From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f195.google.com ([209.85.220.195]:34961 "EHLO mail-qk0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753999AbcITQ4V (ORCPT ); Tue, 20 Sep 2016 12:56:21 -0400 Received: by mail-qk0-f195.google.com with SMTP id w204so1432013qka.2 for ; Tue, 20 Sep 2016 09:56:21 -0700 (PDT) From: Trond Myklebust To: anna.schumaker@netapp.com Cc: linux-nfs@vger.kernel.org, Oleg Drokin Subject: [PATCH v6 04/29] NFSv4: nfs4_copy_delegation_stateid() must fail if the delegation is invalid Date: Tue, 20 Sep 2016 12:55:46 -0400 Message-Id: <1474390571-17106-5-git-send-email-trond.myklebust@primarydata.com> In-Reply-To: <1474390571-17106-4-git-send-email-trond.myklebust@primarydata.com> References: <1474390571-17106-1-git-send-email-trond.myklebust@primarydata.com> <1474390571-17106-2-git-send-email-trond.myklebust@primarydata.com> <1474390571-17106-3-git-send-email-trond.myklebust@primarydata.com> <1474390571-17106-4-git-send-email-trond.myklebust@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: We must not allow the use of delegations that have been revoked or are being returned. Signed-off-by: Trond Myklebust Fixes: 869f9dfa4d6d ("NFSv4: Fix races between nfs_remove_bad_delegation()...") Signed-off-by: Trond Myklebust Cc: stable@vger.kernel.org # v3.19+ --- fs/nfs/delegation.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index 86d2c748140b..b9c65421ed81 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -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); -- 2.7.4