Re: CVS commit: src/sys

["J. Hannken-Illjes" <hannken%eis.cs.tu-bs.de@localhost>]

On Dec 27, 2012, at 11:46 PM, Taylor R Campbell 
<riastradh%netbsd.org@localhost> wrote:

>   From: hannken%NetBSD.org@localhost
>   Date: Thu, 20 Dec 2012 08:03:46 +0000
> 
>   --- sys/fs/msdosfs/msdosfs_vnops.c      29 Apr 2012 22:53:59 -0000      1.83
>   +++ sys/fs/msdosfs/msdosfs_vnops.c      20 Dec 2012 08:03:42 -0000      1.84
>   @@ -527,7 +527,6 @@ msdosfs_read(void *v)
>                       NOCRED, 0, &bp);
>                   n = MIN(n, pmp->pm_bpcluster - bp->b_resid);
>                   if (error) {
>   -                       brelse(bp, 0);
> 
> Looks like you need to move the initialization of n to after the error
> branch.

Fixed, thanks.

>   --- sys/ufs/ext2fs/ext2fs_vfsops.c      21 Nov 2012 23:11:23 -0000      
> 1.167
>   +++ sys/ufs/ext2fs/ext2fs_vfsops.c      20 Dec 2012 08:03:44 -0000      
> 1.168
>   @@ -772,8 +770,8 @@ ext2fs_mountfs(struct vnode *devvp, stru
>           return (0);
> 
>    out:
>   -       KASSERT(bp != NULL);
>   -       brelse(bp, 0);
>   +       if (bp != NULL)
>   +               brelse(bp, 0);
> 
> 
> Are bread &c. supposed to guarantee that bp is null on error, or are
> they supposed to leave it in an undefined state?  Either way, it seems
> to me that the intent ought to be documented in buffercache(9).

Both bread() and breadn() will either return with `error == 0, *bpp != NULL'
or `error != 0, *bpp == NULL'.

--
J. Hannken-Illjes - hannken%eis.cs.tu-bs.de@localhost - TU Braunschweig 
(Germany)