/* * 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 1.77 1999/05/07 07:03:20 phk 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 #include #ifdef DEVFS #include #endif /*DEVFS*/ #include #include #include #include #include #include #include #include #include #include #include static d_ioctl_t vnioctl; static d_open_t vnopen; static d_close_t vnclose; static d_dump_t vndump; static d_psize_t vnsize; static d_strategy_t vnstrategy; static d_parms_t vnparms; #define CDEV_MAJOR 43 #define BDEV_MAJOR 15 /* * cdevsw * D_DISK we want to look like a disk * ( D_NOCLUSTERRW removed - clustering should be ok ) * D_CANFREE We support B_FREEBUF */ static struct cdevsw vn_cdevsw = { vnopen, vnclose, physread, physwrite, vnioctl, nostop, nullreset, nodevtotty, seltrue, nommap, vnstrategy, "vn", vnparms, -1, vndump, vnsize, D_DISK|D_CANFREE, 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 */ int sc_size; /* size of vn, sc_secsize scale */ int sc_secsize; /* sector size */ struct diskslices *sc_slices; struct vnode *sc_vp; /* vnode if not NULL */ vm_object_t sc_object; /* backing object if not NULL */ 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)) #if 0 static void vniodone (struct buf *bp); #endif static int vnsetcred (struct vn_softc *vn, struct ucred *cred); static void vnclear (struct vn_softc *vn); static int vn_modevent (module_t, int, void *); static int vniocattach_file (struct vn_softc *, struct vn_ioctl *, dev_t dev, int flag, struct proc *p); static int vniocattach_swap (struct vn_softc *, struct vn_ioctl *, dev_t dev, int flag, struct proc *p); 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 = vn->sc_secsize; label.d_nsectors = 32; label.d_ntracks = 64 / (vn->sc_secsize / DEV_BSIZE); label.d_secpercyl = label.d_nsectors * label.d_ntracks; label.d_ncylinders = vn->sc_size / label.d_secpercyl; label.d_secperunit = vn->sc_size; 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); } /* * vnstrategy: * * Run strategy routine for VN device. We use VOP_READ/VOP_WRITE calls * for vnode-backed vn's, and the new vm_pager_strategy() call for * vm_object-backed vn's. * * Currently B_ASYNC is only partially handled - for OBJT_SWAP I/O only. * * NOTE: bp->b_blkno is DEV_BSIZE'd. We must generate bp->b_pblkno for * our uio or vn_pager_strategy() call that is vn->sc_secsize'd */ static void vnstrategy(struct buf *bp) { int unit = vnunit(bp->b_dev); struct vn_softc *vn = vn_softc[unit]; 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; } bp->b_resid = bp->b_bcount; IFOPT(vn, VN_LABELS) { if (vn->sc_slices != NULL && dscheck(bp, vn->sc_slices) <= 0) { bp->b_flags |= B_INVAL; biodone(bp); return; } } else { int pbn; pbn = bp->b_blkno * (vn->sc_secsize / DEV_BSIZE); sz = howmany(bp->b_bcount, vn->sc_secsize); if (pbn < 0 || pbn + sz > vn->sc_size) { if (pbn != vn->sc_size) { bp->b_error = EINVAL; bp->b_flags |= B_ERROR | B_INVAL; } biodone(bp); return; } bp->b_pblkno = pbn; } if (vn->sc_vp && (bp->b_flags & B_FREEBUF)) { /* * Not handled for vnode-backed element yet. */ biodone(bp); } else if (vn->sc_vp) { /* * VNODE I/O */ aiov.iov_base = bp->b_data; aiov.iov_len = bp->b_bcount; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = (vm_ooffset_t)bp->b_pblkno * vn->sc_secsize; 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_error = error; bp->b_flags |= B_ERROR; } biodone(bp); } else if (vn->sc_object) { /* * OBJT_SWAP I/O * * ( handles read, write, freebuf ) */ vm_pager_strategy(vn->sc_object, bp); } else { bp->b_flags |= B_ERROR; bp->b_error = EINVAL; biodone(bp); } } #if 0 void vniodone( struct buf *bp) { bp->b_flags |= B_DONE; wakeup((caddr_t) bp); } #endif /* 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; 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); 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); if (vio->vn_file == NULL) error = vniocattach_swap(vn, vio, dev, flag, p); else error = vniocattach_file(vn, vio, dev, flag, p); 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: error = ENOTTY; break; } return(error); } /* * vniocattach_file: * * Attach a file to a VN partition. Return the size in the vn_size * field. */ static int vniocattach_file(vn, vio, dev, flag, p) struct vn_softc *vn; struct vn_ioctl *vio; dev_t dev; int flag; struct proc *p; { struct vattr vattr; struct nameidata