[PATCHv6 00/17] scsi: EH rework prep patches, part 2

[PATCHv6 00/17] scsi: EH rework prep patches, part 2

[Hannes Reinecke]

Hi all,

(taking up an old thread:)
here's the second batch of patches for my EH rework.
It modifies the reset callbacks for SCSI drivers
such that the final conversion to drop the 'struct scsi_cmnd'
argument and use the entity in question (host, bus, target, device)
as the argument to the SCSI EH callbacks becomes possible.
The second part covers drivers which require a bit more love.
In particular the fnic, snic, and csiostor drivers require a tag to
send TMFs. So to handle that I've set aside a tag and used that directly
(for snic host reset), or call scsi_alloc_request() with the NOWAIT flag.
That will return a scsi command with a valid tag, which then can be used
to send the reset. It might fail (eg when the tagset is full),
but in these cases it might be better to fall back to host_reset anyway.

As usual, comments and reviews are welcome.

Changes to v5:
- Modified zfcp host reset to return FAST_IO_FAIL
- Rebased to 6.7/staging
- Add fix for missing scsi_device_put() in pmcraid
- Modify doing_srb_done() in dc395x to not use a scsi command

Changes to v4:
- rework snic to use a dedicated tag for host reset
- rework snic to allocate TMFs on the fly
- rework fnic to allocate TMFs on the fly
- rework csiostor to allocat TMFs on the fly
- drop fc_block_rport() from zfcp host_reset
- Rebase to latest linus tree

Changes to v3:
- Move fnic and snic patches to the next patchset
- Include reviews from Ewan Milne

Changes to v2:
- Include reviews from John Garry
- move mpi3mr, zfcp, sym53c8xx_2, and qla1280 patches to the
  next patchset

Changes to the initial version:
- Include reviews from Christoph
- Fixup build robot issues

Hannes Reinecke (17):
  pmcraid: add missing scsi_device_put() in
    pmcraid_eh_target_reset_handler()
  zfcp: do not wait for rports to become unblocked after host reset
  bfa: Do not use scsi command to signal TMF status
  aha152x: look for stuck command when resetting device
  a1000u2w: do not rely on the command for inia100_device_reset()
  fas216: Rework device reset to not rely on SCSI command pointer
  xen-scsifront: add scsi device as argument to scsifront_do_request()
  xen-scsifront: rework scsifront_action_handler()
  libiscsi: use cls_session as argument for target and session reset
  scsi_transport_iscsi: use session as argument for
    iscsi_block_scsi_eh()
  snic: reserve tag for TMF
  snic: allocate device reset command
  snic: Use scsi_host_busy_iter() to traverse commands
  fnic: allocate device reset command on the fly
  fnic: use fc_block_rport() correctly
  csiostor: use separate TMF command
  dc395x: Remove 'scmd' parameter from doing_srb_done()

 drivers/s390/scsi/zfcp_scsi.c       |   6 +-
 drivers/scsi/a100u2w.c              |  43 +---
 drivers/scsi/aha152x.c              |  26 ++-
 drivers/scsi/arm/fas216.c           |  39 ++--
 drivers/scsi/be2iscsi/be_main.c     |  10 +-
 drivers/scsi/bfa/bfad_im.c          | 112 +++++-----
 drivers/scsi/bfa/bfad_im.h          |   2 +
 drivers/scsi/csiostor/csio_scsi.c   |  72 ++++---
 drivers/scsi/dc395x.c               |  14 +-
 drivers/scsi/fnic/fnic.h            |   1 -
 drivers/scsi/fnic/fnic_scsi.c       | 115 +++++-----
 drivers/scsi/libiscsi.c             |  21 +-
 drivers/scsi/pmcraid.c              |  15 +-
 drivers/scsi/qla4xxx/ql4_os.c       |  34 +--
 drivers/scsi/scsi_transport_iscsi.c |   6 +-
 drivers/scsi/snic/snic.h            |   2 +-
 drivers/scsi/snic/snic_main.c       |   5 +-
 drivers/scsi/snic/snic_scsi.c       | 319 ++++++++++++----------------
 drivers/scsi/xen-scsifront.c        |  49 +++--
 include/scsi/libiscsi.h             |   2 +-
 include/scsi/scsi_transport_iscsi.h |   2 +-
 21 files changed, 429 insertions(+), 466 deletions(-)

-- 
2.35.3

[PATCH 01/17] pmcraid: add missing scsi_device_put() in pmcraid_eh_target_reset_handler()

[Hannes Reinecke]

When breaking out of a shost_for_each_device() loop one need to do
an explicit scsi_device_put(). And while at it convert to use
shost_priv() instead of a direct reference to ->hostdata.

Fixes: c2a14ab3b9b3 ("scsi: pmcraid: Select device in pmcraid_eh_target_reset_handler()")
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/pmcraid.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/pmcraid.c b/drivers/scsi/pmcraid.c
index a831b34c08a4..d946fb014474 100644
--- a/drivers/scsi/pmcraid.c
+++ b/drivers/scsi/pmcraid.c
@@ -2702,8 +2702,7 @@ static int pmcraid_reset_device(
 	unsigned long lock_flags;
 	u32 ioasc;
 
-	pinstance =
-		(struct pmcraid_instance *)scsi_dev->host->hostdata;
+	pinstance = shost_priv(scsi_dev->host);
 	res = scsi_dev->hostdata;
 
 	if (!res) {
@@ -3026,8 +3025,7 @@ static int pmcraid_eh_device_reset_handler(struct scsi_cmnd *scmd)
 static int pmcraid_eh_bus_reset_handler(struct scsi_cmnd *scmd)
 {
 	struct Scsi_Host *host = scmd->device->host;
-	struct pmcraid_instance *pinstance =
-		(struct pmcraid_instance *)host->hostdata;
+	struct pmcraid_instance *pinstance = shost_priv(host);
 	struct pmcraid_resource_entry *res = NULL;
 	struct pmcraid_resource_entry *temp;
 	struct scsi_device *sdev = NULL;
@@ -3066,6 +3064,7 @@ static int pmcraid_eh_target_reset_handler(struct scsi_cmnd *scmd)
 {
 	struct Scsi_Host *shost = scmd->device->host;
 	struct scsi_device *scsi_dev = NULL, *tmp;
+	int ret;
 
 	shost_for_each_device(tmp, shost) {
 		if ((tmp->channel == scmd->device->channel) &&
@@ -3078,9 +3077,11 @@ static int pmcraid_eh_target_reset_handler(struct scsi_cmnd *scmd)
 		return FAILED;
 	sdev_printk(KERN_INFO, scsi_dev,
 		    "Doing target reset due to an I/O command timeout.\n");
-	return pmcraid_reset_device(scsi_dev,
-				    PMCRAID_INTERNAL_TIMEOUT,
-				    RESET_DEVICE_TARGET);
+	ret = pmcraid_reset_device(scsi_dev,
+				   PMCRAID_INTERNAL_TIMEOUT,
+				   RESET_DEVICE_TARGET);
+	scsi_device_put(scsi_dev);
+	return ret;
 }
 
 /**
-- 
2.35.3

[PATCH 02/17] zfcp: do not wait for rports to become unblocked after host reset

[Hannes Reinecke]

zfcp_scsi_eh_host_reset_handler() would call fc_block_rport() to
wait for all rports to become unblocked after host reset.
But after host reset it might happen that the port is gone, hence
fc_block_rport() might fail due to a missing port.
But that's a perfectly legal operation; on FC remote ports might
come and go.
So this patch removes the call to fc_block_rport() after host
reset. But with that rports may still be in blocked state after
host reset, so we need to return FAST_IO_FAIL from host reset
to avoid SCSI EH to fail commands prematurely if the rports
are still blocked.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Cc: Steffen Maier <maier@linux.ibm.com
Cc: Benjamin Block <bblock@linux.ibm.com>
---
 drivers/s390/scsi/zfcp_scsi.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index b2a8cd792266..b1df853e6f66 100644
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -375,7 +375,7 @@ static int zfcp_scsi_eh_host_reset_handler(struct scsi_cmnd *scpnt)
 {
 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(scpnt->device);
 	struct zfcp_adapter *adapter = zfcp_sdev->port->adapter;
-	int ret = SUCCESS, fc_ret;
+	int ret = FAST_IO_FAIL;
 
 	if (!(adapter->connection_features & FSF_FEATURE_NPIV_MODE)) {
 		zfcp_erp_port_forced_reopen_all(adapter, 0, "schrh_p");
@@ -383,10 +383,6 @@ static int zfcp_scsi_eh_host_reset_handler(struct scsi_cmnd *scpnt)
 	}
 	zfcp_erp_adapter_reopen(adapter, 0, "schrh_1");
 	zfcp_erp_wait(adapter);
-	fc_ret = fc_block_scsi_eh(scpnt);
-	if (fc_ret)
-		ret = fc_ret;
-
 	zfcp_dbf_scsi_eh("schrh_r", adapter, ~0, ret);
 	return ret;
 }
-- 
2.35.3

[PATCH 03/17] bfa: Do not use scsi command to signal TMF status

[Hannes Reinecke]

The bfa driver hijacks the scsi command to signal the TMF status,
which will no longer work if the TMF handler will be converted.
So rework TMF handling to not use a scsi command but rather add
new TMF fields to the per-device structure.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/bfa/bfad_im.c | 112 ++++++++++++++++++++-----------------
 drivers/scsi/bfa/bfad_im.h |   2 +
 2 files changed, 63 insertions(+), 51 deletions(-)

diff --git a/drivers/scsi/bfa/bfad_im.c b/drivers/scsi/bfa/bfad_im.c
index a9d3d8562d3c..ef352fc59458 100644
--- a/drivers/scsi/bfa/bfad_im.c
+++ b/drivers/scsi/bfa/bfad_im.c
@@ -147,13 +147,13 @@ void
 bfa_cb_tskim_done(void *bfad, struct bfad_tskim_s *dtsk,
 		   enum bfi_tskim_status tsk_status)
 {
-	struct scsi_cmnd *cmnd = (struct scsi_cmnd *)dtsk;
+	struct bfad_itnim_data_s *itnim_data =
+		(struct bfad_itnim_data_s *)dtsk;
 	wait_queue_head_t *wq;
 
-	bfad_priv(cmnd)->status |= tsk_status << 1;
-	set_bit(IO_DONE_BIT, &bfad_priv(cmnd)->status);
-	wq = bfad_priv(cmnd)->wq;
-	bfad_priv(cmnd)->wq = NULL;
+	itnim_data->tmf_status |= tsk_status << 1;
+	set_bit(IO_DONE_BIT, &itnim_data->tmf_status);
+	wq = itnim_data->tmf_wq;
 
 	if (wq)
 		wake_up(wq);
@@ -238,15 +238,16 @@ bfad_im_abort_handler(struct scsi_cmnd *cmnd)
 }
 
 static bfa_status_t
-bfad_im_target_reset_send(struct bfad_s *bfad, struct scsi_cmnd *cmnd,
-		     struct bfad_itnim_s *itnim)
+bfad_im_target_reset_send(struct bfad_s *bfad,
+			  struct bfad_itnim_data_s *itnim_data)
 {
+	struct bfad_itnim_s *itnim = itnim_data->itnim;
 	struct bfa_tskim_s *tskim;
 	struct bfa_itnim_s *bfa_itnim;
 	bfa_status_t    rc = BFA_STATUS_OK;
 	struct scsi_lun scsilun;
 
-	tskim = bfa_tskim_alloc(&bfad->bfa, (struct bfad_tskim_s *) cmnd);
+	tskim = bfa_tskim_alloc(&bfad->bfa, (struct bfad_tskim_s *) itnim_data);
 	if (!tskim) {
 		BFA_LOG(KERN_ERR, bfad, bfa_log_level,
 			"target reset, fail to allocate tskim\n");
@@ -254,12 +255,6 @@ bfad_im_target_reset_send(struct bfad_s *bfad, struct scsi_cmnd *cmnd,
 		goto out;
 	}
 
-	/*
-	 * Set host_scribble to NULL to avoid aborting a task command if
-	 * happens.
-	 */
-	cmnd->host_scribble = NULL;
-	bfad_priv(cmnd)->status = 0;
 	bfa_itnim = bfa_fcs_itnim_get_halitn(&itnim->fcs_itnim);
 	/*
 	 * bfa_itnim can be NULL if the port gets disconnected and the bfa
@@ -290,10 +285,11 @@ bfad_im_target_reset_send(struct bfad_s *bfad, struct scsi_cmnd *cmnd,
 static int
 bfad_im_reset_lun_handler(struct scsi_cmnd *cmnd)
 {
-	struct Scsi_Host *shost = cmnd->device->host;
+	struct scsi_device *sdev = cmnd->device;
+	struct Scsi_Host *shost = sdev->host;
 	struct bfad_im_port_s *im_port =
 			(struct bfad_im_port_s *) shost->hostdata[0];
-	struct bfad_itnim_data_s *itnim_data = cmnd->device->hostdata;
+	struct bfad_itnim_data_s *itnim_data = sdev->hostdata;
 	struct bfad_s         *bfad = im_port->bfad;
 	struct bfa_tskim_s *tskim;
 	struct bfad_itnim_s   *itnim;
@@ -305,14 +301,20 @@ bfad_im_reset_lun_handler(struct scsi_cmnd *cmnd)
 	struct scsi_lun scsilun;
 
 	spin_lock_irqsave(&bfad->bfad_lock, flags);
+	if (itnim_data->tmf_wq) {
+		BFA_LOG(KERN_ERR, bfad, bfa_log_level,
+			"LUN reset, TMF already active");
+		spin_unlock_irqrestore(&bfad->bfad_lock, flags);
+		rc = FAILED;
+		goto out;
+	}
 	itnim = itnim_data->itnim;
 	if (!itnim) {
 		spin_unlock_irqrestore(&bfad->bfad_lock, flags);
 		rc = FAILED;
 		goto out;
 	}
-
-	tskim = bfa_tskim_alloc(&bfad->bfa, (struct bfad_tskim_s *) cmnd);
+	tskim = bfa_tskim_alloc(&bfad->bfa, (struct bfad_tskim_s *) itnim_data);
 	if (!tskim) {
 		BFA_LOG(KERN_ERR, bfad, bfa_log_level,
 				"LUN reset, fail to allocate tskim");
@@ -321,13 +323,8 @@ bfad_im_reset_lun_handler(struct scsi_cmnd *cmnd)
 		goto out;
 	}
 
-	/*
-	 * Set host_scribble to NULL to avoid aborting a task command
-	 * if happens.
-	 */
-	cmnd->host_scribble = NULL;
-	bfad_priv(cmnd)->wq = &wq;
-	bfad_priv(cmnd)->status = 0;
+	itnim_data->tmf_wq = &wq;
+	itnim_data->tmf_status = 0;
 	bfa_itnim = bfa_fcs_itnim_get_halitn(&itnim->fcs_itnim);
 	/*
 	 * bfa_itnim can be NULL if the port gets disconnected and the bfa
@@ -342,14 +339,15 @@ bfad_im_reset_lun_handler(struct scsi_cmnd *cmnd)
 		rc = FAILED;
 		goto out;
 	}
-	int_to_scsilun(cmnd->device->lun, &scsilun);
+	int_to_scsilun(sdev->lun, &scsilun);
 	bfa_tskim_start(tskim, bfa_itnim, scsilun,
 			    FCP_TM_LUN_RESET, BFAD_LUN_RESET_TMO);
 	spin_unlock_irqrestore(&bfad->bfad_lock, flags);
 
-	wait_event(wq, test_bit(IO_DONE_BIT, &bfad_priv(cmnd)->status));
+	wait_event(wq, test_bit(IO_DONE_BIT, &itnim_data->tmf_status));
 
