Patchwork [Open-FCoE] libfs: Replace rcu_assign_pointer() with RCU_INIT_POINTER()

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Submitter Andreea-Cristina Bernat
Date Aug. 18, 2014, 2:56 p.m.
Message ID <20140818145622.GA14281@ada>
Download mbox | patch
Permalink /patch/159/
State Accepted
Headers show

Comments

Andreea-Cristina Bernat - Aug. 18, 2014, 2:56 p.m.
The uses of "rcu_assign_pointer()" are NULLing out the pointers.
According to RCU_INIT_POINTER()'s block comment:
"1.   This use of RCU_INIT_POINTER() is NULLing out the pointer"
it is better to use it instead of rcu_assign_pointer() because it has a
smaller overhead.

The following Coccinelle semantic patch was used:
@@
@@

- rcu_assign_pointer
+ RCU_INIT_POINTER
  (..., NULL)

Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
---
 drivers/scsi/libfc/fc_libfc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
Vasu Dev - Sept. 25, 2014, 10:01 p.m.
On Mon, 2014-08-18 at 17:56 +0300, Andreea-Cristina Bernat wrote:
> The uses of "rcu_assign_pointer()" are NULLing out the pointers.
> According to RCU_INIT_POINTER()'s block comment:
> "1.   This use of RCU_INIT_POINTER() is NULLing out the pointer"
> it is better to use it instead of rcu_assign_pointer() because it has a
> smaller overhead.
> 
> The following Coccinelle semantic patch was used:
> @@
> @@
> 
> - rcu_assign_pointer
> + RCU_INIT_POINTER
>   (..., NULL)
> 
> Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
> ---
>  drivers/scsi/libfc/fc_libfc.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/libfc/fc_libfc.c b/drivers/scsi/libfc/fc_libfc.c
> index 8d65a51a..c11a638 100644
> --- a/drivers/scsi/libfc/fc_libfc.c
> +++ b/drivers/scsi/libfc/fc_libfc.c
> @@ -296,9 +296,9 @@ void fc_fc4_deregister_provider(enum fc_fh_type type, struct fc4_prov *prov)
>  	BUG_ON(type >= FC_FC4_PROV_SIZE);
>  	mutex_lock(&fc_prov_mutex);
>  	if (prov->recv)
> -		rcu_assign_pointer(fc_passive_prov[type], NULL);
> +		RCU_INIT_POINTER(fc_passive_prov[type], NULL);
>  	else
> -		rcu_assign_pointer(fc_active_prov[type], NULL);
> +		RCU_INIT_POINTER(fc_active_prov[type], NULL);
>  	mutex_unlock(&fc_prov_mutex);
>  	synchronize_rcu();
>  }

Looks like patch is not yet applied.

Acked-by: Vasu Dev <vasu.dev@intel.com>
Christoph Hellwig - Sept. 30, 2014, 3:36 p.m.
Thanks,

applied to drivers-for-3.18

Patch

diff --git a/drivers/scsi/libfc/fc_libfc.c b/drivers/scsi/libfc/fc_libfc.c
index 8d65a51a..c11a638 100644
--- a/drivers/scsi/libfc/fc_libfc.c
+++ b/drivers/scsi/libfc/fc_libfc.c
@@ -296,9 +296,9 @@  void fc_fc4_deregister_provider(enum fc_fh_type type, struct fc4_prov *prov)
 	BUG_ON(type >= FC_FC4_PROV_SIZE);
 	mutex_lock(&fc_prov_mutex);
 	if (prov->recv)
-		rcu_assign_pointer(fc_passive_prov[type], NULL);
+		RCU_INIT_POINTER(fc_passive_prov[type], NULL);
 	else
-		rcu_assign_pointer(fc_active_prov[type], NULL);
+		RCU_INIT_POINTER(fc_active_prov[type], NULL);
 	mutex_unlock(&fc_prov_mutex);
 	synchronize_rcu();
 }