/* * Copyright (c) 1989, 1993, 1995 * 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 8.14 (Berkeley) 5/21/95 * $FreeBSD: src/sys/miscfs/specfs/spec_vnops.c,v 1.131.2.4 2001/02/26 04:23:20 jlemon Exp $ * $DragonFly: src/sys/vfs/specfs/spec_vnops.c,v 1.12 2003/08/20 09:56:33 rob Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int spec_advlock (struct vop_advlock_args *); static int spec_bmap (struct vop_bmap_args *); static int spec_close (struct vop_close_args *); static int spec_freeblks (struct vop_freeblks_args *); static int spec_fsync (struct vop_fsync_args *); static int spec_getpages (struct vop_getpages_args *); static int spec_inactive (struct vop_inactive_args *); static int spec_ioctl (struct vop_ioctl_args *); static int spec_open (struct vop_open_args *); static int spec_poll (struct vop_poll_args *); static int spec_kqfilter (struct vop_kqfilter_args *); static int spec_print (struct vop_print_args *); static int spec_read (struct vop_read_args *); static int spec_strategy (struct vop_strategy_args *); static int spec_write (struct vop_write_args *); vop_t **spec_vnodeop_p; static struct vnodeopv_entry_desc spec_vnodeop_entries[] = { { &vop_default_desc, (vop_t *) vop_defaultop }, { &vop_access_desc, (vop_t *) vop_ebadf }, { &vop_advlock_desc, (vop_t *) spec_advlock }, { &vop_bmap_desc, (vop_t *) spec_bmap }, { &vop_close_desc, (vop_t *) spec_close }, { &vop_create_desc, (vop_t *) vop_panic }, { &vop_freeblks_desc, (vop_t *) spec_freeblks }, { &vop_fsync_desc, (vop_t *) spec_fsync }, { &vop_getpages_desc, (vop_t *) spec_getpages }, { &vop_inactive_desc, (vop_t *) spec_inactive }, { &vop_ioctl_desc, (vop_t *) spec_ioctl }, { &vop_lease_desc, (vop_t *) vop_null }, { &vop_link_desc, (vop_t *) vop_panic }, { &vop_mkdir_desc, (vop_t *) vop_panic }, { &vop_mknod_desc, (vop_t *) vop_panic }, { &vop_open_desc, (vop_t *) spec_open }, { &vop_pathconf_desc, (vop_t *) vop_stdpathconf }, { &vop_poll_desc, (vop_t *) spec_poll }, { &vop_kqfilter_desc, (vop_t *) spec_kqfilter }, { &vop_print_desc, (vop_t *) spec_print }, { &vop_read_desc, (vop_t *) spec_read }, { &vop_readdir_desc, (vop_t *) vop_panic }, { &vop_readlink_desc, (vop_t *) vop_panic }, { &vop_reallocblks_desc, (vop_t *) vop_panic }, { &vop_reclaim_desc, (vop_t *) vop_null }, { &vop_remove_desc, (vop_t *) vop_panic }, { &vop_rename_desc, (vop_t *) vop_panic }, { &vop_rmdir_desc, (vop_t *) vop_panic }, { &vop_setattr_desc, (vop_t *) vop_ebadf }, { &vop_strategy_desc, (vop_t *) spec_strategy }, { &vop_symlink_desc, (vop_t *) vop_panic }, { &vop_write_desc, (vop_t *) spec_write }, { NULL, NULL } }; static struct vnodeopv_desc spec_vnodeop_opv_desc = { &spec_vnodeop_p, spec_vnodeop_entries }; VNODEOP_SET(spec_vnodeop_opv_desc); int spec_vnoperate(ap) struct vop_generic_args /* { struct vnodeop_desc *a_desc; } */ *ap; { return (VOCALL(spec_vnodeop_p, ap->a_desc->vdesc_offset, ap)); } static void spec_getpages_iodone (struct buf *bp); /* * Open a special file. */ /* ARGSUSED */ static int spec_open(ap) struct vop_open_args /* { struct vnode *a_vp; int a_mode; struct ucred *a_cred; struct thread *a_td; } */ *ap; { struct vnode *vp = ap->a_vp; dev_t dev = vp->v_rdev; int error; const char *cp; /* * Don't