Commit c7bd85a7 authored Nov 10, 2025 by Tony Battersby Committed by Martin K. Petersen Nov 12, 2025

scsi: qla2xxx: target: Add back SRR support

Background: loading qla2xxx with "ql2xtgt_tape_enable=1" enables
Sequence Level Error Recovery (SLER), which is most commonly used for
tape drives. With SLER enabled, if there is a recoverable I/O error
during a SCSI command, a Sequence Retransmission Request (SRR) will be
used to retry the I/O at a low-level completely within the driver
without propagating the error to the upper levels of the SCSI stack.

SRR support was removed in 2017 by commit 2c39b5ca ("qla2xxx: Remove
SRR code"). Add it back, new and improved.

The old removed SRR code used sequence numbers to correlate the SRR
CTIOs with SRR immediate notify messages. I don't see how that would
work reliably with MSI-X interrupts and multiple queues. So instead use
the exchange address to find the command associated with the immediate
notify (qlt_srr_to_cmd).

The old removed SRR code had a function qlt_check_srr_debug() to
simulate a SRR, but it didn't work for me. Instead I just used fiber
optic attenuators attached to the FC cable to reduce the strength of the
signal and induce errors. Unfortunately this only worked for inducing
SRRs on Data-Out (write) commands, so that is all I was able to test.

The code to build a new scatterlist for a SRR with nonzero offset has
been improved to reduce memory requirements and has been well-tested.
However it does not support protection information.

When a single cmd gets multiple SRRs, the old removed SRR code would
restore the data buffer from the values in cmd->se_cmd before processing
the new SRR. That might be needed if the offset for the new SRR was
lower than the offset for the previous SRR, but I am not sure if that
can happen. In my testing, when a single cmd gets multiple SRRs, the
SRR offset always increases or stays the same. But in case it can
decrease, I added the function qlt_restore_orig_sg(). If this is not
supposed to happen then qlt_restore_orig_sg() can be removed to simplify
the code.

I ran into some HBA firmware bugs with QLE269x, QLE27xx, and QLE28xx
firmware 9.05.xx - 9.08.xx where a SRR would cause the HBA to misbehave
badly. Since SRRs are rare and therefore difficult to test, I figured
it would be worth checking for the buggy firmware and disabling SLER
with a warning instead of letting others run into the same problem on
the rare occasion that they get a SRR. This turned out to be difficult
because the firmware version isn't known in the normal NVRAM config
routine, so I added a second NVRAM config routine that is called after
the firmware version is known.

Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Link: https://patch.msgid.link/654b7181-b79e-40ed-a15b-6d6e441a5d5f@cybernetics.com

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

parent 04957d8c

drivers/scsi/qla2xxx/qla_dbg.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -58,6 +58,7 @@
		* \| Target Mode Management \| 0xf09b \| 0xf002 \|
		* \| \| \| 0xf046-0xf049 \|
		* \| Target Mode Task Management \| 0x1000d \| \|
		* \| Target Mode SRR \| 0x11038 \| \|
		* ----------------------------------------------------------------------
		*/

drivers/scsi/qla2xxx/qla_init.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -4369,6 +4369,7 @@ qla2x00_setup_chip(scsi_qla_host_t *vha)
		ha->max_npiv_vports =
		MIN_MULTI_ID_FABRIC - 1;
		}
		qlt_config_nvram_with_fw_version(vha);
		qla2x00_get_resource_cnts(vha);
		qla_init_iocb_limit(vha);

drivers/scsi/qla2xxx/qla_target.c

+1043 −1

File changed.

Preview size limit exceeded, changes collapsed.

drivers/scsi/qla2xxx/qla_target.h

+81 −0

Original line number	Diff line number	Diff line
		@@ -184,6 +184,7 @@ struct nack_to_isp {
		#define NOTIFY_ACK_SRR_REJECT_REASON_UNABLE_TO_PERFORM 0x9

		#define NOTIFY_ACK_SRR_FLAGS_REJECT_EXPL_NO_EXPL 0
		#define NOTIFY_ACK_SRR_FLAGS_REJECT_EXPL_INVALID_OX_ID_RX_ID 0x17
		#define NOTIFY_ACK_SRR_FLAGS_REJECT_EXPL_UNABLE_TO_SUPPLY_DATA 0x2a

