xref: /linux/fs/hfsplus/xattr.c (revision 056a5087d87ead77dedbe9cf5bde53b7cd4b4651)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/fs/hfsplus/xattr.c
4  *
5  * Vyacheslav Dubeyko <slava@dubeyko.com>
6  *
7  * Logic of processing extended attributes
8  */
9 
10 #include "hfsplus_fs.h"
11 #include <linux/nls.h>
12 #include "xattr.h"
13 
14 static int hfsplus_removexattr(struct inode *inode, const char *name);
15 
16 const struct xattr_handler * const hfsplus_xattr_handlers[] = {
17 	&hfsplus_xattr_osx_handler,
18 	&hfsplus_xattr_user_handler,
19 	&hfsplus_xattr_trusted_handler,
20 	&hfsplus_xattr_security_handler,
21 	NULL
22 };
23 
24 static int strcmp_xattr_finder_info(const char *name)
25 {
26 	if (name) {
27 		return strncmp(name, HFSPLUS_XATTR_FINDER_INFO_NAME,
28 				sizeof(HFSPLUS_XATTR_FINDER_INFO_NAME));
29 	}
30 	return -1;
31 }
32 
33 static int strcmp_xattr_acl(const char *name)
34 {
35 	if (name) {
36 		return strncmp(name, HFSPLUS_XATTR_ACL_NAME,
37 				sizeof(HFSPLUS_XATTR_ACL_NAME));
38 	}
39 	return -1;
40 }
41 
42 static bool is_known_namespace(const char *name)
43 {
44 	if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) &&
45 	    strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
46 	    strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
47 	    strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
48 		return false;
49 
50 	return true;
51 }
52 
53 static u32 hfsplus_init_header_node(struct inode *attr_file,
54 					u32 clump_size,
55 					char *buf, u16 node_size)
56 {
57 	struct hfs_bnode_desc *desc;
58 	struct hfs_btree_header_rec *head;
59 	u16 offset;
60 	__be16 *rec_offsets;
61 	u32 hdr_node_map_rec_bits;
62 	u32 map_nodes = 0;
63 	char *bmp;
64 	u32 used_nodes;
65 	u32 used_bmp_bytes;
66 	u64 tmp;
67 
68 	hfs_dbg("clump %u, node_size %u\n",
69 		clump_size, node_size);
70 
71 	/* The end of the node contains list of record offsets */
72 	rec_offsets = (__be16 *)(buf + node_size);
73 
74 	desc = (struct hfs_bnode_desc *)buf;
75 	desc->type = HFS_NODE_HEADER;
76 	desc->num_recs = cpu_to_be16(HFSPLUS_BTREE_HDR_NODE_RECS_COUNT);
77 	offset = sizeof(struct hfs_bnode_desc);
78 	*--rec_offsets = cpu_to_be16(offset);
79 
80 	head = (struct hfs_btree_header_rec *)(buf + offset);
81 	head->node_size = cpu_to_be16(node_size);
82 	tmp = i_size_read(attr_file);
83 	do_div(tmp, node_size);
84 	head->node_count = cpu_to_be32(tmp);
85 	head->free_nodes = cpu_to_be32(be32_to_cpu(head->node_count) - 1);
86 	head->clump_size = cpu_to_be32(clump_size);
87 	head->attributes |= cpu_to_be32(HFS_TREE_BIGKEYS | HFS_TREE_VARIDXKEYS);
88 	head->max_key_len = cpu_to_be16(HFSPLUS_ATTR_KEYLEN - sizeof(u16));
89 	offset += sizeof(struct hfs_btree_header_rec);
90 	*--rec_offsets = cpu_to_be16(offset);
91 	offset += HFSPLUS_BTREE_HDR_USER_BYTES;
92 	*--rec_offsets = cpu_to_be16(offset);
93 
94 	hdr_node_map_rec_bits = 8 * (node_size - offset - (4 * sizeof(u16)));
95 	if (be32_to_cpu(head->node_count) > hdr_node_map_rec_bits) {
96 		u32 map_node_bits;
97 
98 		desc->next = cpu_to_be32(be32_to_cpu(head->leaf_tail) + 1);
99 		map_node_bits = 8 * (node_size - sizeof(struct hfs_bnode_desc) -
100 					(2 * sizeof(u16)) - 2);
101 		map_nodes = (be32_to_cpu(head->node_count) -
102 				hdr_node_map_rec_bits +
103 				(map_node_bits - 1)) / map_node_bits;
104 		be32_add_cpu(&head->free_nodes, 0 - map_nodes);
105 	}
106 
107 	bmp = buf + offset;
108 	used_nodes =
109 		be32_to_cpu(head->node_count) - be32_to_cpu(head->free_nodes);
110 	used_bmp_bytes = used_nodes / 8;
111 	if (used_bmp_bytes) {
112 		memset(bmp, 0xFF, used_bmp_bytes);
113 		bmp += used_bmp_bytes;
114 		used_nodes %= 8;
115 	}
116 	*bmp = ~(0xFF >> used_nodes);
117 	offset += hdr_node_map_rec_bits / 8;
118 	*--rec_offsets = cpu_to_be16(offset);
119 
120 	return map_nodes;
121 }
122 
123 /*
124  * Initialize a map node buffer. Map nodes have a single bitmap record.
