int
msdosfs_mountroot(void)
{
struct mount *mp;
struct lwp *l = curlwp; /* XXX */
int error;
struct msdosfs_args args;
if (device_class(root_device) != DV_DISK)
return (ENODEV);
if ((error = vfs_rootmountalloc(MOUNT_MSDOS, "root_device", &mp))) {
vrele(rootvp);
return (error);
}
args.flags = MSDOSFSMNT_VERSIONED;
args.uid = 0;
args.gid = 0;
args.mask = 0777;
args.version = MSDOSFSMNT_VERSION;
args.dirmask = 0777;
if ((error = msdosfs_mountfs(rootvp, mp, l, &args)) != 0) {
vfs_unbusy(mp, false, NULL);
vfs_destroy(mp);
return (error);
}
if ((error = update_mp(mp, &args)) != 0) {
(void)msdosfs_unmount(mp, 0);
vfs_unbusy(mp, false, NULL);
vfs_destroy(mp);
vrele(rootvp);
return (error);
}
mountlist_append(mp);
(void)msdosfs_statvfs(mp, &mp->mnt_stat);
vfs_unbusy(mp, false, NULL);
return (0);
}
/*
* mp - path - addr in user space of mount point (ie /usr or whatever)
* data - addr in user space of mount params including the name of the block
* special file to treat as a filesystem.
*/
static int
msdosfs_mount(struct mount *mp)
{
struct vnode *devvp; /* vnode for blk device to mount */
struct thread *td;
/* msdosfs specific mount control block */
struct msdosfsmount *pmp = NULL;
struct nameidata ndp;
int error, flags;
accmode_t accmode;
char *from;
td = curthread;
if (vfs_filteropt(mp->mnt_optnew, msdosfs_opts))
return (EINVAL);
/*
* If updating, check whether changing from read-only to
* read/write; if there is no device name, that's all we do.
*/
if (mp->mnt_flag & MNT_UPDATE) {
pmp = VFSTOMSDOSFS(mp);
if (vfs_flagopt(mp->mnt_optnew, "export", NULL, 0)) {
/*
* Forbid export requests if filesystem has
* MSDOSFS_LARGEFS flag set.
*/
if ((pmp->pm_flags & MSDOSFS_LARGEFS) != 0) {
vfs_mount_error(mp,
"MSDOSFS_LARGEFS flag set, cannot export");
return (EOPNOTSUPP);
}
}
if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) &&
vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) {
error = VFS_SYNC(mp, MNT_WAIT);
if (error)
return (error);
flags = WRITECLOSE;
if (mp->mnt_flag & MNT_FORCE)
flags |= FORCECLOSE;
error = vflush(mp, 0, flags, td);
if (error)
return (error);
/*
* Now the volume is clean. Mark it so while the
* device is still rw.
*/
error = markvoldirty(pmp, 0);
if (error) {
(void)markvoldirty(pmp, 1);
return (error);
}
/* Downgrade the device from rw to ro. */
DROP_GIANT();
g_topology_lock();
error = g_access(pmp->pm_cp, 0, -1, 0);
g_topology_unlock();
PICKUP_GIANT();
if (error) {
(void)markvoldirty(pmp, 1);
return (error);
}
/*
* Backing out after an error was painful in the
* above. Now we are committed to succeeding.
*/
pmp->pm_fmod = 0;
pmp->pm_flags |= MSDOSFSMNT_RONLY;
MNT_ILOCK(mp);
mp->mnt_flag |= MNT_RDONLY;
MNT_IUNLOCK(mp);
} else if ((pmp->pm_flags & MSDOSFSMNT_RONLY) &&
!vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) {
/*
* If upgrade to read-write by non-root, then verify
* that user has necessary permissions on the device.
