1 // SPDX-License-Identifier: GPL-2.0
7  * Laboratoire MASI - Institut Blaise Pascal
18  *  Big-endian to little-endian byte-swapping/bitmaps by
36  * is_dx_dir() - check if a directory is using htree indexing
39  * Check if the given dir-inode refers to an htree-indexed directory
47 	struct super_block *sb = inode->i_sb;  in is_dx_dir()
49 	if (ext4_has_feature_dir_index(inode->i_sb) &&  in is_dx_dir()
51 	     ((inode->i_size >> sb->s_blocksize_bits) == 1) ||  in is_dx_dir()
58 static bool is_fake_dir_entry(struct ext4_dir_entry_2 *de)  in is_fake_dir_entry()  argument
61 	if ((de->name_len > 0) && (de->name_len <= 2) && (de->name[0] == '.') &&  in is_fake_dir_entry()
62 	    (de->name[1] == '.' || de->name[1] == '\0'))  in is_fake_dir_entry()
65 	if (de->file_type == EXT4_FT_DIR_CSUM)  in is_fake_dir_entry()
75  * bh passed here can be an inode block or a dir data block, depending
80 			   struct ext4_dir_entry_2 *de,  in __ext4_check_dir_entry()  argument
85 	const int rlen = ext4_rec_len_from_disk(de->rec_len,  in __ext4_check_dir_entry()
86 						dir->i_sb->s_blocksize);  in __ext4_check_dir_entry()
87 	const int next_offset = ((char *) de - buf) + rlen;  in __ext4_check_dir_entry()
88 	bool fake = is_fake_dir_entry(de);  in __ext4_check_dir_entry()
89 	bool has_csum = ext4_has_metadata_csum(dir->i_sb);  in __ext4_check_dir_entry()
95 	else if (unlikely(rlen < ext4_dir_rec_len(de->name_len,  in __ext4_check_dir_entry()
100 	else if (unlikely(next_offset > size - ext4_dir_rec_len(1,  in __ext4_check_dir_entry()
104 	else if (unlikely(le32_to_cpu(de->inode) >  in __ext4_check_dir_entry()
105 			le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count)))  in __ext4_check_dir_entry()
107 	else if (unlikely(next_offset == size && de->name_len == 1 &&  in __ext4_check_dir_entry()
108 			  de->name[0] == '.'))  in __ext4_check_dir_entry()
109 		error_msg = "'.' directory cannot be the last in data block";  in __ext4_check_dir_entry()
114 		ext4_error_file(filp, function, line, bh->b_blocknr,  in __ext4_check_dir_entry()
115 				"bad entry in directory: %s - offset=%u, "  in __ext4_check_dir_entry()
117 				error_msg, offset, le32_to_cpu(de->inode),  in __ext4_check_dir_entry()
120 		ext4_error_inode(dir, function, line, bh->b_blocknr,  in __ext4_check_dir_entry()
121 				"bad entry in directory: %s - offset=%u, "  in __ext4_check_dir_entry()
123 				 error_msg, offset, le32_to_cpu(de->inode),  in __ext4_check_dir_entry()
133 	struct ext4_dir_entry_2 *de;  in ext4_readdir()  local
136 	struct super_block *sb = inode->i_sb;  in ext4_readdir()
139 	struct dir_private_info *info = file->private_data;  in ext4_readdir()
174 	while (ctx->pos < inode->i_size) {  in ext4_readdir()
178 			err = -ERESTARTSYS;  in ext4_readdir()
182 		offset = ctx->pos & (sb->s_blocksize - 1);  in ext4_readdir()
183 		map.m_lblk = ctx->pos >> EXT4_BLOCK_SIZE_BITS(sb);  in ext4_readdir()
187 			/* m_len should never be zero but let's avoid  in ext4_readdir()
191 			ctx->pos += map.m_len * sb->s_blocksize;  in ext4_readdir()
196 					(PAGE_SHIFT - inode->i_blkbits);  in ext4_readdir()
197 			if (!ra_has_index(&file->f_ra, index))  in ext4_readdir()
199 					sb->s_bdev->bd_mapping,  in ext4_readdir()
200 					&file->f_ra, file,  in ext4_readdir()
202 			file->f_ra.prev_pos = (loff_t)index << PAGE_SHIFT;  in ext4_readdir()
213 			if (ctx->pos > inode->i_blocks << 9)  in ext4_readdir()
