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 = page->mapping;  in ext2_commit_chunk()
87 	struct inode *dir = mapping->host;  in ext2_commit_chunk()
93 	if (pos+len > dir->i_size) {  in ext2_commit_chunk()
111 	struct inode *dir = page->mapping->host;  in ext2_check_page()
112 	struct super_block *sb = dir->i_sb;  in ext2_check_page()
114 	u32 max_inumber = le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count);  in ext2_check_page()
120 	if ((dir->i_size >> PAGE_SHIFT) == page->index) {  in ext2_check_page()
121 		limit = dir->i_size & ~PAGE_MASK;  in ext2_check_page()
122 		if (limit & (chunk_size - 1))  in ext2_check_page()
127 	for (offs = 0; offs <= limit - EXT2_DIR_REC_LEN(1); offs += rec_len) {  in ext2_check_page()
129 		rec_len = ext2_rec_len_from_disk(p->rec_len);  in ext2_check_page()
135 		if (unlikely(rec_len < EXT2_DIR_REC_LEN(p->name_len)))  in ext2_check_page()
137 		if (unlikely(((offs + rec_len - 1) ^ offs) & ~(chunk_size-1)))  in ext2_check_page()
139 		if (unlikely(le32_to_cpu(p->inode) > max_inumber))  in ext2_check_page()
154 			"of chunk size", dir->i_ino);  in ext2_check_page()
172 		ext2_error(sb, __func__, "bad entry in directory #%lu: : %s - "  in ext2_check_page()
174 			dir->i_ino, error, (page->index<<PAGE_SHIFT)+offs,  in ext2_check_page()
175 			(unsigned long) le32_to_cpu(p->inode),  in ext2_check_page()
176 			rec_len, p->name_len);  in ext2_check_page()
184 			dir->i_ino, (page->index<<PAGE_SHIFT)+offs,  in ext2_check_page()
185 			(unsigned long) le32_to_cpu(p->inode));  in ext2_check_page()
193  * Calls to ext2_get_page()/ext2_put_page() must be nested according to the
197  * and should be treated as a call to ext2_get_page() for nesting purposes.
202 	struct address_space *mapping = dir->i_mapping;  in ext2_get_page()
206 		return &folio->page;  in ext2_get_page()
207 	*page_addr = kmap_local_folio(folio, n & (folio_nr_pages(folio) - 1));  in ext2_get_page()
209 		if (!ext2_check_page(&folio->page, quiet, *page_addr))  in ext2_get_page()
212 	return &folio->page;  in ext2_get_page()
215 	ext2_put_page(&folio->page, *page_addr);  in ext2_get_page()
216 	return ERR_PTR(-EIO);  in ext2_get_page()
222  * len <= EXT2_NAME_LEN and de != NULL are guaranteed by caller.
