/* * Copyright (c) 1988 University of Utah. * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * the Systems Programming Group of the University of Utah Computer * Science Department. * * 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. * * from: Utah Hdr: vn.c 1.13 94/04/02 * * from: @(#)vn.c 8.6 (Berkeley) 4/1/94 * $Id: vn.c,v 1.70 1998/09/12 18:46:06 sos Exp $ */ /* * Vnode disk driver. * * Block/character interface to a vnode. Allows one to treat a file * as a disk (e.g. build a filesystem in it, mount it, etc.). * * NOTE 1: This uses the VOP_BMAP/VOP_STRATEGY interface to the vnode * instead of a simple VOP_RDWR. We do this to avoid distorting the * local buffer cache. * * NOTE 2: There is a security issue involved with this driver. * Once mounted all access to the contents of the "mapped" file via * the special file is controlled by the permissions on the special * file, the protection of the mapped file is ignored (effectively, * by using root credentials in all transactions). * * NOTE 3: Doesn't interact with leases, should it? */ #include "vn.h" #if NVN > 0 /* default is to have 8 VN's */ #if NVN < 8 #undef NVN #define NVN 8 #endif #include "opt_devfs.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DEVFS #include #endif /*DEVFS*/ #include #include static d_ioctl_t vnioctl; static d_open_t vnopen; static d_read_t vnread; static d_write_t vnwrite; static d_close_t vnclose; static d_dump_t vndump; static d_psize_t vnsize; static d_strategy_t vnstrategy; #define CDEV_MAJOR 43 #define BDEV_MAJOR 15 static struct cdevsw vn_cdevsw = { vnopen, vnclose, vnread, vnwrite, vnioctl, nostop, nullreset, nodevtotty, seltrue, nommap, vnstrategy, "vn", NULL, -1, vndump, vnsize, D_DISK|D_NOCLUSTERRW, 0, -1 }; #define vnunit(dev) dkunit(dev) #define getvnbuf() \ ((struct buf *)malloc(sizeof(struct buf), M_DEVBUF, M_WAITOK)) #define putvnbuf(bp) \ free((caddr_t)(bp), M_DEVBUF) struct vn_softc { int sc_flags; /* flags */ size_t sc_size; /* size of vn */ struct diskslices *sc_slices; struct vnode *sc_vp; /* vnode */ struct ucred *sc_cred; /* credentials */ int sc_maxactive; /* max # of active requests */ struct buf sc_tab; /* transfer queue */ u_long sc_options; /* options */ #ifdef DEVFS void *r_devfs_token; void *devfs_token; #endif }; /* sc_flags */ #define VNF_INITED 0x01 static struct vn_softc *vn_softc[NVN]; static u_long vn_options; #define IFOPT(vn,opt) if (((vn)->sc_options|vn_options) & (opt)) static void vniodone (struct buf *bp); static int vnsetcred (struct vn_softc *vn, struct ucred *cred); static void vnshutdown (int, void *); static void vnclear (struct vn_softc *vn); static int vnclose(dev_t dev, int flags, int mode, struct proc *p) { struct vn_softc *vn = vn_softc[vnunit(dev)]; IFOPT(vn, VN_LABELS) if (vn->sc_slices != NULL) dsclose(dev, mode, vn->sc_slices); return (0); } static int vnopen(dev_t dev, int flags, int mode, struct proc *p) { int unit = vnunit(dev); struct vn_softc *vn; if (unit >= NVN) { if (vn_options & VN_FOLLOW) printf("vnopen(0x%lx, 0x%x, 0x%x, %p)\n", (u_long)dev, flags, mode, (void *)p); return(ENOENT); } vn = vn_softc[unit]; if (!vn) { vn = malloc(sizeof *vn, M_DEVBUF, M_WAITOK); if (!vn) return (ENOMEM); bzero(vn, sizeof *vn); vn_softc[unit] = vn; } IFOPT(vn, VN_FOLLOW) printf("vnopen(0x%lx, 0x%x, 0x%x, %p)\n", (u_long)dev, flags, mode, (void *)p); IFOPT(vn, VN_LABELS) { if (vn->sc_flags & VNF_INITED) { struct disklabel label; /* Build label for whole disk. */ bzero(&label, sizeof label); label.d_secsize = DEV_BSIZE; label.d_nsectors = 32; label.d_ntracks = 64; label.d_ncylinders = vn->sc_size / (32 * 64); label.d_secpercyl = 32 * 64; label.d_secperunit = label.d_partitions[RAW_PART].p_size = vn->sc_size; return (dsopen("vn", dev, mode, 0, &vn->sc_slices, &label, vnstrategy, (ds_setgeom_t *)NULL, &vn_cdevsw)); } if (dkslice(dev) != WHOLE_DISK_SLICE || dkpart(dev) != RAW_PART || mode != S_IFCHR) return (ENXIO); } return(0); } static int vnread(dev_t dev, struct uio *uio, int ioflag) { return (physio(vnstrategy, NULL, dev, 1, minphys, uio)); } static int vnwrite(dev_t dev, struct uio *uio, int ioflag) { return (physio(vnstrategy, NULL, dev, 0, minphys, uio)); } /* * this code does I/O calls through the appropriate VOP entry point... * unless a swap_pager I/O request is being done. This strategy (-)) * allows for coherency with mmap except in the case of paging. This * is necessary, because the VOP calls use lots of memory (and actually * are not extremely efficient -- but we want to keep semantics correct), * and the pageout daemon gets really unhappy (and so does the rest of the * system) when it runs out of memory. */ static void vnstrategy(struct buf *bp) { int unit = vnunit(bp->b_dev); register struct vn_softc *vn = vn_softc[unit]; register daddr_t bn; int error; int isvplocked = 0; long sz; struct uio auio; struct iovec aiov; IFOPT(vn, VN_DEBUG) printf("vnstrategy(%p): unit %d\n", bp, unit); if ((vn->sc_flags & VNF_INITED) == 0) { bp->b_error = ENXIO; bp->b_flags |= B_ERROR; biodone(bp); return; } IFOPT(vn, VN_LABELS) { bp->b_resid = bp->b_bcount;/* XXX best place to set this? */ if (vn->sc_slices != NULL && dscheck(bp, vn->sc_slices) <= 0) { biodone(bp); return; } bn = bp->b_pblkno; bp->b_resid = bp->b_bcount;/* XXX best place to set this? */ } else { bn = bp->b_blkno; sz = howmany(bp->b_bcount, DEV_BSIZE); bp->b_resid = bp->b_bcount; if (bn < 0 || bn + sz > vn->sc_size) { if (bn != vn->sc_size) { bp->b_error = EINVAL; bp->b_flags |= B_ERROR; } biodone(bp); return; } } if( (bp->b_flags & B_PAGING) == 0) { aiov.iov_base = bp->b_data; aiov.iov_len = bp->b_bcount; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = dbtob(bn); auio.uio_segflg = UIO_SYSSPACE; if( bp->b_flags & B_READ) auio.uio_rw = UIO_READ; else auio.uio_rw = UIO_WRITE; auio.uio_resid = bp->b_bcount; auio.uio_procp = curproc; if (!VOP_ISLOCKED(vn->sc_vp)) { isvplocked = 1; vn_lock(vn->sc_vp, LK_EXCLUSIVE | LK_RETRY, curproc); } if( bp->b_flags & B_READ) error = VOP_READ(vn->sc_vp, &auio, 0, vn->sc_cred); else error = VOP_WRITE(vn->sc_vp, &auio, 0, vn->sc_cred); if (isvplocked) { VOP_UNLOCK(vn->sc_vp, 0, curproc); isvplocked = 0; } bp->b_resid = auio.uio_resid; if( error ) bp->b_flags |= B_ERROR; biodone(bp); } else { long bsize, resid; off_t byten; int flags; caddr_t addr; struct buf *nbp; nbp = getvnbuf(); bzero(nbp, sizeof(struct buf)); LIST_INIT(&nbp->b_dep); byten = dbtob(bn); bsize = vn->sc_vp->v_mount->mnt_stat.f_iosize; addr = bp->b_data; flags = bp->b_flags | B_CALL; for (resid = bp->b_resid; resid; ) { struct vnode *vp; daddr_t nbn; int off, s, nra; nra = 0; if (!VOP_ISLOCKED(vn->sc_vp)) { isvplocked = 1; vn_lock(vn->sc_vp, LK_EXCLUSIVE | LK_RETRY, curproc); } error = VOP_BMAP(vn->sc_vp, (daddr_t)(byten / bsize), &vp, &nbn, &nra, NULL); if (isvplocked) { VOP_UNLOCK(vn->sc_vp, 0, curproc); isvplocked = 0; } if (error == 0 && nbn == -1) error = EIO; IFOPT(vn, VN_DONTCLUSTER) nra = 0; off = byten % bsize; if (off) sz = bsize - off; else sz = (1 + nra) * bsize; if (resid < sz) sz = resid; if (error) { bp->b_resid -= (resid - sz); bp->b_flags |= B_ERROR; biodone(bp); putvnbuf(nbp); return; } IFOPT(vn,VN_IO) printf( /* XXX no %qx in kernel. Synthesize it. */ "vnstrategy: vp %p/%p bn 0x%lx%08lx/0x%lx sz 0x%lx\n", (void *)vn->sc_vp, (void *)vp, (u_long)(byten >> 32), (u_long)byten, (u_long)nbn, sz); nbp->b_flags = flags; nbp->b_bcount = sz; nbp->b_bufsize = sz; nbp->b_error = 0; if (vp->v_type == VBLK || vp->v_type == VCHR) nbp->b_dev = vp->v_rdev; else nbp->b_dev = NODEV; nbp->b_data = addr; nbp->b_blkno = nbn + btodb(off); nbp->b_offset = dbtob(nbn) + off; nbp->b_proc = bp->b_proc; nbp->b_iodone = vniodone; nbp->b_vp = vp; nbp->b_rcred = vn->sc_cred; /* XXX crdup? */ nbp->b_wcred = vn->sc_cred; /* XXX crdup? */ nbp->b_dirtyoff = bp->b_dirtyoff; nbp->b_dirtyend = bp->b_dirtyend; nbp->b_validoff = bp->b_validoff; nbp->b_validend = bp->b_validend; if ((nbp->b_flags & B_READ) == 0) nbp->b_vp->v_numoutput++; VOP_STRATEGY(vp, nbp); s = splbio(); while ((nbp->b_flags & B_DONE) == 0) { nbp->b_flags |= B_WANTED; tsleep(nbp, PRIBIO, "vnwait", 0); } splx(s); if( nbp->b_flags & B_ERROR) { bp->b_flags |= B_ERROR; bp->b_resid -= (resid - sz); biodone(bp); putvnbuf(nbp); return; } byten += sz; addr += sz; resid -= sz; } biodone(bp); putvnbuf(nbp); } } void vniodone( struct buf *bp) { bp->b_flags |= B_DONE; wakeup((caddr_t) bp); } /* ARGSUSED */ static int vnioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p) { struct vn_softc *vn = vn_softc[vnunit(dev)]; struct vn_ioctl *vio; struct vattr vattr; struct nameidata nd; int error; u_long *f; IFOPT(vn,VN_FOLLOW) printf("vnioctl(0x%lx, 0x%lx, %p, 0x%x, %p): unit %d\n", (u_long)dev, cmd, (void *)data, flag, (void *)p, vnunit(dev)); switch (cmd) { case VNIOCATTACH: case VNIOCDETACH: case VNIOCGSET: case VNIOCGCLEAR: case VNIOCUSET: case VNIOCUCLEAR: goto vn_specific; } IFOPT(vn,VN_LABELS) { if (vn->sc_slices != NULL) { error = dsioctl("vn", dev, cmd, data, flag, &vn->sc_slices, vnstrategy, (ds_setgeom_t *)NULL); if (error != ENOIOCTL) return (error); } if (dkslice(dev) != WHOLE_DISK_SLICE || dkpart(dev) != RAW_PART) return (ENOTTY); } vn_specific: error = suser(p->p_ucred, &p->p_acflag); if (error) return (error); vio = (struct vn_ioctl *)data; f = (u_long*)data; switch (cmd) { case VNIOCATTACH: if (vn->sc_flags & VNF_INITED) return(EBUSY); /* * Always open for read and write. * This is probably bogus, but it lets vn_open() * weed out directories, sockets, etc. so we don't * have to worry about them. */ NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, vio->vn_file, p); error = vn_open(&nd, FREAD|FWRITE, 0); if (error) return(error); error = VOP_GETATTR(nd.ni_vp, &vattr, p->p_ucred, p); if (error) { VOP_UNLOCK(nd.ni_vp, 0, p); (void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p); return(error); } VOP_UNLOCK(nd.ni_vp, 0, p); vn->sc_vp = nd.ni_vp; vn->sc_size = btodb(vattr.va_size); /* note truncation */ error = vnsetcred(vn, p->p_ucred); if (error) { (void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p); return(error); } vio->vn_size = dbtob(vn->sc_size); vn->sc_flags |= VNF_INITED; IFOPT(vn, VN_LABELS) { /* * Reopen so that `ds' knows which devices are open. * If this is the first VNIOCSET, then we've * guaranteed that the device is the cdev and that * no other slices or labels are open. Otherwise, * we rely on VNIOCCLR not being abused. */ error = vnopen(dev, flag, S_IFCHR, p); if (error) vnclear(vn); } IFOPT(vn, VN_FOLLOW) printf("vnioctl: SET vp %p size %x\n", vn->sc_vp, vn->sc_size); break; case VNIOCDETACH: if ((vn->sc_flags & VNF_INITED) == 0) return(ENXIO); /* * XXX handle i/o in progress. Return EBUSY, or wait, or * flush the i/o. * XXX handle multiple opens of the device. Return EBUSY, * or revoke the fd's. * How are these problems handled for removable and failing * hardware devices? */ vnclear(vn); IFOPT(vn, VN_FOLLOW) printf("vnioctl: CLRed\n"); break; case VNIOCGSET: vn_options |= *f; *f = vn_options; break; case VNIOCGCLEAR: vn_options &= ~(*f); *f = vn_options; break; case VNIOCUSET: vn->sc_options |= *f; *f = vn->sc_options; break; case VNIOCUCLEAR: vn->sc_options &= ~(*f); *f = vn->sc_options; break; default: return (ENOTTY); } return(0); } /* * Duplicate the current processes' credentials. Since we are called only * as the result of a SET ioctl and only root can do that, any future access * to this "disk" is essentially as root. Note that credentials may change * if some other uid can write directly to the mapped file (NFS). */ int vnsetcred(struct vn_softc *vn, struct ucred *cred) { struct uio auio; struct iovec aiov; char *tmpbuf; int error; vn->sc_cred = crdup(cred); tmpbuf = malloc(DEV_BSIZE, M_TEMP, M_WAITOK); /* XXX: Horrible kludge to establish credentials for NFS */ aiov.iov_base = tmpbuf; aiov.iov_len = min(DEV_BSIZE, dbtob(vn->sc_size)); auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = 0; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_SYSSPACE; auio.uio_resid = aiov.iov_len; vn_lock(vn->sc_vp, LK_EXCLUSIVE | LK_RETRY, curproc); error = VOP_READ(vn->sc_vp, &auio, 0, vn->sc_cred); VOP_UNLOCK(vn->sc_vp, 0, curproc); free(tmpbuf, M_TEMP); return (error); } void vnshutdown(int howto, void *ignored) { int i; for (i = 0; i < NVN; i++) if (vn_softc[i] && vn_softc[i]->sc_flags & VNF_INITED) vnclear(vn_softc[i]); } void vnclear(struct vn_softc *vn) { register struct vnode *vp = vn->sc_vp; struct proc *p = curproc; /* XXX */ IFOPT(vn, VN_FOLLOW) printf("vnclear(%p): vp=%p\n", vn, vp); if (vn->sc_slices != NULL) dsgone(&vn->sc_slices); vn->sc_flags &= ~VNF_INITED; if (vp == (struct vnode *)0) panic("vnclear: null vp"); (void) vn_close(vp, FREAD|FWRITE, vn->sc_cred, p); crfree(vn->sc_cred); vn->sc_vp = (struct vnode *)0; vn->sc_cred = (struct ucred *)0; vn->sc_size = 0; } static int vnsize(dev_t dev) { int unit = vnunit(dev); if (unit >= NVN || (!vn_softc[unit]) || (vn_softc[unit]->sc_flags & VNF_INITED) == 0) return(-1); return(vn_softc[unit]->sc_size); } static int vndump(dev_t dev) { return (ENODEV); } static vn_devsw_installed = 0; static void vn_drvinit(void *unused) { #ifdef DEVFS int unit; #endif if(!vn_devsw_installed ) { if (at_shutdown(&vnshutdown, NULL, SHUTDOWN_POST_SYNC)) { printf("vn: could not install shutdown hook\n"); return; } cdevsw_add_generic(BDEV_MAJOR, CDEV_MAJOR, &vn_cdevsw); vn_devsw_installed = 1; } #ifdef DEVFS for (unit = 0; unit < NVN; unit++) { struct vn_softc *vn; vn = malloc(sizeof *vn, M_DEVBUF, M_NOWAIT); if (!vn) return; bzero(vn, sizeof *vn); vn_softc[unit] = vn; vn->r_devfs_token = devfs_add_devswf(&vn_cdevsw, dkmakeminor(unit, 0, 0), DV_CHR, UID_ROOT, GID_OPERATOR, 0640, "rvn%d", unit); vn->devfs_token = devfs_add_devswf(&vn_cdevsw, dkmakeminor(unit, 0, 0), DV_BLK, UID_ROOT, GID_OPERATOR, 0640, "vn%d", unit); } #endif } SYSINIT(vndev, SI_SUB_DRIVERS, SI_ORDER_ANY, vn_drvinit, NULL) #endif