xref: /openbmc/linux/fs/hfsplus/dir.c (revision 97a62eae) 
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 	hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, &dentry->d_name);
48 again:
49 	err = hfs_brec_read(&fd, &entry, sizeof(entry));
50 	if (err) {
51 		if (err == -ENOENT) {
52 			hfs_find_exit(&fd);
53 			/* No such entry */
54 			inode = NULL;
55 			goto out;
56 		}
57 		goto fail;
58 	}
59 	type = be16_to_cpu(entry.type);
60 	if (type == HFSPLUS_FOLDER) {
61 		if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
62 			err = -EIO;
63 			goto fail;
64 		}
65 		cnid = be32_to_cpu(entry.folder.id);
66 		dentry->d_fsdata = (void *)(unsigned long)cnid;
67 	} else if (type == HFSPLUS_FILE) {
68 		if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
69 			err = -EIO;
70 			goto fail;
71 		}
72 		cnid = be32_to_cpu(entry.file.id);
73 		if (entry.file.user_info.fdType ==
74 				cpu_to_be32(HFSP_HARDLINK_TYPE) &&
75 				entry.file.user_info.fdCreator ==
76 				cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
77 				(entry.file.create_date ==
78 					HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
79 						create_date ||
80 				entry.file.create_date ==
81 					HFSPLUS_I(sb->s_root->d_inode)->
82 						create_date) &&
83 				HFSPLUS_SB(sb)->hidden_dir) {
84 			struct qstr str;
85 			char name[32];
86 
87 			if (dentry->d_fsdata) {
88 				/*
89 				 * We found a link pointing to another link,
90 				 * so ignore it and treat it as regular file.
91 				 */
92 				cnid = (unsigned long)dentry->d_fsdata;
93 				linkid = 0;
94 			} else {
95 				dentry->d_fsdata = (void *)(unsigned long)cnid;
96 				linkid =
97 					be32_to_cpu(entry.file.permissions.dev);
98 				str.len = sprintf(name, "iNode%d", linkid);
99 				str.name = name;
100 				hfsplus_cat_build_key(sb, fd.search_key,
101 					HFSPLUS_SB(sb)->hidden_dir->i_ino,
102 					&str);
103 				goto again;
104 			}
105 		} else if (!dentry->d_fsdata)
106 			dentry->d_fsdata = (void *)(unsigned long)cnid;
107 	} else {
108 		pr_err("invalid catalog entry type in lookup\n");
109 		err = -EIO;
110 		goto fail;
111 	}
112 	hfs_find_exit(&fd);
113 	inode = hfsplus_iget(dir->i_sb, cnid);
114 	if (IS_ERR(inode))
115 		return ERR_CAST(inode);
116 	if (S_ISREG(inode->i_mode))
117 		HFSPLUS_I(inode)->linkid = linkid;
118 out:
119 	d_add(dentry, inode);
120 	return NULL;
121 fail:
122 	hfs_find_exit(&fd);
123 	return ERR_PTR(err);
124 }
125 
126 static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
127 {
128 	struct inode *inode = file_inode(file);
129 	struct super_block *sb = inode->i_sb;
130 	int len, err;
131 	char *strbuf;
132 	hfsplus_cat_entry entry;
133 	struct hfs_find_data fd;
134 	struct hfsplus_readdir_data *rd;
135 	u16 type;
136 
137 	if (file->f_pos >= inode->i_size)
138 		return 0;
139 
140 	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
141 	if (err)
142 		return err;
143 	strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
144 	if (!strbuf) {
145 		err = -ENOMEM;
146 		goto out;
147 	}
148 	hfsplus_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
149 	err = hfs_brec_find(&fd, hfs_find_rec_by_key);
150 	if (err)
151 		goto out;
152 
153 	if (ctx->pos == 0) {
154 		/* This is completely artificial... */
155 		if (!dir_emit_dot(file, ctx))
156 			goto out;
157 		ctx->pos = 1;
158 	}
159 	if (ctx->pos == 1) {
160 		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
161 			err = -EIO;
162 			goto out;
163 		}
164 
165 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
166 			fd.entrylength);
167 		if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
168 			pr_err("bad catalog folder thread\n");
169 			err = -EIO;
170 			goto out;
