[PATCH v9 0/8] nvme-fc: FPIN link integrity handling

[PATCH v9 0/8] nvme-fc: FPIN link integrity handling

[Bryan Gurney]

FPIN LI (link integrity) messages are received when the attached
fabric detects hardware errors. In response to these messages I/O
should be directed away from the affected ports, and only used
if the 'optimized' paths are unavailable.
Upon port reset the paths should be put back in service as the
affected hardware might have been replaced.
This patch adds a new controller flag 'NVME_CTRL_MARGINAL'
which will be checked during multipath path selection, causing the
path to be skipped when checking for 'optimized' paths. If no
optimized paths are available the 'marginal' paths are considered
for path selection alongside the 'non-optimized' paths.
It also introduces a new nvme-fc callback 'nvme_fc_fpin_rcv()' to
evaluate the FPIN LI TLV payload and set the 'marginal' state on
all affected rports.

The testing for this patch set was performed by Bryan Gurney, using the
process outlined by John Meneghini's presentation at LSFMM 2024, where
the fibre channel switch sends an FPIN notification on a specific switch
port, and the following is checked on the initiator:

1. The controllers corresponding to the paths on the port that has
received the notification are showing a set NVME_CTRL_MARGINAL flag.

   \
    +- nvme4 fc traddr=c,host_traddr=e live optimized
    +- nvme5 fc traddr=8,host_traddr=e live non-optimized
    +- nvme8 fc traddr=e,host_traddr=f marginal optimized
    +- nvme9 fc traddr=a,host_traddr=f marginal non-optimized

2. The I/O statistics of the test namespace show no I/O activity on the
controllers with NVME_CTRL_MARGINAL set.

   Device             tps    MB_read/s    MB_wrtn/s    MB_dscd/s
   nvme4c4n1         0.00         0.00         0.00         0.00
   nvme4c5n1     25001.00         0.00        97.66         0.00
   nvme4c9n1     25000.00         0.00        97.66         0.00
   nvme4n1       50011.00         0.00       195.36         0.00


   Device             tps    MB_read/s    MB_wrtn/s    MB_dscd/s
   nvme4c4n1         0.00         0.00         0.00         0.00
   nvme4c5n1     48360.00         0.00       188.91         0.00
   nvme4c9n1      1642.00         0.00         6.41         0.00
   nvme4n1       49981.00         0.00       195.24         0.00


   Device             tps    MB_read/s    MB_wrtn/s    MB_dscd/s
   nvme4c4n1         0.00         0.00         0.00         0.00
   nvme4c5n1     50001.00         0.00       195.32         0.00
   nvme4c9n1         0.00         0.00         0.00         0.00
   nvme4n1       50016.00         0.00       195.38         0.00

Link: https://people.redhat.com/jmeneghi/LSFMM_2024/LSFMM_2024_NVMe_Cancel_and_FPIN.pdf

Testing has been performed by sending all FPIN LI ELS messages from the
switch to the Host and verifying the proper nvme multi-pathing behavior
is effected with each of the eight different FPIN link integrity events.
Results were verified with iostat and with the nvme list-subsys command.

These tests were run with all scenarios including where there were only
non-optimized paths available, and where all paths were
marginal/degraded. All multi-path io-policies were tested including:
numa, round-robin and queue-depth. When all paths on the host are
marginal/degraded, I/O continues on the optimized path that was most
recently non-marginal.  If both of the optimized paths are down, I/O
properly continues on one of the marginal/degraded non-optimized paths.

Testing has been complete with both Broadcom (lpfc) and Marvell (qla2xx)
32GB HBAs.  Both HBAs successfully complete all tests.

For a complete description of the tests that were run, please see
bugzilla 20329.

Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220329

Changes to the original submission:
- Changed flag name to 'marginal'
- Do not block marginal path; influence path selection instead
  to de-prioritize marginal paths

Changes to v2:
- Split off driver-specific modifications
- Introduce 'union fc_tlv_desc' to avoid casts

Changes to v3:
- Include reviews from Justin Tee
- Split marginal path handling patch

Changes to v4:
- Change 'u8' to '__u8' on fc_tlv_desc to fix a failure to build
- Print 'marginal' instead of 'live' in the state of controllers
  when they are marginal

Changes to v5:
- Minor spelling corrections to patch descriptions

Changes to v6:
- No code changes; added note about additional testing

Changes to v7:
- Split nvme core marginal flag addition into its own patch
- Add patch for queue_depth marginal path support

Changes to v8:
- Rebased patch series to nvme-6.17.
- Added patch from Gustavo Silva, "scsi: qla2xxx: Fix memcpy field-spanning
  write issue", which resolves the field-spanning write issue
- We decided to leave the "marginal" state as is, because the transport
  driver uses the term "marginal".

This patch series is based upon nvme-6.17.

Bryan Gurney (2):
  nvme: add NVME_CTRL_MARGINAL flag
  nvme: sysfs: emit the marginal path state in show_state()

Gustavo A. R. Silva (1):
  scsi: qla2xxx: Fix memcpy field-spanning write issue

Hannes Reinecke (5):
  fc_els: use 'union fc_tlv_desc'
  nvme-fc: marginal path handling
  nvme-fc: nvme_fc_fpin_rcv() callback
  lpfc: enable FPIN notification for NVMe
  qla2xxx: enable FPIN notification for NVMe

John Meneghini (1):
  nvme-multipath: queue-depth support for marginal paths

 drivers/nvme/host/core.c         |   1 +
 drivers/nvme/host/fc.c           |  99 +++++++++++++++++++
 drivers/nvme/host/multipath.c    |  24 +++--
 drivers/nvme/host/nvme.h         |   6 ++
 drivers/nvme/host/sysfs.c        |   4 +-
 drivers/scsi/lpfc/lpfc_els.c     |  84 ++++++++--------
 drivers/scsi/qla2xxx/qla_def.h   |  10 +-
 drivers/scsi/qla2xxx/qla_isr.c   |  20 ++--
 drivers/scsi/qla2xxx/qla_nvme.c  |   2 +-
 drivers/scsi/qla2xxx/qla_os.c    |   5 +-
 drivers/scsi/scsi_transport_fc.c |  27 +++--
 include/linux/nvme-fc-driver.h   |   3 +
 include/uapi/scsi/fc/fc_els.h    | 165 +++++++++++++++++--------------
 13 files changed, 293 insertions(+), 157 deletions(-)

-- 
2.50.1

[PATCH v9 1/9] fc_els: use 'union fc_tlv_desc'

[Bryan Gurney]

From: Hannes Reinecke <hare@kernel.org>

Introduce 'union fc_tlv_desc' to have a common structure for all FC
ELS TLV structures and avoid type casts.

[bgurney: The cast inside the union fc_tlv_next_desc() has "u8",
which causes a failure to build.  Use "__u8" instead.]

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Justin Tee <justin.tee@broadcom.com>
Tested-by: Bryan Gurney <bgurney@redhat.com>
Reviewed-by: John Meneghini <jmeneghi@redhat.com>
Tested-by: Muneendra Kumar <muneendra.kumar@broadcom.com>
---
 drivers/scsi/lpfc/lpfc_els.c     |  75 +++++++-------
 drivers/scsi/scsi_transport_fc.c |  27 +++--
 include/uapi/scsi/fc/fc_els.h    | 165 +++++++++++++++++--------------
 3 files changed, 135 insertions(+), 132 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c
index b1a61eca8295..c7cbc5b50dfe 100644
--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -3937,7 +3937,7 @@ lpfc_cmpl_els_edc(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 {
 	IOCB_t *irsp_iocb;
 	struct fc_els_edc_resp *edc_rsp;
-	struct fc_tlv_desc *tlv;
+	union fc_tlv_desc *tlv;
 	struct fc_diag_cg_sig_desc *pcgd;
 	struct fc_diag_lnkflt_desc *plnkflt;
 	struct lpfc_dmabuf *pcmd, *prsp;
@@ -4028,7 +4028,7 @@ lpfc_cmpl_els_edc(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 			goto out;
 		}
 
