[PATCHv7 00/13] scsi: remove legacy cmd_list implementation

[PATCHv7 00/13] scsi: remove legacy cmd_list implementation

[Hannes Reinecke]

Hi all,

with the switch to blk-mq we have an efficient way of looking up
outstanding commands via blk_mq_rq_busy_iter().
In this patchset the dpt_i2o and aacraid drivers are switched over
to using that function, and the now obsolete cmd_list implemantation
in the SCSI midlayer is removed.

As usual, comments and reviews are welcome.

Changes to v1:
- Fixup kbuild warning

Changes to v2:
- Add scsi_host_busy_iter()
- Include reviews from Christoph

Changes to v3:
- Include reviews from Christoph
- Add midlayer helper to terminate outstanding commands
- Split off aacraid modifcations into several patches

Changes to v4:
- Include reviews from Bart
- Add new midlayer helper scsi_host_quiesce()/scsi_host_resume()
- Improve comments

Changes to v5:
- Add reviews from Balsundar P.
- Rename scsi_host_flush_commands()
- Replace patch using scsi_host_quiesce() by using busy iterator

Changes to v6:
- Add reviews from Balsundar P.

Hannes Reinecke (13):
  dpt_i2o: rename adpt_i2o_to_scsi() to adpt_i2o_scsi_complete()
  scsi: add scsi_host_complete_all_commands() helper
  dpt_i2o: use scsi_host_complete_all_commands() to abort outstanding
    commands
  aacraid: Do not wait for outstanding write commands on
    synchronize_cache
  aacraid: use scsi_host_complete_all_commands() to terminate
    outstanding commands
  aacraid: replace aac_flush_ios() with midlayer helper
  aacraid: move scsi_(block,unblock)_requests out of
    _aac_reset_adapter()
  scsi: add scsi_host_(block,unblock) helper function
  aacraid: use scsi_host_(block,unblock) to block I/O
  scsi: add scsi_host_busy_iter()
  aacraid: use scsi_host_busy_iter() to wait for outstanding commands
  aacraid: use scsi_host_busy_iter() in get_num_of_incomplete_fibs()
  scsi: Remove cmd_list functionality

 drivers/scsi/aacraid/aachba.c   |  76 +------------------------
 drivers/scsi/aacraid/comminit.c |  35 ++++++------
 drivers/scsi/aacraid/commsup.c  |  46 +++------------
 drivers/scsi/aacraid/linit.c    | 120 ++++++++++++++++------------------------
 drivers/scsi/dpt_i2o.c          |  25 +--------
 drivers/scsi/dpti.h             |   3 +-
 drivers/scsi/hosts.c            |  61 ++++++++++++++++++++
 drivers/scsi/scsi.c             |  14 -----
 drivers/scsi/scsi_error.c       |   1 -
 drivers/scsi/scsi_lib.c         |  61 ++++++++++----------
 drivers/scsi/scsi_priv.h        |   2 -
 drivers/scsi/scsi_scan.c        |   1 -
 include/scsi/scsi_cmnd.h        |   1 -
 include/scsi/scsi_device.h      |   1 -
 include/scsi/scsi_host.h        |  10 +++-
 15 files changed, 178 insertions(+), 279 deletions(-)

-- 
2.16.4

[PATCH 01/13] dpt_i2o: rename adpt_i2o_to_scsi() to adpt_i2o_scsi_complete()

[Hannes Reinecke]

Rename the badly named function into adpt_i2o_scsi_complete(),
and make it a void function as the return value is never used.
This also fixes a potential use-after free as the return value
might be evaluated from the command result after the command
has been freed.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/dpt_i2o.c | 5 ++---
 drivers/scsi/dpti.h    | 2 +-
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/dpt_i2o.c b/drivers/scsi/dpt_i2o.c
index abc74fd474dc..c30ace9f251e 100644
--- a/drivers/scsi/dpt_i2o.c
+++ b/drivers/scsi/dpt_i2o.c
@@ -2173,7 +2173,7 @@ static irqreturn_t adpt_isr(int irq, void *dev_id)
 						 readl(reply + 12) - 1);
 			if(cmd != NULL){
 				scsi_dma_unmap(cmd);
-				adpt_i2o_to_scsi(reply, cmd);
+				adpt_i2o_scsi_complete(reply, cmd);
 			}
 		}
 		writel(m, pHba->reply_port);
@@ -2341,7 +2341,7 @@ static s32 adpt_scsi_host_alloc(adpt_hba* pHba, struct scsi_host_template *sht)
 }
 
 
-static s32 adpt_i2o_to_scsi(void __iomem *reply, struct scsi_cmnd* cmd)
+static void adpt_i2o_scsi_complete(void __iomem *reply, struct scsi_cmnd *cmd)
 {
 	adpt_hba* pHba;
 	u32 hba_status;
@@ -2459,7 +2459,6 @@ static s32 adpt_i2o_to_scsi(void __iomem *reply, struct scsi_cmnd* cmd)
 	if(cmd->scsi_done != NULL){
 		cmd->scsi_done(cmd);
 	} 
-	return cmd->result;
 }
 
 
diff --git a/drivers/scsi/dpti.h b/drivers/scsi/dpti.h
index 42b1e28b5884..3ec391134bb0 100644
--- a/drivers/scsi/dpti.h
+++ b/drivers/scsi/dpti.h
@@ -286,7 +286,7 @@ static s32 adpt_i2o_status_get(adpt_hba* pHba);
 static s32 adpt_i2o_init_outbound_q(adpt_hba* pHba);
 static s32 adpt_i2o_hrt_get(adpt_hba* pHba);
 static s32 adpt_scsi_to_i2o(adpt_hba* pHba, struct scsi_cmnd* cmd, struct adpt_device* dptdevice);
-static s32 adpt_i2o_to_scsi(void __iomem *reply, struct scsi_cmnd* cmd);
+static void adpt_i2o_scsi_complete(void __iomem *reply, struct scsi_cmnd *cmd);
 static s32 adpt_scsi_host_alloc(adpt_hba* pHba,struct scsi_host_template * sht);
 static s32 adpt_hba_reset(adpt_hba* pHba);
 static s32 adpt_i2o_reset_hba(adpt_hba* pHba);
-- 
2.16.4

[PATCH 02/13] scsi: add scsi_host_complete_all_commands() helper

[Hannes Reinecke]

Add a helper scsi_host_complete_all_commands() to terminate all outstanding
commands on a scsi host.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/hosts.c     | 28 ++++++++++++++++++++++++++++
 include/scsi/scsi_host.h |  1 +
 2 files changed, 29 insertions(+)

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 1d669e47b692..00ae9d43ce9f 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -650,3 +650,31 @@ void scsi_flush_work(struct Scsi_Host *shost)
 	flush_workqueue(shost->work_q);
 }
 EXPORT_SYMBOL_GPL(scsi_flush_work);
+
+static bool complete_all_cmds_iter(struct request *rq, void *data, bool rsvd)
+{
+	struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
+	int status = *(int *)data;
+
+	scsi_dma_unmap(scmd);
+	scmd->result = status << 16;
+	scmd->scsi_done(scmd);
+	return true;
+}
+
+/**
+ * scsi_host_complete_all_commands - Terminate all running commands
+ * @shost:	Scsi Host on which commands should be terminated
+ * @status:	Status to be set for the terminated commands
+ *
+ * There is no protection against modification of the number
+ * of outstanding commands. It is the responsibility of the
+ * caller to ensure that concurrent I/O submission and/or
+ * completion is stopped when calling this function.
+ */
+void scsi_host_complete_all_commands(struct Scsi_Host *shost, int status)
+{
+	blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter,
+				&status);
+}
+EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 7a97fb8104cf..d11a0a030dd3 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -732,6 +732,7 @@ extern int scsi_host_busy(struct Scsi_Host *shost);
 extern void scsi_host_put(struct Scsi_Host *t);
 extern struct Scsi_Host *scsi_host_lookup(unsigned short);
 extern const char *scsi_host_state_name(enum scsi_host_state);
+extern void scsi_host_complete_all_commands(struct Scsi_Host *shost, int status);
 
 static inline int __must_check scsi_add_host(struct Scsi_Host *host,
 					     struct device *dev)
-- 
2.16.4

