Re: [PATCH 04/25] qla2xxx: Replace usage of spin_lock with spin_lock_irqsave

[Bart Van Assche]

On Fri, 2017-05-19 at 14:53 -0700, Himanshu Madhani wrote:
> From: Quinn Tran 
> 
> qla2xxx driver lives in interrupt context. Remove
> spin_lock usage to prevent leaving CPU in a strange
> state.

Hello Himanshu and Quinn,

Did you perhaps mean that the command lists can be accessed from interrupt
context? If so, please mention this in the patch description.

Thanks,

Bart.

[PATCH 04/25] qla2xxx: Replace usage of spin_lock with spin_lock_irqsave

[Himanshu Madhani]

From: Quinn Tran 

qla2xxx driver lives in interrupt context. Remove
spin_lock usage to prevent leaving CPU in a strange
state.

Cc: 
Signed-off-by: Quinn Tran 
Signed-off-by: Himanshu Madhani 
---
 drivers/scsi/qla2xxx/qla_target.c | 26 ++
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_target.c 
b/drivers/scsi/qla2xxx/qla_target.c
index 0e03ca2ab3e5..4c64f8e3f9b6 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -1762,13 +1762,13 @@ static int abort_cmd_for_tag(struct scsi_qla_host *vha, 
uint32_t tag)
 {
struct qla_tgt_sess_op *op;
struct qla_tgt_cmd *cmd;
+   unsigned long flags;
 
-   spin_lock(>cmd_list_lock);
-
+   spin_lock_irqsave(>cmd_list_lock, flags);
list_for_each_entry(op, >qla_sess_op_cmd_list, cmd_list) {
if (tag == op->atio.u.isp24.exchange_addr) {
op->aborted = true;
-   spin_unlock(>cmd_list_lock);
+   spin_unlock_irqrestore(>cmd_list_lock, flags);
return 1;
}
}
@@ -1776,7 +1776,7 @@ static int abort_cmd_for_tag(struct scsi_qla_host *vha, 
uint32_t tag)
list_for_each_entry(op, >unknown_atio_list, cmd_list) {
if (tag == op->atio.u.isp24.exchange_addr) {
op->aborted = true;
-   spin_unlock(>cmd_list_lock);
+   spin_unlock_irqrestore(>cmd_list_lock, flags);
return 1;
}
}
@@ -1784,12 +1784,12 @@ static int abort_cmd_for_tag(struct scsi_qla_host *vha, 
uint32_t tag)
list_for_each_entry(cmd, >qla_cmd_list, cmd_list) {
if (tag == cmd->atio.u.isp24.exchange_addr) {
cmd->aborted = 1;
-   spin_unlock(>cmd_list_lock);
+   spin_unlock_irqrestore(>cmd_list_lock, flags);
return 1;
}
}
+   spin_unlock_irqrestore(>cmd_list_lock, flags);
 
-   spin_unlock(>cmd_list_lock);
return 0;
 }
 
@@ -1804,9 +1804,10 @@ static void abort_cmds_for_lun(struct scsi_qla_host *vha,
struct qla_tgt_sess_op *op;
struct qla_tgt_cmd *cmd;
uint32_t key;
+   unsigned long flags;
 
key = sid_to_key(s_id);
-   spin_lock(>cmd_list_lock);
+   spin_lock_irqsave(>cmd_list_lock, flags);
list_for_each_entry(op, >qla_sess_op_cmd_list, cmd_list) {
uint32_t op_key;
uint32_t op_lun;
@@ -1839,7 +1840,7 @@ static void abort_cmds_for_lun(struct scsi_qla_host *vha,
if (cmd_key == key && cmd_lun == lun)
cmd->aborted = 1;
}
-   spin_unlock(>cmd_list_lock);
+   spin_unlock_irqrestore(>cmd_list_lock, flags);
 }
 
 /* ha->hardware_lock supposed to be held on entry */
@@ -4214,9 +4215,9 @@ static int qlt_handle_cmd_for_atio(struct scsi_qla_host 
*vha,
memcpy(>atio, atio, sizeof(*atio));
op->vha = vha;
 
-   spin_lock(>cmd_list_lock);
+   spin_lock_irqsave(>cmd_list_lock, flags);
list_add_tail(>cmd_list, >qla_sess_op_cmd_list);
-   spin_unlock(>cmd_list_lock);
+   spin_unlock_irqrestore(>cmd_list_lock, flags);
 
INIT_WORK(>work, qlt_create_sess_from_atio);
queue_work(qla_tgt_wq, >work);
@@ -4527,12 +4528,13 @@ static int abort_cmds_for_s_id(struct scsi_qla_host 
*vha, port_id_t *s_id)
struct qla_tgt_cmd *cmd;
uint32_t key;
int count = 0;
+   unsigned long flags;
 
key = (((u32)s_id->b.domain << 16) |
   ((u32)s_id->b.area   <<  8) |
   ((u32)s_id->b.al_pa));
 
-   spin_lock(>cmd_list_lock);
+   spin_lock_irqsave(>cmd_list_lock, flags);
list_for_each_entry(op, >qla_sess_op_cmd_list, cmd_list) {
uint32_t op_key = sid_to_key(op->atio.u.isp24.fcp_hdr.s_id);
 
@@ -4557,7 +4559,7 @@ static int abort_cmds_for_s_id(struct scsi_qla_host *vha, 
port_id_t *s_id)
count++;
}
}
-   spin_unlock(>cmd_list_lock);
+   spin_unlock_irqrestore(>cmd_list_lock, flags);
 
return count;
 }
-- 
2.12.0