-		dtag = be32_to_cpu(tlv->desc_tag);
+		dtag = be32_to_cpu(tlv->hdr.desc_tag);
 		switch (dtag) {
 		case ELS_DTAG_LNK_FAULT_CAP:
 			if (bytes_remain < FC_TLV_DESC_SZ_FROM_LENGTH(tlv) ||
@@ -4043,7 +4043,7 @@ lpfc_cmpl_els_edc(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 					sizeof(struct fc_diag_lnkflt_desc));
 				goto out;
 			}
-			plnkflt = (struct fc_diag_lnkflt_desc *)tlv;
+			plnkflt = &tlv->lnkflt;
 			lpfc_printf_log(phba, KERN_INFO,
 				LOG_ELS | LOG_LDS_EVENT,
 				"4617 Link Fault Desc Data: 0x%08x 0x%08x "
@@ -4070,7 +4070,7 @@ lpfc_cmpl_els_edc(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 				goto out;
 			}
 
-			pcgd = (struct fc_diag_cg_sig_desc *)tlv;
+			pcgd = &tlv->cg_sig;
 			lpfc_printf_log(
 				phba, KERN_INFO, LOG_ELS | LOG_CGN_MGMT,
 				"4616 CGN Desc Data: 0x%08x 0x%08x "
@@ -4125,10 +4125,8 @@ lpfc_cmpl_els_edc(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 }
 
 static void
-lpfc_format_edc_lft_desc(struct lpfc_hba *phba, struct fc_tlv_desc *tlv)
+lpfc_format_edc_lft_desc(struct lpfc_hba *phba, struct fc_diag_lnkflt_desc *lft)
 {
-	struct fc_diag_lnkflt_desc *lft = (struct fc_diag_lnkflt_desc *)tlv;
-
 	lft->desc_tag = cpu_to_be32(ELS_DTAG_LNK_FAULT_CAP);
 	lft->desc_len = cpu_to_be32(
 		FC_TLV_DESC_LENGTH_FROM_SZ(struct fc_diag_lnkflt_desc));
@@ -4141,10 +4139,8 @@ lpfc_format_edc_lft_desc(struct lpfc_hba *phba, struct fc_tlv_desc *tlv)
 }
 
 static void
-lpfc_format_edc_cgn_desc(struct lpfc_hba *phba, struct fc_tlv_desc *tlv)
+lpfc_format_edc_cgn_desc(struct lpfc_hba *phba, struct fc_diag_cg_sig_desc *cgd)
 {
-	struct fc_diag_cg_sig_desc *cgd = (struct fc_diag_cg_sig_desc *)tlv;
-
 	/* We are assuming cgd was zero'ed before calling this routine */
 
 	/* Configure the congestion detection capability */
@@ -4233,7 +4229,7 @@ lpfc_issue_els_edc(struct lpfc_vport *vport, uint8_t retry)
 	struct lpfc_hba  *phba = vport->phba;
 	struct lpfc_iocbq *elsiocb;
 	struct fc_els_edc *edc_req;
-	struct fc_tlv_desc *tlv;
+	union fc_tlv_desc *tlv;
 	u16 cmdsize;
 	struct lpfc_nodelist *ndlp;
 	u8 *pcmd = NULL;
@@ -4272,13 +4268,13 @@ lpfc_issue_els_edc(struct lpfc_vport *vport, uint8_t retry)
 	tlv = edc_req->desc;
 
 	if (cgn_desc_size) {
-		lpfc_format_edc_cgn_desc(phba, tlv);
+		lpfc_format_edc_cgn_desc(phba, &tlv->cg_sig);
 		phba->cgn_sig_freq = lpfc_fabric_cgn_frequency;
 		tlv = fc_tlv_next_desc(tlv);
 	}
 
 	if (lft_desc_size)
-		lpfc_format_edc_lft_desc(phba, tlv);
+		lpfc_format_edc_lft_desc(phba, &tlv->lnkflt);
 
 	lpfc_printf_vlog(vport, KERN_INFO, LOG_ELS | LOG_CGN_MGMT,
 			 "4623 Xmit EDC to remote "
@@ -5824,7 +5820,7 @@ lpfc_issue_els_edc_rsp(struct lpfc_vport *vport, struct lpfc_iocbq *cmdiocb,
 {
 	struct lpfc_hba  *phba = vport->phba;
 	struct fc_els_edc_resp *edc_rsp;
-	struct fc_tlv_desc *tlv;
+	union fc_tlv_desc *tlv;
 	struct lpfc_iocbq *elsiocb;
 	IOCB_t *icmd, *cmd;
 	union lpfc_wqe128 *wqe;
@@ -5868,10 +5864,10 @@ lpfc_issue_els_edc_rsp(struct lpfc_vport *vport, struct lpfc_iocbq *cmdiocb,
 		FC_TLV_DESC_LENGTH_FROM_SZ(struct fc_els_lsri_desc));
 	edc_rsp->lsri.rqst_w0.cmd = ELS_EDC;
 	tlv = edc_rsp->desc;
-	lpfc_format_edc_cgn_desc(phba, tlv);
+	lpfc_format_edc_cgn_desc(phba, &tlv->cg_sig);
 	tlv = fc_tlv_next_desc(tlv);
 	if (lft_desc_size)
-		lpfc_format_edc_lft_desc(phba, tlv);
+		lpfc_format_edc_lft_desc(phba, &tlv->lnkflt);
 
 	lpfc_debugfs_disc_trc(vport, LPFC_DISC_TRC_ELS_RSP,
 			      "Issue EDC ACC:      did:x%x flg:x%lx refcnt %d",
@@ -9256,7 +9252,7 @@ lpfc_els_rcv_edc(struct lpfc_vport *vport, struct lpfc_iocbq *cmdiocb,
 {
 	struct lpfc_hba  *phba = vport->phba;
 	struct fc_els_edc *edc_req;
-	struct fc_tlv_desc *tlv;
+	union fc_tlv_desc *tlv;
 	uint8_t *payload;
 	uint32_t *ptr, dtag;
 	const char *dtag_nm;
@@ -9299,7 +9295,7 @@ lpfc_els_rcv_edc(struct lpfc_vport *vport, struct lpfc_iocbq *cmdiocb,
 			goto out;
 		}
 
-		dtag = be32_to_cpu(tlv->desc_tag);
+		dtag = be32_to_cpu(tlv->hdr.desc_tag);
 		switch (dtag) {
 		case ELS_DTAG_LNK_FAULT_CAP:
 			if (bytes_remain < FC_TLV_DESC_SZ_FROM_LENGTH(tlv) ||
@@ -9314,7 +9310,7 @@ lpfc_els_rcv_edc(struct lpfc_vport *vport, struct lpfc_iocbq *cmdiocb,
 					sizeof(struct fc_diag_lnkflt_desc));
 				goto out;
 			}
-			plnkflt = (struct fc_diag_lnkflt_desc *)tlv;
+			plnkflt = &tlv->lnkflt;
 			lpfc_printf_log(phba, KERN_INFO,
 				LOG_ELS | LOG_LDS_EVENT,
 				"4626 Link Fault Desc Data: x%08x len x%x "
@@ -9351,7 +9347,7 @@ lpfc_els_rcv_edc(struct lpfc_vport *vport, struct lpfc_iocbq *cmdiocb,
 			phba->cgn_sig_freq = lpfc_fabric_cgn_frequency;
 
 			lpfc_least_capable_settings(
-				phba, (struct fc_diag_cg_sig_desc *)tlv);
+				phba, &tlv->cg_sig);
 			break;
 		default:
 			dtag_nm = lpfc_get_tlv_dtag_nm(dtag);
@@ -9942,14 +9938,13 @@ lpfc_display_fpin_wwpn(struct lpfc_hba *phba, __be64 *wwnlist, u32 cnt)
 /**
  * lpfc_els_rcv_fpin_li - Process an FPIN Link Integrity Event.
  * @phba: Pointer to phba object.
- * @tlv:  Pointer to the Link Integrity Notification Descriptor.
+ * @li:  Pointer to the Link Integrity Notification Descriptor.
  *
  * This function processes a Link Integrity FPIN event by logging a message.
  **/
 static void
-lpfc_els_rcv_fpin_li(struct lpfc_hba *phba, struct fc_tlv_desc *tlv)
+lpfc_els_rcv_fpin_li(struct lpfc_hba *phba, struct fc_fn_li_desc *li)
 {
-	struct fc_fn_li_desc *li = (struct fc_fn_li_desc *)tlv;
 	const char *li_evt_str;
 	u32 li_evt, cnt;
 
