xref: /linux/fs/hfsplus/dir.c (revision 056e065a6b6e01ab54bb9770c0d5a15350e571e2)
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 = hfsplus_brec_read_cat(&fd, &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 	rd = file->private_data;
189 	if (rd && rd->pos == ctx->pos) {
190 		memcpy(fd.search_key, &rd->key, sizeof(struct hfsplus_cat_key));
191 		err = hfs_brec_find(&fd, hfs_find_rec_by_key);
192 		if (err == -ENOENT)
193 			err = hfs_brec_goto(&fd, 1);
194 	} else {
195 		err = hfs_brec_goto(&fd, ctx->pos - 1);
196 	}
197 	if (err)
198 		goto out;
199 	for (;;) {
200 		if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
201 			pr_err("walked past end of dir\n");
202 			err = -EIO;
203 			goto out;
204 		}
205 
206 		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
207 			err = -EIO;
208 			goto out;
209 		}
210 
211 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
212 			fd.entrylength);
213 		type = be16_to_cpu(entry.type);
214 		len = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN;
215 		err = hfsplus_uni2asc_str(sb, &fd.key->cat.name, strbuf, &len);
216 		if (err)
217 			goto out;
218 		if (type == HFSPLUS_FOLDER) {
219 			if (fd.entrylength <
220 					sizeof(struct hfsplus_cat_folder)) {
221 				pr_err("small dir entry\n");
222 				err = -EIO;
223 				goto out;
224 			}
225 			if (HFSPLUS_SB(sb)->hidden_dir &&
226 			    HFSPLUS_SB(sb)->hidden_dir->i_ino ==
227 					be32_to_cpu(entry.folder.id))
228 				goto next;
229 			if (!dir_emit(ctx, strbuf, len,
230 				    be32_to_cpu(entry.folder.id), DT_DIR))
231 				break;
232 		} else if (type == HFSPLUS_FILE) {
233 			u16 mode;
234 			unsigned type = DT_UNKNOWN;
235 
236 			if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
237 				pr_err("small file entry\n");
238 				err = -EIO;
239 				goto out;
240 			}
241 
242 			mode = be16_to_cpu(entry.file.permissions.mode);
243 			if (S_ISREG(mode))
244 				type = DT_REG;
245 			else if (S_ISLNK(mode))
246 				type = DT_LNK;
247 			else if (S_ISFIFO(mode))
248 				type = DT_FIFO;
249 			else if (S_ISCHR(mode))
250 				type = DT_CHR;
251 			else if (S_ISBLK(mode))
252 				type = DT_BLK;
253 			else if (S_ISSOCK(mode))
254 				type = DT_SOCK;
255 
256 			if (!dir_emit(ctx, strbuf, len,
257 				      be32_to_cpu(entry.file.id), type))
258 				break;
259 		} else {
260 			pr_err("bad catalog entry type\n");
261 			err = -EIO;
262 			goto out;
263 		}
264 next:
265 		ctx->pos++;
266 		if (ctx->pos >= inode->i_size)
267 			goto out;
268 		err = hfs_brec_goto(&fd, 1);
269 		if (err)
270 			goto out;
271 	}
272 	if (!rd) {
273 		rd = kmalloc_obj(struct hfsplus_readdir_data);
274 		if (!rd) {
275 			err = -ENOMEM;
276 			goto out;
277 		}
278 		file->private_data = rd;
279 	}
280 	rd->pos = ctx->pos;
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 	kfree(file->private_data);
291 	return 0;
292 }
293 
294 static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
295 			struct dentry *dst_dentry)
296 {
297 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
298 	struct inode *inode = d_inode(src_dentry);
299 	struct inode *src_dir = d_inode(src_dentry->d_parent);
