1 // SPDX-License-Identifier: GPL-2.0
7  * Laboratoire MASI - Institut Blaise Pascal
18  *  Big-endian to little-endian byte-swapping/bitmaps by
61  * ext2 uses block-sized chunks. Arguably, sector-sized ones would be
66 	return inode->i_sb->s_blocksize;  in ext2_chunk_size()
76 	unsigned last_byte = inode->i_size;  in ext2_last_byte()
78 	last_byte -= page_nr << PAGE_SHIFT;  in ext2_last_byte()
86 	struct address_space *mapping = folio->mapping;  in ext2_commit_chunk()
87 	struct inode *dir = mapping->host;  in ext2_commit_chunk()
92 	if (pos+len > dir->i_size) {  in ext2_commit_chunk()
101 	struct inode *dir = folio->mapping->host;  in ext2_check_folio()
102 	struct super_block *sb = dir->i_sb;  in ext2_check_folio()
104 	u32 max_inumber = le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count);  in ext2_check_folio()
110 	if (dir->i_size < folio_pos(folio) + limit) {  in ext2_check_folio()
111 		limit = offset_in_folio(folio, dir->i_size);  in ext2_check_folio()
112 		if (limit & (chunk_size - 1))  in ext2_check_folio()
117 	for (offs = 0; offs <= limit - EXT2_DIR_REC_LEN(1); offs += rec_len) {  in ext2_check_folio()
119 		rec_len = ext2_rec_len_from_disk(p->rec_len);  in ext2_check_folio()
125 		if (unlikely(rec_len < EXT2_DIR_REC_LEN(p->name_len)))  in ext2_check_folio()
127 		if (unlikely(((offs + rec_len - 1) ^ offs) & ~(chunk_size-1)))  in ext2_check_folio()
129 		if (unlikely(le32_to_cpu(p->inode) > max_inumber))  in ext2_check_folio()
144 			"of chunk size", dir->i_ino);  in ext2_check_folio()
162 		ext2_error(sb, __func__, "bad entry in directory #%lu: : %s - "  in ext2_check_folio()
164 			dir->i_ino, error, folio_pos(folio) + offs,  in ext2_check_folio()
165 			(unsigned long) le32_to_cpu(p->inode),  in ext2_check_folio()
166 			rec_len, p->name_len);  in ext2_check_folio()
174 			dir->i_ino, folio_pos(folio) + offs,  in ext2_check_folio()
175 			(unsigned long) le32_to_cpu(p->inode));  in ext2_check_folio()
182  * Calls to ext2_get_folio()/folio_release_kmap() must be nested according
186  * to folio_release_kmap() and should be treated as a call to
192 	struct address_space *mapping = dir->i_mapping;  in ext2_get_folio()
208 	return ERR_PTR(-EIO);  in ext2_get_folio()
214  * len <= EXT2_NAME_LEN and de != NULL are guaranteed by caller.