225 					struct ext2_dir_entry_2 * de)  in ext2_match()  argument
227 	if (len != de->name_len)  in ext2_match()
229 	if (!de->inode)  in ext2_match()
231 	return !memcmp(name, de->name, len);  in ext2_match()
240 			ext2_rec_len_from_disk(p->rec_len));  in ext2_next_entry()
246 	ext2_dirent *de = (ext2_dirent*)(base + offset);  in ext2_validate_entry()  local
248 	while ((char*)p < (char*)de) {  in ext2_validate_entry()
249 		if (p->rec_len == 0)  in ext2_validate_entry()
253 	return (char *)p - base;  in ext2_validate_entry()
256 static inline void ext2_set_de_type(ext2_dirent *de, struct inode *inode)  in ext2_set_de_type()  argument
258 	if (EXT2_HAS_INCOMPAT_FEATURE(inode->i_sb, EXT2_FEATURE_INCOMPAT_FILETYPE))  in ext2_set_de_type()
259 		de->file_type = fs_umode_to_ftype(inode->i_mode);  in ext2_set_de_type()
261 		de->file_type = 0;  in ext2_set_de_type()
267 	loff_t pos = ctx->pos;  in ext2_readdir()
269 	struct super_block *sb = inode->i_sb;  in ext2_readdir()
273 	unsigned chunk_mask = ~(ext2_chunk_size(inode)-1);  in ext2_readdir()
274 	bool need_revalidate = !inode_eq_iversion(inode, file->f_version);  in ext2_readdir()
277 	if (pos > inode->i_size - EXT2_DIR_REC_LEN(1))  in ext2_readdir()
285 		ext2_dirent *de;  in ext2_readdir()  local
291 				   inode->i_ino);  in ext2_readdir()
292 			ctx->pos += PAGE_SIZE - offset;  in ext2_readdir()
298 				ctx->pos = (n<<PAGE_SHIFT) + offset;  in ext2_readdir()
300 			file->f_version = inode_query_iversion(inode);  in ext2_readdir()
303 		de = (ext2_dirent *)(kaddr+offset);  in ext2_readdir()
304 		limit = kaddr + ext2_last_byte(inode, n) - EXT2_DIR_REC_LEN(1);  in ext2_readdir()
305 		for ( ;(char*)de <= limit; de = ext2_next_entry(de)) {  in ext2_readdir()
306 			if (de->rec_len == 0) {  in ext2_readdir()
308 					"zero-length directory entry");  in ext2_readdir()
310 				return -EIO;  in ext2_readdir()
312 			if (de->inode) {  in ext2_readdir()
316 					d_type = fs_ftype_to_dtype(de->file_type);  in ext2_readdir()
318 				if (!dir_emit(ctx, de->name, de->name_len,  in ext2_readdir()
319 						le32_to_cpu(de->inode),  in ext2_readdir()
325 			ctx->pos += ext2_rec_len_from_disk(de->rec_len);  in ext2_readdir()
336  * returns the page in which the entry was found (as a parameter - res_page),
338  * Entry is guaranteed to be valid.
340  * On Success ext2_put_page() should be called on *res_page.
342  * NOTE: Calls to ext2_get_page()/ext2_put_page() must be nested according to
346  * should be treated as a call to ext2_get_page() for nesting purposes.
352 	const char *name = child->name;  in ext2_find_entry()
353 	int namelen = child->len;  in ext2_find_entry()
359 	ext2_dirent * de;  in ext2_find_entry()  local
369 	start = ei->i_dir_start_lookup;  in ext2_find_entry()
380 		de = (ext2_dirent *) kaddr;  in ext2_find_entry()
381 		kaddr += ext2_last_byte(dir, n) - reclen;  in ext2_find_entry()
382 		while ((char *) de <= kaddr) {  in ext2_find_entry()
383 			if (de->rec_len == 0) {  in ext2_find_entry()
384 				ext2_error(dir->i_sb, __func__,  in ext2_find_entry()
385 					"zero-length directory entry");  in ext2_find_entry()
389 			if (ext2_match(namelen, name, de))  in ext2_find_entry()
391 			de = ext2_next_entry(de);  in ext2_find_entry()
398 		if (unlikely(n > (dir->i_blocks >> (PAGE_SHIFT - 9)))) {  in ext2_find_entry()
399 			ext2_error(dir->i_sb, __func__,  in ext2_find_entry()
401 				dir->i_ino, dir->i_size,  in ext2_find_entry()
402 				(unsigned long long)dir->i_blocks);  in ext2_find_entry()
407 	return ERR_PTR(-ENOENT);  in ext2_find_entry()
412 	ei->i_dir_start_lookup = n;  in ext2_find_entry()
413 	return de;  in ext2_find_entry()
418  * (as a parameter - p).
420  * On Success ext2_put_page() should be called on *p.
422  * NOTE: Calls to ext2_get_page()/ext2_put_page() must be nested according to
426  * should be treated as a call to ext2_get_page() for nesting purposes.