-	task_status = bfad_priv(cmnd)->status >> 1;
+	itnim_data->tmf_wq = NULL;
+	task_status = itnim_data->tmf_status >> 1;
 	if (task_status != BFI_TSKIM_STS_OK) {
 		BFA_LOG(KERN_ERR, bfad, bfa_log_level,
 			"LUN reset failure, status: %d\n", task_status);
@@ -368,35 +366,47 @@ bfad_im_reset_target_handler(struct scsi_cmnd *cmnd)
 {
 	struct Scsi_Host *shost = cmnd->device->host;
 	struct scsi_target *starget = scsi_target(cmnd->device);
+	struct fc_rport *rport = starget_to_rport(starget);
 	struct bfad_im_port_s *im_port =
 				(struct bfad_im_port_s *) shost->hostdata[0];
-	struct bfad_s         *bfad = im_port->bfad;
-	struct bfad_itnim_s   *itnim;
-	unsigned long   flags;
-	u32        rc, rtn = FAILED;
+	struct bfad_s *bfad = im_port->bfad;
+	struct bfad_itnim_data_s *itnim_data;
+	struct bfad_itnim_s *itnim;
+	unsigned long flags;
+	u32 rc, rtn = FAILED;
 	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
 	enum bfi_tskim_status task_status;
 
 	spin_lock_irqsave(&bfad->bfad_lock, flags);
-	itnim = bfad_get_itnim(im_port, starget->id);
-	if (itnim) {
-		bfad_priv(cmnd)->wq = &wq;
-		rc = bfad_im_target_reset_send(bfad, cmnd, itnim);
-		if (rc == BFA_STATUS_OK) {
-			/* wait target reset to complete */
-			spin_unlock_irqrestore(&bfad->bfad_lock, flags);
-			wait_event(wq, test_bit(IO_DONE_BIT,
-						&bfad_priv(cmnd)->status));
-			spin_lock_irqsave(&bfad->bfad_lock, flags);
-
-			task_status = bfad_priv(cmnd)->status >> 1;
-			if (task_status != BFI_TSKIM_STS_OK)
-				BFA_LOG(KERN_ERR, bfad, bfa_log_level,
-					"target reset failure,"
-					" status: %d\n", task_status);
-			else
-				rtn = SUCCESS;
-		}
+	if (!rport->dd_data) {
+		spin_unlock_irqrestore(&bfad->bfad_lock, flags);
+		return rtn;
+	}
+	itnim_data = rport->dd_data;
+	if (itnim_data->tmf_wq) {
+		BFA_LOG(KERN_ERR, bfad, bfa_log_level,
+			"target reset failed, TMF already active");
+		spin_unlock_irqrestore(&bfad->bfad_lock, flags);
+		return rtn;
+	}
+	itnim = itnim_data->itnim;
+	itnim_data->tmf_wq = &wq;
+	itnim_data->tmf_status = 0;
+	rc = bfad_im_target_reset_send(bfad, itnim_data);
+	if (rc == BFA_STATUS_OK) {
+		/* wait target reset to complete */
+		spin_unlock_irqrestore(&bfad->bfad_lock, flags);
+		wait_event(wq, test_bit(IO_DONE_BIT,
+					&itnim_data->tmf_status));
+		spin_lock_irqsave(&bfad->bfad_lock, flags);
+
+		task_status = itnim_data->tmf_status >> 1;
+		if (task_status != BFI_TSKIM_STS_OK)
+			BFA_LOG(KERN_ERR, bfad, bfa_log_level,
+				"target reset failure,"
+				" status: %d\n", task_status);
+		else
+			rtn = SUCCESS;
 	}
 	spin_unlock_irqrestore(&bfad->bfad_lock, flags);
 
diff --git a/drivers/scsi/bfa/bfad_im.h b/drivers/scsi/bfa/bfad_im.h
index 4353feedf76a..48e8c12969c9 100644
--- a/drivers/scsi/bfa/bfad_im.h
+++ b/drivers/scsi/bfa/bfad_im.h
@@ -61,6 +61,8 @@ static inline struct bfad_cmd_priv *bfad_priv(struct scsi_cmnd *cmd)
 
 struct bfad_itnim_data_s {
 	struct bfad_itnim_s *itnim;
+	wait_queue_head_t *tmf_wq;
+	unsigned long tmf_status;
 };
 
 struct bfad_im_port_s {
-- 
2.35.3

[PATCH 04/17] aha152x: look for stuck command when resetting device

[Hannes Reinecke]

The LLDD needs a command to send the reset with, so look at the
list of outstanding commands to get one.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/aha152x.c | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/scsi/aha152x.c b/drivers/scsi/aha152x.c
index 055adb349b0e..936c9f5c6f23 100644
--- a/drivers/scsi/aha152x.c
+++ b/drivers/scsi/aha152x.c
@@ -1070,24 +1070,28 @@ static int aha152x_abort(struct scsi_cmnd *SCpnt)
  */
 static int aha152x_device_reset(struct scsi_cmnd * SCpnt)
 {
-	struct Scsi_Host *shpnt = SCpnt->device->host;
+	struct scsi_device *sdev = SCpnt->device;
+	struct Scsi_Host *shpnt = sdev->host;
 	DECLARE_COMPLETION(done);
 	int ret, issued, disconnected;
-	unsigned char old_cmd_len = SCpnt->cmd_len;
+	unsigned char old_cmd_len;
 	unsigned long flags;
 	unsigned long timeleft;
 
-	if(CURRENT_SC==SCpnt) {
-		scmd_printk(KERN_ERR, SCpnt, "cannot reset current device\n");
-		return FAILED;
-	}
-
 	DO_LOCK(flags);
-	issued       = remove_SC(&ISSUE_SC, SCpnt) == NULL;
-	disconnected = issued && remove_SC(&DISCONNECTED_SC, SCpnt);
+	/* Look for the stuck command */
+	SCpnt = remove_lun_SC(&ISSUE_SC, sdev->id, sdev->lun);
+	if (SCpnt)
+		issued = 1;
+	else
+		SCpnt = remove_lun_SC(&DISCONNECTED_SC, sdev->id, sdev->lun);
+	if (!issued && SCpnt)
+		disconnected = 1;
 	DO_UNLOCK(flags);
-
-	SCpnt->cmd_len         = 0;
+	if (!SCpnt)
+		return FAILED;
+	old_cmd_len = SCpnt->cmd_len;
+	SCpnt->cmd_len = 0;
 
 	aha152x_internal_queue(SCpnt, &done, resetting);
 
-- 
2.35.3

[PATCH 05/17] a1000u2w: do not rely on the command for inia100_device_reset()

[Hannes Reinecke]

Use the scsi device as argument to orc_device_reset() instead
of relying on the passed in scsi command.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/a100u2w.c | 43 +++++++++++-------------------------------
 1 file changed, 11 insertions(+), 32 deletions(-)

diff --git a/drivers/scsi/a100u2w.c b/drivers/scsi/a100u2w.c
index b95147fb18b0..43b119add2b9 100644
--- a/drivers/scsi/a100u2w.c
+++ b/drivers/scsi/a100u2w.c
@@ -592,39 +592,20 @@ static int orc_reset_scsi_bus(struct orc_host * host)
  *	commands for target w/o soft reset
  */
 
-static int orc_device_reset(struct orc_host * host, struct scsi_cmnd *cmd, unsigned int target)
+static int orc_device_reset(struct orc_host * host, struct scsi_device *sdev)
 {				/* I need Host Control Block Information */
 	struct orc_scb *scb;
 	struct orc_extended_scb *escb;
-	struct orc_scb *host_scb;
-	u8 i;
 	unsigned long flags;
 
 	spin_lock_irqsave(&(host->allocation_lock), flags);
 	scb = (struct orc_scb *) NULL;
 	escb = (struct orc_extended_scb *) NULL;
 
-	/* setup scatter list address with one buffer */
-	host_scb = host->scb_virt;
-
 	/* FIXME: is this safe if we then fail to issue the reset or race
 	   a completion ? */
 	init_alloc_map(host);
 
-	/* Find the scb corresponding to the command */
-	for (i = 0; i < ORC_MAXQUEUE; i++) {
-		escb = host_scb->escb;
-		if (host_scb->status && escb->srb == cmd)
-			break;
-		host_scb++;
-	}
-
-	if (i == ORC_MAXQUEUE) {
-		printk(KERN_ERR "Unable to Reset - No SCB Found\n");
-		spin_unlock_irqrestore(&(host->allocation_lock), flags);
-		return FAILED;
-	}
-
 	/* Allocate a new SCB for the reset command to the firmware */
 	if ((scb = __orc_alloc_scb(host)) == NULL) {
 		/* Can't happen.. */
@@ -635,7 +616,7 @@ static int orc_device_reset(struct orc_host * host, struct scsi_cmnd *cmd, unsig
 	/* Reset device is handled by the firmware, we fill in an SCB and
 	   fire it at the controller, it does the rest */
 	scb->opcode = ORC_BUSDEVRST;
-	scb->target = target;
+	scb->target = sdev->id;
 	scb->hastat = 0;
 	scb->tastat = 0;
 	scb->status = 0x0;
@@ -645,8 +626,8 @@ static int orc_device_reset(struct orc_host * host, struct scsi_cmnd *cmd, unsig
 	scb->xferlen = cpu_to_le32(0);
 	scb->sg_len = cpu_to_le32(0);
 
+	escb = scb->escb;
 	escb->srb = NULL;
-	escb->srb = cmd;
 	orc_exec_scb(host, scb);	/* Start execute SCB            */
 	spin_unlock_irqrestore(&host->allocation_lock, flags);
 	return SUCCESS;
@@ -971,7 +952,7 @@ static int inia100_device_reset(struct scsi_cmnd * cmd)
 {				/* I need Host Control Block Information */
 	struct orc_host *host;
 	host = (struct orc_host *) cmd->device->host->hostdata;
-	return orc_device_reset(host, cmd, scmd_id(cmd));
+	return orc_device_reset(host, cmd->device);
 
 }
 
@@ -991,11 +972,7 @@ static void inia100_scb_handler(struct orc_host *host, struct orc_scb *scb)
 	struct orc_extended_scb *escb;
 
 	escb = scb->escb;
-	if ((cmd = (struct scsi_cmnd *) escb->srb) == NULL) {
-		printk(KERN_ERR "inia100_scb_handler: SRB pointer is empty\n");
-		orc_release_scb(host, scb);	/* Release SCB for current channel */
-		return;
-	}
+	cmd = (struct scsi_cmnd *)escb->srb;
 	escb->srb = NULL;
 
 	switch (scb->hastat) {
@@ -1033,13 +1010,15 @@ static void inia100_scb_handler(struct orc_host *host, struct orc_scb *scb)
 		break;
 	}
 
-	if (scb->tastat == 2) {	/* Check condition              */
+	if (cmd && scb->tastat == 2) {	/* Check condition              */
 		memcpy((unsigned char *) &cmd->sense_buffer[0],
 		   (unsigned char *) &escb->sglist[0], SENSE_SIZE);
 	}
-	cmd->result = scb->tastat | (scb->hastat << 16);
-	scsi_dma_unmap(cmd);
-	scsi_done(cmd);		/* Notify system DONE           */
+	if (cmd) {
+		cmd->result = scb->tastat | (scb->hastat << 16);
+		scsi_dma_unmap(cmd);
+		scsi_done(cmd);		/* Notify system DONE           */
+	}
 	orc_release_scb(host, scb);	/* Release SCB for current channel */
 }
 
-- 
2.35.3

[PATCH 06/17] fas216: Rework device reset to not rely on SCSI command pointer

[Hannes Reinecke]

The device reset code should not rely on the SCSI command pointer;
it will be going away with the device reset handler rework.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/arm/fas216.c | 39 +++++++++++++++++++--------------------
 1 file changed, 19 insertions(+), 20 deletions(-)

diff --git a/drivers/scsi/arm/fas216.c b/drivers/scsi/arm/fas216.c
index 4ce0b2d73614..e6289c6af5ef 100644
--- a/drivers/scsi/arm/fas216.c
+++ b/drivers/scsi/arm/fas216.c
@@ -1985,7 +1985,6 @@ static void fas216_devicereset_done(FAS216_Info *info, struct scsi_cmnd *SCpnt,
 {
 	fas216_log(info, LOG_ERROR, "fas216 device reset complete");
 
-	info->rstSCpnt = NULL;
 	info->rst_dev_status = 1;
 	wake_up(&info->eh_wait);
 }
@@ -2143,12 +2142,12 @@ static void fas216_done(FAS216_Info *info, unsigned int result)
 
 	fas216_checkmagic(info);
 
-	if (!info->SCpnt)
+	if (!info->SCpnt && info->rst_dev_status)
 		goto no_command;
 
 	SCpnt = info->SCpnt;
 	info->SCpnt = NULL;
-    	info->scsi.phase = PHASE_IDLE;
+	info->scsi.phase = PHASE_IDLE;
 
 	if (info->scsi.aborting) {
 		fas216_log(info, 0, "uncaught abort - returning DID_ABORT");
@@ -2160,7 +2159,7 @@ static void fas216_done(FAS216_Info *info, unsigned int result)
 	 * Sanity check the completion - if we have zero bytes left
 	 * to transfer, we should not have a valid pointer.
 	 */
-	if (info->scsi.SCp.ptr && info->scsi.SCp.this_residual == 0) {
+	if (SCpnt && info->scsi.SCp.ptr && info->scsi.SCp.this_residual == 0) {
 		scmd_printk(KERN_INFO, SCpnt,
 			    "zero bytes left to transfer, but buffer pointer still valid: ptr=%p len=%08x\n",
 			    info->scsi.SCp.ptr, info->scsi.SCp.this_residual);
@@ -2173,12 +2172,18 @@ static void fas216_done(FAS216_Info *info, unsigned int result)
 	 * the sense information, fas216_kick will re-assert the busy
 	 * status.
 	 */
-	info->device[SCpnt->device->id].parity_check = 0;
-	clear_bit(SCpnt->device->id * 8 +
-		  (u8)(SCpnt->device->lun & 0x7), info->busyluns);
-
-	fn = (void (*)(FAS216_Info *, struct scsi_cmnd *, unsigned int))SCpnt->host_scribble;
-	fn(info, SCpnt, result);
+	if (SCpnt) {
+		info->device[SCpnt->device->id].parity_check = 0;
+		clear_bit(SCpnt->device->id * 8 +
+			  (u8)(SCpnt->device->lun & 0x7), info->busyluns);
+	}
+	if (!info->rst_dev_status) {
+		info->rst_dev_status = 1;
+		wake_up(&info->eh_wait);
+	} else {
+		fn = (void (*)(FAS216_Info *, struct scsi_cmnd *, unsigned int))SCpnt->host_scribble;
+		fn(info, SCpnt, result);
+	}
 
 	if (info->scsi.irq) {
 		spin_lock_irqsave(&info->host_lock, flags);
@@ -2478,9 +2483,10 @@ int fas216_eh_abort(struct scsi_cmnd *SCpnt)
  */
 int fas216_eh_device_reset(struct scsi_cmnd *SCpnt)
 {
-	FAS216_Info *info = (FAS216_Info *)SCpnt->device->host->hostdata;
+	struct scsi_device *sdev = SCpnt->device;
+	FAS216_Info *info = (FAS216_Info *)sdev->host->hostdata;
 	unsigned long flags;
-	int i, res = FAILED, target = SCpnt->device->id;
+	int i, res = FAILED, target = sdev->id;
 
 	fas216_log(info, LOG_ERROR, "device reset for target %d", target);
 
@@ -2494,7 +2500,7 @@ int fas216_eh_device_reset(struct scsi_cmnd *SCpnt)
 		 * and we need a bus reset.
 		 */
 		if (info->SCpnt && !info->scsi.disconnectable &&
-		    info->SCpnt->device->id == SCpnt->device->id)
+		    info->SCpnt->device->id == sdev->id)
 			break;
 
 		/*
@@ -2512,14 +2518,7 @@ int fas216_eh_device_reset(struct scsi_cmnd *SCpnt)
 		for (i = 0; i < 8; i++)
 			clear_bit(target * 8 + i, info->busyluns);
 