@@ -9973,14 +9968,13 @@ lpfc_els_rcv_fpin_li(struct lpfc_hba *phba, struct fc_tlv_desc *tlv)
 /**
  * lpfc_els_rcv_fpin_del - Process an FPIN Delivery Event.
  * @phba: Pointer to hba object.
- * @tlv:  Pointer to the Delivery Notification Descriptor TLV
+ * @del:  Pointer to the Delivery Notification Descriptor TLV
  *
  * This function processes a Delivery FPIN event by logging a message.
  **/
 static void
-lpfc_els_rcv_fpin_del(struct lpfc_hba *phba, struct fc_tlv_desc *tlv)
+lpfc_els_rcv_fpin_del(struct lpfc_hba *phba, struct fc_fn_deli_desc *del)
 {
-	struct fc_fn_deli_desc *del = (struct fc_fn_deli_desc *)tlv;
 	const char *del_rsn_str;
 	u32 del_rsn;
 	__be32 *frame;
@@ -10011,14 +10005,14 @@ lpfc_els_rcv_fpin_del(struct lpfc_hba *phba, struct fc_tlv_desc *tlv)
 /**
  * lpfc_els_rcv_fpin_peer_cgn - Process a FPIN Peer Congestion Event.
  * @phba: Pointer to hba object.
- * @tlv:  Pointer to the Peer Congestion Notification Descriptor TLV
+ * @pc:  Pointer to the Peer Congestion Notification Descriptor TLV
  *
  * This function processes a Peer Congestion FPIN event by logging a message.
  **/
 static void
-lpfc_els_rcv_fpin_peer_cgn(struct lpfc_hba *phba, struct fc_tlv_desc *tlv)
+lpfc_els_rcv_fpin_peer_cgn(struct lpfc_hba *phba,
+			   struct fc_fn_peer_congn_desc *pc)
 {
-	struct fc_fn_peer_congn_desc *pc = (struct fc_fn_peer_congn_desc *)tlv;
 	const char *pc_evt_str;
 	u32 pc_evt, cnt;
 
@@ -10046,7 +10040,7 @@ lpfc_els_rcv_fpin_peer_cgn(struct lpfc_hba *phba, struct fc_tlv_desc *tlv)
 /**
  * lpfc_els_rcv_fpin_cgn - Process an FPIN Congestion notification
  * @phba: Pointer to hba object.
- * @tlv:  Pointer to the Congestion Notification Descriptor TLV
+ * @cgn:  Pointer to the Congestion Notification Descriptor TLV
  *
  * This function processes an FPIN Congestion Notifiction.  The notification
  * could be an Alarm or Warning.  This routine feeds that data into driver's
@@ -10055,10 +10049,9 @@ lpfc_els_rcv_fpin_peer_cgn(struct lpfc_hba *phba, struct fc_tlv_desc *tlv)
  * to the upper layer or 0 to indicate don't deliver it.
  **/
 static int
-lpfc_els_rcv_fpin_cgn(struct lpfc_hba *phba, struct fc_tlv_desc *tlv)
+lpfc_els_rcv_fpin_cgn(struct lpfc_hba *phba, struct fc_fn_congn_desc *cgn)
 {
 	struct lpfc_cgn_info *cp;
-	struct fc_fn_congn_desc *cgn = (struct fc_fn_congn_desc *)tlv;
 	const char *cgn_evt_str;
 	u32 cgn_evt;
 	const char *cgn_sev_str;
@@ -10161,7 +10154,7 @@ lpfc_els_rcv_fpin(struct lpfc_vport *vport, void *p, u32 fpin_length)
 {
 	struct lpfc_hba *phba = vport->phba;
 	struct fc_els_fpin *fpin = (struct fc_els_fpin *)p;
-	struct fc_tlv_desc *tlv, *first_tlv, *current_tlv;
+	union fc_tlv_desc *tlv, *first_tlv, *current_tlv;
 	const char *dtag_nm;
 	int desc_cnt = 0, bytes_remain, cnt;
 	u32 dtag, deliver = 0;
@@ -10186,7 +10179,7 @@ lpfc_els_rcv_fpin(struct lpfc_vport *vport, void *p, u32 fpin_length)
 		return;
 	}
 
-	tlv = (struct fc_tlv_desc *)&fpin->fpin_desc[0];
+	tlv = &fpin->fpin_desc[0];
 	first_tlv = tlv;
 	bytes_remain = fpin_length - offsetof(struct fc_els_fpin, fpin_desc);
 	bytes_remain = min_t(u32, bytes_remain, be32_to_cpu(fpin->desc_len));
@@ -10194,22 +10187,22 @@ lpfc_els_rcv_fpin(struct lpfc_vport *vport, void *p, u32 fpin_length)
 	/* process each descriptor separately */
 	while (bytes_remain >= FC_TLV_DESC_HDR_SZ &&
 	       bytes_remain >= FC_TLV_DESC_SZ_FROM_LENGTH(tlv)) {
-		dtag = be32_to_cpu(tlv->desc_tag);
+		dtag = be32_to_cpu(tlv->hdr.desc_tag);
 		switch (dtag) {
 		case ELS_DTAG_LNK_INTEGRITY:
-			lpfc_els_rcv_fpin_li(phba, tlv);
+			lpfc_els_rcv_fpin_li(phba, &tlv->li);
 			deliver = 1;
 			break;
 		case ELS_DTAG_DELIVERY:
-			lpfc_els_rcv_fpin_del(phba, tlv);
+			lpfc_els_rcv_fpin_del(phba, &tlv->deli);
 			deliver = 1;
 			break;
 		case ELS_DTAG_PEER_CONGEST:
-			lpfc_els_rcv_fpin_peer_cgn(phba, tlv);
+			lpfc_els_rcv_fpin_peer_cgn(phba, &tlv->peer_congn);
 			deliver = 1;
 			break;
 		case ELS_DTAG_CONGESTION:
-			deliver = lpfc_els_rcv_fpin_cgn(phba, tlv);
+			deliver = lpfc_els_rcv_fpin_cgn(phba, &tlv->congn);
 			break;
 		default:
 			dtag_nm = lpfc_get_tlv_dtag_nm(dtag);
@@ -10222,12 +10215,12 @@ lpfc_els_rcv_fpin(struct lpfc_vport *vport, void *p, u32 fpin_length)
 			return;
 		}
 		lpfc_cgn_update_stat(phba, dtag);
-		cnt = be32_to_cpu(tlv->desc_len);
+		cnt = be32_to_cpu(tlv->hdr.desc_len);
 
 		/* Sanity check descriptor length. The desc_len value does not
 		 * include space for the desc_tag and the desc_len fields.
 		 */
-		len -= (cnt + sizeof(struct fc_tlv_desc));
+		len -= (cnt + sizeof(struct fc_tlv_desc_hdr));
 		if (len < 0) {
 			dtag_nm = lpfc_get_tlv_dtag_nm(dtag);
 			lpfc_printf_log(phba, KERN_WARNING, LOG_CGN_MGMT,
diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index 6b165a3ec6de..4462f2f7b102 100644
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -750,13 +750,12 @@ fc_cn_stats_update(u16 event_type, struct fc_fpin_stats *stats)
  *
  */
 static void
-fc_fpin_li_stats_update(struct Scsi_Host *shost, struct fc_tlv_desc *tlv)
+fc_fpin_li_stats_update(struct Scsi_Host *shost, struct fc_fn_li_desc *li_desc)
 {
 	u8 i;
 	struct fc_rport *rport = NULL;
 	struct fc_rport *attach_rport = NULL;
 	struct fc_host_attrs *fc_host = shost_to_fc_host(shost);
-	struct fc_fn_li_desc *li_desc = (struct fc_fn_li_desc *)tlv;
 	u16 event_type = be16_to_cpu(li_desc->event_type);
 	u64 wwpn;
 
@@ -799,12 +798,11 @@ fc_fpin_li_stats_update(struct Scsi_Host *shost, struct fc_tlv_desc *tlv)
  */
 static void
 fc_fpin_delivery_stats_update(struct Scsi_Host *shost,
-			      struct fc_tlv_desc *tlv)
+			      struct fc_fn_deli_desc *dn_desc)
 {
 	struct fc_rport *rport = NULL;
 	struct fc_rport *attach_rport = NULL;
 	struct fc_host_attrs *fc_host = shost_to_fc_host(shost);
-	struct fc_fn_deli_desc *dn_desc = (struct fc_fn_deli_desc *)tlv;
 	u32 reason_code = be32_to_cpu(dn_desc->deli_reason_code);
 
 	rport = fc_find_rport_by_wwpn(shost,
@@ -830,13 +828,11 @@ fc_fpin_delivery_stats_update(struct Scsi_Host *shost,
  */
 static void
 fc_fpin_peer_congn_stats_update(struct Scsi_Host *shost,
-				struct fc_tlv_desc *tlv)
+				struct fc_fn_peer_congn_desc *pc_desc)
 {
 	u8 i;
 	struct fc_rport *rport = NULL;
 	struct fc_rport *attach_rport = NULL;
-	struct fc_fn_peer_congn_desc *pc_desc =
-	    (struct fc_fn_peer_congn_desc *)tlv;
 	u16 event_type = be16_to_cpu(pc_desc->event_type);
 	u64 wwpn;
 
