From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx4+N8wE111IjS78Lbw/SOa/arvyTdSeJ5nzk+/l/RYpwjszDsSgVvLsttfz4u4qDIf1VUOXN ARC-Seal: i=1; a=rsa-sha256; t=1524405486; cv=none; d=google.com; s=arc-20160816; b=rkB5gBo0R7T3qqJk/IYBD0Le9t5hN+UTUFAHmdUJvbf9PNvl81LHtfIuDB204JFD32 9Ez3iTvorL9lx4Ow07FWR2Kx8sB7Y8Fm+V3tqewRz15A93Tk25rm1FDy3MQrVrydBhdK mmCyZCCrwdkSTfwvK6sIm1gHWWodB5HIST0yJeHp5OWDcgfMq/gImrsIXMA4DvFlbQVa R20aJ2tbrrVJHKuwGuiJtZMmGA+XLwzwujyowtJ8XMYPIPo1ukxAp4Pt3KQaAo6Y3Dro Bixn4DCCegGyoXIFTeHIjOf4nGRNSLcRXjqi6abNFvejTRkwZxLoOT+J+PcnfCPwTOfI ruLw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=iPhYAjQHvwI5dnsSPFFmfiO/kEMS9oadGxAWh5YIlbQ=; b=hLpi7yNNfIRLZAyINTryCS4rppjoXNvppmXSUwOxhw6+AXjBO+Qq/YQoFsBc3qyd/T c5NUoa2clVc/wLZOMIfCi/qbIR3D9c7InVJPSyvXdmM5091/QFGxKjbL27OvObux7QWK gzfM8VBLaIAOi9kbSCKiUxHz7e8/k6pH0Zeqpx1Lqt4QLDbYze70W9xZ4j8TGJoXhjIg tNtzRYuLJQq9izEzFrnvT1WOHBv9Bj/oC/6NOJu5oKqv8/5Rzgc2doZqnulwesneQvts Sixa1ortC83XtoRKYe7KzQAjNCwH3WsPBF8ZcHl+CaywmCt/znxtbYLl1HvFJvcTZQtW ioLQ== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Long Li , Steve French , Ronnie Sahlberg Subject: [PATCH 4.16 048/196] cifs: smbd: avoid reconnect lockup Date: Sun, 22 Apr 2018 15:51:08 +0200 Message-Id: <20180422135106.570822475@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180422135104.278511750@linuxfoundation.org> References: <20180422135104.278511750@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1598455007640247372?= X-GMAIL-MSGID: =?utf-8?q?1598455007640247372?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Long Li commit 48f238a79f668f8ff013024d83010de551833d7f upstream. During transport reconnect, other processes may have registered memory and blocked on transport. This creates a deadlock situation because the transport resources can't be freed, and reconnect is blocked. Fix this by returning to upper layer on timeout. Before returning, transport status is set to reconnecting so other processes will release memory registration resources. Upper layer will retry the reconnect. This is not in fast I/O path so setting the timeout to 5 seconds. Signed-off-by: Long Li Signed-off-by: Steve French Reviewed-by: Ronnie Sahlberg CC: Stable Signed-off-by: Greg Kroah-Hartman --- fs/cifs/smbdirect.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) --- a/fs/cifs/smbdirect.c +++ b/fs/cifs/smbdirect.c @@ -1498,8 +1498,8 @@ int smbd_reconnect(struct TCP_Server_Inf log_rdma_event(INFO, "reconnecting rdma session\n"); if (!server->smbd_conn) { - log_rdma_event(ERR, "rdma session already destroyed\n"); - return -EINVAL; + log_rdma_event(INFO, "rdma session already destroyed\n"); + goto create_conn; } /* @@ -1512,15 +1512,19 @@ int smbd_reconnect(struct TCP_Server_Inf } /* wait until the transport is destroyed */ - wait_event(server->smbd_conn->wait_destroy, - server->smbd_conn->transport_status == SMBD_DESTROYED); + if (!wait_event_timeout(server->smbd_conn->wait_destroy, + server->smbd_conn->transport_status == SMBD_DESTROYED, 5*HZ)) + return -EAGAIN; destroy_workqueue(server->smbd_conn->workqueue); kfree(server->smbd_conn); +create_conn: log_rdma_event(INFO, "creating rdma session\n"); server->smbd_conn = smbd_get_connection( server, (struct sockaddr *) &server->dstaddr); + log_rdma_event(INFO, "created rdma session info=%p\n", + server->smbd_conn); return server->smbd_conn ? 0 : -ENOENT; }