-		/*
-		 * Hijack this SCSI command structure to send
-		 * a bus device reset message to this device.
-		 */
-		SCpnt->host_scribble = (void *)fas216_devicereset_done;
-
 		info->rst_dev_status = 0;
-		info->rstSCpnt = SCpnt;
 
 		if (info->scsi.phase == PHASE_IDLE)
 			fas216_kick(info);
-- 
2.35.3

[PATCH 07/17] xen-scsifront: add scsi device as argument to scsifront_do_request()

[Hannes Reinecke]

Add scsi device as argument to scsifront_do_request() so that it
will be possible to call it with a NULL command pointer.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/xen-scsifront.c | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c
index 9ec55ddc1204..a0c13200d53a 100644
--- a/drivers/scsi/xen-scsifront.c
+++ b/drivers/scsi/xen-scsifront.c
@@ -178,7 +178,8 @@ static void scsifront_put_rqid(struct vscsifrnt_info *info, uint32_t id)
 		scsifront_wake_up(info);
 }
 
-static int scsifront_do_request(struct vscsifrnt_info *info,
+static int scsifront_do_request(struct scsi_device *sdev,
+				struct vscsifrnt_info *info,
 				struct vscsifrnt_shadow *shadow)
 {
 	struct vscsiif_front_ring *ring = &(info->ring);
@@ -205,17 +206,25 @@ static int scsifront_do_request(struct vscsifrnt_info *info,
 	ring_req->ref_rqid    = shadow->ref_rqid;
 	ring_req->nr_segments = shadow->nr_segments;
 
-	ring_req->id      = sc->device->id;
-	ring_req->lun     = sc->device->lun;
-	ring_req->channel = sc->device->channel;
-	ring_req->cmd_len = sc->cmd_len;
+	ring_req->id      = sdev->id;
+	ring_req->lun     = sdev->lun;
+	ring_req->channel = sdev->channel;
 
-	BUG_ON(sc->cmd_len > VSCSIIF_MAX_COMMAND_SIZE);
+	if (sc) {
+		ring_req->cmd_len = sc->cmd_len;
 
-	memcpy(ring_req->cmnd, sc->cmnd, sc->cmd_len);
+		BUG_ON(sc->cmd_len > VSCSIIF_MAX_COMMAND_SIZE);
 
-	ring_req->sc_data_direction   = (uint8_t)sc->sc_data_direction;
-	ring_req->timeout_per_command = scsi_cmd_to_rq(sc)->timeout / HZ;
+		memcpy(ring_req->cmnd, sc->cmnd, sc->cmd_len);
+
+		ring_req->sc_data_direction   = (uint8_t)sc->sc_data_direction;
+		ring_req->timeout_per_command =
+			scsi_cmd_to_rq(sc)->timeout / HZ;
+	} else {
+		ring_req->cmd_len = VSCSIIF_MAX_COMMAND_SIZE;
+		memset(ring_req->cmnd, 0, VSCSIIF_MAX_COMMAND_SIZE);
+		ring_req->sc_data_direction = DMA_NONE;
+	}
 
 	for (i = 0; i < (shadow->nr_segments & ~VSCSIIF_SG_GRANT); i++)
 		ring_req->seg[i] = shadow->seg[i];
@@ -637,7 +646,7 @@ static int scsifront_queuecommand(struct Scsi_Host *shost,
 		return 0;
 	}
 
-	if (scsifront_do_request(info, shadow)) {
+	if (scsifront_do_request(sc->device, info, shadow)) {
 		scsifront_gnttab_done(info, shadow);
 		goto busy;
 	}
@@ -685,7 +694,7 @@ static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act)
 		if (scsifront_enter(info))
 			goto fail;
 
-		if (!scsifront_do_request(info, shadow))
+		if (!scsifront_do_request(sc->device, info, shadow))
 			break;
 
 		scsifront_return(info);
-- 
2.35.3

[PATCH 08/17] xen-scsifront: rework scsifront_action_handler()

[Hannes Reinecke]

Rework scsifront_action_handler() to add the SCSI device as the
first argument, and select between abort and device reset by
checking whether the scsi_cmnd argument is NULL.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/xen-scsifront.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c
index a0c13200d53a..26dd229aeb22 100644
--- a/drivers/scsi/xen-scsifront.c
+++ b/drivers/scsi/xen-scsifront.c
@@ -668,11 +668,11 @@ static int scsifront_queuecommand(struct Scsi_Host *shost,
  * We have to wait until an answer is returned. This answer contains the
  * result to be returned to the requestor.
  */
-static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act)
+static int scsifront_action_handler(struct scsi_device *sdev, struct scsi_cmnd *sc)
 {
-	struct Scsi_Host *host = sc->device->host;
+	struct Scsi_Host *host = sdev->host;
 	struct vscsifrnt_info *info = shost_priv(host);
-	struct vscsifrnt_shadow *shadow, *s = scsi_cmd_priv(sc);
+	struct vscsifrnt_shadow *shadow;
 	int err = 0;
 
 	if (info->host_active == STATE_ERROR)
@@ -682,10 +682,14 @@ static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act)
 	if (!shadow)
 		return FAILED;
 
-	shadow->act = act;
+	shadow->act = sc ? VSCSIIF_ACT_SCSI_ABORT : VSCSIIF_ACT_SCSI_RESET;
 	shadow->rslt_reset = RSLT_RESET_WAITING;
 	shadow->sc = sc;
-	shadow->ref_rqid = s->rqid;
+	if (sc) {
+		struct vscsifrnt_shadow *s = scsi_cmd_priv(sc);
+
+		shadow->ref_rqid = s->rqid;
+	}
 	init_waitqueue_head(&shadow->wq_reset);
 
 	spin_lock_irq(host->host_lock);
@@ -735,13 +739,13 @@ static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act)
 static int scsifront_eh_abort_handler(struct scsi_cmnd *sc)
 {
 	pr_debug("%s\n", __func__);
-	return scsifront_action_handler(sc, VSCSIIF_ACT_SCSI_ABORT);
+	return scsifront_action_handler(sc->device, sc);
 }
 
 static int scsifront_dev_reset_handler(struct scsi_cmnd *sc)
 {
 	pr_debug("%s\n", __func__);
-	return scsifront_action_handler(sc, VSCSIIF_ACT_SCSI_RESET);
+	return scsifront_action_handler(sc->device, NULL);
 }
 
 static int scsifront_sdev_configure(struct scsi_device *sdev)
-- 
2.35.3

[PATCH 09/17] libiscsi: use cls_session as argument for target and session reset

[Hannes Reinecke]

iscsi_eh_target_reset() and iscsi_eh_session_reset() only depend
on the cls_session, so use that as an argument.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/be2iscsi/be_main.c | 10 +++++++++-
 drivers/scsi/libiscsi.c         | 21 +++++++++------------
 include/scsi/libiscsi.h         |  2 +-
 3 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/drivers/scsi/be2iscsi/be_main.c b/drivers/scsi/be2iscsi/be_main.c
index e48f14ad6dfd..441ad2ebc5d5 100644
--- a/drivers/scsi/be2iscsi/be_main.c
+++ b/drivers/scsi/be2iscsi/be_main.c
@@ -385,6 +385,14 @@ static int beiscsi_eh_device_reset(struct scsi_cmnd *sc)
 	return rc;
 }
 
+static int beiscsi_eh_session_reset(struct scsi_cmnd *sc)
+{
+	struct iscsi_cls_session *cls_session;
+
+	cls_session = starget_to_session(scsi_target(sc->device));
+	return iscsi_eh_session_reset(cls_session);
+}
+
 /*------------------- PCI Driver operations and data ----------------- */
 static const struct pci_device_id beiscsi_pci_id_table[] = {
 	{ PCI_DEVICE(BE_VENDOR_ID, BE_DEVICE_ID1) },
@@ -408,7 +416,7 @@ static const struct scsi_host_template beiscsi_sht = {
 	.eh_timed_out = iscsi_eh_cmd_timed_out,
 	.eh_abort_handler = beiscsi_eh_abort,
 	.eh_device_reset_handler = beiscsi_eh_device_reset,
-	.eh_target_reset_handler = iscsi_eh_session_reset,
+	.eh_target_reset_handler = beiscsi_eh_session_reset,
 	.shost_groups = beiscsi_groups,
 	.sg_tablesize = BEISCSI_SGLIST_ELEMENTS,
 	.can_queue = BE2_IO_DEPTH,
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 0fda8905eabd..a561eefabb50 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -2600,13 +2600,11 @@ EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
  * This function will wait for a relogin, session termination from
  * userspace, or a recovery/replacement timeout.
  */
-int iscsi_eh_session_reset(struct scsi_cmnd *sc)
+int iscsi_eh_session_reset(struct iscsi_cls_session *cls_session)
 {
-	struct iscsi_cls_session *cls_session;
 	struct iscsi_session *session;
 	struct iscsi_conn *conn;
 
-	cls_session = starget_to_session(scsi_target(sc->device));
 	session = cls_session->dd_data;
 
 	mutex_lock(&session->eh_mutex);
@@ -2653,7 +2651,7 @@ int iscsi_eh_session_reset(struct scsi_cmnd *sc)
 }
 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
 
-static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
+static void iscsi_prep_tgt_reset_pdu(struct iscsi_tm *hdr)
 {
 	memset(hdr, 0, sizeof(*hdr));
 	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
@@ -2668,19 +2666,16 @@ static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
  *
  * This will attempt to send a warm target reset.
  */
-static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
+static int iscsi_eh_target_reset(struct iscsi_cls_session *cls_session)
 {
-	struct iscsi_cls_session *cls_session;
 	struct iscsi_session *session;
 	struct iscsi_conn *conn;
 	struct iscsi_tm *hdr;
 	int rc = FAILED;
 
-	cls_session = starget_to_session(scsi_target(sc->device));
 	session = cls_session->dd_data;
 
-	ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
-		     session->targetname);
+	ISCSI_DBG_EH(session, "tgt Reset [tgt %s]\n", session->targetname);
 
 	mutex_lock(&session->eh_mutex);
 	spin_lock_bh(&session->frwd_lock);
@@ -2698,7 +2693,7 @@ static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
 	session->tmf_state = TMF_QUEUED;
 
 	hdr = &session->tmhdr;
-	iscsi_prep_tgt_reset_pdu(sc, hdr);
+	iscsi_prep_tgt_reset_pdu(hdr);
 
 	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
 				    session->tgt_reset_timeout)) {
@@ -2750,11 +2745,13 @@ static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
  */
 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
 {
+	struct iscsi_cls_session *cls_session;
 	int rc;
 
-	rc = iscsi_eh_target_reset(sc);
+	cls_session = starget_to_session(scsi_target(sc->device));
+	rc = iscsi_eh_target_reset(cls_session);
 	if (rc == FAILED)
-		rc = iscsi_eh_session_reset(sc);
+		rc = iscsi_eh_session_reset(cls_session);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 7282555adfd5..7dddf785edd0 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -390,7 +390,7 @@ struct iscsi_host {
  */
 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
-extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
+extern int iscsi_eh_session_reset(struct iscsi_cls_session *cls_session);
 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
 extern enum scsi_timeout_action iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc);
-- 
2.35.3

[PATCH 10/17] scsi_transport_iscsi: use session as argument for iscsi_block_scsi_eh()

[Hannes Reinecke]

We should be passing in the session directly instead of deriving it
from the scsi command.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/qla4xxx/ql4_os.c       | 34 ++++++++++++++++++-----------
 drivers/scsi/scsi_transport_iscsi.c |  6 ++---
 include/scsi/scsi_transport_iscsi.h |  2 +-
 3 files changed, 24 insertions(+), 18 deletions(-)

diff --git a/drivers/scsi/qla4xxx/ql4_os.c b/drivers/scsi/qla4xxx/ql4_os.c
index 675332e49a7b..961fe65bbe65 100644
--- a/drivers/scsi/qla4xxx/ql4_os.c
+++ b/drivers/scsi/qla4xxx/ql4_os.c
@@ -9272,15 +9272,18 @@ static int qla4xxx_eh_abort(struct scsi_cmnd *cmd)
  **/
 static int qla4xxx_eh_device_reset(struct scsi_cmnd *cmd)
 {
-	struct scsi_qla_host *ha = to_qla_host(cmd->device->host);
-	struct ddb_entry *ddb_entry = cmd->device->hostdata;
+	struct scsi_device *sdev = cmd->device;
+	struct scsi_qla_host *ha = to_qla_host(sdev->host);
+	struct iscsi_cls_session *session;
+	struct ddb_entry *ddb_entry = sdev->hostdata;
 	int ret = FAILED, stat;
 	int rval;
 
 	if (!ddb_entry)
 		return ret;
 
-	ret = iscsi_block_scsi_eh(cmd);
+	session = starget_to_session(scsi_target(sdev));
+	ret = iscsi_block_scsi_eh(session);
 	if (ret)
 		return ret;
 	ret = FAILED;
@@ -9341,19 +9344,25 @@ static int qla4xxx_eh_device_reset(struct scsi_cmnd *cmd)
  **/
 static int qla4xxx_eh_target_reset(struct scsi_cmnd *cmd)
 {
-	struct scsi_qla_host *ha = to_qla_host(cmd->device->host);
-	struct ddb_entry *ddb_entry = cmd->device->hostdata;
+	struct scsi_target *starget = scsi_target(cmd->device);
+	struct iscsi_cls_session *cls_session = starget_to_session(starget);
+	struct iscsi_session *sess;
+	struct scsi_qla_host *ha;
+	struct ddb_entry *ddb_entry;
 	int stat, ret;
 	int rval;
 
+	sess = cls_session->dd_data;
+	ddb_entry = sess->dd_data;
 	if (!ddb_entry)
 		return FAILED;
+	ha = ddb_entry->ha;
 
-	ret = iscsi_block_scsi_eh(cmd);
+	ret = iscsi_block_scsi_eh(cls_session);
 	if (ret)
 		return ret;
 
-	starget_printk(KERN_INFO, scsi_target(cmd->device),
+	starget_printk(KERN_INFO, starget,
 		       "WARM TARGET RESET ISSUED.\n");
 
 	DEBUG2(printk(KERN_INFO
@@ -9370,14 +9379,13 @@ static int qla4xxx_eh_target_reset(struct scsi_cmnd *cmd)
 
 	stat = qla4xxx_reset_target(ha, ddb_entry);
 	if (stat != QLA_SUCCESS) {
-		starget_printk(KERN_INFO, scsi_target(cmd->device),
+		starget_printk(KERN_INFO, starget,
 			       "WARM TARGET RESET FAILED.\n");
 		return FAILED;
 	}
 
-	if (qla4xxx_eh_wait_for_commands(ha, scsi_target(cmd->device),
-					 NULL)) {
-		starget_printk(KERN_INFO, scsi_target(cmd->device),
+	if (qla4xxx_eh_wait_for_commands(ha, starget, NULL)) {
+		starget_printk(KERN_INFO, starget,
 			       "WARM TARGET DEVICE RESET FAILED - "
 			       "waiting for commands.\n");
 		return FAILED;
@@ -9386,13 +9394,13 @@ static int qla4xxx_eh_target_reset(struct scsi_cmnd *cmd)
 	/* Send marker. */
 	if (qla4xxx_send_marker_iocb(ha, ddb_entry, cmd->device->lun,
 		MM_TGT_WARM_RESET) != QLA_SUCCESS) {
-		starget_printk(KERN_INFO, scsi_target(cmd->device),
+		starget_printk(KERN_INFO, starget,
 			       "WARM TARGET DEVICE RESET FAILED - "
 			       "marker iocb failed.\n");
 		return FAILED;
 	}
 
-	starget_printk(KERN_INFO, scsi_target(cmd->device),
+	starget_printk(KERN_INFO, starget,
 		       "WARM TARGET RESET SUCCEEDED.\n");
 	return SUCCESS;
 }
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 3075b2ddf7a6..4e81ef882a49 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -1838,17 +1838,15 @@ static void iscsi_scan_session(struct work_struct *work)
 
