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* [PATCH ] scsi/ipr: keep the order of locks
@ 2022-09-23 14:51 Hao Peng
  2022-10-01  9:32 ` Martin K. Petersen
  0 siblings, 1 reply; 4+ messages in thread
From: Hao Peng @ 2022-09-23 14:51 UTC (permalink / raw)
  To: jejb@linux.ibm.com, martin.petersen@oracle.com; +Cc: linux-scsi@vger.kernel.org

From: Peng Hao <flyingpeng@tencent.com>

ipr_ata_post_internal:
    acquire host_lock
       acquire hrrq->_lock
             ipr_device_reset
                 ipr_send_blocking_cmd
                    release host_lock
                    acquire host_lock
       release hrrq->_lock
    release host_lock

As shown above, there are two lock acquisition order changes.
At the same time, when ipr_device_reset is executed, the lock
hrrq->_lock does not need to be held.

Signed-off-by: Peng Hao <flyingpeng@tencent.com>
---
 drivers/scsi/ipr.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index 9d01a3e3c26a..6ca987dda397 100644
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -6837,7 +6837,9 @@ static void ipr_ata_post_internal(struct
ata_queued_cmd *qc)
                spin_lock(&hrrq->_lock);
                list_for_each_entry(ipr_cmd, &hrrq->hrrq_pending_q, queue) {
                        if (ipr_cmd->qc == qc) {
+                               spin_unlock(&hrrq->_lock);
                                ipr_device_reset(ioa_cfg, sata_port->res);
+                               spin_lock(&hrrq->_lock);
                                break;
                        }
                }
--
2.27.0

^ permalink raw reply related	[flat|nested] 4+ messages in thread
* [PATCH ]  scsi/ipr: keep the order of locks
@ 2022-09-18  2:36 flyingpeng(彭浩)
  0 siblings, 0 replies; 4+ messages in thread
From: flyingpeng(彭浩) @ 2022-09-18  2:36 UTC (permalink / raw)
  To: jejb@linux.ibm.com, martin.petersen@oracle.com; +Cc: linux-scsi@vger.kernel.org

ipr_ata_post_internal:
    acquire host_lock
       acquire hrrq->_lock
             ipr_device_reset
                 ipr_send_blocking_cmd
                    release host_lock
                    acquire host_lock
       release hrrq->_lock
    release host_lock

As shown above, there are two lock acquisition order changes.
At the same time, when ipr_device_reset is executed, the lock
hrrq->_lock does not need to be held.

Signed-off-by: Peng Hao <flyingpeng@tencent.com>
---
 drivers/scsi/ipr.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index 9d01a3e3c26a..6ca987dda397 100644
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -6837,7 +6837,9 @@ static void ipr_ata_post_internal(struct ata_queued_cmd *qc)
                spin_lock(&hrrq->_lock);
                list_for_each_entry(ipr_cmd, &hrrq->hrrq_pending_q, queue) {
                        if (ipr_cmd->qc == qc) {
+                               spin_unlock(&hrrq->_lock);
                                ipr_device_reset(ioa_cfg, sata_port->res);
+                               spin_lock(&hrrq->_lock);
                                break;
                        }
                }
--
2.27.0


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2022-10-02  4:14 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2022-09-23 14:51 [PATCH ] scsi/ipr: keep the order of locks Hao Peng
2022-10-01  9:32 ` Martin K. Petersen
2022-10-02  4:14   ` Hao Peng
  -- strict thread matches above, loose matches on Subject: below --
2022-09-18  2:36 flyingpeng(彭浩)

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