*/
devvp = pmp->pm_devvp;
vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
error = VOP_ACCESS(devvp, VREAD | VWRITE,
td->td_ucred, td);
if (error)
error = priv_check(td, PRIV_VFS_MOUNT_PERM);
if (error) {
VOP_UNLOCK(devvp, 0);
return (error);
}
VOP_UNLOCK(devvp, 0);
DROP_GIANT();
g_topology_lock();
error = g_access(pmp->pm_cp, 0, 1, 0);
g_topology_unlock();
PICKUP_GIANT();
if (error)
return (error);
pmp->pm_fmod = 1;
pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
MNT_ILOCK(mp);
mp->mnt_flag &= ~MNT_RDONLY;
MNT_IUNLOCK(mp);
/* Now that the volume is modifiable, mark it dirty. */
error = markvoldirty(pmp, 1);
if (error)
return (error);
}
}
/*
* Not an update, or updating the name: look up the name
* and verify that it refers to a sensible disk device.
*/
if (vfs_getopt(mp->mnt_optnew, "from", (void **)&from, NULL))
return (EINVAL);
NDINIT(&ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, from, td);
error = namei(&ndp);
if (error)
return (error);
devvp = ndp.ni_vp;
NDFREE(&ndp, NDF_ONLY_PNBUF);
if (!vn_isdisk(devvp, &error)) {
vput(devvp);
return (error);
}
/*
* If mount by non-root, then verify that user has necessary
* permissions on the device.
*/
accmode = VREAD;
if ((mp->mnt_flag & MNT_RDONLY) == 0)
accmode |= VWRITE;
error = VOP_ACCESS(devvp, accmode, td->td_ucred, td);
if (error)
error = priv_check(td, PRIV_VFS_MOUNT_PERM);
if (error) {
vput(devvp);
return (error);
}
if ((mp->mnt_flag & MNT_UPDATE) == 0) {
error = mountmsdosfs(devvp, mp);
#ifdef MSDOSFS_DEBUG /* only needed for the printf below */
pmp = VFSTOMSDOSFS(mp);
#endif
} else {
vput(devvp);
if (devvp != pmp->pm_devvp)
return (EINVAL); /* XXX needs translation */
}
if (error) {
vrele(devvp);
return (error);
}
error = update_mp(mp, td);
if (error) {
if ((mp->mnt_flag & MNT_UPDATE) == 0)
msdosfs_unmount(mp, MNT_FORCE);
return error;
}
if (devvp->v_type == VCHR && devvp->v_rdev != NULL)
devvp->v_rdev->si_mountpt = mp;
vfs_mountedfrom(mp, from);
#ifdef MSDOSFS_DEBUG
printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
#endif
return (0);
}
/*
* mp - path - addr in user space of mount point (ie /usr or whatever)
* data - addr in user space of mount params including the name of the block
* special file to treat as a filesystem.
*/
int
msdosfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
{
struct lwp *l = curlwp;
struct vnode *devvp; /* vnode for blk device to mount */
struct msdosfs_args *args = data; /* holds data from mount request */
/* msdosfs specific mount control block */
struct msdosfsmount *pmp = NULL;
int error, flags;
mode_t accessmode;
if (*data_len < sizeof *args)
return EINVAL;
if (mp->mnt_flag & MNT_GETARGS) {
pmp = VFSTOMSDOSFS(mp);
if (pmp == NULL)
return EIO;
args->fspec = NULL;
args->uid = pmp->pm_uid;
args->gid = pmp->pm_gid;
args->mask = pmp->pm_mask;
args->flags = pmp->pm_flags;
args->version = MSDOSFSMNT_VERSION;
args->dirmask = pmp->pm_dirmask;
args->gmtoff = pmp->pm_gmtoff;
*data_len = sizeof *args;
return 0;
}
/*
* If not versioned (i.e. using old mount_msdos(8)), fill in
* the additional structure items with suitable defaults.
*/
if ((args->flags & MSDOSFSMNT_VERSIONED) == 0) {
args->version = 1;
args->dirmask = args->mask;
}
/*
* Reset GMT offset for pre-v3 mount structure args.
*/
if (args->version < 3)
args->gmtoff = 0;
/*
* If updating, check whether changing from read-only to
* read/write; if there is no device name, that's all we do.
