From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31303C433E7 for ; Thu, 3 Sep 2020 09:27:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DAF62206C0 for ; Thu, 3 Sep 2020 09:27:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="QfQGYcOC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727065AbgICJ1U (ORCPT ); Thu, 3 Sep 2020 05:27:20 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:54204 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726047AbgICJ1S (ORCPT ); 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Thu, 3 Sep 2020 09:27:11 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserp3020.oracle.com with ESMTP id 3380x9db3j-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 03 Sep 2020 09:27:11 +0000 Received: from abhmp0004.oracle.com (abhmp0004.oracle.com [141.146.116.10]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 0839RAkX004117; Thu, 3 Sep 2020 09:27:10 GMT Received: from mwanda (/41.57.98.10) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 03 Sep 2020 02:27:10 -0700 Date: Thu, 3 Sep 2020 12:27:05 +0300 From: Dan Carpenter To: nborisov@suse.com Cc: linux-btrfs@vger.kernel.org Subject: [bug report] btrfs: remove err variable from btrfs_get_extent Message-ID: <20200903092705.GA392335@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9732 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 spamscore=0 phishscore=0 mlxlogscore=769 adultscore=0 suspectscore=10 bulkscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009030086 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9732 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 clxscore=1011 priorityscore=1501 lowpriorityscore=0 malwarescore=0 adultscore=0 spamscore=0 mlxscore=0 phishscore=0 impostorscore=0 mlxlogscore=771 bulkscore=0 suspectscore=10 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009030086 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Hello Nikolay Borisov, The patch 85b1eebdaf1d: "btrfs: remove err variable from btrfs_get_extent" from Aug 3, 2020, leads to the following static checker warning: fs/btrfs/inode.c:6737 btrfs_get_extent() error: passing non negative 1 to ERR_PTR fs/btrfs/inode.c 6531 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode, 6532 struct page *page, size_t pg_offset, 6533 u64 start, u64 len) 6534 { 6535 struct btrfs_fs_info *fs_info = inode->root->fs_info; 6536 int ret = 0; 6537 u64 extent_start = 0; 6538 u64 extent_end = 0; 6539 u64 objectid = btrfs_ino(inode); 6540 int extent_type = -1; 6541 struct btrfs_path *path = NULL; 6542 struct btrfs_root *root = inode->root; 6543 struct btrfs_file_extent_item *item; 6544 struct extent_buffer *leaf; 6545 struct btrfs_key found_key; 6546 struct extent_map *em = NULL; 6547 struct extent_map_tree *em_tree = &inode->extent_tree; 6548 struct extent_io_tree *io_tree = &inode->io_tree; 6549 6550 read_lock(&em_tree->lock); 6551 em = lookup_extent_mapping(em_tree, start, len); 6552 read_unlock(&em_tree->lock); 6553 6554 if (em) { 6555 if (em->start > start || em->start + em->len <= start) 6556 free_extent_map(em); 6557 else if (em->block_start == EXTENT_MAP_INLINE && page) 6558 free_extent_map(em); 6559 else 6560 goto out; 6561 } 6562 em = alloc_extent_map(); 6563 if (!em) { 6564 ret = -ENOMEM; 6565 goto out; 6566 } 6567 em->start = EXTENT_MAP_HOLE; 6568 em->orig_start = EXTENT_MAP_HOLE; 6569 em->len = (u64)-1; 6570 em->block_len = (u64)-1; 6571 6572 path = btrfs_alloc_path(); 6573 if (!path) { 6574 ret = -ENOMEM; 6575 goto out; 6576 } 6577 6578 /* Chances are we'll be called again, so go ahead and do readahead */ 6579 path->reada = READA_FORWARD; 6580 6581 /* 6582 * Unless we're going to uncompress the inline extent, no sleep would 6583 * happen. 6584 */ 6585 path->leave_spinning = 1; 6586 6587 ret = btrfs_lookup_file_extent(NULL, root, path, objectid, start, 0); 6588 if (ret < 0) { 6589 goto out; 6590 } else if (ret > 0) { ^^^^^^^ "ret" is 1. 6591 if (path->slots[0] == 0) 6592 goto not_found; 6593 path->slots[0]--; 6594 } 6595 6596 leaf = path->nodes[0]; 6597 item = btrfs_item_ptr(leaf, path->slots[0], 6598 struct btrfs_file_extent_item); 6599 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6600 if (found_key.objectid != objectid || 6601 found_key.type != BTRFS_EXTENT_DATA_KEY) { 6602 /* 6603 * If we backup past the first extent we want to move forward 6604 * and see if there is an extent in front of us, otherwise we'll 6605 * say there is a hole for our whole search range which can 6606 * cause problems. 