From: Chuck Lever <chuck.lever@oracle.com>
To: bfields@fieldses.org
Cc: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org
Subject: [PATCH v3 20/32] SUNRPC: Restructure svc_tcp_recv_record()
Date: Thu, 21 May 2020 10:35:28 -0400 [thread overview]
Message-ID: <20200521143528.3557.32442.stgit@klimt.1015granger.net> (raw)
In-Reply-To: <20200521141100.3557.17098.stgit@klimt.1015granger.net>
Refactor: svc_recvfrom() is going to be converted to read into
bio_vecs in a moment. Unhook the only other caller,
svc_tcp_recv_record(), which just wants to read the 4-byte stream
record marker into a kvec.
While we're in the area, streamline this helper by straight-lining
the hot path, replace dprintk call sites with tracepoints, and
reduce the number of atomic bit operations in this path.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
include/trace/events/sunrpc.h | 24 +++++++++++++++++++
net/sunrpc/svcsock.c | 51 ++++++++++++++++++++---------------------
2 files changed, 49 insertions(+), 26 deletions(-)
diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index 6d85bbb7b8b1..ec4ae34a1f84 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -1443,6 +1443,30 @@ TRACE_EVENT(svcsock_new_socket,
)
);
+TRACE_EVENT(svcsock_marker,
+ TP_PROTO(
+ const struct svc_xprt *xprt,
+ __be32 marker
+ ),
+
+ TP_ARGS(xprt, marker),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, length)
+ __field(bool, last)
+ __string(addr, xprt->xpt_remotebuf)
+ ),
+
+ TP_fast_assign(
+ __entry->length = be32_to_cpu(marker) & RPC_FRAGMENT_SIZE_MASK;
+ __entry->last = be32_to_cpu(marker) & RPC_LAST_STREAM_FRAGMENT;
+ __assign_str(addr, xprt->xpt_remotebuf);
+ ),
+
+ TP_printk("addr=%s length=%u%s", __get_str(addr),
+ __entry->length, __entry->last ? " (last)" : "")
+);
+
DECLARE_EVENT_CLASS(svcsock_class,
TP_PROTO(
const struct svc_xprt *xprt,
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index d63b21f3f207..9c1eb13aa9b8 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -828,47 +828,45 @@ static void svc_tcp_clear_pages(struct svc_sock *svsk)
}
/*
- * Receive fragment record header.
- * If we haven't gotten the record length yet, get the next four bytes.
+ * Receive fragment record header into sk_marker.
*/
-static int svc_tcp_recv_record(struct svc_sock *svsk, struct svc_rqst *rqstp)
+static ssize_t svc_tcp_read_marker(struct svc_sock *svsk,
+ struct svc_rqst *rqstp)
{
- struct svc_serv *serv = svsk->sk_xprt.xpt_server;
- unsigned int want;
- int len;
+ ssize_t want, len;
+ /* If we haven't gotten the record length yet,
+ * get the next four bytes.
+ */
if (svsk->sk_tcplen < sizeof(rpc_fraghdr)) {
+ struct msghdr msg = { NULL };
struct kvec iov;
want = sizeof(rpc_fraghdr) - svsk->sk_tcplen;
iov.iov_base = ((char *)&svsk->sk_marker) + svsk->sk_tcplen;
iov.iov_len = want;
- len = svc_recvfrom(rqstp, &iov, 1, want, 0);
+ iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, want);
+ len = sock_recvmsg(svsk->sk_sock, &msg, MSG_DONTWAIT);
if (len < 0)
- goto error;
+ return len;
svsk->sk_tcplen += len;
-
if (len < want) {
- dprintk("svc: short recvfrom while reading record "
- "length (%d of %d)\n", len, want);
- return -EAGAIN;
+ /* call again to read the remaining bytes */
+ goto err_short;
}
-
- dprintk("svc: TCP record, %d bytes\n", svc_sock_reclen(svsk));
+ trace_svcsock_marker(&svsk->sk_xprt, svsk->sk_marker);
if (svc_sock_reclen(svsk) + svsk->sk_datalen >
- serv->sv_max_mesg) {
- net_notice_ratelimited("RPC: fragment too large: %d\n",
- svc_sock_reclen(svsk));
- goto err_delete;
- }
+ svsk->sk_xprt.xpt_server->sv_max_mesg)
+ goto err_too_large;
}
-
return svc_sock_reclen(svsk);
-error:
- dprintk("RPC: TCP recv_record got %d\n", len);
- return len;
-err_delete:
+
+err_too_large:
+ net_notice_ratelimited("svc: %s %s RPC fragment too large: %d\n",
+ __func__, svsk->sk_xprt.xpt_server->sv_name,
+ svc_sock_reclen(svsk));
set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
