From patchwork Fri May 22 12:38:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Goldwyn Rodrigues X-Patchwork-Id: 11565535 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 D31641392 for ; Fri, 22 May 2020 12:39:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C6779206F6 for ; Fri, 22 May 2020 12:39:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729676AbgEVMjP (ORCPT ); Fri, 22 May 2020 08:39:15 -0400 Received: from mx2.suse.de ([195.135.220.15]:59198 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729570AbgEVMjO (ORCPT ); Fri, 22 May 2020 08:39:14 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 2B9D8AF41; Fri, 22 May 2020 12:39:15 +0000 (UTC) From: Goldwyn Rodrigues To: linux-btrfs@vger.kernel.org Cc: hch@infradead.org, dsterba@suse.cz, Goldwyn Rodrigues , Nikolay Borisov , Johannes Thumshirn Subject: [PATCH 6/7] btrfs: remove BTRFS_INODE_READDIO_NEED_LOCK Date: Fri, 22 May 2020 07:38:36 -0500 Message-Id: <20200522123837.1196-7-rgoldwyn@suse.de> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200522123837.1196-1-rgoldwyn@suse.de> References: <20200522123837.1196-1-rgoldwyn@suse.de> MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@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. Signed-off-by: Goldwyn Rodrigues Reviewed-by: Nikolay Borisov Reviewed-by: Johannes Thumshirn --- 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 e7d709505cb1..aeff56a0e105 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -28,7 +28,6 @@ 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, }; @@ -313,23 +312,6 @@ 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 ebf97286b110..a975d2c61d68 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4752,10 +4752,7 @@ 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) {