 /**
  * iscsi_block_scsi_eh - block scsi eh until session state has transistioned
- * @cmd: scsi cmd passed to scsi eh handler
+ * @session: iscsi session derived from scsi eh handler argument
  *
  * If the session is down this function will wait for the recovery
  * timer to fire or for the session to be logged back in. If the
  * recovery timer fires then FAST_IO_FAIL is returned. The caller
  * should pass this error value to the scsi eh.
  */
-int iscsi_block_scsi_eh(struct scsi_cmnd *cmd)
+int iscsi_block_scsi_eh(struct iscsi_cls_session *session)
 {
-	struct iscsi_cls_session *session =
-			starget_to_session(scsi_target(cmd->device));
 	unsigned long flags;
 	int ret = 0;
 
diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
index fb3399e4cd29..8ec36de5d236 100644
--- a/include/scsi/scsi_transport_iscsi.h
+++ b/include/scsi/scsi_transport_iscsi.h
@@ -466,7 +466,7 @@ extern struct iscsi_endpoint *iscsi_create_endpoint(int dd_size);
 extern void iscsi_destroy_endpoint(struct iscsi_endpoint *ep);
 extern struct iscsi_endpoint *iscsi_lookup_endpoint(u64 handle);
 extern void iscsi_put_endpoint(struct iscsi_endpoint *ep);
-extern int iscsi_block_scsi_eh(struct scsi_cmnd *cmd);
+extern int iscsi_block_scsi_eh(struct iscsi_cls_session *session);
 extern struct iscsi_iface *iscsi_create_iface(struct Scsi_Host *shost,
 					      struct iscsi_transport *t,
 					      uint32_t iface_type,
-- 
2.35.3

[PATCH 11/17] snic: reserve tag for TMF

[Hannes Reinecke]

Rework the hba reset function to not rely on scsi commands and
reserve one command for HBA reset.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/snic/snic.h      |  2 +-
 drivers/scsi/snic/snic_main.c |  5 ++-
 drivers/scsi/snic/snic_scsi.c | 82 ++++++++---------------------------
 3 files changed, 21 insertions(+), 68 deletions(-)

diff --git a/drivers/scsi/snic/snic.h b/drivers/scsi/snic/snic.h
index 32f5a34b6987..0b7411624bcf 100644
--- a/drivers/scsi/snic/snic.h
+++ b/drivers/scsi/snic/snic.h
@@ -366,7 +366,7 @@ int snic_queuecommand(struct Scsi_Host *, struct scsi_cmnd *);
 int snic_abort_cmd(struct scsi_cmnd *);
 int snic_device_reset(struct scsi_cmnd *);
 int snic_host_reset(struct scsi_cmnd *);
-int snic_reset(struct Scsi_Host *, struct scsi_cmnd *);
+int snic_reset(struct Scsi_Host *);
 void snic_shutdown_scsi_cleanup(struct snic *);
 
 
diff --git a/drivers/scsi/snic/snic_main.c b/drivers/scsi/snic/snic_main.c
index cc824dcfe7da..9bee91eedc10 100644
--- a/drivers/scsi/snic/snic_main.c
+++ b/drivers/scsi/snic/snic_main.c
@@ -494,9 +494,10 @@ snic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	/* Configure Maximum Outstanding IO reqs */
 	max_ios = snic->config.io_throttle_count;
 	if (max_ios != SNIC_UCSM_DFLT_THROTTLE_CNT_BLD)
-		shost->can_queue = min_t(u32, SNIC_MAX_IO_REQ,
+		max_ios = min_t(u32, SNIC_MAX_IO_REQ,
 					 max_t(u32, SNIC_MIN_IO_REQ, max_ios));
-
+	/* Reserve one tag for HBA reset */
+	shost->can_queue = max_ios - 1;
 	snic->max_tag_id = shost->can_queue;
 
 	shost->max_lun = snic->config.luns_per_tgt;
diff --git a/drivers/scsi/snic/snic_scsi.c b/drivers/scsi/snic/snic_scsi.c
index c50ede326cc4..f1ef781df837 100644
--- a/drivers/scsi/snic/snic_scsi.c
+++ b/drivers/scsi/snic/snic_scsi.c
@@ -952,13 +952,13 @@ snic_itmf_cmpl_handler(struct snic *snic, struct snic_fw_req *fwreq)
 
 
 static void
-snic_hba_reset_scsi_cleanup(struct snic *snic, struct scsi_cmnd *sc)
+snic_hba_reset_scsi_cleanup(struct snic *snic)
 {
 	struct snic_stats *st = &snic->s_stats;
 	long act_ios = 0, act_fwreqs = 0;
 
 	SNIC_SCSI_DBG(snic->shost, "HBA Reset scsi cleanup.\n");
-	snic_scsi_cleanup(snic, snic_cmd_tag(sc));
+	snic_scsi_cleanup(snic, snic->max_tag_id);
 
 	/* Update stats on pending IOs */
 	act_ios = atomic64_read(&st->io.active);
@@ -984,7 +984,6 @@ snic_hba_reset_cmpl_handler(struct snic *snic, struct snic_fw_req *fwreq)
 	u32 hid;
 	u8 typ;
 	u8 hdr_stat;
-	struct scsi_cmnd *sc = NULL;
 	struct snic_req_info *rqi = NULL;
 	spinlock_t *io_lock = NULL;
 	unsigned long flags, gflags;
@@ -999,18 +998,9 @@ snic_hba_reset_cmpl_handler(struct snic *snic, struct snic_fw_req *fwreq)
 		      "reset_cmpl: type = %x, hdr_stat = %x, cmnd_id = %x, hid = %x, ctx = %lx\n",
 		      typ, hdr_stat, cmnd_id, hid, ctx);
 
-	/* spl case, host reset issued through ioctl */
-	if (cmnd_id == SCSI_NO_TAG) {
-		rqi = (struct snic_req_info *) ctx;
-		SNIC_HOST_INFO(snic->shost,
-			       "reset_cmpl:Tag %d ctx %lx cmpl stat %s\n",
-			       cmnd_id, ctx, snic_io_status_to_str(hdr_stat));
-		sc = rqi->sc;
-
-		goto ioctl_hba_rst;
-	}
+	rqi = (struct snic_req_info *) ctx;
 
-	if (cmnd_id >= snic->max_tag_id) {
+	if (cmnd_id != snic->max_tag_id) {
 		SNIC_HOST_ERR(snic->shost,
 			      "reset_cmpl: Tag 0x%x out of Range,HdrStat %s\n",
 			      cmnd_id, snic_io_status_to_str(hdr_stat));
@@ -1019,55 +1009,35 @@ snic_hba_reset_cmpl_handler(struct snic *snic, struct snic_fw_req *fwreq)
 		return 1;
 	}
 
-	sc = scsi_host_find_tag(snic->shost, cmnd_id);
-ioctl_hba_rst:
-	if (!sc) {
-		atomic64_inc(&snic->s_stats.io.sc_null);
-		SNIC_HOST_ERR(snic->shost,
-			      "reset_cmpl: sc is NULL - Hdr Stat %s Tag 0x%x\n",
-			      snic_io_status_to_str(hdr_stat), cmnd_id);
-		ret = 1;
-
-		return ret;
-	}
-
 	SNIC_HOST_INFO(snic->shost,
-		       "reset_cmpl: sc %p rqi %p Tag %d flags 0x%llx\n",
-		       sc, rqi, cmnd_id, CMD_FLAGS(sc));
+		       "reset_cmpl: rqi %p Tag %d\n", rqi, cmnd_id);
 
-	io_lock = snic_io_lock_hash(snic, sc);
+	io_lock = snic_io_lock_tag(snic, cmnd_id);
 	spin_lock_irqsave(io_lock, flags);
 
 	if (!snic->remove_wait) {
 		spin_unlock_irqrestore(io_lock, flags);
 		SNIC_HOST_ERR(snic->shost,
 			      "reset_cmpl:host reset completed after timeout\n");
-		ret = 1;
-
-		return ret;
+		return 1;
 	}
 
-	rqi = (struct snic_req_info *) CMD_SP(sc);
 	WARN_ON_ONCE(!rqi);
 
 	if (!rqi) {
 		atomic64_inc(&snic->s_stats.io.req_null);
 		spin_unlock_irqrestore(io_lock, flags);
-		CMD_FLAGS(sc) |= SNIC_IO_ABTS_TERM_REQ_NULL;
 		SNIC_HOST_ERR(snic->shost,
-			      "reset_cmpl: rqi is null,Hdr stat %s Tag 0x%x sc 0x%p flags 0x%llx\n",
-			      snic_io_status_to_str(hdr_stat), cmnd_id, sc,
-			      CMD_FLAGS(sc));
-
-		ret = 1;
+			      "reset_cmpl: rqi is null,Hdr stat %s Tag 0x%x\n",
+			      snic_io_status_to_str(hdr_stat), cmnd_id);
 
-		return ret;
+		return 1;
 	}
 	/* stats */
 	spin_unlock_irqrestore(io_lock, flags);
 
 	/* scsi cleanup */
-	snic_hba_reset_scsi_cleanup(snic, sc);
+	snic_hba_reset_scsi_cleanup(snic);
 
 	SNIC_BUG_ON(snic_get_state(snic) != SNIC_OFFLINE &&
 		    snic_get_state(snic) != SNIC_FWRESET);
@@ -2203,7 +2173,7 @@ snic_device_reset(struct scsi_cmnd *sc)
  * snic_issue_hba_reset : Queues FW Reset Request.
  */
 static int
-snic_issue_hba_reset(struct snic *snic, struct scsi_cmnd *sc)
+snic_issue_hba_reset(struct snic *snic)
 {
 	struct snic_req_info *rqi = NULL;
 	struct snic_host_req *req = NULL;
@@ -2219,26 +2189,15 @@ snic_issue_hba_reset(struct snic *snic, struct scsi_cmnd *sc)
 		goto hba_rst_end;
 	}
 
-	if (snic_cmd_tag(sc) == SCSI_NO_TAG) {
-		memset(scsi_cmd_priv(sc), 0,
-			sizeof(struct snic_internal_io_state));
-		SNIC_HOST_INFO(snic->shost, "issu_hr:Host reset thru ioctl.\n");
-		rqi->sc = sc;
-	}
-
 	req = rqi_to_req(rqi);
 
-	io_lock = snic_io_lock_hash(snic, sc);
+	io_lock = snic_io_lock_tag(snic, snic->max_tag_id);
 	spin_lock_irqsave(io_lock, flags);
-	SNIC_BUG_ON(CMD_SP(sc) != NULL);
-	CMD_STATE(sc) = SNIC_IOREQ_PENDING;
-	CMD_SP(sc) = (char *) rqi;
-	CMD_FLAGS(sc) |= SNIC_IO_INITIALIZED;
 	snic->remove_wait = &wait;
 	spin_unlock_irqrestore(io_lock, flags);
 
 	/* Initialize Request */
-	snic_io_hdr_enc(&req->hdr, SNIC_REQ_HBA_RESET, 0, snic_cmd_tag(sc),
+	snic_io_hdr_enc(&req->hdr, SNIC_REQ_HBA_RESET, 0, snic->max_tag_id,
 			snic->config.hid, 0, (ulong) rqi);
 
 	req->u.reset.flags = 0;
@@ -2252,9 +2211,6 @@ snic_issue_hba_reset(struct snic *snic, struct scsi_cmnd *sc)
 		goto hba_rst_err;
 	}
 
-	spin_lock_irqsave(io_lock, flags);
-	CMD_FLAGS(sc) |= SNIC_HOST_RESET_ISSUED;
-	spin_unlock_irqrestore(io_lock, flags);
 	atomic64_inc(&snic->s_stats.reset.hba_resets);
 	SNIC_HOST_INFO(snic->shost, "Queued HBA Reset Successfully.\n");
 
@@ -2270,8 +2226,6 @@ snic_issue_hba_reset(struct snic *snic, struct scsi_cmnd *sc)
 
 	spin_lock_irqsave(io_lock, flags);
 	snic->remove_wait = NULL;
-	rqi = (struct snic_req_info *) CMD_SP(sc);
-	CMD_SP(sc) = NULL;
 	spin_unlock_irqrestore(io_lock, flags);
 
 	if (rqi)
@@ -2284,8 +2238,6 @@ snic_issue_hba_reset(struct snic *snic, struct scsi_cmnd *sc)
 hba_rst_err:
 	spin_lock_irqsave(io_lock, flags);
 	snic->remove_wait = NULL;
-	rqi = (struct snic_req_info *) CMD_SP(sc);
-	CMD_SP(sc) = NULL;
 	spin_unlock_irqrestore(io_lock, flags);
 
 	if (rqi)
@@ -2300,7 +2252,7 @@ snic_issue_hba_reset(struct snic *snic, struct scsi_cmnd *sc)
 } /* end of snic_issue_hba_reset */
 
 int
-snic_reset(struct Scsi_Host *shost, struct scsi_cmnd *sc)
+snic_reset(struct Scsi_Host *shost)
 {
 	struct snic *snic = shost_priv(shost);
 	enum snic_state sv_state;
@@ -2329,7 +2281,7 @@ snic_reset(struct Scsi_Host *shost, struct scsi_cmnd *sc)
 	while (atomic_read(&snic->ios_inflight))
 		schedule_timeout(msecs_to_jiffies(1));
 
-	ret = snic_issue_hba_reset(snic, sc);
+	ret = snic_issue_hba_reset(snic);
 	if (ret) {
 		SNIC_HOST_ERR(shost,
 			      "reset:Host Reset Failed w/ err %d.\n",
@@ -2368,7 +2320,7 @@ snic_host_reset(struct scsi_cmnd *sc)
 		      sc, sc->cmnd[0], scsi_cmd_to_rq(sc),
 		      snic_cmd_tag(sc), CMD_FLAGS(sc));
 
-	ret = snic_reset(shost, sc);
+	ret = snic_reset(shost);
 
 	SNIC_TRC(shost->host_no, snic_cmd_tag(sc), (ulong) sc,
 		 jiffies_to_msecs(jiffies - start_time),
-- 
2.35.3

[PATCH 12/17] snic: allocate device reset command

[Hannes Reinecke]

Allocate a command to send a device reset instead of relying
on using the command which triggered the device failure.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/snic/snic_scsi.c | 63 +++++++++++++++++------------------
 1 file changed, 31 insertions(+), 32 deletions(-)

diff --git a/drivers/scsi/snic/snic_scsi.c b/drivers/scsi/snic/snic_scsi.c
index f1ef781df837..06615619b84c 100644
--- a/drivers/scsi/snic/snic_scsi.c
+++ b/drivers/scsi/snic/snic_scsi.c
@@ -2091,70 +2091,69 @@ snic_unlink_and_release_req(struct snic *snic, struct scsi_cmnd *sc, int flag)
 int
 snic_device_reset(struct scsi_cmnd *sc)
 {
-	struct Scsi_Host *shost = sc->device->host;
+	struct scsi_device *sdev = sc->device;
+	struct Scsi_Host *shost = sdev->host;
 	struct snic *snic = shost_priv(shost);
+	struct request *req;
 	struct snic_req_info *rqi = NULL;
-	int tag = snic_cmd_tag(sc);
 	int start_time = jiffies;
 	int ret = FAILED;
 	int dr_supp = 0;
 
-	SNIC_SCSI_DBG(shost, "dev_reset:sc %p :0x%x :req = %p :tag = %d\n",
-		      sc, sc->cmnd[0], scsi_cmd_to_rq(sc),
-		      snic_cmd_tag(sc));
-	dr_supp = snic_dev_reset_supported(sc->device);
+	SNIC_SCSI_DBG(shost, "dev_reset\n");
+	dr_supp = snic_dev_reset_supported(sdev);
 	if (!dr_supp) {
 		/* device reset op is not supported */
 		SNIC_HOST_INFO(shost, "LUN Reset Op not supported.\n");
-		snic_unlink_and_release_req(snic, sc, SNIC_DEV_RST_NOTSUP);
-
-		goto dev_rst_end;
+		return ret;
 	}
 
 	if (unlikely(snic_get_state(snic) != SNIC_ONLINE)) {
-		snic_unlink_and_release_req(snic, sc, 0);
 		SNIC_HOST_ERR(shost, "Devrst: Parent Devs are not online.\n");
 