allow open if fs is mounted -nodev. */ if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) return (ENXIO); if (dev_dport(dev) == NULL) return ENXIO; /* Make this field valid before any I/O in ->d_open */ if (!dev->si_iosize_max) dev->si_iosize_max = DFLTPHYS; /* * XXX: Disks get special billing here, but it is mostly wrong. * XXX: diskpartitions can overlap and the real checks should * XXX: take this into account, and consequently they need to * XXX: live in the diskslicing code. Some checks do. */ if (vn_isdisk(vp, NULL) && ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) { /* * Never allow opens for write if the device is mounted R/W */ if (vp->v_specmountpoint != NULL && !(vp->v_specmountpoint->mnt_flag & MNT_RDONLY)) return (EBUSY); /* * When running in secure mode, do not allow opens * for writing if the device is mounted */ if (securelevel >= 1 && vp->v_specmountpoint != NULL) return (EPERM); /* * When running in very secure mode, do not allow * opens for writing of any devices. */ if (securelevel >= 2) return (EPERM); } /* XXX: Special casing of ttys for deadfs. Probably redundant */ if (dev_dflags(dev) & D_TTY) vp->v_flag |= VISTTY; VOP_UNLOCK(vp, 0, ap->a_td); error = dev_dopen(dev, ap->a_mode, S_IFCHR, ap->a_td); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, ap->a_td); if (error) return (error); if (dev_dflags(dev) & D_TTY) { if (dev->si_tty) { struct tty *tp; tp = dev->si_tty; if (!tp->t_stop) { printf("Warning:%s: no t_stop, using nottystop\n", devtoname(dev)); tp->t_stop = nottystop; } } } if (vn_isdisk(vp, NULL)) { if (!dev->si_bsize_phys) dev->si_bsize_phys = DEV_BSIZE; } if ((dev_dflags(dev) & D_DISK) == 0) { cp = devtoname(dev); if (*cp == '#') { printf("WARNING: driver %s should register devices with make_dev() (dev_t = \"%s\")\n", dev_dname(dev), cp); } } return (error); } /* * Vnode op for read */ /* ARGSUSED */ static int spec_read(ap) struct vop_read_args /* { struct vnode *a_vp; struct uio *a_uio; int a_ioflag; struct ucred *a_cred; } */ *ap; { struct vnode *vp; struct thread *td; struct uio *uio; dev_t dev; int error; vp = ap->a_vp; dev = vp->v_rdev; uio = ap->a_uio; td = uio->uio_td; if (uio->uio_resid == 0) return (0); VOP_UNLOCK(vp, 0, td); error = dev_dread(dev, uio, ap->a_ioflag); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); return (error); } /* * Vnode op for write */ /* ARGSUSED */ static int spec_write(ap) struct vop_write_args /* { struct vnode *a_vp; struct uio *a_uio; int a_ioflag; struct ucred *a_cred; } */ *ap; { struct vnode *vp; struct thread *td; struct uio *uio; dev_t dev; int error; vp = ap->a_vp; dev = vp->v_rdev; uio = ap->a_uio; td = uio->uio_td; VOP_UNLOCK(vp, 0, td); error = dev_dwrite(dev, uio, ap->a_ioflag); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); return (error); } /* * Device ioctl operation. */ /* ARGSUSED */ static int 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 thread *a_td; } */ *ap; { dev_t dev; dev = ap->a_vp->v_rdev; return (dev_dioctl(dev, ap->a_command, ap->a_data, ap->a_fflag, ap->a_td)); } /* ARGSUSED */ static int spec_poll(ap) struct vop_poll_args /* { struct vnode *a_vp; int a_events; struct ucred *a_cred; struct thread *a_td; } */ *ap; { dev_t