Commit f646f325 authored by Brian King's avatar Brian King Committed by Martin K. Petersen
Browse files

scsi: ipr: Error path locking fixes 



This patch closes up some potential race conditions observed in the
error handling paths in ipr while debugging an issue resulting in a hang
with SATA error handling. These patches ensure we are holding the
correct lock when adding and removing commands from the free and pending
queues in some error scenarios.

Signed-off-by: default avatarBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: default avatarWendy Xiong <wenxiong@linux.vnet.ibm.com>
Tested-by: default avatarWendy Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 439ae285

drivers/scsi/ipr.c

+93 −13
Original line number Diff line number Diff line
@@ -820,7 +820,7 @@ static int ipr_set_pcix_cmd_reg(struct ipr_ioa_cfg *ioa_cfg) 
}



/**

 * ipr_sata_eh_done - done function for aborted SATA commands

 * __ipr_sata_eh_done - done function for aborted SATA commands

 * @ipr_cmd:	ipr command struct

 *

 * This function is invoked for ops generated to SATA
@@ -829,7 +829,7 @@ static int ipr_set_pcix_cmd_reg(struct ipr_ioa_cfg *ioa_cfg) 
 * Return value:

 * 	none

 **/

static void ipr_sata_eh_done(struct ipr_cmnd *ipr_cmd)

static void __ipr_sata_eh_done(struct ipr_cmnd *ipr_cmd)

{

	struct ata_queued_cmd *qc = ipr_cmd->qc;

	struct ipr_sata_port *sata_port = qc->ap->private_data;
@@ -843,7 +843,27 @@ static void ipr_sata_eh_done(struct ipr_cmnd *ipr_cmd) 
}



/**

 * ipr_scsi_eh_done - mid-layer done function for aborted ops

 * ipr_sata_eh_done - done function for aborted SATA commands

 * @ipr_cmd:	ipr command struct

 *

 * This function is invoked for ops generated to SATA

 * devices which are being aborted.

 *

 * Return value:

 * 	none

 **/

static void ipr_sata_eh_done(struct ipr_cmnd *ipr_cmd)

{

	struct ipr_hrr_queue *hrrq = ipr_cmd->hrrq;

	unsigned long hrrq_flags;



	spin_lock_irqsave(&hrrq->_lock, hrrq_flags);

	__ipr_sata_eh_done(ipr_cmd);

	spin_unlock_irqrestore(&hrrq->_lock, hrrq_flags);

}



/**

 * __ipr_scsi_eh_done - mid-layer done function for aborted ops

 * @ipr_cmd:	ipr command struct

 *

 * This function is invoked by the interrupt handler for
@@ -852,7 +872,7 @@ static void ipr_sata_eh_done(struct ipr_cmnd *ipr_cmd) 
 * Return value:

 * 	none

 **/

static void ipr_scsi_eh_done(struct ipr_cmnd *ipr_cmd)

static void __ipr_scsi_eh_done(struct ipr_cmnd *ipr_cmd)

{

	struct scsi_cmnd *scsi_cmd = ipr_cmd->scsi_cmd;
@@ -865,6 +885,26 @@ static void ipr_scsi_eh_done(struct ipr_cmnd *ipr_cmd) 
	list_add_tail(&ipr_cmd->queue, &ipr_cmd->hrrq->hrrq_free_q);

}



/**

 * ipr_scsi_eh_done - mid-layer done function for aborted ops

 * @ipr_cmd:	ipr command struct

 *

 * This function is invoked by the interrupt handler for

 * ops generated by the SCSI mid-layer which are being aborted.

 *

 * Return value:

 * 	none

 **/

static void ipr_scsi_eh_done(struct ipr_cmnd *ipr_cmd)

{

	unsigned long hrrq_flags;

	struct ipr_hrr_queue *hrrq = ipr_cmd->hrrq;



	spin_lock_irqsave(&hrrq->_lock, hrrq_flags);

	__ipr_scsi_eh_done(ipr_cmd);

	spin_unlock_irqrestore(&hrrq->_lock, hrrq_flags);

}



/**

 * ipr_fail_all_ops - Fails all outstanding ops.

 * @ioa_cfg:	ioa config struct
@@ -892,9 +932,9 @@ static void ipr_fail_all_ops(struct ipr_ioa_cfg *ioa_cfg) 
				cpu_to_be32(IPR_DRIVER_ILID);



			if (ipr_cmd->scsi_cmd)

				ipr_cmd->done = ipr_scsi_eh_done;

				ipr_cmd->done = __ipr_scsi_eh_done;

			else if (ipr_cmd->qc)

				ipr_cmd->done = ipr_sata_eh_done;

				ipr_cmd->done = __ipr_sata_eh_done;



			ipr_trc_hook(ipr_cmd, IPR_TRACE_FINISH,

				     IPR_IOASC_IOA_WAS_RESET);
@@ -5948,7 +5988,7 @@ static int ipr_build_ioadl(struct ipr_ioa_cfg *ioa_cfg, 
}