217 					struct ext2_dir_entry_2 * de)  in ext2_match()  argument
219 	if (len != de->name_len)  in ext2_match()
221 	if (!de->inode)  in ext2_match()
223 	return !memcmp(name, de->name, len);  in ext2_match()
232 			ext2_rec_len_from_disk(p->rec_len));  in ext2_next_entry()
238 	ext2_dirent *de = (ext2_dirent*)(base + offset);  in ext2_validate_entry()  local
240 	while ((char*)p < (char*)de) {  in ext2_validate_entry()
241 		if (p->rec_len == 0)  in ext2_validate_entry()
248 static inline void ext2_set_de_type(ext2_dirent *de, struct inode *inode)  in ext2_set_de_type()  argument
250 	if (EXT2_HAS_INCOMPAT_FEATURE(inode->i_sb, EXT2_FEATURE_INCOMPAT_FILETYPE))  in ext2_set_de_type()
251 		de->file_type = fs_umode_to_ftype(inode->i_mode);  in ext2_set_de_type()
253 		de->file_type = 0;  in ext2_set_de_type()
259 	loff_t pos = ctx->pos;  in ext2_readdir()
261 	struct super_block *sb = inode->i_sb;  in ext2_readdir()
265 	unsigned chunk_mask = ~(ext2_chunk_size(inode)-1);  in ext2_readdir()
266 	bool need_revalidate = !inode_eq_iversion(inode, *(u64 *)file->private_data);  in ext2_readdir()
269 	if (pos > inode->i_size - EXT2_DIR_REC_LEN(1))  in ext2_readdir()
276 		ext2_dirent *de;  in ext2_readdir()  local
284 				   inode->i_ino);  in ext2_readdir()
285 			ctx->pos += PAGE_SIZE - offset;  in ext2_readdir()
291 				ctx->pos = (n<<PAGE_SHIFT) + offset;  in ext2_readdir()
293 			*(u64 *)file->private_data = inode_query_iversion(inode);  in ext2_readdir()
296 		de = (ext2_dirent *)(kaddr+offset);  in ext2_readdir()
297 		limit = kaddr + ext2_last_byte(inode, n) - EXT2_DIR_REC_LEN(1);  in ext2_readdir()
298 		for ( ;(char*)de <= limit; de = ext2_next_entry(de)) {  in ext2_readdir()
299 			if (de->rec_len == 0) {  in ext2_readdir()
301 					"zero-length directory entry");  in ext2_readdir()
302 				folio_release_kmap(folio, de);  in ext2_readdir()
303 				return -EIO;  in ext2_readdir()
305 			if (de->inode) {  in ext2_readdir()
309 					d_type = fs_ftype_to_dtype(de->file_type);  in ext2_readdir()
311 				if (!dir_emit(ctx, de->name, de->name_len,  in ext2_readdir()
312 						le32_to_cpu(de->inode),  in ext2_readdir()
314 					folio_release_kmap(folio, de);  in ext2_readdir()
318 			ctx->pos += ext2_rec_len_from_disk(de->rec_len);  in ext2_readdir()
329  * returns the page in which the entry was found (as a parameter - res_page),
331  * Entry is guaranteed to be valid.
333  * On Success folio_release_kmap() should be called on *foliop.
335  * NOTE: Calls to ext2_get_folio()/folio_release_kmap() must be nested
339  * and should be treated as a call to ext2_get_folio() for nesting
345 	const char *name = child->name;  in ext2_find_entry()
346 	int namelen = child->len;  in ext2_find_entry()
351 	ext2_dirent * de;  in ext2_find_entry()  local
356 	start = ei->i_dir_start_lookup;  in ext2_find_entry()
365 		de = (ext2_dirent *) kaddr;  in ext2_find_entry()
366 		kaddr += ext2_last_byte(dir, n) - reclen;  in ext2_find_entry()
367 		while ((char *) de <= kaddr) {  in ext2_find_entry()
368 			if (de->rec_len == 0) {  in ext2_find_entry()
369 				ext2_error(dir->i_sb, __func__,  in ext2_find_entry()
370 					"zero-length directory entry");  in ext2_find_entry()
371 				folio_release_kmap(*foliop, de);  in ext2_find_entry()
374 			if (ext2_match(namelen, name, de))  in ext2_find_entry()
376 			de = ext2_next_entry(de);  in ext2_find_entry()
383 		if (unlikely(n > (dir->i_blocks >> (PAGE_SHIFT - 9)))) {  in ext2_find_entry()
384 			ext2_error(dir->i_sb, __func__,  in ext2_find_entry()
386 				dir->i_ino, dir->i_size,  in ext2_find_entry()
387 				(unsigned long long)dir->i_blocks);  in ext2_find_entry()
392 	return ERR_PTR(-ENOENT);  in ext2_find_entry()
395 	ei->i_dir_start_lookup = n;  in ext2_find_entry()
396 	return de;  in ext2_find_entry()
401  * (as a parameter - p).
403  * On Success folio_release_kmap() should be called on *foliop.
