[PATCH 4.4 061/112] NFSv4: Dont report revoked delegations as valid in nfs_have_delegation()

From: Greg Kroah-Hartman
Date: Wed Oct 26 2016 - 08:52:00 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>

commit b3f9e7239074613aa6bdafa4caf7c104fe1e7276 upstream.

If the delegation is revoked, then it can't be used for caching.

Fixes: 869f9dfa4d6d ("NFSv4: Fix races between nfs_remove_bad_delegation()...")
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Tested-by: Oleg Drokin <green@xxxxxxxxxxxxxx>
Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/nfs/delegation.c | 1 +
1 file changed, 1 insertion(+)

--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -51,6 +51,7 @@ nfs4_do_check_delegation(struct inode *i
rcu_read_lock();
delegation = rcu_dereference(NFS_I(inode)->delegation);
if (delegation != NULL && (delegation->type & flags) == flags &&
+ !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) &&
!test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) {
if (mark)
nfs_mark_delegation_referenced(delegation);