xref: /openbmc/linux/fs/hfsplus/dir.c (revision 2b0143b5) 
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 #include <linux/nls.h>
16 
17 #include "hfsplus_fs.h"
18 #include "hfsplus_raw.h"
19 #include "xattr.h"
20 #include "acl.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 				(entry.file.create_date ==
81 					HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
82 						create_date ||
83 				entry.file.create_date ==
84 					HFSPLUS_I(d_inode(sb->s_root))->
85 						create_date) &&
86 				HFSPLUS_SB(sb)->hidden_dir) {
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 	d_add(dentry, inode);
125 	return NULL;
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 		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
275 	}
276 	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
277 out:
278 	kfree(strbuf);
279 	hfs_find_exit(&fd);
280 	return err;
281 }
282 
283 static int hfsplus_dir_release(struct inode *inode, struct file *file)
284 {
285 	struct hfsplus_readdir_data *rd = file->private_data;
286 	if (rd) {
287 		mutex_lock(&inode->i_mutex);
288 		list_del(&rd->list);
289 		mutex_unlock(&inode->i_mutex);
290 		kfree(rd);
291 	}
292 	return 0;
293 }
294 
295 static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
296 			struct dentry *dst_dentry)
297 {
298 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
299 	struct inode *inode = d_inode(src_dentry);
300 	struct inode *src_dir = d_inode(src_dentry->d_parent);
301 	struct qstr str;
302 	char name[32];
303 	u32 cnid, id;
304 	int res;
305 
306 	if (HFSPLUS_IS_RSRC(inode))
307 		return -EPERM;
308 	if (!S_ISREG(inode->i_mode))
309 		return -EPERM;
310 
311 	mutex_lock(&sbi->vh_mutex);
312 	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
313 		for (;;) {
314 			get_random_bytes(&id, sizeof(cnid));
315 			id &= 0x3fffffff;
316 			str.name = name;
317 			str.len = sprintf(name, "iNode%d", id);
318 			res = hfsplus_rename_cat(inode->i_ino,
319 						 src_dir, &src_dentry->d_name,
320 						 sbi->hidden_dir, &str);
321 			if (!res)
322 				break;
323 			if (res != -EEXIST)
324 				goto out;
325 		}
326 		HFSPLUS_I(inode)->linkid = id;
327 		cnid = sbi->next_cnid++;
328 		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
329 		res = hfsplus_create_cat(cnid, src_dir,
330 			&src_dentry->d_name, inode);
331 		if (res)
332 			/* panic? */
333 			goto out;
334 		sbi->file_count++;
335 	}
336 	cnid = sbi->next_cnid++;
337 	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
338 	if (res)
339 		goto out;
340 
341 	inc_nlink(inode);
342 	hfsplus_instantiate(dst_dentry, inode, cnid);
343 	ihold(inode);
344 	inode->i_ctime = CURRENT_TIME_SEC;
345 	mark_inode_dirty(inode);
346 	sbi->file_count++;
347 	hfsplus_mark_mdb_dirty(dst_dir->i_sb);
348 out:
349 	mutex_unlock(&sbi->vh_mutex);
350 	return res;
351 }
352 
353 static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
354 {
355 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
356 	struct inode *inode = d_inode(dentry);
357 	struct qstr str;
358 	char name[32];
359 	u32 cnid;
360 	int res;
361 
362 	if (HFSPLUS_IS_RSRC(inode))
363 		return -EPERM;
364 
365 	mutex_lock(&sbi->vh_mutex);
366 	cnid = (u32)(unsigned long)dentry->d_fsdata;
367 	if (inode->i_ino == cnid &&
368 	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
369 		str.name = name;
370 		str.len = sprintf(name, "temp%lu", inode->i_ino);
371 		res = hfsplus_rename_cat(inode->i_ino,
372 					 dir, &dentry->d_name,
373 					 sbi->hidden_dir, &str);
374 		if (!res) {
375 			inode->i_flags |= S_DEAD;
376 			drop_nlink(inode);
377 		}
378 		goto out;
379 	}
380 	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
381 	if (res)
382 		goto out;
383 
384 	if (inode->i_nlink > 0)
385 		drop_nlink(inode);
386 	if (inode->i_ino == cnid)
387 		clear_nlink(inode);
388 	if (!inode->i_nlink) {
389 		if (inode->i_ino != cnid) {
390 			sbi->file_count--;
391 			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
392 				res = hfsplus_delete_cat(inode->i_ino,
393 							 sbi->hidden_dir,
394 							 NULL);
395 				if (!res)
396 					hfsplus_delete_inode(inode);
397 			} else
398 				inode->i_flags |= S_DEAD;
399 		} else
400 			hfsplus_delete_inode(inode);
401 	} else
402 		sbi->file_count--;
403 	inode->i_ctime = CURRENT_TIME_SEC;
404 	mark_inode_dirty(inode);
405 out:
406 	mutex_unlock(&sbi->vh_mutex);
407 	return res;
408 }
409 
410 static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
411 {
412 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
413 	struct inode *inode = d_inode(dentry);
