commit 16645db27bb6c1ca3a5d4b7147a2c41ddf5bb9e7
author Baptiste Lepers <baptiste.lepers@gmail.com> Mon Sep 06 11:59:24 2021 +1000
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> Fri Nov 26 11:48:37 2021 +0100
tree 83aa81f315fa9c477389f1cd5bd80663d011db37
parent 52355fd439316fac560f3ade53d8640a41f1450d

pnfs/flexfiles: Fix misplaced barrier in nfs4_ff_layout_prepare_ds

[ Upstream commit a2915fa06227b056a8f9b0d79b61dca08ad5cfc6 ]

_nfs4_pnfs_v3/v4_ds_connect do
   some work
   smp_wmb
   ds->ds_clp = clp;

And nfs4_ff_layout_prepare_ds currently does
   smp_rmb
   if(ds->ds_clp)
      ...

This patch places the smp_rmb after the if. This ensures that following
reads only happen once nfs4_ff_layout_prepare_ds has checked that data
has been properly initialized.

Fixes: d67ae825a59d6 ("pnfs/flexfiles: Add the FlexFile Layout Driver")
Signed-off-by: Baptiste Lepers <baptiste.lepers@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>