From b960a34b73e4c1c972623bc2076e24b97588d09e Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 9 May 2019 08:21:21 +0100 Subject: [PATCH] rxrpc: Allow the kernel to mark a call as being non-interruptible Allow kernel services using AF_RXRPC to indicate that a call should be non-interruptible. This allows kafs to make things like lock-extension and writeback data storage calls non-interruptible. If this is set, signals will be ignored for operations on that call where possible - such as waiting to get a call channel on an rxrpc connection. It doesn't prevent UDP sendmsg from being interrupted, but that will be handled by packet retransmission. rxrpc_kernel_recv_data() isn't affected by this since that never waits, preferring instead to return -EAGAIN and leave the waiting to the caller. Userspace initiated calls can't be set to be uninterruptible at this time. Signed-off-by: David Howells --- Documentation/networking/rxrpc.txt | 11 ++++++++++- fs/afs/rxrpc.c | 1 + include/net/af_rxrpc.h | 1 + net/rxrpc/af_rxrpc.c | 3 +++ net/rxrpc/ar-internal.h | 2 ++ net/rxrpc/call_object.c | 2 ++ net/rxrpc/conn_client.c | 8 ++++++-- net/rxrpc/sendmsg.c | 4 +++- 8 files changed, 28 insertions(+), 4 deletions(-) diff --git a/Documentation/networking/rxrpc.txt b/Documentation/networking/rxrpc.txt index ff035a6418e3..180e07d956a7 100644 --- a/Documentation/networking/rxrpc.txt +++ b/Documentation/networking/rxrpc.txt @@ -796,7 +796,9 @@ The kernel interface functions are as follows: s64 tx_total_len, gfp_t gfp, rxrpc_notify_rx_t notify_rx, - bool upgrade); + bool upgrade, + bool intr, + unsigned int debug_id); This allocates the infrastructure to make a new RxRPC call and assigns call and connection numbers. The call will be made on the UDP port that @@ -824,6 +826,13 @@ The kernel interface functions are as follows: the server upgrade the service to a better one. The resultant service ID is returned by rxrpc_kernel_recv_data(). + intr should be set to true if the call should be interruptible. If this + is not set, this function may not return until a channel has been + allocated; if it is set, the function may return -ERESTARTSYS. + + debug_id is the call debugging ID to be used for tracing. This can be + obtained by atomically incrementing rxrpc_debug_id. + If this function is successful, an opaque reference to the RxRPC call is returned. The caller now holds a reference on this and it must be properly ended. diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c index 4974defb4592..87763379952d 100644 --- a/fs/afs/rxrpc.c +++ b/fs/afs/rxrpc.c @@ -417,6 +417,7 @@ void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp) afs_wake_up_async_call : afs_wake_up_call_waiter), call->upgrade, + true, call->debug_id); if (IS_ERR(rxcall)) { ret = PTR_ERR(rxcall); diff --git a/include/net/af_rxrpc.h b/include/net/af_rxrpc.h index c04602ca4a55..93358bfc0e1b 100644 --- a/include/net/af_rxrpc.h +++ b/include/net/af_rxrpc.h @@ -45,6 +45,7 @@ struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *, gfp_t, rxrpc_notify_rx_t, bool, + bool, unsigned int); int rxrpc_kernel_send_data(struct socket *, struct rxrpc_call *, struct msghdr *, size_t, diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c index 213935fbbbf7..ffde5b187f5d 100644 --- a/net/rxrpc/af_rxrpc.c +++ b/net/rxrpc/af_rxrpc.c @@ -270,6 +270,7 @@ static int rxrpc_listen(struct socket *sock, int backlog) * @gfp: The allocation constraints * @notify_rx: Where to send notifications instead of socket queue * @upgrade: Request service upgrade for call + * @intr: The call is interruptible * @debug_id: The debug ID for tracing to be assigned to the call * * Allow a kernel service to begin a call on the nominated socket. This just @@ -287,6 +288,7 @@ struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *sock, gfp_t gfp, rxrpc_notify_rx_t notify_rx, bool upgrade, + bool intr, unsigned int debug_id) { struct rxrpc_conn_parameters cp; @@ -311,6 +313,7 @@ struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *sock, memset(&p, 0, sizeof(p)); p.user_call_ID = user_call_ID; p.tx_total_len = tx_total_len; + p.intr = intr; memset(&cp, 0, sizeof(cp)); cp.local = rx->local; diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h index 062ca9dc29b8..07fc1dfa4878 100644 --- a/net/rxrpc/ar-internal.h +++ b/net/rxrpc/ar-internal.h @@ -482,6 +482,7 @@ enum rxrpc_call_flag { RXRPC_CALL_BEGAN_RX_TIMER, /* We began the expect_rx_by timer */ RXRPC_CALL_RX_HEARD, /* The peer responded at least once to this call */ RXRPC_CALL_RX_UNDERRUN, /* Got data underrun */ + RXRPC_CALL_IS_INTR, /* The call is interruptible */ }; /* @@ -711,6 +712,7 @@ struct rxrpc_call_params { u32 normal; /* Max time since last call packet (msec) */ } timeouts; u8 nr_timeouts; /* Number of timeouts specified */ + bool intr; /* The call is interruptible */ }; struct rxrpc_send_params { diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c index fe96881a334d..d0ca98d7aef5 100644 --- a/net/rxrpc/call_object.c +++ b/net/rxrpc/call_object.c @@ -241,6 +241,8 @@ struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx, return call; } + if (p->intr) + __set_bit(RXRPC_CALL_IS_INTR, &call->flags); call->tx_total_len = p->tx_total_len; trace_rxrpc_call(call, rxrpc_call_new_client, atomic_read(&call->usage), here, (const void *)p->user_call_ID); diff --git a/net/rxrpc/conn_client.c b/net/rxrpc/conn_client.c index 83797b3949e2..5cf5595a14d8 100644 --- a/net/rxrpc/conn_client.c +++ b/net/rxrpc/conn_client.c @@ -656,10 +656,14 @@ static int rxrpc_wait_for_channel(struct rxrpc_call *call, gfp_t gfp) add_wait_queue_exclusive(&call->waitq, &myself); for (;;) { - set_current_state(TASK_INTERRUPTIBLE); + if (test_bit(RXRPC_CALL_IS_INTR, &call->flags)) + set_current_state(TASK_INTERRUPTIBLE); + else + set_current_state(TASK_UNINTERRUPTIBLE); if (call->call_id) break; - if (signal_pending(current)) { + if (test_bit(RXRPC_CALL_IS_INTR, &call->flags) && + signal_pending(current)) { ret = -ERESTARTSYS; break; } diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c index bec64deb7b0a..45a05d9a27fa 100644 --- a/net/rxrpc/sendmsg.c +++ b/net/rxrpc/sendmsg.c @@ -80,7 +80,8 @@ static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx, if (call->state >= RXRPC_CALL_COMPLETE) return call->error; - if (timeout == 0 && + if (test_bit(RXRPC_CALL_IS_INTR, &call->flags) && + timeout == 0 && tx_win == tx_start && signal_pending(current)) return -EINTR; @@ -620,6 +621,7 @@ int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len) .call.tx_total_len = -1, .call.user_call_ID = 0, .call.nr_timeouts = 0, + .call.intr = true, .abort_code = 0, .command = RXRPC_CMD_SEND_DATA, .exclusive = false,