From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([59.151.112.132]:23099 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751562AbaJ0Mk2 (ORCPT ); Mon, 27 Oct 2014 08:40:28 -0400 Received: from G08CNEXCHPEKD02.g08.fujitsu.local (localhost.localdomain [127.0.0.1]) by edo.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id s9RCeJUH007504 for ; Mon, 27 Oct 2014 20:40:19 +0800 From: Dongsheng Yang To: CC: Dongsheng Yang Subject: [PATCH] btrfs: get the accurate value of used_bytes in btrfs_get_block_group_info(). Date: Mon, 27 Oct 2014 20:38:19 +0800 Message-ID: <1414413499-28826-1-git-send-email-yangds.fnst@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-btrfs-owner@vger.kernel.org List-ID: Reproducer: # mkfs.btrfs -f -b 20G /dev/sdb # mount /dev/sdb /mnt/test # fallocate -l 17G /mnt/test/largefile # btrfs fi df /mnt/test Data, single: total=17.49GiB, used=6.00GiB <- only 6G, but actually it should be 17G. System, DUP: total=8.00MiB, used=16.00KiB System, single: total=4.00MiB, used=0.00B Metadata, DUP: total=1.00GiB, used=112.00KiB Metadata, single: total=8.00MiB, used=0.00B GlobalReserve, single: total=16.00MiB, used=0.00B # sync # btrfs fi df /mnt/test Data, single: total=17.49GiB, used=17.00GiB <- After sync, it is expected. System, DUP: total=8.00MiB, used=16.00KiB System, single: total=4.00MiB, used=0.00B Metadata, DUP: total=1.00GiB, used=112.00KiB Metadata, single: total=8.00MiB, used=0.00B GlobalReserve, single: total=16.00MiB, used=0.00B The value of 6.00GiB is actually calculated in btrfs_get_block_group_info() by adding the @block_group->item->used for each group together. In this way, it did not consider the bytes in cache. This patch adds the value of @pinned, @reserved and @bytes_super in struct btrfs_block_group_cache to make sure we can get the accurate @used_bytes. Reported-by: Qu Wenruo Signed-off-by: Dongsheng Yang --- fs/btrfs/ioctl.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 33c80f5..bc2aaeb 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3892,6 +3892,10 @@ void btrfs_get_block_group_info(struct list_head *groups_list, space->total_bytes += block_group->key.offset; space->used_bytes += btrfs_block_group_used(&block_group->item); + /* Add bytes-info in cache */ + space->used_bytes += block_group->pinned; + space->used_bytes += block_group->reserved; + space->used_bytes += block_group->bytes_super; } } -- 1.8.4.2