/* $NetBSD: spec_vnops.c,v 1.17 1994/07/16 11:40:56 paulus Exp $ */ /* * Copyright (c) 1989, 1993 * The Regents of the University of California. All rights reserved. * * 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. 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. * * @(#)spec_vnops.c 8.6 (Berkeley) 4/9/94 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* symbolic sleep message strings for devices */ char devopn[] = "devopn"; char devio[] = "devio"; char devwait[] = "devwait"; char devin[] = "devin"; char devout[] = "devout"; char devioc[] = "devioc"; char devcls[] = "devcls"; int (**spec_vnodeop_p)(); struct vnodeopv_entry_desc spec_vnodeop_entries[] = { { &vop_default_desc, vn_default_error }, { &vop_lookup_desc, spec_lookup }, /* lookup */ { &vop_create_desc, spec_create }, /* create */ { &vop_mknod_desc, spec_mknod }, /* mknod */ { &vop_open_desc, spec_open }, /* open */ { &vop_close_desc, spec_close }, /* close */ { &vop_access_desc, spec_access }, /* access */ { &vop_getattr_desc, spec_getattr }, /* getattr */ { &vop_setattr_desc, spec_setattr }, /* setattr */ { &vop_read_desc, spec_read }, /* read */ { &vop_write_desc, spec_write }, /* write */ { &vop_ioctl_desc, spec_ioctl }, /* ioctl */ { &vop_select_desc, spec_select }, /* select */ { &vop_mmap_desc, spec_mmap }, /* mmap */ { &vop_fsync_desc, spec_fsync }, /* fsync */ { &vop_seek_desc, spec_seek }, /* seek */ { &vop_remove_desc, spec_remove }, /* remove */ { &vop_link_desc, spec_link }, /* link */ { &vop_rename_desc, spec_rename }, /* rename */ { &vop_mkdir_desc, spec_mkdir }, /* mkdir */ { &vop_rmdir_desc, spec_rmdir }, /* rmdir */ { &vop_symlink_desc, spec_symlink }, /* symlink */ { &vop_readdir_desc, spec_readdir }, /* readdir */ { &vop_readlink_desc, spec_readlink }, /* readlink */ { &vop_abortop_desc, spec_abortop }, /* abortop */ { &vop_inactive_desc, spec_inactive }, /* inactive */ { &vop_reclaim_desc, spec_reclaim }, /* reclaim */ { &vop_lock_desc, spec_lock }, /* lock */ { &vop_unlock_desc, spec_unlock }, /* unlock */ { &vop_bmap_desc, spec_bmap }, /* bmap */ { &vop_strategy_desc, spec_strategy }, /* strategy */ { &vop_print_desc, spec_print }, /* print */ { &vop_islocked_desc, spec_islocked }, /* islocked */ { &vop_pathconf_desc, spec_pathconf }, /* pathconf */ { &vop_advlock_desc, spec_advlock }, /* advlock */ { &vop_blkatoff_desc, spec_blkatoff }, /* blkatoff */ { &vop_valloc_desc, spec_valloc }, /* valloc */ { &vop_vfree_desc, spec_vfree }, /* vfree */ { &vop_truncate_desc, spec_truncate }, /* truncate */ { &vop_update_desc, spec_update }, /* update */ { &vop_bwrite_desc, spec_bwrite }, /* bwrite */ { (struct vnodeop_desc*)NULL, (int(*)())NULL } }; struct vnodeopv_desc spec_vnodeop_opv_desc = { &spec_vnodeop_p, spec_vnodeop_entries }; /* * Trivial lookup routine that always fails. */ int spec_lookup(ap) struct vop_lookup_args /* { struct vnode *a_dvp; struct vnode **a_vpp; struct componentname *a_cnp; } */ *ap; { *ap->a_vpp = NULL; return (ENOTDIR); } /* * Open a special file. */ /* ARGSUSED */ spec_open(ap) struct vop_open_args /* { struct vnode *a_vp; int a_mode; struct ucred *a_cred; struct proc *a_p; } */ *ap; { struct vnode *bvp, *vp = ap->a_vp; dev_t bdev, dev = (dev_t)vp->v_rdev; register int maj = major(dev); int error; /* * Don't allow open if fs is mounted -nodev. */ if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) return (ENXIO); switch (vp->v_type) { case VCHR: if ((u_int)maj >= nchrdev) return (ENXIO); if (ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) { /* * When