This patch added a function tcmu_execute_pr_release() to handle SCSI3 Persistent Reservation Release for TCMU devices.
Signed-off-by: Zhu Lingshan <[email protected]> --- drivers/target/target_core_user.c | 119 ++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index e7daa76317bc..532401a9f433 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -3133,6 +3133,124 @@ tcmu_execute_pr_reserve(struct se_cmd *cmd, int type, u64 key) } +static sense_reason_t +tcmu_execute_pr_release(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; + + if (!cmd->se_sess || !cmd->se_lun) { + pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n"); + return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + } + + rc = tcmu_gen_it_nexus(cmd->se_sess, nexus_buf, + ARRAY_SIZE(nexus_buf)); + if (rc < 0) + return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + mutex_lock(&udev->pr_info.pr_info_lock); + udev->pr_info.pr_info_buf = kzalloc(TCMU_PR_INFO_XATTR_MAX_SIZE, + GFP_KERNEL); + +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 release */ + pr_err("failed to obtain PR info\n"); + ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + goto err_info_free; + } + + if (!pr_info->rsv) { + /* no persistent reservation, return GOOD status */ + goto done; + } + + /* 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 RELEASE\n"); + ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + goto err_info_free; + } + + if (!tcmu_is_rsv_holder(pr_info->rsv, existing_reg, NULL)) { + /* registered but not a persistent reservation holder */ + goto done; + } + + if (key != existing_reg->key) { + pr_err("SPC-3 PR RELEASE: 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->type != type) { + pr_err("SPC-3 PR: Attempted RELEASE from %s with different ", + existing_reg->it_nexus); + pr_err("TYPE, returning RESERVATION_CONFLICT\n"); + ret = TCM_RESERVATION_CONFLICT; + goto err_info_free; + } + + /* release the persistent reservation */ + tcmu_pr_info_rsv_clear(pr_info); + + 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); + mutex_unlock(&udev->pr_info.pr_info_lock); + + return ret; +} + + static int tcmu_configure_device(struct se_device *dev) { struct tcmu_dev *udev = TCMU_DEV(dev); @@ -3888,6 +4006,7 @@ 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, + .pr_release = tcmu_execute_pr_release, }; static struct target_backend_ops tcmu_ops = { -- 2.17.1
