Re: git: ec3c225711ae - main - vfs: call vn_truncate_locked from kern_truncate

On Fri, May 20, 2022 at 05:25:59PM +0000, Mateusz Guzik wrote:
> The branch main has been updated by mjg:
> 
> URL: https://cgit.FreeBSD.org/src/commit/?id=ec3c225711ae7d5b8e71ed036aada09ef91149ec
> 
> commit ec3c225711ae7d5b8e71ed036aada09ef91149ec
> Author:     Mateusz Guzik <mjg@FreeBSD.org>
> AuthorDate: 2022-05-16 01:28:22 +0000
> Commit:     Mateusz Guzik <mjg@FreeBSD.org>
> CommitDate: 2022-05-20 17:25:51 +0000
> 
>     vfs: call vn_truncate_locked from kern_truncate
>     
>     This fixes a bug where the syscall would not bump writecount.
>     
>     PR:     263999
> ---
>  sys/kern/vfs_syscalls.c | 22 ++++++++++++----------
>  1 file changed, 12 insertions(+), 10 deletions(-)
> 
> diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
> index 86ef3fc7a095..600299fbe6eb 100644
> --- a/sys/kern/vfs_syscalls.c
> +++ b/sys/kern/vfs_syscalls.c
> @@ -3460,7 +3460,6 @@ kern_truncate(struct thread *td, const char *path, enum uio_seg pathseg,
>  	struct mount *mp;
>  	struct vnode *vp;
>  	void *rl_cookie;
> -	struct vattr vattr;
>  	struct nameidata nd;
>  	int error;
>  
> @@ -3480,18 +3479,21 @@ retry:
>  		return (error);
>  	}
>  	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
> -	if (vp->v_type == VDIR)
> +	if (vp->v_type == VDIR) {
>  		error = EISDIR;
> -#ifdef MAC
> -	else if ((error = mac_vnode_check_write(td->td_ucred, NOCRED, vp))) {
> +		goto out;
>  	}
> +#ifdef MAC
> +	error = mac_vnode_check_write(td->td_ucred, NOCRED, vp);
> +	if (error != 0)
> +		goto out;
>  #endif
> -	else if ((error = vn_writechk(vp)) == 0 &&
> -	    (error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td)) == 0) {
> -		VATTR_NULL(&vattr);
> -		vattr.va_size = length;
> -		error = VOP_SETATTR(vp, &vattr, td->td_ucred);
> -	}
> +	error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td);
> +	if (error != 0)
> +		goto out;
> +
> +	error = vn_truncate_locked(vp, 0, false, td->td_ucred);
> +out:
>  	VOP_UNLOCK(vp);
>  	vn_finished_write(mp);
>  	vn_rangelock_unlock(vp, rl_cookie);

seems this broke truncate, test attached.