dev; dev = ap->a_vp->v_rdev; return (dev_dpoll(dev, ap->a_events, ap->a_td)); } /* ARGSUSED */ static int spec_kqfilter(ap) struct vop_kqfilter_args /* { struct vnode *a_vp; struct knote *a_kn; } */ *ap; { dev_t dev; dev = ap->a_vp->v_rdev; return (dev_dkqfilter(dev, ap->a_kn)); } /* * Synch buffers associated with a block device */ /* ARGSUSED */ static int spec_fsync(ap) struct vop_fsync_args /* { struct vnode *a_vp; struct ucred *a_cred; int a_waitfor; struct thread *a_td; } */ *ap; { struct vnode *vp = ap->a_vp; struct buf *bp; struct buf *nbp; int s; int maxretry = 10000; /* large, arbitrarily chosen */ if (!vn_isdisk(vp, NULL)) return (0); loop1: /* * MARK/SCAN initialization to avoid infinite loops */ s = splbio(); for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = TAILQ_NEXT(bp, b_vnbufs)) { bp->b_flags &= ~B_SCANNED; } splx(s); /* * Flush all dirty buffers associated with a block device. */ loop2: s = splbio(); for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { nbp = TAILQ_NEXT(bp, b_vnbufs); if ((bp->b_flags & B_SCANNED) != 0) continue; bp->b_flags |= B_SCANNED; if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) continue; if ((bp->b_flags & B_DELWRI) == 0) panic("spec_fsync: not dirty"); if ((vp->v_flag & VOBJBUF) && (bp->b_flags & B_CLUSTEROK)) { BUF_UNLOCK(bp); vfs_bio_awrite(bp); splx(s); } else { bremfree(bp); splx(s); bawrite(bp); } goto loop2; } /* * If synchronous the caller expects us to completely resolve all * dirty buffers in the system. Wait for in-progress I/O to * complete (which could include background bitmap writes), then * retry if dirty blocks still exist. */ if (ap->a_waitfor == MNT_WAIT) { while (vp->v_numoutput) { vp->v_flag |= VBWAIT; (void) tsleep((caddr_t)&vp->v_numoutput, 0, "spfsyn", 0); } if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) { if (--maxretry != 0) { splx(s); goto loop1; } vprint("spec_fsync: giving up on dirty", vp); } } splx(s); return (0); } static int spec_inactive(ap) struct vop_inactive_args /* { struct vnode *a_vp; struct thread *a_td; } */ *ap; { VOP_UNLOCK(ap->a_vp, 0, ap->a_td); return (0); } /* * Just call the device strategy routine */ static int spec_strategy(ap) struct vop_strategy_args /* { struct vnode *a_vp; struct buf *a_bp; } */ *ap; { struct buf *bp; struct vnode *vp; struct mount *mp; bp = ap->a_bp; if (((bp->b_flags & B_READ) == 0) && (LIST_FIRST(&bp->b_dep)) != NULL && bioops.io_start) (*bioops.io_start)(bp); /* * Collect statistics on synchronous and asynchronous read * and write counts for disks that have associated filesystems. */ vp = ap->a_vp; if (vn_isdisk(vp, NULL) && (mp = vp->v_specmountpoint) != NULL) { if ((bp->b_flags & B_READ) == 0) { if (bp->b_lock.lk_lockholder == LK_KERNTHREAD) mp->mnt_stat.f_asyncwrites++; else mp->mnt_stat.f_syncwrites++; } else { if (bp->b_lock.lk_lockholder == LK_KERNTHREAD) mp->mnt_stat.f_asyncreads++; else mp->mnt_stat.f_syncreads++; } } #if 0 KASSERT(devsw(bp->b_dev) != NULL, ("No devsw on dev %s responsible for buffer %p\n", devtoname(bp->b_dev), bp)); KASSERT(devsw(bp->b_dev)->d_strategy != NULL, ("No strategy on dev %s responsible for buffer %p\n", devtoname(bp->b_dev), bp)); #endif BUF_STRATEGY(bp, 0); return (0); } static int