125  */
126 static void hfsplus_init_map_node(u8 *buf, u16 node_size, u32 next_node)
127 {
128 	struct hfs_bnode_desc *desc;
129 	__be16 *rec_offsets;
130 	size_t rec_size = sizeof(__be16);
131 	u16 offset;
132 
133 	memset(buf, 0, node_size);
134 
135 	desc = (struct hfs_bnode_desc *)buf;
136 	desc->type = HFS_NODE_MAP;
137 	desc->num_recs = cpu_to_be16(1);
138 	desc->next = cpu_to_be32(next_node);
139 
140 	/*
141 	 * A map node consists of the node descriptor and a single
142 	 * map record. The map record is a continuation of the map
143 	 * record contained in the header node. The size of the map
144 	 * record is the size of the node, minus the size of
145 	 * the node descriptor (14 bytes), minus the size of two offsets
146 	 * (4 bytes), minus two bytes of free space. That is, the size of
147 	 * the map record is the size of the node minus 20 bytes;
148 	 * this keeps the length of the map record an even multiple of 4 bytes.
149 	 * The start of the map record is not aligned to a 4-byte boundary:
150 	 * it starts immediately after the node descriptor
151 	 * (at an offset of 14 bytes).
152 	 *
153 	 * Two record offsets stored at the end of the node:
154 	 *   record[1] = start of record 0 -> sizeof(hfs_bnode_desc)
155 	 *   record[2] = start of free space
156 	 */
157 	rec_offsets = (__be16 *)(buf + node_size);
158 
159 	/* record #1 */
160 	offset = sizeof(struct hfs_bnode_desc);
161 	*--rec_offsets = cpu_to_be16(offset);
162 
163 	/* record #2 */
164 	offset = node_size;
165 	offset -= (u16)HFSPLUS_BTREE_MAP_NODE_RECS_COUNT * rec_size;
166 	offset -= HFSPLUS_BTREE_MAP_NODE_RESERVED_BYTES;
167 	*--rec_offsets = cpu_to_be16(offset);
168 }
169 
170 static inline
171 int hfsplus_write_attributes_file_node(struct inode *attr_file, char *buf,
172 					u16 node_size, int *index)
173 {
174 	struct address_space *mapping;
175 	struct page *page;
176 	void *kaddr;
177 	u32 written = 0;
178 
179 	mapping = attr_file->i_mapping;
180 
181 	for (; written < node_size; (*index)++, written += PAGE_SIZE) {
182 		page = read_mapping_page(mapping, *index, NULL);
183 		if (IS_ERR(page))
184 			return PTR_ERR(page);
185 
186 		kaddr = kmap_local_page(page);
187 		memcpy(kaddr, buf + written,
188 			min_t(size_t, PAGE_SIZE, node_size - written));
189 		kunmap_local(kaddr);
190 
191 		set_page_dirty(page);
192 		put_page(page);
193 	}
194 
195 	return 0;
196 }
197 
198 static int hfsplus_create_attributes_file(struct super_block *sb)
199 {
200 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
201 	struct inode *attr_file;
202 	struct hfsplus_inode_info *hip;
203 	struct hfs_bnode_desc *desc;
204 	u32 clump_size;
205 	u16 node_size = HFSPLUS_ATTR_TREE_NODE_SIZE;
206 	u32 next_node;
207 	u32 map_node_idx;
208 	u32 map_nodes;
209 	char *buf;
210 	int index;
211 	int old_state = HFSPLUS_EMPTY_ATTR_TREE;
212 	int err = 0;
213 
214 	hfs_dbg("ino %d\n", HFSPLUS_ATTR_CNID);
215 
216 check_attr_tree_state_again:
217 	switch (atomic_read(&sbi->attr_tree_state)) {
218 	case HFSPLUS_EMPTY_ATTR_TREE:
219 		if (old_state != atomic_cmpxchg(&sbi->attr_tree_state,
220 						old_state,
221 						HFSPLUS_CREATING_ATTR_TREE))
222 			goto check_attr_tree_state_again;
223 		break;
224 	case HFSPLUS_CREATING_ATTR_TREE:
225 		/*
226 		 * This state means that another thread is in process
227 		 * of AttributesFile creation. Theoretically, it is
228 		 * possible to be here. But really __setxattr() method
229 		 * first of all calls hfs_find_init() for lookup in
230 		 * B-tree of CatalogFile. This method locks mutex of
231 		 * CatalogFile's B-tree. As a result, if some thread
232 		 * is inside AttributedFile creation operation then
233 		 * another threads will be waiting unlocking of
234 		 * CatalogFile's B-tree's mutex. However, if code will
235 		 * change then we will return error code (-EAGAIN) from
236 		 * here. Really, it means that first try to set of xattr
237 		 * fails with error but second attempt will have success.