[PATCH 03/13] dpt_i2o: use scsi_host_complete_all_commands() to abort outstanding commands

[Hannes Reinecke]

Rather than traversing all outstanding commands manually use the
scsi_host_complete_all_commands() helper to terminate all commands during
reset.
With that we can drop the cmd_list usage from the midlayer.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/dpt_i2o.c | 20 +-------------------
 drivers/scsi/dpti.h    |  1 -
 2 files changed, 1 insertion(+), 20 deletions(-)

diff --git a/drivers/scsi/dpt_i2o.c b/drivers/scsi/dpt_i2o.c
index c30ace9f251e..ac27323ea135 100644
--- a/drivers/scsi/dpt_i2o.c
+++ b/drivers/scsi/dpt_i2o.c
@@ -817,7 +817,7 @@ static int adpt_hba_reset(adpt_hba* pHba)
 	}
 	pHba->state &= ~DPTI_STATE_RESET;
 
-	adpt_fail_posted_scbs(pHba);
+	scsi_host_complete_all_commands(pHba->host, DID_RESET);
 	return 0;	/* return success */
 }
 
@@ -2335,7 +2335,6 @@ static s32 adpt_scsi_host_alloc(adpt_hba* pHba, struct scsi_host_template *sht)
 	host->unique_id = (u32)sys_tbl_pa + pHba->unit;
 	host->sg_tablesize = pHba->sg_tablesize;
 	host->can_queue = pHba->post_fifo_size;
-	host->use_cmd_list = 1;
 
 	return 0;
 }
@@ -2646,23 +2645,6 @@ static s32 adpt_i2o_reparse_lct(adpt_hba* pHba)
 	return 0;
 }
 
-static void adpt_fail_posted_scbs(adpt_hba* pHba)
-{
-	struct scsi_cmnd* 	cmd = NULL;
-	struct scsi_device* 	d = NULL;
-
-	shost_for_each_device(d, pHba->host) {
-		unsigned long flags;
-		spin_lock_irqsave(&d->list_lock, flags);
-		list_for_each_entry(cmd, &d->cmd_list, list) {
-			cmd->result = (DID_OK << 16) | (QUEUE_FULL <<1);
-			cmd->scsi_done(cmd);
-		}
-		spin_unlock_irqrestore(&d->list_lock, flags);
-	}
-}
-
-
 /*============================================================================
  *  Routines from i2o subsystem
  *============================================================================
diff --git a/drivers/scsi/dpti.h b/drivers/scsi/dpti.h
index 3ec391134bb0..72293b8450b6 100644
--- a/drivers/scsi/dpti.h
+++ b/drivers/scsi/dpti.h
@@ -295,7 +295,6 @@ static s32 adpt_i2o_reparse_lct(adpt_hba* pHba);
 static s32 adpt_send_nop(adpt_hba*pHba,u32 m);
 static void adpt_i2o_delete_hba(adpt_hba* pHba);
 static void adpt_inquiry(adpt_hba* pHba);
-static void adpt_fail_posted_scbs(adpt_hba* pHba);
 static struct adpt_device* adpt_find_device(adpt_hba* pHba, u32 chan, u32 id, u64 lun);
 static int adpt_install_hba(struct scsi_host_template* sht, struct pci_dev* pDev) ;
 static int adpt_i2o_online_hba(adpt_hba* pHba);
-- 
2.16.4

[PATCH 04/13] aacraid: Do not wait for outstanding write commands on synchronize_cache

[Hannes Reinecke]

There is no need to wait for outstanding write commands on synchronize
cache; the block layer is responsible for I/O scheduling, no need
to out-guess it on the driver layer.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Acked-by: Balsundar P <balsundar.b@microchip.com>
---
 drivers/scsi/aacraid/aachba.c | 76 ++-----------------------------------------
 1 file changed, 2 insertions(+), 74 deletions(-)

diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/aachba.c
index 33dbc051bff9..474d48eb1348 100644
--- a/drivers/scsi/aacraid/aachba.c
+++ b/drivers/scsi/aacraid/aachba.c
@@ -2601,9 +2601,7 @@ static int aac_write(struct scsi_cmnd * scsicmd)
 static void synchronize_callback(void *context, struct fib *fibptr)
 {
 	struct aac_synchronize_reply *synchronizereply;
-	struct scsi_cmnd *cmd;
-
-	cmd = context;
+	struct scsi_cmnd *cmd = context;
 
 	if (!aac_valid_context(cmd, fibptr))
 		return;
@@ -2644,77 +2642,8 @@ static int aac_synchronize(struct scsi_cmnd *scsicmd)
 	int status;
 	struct fib *cmd_fibcontext;
 	struct aac_synchronize *synchronizecmd;
-	struct scsi_cmnd *cmd;
 	struct scsi_device *sdev = scsicmd->device;
-	int active = 0;
 	struct aac_dev *aac;
-	u64 lba = ((u64)scsicmd->cmnd[2] << 24) | (scsicmd->cmnd[3] << 16) |
-		(scsicmd->cmnd[4] << 8) | scsicmd->cmnd[5];
-	u32 count = (scsicmd->cmnd[7] << 8) | scsicmd->cmnd[8];
-	unsigned long flags;
-
-	/*
-	 * Wait for all outstanding queued commands to complete to this
-	 * specific target (block).
-	 */
-	spin_lock_irqsave(&sdev->list_lock, flags);
-	list_for_each_entry(cmd, &sdev->cmd_list, list)
-		if (cmd->SCp.phase == AAC_OWNER_FIRMWARE) {
-			u64 cmnd_lba;
-			u32 cmnd_count;
-
-			if (cmd->cmnd[0] == WRITE_6) {
-				cmnd_lba = ((cmd->cmnd[1] & 0x1F) << 16) |
-					(cmd->cmnd[2] << 8) |
-					cmd->cmnd[3];
-				cmnd_count = cmd->cmnd[4];
-				if (cmnd_count == 0)
-					cmnd_count = 256;
-			} else if (cmd->cmnd[0] == WRITE_16) {
-				cmnd_lba = ((u64)cmd->cmnd[2] << 56) |
-					((u64)cmd->cmnd[3] << 48) |
-					((u64)cmd->cmnd[4] << 40) |
-					((u64)cmd->cmnd[5] << 32) |
-					((u64)cmd->cmnd[6] << 24) |
-					(cmd->cmnd[7] << 16) |
-					(cmd->cmnd[8] << 8) |
-					cmd->cmnd[9];
-				cmnd_count = (cmd->cmnd[10] << 24) |
-					(cmd->cmnd[11] << 16) |
-					(cmd->cmnd[12] << 8) |
-					cmd->cmnd[13];
-			} else if (cmd->cmnd[0] == WRITE_12) {
-				cmnd_lba = ((u64)cmd->cmnd[2] << 24) |
-					(cmd->cmnd[3] << 16) |
-					(cmd->cmnd[4] << 8) |
-					cmd->cmnd[5];
-				cmnd_count = (cmd->cmnd[6] << 24) |
-					(cmd->cmnd[7] << 16) |
-					(cmd->cmnd[8] << 8) |
-					cmd->cmnd[9];
-			} else if (cmd->cmnd[0] == WRITE_10) {
-				cmnd_lba = ((u64)cmd->cmnd[2] << 24) |
-					(cmd->cmnd[3] << 16) |
-					(cmd->cmnd[4] << 8) |
-					cmd->cmnd[5];
-				cmnd_count = (cmd->cmnd[7] << 8) |
-					cmd->cmnd[8];
-			} else
-				continue;
-			if (((cmnd_lba + cmnd_count) < lba) ||
-			  (count && ((lba + count) < cmnd_lba)))
-				continue;
-			++active;
-			break;
-		}
-
-	spin_unlock_irqrestore(&sdev->list_lock, flags);
-
-	/*
-	 *	Yield the processor (requeue for later)
-	 */
-	if (active)
-		return SCSI_MLQUEUE_DEVICE_BUSY;
 