300 	struct qstr str;
301 	char name[32];
302 	u32 cnid, id;
303 	int res;
304 
305 	if (HFSPLUS_IS_RSRC(inode))
306 		return -EPERM;
307 	if (!S_ISREG(inode->i_mode))
308 		return -EPERM;
309 
310 	hfs_dbg("src_dir->i_ino %llu, dst_dir->i_ino %llu, inode->i_ino %llu\n",
311 		src_dir->i_ino, dst_dir->i_ino, inode->i_ino);
312 
313 	mutex_lock(&sbi->vh_mutex);
314 	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
315 		for (;;) {
316 			get_random_bytes(&id, sizeof(cnid));
317 			id &= 0x3fffffff;
318 			str.name = name;
319 			str.len = sprintf(name, "iNode%d", id);
320 			res = hfsplus_rename_cat(inode->i_ino,
321 						 src_dir, &src_dentry->d_name,
322 						 sbi->hidden_dir, &str);
323 			if (!res)
324 				break;
325 			if (res != -EEXIST)
326 				goto out;
327 		}
328 		HFSPLUS_I(inode)->linkid = id;
329 		cnid = sbi->next_cnid++;
330 		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
331 		res = hfsplus_create_cat(cnid, src_dir,
332 					 &src_dentry->d_name, inode);
333 		if (res)
334 			/* panic? */
335 			goto out;
336 		sbi->file_count++;
337 	}
338 	cnid = sbi->next_cnid++;
339 	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
340 	if (res)
341 		goto out;
342 
343 	inc_nlink(inode);
344 	hfsplus_instantiate(dst_dentry, inode, cnid);
345 	ihold(inode);
346 	inode_set_ctime_current(inode);
347 	mark_inode_dirty(inode);
348 	sbi->file_count++;
349 	hfsplus_mark_mdb_dirty(dst_dir->i_sb);
350 
351 	res = hfsplus_cat_write_inode(src_dir);
352 	if (res)
353 		goto out;
354 
355 	res = hfsplus_cat_write_inode(dst_dir);
356 	if (res)
357 		goto out;
358 
359 	res = hfsplus_cat_write_inode(sbi->hidden_dir);
360 	if (res)
361 		goto out;
362 
363 	res = hfsplus_cat_write_inode(inode);
364 
365 out:
366 	mutex_unlock(&sbi->vh_mutex);
367 	return res;
368 }
369 
370 static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
371 {
372 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
373 	struct inode *inode = d_inode(dentry);
374 	struct qstr str;
375 	char name[32];
376 	u32 cnid;
377 	int res;
378 
379 	if (HFSPLUS_IS_RSRC(inode))
380 		return -EPERM;
381 
382 	hfs_dbg("dir->i_ino %llu, inode->i_ino %llu\n",
383 		dir->i_ino, inode->i_ino);
384 
385 	mutex_lock(&sbi->vh_mutex);
386 	cnid = (u32)(unsigned long)dentry->d_fsdata;
387 	if (inode->i_ino == cnid &&
388 	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
389 		str.name = name;
390 		str.len = sprintf(name, "temp%llu", inode->i_ino);
391 		res = hfsplus_rename_cat(inode->i_ino,
392 					 dir, &dentry->d_name,
393 					 sbi->hidden_dir, &str);
394 		if (!res) {
395 			inode->i_flags |= S_DEAD;
396 			drop_nlink(inode);
397 		}
398 		goto out;
399 	}
400 	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
401 	if (res)
402 		goto out;
403 
404 	if (inode->i_nlink > 0)
405 		drop_nlink(inode);
406 	if (inode->i_ino == cnid)
407 		clear_nlink(inode);
408 	if (!inode->i_nlink) {
409 		if (inode->i_ino != cnid) {
410 			sbi->file_count--;
411 			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
412 				res = hfsplus_delete_cat(inode->i_ino,
413 							 sbi->hidden_dir,
414 							 NULL);
415 				if (!res)