nd; int 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->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_secsize = DEV_BSIZE; vn->sc_vp = nd.ni_vp; vn->sc_size = vattr.va_size / vn->sc_secsize; /* note truncation */ error = vnsetcred(vn, p->p_ucred); if (error) { (void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p); return(error); } 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 blks\n", vn->sc_vp, vn->sc_size); return(0); } /* * vniocattach_swap: * * Attach swap backing store to a VN partition of the size specified * in vn_size. */ static int vniocattach_swap(vn, vio, dev, flag, p) struct vn_softc *vn; struct vn_ioctl *vio; dev_t dev; int flag; struct proc *p; { int error; /* * Range check. Disallow negative sizes or any size less then the * size of a page. Then round to a page. */ if (vio->vn_size <= 0) return(EDOM); /* * Allocate an OBJT_SWAP object. * * sc_secsize is PAGE_SIZE'd * * vio->vn_size is in PAGE_SIZE'd chunks. * sc_size must be in PAGE_SIZE'd chunks. * Note the truncation. */ vn->sc_secsize = PAGE_SIZE; vn->sc_size = vio->vn_size; vn->sc_object = vm_pager_allocate(OBJT_SWAP, NULL, vn->sc_secsize * (vm_ooffset_t)vio->vn_size, VM_PROT_DEFAULT, 0); vn->sc_flags |= VNF_INITED; error = vnsetcred(vn, p->p_ucred); if (error == 0) { 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 == 0) { IFOPT(vn, VN_FOLLOW) { printf("vnioctl: SET vp %p size %x\n", vn->sc_vp, vn->sc_size); } } if (error) vnclear(vn); return(error); } /* * 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 = 0; /* * Set credits in our softc */ if (vn->sc_cred) crfree(vn->sc_cred); vn->sc_cred = crdup(cred); /* * Horrible kludge to establish credentials for NFS XXX. */ if (vn->sc_vp) { tmpbuf = malloc(vn->sc_secsize, M_TEMP, M_WAITOK); aiov.iov_base = tmpbuf; aiov.iov_len = vn->sc_secsize; 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 vnclear(struct vn_softc *vn) { struct proc *p = curproc; /* XXX */ IFOPT(vn, VN_FOLLOW) printf("vnclear(%p): vp=%p\n", vn, vn->sc_vp); if (vn->sc_slices != NULL) dsgone(&vn->sc_slices); vn->sc_flags &= ~VNF_INITED; if (vn->sc_vp != NULL) { (void)vn_close(vn->sc_vp, FREAD|FWRITE, vn->sc_cred, p); vn->sc_vp = NULL; } if (vn->sc_cred) { crfree(vn->sc_cred); vn->sc_cred = NULL; } if (vn->sc_object != NULL) { vm_pager_deallocate(vn->sc_object); vn->sc_object = NULL; } vn->sc_size = 0; } static int vnsize(dev_t dev) { int unit = vnunit(dev); struct vn_softc *vn; if (unit < 0 || unit >= NVN) return(-1); vn = vn_softc[unit]; if ((vn->sc_flags & VNF_INITED) == 0) return(-1); return(vn->sc_size); } /* * vnparms() - return requested device block info * * This is typically called by specfs with DBLK_MIN to get * the minimum read/write block size. If the device does not * exist or has not been configured, 0 is returned. */ static int vnparms(dev_t dev, struct specinfo *sinfo, int ctl) { int unit = vnunit(dev); int r = -1; struct vn_softc *vn; if (unit < 0 || unit >= NVN) return(r); if ((vn = vn_softc[unit]) == NULL || (vn->sc_flags & VNF_INITED) == 0) return(r); switch(ctl) { case DPARM_GET: /* * Retrieve disk parameters. The system has already set * the defaults, we simply override them as necessary. */ r = 0; if (sinfo->si_bsize_phys < vn->sc_secsize) sinfo->si_bsize_phys = vn->sc_secsize; if (sinfo->si_bsize_best < vn->sc_secsize) sinfo->si_bsize_best = vn->sc_secsize; break; default: break; } return(r); } static int vndump(dev_t dev) { return (ENODEV); } static int vn_modevent(module_t mod, int type, void *data) { int unit; #ifdef DEVFS struct vn_softc *vn; #endif switch (type) { case MOD_LOAD: #ifdef DEVFS for (unit = 0; unit < NVN; unit++) { vn = malloc(sizeof *vn, M_DEVBUF, M_WAITOK); if (!vn) continue; /* "oops" */ 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 break; case MOD_UNLOAD: #ifdef DEVFS for (unit = 0; unit < NVN; unit++) { vn = vn_softc[unit]; if (vn->r_devfs_token) { devfs_remove_dev(vn->r_devfs_token); vn->r_devfs_token = 0; } if (vn->devfs_token) { devfs_remove_dev(vn->devfs_token); vn->devfs_token = 0; } } #endif /* fall through */ case MOD_SHUTDOWN: for (unit = 0; unit < NVN; unit++) if (vn_softc[unit] && vn_softc[unit]->sc_flags & VNF_INITED) vnclear(vn_softc[unit]); break; default: break; } return 0; } DEV_MODULE(vn, CDEV_MAJOR, BDEV_MAJOR, vn_cdevsw, vn_modevent, 0); #endif