433 	ext2_dirent *de = NULL;  in ext2_dotdot()  local
436 		de = ext2_next_entry((ext2_dirent *) page_addr);  in ext2_dotdot()
440 	return de;  in ext2_dotdot()
445 	struct ext2_dir_entry_2 *de;  in ext2_inode_by_name()  local
449 	de = ext2_find_entry(dir, child, &page, &page_addr);  in ext2_inode_by_name()
450 	if (IS_ERR(de))  in ext2_inode_by_name()
451 		return PTR_ERR(de);  in ext2_inode_by_name()
453 	*ino = le32_to_cpu(de->inode);  in ext2_inode_by_name()
463 void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,  in ext2_set_link()  argument
468 			(char *) de - (char *) page_addr;  in ext2_set_link()
469 	unsigned len = ext2_rec_len_from_disk(de->rec_len);  in ext2_set_link()
475 	de->inode = cpu_to_le32(inode->i_ino);  in ext2_set_link()
476 	ext2_set_de_type(de, inode);  in ext2_set_link()
479 		dir->i_mtime = dir->i_ctime = current_time(dir);  in ext2_set_link()
480 	EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL;  in ext2_set_link()
489 	struct inode *dir = d_inode(dentry->d_parent);  in ext2_add_link()
490 	const char *name = dentry->d_name.name;  in ext2_add_link()
491 	int namelen = dentry->d_name.len;  in ext2_add_link()
497 	ext2_dirent * de;  in ext2_add_link()  local
519 		de = (ext2_dirent *)kaddr;  in ext2_add_link()
520 		kaddr += PAGE_SIZE - reclen;  in ext2_add_link()
521 		while ((char *)de <= kaddr) {  in ext2_add_link()
522 			if ((char *)de == dir_end) {  in ext2_add_link()
526 				de->rec_len = ext2_rec_len_to_disk(chunk_size);  in ext2_add_link()
527 				de->inode = 0;  in ext2_add_link()
530 			if (de->rec_len == 0) {  in ext2_add_link()
531 				ext2_error(dir->i_sb, __func__,  in ext2_add_link()
532 					"zero-length directory entry");  in ext2_add_link()
533 				err = -EIO;  in ext2_add_link()
536 			err = -EEXIST;  in ext2_add_link()
537 			if (ext2_match (namelen, name, de))  in ext2_add_link()
539 			name_len = EXT2_DIR_REC_LEN(de->name_len);  in ext2_add_link()
540 			rec_len = ext2_rec_len_from_disk(de->rec_len);  in ext2_add_link()
541 			if (!de->inode && rec_len >= reclen)  in ext2_add_link()
545 			de = (ext2_dirent *) ((char *) de + rec_len);  in ext2_add_link()
551 	return -EINVAL;  in ext2_add_link()
555 		(char *)de - (char *)page_addr;  in ext2_add_link()
559 	if (de->inode) {  in ext2_add_link()
560 		ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len);  in ext2_add_link()
561 		de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len);  in ext2_add_link()
562 		de->rec_len = ext2_rec_len_to_disk(name_len);  in ext2_add_link()
563 		de = de1;  in ext2_add_link()
565 	de->name_len = namelen;  in ext2_add_link()
566 	memcpy(de->name, name, namelen);  in ext2_add_link()
567 	de->inode = cpu_to_le32(inode->i_ino);  in ext2_add_link()
568 	ext2_set_de_type (de, inode);  in ext2_add_link()
570 	dir->i_mtime = dir->i_ctime = current_time(dir);  in ext2_add_link()
571 	EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL;  in ext2_add_link()
585  * previous entry. Page is up-to-date.
