xref: /openbmc/linux/fs/hfsplus/dir.c (revision b9b77222)
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 #include "acl.h"
22 
23 static inline void hfsplus_instantiate(struct dentry *dentry,
24 				       struct inode *inode, u32 cnid)
25 {
26 	dentry->d_fsdata = (void *)(unsigned long)cnid;
27 	d_instantiate(dentry, inode);
28 }
29 
30 /* Find the entry inside dir named dentry->d_name */
31 static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
32 				     unsigned int flags)
33 {
34 	struct inode *inode = NULL;
35 	struct hfs_find_data fd;
36 	struct super_block *sb;
37 	hfsplus_cat_entry entry;
38 	int err;
39 	u32 cnid, linkid = 0;
40 	u16 type;
41 
42 	sb = dir->i_sb;
43 
44 	dentry->d_fsdata = NULL;
45 	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
46 	if (err)
47 		return ERR_PTR(err);
48 	err = hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino,
49 			&dentry->d_name);
50 	if (unlikely(err < 0))
51 		goto fail;
52 again:
53 	err = hfs_brec_read(&fd, &entry, sizeof(entry));
54 	if (err) {
55 		if (err == -ENOENT) {
56 			hfs_find_exit(&fd);
57 			/* No such entry */
58 			inode = NULL;
59 			goto out;
60 		}
61 		goto fail;
62 	}
63 	type = be16_to_cpu(entry.type);
64 	if (type == HFSPLUS_FOLDER) {
65 		if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
66 			err = -EIO;
67 			goto fail;
68 		}
69 		cnid = be32_to_cpu(entry.folder.id);
70 		dentry->d_fsdata = (void *)(unsigned long)cnid;
71 	} else if (type == HFSPLUS_FILE) {
72 		if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
73 			err = -EIO;
74 			goto fail;
75 		}
76 		cnid = be32_to_cpu(entry.file.id);
77 		if (entry.file.user_info.fdType ==
78 				cpu_to_be32(HFSP_HARDLINK_TYPE) &&
79 				entry.file.user_info.fdCreator ==
80 				cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
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 				HFSPLUS_SB(sb)->hidden_dir) {
88 			struct qstr str;
89 			char name[32];
90 
91 			if (dentry->d_fsdata) {
92 				/*
93 				 * We found a link pointing to another link,
94 				 * so ignore it and treat it as regular file.
95 				 */
96 				cnid = (unsigned long)dentry->d_fsdata;
97 				linkid = 0;
98 			} else {
99 				dentry->d_fsdata = (void *)(unsigned long)cnid;
100 				linkid =
101 					be32_to_cpu(entry.file.permissions.dev);
102 				str.len = sprintf(name, "iNode%d", linkid);
103 				str.name = name;
104 				err = hfsplus_cat_build_key(sb, fd.search_key,
105 					HFSPLUS_SB(sb)->hidden_dir->i_ino,
106 					&str);
107 				if (unlikely(err < 0))
108 					goto fail;
109 				goto again;
110 			}
111 		} else if (!dentry->d_fsdata)
112 			dentry->d_fsdata = (void *)(unsigned long)cnid;
113 	} else {
114 		pr_err("invalid catalog entry type in lookup\n");
115 		err = -EIO;
116 		goto fail;
117 	}
118 	hfs_find_exit(&fd);
119 	inode = hfsplus_iget(dir->i_sb, cnid);
120 	if (IS_ERR(inode))
121 		return ERR_CAST(inode);
122 	if (S_ISREG(inode->i_mode))
123 		HFSPLUS_I(inode)->linkid = linkid;
124 out:
125 	return d_splice_alias(inode, dentry);
126 fail:
127 	hfs_find_exit(&fd);
128 	return ERR_PTR(err);
129 }
130 
131 static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
132 {
133 	struct inode *inode = file_inode(file);
134 	struct super_block *sb = inode->i_sb;
135 	int len, err;
136 	char *strbuf;
137 	hfsplus_cat_entry entry;
138 	struct hfs_find_data fd;
139 	struct hfsplus_readdir_data *rd;
140 	u16 type;
141 
142 	if (file->f_pos >= inode->i_size)
143 		return 0;
144 
145 	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
146 	if (err)
147 		return err;
148 	strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
149 	if (!strbuf) {
150 		err = -ENOMEM;