spec_freeblks(ap) struct vop_freeblks_args /* { struct vnode *a_vp; daddr_t a_addr; daddr_t a_length; } */ *ap; { struct buf *bp; /* * XXX: This assumes that strategy does the deed right away. * XXX: this may not be TRTTD. */ if ((dev_dflags(ap->a_vp->v_rdev) & D_CANFREE) == 0) return (0); bp = geteblk(ap->a_length); bp->b_flags |= B_FREEBUF; bp->b_dev = ap->a_vp->v_rdev; bp->b_blkno = ap->a_addr; bp->b_offset = dbtob(ap->a_addr); bp->b_bcount = ap->a_length; BUF_STRATEGY(bp, 0); return (0); } /* * Implement degenerate case where the block requested is the block * returned, and assume that the entire device is contiguous in regards * to the contiguous block range (runp and runb). */ static int spec_bmap(ap) struct vop_bmap_args /* { struct vnode *a_vp; daddr_t a_bn; struct vnode **a_vpp; daddr_t *a_bnp; int *a_runp; int *a_runb; } */ *ap; { struct vnode *vp = ap->a_vp; int runp = 0; int runb = 0; if (ap->a_vpp != NULL) *ap->a_vpp = vp; if (ap->a_bnp != NULL) *ap->a_bnp = ap->a_bn; if (vp->v_mount != NULL) runp = runb = MAXBSIZE / vp->v_mount->mnt_stat.f_iosize; if (ap->a_runp != NULL) *ap->a_runp = runp; if (ap->a_runb != NULL) *ap->a_runb = runb; return (0); } /* * Device close routine */ /* ARGSUSED */ static int spec_close(ap) struct vop_close_args /* { struct vnode *a_vp; int a_fflag; struct ucred *a_cred; struct thread *a_td; } */ *ap; { struct proc *p = ap->a_td->td_proc; struct vnode *vp = ap->a_vp; dev_t dev = vp->v_rdev; /* * 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 && p && (vp->v_flag & VXLOCK) == 0 && vp == p->p_session->s_ttyvp) { vrele(vp); p->p_session->s_ttyvp = NULL; } /* * 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 (vp->v_flag & VXLOCK) { /* Forced close */ } else if (dev_dflags(dev) & D_TRACKCLOSE) { /* Keep device updated on status */ } else if (vcount(vp) > 1) { return (0); } return (dev_dclose(dev, ap->a_fflag, S_IFCHR, ap->a_td)); } /* * Print out the contents of a special device vnode. */ static int spec_print(ap) struct vop_print_args /* { struct vnode *a_vp; } */ *ap; { printf("tag VT_NON, dev %s\n", devtoname(ap->a_vp->v_rdev)); return (0); } /* * Special device advisory byte-level locks. */ /* ARGSUSED */ static int 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 (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL); } static void spec_getpages_iodone(bp) struct buf *bp; { bp->b_flags |= B_DONE; wakeup(bp); } static int spec_getpages(ap) struct vop_getpages_args *ap; { vm_offset_t kva; int error; int i, pcount, size, s; daddr_t blkno; struct buf *bp; vm_page_t m; vm_ooffset_t offset; int toff, nextoff, nread; struct vnode *vp = ap->a_vp; int blksiz; int gotreqpage; error = 0; pcount = round_page(ap->a_count) / PAGE_SIZE; /* * Calculate the offset of the transfer and do sanity check. * FreeBSD currently only supports an 8 TB range due to b_blkno * being in DEV_BSIZE ( usually 512 ) byte chunks on call to * VOP_STRATEGY. XXX */ offset = IDX_TO_OFF(ap->a_m[0]->pindex) + ap->a_offset; #define DADDR_T_BIT (sizeof(daddr_t)*8) #define OFFSET_MAX ((1LL << (DADDR_T_BIT + DEV_BSHIFT)) - 1) if (offset < 0 || offset > OFFSET_MAX) { /* XXX still no %q in kernel. */ printf("spec_getpages: preposterous offset 