From nobody Wed Nov 27 13:37:16 2024 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (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 D97C51C3F34; Thu, 10 Oct 2024 13:35:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728567347; cv=none; b=niI+tup7fuWo4BTQPHwf12LGamCq0UhafonDW7/fKSN+K67BzBB9S5NBKGjw4durcAv5ydcfyqxArLyaAWAK6nF4cSNAfkRyk4D8tzUM2OIwTmyTP4rSaE0GjH+vtoP7F8PbElxbzOPnOF9EP2oIKvtchKgR+A/6jsLDLD5lNOY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728567347; c=relaxed/simple; bh=MxLOjZGAOSC9szCGPQl/dXlDGFC5Y8rm8OWUupTbMK4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=srNcCrKEOW45bLuMNfEDxzfM0PxYISk6B/EnX5uly26sscWV5VPKEU8iaXFI722yZxC20JMVr1QqyJmWuB3NQFzEVeMax0ft+GrdnTjhpUj51sBCTYp1aetlAl05puPW5ls1yoGBDw8ri376rdI2bfqLL/h4vfV8XwxaSyxNgcA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4XPW3Q13fqz4f3k6h; Thu, 10 Oct 2024 21:35:30 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id E9BD31A0359; Thu, 10 Oct 2024 21:35:41 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgCXysYc2AdnDRnZDg--.21356S7; Thu, 10 Oct 2024 21:35:41 +0800 (CST) From: Zhang Yi To: linux-ext4@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, jack@suse.cz, ritesh.list@gmail.com, yi.zhang@huawei.com, yi.zhang@huaweicloud.com, chengzhihao1@huawei.com, yukuai3@huawei.com Subject: [PATCH v3 03/10] ext4: don't write back data before punch hole in nojournal mode Date: Thu, 10 Oct 2024 21:33:26 +0800 Message-Id: <20241010133333.146793-4-yi.zhang@huawei.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20241010133333.146793-1-yi.zhang@huawei.com> References: <20241010133333.146793-1-yi.zhang@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: gCh0CgCXysYc2AdnDRnZDg--.21356S7 X-Coremail-Antispam: 1UD129KBjvJXoW7WF1DWr4UAry8Kr1rCF13twb_yoW8Cw1kpr 9IkrW5tF48WFZFkr4SqFsrXF1FgaykCrW8WFyxG3s7WayUAwn7KF4q9F18Ga1UtrZxArWj qF40qa4xWFyUZFDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUHYb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUWw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMc Ij6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_ Jr0_Gr1lF7xvr2IYc2Ij64vIr41lF7Iv64x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YV CY1x02628vn2kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCF04k2 0xvEw4C26cxK6c8Ij28IcwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r 1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij 64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr 0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF 0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07UAEfOUUUUU= Sender: yi.zhang@huaweicloud.com X-CM-SenderInfo: d1lo6xhdqjqx5xdzvxpfor3voofrz/ Content-Type: text/plain; charset="utf-8" There is no need to write back all data before punching a hole in data=3Dordered|writeback mode since it will be dropped soon after removing space, so just remove the filemap_write_and_wait_range() in these modes. However, in data=3Djournal mode, we need to write dirty pages out before discarding page cache in case of crash before committing the freeing data transaction, which could expose old, stale data. Signed-off-by: Zhang Yi --- fs/ext4/inode.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index f8796f7b0f94..94b923afcd9c 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3965,17 +3965,6 @@ int ext4_punch_hole(struct file *file, loff_t offset= , loff_t length) =20 trace_ext4_punch_hole(inode, offset, length, 0); =20 - /* - * Write out all dirty pages to avoid race conditions - * Then release them. - */ - if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) { - ret =3D filemap_write_and_wait_range(mapping, offset, - offset + length - 1); - if (ret) - return ret; - } - inode_lock(inode); =20 /* No need to punch hole beyond i_size */ @@ -4037,6 +4026,21 @@ int ext4_punch_hole(struct file *file, loff_t offset= , loff_t length) ret =3D ext4_update_disksize_before_punch(inode, offset, length); if (ret) goto out_dio; + + /* + * For journalled data we need to write (and checkpoint) pages + * before discarding page cache to avoid inconsitent data on + * disk in case of crash before punching trans is committed. + */ + if (ext4_should_journal_data(inode)) { + ret =3D filemap_write_and_wait_range(mapping, + first_block_offset, last_block_offset); + if (ret) + goto out_dio; + } + + ext4_truncate_folios_range(inode, first_block_offset, + last_block_offset + 1); truncate_pagecache_range(inode, first_block_offset, last_block_offset); } --=20 2.39.2