[PATCH] Fix an assertion check

[Jeremy Allison]

On Fri, Jul 27, 2018 at 12:17:05PM +0530, Anoop C S via samba-technical wrote:
> Hi,
> 
> Attached patch fixes the assertion check while reducing the lock reference count. If it is the right
> thing to do we may also consider changing the assertion check while increasing the same lock
> reference count inside increment_lock_ref_count():
> 
> SMB_ASSERT(lock_ref_count < (INT32_MAX - 1))
> 
> Also the DEBUG statement[inside increment_lock_ref_count() and decrement_lock_ref_count()] prints
> the old reference count value instead of the new one.
> 
> Thanks,
> Anoop C S.

This patch is correct. Reviewed-by: Jeremy Allison <jra at samba.org>

Can I get a second Team reviewer ?

Thanks,

	Jeremy.

> From 406ee976bd4ea407d08f259785f1ec69ebe07b6c Mon Sep 17 00:00:00 2001
> From: Anoop C S <anoopcs at redhat.com>
> Date: Fri, 27 Jul 2018 11:50:39 +0530
> Subject: [PATCH] s3/locking: Fix assertion check on lock reference count
> 
> lock_ref_count will always hold the old value prior to change. Thus it
> would mean that if lock_ref_count is 0 the new value is already -1 which
> is not expected here. Therefore it is better to make sure that it is
> always greater than 0 rather than >= 0.
> 
> Signed-off-by: Anoop C S <anoopcs at redhat.com>
> ---
>  source3/locking/posix.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/source3/locking/posix.c b/source3/locking/posix.c
> index 0b627aaa3e5..13992663280 100644
> --- a/source3/locking/posix.c
> +++ b/source3/locking/posix.c
> @@ -454,7 +454,7 @@ static void decrement_lock_ref_count(const files_struct *fsp)
>  		&lock_ref_count, -1);
>  
>  	SMB_ASSERT(NT_STATUS_IS_OK(status));
> -	SMB_ASSERT(lock_ref_count >= 0);
> +	SMB_ASSERT(lock_ref_count > 0);
>  
>  	DEBUG(10,("lock_ref_count for file %s = %d\n",
>  		  fsp_str_dbg(fsp), (int)lock_ref_count));
> -- 
> 2.17.1
>