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 <[email protected]> --- 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