-		goto dev_rst_end;
+		return ret;
 	}
 
-	/* There is no tag when lun reset is issue through ioctl. */
-	if (unlikely(tag <= SNIC_NO_TAG)) {
-		SNIC_HOST_INFO(snic->shost,
-			       "Devrst: LUN Reset Recvd thru IOCTL.\n");
-
-		rqi = snic_req_init(snic, 0);
-		if (!rqi)
-			goto dev_rst_end;
-
-		memset(scsi_cmd_priv(sc), 0,
-			sizeof(struct snic_internal_io_state));
-		CMD_SP(sc) = (char *)rqi;
-		CMD_FLAGS(sc) = SNIC_NO_FLAGS;
+	rqi = snic_req_init(snic, 0);
+	if (!rqi)
+		return ret;
 
-		/* Add special tag for dr coming from user spc */
-		rqi->tm_tag = SNIC_TAG_IOCTL_DEV_RST;
-		rqi->sc = sc;
+	req = scsi_alloc_request(sdev->request_queue, REQ_OP_DRV_IN,
+				 BLK_MQ_REQ_NOWAIT);
+	if (!req) {
+		SNIC_HOST_ERR(snic->shost,
+			      "Devrst: TMF busy\n");
+		goto dev_rst_end;
 	}
+	sc = blk_mq_rq_to_pdu(req);
+	memset(scsi_cmd_priv(sc), 0,
+	       sizeof(struct snic_internal_io_state));
+	CMD_SP(sc) = (char *)rqi;
+	CMD_FLAGS(sc) = SNIC_NO_FLAGS;
 
+	/* Add special tag for dr coming from user spc */
+	rqi->tm_tag = SNIC_TAG_IOCTL_DEV_RST;
+	rqi->sc = sc;
+	WRITE_ONCE(req->state, MQ_RQ_IN_FLIGHT);
 	ret = snic_send_dr_and_wait(snic, sc);
 	if (ret) {
 		SNIC_HOST_ERR(snic->shost,
 			      "Devrst: IO w/ Tag %x Failed w/ err = %d\n",
-			      tag, ret);
-
+			      snic_cmd_tag(sc), ret);
+		blk_mq_set_request_complete(req);
 		snic_unlink_and_release_req(snic, sc, 0);
 
 		goto dev_rst_end;
 	}
-
+	blk_mq_set_request_complete(req);
 	ret = snic_dr_finish(snic, sc);
 
 dev_rst_end:
-	SNIC_TRC(snic->shost->host_no, tag, (ulong) sc,
+	SNIC_TRC(snic->shost->host_no, snic_cmd_tag(sc), (ulong) sc,
 		 jiffies_to_msecs(jiffies - start_time),
 		 0, SNIC_TRC_CMD(sc), SNIC_TRC_CMD_STATE_FLAGS(sc));
-
+	if (req)
+		blk_mq_free_request(req);
 	SNIC_SCSI_DBG(snic->shost,
 		      "Devrst: Returning from Device Reset : %s\n",
 		      (ret == SUCCESS) ? "SUCCESS" : "FAILED");
-- 
2.35.3

[PATCH 13/17] snic: Use scsi_host_busy_iter() to traverse commands

[Hannes Reinecke]

Use scsi_host_busy_iter() to traverse commands instead of hand-crafted
routines walking the command list.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
 drivers/scsi/snic/snic_scsi.c | 177 ++++++++++++++++------------------
 1 file changed, 84 insertions(+), 93 deletions(-)

diff --git a/drivers/scsi/snic/snic_scsi.c b/drivers/scsi/snic/snic_scsi.c
index 06615619b84c..48261a37d4a6 100644
--- a/drivers/scsi/snic/snic_scsi.c
+++ b/drivers/scsi/snic/snic_scsi.c
@@ -63,7 +63,7 @@ static const char * const snic_io_status_str[] = {
 	[SNIC_STAT_FATAL_ERROR]	= "SNIC_STAT_FATAL_ERROR",
 };
 
-static void snic_scsi_cleanup(struct snic *, int);
+static void snic_scsi_cleanup(struct snic *);
 
 const char *
 snic_state_to_str(unsigned int state)
@@ -958,7 +958,7 @@ snic_hba_reset_scsi_cleanup(struct snic *snic)
 	long act_ios = 0, act_fwreqs = 0;
 
 	SNIC_SCSI_DBG(snic->shost, "HBA Reset scsi cleanup.\n");
-	snic_scsi_cleanup(snic, snic->max_tag_id);
+	snic_scsi_cleanup(snic);
 
 	/* Update stats on pending IOs */
 	act_ios = atomic64_read(&st->io.active);
@@ -2357,53 +2357,36 @@ snic_cmpl_pending_tmreq(struct snic *snic, struct scsi_cmnd *sc)
 		complete(rqi->abts_done);
 }
 
-/*
- * snic_scsi_cleanup: Walks through tag map and releases the reqs
- */
-static void
-snic_scsi_cleanup(struct snic *snic, int ex_tag)
+static bool
+snic_scsi_cleanup_iter(struct scsi_cmnd *sc, void *data, bool reserved)
 {
+	struct snic *snic = data;
 	struct snic_req_info *rqi = NULL;
-	struct scsi_cmnd *sc = NULL;
 	spinlock_t *io_lock = NULL;
 	unsigned long flags;
-	int tag;
+	int tag = scsi_cmd_to_rq(sc)->tag;
 	u64 st_time = 0;
 
 	SNIC_SCSI_DBG(snic->shost, "sc_clean: scsi cleanup.\n");
 
-	for (tag = 0; tag < snic->max_tag_id; tag++) {
-		/* Skip ex_tag */
-		if (tag == ex_tag)
-			continue;
-
-		io_lock = snic_io_lock_tag(snic, tag);
-		spin_lock_irqsave(io_lock, flags);
-		sc = scsi_host_find_tag(snic->shost, tag);
-		if (!sc) {
-			spin_unlock_irqrestore(io_lock, flags);
-
-			continue;
-		}
-
-		if (unlikely(snic_tmreq_pending(sc))) {
-			/*
-			 * When FW Completes reset w/o sending completions
-			 * for outstanding ios.
-			 */
-			snic_cmpl_pending_tmreq(snic, sc);
-			spin_unlock_irqrestore(io_lock, flags);
-
-			continue;
-		}
+	io_lock = snic_io_lock_tag(snic, tag);
+	spin_lock_irqsave(io_lock, flags);
 
-		rqi = (struct snic_req_info *) CMD_SP(sc);
-		if (!rqi) {
-			spin_unlock_irqrestore(io_lock, flags);
+	if (unlikely(snic_tmreq_pending(sc))) {
+		/*
+		 * When FW Completes reset w/o sending completions
+		 * for outstanding ios.
+		 */
+		snic_cmpl_pending_tmreq(snic, sc);
+		spin_unlock_irqrestore(io_lock, flags);
 
-			goto cleanup;
-		}
+		return true;
+	}
 
+	rqi = (struct snic_req_info *) CMD_SP(sc);
+	if (!rqi)
+		spin_unlock_irqrestore(io_lock, flags);
+	else {
 		SNIC_SCSI_DBG(snic->shost,
 			      "sc_clean: sc %p, rqi %p, tag %d flags 0x%llx\n",
 			      sc, rqi, tag, CMD_FLAGS(sc));
@@ -2418,24 +2401,34 @@ snic_scsi_cleanup(struct snic *snic, int ex_tag)
 			       rqi, CMD_FLAGS(sc));
 
 		snic_release_req_buf(snic, rqi, sc);
+	}
+	sc->result = DID_TRANSPORT_DISRUPTED << 16;
+	SNIC_HOST_INFO(snic->shost,
+		       "sc_clean: DID_TRANSPORT_DISRUPTED for sc %p, Tag %d flags 0x%llx rqi %p duration %u msecs\n",
+		       sc, tag, CMD_FLAGS(sc), rqi,
+		       jiffies_to_msecs(jiffies - st_time));
 
-cleanup:
-		sc->result = DID_TRANSPORT_DISRUPTED << 16;
-		SNIC_HOST_INFO(snic->shost,
-			       "sc_clean: DID_TRANSPORT_DISRUPTED for sc %p, Tag %d flags 0x%llx rqi %p duration %u msecs\n",
-			       sc, scsi_cmd_to_rq(sc)->tag, CMD_FLAGS(sc), rqi,
-			       jiffies_to_msecs(jiffies - st_time));
+	/* Update IO stats */
+	snic_stats_update_io_cmpl(&snic->s_stats);
 
-		/* Update IO stats */
-		snic_stats_update_io_cmpl(&snic->s_stats);
+	SNIC_TRC(snic->shost->host_no, tag, (ulong) sc,
+		 jiffies_to_msecs(jiffies - st_time), 0,
+		 SNIC_TRC_CMD(sc),
+		 SNIC_TRC_CMD_STATE_FLAGS(sc));
 
-		SNIC_TRC(snic->shost->host_no, tag, (ulong) sc,
-			 jiffies_to_msecs(jiffies - st_time), 0,
-			 SNIC_TRC_CMD(sc),
-			 SNIC_TRC_CMD_STATE_FLAGS(sc));
+	scsi_done(sc);
+	return true;
+}
 
-		scsi_done(sc);
-	}
+/*
+ * snic_scsi_cleanup: Walks through tag map and releases the reqs
+ */
+static void
+snic_scsi_cleanup(struct snic *snic)
+{
+	SNIC_SCSI_DBG(snic->shost, "sc_clean: scsi cleanup\n");
+
+	scsi_host_busy_iter(snic->shost, snic_scsi_cleanup_iter, snic);
 } /* end of snic_scsi_cleanup */
 
 void
@@ -2443,7 +2436,7 @@ snic_shutdown_scsi_cleanup(struct snic *snic)
 {
 	SNIC_HOST_INFO(snic->shost, "Shutdown time SCSI Cleanup.\n");
 
-	snic_scsi_cleanup(snic, SCSI_NO_TAG);
+	snic_scsi_cleanup(snic);
 } /* end of snic_shutdown_scsi_cleanup */
 
 /*
@@ -2457,7 +2450,7 @@ snic_internal_abort_io(struct snic *snic, struct scsi_cmnd *sc, int tmf)
 	spinlock_t *io_lock = NULL;
 	unsigned long flags;
 	u32 sv_state = 0;
-	int ret = 0;
+	int ret = FAILED;
 
 	io_lock = snic_io_lock_hash(snic, sc);
 	spin_lock_irqsave(io_lock, flags);
@@ -2532,6 +2525,35 @@ snic_internal_abort_io(struct snic *snic, struct scsi_cmnd *sc, int tmf)
 	return ret;
 } /* end of snic_internal_abort_io */
 
+struct snic_tgt_scsi_abort_io_data {
+	struct snic *snic;
+	struct snic_tgt *tgt;
+	int tmf;
+	int abt_cnt;
+};
+
+static bool snic_tgt_scsi_abort_io_iter(struct scsi_cmnd *sc, void *data,
+					bool reserved)
+{
+	struct snic_tgt_scsi_abort_io_data *iter_data = data;
+	struct snic *snic = iter_data->snic;
+	struct snic_tgt *sc_tgt;
+	int ret;
+
+	sc_tgt = starget_to_tgt(scsi_target(sc->device));
+	if (sc_tgt != iter_data->tgt)
+		return true;
+
+	ret = snic_internal_abort_io(snic, sc, iter_data->tmf);
+	if (ret == SUCCESS)
+		iter_data->abt_cnt++;
+	else
+		SNIC_HOST_ERR(snic->shost,
+			      "tgt_abt_io: Tag %x, Failed w err = %d\n",
+			      scsi_cmd_to_rq(sc)->tag, ret);
+	return true;
+}
+
 /*
  * snic_tgt_scsi_abort_io : called by snic_tgt_del
  */
@@ -2539,11 +2561,9 @@ int
 snic_tgt_scsi_abort_io(struct snic_tgt *tgt)
 {
 	struct snic *snic = NULL;
-	struct scsi_cmnd *sc = NULL;
-	struct snic_tgt *sc_tgt = NULL;
-	spinlock_t *io_lock = NULL;
-	unsigned long flags;
-	int ret = 0, tag, abt_cnt = 0, tmf = 0;
+	struct snic_tgt_scsi_abort_io_data data = {
+		.abt_cnt = 0,
+	};
 
 	if (!tgt)
 		return -1;
@@ -2551,44 +2571,15 @@ snic_tgt_scsi_abort_io(struct snic_tgt *tgt)
 	snic = shost_priv(snic_tgt_to_shost(tgt));
 	SNIC_SCSI_DBG(snic->shost, "tgt_abt_io: Cleaning Pending IOs.\n");
 
+	data.snic = snic;
 	if (tgt->tdata.typ == SNIC_TGT_DAS)
-		tmf = SNIC_ITMF_ABTS_TASK;
+		data.tmf = SNIC_ITMF_ABTS_TASK;
 	else
-		tmf = SNIC_ITMF_ABTS_TASK_TERM;
-
-	for (tag = 0; tag < snic->max_tag_id; tag++) {
-		io_lock = snic_io_lock_tag(snic, tag);
-
-		spin_lock_irqsave(io_lock, flags);
-		sc = scsi_host_find_tag(snic->shost, tag);
-		if (!sc) {
-			spin_unlock_irqrestore(io_lock, flags);
-
-			continue;
-		}
+		data.tmf = SNIC_ITMF_ABTS_TASK_TERM;
 
-		sc_tgt = starget_to_tgt(scsi_target(sc->device));
-		if (sc_tgt != tgt) {
-			spin_unlock_irqrestore(io_lock, flags);
-
-			continue;
-		}
-		spin_unlock_irqrestore(io_lock, flags);
-
-		ret = snic_internal_abort_io(snic, sc, tmf);
-		if (ret < 0) {
-			SNIC_HOST_ERR(snic->shost,
-				      "tgt_abt_io: Tag %x, Failed w err = %d\n",
-				      tag, ret);
-
-			continue;
-		}
-
-		if (ret == SUCCESS)
-			abt_cnt++;
-	}
+	scsi_host_busy_iter(snic->shost, snic_tgt_scsi_abort_io_iter, &data);
 
-	SNIC_SCSI_DBG(snic->shost, "tgt_abt_io: abt_cnt = %d\n", abt_cnt);
+	SNIC_SCSI_DBG(snic->shost, "tgt_abt_io: abt_cnt = %d\n", data.abt_cnt);
 
 	return 0;
 } /* end of snic_tgt_scsi_abort_io */
-- 
2.35.3

[PATCH 14/17] fnic: allocate device reset command on the fly

[Hannes Reinecke]

Allocate a reset command on the fly instead of relying
on using the command which triggered the device failure.
This might fail if all available tags are busy, but in
that case it'll be safer to fall back to host reset anyway.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/fnic/fnic.h      |   1 -
 drivers/scsi/fnic/fnic_scsi.c | 108 +++++++++++++++-------------------
 drivers/scsi/snic/snic_scsi.c |   5 +-
 3 files changed, 48 insertions(+), 66 deletions(-)

diff --git a/drivers/scsi/fnic/fnic.h b/drivers/scsi/fnic/fnic.h
index 93c68931a593..8ffcafb4687f 100644
--- a/drivers/scsi/fnic/fnic.h
+++ b/drivers/scsi/fnic/fnic.h
@@ -236,7 +236,6 @@ struct fnic {
 	unsigned int wq_count;
 	unsigned int cq_count;
 
