From patchwork Fri May 11 15:19:00 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Scott Mayhew X-Patchwork-Id: 10394597 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 551D5601A0 for ; Fri, 11 May 2018 15:19:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 479B928F38 for ; Fri, 11 May 2018 15:19:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3BBA128F3A; Fri, 11 May 2018 15:19:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A3AB728F39 for ; Fri, 11 May 2018 15:19:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750876AbeEKPTB (ORCPT ); Fri, 11 May 2018 11:19:01 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:48264 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750726AbeEKPTA (ORCPT ); Fri, 11 May 2018 11:19:00 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6DCCD7D65F; Fri, 11 May 2018 15:19:00 +0000 (UTC) Received: from coeurl.usersys.redhat.com (ovpn-120-212.rdu2.redhat.com [10.10.120.212]) by smtp.corp.redhat.com (Postfix) with ESMTP id 56BB82026DFD; Fri, 11 May 2018 15:19:00 +0000 (UTC) Received: by coeurl.usersys.redhat.com (Postfix, from userid 1000) id 0A7F32045A; Fri, 11 May 2018 11:19:00 -0400 (EDT) From: Scott Mayhew To: bfields@fieldses.org, jlayton@kernel.org Cc: linux-nfs@vger.kernel.org Subject: [PATCH v3] nfsd: make nfsd4_scsi_identify_device retry with a larger buffer Date: Fri, 11 May 2018 11:19:00 -0400 Message-Id: <20180511151900.16454-1-smayhew@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Fri, 11 May 2018 15:19:00 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Fri, 11 May 2018 15:19:00 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'smayhew@redhat.com' RCPT:'' Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP nfsd4_scsi_identify_device() performs a single IDENTIFY command for the device identification VPD page using a small buffer. If the reply is too large to fit in this buffer then the GETDEVICEINFO reply will not contain any info for the SCSI volume aside from the registration key. This can happen for example if the device has descriptors using long SCSI name strings. When the initial reply from the device indicates a larger buffer is needed, retry once using the page length from that reply. Signed-off-by: Scott Mayhew Reviewed-by: Christoph Hellwig --- fs/nfsd/blocklayout.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) Changes since v2: - removed unnecessary else clause after goto Changes since v1: - added comment explaining the initial and max buffer lengths - changed the len-to-maxlen comparison from "<" to "<=" diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c index 70b8bf7..a066134 100644 --- a/fs/nfsd/blocklayout.c +++ b/fs/nfsd/blocklayout.c @@ -216,13 +216,21 @@ static int nfsd4_scsi_identify_device(struct block_device *bdev, struct request_queue *q = bdev->bd_disk->queue; struct request *rq; struct scsi_request *req; - size_t bufflen = 252, len, id_len; + /* + * The allocation length (passed in bytes 3 and 4 of the INQUIRY + * command descriptor block) specifies the number of bytes that have + * been allocated for the data-in buffer. + * 252 is the highest one-byte value that is a multiple of 4. + * 65532 is the highest two-byte value that is a multiple of 4. + */ + size_t bufflen = 252, maxlen = 65532, len, id_len; u8 *buf, *d, type, assoc; - int error; + int retries = 1, error; if (WARN_ON_ONCE(!blk_queue_scsi_passthrough(q))) return -EINVAL; +again: buf = kzalloc(bufflen, GFP_KERNEL); if (!buf) return -ENOMEM; @@ -255,6 +263,12 @@ static int nfsd4_scsi_identify_device(struct block_device *bdev, len = (buf[2] << 8) + buf[3] + 4; if (len > bufflen) { + if (len <= maxlen && retries--) { + blk_put_request(rq); + kfree(buf); + bufflen = len; + goto again; + } pr_err("pNFS: INQUIRY 0x83 response invalid (len = %zd)\n", len); goto out_put_request;