/* $NetBSD: fdesc_vfsops.c,v 1.92 2017/02/17 08:31:25 hannken 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. * * @(#)fdesc_vfsops.c 8.10 (Berkeley) 5/14/95 * * #Id: fdesc_vfsops.c,v 1.9 1993/04/06 15:28:33 jsp Exp # */ /* * /dev/fd Filesystem */ #include __KERNEL_RCSID(0, "$NetBSD: fdesc_vfsops.c,v 1.92 2017/02/17 08:31:25 hannken Exp $"); #if defined(_KERNEL_OPT) #include "opt_compat_netbsd.h" #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include MODULE(MODULE_CLASS_VFS, fdesc, NULL); VFS_PROTOS(fdesc); static struct sysctllog *fdesc_sysctl_log; /* * Mount the per-process file descriptors (/dev/fd) */ int fdesc_mount(struct mount *mp, const char *path, void *data, size_t *data_len) { struct lwp *l = curlwp; int error = 0, ix; struct vnode *rvp; if (mp->mnt_flag & MNT_GETARGS) { *data_len = 0; return 0; } /* * Update is a no-op */ if (mp->mnt_flag & MNT_UPDATE) return (EOPNOTSUPP); ix = FD_ROOT; error = vcache_get(mp, &ix, sizeof(ix), &rvp); if (error) return error; mp->mnt_stat.f_namemax = FDESC_MAXNAMLEN; mp->mnt_flag |= MNT_LOCAL; mp->mnt_data = rvp; vfs_getnewfsid(mp); error = set_statvfs_info(path, UIO_USERSPACE, "fdesc", UIO_SYSSPACE, mp->mnt_op->vfs_name, mp, l); return error; } int fdesc_start(struct mount *mp, int flags) { return (0); } int fdesc_unmount(struct mount *mp, int mntflags) { int error; int flags = 0; struct vnode *rtvp = mp->mnt_data; 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); /* * Blow it away for future re-use */ vgone(rtvp); mp->mnt_data = NULL; return (0); } int fdesc_root(struct mount *mp, struct vnode **vpp) { struct vnode *vp; /* * Return locked reference to root. */ vp = mp->mnt_data; vref(vp); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); *vpp = vp; return (0); } /*ARGSUSED*/ int fdesc_sync(struct mount *mp, int waitfor, kauth_cred_t uc) { return (0); } /* * Fdesc flat namespace lookup. * Currently unsupported. */ int fdesc_vget(struct mount *mp, ino_t ino, struct vnode **vpp) { return (EOPNOTSUPP); } int fdesc_loadvnode(struct mount *mp, struct vnode *vp, const void *key, size_t key_len, const void **new_key) { int ix; struct fdescnode *fd; KASSERT(key_len == sizeof(ix)); memcpy(&ix, key, key_len); fd = kmem_alloc(sizeof(struct fdescnode), KM_SLEEP); fd->fd_fd = -1; fd->fd_link = NULL; fd->fd_ix = ix; fd->fd_vnode = vp; vp->v_tag = VT_FDESC; vp->v_op = fdesc_vnodeop_p; vp->v_data = fd; switch (ix) { case FD_ROOT: fd->fd_type = Froot; vp->v_type = VDIR; vp->v_vflag |= VV_ROOT; break; case FD_DEVFD: fd->fd_type = Fdevfd; vp->v_type = VDIR; break; case FD_CTTY: fd->fd_type = Fctty; vp->v_type = VCHR; break; case FD_STDIN: fd->fd_type = Flink; fd->fd_link = "fd/0"; vp->v_type = VLNK; break; case FD_STDOUT: fd->fd_type = Flink; fd->fd_link = "fd/1"; vp->v_type = VLNK; break; case FD_STDERR: fd->fd_type = Flink; fd->fd_link = "fd/2"; vp->v_type = VLNK; break; default: KASSERT(ix >= FD_DESC); fd->fd_type = Fdesc; fd->fd_fd = ix - FD_DESC; vp->v_type = VNON; break; } uvm_vnp_setsize(vp, 0); *new_key = &fd->fd_ix; return 0; } extern const struct vnodeopv_desc fdesc_vnodeop_opv_desc; const struct vnodeopv_desc * const fdesc_vnodeopv_descs[] = { &fdesc_vnodeop_opv_desc, NULL, }; struct vfsops fdesc_vfsops = { .vfs_name = MOUNT_FDESC, .vfs_min_mount_data = 0, .vfs_mount = fdesc_mount, .vfs_start = fdesc_start, .vfs_unmount = fdesc_unmount, .vfs_root = fdesc_root, .vfs_quotactl = (void *)eopnotsupp, .vfs_statvfs = genfs_statvfs, .vfs_sync = fdesc_sync, .vfs_vget = fdesc_vget, .vfs_loadvnode = fdesc_loadvnode, .vfs_fhtovp = (void *)eopnotsupp, .vfs_vptofh = (void *)eopnotsupp, .vfs_init = fdesc_init, .vfs_done = fdesc_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 = fdesc_vnodeopv_descs }; static int fdesc_modcmd(modcmd_t cmd, void *arg) { int error; switch (cmd) { case MODULE_CMD_INIT: error = vfs_attach(&fdesc_vfsops); if (error != 0) break; sysctl_createv(&fdesc_sysctl_log, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_NODE, "fdesc", SYSCTL_DESCR("File-descriptor file system"), NULL, 0, NULL, 0, CTL_VFS, 7, CTL_EOL); /* * XXX the "7" above could be dynamic, thereby eliminating one * more instance of the "number to vfs" mapping problem, but * "7" is the order as taken from sys/mount.h */ break; case MODULE_CMD_FINI: error = vfs_detach(&fdesc_vfsops); if (error != 0) break; sysctl_teardown(&fdesc_sysctl_log); break; default: error = ENOTTY; break; } return (error); }