[PATCH 1/1] PCI: Deletion of unnecessary checks before three function calls

[PATCH 1/1] PCI: Deletion of unnecessary checks before three function calls

[SF Markus Elfring]

The functions pci_dev_put(), pci_pme_wakeup_bus() and put_device() test
whether their argument is NULL and then return immediately. Thus the test
around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/pci/pci-acpi.c     | 3 +--
 drivers/pci/probe.c        | 3 +--
 drivers/pci/search.c       | 3 +--
 drivers/pci/xen-pcifront.c | 3 +--
 4 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 37263b0..a8fe5de 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -60,8 +60,7 @@ static void pci_acpi_wake_dev(struct work_struct *work)
 	pci_wakeup_event(pci_dev);
 	pm_runtime_resume(&pci_dev->dev);

-	if (pci_dev->subordinate)
-		pci_pme_wakeup_bus(pci_dev->subordinate);
+	pci_pme_wakeup_bus(pci_dev->subordinate);
 }

 /**
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 4170113..e93f16e 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -86,8 +86,7 @@ static void release_pcibus_dev(struct device *dev)
 {
 	struct pci_bus *pci_bus = to_pci_bus(dev);

-	if (pci_bus->bridge)
-		put_device(pci_bus->bridge);
+	put_device(pci_bus->bridge);
 	pci_bus_remove_resources(pci_bus);
 	pci_release_bus_of_node(pci_bus);
 	kfree(pci_bus);
diff --git a/drivers/pci/search.c b/drivers/pci/search.c
index 827ad83..2d806bd 100644
--- a/drivers/pci/search.c
+++ b/drivers/pci/search.c
@@ -305,8 +305,7 @@ static struct pci_dev *pci_get_dev_by_id(const struct
pci_device_id *id,
 			      match_pci_dev_by_id);
 	if (dev)
 		pdev = to_pci_dev(dev);
-	if (from)
-		pci_dev_put(from);
+	pci_dev_put(from);
 	return pdev;
 }

diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c
index 53df39a..46664cc 100644
--- a/drivers/pci/xen-pcifront.c
+++ b/drivers/pci/xen-pcifront.c
@@ -596,8 +596,7 @@ static pci_ers_result_t pcifront_common_process(int cmd,
 	pcidev = pci_get_bus_and_slot(bus, devfn);
 	if (!pcidev || !pcidev->driver) {
 		dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n");
-		if (pcidev)
-			pci_dev_put(pcidev);
+		pci_dev_put(pcidev);
 		return result;
 	}
 	pdrv = pcidev->driver;
-- 
2.1.3

Re: [PATCH 1/1] PCI: Deletion of unnecessary checks before three function calls

[Bjorn Helgaas]

On Sun, Nov 02, 2014 at 04:12:30PM +0100, SF Markus Elfring wrote:
> The functions pci_dev_put(), pci_pme_wakeup_bus() and put_device() test
> whether their argument is NULL and then return immediately. Thus the test
> around the call is not needed.
> 
> This issue was detected by using the Coccinelle software.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>

Applied to pci/misc for v3.19, thanks!

> ---
>  drivers/pci/pci-acpi.c     | 3 +--
>  drivers/pci/probe.c        | 3 +--
>  drivers/pci/search.c       | 3 +--
>  drivers/pci/xen-pcifront.c | 3 +--
>  4 files changed, 4 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
> index 37263b0..a8fe5de 100644
> --- a/drivers/pci/pci-acpi.c
> +++ b/drivers/pci/pci-acpi.c
> @@ -60,8 +60,7 @@ static void pci_acpi_wake_dev(struct work_struct *work)
>  	pci_wakeup_event(pci_dev);
>  	pm_runtime_resume(&pci_dev->dev);
> 
> -	if (pci_dev->subordinate)
> -		pci_pme_wakeup_bus(pci_dev->subordinate);
> +	pci_pme_wakeup_bus(pci_dev->subordinate);
>  }
> 
>  /**
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 4170113..e93f16e 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -86,8 +86,7 @@ static void release_pcibus_dev(struct device *dev)
>  {
>  	struct pci_bus *pci_bus = to_pci_bus(dev);
> 
> -	if (pci_bus->bridge)
> -		put_device(pci_bus->bridge);
> +	put_device(pci_bus->bridge);
>  	pci_bus_remove_resources(pci_bus);
>  	pci_release_bus_of_node(pci_bus);
>  	kfree(pci_bus);
> diff --git a/drivers/pci/search.c b/drivers/pci/search.c
> index 827ad83..2d806bd 100644
> --- a/drivers/pci/search.c
> +++ b/drivers/pci/search.c
> @@ -305,8 +305,7 @@ static struct pci_dev *pci_get_dev_by_id(const struct
> pci_device_id *id,
>  			      match_pci_dev_by_id);
>  	if (dev)
>  		pdev = to_pci_dev(dev);
> -	if (from)
> -		pci_dev_put(from);
> +	pci_dev_put(from);
>  	return pdev;
>  }
> 
> diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c
> index 53df39a..46664cc 100644
> --- a/drivers/pci/xen-pcifront.c
> +++ b/drivers/pci/xen-pcifront.c
> @@ -596,8 +596,7 @@ static pci_ers_result_t pcifront_common_process(int cmd,
>  	pcidev = pci_get_bus_and_slot(bus, devfn);
>  	if (!pcidev || !pcidev->driver) {
>  		dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n");
> -		if (pcidev)
> -			pci_dev_put(pcidev);
> +		pci_dev_put(pcidev);
>  		return result;
>  	}
>  	pdrv = pcidev->driver;
> -- 
> 2.1.3
> 
> 