215 			ctx->pos += sb->s_blocksize - offset;  in ext4_readdir()
224 					(unsigned long long)ctx->pos);  in ext4_readdir()
225 			ctx->pos += sb->s_blocksize - offset;  in ext4_readdir()
233 		 * readdir(2), then we might be pointing to an invalid  in ext4_readdir()
236 		if (!inode_eq_iversion(inode, info->cookie)) {  in ext4_readdir()
237 			for (i = 0; i < sb->s_blocksize && i < offset; ) {  in ext4_readdir()
238 				de = (struct ext4_dir_entry_2 *)  in ext4_readdir()
239 					(bh->b_data + i);  in ext4_readdir()
243 				 * least that it is non-zero.  A  in ext4_readdir()
244 				 * failure will be detected in the  in ext4_readdir()
246 				if (ext4_rec_len_from_disk(de->rec_len,  in ext4_readdir()
247 					sb->s_blocksize) < ext4_dir_rec_len(1,  in ext4_readdir()
250 				i += ext4_rec_len_from_disk(de->rec_len,  in ext4_readdir()
251 							    sb->s_blocksize);  in ext4_readdir()
254 			ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1))  in ext4_readdir()
256 			info->cookie = inode_query_iversion(inode);  in ext4_readdir()
259 		while (ctx->pos < inode->i_size  in ext4_readdir()
260 		       && offset < sb->s_blocksize) {  in ext4_readdir()
261 			de = (struct ext4_dir_entry_2 *) (bh->b_data + offset);  in ext4_readdir()
262 			if (ext4_check_dir_entry(inode, file, de, bh,  in ext4_readdir()
263 						 bh->b_data, bh->b_size,  in ext4_readdir()
268 				ctx->pos = (ctx->pos |  in ext4_readdir()
269 						(sb->s_blocksize - 1)) + 1;  in ext4_readdir()
272 			offset += ext4_rec_len_from_disk(de->rec_len,  in ext4_readdir()
273 					sb->s_blocksize);  in ext4_readdir()
274 			if (le32_to_cpu(de->inode)) {  in ext4_readdir()
276 					if (!dir_emit(ctx, de->name,  in ext4_readdir()
277 					    de->name_len,  in ext4_readdir()
278 					    le32_to_cpu(de->inode),  in ext4_readdir()
279 					    get_dtype(sb, de->file_type)))  in ext4_readdir()
284 							FSTR_INIT(de->name,  in ext4_readdir()
285 								de->name_len);  in ext4_readdir()
290 						hash = EXT4_DIRENT_HASH(de);  in ext4_readdir()
291 						minor_hash = EXT4_DIRENT_MINOR_HASH(de);  in ext4_readdir()
306 					    le32_to_cpu(de->inode),  in ext4_readdir()
307 					    get_dtype(sb, de->file_type)))  in ext4_readdir()
311 			ctx->pos += ext4_rec_len_from_disk(de->rec_len,  in ext4_readdir()
312 						sb->s_blocksize);  in ext4_readdir()
314 		if ((ctx->pos < inode->i_size) && !dir_relax_shared(inode))  in ext4_readdir()
341  * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted
342  * directly on both 32-bit and 64-bit nodes, under such case, neither
347 	if ((filp->f_mode & FMODE_32BITHASH) ||  in hash2pos()
348 	    (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))  in hash2pos()
356 	if ((filp->f_mode & FMODE_32BITHASH) ||  in pos2maj_hash()
357 	    (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))  in pos2maj_hash()
365 	if ((filp->f_mode & FMODE_32BITHASH) ||  in pos2min_hash()
366 	    (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))  in pos2min_hash()
373  * Return 32- or 64-bit end-of-file for dx directories
377 	if ((filp->f_mode & FMODE_32BITHASH) ||  in ext4_get_htree_eof()
378 	    (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))  in ext4_get_htree_eof()
390  * Because we may return a 64-bit hash that is well beyond offset limits,
394  * For non-htree, ext4_llseek already chooses the proper max offset.