*/
if (mp->mnt_flag & MNT_UPDATE) {
pmp = VFSTOMSDOSFS(mp);
error = 0;
if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) &&
(mp->mnt_flag & MNT_RDONLY)) {
flags = WRITECLOSE;
if (mp->mnt_flag & MNT_FORCE)
flags |= FORCECLOSE;
error = vflush(mp, NULLVP, flags);
}
if (!error && (mp->mnt_flag & MNT_RELOAD))
/* not yet implemented */
error = EOPNOTSUPP;
if (error) {
DPRINTF(("vflush %d\n", error));
return (error);
}
if ((pmp->pm_flags & MSDOSFSMNT_RONLY) &&
(mp->mnt_iflag & IMNT_WANTRDWR)) {
/*
* If upgrade to read-write by non-root, then verify
* that user has necessary permissions on the device.
*
* Permission to update a mount is checked higher, so
* here we presume updating the mount is okay (for
* example, as far as securelevel goes) which leaves us
* with the normal check.
*/
devvp = pmp->pm_devvp;
vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
error = kauth_authorize_system(l->l_cred,
KAUTH_SYSTEM_MOUNT, KAUTH_REQ_SYSTEM_MOUNT_DEVICE,
mp, devvp, KAUTH_ARG(VREAD | VWRITE));
VOP_UNLOCK(devvp);
DPRINTF(("KAUTH_REQ_SYSTEM_MOUNT_DEVICE %d\n", error));
if (error)
return (error);
pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
}
if (args->fspec == NULL) {
DPRINTF(("missing fspec\n"));
return EINVAL;
}
}
/*
* Not an update, or updating the name: look up the name
* and verify that it refers to a sensible block device.
*/
error = namei_simple_user(args->fspec,
NSM_FOLLOW_NOEMULROOT, &devvp);
if (error != 0) {
DPRINTF(("namei %d\n", error));
return (error);
}
if (devvp->v_type != VBLK) {
DPRINTF(("not block\n"));
vrele(devvp);
return (ENOTBLK);
}
if (bdevsw_lookup(devvp->v_rdev) == NULL) {
DPRINTF(("no block switch\n"));
vrele(devvp);
return (ENXIO);
}
/*
* If mount by non-root, then verify that user has necessary
* permissions on the device.
*/
accessmode = VREAD;
if ((mp->mnt_flag & MNT_RDONLY) == 0)
accessmode |= VWRITE;
vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT,
KAUTH_REQ_SYSTEM_MOUNT_DEVICE, mp, devvp, KAUTH_ARG(accessmode));
VOP_UNLOCK(devvp);
if (error) {
DPRINTF(("KAUTH_REQ_SYSTEM_MOUNT_DEVICE %d\n", error));
vrele(devvp);
return (error);
}
if ((mp->mnt_flag & MNT_UPDATE) == 0) {
int xflags;
if (mp->mnt_flag & MNT_RDONLY)
xflags = FREAD;
else
xflags = FREAD|FWRITE;
vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
error = VOP_OPEN(devvp, xflags, FSCRED);
VOP_UNLOCK(devvp);
if (error) {
DPRINTF(("VOP_OPEN %d\n", error));
goto fail;
}
error = msdosfs_mountfs(devvp, mp, l, args);
if (error) {
DPRINTF(("msdosfs_mountfs %d\n", error));
vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
(void) VOP_CLOSE(devvp, xflags, NOCRED);
VOP_UNLOCK(devvp);
goto fail;
}
#ifdef MSDOSFS_DEBUG /* only needed for the printf below */
pmp = VFSTOMSDOSFS(mp);
#endif
} else {
vrele(devvp);
if (devvp != pmp->pm_devvp) {
DPRINTF(("devvp %p pmp %p\n",
devvp, pmp->pm_devvp));
return (EINVAL); /* needs translation */
}
}
if ((error = update_mp(mp, args)) != 0) {
msdosfs_unmount(mp, MNT_FORCE);
DPRINTF(("update_mp %d\n", error));
return error;
}
#ifdef MSDOSFS_DEBUG
printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
#endif
return set_statvfs_info(path, UIO_USERSPACE, args->fspec, UIO_USERSPACE,
mp->mnt_op->vfs_name, mp, l);
fail:
vrele(devvp);
return (error);
}
