xref: /openbmc/linux/fs/hfsplus/dir.c (revision 4cff79e9)
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 	d_add(dentry, inode);
126 	return NULL;
127 fail:
128 	hfs_find_exit(&fd);
129 	return ERR_PTR(err);
130 }
131 
132 static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
133 {
134 	struct inode *inode = file_inode(file);
135 	struct super_block *sb = inode->i_sb;
136 	int len, err;
137 	char *strbuf;
138 	hfsplus_cat_entry entry;
139 	struct hfs_find_data fd;
140 	struct hfsplus_readdir_data *rd;
141 	u16 type;
142 
143 	if (file->f_pos >= inode->i_size)
144 		return 0;
145 
146 	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
147 	if (err)
148 		return err;
149 	strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
150 	if (!strbuf) {
151 		err = -ENOMEM;
152 		goto out;
153 	}
154 	hfsplus_cat_build_key_with_cnid(sb, fd.search_key, inode->i_ino);
155 	err = hfs_brec_find(&fd, hfs_find_rec_by_key);
156 	if (err)
157 		goto out;
158 
159 	if (ctx->pos == 0) {
160 		/* This is completely artificial... */
161 		if (!dir_emit_dot(file, ctx))
162 			goto out;
163 		ctx->pos = 1;
164 	}
165 	if (ctx->pos == 1) {
166 		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
167 			err = -EIO;
168 			goto out;
169 		}
170 
171 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
172 			fd.entrylength);
173 		if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
174 			pr_err("bad catalog folder thread\n");
175 			err = -EIO;
176 			goto out;
177 		}
178 		if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
179 			pr_err("truncated catalog thread\n");
180 			err = -EIO;
181 			goto out;
182 		}
183 		if (!dir_emit(ctx, "..", 2,
184 			    be32_to_cpu(entry.thread.parentID), DT_DIR))
185 			goto out;
186 		ctx->pos = 2;
187 	}
188 	if (ctx->pos >= inode->i_size)
189 		goto out;
190 	err = hfs_brec_goto(&fd, ctx->pos - 1);
191 	if (err)
192 		goto out;
193 	for (;;) {
194 		if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
195 			pr_err("walked past end of dir\n");
196 			err = -EIO;
197 			goto out;
198 		}
199 
200 		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
201 			err = -EIO;
202 			goto out;
203 		}
204 
205 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
206 			fd.entrylength);
207 		type = be16_to_cpu(entry.type);
208 		len = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN;
209 		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
210 		if (err)
211 			goto out;
212 		if (type == HFSPLUS_FOLDER) {
213 			if (fd.entrylength <
214 					sizeof(struct hfsplus_cat_folder)) {
215 				pr_err("small dir entry\n");
216 				err = -EIO;
217 				goto out;
218 			}
219 			if (HFSPLUS_SB(sb)->hidden_dir &&
220 			    HFSPLUS_SB(sb)->hidden_dir->i_ino ==
221 					be32_to_cpu(entry.folder.id))
222 				goto next;
223 			if (!dir_emit(ctx, strbuf, len,
224 				    be32_to_cpu(entry.folder.id), DT_DIR))
225 				break;
226 		} else if (type == HFSPLUS_FILE) {
227 			u16 mode;
228 			unsigned type = DT_UNKNOWN;
229 
230 			if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
231 				pr_err("small file entry\n");
232 				err = -EIO;
233 				goto out;
234 			}
235 
236 			mode = be16_to_cpu(entry.file.permissions.mode);
237 			if (S_ISREG(mode))
238 				type = DT_REG;
239 			else if (S_ISLNK(mode))
240 				type = DT_LNK;
241 			else if (S_ISFIFO(mode))
242 				type = DT_FIFO;
243 			else if (S_ISCHR(mode))
244 				type = DT_CHR;
245 			else if (S_ISBLK(mode))
246 				type = DT_BLK;
247 			else if (S_ISSOCK(mode))
248 				type = DT_SOCK;
249 
250 			if (!dir_emit(ctx, strbuf, len,
251 				      be32_to_cpu(entry.file.id), type))
252 				break;
253 		} else {
254 			pr_err("bad catalog entry type\n");
255 			err = -EIO;
256 			goto out;
257 		}
258 next:
259 		ctx->pos++;
260 		if (ctx->pos >= inode->i_size)
261 			goto out;
262 		err = hfs_brec_goto(&fd, 1);
263 		if (err)
264 			goto out;
265 	}
266 	rd = file->private_data;
267 	if (!rd) {
268 		rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
269 		if (!rd) {
270 			err = -ENOMEM;
271 			goto out;
272 		}
273 		file->private_data = rd;
274 		rd->file = file;
275 		spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
276 		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
277 		spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
278 	}
279 	/*
280 	 * Can be done after the list insertion; exclusion with
281 	 * hfsplus_delete_cat() is provided by directory lock.