398 	struct inode *inode = file->f_mapping->host;  in ext4_dir_llseek()
399 	struct dir_private_info *info = file->private_data;  in ext4_dir_llseek()
408 	info->cookie = inode_peek_iversion(inode) - 1;  in ext4_dir_llseek()
413  * This structure holds the nodes of the red-black tree used to store
428  * This function implements a non-recursive way of freeing all of the
429  * nodes in the red-black tree.
438 			fname = fname->next;  in free_rb_tree_fname()
447 	struct dir_private_info *p = filp->private_data;  in ext4_htree_init_dir_info()
449 	if (is_dx_dir(file_inode(filp)) && !p->initialized) {  in ext4_htree_init_dir_info()
450 		p->curr_hash = pos2maj_hash(filp, pos);  in ext4_htree_init_dir_info()
451 		p->curr_minor_hash = pos2min_hash(filp, pos);  in ext4_htree_init_dir_info()
452 		p->initialized = true;  in ext4_htree_init_dir_info()
458 	free_rb_tree_fname(&p->root);  in ext4_htree_free_dir_info()
478 	info = dir_file->private_data;  in ext4_htree_store_dirent()
479 	p = &info->root.rb_node;  in ext4_htree_store_dirent()
482 	new_fn = kzalloc(struct_size(new_fn, name, ent_name->len + 1),  in ext4_htree_store_dirent()
485 		return -ENOMEM;  in ext4_htree_store_dirent()
486 	new_fn->hash = hash;  in ext4_htree_store_dirent()
487 	new_fn->minor_hash = minor_hash;  in ext4_htree_store_dirent()
488 	new_fn->inode = le32_to_cpu(dirent->inode);  in ext4_htree_store_dirent()
489 	new_fn->name_len = ent_name->len;  in ext4_htree_store_dirent()
490 	new_fn->file_type = dirent->file_type;  in ext4_htree_store_dirent()
491 	memcpy(new_fn->name, ent_name->name, ent_name->len);  in ext4_htree_store_dirent()
501 		if ((new_fn->hash == fname->hash) &&  in ext4_htree_store_dirent()
502 		    (new_fn->minor_hash == fname->minor_hash)) {  in ext4_htree_store_dirent()
503 			new_fn->next = fname->next;  in ext4_htree_store_dirent()
504 			fname->next = new_fn;  in ext4_htree_store_dirent()
508 		if (new_fn->hash < fname->hash)  in ext4_htree_store_dirent()
509 			p = &(*p)->rb_left;  in ext4_htree_store_dirent()
510 		else if (new_fn->hash > fname->hash)  in ext4_htree_store_dirent()
511 			p = &(*p)->rb_right;  in ext4_htree_store_dirent()
512 		else if (new_fn->minor_hash < fname->minor_hash)  in ext4_htree_store_dirent()
513 			p = &(*p)->rb_left;  in ext4_htree_store_dirent()
514 		else /* if (new_fn->minor_hash > fname->minor_hash) */  in ext4_htree_store_dirent()
515 			p = &(*p)->rb_right;  in ext4_htree_store_dirent()
518 	rb_link_node(&new_fn->rb_hash, parent, p);  in ext4_htree_store_dirent()
519 	rb_insert_color(&new_fn->rb_hash, &info->root);  in ext4_htree_store_dirent()
533 	struct dir_private_info *info = file->private_data;  in call_filldir()
535 	struct super_block *sb = inode->i_sb;  in call_filldir()
540 			 inode->i_ino, current->comm);  in call_filldir()
543 	ctx->pos = hash2pos(file, fname->hash, fname->minor_hash);  in call_filldir()
545 		if (!dir_emit(ctx, fname->name,  in call_filldir()
546 				fname->name_len,  in call_filldir()
547 				fname->inode,  in call_filldir()
548 				get_dtype(sb, fname->file_type))) {  in call_filldir()
549 			info->extra_fname = fname;  in call_filldir()
552 		fname = fname->next;  in call_filldir()