238 		 */
239 		return -EAGAIN;
240 	case HFSPLUS_VALID_ATTR_TREE:
241 		return 0;
242 	case HFSPLUS_FAILED_ATTR_TREE:
243 		return -EOPNOTSUPP;
244 	default:
245 		BUG();
246 	}
247 
248 	attr_file = hfsplus_iget(sb, HFSPLUS_ATTR_CNID);
249 	if (IS_ERR(attr_file)) {
250 		pr_err("failed to load attributes file\n");
251 		return PTR_ERR(attr_file);
252 	}
253 
254 	if (i_size_read(attr_file) != 0) {
255 		err = -EIO;
256 		pr_err("detected inconsistent attributes file, running fsck.hfsplus is recommended.\n");
257 		goto end_attr_file_creation;
258 	}
259 
260 	hip = HFSPLUS_I(attr_file);
261 
262 	clump_size = hfsplus_calc_btree_clump_size(sb->s_blocksize,
263 						    node_size,
264 						    sbi->sect_count,
265 						    HFSPLUS_ATTR_CNID);
266 
267 	mutex_lock(&hip->extents_lock);
268 	hip->clump_blocks = clump_size >> sbi->alloc_blksz_shift;
269 	mutex_unlock(&hip->extents_lock);
270 
271 	if (sbi->free_blocks <= (hip->clump_blocks << 1)) {
272 		err = -ENOSPC;
273 		goto end_attr_file_creation;
274 	}
275 
276 	while (hip->alloc_blocks < hip->clump_blocks) {
277 		err = hfsplus_file_extend(attr_file, true);
278 		if (unlikely(err)) {
279 			pr_err("failed to extend attributes file\n");
280 			goto end_attr_file_creation;
281 		}
282 		hip->phys_size = attr_file->i_size =
283 			(loff_t)hip->alloc_blocks << sbi->alloc_blksz_shift;
284 		hip->fs_blocks = hip->alloc_blocks << sbi->fs_shift;
285 		inode_set_bytes(attr_file, attr_file->i_size);
286 	}
287 
288 	buf = kzalloc(node_size, GFP_NOFS);
289 	if (!buf) {
290 		err = -ENOMEM;
291 		goto end_attr_file_creation;
292 	}
293 
294 	map_nodes = hfsplus_init_header_node(attr_file, clump_size, buf, node_size);
295 
296 	desc = (struct hfs_bnode_desc *)buf;
297 	next_node = be32_to_cpu(desc->next);
298 
299 	index = 0;
300 
301 	err = hfsplus_write_attributes_file_node(attr_file, buf,
302 						 node_size, &index);
303 	if (unlikely(err))
304 		goto failed_header_node_init;
305 
306 	for (map_node_idx = 0; map_node_idx < map_nodes; map_node_idx++) {
307 		if (next_node >= map_nodes)
308 			next_node = 0;
309 
310 		hfsplus_init_map_node(buf, node_size, next_node);
311 
312 		err = hfsplus_write_attributes_file_node(attr_file, buf,
313 							 node_size, &index);
314 		if (unlikely(err))
315 			goto failed_header_node_init;
316 
317 		next_node++;
318 	}
319 
320 	hfsplus_mark_inode_dirty(attr_file, HFSPLUS_I_ATTR_DIRTY);
321 
322 	sbi->attr_tree = hfs_btree_open(sb, HFSPLUS_ATTR_CNID);
323 	if (!sbi->attr_tree)
324 		pr_err("failed to load attributes file\n");
325 
326 failed_header_node_init:
327 	kfree(buf);
328 
329 end_attr_file_creation:
330 	iput(attr_file);
331 
332 	if (!err)
333 		atomic_set(&sbi->attr_tree_state, HFSPLUS_VALID_ATTR_TREE);
334 	else if (err == -ENOSPC)
335 		atomic_set(&sbi->attr_tree_state, HFSPLUS_EMPTY_ATTR_TREE);
336 	else
337 		atomic_set(&sbi->attr_tree_state, HFSPLUS_FAILED_ATTR_TREE);
338 
339 	return err;
340 }
341 
342 static inline
343 bool is_xattr_operation_supported(struct inode *inode)
344 {
345 	if (HFSPLUS_IS_RSRC(inode))
346 		return false;
347 
348 	return true;
349 }
350 
351 int __hfsplus_setxattr(struct inode *inode, const char *name,
352 			const void *value, size_t size, int flags)
353 {
354 	int err;
355 	struct hfs_find_data cat_fd;
356 	hfsplus_cat_entry entry;
357 	u16 cat_entry_flags, cat_entry_type;
358 	u16 folder_finderinfo_len = sizeof(DInfo) + sizeof(DXInfo);
359 	u16 file_finderinfo_len = sizeof(FInfo) + sizeof(FXInfo);
360 
361 	hfs_dbg("ino %llu, name %s, value %p, size %zu\n",
362 		inode->i_ino, name ? name : NULL,
363 		value, size);
364 
365 	if (!is_xattr_operation_supported(inode))
366 		return -EOPNOTSUPP;
367 
368 	if (value == NULL)
369 		return hfsplus_removexattr(inode, name);
370 
371 	err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &cat_fd);
372 	if (err) {
373 		pr_err("can't init xattr find struct\n");
374 		return err;
375 	}
376 
377 	err = hfsplus_find_cat(inode->i_sb, inode->i_ino, &cat_fd);
378 	if (err) {
