Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx12.netapp.com ([216.240.18.77]:54928 "EHLO mx12.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753330AbaHZUVT (ORCPT ); Tue, 26 Aug 2014 16:21:19 -0400 Message-ID: <53FCEC3C.80909@Netapp.com> Date: Tue, 26 Aug 2014 16:21:16 -0400 From: Anna Schumaker MIME-Version: 1.0 To: Trond Myklebust CC: Linux NFS Mailing List , James Drews , Subject: Re: [PATCH v2 1/2] NFSv4: Fix problems with close in the presence of a delegation References: <1409077853-15680-1-git-send-email-trond.myklebust@primarydata.com> <53FCE9DF.1050407@Netapp.com> In-Reply-To: Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: On 08/26/2014 04:15 PM, Trond Myklebust wrote: > On Tue, Aug 26, 2014 at 4:11 PM, Anna Schumaker > wrote: >> On 08/26/2014 02:30 PM, Trond Myklebust wrote: >>> In the presence of delegations, we can no longer assume that the >>> state->n_rdwr, state->n_rdonly, state->n_wronly reflect the open >>> stateid share mode, and so we need to need to calculate the initial >> Nit: Remove the duplicate "need to" (above). >> >>> value for calldata->arg.fmode using the state->flags. >>> >>> Reported-by: James Drews >>> Fixes: 88069f77e1ac5 (NFSv41: Fix a potential state leakage when...) >>> Cc: stable@vger.kernel.org # 2.6.33+ >>> Signed-off-by: Trond Myklebust >>> --- >>> fs/nfs/nfs4proc.c | 19 +++++++++++++------ >>> 1 file changed, 13 insertions(+), 6 deletions(-) >>> >>> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c >>> index 75ae8d22f067..7d67d5b332d4 100644 >>> --- a/fs/nfs/nfs4proc.c >>> +++ b/fs/nfs/nfs4proc.c >>> @@ -2601,6 +2601,7 @@ static void nfs4_close_prepare(struct rpc_task *task, void *data) >>> struct nfs4_closedata *calldata = data; >>> struct nfs4_state *state = calldata->state; >>> struct inode *inode = calldata->inode; >>> + bool is_rdonly, is_wronly, is_rdwr; >>> int call_close = 0; >>> >>> dprintk("%s: begin!\n", __func__); >>> @@ -2608,24 +2609,30 @@ static void nfs4_close_prepare(struct rpc_task *task, void *data) >>> goto out_wait; >>> >>> task->tk_msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN_DOWNGRADE]; >>> - calldata->arg.fmode = FMODE_READ|FMODE_WRITE; >>> spin_lock(&state->owner->so_lock); >>> + is_rdwr = test_bit(NFS_O_RDWR_STATE, &state->flags); >>> + is_rdonly = test_bit(NFS_O_RDONLY_STATE, &state->flags); >>> + is_wronly = test_bit(NFS_O_WRONLY_STATE, &state->flags); >>> + spin_unlock(&state->owner->so_lock); >>> + /* Calculate the current open share mode */ >>> + calldata->arg.fmode = 0; >>> + if (is_rdonly || is_rdwr) >>> + calldata->arg.fmode |= FMODE_READ; >>> + if (is_wronly || is_rdwr) >>> + calldata->arg.fmode |= FMODE_WRITE; >>> /* Calculate the change in open mode */ >>> if (state->n_rdwr == 0) { >> Do we need the owner lock for reading state->n_rdwr, n_rdonly, and n_wronly? > > Duh, yes, you're right. I'll revert that part of the change. I could be wrong! I checked for other uses, and nfs4proc.c:can_open_cached() reads these values without a lock. Anna > >> Anna >>> if (state->n_rdonly == 0) { >>> - call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags); >>> - call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags); >>> + call_close |= is_rdonly || is_rdwr; >>> calldata->arg.fmode &= ~FMODE_READ; >>> } >>> if (state->n_wronly == 0) { >>> - call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags); >>> - call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags); >>> + call_close |= is_wronly || is_rdwr; >>> calldata->arg.fmode &= ~FMODE_WRITE; >>> } >>> } >>> if (!nfs4_valid_open_stateid(state)) >>> call_close = 0; >>> - spin_unlock(&state->owner->so_lock); >>> >>> if (!call_close) { >>> /* Note: exit _without_ calling nfs4_close_done */ >> > > >