From: David Sterba <dsterba@suse.cz>
Date: Fri, 14 Nov 2014 14:05:06 +0000 (+0100)
Subject: btrfs: fix wrong accounting of raid1 data profile in statfs
X-Git-Tag: v3.18.2~4
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=37ea7a1f6b84ffc6f8e45b5377e29609b58330a4;p=platform%2Fkernel%2Flinux-stable.git

btrfs: fix wrong accounting of raid1 data profile in statfs

commit 0d95c1bec906dd1ad951c9c001e798ca52baeb0f upstream.

The sizes that are obtained from space infos are in raw units and have
to be adjusted according to the raid factor. This was missing for
f_bavail and df reported doubled size for raid1.

Reported-by: Martin Steigerwald <Martin@lichtvoll.de>
Fixes: ba7b6e62f420 ("btrfs: adjust statfs calculations according to raid profiles")
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 54bd91ece35b..cde9c03e3913 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1824,7 +1824,7 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	buf->f_bfree -= block_rsv->size >> bits;
 	spin_unlock(&block_rsv->lock);
 
-	buf->f_bavail = total_free_data;
+	buf->f_bavail = div_u64(total_free_data, factor);
 	ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
 	if (ret) {
 		mutex_unlock(&fs_info->chunk_mutex);