559 	struct dir_private_info *info = file->private_data;  in ext4_dx_readdir()
564 	ext4_htree_init_dir_info(file, ctx->pos);  in ext4_dx_readdir()
566 	if (ctx->pos == ext4_get_htree_eof(file))  in ext4_dx_readdir()
570 	if (info->last_pos != ctx->pos) {  in ext4_dx_readdir()
571 		free_rb_tree_fname(&info->root);  in ext4_dx_readdir()
572 		info->curr_node = NULL;  in ext4_dx_readdir()
573 		info->extra_fname = NULL;  in ext4_dx_readdir()
574 		info->curr_hash = pos2maj_hash(file, ctx->pos);  in ext4_dx_readdir()
575 		info->curr_minor_hash = pos2min_hash(file, ctx->pos);  in ext4_dx_readdir()
582 	if (info->extra_fname) {  in ext4_dx_readdir()
583 		if (call_filldir(file, ctx, info->extra_fname))  in ext4_dx_readdir()
585 		info->extra_fname = NULL;  in ext4_dx_readdir()
587 	} else if (!info->curr_node)  in ext4_dx_readdir()
588 		info->curr_node = rb_first(&info->root);  in ext4_dx_readdir()
596 		if ((!info->curr_node) ||  in ext4_dx_readdir()
597 		    !inode_eq_iversion(inode, info->cookie)) {  in ext4_dx_readdir()
598 			info->curr_node = NULL;  in ext4_dx_readdir()
599 			free_rb_tree_fname(&info->root);  in ext4_dx_readdir()
600 			info->cookie = inode_query_iversion(inode);  in ext4_dx_readdir()
601 			ret = ext4_htree_fill_tree(file, info->curr_hash,  in ext4_dx_readdir()
602 						   info->curr_minor_hash,  in ext4_dx_readdir()
603 						   &info->next_hash);  in ext4_dx_readdir()
607 				ctx->pos = ext4_get_htree_eof(file);  in ext4_dx_readdir()
610 			info->curr_node = rb_first(&info->root);  in ext4_dx_readdir()
613 		fname = rb_entry(info->curr_node, struct fname, rb_hash);  in ext4_dx_readdir()
614 		info->curr_hash = fname->hash;  in ext4_dx_readdir()
615 		info->curr_minor_hash = fname->minor_hash;  in ext4_dx_readdir()
619 		info->curr_node = rb_next(info->curr_node);  in ext4_dx_readdir()
620 		if (info->curr_node) {  in ext4_dx_readdir()
621 			fname = rb_entry(info->curr_node, struct fname,  in ext4_dx_readdir()
623 			info->curr_hash = fname->hash;  in ext4_dx_readdir()
624 			info->curr_minor_hash = fname->minor_hash;  in ext4_dx_readdir()
626 			if (info->next_hash == ~0) {  in ext4_dx_readdir()
627 				ctx->pos = ext4_get_htree_eof(file);  in ext4_dx_readdir()
630 			info->curr_hash = info->next_hash;  in ext4_dx_readdir()
631 			info->curr_minor_hash = 0;  in ext4_dx_readdir()
635 	info->last_pos = ctx->pos;  in ext4_dx_readdir()
641 	if (filp->private_data)  in ext4_release_dir()
642 		ext4_htree_free_dir_info(filp->private_data);  in ext4_release_dir()
650 	struct ext4_dir_entry_2 *de;  in ext4_check_all_de()  local
655 	de = buf;  in ext4_check_all_de()
657 	while ((char *) de < top) {  in ext4_check_all_de()
658 		if (ext4_check_dir_entry(dir, NULL, de, bh,  in ext4_check_all_de()
660 			return -EFSCORRUPTED;  in ext4_check_all_de()
661 		rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);  in ext4_check_all_de()
662 		de = (struct ext4_dir_entry_2 *)((char *)de + rlen);  in ext4_check_all_de()
665 	if ((char *) de > top)  in ext4_check_all_de()
666 		return -EFSCORRUPTED;  in ext4_check_all_de()
677 		return -ENOMEM;  in ext4_dir_open()
678 	file->private_data = info;  in ext4_dir_open()