6607 */ 6608 extent_end = start; 6609 goto next; 6610 } 6611 6612 extent_type = btrfs_file_extent_type(leaf, item); 6613 extent_start = found_key.offset; 6614 extent_end = btrfs_file_extent_end(path); 6615 if (extent_type == BTRFS_FILE_EXTENT_REG || 6616 extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 6617 /* Only regular file could have regular/prealloc extent */ 6618 if (!S_ISREG(inode->vfs_inode.i_mode)) { 6619 ret = -EUCLEAN; 6620 btrfs_crit(fs_info, 6621 "regular/prealloc extent found for non-regular inode %llu", 6622 btrfs_ino(inode)); 6623 goto out; 6624 } 6625 trace_btrfs_get_extent_show_fi_regular(inode, leaf, item, 6626 extent_start); 6627 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 6628 trace_btrfs_get_extent_show_fi_inline(inode, leaf, item, 6629 path->slots[0], 6630 extent_start); 6631 } 6632 next: 6633 if (start >= extent_end) { 6634 path->slots[0]++; 6635 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 6636 ret = btrfs_next_leaf(root, path); 6637 if (ret < 0) 6638 goto out; 6639 else if (ret > 0) 6640 goto not_found; 6641 6642 leaf = path->nodes[0]; 6643 } 6644 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6645 if (found_key.objectid != objectid || 6646 found_key.type != BTRFS_EXTENT_DATA_KEY) 6647 goto not_found; 6648 if (start + len <= found_key.offset) 6649 goto not_found; 6650 if (start > found_key.offset) 6651 goto next; 6652 6653 /* New extent overlaps with existing one */ 6654 em->start = start; 6655 em->orig_start = start; 6656 em->len = found_key.offset - start; 6657 em->block_start = EXTENT_MAP_HOLE; 6658 goto insert; 6659 } 6660 6661 btrfs_extent_item_to_extent_map(inode, path, item, !page, em); 6662 6663 if (extent_type == BTRFS_FILE_EXTENT_REG || 6664 extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 6665 goto insert; 6666 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 6667 unsigned long ptr; 6668 char *map; 6669 size_t size; 6670 size_t extent_offset; 6671 size_t copy_size; 6672 6673 if (!page) 6674 goto out; ^^^^^^^^ Assume we reach here. 6675 6676 size = btrfs_file_extent_ram_bytes(leaf, item); 6677 extent_offset = page_offset(page) + pg_offset - extent_start; 6678 copy_size = min_t(u64, PAGE_SIZE - pg_offset, 6679 size - extent_offset); 6680 em->start = extent_start + extent_offset; 6681 em->len = ALIGN(copy_size, fs_info->sectorsize); 6682 em->orig_block_len = em->len; 6683 em->orig_start = em->start; 6684 ptr = btrfs_file_extent_inline_start(item) + extent_offset; 6685 6686 btrfs_set_path_blocking(path); 6687 if (!PageUptodate(page)) { 6688 if (btrfs_file_extent_compression(leaf, item) != 6689 BTRFS_COMPRESS_NONE) { 6690 ret = uncompress_inline(path, page, pg_offset, 6691 extent_offset, item); 6692 if (ret) 6693 goto out; 6693 goto out; 6694 } else { 6695 map = kmap(page); 6696 read_extent_buffer(leaf, map + pg_offset, ptr, 6697 copy_size); 6698 if (pg_offset + copy_size < PAGE_SIZE) { 6699 memset(map + pg_offset + copy_size, 0, 6700 PAGE_SIZE - pg_offset - 6701 copy_size); 6702 } 6703 kunmap(page); 6704 } 6705 flush_dcache_page(page); 6706 } 6707 set_extent_uptodate(io_tree, em->start, 6708 extent_map_end(em) - 1, NULL, GFP_NOFS); 6709 goto insert; 6710 } 6711 not_found: 6712 em->start = start; 6713 em->orig_start = start; 6714 em->len = len; 6715 em->block_start = EXTENT_MAP_HOLE; 6716 insert: 6717 ret = 0; 6718 btrfs_release_path(path); 6719 if (em->start > start || extent_map_end(em) <= start) { 6720 btrfs_err(fs_info, 6721 "bad extent! em: [%llu %llu] passed [%llu %llu]", 6722 em->start, em->len, start, len); 6723 ret = -EIO; 6724 goto out; 6725 } 6726 6727 write_lock(&em_tree->lock); 6728 ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len); 6729 write_unlock(&em_tree->lock); 6730 out: 6731 btrfs_free_path(path); 6732 6733 trace_btrfs_get_extent(root, inode, em); 6734 6735 if (ret) { 6736 free_extent_map(em); 6737 return ERR_PTR(ret); ^^^ BOOM! The caller will Oops. 6738 } 6739 return em; 6740 } regards, dan carpenter