/**

 * ipr_erp_done - Process completion of ERP for a device

 * __ipr_erp_done - Process completion of ERP for a device

 * @ipr_cmd:		ipr command struct

 *

 * This function copies the sense buffer into the scsi_cmd
@@ -5957,7 +5997,7 @@ static int ipr_build_ioadl(struct ipr_ioa_cfg *ioa_cfg, 
 * Return value:

 * 	nothing

 **/

static void ipr_erp_done(struct ipr_cmnd *ipr_cmd)

static void __ipr_erp_done(struct ipr_cmnd *ipr_cmd)

{

	struct scsi_cmnd *scsi_cmd = ipr_cmd->scsi_cmd;

	struct ipr_resource_entry *res = scsi_cmd->device->hostdata;
@@ -5984,6 +6024,26 @@ static void ipr_erp_done(struct ipr_cmnd *ipr_cmd) 
	list_add_tail(&ipr_cmd->queue, &ipr_cmd->hrrq->hrrq_free_q);

}



/**

 * ipr_erp_done - Process completion of ERP for a device

 * @ipr_cmd:		ipr command struct

 *

 * This function copies the sense buffer into the scsi_cmd

 * struct and pushes the scsi_done function.

 *

 * Return value:

 * 	nothing

 **/

static void ipr_erp_done(struct ipr_cmnd *ipr_cmd)

{

	struct ipr_hrr_queue *hrrq = ipr_cmd->hrrq;

	unsigned long hrrq_flags;



	spin_lock_irqsave(&hrrq->_lock, hrrq_flags);

	__ipr_erp_done(ipr_cmd);

	spin_unlock_irqrestore(&hrrq->_lock, hrrq_flags);

}



/**

 * ipr_reinit_ipr_cmnd_for_erp - Re-initialize a cmnd block to be used for ERP

 * @ipr_cmd:	ipr command struct
@@ -6016,7 +6076,7 @@ static void ipr_reinit_ipr_cmnd_for_erp(struct ipr_cmnd *ipr_cmd) 
}



/**

 * ipr_erp_request_sense - Send request sense to a device

 * __ipr_erp_request_sense - Send request sense to a device

 * @ipr_cmd:	ipr command struct

 *

 * This function sends a request sense to a device as a result
@@ -6025,13 +6085,13 @@ static void ipr_reinit_ipr_cmnd_for_erp(struct ipr_cmnd *ipr_cmd) 
 * Return value:

 * 	nothing

 **/

static void ipr_erp_request_sense(struct ipr_cmnd *ipr_cmd)

static void __ipr_erp_request_sense(struct ipr_cmnd *ipr_cmd)

{

	struct ipr_cmd_pkt *cmd_pkt = &ipr_cmd->ioarcb.cmd_pkt;

	u32 ioasc = be32_to_cpu(ipr_cmd->s.ioasa.hdr.ioasc);



	if (IPR_IOASC_SENSE_KEY(ioasc) > 0) {

		ipr_erp_done(ipr_cmd);

		__ipr_erp_done(ipr_cmd);

		return;

	}
@@ -6051,6 +6111,26 @@ static void ipr_erp_request_sense(struct ipr_cmnd *ipr_cmd) 
		   IPR_REQUEST_SENSE_TIMEOUT * 2);

}



/**

 * ipr_erp_request_sense - Send request sense to a device

 * @ipr_cmd:	ipr command struct

 *

 * This function sends a request sense to a device as a result

 * of a check condition.

 *

 * Return value:

 * 	nothing

 **/

static void ipr_erp_request_sense(struct ipr_cmnd *ipr_cmd)

{

	struct ipr_hrr_queue *hrrq = ipr_cmd->hrrq;

	unsigned long hrrq_flags;



	spin_lock_irqsave(&hrrq->_lock, hrrq_flags);

	__ipr_erp_request_sense(ipr_cmd);

	spin_unlock_irqrestore(&hrrq->_lock, hrrq_flags);

}



/**

 * ipr_erp_cancel_all - Send cancel all to a device

 * @ipr_cmd:	ipr command struct
@@ -6074,7 +6154,7 @@ static void ipr_erp_cancel_all(struct ipr_cmnd *ipr_cmd) 
	ipr_reinit_ipr_cmnd_for_erp(ipr_cmd);



	if (!scsi_cmd->device->simple_tags) {

		ipr_erp_request_sense(ipr_cmd);

		__ipr_erp_request_sense(ipr_cmd);

		return;

	}
@@ -6294,7 +6374,7 @@ static void ipr_erp_start(struct ipr_ioa_cfg *ioa_cfg, 
	u32 masked_ioasc = ioasc & IPR_IOASC_IOASC_MASK;



	if (!res) {

		ipr_scsi_eh_done(ipr_cmd);

		__ipr_scsi_eh_done(ipr_cmd);

		return;

	}

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