From patchwork Sun Jan 2 23:23:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Maciej W. Rozycki" X-Patchwork-Id: 529606 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE3A7C43219 for ; Sun, 2 Jan 2022 23:32:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231152AbiABXc4 (ORCPT ); Sun, 2 Jan 2022 18:32:56 -0500 Received: from angie.orcam.me.uk ([78.133.224.34]:38422 "EHLO angie.orcam.me.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229994AbiABXcz (ORCPT ); Sun, 2 Jan 2022 18:32:55 -0500 X-Greylist: delayed 555 seconds by postgrey-1.27 at vger.kernel.org; Sun, 02 Jan 2022 18:32:55 EST Received: by angie.orcam.me.uk (Postfix, from userid 500) id F3B4C92009D; Mon, 3 Jan 2022 00:23:45 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by angie.orcam.me.uk (Postfix) with ESMTP id EC96192009B; Sun, 2 Jan 2022 23:23:45 +0000 (GMT) Date: Sun, 2 Jan 2022 23:23:45 +0000 (GMT) From: "Maciej W. Rozycki" To: Khalid Aziz , "James E.J. Bottomley" , "Martin K. Petersen" cc: Christoph Hellwig , Nix , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 1/3] scsi: Provide for avoiding trailing allocation length with VPD inquiries In-Reply-To: Message-ID: References: User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Allow SCSI hosts to request avoiding trailing allocation length with VPD inquiries, and use the mechanism to work around an issue with at least some BusLogic MultiMaster host bus adapters and observed with the BT-958 model specifically where issuing commands that return less data than provided for causes fatal failures: scsi host0: BusLogic BT-958 scsi 0:0:0:0: Direct-Access IBM DDYS-T18350M SA5A PQ: 0 ANSI: 3 scsi 0:0:1:0: Direct-Access SEAGATE ST336607LW 0006 PQ: 0 ANSI: 3 scsi 0:0:5:0: Direct-Access IOMEGA ZIP 100 E.08 PQ: 0 ANSI: 2 sd 0:0:1:0: [sdb] 71687372 512-byte logical blocks: (36.7 GB/34.2 GiB) sd 0:0:0:0: [sda] 35843670 512-byte logical blocks: (18.4 GB/17.1 GiB) sd 0:0:1:0: [sdb] Write Protect is off sd 0:0:5:0: [sdc] Attached SCSI removable disk sd 0:0:0:0: [sda] Write Protect is off sd 0:0:1:0: [sdb] Write cache: enabled, read cache: enabled, supports DPO and FUA sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA scsi0: *** BusLogic BT-958 Initialized Successfully *** scsi0: *** BusLogic BT-958 Initialized Successfully *** scsi0: *** BusLogic BT-958 Initialized Successfully *** scsi0: *** BusLogic BT-958 Initialized Successfully *** sd 0:0:0:0: Device offlined - not ready after error recovery sd 0:0:1:0: Device offlined - not ready after error recovery sd 0:0:0:0: scsi_vpd_inquiry(0): buf[64] => -5 sd 0:0:1:0: scsi_vpd_inquiry(0): buf[64] => -5 sd 0:0:0:0: [sda] Attached SCSI disk sd 0:0:1:0: [sdb] Attached SCSI disk VFS: Cannot open root device "802" or unknown-block(8,2): error -6 (here and elsewhere reported with some instrumentation added so as to show the causing requests and with irrelevant messages filtered out). As already observed back in 2003 and worked around in smartmontools at least some versions of BusLogic firmware such as 5.07B are unable to handle such commands, but it is possible to request enough data first for the length of the data response to be determined and then reissue the same command with the allocation length matching the response expected. It is what this change does on a host-by-host basis, by providing a flag for individual HBA drivers to enable this workaround, currently set by the BusLogic driver, and then issuing these double calls as requested, which then produce results as