Commit b9ab7db4 authored by Trond Myklebust's avatar Trond Myklebust Committed by Greg Kroah-Hartman

NFSv4: nfs4_copy_delegation_stateid() must fail if the delegation is invalid

commit aa05c87f upstream.

We must not allow the use of delegations that have been revoked or are
being returned.
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
Fixes: 869f9dfa ("NFSv4: Fix races between nfs_remove_bad_delegation()...")
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
Tested-by: default avatarOleg Drokin <green@linuxhacker.ru>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 26bd9968
......@@ -41,6 +41,17 @@ void nfs_mark_delegation_referenced(struct nfs_delegation *delegation)
set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags);
}
static bool
nfs4_is_valid_delegation(const struct nfs_delegation *delegation,
fmode_t flags)
{
if (delegation != NULL && (delegation->type & flags) == flags &&
!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) &&
!test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
return true;
return false;
}
static int
nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark)
{
......@@ -50,9 +61,7 @@ nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark)
flags &= FMODE_READ|FMODE_WRITE;
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 (nfs4_is_valid_delegation(delegation, flags)) {
if (mark)
nfs_mark_delegation_referenced(delegation);
ret = 1;
......@@ -894,7 +903,7 @@ bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags,
flags &= FMODE_READ|FMODE_WRITE;
rcu_read_lock();
delegation = rcu_dereference(nfsi->delegation);
ret = (delegation != NULL && (delegation->type & flags) == flags);
ret = nfs4_is_valid_delegation(delegation, flags);
if (ret) {
nfs4_stateid_copy(dst, &delegation->stateid);
nfs_mark_delegation_referenced(delegation);
......
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