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authorTrond Myklebust <trond.myklebust@hammerspace.com>2018-12-04 15:52:11 +0300
committerTrond Myklebust <trond.myklebust@hammerspace.com>2018-12-05 15:10:06 +0300
commitc443305529d1d3d3bee0d68fdd14ae89835e091f (patch)
tree0d66728dfa1f6c85bcffb69456c838788c515bfe /net/sunrpc
parent0a9a4304f3614e25d9de9b63502ca633c01c0d70 (diff)
downloadlinux-c443305529d1d3d3bee0d68fdd14ae89835e091f.tar.xz
SUNRPC: Fix RPC receive hangs
The RPC code is occasionally hanging when the receive code fails to empty the socket buffer due to a partial read of the data. When we convert that to an EAGAIN, it appears we occasionally leave data in the socket. The fix is to just keep reading until the socket returns EAGAIN/EWOULDBLOCK. Reported-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Cristian Marussi <cristian.marussi@arm.com> Reported-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Tested-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Cristian Marussi <cristian.marussi@arm.com>
Diffstat (limited to 'net/sunrpc')
-rw-r--r--net/sunrpc/xprtsock.c39
1 files changed, 19 insertions, 20 deletions
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index ae77c71c1f64..0898752cecfe 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -398,7 +398,7 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
goto out;
if (ret != want)
- goto eagain;
+ goto out;
seek = 0;
} else {
seek -= buf->head[0].iov_len;
@@ -418,7 +418,7 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
goto out;
if (ret != want)
- goto eagain;
+ goto out;
seek = 0;
} else {
seek -= buf->page_len;
@@ -433,7 +433,7 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
goto out;
if (ret != want)
- goto eagain;
+ goto out;
} else
offset += buf->tail[0].iov_len;
ret = -EMSGSIZE;
@@ -441,9 +441,6 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
out:
*read = offset - seek_init;
return ret;
-eagain:
- ret = -EAGAIN;
- goto out;
sock_err:
offset += seek;
goto out;
@@ -486,19 +483,18 @@ xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
if (transport->recv.offset == transport->recv.len) {
if (xs_read_stream_request_done(transport))
msg->msg_flags |= MSG_EOR;
- return transport->recv.copied;
+ return read;
}
switch (ret) {
+ default:
+ break;
case -EMSGSIZE:
- return transport->recv.copied;
+ return read;
case 0:
return -ESHUTDOWN;
- default:
- if (ret < 0)
- return ret;
}
- return -EAGAIN;
+ return ret < 0 ? ret : read;
}
static size_t
@@ -537,7 +533,7 @@ xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
ret = xs_read_stream_request(transport, msg, flags, req);
if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
- xprt_complete_bc_request(req, ret);
+ xprt_complete_bc_request(req, transport->recv.copied);
return ret;
}
@@ -570,7 +566,7 @@ xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
spin_lock(&xprt->queue_lock);
if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
- xprt_complete_rqst(req->rq_task, ret);
+ xprt_complete_rqst(req->rq_task, transport->recv.copied);
xprt_unpin_rqst(req);
out:
spin_unlock(&xprt->queue_lock);
@@ -591,10 +587,8 @@ xs_read_stream(struct sock_xprt *transport, int flags)
if (ret <= 0)
goto out_err;
transport->recv.offset = ret;
- if (ret != want) {
- ret = -EAGAIN;
- goto out_err;
- }
+ if (transport->recv.offset != want)
+ return transport->recv.offset;
transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
RPC_FRAGMENT_SIZE_MASK;
transport->recv.offset -= sizeof(transport->recv.fraghdr);
@@ -602,6 +596,9 @@ xs_read_stream(struct sock_xprt *transport, int flags)
}
switch (be32_to_cpu(transport->recv.calldir)) {
+ default:
+ msg.msg_flags |= MSG_TRUNC;
+ break;
case RPC_CALL:
ret = xs_read_stream_call(transport, &msg, flags);
break;
@@ -616,6 +613,8 @@ xs_read_stream(struct sock_xprt *transport, int flags)
goto out_err;
read += ret;
if (transport->recv.offset < transport->recv.len) {
+ if (!(msg.msg_flags & MSG_TRUNC))
+ return read;
ret = xs_read_discard(transport->sock, &msg, flags,
transport->recv.len - transport->recv.offset);
if (ret <= 0)
@@ -623,7 +622,7 @@ xs_read_stream(struct sock_xprt *transport, int flags)
transport->recv.offset += ret;
read += ret;
if (transport->recv.offset != transport->recv.len)
- return -EAGAIN;
+ return read;
}
if (xs_read_stream_request_done(transport)) {
trace_xs_stream_read_request(transport);
@@ -653,7 +652,7 @@ static void xs_stream_data_receive(struct sock_xprt *transport)
clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
for (;;) {
ret = xs_read_stream(transport, MSG_DONTWAIT);
- if (ret <= 0)
+ if (ret < 0)
break;
read += ret;
cond_resched();