From: Chandrakanth Patil <chandrakanth.patil@broadcom.com>
Date: Tue, 25 Jun 2019 16:34:23 +0530
Subject: scsi: megaraid_sas: Release Mutex lock before OCR in case of DCMD
timeout
Patch-mainline: v5.3-rc1
Git-commit: 7fa3174b3ef4e517ebb8a08078871ceab705a969
References: bsc#1143962
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: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Chandrakanth Patil <chandrakanth.patil@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Daniel Wagner <dwagner@suse.de>
---
drivers/scsi/megaraid/megaraid_sas_base.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -4275,8 +4275,10 @@ megasas_get_pd_info(struct megasas_insta
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);
@@ -4734,8 +4736,10 @@ megasas_host_device_list_query(struct me
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);
@@ -4883,8 +4887,10 @@ void megasas_get_snapdump_properties(str
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);
@@ -5014,8 +5020,10 @@ megasas_get_ctrl_info(struct megasas_ins
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);
@@ -6250,8 +6258,10 @@ megasas_get_target_prop(struct megasas_i
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);
@@ -7624,10 +7634,13 @@ megasas_mgmt_fw_ioctl(struct megasas_ins
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) {