Commit a22f1eca authored Jan 27, 2023 by Benjamin Coddington Committed by Greg Kroah-Hartman Mar 11, 2023

nfsd: fix race to check ls_layouts



[ 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: c5c707f9 ("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>

parent 5a195fa4

fs/nfsd/nfs4layouts.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -322,11 +322,11 @@ 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);