my initial attempt to send a response is not moving out of the
queue...so here is a second attempt.
On 1/10/17, Alexander Bluhm <alexander.bl...@gmx.net> wrote:
> Hi,
>
> When I force to unmount a filesystem where another mountpoint is
> located, an unlinked mountpoint will remain. I have not found a
> way to restore the kernel to a sane state.
>
> # mount /dev/vnd0a /mnt
> # mkdir /mnt/mnt
> # mount /dev/vnd1a /mnt/mnt
> # mount
> /dev/sd0a on / type ffs (local)
> /dev/vnd0a on /mnt type ffs (local)
> /dev/vnd1a on /mnt/mnt type ffs (local)
> # umount /mnt
> umount: /mnt: Device busy
> # umount -f /mnt
> # mount
> /dev/sd0a on / type ffs (local)
> /dev/vnd1a on /mnt/mnt type ffs (local)
> # umount /mnt/mnt
> umount: /mnt/mnt: No such file or directory
does
# umount /dev/vnd1a
not do the trick?
--patrick
> # mkdir /mnt/mnt
> # umount /mnt/mnt
> umount: /mnt/mnt: Invalid argument
> # vnconfig -u vnd1
> vnconfig: VNDIOCCLR: Device busy
>
> The fix could be to unmount recursively.
>
> ok?
>
> bluhm
>
> Index: kern/vfs_syscalls.c
> ===================================================================
> RCS file: /cvs/src/sys/kern/vfs_syscalls.c,v
> retrieving revision 1.267
> diff -u -p -r1.267 vfs_syscalls.c
> --- kern/vfs_syscalls.c 10 Jan 2017 20:13:17 -0000 1.267
> +++ kern/vfs_syscalls.c 10 Jan 2017 20:36:05 -0000
> @@ -88,6 +88,7 @@ int domkdirat(struct proc *, int, const
> int doutimensat(struct proc *, int, const char *, struct timespec [2],
> int);
> int dovutimens(struct proc *, struct vnode *, struct timespec [2]);
> int dofutimens(struct proc *, int, struct timespec [2]);
> +int unmount_vnode(struct vnode *, void *);
>
> /*
> * Virtual File System System Calls
> @@ -368,15 +369,56 @@ sys_unmount(struct proc *p, void *v, reg
> return (dounmount(mp, SCARG(uap, flags) & MNT_FORCE, p));
> }
>
> +struct unmount_args {
> + struct proc *ua_proc;
> + int ua_flags;
> + int ua_error;
> +};
> +
> +int
> +unmount_vnode(struct vnode *vp, void *args)
> +{
> + struct unmount_args *ua = args;
> + struct mount *mp;
> + int error;
> +
> + if (vp->v_type != VDIR)
> + return (0);
> + if ((mp = vp->v_mountedhere) == NULL)
> + return (0);
> + if (!(ua->ua_flags & MNT_FORCE)) {
> + ua->ua_error = EBUSY;
> + return (EBUSY);
> + }
> + if (vfs_busy(mp, VB_WRITE|VB_WAIT)) {
> + ua->ua_error = EBUSY;
> + return (0);
> + }
> + error = dounmount(mp, ua->ua_flags, ua->ua_proc);
> + if (error)
> + ua->ua_error = error;
> + return (0);
> +}
> +
> /*
> * Do the actual file system unmount.
> */
> int
> dounmount(struct mount *mp, int flags, struct proc *p)
> {
> + struct unmount_args ua;
> struct vnode *coveredvp;
> int error;
> int hadsyncer = 0;
> +
> + ua.ua_proc = p;
> + ua.ua_flags = flags;
> + ua.ua_error = 0;
> + vfs_mount_foreach_vnode(mp, unmount_vnode, &ua);
> + if (ua.ua_error && !(flags & MNT_DOOMED)) {
> + vfs_unbusy(mp);
> + return (ua.ua_error);
> + }
>
> mp->mnt_flag &=~ MNT_ASYNC;
> cache_purgevfs(mp); /* remove cache entries for this file sys */
>
>
