/* $NetBSD: vnd.c,v 1.28 1996/09/25 02:22:10 christos Exp $ */ /* * 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 $Hdr: vn.c 1.13 94/04/02$ * * @(#)vn.c 8.6 (Berkeley) 4/1/94 */ /* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DEBUG int dovndcluster = 1; int vnddebug = 0x00; #define VDB_FOLLOW 0x01 #define VDB_INIT 0x02 #define VDB_IO 0x04 #endif #define b_cylin b_resid #define vndunit(x) DISKUNIT(x) struct vndbuf { struct buf vb_buf; struct buf *vb_obp; }; #define getvndbuf() \ ((struct vndbuf *)malloc(sizeof(struct vndbuf), M_DEVBUF, M_WAITOK)) #define putvndbuf(vbp) \ free((caddr_t)(vbp), M_DEVBUF) struct vnd_softc { int sc_flags; /* flags */ size_t sc_size; /* size of vnd */ struct vnode *sc_vp; /* vnode */ struct ucred *sc_cred; /* credentials */ int sc_maxactive; /* max # of active requests */ struct buf sc_tab; /* transfer queue */ char sc_xname[8]; /* XXX external name */ struct disk sc_dkdev; /* generic disk device info */ }; /* sc_flags */ #define VNF_ALIVE 0x01 #define VNF_INITED 0x02 #define VNF_WANTED 0x40 #define VNF_LOCKED 0x80 struct vnd_softc *vnd_softc; int numvnd = 0; /* called by main() at boot time */ void vndattach __P((int)); void vndclear __P((struct vnd_softc *)); void vndstart __P((struct vnd_softc *)); int vndsetcred __P((struct vnd_softc *, struct ucred *)); void vndthrottle __P((struct vnd_softc *, struct vnode *)); void vndiodone __P((struct buf *)); void vndshutdown __P((void)); static int vndlock __P((struct vnd_softc *)); static void vndunlock __P((struct vnd_softc *)); void vndattach(num) int num; { char *mem; register u_long size; if (num <= 0) return; size = num * sizeof(struct vnd_softc); mem = malloc(size, M_DEVBUF, M_NOWAIT); if (mem == NULL) { printf("WARNING: no memory for vnode disks\n"); return; } bzero(mem, size); vnd_softc = (struct vnd_softc *)mem; numvnd = num; } int vndopen(dev, flags, mode, p) dev_t dev; int flags, mode; struct proc *p; { int unit = vndunit(dev); struct vnd_softc *sc; int error = 0, part, pmask; /* * XXX Should support disklabels. */ #ifdef DEBUG if (vnddebug & VDB_FOLLOW) printf("vndopen(%x, %x, %x, %p)\n", dev, flags, mode, p); #endif if (unit >= numvnd) return (ENXIO); sc = &vnd_softc[unit]; if ((error = vndlock(sc)) != 0) return (error); part = DISKPART(dev); pmask = (1 << part); /* Prevent our unit from being unconfigured while open. */ switch (mode) { case S_IFCHR: sc->sc_dkdev.dk_copenmask |= pmask; break; case S_IFBLK: sc->sc_dkdev.dk_bopenmask |= pmask; break; } sc->sc_dkdev.dk_openmask = sc->sc_dkdev.dk_copenmask | sc->sc_dkdev.dk_bopenmask; vndunlock(sc); return (0); } int vndclose(dev, flags, mode, p) dev_t dev; int flags, mode; struct proc *p; { int unit = vndunit(dev); struct vnd_softc *sc; int error = 0, part; #ifdef DEBUG if (vnddebug & VDB_FOLLOW) printf("vndclose(%x, %x, %x, %p)\n", dev, flags, mode, p); #endif if (unit >= numvnd) return (ENXIO); sc = &vnd_softc[unit]; if ((error = vndlock(sc)) != 0) return (error); part = DISKPART(dev); /* ...that much closer to allowing unconfiguration... */ switch (mode) { case S_IFCHR: sc->sc_dkdev.dk_copenmask &= ~(1 << part); break; case S_IFBLK: sc->sc_dkdev.dk_bopenmask &= ~(1 << part); break; } sc->sc_dkdev.dk_openmask = sc->sc_dkdev.dk_copenmask | sc->sc_dkdev.dk_bopenmask; vndunlock(sc); return (0); } /* * Break the request into bsize pieces and submit using VOP_BMAP/VOP_STRATEGY. * Note