171 		}
172 		if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
173 			pr_err("truncated catalog thread\n");
174 			err = -EIO;
175 			goto out;
176 		}
177 		if (!dir_emit(ctx, "..", 2,
178 			    be32_to_cpu(entry.thread.parentID), DT_DIR))
179 			goto out;
180 		ctx->pos = 2;
181 	}
182 	if (ctx->pos >= inode->i_size)
183 		goto out;
184 	err = hfs_brec_goto(&fd, ctx->pos - 1);
185 	if (err)
186 		goto out;
187 	for (;;) {
188 		if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
189 			pr_err("walked past end of dir\n");
190 			err = -EIO;
191 			goto out;
192 		}
193 
194 		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
195 			err = -EIO;
196 			goto out;
197 		}
198 
199 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
200 			fd.entrylength);
201 		type = be16_to_cpu(entry.type);
202 		len = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN;
203 		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
204 		if (err)
205 			goto out;
206 		if (type == HFSPLUS_FOLDER) {
207 			if (fd.entrylength <
208 					sizeof(struct hfsplus_cat_folder)) {
209 				pr_err("small dir entry\n");
210 				err = -EIO;
211 				goto out;
212 			}
213 			if (HFSPLUS_SB(sb)->hidden_dir &&
214 			    HFSPLUS_SB(sb)->hidden_dir->i_ino ==
215 					be32_to_cpu(entry.folder.id))
216 				goto next;
217 			if (!dir_emit(ctx, strbuf, len,
218 				    be32_to_cpu(entry.folder.id), DT_DIR))
219 				break;
220 		} else if (type == HFSPLUS_FILE) {
221 			u16 mode;
222 			unsigned type = DT_UNKNOWN;
223 
224 			if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
225 				pr_err("small file entry\n");
226 				err = -EIO;
227 				goto out;
228 			}
229 
230 			mode = be16_to_cpu(entry.file.permissions.mode);
231 			if (S_ISREG(mode))
232 				type = DT_REG;
233 			else if (S_ISLNK(mode))
234 				type = DT_LNK;
235 			else if (S_ISFIFO(mode))
236 				type = DT_FIFO;
237 			else if (S_ISCHR(mode))
238 				type = DT_CHR;
239 			else if (S_ISBLK(mode))
240 				type = DT_BLK;
241 			else if (S_ISSOCK(mode))
242 				type = DT_SOCK;
243 
244 			if (!dir_emit(ctx, strbuf, len,
245 				      be32_to_cpu(entry.file.id), type))
246 				break;
247 		} else {
248 			pr_err("bad catalog entry type\n");
249 			err = -EIO;
250 			goto out;
251 		}
252 next:
253 		ctx->pos++;
254 		if (ctx->pos >= inode->i_size)
255 			goto out;
256 		err = hfs_brec_goto(&fd, 1);
257 		if (err)
258 			goto out;
259 	}
260 	rd = file->private_data;
261 	if (!rd) {
262 		rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
263 		if (!rd) {
264 			err = -ENOMEM;
265 			goto out;
266 		}
267 		file->private_data = rd;
268 		rd->file = file;
269 		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
270 	}
271 	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
272 out:
273 	kfree(strbuf);
274 	hfs_find_exit(&fd);
275 	return err;
276 }
277 
278 static int hfsplus_dir_release(struct inode *inode, struct file *file)
279 {
280 	struct hfsplus_readdir_data *rd = file->private_data;
281 	if (rd) {
282 		mutex_lock(&inode->i_mutex);
283 		list_del(&rd->list);
284 		mutex_unlock(&inode->i_mutex);
285 		kfree(rd);
286 	}
287 	return 0;
288 }
289 
290 static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
291 			struct dentry *dst_dentry)
292 {
293 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
294 	struct inode *inode = src_dentry->d_inode;
295 	struct inode *src_dir = src_dentry->d_parent->d_inode;
296 	struct qstr str;
297 	char name[32];
298 	u32 cnid, id;
299 	int res;
300 
301 	if (HFSPLUS_IS_RSRC(inode))
302 		return -EPERM;
303 	if (!S_ISREG(inode->i_mode))
304 		return -EPERM;
305 
306 	mutex_lock(&sbi->vh_mutex);
307 	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
