[PATCH v2 1/2] NFSv4: Fix problems with close in the presence of a delegation

[PATCH v2 1/2] NFSv4: Fix problems with close in the presence of a delegation

[Trond Myklebust]

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
value for calldata->arg.fmode using the state->flags.

Reported-by: James Drews <drews@engr.wisc.edu>
Fixes: 88069f77e1ac5 (NFSv41: Fix a potential state leakage when...)
Cc: stable@vger.kernel.org # 2.6.33+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
---
 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) {
 		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 */
-- 
1.9.3

[PATCH v2 2/2] NFSv4: Don't clear the open state when we just did an OPEN_DOWNGRADE

[Trond Myklebust]

If we did an OPEN_DOWNGRADE, then the right thing to do on success, is
to apply the new open mode to the struct nfs4_state. Instead, we were
unconditionally clearing the state, making it appear to our state
machinery as if we had just performed a CLOSE.

Fixes: 226056c5c312b (NFSv4: Use correct locking when updating nfs4_state...)
Cc: stable@vger.kernel.org # 3.15+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
---
 fs/nfs/nfs4proc.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 7d67d5b332d4..fe63691822bc 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2560,6 +2560,7 @@ static void nfs4_close_done(struct rpc_task *task, void *data)
 	struct nfs4_closedata *calldata = data;
 	struct nfs4_state *state = calldata->state;
 	struct nfs_server *server = NFS_SERVER(calldata->inode);
+	nfs4_stateid *res_stateid = NULL;
 
 	dprintk("%s: begin!\n", __func__);
 	if (!nfs4_sequence_done(task, &calldata->res.seq_res))
@@ -2570,12 +2571,12 @@ static void nfs4_close_done(struct rpc_task *task, void *data)
 	 */
 	switch (task->tk_status) {
 		case 0:
-			if (calldata->roc)
+			res_stateid = &calldata->res.stateid;
+			if (calldata->arg.fmode == 0 && calldata->roc)
 				pnfs_roc_set_barrier(state->inode,
 						     calldata->roc_barrier);
-			nfs_clear_open_stateid(state, &calldata->res.stateid, 0);
 			renew_lease(server, calldata->timestamp);
-			goto out_release;
+			break;
 		case -NFS4ERR_ADMIN_REVOKED:
 		case -NFS4ERR_STALE_STATEID:
 		case -NFS4ERR_OLD_STATEID:
@@ -2589,7 +2590,7 @@ static void nfs4_close_done(struct rpc_task *task, void *data)
 				goto out_release;
 			}
 	}
-	nfs_clear_open_stateid(state, NULL, calldata->arg.fmode);
+	nfs_clear_open_stateid(state, res_stateid, calldata->arg.fmode);
 out_release:
 	nfs_release_seqid(calldata->arg.seqid);
 	nfs_refresh_inode(calldata->inode, calldata->res.fattr);
-- 
1.9.3

Re: [PATCH v2 1/2] NFSv4: Fix problems with close in the presence of a delegation

[Anna Schumaker]

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 <drews@engr.wisc.edu>
> Fixes: 88069f77e1ac5 (NFSv41: Fix a potential state leakage when...)
> Cc: stable@vger.kernel.org # 2.6.33+
> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
> ---
>  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?

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 */

Re: [PATCH v2 1/2] NFSv4: Fix problems with close in the presence of a delegation

[Trond Myklebust]

On Tue, Aug 26, 2014 at 4:11 PM, Anna Schumaker
<Anna.Schumaker@netapp.com> 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 <drews@engr.wisc.edu>
>> Fixes: 88069f77e1ac5 (NFSv41: Fix a potential state leakage when...)
>> Cc: stable@vger.kernel.org # 2.6.33+
>> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
>> ---
>>  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.

> 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 */
>



-- 
Trond Myklebust

Linux NFS client maintainer, PrimaryData

trond.myklebust@primarydata.com

Re: [PATCH v2 1/2] NFSv4: Fix problems with close in the presence of a delegation

[Anna Schumaker]

On 08/26/2014 04:15 PM, Trond Myklebust wrote:
> On Tue, Aug 26, 2014 at 4:11 PM, Anna Schumaker
> <Anna.Schumaker@netapp.com> 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 <drews@engr.wisc.edu>
>>> Fixes: 88069f77e1ac5 (NFSv41: Fix a potential state leakage when...)
>>> Cc: stable@vger.kernel.org # 2.6.33+
>>> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
>>> ---
>>>  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 */
>>
> 
> 
> 

Re: NFSv4.2 Linux client

[Marc Eshel]

Hi Anna,

Any plans to update  the Linux client with the latest changes to the 
NFSv4.2 draft?

Marc.