that this driver can only be used for swapping over NFS on the hp * since nfs_strategy on the vax cannot handle u-areas and page tables. */ void vndstrategy(bp) register struct buf *bp; { int unit = vndunit(bp->b_dev); register struct vnd_softc *vnd = &vnd_softc[unit]; register struct vndbuf *nbp; register int bn, bsize, resid; register caddr_t addr; int sz, flags, error; #ifdef DEBUG if (vnddebug & VDB_FOLLOW) printf("vndstrategy(%p): unit %d\n", bp, unit); #endif if ((vnd->sc_flags & VNF_INITED) == 0) { bp->b_error = ENXIO; bp->b_flags |= B_ERROR; biodone(bp); return; } bn = bp->b_blkno; sz = howmany(bp->b_bcount, DEV_BSIZE); bp->b_resid = bp->b_bcount; if (bn < 0 || bn + sz > vnd->sc_size) { if (bn != vnd->sc_size) { bp->b_error = EINVAL; bp->b_flags |= B_ERROR; } biodone(bp); return; } bn = dbtob(bn); bsize = vnd->sc_vp->v_mount->mnt_stat.f_iosize; addr = bp->b_data; flags = bp->b_flags | B_CALL; for (resid = bp->b_resid; resid; resid -= sz) { struct vnode *vp; daddr_t nbn; int off, s, nra; nra = 0; VOP_LOCK(vnd->sc_vp); error = VOP_BMAP(vnd->sc_vp, bn / bsize, &vp, &nbn, &nra); VOP_UNLOCK(vnd->sc_vp); if (error == 0 && (long)nbn == -1) error = EIO; #ifdef DEBUG if (!dovndcluster) nra = 0; #endif if ((off = bn % bsize) != 0) sz = bsize - off; else sz = (1 + nra) * bsize; if (resid < sz) sz = resid; #ifdef DEBUG if (vnddebug & VDB_IO) printf("vndstrategy: vp %p/%p bn %x/%x sz %x\n", vnd->sc_vp, vp, bn, nbn, sz); #endif nbp = getvndbuf(); nbp->vb_buf.b_flags = flags; nbp->vb_buf.b_bcount = sz; nbp->vb_buf.b_bufsize = bp->b_bufsize; nbp->vb_buf.b_error = 0; if (vp->v_type == VBLK || vp->v_type == VCHR) nbp->vb_buf.b_dev = vp->v_rdev; else nbp->vb_buf.b_dev = NODEV; nbp->vb_buf.b_data = addr; nbp->vb_buf.b_blkno = nbn + btodb(off); nbp->vb_buf.b_proc = bp->b_proc; nbp->vb_buf.b_iodone = vndiodone; nbp->vb_buf.b_vp = vp; nbp->vb_buf.b_rcred = vnd->sc_cred; /* XXX crdup? */ nbp->vb_buf.b_wcred = vnd->sc_cred; /* XXX crdup? */ nbp->vb_buf.b_dirtyoff = bp->b_dirtyoff; nbp->vb_buf.b_dirtyend = bp->b_dirtyend; nbp->vb_buf.b_validoff = bp->b_validoff; nbp->vb_buf.b_validend = bp->b_validend; /* save a reference to the old buffer */ nbp->vb_obp = bp; /* * If there was an error or a hole in the file...punt. * Note that we deal with this after the nbp allocation. * This ensures that we properly clean up any operations * that we have already fired off. * * XXX we could deal with holes here but it would be * a hassle (in the write case). */ if (error) { nbp->vb_buf.b_error = error; nbp->vb_buf.b_flags |= B_ERROR; bp->b_resid -= (resid - sz); biodone(&nbp->vb_buf); return; } /* * Just sort by block number */ nbp->vb_buf.b_cylin = nbp->vb_buf.b_blkno; s = splbio(); disksort(&vnd->sc_tab, &nbp->vb_buf); if (vnd->sc_tab.b_active < vnd->sc_maxactive) { vnd->sc_tab.b_active++; vndstart(vnd); } splx(s); bn += sz; addr += sz; } } /* * Feed requests sequentially. * We do it this way to keep from flooding NFS servers if we are connected * to an NFS file. This places the burden on the client rather than the * server. */ void vndstart(vnd) register struct vnd_softc *vnd; { register struct buf *bp; /* * Dequeue now since lower level strategy routine might * queue using same links */ bp = vnd->sc_tab.b_actf; vnd->sc_tab.b_actf = bp->b_actf; #ifdef DEBUG if (vnddebug & VDB_IO) printf("vndstart(%ld): bp %p vp %p blkno %x addr %p