0x%x%08x\n", (u_int)((u_quad_t)offset >> 32), (u_int)(offset & 0xffffffff)); return (VM_PAGER_ERROR); } blkno = btodb(offset); /* * Round up physical size for real devices. We cannot round using * v_mount's block size data because v_mount has nothing to do with * the device. i.e. it's usually '/dev'. We need the physical block * size for the device itself. * * We can't use v_specmountpoint because it only exists when the * block device is mounted. However, we can use v_rdev. */ if (vn_isdisk(vp, NULL)) blksiz = vp->v_rdev->si_bsize_phys; else blksiz = DEV_BSIZE; size = (ap->a_count + blksiz - 1) & ~(blksiz - 1); bp = getpbuf(NULL); kva = (vm_offset_t)bp->b_data; /* * Map the pages to be read into the kva. */ pmap_qenter(kva, ap->a_m, pcount); /* Build a minimal buffer header. */ bp->b_flags = B_READ | B_CALL; bp->b_iodone = spec_getpages_iodone; /* B_PHYS is not set, but it is nice to fill this in. */ bp->b_blkno = blkno; bp->b_lblkno = blkno; pbgetvp(ap->a_vp, bp); bp->b_bcount = size; bp->b_bufsize = size; bp->b_resid = 0; bp->b_runningbufspace = bp->b_bufsize; runningbufspace += bp->b_runningbufspace; mycpu->gd_cnt.v_vnodein++; mycpu->gd_cnt.v_vnodepgsin += pcount; /* Do the input. */ VOP_STRATEGY(bp->b_vp, bp); s = splbio(); /* We definitely need to be at splbio here. */ while ((bp->b_flags & B_DONE) == 0) { tsleep(bp, 0, "spread", 0); } splx(s); if ((bp->b_flags & B_ERROR) != 0) { if (bp->b_error) error = bp->b_error; else error = EIO; } nread = size - bp->b_resid; if (nread < ap->a_count) { bzero((caddr_t)kva + nread, ap->a_count - nread); } pmap_qremove(kva, pcount); gotreqpage = 0; for (i = 0, toff = 0; i < pcount; i++, toff = nextoff) { nextoff = toff + PAGE_SIZE; m = ap->a_m[i]; m->flags &= ~PG_ZERO; if (nextoff <= nread) { m->valid = VM_PAGE_BITS_ALL; vm_page_undirty(m); } else if (toff < nread) { /* * Since this is a VM request, we have to supply the * unaligned offset to allow vm_page_set_validclean() * to zero sub-DEV_BSIZE'd portions of the page. */ vm_page_set_validclean(m, 0, nread - toff); } else { m->valid = 0; vm_page_undirty(m); } if (i != ap->a_reqpage) { /* * Just in case someone was asking for this page we * now tell them that it is ok to use. */ if (!error || (m->valid == VM_PAGE_BITS_ALL)) { if (m->valid) { if (m->flags & PG_WANTED) { vm_page_activate(m); } else { vm_page_deactivate(m); } vm_page_wakeup(m); } else { vm_page_free(m); } } else { vm_page_free(m); } } else if (m->valid) { gotreqpage = 1; /* * Since this is a VM request, we need to make the * entire page presentable by zeroing invalid sections. */ if (m->valid != VM_PAGE_BITS_ALL) vm_page_zero_invalid(m, FALSE); } } if (!gotreqpage) { m = ap->a_m[ap->a_reqpage]; printf( "spec_getpages:(%s) I/O read failure: (error=%d) bp %p vp %p\n", devtoname(bp->b_dev), error, bp, bp->b_vp); printf( " size: %d, resid: %ld, a_count: %d, valid: 0x%x\n", size, bp->b_resid, ap->a_count, m->valid); printf( " nread: %d, reqpage: %d, pindex: %lu, pcount: %d\n", nread, ap->a_reqpage, (u_long)m->pindex, pcount); /* * Free the buffer header back to the swap buffer pool. */ relpbuf(bp, NULL); return VM_PAGER_ERROR; } /* * Free the buffer header back to the swap buffer pool. */ relpbuf(bp, NULL); return VM_PAGER_OK; }