From patchwork Thu Feb 27 21:14:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Simmons X-Patchwork-Id: 11410341 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2F223138D for ; Thu, 27 Feb 2020 21:35:28 +0000 (UTC) Received: from pdx1-mailman02.dreamhost.com (pdx1-mailman02.dreamhost.com [64.90.62.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1802F24677 for ; Thu, 27 Feb 2020 21:35:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1802F24677 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lustre-devel-bounces@lists.lustre.org Received: from pdx1-mailman02.dreamhost.com (localhost [IPv6:::1]) by pdx1-mailman02.dreamhost.com (Postfix) with ESMTP id 0253134A0ED; Thu, 27 Feb 2020 13:29:47 -0800 (PST) X-Original-To: lustre-devel@lists.lustre.org Delivered-To: lustre-devel-lustre.org@pdx1-mailman02.dreamhost.com Received: from smtp3.ccs.ornl.gov (smtp3.ccs.ornl.gov [160.91.203.39]) by pdx1-mailman02.dreamhost.com (Postfix) with ESMTP id CC6AB21FBA2 for ; Thu, 27 Feb 2020 13:20:17 -0800 (PST) Received: from star.ccs.ornl.gov (star.ccs.ornl.gov [160.91.202.134]) by smtp3.ccs.ornl.gov (Postfix) with ESMTP id CD3FC8AB7; Thu, 27 Feb 2020 16:18:17 -0500 (EST) Received: by star.ccs.ornl.gov (Postfix, from userid 2004) id CB35746D; Thu, 27 Feb 2020 16:18:17 -0500 (EST) From: James Simmons To: Andreas Dilger , Oleg Drokin , NeilBrown Date: Thu, 27 Feb 2020 16:14:12 -0500 Message-Id: <1582838290-17243-385-git-send-email-jsimmons@infradead.org> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1582838290-17243-1-git-send-email-jsimmons@infradead.org> References: <1582838290-17243-1-git-send-email-jsimmons@infradead.org> Subject: [lustre-devel] [PATCH 384/622] lustre: obdclass: use RCU to release lu_env_item X-BeenThere: lustre-devel@lists.lustre.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "For discussing Lustre software development." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Lustre Development List MIME-Version: 1.0 Errors-To: lustre-devel-bounces@lists.lustre.org Sender: "lustre-devel" From: Alex Zhuravlev as rhashtable_lookup_fast() is lockless and can find just released objects. Fixes: c678ad5a25 ("lustre: obdclass: put all service's env on the list") WC-bug-id: https://jira.whamcloud.com/browse/LU-12491 Lustre-commit: 87306c22e4b9 ("LU-12491 obdclass: use RCU to release lu_env_item") Signed-off-by: Alex Zhuravlev Reviewed-on: https://review.whamcloud.com/35038 Reviewed-by: Neil Brown Reviewed-by: Shaun Tancheff Reviewed-by: James Simmons Reviewed-by: Oleg Drokin Signed-off-by: James Simmons --- fs/lustre/obdclass/lu_object.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/fs/lustre/obdclass/lu_object.c b/fs/lustre/obdclass/lu_object.c index bafd817..c94911d 100644 --- a/fs/lustre/obdclass/lu_object.c +++ b/fs/lustre/obdclass/lu_object.c @@ -1870,6 +1870,7 @@ struct lu_env_item { struct task_struct *lei_task; /* rhashtable key */ struct rhash_head lei_linkage; struct lu_env *lei_env; + struct rcu_head lei_rcu_head; }; static const struct rhashtable_params lu_env_rhash_params = { @@ -1909,6 +1910,14 @@ int lu_env_add(struct lu_env *env) } EXPORT_SYMBOL(lu_env_add); +static void lu_env_item_free(struct rcu_head *head) +{ + struct lu_env_item *lei; + + lei = container_of(head, struct lu_env_item, lei_rcu_head); + kfree(lei); +} + void lu_env_remove(struct lu_env *env) { struct lu_env_item *lei; @@ -1923,13 +1932,11 @@ void lu_env_remove(struct lu_env *env) } } - rcu_read_lock(); lei = rhashtable_lookup_fast(&lu_env_rhash, &task, lu_env_rhash_params); if (lei && rhashtable_remove_fast(&lu_env_rhash, &lei->lei_linkage, lu_env_rhash_params) == 0) - kfree(lei); - rcu_read_unlock(); + call_rcu(&lei->lei_rcu_head, lu_env_item_free); } EXPORT_SYMBOL(lu_env_remove);