Hello James Smart,
This is a semi-automatic email about new static checker warnings.
The patch 4430f7fd09ec: "scsi: lpfc: Rework locations of ndlp
reference taking" from Nov 15, 2020, leads to the following Smatch
complaint:
drivers/scsi/lpfc/lpfc_els.c:2043 lpfc_cmpl_els_plogi()
error: we previously assumed 'ndlp' could be null (see line 1942)
drivers/scsi/lpfc/lpfc_els.c
1941 ndlp = lpfc_findnode_did(vport, irsp->un.elsreq64.remoteID);
1942 if (!ndlp) {
^^^^
1943 lpfc_printf_vlog(vport, KERN_ERR, LOG_TRACE_EVENT,
1944 "0136 PLOGI completes to NPort x%x "
1945 "with no ndlp. Data: x%x x%x x%x\n",
1946 irsp->un.elsreq64.remoteID,
1947 irsp->ulpStatus, irsp->un.ulpWord[4],
1948 irsp->ulpIoTag);
1949 goto out;
^^^^^^^^
"ndlp" is NULL
1950 }
1951
1952 /* Since ndlp can be freed in the disc state machine, note if this node
1953 * is being used during discovery.
1954 */
1955 spin_lock_irq(&ndlp->lock);
1956 disc = (ndlp->nlp_flag & NLP_NPR_2B_DISC);
1957 ndlp->nlp_flag &= ~NLP_NPR_2B_DISC;
1958 spin_unlock_irq(&ndlp->lock);
1959
1960 /* PLOGI completes to NPort <nlp_DID> */
1961 lpfc_printf_vlog(vport, KERN_INFO, LOG_ELS,
1962 "0102 PLOGI completes to NPort x%06x "
1963 "Data: x%x x%x x%x x%x x%x\n",
1964 ndlp->nlp_DID, ndlp->nlp_fc4_type,
1965 irsp->ulpStatus, irsp->un.ulpWord[4],
1966 disc, vport->num_disc_nodes);
1967
1968 /* Check to see if link went down during discovery */
1969 if (lpfc_els_chk_latt(vport)) {
1970 spin_lock_irq(&ndlp->lock);
1971 ndlp->nlp_flag |= NLP_NPR_2B_DISC;
1972 spin_unlock_irq(&ndlp->lock);
1973 goto out;
1974 }
1975
1976 if (irsp->ulpStatus) {
1977 /* Check for retry */
1978 if (lpfc_els_retry(phba, cmdiocb, rspiocb)) {
1979 /* ELS command is being retried */
1980 if (disc) {
1981 spin_lock_irq(&ndlp->lock);
1982 ndlp->nlp_flag |= NLP_NPR_2B_DISC;
1983 spin_unlock_irq(&ndlp->lock);
1984 }
1985 goto out;
1986 }
1987 /* PLOGI failed Don't print the vport to vport rjts */
1988 if (irsp->ulpStatus != IOSTAT_LS_RJT ||
1989 (((irsp->un.ulpWord[4]) >> 16 != LSRJT_INVALID_CMD) &&
1990 ((irsp->un.ulpWord[4]) >> 16 != LSRJT_UNABLE_TPC)) ||
1991 (phba)->pport->cfg_log_verbose & LOG_ELS)
1992 lpfc_printf_vlog(vport, KERN_ERR, LOG_TRACE_EVENT,
1993 "2753 PLOGI failure DID:%06X Status:x%x/x%x\n",
1994 ndlp->nlp_DID, irsp->ulpStatus,
1995 irsp->un.ulpWord[4]);
1996
1997 /* Do not call DSM for lpfc_els_abort'ed ELS cmds */
1998 if (lpfc_error_lost_link(irsp))
1999 goto check_plogi;
2000 else
2001 lpfc_disc_state_machine(vport, ndlp, cmdiocb,
2002 NLP_EVT_CMPL_PLOGI);
2003
2004 /* As long as this node is not registered with the scsi or nvme
2005 * transport, it is no longer an active node. Otherwise
2006 * devloss handles the final cleanup.
2007 */
2008 if (!(ndlp->fc4_xpt_flags & (SCSI_XPT_REGD | NVME_XPT_REGD))) {
2009 spin_lock_irq(&ndlp->lock);
2010 ndlp->nlp_flag &= ~NLP_NPR_2B_DISC;
2011 spin_unlock_irq(&ndlp->lock);
2012 lpfc_disc_state_machine(vport, ndlp, cmdiocb,
2013 NLP_EVT_DEVICE_RM);
2014 }
2015 } else {
2016 /* Good status, call state machine */
2017 prsp = list_entry(((struct lpfc_dmabuf *)
2018 cmdiocb->context2)->list.next,
2019 struct lpfc_dmabuf, list);
2020 ndlp = lpfc_plogi_confirm_nport(phba, prsp->virt, ndlp);
2021 lpfc_disc_state_machine(vport, ndlp, cmdiocb,
2022 NLP_EVT_CMPL_PLOGI);
2023 }
2024
2025 check_plogi:
2026 if (disc && vport->num_disc_nodes) {
2027 /* Check to see if there are more PLOGIs to be sent */
2028 lpfc_more_plogi(vport);
2029
2030 if (vport->num_disc_nodes == 0) {
2031 spin_lock_irq(shost->host_lock);
2032 vport->fc_flag &= ~FC_NDISC_ACTIVE;
2033 spin_unlock_irq(shost->host_lock);
2034
2035 lpfc_can_disctmo(vport);
2036 lpfc_end_rscn(vport);
2037 }
2038 }
2039
2040 out:
2041 lpfc_debugfs_disc_trc(vport, LPFC_DISC_TRC_NODE,
2042 "PLOGI Cmpl PUT: did:x%x refcnt %d",
2043 ndlp->nlp_DID, kref_read(&ndlp->kref), 0);
^^^^^^^^^^^^^ ^^^^^^^^^^^
Dereferenced here.
2044
2045 /* Release the reference on the original I/O request. */
regards,
dan carpenter
