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| author |   NeilBrown <neilb@suse.de> | 2014-07-14 11:28:20 +1000 |
|---|---|---|
| committer |   Trond Myklebust <trond.myklebust@primarydata.com> | 2014-08-03 17:14:12 -0400 |
| commit | bd95608053b7f7813351b0defc0e3e7ef8cf2803 (patch) | |
| tree | fde08b1ecc2c4aedd30a68244ca502ce5f81f0fe /net/sunrpc/auth_null.c | |
| parent | NFS: prepare for RCU-walk support but pushing tests later in code. (diff) | |
| download | linux-dev-bd95608053b7f7813351b0defc0e3e7ef8cf2803.tar.xz linux-dev-bd95608053b7f7813351b0defc0e3e7ef8cf2803.zip | |
sunrpc/auth: allow lockless (rcu) lookup of credential cache.
The new flag RPCAUTH_LOOKUP_RCU to credential lookup avoids locking,
does not take a reference on the returned credential, and returns
-ECHILD if a simple lookup was not possible.
The returned value can only be used within an rcu_read_lock protected
region.
The main user of this is the new rpc_lookup_cred_nonblock() which
returns a pointer to the current credential which is only rcu-safe (no
ref-count held), and might return -ECHILD if allocation was required.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'net/sunrpc/auth_null.c')
| -rw-r--r-- | net/sunrpc/auth_null.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/sunrpc/auth_null.c b/net/sunrpc/auth_null.c index f0ebe07978a2..712c123e04e9 100644 --- a/net/sunrpc/auth_null.c +++ b/net/sunrpc/auth_null.c @@ -35,6 +35,8 @@ nul_destroy(struct rpc_auth *auth) static struct rpc_cred * nul_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) { + if (flags & RPCAUTH_LOOKUP_RCU) + return &null_cred; return get_rpccred(&null_cred); } |