BSD 4.4 Lite Kernel Sources

1 files changed, 689 insertions, 0 deletions

diff --git a/sys/fs/specfs/spec_vnops.c b/sys/fs/specfs/spec_vnops.c
new file mode 100644
index 0000000..111c517
--- /dev/null
+++ b/sys/fs/specfs/spec_vnops.c
@@ -0,0 +1,689 @@
+/*
+ * 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 <sys/param.h>
+#include <sys/proc.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/conf.h>
+#include <sys/buf.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/vnode.h>
+#include <sys/stat.h>
+#include <sys/errno.h>
+#include <sys/ioctl.h>
+#include <sys/file.h>
+#include <sys/disklabel.h>
+#include <miscfs/specfs/specdev.h>
+
+/* 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;
+	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;
+		dev = vp->v_rdev;
+		if ((majordev = major(dev)) < nblkdev &&
+		    (ioctl = bdevsw[majordev].d_ioctl) != NULL &&
+		    (*ioctl)(dev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0 &&
+		    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;
+		bscale = bsize / DEV_BSIZE;
+		do {
+			bn = (uio->uio_offset / DEV_BSIZE) &~ (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;
+	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;
+		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;
+		}
+		blkmask = (bsize / DEV_BSIZE) - 1;
+		do {
+			bn = (uio->uio_offset / DEV_BSIZE) &~ 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 */
+}