		#define NOTIFY_ACK_SUCCESS 0x01
		@@ -686,6 +687,8 @@ struct qla_tgt_func_tmpl {
		int (handle_tmr)(struct qla_tgt_mgmt_cmd , u64, uint16_t,
		uint32_t);
		struct qla_tgt_cmd (get_cmd)(struct fc_port *);
		int (get_cmd_ref)(struct qla_tgt_cmd cmd);
		void (put_cmd_ref)(struct qla_tgt_cmd cmd);
		void (rel_cmd)(struct qla_tgt_cmd );
		void (free_cmd)(struct qla_tgt_cmd );
		void (free_mcmd)(struct qla_tgt_mgmt_cmd );
		@@ -823,7 +826,13 @@ struct qla_tgt {
		int notify_ack_expected;
		int abts_resp_expected;
		int modify_lun_expected;

		spinlock_t srr_lock;
		struct list_head srr_list;
		struct work_struct srr_work;

		atomic_t tgt_global_resets_count;

		struct list_head tgt_list_entry;
		};

		@@ -861,6 +870,7 @@ enum trace_flags {
		TRC_DATA_IN = BIT_18,
		TRC_ABORT = BIT_19,
		TRC_DIF_ERR = BIT_20,
		TRC_SRR_IMM = BIT_21,
		};

		struct qla_tgt_cmd {
		@@ -881,6 +891,10 @@ struct qla_tgt_cmd {

		unsigned int conf_compl_supported:1;
		unsigned int sg_mapped:1;

		/* Call qlt_free_sg() if set. */
		unsigned int free_sg:1;

		unsigned int write_data_transferred:1;

		/* Set if the SCSI status was sent successfully. */
		@@ -892,6 +906,9 @@ struct qla_tgt_cmd {
		unsigned int cmd_in_wq:1;
		unsigned int edif:1;

		/* Set if a SRR was rejected. */
		unsigned int srr_failed:1;

		/* Set if the exchange has been terminated. */
		unsigned int sent_term_exchg:1;

		@@ -901,6 +918,7 @@ struct qla_tgt_cmd {
		*/
		unsigned int aborted:1;

		struct qla_tgt_srr *srr;
		struct scatterlist sg; / cmd data buffer SG vector */
		int sg_cnt; /* SG segments count */
		int bufflen; /* cmd buffer length */
		@@ -940,6 +958,14 @@ struct qla_tgt_cmd {
		uint16_t prot_flags;

		unsigned long jiffies_at_term_exchg;

		/*
		* jiffies64 when qlt_rdy_to_xfer() or qlt_xmit_response() first
		* called, or 0 when not in those states. Used to limit the number of
		* SRR retries.
		*/
		uint64_t jiffies_at_hw_st_entry;

		uint64_t jiffies_at_alloc;
		uint64_t jiffies_at_free;

		@@ -1002,6 +1028,45 @@ struct qla_tgt_prm {
		uint16_t tot_dsds;
		};

		/*
		* SRR (Sequence Retransmission Request) - resend or re-receive some or all
		* data or status to recover from a transient I/O error.
		*/
		struct qla_tgt_srr {
		/*
		* Copy of immediate notify SRR message received from hw; valid only if
		* imm_ntfy_recvd is true.
		*/
		struct imm_ntfy_from_isp imm_ntfy;

		struct list_head srr_list_entry;

		/* The command affected by this SRR, or NULL if not yet determined. */
		struct qla_tgt_cmd *cmd;

		/* Used to detect if the HBA has been reset since receiving the SRR. */
		uint32_t reset_count;

		/*
		* The hardware sends two messages for each SRR - an immediate notify
		* and a CTIO with CTIO_SRR_RECEIVED status. These keep track of which
		* messages have been received. The SRR can be processed once both of
		* these are true.
		*/
		bool imm_ntfy_recvd;
		bool ctio_recvd;

		/*
		* This is set to true if the affected command was aborted (cmd may be
		* set to NULL), in which case the immediate notify exchange also needs
		* to be aborted.
		*/
		bool aborted;

		/* This is set to true to force the SRR to be rejected. */
		bool reject;
		};