[PATCH 0/3] xen-scsiback: Fine-tuning for scsiback_device_action()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sat, 16 Jul 2016 22:06:54 +0200

Further update suggestions were taken into account
after a patch was applied from static source code analysis.

Markus Elfring (3):
  Delete an unnecessary check before the function call "kfree"
  One function call less in scsiback_device_action() after error detection
  Pass a failure indication as a constant

 drivers/xen/xen-scsiback.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

-- 
2.9.1


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[PATCH 1/3] xen-scsiback: Delete an unnecessary check before the function call "kfree"

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sat, 16 Jul 2016 21:21:05 +0200

The kfree() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/xen/xen-scsiback.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index d6950e0..4a48c06 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -627,8 +627,7 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
 	transport_generic_free_cmd(&pending_req->se_cmd, 1);
 	return;
 err:
-	if (tmr)
-		kfree(tmr);
+	kfree(tmr);
 	scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
 }
 
-- 
2.9.1


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[PATCH 2/3] xen-scsiback: One function call less in scsiback_device_action() after error detection

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sat, 16 Jul 2016 21:42:42 +0200

The kfree() function was called in one case by the
scsiback_device_action() function during error handling
even if the passed variable "tmr" contained a null pointer.

Adjust jump targets according to the Linux coding style convention.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/xen/xen-scsiback.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index 4a48c06..7612bc9 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -606,7 +606,7 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
 	tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
 	if (!tmr) {
 		target_put_sess_cmd(se_cmd);
-		goto err;
+		goto do_resp;
 	}
 
 	init_waitqueue_head(&tmr->tmr_wait);
@@ -616,7 +616,7 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
 			       unpacked_lun, tmr, act, GFP_KERNEL,
 			       tag, TARGET_SCF_ACK_KREF);
 	if (rc)
-		goto err;
+		goto free_tmr;
 
 	wait_event(tmr->tmr_wait, atomic_read(&tmr->tmr_complete));
 
@@ -626,8 +626,9 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
 	scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
 	transport_generic_free_cmd(&pending_req->se_cmd, 1);
 	return;
-err:
+free_tmr:
 	kfree(tmr);
+do_resp:
 	scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
 }
 
-- 
2.9.1


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[PATCH 3/3] xen-scsiback: Pass a failure indication as a constant

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sat, 16 Jul 2016 21:55:01 +0200

Pass the constant "FAILED" in a function call directly instead of
using an intialisation for a local variable.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/xen/xen-scsiback.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index 7612bc9..ec5546c 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -601,7 +601,7 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
 	struct se_cmd *se_cmd = &pending_req->se_cmd;
 	struct scsiback_tmr *tmr;
 	u64 unpacked_lun = pending_req->v2p->lun;
-	int rc, err = FAILED;
+	int rc, err;
 
 	tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
 	if (!tmr) {
@@ -629,7 +629,7 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
 free_tmr:
 	kfree(tmr);
 do_resp:
-	scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
+	scsiback_do_resp_with_sense(NULL, FAILED, 0, pending_req);
 }
 
 /*
-- 
2.9.1


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Re: [PATCH 1/3] xen-scsiback: Delete an unnecessary check before the function call "kfree"

[Juergen Gross]

On 16/07/16 22:22, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Sat, 16 Jul 2016 21:21:05 +0200
> 
> The kfree() function tests whether its argument is NULL and then
> returns immediately. Thus the test around the call is not needed.
> 
> This issue was detected by using the Coccinelle software.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>