cnt %lx\n", (long) (vnd-vnd_softc), bp, bp->b_vp, bp->b_blkno, bp->b_data, bp->b_bcount); #endif /* Instrumentation. */ disk_busy(&vnd->sc_dkdev); if ((bp->b_flags & B_READ) == 0) bp->b_vp->v_numoutput++; VOP_STRATEGY(bp); } void vndiodone(bp) struct buf *bp; { register struct vndbuf *vbp = (struct vndbuf *) bp; register struct buf *pbp = vbp->vb_obp; register struct vnd_softc *vnd = &vnd_softc[vndunit(pbp->b_dev)]; int s; s = splbio(); #ifdef DEBUG if (vnddebug & VDB_IO) printf("vndiodone(%ld): vbp %p vp %p blkno %x addr %p cnt %lx\n", (long) (vnd-vnd_softc), vbp, vbp->vb_buf.b_vp, vbp->vb_buf.b_blkno, vbp->vb_buf.b_data, vbp->vb_buf.b_bcount); #endif if (vbp->vb_buf.b_error) { #ifdef DEBUG if (vnddebug & VDB_IO) printf("vndiodone: vbp %p error %d\n", vbp, vbp->vb_buf.b_error); #endif pbp->b_flags |= B_ERROR; pbp->b_error = biowait(&vbp->vb_buf); } pbp->b_resid -= vbp->vb_buf.b_bcount; putvndbuf(vbp); disk_unbusy(&vnd->sc_dkdev, (pbp->b_bcount - pbp->b_resid)); if (pbp->b_resid == 0) { #ifdef DEBUG if (vnddebug & VDB_IO) printf("vndiodone: pbp %p iodone\n", pbp); #endif biodone(pbp); } if (vnd->sc_tab.b_actf) vndstart(vnd); else vnd->sc_tab.b_active--; splx(s); } /* ARGSUSED */ int vndread(dev, uio, flags) dev_t dev; struct uio *uio; int flags; { int unit = vndunit(dev); struct vnd_softc *sc; #ifdef DEBUG if (vnddebug & VDB_FOLLOW) printf("vndread(%x, %p)\n", dev, uio); #endif if (unit >= numvnd) return (ENXIO); sc = &vnd_softc[unit]; if ((sc->sc_flags & VNF_INITED) == 0) return (ENXIO); return (physio(vndstrategy, NULL, dev, B_READ, minphys, uio)); } /* ARGSUSED */ int vndwrite(dev, uio, flags) dev_t dev; struct uio *uio; int flags; { int unit = vndunit(dev); struct vnd_softc *sc; #ifdef DEBUG if (vnddebug & VDB_FOLLOW) printf("vndwrite(%x, %p)\n", dev, uio); #endif if (unit >= numvnd) return (ENXIO); sc = &vnd_softc[unit]; if ((sc->sc_flags & VNF_INITED) == 0) return (ENXIO); return (physio(vndstrategy, NULL, dev, B_WRITE, minphys, uio)); } /* ARGSUSED */ int vndioctl(dev, cmd, data, flag, p) dev_t dev; u_long cmd; caddr_t data; int flag; struct proc *p; { int unit = vndunit(dev); register struct vnd_softc *vnd; struct vnd_ioctl *vio; struct vattr vattr; struct nameidata nd; int error, part, pmask, s; #ifdef DEBUG if (vnddebug & VDB_FOLLOW) printf("vndioctl(%x, %lx, %p, %x, %p): unit %d\n", dev, cmd, data, flag, p, unit); #endif error = suser(p->p_ucred, &p->p_acflag); if (error) return (error); if (unit >= numvnd) return (ENXIO); vnd = &vnd_softc[unit]; vio = (struct vnd_ioctl *)data; switch (cmd) { case VNDIOCSET: if (vnd->sc_flags & VNF_INITED) return (EBUSY); if ((error = vndlock(vnd)) != 0) return (error); /* * 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->vnd_file, p); if ((error = vn_open(&nd, FREAD|FWRITE, 0)) != 0) { vndunlock(vnd); return(error); } error = VOP_GETATTR(nd.ni_vp, &vattr, p->p_ucred, p); if (error) { VOP_UNLOCK(nd.ni_vp); (void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p); vndunlock(vnd); return(error); } VOP_UNLOCK(nd.ni_vp); vnd->sc_vp = nd.ni_vp; vnd->sc_size = btodb(vattr.va_size); /* note truncation */ if ((error = vndsetcred(vnd, p->p_ucred)) != 0) { (void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p); vndunlock(vnd); return(error); } vndthrottle(vnd, vnd->sc_vp); vio->vnd_size = dbtob(vnd->sc_size); vnd->sc_flags |= VNF_INITED; #ifdef DEBUG if (vnddebug & VDB_INIT) printf("vndioctl: SET vp %p size %lx\n", vnd->sc_vp, (unsigned long) vnd->sc_size); #endif /* Attach the disk. */ bzero(vnd->sc_xname, sizeof(vnd->sc_xname)); /* XXX */ sprintf(vnd->sc_xname, "vnd%d", unit); /* XXX */ vnd->sc_dkdev.dk_name = vnd->sc_xname; disk_attach(&vnd->sc_dkdev); vndunlock(vnd); break; case VNDIOCCLR: if ((vnd->sc_flags & VNF_INITED) == 0) return (ENXIO); if ((error = vndlock(vnd)) != 0) return (error); /* * Don't unconfigure if any other partitions are open * or if both the character and block flavors of this * partition are open. */ part = DISKPART(dev); pmask = (1 << part); if ((vnd->sc_dkdev.dk_openmask & ~pmask) || ((vnd->sc_dkdev.dk_bopenmask & pmask) && (vnd->sc_dkdev.dk_copenmask & pmask))) { vndunlock(vnd); return (EBUSY); } vndclear(vnd); #ifdef DEBUG if (vnddebug & VDB_INIT) printf("vndioctl: CLRed\n"); #endif /* Detatch the disk. */ disk_detach(&vnd->sc_dkdev); /* This must be atomic. */ s = splhigh(); vndunlock(vnd); bzero(vnd, sizeof(struct vnd_softc)); splx(s); break; /* * XXX Should support disklabels. */ 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 vndsetcred(vnd, cred) register struct vnd_softc *vnd; struct ucred *cred; { struct uio auio; struct iovec aiov; char *tmpbuf; int error; vnd->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(vnd->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; VOP_LOCK(vnd->sc_vp); error = VOP_READ(vnd->sc_vp, &auio, 0, vnd->sc_cred); VOP_UNLOCK(vnd->sc_vp); free(tmpbuf, M_TEMP); return (error); } /* * Set maxactive based on FS type */ void vndthrottle(vnd, vp) register struct vnd_softc *vnd; struct vnode *vp; { #ifdef NFSCLIENT extern int (**nfsv2_vnodeop_p) __P((void *)); if (vp->v_op == nfsv2_vnodeop_p) vnd->sc_maxactive = 2; else #endif vnd->sc_maxactive = 8; if (vnd->sc_maxactive < 1) vnd->sc_maxactive = 1; } void vndshutdown() { register struct vnd_softc *vnd; for (vnd = &vnd_softc[0]; vnd < &vnd_softc[numvnd]; vnd++) if (vnd->sc_flags & VNF_INITED) vndclear(vnd); } void vndclear(vnd) register struct vnd_softc *vnd; { register struct vnode *vp = vnd->sc_vp; struct proc *p = curproc; /* XXX */ #ifdef DEBUG if (vnddebug & VDB_FOLLOW) printf("vndclear(%p): vp %p\n", vnd, vp); #endif vnd->sc_flags &= ~VNF_INITED; if (vp == (struct vnode *)0) panic("vndioctl: null vp"); (void) vn_close(vp, FREAD|FWRITE, vnd->sc_cred, p); crfree(vnd->sc_cred); vnd->sc_vp = (struct vnode *)0; vnd->sc_cred = (struct ucred *)0; vnd->sc_size = 0; } int vndsize(dev) dev_t dev; { int unit = vndunit(dev); register struct vnd_softc *vnd = &vnd_softc[unit]; if (unit >= numvnd || (vnd->sc_flags & VNF_INITED) == 0) return(-1); return(vnd->sc_size); } int vnddump(dev, blkno, va, size) dev_t dev; daddr_t blkno; caddr_t va; size_t size; { /* Not implemented. */ return ENXIO; } /* * Wait interruptibly for an exclusive lock. * * XXX * Several drivers do this; it should be abstracted and made MP-safe. */ static int vndlock(sc) struct vnd_softc *sc; { int error; while ((sc->sc_flags & VNF_LOCKED) != 0) { sc->sc_flags |= VNF_WANTED; if ((error = tsleep(sc, PRIBIO | PCATCH, "vndlck", 0)) != 0) return (error); } sc->sc_flags |= VNF_LOCKED; return (0); } /* * Unlock and wake up any waiters. */ static void vndunlock(sc) struct vnd_softc *sc; { sc->sc_flags &= ~VNF_LOCKED; if ((sc->sc_flags & VNF_WANTED) != 0) { sc->sc_flags &= ~VNF_WANTED; wakeup(sc); } }