From patchwork Fri Jan 5 19:51:12 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liu Bo X-Patchwork-Id: 10147065 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0E84160153 for ; Fri, 5 Jan 2018 20:54:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9D05A28926 for ; Fri, 5 Jan 2018 20:54:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 912F228929; Fri, 5 Jan 2018 20:54:36 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E084E28926 for ; Fri, 5 Jan 2018 20:54:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753008AbeAEUyd (ORCPT ); Fri, 5 Jan 2018 15:54:33 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:52854 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752917AbeAEUyL (ORCPT ); Fri, 5 Jan 2018 15:54:11 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.21/8.16.0.21) with SMTP id w05KqclU146654 for ; Fri, 5 Jan 2018 20:54:10 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : subject : date : message-id : in-reply-to : references; s=corp-2017-10-26; bh=M+lWb6dXQpfYSOeiXCtiAE0zFGlRfvTwXwXn2u8ljE8=; b=eNc0VJanbs2eAzOhS1UAD4qIVhg5+56/GM7ZKj3SwYxWaLGI0SnMRqm+obTdJEU2kjQS Vh//YZ76VXsmL5CaGWtVwmL4w3Soy8ObTViiKeIFWdYogYwEnRqMIW8R2Za9+7C6v897 B/xapCQcapUH+M1lSWU6Syd0xGi/fSw/3ryV7NhHQMsLW58xChHSYwBzvHQsIDojnN4M zhanD/IyqlQrBilVW1oQPbbagoZFR51qoUJcJC5InQm4ueSo99Fh2kFMD1cwmvhf8uMt IGY6FeAFa/AcDK9adnnjPXsU428bgR6L4WcTHlkWLNKrnhTakhsiGpungg1YzxSqVAL2 KQ== Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by userp2120.oracle.com with ESMTP id 2fag5k06ef-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Fri, 05 Jan 2018 20:54:09 +0000 Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w05Ks9kZ000467 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Fri, 5 Jan 2018 20:54:09 GMT Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id w05Ks9qr027723 for ; Fri, 5 Jan 2018 20:54:09 GMT Received: from dhcp-10-211-47-181.usdhcp.oraclecorp.com.com (/10.211.47.181) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 05 Jan 2018 12:54:09 -0800 From: Liu Bo To: linux-btrfs@vger.kernel.org Subject: [PATCH v2 05/10] Btrfs: add extent map selftests Date: Fri, 5 Jan 2018 12:51:12 -0700 Message-Id: <20180105195117.5131-6-bo.li.liu@oracle.com> X-Mailer: git-send-email 2.9.4 In-Reply-To: <20180105195117.5131-1-bo.li.liu@oracle.com> References: <20180105195117.5131-1-bo.li.liu@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8765 signatures=668651 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=18 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=825 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1801050287 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We've observed that btrfs_get_extent() and merge_extent_mapping() could return -EEXIST in several cases, and they are caused by some racy condition, e.g dio read vs dio write, which makes the problem very tricky to reproduce. This adds extent map selftests in order to simulate those racy situations. Signed-off-by: Liu Bo Reviewed-by: Josef Bacik --- fs/btrfs/Makefile | 2 +- fs/btrfs/tests/btrfs-tests.c | 3 + fs/btrfs/tests/btrfs-tests.h | 1 + fs/btrfs/tests/extent-map-tests.c | 202 ++++++++++++++++++++++++++++++++++++++ 4 files changed, 207 insertions(+), 1 deletion(-) create mode 100644 fs/btrfs/tests/extent-map-tests.c diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile index 6fe881d..0c43736 100644 --- a/fs/btrfs/Makefile +++ b/fs/btrfs/Makefile @@ -19,4 +19,4 @@ btrfs-$(CONFIG_BTRFS_FS_REF_VERIFY) += ref-verify.o btrfs-$(CONFIG_BTRFS_FS_RUN_SANITY_TESTS) += tests/free-space-tests.o \ tests/extent-buffer-tests.o tests/btrfs-tests.o \ tests/extent-io-tests.o tests/inode-tests.o tests/qgroup-tests.o \ - tests/free-space-tree-tests.o + tests/free-space-tree-tests.o tests/extent-map-tests.o diff --git a/fs/btrfs/tests/btrfs-tests.c b/fs/btrfs/tests/btrfs-tests.c index d3f2537..9786d8c 100644 --- a/fs/btrfs/tests/btrfs-tests.c +++ b/fs/btrfs/tests/btrfs-tests.c @@ -277,6 +277,9 @@ int btrfs_run_sanity_tests(void) goto out; } } + ret = btrfs_test_extent_map(); + if (ret) + goto out; out: btrfs_destroy_test_fs(); return ret; diff --git a/fs/btrfs/tests/btrfs-tests.h b/fs/btrfs/tests/btrfs-tests.h index 266f1e3..bc0615b 100644 --- a/fs/btrfs/tests/btrfs-tests.h +++ b/fs/btrfs/tests/btrfs-tests.h @@ -33,6 +33,7 @@ int btrfs_test_extent_io(u32 sectorsize, u32 nodesize); int btrfs_test_inodes(u32 sectorsize, u32 nodesize); int btrfs_test_qgroups(u32 sectorsize, u32 nodesize); int btrfs_test_free_space_tree(u32 sectorsize, u32 nodesize); +int btrfs_test_extent_map(void); struct inode *btrfs_new_test_inode(void); struct btrfs_fs_info *btrfs_alloc_dummy_fs_info(u32 nodesize, u32 sectorsize); void btrfs_free_dummy_fs_info(struct btrfs_fs_info *fs_info); diff --git