Reviewed-by: Juergen Gross <jgross@suse.com>


Juergen

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Re: [PATCH 3/3] xen-scsiback: Pass a failure indication as a constant

[Juergen Gross]

On 16/07/16 22:24, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Sat, 16 Jul 2016 21:55:01 +0200
> 
> Pass the constant "FAILED" in a function call directly instead of
> using an intialisation for a local variable.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>

Reviewed-by: Juergen Gross <jgross@suse.com>


Juergen

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Re: [PATCH 2/3] xen-scsiback: One function call less in scsiback_device_action() after error detection

[Juergen Gross]

On 16/07/16 22:23, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Sat, 16 Jul 2016 21:42:42 +0200
> 
> The kfree() function was called in one case by the
> scsiback_device_action() function during error handling
> even if the passed variable "tmr" contained a null pointer.
> 
> Adjust jump targets according to the Linux coding style convention.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
>  drivers/xen/xen-scsiback.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
> index 4a48c06..7612bc9 100644
> --- a/drivers/xen/xen-scsiback.c
> +++ b/drivers/xen/xen-scsiback.c
> @@ -606,7 +606,7 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
>  	tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
>  	if (!tmr) {
>  		target_put_sess_cmd(se_cmd);
> -		goto err;
> +		goto do_resp;
>  	}

Hmm, I'm not convinced this is an improvement.

I'd rather rename the new error label to "put_cmd" and get rid of the
braces in above if statement:

-	if (!tmr) {
-		target_put_sess_cmd(se_cmd);
-		goto err;
-	}
+	if (!tmr)
+		goto put_cmd;

and then in the error path:

-err:
+put_cmd:
+	target_put_sess_cmd(se_cmd);
+free_tmr:
	kfree(tmr);


Juergen

>  
>  	init_waitqueue_head(&tmr->tmr_wait);
> @@ -616,7 +616,7 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
>  			       unpacked_lun, tmr, act, GFP_KERNEL,
>  			       tag, TARGET_SCF_ACK_KREF);
>  	if (rc)
> -		goto err;
> +		goto free_tmr;
>  
>  	wait_event(tmr->tmr_wait, atomic_read(&tmr->tmr_complete));
>  
> @@ -626,8 +626,9 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
>  	scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
>  	transport_generic_free_cmd(&pending_req->se_cmd, 1);
>  	return;
> -err:
> +free_tmr:
>  	kfree(tmr);
> +do_resp:
>  	scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
>  }
>  
> 


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Re: [PATCH 2/3] xen-scsiback: One function call less in scsiback_device_action() after error detection

[SF Markus Elfring]

>> @@ -606,7 +606,7 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
>>  	tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
>>  	if (!tmr) {
>>  		target_put_sess_cmd(se_cmd);
>> -		goto err;
>> +		goto do_resp;
>>  	}
> 
> Hmm, I'm not convinced this is an improvement.
> 
> I'd rather rename the new error label to "put_cmd" and get rid of the
> braces in above if statement:
> 
> -	if (!tmr) {
> -		target_put_sess_cmd(se_cmd);
> -		goto err;
> -	}
> +	if (!tmr)
> +		goto put_cmd;
> 
> and then in the error path:
> 
> -err:
> +put_cmd:
> +	target_put_sess_cmd(se_cmd);

I am unsure on the relevance of this function on such a source position.
Would it make sense to move it further down at the end?


> +free_tmr:
> 	kfree(tmr);

How do you think about to skip this function call after a memory
allocation failure?

Regards,
Markus

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Re: [PATCH 2/3] xen-scsiback: One function call less in scsiback_device_action() after error detection

[Juergen Gross]

On 19/07/16 16:56, SF Markus Elfring wrote:
>>> @@ -606,7 +606,7 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
>>>  	tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
>>>  	if (!tmr) {
>>>  		target_put_sess_cmd(se_cmd);
>>> -		goto err;
>>> +		goto do_resp;
>>>  	}
>>
>> Hmm, I'm not convinced this is an improvement.
>>
>> I'd rather rename the new error label to "put_cmd" and get rid of the
>> braces in above if statement:
>>
>> -	if (!tmr) {
>> -		target_put_sess_cmd(se_cmd);
>> -		goto err;
>> -	}
>> +	if (!tmr)
>> +		goto put_cmd;
>>
>> and then in the error path:
>>
>> -err:
>> +put_cmd:
>> +	target_put_sess_cmd(se_cmd);
> 
> I am unsure on the relevance of this function on such a source position.
> Would it make sense to move it further down at the end?

You only want to call it in the first error case (allocation failure).