expected: sd 0:0:1:0: [sdb] Write cache: enabled, read cache: enabled, supports DPO and FUA sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA sd 0:0:1:0: scsi_vpd_inquiry(0): buf[64] => 13 sd 0:0:0:0: scsi_vpd_inquiry(0): buf[64] => 7 sdb: sdb1 sdb2 sd 0:0:1:0: scsi_vpd_inquiry(0): buf[64] => 13 sd 0:0:1:0: [sdb] Attached SCSI disk sda: sda1 sda2 sda3 sda4 < sda5 sda6 sda7 sda8 sda9 sda10 > sd 0:0:0:0: scsi_vpd_inquiry(0): buf[64] => 7 sd 0:0:0:0: [sda] Attached SCSI disk EXT4-fs (sda2): mounting ext2 file system using the ext4 subsystem EXT4-fs (sda2): mounted filesystem without journal. Opts: (null). Quota mode: disabled. VFS: Mounted root (ext2 filesystem) readonly on device 8:2. The minimum request size of 4 for the repeated call has been chosen to match one required for a successful return from `scsi_vpd_inquiry'. Interestingly enough it has only started triggering with not so recent commit af73623f5f10 ("[SCSI] sd: Reduce buffer size for vpd request") that decreased the allocation length for the originating request from 512 down to 64. Previously the request was rejected outright by the respective targets as invalid and therefore did not trigger the issue with MultiMaster firmware as that would only happen for a command that succeeded but produced less data than provided for: scsi0: CCB #36 Target 0: Result 2 Host Adapter Status 00 Target Status 02 scsi0: CDB 12 01 00 02 00 00 scsi0: Sense 70 00 05 00 00 00 00 18 00 00 00 00 24 00 00 C0 00 03 00 [...] sd 0:0:0:0: scsi_vpd_inquiry(0): buf[512] => -5 scsi0: CCB #37 Target 1: Result 2 Host Adapter Status 00 Target Status 02 scsi0: CDB 12 01 00 02 00 00 scsi0: Sense 70 00 05 00 00 00 00 0A 00 00 00 00 24 00 01 C9 00 03 00 [...] sd 0:0:1:0: scsi_vpd_inquiry(0): buf[512] => -5 (here with the buffer size set back to 512, the `BusLogic=TraceErrors' parameter and trailing sense data zeros trimmed for brevity). Note the sense key of 0x5 returned denoting an illegal request even for page 0. Signed-off-by: Maciej W. Rozycki Fixes: 881a256d84e6 ("[SCSI] Add VPD helper") Cc: stable@vger.kernel.org # v2.6.30+ --- No changes from v2. No changes from v1. --- drivers/scsi/BusLogic.c | 1 + drivers/scsi/scsi.c | 24 +++++++++++++++++++++--- include/scsi/scsi_host.h | 3 +++ 3 files changed, 25 insertions(+), 3 deletions(-) linux-buslogic-get-vpd-page-buffer.diff Index: linux-macro/drivers/scsi/BusLogic.c =================================================================== --- linux-macro.orig/drivers/scsi/BusLogic.c +++ linux-macro/drivers/scsi/BusLogic.c @@ -2149,6 +2149,7 @@ static void __init blogic_inithoststruct host->can_queue = adapter->drvr_qdepth; host->sg_tablesize = adapter->drvr_sglimit; host->cmd_per_lun = adapter->untag_qdepth; + host->no_trailing_allocation_length = true; } /* Index: linux-macro/drivers/scsi/scsi.c =================================================================== --- linux-macro.orig/drivers/scsi/scsi.c +++ linux-macro/drivers/scsi/scsi.c @@ -344,8 +344,19 @@ int scsi_get_vpd_page(struct scsi_device if (sdev->skip_vpd_pages) goto fail; - /* Ask for all the pages supported by this device */ - result = scsi_vpd_inquiry(sdev, buf, 0, buf_len); + /* + * Ask for all the pages supported by this device. Determine the + * actual data length first if so required by the host, e.g. + * BusLogic BT-958. + */ + if (sdev->host->no_trailing_allocation_length) { + result = scsi_vpd_inquiry(sdev, buf, 0, min(4, buf_len)); + if (result < 4) + goto fail; + } else { + result = buf_len; + } + result = scsi_vpd_inquiry(sdev, buf, 0, min(result, buf_len)); if (result < 4) goto fail; @@ -364,7 +375,14 @@ int scsi_get_vpd_page(struct scsi_device goto fail; found: - result = scsi_vpd_inquiry(sdev, buf, page, buf_len); + if (sdev->host->no_trailing_allocation_length) { + result = scsi_vpd_inquiry(sdev, buf, page, min(4, buf_len)); + if (result < 4) + goto fail; + } else { + result = buf_len; + } + result = scsi_vpd_inquiry(sdev, buf, page, min(result, buf_len)); if (result < 0) goto fail; Index: linux-macro/include/scsi/scsi_host.h =================================================================== --- linux-macro.orig/include/scsi/scsi_host.h +++ linux-macro/include/scsi/scsi_host.h @@ -659,6 +659,9 @@ struct Scsi_Host { /* The transport requires the LUN bits NOT to be stored in CDB[1] */ unsigned no_scsi2_lun_in_cdb:1; + /* Allocation length must not exceed actual data length. */ + unsigned no_trailing_allocation_length:1; + /* * Optional work queue to be utilized by the transport */ From patchwork Sun Jan 2 23:23:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Maciej W. Rozycki" X-Patchwork-Id: 529605 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7DAE0C433EF for ; Sun, 2 Jan 2022 23:33:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231168AbiABXc6 (ORCPT ); Sun, 2 Jan 2022 18:32:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41950 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231140AbiABXcz (ORCPT ); Sun, 2 Jan 2022 18:32:55 -0500 Received: from angie.orcam.me.uk (angie.orcam.me.uk [IPv6:2001:4190:8020::34]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 7EA04C061761; Sun, 2 Jan 2022 15:32:54 -0800 (PST) Received: by angie.orcam.me.uk (Postfix, from userid 500) id F3BE192009E; Mon, 3 Jan 2022 00:23:51 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by angie.orcam.me.uk (Postfix) with ESMTP id ECFF792009B; Sun, 2 Jan 2022 23:23:51 +0000 (GMT) Date: Sun, 2 Jan 2022 23:23:51 +0000 (GMT) From: "Maciej W. Rozycki" To: Khalid Aziz , "James E.J. Bottomley" , "Martin K. Petersen" cc: Christoph Hellwig , Nix , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 2/3] scsi: Avoid using reserved length byte with VPD inquiries In-Reply-To: Message-ID: References: User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org As discussed in a previous workaround for a BusLogic BT-958 problem with VPD inquiries with an allocation length of 512 bytes as requested before commit af73623f5f10 ("[SCSI] sd: Reduce buffer size for vpd request") are rejected outright as invalid at least by some SCSI target devices as are any requests with a non-zero value in byte #3: scsi host0: BusLogic BT-958 scsi 0:0:0:0: Direct-Access IBM DDYS-T18350M SA5A PQ: 0 ANSI: 3 scsi 0:0:1:0: Direct-Access SEAGATE ST336607LW 0006 PQ: 0 ANSI: 3 scsi 0:0:5:0: Direct-Access IOMEGA ZIP 100 E.08 PQ: 0 ANSI: 2 [...] scsi0: CCB #36 Target 0: Result 2 Host Adapter Status 00 Target Status 02 scsi0: CDB 12 01 00 01 06 00 scsi0: Sense 70 00 05 00 00 00 00 18 00 00 00 00 24 00 00 C0 00 03 00 [...] sd 0:0:0:0: scsi_vpd_inquiry(0): buf[262] => -5 scsi0: CCB #37 Target 1: Result 2 Host Adapter Status 00 Target Status 02 scsi0: CDB 12 01 00 01 06 00 scsi0: Sense 70 00 05 00 00 00 00 0A 00 00 00 00 24 00 01 C8 00 03 00 [...] sd 0:0:1:0: scsi_vpd_inquiry(0): buf[262] => -5 (here with the buffer size tweaked to 262 so as to verify if a bit in byte #3 of the INQUIRY command is ignored and the length of 6 assumed or tripped over, the `BusLogic=TraceErrors' parameter and trailing sense data