fscache: Use clear_and_wake_up_bit() in fscache_create_volume_work()
authorHou Tao <houtao1@huawei.com>
Fri, 13 Jan 2023 11:52:11 +0000 (19:52 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 22 Feb 2023 11:59:43 +0000 (12:59 +0100)
commitb266c2e72ef319ebc6ae298766c81bfd3ec33f57
treee4630135e2dfca42762ff6de4805295f12263161
parent63c12d00d8565bc0d36ec32491e3f52f91498a49
fscache: Use clear_and_wake_up_bit() in fscache_create_volume_work()

[ Upstream commit 3288666c72568fe1cc7f5c5ae33dfd3ab18004c8 ]

fscache_create_volume_work() uses wake_up_bit() to wake up the processes
which are waiting for the completion of volume creation. According to
comments in wake_up_bit() and waitqueue_active(), an extra smp_mb() is
needed to guarantee the memory order between FSCACHE_VOLUME_CREATING
flag and waitqueue_active() before invoking wake_up_bit().

Fixing it by using clear_and_wake_up_bit() to add the missing memory
barrier.

Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20230113115211.2895845-3-houtao@huaweicloud.com/
Signed-off-by: Sasha Levin <sashal@kernel.org>
fs/fscache/volume.c