379 		pr_err("catalog searching failed\n");
380 		goto end_setxattr;
381 	}
382 
383 	if (!strcmp_xattr_finder_info(name)) {
384 		if (flags & XATTR_CREATE) {
385 			pr_err("xattr exists yet\n");
386 			err = -EOPNOTSUPP;
387 			goto end_setxattr;
388 		}
389 		hfs_bnode_read(cat_fd.bnode, &entry, cat_fd.entryoffset,
390 					sizeof(hfsplus_cat_entry));
391 		if (be16_to_cpu(entry.type) == HFSPLUS_FOLDER) {
392 			if (size == folder_finderinfo_len) {
393 				memcpy(&entry.folder.info, value,
394 						folder_finderinfo_len);
395 				hfs_bnode_write(cat_fd.bnode, &entry,
396 					cat_fd.entryoffset,
397 					sizeof(struct hfsplus_cat_folder));
398 				hfsplus_mark_inode_dirty(
399 						HFSPLUS_CAT_TREE_I(inode->i_sb),
400 						HFSPLUS_I_CAT_DIRTY);
401 				hfsplus_mark_inode_dirty(inode,
402 							 HFSPLUS_I_CAT_DIRTY);
403 			} else {
404 				err = -ERANGE;
405 				goto end_setxattr;
406 			}
407 		} else if (be16_to_cpu(entry.type) == HFSPLUS_FILE) {
408 			if (size == file_finderinfo_len) {
409 				memcpy(&entry.file.info, value,
410 						file_finderinfo_len);
411 				hfs_bnode_write(cat_fd.bnode, &entry,
412 					cat_fd.entryoffset,
413 					sizeof(struct hfsplus_cat_file));
414 				hfsplus_mark_inode_dirty(
415 						HFSPLUS_CAT_TREE_I(inode->i_sb),
416 						HFSPLUS_I_CAT_DIRTY);
417 				hfsplus_mark_inode_dirty(inode,
418 							 HFSPLUS_I_CAT_DIRTY);
419 			} else {
420 				err = -ERANGE;
421 				goto end_setxattr;
422 			}
423 		} else {
424 			err = -EOPNOTSUPP;
425 			goto end_setxattr;
426 		}
427 		goto end_setxattr;
428 	}
429 
430 	if (!HFSPLUS_SB(inode->i_sb)->attr_tree) {
431 		err = hfsplus_create_attributes_file(inode->i_sb);
432 		if (unlikely(err))
433 			goto end_setxattr;
434 	}
435 
436 	if (hfsplus_attr_exists(inode, name)) {
437 		if (flags & XATTR_CREATE) {
438 			pr_err("xattr exists yet\n");
439 			err = -EOPNOTSUPP;
440 			goto end_setxattr;
441 		}
442 		err = hfsplus_replace_attr(inode, name, value, size);
443 		if (err) {
444 			hfs_dbg("unable to replace xattr: err %d\n", err);
445 			goto end_setxattr;
446 		}
447 	} else {
448 		if (flags & XATTR_REPLACE) {
449 			pr_err("cannot replace xattr\n");
450 			err = -EOPNOTSUPP;
451 			goto end_setxattr;
452 		}
453 		err = hfsplus_create_attr(inode, name, value, size);
454 		if (err) {
455 			hfs_dbg("unable to store value: err %d\n", err);
456 			goto end_setxattr;
457 		}
458 	}
459 
460 	cat_entry_type = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset);
461 	if (cat_entry_type == HFSPLUS_FOLDER) {
462 		cat_entry_flags = hfs_bnode_read_u16(cat_fd.bnode,
463 				    cat_fd.entryoffset +
464 				    offsetof(struct hfsplus_cat_folder, flags));
465 		cat_entry_flags |= HFSPLUS_XATTR_EXISTS;
466 		if (!strcmp_xattr_acl(name))
467 			cat_entry_flags |= HFSPLUS_ACL_EXISTS;
468 		hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
469 				offsetof(struct hfsplus_cat_folder, flags),
470 				cat_entry_flags);
471 		hfsplus_mark_inode_dirty(HFSPLUS_CAT_TREE_I(inode->i_sb),
472 					 HFSPLUS_I_CAT_DIRTY);
473 		hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
474 	} else if (cat_entry_type == HFSPLUS_FILE) {
475 		cat_entry_flags = hfs_bnode_read_u16(cat_fd.bnode,
476 				    cat_fd.entryoffset +
477 				    offsetof(struct hfsplus_cat_file, flags));
478 		cat_entry_flags |= HFSPLUS_XATTR_EXISTS;
479 		if (!strcmp_xattr_acl(name))
480 			cat_entry_flags |= HFSPLUS_ACL_EXISTS;
481 		hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
482 				    offsetof(struct hfsplus_cat_file, flags),
483 				    cat_entry_flags);
484 		hfsplus_mark_inode_dirty(HFSPLUS_CAT_TREE_I(inode->i_sb),
485 					 HFSPLUS_I_CAT_DIRTY);
486 		hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
487 	} else {
488 		pr_err("invalid catalog entry type\n");
489 		err = -EIO;
490 		goto end_setxattr;
491 	}
492 
493 	inode_set_ctime_current(inode);
494 
495 end_setxattr:
496 	hfs_find_exit(&cat_fd);
497 	hfs_dbg("finished: res %d\n", err);
498 	return err;
499 }
500 