zeros trimmed for brevity). Note the sense key of 0x5 denoting an illegal request. For the record with the buffer size of 6 requests for page 0 complete successfully and due to page truncation `scsi_get_vpd_page' proceeds with an attempt to get inexistent page 0x89: sd 0:0:0:0: scsi_vpd_inquiry(0): buf[6] => 7 sd 0:0:1:0: scsi_vpd_inquiry(0): buf[6] => 13 sd 0:0:0:0: scsi_vpd_inquiry(137): buf[6] => -5 sd 0:0:1:0: scsi_vpd_inquiry(137): buf[6] => -5 Upon a further investigation it has turned out at least SCSI-2 considers byte #3 of the INQUIRY command[1] as well as byte #2 of vital product data pages[2] reserved and expects a value of zero there. The response from SCSI-3 devices shown above indicates the same expectation. Therefore it is unsafe to issue INQUIRY requests unconditionally with the allocation length beyond 255, as they may fail with an otherwise supported request or cause undefined behaviour with some hardware. Now we actually never do that as all our callers of `scsi_get_vpd_page' either hardcode the buffer size to a value between 8 and 255 or calculate it from a structure size, of which the largest is: struct c2_inquiry { u8 peripheral_info; /* 0 1 */ u8 page_code; /* 1 1 */ u8 reserved1; /* 2 1 */ u8 page_len; /* 3 1 */ u8 page_id[4]; /* 4 4 */ u8 sw_version[3]; /* 8 3 */ u8 sw_date[3]; /* 11 3 */ u8 features_enabled; /* 14 1 */ u8 max_lun_supported; /* 15 1 */ u8 partitions[239]; /* 16 239 */ /* size: 255, cachelines: 2, members: 10 */ /* last cacheline: 127 bytes */ }; As from commit b3ae8780b429 ("[SCSI] Add EVPD page 0x83 and 0x80 to sysfs") we now also have the SCSI_VPD_PG_LEN macro that reflects the limitation. However for the sake of a possible future requirement to support VPD pages that do have a length exceeding 255 bytes and now that the danger of using the formerly reserved byte #3 of the INQUIRY command has been identified execute calls to `scsi_get_vpd_page' with a request size exceeding 255 bytes in two stages, by determining the actual length of data to be returned first and only then issuing the intended request for full data. References: [1] "Information technology - Small Computer System Interface - 2", WORKING DRAFT, X3T9.2, Project 375D, Revision 10L, 7-SEP-93, Section 8.2.5 "INQUIRY command", pp.104-108 [2] same, Section 8.3.4 "Vital product data parameters", pp.154-159 Signed-off-by: Maciej W. Rozycki Fixes: 881a256d84e6 ("[SCSI] Add VPD helper") --- No changes from v2. No changes from v1. --- drivers/scsi/scsi.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) linux-scsi-vpd-inquiry-buffer.diff Index: linux-macro/drivers/scsi/scsi.c =================================================================== --- linux-macro.orig/drivers/scsi/scsi.c +++ linux-macro/drivers/scsi/scsi.c @@ -346,10 +346,15 @@ int scsi_get_vpd_page(struct scsi_device /* * Ask for all the pages supported by this device. Determine the - * actual data length first if so required by the host, e.g. - * BusLogic BT-958. + * actual data length first if the length requested is beyond 255 + * bytes as the high order length byte used to be reserved with + * older SCSI standard revisions and a non-zero value there may + * cause either such an INQUIRY command to be rejected by a target + * or undefined behaviour to occur. Also do so if so required by + * the host, e.g. BusLogic BT-958. */ - if (sdev->host->no_trailing_allocation_length) { + if (buf_len > SCSI_VPD_PG_LEN || + sdev->host->no_trailing_allocation_length) { result = scsi_vpd_inquiry(sdev, buf, 