linux-kernel - [PATCH net 4/6] afs: Check for rxrpc call completion in wait loop

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Date:   Fri, 12 Apr 2019 16:34:02 +0100
From:   David Howells <dhowells@...hat.com>
To:     netdev@...r.kernel.org
Cc:     dhowells@...hat.com, linux-afs@...ts.infradead.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH net 4/6] afs: Check for rxrpc call completion in wait loop

From: Marc Dionne <marc.dionne@...istor.com>

Check the state of the rxrpc call backing an afs call in each iteration of
the call wait loop in case the rxrpc call has already been terminated at
the rxrpc layer.

Interrupt the wait loop and mark the afs call as complete if the rxrpc
layer call is complete.

There were cases where rxrpc errors were not passed up to afs, which could
result in this loop waiting forever for an afs call to transition to
AFS_CALL_COMPLETE while the rx call was already complete.

Signed-off-by: Marc Dionne <marc.dionne@...istor.com>
Signed-off-by: David Howells <dhowells@...hat.com>
---

 fs/afs/rxrpc.c |   22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 5cb11aff9298..c14001b42d20 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -610,6 +610,7 @@ static long afs_wait_for_call_to_complete(struct afs_call *call,
 	bool stalled = false;
 	u64 rtt;
 	u32 life, last_life;
+	bool rxrpc_complete = false;
 
 	DECLARE_WAITQUEUE(myself, current);
 
@@ -639,7 +640,12 @@ static long afs_wait_for_call_to_complete(struct afs_call *call,
 		if (afs_check_call_state(call, AFS_CALL_COMPLETE))
 			break;
 
-		rxrpc_kernel_check_life(call->net->socket, call->rxcall, &life);
+		if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall, &life)) {
+			/* rxrpc terminated the call. */
+			rxrpc_complete = true;
+			break;
+		}
+
 		if (timeout == 0 &&
 		    life == last_life && signal_pending(current)) {
 			if (stalled)
@@ -663,12 +669,16 @@ static long afs_wait_for_call_to_complete(struct afs_call *call,
 	remove_wait_queue(&call->waitq, &myself);
 	__set_current_state(TASK_RUNNING);
 
-	/* Kill off the call if it's still live. */
 	if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
-		_debug("call interrupted");
-		if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
-					    RX_USER_ABORT, -EINTR, "KWI"))
-			afs_set_call_complete(call, -EINTR, 0);
+		if (rxrpc_complete) {
+			afs_set_call_complete(call, call->error, call->abort_code);
+		} else {
+			/* Kill off the call if it's still live. */
+			_debug("call interrupted");
+			if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
+						    RX_USER_ABORT, -EINTR, "KWI"))
+				afs_set_call_complete(call, -EINTR, 0);
+		}
 	}
 
 	spin_lock_bh(&call->state_lock);