-	struct mutex sgreset_mutex;
 	struct dentry *fnic_stats_debugfs_host;
 	struct dentry *fnic_stats_debugfs_file;
 	struct dentry *fnic_reset_debugfs_file;
diff --git a/drivers/scsi/fnic/fnic_scsi.c b/drivers/scsi/fnic/fnic_scsi.c
index 9761b2c9db48..72352ac89eab 100644
--- a/drivers/scsi/fnic/fnic_scsi.c
+++ b/drivers/scsi/fnic/fnic_scsi.c
@@ -1984,7 +1984,6 @@ static inline int fnic_queue_dr_io_req(struct fnic *fnic,
 
 struct fnic_pending_aborts_iter_data {
 	struct fnic *fnic;
-	struct scsi_cmnd *lr_sc;
 	struct scsi_device *lun_dev;
 	int ret;
 };
@@ -2002,7 +2001,7 @@ static bool fnic_pending_aborts_iter(struct scsi_cmnd *sc, void *data)
 	DECLARE_COMPLETION_ONSTACK(tm_done);
 	enum fnic_ioreq_state old_ioreq_state;
 
-	if (sc == iter_data->lr_sc || sc->device != lun_dev)
+	if (sc->device != lun_dev)
 		return true;
 
 	io_lock = fnic_io_lock_tag(fnic, abt_tag);
@@ -2105,17 +2104,11 @@ static bool fnic_pending_aborts_iter(struct scsi_cmnd *sc, void *data)
 		return false;
 	}
 	fnic_priv(sc)->state = FNIC_IOREQ_ABTS_COMPLETE;
-
-	/* original sc used for lr is handled by dev reset code */
-	if (sc != iter_data->lr_sc)
-		fnic_priv(sc)->io_req = NULL;
+	fnic_priv(sc)->io_req = NULL;
 	spin_unlock_irqrestore(io_lock, flags);
 
-	/* original sc used for lr is handled by dev reset code */
-	if (sc != iter_data->lr_sc) {
-		fnic_release_ioreq_buf(fnic, io_req, sc);
-		mempool_free(io_req, fnic->io_req_pool);
-	}
+	fnic_release_ioreq_buf(fnic, io_req, sc);
+	mempool_free(io_req, fnic->io_req_pool);
 
 	/*
 	 * Any IO is returned during reset, it needs to call scsi_done
@@ -2135,8 +2128,7 @@ static bool fnic_pending_aborts_iter(struct scsi_cmnd *sc, void *data)
  * successfully aborted, 1 otherwise
  */
 static int fnic_clean_pending_aborts(struct fnic *fnic,
-				     struct scsi_cmnd *lr_sc,
-				     bool new_sc)
+				     struct scsi_cmnd *lr_sc)
 
 {
 	int ret = 0;
@@ -2146,9 +2138,6 @@ static int fnic_clean_pending_aborts(struct fnic *fnic,
 		.ret = SUCCESS,
 	};
 
-	if (new_sc)
-		iter_data.lr_sc = lr_sc;
-
 	scsi_host_busy_iter(fnic->lport->host,
 			    fnic_pending_aborts_iter, &iter_data);
 	if (iter_data.ret == FAILED) {
@@ -2174,7 +2163,8 @@ static int fnic_clean_pending_aborts(struct fnic *fnic,
  */
 int fnic_device_reset(struct scsi_cmnd *sc)
 {
-	struct request *rq = scsi_cmd_to_rq(sc);
+	struct scsi_device *sdev = sc->device;
+	struct request *req;
 	struct fc_lport *lp;
 	struct fnic *fnic;
 	struct fnic_io_req *io_req = NULL;
@@ -2187,15 +2177,17 @@ int fnic_device_reset(struct scsi_cmnd *sc)
 	struct scsi_lun fc_lun;
 	struct fnic_stats *fnic_stats;
 	struct reset_stats *reset_stats;
-	int tag = rq->tag;
+	int tag;
 	DECLARE_COMPLETION_ONSTACK(tm_done);
-	bool new_sc = 0;
 
 	/* Wait for rport to unblock */
-	fc_block_scsi_eh(sc);
+	rport = starget_to_rport(scsi_target(sdev));
+	ret = fc_block_rport(rport);
+	if (ret)
+		return ret;
 
 	/* Get local-port, check ready and link up */
-	lp = shost_priv(sc->device->host);
+	lp = shost_priv(sdev->host);
 
 	fnic = lport_priv(lp);
 	fnic_stats = &fnic->fnic_stats;
@@ -2203,53 +2195,46 @@ int fnic_device_reset(struct scsi_cmnd *sc)
 
 	atomic64_inc(&reset_stats->device_resets);
 
-	rport = starget_to_rport(scsi_target(sc->device));
 	FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
-		      "Device reset called FCID 0x%x, LUN 0x%llx sc 0x%p\n",
-		      rport->port_id, sc->device->lun, sc);
+		      "Device reset called FCID 0x%x, LUN 0x%llx\n",
+		      rport->port_id, sdev->lun);
 
 	if (lp->state != LPORT_ST_READY || !(lp->link_up))
-		goto fnic_device_reset_end;
+		return ret;
 
 	/* Check if remote port up */
 	if (fc_remote_port_chkready(rport)) {
 		atomic64_inc(&fnic_stats->misc_stats.rport_not_ready);
-		goto fnic_device_reset_end;
+		return ret;
 	}
 
-	fnic_priv(sc)->flags = FNIC_DEVICE_RESET;
-
-	if (unlikely(tag < 0)) {
-		/*
-		 * For device reset issued through sg3utils, we let
-		 * only one LUN_RESET to go through and use a special
-		 * tag equal to max_tag_id so that we don't have to allocate
-		 * or free it. It won't interact with tags
-		 * allocated by mid layer.
-		 */
-		mutex_lock(&fnic->sgreset_mutex);
-		tag = fnic->fnic_max_tag_id;
-		new_sc = 1;
+	req = scsi_alloc_request(sdev->request_queue, REQ_OP_DRV_IN,
+				 BLK_MQ_REQ_NOWAIT);
+	if (!req) {
+		FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
+			      "Device reset all commands busy\n");
+		return ret;
 	}
+	sc = blk_mq_rq_to_pdu(req);
+
+	tag = req->tag;
 	io_lock = fnic_io_lock_hash(fnic, sc);
 	spin_lock_irqsave(io_lock, flags);
 	io_req = fnic_priv(sc)->io_req;
+	if (io_req)
+		goto fnic_device_reset_end;
 
-	/*
-	 * If there is a io_req attached to this command, then use it,
-	 * else allocate a new one.
-	 */
+	io_req = mempool_alloc(fnic->io_req_pool, GFP_ATOMIC);
 	if (!io_req) {
-		io_req = mempool_alloc(fnic->io_req_pool, GFP_ATOMIC);
-		if (!io_req) {
-			spin_unlock_irqrestore(io_lock, flags);
-			goto fnic_device_reset_end;
-		}
-		memset(io_req, 0, sizeof(*io_req));
-		io_req->port_id = rport->port_id;
-		fnic_priv(sc)->io_req = io_req;
+		spin_unlock_irqrestore(io_lock, flags);
+		goto fnic_device_reset_end;
 	}
+	memset(io_req, 0, sizeof(*io_req));
+	io_req->port_id = rport->port_id;
+	fnic_priv(sc)->io_req = io_req;
+
 	io_req->dr_done = &tm_done;
+	fnic_priv(sc)->flags = FNIC_DEVICE_RESET;
 	fnic_priv(sc)->state = FNIC_IOREQ_CMD_PENDING;
 	fnic_priv(sc)->lr_status = FCPIO_INVALID_CODE;
 	spin_unlock_irqrestore(io_lock, flags);
@@ -2260,11 +2245,13 @@ int fnic_device_reset(struct scsi_cmnd *sc)
 	 * issue the device reset, if enqueue failed, clean up the ioreq
 	 * and break assoc with scsi cmd
 	 */
+	WRITE_ONCE(req->state, MQ_RQ_IN_FLIGHT);
 	if (fnic_queue_dr_io_req(fnic, sc, io_req)) {
 		spin_lock_irqsave(io_lock, flags);
 		io_req = fnic_priv(sc)->io_req;
 		if (io_req)
 			io_req->dr_done = NULL;
+		WRITE_ONCE(req->state, MQ_RQ_IDLE);
 		goto fnic_device_reset_clean;
 	}
 	spin_lock_irqsave(io_lock, flags);
@@ -2279,11 +2266,12 @@ int fnic_device_reset(struct scsi_cmnd *sc)
 				    msecs_to_jiffies(FNIC_LUN_RESET_TIMEOUT));
 
 	spin_lock_irqsave(io_lock, flags);
+	WRITE_ONCE(req->state, MQ_RQ_IDLE);
 	io_req = fnic_priv(sc)->io_req;
 	if (!io_req) {
 		spin_unlock_irqrestore(io_lock, flags);
 		FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
-				"io_req is null tag 0x%x sc 0x%p\n", tag, sc);
+				"io_req is null tag 0x%x\n", tag);
 		goto fnic_device_reset_end;
 	}
 	io_req->dr_done = NULL;
@@ -2326,7 +2314,7 @@ int fnic_device_reset(struct scsi_cmnd *sc)
 				spin_unlock_irqrestore(io_lock, flags);
 				FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
 				"Abort and terminate issued on Device reset "
-				"tag 0x%x sc 0x%p\n", tag, sc);
+				"tag 0x%x\n", tag);
 				break;
 			}
 		}
@@ -2364,7 +2352,7 @@ int fnic_device_reset(struct scsi_cmnd *sc)
 	 * the lun reset cmd. If all cmds get cleaned, the lun reset
 	 * succeeds
 	 */
-	if (fnic_clean_pending_aborts(fnic, sc, new_sc)) {
+	if (fnic_clean_pending_aborts(fnic, sc)) {
 		spin_lock_irqsave(io_lock, flags);
 		io_req = fnic_priv(sc)->io_req;
 		FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
@@ -2393,15 +2381,15 @@ int fnic_device_reset(struct scsi_cmnd *sc)
 	}
 
 fnic_device_reset_end:
-	FNIC_TRACE(fnic_device_reset, sc->device->host->host_no, rq->tag, sc,
+	FNIC_TRACE(fnic_device_reset, sc->device->host->host_no,
+		  scsi_cmd_to_rq(sc)->tag, sc,
 		  jiffies_to_msecs(jiffies - start_time),
 		  0, ((u64)sc->cmnd[0] << 32 |
 		  (u64)sc->cmnd[2] << 24 | (u64)sc->cmnd[3] << 16 |
 		  (u64)sc->cmnd[4] << 8 | sc->cmnd[5]),
 		  fnic_flags_and_state(sc));
 
-	if (new_sc)
-		mutex_unlock(&fnic->sgreset_mutex);
+	blk_mq_free_request(req);
 
 	FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
 		      "Returning from device reset %s\n",
@@ -2633,8 +2621,6 @@ static bool fnic_abts_pending_iter(struct scsi_cmnd *sc, void *data)
 	 * ignore this lun reset cmd or cmds that do not belong to
 	 * this lun
 	 */
-	if (iter_data->lr_sc && sc == iter_data->lr_sc)
-		return true;
 	if (iter_data->lun_dev && sc->device != iter_data->lun_dev)
 		return true;
 
@@ -2677,10 +2663,8 @@ int fnic_is_abts_pending(struct fnic *fnic, struct scsi_cmnd *lr_sc)
 		.ret = 0,
 	};
 
-	if (lr_sc) {
+	if (lr_sc)
 		iter_data.lun_dev = lr_sc->device;
-		iter_data.lr_sc = lr_sc;
-	}
 
 	/* walk again to check, if IOs are still pending in fw */
 	scsi_host_busy_iter(fnic->lport->host,
diff --git a/drivers/scsi/snic/snic_scsi.c b/drivers/scsi/snic/snic_scsi.c
index 48261a37d4a6..67b78029e557 100644
--- a/drivers/scsi/snic/snic_scsi.c
+++ b/drivers/scsi/snic/snic_scsi.c
@@ -2358,7 +2358,7 @@ snic_cmpl_pending_tmreq(struct snic *snic, struct scsi_cmnd *sc)
 }
 
 static bool
-snic_scsi_cleanup_iter(struct scsi_cmnd *sc, void *data, bool reserved)
+snic_scsi_cleanup_iter(struct scsi_cmnd *sc, void *data)
 {
 	struct snic *snic = data;
 	struct snic_req_info *rqi = NULL;
@@ -2532,8 +2532,7 @@ struct snic_tgt_scsi_abort_io_data {
 	int abt_cnt;
 };
 
-static bool snic_tgt_scsi_abort_io_iter(struct scsi_cmnd *sc, void *data,
-					bool reserved)
+static bool snic_tgt_scsi_abort_io_iter(struct scsi_cmnd *sc, void *data)
 {
 	struct snic_tgt_scsi_abort_io_data *iter_data = data;
 	struct snic *snic = iter_data->snic;
-- 
2.35.3

[PATCH 15/17] fnic: use fc_block_rport() correctly

[Hannes Reinecke]

Use fc_block_rport() instead of fc_block_scsi_eh() and evaluate
the return value to avoid issuing TMF commands when the port
is still blocked.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
 drivers/scsi/fnic/fnic_scsi.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/fnic/fnic_scsi.c b/drivers/scsi/fnic/fnic_scsi.c
index 72352ac89eab..25af91081baf 100644
--- a/drivers/scsi/fnic/fnic_scsi.c
+++ b/drivers/scsi/fnic/fnic_scsi.c
@@ -1719,9 +1719,6 @@ int fnic_abort_cmd(struct scsi_cmnd *sc)
 	unsigned long abt_issued_time;
 	DECLARE_COMPLETION_ONSTACK(tm_done);
 
-	/* Wait for rport to unblock */
-	fc_block_scsi_eh(sc);
-
 	/* Get local-port, check ready and link up */
 	lp = shost_priv(sc->device->host);
 
@@ -1731,6 +1728,10 @@ int fnic_abort_cmd(struct scsi_cmnd *sc)
 	term_stats = &fnic->fnic_stats.term_stats;
 
 	rport = starget_to_rport(scsi_target(sc->device));
+	ret = fc_block_rport(rport);
+	if (ret)
+		return ret;
+
 	FNIC_SCSI_DBG(KERN_DEBUG,
 		fnic->lport->host,
 		"Abort Cmd called FCID 0x%x, LUN 0x%llx TAG %x flags %x\n",
-- 
2.35.3

[PATCH 16/17] csiostor: use separate TMF command

[Hannes Reinecke]

Set one command aside as a TMF command, and use this command to
send the TMF. This avoids having to rely on the passed-in scsi
command when resetting the device.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/csiostor/csio_scsi.c | 72 ++++++++++++++++++++-----------
 1 file changed, 48 insertions(+), 24 deletions(-)

diff --git a/drivers/scsi/csiostor/csio_scsi.c b/drivers/scsi/csiostor/csio_scsi.c
index 05e1a63e00c3..08597de49b7f 100644
--- a/drivers/scsi/csiostor/csio_scsi.c
+++ b/drivers/scsi/csiostor/csio_scsi.c
@@ -1724,7 +1724,10 @@ csio_scsi_err_handler(struct csio_hw *hw, struct csio_ioreq *req)
 	}
 
 	cmnd->result = (((host_status) << 16) | scsi_status);
-	scsi_done(cmnd);
+	if (csio_priv(cmnd)->fc_tm_flags == FCP_TMF_LUN_RESET)
+		blk_mq_set_request_complete(scsi_cmd_to_rq(cmnd));
+	else
+		scsi_done(cmnd);
 
 	/* Wake up waiting threads */
 	csio_scsi_cmnd(req) = NULL;
@@ -1752,7 +1755,10 @@ csio_scsi_cbfn(struct csio_hw *hw, struct csio_ioreq *req)
 		}
 
 		cmnd->result = (((host_status) << 16) | scsi_status);
-		scsi_done(cmnd);
+		if (csio_priv(cmnd)->fc_tm_flags == FCP_TMF_LUN_RESET)
+			blk_mq_set_request_complete(scsi_cmd_to_rq(cmnd));
+		else
+			scsi_done(cmnd);
 		csio_scsi_cmnd(req) = NULL;
 		CSIO_INC_STATS(csio_hw_to_scsim(hw), n_tot_success);
 	} else {
@@ -2056,17 +2062,21 @@ csio_tm_cbfn(struct csio_hw *hw, struct csio_ioreq *req)
 
