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 <lszhu@xxxxxxxx>
---
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
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