416 					hfsplus_delete_inode(inode);
417 			} else
418 				inode->i_flags |= S_DEAD;
419 		} else
420 			hfsplus_delete_inode(inode);
421 	} else
422 		sbi->file_count--;
423 	inode_set_ctime_current(inode);
424 	mark_inode_dirty(inode);
425 out:
426 	if (!res) {
427 		res = hfsplus_cat_write_inode(dir);
428 		if (!res) {
429 			res = hfsplus_cat_write_inode(sbi->hidden_dir);
430 			if (!res)
431 				res = hfsplus_cat_write_inode(inode);
432 		}
433 	}
434 
435 	mutex_unlock(&sbi->vh_mutex);
436 	return res;
437 }
438 
439 static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
440 {
441 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
442 	struct inode *inode = d_inode(dentry);
443 	int res;
444 
445 	if (inode->i_size != 2)
446 		return -ENOTEMPTY;
447 
448 	mutex_lock(&sbi->vh_mutex);
449 	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
450 	if (res)
451 		goto out;
452 	clear_nlink(inode);
453 	inode_set_ctime_current(inode);
454 	hfsplus_delete_inode(inode);
455 	mark_inode_dirty(inode);
456 
457 	res = hfsplus_cat_write_inode(dir);
458 out:
459 	mutex_unlock(&sbi->vh_mutex);
460 	return res;
461 }
462 
463 static int hfsplus_symlink(struct mnt_idmap *idmap, struct inode *dir,
464 			   struct dentry *dentry, const char *symname)
465 {
466 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
467 	struct inode *inode;
468 	int res = -ENOMEM;
469 
470 	mutex_lock(&sbi->vh_mutex);
471 	inode = hfsplus_new_inode(dir->i_sb, dir, S_IFLNK | S_IRWXUGO);
472 	if (!inode)
473 		goto out;
474 
475 	hfs_dbg("dir->i_ino %llu, inode->i_ino %llu\n",
476 		dir->i_ino, inode->i_ino);
477 
478 	res = page_symlink(inode, symname, strlen(symname) + 1);
479 	if (res)
480 		goto out_err;
481 
482 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
483 	if (res)
484 		goto out_err;
485 
486 	res = hfsplus_init_security(inode, dir, &dentry->d_name);
487 	if (res == -EOPNOTSUPP)
488 		res = 0; /* Operation is not supported. */
489 	else if (res) {
490 		/* Try to delete anyway without error analysis. */
491 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
492 		goto out_err;
493 	}
494 
495 	hfsplus_instantiate(dentry, inode, inode->i_ino);
496 	mark_inode_dirty(inode);
497 
498 	res = hfsplus_cat_write_inode(dir);
499 	if (res)
500 		goto out;
501 
502 	res = hfsplus_cat_write_inode(inode);
503 	goto out;
504 
505 out_err:
506 	clear_nlink(inode);
507 	hfsplus_delete_inode(inode);
508 	iput(inode);
509 out:
510 	mutex_unlock(&sbi->vh_mutex);
511 	return res;
512 }
513 
514 static int hfsplus_mknod(struct mnt_idmap *idmap, struct inode *dir,
515 			 struct dentry *dentry, umode_t mode, dev_t rdev)
516 {
517 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
518 	struct inode *inode;
519 	int res = -ENOMEM;
520 
521 	mutex_lock(&sbi->vh_mutex);
522 	inode = hfsplus_new_inode(dir->i_sb, dir, mode);
523 	if (!inode)
524 		goto out;
525 
526 	hfs_dbg("dir->i_ino %llu, inode->i_ino %llu\n",
527 		dir->i_ino, inode->i_ino);
528 
529 	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
530 		init_special_inode(inode, mode, rdev);
531 
532 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
533 	if (res)
