Currently in btrfs, there is something wrong with fallocate(2)'s
data space reservation, it'll temporarily occupy more data space
thant it really needs, which in turn will impact other operations'
data request.
In this test case, it runs write(2) and fallocate(2) in parallel and
the total needed data space for these two operations don't exceed
whole fs free data space, to see whether we will get any unexpected
ENOSPC error.
Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>
Wang Xiaoguang