running in very secure mode, do not allow * opens for writing of any disk character devices. */ if (securelevel >= 2 && isdisk(dev, VCHR)) return (EPERM); /* * When running in secure mode, do not allow opens * for writing of /dev/mem, /dev/kmem, or character * devices whose corresponding block devices are * currently mounted. */ if (securelevel >= 1) { if ((bdev = chrtoblk(dev)) != NODEV && vfinddev(bdev, VBLK, &bvp) && bvp->v_usecount > 0 && (error = vfs_mountedon(bvp))) return (error); if (iskmemdev(dev)) return (EPERM); } } VOP_UNLOCK(vp); error = (*cdevsw[maj].d_open)(dev, ap->a_mode, S_IFCHR, ap->a_p); VOP_LOCK(vp); return (error); case VBLK: if ((u_int)maj >= nblkdev) return (ENXIO); /* * When running in very secure mode, do not allow * opens for writing of any disk block devices. */ if (securelevel >= 2 && ap->a_cred != FSCRED && (ap->a_mode & FWRITE) && isdisk(dev, VBLK)) return (EPERM); /* * Do not allow opens of block devices that are * currently mounted. */ if (error = vfs_mountedon(vp)) return (error); return ((*bdevsw[maj].d_open)(dev, ap->a_mode, S_IFBLK, ap->a_p)); } return (0); } /* * Vnode op for read */ /* ARGSUSED */ spec_read(ap) struct vop_read_args /* { struct vnode *a_vp; struct uio *a_uio; int a_ioflag; struct ucred *a_cred; } */ *ap; { register struct vnode *vp = ap->a_vp; register struct uio *uio = ap->a_uio; struct proc *p = uio->uio_procp; struct buf *bp; daddr_t bn, nextbn; long bsize, bscale, ssize; struct partinfo dpart; int n, on, majordev, (*ioctl)(); int error = 0; dev_t dev; #ifdef DIAGNOSTIC if (uio->uio_rw != UIO_READ) panic("spec_read mode"); if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) panic("spec_read proc"); #endif if (uio->uio_resid == 0) return (0); switch (vp->v_type) { case VCHR: VOP_UNLOCK(vp); error = (*cdevsw[major(vp->v_rdev)].d_read) (vp->v_rdev, uio, ap->a_ioflag); VOP_LOCK(vp); return (error); case VBLK: if (uio->uio_offset < 0) return (EINVAL); bsize = BLKDEV_IOSIZE; ssize = DEV_BSIZE; dev = vp->v_rdev; if ((majordev = major(dev)) < nblkdev && (ioctl = bdevsw[majordev].d_ioctl) != NULL && (*ioctl)(dev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) { if (dpart.part->p_fstype == FS_BSDFFS && dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) bsize = dpart.part->p_frag * dpart.part->p_fsize; if (dpart.disklab->d_secsize != 0) ssize = dpart.disklab->d_secsize; } bscale = bsize / ssize; do { bn = (uio->uio_offset / ssize) &~ (bscale - 1); on = uio->uio_offset % bsize; n = min((unsigned)(bsize - on), uio->uio_resid); if (vp->v_lastr + bscale == bn) { nextbn = bn + bscale; error = breadn(vp, bn, (int)bsize, &nextbn, (int *)&bsize, 1, NOCRED, &bp); } else error = bread(vp, bn, (int)bsize, NOCRED, &bp); vp->v_lastr = bn; n = min(n, bsize - bp->b_resid); if (error) { brelse(bp); return (error); } error = uiomove((char *)bp->b_data + on, n, uio); if (n + on == bsize) bp->b_flags |= B_AGE; brelse(bp); } while (error == 0 && uio->uio_resid > 0 && n != 0); return (error); default: panic("spec_read type"); } /* NOTREACHED */ } /* * Vnode op for write */ /* ARGSUSED */ spec_write(ap) struct vop_write_args /* { struct vnode *a_vp; struct uio *a_uio; int a_ioflag; struct ucred *a_cred; } */ *ap; { register struct vnode *vp = ap->a_vp; register struct uio *uio = ap->a_uio; struct proc *p = uio->uio_procp; struct buf *bp; daddr_t bn; int bsize, blkmask, ssize; struct partinfo dpart; register int n, on; int error = 0; #ifdef DIAGNOSTIC if (uio->uio_rw != UIO_WRITE) panic("spec_write