From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp2120.oracle.com ([156.151.31.85]:52874 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752944AbeAEUyL (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 w05Kqeus146660 for ; Fri, 5 Jan 2018 20:54:11 GMT Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by userp2120.oracle.com with ESMTP id 2fag5k06ep-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Fri, 05 Jan 2018 20:54:11 +0000 Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w05KsAUe005008 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Fri, 5 Jan 2018 20:54:10 GMT Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id w05Ks9UB000477 for ; Fri, 5 Jan 2018 20:54:09 GMT From: Liu Bo To: linux-btrfs@vger.kernel.org Subject: [PATCH v2 07/10] Btrfs: extent map selftest: dio write vs dio read Date: Fri, 5 Jan 2018 12:51:14 -0700 Message-Id: <20180105195117.5131-8-bo.li.liu@oracle.com> In-Reply-To: <20180105195117.5131-1-bo.li.liu@oracle.com> References: <20180105195117.5131-1-bo.li.liu@oracle.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: This test case simulates the racy situation of dio write vs dio read, and see if btrfs_get_extent() would return -EEXIST. Signed-off-by: Liu Bo --- fs/btrfs/tests/extent-map-tests.c | 88 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) diff --git a/fs/btrfs/tests/extent-map-tests.c b/fs/btrfs/tests/extent-map-tests.c index 2adf55f..66d5523 100644 --- a/fs/btrfs/tests/extent-map-tests.c +++ b/fs/btrfs/tests/extent-map-tests.c @@ -253,6 +253,93 @@ static void test_case_3(struct extent_map_tree *em_tree) __test_case_3(em_tree, (12 * 1024ULL)); } +static void __test_case_4(struct extent_map_tree *em_tree, u64 start) +{ + struct extent_map *em; + u64 len = SZ_4K; + int ret; + + em = alloc_extent_map(); + if (!em) + /* Skip this test on error. */ + return; + + /* Add [0K, 8K) */ + em->start = 0; + em->len = SZ_8K; + em->block_start = 0; + em->block_len = SZ_8K; + ret = add_extent_mapping(em_tree, em, 0); + ASSERT(ret == 0); + free_extent_map(em); + + em = alloc_extent_map(); + if (!em) + goto out; + + /* Add [8K, 24K) */ + em->start = SZ_8K; + em->len = 24 * 1024ULL; + em->block_start = SZ_16K; /* avoid merging */ + em->block_len = 24 * 1024ULL; + ret = add_extent_mapping(em_tree, em, 0); + ASSERT(ret == 0); + free_extent_map(em); + + em = alloc_extent_map(); + if (!em) + goto out; + /* Add [0K, 32K) */ + em->start = 0; + em->len = SZ_32K; + em->block_start = 0; + em->block_len = SZ_32K; + ret = btrfs_add_extent_mapping(em_tree, &em, start, len); + if (ret) + test_msg("case4 [0x%llx 0x%llx): ret %d\n", + start, len, ret); + if (em && + (start < em->start || start + len > extent_map_end(em))) + test_msg("case4 [0x%llx 0x%llx): ret %d, added wrong em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx)\n", + 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: + * + * Suppose that no extent map has been loaded into memory yet. + * There is a file extent [0, 32K), two jobs are running concurrently + * against it, t1 is doing dio write to [8K, 32K) and t2 is doing dio + * read from [0, 4K) or [4K, 8K). + * + * t1 goes ahead of t2 and splits em [0, 32K) to em [0K, 8K) and [8K 32K). + * + * t1 t2 + * btrfs_get_blocks_direct() btrfs_get_blocks_direct() + * -> btrfs_get_extent() -> btrfs_get_extent() + * -> lookup_extent_mapping() + * -> add_extent_mapping() -> lookup_extent_mapping() + * # load [0, 32K) + * -> btrfs_new_extent_direct() + * -> btrfs_drop_extent_cache() + * # split [0, 32K) + * -> add_extent_mapping() + * # add [8K, 32K) + * -> add_extent_mapping() + * # handle -EEXIST when adding + * # [0, 32K) + */ +static void test_case_4(struct extent_map_tree *em_tree) +{ + __test_case_4(em_tree, 0); + __test_case_4(em_tree, SZ_4K); +} + int btrfs_test_extent_map() { struct extent_map_tree *em_tree; @@ -269,6 +356,7 @@ int btrfs_test_extent_map() test_case_1(em_tree); test_case_2(em_tree); test_case_3(em_tree); + test_case_4(em_tree); kfree(em_tree); return 0; -- 2.9.4