From patchwork Fri Jun 15 18:23:37 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhu Lingshan X-Patchwork-Id: 10467335 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 9B433601C2 for ; Fri, 15 Jun 2018 18:25:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8B7E828E3D for ; Fri, 15 Jun 2018 18:25:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7DDC728E41; Fri, 15 Jun 2018 18:25:40 +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 0586B28E3B for ; Fri, 15 Jun 2018 18:25:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756444AbeFOSZi (ORCPT ); Fri, 15 Jun 2018 14:25:38 -0400 Received: from smtp2.provo.novell.com ([137.65.250.81]:33609 "EHLO smtp2.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756532AbeFOSZb (ORCPT ); Fri, 15 Jun 2018 14:25:31 -0400 Received: from vstart.localdomain (prv-ext-foundry1int.gns.novell.com [137.65.251.240]) by smtp2.provo.novell.com with ESMTP (TLS encrypted); Fri, 15 Jun 2018 12:25:24 -0600 From: Zhu Lingshan To: target-devel@vger.kernel.org, linux-scsi@vger.kernel.org, nab@linux-iscsi.org, mchristi@redhat.com, martin.petersen@oracle.com Cc: hare@suse.de, lduncan@suse.com, ddiss@suse.de, lszhu@suse.de, Zhu Lingshan Subject: [PATCH 28/33] TCMU PR: implementation of PR Reserve for TCMU Date: Sat, 16 Jun 2018 02:23:37 +0800 Message-Id: <20180615182342.6239-28-lszhu@suse.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180615182342.6239-1-lszhu@suse.com> References: <20180615182342.6239-1-lszhu@suse.com> Sender: target-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: target-devel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch added functions to handle Persistent Reservation Reserve against TCMU devices. Function tcm_rbd_pr_info_rsv_set() will help set PR information in struct tcmu_pr_info, function tcmu_execute_pr_reserve() will help handle PR reserve requests against TCMU devices. Signed-off-by: Zhu Lingshan --- drivers/target/target_core_user.c | 162 ++++++++++++++++++++++++++++++ 1 file changed, 162 insertions(+) diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index bde325888477..8390b1d37873 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -2970,6 +2970,167 @@ static int is_passthrough_pr_supportive_dev(struct tcmu_dev *udev) return ret; } + + +static int tcm_rbd_pr_info_rsv_set(struct tcmu_pr_info *pr_info, u64 key, + char *nexus, int type) +{ + struct tcmu_pr_rsv *rsv; + + if (pr_info->rsv != NULL) { + pr_debug("rsv_set called with existing reservation\n"); + return -EINVAL; + } + + rsv = kmalloc(sizeof(*rsv), GFP_KERNEL); + if (!rsv) + return -ENOMEM; + + rsv->key = key; + strlcpy(rsv->it_nexus, nexus, ARRAY_SIZE(rsv->it_nexus)); + rsv->type = type; + pr_info->rsv = rsv; + pr_debug("pr_info rsv set: 0x%llx %s %d\n", key, nexus, type); + + return 0; +} + + +static sense_reason_t +tcmu_execute_pr_reserve(struct se_cmd *cmd, int type, u64 key) +{ + struct se_device *dev = cmd->se_dev; + struct tcmu_dev *udev = TCMU_DEV(dev); + char nexus_buf[TCMU_PR_IT_NEXUS_MAXLEN]; + struct tcmu_pr_info *pr_info; + struct tcmu_pr_reg *reg; + struct tcmu_pr_reg *existing_reg; + char *pr_xattr; + int pr_xattr_len; + int rc; + sense_reason_t ret; + int retries = 0; + + udev->pr_info.pr_info_buf = kzalloc(TCMU_PR_INFO_XATTR_MAX_SIZE, + GFP_KERNEL); + if (!udev->pr_info.pr_info_buf) + return TCM_OUT_OF_RESOURCES; + + if (!cmd->se_sess || !cmd->se_lun) { + pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n"); + ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + goto err_info_free; + } + + rc = tcmu_gen_it_nexus(cmd->se_sess, nexus_buf, + ARRAY_SIZE(nexus_buf)); + if (rc < 0) { + ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + goto err_info_free; + } + +retry: + pr_info = NULL; + pr_xattr = NULL; + pr_xattr_len = 0; + rc = tcmu_pr_info_get(udev, &pr_info, &pr_xattr, + &pr_xattr_len); + if (rc < 0) { + /* existing registration required for reservation */ + pr_err("failed to obtain PR info\n"); + ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + goto err_info_free; + } + + /* check for an existing registration */ + existing_reg = NULL; + list_for_each_entry(reg, &pr_info->regs, regs_node) { + if (!strncmp(reg->it_nexus, nexus_buf, + ARRAY_SIZE(nexus_buf))) { + pr_debug("found existing PR reg for %s\n", + nexus_buf); + existing_reg = reg; + break; + } + } + + if (!existing_reg) { + pr_err("SPC-3 PR: Unable to locate registration for RESERVE\n"); + ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + goto err_info_free; + } + + if (key != existing_reg->key) { + pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016llx ", key); + pr_err("does not match existing SA REGISTER res_key: "); + pr_err("0x%016llx\n", existing_reg->key); + ret = TCM_RESERVATION_CONFLICT; + goto err_info_free; + } + + if (pr_info->rsv) { + if (!tcmu_is_rsv_holder(pr_info->rsv, existing_reg, NULL)) { + pr_err("SPC-3 PR: Attempted RESERVE from %s while ", + nexus_buf); + pr_err("reservation already held by %s, ", + pr_info->rsv->it_nexus); + pr_err("returning RESERVATION_CONFLICT\n"); + ret = TCM_RESERVATION_CONFLICT; + goto err_info_free; + } + + if (pr_info->rsv->type != type) { + /* scope already checked */ + pr_err("SPC-3 PR: Attempted RESERVE from %s ", + existing_reg->it_nexus); + pr_err("trying to change TYPE, "); + pr_err("returning RESERVATION_CONFLICT\n"); + ret = TCM_RESERVATION_CONFLICT; + goto err_info_free; + } + + pr_debug("reserve matches existing reservation, "); + pr_debug("nothing to do\n"); + goto done; + } + + /* new reservation */ + rc = tcm_rbd_pr_info_rsv_set(pr_info, key, nexus_buf, type); + if (rc < 0) { + pr_err("failed to set PR info reservation\n"); + ret = TCM_OUT_OF_RESOURCES; + goto err_info_free; + } + + rc = tcmu_pr_info_replace(udev, pr_xattr, pr_xattr_len, + pr_info); + if (rc == -ECANCELED) { + pr_warn("atomic PR info update failed due to parallel "); + pr_warn("change, expected(%d) %s. Retrying...\n", + pr_xattr_len, pr_xattr); + retries++; + if (retries <= TCMU_PR_REG_MAX_RETRIES) { + tcmu_pr_info_free(pr_info); + kfree(pr_xattr); + goto retry; + } + } + if (rc < 0) { + pr_err("atomic PR info update failed: %d\n", rc); + ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + goto err_info_free; + } + +done: + ret = TCM_NO_SENSE; +err_info_free: + tcmu_pr_info_free(pr_info); + kfree(pr_xattr); + kfree(udev->pr_info.pr_info_buf); + return ret; +} + + static int tcmu_configure_device(struct se_device *dev) { struct tcmu_dev *udev = TCMU_DEV(dev); @@ -3724,6 +3885,7 @@ static struct configfs_attribute *tcmu_action_attrs[] = { static struct target_pr_ops tcmu_pr_ops = { .pr_read_keys = tcmu_execute_pr_read_keys, .pr_register = tcmu_execute_pr_register, + .pr_reserve = tcmu_execute_pr_reserve, }; static struct target_backend_ops tcmu_ops = {