a/fs/btrfs/tests/extent-map-tests.c b/fs/btrfs/tests/extent-map-tests.c new file mode 100644 index 0000000..0407396 --- /dev/null +++ b/fs/btrfs/tests/extent-map-tests.c @@ -0,0 +1,202 @@ +/* + * Copyright (C) 2017 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#include +#include "btrfs-tests.h" +#include "../ctree.h" + +static void free_extent_map_tree(struct extent_map_tree *em_tree) +{ + struct extent_map *em; + struct rb_node *node; + + while (!RB_EMPTY_ROOT(&em_tree->map)) { + node = rb_first(&em_tree->map); + em = rb_entry(node, struct extent_map, rb_node); + remove_extent_mapping(em_tree, em); + +#ifdef CONFIG_BTRFS_DEBUG + if (refcount_read(&em->refs) != 1) { + test_msg( + "Oops we have a em leak: em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx) refs %d\n", + em->start, em->len, em->block_start, + em->block_len, refcount_read(&em->refs)); + + refcount_set(&em->refs, 1); + } +#endif + free_extent_map(em); + } +} + +/* + * Test scenario: + * + * Suppose that no extent map has been loaded into memory yet, there is a file + * extent [0, 16K), followed by another file extent [16K, 20K), two dio reads + * are entering btrfs_get_extent() concurrently, t1 is reading [8K, 16K), t2 is + * reading [0, 8K) + * + * t1 t2 + * btrfs_get_extent() btrfs_get_extent() + * -> lookup_extent_mapping() ->lookup_extent_mapping() + * -> add_extent_mapping(0, 16K) + * -> return em + * ->add_extent_mapping(0, 16K) + * -> #handle -EEXIST + */ +static void test_case_1(struct extent_map_tree *em_tree) +{ + struct extent_map *em; + u64 start = 0; + u64 len = SZ_8K; + int ret; + + em = alloc_extent_map(); + if (!em) + /* Skip the test on error. */ + return; + + /* Add [0, 16K) */ + em->start = 0; + em->len = SZ_16K; + em->block_start = 0; + em->block_len = SZ_16K; + ret = add_extent_mapping(em_tree, em, 0); + ASSERT(ret == 0); + free_extent_map(em); + + /* Add [16K, 20K) following [0, 16K) */ + em = alloc_extent_map(); + if (!em) + goto out; + + em->start = SZ_16K; + em->len = SZ_4K; + em->block_start = SZ_32K; /* avoid merging */ + em->block_len = SZ_4K; + ret = add_extent_mapping(em_tree, em, 0); + ASSERT(ret == 0); + free_extent_map(em); + + em = alloc_extent_map(); + if (!em) + goto out; + + /* Add [0, 8K), should return [0, 16K) instead. */ + em->start = start; + em->len = len; + em->block_start = start; + em->block_len = len; + ret = btrfs_add_extent_mapping(em_tree, &em, em->start, em->len); + if (ret) + test_msg("case1 [%llu %llu]: ret %d\n", + start, start + len, ret); + if (em && + (em->start != 0 || extent_map_end(em) != SZ_16K || + em->block_start != 0 || em->block_len != SZ_16K)) + test_msg("case1 [%llu %llu]: ret %d return a wrong em (start %llu len %llu block_start %llu block_len %llu\n", + start, start + len, ret, em->start, em->len, + em->block_start, em->block_len); + free_extent_map(em); +out: + /* free memory */ + free_extent_map_tree(em_tree); +} + +/* + * Test scenario: + * + * Reading the inline ending up with EEXIST, ie. read an inline + * extent and discard page cache and read it again. + */ +static void test_case_2(struct extent_map_tree *em_tree) +{ + struct extent_map *em; + int ret; + + em = alloc_extent_map(); + if (!em) + /* Skip the test on error. */ + return; + + /* Add [0, 1K) */ + em->start = 0; + em->len = SZ_1K; + em->block_start = EXTENT_MAP_INLINE; + em->block_len = (u64)-1; + ret = add_extent_mapping(em_tree, em, 0); + ASSERT(ret == 0); + free_extent_map(em); + + /* Add [4K, 4K) following [0, 1K) */ + em = alloc_extent_map(); + if (!em) + goto out; + + em->start = SZ_4K; + em->len = SZ_4K; + em->block_start = SZ_4K; + em->block_len = SZ_4K; + ret = add_extent_mapping(em_tree, em, 0); + ASSERT(ret == 0); + free_extent_map(em); + + em = alloc_extent_map(); + if (!em) + goto out; + + /* Add [0, 1K) */ + em->start = 0; + em->len = SZ_1K; + em->block_start = EXTENT_MAP_INLINE; + em->block_len = (u64)-1; + ret = btrfs_add_extent_mapping(em_tree, &em, em->start, em->len); + if (ret) + test_msg("case2 [0 1K]: ret %d\n", ret); + if (em && + (em->start != 0 || extent_map_end(em) != SZ_1K || + em->block_start != EXTENT_MAP_INLINE || em->block_len != (u64)-1)) + test_msg("case2 [0 1K]: ret %d return a wrong em (start %llu len %llu block_start %llu block_len %llu\n", + ret, em->start, em->len, em->block_start, + em->block_len); + free_extent_map(em); +out: + /* free memory */ + free_extent_map_tree(em_tree); +} + +int btrfs_test_extent_map() +{ + struct extent_map_tree *em_tree; + + test_msg("Running extent_map tests\n"); + + em_tree = kzalloc(sizeof(*em_tree), GFP_KERNEL); + if (!em_tree) + /* Skip the test on error. */ + return 0; + + extent_map_tree_init(em_tree); + + test_case_1(em_tree); + test_case_2(em_tree); + + kfree(em_tree); + return 0; +}