>> +free_tmr:
>> 	kfree(tmr);
> 
> How do you think about to skip this function call after a memory
> allocation failure?

I think this just doesn't matter. If it were a hot path, yes. But trying
to do micro-optimizations in an error path is just not worth the effort.

I like a linear error path containing all the needed cleanups best.


Juergen

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Re: [PATCH 2/3] xen-scsiback: One function call less in scsiback_device_action() after error detection

[SF Markus Elfring]

>>>> @@ -606,7 +606,7 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
>>>>  	tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
>>>>  	if (!tmr) {
>>>>  		target_put_sess_cmd(se_cmd);
>>>> -		goto err;
>>>> +		goto do_resp;
>>>>  	}
>>>
>>> Hmm, I'm not convinced this is an improvement.
>>>
>>> I'd rather rename the new error label to "put_cmd" and get rid of the
>>> braces in above if statement:
>>>
>>> -	if (!tmr) {
>>> -		target_put_sess_cmd(se_cmd);
>>> -		goto err;
>>> -	}
>>> +	if (!tmr)
>>> +		goto put_cmd;
>>>
>>> and then in the error path:
>>>
>>> -err:
>>> +put_cmd:
>>> +	target_put_sess_cmd(se_cmd);
>>
>> I am unsure on the relevance of this function on such a source position.
>> Would it make sense to move it further down at the end?
> 
> You only want to call it in the first error case (allocation failure).

Thanks for your clarification.

I find that my update suggestion (from Saturday) is still appropriate
in this case.
https://lkml.org/lkml/2016/7/16/172


>>> +free_tmr:
>>> 	kfree(tmr);
>>
>> How do you think about to skip this function call after a memory
>> allocation failure?
> 
> I think this just doesn't matter. If it were a hot path, yes. But trying
> to do micro-optimizations in an error path is just not worth the effort.

Would you like to reduce also the amount of function calls in such special
run-time situations?


> I like a linear error path containing all the needed cleanups best.

I would prefer to keep the discussed single function call within
the basic block of the if statement.

Have we got different opinions about the shown implementation details?

Regards,
Markus

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Re: [PATCH 2/3] xen-scsiback: One function call less in scsiback_device_action() after error detection

[Juergen Gross]

On 20/07/16 07:10, SF Markus Elfring wrote:
>>>>> @@ -606,7 +606,7 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
>>>>>  	tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
>>>>>  	if (!tmr) {
>>>>>  		target_put_sess_cmd(se_cmd);
>>>>> -		goto err;
>>>>> +		goto do_resp;
>>>>>  	}
>>>>
>>>> Hmm, I'm not convinced this is an improvement.
>>>>
>>>> I'd rather rename the new error label to "put_cmd" and get rid of the
>>>> braces in above if statement:
>>>>
>>>> -	if (!tmr) {
>>>> -		target_put_sess_cmd(se_cmd);
>>>> -		goto err;
>>>> -	}
>>>> +	if (!tmr)
>>>> +		goto put_cmd;
>>>>
>>>> and then in the error path:
>>>>
>>>> -err:
>>>> +put_cmd:
>>>> +	target_put_sess_cmd(se_cmd);
>>>
>>> I am unsure on the relevance of this function on such a source position.
>>> Would it make sense to move it further down at the end?
>>
>> You only want to call it in the first error case (allocation failure).
> 
> Thanks for your clarification.
> 
> I find that my update suggestion (from Saturday) is still appropriate
> in this case.
> https://lkml.org/lkml/2016/7/16/172

And I still think it isn't an improvement: Nack

>>>> +free_tmr:
>>>> 	kfree(tmr);
>>>
>>> How do you think about to skip this function call after a memory
>>> allocation failure?
>>
>> I think this just doesn't matter. If it were a hot path, yes. But trying
>> to do micro-optimizations in an error path is just not worth the effort.
> 
> Would you like to reduce also the amount of function calls in such special
> run-time situations?

I just don't care for the extra 2 or 3 nsecs. Readability is more
important here.

>> I like a linear error path containing all the needed cleanups best.
> 
> I would prefer to keep the discussed single function call within
> the basic block of the if statement.
> 
> Have we got different opinions about the shown implementation details?

Yes.


Juergen


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[PATCH v2 0/3] xen-scsiback: Fine-tuning for scsiback_device_action()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Wed, 20 Jul 2016 13:20:04 +0200

Further update suggestions were taken into account
after a patch was applied from static source code analysis.

