[PATCH AUTOSEL 6.11 200/244] scsi: lpfc: Fix unsolicited FLOGI kref imbalance when in direct attached topology

Sasha Levin
2024-09-25T11:50:30Z

From: Justin Tee <justin.tee@broadcom.com>

[ Upstream commit b5c18c9dd138733c16893613345af44deadcf05e ]

In direct attached topology, certain target vendors that are quick to issue
FLOGI followed by a cable pull for more than dev_loss_tmo may result in a
kref imbalance for the remote port ndlp object.

Add an nlp_get when the defer_flogi_acc flag is set. This is expected to
balance the nlp_put in the defer_flogi_acc clause in the
lpfc_issue_els_flogi() routine. Because we need to retain the ndlp ptr,
reorganize all of the defer_flogi_acc information into one
lpfc_defer_flogi_acc struct.

Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20240726231512.92867-6-justintee8345@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/scsi/lpfc/lpfc.h | 12 ++++++---
drivers/scsi/lpfc/lpfc_els.c | 46 +++++++++++++++++++-------------
drivers/scsi/lpfc/lpfc_hbadisc.c | 11 ++++++--
3 files changed, 46 insertions(+), 23 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc.h b/drivers/scsi/lpfc/lpfc.h
index 7c147d6ea8a8f..e5a9c5a323f8b 100644
--- a/drivers/scsi/lpfc/lpfc.h
+++ b/drivers/scsi/lpfc/lpfc.h
@@ -306,6 +306,14 @@ struct lpfc_stats {

struct lpfc_hba;

+/* Data structure to keep withheld FLOGI_ACC information */
+struct lpfc_defer_flogi_acc {
+ bool flag;
+ u16 rx_id;
+ u16 ox_id;
+ struct lpfc_nodelist *ndlp;
+
+};

#define LPFC_VMID_TIMER 300 /* timer interval in seconds */

@@ -1430,9 +1438,7 @@ struct lpfc_hba {
uint16_t vlan_id;
struct list_head fcf_conn_rec_list;

- bool defer_flogi_acc_flag;
- uint16_t defer_flogi_acc_rx_id;
- uint16_t defer_flogi_acc_ox_id;
+ struct lpfc_defer_flogi_acc defer_flogi_acc;

spinlock_t ct_ev_lock; /* synchronize access to ct_ev_waiters */
struct list_head ct_ev_waiters;
diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c
index 929cbfc95163b..8c0926ffee1bf 100644
--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -1390,7 +1390,7 @@ lpfc_issue_els_flogi(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
phba->link_flag &= ~LS_EXTERNAL_LOOPBACK;

/* Check for a deferred FLOGI ACC condition */
- if (phba->defer_flogi_acc_flag) {
+ if (phba->defer_flogi_acc.flag) {
/* lookup ndlp for received FLOGI */
ndlp = lpfc_findnode_did(vport, 0);
if (!ndlp)
@@ -1404,34 +1404,38 @@ lpfc_issue_els_flogi(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
if (phba->sli_rev == LPFC_SLI_REV4) {
bf_set(wqe_ctxt_tag,
&defer_flogi_acc.wqe.xmit_els_rsp.wqe_com,
- phba->defer_flogi_acc_rx_id);
+ phba->defer_flogi_acc.rx_id);
bf_set(wqe_rcvoxid,
&defer_flogi_acc.wqe.xmit_els_rsp.wqe_com,
- phba->defer_flogi_acc_ox_id);
+ phba->defer_flogi_acc.ox_id);
} else {
icmd = &defer_flogi_acc.iocb;
- icmd->ulpContext = phba->defer_flogi_acc_rx_id;
+ icmd->ulpContext = phba->defer_flogi_acc.rx_id;
icmd->unsli3.rcvsli3.ox_id =
- phba->defer_flogi_acc_ox_id;
+ phba->defer_flogi_acc.ox_id;
}

lpfc_printf_vlog(vport, KERN_INFO, LOG_ELS,
"3354 Xmit deferred FLOGI ACC: rx_id: x%x,"
" ox_id: x%x, hba_flag x%lx\n",
- phba->defer_flogi_acc_rx_id,
- phba->defer_flogi_acc_ox_id, phba->hba_flag);
+ phba->defer_flogi_acc.rx_id,
+ phba->defer_flogi_acc.ox_id, phba->hba_flag);

/* Send deferred FLOGI ACC */
lpfc_els_rsp_acc(vport, ELS_CMD_FLOGI, &defer_flogi_acc,
ndlp, NULL);