308 		for (;;) {
309 			get_random_bytes(&id, sizeof(cnid));
310 			id &= 0x3fffffff;
311 			str.name = name;
312 			str.len = sprintf(name, "iNode%d", id);
313 			res = hfsplus_rename_cat(inode->i_ino,
314 						 src_dir, &src_dentry->d_name,
315 						 sbi->hidden_dir, &str);
316 			if (!res)
317 				break;
318 			if (res != -EEXIST)
319 				goto out;
320 		}
321 		HFSPLUS_I(inode)->linkid = id;
322 		cnid = sbi->next_cnid++;
323 		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
324 		res = hfsplus_create_cat(cnid, src_dir,
325 			&src_dentry->d_name, inode);
326 		if (res)
327 			/* panic? */
328 			goto out;
329 		sbi->file_count++;
330 	}
331 	cnid = sbi->next_cnid++;
332 	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
333 	if (res)
334 		goto out;
335 
336 	inc_nlink(inode);
337 	hfsplus_instantiate(dst_dentry, inode, cnid);
338 	ihold(inode);
339 	inode->i_ctime = CURRENT_TIME_SEC;
340 	mark_inode_dirty(inode);
341 	sbi->file_count++;
342 	hfsplus_mark_mdb_dirty(dst_dir->i_sb);
343 out:
344 	mutex_unlock(&sbi->vh_mutex);
345 	return res;
346 }
347 
348 static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
349 {
350 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
351 	struct inode *inode = dentry->d_inode;
352 	struct qstr str;
353 	char name[32];
354 	u32 cnid;
355 	int res;
356 
357 	if (HFSPLUS_IS_RSRC(inode))
358 		return -EPERM;
359 
360 	mutex_lock(&sbi->vh_mutex);
361 	cnid = (u32)(unsigned long)dentry->d_fsdata;
362 	if (inode->i_ino == cnid &&
363 	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
364 		str.name = name;
365 		str.len = sprintf(name, "temp%lu", inode->i_ino);
366 		res = hfsplus_rename_cat(inode->i_ino,
367 					 dir, &dentry->d_name,
368 					 sbi->hidden_dir, &str);
369 		if (!res) {
370 			inode->i_flags |= S_DEAD;
371 			drop_nlink(inode);
372 		}
373 		goto out;
374 	}
375 	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
376 	if (res)
377 		goto out;
378 
379 	if (inode->i_nlink > 0)
380 		drop_nlink(inode);
381 	if (inode->i_ino == cnid)
382 		clear_nlink(inode);
383 	if (!inode->i_nlink) {
384 		if (inode->i_ino != cnid) {
385 			sbi->file_count--;
386 			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
387 				res = hfsplus_delete_cat(inode->i_ino,
388 							 sbi->hidden_dir,
389 							 NULL);
390 				if (!res)
391 					hfsplus_delete_inode(inode);
392 			} else
393 				inode->i_flags |= S_DEAD;
394 		} else
395 			hfsplus_delete_inode(inode);
396 	} else
397 		sbi->file_count--;
398 	inode->i_ctime = CURRENT_TIME_SEC;
399 	mark_inode_dirty(inode);
400 out:
401 	mutex_unlock(&sbi->vh_mutex);
402 	return res;
403 }
404 
405 static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
406 {
407 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
408 	struct inode *inode = dentry->d_inode;
409 	int res;
410 
411 	if (inode->i_size != 2)
412 		return -ENOTEMPTY;
413 
414 	mutex_lock(&sbi->vh_mutex);
415 	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
416 	if (res)
417 		goto out;
418 	clear_nlink(inode);
419 	inode->i_ctime = CURRENT_TIME_SEC;
420 	hfsplus_delete_inode(inode);
421 	mark_inode_dirty(inode);
422 out:
423 	mutex_unlock(&sbi->vh_mutex);
424 	return res;
425 }
426 
427 static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
428 			   const char *symname)
429 {
430 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
431 	struct inode *inode;
432 	int res = -ENOSPC;
433 
434 	mutex_lock(&sbi->vh_mutex);
435 	inode = hfsplus_new_inode(dir->i_sb, S_IFLNK | S_IRWXUGO);
436 	if (!inode)
437 		goto out;
438 
439 	res = page_symlink(inode, symname, strlen(symname) + 1);
440 	if (res)
441 		goto out_err;
442 