 	aac = (struct aac_dev *)sdev->host->hostdata;
 	if (aac->in_reset)
@@ -2723,8 +2652,7 @@ static int aac_synchronize(struct scsi_cmnd *scsicmd)
 	/*
 	 *	Allocate and initialize a Fib
 	 */
-	if (!(cmd_fibcontext = aac_fib_alloc(aac)))
-		return SCSI_MLQUEUE_HOST_BUSY;
+	cmd_fibcontext = aac_fib_alloc_tag(aac, scsicmd);
 
 	aac_fib_init(cmd_fibcontext);
 
-- 
2.16.4

[PATCH 05/13] aacraid: use scsi_host_complete_all_commands() to terminate outstanding commands

[Hannes Reinecke]

Use scsi_host_complete_all_commands() to terminate all outstanding commands
instead, and change the command result for terminated commands to
the more common 'DID_RESET' instead of 'QUEUE_FULL'.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Balsundar P <balsundar.p@microchip.com>
---
 drivers/scsi/aacraid/commsup.c | 24 ++----------------------
 1 file changed, 2 insertions(+), 22 deletions(-)

diff --git a/drivers/scsi/aacraid/commsup.c b/drivers/scsi/aacraid/commsup.c
index 5a8a999606ea..8736a540a048 100644
--- a/drivers/scsi/aacraid/commsup.c
+++ b/drivers/scsi/aacraid/commsup.c
@@ -1478,8 +1478,6 @@ static int _aac_reset_adapter(struct aac_dev *aac, int forced, u8 reset_type)
 	int retval;
 	struct Scsi_Host *host;
 	struct scsi_device *dev;
-	struct scsi_cmnd *command;
-	struct scsi_cmnd *command_list;
 	int jafo = 0;
 	int bled;
 	u64 dmamask;
@@ -1607,26 +1605,8 @@ static int _aac_reset_adapter(struct aac_dev *aac, int forced, u8 reset_type)
 	 * This is where the assumption that the Adapter is quiesced
 	 * is important.
 	 */
-	command_list = NULL;
-	__shost_for_each_device(dev, host) {
-		unsigned long flags;
-		spin_lock_irqsave(&dev->list_lock, flags);
-		list_for_each_entry(command, &dev->cmd_list, list)
-			if (command->SCp.phase == AAC_OWNER_FIRMWARE) {
-				command->SCp.buffer = (struct scatterlist *)command_list;
-				command_list = command;
-			}
-		spin_unlock_irqrestore(&dev->list_lock, flags);
-	}
-	while ((command = command_list)) {
-		command_list = (struct scsi_cmnd *)command->SCp.buffer;
-		command->SCp.buffer = NULL;
-		command->result = DID_OK << 16
-		  | COMMAND_COMPLETE << 8
-		  | SAM_STAT_TASK_SET_FULL;
-		command->SCp.phase = AAC_OWNER_ERROR_HANDLER;
-		command->scsi_done(command);
-	}
+	scsi_host_complete_all_commands(host, DID_RESET);
+
 	/*
 	 * Any Device that was already marked offline needs to be marked
 	 * running
-- 
2.16.4

[PATCH 06/13] aacraid: replace aac_flush_ios() with midlayer helper

[Hannes Reinecke]

Use the midlayer helper scsi_host_complete_all_commands() to flush all
outstanding commands.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Balsundar P <balsundar.p@microchip.com>
---
 drivers/scsi/aacraid/linit.c | 24 ++----------------------
 1 file changed, 2 insertions(+), 22 deletions(-)

diff --git a/drivers/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c
index ee6bc2f9b80a..4d5b34e0d3a9 100644
--- a/drivers/scsi/aacraid/linit.c
+++ b/drivers/scsi/aacraid/linit.c
@@ -1977,26 +1977,6 @@ static void aac_remove_one(struct pci_dev *pdev)
 	}
 }
 
-static void aac_flush_ios(struct aac_dev *aac)
-{
-	int i;
-	struct scsi_cmnd *cmd;
-
-	for (i = 0; i < aac->scsi_host_ptr->can_queue; i++) {
-		cmd = (struct scsi_cmnd *)aac->fibs[i].callback_data;
-		if (cmd && (cmd->SCp.phase == AAC_OWNER_FIRMWARE)) {
-			scsi_dma_unmap(cmd);
-
-			if (aac->handle_pci_error)
-				cmd->result = DID_NO_CONNECT << 16;
-			else
-				cmd->result = DID_RESET << 16;
-
-			cmd->scsi_done(cmd);
-		}
-	}
-}
-
 static pci_ers_result_t aac_pci_error_detected(struct pci_dev *pdev,
 					enum pci_channel_state error)
 {
@@ -2013,7 +1993,7 @@ static pci_ers_result_t aac_pci_error_detected(struct pci_dev *pdev,
 
 		scsi_block_requests(aac->scsi_host_ptr);
 		aac_cancel_rescan_worker(aac);
-		aac_flush_ios(aac);
+		scsi_host_complete_all_commands(shost, DID_NO_CONNECT);
 		aac_release_resources(aac);
 
 		pci_disable_pcie_error_reporting(pdev);
@@ -2023,7 +2003,7 @@ static pci_ers_result_t aac_pci_error_detected(struct pci_dev *pdev,
 	case pci_channel_io_perm_failure:
 		aac->handle_pci_error = 1;
 
-		aac_flush_ios(aac);
+		scsi_host_complete_all_commands(shost, DID_NO_CONNECT);
 		return PCI_ERS_RESULT_DISCONNECT;
 	}
 
-- 
2.16.4

[PATCH 07/13] aacraid: move scsi_(block,unblock)_requests out of _aac_reset_adapter()

[Hannes Reinecke]

_aac_reset_adapter() only has one caller, and that one already calls
scsi_block_requests(). So move the calls out of _aac_reset_adapter()
to avoid calling scsi_block_requests() twice.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Acked-by: Balsundar P < Balsundar.P@microchip.com>
---
 drivers/scsi/aacraid/commsup.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/scsi/aacraid/commsup.c b/drivers/scsi/aacraid/commsup.c
index 8736a540a048..0d8c1ee40759 100644
--- a/drivers/scsi/aacraid/commsup.c
+++ b/drivers/scsi/aacraid/commsup.c
@@ -1476,7 +1476,7 @@ static int _aac_reset_adapter(struct aac_dev *aac, int forced, u8 reset_type)
 {
 	int index, quirks;
 	int retval;
-	struct Scsi_Host *host;
+	struct Scsi_Host *host = aac->scsi_host_ptr;
 	struct scsi_device *dev;
 	int jafo = 0;
 	int bled;
@@ -1493,8 +1493,6 @@ static int _aac_reset_adapter(struct aac_dev *aac, int forced, u8 reset_type)
 	 *	- The card is dead, or will be very shortly ;-/ so no new
 	 *	  commands are completing in the interrupt service.
 	 */
-	host = aac->scsi_host_ptr;
-	scsi_block_requests(host);
 	aac_adapter_disable_int(aac);
 	if (aac->thread && aac->thread->pid != current->pid) {
 		spin_unlock_irq(host->host_lock);
@@ -1619,7 +1617,6 @@ static int _aac_reset_adapter(struct aac_dev *aac, int forced, u8 reset_type)
 
 out:
 	aac->in_reset = 0;
-	scsi_unblock_requests(host);
 