501 static size_t name_len(const char *xattr_name, size_t xattr_name_len)
502 {
503 	size_t len = xattr_name_len + 1;
504 
505 	if (!is_known_namespace(xattr_name))
506 		len += XATTR_MAC_OSX_PREFIX_LEN;
507 
508 	return len;
509 }
510 
511 static ssize_t copy_name(char *buffer, const char *xattr_name, size_t name_len)
512 {
513 	ssize_t len;
514 
515 	memset(buffer, 0, name_len);
516 
517 	if (!is_known_namespace(xattr_name)) {
518 		len = scnprintf(buffer, name_len + XATTR_MAC_OSX_PREFIX_LEN,
519 				 "%s%s", XATTR_MAC_OSX_PREFIX, xattr_name);
520 	} else {
521 		len = strscpy(buffer, xattr_name, name_len + 1);
522 		if (len < 0) {
523 			pr_err("fail to copy name: err %zd\n", len);
524 			len = 0;
525 		}
526 	}
527 
528 	/* include NUL-byte in length for non-empty name */
529 	if (len >= 0)
530 		len++;
531 	return len;
532 }
533 
534 int hfsplus_setxattr(struct inode *inode, const char *name,
535 		     const void *value, size_t size, int flags,
536 		     const char *prefix, size_t prefixlen)
537 {
538 	char *xattr_name;
539 	size_t xattr_name_len =
540 		NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1;
541 	int res;
542 
543 	hfs_dbg("ino %llu, name %s, prefix %s, prefixlen %zu, "
544 		"value %p, size %zu\n",
545 		inode->i_ino, name ? name : NULL,
546 		prefix ? prefix : NULL, prefixlen,
547 		value, size);
548 
549 	xattr_name = kmalloc(xattr_name_len, GFP_KERNEL);
550 	if (!xattr_name)
551 		return -ENOMEM;
552 	strcpy(xattr_name, prefix);
553 	strcpy(xattr_name + prefixlen, name);
554 	res = __hfsplus_setxattr(inode, xattr_name, value, size, flags);
555 	kfree(xattr_name);
556 
557 	hfs_dbg("finished: res %d\n", res);
558 
559 	return res;
560 }
561 
562 static ssize_t hfsplus_getxattr_finder_info(struct inode *inode,
563 						void *value, size_t size)
564 {
565 	ssize_t res = 0;
566 	struct hfs_find_data fd;
567 	u16 entry_type;
568 	u16 folder_rec_len = sizeof(DInfo) + sizeof(DXInfo);
569 	u16 file_rec_len = sizeof(FInfo) + sizeof(FXInfo);
570 	u16 record_len = max(folder_rec_len, file_rec_len);
571 	u8 folder_finder_info[sizeof(DInfo) + sizeof(DXInfo)];
572 	u8 file_finder_info[sizeof(FInfo) + sizeof(FXInfo)];
573 
574 	if (size >= record_len) {
575 		res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
576 		if (res) {
577 			pr_err("can't init xattr find struct\n");
578 			return res;
579 		}
580 		res = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
581 		if (res)
582 			goto end_getxattr_finder_info;
583 		entry_type = hfs_bnode_read_u16(fd.bnode, fd.entryoffset);
584 
585 		if (entry_type == HFSPLUS_FOLDER) {
586 			hfs_bnode_read(fd.bnode, folder_finder_info,
587 				fd.entryoffset +
588 				offsetof(struct hfsplus_cat_folder, user_info),
589 				folder_rec_len);
590 			memcpy(value, folder_finder_info, folder_rec_len);
591 			res = folder_rec_len;
592 		} else if (entry_type == HFSPLUS_FILE) {
593 			hfs_bnode_read(fd.bnode, file_finder_info,
594 				fd.entryoffset +
595 				offsetof(struct hfsplus_cat_file, user_info),
596 				file_rec_len);
597 			memcpy(value, file_finder_info, file_rec_len);
598 			res = file_rec_len;
599 		} else {
600 			res = -EOPNOTSUPP;
601 			goto end_getxattr_finder_info;
602 		}
603 	} else
604 		res = size ? -ERANGE : record_len;
605 
606 end_getxattr_finder_info:
607 	if (size >= record_len)
608 		hfs_find_exit(&fd);
609 	return res;
610 }
611 
612 ssize_t __hfsplus_getxattr(struct inode *inode, const char *name,
613 			 void *value, size_t size)
614 {
615 	struct hfs_find_data fd;
616 	hfsplus_attr_entry *entry;
617 	__be32 xattr_record_type;
618 	u32 record_type;
619 	u16 record_length = 0;
620 	ssize_t res;
621 
622 	if (!is_xattr_operation_supported(inode))
623 		return -EOPNOTSUPP;
624 
625 	if (!strcmp_xattr_finder_info(name))
626 		return hfsplus_getxattr_finder_info(inode, value, size);
627 
628 	if (!HFSPLUS_SB(inode->i_sb)->attr_tree)
629 		return -EOPNOTSUPP;
630 
631 	entry = hfsplus_alloc_attr_entry();
632 	if (!entry) {
633 		pr_err("can't allocate xattr entry\n");
