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Commit 30bd7df8 authored by Mike Christie's avatar Mike Christie Committed by James Bottomley
Browse files

[SCSI] scsi_error: add target reset handler 



The problem is that serveral drivers are sending a target reset from the
device reset handler, and if we have multiple devices a target reset gets
sent for each device when only one would be sufficient. And if we do a target
reset it affects all the commands on the target so the device reset handler
code only cleaning up one devices's commands makes programming the driver a
little more difficult than it should be.

This patch adds a target reset handler, which drivers can use to send
a target reset. If successful it cleans up the commands for a devices
accessed through that starget.

Signed-off-by: default avatarMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent f7441a79

drivers/scsi/scsi_error.c

+104 −18
Original line number Original line Diff line number Diff line
@@ -524,6 +524,41 @@ static int scsi_try_bus_reset(struct scsi_cmnd *scmd) 
	return rtn;

	return rtn;

}

}





static void __scsi_report_device_reset(struct scsi_device *sdev, void *data)

{

	sdev->was_reset = 1;

	sdev->expecting_cc_ua = 1;

}



/**

 * scsi_try_target_reset - Ask host to perform a target reset

 * @scmd:	SCSI cmd used to send a target reset

 *

 * Notes:

 *    There is no timeout for this operation.  if this operation is

 *    unreliable for a given host, then the host itself needs to put a

 *    timer on it, and set the host back to a consistent state prior to

 *    returning.

 */

static int scsi_try_target_reset(struct scsi_cmnd *scmd)

{

	unsigned long flags;

	int rtn;



	if (!scmd->device->host->hostt->eh_target_reset_handler)

		return FAILED;



	rtn = scmd->device->host->hostt->eh_target_reset_handler(scmd);

	if (rtn == SUCCESS) {

		spin_lock_irqsave(scmd->device->host->host_lock, flags);

		__starget_for_each_device(scsi_target(scmd->device), NULL,

					  __scsi_report_device_reset);

		spin_unlock_irqrestore(scmd->device->host->host_lock, flags);

	}



	return rtn;

}



/**

/**

 * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev

 * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev

 * @scmd:	SCSI cmd used to send BDR

 * @scmd:	SCSI cmd used to send BDR
@@ -542,11 +577,8 @@ static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd) 
		return FAILED;

		return FAILED;





	rtn = scmd->device->host->hostt->eh_device_reset_handler(scmd);

	rtn = scmd->device->host->hostt->eh_device_reset_handler(scmd);

	if (rtn == SUCCESS) {

	if (rtn == SUCCESS)

		scmd->device->was_reset = 1;

		__scsi_report_device_reset(scmd->device, NULL);

		scmd->device->expecting_cc_ua = 1;

	}



	return rtn;

	return rtn;

}

}
@@ -584,6 +616,7 @@ static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd) 
{

{

	if (__scsi_try_to_abort_cmd(scmd) != SUCCESS)

	if (__scsi_try_to_abort_cmd(scmd) != SUCCESS)

		if (scsi_try_bus_device_reset(scmd) != SUCCESS)

		if (scsi_try_bus_device_reset(scmd) != SUCCESS)

			if (scsi_try_target_reset(scmd) != SUCCESS)

				if (scsi_try_bus_reset(scmd) != SUCCESS)

				if (scsi_try_bus_reset(scmd) != SUCCESS)

					scsi_try_host_reset(scmd);

					scsi_try_host_reset(scmd);

}

}
@@ -1059,6 +1092,56 @@ static int scsi_eh_bus_device_reset(struct Scsi_Host *shost, 
	return list_empty(work_q);

	return list_empty(work_q);

}

}





/**

 * scsi_eh_target_reset - send target reset if needed

 * @shost:	scsi host being recovered.

 * @work_q:     &list_head for pending commands.

 * @done_q:	&list_head for processed commands.

 *

 * Notes:

 *    Try a target reset.

 */

static int scsi_eh_target_reset(struct Scsi_Host *shost,

				struct list_head *work_q,

				struct list_head *done_q)

{

	struct scsi_cmnd *scmd, *tgtr_scmd, *next;

	unsigned int id;

	int rtn;



	for (id = 0; id <= shost->max_id; id++) {

		tgtr_scmd = NULL;

		list_for_each_entry(scmd, work_q, eh_entry) {

			if (id == scmd_id(scmd)) {

				tgtr_scmd = scmd;

				break;

			}

		}

		if (!tgtr_scmd)

			continue;



		SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending target reset "

						  "to target %d\n",

						  current->comm, id));

		rtn = scsi_try_target_reset(tgtr_scmd);

		if (rtn == SUCCESS) {

			list_for_each_entry_safe(scmd, next, work_q, eh_entry) {

				if (id == scmd_id(scmd))

					if (!scsi_device_online(scmd->device) ||

					    !scsi_eh_tur(tgtr_scmd))

						scsi_eh_finish_cmd(scmd,

								   done_q);

			}

		} else

			SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Target reset"

							  " failed target: "

							  "%d\n",

							  current->comm, id));

	}



	return list_empty(work_q);

}



/**

/**

 * scsi_eh_bus_reset - send a bus reset 

 * scsi_eh_bus_reset - send a bus reset 

 * @shost:	&scsi host being recovered.