 	/*
 	 * Issue bus rescan to catch any configuration that might have
@@ -1640,7 +1637,7 @@ int aac_reset_adapter(struct aac_dev *aac, int forced, u8 reset_type)
 {
 	unsigned long flagv = 0;
 	int retval;
-	struct Scsi_Host * host;
+	struct Scsi_Host * host = aac->scsi_host_ptr;
 	int bled;
 
 	if (spin_trylock_irqsave(&aac->fib_lock, flagv) == 0)
@@ -1658,7 +1655,6 @@ int aac_reset_adapter(struct aac_dev *aac, int forced, u8 reset_type)
 	 * target (block maximum 60 seconds). Although not necessary,
 	 * it does make us a good storage citizen.
 	 */
-	host = aac->scsi_host_ptr;
 	scsi_block_requests(host);
 
 	/* Quiesce build, flush cache, write through mode */
@@ -1670,6 +1666,8 @@ int aac_reset_adapter(struct aac_dev *aac, int forced, u8 reset_type)
 	retval = _aac_reset_adapter(aac, bled, reset_type);
 	spin_unlock_irqrestore(host->host_lock, flagv);
 
+	scsi_unblock_requests(host);
+
 	if ((forced < 2) && (retval == -ENODEV)) {
 		/* Unwind aac_send_shutdown() IOP_RESET unsupported/disabled */
 		struct fib * fibctx = aac_fib_alloc(aac);
-- 
2.16.4

[PATCH 08/13] scsi: add scsi_host_(block,unblock) helper function

[Hannes Reinecke]

Add helper functions to call scsi_internal_device_block()/
scsi_internal_device_unblock() for all attached devices on a
scsi host.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/scsi_lib.c  | 30 ++++++++++++++++++++++++++++++
 include/scsi/scsi_host.h |  2 ++
 2 files changed, 32 insertions(+)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 610ee41fa54c..a48a5727831b 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2845,6 +2845,36 @@ scsi_target_unblock(struct device *dev, enum scsi_device_state new_state)
 }
 EXPORT_SYMBOL_GPL(scsi_target_unblock);
 
+int
+scsi_host_block(struct Scsi_Host *shost)
+{
+	struct scsi_device *sdev;
+	int ret = 0;
+
+	shost_for_each_device(sdev, shost) {
+		ret = scsi_internal_device_block(sdev);
+		if (ret)
+			break;
+	}
+	return ret;
+}
+EXPORT_SYMBOL_GPL(scsi_host_block);
+
+int
+scsi_host_unblock(struct Scsi_Host *shost, int new_state)
+{
+	struct scsi_device *sdev;
+	int ret = 0;
+
+	shost_for_each_device(sdev, shost) {
+		ret = scsi_internal_device_unblock(sdev, new_state);
+		if (ret)
+			break;
+	}
+	return ret;
+}
+EXPORT_SYMBOL_GPL(scsi_host_unblock);
+
 /**
  * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt
  * @sgl:	scatter-gather list
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index d11a0a030dd3..a230e2c0e11f 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -757,6 +757,8 @@ static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
 
 extern void scsi_unblock_requests(struct Scsi_Host *);
 extern void scsi_block_requests(struct Scsi_Host *);
+extern int scsi_host_block(struct Scsi_Host *shost);
+extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state);
 
 struct class_container;
 
-- 
2.16.4

[PATCH 09/13] aacraid: use scsi_host_(block,unblock) to block I/O

[Hannes Reinecke]

Use scsi_host_block() and scsi_host_unblock() instead of
scsi_block_requests()/scsi_unblock_requests() to block and unblock I/O.
This has the advantage that the block layer will stop sending I/O
to the adapter instead of having the SCSI midlayer requeueing I/O
internally.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Acked-by: Balsundar P < Balsundar.P@microchip.com>
---
 drivers/scsi/aacraid/commsup.c | 14 ++------------
 drivers/scsi/aacraid/linit.c   | 15 ++++++---------
 2 files changed, 8 insertions(+), 21 deletions(-)

diff --git a/drivers/scsi/aacraid/commsup.c b/drivers/scsi/aacraid/commsup.c
index 0d8c1ee40759..9c227eefd14c 100644
--- a/drivers/scsi/aacraid/commsup.c
+++ b/drivers/scsi/aacraid/commsup.c
@@ -1477,7 +1477,6 @@ static int _aac_reset_adapter(struct aac_dev *aac, int forced, u8 reset_type)
 	int index, quirks;
 	int retval;
 	struct Scsi_Host *host = aac->scsi_host_ptr;
-	struct scsi_device *dev;
 	int jafo = 0;
 	int bled;
 	u64 dmamask;
@@ -1605,16 +1604,7 @@ static int _aac_reset_adapter(struct aac_dev *aac, int forced, u8 reset_type)
 	 */
 	scsi_host_complete_all_commands(host, DID_RESET);
 
-	/*
-	 * Any Device that was already marked offline needs to be marked
-	 * running
-	 */
-	__shost_for_each_device(dev, host) {
-		if (!scsi_device_online(dev))
-			scsi_device_set_state(dev, SDEV_RUNNING);
-	}
 	retval = 0;
-
 out:
 	aac->in_reset = 0;
 
@@ -1655,7 +1645,7 @@ int aac_reset_adapter(struct aac_dev *aac, int forced, u8 reset_type)
 	 * target (block maximum 60 seconds). Although not necessary,
 	 * it does make us a good storage citizen.
 	 */
-	scsi_block_requests(host);
+	scsi_host_block(host);
 
 	/* Quiesce build, flush cache, write through mode */
 	if (forced < 2)
@@ -1666,7 +1656,7 @@ int aac_reset_adapter(struct aac_dev *aac, int forced, u8 reset_type)
 	retval = _aac_reset_adapter(aac, bled, reset_type);
 	spin_unlock_irqrestore(host->host_lock, flagv);
 
-	scsi_unblock_requests(host);
+	retval = scsi_host_unblock(host, SDEV_RUNNING);
 
 	if ((forced < 2) && (retval == -ENODEV)) {
 		/* Unwind aac_send_shutdown() IOP_RESET unsupported/disabled */
diff --git a/drivers/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c
index 4d5b34e0d3a9..877464e9d520 100644
--- a/drivers/scsi/aacraid/linit.c
+++ b/drivers/scsi/aacraid/linit.c
@@ -1894,7 +1894,7 @@ static int aac_suspend(struct pci_dev *pdev, pm_message_t state)
 	struct Scsi_Host *shost = pci_get_drvdata(pdev);
 	struct aac_dev *aac = (struct aac_dev *)shost->hostdata;
 
-	scsi_block_requests(shost);
+	scsi_host_block(shost);
 	aac_cancel_rescan_worker(aac);
 	aac_send_shutdown(aac);
 
@@ -1930,7 +1930,7 @@ static int aac_resume(struct pci_dev *pdev)
 	* aac_send_shutdown() to block ioctls from upperlayer
 	*/
 	aac->adapter_shutdown = 0;
-	scsi_unblock_requests(shost);
+	scsi_host_unblock(shost, SDEV_RUNNING);
 
 	return 0;
 
