/* $NetBSD: umap_vfsops.c,v 1.99 2017/04/11 07:51:37 hannken Exp $ */ /* * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software donated to Berkeley by * the UCLA Ficus project. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: @(#)null_vfsops.c 1.5 (Berkeley) 7/10/92 * @(#)umap_vfsops.c 8.8 (Berkeley) 5/14/95 */ /* * Umap Layer * (See mount_umap(8) for a description of this layer.) */ #include __KERNEL_RCSID(0, "$NetBSD: umap_vfsops.c,v 1.99 2017/04/11 07:51:37 hannken Exp $"); #include #include #include #include #include #include #include #include #include #include #include #include MODULE(MODULE_CLASS_VFS, umap, "layerfs"); VFS_PROTOS(umapfs); static struct sysctllog *umapfs_sysctl_log; /* * Mount umap layer */ int umapfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len) { struct lwp *l = curlwp; struct pathbuf *pb; struct nameidata nd; struct umap_args *args = data; struct vnode *lowerrootvp, *vp; struct umap_mount *amp; int error; #ifdef UMAPFS_DIAGNOSTIC int i; #endif if (args == NULL) return EINVAL; if (*data_len < sizeof *args) return EINVAL; if (mp->mnt_flag & MNT_GETARGS) { amp = MOUNTTOUMAPMOUNT(mp); if (amp == NULL) return EIO; args->la.target = NULL; args->nentries = amp->info_nentries; args->gnentries = amp->info_gnentries; *data_len = sizeof *args; return 0; } /* only for root */ error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT, KAUTH_REQ_SYSTEM_MOUNT_UMAP, NULL, NULL, NULL); if (error) return error; #ifdef UMAPFS_DIAGNOSTIC printf("umapfs_mount(mp = %p)\n", mp); #endif /* * Update is not supported */ if (mp->mnt_flag & MNT_UPDATE) return EOPNOTSUPP; /* * Find lower node */ error = pathbuf_copyin(args->umap_target, &pb); if (error) { return error; } NDINIT(&nd, LOOKUP, FOLLOW|LOCKLEAF, pb); if ((error = namei(&nd)) != 0) { pathbuf_destroy(pb); return error; } /* * Sanity check on lower vnode */ lowerrootvp = nd.ni_vp; pathbuf_destroy(pb); #ifdef UMAPFS_DIAGNOSTIC printf("vp = %p, check for VDIR...\n", lowerrootvp); #endif if (lowerrootvp->v_type != VDIR) { vput(lowerrootvp); return (EINVAL); } #ifdef UMAPFS_DIAGNOSTIC printf("mp = %p\n", mp); #endif amp = kmem_zalloc(sizeof(struct umap_mount), KM_SLEEP); mp->mnt_data = amp; /* * Now copy in the number of entries and maps for umap mapping. */ if (args->nentries < 0 || args->nentries > MAPFILEENTRIES || args->gnentries < 0 || args->gnentries > GMAPFILEENTRIES) { vput(lowerrootvp); return (EINVAL); } amp->info_nentries = args->nentries; amp->info_gnentries = args->gnentries; error = copyin(args->mapdata, amp->info_mapdata, 2*sizeof(u_long)*args->nentries); if (error) { vput(lowerrootvp); return (error); } #ifdef UMAPFS_DIAGNOSTIC printf("umap_mount:nentries %d\n",args->nentries); for (i = 0; i < args->nentries; i++) printf(" %ld maps to %ld\n", amp->info_mapdata[i][0], amp->info_mapdata[i][1]); #endif error = copyin(args->gmapdata, amp->info_gmapdata, 2*sizeof(u_long)*args->gnentries); if (error) { vput(lowerrootvp); return (error); } #ifdef UMAPFS_DIAGNOSTIC printf("umap_mount:gnentries %d\n",args->gnentries); for (i = 0; i < args->gnentries; i++) printf("\tgroup %ld maps to %ld\n", amp->info_gmapdata[i][0], amp->info_gmapdata[i][1]); #endif /* * Make sure the mount point's sufficiently initialized * that the node create call will work. */ vfs_getnewfsid(mp); amp->umapm_size = sizeof(struct umap_node); amp->umapm_tag = VT_UMAP; amp->umapm_bypass = umap_bypass; amp->umapm_vnodeop_p = umap_vnodeop_p; /* * fix up umap node for root vnode. */ VOP_UNLOCK(lowerrootvp); error = layer_node_create(mp, lowerrootvp, &vp); /* * Make sure the node alias worked */ if (error) { vrele(lowerrootvp); kmem_free(amp, sizeof(struct umap_mount)); return error; } /* * Keep a held reference to the root vnode. * It is vrele'd in umapfs_unmount. */ vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); vp->v_vflag |= VV_ROOT; amp->umapm_rootvp = vp; VOP_UNLOCK(vp); error = set_statvfs_info(path, UIO_USERSPACE, args->umap_target, UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l); if (error) return error; mp->mnt_lower = lowerrootvp->v_mount; if (mp->mnt_lower->mnt_flag & MNT_LOCAL) mp->mnt_flag |= MNT_LOCAL; #ifdef UMAPFS_DIAGNOSTIC printf("umapfs_mount: lower %s, alias at %s\n", mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); #endif return 0; } /* * Free reference to umap layer */ int umapfs_unmount(struct mount *mp, int mntflags) { struct umap_mount *amp = MOUNTTOUMAPMOUNT(mp); struct vnode *rtvp = amp->umapm_rootvp; int error; int flags = 0; #ifdef UMAPFS_DIAGNOSTIC printf("umapfs_unmount(mp = %p)\n", mp); #endif if (mntflags & MNT_FORCE) flags |= FORCECLOSE; if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) return (EBUSY); if ((error = vflush(mp, rtvp, flags)) != 0) return (error); #ifdef UMAPFS_DIAGNOSTIC vprint("alias root of lower", rtvp); #endif /* * Blow it away for future re-use */ vgone(rtvp); /* * Finally, throw away the umap_mount structure */ kmem_free(amp, sizeof(struct umap_mount)); mp->mnt_data = NULL; return 0; } extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc; const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = { &umapfs_vnodeop_opv_desc, NULL, }; struct vfsops umapfs_vfsops = { .vfs_name = MOUNT_UMAP, .vfs_min_mount_data = sizeof (struct umap_args), .vfs_mount = umapfs_mount, .vfs_start = layerfs_start, .vfs_unmount = umapfs_unmount, .vfs_root = layerfs_root, .vfs_quotactl = layerfs_quotactl, .vfs_statvfs = layerfs_statvfs, .vfs_sync = layerfs_sync, .vfs_loadvnode = layerfs_loadvnode, .vfs_vget = layerfs_vget, .vfs_fhtovp = layerfs_fhtovp, .vfs_vptofh = layerfs_vptofh, .vfs_init = layerfs_init, .vfs_done = layerfs_done, .vfs_snapshot = layerfs_snapshot, .vfs_extattrctl = vfs_stdextattrctl, .vfs_suspendctl = layerfs_suspendctl, .vfs_renamelock_enter = layerfs_renamelock_enter, .vfs_renamelock_exit = layerfs_renamelock_exit, .vfs_fsync = (void *)eopnotsupp, .vfs_opv_descs = umapfs_vnodeopv_descs }; static int umap_modcmd(modcmd_t cmd, void *arg) { int error; switch (cmd) { case MODULE_CMD_INIT: error = vfs_attach(&umapfs_vfsops); if (error != 0) break; sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_NODE, "umap", SYSCTL_DESCR("UID/GID remapping file system"), NULL, 0, NULL, 0, CTL_VFS, 10, CTL_EOL); /* * XXX the "10" above could be dynamic, thereby eliminating * one more instance of the "number to vfs" mapping problem, * but "10" is the order as taken from sys/mount.h */ break; case MODULE_CMD_FINI: error = vfs_detach(&umapfs_vfsops); if (error != 0) break; sysctl_teardown(&umapfs_sysctl_log); break; default: error = ENOTTY; break; } return (error); }