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Commit b48fa6b9 authored by Neil Brown's avatar Neil Brown Committed by J. Bruce Fields
Browse files

sunrpc: centralise most calls to svc_xprt_received 



svc_xprt_received must be called when ->xpo_recvfrom has finished
receiving a message, so that the XPT_BUSY flag will be cleared and
if necessary, requeued for further work.

This call is currently made in each ->xpo_recvfrom function, often
from multiple different points.  In each case it is the earliest point
on a particular path where it is known that the protection provided by
XPT_BUSY is no longer needed.

However there are (still) some error paths which do not call
svc_xprt_received, and requiring each ->xpo_recvfrom to make the call
does not encourage robustness.

So: move the svc_xprt_received call to be made just after the
call to ->xpo_recvfrom(), and move it of the various ->xpo_recvfrom
methods.

This means that it may not be called at the earliest possible instant,
but this is unlikely to be a measurable performance issue.

Note that there are still other calls to svc_xprt_received as it is
also needed when an xprt is newly created.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
parent 26c0c75e

net/sunrpc/svc_xprt.c

+3 −1
Original line number Diff line number Diff line
@@ -743,8 +743,10 @@ int svc_recv(struct svc_rqst *rqstp, long timeout) 
		if (rqstp->rq_deferred) {

			svc_xprt_received(xprt);

			len = svc_deferred_recv(rqstp);

		} else

		} else {

			len = xprt->xpt_ops->xpo_recvfrom(rqstp);

			svc_xprt_received(xprt);

		}

		dprintk("svc: got len=%d\n", len);

	}

net/sunrpc/svcsock.c

+1 −14
Original line number Diff line number Diff line
@@ -547,7 +547,6 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp) 
			dprintk("svc: recvfrom returned error %d\n", -err);

			set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);

		}

		svc_xprt_received(&svsk->sk_xprt);

		return -EAGAIN;

	}

	len = svc_addr_len(svc_addr(rqstp));
@@ -562,11 +561,6 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp) 
	svsk->sk_sk->sk_stamp = skb->tstamp;

	set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); /* there may be more data... */



	/*

	 * Maybe more packets - kick another thread ASAP.

	 */

	svc_xprt_received(&svsk->sk_xprt);



	len  = skb->len - sizeof(struct udphdr);

	rqstp->rq_arg.len = len;
@@ -917,7 +911,6 @@ static int svc_tcp_recv_record(struct svc_sock *svsk, struct svc_rqst *rqstp) 
		if (len < want) {

			dprintk("svc: short recvfrom while reading record "

				"length (%d of %d)\n", len, want);

			svc_xprt_received(&svsk->sk_xprt);

			goto err_again; /* record header not complete */

		}
@@ -953,7 +946,6 @@ static int svc_tcp_recv_record(struct svc_sock *svsk, struct svc_rqst *rqstp) 
	if (len < svsk->sk_reclen) {

		dprintk("svc: incomplete TCP record (%d of %d)\n",

			len, svsk->sk_reclen);

		svc_xprt_received(&svsk->sk_xprt);

		goto err_again;	/* record not complete */

	}

	len = svsk->sk_reclen;
@@ -961,14 +953,11 @@ static int svc_tcp_recv_record(struct svc_sock *svsk, struct svc_rqst *rqstp) 


	return len;

 error:

	if (len == -EAGAIN) {

	if (len == -EAGAIN)

		dprintk("RPC: TCP recv_record got EAGAIN\n");

		svc_xprt_received(&svsk->sk_xprt);

	}

	return len;

 err_delete:

	set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);

	svc_xprt_received(&svsk->sk_xprt);

 err_again:

	return -EAGAIN;

}
@@ -1110,7 +1099,6 @@ static int svc_tcp_recvfrom(struct svc_rqst *rqstp) 
	svsk->sk_tcplen = 0;



	svc_xprt_copy_addrs(rqstp, &svsk->sk_xprt);

	svc_xprt_received(&svsk->sk_xprt);

	if (serv->sv_stats)

		serv->sv_stats->nettcpcnt++;
@@ -1119,7 +1107,6 @@ static int svc_tcp_recvfrom(struct svc_rqst *rqstp) 
err_again:

	if (len == -EAGAIN) {

		dprintk("RPC: TCP recvfrom got EAGAIN\n");

		svc_xprt_received(&svsk->sk_xprt);

		return len;

	}

error:

net/sunrpc/xprtrdma/svc_rdma_recvfrom.c

+0 −3
Original line number Diff line number Diff line
@@ -566,7 +566,6 @@ static int rdma_read_complete(struct svc_rqst *rqstp, 
		ret, rqstp->rq_arg.len,	rqstp->rq_arg.head[0].iov_base,

		rqstp->rq_arg.head[0].iov_len);



	svc_xprt_received(rqstp->rq_xprt);

	return ret;

}
@@ -665,7 +664,6 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp) 
		rqstp->rq_arg.head[0].iov_len);

	rqstp->rq_prot = IPPROTO_MAX;

	svc_xprt_copy_addrs(rqstp, xprt);

	svc_xprt_received(xprt);

	return ret;



 close_out:
@@ -678,6 +676,5 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp) 
	 */

	set_bit(XPT_CLOSE, &xprt->xpt_flags);

defer:

	svc_xprt_received(xprt);

	return 0;

}