This patch added a function tcmu_execute_pr_clear() which can help perform Persistent Reservation clear operation, this means clear reservations and registrations.
Signed-off-by: Zhu Lingshan <[email protected]> --- drivers/target/target_core_user.c | 108 ++++++++++++++++++++++++++++++ 1 file changed, 108 insertions(+) diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 532401a9f433..c8d0ea330984 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -3251,6 +3251,114 @@ tcmu_execute_pr_release(struct se_cmd *cmd, int type, u64 key) } +static sense_reason_t +tcmu_execute_pr_clear(struct se_cmd *cmd, 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 clear */ + 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 CLEAR\n"); + ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + goto err_info_free; + } + + if (key != existing_reg->key) { + pr_err("SPC-3 PR CLEAR: Received res_key: 0x%016llx ", key); + pr_err("does not match existing SA res_key: 0x%016llx\n", + existing_reg->key); + ret = TCM_RESERVATION_CONFLICT; + goto err_info_free; + } + + /* release the persistent reservation, if any */ + if (pr_info->rsv) + tcmu_pr_info_rsv_clear(pr_info); + + /* remove all registrations */ + list_for_each_entry_safe(existing_reg, reg, &pr_info->regs, regs_node) { + tcmu_pr_info_clear_reg(pr_info, existing_reg); + } + + /* PR generation must be incremented on successful CLEAR */ + pr_info->gen++; + + 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; + } + + 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); -- 2.17.1
