[PATCH 11/17] fs/xfs/quota: Add missing mutex_unlock

[PATCH 11/17] fs/xfs/quota: Add missing mutex_unlock

[Julia Lawall]

From: Julia Lawall <julia@diku.dk>

Add a mutex_unlock missing on the error path.  The use of this lock is
balanced elsewhere in the file.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression E1;
@@

* mutex_lock(E1,...);
  <+... when != E1
  if (...) {
    ... when != E1
*   return ...;
  }
  ...+>
* mutex_unlock(E1,...);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
The use of ENOMEM rather than -ENOMEM is also a bit odd.

 fs/xfs/quota/xfs_qm.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/quota/xfs_qm.c b/fs/xfs/quota/xfs_qm.c
index 38e7641..2d8b7bc 100644
--- a/fs/xfs/quota/xfs_qm.c
+++ b/fs/xfs/quota/xfs_qm.c
@@ -249,8 +249,10 @@ xfs_qm_hold_quotafs_ref(
 
 	if (!xfs_Gqm) {
 		xfs_Gqm = xfs_Gqm_init();
-		if (!xfs_Gqm)
+		if (!xfs_Gqm) {
+			mutex_unlock(&xfs_Gqm_lock);
 			return ENOMEM;
+		}
 	}
 
 	/*

Re: [PATCH 11/17] fs/xfs/quota: Add missing mutex_unlock

[Alex Elder]

On Wed, 2010-05-26 at 17:57 +0200, Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
> 
> Add a mutex_unlock missing on the error path.  The use of this lock is
> balanced elsewhere in the file.

Looks good.  I'll pull this one into the XFS tree.

Reviewed-by: Alex Elder <aelder@sgi.com>

> The semantic match that finds this problem is as follows:
> (http://coccinelle.lip6.fr/)
> 
> // <smpl>
> @@
> expression E1;
> @@
> 
> * mutex_lock(E1,...);
>   <+... when != E1
>   if (...) {
>     ... when != E1
> *   return ...;
>   }
>   ...+>
> * mutex_unlock(E1,...);
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>
> 
> ---
> The use of ENOMEM rather than -ENOMEM is also a bit odd.
> 
>  fs/xfs/quota/xfs_qm.c |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/quota/xfs_qm.c b/fs/xfs/quota/xfs_qm.c
> index 38e7641..2d8b7bc 100644
> --- a/fs/xfs/quota/xfs_qm.c
> +++ b/fs/xfs/quota/xfs_qm.c
> @@ -249,8 +249,10 @@ xfs_qm_hold_quotafs_ref(
>  
>  	if (!xfs_Gqm) {
>  		xfs_Gqm = xfs_Gqm_init();
> -		if (!xfs_Gqm)
> +		if (!xfs_Gqm) {
> +			mutex_unlock(&xfs_Gqm_lock);
>  			return ENOMEM;
> +		}
>  	}
>  
>  	/*

Re: [xfs-masters] [PATCH 11/17] fs/xfs/quota: Add missing mutex_unlock

[Eric Sandeen]

Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
> 
> Add a mutex_unlock missing on the error path.  The use of this lock is
> balanced elsewhere in the file.
> 
> The semantic match that finds this problem is as follows:
> (http://coccinelle.lip6.fr/)
> 
> // <smpl>
> @@
> expression E1;
> @@
> 
> * mutex_lock(E1,...);
>   <+... when != E1
>   if (...) {
>     ... when != E1
> *   return ...;
>   }
>   ...+>
> * mutex_unlock(E1,...);
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>
> 
> ---
> The use of ENOMEM rather than -ENOMEM is also a bit odd.

All the xfs core code uses positive errors, it's an irix holdover.

As things bubble up to the vfs interface, signs get switched.

Yeah, it's a bit odd, but nobody dares change it ;)

Maybe semantic patching could fix it ;)

-Eric