diff options
| author | Benjamin Coddington <bcodding@redhat.com> | 2019-10-02 17:40:55 +0300 |
|---|---|---|
| committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2019-10-10 23:14:28 +0300 |
| commit | af84537dbd1b39505d1f3d8023029b4a59666513 (patch) | |
| tree | 0c176e56553e0ac8c56b28794b6343128df56d6e | |
| parent | 1047ec868332034d1fbcb2fae19fe6d4cb869ff2 (diff) | |
| download | linux-af84537dbd1b39505d1f3d8023029b4a59666513.tar.xz | |
SUNRPC: fix race to sk_err after xs_error_report
Since commit 4f8943f80883 ("SUNRPC: Replace direct task wakeups from
softirq context") there has been a race to the value of the sk_err if both
XPRT_SOCK_WAKE_ERROR and XPRT_SOCK_WAKE_DISCONNECT are set. In that case,
we may end up losing the sk_err value that existed when xs_error_report was
called.
Fix this by reverting to the previous behavior: instead of using SO_ERROR
to retrieve the value at a later time (which might also return sk_err_soft),
copy the sk_err value onto struct sock_xprt, and use that value to wake
pending tasks.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Fixes: 4f8943f80883 ("SUNRPC: Replace direct task wakeups from softirq context")
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| -rw-r--r-- | include/linux/sunrpc/xprtsock.h | 1 | ||||
| -rw-r--r-- | net/sunrpc/xprtsock.c | 17 |
2 files changed, 9 insertions, 9 deletions
diff --git a/include/linux/sunrpc/xprtsock.h b/include/linux/sunrpc/xprtsock.h index 7638dbe7bc50..a940de03808d 100644 --- a/include/linux/sunrpc/xprtsock.h +++ b/include/linux/sunrpc/xprtsock.h @@ -61,6 +61,7 @@ struct sock_xprt { struct mutex recv_mutex; struct sockaddr_storage srcaddr; unsigned short srcport; + int xprt_err; /* * UDP socket buffer size parameters diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 9ac88722fa83..70e52f567b2a 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -1249,19 +1249,21 @@ static void xs_error_report(struct sock *sk) { struct sock_xprt *transport; struct rpc_xprt *xprt; - int err; read_lock_bh(&sk->sk_callback_lock); if (!(xprt = xprt_from_sock(sk))) goto out; transport = container_of(xprt, struct sock_xprt, xprt); - err = -sk->sk_err; - if (err == 0) + transport->xprt_err = -sk->sk_err; + if (transport->xprt_err == 0) goto out; dprintk("RPC: xs_error_report client %p, error=%d...\n", - xprt, -err); - trace_rpc_socket_error(xprt, sk->sk_socket, err); + xprt, -transport->xprt_err); + trace_rpc_socket_error(xprt, sk->sk_socket, transport->xprt_err); + + /* barrier ensures xprt_err is set before XPRT_SOCK_WAKE_ERROR */ + smp_mb__before_atomic(); xs_run_error_worker(transport, XPRT_SOCK_WAKE_ERROR); out: read_unlock_bh(&sk->sk_callback_lock); @@ -2476,7 +2478,6 @@ static void xs_wake_write(struct sock_xprt *transport) static void xs_wake_error(struct sock_xprt *transport) { int sockerr; - int sockerr_len = sizeof(sockerr); if (!test_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state)) return; @@ -2485,9 +2486,7 @@ static void xs_wake_error(struct sock_xprt *transport) goto out; if (!test_and_clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state)) goto out; - if (kernel_getsockopt(transport->sock, SOL_SOCKET, SO_ERROR, - (char *)&sockerr, &sockerr_len) != 0) - goto out; + sockerr = xchg(&transport->xprt_err, 0); if (sockerr < 0) xprt_wake_pending_tasks(&transport->xprt, sockerr); out: |