[PATCHv8 00/13] scsi: remove legacy cmd_list implementation

[PATCHv8 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.

Changes to v7:
- Add reviews from Christoph

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            |  65 ++++++++++++++++++++++
 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        |   9 ++-
 15 files changed, 181 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 |  2 ++
 2 files changed, 30 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..25bef781cbe1 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -732,6 +732,8 @@ 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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 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>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.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 25bef781cbe1..613c3820028e 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -758,6 +758,8 @@ 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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 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     | 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 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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 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 4b9fdfab77d9..56c24a73e0c7 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 25b0aaaf5ae8..22b6585e28b4 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -83,8 +83,6 @@ 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 eff12445b823..74dc7d4f2a96 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: [PATCHv8 00/13] scsi: remove legacy cmd_list implementation

[Martin K. Petersen]

Hannes,

> 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.

Applied to 5.7/scsi-queue, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering

[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 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.

Cc: Adaptec OEM Raid Solutions <aacraid@microsemi.com>
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