@@ -1945,7 +1945,8 @@ static int aac_resume(struct pci_dev *pdev)
 static void aac_shutdown(struct pci_dev *dev)
 {
 	struct Scsi_Host *shost = pci_get_drvdata(dev);
-	scsi_block_requests(shost);
+
+	scsi_host_block(shost);
 	__aac_shutdown((struct aac_dev *)shost->hostdata);
 }
 
@@ -1991,7 +1992,7 @@ static pci_ers_result_t aac_pci_error_detected(struct pci_dev *pdev,
 	case pci_channel_io_frozen:
 		aac->handle_pci_error = 1;
 
-		scsi_block_requests(aac->scsi_host_ptr);
+		scsi_host_block(shost);
 		aac_cancel_rescan_worker(aac);
 		scsi_host_complete_all_commands(shost, DID_NO_CONNECT);
 		aac_release_resources(aac);
@@ -2044,7 +2045,6 @@ static pci_ers_result_t aac_pci_slot_reset(struct pci_dev *pdev)
 static void aac_pci_resume(struct pci_dev *pdev)
 {
 	struct Scsi_Host *shost = pci_get_drvdata(pdev);
-	struct scsi_device *sdev = NULL;
 	struct aac_dev *aac = (struct aac_dev *)shost_priv(shost);
 
 	if (aac_adapter_ioremap(aac, aac->base_size)) {
@@ -2071,10 +2071,7 @@ static void aac_pci_resume(struct pci_dev *pdev)
 	aac->adapter_shutdown = 0;
 	aac->handle_pci_error = 0;
 
-	shost_for_each_device(sdev, shost)
-		if (sdev->sdev_state == SDEV_OFFLINE)
-			sdev->sdev_state = SDEV_RUNNING;
-	scsi_unblock_requests(aac->scsi_host_ptr);
+	scsi_host_unblock(shost, SDEV_RUNNING);
 	aac_scan_host(aac);
 	pci_save_state(pdev);
 
-- 
2.16.4

[PATCH 10/13] scsi: add scsi_host_busy_iter()

[Hannes Reinecke]

Add an iterator scsi_host_busy_iter() to traverse all busy commands.
If locking against concurrent command completions is required it
has to be provided by the caller.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/hosts.c     | 33 +++++++++++++++++++++++++++++++++
 include/scsi/scsi_host.h |  5 +++++
 2 files changed, 38 insertions(+)

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 00ae9d43ce9f..91987b9fb45f 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -678,3 +678,36 @@ void scsi_host_complete_all_commands(struct Scsi_Host *shost, int status)
 				&status);
 }
 EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
+
+struct scsi_host_busy_iter_data {
+	scsi_host_busy_iter_fn *fn;
+	void *priv;
+};
+
+static bool __scsi_host_busy_iter_fn(struct request *req, void *priv,
+				   bool reserved)
+{
+	struct scsi_host_busy_iter_data *iter_data = priv;
+	struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
+
+	return iter_data->fn(sc, iter_data->priv, reserved);
+}
+
+/**
+ * scsi_host_busy_iter - Iterate over all busy commands
+ * @shost:	Pointer to Scsi_Host.
+ * @fn:		Function to call on each busy command
+ * @priv:	Data pointer passed to @fn
+ **/
+void scsi_host_busy_iter(struct Scsi_Host *shost,
+			 scsi_host_busy_iter_fn *fn, void *priv)
+{
+	struct scsi_host_busy_iter_data iter_data = {
+		.fn = fn,
+		.priv = priv,
+	};
+
+	blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
+				&iter_data);
+}
+EXPORT_SYMBOL_GPL(scsi_host_busy_iter);
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index a230e2c0e11f..f5300ad887c4 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -760,6 +760,11 @@ extern void scsi_block_requests(struct Scsi_Host *);
 extern int scsi_host_block(struct Scsi_Host *shost);
 extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state);
 
+typedef bool (scsi_host_busy_iter_fn)(struct scsi_cmnd *, void *, bool);
+
+void scsi_host_busy_iter(struct Scsi_Host *,
+			 scsi_host_busy_iter_fn *fn, void *priv);
+
 struct class_container;
 
 /*
-- 
2.16.4

[PATCH 11/13] aacraid: use scsi_host_busy_iter() to wait for outstanding commands

[Hannes Reinecke]

Instead of traversing the list of possible commands by hands we
should be using scsi_host_busy_iter() to figure out if there are
outstanding commands.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Acked-by: Balsundar P < Balsundar.P@microchip.com>
---
 drivers/scsi/aacraid/comminit.c | 35 +++++++++++++++++------------------
 1 file changed, 17 insertions(+), 18 deletions(-)

diff --git a/drivers/scsi/aacraid/comminit.c b/drivers/scsi/aacraid/comminit.c
index f75878d773cf..355b16f0b145 100644
--- a/drivers/scsi/aacraid/comminit.c
+++ b/drivers/scsi/aacraid/comminit.c
@@ -272,36 +272,35 @@ static void aac_queue_init(struct aac_dev * dev, struct aac_queue * q, u32 *mem,
 	q->entries = qsize;
 }
 
+static bool wait_for_io_iter(struct scsi_cmnd *cmd, void *data, bool rsvd)
+{
+	int *active = data;
+
+	if (cmd->SCp.phase == AAC_OWNER_FIRMWARE)
+		*active = *active + 1;
+	return true;
+}
 static void aac_wait_for_io_completion(struct aac_dev *aac)
 {
-	unsigned long flagv = 0;
-	int i = 0;
+	int i = 0, active;
 
 	for (i = 60; i; --i) {
-		struct scsi_device *dev;
-		struct scsi_cmnd *command;
-		int active = 0;
-
-		__shost_for_each_device(dev, aac->scsi_host_ptr) {
-			spin_lock_irqsave(&dev->list_lock, flagv);
-			list_for_each_entry(command, &dev->cmd_list, list) {
-				if (command->SCp.phase == AAC_OWNER_FIRMWARE) {
-					active++;
-					break;
-				}
-			}
-			spin_unlock_irqrestore(&dev->list_lock, flagv);
-			if (active)
-				break;
 
-		}
+		active = 0;
+		scsi_host_busy_iter(aac->scsi_host_ptr,
+				    wait_for_io_iter, &active);
 		/*
 		 * We can exit If all the commands are complete
 		 */
 		if (active == 0)
 			break;
+		dev_info(&aac->pdev->dev,
+			 "Wait for %d commands to complete\n", active);
 		ssleep(1);
 	}
+	if (active)
+		dev_err(&aac->pdev->dev,
+			"%d outstanding commands during shutdown\n", active);
 }
 
 /**
-- 
2.16.4

[PATCH 12/13] aacraid: use scsi_host_busy_iter() in get_num_of_incomplete_fibs()

[Hannes Reinecke]

Use the scsi midlayer helper to traverse the number of outstanding
commands. This also eliminates the last usage for the cmd_list
functionality so we can drop it.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Acked-by: Balsundar P <balsundar.p@microchip.com>
---
 drivers/scsi/aacraid/linit.c | 81 ++++++++++++++++++++++----------------------
 1 file changed, 41 insertions(+), 40 deletions(-)

diff --git a/drivers/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c
index 877464e9d520..d0d1f3072c0c 100644
--- a/drivers/scsi/aacraid/linit.c
+++ b/drivers/scsi/aacraid/linit.c
@@ -622,54 +622,56 @@ static int aac_ioctl(struct scsi_device *sdev, unsigned int cmd,
 	return aac_do_ioctl(dev, cmd, arg);
 }
 
