From: Benjamin Coddington <bcodding@redhat.com>
Date: Fri, 27 Jan 2023 11:18:56 -0500
Subject: [PATCH] nfsd: fix race to check ls_layouts
Git-commit: fb610c4dbc996415d57d7090957ecddd4fd64fb6
Patch-mainline: v6.3
References: git-fixes

Its possible for __break_lease to find the layout's lease before we've
added the layout to the owner's ls_layouts list.  In that case, setting
ls_recalled = true without actually recalling the layout will cause the
server to never send a recall callback.

Move the check for ls_layouts before setting ls_recalled.

Fixes: c5c707f96fc9 ("nfsd: implement pNFS layout recalls")
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: NeilBrown <neilb@suse.com>

---
 fs/nfsd/nfs4layouts.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/nfsd/nfs4layouts.c
+++ b/fs/nfsd/nfs4layouts.c
@@ -328,11 +328,11 @@ nfsd4_recall_file_layout(struct nfs4_lay
 	if (ls->ls_recalled)
 		goto out_unlock;
 
-	ls->ls_recalled = true;
-	atomic_inc(&ls->ls_stid.sc_file->fi_lo_recalls);
 	if (list_empty(&ls->ls_layouts))
 		goto out_unlock;
 
+	ls->ls_recalled = true;
+	atomic_inc(&ls->ls_stid.sc_file->fi_lo_recalls);
 	trace_layout_recall(&ls->ls_stid.sc_stateid);
 
 	atomic_inc(&ls->ls_stid.sc_count);