634 		return -ENOMEM;
635 	}
636 
637 	res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->attr_tree, &fd);
638 	if (res) {
639 		pr_err("can't init xattr find struct\n");
640 		goto failed_getxattr_init;
641 	}
642 
643 	res = hfsplus_find_attr(inode->i_sb, inode->i_ino, name, &fd);
644 	if (res) {
645 		if (res == -ENOENT || res == -ENODATA)
646 			res = -ENODATA;
647 		else
648 			pr_err("xattr search failed\n");
649 		goto out;
650 	}
651 
652 	hfs_bnode_read(fd.bnode, &xattr_record_type,
653 			fd.entryoffset, sizeof(xattr_record_type));
654 	record_type = be32_to_cpu(xattr_record_type);
655 	if (record_type == HFSPLUS_ATTR_INLINE_DATA) {
656 		record_length = hfs_bnode_read_u16(fd.bnode,
657 				fd.entryoffset +
658 				offsetof(struct hfsplus_attr_inline_data,
659 				length));
660 		if (record_length > HFSPLUS_MAX_INLINE_DATA_SIZE) {
661 			pr_err("invalid xattr record size\n");
662 			res = -EIO;
663 			goto out;
664 		}
665 	} else if (record_type == HFSPLUS_ATTR_FORK_DATA ||
666 			record_type == HFSPLUS_ATTR_EXTENTS) {
667 		pr_err("only inline data xattr are supported\n");
668 		res = -EOPNOTSUPP;
669 		goto out;
670 	} else {
671 		pr_err("invalid xattr record\n");
672 		res = -EIO;
673 		goto out;
674 	}
675 
676 	if (size) {
677 		hfs_bnode_read(fd.bnode, entry, fd.entryoffset,
678 				offsetof(struct hfsplus_attr_inline_data,
679 					raw_bytes) + record_length);
680 	}
681 
682 	if (size >= record_length) {
683 		memcpy(value, entry->inline_data.raw_bytes, record_length);
684 		res = record_length;
685 	} else
686 		res = size ? -ERANGE : record_length;
687 
688 out:
689 	hfs_find_exit(&fd);
690 
691 failed_getxattr_init:
692 	hfsplus_destroy_attr_entry(entry);
693 	return res;
694 }
695 
696 ssize_t hfsplus_getxattr(struct inode *inode, const char *name,
697 			 void *value, size_t size,
698 			 const char *prefix, size_t prefixlen)
699 {
700 	int res;
701 	char *xattr_name;
702 
703 	hfs_dbg("ino %llu, name %s, prefix %s\n",
704 		inode->i_ino, name ? name : NULL,
705 		prefix ? prefix : NULL);
706 
707 	xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
708 			     GFP_KERNEL);
709 	if (!xattr_name)
710 		return -ENOMEM;
711 
712 	strcpy(xattr_name, prefix);
713 	strcpy(xattr_name + prefixlen, name);
714 
715 	res = __hfsplus_getxattr(inode, xattr_name, value, size);
716 	kfree(xattr_name);
717 
718 	hfs_dbg("finished: res %d\n", res);
719 
720 	return res;
721 
722 }
723 
724 static inline int can_list(const char *xattr_name)
725 {
726 	if (!xattr_name)
727 		return 0;
728 
729 	return strncmp(xattr_name, XATTR_TRUSTED_PREFIX,
730 			XATTR_TRUSTED_PREFIX_LEN) ||
731 				capable(CAP_SYS_ADMIN);
732 }
733 
734 static ssize_t hfsplus_listxattr_finder_info(struct dentry *dentry,
735 						char *buffer, size_t size)
736 {
737 	ssize_t res;
738 	struct inode *inode = d_inode(dentry);
739 	struct hfs_find_data fd;
740 	u16 entry_type;
741 	u8 folder_finder_info[sizeof(DInfo) + sizeof(DXInfo)];
742 	u8 file_finder_info[sizeof(FInfo) + sizeof(FXInfo)];
743 	unsigned long len, found_bit;
744 	int xattr_name_len, symbols_count;
745 
746 	res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
747 	if (res) {
748 		pr_err("can't init xattr find struct\n");
749 		return res;
750 	}
751 
752 	res = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
753 	if (res)
754 		goto end_listxattr_finder_info;
755 
756 	entry_type = hfs_bnode_read_u16(fd.bnode, fd.entryoffset);
757 	if (entry_type == HFSPLUS_FOLDER) {
758 		len = sizeof(DInfo) + sizeof(DXInfo);
759 		hfs_bnode_read(fd.bnode, folder_finder_info,
760 				fd.entryoffset +
761 				offsetof(struct hfsplus_cat_folder, user_info),
762 				len);
763 		found_bit = find_first_bit((void *)folder_finder_info, len*8);
764 	} else if (entry_type == HFSPLUS_FILE) {
765 		len = sizeof(FInfo) + sizeof(FXInfo);
766 		hfs_bnode_read(fd.bnode, file_finder_info,
767 				fd.entryoffset +
768 				offsetof(struct hfsplus_cat_file, user_info),
769 				len);