534 		goto failed_mknod;
535 
536 	res = hfsplus_init_security(inode, dir, &dentry->d_name);
537 	if (res == -EOPNOTSUPP)
538 		res = 0; /* Operation is not supported. */
539 	else if (res) {
540 		/* Try to delete anyway without error analysis. */
541 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
542 		goto failed_mknod;
543 	}
544 
545 	hfsplus_instantiate(dentry, inode, inode->i_ino);
546 	mark_inode_dirty(inode);
547 
548 	res = hfsplus_cat_write_inode(dir);
549 	if (res)
550 		goto out;
551 
552 	res = hfsplus_cat_write_inode(inode);
553 	goto out;
554 
555 failed_mknod:
556 	clear_nlink(inode);
557 	hfsplus_delete_inode(inode);
558 	iput(inode);
559 out:
560 	mutex_unlock(&sbi->vh_mutex);
561 	return res;
562 }
563 
564 static int hfsplus_create(struct mnt_idmap *idmap, struct inode *dir,
565 			  struct dentry *dentry, umode_t mode, bool excl)
566 {
567 	return hfsplus_mknod(&nop_mnt_idmap, dir, dentry, mode, 0);
568 }
569 
570 static struct dentry *hfsplus_mkdir(struct mnt_idmap *idmap, struct inode *dir,
571 				    struct dentry *dentry, umode_t mode)
572 {
573 	return ERR_PTR(hfsplus_mknod(&nop_mnt_idmap, dir, dentry, mode | S_IFDIR, 0));
574 }
575 
576 static int hfsplus_rename(struct mnt_idmap *idmap,
577 			  struct inode *old_dir, struct dentry *old_dentry,
578 			  struct inode *new_dir, struct dentry *new_dentry,
579 			  unsigned int flags)
580 {
581 	int res;
582 
583 	if (flags & ~RENAME_NOREPLACE)
584 		return -EINVAL;
585 
586 	/* Unlink destination if it already exists */
587 	if (d_really_is_positive(new_dentry)) {
588 		if (d_is_dir(new_dentry))
589 			res = hfsplus_rmdir(new_dir, new_dentry);
590 		else
591 			res = hfsplus_unlink(new_dir, new_dentry);
592 		if (res)
593 			return res;
594 	}
595 
596 	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
597 				 old_dir, &old_dentry->d_name,
598 				 new_dir, &new_dentry->d_name);
599 	if (!res) {
600 		struct inode *inode = d_inode(old_dentry);
601 
602 		new_dentry->d_fsdata = old_dentry->d_fsdata;
603 
604 		inode_set_ctime_current(inode);
605 		mark_inode_dirty(inode);
606 
607 		res = hfsplus_cat_write_inode(old_dir);
608 		if (res)
609 			return res;
610 
611 		res = hfsplus_cat_write_inode(new_dir);
612 		if (res)
613 			return res;
614 
615 		res = hfsplus_cat_write_inode(inode);
616 	}
617 	return res;
618 }
619 
620 const struct inode_operations hfsplus_dir_inode_operations = {
621 	.lookup			= hfsplus_lookup,
622 	.create			= hfsplus_create,
623 	.link			= hfsplus_link,
624 	.unlink			= hfsplus_unlink,
625 	.mkdir			= hfsplus_mkdir,
626 	.rmdir			= hfsplus_rmdir,
627 	.symlink		= hfsplus_symlink,
628 	.mknod			= hfsplus_mknod,
629 	.rename			= hfsplus_rename,
630 	.getattr		= hfsplus_getattr,
631 	.listxattr		= hfsplus_listxattr,
632 	.fileattr_get		= hfsplus_fileattr_get,
633 	.fileattr_set		= hfsplus_fileattr_set,
634 };
635 
636 const struct file_operations hfsplus_dir_operations = {
637 	.fsync		= hfsplus_file_fsync,
638 	.read		= generic_read_dir,
639 	.iterate_shared	= hfsplus_readdir,
640 	.unlocked_ioctl = hfsplus_ioctl,
641 	.llseek		= generic_file_llseek,
642 	.release	= hfsplus_dir_release,
643 };
644