From patchwork Fri Oct 23 20:57:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Disseldorp X-Patchwork-Id: 11854537 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E06CC1580 for ; Fri, 23 Oct 2020 20:57:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA0ED20936 for ; Fri, 23 Oct 2020 20:57:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756459AbgJWU5g (ORCPT ); Fri, 23 Oct 2020 16:57:36 -0400 Received: from mx2.suse.de ([195.135.220.15]:42012 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755550AbgJWU5g (ORCPT ); Fri, 23 Oct 2020 16:57:36 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 4F436B24C; Fri, 23 Oct 2020 20:57:34 +0000 (UTC) From: David Disseldorp To: target-devel@vger.kernel.org Cc: linux-scsi@vger.kernel.org, David Disseldorp Subject: [PATCH 5/5] scsi: target: return COMPARE AND WRITE miscompare offsets Date: Fri, 23 Oct 2020 22:57:23 +0200 Message-Id: <20201023205723.17880-6-ddiss@suse.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201023205723.17880-1-ddiss@suse.de> References: <20201023205723.17880-1-ddiss@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org SBC-4 r15 5.3 COMPARE AND WRITE command states: if the compare operation does not indicate a match, then terminate the command with CHECK CONDITION status with the sense key set to MISCOMPARE and the additional sense code set to MISCOMPARE DURING VERIFY OPERATION. In the sense data (see 4.18 and SPC-5) the offset from the start of the Data-Out Buffer to the first byte of data that was not equal shall be reported in the INFORMATION field. This change implements the missing logic to report the miscompare offset in the sense data INFORMATION field. Signed-off-by: David Disseldorp --- drivers/target/target_core_sbc.c | 35 ++++++++++++++++++-------- drivers/target/target_core_transport.c | 1 + 2 files changed, 26 insertions(+), 10 deletions(-) diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index 79216d0355e7..e40359e45726 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -435,13 +435,13 @@ static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success, } /* - * compare @cmp_len bytes of @read_sgl with @cmp_sgl. On miscompare return - * TCM_MISCOMPARE_VERIFY. + * compare @cmp_len bytes of @read_sgl with @cmp_sgl. On miscompare, fill + * @miscmp_off and return TCM_MISCOMPARE_VERIFY. */ static sense_reason_t compare_and_write_do_cmp(struct scatterlist *read_sgl, unsigned int read_nents, struct scatterlist *cmp_sgl, unsigned int cmp_nents, - unsigned int cmp_len) + unsigned int cmp_len, unsigned int *miscmp_off) { unsigned char *buf = NULL; struct scatterlist *sg; @@ -468,17 +468,20 @@ compare_and_write_do_cmp(struct scatterlist *read_sgl, unsigned int read_nents, */ offset = 0; for_each_sg(read_sgl, sg, read_nents, i) { + unsigned int i; unsigned int len = min(sg->length, cmp_len); unsigned char *addr = kmap_atomic(sg_page(sg)); - if (memcmp(addr, buf + offset, len)) { - pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n", - addr, buf + offset); - kunmap_atomic(addr); + for (i = 0; i < len && addr[i] == buf[offset + i]; i++); + + kunmap_atomic(addr); + if (i < len) { + *miscmp_off = offset + i; + pr_warn("Detected MISCOMPARE at offset %u\n", + *miscmp_off); ret = TCM_MISCOMPARE_VERIFY; goto out; } - kunmap_atomic(addr); offset += len; cmp_len -= len; @@ -503,6 +506,7 @@ static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool succes unsigned int nlbas = cmd->t_task_nolb; unsigned int block_size = dev->dev_attrib.block_size; unsigned int compare_len = (nlbas * block_size); + unsigned int miscmp_off = 0; sense_reason_t ret = TCM_NO_SENSE; int i; @@ -534,8 +538,19 @@ static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool succes cmd->t_bidi_data_nents, cmd->t_data_sg, cmd->t_data_nents, - compare_len); - if (ret) + compare_len, + &miscmp_off); + if (ret == TCM_MISCOMPARE_VERIFY) { + /* + * SBC-4 r15: 5.3 COMPARE AND WRITE command + * In the sense data (see 4.18 and SPC-5) the offset from the + * start of the Data-Out Buffer to the first byte of data that + * was not equal shall be reported in the INFORMATION field. + */ + WARN_ON(miscmp_off >= compare_len); + cmd->sense_info = miscmp_off; + goto out; + } else if (ret) goto out; if (sg_alloc_table(&write_tbl, cmd->t_data_nents, GFP_KERNEL) < 0) { diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index c6f45c12d564..693ed3fe4388 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -3196,6 +3196,7 @@ static const struct sense_detail sense_detail_table[] = { .key = MISCOMPARE, .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */ .ascq = 0x00, + .add_sense_info = true, }, [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = { .key = ABORTED_COMMAND,