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bnx2fc:Add proper locking protection in bnx2fc_ctrlr_enabled

PATCH Chad Dupuis 2 participants 2 messages Dec 15, 2015 1 message not in the archive SCSI

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A message that is not in the archive (sent off-list or not yet received): [email protected]

Chad Dupuis

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#1 lore raw
Quoted 27 lines · Nicholas Krause

This adds proper locking protection in bnx2fc_ctrl_enabled around the calls to the functions, _bnx2fc_enable and _bnx2fc_disable in order to avoid concurrent access on these functions accessing global referenced data structures in their internal intended work.

Signed-off-by Nicholas Krause <[email protected]>

---
drivers/scsi/bnx2fc/bnx2fc_fcoe.c | 8 ++++++++

1 file changed, 8 insertions(+)
drivers/scsi/bnx2fc/bnx2fc_fcoe.c +4 -0
index 67405c6..e43648f 100644
@@ -2177,13 +2177,21 @@ static int bnx2fc_ctlr_enabled(struct fcoe_ctlr_device *cdev)
 {
 	struct fcoe_ctlr *ctlr = fcoe_ctlr_device_priv(cdev);
 
+	rtnl_lock();
+	mutex_lock(&bnx2fc_dev_lock);
 	switch (cdev->enabled) {
 	case FCOE_CTLR_ENABLED:
+		rtnl_unlock();
+		mutex_unlock(&bnx2fc_dev_lock);
 		return __bnx2fc_enable(ctlr);
 	case FCOE_CTLR_DISABLED:

drivers/scsi/bnx2fc/bnx2fc_fcoe.c static int bnx2fc_ctlr_enabled(struct fcoe_ctlr_device *cdev) · line 2197

Quoted 10 lines
drivers/scsi/bnx2fc/bnx2fc_fcoe.c +4 -0
+		rtnl_unlock();
+		mutex_unlock(&bnx2fc_dev_lock);
 		return __bnx2fc_disable(ctlr);
 	case FCOE_CTLR_UNUSED:
 	default:
+		rtnl_unlock();
+		mutex_unlock(&bnx2fc_dev_lock);
 		return -ENOTSUPP;
 	};
 }

Nack. All we end up protecting is the check of cdev->enabled and I do not believe taking two mutexes is required for that.

#2 lore raw

Also, the patch fails to do what it's message describes, i.e. the calls _bnx2fc_enable() and _bnx2fc_disable() are outside the lock/unlock.

-----Original Message-----
From: Chad Dupuis
Sent: Tuesday, December 15, 2015 8:43 AM
To: Nicholas Krause <[email protected]>
Cc: Dept-Eng QLogic Storage Upstream <[email protected]>; [email protected]; [email protected]; linux-scsi <[email protected]>; linux-kernel <[email protected]>
Subject: Re: [PATCH] bnx2fc:Add proper locking protection in bnx2fc_ctrlr_enabled

Quoted 28 lines · Nicholas Krause

This adds proper locking protection in bnx2fc_ctrl_enabled around the calls to the functions, _bnx2fc_enable and _bnx2fc_disable in order to avoid concurrent access on these functions accessing global referenced data structures in their internal intended work.

Signed-off-by Nicholas Krause <[email protected]>

---
drivers/scsi/bnx2fc/bnx2fc_fcoe.c | 8 ++++++++

1 file changed, 8 insertions(+)
drivers/scsi/bnx2fc/bnx2fc_fcoe.c +4 -0
index 67405c6..e43648f 100644
@@ -2177,13 +2177,21 @@ static int bnx2fc_ctlr_enabled(struct 
 fcoe_ctlr_device *cdev) {
 	struct fcoe_ctlr *ctlr = fcoe_ctlr_device_priv(cdev);
 
+	rtnl_lock();
+	mutex_lock(&bnx2fc_dev_lock);
 	switch (cdev->enabled) {
 	case FCOE_CTLR_ENABLED:
+		rtnl_unlock();
+		mutex_unlock(&bnx2fc_dev_lock);
 		return __bnx2fc_enable(ctlr);
 	case FCOE_CTLR_DISABLED:

drivers/scsi/bnx2fc/bnx2fc_fcoe.c static int bnx2fc_ctlr_enabled(struct · line 2197

Quoted 10 lines
drivers/scsi/bnx2fc/bnx2fc_fcoe.c +4 -0
+		rtnl_unlock();
+		mutex_unlock(&bnx2fc_dev_lock);
 		return __bnx2fc_disable(ctlr);
 	case FCOE_CTLR_UNUSED:
 	default:
+		rtnl_unlock();
+		mutex_unlock(&bnx2fc_dev_lock);
 		return -ENOTSUPP;
 	};
 }

Nack. All we end up protecting is the check of cdev->enabled and I do not believe taking two mutexes is required for that.