405  * NOTE: Calls to ext2_get_folio()/folio_release_kmap() must be nested
409  * and should be treated as a call to ext2_get_folio() for nesting
414 	ext2_dirent *de = ext2_get_folio(dir, 0, 0, foliop);  in ext2_dotdot()  local
416 	if (!IS_ERR(de))  in ext2_dotdot()
417 		return ext2_next_entry(de);  in ext2_dotdot()
423 	struct ext2_dir_entry_2 *de;  in ext2_inode_by_name()  local
426 	de = ext2_find_entry(dir, child, &folio);  in ext2_inode_by_name()
427 	if (IS_ERR(de))  in ext2_inode_by_name()
428 		return PTR_ERR(de);  in ext2_inode_by_name()
430 	*ino = le32_to_cpu(de->inode);  in ext2_inode_by_name()
431 	folio_release_kmap(folio, de);  in ext2_inode_by_name()
444 	err = filemap_write_and_wait(dir->i_mapping);  in ext2_handle_dirsync()
450 int ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,  in ext2_set_link()  argument
453 	loff_t pos = folio_pos(folio) + offset_in_folio(folio, de);  in ext2_set_link()
454 	unsigned len = ext2_rec_len_from_disk(de->rec_len);  in ext2_set_link()
463 	de->inode = cpu_to_le32(inode->i_ino);  in ext2_set_link()
464 	ext2_set_de_type(de, inode);  in ext2_set_link()
468 	EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL;  in ext2_set_link()
478 	struct inode *dir = d_inode(dentry->d_parent);  in ext2_add_link()
479 	const char *name = dentry->d_name.name;  in ext2_add_link()
480 	int namelen = dentry->d_name.len;  in ext2_add_link()
485 	ext2_dirent * de;  in ext2_add_link()  local
504 		de = (ext2_dirent *)kaddr;  in ext2_add_link()
505 		kaddr += folio_size(folio) - reclen;  in ext2_add_link()
506 		while ((char *)de <= kaddr) {  in ext2_add_link()
507 			if ((char *)de == dir_end) {  in ext2_add_link()
511 				de->rec_len = ext2_rec_len_to_disk(chunk_size);  in ext2_add_link()
512 				de->inode = 0;  in ext2_add_link()
515 			if (de->rec_len == 0) {  in ext2_add_link()
516 				ext2_error(dir->i_sb, __func__,  in ext2_add_link()
517 					"zero-length directory entry");  in ext2_add_link()
518 				err = -EIO;  in ext2_add_link()
521 			err = -EEXIST;  in ext2_add_link()
522 			if (ext2_match (namelen, name, de))  in ext2_add_link()
524 			name_len = EXT2_DIR_REC_LEN(de->name_len);  in ext2_add_link()
525 			rec_len = ext2_rec_len_from_disk(de->rec_len);  in ext2_add_link()
526 			if (!de->inode && rec_len >= reclen)  in ext2_add_link()
530 			de = (ext2_dirent *) ((char *) de + rec_len);  in ext2_add_link()
536 	return -EINVAL;  in ext2_add_link()
539 	pos = folio_pos(folio) + offset_in_folio(folio, de);  in ext2_add_link()
543 	if (de->inode) {  in ext2_add_link()
544 		ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len);  in ext2_add_link()
545 		de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len);  in ext2_add_link()
546 		de->rec_len = ext2_rec_len_to_disk(name_len);  in ext2_add_link()
547 		de = de1;  in ext2_add_link()
549 	de->name_len = namelen;  in ext2_add_link()
550 	memcpy(de->name, name, namelen);  in ext2_add_link()
551 	de->inode = cpu_to_le32(inode->i_ino);  in ext2_add_link()
552 	ext2_set_de_type (de, inode);  in ext2_add_link()
555 	EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL;  in ext2_add_link()
560 	folio_release_kmap(folio, de);  in ext2_add_link()
569  * previous entry. Page is up-to-date.