mode"); if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) panic("spec_write proc"); #endif switch (vp->v_type) { case VCHR: VOP_UNLOCK(vp); error = (*cdevsw[major(vp->v_rdev)].d_write) (vp->v_rdev, uio, ap->a_ioflag); VOP_LOCK(vp); return (error); case VBLK: if (uio->uio_resid == 0) return (0); if (uio->uio_offset < 0) return (EINVAL); bsize = BLKDEV_IOSIZE; ssize = DEV_BSIZE; if ((*bdevsw[major(vp->v_rdev)].d_ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) { if (dpart.part->p_fstype == FS_BSDFFS && dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) bsize = dpart.part->p_frag * dpart.part->p_fsize; if (dpart.disklab->d_secsize != 0) ssize = dpart.disklab->d_secsize; } blkmask = (bsize / ssize) - 1; do { bn = (uio->uio_offset / ssize) &~ blkmask; on = uio->uio_offset % bsize; n = min((unsigned)(bsize - on), uio->uio_resid); if (n == bsize) bp = getblk(vp, bn, bsize, 0, 0); else error = bread(vp, bn, bsize, NOCRED, &bp); n = min(n, bsize - bp->b_resid); if (error) { brelse(bp); return (error); } error = uiomove((char *)bp->b_data + on, n, uio); if (n + on == bsize) { bp->b_flags |= B_AGE; bawrite(bp); } else bdwrite(bp); } while (error == 0 && uio->uio_resid > 0 && n != 0); return (error); default: panic("spec_write type"); } /* NOTREACHED */ } /* * Device ioctl operation. */ /* ARGSUSED */ spec_ioctl(ap) struct vop_ioctl_args /* { struct vnode *a_vp; int a_command; caddr_t a_data; int a_fflag; struct ucred *a_cred; struct proc *a_p; } */ *ap; { dev_t dev = ap->a_vp->v_rdev; switch (ap->a_vp->v_type) { case VCHR: return ((*cdevsw[major(dev)].d_ioctl)(dev, ap->a_command, ap->a_data, ap->a_fflag, ap->a_p)); case VBLK: if (ap->a_command == 0 && (int)ap->a_data == B_TAPE) if (bdevsw[major(dev)].d_flags & B_TAPE) return (0); else return (1); return ((*bdevsw[major(dev)].d_ioctl)(dev, ap->a_command, ap->a_data, ap->a_fflag, ap->a_p)); default: panic("spec_ioctl"); /* NOTREACHED */ } } /* ARGSUSED */ spec_select(ap) struct vop_select_args /* { struct vnode *a_vp; int a_which; int a_fflags; struct ucred *a_cred; struct proc *a_p; } */ *ap; { register dev_t dev; switch (ap->a_vp->v_type) { default: return (1); /* XXX */ case VCHR: dev = ap->a_vp->v_rdev; return (*cdevsw[major(dev)].d_select)(dev, ap->a_which, ap->a_p); } } /* * Synch buffers associated with a block device */ /* ARGSUSED */ int spec_fsync(ap) struct vop_fsync_args /* { struct vnode *a_vp; struct ucred *a_cred; int a_waitfor; struct proc *a_p; } */ *ap; { register struct vnode *vp = ap->a_vp; register struct buf *bp; struct buf *nbp; int s; if (vp->v_type == VCHR) return (0); /* * Flush all dirty buffers associated with a block device. */ loop: s = splbio(); for (bp = vp->v_dirtyblkhd.lh_first; bp; bp = nbp) { nbp = bp->b_vnbufs.le_next; if ((bp->b_flags & B_BUSY)) continue; if ((bp->b_flags & B_DELWRI) == 0) panic("spec_fsync: not dirty"); bremfree(bp); bp->b_flags |= B_BUSY; splx(s); bawrite(bp); goto loop; } if (ap->a_waitfor == MNT_WAIT) { while (vp->v_numoutput) { vp->v_flag |= VBWAIT; sleep((caddr_t)&vp->v_numoutput, PRIBIO + 1); } #ifdef DIAGNOSTIC if (vp->v_dirtyblkhd.lh_first) { vprint("spec_fsync: dirty", vp); goto loop; } #endif } splx(s); return (0); } /* * Just call the device strategy routine */ spec_strategy(ap) struct vop_strategy_args /* { struct buf *a_bp; } */ *ap; { (*bdevsw[major(ap->a_bp->b_dev)].d_strategy)(ap->a_bp); return (0); } /* * This is a noop, simply returning what one has been given. */ spec_bmap(ap) struct vop_bmap_args /* { struct vnode *a_vp; daddr_t a_bn; struct vnode **a_vpp; daddr_t *a_bnp; } */ *ap; { if (ap->a_vpp != NULL) *ap->a_vpp = ap->a_vp; if (ap->a_bnp != NULL) *ap->a_bnp = ap->a_bn; return (0); } /* * At the moment we do not do any locking. */ /* ARGSUSED */ spec_lock(ap) struct vop_lock_args /* { struct vnode *a_vp; } */ *ap; { return (0); } /* ARGSUSED */ spec_unlock(ap) struct vop_unlock_args /* { struct vnode *a_vp; } */ *ap; { return (0); } /* * Device close routine */ /* ARGSUSED */ spec_close(ap) struct vop_close_args /* { struct vnode *a_vp; int a_fflag; struct ucred *a_cred; struct proc *a_p; } */ *ap; { register struct vnode *vp = ap->a_vp; dev_t dev = vp->v_rdev; int (*devclose) __P((dev_t, int, int, struct proc *)); int mode, error; switch (vp->v_type) { case VCHR: /* * Hack: a tty device that is a controlling terminal * has a reference from the session structure. * We cannot easily tell that a character device is * a controlling terminal, unless it is the closing * process' controlling terminal. In that case, * if the reference count is 2 (this last descriptor * plus the session), release the reference from the session. */ if (vcount(vp) == 2 && ap->a_p && vp == ap->a_p->p_session->s_ttyvp) { vrele(vp); ap->a_p->p_session->s_ttyvp = NULL; } /* * If the vnode is locked, then we are in the midst * of forcably closing the device, otherwise we only * close on last reference. */ if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0) return (0); devclose = cdevsw[major(dev)].d_close; mode = S_IFCHR; break; case VBLK: /* * On last close of a block device (that isn't mounted) * we must invalidate any in core blocks, so that * we can, for instance, change floppy disks. */ if (error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0)) return (error); /* * We do not want to really close the device if it * is still in use unless we are trying to close it * forcibly. Since every use (buffer, vnode, swap, cmap) * holds a reference to the vnode, and because we mark * any other vnodes that alias this device, when the * sum of the reference counts on all the aliased * vnodes descends to one, we are on last close. */ if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0) return (0); devclose = bdevsw[major(dev)].d_close; mode = S_IFBLK; break; default: panic("spec_close: not special"); } return ((*devclose)(dev, ap->a_fflag, mode, ap->a_p)); } /* * Print out the contents of a special device vnode. */ spec_print(ap) struct vop_print_args /* { struct vnode *a_vp; } */ *ap; { printf("tag VT_NON, dev %d, %d\n", major(ap->a_vp->v_rdev), minor(ap->a_vp->v_rdev)); } /* * Return POSIX pathconf information applicable to special devices. */ spec_pathconf(ap) struct vop_pathconf_args /* { struct vnode *a_vp; int a_name; int *a_retval; } */ *ap; { switch (ap->a_name) { case _PC_LINK_MAX: *ap->a_retval = LINK_MAX; return (0); case _PC_MAX_CANON: *ap->a_retval = MAX_CANON; return (0); case _PC_MAX_INPUT: *ap->a_retval = MAX_INPUT; return (0); case _PC_PIPE_BUF: *ap->a_retval = PIPE_BUF; return (0); case _PC_CHOWN_RESTRICTED: *ap->a_retval = 1; return (0); case _PC_VDISABLE: *ap->a_retval = _POSIX_VDISABLE; return (0); default: return (EINVAL); } /* NOTREACHED */ } /* * Special device advisory byte-level locks. */ /* ARGSUSED */ spec_advlock(ap) struct vop_advlock_args /* { struct vnode *a_vp; caddr_t a_id; int a_op; struct flock *a_fl; int a_flags; } */ *ap; { return (EOPNOTSUPP); } /* * Special device failed operation */ spec_ebadf() { return (EBADF); } /* * Special device bad operation */ spec_badop() { panic("spec_badop called"); /* NOTREACHED */ }