443 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
444 	if (res)
445 		goto out_err;
446 
447 	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
448 	if (res == -EOPNOTSUPP)
449 		res = 0; /* Operation is not supported. */
450 	else if (res) {
451 		/* Try to delete anyway without error analysis. */
452 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
453 		goto out_err;
454 	}
455 
456 	hfsplus_instantiate(dentry, inode, inode->i_ino);
457 	mark_inode_dirty(inode);
458 	goto out;
459 
460 out_err:
461 	clear_nlink(inode);
462 	hfsplus_delete_inode(inode);
463 	iput(inode);
464 out:
465 	mutex_unlock(&sbi->vh_mutex);
466 	return res;
467 }
468 
469 static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
470 			 umode_t mode, dev_t rdev)
471 {
472 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
473 	struct inode *inode;
474 	int res = -ENOSPC;
475 
476 	mutex_lock(&sbi->vh_mutex);
477 	inode = hfsplus_new_inode(dir->i_sb, mode);
478 	if (!inode)
479 		goto out;
480 
481 	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
482 		init_special_inode(inode, mode, rdev);
483 
484 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
485 	if (res)
486 		goto failed_mknod;
487 
488 	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
489 	if (res == -EOPNOTSUPP)
490 		res = 0; /* Operation is not supported. */
491 	else if (res) {
492 		/* Try to delete anyway without error analysis. */
493 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
494 		goto failed_mknod;
495 	}
496 
497 	hfsplus_instantiate(dentry, inode, inode->i_ino);
498 	mark_inode_dirty(inode);
499 	goto out;
500 
501 failed_mknod:
502 	clear_nlink(inode);
503 	hfsplus_delete_inode(inode);
504 	iput(inode);
505 out:
506 	mutex_unlock(&sbi->vh_mutex);
507 	return res;
508 }
509 
510 static int hfsplus_create(struct inode *dir, struct dentry *dentry, umode_t mode,
511 			  bool excl)
512 {
513 	return hfsplus_mknod(dir, dentry, mode, 0);
514 }
515 
516 static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
517 {
518 	return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
519 }
520 
521 static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
522 			  struct inode *new_dir, struct dentry *new_dentry)
523 {
524 	int res;
525 
526 	/* Unlink destination if it already exists */
527 	if (new_dentry->d_inode) {
528 		if (S_ISDIR(new_dentry->d_inode->i_mode))
529 			res = hfsplus_rmdir(new_dir, new_dentry);
530 		else
531 			res = hfsplus_unlink(new_dir, new_dentry);
532 		if (res)
533 			return res;
534 	}
535 
536 	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
537 				 old_dir, &old_dentry->d_name,
538 				 new_dir, &new_dentry->d_name);
539 	if (!res)
540 		new_dentry->d_fsdata = old_dentry->d_fsdata;
541 	return res;
542 }
543 
544 const struct inode_operations hfsplus_dir_inode_operations = {
545 	.lookup			= hfsplus_lookup,
546 	.create			= hfsplus_create,
547 	.link			= hfsplus_link,
548 	.unlink			= hfsplus_unlink,
549 	.mkdir			= hfsplus_mkdir,
550 	.rmdir			= hfsplus_rmdir,
551 	.symlink		= hfsplus_symlink,
552 	.mknod			= hfsplus_mknod,
553 	.rename			= hfsplus_rename,
554 	.setxattr		= generic_setxattr,
555 	.getxattr		= generic_getxattr,
556 	.listxattr		= hfsplus_listxattr,
557 	.removexattr		= generic_removexattr,
558 #ifdef CONFIG_HFSPLUS_FS_POSIX_ACL
559 	.get_acl		= hfsplus_get_posix_acl,
560 	.set_acl		= hfsplus_set_posix_acl,
561 #endif
562 };
563 
564 const struct file_operations hfsplus_dir_operations = {
565 	.fsync		= hfsplus_file_fsync,
566 	.read		= generic_read_dir,
567 	.iterate	= hfsplus_readdir,
568 	.unlocked_ioctl = hfsplus_ioctl,
569 	.llseek		= generic_file_llseek,
570 	.release	= hfsplus_dir_release,
571 };
572