@@ -876,10 +872,9 @@ fc_fpin_peer_congn_stats_update(struct Scsi_Host *shost,
  */
 static void
 fc_fpin_congn_stats_update(struct Scsi_Host *shost,
-			   struct fc_tlv_desc *tlv)
+			   struct fc_fn_congn_desc *congn)
 {
 	struct fc_host_attrs *fc_host = shost_to_fc_host(shost);
-	struct fc_fn_congn_desc *congn = (struct fc_fn_congn_desc *)tlv;
 
 	fc_cn_stats_update(be16_to_cpu(congn->event_type),
 			   &fc_host->fpin_stats);
@@ -899,32 +894,32 @@ fc_host_fpin_rcv(struct Scsi_Host *shost, u32 fpin_len, char *fpin_buf,
 		u8 event_acknowledge)
 {
 	struct fc_els_fpin *fpin = (struct fc_els_fpin *)fpin_buf;
-	struct fc_tlv_desc *tlv;
+	union fc_tlv_desc *tlv;
 	u32 bytes_remain;
 	u32 dtag;
 	enum fc_host_event_code event_code =
 		event_acknowledge ? FCH_EVT_LINK_FPIN_ACK : FCH_EVT_LINK_FPIN;
 
 	/* Update Statistics */
-	tlv = (struct fc_tlv_desc *)&fpin->fpin_desc[0];
+	tlv = &fpin->fpin_desc[0];
 	bytes_remain = fpin_len - offsetof(struct fc_els_fpin, fpin_desc);
 	bytes_remain = min_t(u32, bytes_remain, be32_to_cpu(fpin->desc_len));
 
 	while (bytes_remain >= FC_TLV_DESC_HDR_SZ &&
 	       bytes_remain >= FC_TLV_DESC_SZ_FROM_LENGTH(tlv)) {
-		dtag = be32_to_cpu(tlv->desc_tag);
+		dtag = be32_to_cpu(tlv->hdr.desc_tag);
 		switch (dtag) {
 		case ELS_DTAG_LNK_INTEGRITY:
-			fc_fpin_li_stats_update(shost, tlv);
+			fc_fpin_li_stats_update(shost, &tlv->li);
 			break;
 		case ELS_DTAG_DELIVERY:
-			fc_fpin_delivery_stats_update(shost, tlv);
+			fc_fpin_delivery_stats_update(shost, &tlv->deli);
 			break;
 		case ELS_DTAG_PEER_CONGEST:
-			fc_fpin_peer_congn_stats_update(shost, tlv);
+			fc_fpin_peer_congn_stats_update(shost, &tlv->peer_congn);
 			break;
 		case ELS_DTAG_CONGESTION:
-			fc_fpin_congn_stats_update(shost, tlv);
+			fc_fpin_congn_stats_update(shost, &tlv->congn);
 		}
 
 		bytes_remain -= FC_TLV_DESC_SZ_FROM_LENGTH(tlv);
diff --git a/include/uapi/scsi/fc/fc_els.h b/include/uapi/scsi/fc/fc_els.h
index 16782c360de3..3598dc553f4d 100644
--- a/include/uapi/scsi/fc/fc_els.h
+++ b/include/uapi/scsi/fc/fc_els.h
@@ -253,12 +253,12 @@ enum fc_ls_tlv_dtag {
 
 
 /*
- * Generic Link Service TLV Descriptor format
+ * Generic Link Service TLV Descriptor header
  *
  * This structure, as it defines no payload, will also be referred to
  * as the "tlv header" - which contains the tag and len fields.
  */
-struct fc_tlv_desc {
+struct fc_tlv_desc_hdr {
 	__be32		desc_tag;	/* Notification Descriptor Tag */
 	__be32		desc_len;	/* Length of Descriptor (in bytes).
 					 * Size of descriptor excluding
@@ -267,36 +267,6 @@ struct fc_tlv_desc {
 	__u8		desc_value[];  /* Descriptor Value */
 };
 
-/* Descriptor tag and len fields are considered the mandatory header
- * for a descriptor
- */
-#define FC_TLV_DESC_HDR_SZ	sizeof(struct fc_tlv_desc)
-
-/*
- * Macro, used when initializing payloads, to return the descriptor length.
- * Length is size of descriptor minus the tag and len fields.
- */
-#define FC_TLV_DESC_LENGTH_FROM_SZ(desc)	\
-		(sizeof(desc) - FC_TLV_DESC_HDR_SZ)
-
-/* Macro, used on received payloads, to return the descriptor length */
-#define FC_TLV_DESC_SZ_FROM_LENGTH(tlv)		\
-		(__be32_to_cpu((tlv)->desc_len) + FC_TLV_DESC_HDR_SZ)
-
-/*
- * This helper is used to walk descriptors in a descriptor list.
- * Given the address of the current descriptor, which minimally contains a
- * tag and len field, calculate the address of the next descriptor based
- * on the len field.
- */
-static inline void *fc_tlv_next_desc(void *desc)
-{
-	struct fc_tlv_desc *tlv = desc;
-
-	return (desc + FC_TLV_DESC_SZ_FROM_LENGTH(tlv));
-}
-
-
 /*
  * Link Service Request Information Descriptor
  */
@@ -1094,19 +1064,6 @@ struct fc_fn_congn_desc {
 	__u8		resv[3];	/* reserved - must be zero */
 };
 
-/*
- * ELS_FPIN - Fabric Performance Impact Notification
- */
-struct fc_els_fpin {
-	__u8		fpin_cmd;	/* command (0x16) */
-	__u8		fpin_zero[3];	/* specified as zero - part of cmd */
-	__be32		desc_len;	/* Length of Descriptor List (in bytes).
-					 * Size of ELS excluding fpin_cmd,
-					 * fpin_zero and desc_len fields.
-					 */
-	struct fc_tlv_desc	fpin_desc[];	/* Descriptor list */
-};
-
 /* Diagnostic Function Descriptor - FPIN Registration */
 struct fc_df_desc_fpin_reg {
 	__be32		desc_tag;	/* FPIN Registration (0x00030001) */
@@ -1125,33 +1082,6 @@ struct fc_df_desc_fpin_reg {
 					 */
 };
 
-/*
- * ELS_RDF - Register Diagnostic Functions
- */
-struct fc_els_rdf {
-	__u8		fpin_cmd;	/* command (0x19) */
-	__u8		fpin_zero[3];	/* specified as zero - part of cmd */
-	__be32		desc_len;	/* Length of Descriptor List (in bytes).
-					 * Size of ELS excluding fpin_cmd,
-					 * fpin_zero and desc_len fields.
-					 */
-	struct fc_tlv_desc	desc[];	/* Descriptor list */
-};
-
-/*
- * ELS RDF LS_ACC Response.
- */
-struct fc_els_rdf_resp {
-	struct fc_els_ls_acc	acc_hdr;
-	__be32			desc_list_len;	/* Length of response (in
-						 * bytes). Excludes acc_hdr
-						 * and desc_list_len fields.
-						 */
-	struct fc_els_lsri_desc	lsri;
-	struct fc_tlv_desc	desc[];	/* Supported Descriptor list */
-};
-
-
 /*
  * Diagnostic Capability Descriptors for EDC ELS
  */
@@ -1221,6 +1151,65 @@ struct fc_diag_cg_sig_desc {
 	struct fc_diag_cg_sig_freq	rcv_signal_frequency;
 };
 
