xref: /linux/fs/hfsplus/dir.c (revision 44f57d78) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/hfsplus/dir.c
4  *
5  * Copyright (C) 2001
6  * Brad Boyer (flar@allandria.com)
7  * (C) 2003 Ardis Technologies <roman@ardistech.com>
8  *
9  * Handling of directories
10  */
11 
12 #include <linux/errno.h>
13 #include <linux/fs.h>
14 #include <linux/slab.h>
15 #include <linux/random.h>
16 #include <linux/nls.h>
17 
18 #include "hfsplus_fs.h"
19 #include "hfsplus_raw.h"
20 #include "xattr.h"
21 
22 static inline void hfsplus_instantiate(struct dentry *dentry,
23 				       struct inode *inode, u32 cnid)
24 {
25 	dentry->d_fsdata = (void *)(unsigned long)cnid;
26 	d_instantiate(dentry, inode);
27 }
28 
29 /* Find the entry inside dir named dentry->d_name */
30 static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
31 				     unsigned int flags)
32 {
33 	struct inode *inode = NULL;
34 	struct hfs_find_data fd;
35 	struct super_block *sb;
36 	hfsplus_cat_entry entry;
37 	int err;
38 	u32 cnid, linkid = 0;
39 	u16 type;
40 
41 	sb = dir->i_sb;
42 
43 	dentry->d_fsdata = NULL;
44 	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
45 	if (err)
46 		return ERR_PTR(err);
47 	err = hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino,
48 			&dentry->d_name);
49 	if (unlikely(err < 0))
50 		goto fail;
51 again:
52 	err = hfs_brec_read(&fd, &entry, sizeof(entry));
53 	if (err) {
54 		if (err == -ENOENT) {
55 			hfs_find_exit(&fd);
56 			/* No such entry */
57 			inode = NULL;
58 			goto out;
59 		}
60 		goto fail;
61 	}
62 	type = be16_to_cpu(entry.type);
63 	if (type == HFSPLUS_FOLDER) {
64 		if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
65 			err = -EIO;
66 			goto fail;
67 		}
68 		cnid = be32_to_cpu(entry.folder.id);
69 		dentry->d_fsdata = (void *)(unsigned long)cnid;
70 	} else if (type == HFSPLUS_FILE) {
71 		if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
72 			err = -EIO;
73 			goto fail;
74 		}
75 		cnid = be32_to_cpu(entry.file.id);
76 		if (entry.file.user_info.fdType ==
77 				cpu_to_be32(HFSP_HARDLINK_TYPE) &&
78 				entry.file.user_info.fdCreator ==
79 				cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
80 				HFSPLUS_SB(sb)->hidden_dir &&
81 				(entry.file.create_date ==
82 					HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
83 						create_date ||
84 				entry.file.create_date ==
85 					HFSPLUS_I(d_inode(sb->s_root))->
86 						create_date)) {
87 			struct qstr str;
88 			char name[32];
89 
90 			if (dentry->d_fsdata) {
91 				/*
92 				 * We found a link pointing to another link,
93 				 * so ignore it and treat it as regular file.
94 				 */
95 				cnid = (unsigned long)dentry->d_fsdata;
96 				linkid = 0;
97 			} else {
98 				dentry->d_fsdata = (void *)(unsigned long)cnid;
99 				linkid =
100 					be32_to_cpu(entry.file.permissions.dev);
101 				str.len = sprintf(name, "iNode%d", linkid);
102 				str.name = name;
103 				err = hfsplus_cat_build_key(sb, fd.search_key,
104 					HFSPLUS_SB(sb)->hidden_dir->i_ino,
105 					&str);
106 				if (unlikely(err < 0))
107 					goto fail;
108 				goto again;
109 			}
110 		} else if (!dentry->d_fsdata)
111 			dentry->d_fsdata = (void *)(unsigned long)cnid;
112 	} else {
113 		pr_err("invalid catalog entry type in lookup\n");
114 		err = -EIO;
115 		goto fail;
116 	}
117 	hfs_find_exit(&fd);
118 	inode = hfsplus_iget(dir->i_sb, cnid);
119 	if (IS_ERR(inode))
120 		return ERR_CAST(inode);
121 	if (S_ISREG(inode->i_mode))
122 		HFSPLUS_I(inode)->linkid = linkid;
123 out:
124 	return d_splice_alias(inode, dentry);
125 fail:
126 	hfs_find_exit(&fd);
127 	return ERR_PTR(err);
128 }
129 
130 static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
131 {
132 	struct inode *inode = file_inode(file);
133 	struct super_block *sb = inode->i_sb;
134 	int len, err;
135 	char *strbuf;
136 	hfsplus_cat_entry entry;
137 	struct hfs_find_data fd;
138 	struct hfsplus_readdir_data *rd;
