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=-8.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 62784C43610 for ; Tue, 20 Nov 2018 10:22:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DDF7C2087E for ; Tue, 20 Nov 2018 10:22:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=zoho.com header.i=yehs2007@zoho.com header.b="mKwGN9wE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DDF7C2087E Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=zoho.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727582AbeKTUuc (ORCPT ); Tue, 20 Nov 2018 15:50:32 -0500 Received: from sender-pp-092.zoho.com ([135.84.80.237]:25466 "EHLO sender-pp-092.zoho.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726548AbeKTUub (ORCPT ); Tue, 20 Nov 2018 15:50:31 -0500 ARC-Seal: i=1; a=rsa-sha256; t=1542709282; cv=none; d=zoho.com; s=zohoarc; b=hTxHz5DGo19Ny9KMCReq6pElGw2VHGwsKbTeYoZXI9kGN6S8H8sDecAp8pVyLs6ninaT9miuDLW/P1sjNUFXmNVVOzAcz/Dzq2q0TUNJLS2e/kx7FsHOpcJh2qEQK4qQO0oEdbGHpIrS0J5NNoiA0nu/8kLLMNftUEOhfmOZvAA= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1542709282; h=Cc:Date:From:In-Reply-To:Message-ID:References:Subject:To:ARC-Authentication-Results; bh=jTSA+Zs1+7240+81mturwydytJwomKEmU0d3STdG9hM=; b=lhNnEjVi2k4UpZtnIZz/EDS7ttApQ/sADEH91ZlSLW5cS+Oc3tmyuCE0qHlpp6T6cvCOj1olkjEkCxXSXhAAt0NW361kESDQVlAO6HHjFuVGiireWzgmg3KxbKzw6DnmpZpoDRs5U5EXBVM6ybDY4ps4hWbk0ZWEFqzMpTL8PU0= ARC-Authentication-Results: i=1; mx.zoho.com; dkim=pass header.i=zoho.com; spf=pass smtp.mailfrom=yehs2007@zoho.com; dmarc=pass header.from= header.from= DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=zapps768; d=zoho.com; h=from:to:cc:subject:date:message-id:in-reply-to:references; b=v+ol4wC+zrNtnk+7oNXY8mD2caQFtrhFLHi8DranfE7G2ydwK/v8awFDm4DJIUXtg1a3jBV2ZPoy 0N8oJCLZ77iYZGI1IBj/4EJlTTg9IyBqTVRHRhfMI5kMRzHSp0Qy DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1542709282; s=default; d=zoho.com; i=yehs2007@zoho.com; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; l=3228; bh=jTSA+Zs1+7240+81mturwydytJwomKEmU0d3STdG9hM=; b=mKwGN9wEH4U4+Hj3tm2/faI6lZ14eTWQJdCZobeae/vUakbmNjb+CTrCsak7245Z Apa9FCzTzlTLQhL9M0ePhrGIsJuVqvzbRuAny07KUklZsUV7A+9bEAL1HfOYMPiLPi4 Xmq9ZdeOThiJhtQ1bCi3r75IYym1qYMdZlo78+g4= Received: from YEHS1XR956R00D1.lenovo.com (58.243.153.247 [58.243.153.247]) by mx.zohomail.com with SMTPS id 1542709279011240.5816416360435; Tue, 20 Nov 2018 02:21:19 -0800 (PST) From: Huaisheng Ye To: linux-nvdimm@lists.01.org, agk@redhat.com, snitzer@redhat.com, dm-devel@redhat.com, dan.j.williams@intel.com, willy@infradead.org, zwisler@kernel.org, jack@suse.cz, dave.jiang@intel.com, vishal.l.verma@intel.com Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, chengnt@lenovo.com, Huaisheng Ye Subject: [RFC PATCH 2/3] dm: expand hc_map in mapped_device for lack of map Date: Tue, 20 Nov 2018 18:20:36 +0800 Message-Id: <20181120102037.4536-3-yehs2007@zoho.com> X-Mailer: git-send-email 2.17.0.windows.1 In-Reply-To: <20181120102037.4536-1-yehs2007@zoho.com> References: <20181120102037.4536-1-yehs2007@zoho.com> X-ZohoMailClient: External Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Huaisheng Ye Sometimes dm_swap_table couldn't be used in time. For example, during the origin construction of dm-snapshot, the sys_ioctl table_load will try to detect the lower device origin-real whether support direct access or not. But origin-real md's struct dm-table pointer has not yet been assigned real address in time by dev_suspend. So I expand hc_map for get the address from struct hash_cell directly in this case. Here is the call trace, dm_dax_direct_access will call dm_dax_get_live_target for get the struct dm_table pointer. [ 213.975827] Call Trace: [ 213.975832] dump_stack+0x5a/0x73 [ 213.975840] dm_dax_direct_access+0x12b/0x1b0 [dm_mod] [ 213.975845] dax_direct_access+0x2d/0x60 [ 213.975848] __bdev_dax_supported+0x162/0x2a0 [ 213.975851] ? dump_stack+0x5a/0x73 [ 213.975859] device_supports_dax+0x15/0x20 [dm_mod] [ 213.975867] dm_table_supports_dax.isra.13+0x7d/0xa0 [dm_mod] [ 213.975875] dm_table_complete+0x3fb/0x750 [dm_mod] [ 213.975883] table_load+0x19a/0x390 [dm_mod] [ 213.975891] ? retrieve_status+0x1c0/0x1c0 [dm_mod] [ 213.975898] ctl_ioctl+0x1d8/0x450 [dm_mod] [ 213.975909] dm_ctl_ioctl+0xa/0x10 [dm_mod] [ 213.975913] do_vfs_ioctl+0xa9/0x620 [ 213.975918] ? syscall_trace_enter+0x1c9/0x2b0 [ 213.975923] ksys_ioctl+0x60/0x90 [ 213.975927] __x64_sys_ioctl+0x16/0x20 [ 213.975931] do_syscall_64+0x5b/0x180 [ 213.975936] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Huaisheng Ye --- drivers/md/dm-core.h | 1 + drivers/md/dm-ioctl.c | 1 + drivers/md/dm.c | 15 +++++++++++++++ 3 files changed, 17 insertions(+) diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h index 224d445..5577d90 100644 --- a/drivers/md/dm-core.h +++ b/drivers/md/dm-core.h @@ -40,6 +40,7 @@ struct mapped_device { * dereference. */ void __rcu *map; + struct dm_table *hc_map; unsigned long flags; diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index f666778..a27016e 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1365,6 +1365,7 @@ static int table_load(struct file *filp, struct dm_ioctl *param, size_t param_si if (hc->new_map) old_map = hc->new_map; hc->new_map = t; + hc->md->hc_map = hc->new_map; up_write(&_hash_lock); param->flags |= DM_INACTIVE_PRESENT_FLAG; diff --git a/drivers/md/dm.c b/drivers/md/dm.c index c510179..19b48bb 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1080,6 +1080,21 @@ static struct dm_target *dm_dax_get_live_target(struct mapped_device *md, struct dm_target *ti; map = dm_get_live_table(md, srcu_idx); + if (!map) { + /* Sometimes dm_swap_table couldn't be used in time. + * + * For example, during the origin construction of + * dm-snapshot, the sys_ioctl table_load will try to + * detect the lower device origin-real whether support + * direct access or not. But origin-real device md's struct + * dm-table pointer has not yet been assigned real address. + * So hc_map has been used for get the address from + * struct hash_cell directly. + */ + DMINFO("failed to get map, use hc_map insteadly"); + map = md->hc_map; + } + if (!map) return NULL; -- 1.8.3.1