151 		goto out;
152 	}
153 	hfsplus_cat_build_key_with_cnid(sb, fd.search_key, inode->i_ino);
154 	err = hfs_brec_find(&fd, hfs_find_rec_by_key);
155 	if (err)
156 		goto out;
157 
158 	if (ctx->pos == 0) {
159 		/* This is completely artificial... */
160 		if (!dir_emit_dot(file, ctx))
161 			goto out;
162 		ctx->pos = 1;
163 	}
164 	if (ctx->pos == 1) {
165 		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
166 			err = -EIO;
167 			goto out;
168 		}
169 
170 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
171 			fd.entrylength);
172 		if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
173 			pr_err("bad catalog folder thread\n");
174 			err = -EIO;
175 			goto out;
176 		}
177 		if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
178 			pr_err("truncated catalog thread\n");
179 			err = -EIO;
180 			goto out;
181 		}
182 		if (!dir_emit(ctx, "..", 2,
183 			    be32_to_cpu(entry.thread.parentID), DT_DIR))
184 			goto out;
185 		ctx->pos = 2;
186 	}
187 	if (ctx->pos >= inode->i_size)
188 		goto out;
189 	err = hfs_brec_goto(&fd, ctx->pos - 1);
190 	if (err)
191 		goto out;
192 	for (;;) {
193 		if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
194 			pr_err("walked past end of dir\n");
195 			err = -EIO;
196 			goto out;
197 		}
198 
199 		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
200 			err = -EIO;
201 			goto out;
202 		}
203 
204 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
205 			fd.entrylength);
206 		type = be16_to_cpu(entry.type);
207 		len = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN;
208 		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
209 		if (err)
210 			goto out;
211 		if (type == HFSPLUS_FOLDER) {
212 			if (fd.entrylength <
213 					sizeof(struct hfsplus_cat_folder)) {
214 				pr_err("small dir entry\n");
215 				err = -EIO;
216 				goto out;
217 			}
218 			if (HFSPLUS_SB(sb)->hidden_dir &&
219 			    HFSPLUS_SB(sb)->hidden_dir->i_ino ==
220 					be32_to_cpu(entry.folder.id))
221 				goto next;
222 			if (!dir_emit(ctx, strbuf, len,
223 				    be32_to_cpu(entry.folder.id), DT_DIR))
224 				break;
225 		} else if (type == HFSPLUS_FILE) {
226 			u16 mode;
227 			unsigned type = DT_UNKNOWN;
228 
229 			if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
230 				pr_err("small file entry\n");
231 				err = -EIO;
232 				goto out;
233 			}
234 
235 			mode = be16_to_cpu(entry.file.permissions.mode);
236 			if (S_ISREG(mode))
237 				type = DT_REG;
238 			else if (S_ISLNK(mode))
239 				type = DT_LNK;
240 			else if (S_ISFIFO(mode))
241 				type = DT_FIFO;
242 			else if (S_ISCHR(mode))
243 				type = DT_CHR;
244 			else if (S_ISBLK(mode))
245 				type = DT_BLK;
246 			else if (S_ISSOCK(mode))
247 				type = DT_SOCK;
248 
249 			if (!dir_emit(ctx, strbuf, len,
250 				      be32_to_cpu(entry.file.id), type))
251 				break;
252 		} else {
253 			pr_err("bad catalog entry type\n");
254 			err = -EIO;
255 			goto out;
256 		}
257 next:
258 		ctx->pos++;
259 		if (ctx->pos >= inode->i_size)
260 			goto out;
261 		err = hfs_brec_goto(&fd, 1);
262 		if (err)
263 			goto out;
264 	}
265 	rd = file->private_data;
266 	if (!rd) {
267 		rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
268 		if (!rd) {
269 			err = -ENOMEM;
270 			goto out;
271 		}
272 		file->private_data = rd;
273 		rd->file = file;
274 		spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
275 		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
276 		spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
277 	}
278 	/*
279 	 * Can be done after the list insertion; exclusion with
280 	 * hfsplus_delete_cat() is provided by directory lock.