770 		found_bit = find_first_bit((void *)file_finder_info, len*8);
771 	} else {
772 		res = -EOPNOTSUPP;
773 		goto end_listxattr_finder_info;
774 	}
775 
776 	if (found_bit >= (len*8))
777 		res = 0;
778 	else {
779 		symbols_count = sizeof(HFSPLUS_XATTR_FINDER_INFO_NAME) - 1;
780 		xattr_name_len =
781 			name_len(HFSPLUS_XATTR_FINDER_INFO_NAME, symbols_count);
782 		if (!buffer || !size) {
783 			if (can_list(HFSPLUS_XATTR_FINDER_INFO_NAME))
784 				res = xattr_name_len;
785 		} else if (can_list(HFSPLUS_XATTR_FINDER_INFO_NAME)) {
786 			if (size < xattr_name_len)
787 				res = -ERANGE;
788 			else {
789 				res = copy_name(buffer,
790 						HFSPLUS_XATTR_FINDER_INFO_NAME,
791 						symbols_count);
792 			}
793 		}
794 	}
795 
796 end_listxattr_finder_info:
797 	hfs_find_exit(&fd);
798 
799 	return res;
800 }
801 
802 ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size)
803 {
804 	ssize_t err;
805 	ssize_t res;
806 	struct inode *inode = d_inode(dentry);
807 	struct hfs_find_data fd;
808 	struct hfsplus_attr_key attr_key;
809 	char *strbuf;
810 	size_t strbuf_size;
811 	int xattr_name_len;
812 
813 	hfs_dbg("ino %llu\n", inode->i_ino);
814 
815 	if (!is_xattr_operation_supported(inode))
816 		return -EOPNOTSUPP;
817 
818 	res = hfsplus_listxattr_finder_info(dentry, buffer, size);
819 	if (res < 0)
820 		return res;
821 	else if (!HFSPLUS_SB(inode->i_sb)->attr_tree)
822 		return (res == 0) ? -EOPNOTSUPP : res;
823 
824 	err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->attr_tree, &fd);
825 	if (err) {
826 		pr_err("can't init xattr find struct\n");
827 		return err;
828 	}
829 
830 	strbuf_size = NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN +
831 			XATTR_MAC_OSX_PREFIX_LEN + 1;
832 	strbuf = kzalloc(strbuf_size, GFP_KERNEL);
833 	if (!strbuf) {
834 		res = -ENOMEM;
835 		goto out;
836 	}
837 
838 	err = hfsplus_find_attr(inode->i_sb, inode->i_ino, NULL, &fd);
839 	if (err) {
840 		if (err == -ENOENT || err == -ENODATA) {
841 			res = 0;
842 			goto end_listxattr;
843 		} else {
844 			res = err;
845 			goto end_listxattr;
846 		}
847 	}
848 
849 	for (;;) {
850 		u16 key_len = hfs_bnode_read_u16(fd.bnode, fd.keyoffset);
851 
852 		if (key_len == 0 || key_len > fd.tree->max_key_len) {
853 			pr_err("invalid xattr key length: %d\n", key_len);
854 			res = -EIO;
855 			goto end_listxattr;
856 		}
857 
858 		hfs_bnode_read(fd.bnode, &attr_key,
859 				fd.keyoffset, key_len + sizeof(key_len));
860 
861 		if (be32_to_cpu(attr_key.cnid) != inode->i_ino)
862 			goto end_listxattr;
863 
864 		xattr_name_len = NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN;
865 		if (hfsplus_uni2asc_xattr_str(inode->i_sb,
866 					      &fd.key->attr.key_name, strbuf,
867 					      &xattr_name_len)) {
868 			pr_err("unicode conversion failed\n");
869 			res = -EIO;
870 			goto end_listxattr;
871 		}
872 
873 		if (!buffer || !size) {
874 			if (can_list(strbuf))
875 				res += name_len(strbuf, xattr_name_len);
876 		} else if (can_list(strbuf)) {
877 			if (size < (res + name_len(strbuf, xattr_name_len))) {
878 				pr_err("size %zu, res %zd, name_len %zu\n",
879 					size, res,
880 					name_len(strbuf, xattr_name_len));
881 				res = -ERANGE;
882 				goto end_listxattr;
883 			} else
884 				res += copy_name(buffer + res,
885 						strbuf, xattr_name_len);
886 		}
887 
888 		memset(fd.key->attr.key_name.unicode, 0,
889 			sizeof(fd.key->attr.key_name.unicode));
890 		memset(strbuf, 0, strbuf_size);
891 
892 		if (hfs_brec_goto(&fd, 1))
893 			goto end_listxattr;
894 	}
895 
896 end_listxattr:
897 	kfree(strbuf);
898 out:
899 	hfs_find_exit(&fd);
900 
901 	hfs_dbg("finished: res %zd\n", res);
902 
903 	return res;
904 }
905 
906 static int hfsplus_removexattr(struct inode *inode, const char *name)
907 {
908 	int err;
909 	struct hfs_find_data cat_fd;
910 	u16 flags;
911 	u16 cat_entry_type;
912 	int is_xattr_acl_deleted;
913 	int is_all_xattrs_deleted;
914 
915 	hfs_dbg("ino %llu, name %s\n",
916 		inode->i_ino, name ? name : NULL);
917 