+/*
+ * Generic Link Service TLV Descriptor format
+ *
+ * This structure, as it defines no payload, will also be referred to
+ * as the "tlv header" - which contains the tag and len fields.
+ */
+union fc_tlv_desc {
+	struct fc_tlv_desc_hdr hdr;
+	struct fc_els_lsri_desc lsri;
+	struct fc_fn_li_desc li;
+	struct fc_fn_deli_desc deli;
+	struct fc_fn_peer_congn_desc peer_congn;
+	struct fc_fn_congn_desc congn;
+	struct fc_df_desc_fpin_reg fpin_reg;
+	struct fc_diag_lnkflt_desc lnkflt;
+	struct fc_diag_cg_sig_desc cg_sig;
+};
+
+/* Descriptor tag and len fields are considered the mandatory header
+ * for a descriptor
+ */
+#define FC_TLV_DESC_HDR_SZ	sizeof(struct fc_tlv_desc_hdr)
+
+/*
+ * Macro, used when initializing payloads, to return the descriptor length.
+ * Length is size of descriptor minus the tag and len fields.
+ */
+#define FC_TLV_DESC_LENGTH_FROM_SZ(desc)	\
+		(sizeof(desc) - FC_TLV_DESC_HDR_SZ)
+
+/* Macro, used on received payloads, to return the descriptor length */
+#define FC_TLV_DESC_SZ_FROM_LENGTH(tlv)		\
+		(__be32_to_cpu((tlv)->hdr.desc_len) + FC_TLV_DESC_HDR_SZ)
+
+/*
+ * This helper is used to walk descriptors in a descriptor list.
+ * Given the address of the current descriptor, which minimally contains a
+ * tag and len field, calculate the address of the next descriptor based
+ * on the len field.
+ */
+static inline union fc_tlv_desc *fc_tlv_next_desc(union fc_tlv_desc *desc)
+{
+	return (union fc_tlv_desc *)((__u8 *)desc + FC_TLV_DESC_SZ_FROM_LENGTH(desc));
+}
+
+
+/*
+ * ELS_FPIN - Fabric Performance Impact Notification
+ */
+struct fc_els_fpin {
+	__u8		fpin_cmd;	/* command (0x16) */
+	__u8		fpin_zero[3];	/* specified as zero - part of cmd */
+	__be32		desc_len;	/* Length of Descriptor List (in bytes).
+					 * Size of ELS excluding fpin_cmd,
+					 * fpin_zero and desc_len fields.
+					 */
+	union fc_tlv_desc	fpin_desc[];	/* Descriptor list */
+};
+
 /*
  * ELS_EDC - Exchange Diagnostic Capabilities
  */
@@ -1231,10 +1220,37 @@ struct fc_els_edc {
 					 * Size of ELS excluding edc_cmd,
 					 * edc_zero and desc_len fields.
 					 */
-	struct fc_tlv_desc	desc[];
+	union fc_tlv_desc	desc[];
 					/* Diagnostic Descriptor list */
 };
 
+/*
+ * ELS_RDF - Register Diagnostic Functions
+ */
+struct fc_els_rdf {
+	__u8		fpin_cmd;	/* command (0x19) */
+	__u8		fpin_zero[3];	/* specified as zero - part of cmd */
+	__be32		desc_len;	/* Length of Descriptor List (in bytes).
+					 * Size of ELS excluding fpin_cmd,
+					 * fpin_zero and desc_len fields.
+					 */
+	union fc_tlv_desc	desc[];	/* Descriptor list */
+};
+
+/*
+ * ELS RDF LS_ACC Response.
+ */
+struct fc_els_rdf_resp {
+	struct fc_els_ls_acc	acc_hdr;
+	__be32			desc_list_len;	/* Length of response (in
+						 * bytes). Excludes acc_hdr
+						 * and desc_list_len fields.
+						 */
+	struct fc_els_lsri_desc	lsri;
+	union fc_tlv_desc	desc[];	/* Supported Descriptor list */
+};
+
+
 /*
  * ELS EDC LS_ACC Response.
  */
@@ -1245,9 +1261,8 @@ struct fc_els_edc_resp {
 						 * and desc_list_len fields.
 						 */
 	struct fc_els_lsri_desc	lsri;
-	struct fc_tlv_desc	desc[];
+	union fc_tlv_desc	desc[];
 				    /* Supported Diagnostic Descriptor list */
 };
 
-
 #endif /* _FC_ELS_H_ */
-- 
2.50.1

[PATCH v9 2/9] nvme: add NVME_CTRL_MARGINAL flag

[Bryan Gurney]

Add a new controller flag, NVME_CTRL_MARGINAL, to help multipath I/O
policies to react to a path that is set to a "marginal" state.

The flag is cleared on controller reset, which is often the case when
faulty cabling or transceiver hardware is replaced.

Signed-off-by: Bryan Gurney <bgurney@redhat.com>
---
 drivers/nvme/host/core.c | 1 +
 drivers/nvme/host/nvme.h | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 812c1565114f..fafbd5c9c53d 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -5069,6 +5069,7 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
 	WRITE_ONCE(ctrl->state, NVME_CTRL_NEW);
 	ctrl->passthru_err_log_enabled = false;
 	clear_bit(NVME_CTRL_FAILFAST_EXPIRED, &ctrl->flags);
+	clear_bit(NVME_CTRL_MARGINAL, &ctrl->flags);
 	spin_lock_init(&ctrl->lock);
 	mutex_init(&ctrl->namespaces_lock);
 
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index cfd2b5b90b91..d71e6668f11c 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -275,6 +275,7 @@ enum nvme_ctrl_flags {
 	NVME_CTRL_SKIP_ID_CNS_CS	= 4,
 	NVME_CTRL_DIRTY_CAPABILITY	= 5,
 	NVME_CTRL_FROZEN		= 6,
+	NVME_CTRL_MARGINAL		= 7,
 };
 
 struct nvme_ctrl {
@@ -417,6 +418,11 @@ static inline enum nvme_ctrl_state nvme_ctrl_state(struct nvme_ctrl *ctrl)
 	return READ_ONCE(ctrl->state);
 }
 
+static inline bool nvme_ctrl_is_marginal(struct nvme_ctrl *ctrl)
+{
+	return test_bit(NVME_CTRL_MARGINAL, &ctrl->flags);
+}
+
 enum nvme_iopolicy {
 	NVME_IOPOLICY_NUMA,
 	NVME_IOPOLICY_RR,
-- 
2.50.1

[PATCH v9 3/9] nvme-fc: marginal path handling

[Bryan Gurney]

From: Hannes Reinecke <hare@kernel.org>

FPIN LI (link integrity) messages are received when the attached
fabric detects hardware errors. In response to these messages I/O
should be directed away from the affected ports, and only used
if the 'optimized' paths are unavailable.
To handle this a new controller flag 'NVME_CTRL_MARGINAL' is added
which will cause the multipath scheduler to skip these paths when
checking for 'optimized' paths. They are, however, still eligible
for non-optimized path selected. The flag is cleared upon reset as then the
faulty hardware might be replaced.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Tested-by: Bryan Gurney <bgurney@redhat.com>
Reviewed-by: John Meneghini <jmeneghi@redhat.com>
Tested-by: Muneendra Kumar <muneendra.kumar@broadcom.com>
---
 drivers/nvme/host/fc.c        |  4 ++++
 drivers/nvme/host/multipath.c | 17 +++++++++++------
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 3e12d4683ac7..bf6188b554ce 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -786,6 +786,10 @@ nvme_fc_ctrl_connectivity_loss(struct nvme_fc_ctrl *ctrl)
 		"Reconnect", ctrl->cnum);
 
 	set_bit(ASSOC_FAILED, &ctrl->flags);
+
+	/* clear 'marginal' flag as controller will be reset */
+	clear_bit(NVME_CTRL_MARGINAL, &ctrl->flags);
+
 	nvme_reset_ctrl(&ctrl->ctrl);
 }
 
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 3da980dc60d9..c042a9a11ce3 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -324,11 +324,14 @@ static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head, int node)
 
 		switch (ns->ana_state) {
 		case NVME_ANA_OPTIMIZED:
-			if (distance < found_distance) {
-				found_distance = distance;
-				found = ns;
+			if (!nvme_ctrl_is_marginal(ns->ctrl)) {
+				if (distance < found_distance) {
+					found_distance = distance;
+					found = ns;
+				}
+				break;
 			}
-			break;
+			fallthrough;
 		case NVME_ANA_NONOPTIMIZED:
 			if (distance < fallback_distance) {
 				fallback_distance = distance;
@@ -381,7 +384,8 @@ static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head)
 
 		if (ns->ana_state == NVME_ANA_OPTIMIZED) {
 			found = ns;
-			goto out;
+			if (!nvme_ctrl_is_marginal(ns->ctrl))
+				goto out;
 		}
 		if (ns->ana_state == NVME_ANA_NONOPTIMIZED)
 			found = ns;
@@ -445,7 +449,8 @@ static struct nvme_ns *nvme_queue_depth_path(struct nvme_ns_head *head)
 static inline bool nvme_path_is_optimized(struct nvme_ns *ns)
 {
 	return nvme_ctrl_state(ns->ctrl) == NVME_CTRL_LIVE &&
-		ns->ana_state == NVME_ANA_OPTIMIZED;
+		ns->ana_state == NVME_ANA_OPTIMIZED &&
+		!nvme_ctrl_is_marginal(ns->ctrl);
 }
 
 static struct nvme_ns *nvme_numa_path(struct nvme_ns_head *head)
-- 
2.50.1

[PATCH v9 4/9] nvme-fc: nvme_fc_fpin_rcv() callback

[Bryan Gurney]

