svn commit: r184568 - head/sys/netsmb

[John Baldwin]

On Sunday 02 November 2008 03:22:24 pm Robert Watson wrote:
> Author: rwatson
> Date: Sun Nov  2 20:22:24 2008
> New Revision: 184568
> URL: http://svn.freebsd.org/changeset/base/184568
> 
> Log:
>   smb_vc_put() requires that the passed vcp be locked, so lock it before
>   dropping the connection when the requested service isn't available, or
>   we may try to release a lock that isn't locked.
>   
>   This prevents an assertion failure when trying to mount a non-present
>   share using smbfs with INVARIANTS; a lock order reversal warning that
>   immediately follows is not yet fixed.
>   
>   Reported by:	attilio
>   MFC after:	3 days
> 
> Modified:
>   head/sys/netsmb/smb_conn.c
> 
> Modified: head/sys/netsmb/smb_conn.c
> 
==============================================================================
> --- head/sys/netsmb/smb_conn.c	Sun Nov  2 19:48:15 2008	(r184567)
> +++ head/sys/netsmb/smb_conn.c	Sun Nov  2 20:22:24 2008	(r184568)
> @@ -218,8 +218,10 @@ out:
>  	smb_sm_unlockvclist(td);
>  	if (error == 0)
>  		*vcpp = vcp;
> -	else if (vcp)
> +	else if (vcp) {
> +		smb_vc_lock(vcp, LK_EXCLUSIVE, scred->scr_td);
>  		smb_vc_put(vcp, scred);
> +	}
>  	return error;
>  }

Can't you just do 'smb_vc_rele()' to avoid pointlessly acquiring the lock only 
to drop it again?  Just as with vput/vrele for vnodes, smb_XX_rele() drops 
the reference count and smb_xx_put() is equivalent to 'smb_XX_rele() + 
lockmgr(LK_RELEASE)'

-- 
John Baldwin