static int
vfs_mountroot_devfs(struct thread *td, struct mount **mpp)
{
struct vfsoptlist *opts;
struct vfsconf *vfsp;
struct mount *mp;
int error;
*mpp = NULL;
vfsp = vfs_byname("devfs");
KASSERT(vfsp != NULL, ("Could not find devfs by name"));
if (vfsp == NULL)
return (ENOENT);
mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td->td_ucred);
error = VFS_MOUNT(mp);
KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error));
if (error)
return (error);
opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
TAILQ_INIT(opts);
mp->mnt_opt = opts;
mtx_lock(&mountlist_mtx);
TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
mtx_unlock(&mountlist_mtx);
*mpp = mp;
rootdevmp = mp;
set_rootvnode();
error = kern_symlinkat(td, "/", AT_FDCWD, "dev", UIO_SYSSPACE);
if (error)
printf("kern_symlink /dev -> / returns %d\n", error);
return (error);
}
static int
vfs_mountroot_shuffle(struct thread *td, struct mount *mpdevfs)
{
struct nameidata nd;
struct mount *mporoot, *mpnroot;
struct vnode *vp, *vporoot, *vpdevfs;
char *fspath;
int error;
mpnroot = TAILQ_NEXT(mpdevfs, mnt_list);
/* Shuffle the mountlist. */
mtx_lock(&mountlist_mtx);
mporoot = TAILQ_FIRST(&mountlist);
TAILQ_REMOVE(&mountlist, mpdevfs, mnt_list);
if (mporoot != mpdevfs) {
TAILQ_REMOVE(&mountlist, mpnroot, mnt_list);
TAILQ_INSERT_HEAD(&mountlist, mpnroot, mnt_list);
}
TAILQ_INSERT_TAIL(&mountlist, mpdevfs, mnt_list);
mtx_unlock(&mountlist_mtx);
cache_purgevfs(mporoot);
if (mporoot != mpdevfs)
cache_purgevfs(mpdevfs);
VFS_ROOT(mporoot, LK_EXCLUSIVE, &vporoot);
VI_LOCK(vporoot);
vporoot->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vporoot);
vporoot->v_mountedhere = NULL;
mporoot->mnt_flag &= ~MNT_ROOTFS;
mporoot->mnt_vnodecovered = NULL;
vput(vporoot);
/* Set up the new rootvnode, and purge the cache */
mpnroot->mnt_vnodecovered = NULL;
set_rootvnode();
cache_purgevfs(rootvnode->v_mount);
if (mporoot != mpdevfs) {
/* Remount old root under /.mount or /mnt */
fspath = "/.mount";
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
fspath, td);
error = namei(&nd);
if (error) {
NDFREE(&nd, NDF_ONLY_PNBUF);
fspath = "/mnt";
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
fspath, td);
error = namei(&nd);
}
if (!error) {
vp = nd.ni_vp;
error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
if (!error)
error = vinvalbuf(vp, V_SAVE, 0, 0);
if (!error) {
cache_purge(vp);
mporoot->mnt_vnodecovered = vp;
vp->v_mountedhere = mporoot;
strlcpy(mporoot->mnt_stat.f_mntonname,
fspath, MNAMELEN);
VOP_UNLOCK(vp, 0);
} else
vput(vp);
}
NDFREE(&nd, NDF_ONLY_PNBUF);
if (error && bootverbose)
printf("mountroot: unable to remount previous root "
"under /.mount or /mnt (error %d).\n", error);
}
/* Remount devfs under /dev */
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td);
error = namei(&nd);
if (!error) {
vp = nd.ni_vp;
error = (vp->v_type == VDIR) ? 0 : ENOTDIR;
if (!error)
error = vinvalbuf(vp, V_SAVE, 0, 0);
if (!error) {
vpdevfs = mpdevfs->mnt_vnodecovered;
if (vpdevfs != NULL) {
cache_purge(vpdevfs);
vpdevfs->v_mountedhere = NULL;
vrele(vpdevfs);
}
mpdevfs->mnt_vnodecovered = vp;
vp->v_mountedhere = mpdevfs;
VOP_UNLOCK(vp, 0);
} else
vput(vp);
}
if (error && bootverbose)
printf("mountroot: unable to remount devfs under /dev "
"(error %d).\n", error);
NDFREE(&nd, NDF_ONLY_PNBUF);
if (mporoot == mpdevfs) {
vfs_unbusy(mpdevfs);
/* Unlink the no longer needed /dev/dev -> / symlink */
error = kern_unlink(td, "/dev/dev", UIO_SYSSPACE);
if (error && bootverbose)
printf("mountroot: unable to unlink /dev/dev "
"(error %d)\n", error);
}
return (0);
}