-static int get_num_of_incomplete_fibs(struct aac_dev *aac)
+struct fib_count_data {
+	int mlcnt;
+	int llcnt;
+	int ehcnt;
+	int fwcnt;
+	int krlcnt;
+};
+
+static bool fib_count_iter(struct scsi_cmnd *scmnd, void *data, bool reserved)
 {
+	struct fib_count_data *fib_count = data;
+
+	switch (scmnd->SCp.phase) {
+	case AAC_OWNER_FIRMWARE:
+		fib_count->fwcnt++;
+		break;
+	case AAC_OWNER_ERROR_HANDLER:
+		fib_count->ehcnt++;
+		break;
+	case AAC_OWNER_LOWLEVEL:
+		fib_count->llcnt++;
+		break;
+	case AAC_OWNER_MIDLEVEL:
+		fib_count->mlcnt++;
+		break;
+	default:
+		fib_count->krlcnt++;
+		break;
+	}
+	return true;
+}
 
-	unsigned long flags;
-	struct scsi_device *sdev = NULL;
+/* Called during SCSI EH, so we don't need to block requests */
+static int get_num_of_incomplete_fibs(struct aac_dev *aac)
+{
 	struct Scsi_Host *shost = aac->scsi_host_ptr;
-	struct scsi_cmnd *scmnd = NULL;
 	struct device *ctrl_dev;
+	struct fib_count_data fcnt = { };
 
-	int mlcnt  = 0;
-	int llcnt  = 0;
-	int ehcnt  = 0;
-	int fwcnt  = 0;
-	int krlcnt = 0;
-
-	__shost_for_each_device(sdev, shost) {
-		spin_lock_irqsave(&sdev->list_lock, flags);
-		list_for_each_entry(scmnd, &sdev->cmd_list, list) {
-			switch (scmnd->SCp.phase) {
-			case AAC_OWNER_FIRMWARE:
-				fwcnt++;
-				break;
-			case AAC_OWNER_ERROR_HANDLER:
-				ehcnt++;
-				break;
-			case AAC_OWNER_LOWLEVEL:
-				llcnt++;
-				break;
-			case AAC_OWNER_MIDLEVEL:
-				mlcnt++;
-				break;
-			default:
-				krlcnt++;
-				break;
-			}
-		}
-		spin_unlock_irqrestore(&sdev->list_lock, flags);
-	}
+	scsi_host_busy_iter(shost, fib_count_iter, &fcnt);
 
 	ctrl_dev = &aac->pdev->dev;
 
-	dev_info(ctrl_dev, "outstanding cmd: midlevel-%d\n", mlcnt);
-	dev_info(ctrl_dev, "outstanding cmd: lowlevel-%d\n", llcnt);
-	dev_info(ctrl_dev, "outstanding cmd: error handler-%d\n", ehcnt);
-	dev_info(ctrl_dev, "outstanding cmd: firmware-%d\n", fwcnt);
-	dev_info(ctrl_dev, "outstanding cmd: kernel-%d\n", krlcnt);
+	dev_info(ctrl_dev, "outstanding cmd: midlevel-%d\n", fcnt.mlcnt);
+	dev_info(ctrl_dev, "outstanding cmd: lowlevel-%d\n", fcnt.llcnt);
+	dev_info(ctrl_dev, "outstanding cmd: error handler-%d\n", fcnt.ehcnt);
+	dev_info(ctrl_dev, "outstanding cmd: firmware-%d\n", fcnt.fwcnt);
+	dev_info(ctrl_dev, "outstanding cmd: kernel-%d\n", fcnt.krlcnt);
 
-	return mlcnt + llcnt + ehcnt + fwcnt;
+	return fcnt.mlcnt + fcnt.llcnt + fcnt.ehcnt + fcnt.fwcnt;
 }
 
 static int aac_eh_abort(struct scsi_cmnd* cmd)
@@ -1675,7 +1677,6 @@ static int aac_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 	shost->irq = pdev->irq;
 	shost->unique_id = unique_id;
 	shost->max_cmd_len = 16;
-	shost->use_cmd_list = 1;
 
 	if (aac_cfg_major == AAC_CHARDEV_NEEDS_REINIT)
 		aac_init_char();
-- 
2.16.4

[PATCH 13/13] scsi: Remove cmd_list functionality

[Hannes Reinecke]

Remove cmd_list functionality; no users left.
With that the scsi_put_command() becomes empty,
so remove that one, too.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi.c        | 14 --------------
 drivers/scsi/scsi_error.c  |  1 -
 drivers/scsi/scsi_lib.c    | 31 -------------------------------
 drivers/scsi/scsi_priv.h   |  2 --
 drivers/scsi/scsi_scan.c   |  1 -
 include/scsi/scsi_cmnd.h   |  1 -
 include/scsi/scsi_device.h |  1 -
 include/scsi/scsi_host.h   |  2 --
 8 files changed, 53 deletions(-)

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 930e4803d888..3c4bb92a451d 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -94,20 +94,6 @@ EXPORT_SYMBOL(scsi_logging_level);
 ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain);
 EXPORT_SYMBOL(scsi_sd_pm_domain);
 
-/**
- * scsi_put_command - Free a scsi command block
- * @cmd: command block to free
- *
- * Returns:	Nothing.
- *
- * Notes:	The command must not belong to any lists.
- */
-void scsi_put_command(struct scsi_cmnd *cmd)
-{
-	scsi_del_cmd_from_list(cmd);
-	BUG_ON(delayed_work_pending(&cmd->abort_work));
-}
-
 #ifdef CONFIG_SCSI_LOGGING
 void scsi_log_send(struct scsi_cmnd *cmd)
 {
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index ae2fa170f6ad..978be1602f71 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -2412,7 +2412,6 @@ scsi_ioctl_reset(struct scsi_device *dev, int __user *arg)
 	wake_up(&shost->host_wait);
 	scsi_run_host_queues(shost);
 
-	scsi_put_command(scmd);
 	kfree(rq);
 
 out_put_autopm_host:
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index a48a5727831b..258a428a0a3f 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -562,7 +562,6 @@ static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
 {
 	scsi_mq_free_sgtables(cmd);
 	scsi_uninit_cmd(cmd);
-	scsi_del_cmd_from_list(cmd);
 }
 
 /* Returns false when no more bytes to process, true if there are more */
@@ -1098,35 +1097,6 @@ static void scsi_cleanup_rq(struct request *rq)
 	}
 }
 
-/* Add a command to the list used by the aacraid and dpt_i2o drivers */
-void scsi_add_cmd_to_list(struct scsi_cmnd *cmd)
-{
-	struct scsi_device *sdev = cmd->device;
-	struct Scsi_Host *shost = sdev->host;
-	unsigned long flags;
-
-	if (shost->use_cmd_list) {
-		spin_lock_irqsave(&sdev->list_lock, flags);
-		list_add_tail(&cmd->list, &sdev->cmd_list);
-		spin_unlock_irqrestore(&sdev->list_lock, flags);
-	}
-}
-
-/* Remove a command from the list used by the aacraid and dpt_i2o drivers */
-void scsi_del_cmd_from_list(struct scsi_cmnd *cmd)
-{
-	struct scsi_device *sdev = cmd->device;
-	struct Scsi_Host *shost = sdev->host;
-	unsigned long flags;
-
-	if (shost->use_cmd_list) {
-		spin_lock_irqsave(&sdev->list_lock, flags);
-		BUG_ON(list_empty(&cmd->list));
-		list_del_init(&cmd->list);
-		spin_unlock_irqrestore(&sdev->list_lock, flags);
-	}
-}
-
 /* Called after a request has been started. */
 void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
 {
@@ -1160,7 +1130,6 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
 	if (in_flight)
 		__set_bit(SCMD_STATE_INFLIGHT, &cmd->state);
 