		/* Check for Switch reserved address */
		#define IS_SW_RESV_ADDR(_s_id) \
		((_s_id.b.domain == 0xff) && ((_s_id.b.area & 0xf0) == 0xf0))
		@@ -1056,6 +1121,20 @@ static inline uint32_t sid_to_key(const be_id_t s_id)
		s_id.al_pa;
		}

		/*
		* Free the scatterlist allocated by qlt_set_data_offset(). Call this only if
		* cmd->free_sg is set.
		*/
		static inline void qlt_free_sg(struct qla_tgt_cmd *cmd)
		{
		/*
		* The scatterlist may be chained to the original scatterlist, but we
		* only need to free the first segment here since that is the only part
		* allocated by qlt_set_data_offset().
		*/
		kfree(cmd->sg);
		}

		/*
		* Exported symbols from qla_target.c LLD logic used by qla2xxx code..
		*/
		@@ -1064,6 +1143,7 @@ extern void qlt_response_pkt_all_vps(struct scsi_qla_host , struct rsp_que ,
		extern int qlt_rdy_to_xfer(struct qla_tgt_cmd *);
		extern int qlt_xmit_response(struct qla_tgt_cmd *, int, uint8_t);
		extern int qlt_abort_cmd(struct qla_tgt_cmd *);
		void qlt_srr_abort(struct qla_tgt_cmd *cmd, bool reject);
		void qlt_send_term_exchange(struct qla_qpair *qpair,
		struct qla_tgt_cmd cmd, struct atio_from_isp atio, int ha_locked);
		extern void qlt_xmit_tm_rsp(struct qla_tgt_mgmt_cmd *);
		@@ -1086,6 +1166,7 @@ extern void qlt_81xx_config_nvram_stage2(struct scsi_qla_host *,
		struct init_cb_81xx *);
		extern void qlt_81xx_config_nvram_stage1(struct scsi_qla_host *,
		struct nvram_81xx *);
		void qlt_config_nvram_with_fw_version(struct scsi_qla_host *vha);
		extern void qlt_modify_vp_config(struct scsi_qla_host *,
		struct vp_config_entry_24xx *);
		extern void qlt_probe_one_stage1(struct scsi_qla_host , struct qla_hw_data );

drivers/scsi/qla2xxx/tcm_qla2xxx.c

+15 −0

Original line number	Diff line number	Diff line
		@@ -291,6 +291,16 @@ static struct qla_tgt_cmd tcm_qla2xxx_get_cmd(struct fc_port sess)
		return cmd;
		}

		static int tcm_qla2xxx_get_cmd_ref(struct qla_tgt_cmd *cmd)
		{
		return target_get_sess_cmd(&cmd->se_cmd, true);
		}

		static void tcm_qla2xxx_put_cmd_ref(struct qla_tgt_cmd *cmd)
		{
		target_put_sess_cmd(&cmd->se_cmd);
		}

		static void tcm_qla2xxx_rel_cmd(struct qla_tgt_cmd *cmd)
		{
		target_free_tag(cmd->sess->se_sess, &cmd->se_cmd);
		@@ -531,6 +541,9 @@ static void tcm_qla2xxx_handle_data_work(struct work_struct *work)
		if (cmd->se_cmd.pi_err)
		transport_generic_request_failure(&cmd->se_cmd,
		cmd->se_cmd.pi_err);
		else if (cmd->srr_failed)
		transport_generic_request_failure(&cmd->se_cmd,
		TCM_SNACK_REJECTED);
		else
		transport_generic_request_failure(&cmd->se_cmd,
		TCM_CHECK_CONDITION_ABORT_CMD);
		@@ -1526,6 +1539,8 @@ static const struct qla_tgt_func_tmpl tcm_qla2xxx_template = {
		.handle_data = tcm_qla2xxx_handle_data,
		.handle_tmr = tcm_qla2xxx_handle_tmr,
		.get_cmd = tcm_qla2xxx_get_cmd,
		.get_cmd_ref = tcm_qla2xxx_get_cmd_ref,
		.put_cmd_ref = tcm_qla2xxx_put_cmd_ref,
		.rel_cmd = tcm_qla2xxx_rel_cmd,
		.free_cmd = tcm_qla2xxx_free_cmd,
		.free_mcmd = tcm_qla2xxx_free_mcmd,