282 	 */
283 	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
284 out:
285 	kfree(strbuf);
286 	hfs_find_exit(&fd);
287 	return err;
288 }
289 
290 static int hfsplus_dir_release(struct inode *inode, struct file *file)
291 {
292 	struct hfsplus_readdir_data *rd = file->private_data;
293 	if (rd) {
294 		spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
295 		list_del(&rd->list);
296 		spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
297 		kfree(rd);
298 	}
299 	return 0;
300 }
301 
302 static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
303 			struct dentry *dst_dentry)
304 {
305 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
306 	struct inode *inode = d_inode(src_dentry);
307 	struct inode *src_dir = d_inode(src_dentry->d_parent);
308 	struct qstr str;
309 	char name[32];
310 	u32 cnid, id;
311 	int res;
312 
313 	if (HFSPLUS_IS_RSRC(inode))
314 		return -EPERM;
315 	if (!S_ISREG(inode->i_mode))
316 		return -EPERM;
317 
318 	mutex_lock(&sbi->vh_mutex);
319 	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
320 		for (;;) {
321 			get_random_bytes(&id, sizeof(cnid));
322 			id &= 0x3fffffff;
323 			str.name = name;
324 			str.len = sprintf(name, "iNode%d", id);
325 			res = hfsplus_rename_cat(inode->i_ino,
326 						 src_dir, &src_dentry->d_name,
327 						 sbi->hidden_dir, &str);
328 			if (!res)
329 				break;
330 			if (res != -EEXIST)
331 				goto out;
332 		}
333 		HFSPLUS_I(inode)->linkid = id;
334 		cnid = sbi->next_cnid++;
335 		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
336 		res = hfsplus_create_cat(cnid, src_dir,
337 			&src_dentry->d_name, inode);
338 		if (res)
339 			/* panic? */
340 			goto out;
341 		sbi->file_count++;
342 	}
343 	cnid = sbi->next_cnid++;
344 	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
345 	if (res)
346 		goto out;
347 
348 	inc_nlink(inode);
349 	hfsplus_instantiate(dst_dentry, inode, cnid);
350 	ihold(inode);
351 	inode->i_ctime = current_time(inode);
352 	mark_inode_dirty(inode);
353 	sbi->file_count++;
354 	hfsplus_mark_mdb_dirty(dst_dir->i_sb);
355 out:
356 	mutex_unlock(&sbi->vh_mutex);
357 	return res;
358 }
359 
360 static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
361 {
362 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
363 	struct inode *inode = d_inode(dentry);
364 	struct qstr str;
365 	char name[32];
366 	u32 cnid;
367 	int res;
368 
369 	if (HFSPLUS_IS_RSRC(inode))
370 		return -EPERM;
371 
372 	mutex_lock(&sbi->vh_mutex);
373 	cnid = (u32)(unsigned long)dentry->d_fsdata;
374 	if (inode->i_ino == cnid &&
375 	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
376 		str.name = name;
377 		str.len = sprintf(name, "temp%lu", inode->i_ino);
378 		res = hfsplus_rename_cat(inode->i_ino,
379 					 dir, &dentry->d_name,
380 					 sbi->hidden_dir, &str);
381 		if (!res) {
382 			inode->i_flags |= S_DEAD;
383 			drop_nlink(inode);
384 		}
385 		goto out;
386 	}
387 	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
388 	if (res)
389 		goto out;
390 
391 	if (inode->i_nlink > 0)
392 		drop_nlink(inode);
393 	if (inode->i_ino == cnid)
394 		clear_nlink(inode);
395 	if (!inode->i_nlink) {
396 		if (inode->i_ino != cnid) {
397 			sbi->file_count--;
398 			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
399 				res = hfsplus_delete_cat(inode->i_ino,
400 							 sbi->hidden_dir,
401 							 NULL);
402 				if (!res)
403 					hfsplus_delete_inode(inode);
404 			} else
405 				inode->i_flags |= S_DEAD;
406 		} else
407 			hfsplus_delete_inode(inode);
408 	} else
409 		sbi->file_count--;
410 	inode->i_ctime = current_time(inode);
411 	mark_inode_dirty(inode);
412 out:
413 	mutex_unlock(&sbi->vh_mutex);
414 	return res;
415 }
416 
417 static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
418 {
419 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
420 	struct inode *inode = d_inode(dentry);
421 	int res;
422 
423 	if (inode->i_size != 2)
424 		return -ENOTEMPTY;
425 
426 	mutex_lock(&sbi->vh_mutex);
427 	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
428 	if (res)
429 		goto out;
430 	clear_nlink(inode);
431 	inode->i_ctime = current_time(inode);
432 	hfsplus_delete_inode(inode);
433 	mark_inode_dirty(inode);
434 out:
435 	mutex_unlock(&sbi->vh_mutex);
436 	return res;
437 }
438 
439 static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
440 			   const char *symname)
441 {
442 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
443 	struct inode *inode;
444 	int res = -ENOMEM;
445 
446 	mutex_lock(&sbi->vh_mutex);
447 	inode = hfsplus_new_inode(dir->i_sb, dir, S_IFLNK | S_IRWXUGO);
448 	if (!inode)
449 		goto out;
450 
451 	res = page_symlink(inode, symname, strlen(symname) + 1);
452 	if (res)
453 		goto out_err;
454 
455 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
456 	if (res)
457 		goto out_err;
458 
459 	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
460 	if (res == -EOPNOTSUPP)
461 		res = 0; /* Operation is not supported. */
462 	else if (res) {
463 		/* Try to delete anyway without error analysis. */
464 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
465 		goto out_err;
466 	}
467 
468 	hfsplus_instantiate(dentry, inode, inode->i_ino);
469 	mark_inode_dirty(inode);
470 	goto out;
471 
472 out_err:
473 	clear_nlink(inode);
474 	hfsplus_delete_inode(inode);
475 	iput(inode);
476 out:
477 	mutex_unlock(&sbi->vh_mutex);
478 	return res;
479 }
480 
481 static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
482 			 umode_t mode, dev_t rdev)
483 {
484 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
485 	struct inode *inode;
486 	int res = -ENOMEM;
487 
488 	mutex_lock(&sbi->vh_mutex);
489 	inode = hfsplus_new_inode(dir->i_sb, dir, mode);
490 	if (!inode)
491 		goto out;
492 
493 	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
494 		init_special_inode(inode, mode, rdev);
495 
496 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
497 	if (res)
498 		goto failed_mknod;
499 
500 	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
501 	if (res == -EOPNOTSUPP)
502 		res = 0; /* Operation is not supported. */
503 	else if (res) {
504 		/* Try to delete anyway without error analysis. */
505 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
506 		goto failed_mknod;
507 	}
508 
509 	hfsplus_instantiate(dentry, inode, inode->i_ino);
510 	mark_inode_dirty(inode);
511 	goto out;
512 
513 failed_mknod:
514 	clear_nlink(inode);
515 	hfsplus_delete_inode(inode);
516 	iput(inode);
517 out:
518 	mutex_unlock(&sbi->vh_mutex);
519 	return res;
520 }
521 
522 static int hfsplus_create(struct inode *dir, struct dentry *dentry, umode_t mode,
523 			  bool excl)
524 {
525 	return hfsplus_mknod(dir, dentry, mode, 0);
526 }
527 
528 static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
529 {
530 	return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
531 }
532 
533 static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
534 			  struct inode *new_dir, struct dentry *new_dentry,
535 			  unsigned int flags)
536 {
537 	int res;
538 
539 	if (flags & ~RENAME_NOREPLACE)
540 		return -EINVAL;
541 
542 	/* Unlink destination if it already exists */
543 	if (d_really_is_positive(new_dentry)) {
544 		if (d_is_dir(new_dentry))
545 			res = hfsplus_rmdir(new_dir, new_dentry);
546 		else
547 			res = hfsplus_unlink(new_dir, new_dentry);
548 		if (res)
549 			return res;
550 	}
551 
552 	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
553 				 old_dir, &old_dentry->d_name,
554 				 new_dir, &new_dentry->d_name);
555 	if (!res)
556 		new_dentry->d_fsdata = old_dentry->d_fsdata;
557 	return res;
558 }
559 
560 const struct inode_operations hfsplus_dir_inode_operations = {
561 	.lookup			= hfsplus_lookup,
562 	.create			= hfsplus_create,
563 	.link			= hfsplus_link,
564 	.unlink			= hfsplus_unlink,
565 	.mkdir			= hfsplus_mkdir,
566 	.rmdir			= hfsplus_rmdir,
567 	.symlink		= hfsplus_symlink,
568 	.mknod			= hfsplus_mknod,
569 	.rename			= hfsplus_rename,
570 	.listxattr		= hfsplus_listxattr,
571 #ifdef CONFIG_HFSPLUS_FS_POSIX_ACL
572 	.get_acl		= hfsplus_get_posix_acl,
573 	.set_acl		= hfsplus_set_posix_acl,
574 #endif
575 };
576 
577 const struct file_operations hfsplus_dir_operations = {
578 	.fsync		= hfsplus_file_fsync,
579 	.read		= generic_read_dir,
580 	.iterate_shared	= hfsplus_readdir,
581 	.unlocked_ioctl = hfsplus_ioctl,
582 	.llseek		= generic_file_llseek,
583 	.release	= hfsplus_dir_release,
584 };
585