0, min(4, buf_len)); if (result < 4) goto fail; @@ -375,7 +380,8 @@ int scsi_get_vpd_page(struct scsi_device goto fail; found: - if (sdev->host->no_trailing_allocation_length) { + if (buf_len > SCSI_VPD_PG_LEN || + sdev->host->no_trailing_allocation_length) { result = scsi_vpd_inquiry(sdev, buf, page, min(4, buf_len)); if (result < 4) goto fail; From patchwork Sun Jan 2 23:23:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Maciej W. Rozycki" X-Patchwork-Id: 529728 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 13544C433F5 for ; Sun, 2 Jan 2022 23:33:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231162AbiABXc6 (ORCPT ); Sun, 2 Jan 2022 18:32:58 -0500 Received: from angie.orcam.me.uk ([78.133.224.34]:38430 "EHLO angie.orcam.me.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230115AbiABXcz (ORCPT ); Sun, 2 Jan 2022 18:32:55 -0500 Received: by angie.orcam.me.uk (Postfix, from userid 500) id 6D8829200B3; Mon, 3 Jan 2022 00:23:57 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by angie.orcam.me.uk (Postfix) with ESMTP id 69AB092009B; Sun, 2 Jan 2022 23:23:57 +0000 (GMT) Date: Sun, 2 Jan 2022 23:23:57 +0000 (GMT) From: "Maciej W. Rozycki" To: Khalid Aziz , "James E.J. Bottomley" , "Martin K. Petersen" cc: Christoph Hellwig , Nix , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 3/3] scsi: Set allocation length to 255 for ATA Information VPD page In-Reply-To: Message-ID: References: User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Set the allocation length to 255 for the ATA Information VPD page requested in the WRITE SAME handler, so as not to limit information examined by `scsi_get_vpd_page' in the supported vital product data pages unnecessarily. Originally it was thought that Areca hardware may have issues with a valid allocation length supplied for a VPD inquiry, however older SCSI standard revisions[1] consider 255 the maximum length allowed and what has later become the high order byte is considered reserved and must be zero with the INQUIRY command. Therefore it was unnecessary to reduce the amount of data requested from 512 as far down as to 64, arbitrarily chosen, and 255 would as well do. With commit b3ae8780b429 ("[SCSI] Add EVPD page 0x83 and 0x80 to sysfs") we have since got the SCSI_VPD_PG_LEN macro, so use that instead. References: [1] "Information technology - Small Computer System Interface - 2", WORKING DRAFT, X3T9.2, Project 375D, Revision 10L, 7-SEP-93, Section 8.2.5 "INQUIRY command", pp.104-108 Signed-off-by: Maciej W. Rozycki Fixes: af73623f5f10 ("[SCSI] sd: Reduce buffer size for vpd request") Tested-by: Nick Alcock --- Changes from v2: - Add Nick's Tested-by annotation. No changes from v1. --- drivers/scsi/sd.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) linux-scsi-write-same-vpd-buffer.diff Index: linux-macro/drivers/scsi/sd.c =================================================================== --- linux-macro.orig/drivers/scsi/sd.c +++ linux-macro/drivers/scsi/sd.c @@ -3101,16 +3101,13 @@ static void sd_read_write_same(struct sc } if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, INQUIRY) < 0) { - /* too large values might cause issues with arcmsr */ - int vpd_buf_len = 64; - sdev->no_report_opcodes = 1; /* Disable WRITE SAME if REPORT SUPPORTED OPERATION * CODES is unsupported and the device has an ATA * Information VPD page (SAT). */ - if (!scsi_get_vpd_page(sdev, 0x89, buffer, vpd_buf_len)) + if (!scsi_get_vpd_page(sdev, 0x89, buffer, SCSI_VPD_PG_LEN)) sdev->no_write_same = 1; }