/* $NetBSD: kernfs_vfsops.c,v 1.96.18.1 2020/02/12 19:59:22 martin Exp $ */ /* * Copyright (c) 1992, 1993, 1995 * The Regents of the University of California. All rights reserved. * * This code is derived from software donated to Berkeley by * Jan-Simon Pendry. * * 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. * * @(#)kernfs_vfsops.c 8.10 (Berkeley) 5/14/95 */ /* * Kernel params Filesystem */ #include __KERNEL_RCSID(0, "$NetBSD: kernfs_vfsops.c,v 1.96.18.1 2020/02/12 19:59:22 martin Exp $"); #ifdef _KERNEL_OPT #include "opt_compat_netbsd.h" #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include MODULE(MODULE_CLASS_VFS, kernfs, NULL); MALLOC_JUSTDEFINE(M_KERNFSMNT, "kernfs mount", "kernfs mount structures"); dev_t rrootdev = NODEV; kmutex_t kfs_lock; VFS_PROTOS(kernfs); void kernfs_get_rrootdev(void); static struct sysctllog *kernfs_sysctl_log; void kernfs_init(void) { malloc_type_attach(M_KERNFSMNT); mutex_init(&kfs_lock, MUTEX_DEFAULT, IPL_NONE); } void kernfs_reinit(void) { } void kernfs_done(void) { mutex_destroy(&kfs_lock); malloc_type_detach(M_KERNFSMNT); } void kernfs_get_rrootdev(void) { static int tried = 0; if (tried) { /* Already did it once. */ return; } tried = 1; if (rootdev == NODEV) return; rrootdev = devsw_blk2chr(rootdev); if (rrootdev != NODEV) return; rrootdev = NODEV; printf("kernfs_get_rrootdev: no raw root device\n"); } /* * Mount the Kernel params filesystem */ int kernfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len) { struct lwp *l = curlwp; int error = 0; struct kernfs_mount *fmp; if (UIO_MX & (UIO_MX - 1)) { log(LOG_ERR, "kernfs: invalid directory entry size"); return (EINVAL); } if (mp->mnt_flag & MNT_GETARGS) { *data_len = 0; return 0; } /* * Update is a no-op */ if (mp->mnt_flag & MNT_UPDATE) return (EOPNOTSUPP); fmp = malloc(sizeof(struct kernfs_mount), M_KERNFSMNT, M_WAITOK|M_ZERO); TAILQ_INIT(&fmp->nodelist); mp->mnt_stat.f_namemax = KERNFS_MAXNAMLEN; mp->mnt_flag |= MNT_LOCAL; mp->mnt_data = fmp; vfs_getnewfsid(mp); if ((error = set_statvfs_info(path, UIO_USERSPACE, "kernfs", UIO_SYSSPACE, mp->mnt_op->vfs_name, mp, l)) != 0) { free(fmp, M_KERNFSMNT); return error; } kernfs_get_rrootdev(); return 0; } int kernfs_start(struct mount *mp, int flags) { return (0); } int kernfs_unmount(struct mount *mp, int mntflags) { int error; int flags = 0; if (mntflags & MNT_FORCE) flags |= FORCECLOSE; if ((error = vflush(mp, 0, flags)) != 0) return (error); /* * Finally, throw away the kernfs_mount structure */ free(mp->mnt_data, M_KERNFSMNT); mp->mnt_data = NULL; return (0); } int kernfs_root(struct mount *mp, struct vnode **vpp) { const struct kern_target *root_target = &kern_targets[0]; int error; /* setup "." */ error = vcache_get(mp, &root_target, sizeof(root_target), vpp); if (error) return error; error = vn_lock(*vpp, LK_EXCLUSIVE); if (error) { vrele(*vpp); *vpp = NULL; return error; } return 0; } /*ARGSUSED*/ int kernfs_sync(struct mount *mp, int waitfor, kauth_cred_t uc) { return (0); } /* * Kernfs flat namespace lookup. * Currently unsupported. */ int kernfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp) { return (EOPNOTSUPP); } int kernfs_loadvnode(struct mount *mp, struct vnode *vp, const void *key, size_t key_len, const void **new_key) { const struct kern_target *kt; struct kernfs_node *kfs, *kfsp; long *cookie; KASSERT(key_len == sizeof(kt)); memcpy(&kt, key, key_len); kfs = kmem_zalloc(sizeof(struct kernfs_node), KM_SLEEP); cookie = &(VFSTOKERNFS(mp)->fileno_cookie); mutex_enter(&kfs_lock); again: TAILQ_FOREACH(kfsp, &VFSTOKERNFS(mp)->nodelist, kfs_list) { if (kfsp->kfs_cookie == *cookie) { (*cookie) ++; goto again; } if (TAILQ_NEXT(kfsp, kfs_list)) { if (kfsp->kfs_cookie < *cookie && *cookie < TAILQ_NEXT(kfsp, kfs_list)->kfs_cookie) break; if (kfsp->kfs_cookie + 1 < TAILQ_NEXT(kfsp, kfs_list)->kfs_cookie) { *cookie = kfsp->kfs_cookie + 1; break; } } } kfs->kfs_cookie = *cookie; if (kfsp) TAILQ_INSERT_AFTER(&VFSTOKERNFS(mp)->nodelist, kfsp, kfs, kfs_list); else TAILQ_INSERT_TAIL(&VFSTOKERNFS(mp)->nodelist, kfs, kfs_list); kfs->kfs_type = kt->kt_tag; kfs->kfs_vnode = vp; kfs->kfs_fileno = KERNFS_FILENO(kt, kt->kt_tag, kfs->kfs_cookie); kfs->kfs_kt = kt; kfs->kfs_mode = kt->kt_mode; vp->v_tag = VT_KERNFS; vp->v_op = kernfs_vnodeop_p; vp->v_data = kfs; vp->v_type = kt->kt_vtype; mutex_exit(&kfs_lock); if (kt->kt_tag == KFSkern) vp->v_vflag = VV_ROOT; if (kt->kt_tag == KFSdevice) { vp->v_op = kernfs_specop_p; spec_node_init(vp, *(dev_t *)kt->kt_data); } uvm_vnp_setsize(vp, 0); *new_key = &kfs->kfs_kt; return 0; } extern const struct vnodeopv_desc kernfs_vnodeop_opv_desc; extern const struct vnodeopv_desc kernfs_specop_opv_desc; const struct vnodeopv_desc * const kernfs_vnodeopv_descs[] = { &kernfs_vnodeop_opv_desc, &kernfs_specop_opv_desc, NULL, }; struct vfsops kernfs_vfsops = { .vfs_name = MOUNT_KERNFS, .vfs_min_mount_data = 0, .vfs_mount = kernfs_mount, .vfs_start = kernfs_start, .vfs_unmount = kernfs_unmount, .vfs_root = kernfs_root, .vfs_quotactl = (void *)eopnotsupp, .vfs_statvfs = genfs_statvfs, .vfs_sync = kernfs_sync, .vfs_vget = kernfs_vget, .vfs_loadvnode = kernfs_loadvnode, .vfs_fhtovp = (void *)eopnotsupp, .vfs_vptofh = (void *)eopnotsupp, .vfs_init = kernfs_init, .vfs_reinit = kernfs_reinit, .vfs_done = kernfs_done, .vfs_snapshot = (void *)eopnotsupp, .vfs_extattrctl = vfs_stdextattrctl, .vfs_suspendctl = genfs_suspendctl, .vfs_renamelock_enter = genfs_renamelock_enter, .vfs_renamelock_exit = genfs_renamelock_exit, .vfs_fsync = (void *)eopnotsupp, .vfs_opv_descs = kernfs_vnodeopv_descs }; static int kernfs_modcmd(modcmd_t cmd, void *arg) { int error; switch (cmd) { case MODULE_CMD_INIT: error = vfs_attach(&kernfs_vfsops); if (error != 0) break; sysctl_createv(&kernfs_sysctl_log, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_NODE, "kernfs", SYSCTL_DESCR("/kern file system"), NULL, 0, NULL, 0, CTL_VFS, 11, CTL_EOL); /* * XXX the "11" above could be dynamic, thereby eliminating one * more instance of the "number to vfs" mapping problem, but * "11" is the order as taken from sys/mount.h */ break; case MODULE_CMD_FINI: error = vfs_detach(&kernfs_vfsops); if (error != 0) break; sysctl_teardown(&kernfs_sysctl_log); break; default: error = ENOTTY; break; } return (error); }