This patch add two functions: tcmu_pr_info_rsv_decode() and
tcmu_pr_info_rsv_encode() to handle Persistent Reservations type,
key and IT_Nexus. This patch added a struct tcmu_pr_rsv to
store such information as well.
Signed-off-by: Zhu Lingshan <lszhu@xxxxxxxx>
---
drivers/target/target_core_user.c | 72 +++++++++++++++++++++++++++++++
1 file changed, 72 insertions(+)
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index ef79de7622b6..b72c61d81f98 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -95,6 +95,7 @@
#define TCMU_PR_INFO_XATTR_VERS 1
#define TCMU_PR_INFO_XATTR_VAL_SCSI2_RSV_ABSENT "No SPC-2 Reservation holder"
+#define TCMU_PR_INFO_XATTR_VAL_SCSI3_RSV_ABSENT "No SPC-3 Reservation holder"
#define TCMU_PR_IT_NEXUS_MAXLEN 484
@@ -123,6 +124,22 @@ struct tcmu_dev_pr_info {
char *pr_info_buf;
};
+/*
+ * Persistent reservation info. This structure is converted to and from a
+ * string in a TCMU device storage (for example, if we use a RBD, we store such
+ * a string in it's metadata) which contain PR information.
+ */
+struct tcmu_pr_rsv {
+ u64 key; /* registered key */
+ /*
+ * I-T nexus for reservation. Separate to reg, so that all_tg_pt flag
+ * can be supported in future.
+ */
+ char it_nexus[TCMU_PR_IT_NEXUS_MAXLEN];
+ int type; /* PR_TYPE */
+ /* scope is always PR_SCOPE_LU_SCOPE */
+ };
+
struct tcmu_dev {
struct list_head node;
struct kref kref;
@@ -1974,6 +1991,61 @@ tcmu_pr_info_gen_encode(char *buf, size_t buf_remain, u32 gen)
return rc;
}
+static int tcmu_pr_info_rsv_decode(char *str, struct tcmu_pr_rsv **_rsv)
+{
+ struct tcmu_pr_rsv *rsv;
+ int rc;
+
+ if (!_rsv) {
+ WARN_ON(1);
+ return -EINVAL;
+ }
+ if (!strncmp(str, TCMU_PR_INFO_XATTR_VAL_SCSI3_RSV_ABSENT,
+ sizeof(TCMU_PR_INFO_XATTR_VAL_SCSI3_RSV_ABSENT))) {
+ /* no reservation. Ensure pr_info->rsv is NULL */
+ rsv = NULL;
+ } else {
+ rsv = kzalloc(sizeof(*rsv), GFP_KERNEL);
+ if (!rsv)
+ return -ENOMEM;
+
+ /* reservation key, I-T nexus and type with space separators */
+ rc = sscanf(str, "0x%016llx %"
+ __stringify(TCMU_PR_IT_NEXUS_MAXLEN)
+ "s 0x%08x", &rsv->key, rsv->it_nexus, &rsv->type);
+ if (rc != 3) {
+ pr_err("failed to parse PR rsv: %s\n", str);
+ kfree(rsv);
+ return -EINVAL;
+ }
+ }
+
+ pr_debug("processed pr_info rsv: %s\n", str);
+ *_rsv = rsv;
+ return 0;
+}
+
+static int tcmu_pr_info_rsv_encode(char *buf, size_t buf_remain,
+ struct tcmu_pr_rsv *rsv)
+{
+ int rc;
+
+ if (!rsv) {
+ /* no reservation */
+ rc = snprintf(buf, buf_remain, "%s\n",
+ TCMU_PR_INFO_XATTR_VAL_SCSI3_RSV_ABSENT);
+ } else {
+ rc = snprintf(buf, buf_remain, "0x%016llx %s 0x%08x\n",
+ rsv->key, rsv->it_nexus, rsv->type);
+ }
+ if ((rc < 0) || (rc >= buf_remain)) {
+ pr_err("failed to encode PR reservation\n");
+ return -EINVAL;
+ }
+
+ return rc;
+}
+
static int tcmu_configure_device(struct se_device *dev)
{
struct tcmu_dev *udev = TCMU_DEV(dev);
--
2.17.1
--
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