From patchwork Fri May 17 12:39:59 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhang Yi X-Patchwork-Id: 13666950 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (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 661D65C603; Fri, 17 May 2024 12:51:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715950267; cv=none; b=TMQYtn3saZNUc+shwHbqfdt0vm31SYeeOxIJ/dNILJM5sbZdrmNVOPDDi/cVIfJE/fszQS6xARLouL2BUZNgeFHxEyXd10kq1LsytPE2vHEz19j3t9mLGxM/DdserTan+HZcb0PhMcjRC5+jDblnDq0STnBqLFWizmrENe9hHn4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715950267; c=relaxed/simple; bh=s1IkFJd7/I77fwUqJvPyYPWZdG81k2OWJkUa6a76Vkg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=NTUQiq2Ab6ESUpYdy0unt6P7BX1u505QBRIFpzl34xq+y1hkCvLM9Ff/HkelEZE0VYDwpEn9sBsICtPFwHe3oPob1+QZGzEm3OX7QR7J1ASqN3kDcbRffuFfPCU8QnmD6kEARfgC+ibxBxOGnNRdNIPv2cfBk6rliKkdqrVcfUk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4VgmzC6FYVz4f3jrg; Fri, 17 May 2024 20:50:47 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.112]) by mail.maildlp.com (Postfix) with ESMTP id 9BFD71A0AE0; Fri, 17 May 2024 20:50:56 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP1 (Coremail) with SMTP id cCh0CgBXKBGdUkdmdAmqMw--.14380S8; Fri, 17 May 2024 20:50:56 +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 v5 04/10] ext4: trim delalloc extent Date: Fri, 17 May 2024 20:39:59 +0800 Message-Id: <20240517124005.347221-5-yi.zhang@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240517124005.347221-1-yi.zhang@huaweicloud.com> References: <20240517124005.347221-1-yi.zhang@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: cCh0CgBXKBGdUkdmdAmqMw--.14380S8 X-Coremail-Antispam: 1UD129KBjvJXoWxWFyrAF4kXFy3Wr1UZr4DXFb_yoW5KF45pr Z3CF1rGr4xW3429ayxJF1UXF1rG3Z8KrW7Grn5GryrZas8Gr1Ska4qya42yFyjgrs3XF1Y qFW8t34UCa1ayrJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUP214x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F 4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq 3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7 IYx2IY67AKxVWUGVWUXwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4U M4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2 kIc2xKxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E 14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIx kGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAF wI0_Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJV W8JwCI42IY6I8E87Iv6xkF7I0E14v26r4UJVWxJrUvcSsGvfC2KfnxnUUI43ZEXa7VU17G YJUUUUU== X-CM-SenderInfo: d1lo6xhdqjqx5xdzvxpfor3voofrz/ From: Zhang Yi In ext4_da_map_blocks(), we could find four kind of extents in the extent status tree: hole, unwritten, written and delayed extent. Now we only trim the map len if we found an unwritten extent or a written extent. This is okay now since map->m_len is always set to one and we always insert one delayed block at a time. But this will become isn't okay for other two cases if ext4_insert_delayed_block() and ext4_da_map_blocks() support inserting multiple map->len blocks later. 1. If we found a hole in the extent status tree which es->es_len is shorter than the length we want to write, we should trim the map->m_len to prevent adding extra delay more blocks than we expected. For example, assume we write data [A, C) to a file that contains a hole extent [A, B) and a written extent [B, D) in the cache. A B C D before da write: ...hhhhhh|wwwwww.... Then we will get extent [A, B), we should trim map->m_len to B-A before inserting new delalloc blocks, if not, the range [B, C) will be duplicated. 2. If we found a delayed extent in the extent status tree which es->es_len is shorter than the length we want to write, we should trim the map->m_len to es->es_len and return directly since the front part of this map has been delayed, we can't insert the delalloc extent that contains the latter part in this round, we should return the delayed length and the caller should increase the position and call ext4_da_map_blocks() again. For example, assume we write data [A, C) to a file that contains a delayed extent [A, B) in the cache. A B C before da write: ...dddddd|hhh.... Then we will get delayed extent [A, B), we should also trim map->m_len to B-A and return, if not, we will incorrectly assume that the write is complete and won't insert [B, C). So we need to always trim the map->m_len if the found es->es_len in the extent status tree is shorter than the map->m_len, prearing for inserting a extent with multiple delalloc blocks. This patch only does a pre-fix, the handle is crude and ext4_da_map_blocks() deserve a cleanup, we will do that later. Signed-off-by: Zhang Yi Reviewed-by: Jan Kara --- fs/ext4/inode.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 6114ca79f464..fb76016e2ab7 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1734,6 +1734,11 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock, /* Lookup extent status tree firstly */ if (ext4_es_lookup_extent(inode, iblock, NULL, &es)) { + retval = es.es_len - (iblock - es.es_lblk); + if (retval > map->m_len) + retval = map->m_len; + map->m_len = retval; + if (ext4_es_is_hole(&es)) goto add_delayed; @@ -1750,10 +1755,6 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock, } map->m_pblk = ext4_es_pblock(&es) + iblock - es.es_lblk; - retval = es.es_len - (iblock - es.es_lblk); - if (retval > map->m_len) - retval = map->m_len; - map->m_len = retval; if (ext4_es_is_written(&es)) map->m_flags |= EXT4_MAP_MAPPED; else if (ext4_es_is_unwritten(&es)) @@ -1790,6 +1791,11 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock, * the extent status tree. */ if (ext4_es_lookup_extent(inode, iblock, NULL, &es)) { + retval = es.es_len - (iblock - es.es_lblk); + if (retval > map->m_len) + retval = map->m_len; + map->m_len = retval; + if (!ext4_es_is_hole(&es)) { up_write(&EXT4_I(inode)->i_data_sem); goto found;