Markus Elfring (3):
  Delete an unnecessary check before the function call "kfree"
  Rename jump labels in scsiback_device_action()
  Pass a failure indication as a constant

 drivers/xen/xen-scsiback.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

-- 
2.9.2


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[PATCH v2 1/3] xen-scsiback: Delete an unnecessary check before the function call "kfree"

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Tue, 19 Jul 2016 15:42:19 +0200

The kfree() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
v2: Rebased on source files from "Linux next-20160719"

 drivers/xen/xen-scsiback.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index d6950e0..4a48c06 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -627,8 +627,7 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
 	transport_generic_free_cmd(&pending_req->se_cmd, 1);
 	return;
 err:
-	if (tmr)
-		kfree(tmr);
+	kfree(tmr);
 	scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
 }
 
-- 
2.9.2


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[PATCH v2 2/3] xen-scsiback: Rename jump labels in scsiback_device_action()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Wed, 20 Jul 2016 13:03:16 +0200

* Adjust jump targets according to the Linux coding style convention.

* A bit of refactoring for the control flow

Suggested-by: Jürgen Groß <jgross@suse.com>
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
v2: Rebased on source files from "Linux next-20160719"
    Changes from a bit of code review

 drivers/xen/xen-scsiback.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index 4a48c06..eb274df 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -604,10 +604,8 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
 	int rc, err = FAILED;
 
 	tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
-	if (!tmr) {
-		target_put_sess_cmd(se_cmd);
-		goto err;
-	}
+	if (!tmr)
+		goto put_cmd;
 
 	init_waitqueue_head(&tmr->tmr_wait);
 
@@ -616,7 +614,7 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
 			       unpacked_lun, tmr, act, GFP_KERNEL,
 			       tag, TARGET_SCF_ACK_KREF);
 	if (rc)
-		goto err;
+		goto free_tmr;
 
 	wait_event(tmr->tmr_wait, atomic_read(&tmr->tmr_complete));
 
@@ -626,7 +624,9 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
 	scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
 	transport_generic_free_cmd(&pending_req->se_cmd, 1);
 	return;
-err:
+put_cmd:
+	target_put_sess_cmd(se_cmd);
+free_tmr:
 	kfree(tmr);
 	scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
 }
-- 
2.9.2


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[PATCH v2 3/3] xen-scsiback: Pass a failure indication as a constant

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Wed, 20 Jul 2016 13:12:33 +0200

Pass the constant "FAILED" in a function call directly instead of
using an intialisation for a local variable.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
v2: Rebased on source files from "Linux next-20160719"

 drivers/xen/xen-scsiback.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index eb274df..fa08ec6 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -601,7 +601,7 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
 	struct se_cmd *se_cmd = &pending_req->se_cmd;
 	struct scsiback_tmr *tmr;
 	u64 unpacked_lun = pending_req->v2p->lun;
-	int rc, err = FAILED;
+	int rc, err;
 
 	tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
 	if (!tmr)
@@ -628,7 +628,7 @@ put_cmd:
 	target_put_sess_cmd(se_cmd);
 free_tmr:
 	kfree(tmr);
-	scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
+	scsiback_do_resp_with_sense(NULL, FAILED, 0, pending_req);
 }
 
 /*
-- 
2.9.2


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Re: [PATCH v2 1/3] xen-scsiback: Delete an unnecessary check before the function call "kfree"

[Juergen Gross]

On 20/07/16 13:30, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Tue, 19 Jul 2016 15:42:19 +0200
> 
> The kfree() function tests whether its argument is NULL and then
> returns immediately. Thus the test around the call is not needed.
> 
> This issue was detected by using the Coccinelle software.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>

Even if already given, here it is again:

Reviewed-by: Juergen Gross <jgross@suse.com>


Juergen

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Re: [PATCH v2 3/3] xen-scsiback: Pass a failure indication as a constant

[Juergen Gross]

On 20/07/16 13:36, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Wed, 20 Jul 2016 13:12:33 +0200
> 
> Pass the constant "FAILED" in a function call directly instead of
> using an intialisation for a local variable.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>

Even if already given, here it is again:

Reviewed-by: Juergen Gross <jgross@suse.com>


Juergen

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Re: [PATCH v2 2/3] xen-scsiback: Rename jump labels in scsiback_device_action()

[Juergen Gross]

On 20/07/16 13:34, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Wed, 20 Jul 2016 13:03:16 +0200
> 
> * Adjust jump targets according to the Linux coding style convention.
> 
> * A bit of refactoring for the control flow
> 
> Suggested-by: Jürgen Groß <jgross@suse.com>
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>

Reviewed-by: Juergen Gross <jgross@suse.com>


Juergen

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