-	scsi_add_cmd_to_list(cmd);
 }
 
 static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev,
diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index 3bff9f7aa684..5eab5da4efe7 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -84,8 +84,6 @@ int scsi_eh_get_sense(struct list_head *work_q,
 int scsi_noretry_cmd(struct scsi_cmnd *scmd);
 
 /* scsi_lib.c */
-extern void scsi_add_cmd_to_list(struct scsi_cmnd *cmd);
-extern void scsi_del_cmd_from_list(struct scsi_cmnd *cmd);
 extern int scsi_maybe_unblock_host(struct scsi_device *sdev);
 extern void scsi_device_unbusy(struct scsi_device *sdev, struct scsi_cmnd *cmd);
 extern void scsi_queue_insert(struct scsi_cmnd *cmd, int reason);
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 058079f915f1..f2437a7570ce 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -236,7 +236,6 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
 	sdev->sdev_state = SDEV_CREATED;
 	INIT_LIST_HEAD(&sdev->siblings);
 	INIT_LIST_HEAD(&sdev->same_target_siblings);
-	INIT_LIST_HEAD(&sdev->cmd_list);
 	INIT_LIST_HEAD(&sdev->starved_entry);
 	INIT_LIST_HEAD(&sdev->event_list);
 	spin_lock_init(&sdev->list_lock);
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index a2849bb9cd19..80ac89e47b47 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -159,7 +159,6 @@ static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
 	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
 }
 
-extern void scsi_put_command(struct scsi_cmnd *);
 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 
 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index f8312a3e5b42..f146a4557787 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -110,7 +110,6 @@ struct scsi_device {
 	atomic_t device_blocked;	/* Device returned QUEUE_FULL. */
 
 	spinlock_t list_lock;
-	struct list_head cmd_list;	/* queue of in use SCSI Command structures */
 	struct list_head starved_entry;
 	unsigned short queue_depth;	/* How deep of a queue we want */
 	unsigned short max_queue_depth;	/* max queue depth */
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index f5300ad887c4..18321103a04f 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -624,8 +624,6 @@ struct Scsi_Host {
 	/* The controller does not support WRITE SAME */
 	unsigned no_write_same:1;
 
-	unsigned use_cmd_list:1;
-
 	/* Host responded with short (<36 bytes) INQUIRY result */
 	unsigned short_inquiry:1;
 
-- 
2.16.4

Re: [PATCH 08/13] scsi: add scsi_host_(block,unblock) helper function

[Bart Van Assche]

On 2020-02-13 06:04, Hannes Reinecke wrote:
> Add helper functions to call scsi_internal_device_block()/
> scsi_internal_device_unblock() for all attached devices on a
> scsi host.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: [PATCH 02/13] scsi: add scsi_host_complete_all_commands() helper

[Christoph Hellwig]

On Thu, Feb 13, 2020 at 03:04:11PM +0100, Hannes Reinecke wrote:
>  extern void scsi_host_put(struct Scsi_Host *t);
>  extern struct Scsi_Host *scsi_host_lookup(unsigned short);
>  extern const char *scsi_host_state_name(enum scsi_host_state);
> +extern void scsi_host_complete_all_commands(struct Scsi_Host *shost, int status);

This adds an > 80 char line.  And externs on function declarations in
headers are never needed anyway.

Re: [PATCH 04/13] aacraid: Do not wait for outstanding write commands on synchronize_cache

[Christoph Hellwig]

On Thu, Feb 13, 2020 at 03:04:13PM +0100, Hannes Reinecke wrote:
> There is no need to wait for outstanding write commands on synchronize
> cache; the block layer is responsible for I/O scheduling, no need
> to out-guess it on the driver layer.
> 
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> Acked-by: Balsundar P <balsundar.b@microchip.com>

Looks good,

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

Re: [PATCH 06/13] aacraid: replace aac_flush_ios() with midlayer helper

[Christoph Hellwig]

On Thu, Feb 13, 2020 at 03:04:15PM +0100, Hannes Reinecke wrote:
> Use the midlayer helper scsi_host_complete_all_commands() to flush all
> outstanding commands.
> 
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> Reviewed-by: Bart Van Assche <bvanassche@acm.org>
> Acked-by: Balsundar P <balsundar.p@microchip.com>

Looks good,

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

Re: [PATCH 07/13] aacraid: move scsi_(block,unblock)_requests out of _aac_reset_adapter()

[Christoph Hellwig]

On Thu, Feb 13, 2020 at 03:04:16PM +0100, Hannes Reinecke wrote:
> _aac_reset_adapter() only has one caller, and that one already calls
> scsi_block_requests(). So move the calls out of _aac_reset_adapter()
> to avoid calling scsi_block_requests() twice.

Looks good,

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

Re: [PATCH 08/13] scsi: add scsi_host_(block,unblock) helper function

[Christoph Hellwig]

On Thu, Feb 13, 2020 at 03:04:17PM +0100, Hannes Reinecke wrote:

> +extern int scsi_host_block(struct Scsi_Host *shost);
> +extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state);

No need for the externs here.  Otherwise looks good:

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

Re: [PATCH 09/13] aacraid: use scsi_host_(block,unblock) to block I/O

[Christoph Hellwig]

On Thu, Feb 13, 2020 at 03:04:18PM +0100, Hannes Reinecke wrote:
> Use scsi_host_block() and scsi_host_unblock() instead of
> scsi_block_requests()/scsi_unblock_requests() to block and unblock I/O.
> This has the advantage that the block layer will stop sending I/O
> to the adapter instead of having the SCSI midlayer requeueing I/O
> internally.

Looks good,

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

Re: [PATCH 10/13] scsi: add scsi_host_busy_iter()

[Christoph Hellwig]

> +/**
> + * scsi_host_busy_iter - Iterate over all busy commands
> + * @shost:	Pointer to Scsi_Host.
> + * @fn:		Function to call on each busy command
> + * @priv:	Data pointer passed to @fn
> + **/

Can you add the context information from the commit log to the kerneldoc
comment her?

> +typedef bool (scsi_host_busy_iter_fn)(struct scsi_cmnd *, void *, bool);

Is there much of a point in having this typedef?

> +
> +void scsi_host_busy_iter(struct Scsi_Host *,
> +			 scsi_host_busy_iter_fn *fn, void *priv);

Any reason to spell out to argument names, but not the third one?

Re: [PATCH 11/13] aacraid: use scsi_host_busy_iter() to wait for outstanding commands

[Christoph Hellwig]

On Thu, Feb 13, 2020 at 03:04:20PM +0100, Hannes Reinecke wrote:
> Instead of traversing the list of possible commands by hands we
> should be using scsi_host_busy_iter() to figure out if there are
> outstanding commands.
> 
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> Acked-by: Balsundar P < Balsundar.P@microchip.com>

Looks good,

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

Re: [PATCH 12/13] aacraid: use scsi_host_busy_iter() in get_num_of_incomplete_fibs()

[Christoph Hellwig]

On Thu, Feb 13, 2020 at 03:04:21PM +0100, Hannes Reinecke wrote:
> Use the scsi midlayer helper to traverse the number of outstanding
> commands. This also eliminates the last usage for the cmd_list
> functionality so we can drop it.
> 
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> Acked-by: Balsundar P <balsundar.p@microchip.com>

Looks good,

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

Re: [PATCH 13/13] scsi: Remove cmd_list functionality

[Christoph Hellwig]

On Thu, Feb 13, 2020 at 03:04:22PM +0100, Hannes Reinecke wrote:
> Remove cmd_list functionality; no users left.
> With that the scsi_put_command() becomes empty,
> so remove that one, too.