From: Hannes Reinecke <hare@kernel.org>

Add a callback nvme_fc_fpin_rcv() to evaluate the FPIN LI TLV
information and set the 'marginal' path status for all affected
rports.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Tested-by: Bryan Gurney <bgurney@redhat.com>
Reviewed-by: John Meneghini <jmeneghi@redhat.com>
Tested-by: Muneendra Kumar <muneendra.kumar@broadcom.com>
---
 drivers/nvme/host/fc.c         | 95 ++++++++++++++++++++++++++++++++++
 include/linux/nvme-fc-driver.h |  3 ++
 2 files changed, 98 insertions(+)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index bf6188b554ce..a640310f1424 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -3724,6 +3724,101 @@ static struct nvmf_transport_ops nvme_fc_transport = {
 	.create_ctrl	= nvme_fc_create_ctrl,
 };
 
+static struct nvme_fc_rport *nvme_fc_rport_from_wwpn(struct nvme_fc_lport *lport,
+		u64 rport_wwpn)
+{
+	struct nvme_fc_rport *rport;
+
+	list_for_each_entry(rport, &lport->endp_list, endp_list) {
+		if (!nvme_fc_rport_get(rport))
+			continue;
+		if (rport->remoteport.port_name == rport_wwpn &&
+		    rport->remoteport.port_role & FC_PORT_ROLE_NVME_TARGET)
+			return rport;
+		nvme_fc_rport_put(rport);
+	}
+	return NULL;
+}
+
+static void
+nvme_fc_fpin_li_lport_update(struct nvme_fc_lport *lport, struct fc_fn_li_desc *li)
+{
+	unsigned int i, pname_count = be32_to_cpu(li->pname_count);
+	u64 attached_wwpn = be64_to_cpu(li->attached_wwpn);
+	struct nvme_fc_rport *attached_rport;
+
+	for (i = 0; i < pname_count; i++) {
+		struct nvme_fc_rport *rport;
+		u64 wwpn = be64_to_cpu(li->pname_list[i]);
+
+		rport = nvme_fc_rport_from_wwpn(lport, wwpn);
+		if (!rport)
+			continue;
+		if (wwpn != attached_wwpn) {
+			struct nvme_fc_ctrl *ctrl;
+
+			spin_lock_irq(&rport->lock);
+			list_for_each_entry(ctrl, &rport->ctrl_list, ctrl_list)
+				set_bit(NVME_CTRL_MARGINAL, &ctrl->ctrl.flags);
+			spin_unlock_irq(&rport->lock);
+		}
+		nvme_fc_rport_put(rport);
+	}
+
+	attached_rport = nvme_fc_rport_from_wwpn(lport, attached_wwpn);
+	if (attached_rport) {
+		struct nvme_fc_ctrl *ctrl;
+
+		spin_lock_irq(&attached_rport->lock);
+		list_for_each_entry(ctrl, &attached_rport->ctrl_list, ctrl_list)
+			set_bit(NVME_CTRL_MARGINAL, &ctrl->ctrl.flags);
+		spin_unlock_irq(&attached_rport->lock);
+		nvme_fc_rport_put(attached_rport);
+	}
+}
+
+/**
+ * fc_host_fpin_rcv() - Process a received FPIN.
+ * @localport:		local port the FPIN was received on
+ * @fpin_len:		length of FPIN payload, in bytes
+ * @fpin_buf:		pointer to FPIN payload
+ * Notes:
+ *	This routine assumes no locks are held on entry.
+ */
+void
+nvme_fc_fpin_rcv(struct nvme_fc_local_port *localport,
+		 u32 fpin_len, char *fpin_buf)
+{
+	struct nvme_fc_lport *lport;
+	struct fc_els_fpin *fpin = (struct fc_els_fpin *)fpin_buf;
+	union fc_tlv_desc *tlv;
+	u32 bytes_remain;
+	u32 dtag;
+
+	if (!localport)
+		return;
+	lport = localport_to_lport(localport);
+	tlv = &fpin->fpin_desc[0];
+	bytes_remain = fpin_len - offsetof(struct fc_els_fpin, fpin_desc);
+	bytes_remain = min_t(u32, bytes_remain, be32_to_cpu(fpin->desc_len));
+
+	while (bytes_remain >= FC_TLV_DESC_HDR_SZ &&
+	       bytes_remain >= FC_TLV_DESC_SZ_FROM_LENGTH(tlv)) {
+		dtag = be32_to_cpu(tlv->hdr.desc_tag);
+		switch (dtag) {
+		case ELS_DTAG_LNK_INTEGRITY:
+			nvme_fc_fpin_li_lport_update(lport, &tlv->li);
+			break;
+		default:
+			break;
+		}
+
+		bytes_remain -= FC_TLV_DESC_SZ_FROM_LENGTH(tlv);
+		tlv = fc_tlv_next_desc(tlv);
+	}
+}
+EXPORT_SYMBOL(nvme_fc_fpin_rcv);
+
 /* Arbitrary successive failures max. With lots of subsystems could be high */
 #define DISCOVERY_MAX_FAIL	20
 
diff --git a/include/linux/nvme-fc-driver.h b/include/linux/nvme-fc-driver.h
index 9f6acadfe0c8..bcd3b1e5a256 100644
--- a/include/linux/nvme-fc-driver.h
+++ b/include/linux/nvme-fc-driver.h
@@ -536,6 +536,9 @@ void nvme_fc_rescan_remoteport(struct nvme_fc_remote_port *remoteport);
 int nvme_fc_set_remoteport_devloss(struct nvme_fc_remote_port *remoteport,
 			u32 dev_loss_tmo);
 
+void nvme_fc_fpin_rcv(struct nvme_fc_local_port *localport,
+		      u32 fpin_len, char *fpin_buf);
+
 /*
  * Routine called to pass a NVME-FC LS request, received by the lldd,
  * to the nvme-fc transport.
-- 
2.50.1

[PATCH v9 5/9] lpfc: enable FPIN notification for NVMe

[Bryan Gurney]

From: Hannes Reinecke <hare@kernel.org>

Call 'nvme_fc_fpin_rcv()' to enable FPIN notifications for NVMe.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Justin Tee <justin.tee@broadcom.com>
Tested-by: Bryan Gurney <bgurney@redhat.com>
Tested-by: Muneendra Kumar <muneendra.kumar@broadcom.com>
---
 drivers/scsi/lpfc/lpfc_els.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c
index c7cbc5b50dfe..146ed6fd41af 100644
--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -33,6 +33,7 @@
 #include <scsi/scsi_transport_fc.h>
 #include <uapi/scsi/fc/fc_fs.h>
 #include <uapi/scsi/fc/fc_els.h>
+#include <linux/nvme-fc-driver.h>
 
 #include "lpfc_hw4.h"
 #include "lpfc_hw.h"
@@ -10249,9 +10250,15 @@ lpfc_els_rcv_fpin(struct lpfc_vport *vport, void *p, u32 fpin_length)
 		fpin_length += sizeof(struct fc_els_fpin); /* the entire FPIN */
 
 		/* Send every descriptor individually to the upper layer */
-		if (deliver)
+		if (deliver) {
 			fc_host_fpin_rcv(lpfc_shost_from_vport(vport),
 					 fpin_length, (char *)fpin, 0);
+#if (IS_ENABLED(CONFIG_NVME_FC))
+			if (vport->cfg_enable_fc4_type & LPFC_ENABLE_NVME)
+				nvme_fc_fpin_rcv(vport->localport,
+						 fpin_length, (char *)fpin);
+#endif
+		}
 		desc_cnt++;
 	}
 }
-- 
2.50.1

[PATCH v9 6/9] qla2xxx: enable FPIN notification for NVMe

[Bryan Gurney]

From: Hannes Reinecke <hare@kernel.org>

Call 'nvme_fc_fpin_rcv()' to enable FPIN notifications for NVMe.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: John Meneghini <jmeneghi@redhat.com>
Tested-by: Muneendra Kumar <muneendra.kumar@broadcom.com>
---
 drivers/scsi/qla2xxx/qla_isr.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index c4c6b5c6658c..f5e40e22ad7d 100644
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -46,6 +46,9 @@ qla27xx_process_purex_fpin(struct scsi_qla_host *vha, struct purex_item *item)
 		       pkt, pkt_size);
 
 	fc_host_fpin_rcv(vha->host, pkt_size, (char *)pkt, 0);
+#if (IS_ENABLED(CONFIG_NVME_FC))
+	nvme_fc_fpin_rcv(vha->nvme_local_port, pkt_size, (char *)pkt);
+#endif
 }
 
 const char *const port_state_str[] = {
-- 
2.50.1

[PATCH v9 7/9] nvme: sysfs: emit the marginal path state in show_state()

[Bryan Gurney]

If a controller has received a link integrity or congestion event, and
has the NVME_CTRL_MARGINAL flag set, emit "marginal" in the state
instead of "live", to identify the marginal paths.