 	/* Wake up the TM handler thread */
 	csio_scsi_cmnd(req) = NULL;
+	cmnd->host_scribble = NULL;
 }
 
 static int
 csio_eh_lun_reset_handler(struct scsi_cmnd *cmnd)
 {
-	struct csio_lnode *ln = shost_priv(cmnd->device->host);
+	struct scsi_device *sdev = cmnd->device;
+	struct csio_lnode *ln = shost_priv(sdev->host);
 	struct csio_hw *hw = csio_lnode_to_hw(ln);
 	struct csio_scsim *scsim = csio_hw_to_scsim(hw);
-	struct csio_rnode *rn = (struct csio_rnode *)(cmnd->device->hostdata);
+	struct csio_rnode *rn = (struct csio_rnode *)(sdev->hostdata);
 	struct csio_ioreq *ioreq = NULL;
 	struct csio_scsi_qset *sqset;
+	struct scsi_cmnd *tmf_cmnd;
+	struct request *req;
 	unsigned long flags;
 	int retval;
 	int count, ret;
@@ -2074,17 +2084,17 @@ csio_eh_lun_reset_handler(struct scsi_cmnd *cmnd)
 	struct csio_scsi_level_data sld;
 
 	if (!rn)
-		goto fail;
+		return FAILED;
 
 	csio_dbg(hw, "Request to reset LUN:%llu (ssni:0x%x tgtid:%d)\n",
-		      cmnd->device->lun, rn->flowid, rn->scsi_id);
+		      sdev->lun, rn->flowid, rn->scsi_id);
 
 	if (!csio_is_lnode_ready(ln)) {
 		csio_err(hw,
 			 "LUN reset cannot be issued on non-ready"
 			 " local node vnpi:0x%x (LUN:%llu)\n",
-			 ln->vnp_flowid, cmnd->device->lun);
-		goto fail;
+			 ln->vnp_flowid, sdev->lun);
+		return FAILED;
 	}
 
 	/* Lnode is ready, now wait on rport node readiness */
@@ -2103,10 +2113,19 @@ csio_eh_lun_reset_handler(struct scsi_cmnd *cmnd)
 		csio_err(hw,
 			 "LUN reset cannot be issued on non-ready"
 			 " remote node ssni:0x%x (LUN:%llu)\n",
-			 rn->flowid, cmnd->device->lun);
-		goto fail;
+			 rn->flowid, sdev->lun);
+		return FAILED;
 	}
 
+	req = scsi_alloc_request(sdev->request_queue, REQ_OP_DRV_IN,
+				 BLK_MQ_REQ_NOWAIT);
+	if (!req) {
+		csio_err(hw,
+			 "LUN reset TMF already busy (LUN:%llu)\n",
+			 sdev->lun);
+		return FAILED;
+	}
+	tmf_cmnd = blk_mq_rq_to_pdu(req);
 	/* Get a free ioreq structure - SM is already set to uninit */
 	ioreq = csio_get_scsi_ioreq_lock(hw, scsim);
 
@@ -2123,11 +2142,11 @@ csio_eh_lun_reset_handler(struct scsi_cmnd *cmnd)
 	ioreq->iq_idx		= sqset->iq_idx;
 	ioreq->eq_idx		= sqset->eq_idx;
 
-	csio_scsi_cmnd(ioreq)	= cmnd;
-	cmnd->host_scribble	= (unsigned char *)ioreq;
-	csio_priv(cmnd)->wr_status = 0;
+	csio_scsi_cmnd(ioreq)	= tmf_cmnd;
+	tmf_cmnd->host_scribble	= (unsigned char *)ioreq;
+	csio_priv(tmf_cmnd)->wr_status = 0;
 
-	csio_priv(cmnd)->fc_tm_flags = FCP_TMF_LUN_RESET;
+	csio_priv(tmf_cmnd)->fc_tm_flags = FCP_TMF_LUN_RESET;
 	ioreq->tmo		= CSIO_SCSI_LUNRST_TMO_MS / 1000;
 
 	/*
@@ -2144,30 +2163,33 @@ csio_eh_lun_reset_handler(struct scsi_cmnd *cmnd)
 	sld.level = CSIO_LEV_LUN;
 	sld.lnode = ioreq->lnode;
 	sld.rnode = ioreq->rnode;
-	sld.oslun = cmnd->device->lun;
+	sld.oslun = sdev->lun;
 
+	WRITE_ONCE(req->state, MQ_RQ_IN_FLIGHT);
 	spin_lock_irqsave(&hw->lock, flags);
 	/* Kick off TM SM on the ioreq */
 	retval = csio_scsi_start_tm(ioreq);
 	spin_unlock_irqrestore(&hw->lock, flags);
 
 	if (retval != 0) {
+		blk_mq_set_request_complete(req);
 		csio_err(hw, "Failed to issue LUN reset, req:%p, status:%d\n",
 			    ioreq, retval);
+		tmf_cmnd->host_scribble = NULL;
 		goto fail_ret_ioreq;
 	}
 
 	csio_dbg(hw, "Waiting max %d secs for LUN reset completion\n",
 		    count * (CSIO_SCSI_TM_POLL_MS / 1000));
 	/* Wait for completion */
-	while ((((struct scsi_cmnd *)csio_scsi_cmnd(ioreq)) == cmnd)
+	while ((((struct scsi_cmnd *)csio_scsi_cmnd(ioreq)) == tmf_cmnd)
 								&& count--)
 		msleep(CSIO_SCSI_TM_POLL_MS);
 
 	/* LUN reset timed-out */
-	if (((struct scsi_cmnd *)csio_scsi_cmnd(ioreq)) == cmnd) {
+	if (((struct scsi_cmnd *)csio_scsi_cmnd(ioreq)) == tmf_cmnd) {
 		csio_err(hw, "LUN reset (%d:%llu) timed out\n",
-			 cmnd->device->id, cmnd->device->lun);
+			 sdev->id, sdev->lun);
 
 		spin_lock_irq(&hw->lock);
 		csio_scsi_drvcleanup(ioreq);
@@ -2178,10 +2200,10 @@ csio_eh_lun_reset_handler(struct scsi_cmnd *cmnd)
 	}
 
 	/* LUN reset returned, check cached status */
-	if (csio_priv(cmnd)->wr_status != FW_SUCCESS) {
+	if (csio_priv(tmf_cmnd)->wr_status != FW_SUCCESS) {
 		csio_err(hw, "LUN reset failed (%d:%llu), status: %d\n",
-			 cmnd->device->id, cmnd->device->lun,
-			 csio_priv(cmnd)->wr_status);
+			 sdev->id, sdev->lun,
+			 csio_priv(tmf_cmnd)->wr_status);
 		goto fail;
 	}
 
@@ -2201,7 +2223,7 @@ csio_eh_lun_reset_handler(struct scsi_cmnd *cmnd)
 	if (retval != 0) {
 		csio_err(hw,
 			 "Attempt to abort I/Os during LUN reset of %llu"
-			 " returned %d\n", cmnd->device->lun, retval);
+			 " returned %d\n", sdev->lun, retval);
 		/* Return I/Os back to active_q */
 		spin_lock_irq(&hw->lock);
 		list_splice_tail_init(&local_q, &scsim->active_q);
@@ -2212,14 +2234,16 @@ csio_eh_lun_reset_handler(struct scsi_cmnd *cmnd)
 	CSIO_INC_STATS(rn, n_lun_rst);
 
 	csio_info(hw, "LUN reset occurred (%d:%llu)\n",
-		  cmnd->device->id, cmnd->device->lun);
-
+		  sdev->id, sdev->lun);
+	blk_mq_free_request(req);
 	return SUCCESS;
 
 fail_ret_ioreq:
 	csio_put_scsi_ioreq_lock(hw, scsim, ioreq);
 fail:
 	CSIO_INC_STATS(rn, n_lun_rst_fail);
+	if (req)
+		blk_mq_free_request(req);
 	return FAILED;
 }
 
-- 
2.35.3

[PATCH 17/17] dc395x: Remove 'scmd' parameter from doing_srb_done()

[Hannes Reinecke]

doing_srb_done() has two passes, one for the 'going' list
and one for the 'waiting' list. When aborting commands on these
lists we should be calling scsi_done() for each command, and
not only for the command which triggered the error.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/dc395x.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/scsi/dc395x.c b/drivers/scsi/dc395x.c
index c8e86f8a631e..822d21e7da14 100644
--- a/drivers/scsi/dc395x.c
+++ b/drivers/scsi/dc395x.c
@@ -367,8 +367,7 @@ static inline void enable_msgout_abort(struct AdapterCtlBlk *acb,
 		struct ScsiReqBlk *srb);
 static void build_srb(struct scsi_cmnd *cmd, struct DeviceCtlBlk *dcb,
 		struct ScsiReqBlk *srb);
-static void doing_srb_done(struct AdapterCtlBlk *acb, u8 did_code,
-		struct scsi_cmnd *cmd, u8 force);
+static void doing_srb_done(struct AdapterCtlBlk *acb, u8 did_code, u8 force);
 static void scsi_reset_detect(struct AdapterCtlBlk *acb);
 static void pci_unmap_srb(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb);
 static void pci_unmap_srb_sense(struct AdapterCtlBlk *acb,
@@ -1182,7 +1181,7 @@ static int __dc395x_eh_bus_reset(struct scsi_cmnd *cmd)
 	set_basic_config(acb);
 
 	reset_dev_param(acb);
-	doing_srb_done(acb, DID_RESET, cmd, 0);
+	doing_srb_done(acb, DID_RESET, 0);
 	acb->active_dcb = NULL;
 	acb->acb_flag = 0;	/* RESET_DETECT, RESET_DONE ,RESET_DEV */
 	waiting_process_next(acb);
@@ -2896,7 +2895,7 @@ static void disconnect(struct AdapterCtlBlk *acb)
 		dcb->flag &= ~ABORT_DEV_;
 		acb->last_reset = jiffies + HZ / 2 + 1;
 		dprintkl(KERN_ERR, "disconnect: SRB_ABORT_SENT\n");
-		doing_srb_done(acb, DID_ABORT, srb->cmd, 1);
+		doing_srb_done(acb, DID_ABORT, 1);
 		waiting_process_next(acb);
 	} else {
 		if ((srb->state & (SRB_START_ + SRB_MSGOUT))
@@ -3337,8 +3336,7 @@ static void srb_done(struct AdapterCtlBlk *acb, struct DeviceCtlBlk *dcb,
 
 
 /* abort all cmds in our queues */
-static void doing_srb_done(struct AdapterCtlBlk *acb, u8 did_flag,
-		struct scsi_cmnd *cmd, u8 force)
+static void doing_srb_done(struct AdapterCtlBlk *acb, u8 did_flag, u8 force)
 {
 	struct DeviceCtlBlk *dcb;
 	dprintkl(KERN_INFO, "doing_srb_done: pids ");
@@ -3389,7 +3387,7 @@ static void doing_srb_done(struct AdapterCtlBlk *acb, u8 did_flag,
 			if (force) {
 				/* For new EH, we normally don't need to give commands back,
 				 * as they all complete or all time out */
-				scsi_done(cmd);
+				scsi_done(p);
 			}
 		}
 		if (!list_empty(&dcb->srb_waiting_list))
@@ -3475,7 +3473,7 @@ static void scsi_reset_detect(struct AdapterCtlBlk *acb)
 	} else {
 		acb->acb_flag |= RESET_DETECT;
 		reset_dev_param(acb);
-		doing_srb_done(acb, DID_RESET, NULL, 1);
+		doing_srb_done(acb, DID_RESET, 1);
 		/*DC395x_RecoverSRB( acb ); */
 		acb->active_dcb = NULL;
 		acb->acb_flag = 0;
-- 
2.35.3

Re: [PATCH 01/17] pmcraid: add missing scsi_device_put() in pmcraid_eh_target_reset_handler()

[Christoph Hellwig]

On Mon, Oct 16, 2023 at 11:24:14AM +0200, Hannes Reinecke wrote:
> When breaking out of a shost_for_each_device() loop one need to do
> an explicit scsi_device_put(). And while at it convert to use
> shost_priv() instead of a direct reference to ->hostdata.

While both part of the patch looks good, mixing these totally unrelated
bits doesn't seem like a good idea.

Re: [PATCH 03/17] bfa: Do not use scsi command to signal TMF status

[Christoph Hellwig]

On Mon, Oct 16, 2023 at 11:24:16AM +0200, Hannes Reinecke wrote:
> The bfa driver hijacks the scsi command to signal the TMF status,
> which will no longer work if the TMF handler will be converted.
> So rework TMF handling to not use a scsi command but rather add
> new TMF fields to the per-device structure.

This looks good from a cursory review:

Reviewed-by: Christoph Hellwig <hch@lst.de>

but I'm not sure I'd even trust the current state of this driver.
Given that it's a giant unmaintained mess maybe it's time to mark
it broken or remove it?

Re: [PATCH 04/17] aha152x: look for stuck command when resetting device

[Christoph Hellwig]

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH 05/17] a1000u2w: do not rely on the command for inia100_device_reset()

[Christoph Hellwig]

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH 08/17] xen-scsifront: rework scsifront_action_handler()

[Christoph Hellwig]

On Mon, Oct 16, 2023 at 11:24:21AM +0200, Hannes Reinecke wrote:
> Rework scsifront_action_handler() to add the SCSI device as the
> first argument, and select between abort and device reset by
> checking whether the scsi_cmnd argument is NULL.
> 
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> ---
>  drivers/scsi/xen-scsifront.c | 18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c
> index a0c13200d53a..26dd229aeb22 100644
> --- a/drivers/scsi/xen-scsifront.c
> +++ b/drivers/scsi/xen-scsifront.c
> @@ -668,11 +668,11 @@ static int scsifront_queuecommand(struct Scsi_Host *shost,
>   * We have to wait until an answer is returned. This answer contains the
>   * result to be returned to the requestor.
>   */
> -static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act)
> +static int scsifront_action_handler(struct scsi_device *sdev, struct scsi_cmnd *sc)

Please avoid the overly long line here.

Otherwise looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH 01/17] pmcraid: add missing scsi_device_put() in pmcraid_eh_target_reset_handler()

[Hannes Reinecke]

On 10/16/23 15:29, Christoph Hellwig wrote:
> On Mon, Oct 16, 2023 at 11:24:14AM +0200, Hannes Reinecke wrote:
>> When breaking out of a shost_for_each_device() loop one need to do
>> an explicit scsi_device_put(). And while at it convert to use
>> shost_priv() instead of a direct reference to ->hostdata.
> 
> While both part of the patch looks good, mixing these totally unrelated
> bits doesn't seem like a good idea.
> 
I can easily send this as a separate patch, seeing that it's a bugfix to 
the previous merge.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		           Kernel Storage Architect
hare@suse.de			                  +49 911 74053 688
SUSE Software Solutions Germany GmbH, Frankenstr. 146, 90461 Nürnberg
Managing Directors: I. Totev, A. Myers, A. McDonald, M. B. Moerman
(HRB 36809, AG Nürnberg)

Re: [PATCH 11/17] snic: reserve tag for TMF

[Christoph Hellwig]

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH 12/17] snic: allocate device reset command

[Christoph Hellwig]

On Mon, Oct 16, 2023 at 11:24:25AM +0200, Hannes Reinecke wrote:
> +	req = scsi_alloc_request(sdev->request_queue, REQ_OP_DRV_IN,
> +				 BLK_MQ_REQ_NOWAIT);
> +	if (!req) {
> +		SNIC_HOST_ERR(snic->shost,
> +			      "Devrst: TMF busy\n");
> +		goto dev_rst_end;

So if we fail this allocation, which can easily happen, we just fail
the reset and escalate.  If that's fine we probably want a big fat
comment about that here.