139 	u16 type;
140 
141 	if (file->f_pos >= inode->i_size)
142 		return 0;
143 
144 	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
145 	if (err)
146 		return err;
147 	strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
148 	if (!strbuf) {
149 		err = -ENOMEM;
150 		goto out;
151 	}
152 	hfsplus_cat_build_key_with_cnid(sb, fd.search_key, inode->i_ino);
153 	err = hfs_brec_find(&fd, hfs_find_rec_by_key);
154 	if (err)
155 		goto out;
156 
157 	if (ctx->pos == 0) {
158 		/* This is completely artificial... */
159 		if (!dir_emit_dot(file, ctx))
160 			goto out;
161 		ctx->pos = 1;
162 	}
163 	if (ctx->pos == 1) {
164 		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
165 			err = -EIO;
166 			goto out;
167 		}
168 
169 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
170 			fd.entrylength);
171 		if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
172 			pr_err("bad catalog folder thread\n");
173 			err = -EIO;
174 			goto out;
175 		}
176 		if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
177 			pr_err("truncated catalog thread\n");
178 			err = -EIO;
179 			goto out;
180 		}
181 		if (!dir_emit(ctx, "..", 2,
182 			    be32_to_cpu(entry.thread.parentID), DT_DIR))
183 			goto out;
184 		ctx->pos = 2;
185 	}
186 	if (ctx->pos >= inode->i_size)
187 		goto out;
188 	err = hfs_brec_goto(&fd, ctx->pos - 1);
189 	if (err)
190 		goto out;
191 	for (;;) {
192 		if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
193 			pr_err("walked past end of dir\n");
194 			err = -EIO;
195 			goto out;
196 		}
197 
198 		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
199 			err = -EIO;
200 			goto out;
201 		}
202 
203 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
204 			fd.entrylength);
205 		type = be16_to_cpu(entry.type);
206 		len = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN;
207 		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
208 		if (err)
209 			goto out;
210 		if (type == HFSPLUS_FOLDER) {
211 			if (fd.entrylength <
212 					sizeof(struct hfsplus_cat_folder)) {
213 				pr_err("small dir entry\n");
214 				err = -EIO;
215 				goto out;
216 			}
217 			if (HFSPLUS_SB(sb)->hidden_dir &&
218 			    HFSPLUS_SB(sb)->hidden_dir->i_ino ==
219 					be32_to_cpu(entry.folder.id))
220 				goto next;
221 			if (!dir_emit(ctx, strbuf, len,
222 				    be32_to_cpu(entry.folder.id), DT_DIR))
223 				break;
224 		} else if (type == HFSPLUS_FILE) {
225 			u16 mode;
226 			unsigned type = DT_UNKNOWN;
227 
228 			if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
229 				pr_err("small file entry\n");
230 				err = -EIO;
231 				goto out;
232 			}
233 
234 			mode = be16_to_cpu(entry.file.permissions.mode);
235 			if (S_ISREG(mode))
236 				type = DT_REG;
237 			else if (S_ISLNK(mode))
238 				type = DT_LNK;
239 			else if (S_ISFIFO(mode))
240 				type = DT_FIFO;
241 			else if (S_ISCHR(mode))
242 				type = DT_CHR;
243 			else if (S_ISBLK(mode))
244 				type = DT_BLK;
245 			else if (S_ISSOCK(mode))
246 				type = DT_SOCK;
247 
248 			if (!dir_emit(ctx, strbuf, len,
249 				      be32_to_cpu(entry.file.id), type))
250 				break;
251 		} else {
252 			pr_err("bad catalog entry type\n");
253 			err = -EIO;
254 			goto out;
255 		}
256 next:
257 		ctx->pos++;
258 		if (ctx->pos >= inode->i_size)
259 			goto out;
260 		err = hfs_brec_goto(&fd, 1);
261 		if (err)
262 			goto out;
263 	}
264 	rd = file->private_data;
265 	if (!rd) {
266 		rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
267 		if (!rd) {
268 			err = -ENOMEM;
269 			goto out;
270 		}
271 		file->private_data = rd;
272 		rd->file = file;
273 		spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
274 		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
275 		spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
276 	}
277 	/*
278 	 * Can be done after the list insertion; exclusion with
279 	 * hfsplus_delete_cat() is provided by directory lock.
