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Commit 7fa3174b authored by Chandrakanth Patil's avatar Chandrakanth Patil Committed by Martin K. Petersen
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scsi: megaraid_sas: Release Mutex lock before OCR in case of DCMD timeout 



Issue: There is possibility of few DCMDs timing out with 'reset_mutex' lock
held. As part of DCMD timeout handling, driver calls function
megasas_reset_fusion which also tries to acquire same lock 'reset_mutex'
and end up with deadlock.

Fix: Upon timeout of DCMDs (which are fired with 'reset_mutex' lock held),
driver will release 'reset_mutex' before calling OCR function and will
acquire lock again after OCR function returns.

Signed-off-by: default avatarSumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: default avatarChandrakanth Patil <chandrakanth.patil@broadcom.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent a6ffd5bf

drivers/scsi/megaraid/megaraid_sas_base.c

+13 −0
Original line number Diff line number Diff line
@@ -4369,8 +4369,10 @@ megasas_get_pd_info(struct megasas_instance *instance, struct scsi_device *sdev) 
		switch (dcmd_timeout_ocr_possible(instance)) {

		case INITIATE_OCR:

			cmd->flags |= DRV_DCMD_SKIP_REFIRE;

			mutex_unlock(&instance->reset_mutex);

			megasas_reset_fusion(instance->host,

				MFI_IO_TIMEOUT_OCR);

			mutex_lock(&instance->reset_mutex);

			break;

		case KILL_ADAPTER:

			megaraid_sas_kill_hba(instance);
@@ -4861,8 +4863,10 @@ megasas_host_device_list_query(struct megasas_instance *instance, 
		switch (dcmd_timeout_ocr_possible(instance)) {

		case INITIATE_OCR:

			cmd->flags |= DRV_DCMD_SKIP_REFIRE;

			mutex_unlock(&instance->reset_mutex);

			megasas_reset_fusion(instance->host,

				MFI_IO_TIMEOUT_OCR);

			mutex_lock(&instance->reset_mutex);

			break;

		case KILL_ADAPTER:

			megaraid_sas_kill_hba(instance);
@@ -5010,8 +5014,10 @@ void megasas_get_snapdump_properties(struct megasas_instance *instance) 
		switch (dcmd_timeout_ocr_possible(instance)) {

		case INITIATE_OCR:

			cmd->flags |= DRV_DCMD_SKIP_REFIRE;

			mutex_unlock(&instance->reset_mutex);

			megasas_reset_fusion(instance->host,

				MFI_IO_TIMEOUT_OCR);

			mutex_lock(&instance->reset_mutex);

			break;

		case KILL_ADAPTER:

			megaraid_sas_kill_hba(instance);
@@ -5141,8 +5147,10 @@ megasas_get_ctrl_info(struct megasas_instance *instance) 
		switch (dcmd_timeout_ocr_possible(instance)) {

		case INITIATE_OCR:

			cmd->flags |= DRV_DCMD_SKIP_REFIRE;

			mutex_unlock(&instance->reset_mutex);

			megasas_reset_fusion(instance->host,

				MFI_IO_TIMEOUT_OCR);

			mutex_lock(&instance->reset_mutex);

			break;

		case KILL_ADAPTER:

			megaraid_sas_kill_hba(instance);
@@ -6398,8 +6406,10 @@ megasas_get_target_prop(struct megasas_instance *instance, 
		switch (dcmd_timeout_ocr_possible(instance)) {

		case INITIATE_OCR:

			cmd->flags |= DRV_DCMD_SKIP_REFIRE;

			mutex_unlock(&instance->reset_mutex);

			megasas_reset_fusion(instance->host,

					     MFI_IO_TIMEOUT_OCR);

			mutex_lock(&instance->reset_mutex);

			break;

		case KILL_ADAPTER:

			megaraid_sas_kill_hba(instance);
@@ -7801,10 +7811,13 @@ megasas_mgmt_fw_ioctl(struct megasas_instance *instance, 
		opcode = le32_to_cpu(cmd->frame->dcmd.opcode);



	if (opcode == MR_DCMD_CTRL_SHUTDOWN) {

		mutex_lock(&instance->reset_mutex);

		if (megasas_get_ctrl_info(instance) != DCMD_SUCCESS) {

			megasas_return_cmd(instance, cmd);

			mutex_unlock(&instance->reset_mutex);

			return -1;

		}

		mutex_unlock(&instance->reset_mutex);

	}



	if (opcode == MR_DRIVER_SET_APP_CRASHDUMP_MODE) {