590 	struct inode *inode = page->mapping->host;  in ext2_delete_entry()
591 	unsigned from = ((char*)dir - kaddr) & ~(ext2_chunk_size(inode)-1);  in ext2_delete_entry()
592 	unsigned to = ((char *)dir - kaddr) +  in ext2_delete_entry()
593 				ext2_rec_len_from_disk(dir->rec_len);  in ext2_delete_entry()
596 	ext2_dirent * de = (ext2_dirent *) (kaddr + from);  in ext2_delete_entry()  local
599 	while ((char*)de < (char*)dir) {  in ext2_delete_entry()
600 		if (de->rec_len == 0) {  in ext2_delete_entry()
601 			ext2_error(inode->i_sb, __func__,  in ext2_delete_entry()
602 				"zero-length directory entry");  in ext2_delete_entry()
603 			err = -EIO;  in ext2_delete_entry()
606 		pde = de;  in ext2_delete_entry()
607 		de = ext2_next_entry(de);  in ext2_delete_entry()
610 		from = (char *)pde - kaddr;  in ext2_delete_entry()
613 	err = ext2_prepare_chunk(page, pos, to - from);  in ext2_delete_entry()
616 		pde->rec_len = ext2_rec_len_to_disk(to - from);  in ext2_delete_entry()
617 	dir->inode = 0;  in ext2_delete_entry()
618 	err = ext2_commit_chunk(page, pos, to - from);  in ext2_delete_entry()
619 	inode->i_ctime = inode->i_mtime = current_time(inode);  in ext2_delete_entry()
620 	EXT2_I(inode)->i_flags &= ~EXT2_BTREE_FL;  in ext2_delete_entry()
631 	struct page *page = grab_cache_page(inode->i_mapping, 0);  in ext2_make_empty()
633 	struct ext2_dir_entry_2 * de;  in ext2_make_empty()  local
638 		return -ENOMEM;  in ext2_make_empty()
647 	de = (struct ext2_dir_entry_2 *)kaddr;  in ext2_make_empty()
648 	de->name_len = 1;  in ext2_make_empty()
649 	de->rec_len = ext2_rec_len_to_disk(EXT2_DIR_REC_LEN(1));  in ext2_make_empty()
650 	memcpy (de->name, ".\0\0", 4);  in ext2_make_empty()
651 	de->inode = cpu_to_le32(inode->i_ino);  in ext2_make_empty()
652 	ext2_set_de_type (de, inode);  in ext2_make_empty()
654 	de = (struct ext2_dir_entry_2 *)(kaddr + EXT2_DIR_REC_LEN(1));  in ext2_make_empty()
655 	de->name_len = 2;  in ext2_make_empty()
656 	de->rec_len = ext2_rec_len_to_disk(chunk_size - EXT2_DIR_REC_LEN(1));  in ext2_make_empty()
657 	de->inode = cpu_to_le32(parent->i_ino);  in ext2_make_empty()
658 	memcpy (de->name, "..\0", 4);  in ext2_make_empty()
659 	ext2_set_de_type (de, inode);  in ext2_make_empty()
678 		ext2_dirent * de;  in ext2_empty_dir()  local
685 		de = (ext2_dirent *)kaddr;  in ext2_empty_dir()
686 		kaddr += ext2_last_byte(inode, i) - EXT2_DIR_REC_LEN(1);  in ext2_empty_dir()
688 		while ((char *)de <= kaddr) {  in ext2_empty_dir()
689 			if (de->rec_len == 0) {  in ext2_empty_dir()
690 				ext2_error(inode->i_sb, __func__,  in ext2_empty_dir()
691 					"zero-length directory entry");  in ext2_empty_dir()
692 				printk("kaddr=%p, de=%p\n", kaddr, de);  in ext2_empty_dir()
695 			if (de->inode != 0) {  in ext2_empty_dir()
697 				if (de->name[0] != '.')  in ext2_empty_dir()
699 				if (de->name_len > 2)  in ext2_empty_dir()
701 				if (de->name_len < 2) {  in ext2_empty_dir()
702 					if (de->inode !=  in ext2_empty_dir()
703 					    cpu_to_le32(inode->i_ino))  in ext2_empty_dir()
705 				} else if (de->name[1] != '.')  in ext2_empty_dir()
708 			de = ext2_next_entry(de);  in ext2_empty_dir()