 * @shost:	&scsi host being recovered.
@@ -1447,9 +1530,11 @@ void scsi_eh_ready_devs(struct Scsi_Host *shost, 
{

{

	if (!scsi_eh_stu(shost, work_q, done_q))

	if (!scsi_eh_stu(shost, work_q, done_q))

		if (!scsi_eh_bus_device_reset(shost, work_q, done_q))

		if (!scsi_eh_bus_device_reset(shost, work_q, done_q))

			if (!scsi_eh_target_reset(shost, work_q, done_q))

				if (!scsi_eh_bus_reset(shost, work_q, done_q))

				if (!scsi_eh_bus_reset(shost, work_q, done_q))

					if (!scsi_eh_host_reset(work_q, done_q))

					if (!scsi_eh_host_reset(work_q, done_q))

					scsi_eh_offline_sdevs(work_q, done_q);

						scsi_eh_offline_sdevs(work_q,

								      done_q);

}

}

EXPORT_SYMBOL_GPL(scsi_eh_ready_devs);

EXPORT_SYMBOL_GPL(scsi_eh_ready_devs);
@@ -1619,10 +1704,8 @@ void scsi_report_bus_reset(struct Scsi_Host *shost, int channel) 
	struct scsi_device *sdev;

	struct scsi_device *sdev;





	__shost_for_each_device(sdev, shost) {

	__shost_for_each_device(sdev, shost) {

		if (channel == sdev_channel(sdev)) {

		if (channel == sdev_channel(sdev))

			sdev->was_reset = 1;

			__scsi_report_device_reset(sdev, NULL);

			sdev->expecting_cc_ua = 1;

		}

	}

	}

}

}

EXPORT_SYMBOL(scsi_report_bus_reset);

EXPORT_SYMBOL(scsi_report_bus_reset);
@@ -1655,10 +1738,8 @@ void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target) 




	__shost_for_each_device(sdev, shost) {

	__shost_for_each_device(sdev, shost) {

		if (channel == sdev_channel(sdev) &&

		if (channel == sdev_channel(sdev) &&

		    target == sdev_id(sdev)) {

		    target == sdev_id(sdev))

			sdev->was_reset = 1;

			__scsi_report_device_reset(sdev, NULL);

			sdev->expecting_cc_ua = 1;

		}

	}

	}

}

}

EXPORT_SYMBOL(scsi_report_device_reset);

EXPORT_SYMBOL(scsi_report_device_reset);
@@ -1714,6 +1795,11 @@ scsi_reset_provider(struct scsi_device *dev, int flag) 
		if (rtn == SUCCESS)

		if (rtn == SUCCESS)

			break;

			break;

		/* FALLTHROUGH */

		/* FALLTHROUGH */

	case SCSI_TRY_RESET_TARGET:

		rtn = scsi_try_target_reset(scmd);

		if (rtn == SUCCESS)

			break;

		/* FALLTHROUGH */

	case SCSI_TRY_RESET_BUS:

	case SCSI_TRY_RESET_BUS:

		rtn = scsi_try_bus_reset(scmd);

		rtn = scsi_try_bus_reset(scmd);

		if (rtn == SUCCESS)

		if (rtn == SUCCESS)

include/scsi/scsi_eh.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -64,6 +64,7 @@ extern int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len, 
#define SCSI_TRY_RESET_DEVICE	1

#define SCSI_TRY_RESET_DEVICE	1

#define SCSI_TRY_RESET_BUS	2

#define SCSI_TRY_RESET_BUS	2

#define SCSI_TRY_RESET_HOST	3

#define SCSI_TRY_RESET_HOST	3

#define SCSI_TRY_RESET_TARGET	4





extern int scsi_reset_provider(struct scsi_device *, int);

extern int scsi_reset_provider(struct scsi_device *, int);

include/scsi/scsi_host.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -172,6 +172,7 @@ struct scsi_host_template { 
	 */

	 */

	int (* eh_abort_handler)(struct scsi_cmnd *);

	int (* eh_abort_handler)(struct scsi_cmnd *);

	int (* eh_device_reset_handler)(struct scsi_cmnd *);

	int (* eh_device_reset_handler)(struct scsi_cmnd *);

	int (* eh_target_reset_handler)(struct scsi_cmnd *);

	int (* eh_bus_reset_handler)(struct scsi_cmnd *);

	int (* eh_bus_reset_handler)(struct scsi_cmnd *);

	int (* eh_host_reset_handler)(struct scsi_cmnd *);

	int (* eh_host_reset_handler)(struct scsi_cmnd *);