918 	if (!HFSPLUS_SB(inode->i_sb)->attr_tree)
919 		return -EOPNOTSUPP;
920 
921 	if (!strcmp_xattr_finder_info(name))
922 		return -EOPNOTSUPP;
923 
924 	err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &cat_fd);
925 	if (err) {
926 		pr_err("can't init xattr find struct\n");
927 		return err;
928 	}
929 
930 	err = hfsplus_find_cat(inode->i_sb, inode->i_ino, &cat_fd);
931 	if (err) {
932 		pr_err("catalog searching failed\n");
933 		goto end_removexattr;
934 	}
935 
936 	err = hfsplus_delete_attr(inode, name);
937 	if (err)
938 		goto end_removexattr;
939 
940 	is_xattr_acl_deleted = !strcmp_xattr_acl(name);
941 	is_all_xattrs_deleted = !hfsplus_attr_exists(inode, NULL);
942 
943 	if (!is_xattr_acl_deleted && !is_all_xattrs_deleted)
944 		goto end_removexattr;
945 
946 	cat_entry_type = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset);
947 
948 	if (cat_entry_type == HFSPLUS_FOLDER) {
949 		flags = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset +
950 				offsetof(struct hfsplus_cat_folder, flags));
951 		if (is_xattr_acl_deleted)
952 			flags &= ~HFSPLUS_ACL_EXISTS;
953 		if (is_all_xattrs_deleted)
954 			flags &= ~HFSPLUS_XATTR_EXISTS;
955 		hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
956 				offsetof(struct hfsplus_cat_folder, flags),
957 				flags);
958 		hfsplus_mark_inode_dirty(HFSPLUS_CAT_TREE_I(inode->i_sb),
959 					 HFSPLUS_I_CAT_DIRTY);
960 		hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
961 	} else if (cat_entry_type == HFSPLUS_FILE) {
962 		flags = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset +
963 				offsetof(struct hfsplus_cat_file, flags));
964 		if (is_xattr_acl_deleted)
965 			flags &= ~HFSPLUS_ACL_EXISTS;
966 		if (is_all_xattrs_deleted)
967 			flags &= ~HFSPLUS_XATTR_EXISTS;
968 		hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
969 				offsetof(struct hfsplus_cat_file, flags),
970 				flags);
971 		hfsplus_mark_inode_dirty(HFSPLUS_CAT_TREE_I(inode->i_sb),
972 					 HFSPLUS_I_CAT_DIRTY);
973 		hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
974 	} else {
975 		pr_err("invalid catalog entry type\n");
976 		err = -EIO;
977 		goto end_removexattr;
978 	}
979 
980 	inode_set_ctime_current(inode);
981 
982 end_removexattr:
983 	hfs_find_exit(&cat_fd);
984 
985 	hfs_dbg("finished: err %d\n", err);
986 
987 	return err;
988 }
989 
990 static int hfsplus_osx_getxattr(const struct xattr_handler *handler,
991 				struct dentry *unused, struct inode *inode,
992 				const char *name, void *buffer, size_t size)
993 {
994 	/*
995 	 * Don't allow retrieving properly prefixed attributes
996 	 * by prepending them with "osx."
997 	 */
998 	if (is_known_namespace(name))
999 		return -EOPNOTSUPP;
1000 
1001 	/*
1002 	 * osx is the namespace we use to indicate an unprefixed
1003 	 * attribute on the filesystem (like the ones that OS X
1004 	 * creates), so we pass the name through unmodified (after
1005 	 * ensuring it doesn't conflict with another namespace).
1006 	 */
1007 	return __hfsplus_getxattr(inode, name, buffer, size);
1008 }
1009 
1010 static int hfsplus_osx_setxattr(const struct xattr_handler *handler,
1011 				struct mnt_idmap *idmap,
1012 				struct dentry *unused, struct inode *inode,
1013 				const char *name, const void *buffer,
1014 				size_t size, int flags)
1015 {
1016 	/*
1017 	 * Don't allow setting properly prefixed attributes
1018 	 * by prepending them with "osx."
1019 	 */
1020 	if (is_known_namespace(name))
1021 		return -EOPNOTSUPP;
1022 
1023 	/*
1024 	 * osx is the namespace we use to indicate an unprefixed
1025 	 * attribute on the filesystem (like the ones that OS X
1026 	 * creates), so we pass the name through unmodified (after
1027 	 * ensuring it doesn't conflict with another namespace).
1028 	 */
1029 	return __hfsplus_setxattr(inode, name, buffer, size, flags);
1030 }
1031 
1032 const struct xattr_handler hfsplus_xattr_osx_handler = {
1033 	.prefix	= XATTR_MAC_OSX_PREFIX,
1034 	.get	= hfsplus_osx_getxattr,
1035 	.set	= hfsplus_osx_setxattr,
1036 };
1037