Re: [PATCH 1/2] megaraid_sas: Fix for IO failing post OCR in SRIOV environment

[Tomas Henzl <thenzl@redhat.com>]

On 28.1.2016 16:44, Sumit Saxena wrote:
> Driver assumes that VFs always have peers present whenever they have same LD IDs. But this is not the case.
> This patch handles the above mentioned by explicitly checking for a peer before making HA/non-HA path decision.
>
> Signed-off-by: Uday Lingala <uday.lingala@avagotech.com>
> Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
>
> ---
>  drivers/scsi/megaraid/megaraid_sas.h        | 13 ++++++---
>  drivers/scsi/megaraid/megaraid_sas_base.c   |  6 +++--
>  drivers/scsi/megaraid/megaraid_sas_fusion.c | 42 ++++++++++++++++++-----------
>  3 files changed, 39 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/scsi/megaraid/megaraid_sas.h b/drivers/scsi/megaraid/megaraid_sas.h
> index b6fdb48..4484e63 100644
> --- a/drivers/scsi/megaraid/megaraid_sas.h
> +++ b/drivers/scsi/megaraid/megaraid_sas.h
> @@ -393,6 +393,7 @@ enum MR_EVT_ARGS {
>  
>  
>  #define SGE_BUFFER_SIZE	4096
> +#define MEGASAS_CLUSTER_ID_SIZE	16
>  /*
>   * define constants for device list query options
>   */
> @@ -1227,7 +1228,8 @@ struct megasas_ctrl_info {
>  	*/
>  	struct {
>  #if defined(__BIG_ENDIAN_BITFIELD)
> -		u32     reserved:26;
> +		u32     reserved:25;
> +		u32     passive:1;
>  		u32     premiumFeatureMismatch:1;
>  		u32     ctrlPropIncompatible:1;
>  		u32     fwVersionMismatch:1;
> @@ -1241,11 +1243,12 @@ struct megasas_ctrl_info {
>  		u32     fwVersionMismatch:1;
>  		u32     ctrlPropIncompatible:1;
>  		u32     premiumFeatureMismatch:1;
> -		u32     reserved:26;
> +		u32     passive:1;
> +		u32     reserved:25;
>  #endif
>  	} cluster;
>  
> -	char clusterId[16];                     /*7D4h */
> +	char clusterId[MEGASAS_CLUSTER_ID_SIZE]; /*0x7D4 */
>  	struct {
>  		u8  maxVFsSupported;            /*0x7E4*/
>  		u8  numVFsEnabled;              /*0x7E5*/
> @@ -2126,7 +2129,9 @@ struct megasas_instance {
>  	char skip_heartbeat_timer_del;
>  	u8 requestorId;
>  	char PlasmaFW111;
> -	char mpio;
> +	char clusterId[MEGASAS_CLUSTER_ID_SIZE];
> +	u8 peerIsPresent;
> +	u8 passive;
>  	u16 throttlequeuedepth;
>  	u8 mask_interrupts;
>  	u16 max_chain_frame_sz;
> diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
> index 54922e5..52f3419 100644
> --- a/drivers/scsi/megaraid/megaraid_sas_base.c
> +++ b/drivers/scsi/megaraid/megaraid_sas_base.c
> @@ -1943,7 +1943,7 @@ void megaraid_sas_kill_hba(struct megasas_instance *instance)
>  		writel(MFI_STOP_ADP, &instance->reg_set->doorbell);
>  		/* Flush */
>  		readl(&instance->reg_set->doorbell);
> -		if (instance->mpio && instance->requestorId)
> +		if (instance->requestorId && instance->peerIsPresent)
>  			memset(instance->ld_ids, 0xff, MEGASAS_MAX_LD_IDS);
>  	} else {
>  		writel(MFI_STOP_ADP,
> @@ -5182,7 +5182,9 @@ static int megasas_init_fw(struct megasas_instance *instance)
>  
>  	tmp_sectors = min_t(u32, max_sectors_1, max_sectors_2);
>  
> -	instance->mpio = ctrl_info->adapterOperations2.mpio;
> +	instance->peerIsPresent = ctrl_info->cluster.peerIsPresent;
> +	instance->passive = ctrl_info->cluster.passive;
> +	memcpy(instance->clusterId, ctrl_info->clusterId, sizeof(instance->clusterId));
>  	instance->UnevenSpanSupport =
>  		ctrl_info->adapterOperations2.supportUnevenSpans;
>  	if (instance->UnevenSpanSupport) {
> diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c
> index be9c3f1..d9d0029 100644
> --- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
> +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
> @@ -3325,27 +3325,37 @@ out:
>  	return ret;
>  }
>  
> +/*SRIOV get other instance in cluster if any*/
> +struct megasas_instance *megasas_get_peer_instance(struct megasas_instance *instance)
> +{
> +	int i;
> +
> +	for (i = 0; i < MAX_MGMT_ADAPTERS; i++) {
> +		if (megasas_mgmt_info.instance[i] &&
> +			(megasas_mgmt_info.instance[i] != instance) &&
> +			 megasas_mgmt_info.instance[i]->requestorId &&
> +			 megasas_mgmt_info.instance[i]->peerIsPresent &&
> +			(memcmp((megasas_mgmt_info.instance[i]->clusterId),
> +			instance->clusterId, MEGASAS_CLUSTER_ID_SIZE) == 0))
> +			return megasas_mgmt_info.instance[i];
> +	}
> +	return NULL;
> +}
> +
>  /* Check for a second path that is currently UP */
>  int megasas_check_mpio_paths(struct megasas_instance *instance,
>  	struct scsi_cmnd *scmd)
>  {
> -	int i, j, retval = (DID_RESET << 16);
> -
> -	if (instance->mpio && instance->requestorId) {

Seems to me that you've removed this test (instance->requestorId) maybe it is not needed,
is it removed intentionally ? 

--tm


> -		for (i = 0 ; i < MAX_MGMT_ADAPTERS ; i++)
> -			for (j = 0 ; j < MAX_LOGICAL_DRIVES; j++)
> -				if (megasas_mgmt_info.instance[i] &&
> -				    (megasas_mgmt_info.instance[i] != instance) &&
> -				    megasas_mgmt_info.instance[i]->mpio &&
> -				    megasas_mgmt_info.instance[i]->requestorId
> -				    &&
> -				    (megasas_mgmt_info.instance[i]->ld_ids[j]
> -				     == scmd->device->id)) {
> -					    retval = (DID_NO_CONNECT << 16);
> -					    goto out;
> -				}
> +	struct megasas_instance *peer_instance = NULL;
> +	int retval = (DID_RESET << 16);
> +
> +	if (instance->peerIsPresent) {
> +		peer_instance = megasas_get_peer_instance(instance);
> +		if ((peer_instance) &&
> +			(atomic_read(&peer_instance->adprecovery) ==
> +			MEGASAS_HBA_OPERATIONAL))
> +			retval = (DID_NO_CONNECT << 16);
>  	}
> -out:
>  	return retval;
>  }
>