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Subject: [PATCH 20/33] afs: Log remote unmarshalling errors
From:   David Howells <dhowells@redhat.com>
To:     Trond Myklebust <trondmy@hammerspace.com>,
        Anna Schumaker <anna.schumaker@netapp.com>,
        Steve French <sfrench@samba.org>,
        Dominique Martinet <asmadeus@codewreck.org>
Cc:     linux-afs@lists.infradead.org, linux-cachefs@redhat.com,
        linux-fsdevel@vger.kernel.org, dhowells@redhat.com,
        Jeff Layton <jlayton@redhat.com>,
        David Wysochanski <dwysocha@redhat.com>,
        "Matthew Wilcox (Oracle)" <willy@infradead.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        linux-cachefs@redhat.com, linux-afs@lists.infradead.org,
        linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org,
        ceph-devel@vger.kernel.org, v9fs-developer@lists.sourceforge.net,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Date:   Mon, 15 Feb 2021 15:48:11 +0000
Message-ID: <161340409118.1303470.17812607349396199116.stgit@warthog.procyon.org.uk>
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References: <161340385320.1303470.2392622971006879777.stgit@warthog.procyon.org.uk>
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Log unmarshalling errors reported by the peer (ie. it can't parse what we
sent it).  Limit the maximum number of messages to 3.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
---

 fs/afs/rxrpc.c |   34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 0ec38b758f29..ae68576f822f 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -500,6 +500,39 @@ void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
 	_leave(" = %d", ret);
 }
 
+/*
+ * Log remote abort codes that indicate that we have a protocol disagreement
+ * with the server.
+ */
+static void afs_log_error(struct afs_call *call, s32 remote_abort)
+{
+	static int max = 0;
+	const char *msg;
+	int m;
+
+	switch (remote_abort) {
+	case RX_EOF:		 msg = "unexpected EOF";	break;
+	case RXGEN_CC_MARSHAL:	 msg = "client marshalling";	break;
+	case RXGEN_CC_UNMARSHAL: msg = "client unmarshalling";	break;
+	case RXGEN_SS_MARSHAL:	 msg = "server marshalling";	break;
+	case RXGEN_SS_UNMARSHAL: msg = "server unmarshalling";	break;
+	case RXGEN_DECODE:	 msg = "opcode decode";		break;
+	case RXGEN_SS_XDRFREE:	 msg = "server XDR cleanup";	break;
+	case RXGEN_CC_XDRFREE:	 msg = "client XDR cleanup";	break;
+	case -32:		 msg = "insufficient data";	break;
+	default:
+		return;
+	}
+
+	m = max;
+	if (m < 3) {
+		max = m + 1;
+		pr_notice("kAFS: Peer reported %s failure on %s [%pISp]\n",
+			  msg, call->type->name,
+			  &call->alist->addrs[call->addr_ix].transport);
+	}
+}
+
 /*
  * deliver messages to a call
  */
@@ -563,6 +596,7 @@ static void afs_deliver_to_call(struct afs_call *call)
 			goto out;
 		case -ECONNABORTED:
 			ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
+			afs_log_error(call, call->abort_code);
 			goto done;
 		case -ENOTSUPP:
 			abort_code = RXGEN_OPCODE;