Co-developed-by: John Meneghini <jmeneghi@redhat.com>
Signed-off-by: John Meneghini <jmeneghi@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Tested-by: Muneendra Kumar <muneendra.kumar@broadcom.com>
Signed-off-by: Bryan Gurney <bgurney@redhat.com>
---
 drivers/nvme/host/sysfs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/sysfs.c b/drivers/nvme/host/sysfs.c
index 29430949ce2f..4a6135c2f9cb 100644
--- a/drivers/nvme/host/sysfs.c
+++ b/drivers/nvme/host/sysfs.c
@@ -430,7 +430,9 @@ static ssize_t nvme_sysfs_show_state(struct device *dev,
 	};
 
 	if (state < ARRAY_SIZE(state_name) && state_name[state])
-		return sysfs_emit(buf, "%s\n", state_name[state]);
+		return sysfs_emit(buf, "%s\n",
+			(nvme_ctrl_is_marginal(ctrl)) ? "marginal" :
+			state_name[state]);
 
 	return sysfs_emit(buf, "unknown state\n");
 }
-- 
2.50.1

[PATCH v9 8/9] nvme-multipath: queue-depth support for marginal paths

[Bryan Gurney]

From: John Meneghini <jmeneghi@redhat.com>

Exclude marginal paths from queue-depth io policy. In the case where all
paths are marginal and no optimized or non-optimized path is found, we
fall back to __nvme_find_path which selects the best marginal path.

Tested-by: Bryan Gurney <bgurney@redhat.com>
Signed-off-by: John Meneghini <jmeneghi@redhat.com>
---
 drivers/nvme/host/multipath.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index c042a9a11ce3..38e40dd88e52 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -420,6 +420,9 @@ static struct nvme_ns *nvme_queue_depth_path(struct nvme_ns_head *head)
 		if (nvme_path_is_disabled(ns))
 			continue;
 
+		if (nvme_ctrl_is_marginal(ns->ctrl))
+			continue;
+
 		depth = atomic_read(&ns->ctrl->nr_active);
 
 		switch (ns->ana_state) {
@@ -443,7 +446,9 @@ static struct nvme_ns *nvme_queue_depth_path(struct nvme_ns_head *head)
 			return best_opt;
 	}
 
-	return best_opt ? best_opt : best_nonopt;
+	best_opt = (best_opt) ? best_opt : best_nonopt;
+
+	return best_opt ? best_opt : __nvme_find_path(head, numa_node_id());
 }
 
 static inline bool nvme_path_is_optimized(struct nvme_ns *ns)
-- 
2.50.1

[PATCH v9 9/9] scsi: qla2xxx: Fix memcpy field-spanning write issue

[Bryan Gurney]

From: "Gustavo A. R. Silva" <gustavoars@kernel.org>

purex_item.iocb is defined as a 64-element u8 array, but 64 is the
minimum size and it can be allocated larger. This makes it a standard
empty flex array.

This was motivated by field-spanning write warnings during FPIN testing.
https://lore.kernel.org/linux-nvme/20250709211919.49100-1-bgurney@redhat.com/

  >  kernel: memcpy: detected field-spanning write (size 60) of single field
  >  "((uint8_t *)fpin_pkt + buffer_copy_offset)"
  >  at drivers/scsi/qla2xxx/qla_isr.c:1221 (size 44)

I removed the outer wrapper from the iocb flex array, so that it can be
linked to `purex_item.size` with `__counted_by`.

These changes remove the default minimum 64-byte allocation, requiring
further changes.

  In `struct scsi_qla_host` the embedded `default_item` is now followed
  by `__default_item_iocb[QLA_DEFAULT_PAYLOAD_SIZE]` to reserve space
  that will be used as `default_item.iocb`. This is wrapped using the
  `TRAILING_OVERLAP()` macro helper, which effectively creates a union
  between flexible-array member `default_item.iocb` and `__default_item_iocb`.

  Since `struct pure_item` now contains a flexible-array member, the
  helper must be placed at the end of `struct scsi_qla_host` to prevent
  a `-Wflex-array-member-not-at-end` warning.

  `qla24xx_alloc_purex_item()` is adjusted to no longer expect the
  default minimum size to be part of `sizeof(struct purex_item)`,
  the entire flexible array size is added to the structure size for
  allocation.

This also slightly changes the layout of the purex_item struct, as
2-bytes of padding are added between `size` and `iocb`. The resulting
size is the same, but iocb is shifted 2-bytes (the original `purex_item`
structure was padded at the end, after the 64-byte defined array size).
I don't think this is a problem.

Tested-by: Bryan Gurney <bgurney@redhat.com>
Co-developed-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/scsi/qla2xxx/qla_def.h  | 10 ++++++----
 drivers/scsi/qla2xxx/qla_isr.c  | 17 ++++++++---------
 drivers/scsi/qla2xxx/qla_nvme.c |  2 +-
 drivers/scsi/qla2xxx/qla_os.c   |  5 +++--
 4 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index cb95b7b12051..604e66bead1e 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -4890,9 +4890,7 @@ struct purex_item {
 			     struct purex_item *pkt);
 	atomic_t in_use;
 	uint16_t size;
-	struct {
-		uint8_t iocb[64];
-	} iocb;
+	uint8_t iocb[] __counted_by(size);
 };
 
 #include "qla_edif.h"
@@ -5101,7 +5099,6 @@ typedef struct scsi_qla_host {
 		struct list_head head;
 		spinlock_t lock;
 	} purex_list;
-	struct purex_item default_item;
 
 	struct name_list_extended gnl;
 	/* Count of active session/fcport */
@@ -5130,6 +5127,11 @@ typedef struct scsi_qla_host {
 #define DPORT_DIAG_IN_PROGRESS                 BIT_0
 #define DPORT_DIAG_CHIP_RESET_IN_PROGRESS      BIT_1
 	uint16_t dport_status;
+
+	/* Must be last --ends in a flexible-array member. */
+	TRAILING_OVERLAP(struct purex_item, default_item, iocb,
+		uint8_t __default_item_iocb[QLA_DEFAULT_PAYLOAD_SIZE];
+	);
 } scsi_qla_host_t;
 
 struct qla27xx_image_status {
diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index f5e40e22ad7d..b90879e844aa 100644
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -1080,17 +1080,17 @@ static struct purex_item *
 qla24xx_alloc_purex_item(scsi_qla_host_t *vha, uint16_t size)
 {
 	struct purex_item *item = NULL;
-	uint8_t item_hdr_size = sizeof(*item);
 
 	if (size > QLA_DEFAULT_PAYLOAD_SIZE) {
-		item = kzalloc(item_hdr_size +
-		    (size - QLA_DEFAULT_PAYLOAD_SIZE), GFP_ATOMIC);
+		item = kzalloc(struct_size(item, iocb, size), GFP_ATOMIC);
 	} else {
 		if (atomic_inc_return(&vha->default_item.in_use) == 1) {
 			item = &vha->default_item;
 			goto initialize_purex_header;
 		} else {
-			item = kzalloc(item_hdr_size, GFP_ATOMIC);
+			item = kzalloc(
+				struct_size(item, iocb, QLA_DEFAULT_PAYLOAD_SIZE),
+				GFP_ATOMIC);
 		}
 	}
 	if (!item) {
@@ -1130,17 +1130,16 @@ qla24xx_queue_purex_item(scsi_qla_host_t *vha, struct purex_item *pkt,
  * @vha: SCSI driver HA context
  * @pkt: ELS packet
  */
-static struct purex_item
-*qla24xx_copy_std_pkt(struct scsi_qla_host *vha, void *pkt)
+static struct purex_item *
+qla24xx_copy_std_pkt(struct scsi_qla_host *vha, void *pkt)
 {
 	struct purex_item *item;
 