280 	 */
281 	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
282 out:
283 	kfree(strbuf);
284 	hfs_find_exit(&fd);
285 	return err;
286 }
287 
288 static int hfsplus_dir_release(struct inode *inode, struct file *file)
289 {
290 	struct hfsplus_readdir_data *rd = file->private_data;
291 	if (rd) {
292 		spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
293 		list_del(&rd->list);
294 		spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
295 		kfree(rd);
296 	}
297 	return 0;
298 }
299 
300 static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
301 			struct dentry *dst_dentry)
302 {
303 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
304 	struct inode *inode = d_inode(src_dentry);
305 	struct inode *src_dir = d_inode(src_dentry->d_parent);
306 	struct qstr str;
307 	char name[32];
308 	u32 cnid, id;
309 	int res;
310 
311 	if (HFSPLUS_IS_RSRC(inode))
312 		return -EPERM;
313 	if (!S_ISREG(inode->i_mode))
314 		return -EPERM;
315 
316 	mutex_lock(&sbi->vh_mutex);
317 	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
318 		for (;;) {
319 			get_random_bytes(&id, sizeof(cnid));
320 			id &= 0x3fffffff;
321 			str.name = name;
322 			str.len = sprintf(name, "iNode%d", id);
323 			res = hfsplus_rename_cat(inode->i_ino,
324 						 src_dir, &src_dentry->d_name,
325 						 sbi->hidden_dir, &str);
326 			if (!res)
327 				break;
328 			if (res != -EEXIST)
329 				goto out;
330 		}
331 		HFSPLUS_I(inode)->linkid = id;
332 		cnid = sbi->next_cnid++;
333 		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
334 		res = hfsplus_create_cat(cnid, src_dir,
335 			&src_dentry->d_name, inode);
336 		if (res)
337 			/* panic? */
338 			goto out;
339 		sbi->file_count++;
340 	}
341 	cnid = sbi->next_cnid++;
342 	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
343 	if (res)
344 		goto out;
345 
346 	inc_nlink(inode);
347 	hfsplus_instantiate(dst_dentry, inode, cnid);
348 	ihold(inode);
349 	inode->i_ctime = current_time(inode);
350 	mark_inode_dirty(inode);
351 	sbi->file_count++;
352 	hfsplus_mark_mdb_dirty(dst_dir->i_sb);
353 out:
354 	mutex_unlock(&sbi->vh_mutex);
355 	return res;
356 }
357 
358 static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
359 {
360 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
361 	struct inode *inode = d_inode(dentry);
362 	struct qstr str;
363 	char name[32];
364 	u32 cnid;
365 	int res;
366 
367 	if (HFSPLUS_IS_RSRC(inode))
368 		return -EPERM;
369 
370 	mutex_lock(&sbi->vh_mutex);
371 	cnid = (u32)(unsigned long)dentry->d_fsdata;
372 	if (inode->i_ino == cnid &&
373 	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
374 		str.name = name;
375 		str.len = sprintf(name, "temp%lu", inode->i_ino);
376 		res = hfsplus_rename_cat(inode->i_ino,
377 					 dir, &dentry->d_name,
378 					 sbi->hidden_dir, &str);
379 		if (!res) {
380 			inode->i_flags |= S_DEAD;
381 			drop_nlink(inode);
382 		}
383 		goto out;
384 	}
385 	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
386 	if (res)
387 		goto out;
388 
389 	if (inode->i_nlink > 0)
390 		drop_nlink(inode);
391 	if (inode->i_ino == cnid)
392 		clear_nlink(inode);
393 	if (!inode->i_nlink) {
394 		if (inode->i_ino != cnid) {
395 			sbi->file_count--;
396 			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
397 				res = hfsplus_delete_cat(inode->i_ino,
398 							 sbi->hidden_dir,
399 							 NULL);
400 				if (!res)
401 					hfsplus_delete_inode(inode);
402 			} else
403 				inode->i_flags |= S_DEAD;
404 		} else
405 			hfsplus_delete_inode(inode);
406 	} else
407 		sbi->file_count--;
408 	inode->i_ctime = current_time(inode);
409 	mark_inode_dirty(inode);
410 out:
411 	mutex_unlock(&sbi->vh_mutex);
412 	return res;
413 }
414 
415 static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
416 {
417 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
418 	struct inode *inode = d_inode(dentry);
419 	int res;
420 
421 	if (inode->i_size != 2)
422 		return -ENOTEMPTY;
423 
424 	mutex_lock(&sbi->vh_mutex);
425 	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
426 	if (res)
427 		goto out;
428 	clear_nlink(inode);
429 	inode->i_ctime = current_time(inode);
430 	hfsplus_delete_inode(inode);