281 	 */
282 	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
283 out:
284 	kfree(strbuf);
285 	hfs_find_exit(&fd);
286 	return err;
287 }
288 
289 static int hfsplus_dir_release(struct inode *inode, struct file *file)
290 {
291 	struct hfsplus_readdir_data *rd = file->private_data;
292 	if (rd) {
293 		spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
294 		list_del(&rd->list);
295 		spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
296 		kfree(rd);
297 	}
298 	return 0;
299 }
300 
301 static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
302 			struct dentry *dst_dentry)
303 {
304 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
305 	struct inode *inode = d_inode(src_dentry);
306 	struct inode *src_dir = d_inode(src_dentry->d_parent);
307 	struct qstr str;
308 	char name[32];
309 	u32 cnid, id;
310 	int res;
311 
312 	if (HFSPLUS_IS_RSRC(inode))
313 		return -EPERM;
314 	if (!S_ISREG(inode->i_mode))
315 		return -EPERM;
316 
317 	mutex_lock(&sbi->vh_mutex);
318 	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
319 		for (;;) {
320 			get_random_bytes(&id, sizeof(cnid));
321 			id &= 0x3fffffff;
322 			str.name = name;
323 			str.len = sprintf(name, "iNode%d", id);
324 			res = hfsplus_rename_cat(inode->i_ino,
325 						 src_dir, &src_dentry->d_name,
326 						 sbi->hidden_dir, &str);
327 			if (!res)
328 				break;
329 			if (res != -EEXIST)
330 				goto out;
331 		}
332 		HFSPLUS_I(inode)->linkid = id;
333 		cnid = sbi->next_cnid++;
334 		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
335 		res = hfsplus_create_cat(cnid, src_dir,
336 			&src_dentry->d_name, inode);
337 		if (res)
338 			/* panic? */
339 			goto out;
340 		sbi->file_count++;
341 	}
342 	cnid = sbi->next_cnid++;
343 	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
344 	if (res)
345 		goto out;
346 
347 	inc_nlink(inode);
348 	hfsplus_instantiate(dst_dentry, inode, cnid);
349 	ihold(inode);
350 	inode->i_ctime = current_time(inode);
351 	mark_inode_dirty(inode);
352 	sbi->file_count++;
353 	hfsplus_mark_mdb_dirty(dst_dir->i_sb);
354 out:
355 	mutex_unlock(&sbi->vh_mutex);
356 	return res;
357 }
358 
359 static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
360 {
361 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
362 	struct inode *inode = d_inode(dentry);
363 	struct qstr str;
364 	char name[32];
365 	u32 cnid;
366 	int res;
367 
368 	if (HFSPLUS_IS_RSRC(inode))
369 		return -EPERM;
370 
371 	mutex_lock(&sbi->vh_mutex);
372 	cnid = (u32)(unsigned long)dentry->d_fsdata;
373 	if (inode->i_ino == cnid &&
374 	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
375 		str.name = name;
376 		str.len = sprintf(name, "temp%lu", inode->i_ino);
377 		res = hfsplus_rename_cat(inode->i_ino,
378 					 dir, &dentry->d_name,
379 					 sbi->hidden_dir, &str);
380 		if (!res) {
381 			inode->i_flags |= S_DEAD;
382 			drop_nlink(inode);
383 		}
384 		goto out;
385 	}
386 	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
387 	if (res)
388 		goto out;
389 
390 	if (inode->i_nlink > 0)
391 		drop_nlink(inode);
392 	if (inode->i_ino == cnid)
393 		clear_nlink(inode);
394 	if (!inode->i_nlink) {
395 		if (inode->i_ino != cnid) {
396 			sbi->file_count--;
397 			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
398 				res = hfsplus_delete_cat(inode->i_ino,
399 							 sbi->hidden_dir,
400 							 NULL);
401 				if (!res)
402 					hfsplus_delete_inode(inode);
403 			} else
404 				inode->i_flags |= S_DEAD;
405 		} else
406 			hfsplus_delete_inode(inode);
407 	} else
408 		sbi->file_count--;
409 	inode->i_ctime = current_time(inode);
410 	mark_inode_dirty(inode);
411 out:
412 	mutex_unlock(&sbi->vh_mutex);
413 	return res;
414 }
415 
416 static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
417 {
418 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
419 	struct inode *inode = d_inode(dentry);
420 	int res;
421 
422 	if (inode->i_size != 2)
423 		return -ENOTEMPTY;
424 
425 	mutex_lock(&sbi->vh_mutex);
426 	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
427 	if (res)
428 		goto out;
429 	clear_nlink(inode);
430 	inode->i_ctime = current_time(inode);
431 	hfsplus_delete_inode(inode);
432 	mark_inode_dirty(inode);
433 out:
434 	mutex_unlock(&sbi->vh_mutex);
435 	return res;
436 }
437 
438 static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
439 			   const char *symname)
440 {
441 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
442 	struct inode *inode;
443 	int res = -ENOMEM;
444 
445 	mutex_lock(&sbi->vh_mutex);
446 	inode = hfsplus_new_inode(dir->i_sb, dir, S_IFLNK | S_IRWXUGO);
447 	if (!inode)
448 		goto out;
449 
450 	res = page_symlink(inode, symname, strlen(symname) + 1);
451 	if (res)
452 		goto out_err;
453 
454 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
455 	if (res)
456 		goto out_err;
457 
458 	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
459 	if (res == -EOPNOTSUPP)
460 		res = 0; /* Operation is not supported. */
461 	else if (res) {
462 		/* Try to delete anyway without error analysis. */
463 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
464 		goto out_err;
465 	}
466 
467 	hfsplus_instantiate(dentry, inode, inode->i_ino);
468 	mark_inode_dirty(inode);
469 	goto out;
470 
471 out_err:
472 	clear_nlink(inode);
473 	hfsplus_delete_inode(inode);
474 	iput(inode);
475 out:
476 	mutex_unlock(&sbi->vh_mutex);
477 	return res;
478 }
479 
480 static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
481 			 umode_t mode, dev_t rdev)
482 {
483 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
484 	struct inode *inode;
485 	int res = -ENOMEM;
486 
487 	mutex_lock(&sbi->vh_mutex);
488 	inode = hfsplus_new_inode(dir->i_sb, dir, mode);
489 	if (!inode)
490 		goto out;
491 
492 	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
493 		init_special_inode(inode, mode, rdev);
494 
495 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
496 	if (res)
497 		goto failed_mknod;
498 
499 	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
500 	if (res == -EOPNOTSUPP)
501 		res = 0; /* Operation is not supported. */
502 	else if (res) {
503 		/* Try to delete anyway without error analysis. */
504 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
505 		goto failed_mknod;
506 	}
507 
508 	hfsplus_instantiate(dentry, inode, inode->i_ino);
509 	mark_inode_dirty(inode);
510 	goto out;
511 
512 failed_mknod:
513 	clear_nlink(inode);
514 	hfsplus_delete_inode(inode);
515 	iput(inode);
516 out:
517 	mutex_unlock(&sbi->vh_mutex);
518 	return res;
519 }
520 
521 static int hfsplus_create(struct inode *dir, struct dentry *dentry, umode_t mode,
522 			  bool excl)
523 {
524 	return hfsplus_mknod(dir, dentry, mode, 0);
525 }
526 
527 static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
528 {
529 	return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
530 }
531 
532 static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
533 			  struct inode *new_dir, struct dentry *new_dentry,
534 			  unsigned int flags)
535 {
536 	int res;
537 
538 	if (flags & ~RENAME_NOREPLACE)
539 		return -EINVAL;
540 
541 	/* Unlink destination if it already exists */
542 	if (d_really_is_positive(new_dentry)) {
543 		if (d_is_dir(new_dentry))
544 			res = hfsplus_rmdir(new_dir, new_dentry);
545 		else
546 			res = hfsplus_unlink(new_dir, new_dentry);
547 		if (res)
548 			return res;
549 	}
550 
551 	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
552 				 old_dir, &old_dentry->d_name,
553 				 new_dir, &new_dentry->d_name);
554 	if (!res)
555 		new_dentry->d_fsdata = old_dentry->d_fsdata;
556 	return res;
557 }
558 
559 const struct inode_operations hfsplus_dir_inode_operations = {
560 	.lookup			= hfsplus_lookup,
561 	.create			= hfsplus_create,
562 	.link			= hfsplus_link,
563 	.unlink			= hfsplus_unlink,
564 	.mkdir			= hfsplus_mkdir,
565 	.rmdir			= hfsplus_rmdir,
566 	.symlink		= hfsplus_symlink,
567 	.mknod			= hfsplus_mknod,
568 	.rename			= hfsplus_rename,
569 	.listxattr		= hfsplus_listxattr,
570 #ifdef CONFIG_HFSPLUS_FS_POSIX_ACL
571 	.get_acl		= hfsplus_get_posix_acl,
572 	.set_acl		= hfsplus_set_posix_acl,
573 #endif
574 };
575 
576 const struct file_operations hfsplus_dir_operations = {
577 	.fsync		= hfsplus_file_fsync,
578 	.read		= generic_read_dir,
579 	.iterate_shared	= hfsplus_readdir,
580 	.unlocked_ioctl = hfsplus_ioctl,
581 	.llseek		= generic_file_llseek,
582 	.release	= hfsplus_dir_release,
583 };
584