From: Benjamin Coddington <bcodding@redhat.com>
Date: Fri, 27 Jan 2023 11:18:56 -0500
Subject: [PATCH] nfsd: fix race to check ls_layouts
References: bsc#1012628
Patch-mainline: 6.2.3
Git-commit: fb610c4dbc996415d57d7090957ecddd4fd64fb6

[ Upstream commit fb610c4dbc996415d57d7090957ecddd4fd64fb6 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 fs/nfsd/nfs4layouts.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c
index 3564d1c6..e8a80052 100644
--- a/fs/nfsd/nfs4layouts.c
+++ b/fs/nfsd/nfs4layouts.c
@@ -323,11 +323,11 @@ nfsd4_recall_file_layout(struct nfs4_layout_stateid *ls)
 	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_nfsd_layout_recall(&ls->ls_stid.sc_stateid);
 
 	refcount_inc(&ls->ls_stid.sc_count);
-- 
2.35.3