From patchwork Thu Sep 24 16:39:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Goldwyn Rodrigues X-Patchwork-Id: 11797975 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 2CF9B59D for ; Thu, 24 Sep 2020 16:40:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B6A52396D for ; Thu, 24 Sep 2020 16:40:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728641AbgIXQkN (ORCPT ); Thu, 24 Sep 2020 12:40:13 -0400 Received: from mx2.suse.de ([195.135.220.15]:36770 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726924AbgIXQkN (ORCPT ); Thu, 24 Sep 2020 12:40:13 -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 B3E45B28F; Thu, 24 Sep 2020 16:40:10 +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 Subject: [PATCH 12/14] btrfs: Remove dio_sem Date: Thu, 24 Sep 2020 11:39:19 -0500 Message-Id: <20200924163922.2547-13-rgoldwyn@suse.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200924163922.2547-1-rgoldwyn@suse.de> References: <20200924163922.2547-1-rgoldwyn@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Goldwyn Rodrigues dio_sem can be eliminated because all DIO synchronization is performed through inode->i_rwsem now. Signed-off-by: Goldwyn Rodrigues Reviewed-by: Josef Bacik --- fs/btrfs/btrfs_inode.h | 10 ---------- fs/btrfs/file.c | 13 ------------- fs/btrfs/inode.c | 1 - 3 files changed, 24 deletions(-) diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index 738009a22320..176abce59467 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -203,16 +203,6 @@ struct btrfs_inode { /* Hook into fs_info->delayed_iputs */ struct list_head delayed_iput; - /* - * To avoid races between lockless (i_mutex not held) direct IO writes - * and concurrent fsync requests. Direct IO writes must acquire read - * access on this semaphore for creating an extent map and its - * corresponding ordered extent. The fast fsync path must acquire write - * access on this semaphore before it collects ordered extents and - * extent maps. - */ - struct rw_semaphore dio_sem; - struct inode vfs_inode; }; diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 83012d1e6f29..6854bf78d677 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -2021,8 +2021,6 @@ static ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from) goto buffered; } - down_read(&BTRFS_I(inode)->dio_sem); - /* * We have are actually a sync iocb, so we need our fancy endio to know * if we need to sync. @@ -2037,7 +2035,6 @@ static ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from) if (written == -ENOTBLK) written = 0; - up_read(&BTRFS_I(inode)->dio_sem); btrfs_inode_unlock(inode, ilock_flags); if (written < 0 || !iov_iter_count(from)) { @@ -2245,13 +2242,6 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) inode_lock(inode); - /* - * We take the dio_sem here because the tree log stuff can race with - * lockless dio writes and get an extent map logged for an extent we - * never waited on. We need it this high up for lockdep reasons. - */ - down_write(&BTRFS_I(inode)->dio_sem); - atomic_inc(&root->log_batch); /* @@ -2282,7 +2272,6 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) */ ret = start_ordered_ops(inode, start, end); if (ret) { - up_write(&BTRFS_I(inode)->dio_sem); inode_unlock(inode); goto out; } @@ -2379,7 +2368,6 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) * file again, but that will end up using the synchronization * inside btrfs_sync_log to keep things safe. */ - up_write(&BTRFS_I(inode)->dio_sem); inode_unlock(inode); if (ret != BTRFS_NO_LOG_SYNC) { @@ -2410,7 +2398,6 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) out_release_extents: btrfs_release_log_ctx_extents(&ctx); - up_write(&BTRFS_I(inode)->dio_sem); inode_unlock(inode); goto out; } diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index cdde4422a6fa..17c97f30459c 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8594,7 +8594,6 @@ struct inode *btrfs_alloc_inode(struct super_block *sb) INIT_LIST_HEAD(&ei->delalloc_inodes); INIT_LIST_HEAD(&ei->delayed_iput); RB_CLEAR_NODE(&ei->rb_node); - init_rwsem(&ei->dio_sem); return inode; }