On Jun 26, 2012, at 3:00 PM, Bryan Schumaker wrote:
> On 06/26/2012 02:23 PM, Chuck Lever wrote:
>>
>> On Jun 26, 2012, at 2:12 PM, bjschuma@xxxxxxxxxx wrote:
>>
>>> From: Bryan Schumaker <bjschuma@xxxxxxxxxx>
>>>
>>> I was treating a NULL return value as an error, but this function will
>>> instead return an ERR_PTR(). Now that I'm checking if the function
>>> returns an error, I should also pass the error up the call stack.
>>
>>
>>> Signed-off-by: Bryan Schumaker <bjschuma@xxxxxxxxxx>
>>> ---
>>> fs/nfs/nfs4namespace.c | 4 ++--
>>> fs/nfs/nfs4proc.c | 15 ++++-----------
>>> 2 files changed, 6 insertions(+), 13 deletions(-)
>>>
>>> diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
>>> index 017b4b0..a8aafc6 100644
>>> --- a/fs/nfs/nfs4namespace.c
>>> +++ b/fs/nfs/nfs4namespace.c
>>> @@ -205,9 +205,9 @@ struct rpc_clnt *nfs4_create_sec_client(struct rpc_clnt *clnt, struct inode *ino
>>> return clone;
>>>
>>> auth = rpcauth_create(flavor, clone);
>>> - if (!auth) {
>>> + if (IS_ERR(auth)) {
>>> rpc_shutdown_client(clone);
>>> - clone = ERR_PTR(-EIO);
>>> + clone = ERR_CAST(auth);
>>> }
>>
>> This echoes nfs_init_server_rpcclient(), so it should be adequate.
>>
>>>
>>> return clone;
>>> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
>>> index 5a7b372..f817587 100644
>>> --- a/fs/nfs/nfs4proc.c
>>> +++ b/fs/nfs/nfs4proc.c
>>> @@ -2356,17 +2356,10 @@ out:
>>> static int nfs4_lookup_root_sec(struct nfs_server *server, struct nfs_fh *fhandle,
>>> struct nfs_fsinfo *info, rpc_authflavor_t flavor)
>>> {
>>> - struct rpc_auth *auth;
>>> - int ret;
>>> -
>>> - auth = rpcauth_create(flavor, server->client);
>>> - if (!auth) {
>>> - ret = -EIO;
>>> - goto out;
>>> - }
>>> - ret = nfs4_lookup_root(server, fhandle, info);
>>> -out:
>>> - return ret;
>>> + struct rpc_auth *auth = rpcauth_create(flavor, server->client);
>>> + if (IS_ERR(auth))
>>> + return PTR_ERR(auth);
>>> + return nfs4_lookup_root(server, fhandle, info);
>>> }
>>>
>>> static int nfs4_find_root_sec(struct nfs_server *server, struct nfs_fh *fhandle,
>>
>> This logic calls rpcauth_create() in a loop, correct? The expectation is that rpcauth_create() should simply replace the nfs_client's rpc_auth with the next flavor each time it is called?
>>
>
> Yeah, that's what I'm expecting to happen.
>
>> With the current code in nfs4_find_root_sec(), rpcauth_create() with a GSS flavor fails the second time you call it because (I suspect) there's a pipe dentry left over from the previous call. So there's no way to walk an entire list returned from gss_mech_list_flavors(), it will fail on the second GSS flavor every time.
>
> rpcauth_create() has this bit of code in it:
>
> if (clnt->cl_auth)
> rpcauth_release(clnt->cl_auth);
> clnt->cl_auth = auth;
>
>
> I guess I figured rpcauth_release() was already doing the necessary cleanup.
It's doing clean-up _after_ the op->create() call. That way if op->create() fails, clnt->cl_auth is unchanged, as rpcauth_create()'s caller expects.
But that means that any pipes created for clnt->cl_auth are still around while op->create() is working, and will cause rpc_mkpipe() to barf. I'm toying with these solutions:
>> We could:
>>
>> a) have gss_pipes_dentries_create_net() ignore -EEXIST and return zero instead, or
>>
>> b) make sure rpcauth_create() releases the old rpc_auth before calling op->create()
>>
>> c) ??
>>
--
Chuck Lever
chuck[dot]lever[at]oracle[dot]com
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