Re: [PATCH 12/17] snic: allocate device reset command

[Hannes Reinecke]

On 10/16/23 15:38, Christoph Hellwig wrote:
> On Mon, Oct 16, 2023 at 11:24:25AM +0200, Hannes Reinecke wrote:
>> +	req = scsi_alloc_request(sdev->request_queue, REQ_OP_DRV_IN,
>> +				 BLK_MQ_REQ_NOWAIT);
>> +	if (!req) {
>> +		SNIC_HOST_ERR(snic->shost,
>> +			      "Devrst: TMF busy\n");
>> +		goto dev_rst_end;
> 
> So if we fail this allocation, which can easily happen, we just fail
> the reset and escalate.  If that's fine we probably want a big fat
> comment about that here.
> 
Yes, that is precisely the intention.
If scsi_alloc_request() fails it means the we're on a quite busy system,
where _all_ requests are in error (remember, this is SCSI EH where all
commands are completed except for the failed ones).
And in that case a host reset is probably the better option.

But okay, I'll be adding a warning / comment here.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

Re: [PATCH 14/17] fnic: allocate device reset command on the fly

[Christoph Hellwig]

Just as for fnic a comment on the request allocation failure would
be good.  Otherwise this looks good to me.

Re: [PATCH 16/17] csiostor: use separate TMF command

[Christoph Hellwig]

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH 17/17] dc395x: Remove 'scmd' parameter from doing_srb_done()

[Christoph Hellwig]

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH 09/17] libiscsi: use cls_session as argument for target and session reset

[Mike Christie]

On 10/16/23 4:24 AM, Hannes Reinecke wrote:
> iscsi_eh_target_reset() and iscsi_eh_session_reset() only depend
> on the cls_session, so use that as an argument.
> 
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> ---
>  drivers/scsi/be2iscsi/be_main.c | 10 +++++++++-
>  drivers/scsi/libiscsi.c         | 21 +++++++++------------
>  include/scsi/libiscsi.h         |  2 +-
>  3 files changed, 19 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/scsi/be2iscsi/be_main.c b/drivers/scsi/be2iscsi/be_main.c
> index e48f14ad6dfd..441ad2ebc5d5 100644
> --- a/drivers/scsi/be2iscsi/be_main.c
> +++ b/drivers/scsi/be2iscsi/be_main.c
> @@ -385,6 +385,14 @@ static int beiscsi_eh_device_reset(struct scsi_cmnd *sc)
>  	return rc;
>  }
>  
> +static int beiscsi_eh_session_reset(struct scsi_cmnd *sc)
> +{
> +	struct iscsi_cls_session *cls_session;
> +
> +	cls_session = starget_to_session(scsi_target(sc->device));
> +	return iscsi_eh_session_reset(cls_session);
> +}
> +
>  /*------------------- PCI Driver operations and data ----------------- */
>  static const struct pci_device_id beiscsi_pci_id_table[] = {
>  	{ PCI_DEVICE(BE_VENDOR_ID, BE_DEVICE_ID1) },
> @@ -408,7 +416,7 @@ static const struct scsi_host_template beiscsi_sht = {
>  	.eh_timed_out = iscsi_eh_cmd_timed_out,
>  	.eh_abort_handler = beiscsi_eh_abort,
>  	.eh_device_reset_handler = beiscsi_eh_device_reset,
> -	.eh_target_reset_handler = iscsi_eh_session_reset,
> +	.eh_target_reset_handler = beiscsi_eh_session_reset,
>  	.shost_groups = beiscsi_groups,
>  	.sg_tablesize = BEISCSI_SGLIST_ELEMENTS,
>  	.can_queue = BE2_IO_DEPTH,
> diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
> index 0fda8905eabd..a561eefabb50 100644
> --- a/drivers/scsi/libiscsi.c
> +++ b/drivers/scsi/libiscsi.c
> @@ -2600,13 +2600,11 @@ EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
>   * This function will wait for a relogin, session termination from
>   * userspace, or a recovery/replacement timeout.
>   */
> -int iscsi_eh_session_reset(struct scsi_cmnd *sc)
> +int iscsi_eh_session_reset(struct iscsi_cls_session *cls_session)
>  {

Patch looks ok to me.

Reviewed-by: Mike Christie <michael.christie@oracle.com>

As an alternative to this approach though it might be easier to have
this function take a scsi_target. You won't need beiscsi_eh_session_reset
and for iscsi_eh_recover_target you can pass the scsi_target to
iscsi_eh_recover_target/iscsi_eh_session_reset.

Either way is ok to me though since we have to convert from scsi_target
to cls_session somewhere.

> -	struct iscsi_cls_session *cls_session;
>  	struct iscsi_session *session;
>  	struct iscsi_conn *conn;
>  
> -	cls_session = starget_to_session(scsi_target(sc->device));
>  	session = cls_session->dd_data;
>  
>  	mutex_lock(&session->eh_mutex);
> @@ -2653,7 +2651,7 @@ int iscsi_eh_session_reset(struct scsi_cmnd *sc)
>  }
>  EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
>  
> -static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
> +static void iscsi_prep_tgt_reset_pdu(struct iscsi_tm *hdr)
>  {
>  	memset(hdr, 0, sizeof(*hdr));
>  	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
> @@ -2668,19 +2666,16 @@ static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
>   *
>   * This will attempt to send a warm target reset.
>   */
> -static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
> +static int iscsi_eh_target_reset(struct iscsi_cls_session *cls_session)
>  {
> -	struct iscsi_cls_session *cls_session;
>  	struct iscsi_session *session;
>  	struct iscsi_conn *conn;
>  	struct iscsi_tm *hdr;
>  	int rc = FAILED;
>  
> -	cls_session = starget_to_session(scsi_target(sc->device));
>  	session = cls_session->dd_data;
>  
> -	ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
> -		     session->targetname);
> +	ISCSI_DBG_EH(session, "tgt Reset [tgt %s]\n", session->targetname);
>  
>  	mutex_lock(&session->eh_mutex);
>  	spin_lock_bh(&session->frwd_lock);
> @@ -2698,7 +2693,7 @@ static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
>  	session->tmf_state = TMF_QUEUED;
>  
>  	hdr = &session->tmhdr;
> -	iscsi_prep_tgt_reset_pdu(sc, hdr);
> +	iscsi_prep_tgt_reset_pdu(hdr);
>  
>  	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
>  				    session->tgt_reset_timeout)) {
> @@ -2750,11 +2745,13 @@ static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
>   */
>  int iscsi_eh_recover_target(struct scsi_cmnd *sc)
>  {
> +	struct iscsi_cls_session *cls_session;
>  	int rc;
>  
> -	rc = iscsi_eh_target_reset(sc);
> +	cls_session = starget_to_session(scsi_target(sc->device));
> +	rc = iscsi_eh_target_reset(cls_session);
>  	if (rc == FAILED)
> -		rc = iscsi_eh_session_reset(sc);
> +		rc = iscsi_eh_session_reset(cls_session);
>  	return rc;
>  }
>  EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
> diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
> index 7282555adfd5..7dddf785edd0 100644
> --- a/include/scsi/libiscsi.h
> +++ b/include/scsi/libiscsi.h
> @@ -390,7 +390,7 @@ struct iscsi_host {
>   */
>  extern int iscsi_eh_abort(struct scsi_cmnd *sc);
>  extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
> -extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
> +extern int iscsi_eh_session_reset(struct iscsi_cls_session *cls_session);
>  extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
>  extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
>  extern enum scsi_timeout_action iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc);

Re: [PATCH 09/17] libiscsi: use cls_session as argument for target and session reset

[Hannes Reinecke]

On 10/19/23 22:02, Mike Christie wrote:
> On 10/16/23 4:24 AM, Hannes Reinecke wrote:
>> iscsi_eh_target_reset() and iscsi_eh_session_reset() only depend
>> on the cls_session, so use that as an argument.
>>
>> Signed-off-by: Hannes Reinecke <hare@suse.de>
>> Reviewed-by: Christoph Hellwig <hch@lst.de>
>> ---
>>   drivers/scsi/be2iscsi/be_main.c | 10 +++++++++-
>>   drivers/scsi/libiscsi.c         | 21 +++++++++------------
>>   include/scsi/libiscsi.h         |  2 +-
>>   3 files changed, 19 insertions(+), 14 deletions(-)
>>
>> diff --git a/drivers/scsi/be2iscsi/be_main.c b/drivers/scsi/be2iscsi/be_main.c
>> index e48f14ad6dfd..441ad2ebc5d5 100644
>> --- a/drivers/scsi/be2iscsi/be_main.c
>> +++ b/drivers/scsi/be2iscsi/be_main.c
>> @@ -385,6 +385,14 @@ static int beiscsi_eh_device_reset(struct scsi_cmnd *sc)
>>   	return rc;
>>   }
>>   
>> +static int beiscsi_eh_session_reset(struct scsi_cmnd *sc)
>> +{
>> +	struct iscsi_cls_session *cls_session;
>> +
>> +	cls_session = starget_to_session(scsi_target(sc->device));
>> +	return iscsi_eh_session_reset(cls_session);
>> +}
>> +
>>   /*------------------- PCI Driver operations and data ----------------- */
>>   static const struct pci_device_id beiscsi_pci_id_table[] = {
>>   	{ PCI_DEVICE(BE_VENDOR_ID, BE_DEVICE_ID1) },
>> @@ -408,7 +416,7 @@ static const struct scsi_host_template beiscsi_sht = {
>>   	.eh_timed_out = iscsi_eh_cmd_timed_out,
>>   	.eh_abort_handler = beiscsi_eh_abort,
>>   	.eh_device_reset_handler = beiscsi_eh_device_reset,
>> -	.eh_target_reset_handler = iscsi_eh_session_reset,
>> +	.eh_target_reset_handler = beiscsi_eh_session_reset,
>>   	.shost_groups = beiscsi_groups,
>>   	.sg_tablesize = BEISCSI_SGLIST_ELEMENTS,
>>   	.can_queue = BE2_IO_DEPTH,
>> diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
>> index 0fda8905eabd..a561eefabb50 100644
>> --- a/drivers/scsi/libiscsi.c
>> +++ b/drivers/scsi/libiscsi.c
>> @@ -2600,13 +2600,11 @@ EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
>>    * This function will wait for a relogin, session termination from
>>    * userspace, or a recovery/replacement timeout.
>>    */
>> -int iscsi_eh_session_reset(struct scsi_cmnd *sc)
>> +int iscsi_eh_session_reset(struct iscsi_cls_session *cls_session)
>>   {
> 
> Patch looks ok to me.
> 
> Reviewed-by: Mike Christie <michael.christie@oracle.com>
> 
> As an alternative to this approach though it might be easier to have
> this function take a scsi_target. You won't need beiscsi_eh_session_reset
> and for iscsi_eh_recover_target you can pass the scsi_target to
> iscsi_eh_recover_target/iscsi_eh_session_reset.
> 
> Either way is ok to me though since we have to convert from scsi_target
> to cls_session somewhere.
> 
Yeah, one could do that. But the relationship between the target and
the host is not fixed, but rather depends on the driver and/or transport 
class. For simpler devices the host is the parent, for others there are 
elements in between so the parent device is something else entirely.
So for generic routines (like libiscsi) I prefer to use dedicated
elements such that the relationship is known.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

Re: [PATCH 09/17] libiscsi: use cls_session as argument for target and session reset

[michael.christie]

On 10/20/23 12:53 AM, Hannes Reinecke wrote:
> On 10/19/23 22:02, Mike Christie wrote:
>> On 10/16/23 4:24 AM, Hannes Reinecke wrote:
>>> iscsi_eh_target_reset() and iscsi_eh_session_reset() only depend
>>> on the cls_session, so use that as an argument.
>>>
>>> Signed-off-by: Hannes Reinecke <hare@suse.de>
>>> Reviewed-by: Christoph Hellwig <hch@lst.de>
>>> ---
>>>   drivers/scsi/be2iscsi/be_main.c | 10 +++++++++-
>>>   drivers/scsi/libiscsi.c         | 21 +++++++++------------
>>>   include/scsi/libiscsi.h         |  2 +-
>>>   3 files changed, 19 insertions(+), 14 deletions(-)
>>>
>>> diff --git a/drivers/scsi/be2iscsi/be_main.c b/drivers/scsi/be2iscsi/be_main.c
>>> index e48f14ad6dfd..441ad2ebc5d5 100644
>>> --- a/drivers/scsi/be2iscsi/be_main.c
>>> +++ b/drivers/scsi/be2iscsi/be_main.c
>>> @@ -385,6 +385,14 @@ static int beiscsi_eh_device_reset(struct scsi_cmnd *sc)
>>>       return rc;
>>>   }
>>>   +static int beiscsi_eh_session_reset(struct scsi_cmnd *sc)
>>> +{
>>> +    struct iscsi_cls_session *cls_session;
>>> +
>>> +    cls_session = starget_to_session(scsi_target(sc->device));
>>> +    return iscsi_eh_session_reset(cls_session);
>>> +}
>>> +
>>>   /*------------------- PCI Driver operations and data ----------------- */
>>>   static const struct pci_device_id beiscsi_pci_id_table[] = {
>>>       { PCI_DEVICE(BE_VENDOR_ID, BE_DEVICE_ID1) },
>>> @@ -408,7 +416,7 @@ static const struct scsi_host_template beiscsi_sht = {
>>>       .eh_timed_out = iscsi_eh_cmd_timed_out,
>>>       .eh_abort_handler = beiscsi_eh_abort,
>>>       .eh_device_reset_handler = beiscsi_eh_device_reset,
>>> -    .eh_target_reset_handler = iscsi_eh_session_reset,
>>> +    .eh_target_reset_handler = beiscsi_eh_session_reset,
>>>       .shost_groups = beiscsi_groups,
>>>       .sg_tablesize = BEISCSI_SGLIST_ELEMENTS,
>>>       .can_queue = BE2_IO_DEPTH,
>>> diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
>>> index 0fda8905eabd..a561eefabb50 100644
>>> --- a/drivers/scsi/libiscsi.c
>>> +++ b/drivers/scsi/libiscsi.c
>>> @@ -2600,13 +2600,11 @@ EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
>>>    * This function will wait for a relogin, session termination from
>>>    * userspace, or a recovery/replacement timeout.
>>>    */
>>> -int iscsi_eh_session_reset(struct scsi_cmnd *sc)
>>> +int iscsi_eh_session_reset(struct iscsi_cls_session *cls_session)
>>>   {
>>
>> Patch looks ok to me.
>>
>> Reviewed-by: Mike Christie <michael.christie@oracle.com>
>>
>> As an alternative to this approach though it might be easier to have
>> this function take a scsi_target. You won't need beiscsi_eh_session_reset
>> and for iscsi_eh_recover_target you can pass the scsi_target to
>> iscsi_eh_recover_target/iscsi_eh_session_reset.
>>
>> Either way is ok to me though since we have to convert from scsi_target
>> to cls_session somewhere.
>>
> Yeah, one could do that. But the relationship between the target and
> the host is not fixed, but rather depends on the driver and/or transport class. For simpler devices the host is the parent, for others there are elements in between so the parent device is something else entirely.
> So for generic routines (like libiscsi) I prefer to use dedicated
> elements such that the relationship is known.
> 

Based on the first part of your mail, I think you want what I suggested :)

libiscsi and the transport class setup the relationship between the scsi_target
and iscsi session. They handle deciding what is the targe's parent and pass the
session struct device as the parent. The drivers like be2iscsi don't know this
info normally (be2iscsi has to do it in the abort and reset function because
it works reverse of the other drivers). So, you don't want
beiscsi_eh_session_reset function since all it does it translate between target
and session which it shouldn't be handling since the class/lib handle it.

You just want to pass the libiscsi function iscsi_eh_session_reset the target and it
will figure out the relationship since it set it up.