+err_short:
return -EAGAIN;
}
@@ -961,12 +959,13 @@ static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
test_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags),
test_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags));
- len = svc_tcp_recv_record(svsk, rqstp);
+ clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
+ len = svc_tcp_read_marker(svsk, rqstp);
if (len < 0)
goto error;
base = svc_tcp_restore_pages(svsk, rqstp);
- want = svc_sock_reclen(svsk) - (svsk->sk_tcplen - sizeof(rpc_fraghdr));
+ want = len - (svsk->sk_tcplen - sizeof(rpc_fraghdr));
vec = rqstp->rq_vec;
next prev parent reply other threads:[~2020-05-21 14:35 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-21 14:33 [PATCH v3 00/32] Possible NFSD patches for v5.8 Chuck Lever
2020-05-21 14:33 ` [PATCH v3 01/32] SUNRPC: Move xpt_mutex into socket xpo_sendto methods Chuck Lever
2020-05-21 14:33 ` [PATCH v3 02/32] svcrdma: Clean up the tracing for rw_ctx_init errors Chuck Lever
2020-05-21 14:33 ` [PATCH v3 03/32] svcrdma: Clean up handling of get_rw_ctx errors Chuck Lever
2020-05-21 14:34 ` [PATCH v3 04/32] svcrdma: Trace page overruns when constructing RDMA Reads Chuck Lever
2020-05-21 14:34 ` [PATCH v3 05/32] svcrdma: trace undersized Write chunks Chuck Lever
2020-05-21 14:34 ` [PATCH v3 06/32] svcrdma: Fix backchannel return code Chuck Lever
2020-05-21 14:34 ` [PATCH v3 07/32] svcrdma: Remove backchannel dprintk call sites Chuck Lever
2020-05-21 14:34 ` [PATCH v3 08/32] svcrdma: Rename tracepoints that record header decoding errors Chuck Lever
2020-05-21 14:34 ` [PATCH v3 09/32] svcrdma: Remove the SVCRDMA_DEBUG macro Chuck Lever
2020-05-21 14:34 ` [PATCH v3 10/32] svcrdma: Displayed remote IP address should match stored address Chuck Lever
2020-05-21 14:34 ` [PATCH v3 11/32] svcrdma: Add tracepoints to report ->xpo_accept failures Chuck Lever
2020-05-21 14:34 ` [PATCH v3 12/32] SUNRPC: Remove kernel memory address from svc_xprt tracepoints Chuck Lever
2020-05-21 14:34 ` [PATCH v3 13/32] SUNRPC: Tracepoint to record errors in svc_xpo_create() Chuck Lever
2020-05-21 14:34 ` [PATCH v3 14/32] SUNRPC: Trace a few more generic svc_xprt events Chuck Lever
2020-05-21 14:35 ` [PATCH v3 15/32] SUNRPC: Remove "#include <trace/events/skb.h>" Chuck Lever
2020-05-21 14:35 ` [PATCH v3 16/32] SUNRPC: Add more svcsock tracepoints Chuck Lever
2020-05-21 14:35 ` [PATCH v3 17/32] SUNRPC: Replace dprintk call sites in TCP state change callouts Chuck Lever
2020-05-21 14:35 ` [PATCH v3 18/32] SUNRPC: Trace server-side rpcbind registration events Chuck Lever
2020-05-21 14:35 ` [PATCH v3 19/32] SUNRPC: Rename svc_sock::sk_reclen Chuck Lever
2020-05-21 14:35 ` Chuck Lever [this message]
2020-05-21 14:35 ` [PATCH v3 21/32] SUNRPC: Replace dprintk() call sites in TCP receive path Chuck Lever
2020-05-21 14:35 ` [PATCH v3 22/32] SUNRPC: Refactor recvfrom path dealing with incomplete TCP receives Chuck Lever
2020-05-21 14:35 ` [PATCH v3 23/32] SUNRPC: Clean up svc_release_skb() functions Chuck Lever
2020-05-21 14:35 ` [PATCH v3 24/32] SUNRPC: Refactor svc_recvfrom() Chuck Lever
2020-05-21 14:35 ` [PATCH v3 25/32] SUNRPC: Restructure svc_udp_recvfrom() Chuck Lever
2020-05-21 14:36 ` [PATCH v3 26/32] SUNRPC: svc_show_status() macro should have enum definitions Chuck Lever
2020-05-21 14:36 ` [PATCH v3 27/32] NFSD: Add tracepoints to NFSD's duplicate reply cache Chuck Lever
2020-05-21 14:36 ` [PATCH v3 28/32] NFSD: Add tracepoints to the NFSD state management code Chuck Lever
2020-05-21 14:36 ` [PATCH v3 29/32] NFSD: Add tracepoints for monitoring NFSD callbacks Chuck Lever
2020-05-21 14:36 ` [PATCH v3 30/32] SUNRPC: Clean up request deferral tracepoints Chuck Lever
2020-05-21 14:36 ` [PATCH v3 31/32] NFSD: Squash an annoying compiler warning Chuck Lever
2020-05-21 14:36 ` [PATCH v3 32/32] NFSD: Fix improperly-formatted Doxygen comments Chuck Lever
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