-	item = qla24xx_alloc_purex_item(vha,
-					QLA_DEFAULT_PAYLOAD_SIZE);
+	item = qla24xx_alloc_purex_item(vha, QLA_DEFAULT_PAYLOAD_SIZE);
 	if (!item)
 		return item;
 
-	memcpy(&item->iocb, pkt, sizeof(item->iocb));
+	memcpy(&item->iocb, pkt, QLA_DEFAULT_PAYLOAD_SIZE);
 	return item;
 }
 
diff --git a/drivers/scsi/qla2xxx/qla_nvme.c b/drivers/scsi/qla2xxx/qla_nvme.c
index 8ee2e337c9e1..92488890bc04 100644
--- a/drivers/scsi/qla2xxx/qla_nvme.c
+++ b/drivers/scsi/qla2xxx/qla_nvme.c
@@ -1308,7 +1308,7 @@ void qla2xxx_process_purls_iocb(void **pkt, struct rsp_que **rsp)
 
 	ql_dbg(ql_dbg_unsol, vha, 0x2121,
 	       "PURLS OP[%01x] size %d xchg addr 0x%x portid %06x\n",
-	       item->iocb.iocb[3], item->size, uctx->exchange_address,
+	       item->iocb[3], item->size, uctx->exchange_address,
 	       fcport->d_id.b24);
 	/* +48    0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
 	 * ----- -----------------------------------------------
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index d4b484c0fd9d..253f802605d6 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -6459,9 +6459,10 @@ void qla24xx_process_purex_rdp(struct scsi_qla_host *vha,
 void
 qla24xx_free_purex_item(struct purex_item *item)
 {
-	if (item == &item->vha->default_item)
+	if (item == &item->vha->default_item) {
 		memset(&item->vha->default_item, 0, sizeof(struct purex_item));
-	else
+		memset(&item->vha->__default_item_iocb, 0, QLA_DEFAULT_PAYLOAD_SIZE);
+	} else
 		kfree(item);
 }
 
-- 
2.50.1

Re: [PATCH v9 2/9] nvme: add NVME_CTRL_MARGINAL flag

[Hannes Reinecke]

On 8/13/25 22:07, Bryan Gurney wrote:
> Add a new controller flag, NVME_CTRL_MARGINAL, to help multipath I/O
> policies to react to a path that is set to a "marginal" state.
> 
> The flag is cleared on controller reset, which is often the case when
> faulty cabling or transceiver hardware is replaced.
> 
> Signed-off-by: Bryan Gurney <bgurney@redhat.com>
> ---
>   drivers/nvme/host/core.c | 1 +
>   drivers/nvme/host/nvme.h | 6 ++++++
>   2 files changed, 7 insertions(+)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich

Re: [PATCH v9 8/9] nvme-multipath: queue-depth support for marginal paths

[Hannes Reinecke]

On 8/13/25 22:07, Bryan Gurney wrote:
> From: John Meneghini <jmeneghi@redhat.com>
> 
> Exclude marginal paths from queue-depth io policy. In the case where all
> paths are marginal and no optimized or non-optimized path is found, we
> fall back to __nvme_find_path which selects the best marginal path.
> 
> Tested-by: Bryan Gurney <bgurney@redhat.com>
> Signed-off-by: John Meneghini <jmeneghi@redhat.com>
> ---
>   drivers/nvme/host/multipath.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich

Re: [PATCH v9 9/9] scsi: qla2xxx: Fix memcpy field-spanning write issue

[Hannes Reinecke]

On 8/13/25 22:07, Bryan Gurney wrote:
> From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
> 
> purex_item.iocb is defined as a 64-element u8 array, but 64 is the
> minimum size and it can be allocated larger. This makes it a standard
> empty flex array.
> 
> This was motivated by field-spanning write warnings during FPIN testing.
> https://lore.kernel.org/linux-nvme/20250709211919.49100-1-bgurney@redhat.com/
> 
>    >  kernel: memcpy: detected field-spanning write (size 60) of single field
>    >  "((uint8_t *)fpin_pkt + buffer_copy_offset)"
>    >  at drivers/scsi/qla2xxx/qla_isr.c:1221 (size 44)
> 
> I removed the outer wrapper from the iocb flex array, so that it can be
> linked to `purex_item.size` with `__counted_by`.
> 
> These changes remove the default minimum 64-byte allocation, requiring
> further changes.
> 
>    In `struct scsi_qla_host` the embedded `default_item` is now followed
>    by `__default_item_iocb[QLA_DEFAULT_PAYLOAD_SIZE]` to reserve space
>    that will be used as `default_item.iocb`. This is wrapped using the
>    `TRAILING_OVERLAP()` macro helper, which effectively creates a union
>    between flexible-array member `default_item.iocb` and `__default_item_iocb`.
> 
>    Since `struct pure_item` now contains a flexible-array member, the
>    helper must be placed at the end of `struct scsi_qla_host` to prevent
>    a `-Wflex-array-member-not-at-end` warning.
> 
>    `qla24xx_alloc_purex_item()` is adjusted to no longer expect the
>    default minimum size to be part of `sizeof(struct purex_item)`,
>    the entire flexible array size is added to the structure size for
>    allocation.
> 
> This also slightly changes the layout of the purex_item struct, as
> 2-bytes of padding are added between `size` and `iocb`. The resulting
> size is the same, but iocb is shifted 2-bytes (the original `purex_item`
> structure was padded at the end, after the 64-byte defined array size).
> I don't think this is a problem.
> 
> Tested-by: Bryan Gurney <bgurney@redhat.com>
> Co-developed-by: Chris Leech <cleech@redhat.com>
> Signed-off-by: Chris Leech <cleech@redhat.com>
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
>   drivers/scsi/qla2xxx/qla_def.h  | 10 ++++++----
>   drivers/scsi/qla2xxx/qla_isr.c  | 17 ++++++++---------
>   drivers/scsi/qla2xxx/qla_nvme.c |  2 +-
>   drivers/scsi/qla2xxx/qla_os.c   |  5 +++--
>   4 files changed, 18 insertions(+), 16 deletions(-)
> 
Not sure if this shouldn't be a stand-alone patch, but anyway:

Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich

Re: [PATCH v9 9/9] scsi: qla2xxx: Fix memcpy field-spanning write issue

[Martin K. Petersen]

Bryan,

> purex_item.iocb is defined as a 64-element u8 array, but 64 is the
> minimum size and it can be allocated larger. This makes it a standard
> empty flex array.

Applied to 6.18/scsi-staging, thanks!

-- 
Martin K. Petersen

Re: [PATCH v9 0/8] nvme-fc: FPIN link integrity handling

[Martin K. Petersen]

Bryan,

> FPIN LI (link integrity) messages are received when the attached
> fabric detects hardware errors. In response to these messages I/O
> should be directed away from the affected ports, and only used if the
> 'optimized' paths are unavailable.

SCSI bits look OK to me. I am fine with this series going through the
NVMe tree.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

-- 
Martin K. Petersen

Re: (subset) [PATCH v9 0/8] nvme-fc: FPIN link integrity handling

[Martin K. Petersen]

On Wed, 13 Aug 2025 16:07:35 -0400, Bryan Gurney wrote:

> FPIN LI (link integrity) messages are received when the attached
> fabric detects hardware errors. In response to these messages I/O
> should be directed away from the affected ports, and only used
> if the 'optimized' paths are unavailable.
> Upon port reset the paths should be put back in service as the
> affected hardware might have been replaced.
> This patch adds a new controller flag 'NVME_CTRL_MARGINAL'
> which will be checked during multipath path selection, causing the
> path to be skipped when checking for 'optimized' paths. If no
> optimized paths are available the 'marginal' paths are considered
> for path selection alongside the 'non-optimized' paths.
> It also introduces a new nvme-fc callback 'nvme_fc_fpin_rcv()' to
> evaluate the FPIN LI TLV payload and set the 'marginal' state on
> all affected rports.
> 
> [...]

Applied to 6.18/scsi-queue, thanks!

[9/9] scsi: qla2xxx: Fix memcpy field-spanning write issue
      https://git.kernel.org/mkp/scsi/c/6f4b10226b6b

-- 
Martin K. Petersen