From patchwork Mon Sep 21 14:43:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Goldwyn Rodrigues X-Patchwork-Id: 11790191 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 1901E59D for ; Mon, 21 Sep 2020 14:44:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 01875221EC for ; Mon, 21 Sep 2020 14:44:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728285AbgIUOoT (ORCPT ); Mon, 21 Sep 2020 10:44:19 -0400 Received: from mx2.suse.de ([195.135.220.15]:55414 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727109AbgIUOoM (ORCPT ); Mon, 21 Sep 2020 10:44:12 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id A43DBAD6B; Mon, 21 Sep 2020 14:44:46 +0000 (UTC) From: Goldwyn Rodrigues To: linux-fsdevel@vger.kernel.org Cc: linux-btrfs@vger.kernel.org, david@fromorbit.com, hch@lst.de, johannes.thumshirn@wdc.com, dsterba@suse.com, darrick.wong@oracle.com, josef@toxicpanda.com, Goldwyn Rodrigues , Nikolay Borisov , Johannes Thumshirn Subject: [PATCH 02/15] btrfs: remove BTRFS_INODE_READDIO_NEED_LOCK Date: Mon, 21 Sep 2020 09:43:40 -0500 Message-Id: <20200921144353.31319-3-rgoldwyn@suse.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200921144353.31319-1-rgoldwyn@suse.de> References: <20200921144353.31319-1-rgoldwyn@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Goldwyn Rodrigues Since we now perform direct reads using i_rwsem, we can remove this inode flag used to co-ordinate unlocked reads. The truncate call takes i_rwsem. This means it is correctly synchronized with concurrent direct reads. Reviewed-by: Nikolay Borisov Reviewed-by: Johannes Thumshirn Signed-off-by: Goldwyn Rodrigues Reviewed-by: Christoph Hellwig Reviewed-by: Josef Bacik --- fs/btrfs/btrfs_inode.h | 18 ------------------ fs/btrfs/inode.c | 3 --- 2 files changed, 21 deletions(-) diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index 6fdb46d58299..738009a22320 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -33,7 +33,6 @@ enum { BTRFS_INODE_NEEDS_FULL_SYNC, BTRFS_INODE_COPY_EVERYTHING, BTRFS_INODE_IN_DELALLOC_LIST, - BTRFS_INODE_READDIO_NEED_LOCK, BTRFS_INODE_HAS_PROPS, BTRFS_INODE_SNAPSHOT_FLUSH, }; @@ -334,23 +333,6 @@ struct btrfs_dio_private { u8 csums[]; }; -/* - * Disable DIO read nolock optimization, so new dio readers will be forced - * to grab i_mutex. It is used to avoid the endless truncate due to - * nonlocked dio read. - */ -static inline void btrfs_inode_block_unlocked_dio(struct btrfs_inode *inode) -{ - set_bit(BTRFS_INODE_READDIO_NEED_LOCK, &inode->runtime_flags); - smp_mb(); -} - -static inline void btrfs_inode_resume_unlocked_dio(struct btrfs_inode *inode) -{ - smp_mb__before_atomic(); - clear_bit(BTRFS_INODE_READDIO_NEED_LOCK, &inode->runtime_flags); -} - /* Array of bytes with variable length, hexadecimal format 0x1234 */ #define CSUM_FMT "0x%*phN" #define CSUM_FMT_VALUE(size, bytes) size, bytes diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 18d171b2d544..3db4697ff1ba 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4855,10 +4855,7 @@ static int btrfs_setsize(struct inode *inode, struct iattr *attr) truncate_setsize(inode, newsize); - /* Disable nonlocked read DIO to avoid the endless truncate */ - btrfs_inode_block_unlocked_dio(BTRFS_I(inode)); inode_dio_wait(inode); - btrfs_inode_resume_unlocked_dio(BTRFS_I(inode)); ret = btrfs_truncate(inode, newsize == oldsize); if (ret && inode->i_nlink) {