From patchwork Mon Aug 19 00:53:19 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zizhi Wo X-Patchwork-Id: 13767694 Received: from szxga05-in.huawei.com (szxga05-in.huawei.com [45.249.212.191]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F12991DFEF; Mon, 19 Aug 2024 00:57:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.191 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724029081; cv=none; b=AnwBUCEhW/Bk95sZK/n6nA0EC5L5yHf7lWhCtU8QXQODXybquUtgMBzjQF5Nr9EP4LX8HvoSI4wfZHucoF0U8uidMRvjNFDOwKp/PMCS+bzNHC0MeVGbE9MCzMB57kBlsqyk18W4X1qfEtSI6HEAi5n7kAdskcuWUBSBhkTJc3E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724029081; c=relaxed/simple; bh=IzNGChZSUnP7hsxBuw3BpAjJNMnR/k+zsHHP8CbX6tI=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Kp+/13+eEpB4U8zJ1SwfMXI96P616xWPj7BljGACtuZVk84x+hrxun1b8/2Fp3SoBUnj6pbPGlMCch0NunYNKjlmMA1LSf48ct+6n99bpzFM5bNAjefrPA4q/gtUud/ubKd6KebOS6AmlcoqGuamUBl9JNGOGAo0s6L7+1q57qo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.191 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.88.214]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4WnDdX6XGqz1HGjl; Mon, 19 Aug 2024 08:54:40 +0800 (CST) Received: from kwepemf100017.china.huawei.com (unknown [7.202.181.16]) by mail.maildlp.com (Postfix) with ESMTPS id 5233A1A016C; Mon, 19 Aug 2024 08:57:50 +0800 (CST) Received: from localhost.localdomain (10.175.104.67) by kwepemf100017.china.huawei.com (7.202.181.16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Mon, 19 Aug 2024 08:57:49 +0800 From: Zizhi Wo To: , , , , CC: , , , Subject: [PATCH V4 1/2] xfs: Fix the owner setting issue for rmap query in xfs fsmap Date: Mon, 19 Aug 2024 08:53:19 +0800 Message-ID: <20240819005320.304211-2-wozizhi@huawei.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240819005320.304211-1-wozizhi@huawei.com> References: <20240819005320.304211-1-wozizhi@huawei.com> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemf100017.china.huawei.com (7.202.181.16) I notice a rmap query bug in xfs_io fsmap: [root@fedora ~]# xfs_io -c 'fsmap -vvvv' /mnt EXT: DEV BLOCK-RANGE OWNER FILE-OFFSET AG AG-OFFSET TOTAL 0: 253:16 [0..7]: static fs metadata 0 (0..7) 8 1: 253:16 [8..23]: per-AG metadata 0 (8..23) 16 2: 253:16 [24..39]: inode btree 0 (24..39) 16 3: 253:16 [40..47]: per-AG metadata 0 (40..47) 8 4: 253:16 [48..55]: refcount btree 0 (48..55) 8 5: 253:16 [56..103]: per-AG metadata 0 (56..103) 48 6: 253:16 [104..127]: free space 0 (104..127) 24 ...... Bug: [root@fedora ~]# xfs_io -c 'fsmap -vvvv -d 0 3' /mnt [root@fedora ~]# Normally, we should be able to get one record, but we got nothing. The root cause of this problem lies in the incorrect setting of rm_owner in the rmap query. In the case of the initial query where the owner is not set, __xfs_getfsmap_datadev() first sets info->high.rm_owner to ULLONG_MAX. This is done to prevent any omissions when comparing rmap items. However, if the current ag is detected to be the last one, the function sets info's high_irec based on the provided key. If high->rm_owner is not specified, it should continue to be set to ULLONG_MAX; otherwise, there will be issues with interval omissions. For example, consider "start" and "end" within the same block. If high->rm_owner == 0, it will be smaller than the founded record in rmapbt, resulting in a query with no records. The main call stack is as follows: xfs_ioc_getfsmap xfs_getfsmap xfs_getfsmap_datadev_rmapbt __xfs_getfsmap_datadev info->high.rm_owner = ULLONG_MAX if (pag->pag_agno == end_ag) xfs_fsmap_owner_to_rmap // set info->high.rm_owner = 0 because fmr_owner == -1ULL dest->rm_owner = 0 // get nothing xfs_getfsmap_datadev_rmapbt_query The problem can be resolved by simply modify the xfs_fsmap_owner_to_rmap function internal logic to achieve. After applying this patch, the above problem have been solved: [root@fedora ~]# xfs_io -c 'fsmap -vvvv -d 0 3' /mnt EXT: DEV BLOCK-RANGE OWNER FILE-OFFSET AG AG-OFFSET TOTAL 0: 253:16 [0..7]: static fs metadata 0 (0..7) 8 Fixes: e89c041338ed ("xfs: implement the GETFSMAP ioctl") Signed-off-by: Zizhi Wo Reviewed-by: Darrick J. Wong --- fs/xfs/xfs_fsmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/xfs/xfs_fsmap.c b/fs/xfs/xfs_fsmap.c index 85dbb46452ca..3a30b36779db 100644 --- a/fs/xfs/xfs_fsmap.c +++ b/fs/xfs/xfs_fsmap.c @@ -71,7 +71,7 @@ xfs_fsmap_owner_to_rmap( switch (src->fmr_owner) { case 0: /* "lowest owner id possible" */ case -1ULL: /* "highest owner id possible" */ - dest->rm_owner = 0; + dest->rm_owner = src->fmr_owner; break; case XFS_FMR_OWN_FREE: dest->rm_owner = XFS_RMAP_OWN_NULL;