		sbi->file_count--;
376 	inode->i_ctime = CURRENT_TIME_SEC;
377 	mark_inode_dirty(inode);
378 out:
379 	mutex_unlock(&sbi->vh_mutex);
380 	return res;
381 }
382 
383 static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
384 {
385 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
386 	struct inode *inode = dentry->d_inode;
387 	int res;
388 
389 	if (inode->i_size != 2)
390 		return -ENOTEMPTY;
391 
392 	mutex_lock(&sbi->vh_mutex);
393 	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
394 	if (res)
395 		goto out;
396 	clear_nlink(inode);
397 	inode->i_ctime = CURRENT_TIME_SEC;
398 	hfsplus_delete_inode(inode);
399 	mark_inode_dirty(inode);
400 out:
401 	mutex_unlock(&sbi->vh_mutex);
402 	return res;
403 }
404 
405 static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
406 			   const char *symname)
407 {
408 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
409 	struct inode *inode;
410 	int res = -ENOSPC;
411 
412 	mutex_lock(&sbi->vh_mutex);
413 	inode = hfsplus_new_inode(dir->i_sb, S_IFLNK | S_IRWXUGO);
414 	if (!inode)
415 		goto out;
416 
417 	res = page_symlink(inode, symname, strlen(symname) + 1);
418 	if (res)
419 		goto out_err;
420 
421 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
422 	if (res)
423 		goto out_err;
424 
425 	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
426 	if (res == -EOPNOTSUPP)
427 		res = 0; /* Operation is not supported. */
428 	else if (res) {
429 		/* Try to delete anyway without error analysis. */
430 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
431 		goto out_err;
432 	}
433 
434 	hfsplus_instantiate(dentry, inode, inode->i_ino);
435 	mark_inode_dirty(inode);
436 	goto out;
437 
438 out_err:
439 	clear_nlink(inode);
440 	hfsplus_delete_inode(inode);
441 	iput(inode);
442 out:
443 	mutex_unlock(&sbi->vh_mutex);
444 	return res;
445 }
446 
447 static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
448 			 umode_t mode, dev_t rdev)
449 {
450 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
451 	struct inode *inode;
452 	int res = -ENOSPC;
453 
454 	mutex_lock(&sbi->vh_mutex);
455 	inode = hfsplus_new_inode(dir->i_sb, mode);
456 	if (!inode)
457 		goto out;
458 
459 	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
460 		init_special_inode(inode, mode, rdev);
461 
462 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
463 	if (res)
464 		goto failed_mknod;
465 
466 	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
467 	if (res == -EOPNOTSUPP)
468 		res = 0; /* Operation is not supported. */
469 	else if (res) {
470 		/* Try to delete anyway without error analysis. */
471 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
472 		goto failed_mknod;
473 	}
474 
475 	hfsplus_instantiate(dentry, inode, inode->i_ino);
476 	mark_inode_dirty(inode);
477 	goto out;
478 
479 failed_mknod:
480 	clear_nlink(inode);
481 	hfsplus_delete_inode(inode);
482 	iput(inode);
483 out:
484 	mutex_unlock(&sbi->vh_mutex);
485 	return res;
486 }
487 
488 static int hfsplus_create(struct inode *dir, struct dentry *dentry, umode_t mode,
489 			  bool excl)
490 {
491 	return hfsplus_mknod(dir, dentry, mode, 0);
492 }
493 
494 static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
495 {
496 	return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
497 }
498 
499 static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
500 			  struct inode *new_dir, struct dentry *new_dentry)
501 {
502 	int res;
503 
504 	/* Unlink destination if it already exists */
505 	if (new_dentry->d_inode) {
506 		if (S_ISDIR(new_dentry->d_inode->i_mode))
507 			res = hfsplus_rmdir(new_dir, new_dentry);
508 		else
509 			res = hfsplus_unlink(new_dir, new_dentry);
510 		if (res)
511 			return res;
512 	}
513 
514 	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
515 				 old_dir, &old_dentry->d_name,
516 				 new_dir, &new_dentry->d_name);
517 	if (!res)
518 		new_dentry->d_fsdata = old_dentry->d_fsdata;
519 	return res;
520 }
521 
522 const struct inode_operations hfsplus_dir_inode_operations = {
523 	.lookup			= hfsplus_lookup,
524 	.create			= hfsplus_create,
525 	.link			= hfsplus_link,
526 	.unlink			= hfsplus_unlink,
527 	.mkdir			= hfsplus_mkdir,
528 	.rmdir			= hfsplus_rmdir,
529 	.symlink		= hfsplus_symlink,
530 	.mknod			= hfsplus_mknod,
531 	.rename			= hfsplus_rename,
532 	.setxattr		= generic_setxattr,
533 	.getxattr		= generic_getxattr,
534 	.listxattr		= hfsplus_listxattr,
535 	.removexattr		= hfsplus_removexattr,
536 };
537 
538 const struct file_operations hfsplus_dir_operations = {
539 	.fsync		= hfsplus_file_fsync,
540 	.read		= generic_read_dir,
541 	.readdir	= hfsplus_readdir,
542 	.unlocked_ioctl = hfsplus_ioctl,
543 	.llseek		= generic_file_llseek,
544 	.release	= hfsplus_dir_release,
545 };
546