431 	mark_inode_dirty(inode);
432 out:
433 	mutex_unlock(&sbi->vh_mutex);
434 	return res;
435 }
436 
437 static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
438 			   const char *symname)
439 {
440 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
441 	struct inode *inode;
442 	int res = -ENOMEM;
443 
444 	mutex_lock(&sbi->vh_mutex);
445 	inode = hfsplus_new_inode(dir->i_sb, dir, S_IFLNK | S_IRWXUGO);
446 	if (!inode)
447 		goto out;
448 
449 	res = page_symlink(inode, symname, strlen(symname) + 1);
450 	if (res)
451 		goto out_err;
452 
453 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
454 	if (res)
455 		goto out_err;
456 
457 	res = hfsplus_init_security(inode, dir, &dentry->d_name);
458 	if (res == -EOPNOTSUPP)
459 		res = 0; /* Operation is not supported. */
460 	else if (res) {
461 		/* Try to delete anyway without error analysis. */
462 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
463 		goto out_err;
464 	}
465 
466 	hfsplus_instantiate(dentry, inode, inode->i_ino);
467 	mark_inode_dirty(inode);
468 	goto out;
469 
470 out_err:
471 	clear_nlink(inode);
472 	hfsplus_delete_inode(inode);
473 	iput(inode);
474 out:
475 	mutex_unlock(&sbi->vh_mutex);
476 	return res;
477 }
478 
479 static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
480 			 umode_t mode, dev_t rdev)
481 {
482 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
483 	struct inode *inode;
484 	int res = -ENOMEM;
485 
486 	mutex_lock(&sbi->vh_mutex);
487 	inode = hfsplus_new_inode(dir->i_sb, dir, mode);
488 	if (!inode)
489 		goto out;
490 
491 	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
492 		init_special_inode(inode, mode, rdev);
493 
494 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
495 	if (res)
496 		goto failed_mknod;
497 
498 	res = hfsplus_init_security(inode, dir, &dentry->d_name);
499 	if (res == -EOPNOTSUPP)
500 		res = 0; /* Operation is not supported. */
501 	else if (res) {
502 		/* Try to delete anyway without error analysis. */
503 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
504 		goto failed_mknod;
505 	}
506 
507 	hfsplus_instantiate(dentry, inode, inode->i_ino);
508 	mark_inode_dirty(inode);
509 	goto out;
510 
511 failed_mknod:
512 	clear_nlink(inode);
513 	hfsplus_delete_inode(inode);
514 	iput(inode);
515 out:
516 	mutex_unlock(&sbi->vh_mutex);
517 	return res;
518 }
519 
520 static int hfsplus_create(struct inode *dir, struct dentry *dentry, umode_t mode,
521 			  bool excl)
522 {
523 	return hfsplus_mknod(dir, dentry, mode, 0);
524 }
525 
526 static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
527 {
528 	return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
529 }
530 
531 static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
532 			  struct inode *new_dir, struct dentry *new_dentry,
533 			  unsigned int flags)
534 {
535 	int res;
536 
537 	if (flags & ~RENAME_NOREPLACE)
538 		return -EINVAL;
539 
540 	/* Unlink destination if it already exists */
541 	if (d_really_is_positive(new_dentry)) {
542 		if (d_is_dir(new_dentry))
543 			res = hfsplus_rmdir(new_dir, new_dentry);
544 		else
545 			res = hfsplus_unlink(new_dir, new_dentry);
546 		if (res)
547 			return res;
548 	}
549 
550 	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
551 				 old_dir, &old_dentry->d_name,
552 				 new_dir, &new_dentry->d_name);
553 	if (!res)
554 		new_dentry->d_fsdata = old_dentry->d_fsdata;
555 	return res;
556 }
557 
558 const struct inode_operations hfsplus_dir_inode_operations = {
559 	.lookup			= hfsplus_lookup,
560 	.create			= hfsplus_create,
561 	.link			= hfsplus_link,
562 	.unlink			= hfsplus_unlink,
563 	.mkdir			= hfsplus_mkdir,
564 	.rmdir			= hfsplus_rmdir,
565 	.symlink		= hfsplus_symlink,
566 	.mknod			= hfsplus_mknod,
567 	.rename			= hfsplus_rename,
568 	.getattr		= hfsplus_getattr,
569 	.listxattr		= hfsplus_listxattr,
570 };
571 
572 const struct file_operations hfsplus_dir_operations = {
573 	.fsync		= hfsplus_file_fsync,
574 	.read		= generic_read_dir,
575 	.iterate_shared	= hfsplus_readdir,
576 	.unlocked_ioctl = hfsplus_ioctl,
577 	.llseek		= generic_file_llseek,
578 	.release	= hfsplus_dir_release,
579 };
580