From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 89048C3DA6F for ; Thu, 24 Aug 2023 09:31:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240641AbjHXJbD (ORCPT ); Thu, 24 Aug 2023 05:31:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240793AbjHXJav (ORCPT ); Thu, 24 Aug 2023 05:30:51 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D2B2172D for ; Thu, 24 Aug 2023 02:30:48 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.169]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4RWd9c0mCGz4f41SJ for ; Thu, 24 Aug 2023 17:30:44 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgAHl6kzI+dkL1rbBQ--.46575S17; Thu, 24 Aug 2023 17:30:45 +0800 (CST) From: Zhang Yi To: linux-ext4@vger.kernel.org Cc: tytso@mit.edu, adilger.kernel@dilger.ca, jack@suse.cz, yi.zhang@huawei.com, yi.zhang@huaweicloud.com, chengzhihao1@huawei.com, yukuai3@huawei.com Subject: [RFC PATCH 13/16] ext4: calculate the worst extent blocks needed of a delalloc es entry Date: Thu, 24 Aug 2023 17:26:16 +0800 Message-Id: <20230824092619.1327976-14-yi.zhang@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230824092619.1327976-1-yi.zhang@huaweicloud.com> References: <20230824092619.1327976-1-yi.zhang@huaweicloud.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: gCh0CgAHl6kzI+dkL1rbBQ--.46575S17 X-Coremail-Antispam: 1UD129KBjvJXoWxZr1fury3Jr1DurW3uF45ZFb_yoW5WF1Dpr 9xZr15Gr43Ww129ayfCw48Zr1Fg3WxGrWUXrWfGryYqFW8Jr1xKFn8tFW2qFy0qFWfXa12 vF45tryUGw4Y9FDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9E14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Cr1j6r xdM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0D M2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjx v20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1l F7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7MxAIw28IcxkI7VAKI48JMx C20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAF wI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20x vE14v26r4j6ryUMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8Jr0_Cr1UMIIF0xvE42xK8VAv wI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVW8JVWxJwCI42IY6I8E87Iv6xkF7I0E14 v26r4UJVWxJrUvcSsGvfC2KfnxnUUI43ZEXa7VUbmZX7UUUUU== X-CM-SenderInfo: d1lo6xhdqjqx5xdzvxpfor3voofrz/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org From: Zhang Yi Add a new helper to calculate the worst case of extent blocks that needed while mapping a new delalloc extent_status entry. In the worst case, one delay data block consumes one extent enrty, the worst extent blocks should be 'leaf blocks + index blocks + (max depth - depth increasing costs)'. The detailed calculation formula is: / DIV_ROUND_UP(da_blocks, ext_per_block); (i = 0) f(i) = \ DIV_ROUND_UP(f(i-1), idx_per_block); (0 < i < max_depth) SUM = f(0) + .. + f(n) + max_depth - n - 1; (0 <= n < max_depth, f(n) > 0) For example: On the default 4k block size, the default ext_per_block and idx_per_block are 340. (1) If we map 50 length of blocks, the worst entent block is DIV_ROUND_UP(50, 340) + EXT4_MAX_EXTENT_DEPTH - 1 = 5, (2) if we map 500 length of blocks, the worst extent block is DIV_ROUND_UP(500, 340) + DIV_ROUND_UP(DIV_ROUND_UP(500, 340), 340) + EXT4_MAX_EXTENT_DEPTH - 2 = 6, and so on. It is a preparation for reserving meta blocks of delalloc. Signed-off-by: Zhang Yi --- fs/ext4/ext4.h | 2 ++ fs/ext4/extents.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 3e0a39653469..11813382fbcc 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -3699,6 +3699,8 @@ extern int ext4_swap_extents(handle_t *handle, struct inode *inode1, ext4_lblk_t lblk2, ext4_lblk_t count, int mark_unwritten,int *err); extern int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu); +extern unsigned int ext4_map_worst_ext_blocks(struct inode *inode, + unsigned int len); extern int ext4_datasem_ensure_credits(handle_t *handle, struct inode *inode, int check_cred, int restart_cred, int revoke_cred); diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 592383effe80..43c251a42144 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -5797,6 +5797,34 @@ int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu) return err ? err : mapped; } +/* + * Calculate the worst case of extents blocks needed while mapping 'len' + * data blocks. + */ +unsigned int ext4_map_worst_ext_blocks(struct inode *inode, unsigned int len) +{ + unsigned int ext_blocks = 0; + int max_entries; + int depth, max_depth; + + if (!len) + return 0; + + max_entries = ext4_ext_space_block(inode, 0); + max_depth = EXT4_MAX_EXTENT_DEPTH; + + for (depth = 0; depth < max_depth; depth++) { + len = DIV_ROUND_UP(len, max_entries); + ext_blocks += len; + if (len == 1) + break; + if (depth == 0) + max_entries = ext4_ext_space_block_idx(inode, 0); + } + + return ext_blocks + max_depth - depth - 1; +} + /* * Updates physical block address and unwritten status of extent * starting at lblk start and of len. If such an extent doesn't exist, -- 2.39.2