414 	int res;
415 
416 	if (inode->i_size != 2)
417 		return -ENOTEMPTY;
418 
419 	mutex_lock(&sbi->vh_mutex);
420 	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
421 	if (res)
422 		goto out;
423 	clear_nlink(inode);
424 	inode->i_ctime = CURRENT_TIME_SEC;
425 	hfsplus_delete_inode(inode);
426 	mark_inode_dirty(inode);
427 out:
428 	mutex_unlock(&sbi->vh_mutex);
429 	return res;
430 }
431 
432 static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
433 			   const char *symname)
434 {
435 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
436 	struct inode *inode;
437 	int res = -ENOSPC;
438 
439 	mutex_lock(&sbi->vh_mutex);
440 	inode = hfsplus_new_inode(dir->i_sb, S_IFLNK | S_IRWXUGO);
441 	if (!inode)
442 		goto out;
443 
444 	res = page_symlink(inode, symname, strlen(symname) + 1);
445 	if (res)
446 		goto out_err;
447 
448 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
449 	if (res)
450 		goto out_err;
451 
452 	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
453 	if (res == -EOPNOTSUPP)
454 		res = 0; /* Operation is not supported. */
455 	else if (res) {
456 		/* Try to delete anyway without error analysis. */
457 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
458 		goto out_err;
459 	}
460 
461 	hfsplus_instantiate(dentry, inode, inode->i_ino);
462 	mark_inode_dirty(inode);
463 	goto out;
464 
465 out_err:
466 	clear_nlink(inode);
467 	hfsplus_delete_inode(inode);
468 	iput(inode);
469 out:
470 	mutex_unlock(&sbi->vh_mutex);
471 	return res;
472 }
473 
474 static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
475 			 umode_t mode, dev_t rdev)
476 {
477 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
478 	struct inode *inode;
479 	int res = -ENOSPC;
480 
481 	mutex_lock(&sbi->vh_mutex);
482 	inode = hfsplus_new_inode(dir->i_sb, mode);
483 	if (!inode)
484 		goto out;
485 
486 	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
487 		init_special_inode(inode, mode, rdev);
488 
489 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
490 	if (res)
491 		goto failed_mknod;
492 
493 	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
494 	if (res == -EOPNOTSUPP)
495 		res = 0; /* Operation is not supported. */
496 	else if (res) {
497 		/* Try to delete anyway without error analysis. */
498 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
499 		goto failed_mknod;
500 	}
501 
502 	hfsplus_instantiate(dentry, inode, inode->i_ino);
503 	mark_inode_dirty(inode);
504 	goto out;
505 
506 failed_mknod:
507 	clear_nlink(inode);
508 	hfsplus_delete_inode(inode);
509 	iput(inode);
510 out:
511 	mutex_unlock(&sbi->vh_mutex);
512 	return res;
513 }
514 
515 static int hfsplus_create(struct inode *dir, struct dentry *dentry, umode_t mode,
516 			  bool excl)
517 {
518 	return hfsplus_mknod(dir, dentry, mode, 0);
519 }
520 
521 static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
522 {
523 	return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
524 }
525 
526 static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
527 			  struct inode *new_dir, struct dentry *new_dentry)
528 {
529 	int res;
530 
531 	/* Unlink destination if it already exists */
532 	if (d_really_is_positive(new_dentry)) {
533 		if (d_is_dir(new_dentry))
534 			res = hfsplus_rmdir(new_dir, new_dentry);
535 		else
536 			res = hfsplus_unlink(new_dir, new_dentry);
537 		if (res)
538 			return res;
539 	}
540 
541 	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
542 				 old_dir, &old_dentry->d_name,
543 				 new_dir, &new_dentry->d_name);
544 	if (!res)
545 		new_dentry->d_fsdata = old_dentry->d_fsdata;
546 	return res;
547 }
548 
549 const struct inode_operations hfsplus_dir_inode_operations = {
550 	.lookup			= hfsplus_lookup,
551 	.create			= hfsplus_create,
552 	.link			= hfsplus_link,
553 	.unlink			= hfsplus_unlink,
554 	.mkdir			= hfsplus_mkdir,
555 	.rmdir			= hfsplus_rmdir,
556 	.symlink		= hfsplus_symlink,
557 	.mknod			= hfsplus_mknod,
558 	.rename			= hfsplus_rename,
559 	.setxattr		= generic_setxattr,
560 	.getxattr		= generic_getxattr,
561 	.listxattr		= hfsplus_listxattr,
562 	.removexattr		= generic_removexattr,
563 #ifdef CONFIG_HFSPLUS_FS_POSIX_ACL
564 	.get_acl		= hfsplus_get_posix_acl,
565 	.set_acl		= hfsplus_set_posix_acl,
566 #endif
567 };
568 
569 const struct file_operations hfsplus_dir_operations = {
570 	.fsync		= hfsplus_file_fsync,
571 	.read		= generic_read_dir,
572 	.iterate	= hfsplus_readdir,
573 	.unlocked_ioctl = hfsplus_ioctl,
574 	.llseek		= generic_file_llseek,
575 	.release	= hfsplus_dir_release,
576 };
577