From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-op-o15.zoho.com (sender4-op-o15.zoho.com [136.143.188.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B4ACA2EFD86; Thu, 19 Feb 2026 11:48:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.15 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771501702; cv=pass; b=uG2jDayJyHvaZHykKdAHNrMCfHCn4YpBv6hoJyLTjWEqY6jN9le3qq8BuNrNyp+y6xLgyTHoTbg97tsgCyx16I4wHZJdBQX8xdSWZgKUH/DBz2nTBfiPrwnKY6tb5izCFmkwiomQ3WkqpCJYdX1FTQVFxGXqeZKd5gyxJu5/h4Y= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771501702; c=relaxed/simple; bh=Ole/adKa/E4g2kQnOjK+SLIVG2KZQBU0gCHp48N2DBc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=M/RKOqKFBoMAHaUkBb1svSHsedUTGhLoW74EoX/TanDi1tr9j7XXs50Bs7gs7OA9m2de6uhv3zHSjZjAQsee4wgcAJKp74lPA8sbil3JEQqq4KGSevHLi27sMVekUdTbx/WtBAsLv+hFtPfHMu6055OY/Tjlw0d29kqEngrLvow= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.beauty; spf=pass smtp.mailfrom=linux.beauty; dkim=pass (1024-bit key) header.d=linux.beauty header.i=me@linux.beauty header.b=eAFAeZ7n; arc=pass smtp.client-ip=136.143.188.15 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.beauty Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.beauty Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.beauty header.i=me@linux.beauty header.b="eAFAeZ7n" ARC-Seal: i=1; a=rsa-sha256; t=1771501631; cv=none; d=zohomail.com; s=zohoarc; b=BLLjINCRcCrNf9rP94nXr8sycTIoyTwYEn0NWtyoa0fxMWFlddOCcgnB5si2ZTgfhQQSl7it20roIu691iqDwVQQ/GuSbj8uzCDnV+gs6+T8KKYLdVp+/yor4EetvQgvS+0MaIzVBo8aCuy9C5JzpBtURNbtBmYJIB+zj9kI2Rc= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1771501631; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=IQX5SyqcG0wh5Bi5VE3B6d+bUgJTb51NNcjjNAFka70=; b=Vq7kO7NhT5Z1XnDag9UVctdnIIQ6wCaDxQbCqUqpWSfWw4H6wo8+hCXIFaHMj0j9ZX6el8yql3+0yBkSk82j82Cc/UWZCStPhui50HLmKszP6xztPkgsilXaQH0EscCdkal+6r4i4UBkOZDw268AIEI4T/ltasCJf1SFuxnH6IQ= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=linux.beauty; spf=pass smtp.mailfrom=me@linux.beauty; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1771501631; s=zmail; d=linux.beauty; i=me@linux.beauty; h=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-ID:In-Reply-To:References:MIME-Version:Content-Transfer-Encoding:Message-Id:Reply-To; bh=IQX5SyqcG0wh5Bi5VE3B6d+bUgJTb51NNcjjNAFka70=; b=eAFAeZ7n7qruS6FoC6n5Ua4W/5U5cfFQCVEo6vMjnjTjsXGlua06lIkPQFyTPAWM Pw92xUJig0NdVI2mZUhBSXd97sijZCR3k3cyfaR2OINFQCXQWhDkKO2EhC+AqBAxf8e S4qjUXQM81PepLLG7jP1FI3/QpT6vOqf9b7Q3S9w= Received: by mx.zohomail.com with SMTPS id 1771501628192513.36154051907; Thu, 19 Feb 2026 03:47:08 -0800 (PST) From: Li Chen To: Theodore Ts'o , Jan Kara , Mark Fasheh , linux-ext4@vger.kernel.org, ocfs2-devel@lists.linux.dev, Matthew Wilcox , Andreas Dilger , linux-kernel@vger.kernel.org Cc: Li Chen Subject: [PATCH v2 2/3] ext4: use READ_ONCE for lockless jinode reads Date: Thu, 19 Feb 2026 19:46:43 +0800 Message-ID: <20260219114645.778338-3-me@linux.beauty> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260219114645.778338-1-me@linux.beauty> References: <20260219114645.778338-1-me@linux.beauty> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-ZohoMailClient: External ext4 journal commit callbacks access jbd2_inode fields such as i_transaction and i_dirty_start/end without holding journal->j_list_lock. Use READ_ONCE() for these reads to match the lockless access pattern. Convert the dirty range from PAGE_SIZE units back to byte offsets before passing it to writeback. Suggested-by: Jan Kara Reviewed-by: Jan Kara Signed-off-by: Li Chen --- Changes since v1: - Convert the jinode dirty range from PAGE_SIZE units (pgoff_t) back to byte offsets before passing it to writeback. fs/ext4/inode.c | 12 ++++++++++-- fs/ext4/super.c | 19 ++++++++++++++----- 2 files changed, 24 insertions(+), 7 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index d99296d7315f..5ec60580a2d0 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3033,11 +3033,19 @@ static int ext4_writepages(struct address_space *mapping, int ext4_normal_submit_inode_data_buffers(struct jbd2_inode *jinode) { + pgoff_t dirty_start = READ_ONCE(jinode->i_dirty_start); + pgoff_t dirty_end = READ_ONCE(jinode->i_dirty_end); + loff_t range_start, range_end; + + if (dirty_end == JBD2_INODE_DIRTY_RANGE_NONE) + return 0; + range_start = (loff_t)dirty_start << PAGE_SHIFT; + range_end = ((loff_t)dirty_end << PAGE_SHIFT) + PAGE_SIZE - 1; struct writeback_control wbc = { .sync_mode = WB_SYNC_ALL, .nr_to_write = LONG_MAX, - .range_start = jinode->i_dirty_start, - .range_end = jinode->i_dirty_end, + .range_start = range_start, + .range_end = range_end, }; struct mpage_da_data mpd = { .inode = jinode->i_vfs_inode, diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 69eb63dde983..27062c8ad60a 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -521,6 +521,7 @@ static bool ext4_journalled_writepage_needs_redirty(struct jbd2_inode *jinode, { struct buffer_head *bh, *head; struct journal_head *jh; + transaction_t *trans = READ_ONCE(jinode->i_transaction); bh = head = folio_buffers(folio); do { @@ -539,7 +540,7 @@ static bool ext4_journalled_writepage_needs_redirty(struct jbd2_inode *jinode, */ jh = bh2jh(bh); if (buffer_dirty(bh) || - (jh && (jh->b_transaction != jinode->i_transaction || + (jh && (jh->b_transaction != trans || jh->b_next_transaction))) return true; } while ((bh = bh->b_this_page) != head); @@ -550,12 +551,20 @@ static bool ext4_journalled_writepage_needs_redirty(struct jbd2_inode *jinode, static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode) { struct address_space *mapping = jinode->i_vfs_inode->i_mapping; + pgoff_t dirty_start = READ_ONCE(jinode->i_dirty_start); + pgoff_t dirty_end = READ_ONCE(jinode->i_dirty_end); + loff_t range_start, range_end; + + if (dirty_end == JBD2_INODE_DIRTY_RANGE_NONE) + return 0; + range_start = (loff_t)dirty_start << PAGE_SHIFT; + range_end = ((loff_t)dirty_end << PAGE_SHIFT) + PAGE_SIZE - 1; struct writeback_control wbc = { - .sync_mode = WB_SYNC_ALL, + .sync_mode = WB_SYNC_ALL, .nr_to_write = LONG_MAX, - .range_start = jinode->i_dirty_start, - .range_end = jinode->i_dirty_end, - }; + .range_start = range_start, + .range_end = range_end, + }; struct folio *folio = NULL; int error; -- 2.52.0