573 	struct inode *inode = folio->mapping->host;  in ext2_delete_entry()
577 	ext2_dirent *de, *pde = NULL;  in ext2_delete_entry()  local
581 	to = from + ext2_rec_len_from_disk(dir->rec_len);  in ext2_delete_entry()
582 	kaddr = (char *)dir - from;  in ext2_delete_entry()
583 	from &= ~(ext2_chunk_size(inode)-1);  in ext2_delete_entry()
584 	de = (ext2_dirent *)(kaddr + from);  in ext2_delete_entry()
586 	while ((char*)de < (char*)dir) {  in ext2_delete_entry()
587 		if (de->rec_len == 0) {  in ext2_delete_entry()
588 			ext2_error(inode->i_sb, __func__,  in ext2_delete_entry()
589 				"zero-length directory entry");  in ext2_delete_entry()
590 			return -EIO;  in ext2_delete_entry()
592 		pde = de;  in ext2_delete_entry()
593 		de = ext2_next_entry(de);  in ext2_delete_entry()
599 	err = ext2_prepare_chunk(folio, pos, to - from);  in ext2_delete_entry()
605 		pde->rec_len = ext2_rec_len_to_disk(to - from);  in ext2_delete_entry()
606 	dir->inode = 0;  in ext2_delete_entry()
607 	ext2_commit_chunk(folio, pos, to - from);  in ext2_delete_entry()
609 	EXT2_I(inode)->i_flags &= ~EXT2_BTREE_FL;  in ext2_delete_entry()
619 	struct folio *folio = filemap_grab_folio(inode->i_mapping, 0);  in ext2_make_empty()
621 	struct ext2_dir_entry_2 * de;  in ext2_make_empty()  local
635 	de = (struct ext2_dir_entry_2 *)kaddr;  in ext2_make_empty()
636 	de->name_len = 1;  in ext2_make_empty()
637 	de->rec_len = ext2_rec_len_to_disk(EXT2_DIR_REC_LEN(1));  in ext2_make_empty()
638 	memcpy (de->name, ".\0\0", 4);  in ext2_make_empty()
639 	de->inode = cpu_to_le32(inode->i_ino);  in ext2_make_empty()
640 	ext2_set_de_type (de, inode);  in ext2_make_empty()
642 	de = (struct ext2_dir_entry_2 *)(kaddr + EXT2_DIR_REC_LEN(1));  in ext2_make_empty()
643 	de->name_len = 2;  in ext2_make_empty()
644 	de->rec_len = ext2_rec_len_to_disk(chunk_size - EXT2_DIR_REC_LEN(1));  in ext2_make_empty()
645 	de->inode = cpu_to_le32(parent->i_ino);  in ext2_make_empty()
646 	memcpy (de->name, "..\0", 4);  in ext2_make_empty()
647 	ext2_set_de_type (de, inode);  in ext2_make_empty()
666 		ext2_dirent *de;  in ext2_empty_dir()  local
672 		de = (ext2_dirent *)kaddr;  in ext2_empty_dir()
673 		kaddr += ext2_last_byte(inode, i) - EXT2_DIR_REC_LEN(1);  in ext2_empty_dir()
675 		while ((char *)de <= kaddr) {  in ext2_empty_dir()
676 			if (de->rec_len == 0) {  in ext2_empty_dir()
677 				ext2_error(inode->i_sb, __func__,  in ext2_empty_dir()
678 					"zero-length directory entry");  in ext2_empty_dir()
679 				printk("kaddr=%p, de=%p\n", kaddr, de);  in ext2_empty_dir()
682 			if (de->inode != 0) {  in ext2_empty_dir()
684 				if (de->name[0] != '.')  in ext2_empty_dir()
686 				if (de->name_len > 2)  in ext2_empty_dir()
688 				if (de->name_len < 2) {  in ext2_empty_dir()
689 					if (de->inode !=  in ext2_empty_dir()
690 					    cpu_to_le32(inode->i_ino))  in ext2_empty_dir()
692 				} else if (de->name[1] != '.')  in ext2_empty_dir()
695 			de = ext2_next_entry(de);  in ext2_empty_dir()
708 	file->private_data = kzalloc(sizeof(u64), GFP_KERNEL);  in ext2_dir_open()
709 	if (!file->private_data)  in ext2_dir_open()
710 		return -ENOMEM;  in ext2_dir_open()
716 	kfree(file->private_data);  in ext2_dir_release()
723 				     (u64 *)file->private_data);  in ext2_dir_llseek()