Maybe use up all 73 chars for the commit message?

Otherwise looks good:

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

Re: [PATCH 02/13] scsi: add scsi_host_complete_all_commands() helper

[Hannes Reinecke]

On 2/26/20 6:39 PM, Christoph Hellwig wrote:
> On Thu, Feb 13, 2020 at 03:04:11PM +0100, Hannes Reinecke wrote:
>>   extern void scsi_host_put(struct Scsi_Host *t);
>>   extern struct Scsi_Host *scsi_host_lookup(unsigned short);
>>   extern const char *scsi_host_state_name(enum scsi_host_state);
>> +extern void scsi_host_complete_all_commands(struct Scsi_Host *shost, int status);
> 
> This adds an > 80 char line.  And externs on function declarations in
> headers are never needed anyway.
> 
Ok, will be cleaning it up.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke            Teamlead Storage & Networking
hare@suse.de                               +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer

Re: [PATCH 10/13] scsi: add scsi_host_busy_iter()

[Hannes Reinecke]

On 2/26/20 6:45 PM, Christoph Hellwig wrote:
>> +/**
>> + * scsi_host_busy_iter - Iterate over all busy commands
>> + * @shost:	Pointer to Scsi_Host.
>> + * @fn:		Function to call on each busy command
>> + * @priv:	Data pointer passed to @fn
>> + **/
> 
> Can you add the context information from the commit log to the kerneldoc
> comment her?
> 
Yes.

>> +typedef bool (scsi_host_busy_iter_fn)(struct scsi_cmnd *, void *, bool);
> 
> Is there much of a point in having this typedef?
> 
Hmm. Idea was to save typing, but as it's being used only once I'll drop
it for the next round.

>> +
>> +void scsi_host_busy_iter(struct Scsi_Host *,
>> +			 scsi_host_busy_iter_fn *fn, void *priv);
> 
> Any reason to spell out to argument names, but not the third one?
> 
Probably not. Will be fixing it up.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke            Teamlead Storage & Networking
hare@suse.de                               +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer

Re: [PATCH 02/13] scsi: add scsi_host_complete_all_commands() helper

[Hannes Reinecke]

On 2/26/20 6:39 PM, Christoph Hellwig wrote:
> On Thu, Feb 13, 2020 at 03:04:11PM +0100, Hannes Reinecke wrote:
>>   extern void scsi_host_put(struct Scsi_Host *t);
>>   extern struct Scsi_Host *scsi_host_lookup(unsigned short);
>>   extern const char *scsi_host_state_name(enum scsi_host_state);
>> +extern void scsi_host_complete_all_commands(struct Scsi_Host *shost, int status);
> 
> This adds an > 80 char line.  And externs on function declarations in
> headers are never needed anyway.
> 
As for the "extern": I'm just following what all the other function 
declarations in the header file do.

If your argument is valid it would apply to all declarations in this 
file, not just this one.
And that would be a separate patch.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke            Teamlead Storage & Networking
hare@suse.de                               +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer

[PATCH 10/13] scsi: add scsi_host_busy_iter()

[Hannes Reinecke]

Add an iterator scsi_host_busy_iter() to traverse all busy commands.
If locking against concurrent command completions is required it
has to be provided by the caller.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/hosts.c     | 37 +++++++++++++++++++++++++++++++++++++
 include/scsi/scsi_host.h |  3 +++
 2 files changed, 40 insertions(+)

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 00ae9d43ce9f..7ec91c3a66ca 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -678,3 +678,40 @@ void scsi_host_complete_all_commands(struct Scsi_Host *shost, int status)
 				&status);
 }
 EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
+
+struct scsi_host_busy_iter_data {
+	bool (*fn)(struct scsi_cmnd *, void *, bool);
+	void *priv;
+};
+
+static bool __scsi_host_busy_iter_fn(struct request *req, void *priv,
+				   bool reserved)
+{
+	struct scsi_host_busy_iter_data *iter_data = priv;
+	struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
+
+	return iter_data->fn(sc, iter_data->priv, reserved);
+}
+
+/**
+ * scsi_host_busy_iter - Iterate over all busy commands
+ * @shost:	Pointer to Scsi_Host.
+ * @fn:		Function to call on each busy command
+ * @priv:	Data pointer passed to @fn
+ *
+ * If locking against concurrent command completions is required
+ * ithas to be provided by the caller
+ **/
+void scsi_host_busy_iter(struct Scsi_Host *shost,
+			 bool (*fn)(struct scsi_cmnd *, void *, bool),
+			 void *priv)
+{
+	struct scsi_host_busy_iter_data iter_data = {
+		.fn = fn,
+		.priv = priv,
+	};
+
+	blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
+				&iter_data);
+}
+EXPORT_SYMBOL_GPL(scsi_host_busy_iter);
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 613c3820028e..eff12445b823 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -761,6 +761,9 @@ extern void scsi_block_requests(struct Scsi_Host *);
 extern int scsi_host_block(struct Scsi_Host *shost);
 extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state);
 
+void scsi_host_busy_iter(struct Scsi_Host *,
+			 bool (*fn)(struct scsi_cmnd *, void *, bool), void *priv);
+
 struct class_container;
 
 /*
-- 
2.16.4

[PATCH 10/13] scsi: add scsi_host_busy_iter()

[Hannes Reinecke]

Add an iterator scsi_host_busy_iter() to traverse all busy commands.
If locking against concurrent command completions is required it
has to be provided by the caller.

Signed-off-by: Hannes Reinecke <hare@suse.com>
---
 drivers/scsi/hosts.c     | 33 +++++++++++++++++++++++++++++++++
 include/scsi/scsi_host.h |  5 +++++
 2 files changed, 38 insertions(+)

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 00ae9d43ce9f..91987b9fb45f 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -678,3 +678,36 @@ void scsi_host_complete_all_commands(struct Scsi_Host *shost, int status)
 				&status);
 }
 EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
+
+struct scsi_host_busy_iter_data {
+	scsi_host_busy_iter_fn *fn;
+	void *priv;
+};
+
+static bool __scsi_host_busy_iter_fn(struct request *req, void *priv,
+				   bool reserved)
+{
+	struct scsi_host_busy_iter_data *iter_data = priv;
+	struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
+
+	return iter_data->fn(sc, iter_data->priv, reserved);
+}
+
+/**
+ * scsi_host_busy_iter - Iterate over all busy commands
+ * @shost:	Pointer to Scsi_Host.
+ * @fn:		Function to call on each busy command
+ * @priv:	Data pointer passed to @fn
+ **/
+void scsi_host_busy_iter(struct Scsi_Host *shost,
+			 scsi_host_busy_iter_fn *fn, void *priv)
+{
+	struct scsi_host_busy_iter_data iter_data = {
+		.fn = fn,
+		.priv = priv,
+	};
+
+	blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
+				&iter_data);
+}
+EXPORT_SYMBOL_GPL(scsi_host_busy_iter);
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 71472eace583..02ac2c61b5af 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -763,6 +763,11 @@ extern void scsi_block_requests(struct Scsi_Host *);
 extern int scsi_host_block(struct Scsi_Host *shost);
 extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state);
 
+typedef bool (scsi_host_busy_iter_fn)(struct scsi_cmnd *, void *, bool);
+
+void scsi_host_busy_iter(struct Scsi_Host *,
+			 scsi_host_busy_iter_fn *fn, void *priv);
+
 struct class_container;
 
 /*
-- 
2.16.4