- phba->defer_flogi_acc_flag = false;
- vport->fc_myDID = did;
+ phba->defer_flogi_acc.flag = false;

- /* Decrement ndlp reference count to indicate the node can be
- * released when other references are removed.
+ /* Decrement the held ndlp that was incremented when the
+ * deferred flogi acc flag was set.
*/
- lpfc_nlp_put(ndlp);
+ if (phba->defer_flogi_acc.ndlp) {
+ lpfc_nlp_put(phba->defer_flogi_acc.ndlp);
+ phba->defer_flogi_acc.ndlp = NULL;
+ }
+
+ vport->fc_myDID = did;
}

return 0;
@@ -8454,9 +8458,9 @@ lpfc_els_rcv_flogi(struct lpfc_vport *vport, struct lpfc_iocbq *cmdiocb,

/* Defer ACC response until AFTER we issue a FLOGI */
if (!test_bit(HBA_FLOGI_ISSUED, &phba->hba_flag)) {
- phba->defer_flogi_acc_rx_id = bf_get(wqe_ctxt_tag,
+ phba->defer_flogi_acc.rx_id = bf_get(wqe_ctxt_tag,
&wqe->xmit_els_rsp.wqe_com);
- phba->defer_flogi_acc_ox_id = bf_get(wqe_rcvoxid,
+ phba->defer_flogi_acc.ox_id = bf_get(wqe_rcvoxid,
&wqe->xmit_els_rsp.wqe_com);

vport->fc_myDID = did;
@@ -8464,11 +8468,17 @@ lpfc_els_rcv_flogi(struct lpfc_vport *vport, struct lpfc_iocbq *cmdiocb,
lpfc_printf_vlog(vport, KERN_INFO, LOG_ELS,
"3344 Deferring FLOGI ACC: rx_id: x%x,"
" ox_id: x%x, hba_flag x%lx\n",
- phba->defer_flogi_acc_rx_id,
- phba->defer_flogi_acc_ox_id, phba->hba_flag);
+ phba->defer_flogi_acc.rx_id,
+ phba->defer_flogi_acc.ox_id, phba->hba_flag);

- phba->defer_flogi_acc_flag = true;
+ phba->defer_flogi_acc.flag = true;

+ /* This nlp_get is paired with nlp_puts that reset the
+ * defer_flogi_acc.flag back to false. We need to retain
+ * a kref on the ndlp until the deferred FLOGI ACC is
+ * processed or cancelled.
+ */
+ phba->defer_flogi_acc.ndlp = lpfc_nlp_get(ndlp);
return 0;
}

@@ -10504,7 +10514,7 @@ lpfc_els_unsol_buffer(struct lpfc_hba *phba, struct lpfc_sli_ring *pring,

lpfc_els_rcv_flogi(vport, elsiocb, ndlp);
/* retain node if our response is deferred */
- if (phba->defer_flogi_acc_flag)
+ if (phba->defer_flogi_acc.flag)
break;
if (newnode)
lpfc_disc_state_machine(vport, ndlp, NULL,
diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
index f21c5993e8d72..35c9181c6608a 100644
--- a/drivers/scsi/lpfc/lpfc_hbadisc.c
+++ b/drivers/scsi/lpfc/lpfc_hbadisc.c
@@ -1255,7 +1255,14 @@ lpfc_linkdown(struct lpfc_hba *phba)
lpfc_scsi_dev_block(phba);
offline = pci_channel_offline(phba->pcidev);

- phba->defer_flogi_acc_flag = false;
+ /* Decrement the held ndlp if there is a deferred flogi acc */
+ if (phba->defer_flogi_acc.flag) {
+ if (phba->defer_flogi_acc.ndlp) {
+ lpfc_nlp_put(phba->defer_flogi_acc.ndlp);
+ phba->defer_flogi_acc.ndlp = NULL;
+ }
+ }
+ phba->defer_flogi_acc.flag = false;

/* Clear external loopback plug detected flag */
phba->link_flag &= ~LS_EXTERNAL_LOOPBACK;
@@ -1377,7 +1384,7 @@ lpfc_linkup_port(struct lpfc_vport *vport)
(vport != phba->pport))
return;

- if (phba->defer_flogi_acc_flag) {
+ if (phba->defer_flogi_acc.flag) {
clear_bit(FC_ABORT_DISCOVERY, &vport->fc_flag);
clear_bit(FC_RSCN_MODE, &vport->fc_flag);
clear_bit(FC_NLP_MORE, &vport->fc_flag);
--
2.43.0