/* * Copyright (c) 1990 University of Utah. * Copyright (c) 1991 The Regents of the University of California. * All rights reserved. * Copyright (c) 1993,1994 John S. Dyson * * 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: @(#)vnode_pager.c 7.5 (Berkeley) 4/20/91 * $Id: vnode_pager.c,v 1.21 1995/01/24 10:14:09 davidg Exp $ */ /* * Page to/from files (vnodes). * * TODO: * pageouts * fix credential use (uses current process credentials now) */ /* * MODIFICATIONS: * John S. Dyson 08 Dec 93 * * This file in conjunction with some vm_fault mods, eliminate the performance * advantage for using the buffer cache and minimize memory copies. * * 1) Supports multiple - block reads * 2) Bypasses buffer cache for reads * * TODO: * * 1) Totally bypass buffer cache for reads * (Currently will still sometimes use buffer cache for reads) * 2) Bypass buffer cache for writes * (Code does not support it, but mods are simple) */ #include #include #include #include #include #include #include #include #include #include #include #include #include int vnode_pager_putmulti(); void vnode_pager_init(); vm_pager_t vnode_pager_alloc(caddr_t, vm_offset_t, vm_prot_t, vm_offset_t); void vnode_pager_dealloc(); int vnode_pager_getpage(); int vnode_pager_getmulti(); int vnode_pager_putpage(); boolean_t vnode_pager_haspage(); struct pagerops vnodepagerops = { vnode_pager_init, vnode_pager_alloc, vnode_pager_dealloc, vnode_pager_getpage, vnode_pager_getmulti, vnode_pager_putpage, vnode_pager_putmulti, vnode_pager_haspage }; static int vnode_pager_input(vn_pager_t vnp, vm_page_t * m, int count, int reqpage); static int vnode_pager_output(vn_pager_t vnp, vm_page_t * m, int count, int *rtvals); extern vm_map_t pager_map; struct pagerlst vnode_pager_list; /* list of managed vnodes */ #define MAXBP (PAGE_SIZE/DEV_BSIZE); void vnode_pager_init() { TAILQ_INIT(&vnode_pager_list); } /* * Allocate (or lookup) pager for a vnode. * Handle is a vnode pointer. */ vm_pager_t vnode_pager_alloc(handle, size, prot, offset) caddr_t handle; vm_size_t size; vm_prot_t prot; vm_offset_t offset; { register vm_pager_t pager; register vn_pager_t vnp; vm_object_t object, tobject; struct vattr vattr; struct vnode *vp; struct proc *p = curproc; /* XXX */ int rtval; /* * Pageout to vnode, no can do yet. */ if (handle == NULL) return (NULL); /* * Vnodes keep a pointer to any associated pager so no need to lookup * with vm_pager_lookup. */ vp = (struct vnode *) handle; while ((object = (vm_object_t) vp->v_vmdata) && (object->flags & OBJ_DEAD)) tsleep((caddr_t) object, PVM, "vadead", 0); pager = NULL; if (object != NULL) pager = object->pager; if (pager == NULL) { /* * Allocate pager structures */ pager = (vm_pager_t) malloc(sizeof *pager, M_VMPAGER, M_WAITOK); if (pager == NULL) return (NULL); vnp = (vn_pager_t) malloc(sizeof *vnp, M_VMPGDATA, M_WAITOK); if (vnp == NULL) { free((caddr_t) pager, M_VMPAGER); return (NULL); } /* * And an object of the appropriate size */ if ((rtval = VOP_GETATTR(vp, &vattr, p->p_ucred, p)) == 0) { object = vm_object_allocate(round_page(vattr.va_size)); object->flags &= ~OBJ_INTERNAL; vm_object_enter(object, pager); vm_object_setpager(object, pager, 0, TRUE); } else { printf("Error in getattr: %d\n", rtval); free((caddr_t) vnp, M_VMPGDATA); free((caddr_t) pager, M_VMPAGER); return (NULL); } /* * Hold a reference to the vnode and initialize pager data. */ VREF(vp); vnp->vnp_flags = 0; vnp->vnp_vp = vp; vnp->vnp_size = vattr.va_size; TAILQ_INSERT_TAIL(&vnode_pager_list, pager, pg_list); pager->pg_handle = handle; pager->pg_type = PG_VNODE; pager->pg_ops = &vnodepagerops; pager->pg_data = (caddr_t) vnp; vp->v_vmdata = (caddr_t) object; } else { /* * vm_object_lookup() will remove the object from the cache if * found and also gain a reference to the object. */ (void) vm_object_lookup(pager); } return (pager); } void vnode_pager_dealloc(pager) vm_pager_t pager; { register vn_pager_t vnp = (vn_pager_t) pager->pg_data; register struct vnode *vp; vm_object_t object; vp = vnp->vnp_vp; if (vp) { int s = splbio(); object = (vm_object_t) vp->v_vmdata; if (object) { while (object->paging_in_progress) { tsleep(object, PVM, "vnpdea", 0); } } splx(s); vp->v_vmdata = NULL; vp->v_flag &= ~(VTEXT | VVMIO); vrele(vp); } TAILQ_REMOVE(&vnode_pager_list, pager, pg_list); free((caddr_t) vnp, M_VMPGDATA); free((caddr_t) pager, M_VMPAGER); } int vnode_pager_getmulti(pager, m, count, reqpage, sync) vm_pager_t pager; vm_page_t *m; int count; int reqpage; boolean_t sync; { return vnode_pager_input((vn_pager_t) pager->pg_data, m, count, reqpage); } int vnode_pager_getpage(pager, m, sync) vm_pager_t pager; vm_page_t m; boolean_t sync; { vm_page_t marray[1]; if (pager == NULL) return FALSE; marray[0] = m; return vnode_pager_input((vn_pager_t) pager->pg_data, marray, 1, 0); } boolean_t vnode_pager_putpage(pager, m, sync) vm_pager_t pager; vm_page_t m; boolean_t sync; { vm_page_t marray[1]; int rtvals[1]; if (pager == NULL) return FALSE; marray[0] = m; vnode_pager_output((vn_pager_t) pager->pg_data, marray, 1, rtvals); return rtvals[0]; } int vnode_pager_putmulti(pager, m, c, sync, rtvals) vm_pager_t pager; vm_page_t *m; int c; boolean_t sync; int *rtvals; { return vnode_pager_output((vn_pager_t) pager->pg_data, m, c, rtvals); } boolean_t vnode_pager_haspage(pager, offset) vm_pager_t pager; vm_offset_t offset; { register vn_pager_t vnp = (vn_pager_t) pager->pg_data; register struct vnode *vp = vnp->vnp_vp; daddr_t bn; int err; daddr_t block; /* * If filesystem no longer mounted or offset beyond end of file we do * not have the page. */ if ((vp->v_mount == NULL) || (offset >= vnp->vnp_size)) return FALSE; block = offset / vp->v_mount->mnt_stat.f_iosize; if (incore(vp, block)) return TRUE; /* * Read the index to find the disk block to read from. If there is no * block, report that we don't have this data. * * Assumes that the vnode has whole page or nothing. */ err = VOP_BMAP(vp, block, (struct vnode **) 0, &bn, 0); if (err) return (TRUE); return ((long) bn < 0 ? FALSE : TRUE); } /* * Lets the VM system know about a change in size for a file. * If this vnode is mapped into some address space (i.e. we have a pager * for it) we adjust our own internal size and flush any cached pages in * the associated object that are affected by the size change. * * Note: this routine may be invoked as a result of a pager put * operation (possibly at object termination time), so we must be careful. */ void vnode_pager_setsize(vp, nsize) struct vnode *vp; u_long nsize; { register vn_pager_t vnp; register vm_object_t object; vm_pager_t pager; /* * Not a mapped vnode */ if (vp == NULL || vp->v_type != VREG || vp->v_vmdata == NULL) return; /* * Hasn't changed size */ object = (vm_object_t) vp->v_vmdata; if (object == NULL) return; if ((pager = object->pager) == NULL) return; vnp = (vn_pager_t) pager->pg_data; if (nsize == vnp->vnp_size) return; /* * No object. This can happen during object termination since * vm_object_page_clean is called after the object has been removed * from the hash table, and clean may cause vnode write operations * which can wind up back here. */ object = vm_object_lookup(pager); if (object == NULL) return; /* * File has shrunk. Toss any cached pages beyond the new EOF. */ if (nsize < vnp->vnp_size) { if (round_page((vm_offset_t) nsize) < vnp->vnp_size) { vm_object_lock(object); vm_object_page_remove(object, round_page((vm_offset_t) nsize), vnp->vnp_size); vm_object_unlock(object); } /* * this gets rid of garbage at the end of a page that is now * only partially backed by the vnode... */ if (nsize & PAGE_MASK) { vm_offset_t kva; vm_page_t m; m = vm_page_lookup(object, trunc_page((vm_offset_t) nsize)); if (m) { kva = vm_pager_map_page(m); bzero((caddr_t) kva + (nsize & PAGE_MASK), round_page(nsize) - nsize); vm_pager_unmap_page(kva); } } } vnp->vnp_size = (vm_offset_t) nsize; object->size = round_page(nsize); vm_object_deallocate(object); } void vnode_pager_umount(mp) register struct mount *mp; { register vm_pager_t pager, npager; struct vnode *vp; pager = vnode_pager_list.tqh_first; while (pager) { /* * Save the next pointer now since uncaching may terminate the * object and render pager invalid */ vp = ((vn_pager_t) pager->pg_data)->vnp_vp; npager = pager->pg_list.tqe_next; if (mp == (struct mount *) 0 || vp->v_mount == mp) (void) vnode_pager_uncache(vp); pager = npager; } } /* * Remove vnode associated object from the object cache. * * Note: this routine may be invoked as a result of a pager put * operation (possibly at object termination time), so we must be careful. */ boolean_t vnode_pager_uncache(vp) register struct vnode *vp; { register vm_object_t object; boolean_t uncached, locked; vm_pager_t pager; /* * Not a mapped vnode */ object = (vm_object_t) vp->v_vmdata; if (object == NULL) return (TRUE); pager = object->pager; if (pager == NULL) return (TRUE); /* * Unlock the vnode if it is currently locked. We do this since * uncaching the object may result in its destruction which may * initiate paging activity which may necessitate locking the vnode. */ locked = VOP_ISLOCKED(vp); if (locked) VOP_UNLOCK(vp); /* * Must use vm_object_lookup() as it actually removes the object from * the cache list. */ object = vm_object_lookup(pager); if (object) { uncached = (object->ref_count <= 1); pager_cache(object, FALSE); } else uncached = TRUE; if (locked) VOP_LOCK(vp); return (uncached); } void vnode_pager_freepage(m) vm_page_t m; { PAGE_WAKEUP(m); vm_page_free(m); } /* * calculate the linear (byte) disk address of specified virtual * file address */ vm_offset_t vnode_pager_addr(vp, address, run) struct vnode *vp; vm_offset_t address; int *run; { int rtaddress; int bsize; vm_offset_t block; struct vnode *rtvp; int err; int vblock, voffset; if ((int) address < 0) return -1; bsize = vp->v_mount->mnt_stat.f_iosize; vblock = address / bsize; voffset = address % bsize; err = VOP_BMAP(vp, vblock, &rtvp, &block, run); if (err || (block == -1)) rtaddress = -1; else { rtaddress = block * DEV_BSIZE + voffset; if( run) { *run += 1; *run *= bsize/PAGE_SIZE; *run -= voffset/PAGE_SIZE; } } return rtaddress; } /* * interrupt routine for I/O completion */ void vnode_pager_iodone(bp) struct buf *bp; { bp->b_flags |= B_DONE; wakeup((caddr_t) bp); if (bp->b_flags & B_ASYNC) { vm_offset_t paddr; vm_page_t m; vm_object_t obj = 0; int i; int npages; paddr = (vm_offset_t) bp->b_data; if (bp->b_bufsize != bp->b_bcount) bzero(bp->b_data + bp->b_bcount, bp->b_bufsize - bp->b_bcount); npages = (bp->b_bufsize + PAGE_SIZE - 1) / PAGE_SIZE; for (i = 0; i < npages; i++) { m = PHYS_TO_VM_PAGE(pmap_kextract(paddr + i * PAGE_SIZE)); obj = m->object; if (m) { m->dirty = 0; m->valid = VM_PAGE_BITS_ALL; if (m->flags & PG_WANTED) m->flags |= PG_REFERENCED; PAGE_WAKEUP(m); } else { panic("vnode_pager_iodone: page is gone!!!"); } } pmap_qremove(paddr, npages); if (obj) { --obj->paging_in_progress; if (obj->paging_in_progress == 0) wakeup((caddr_t) obj); } else { panic("vnode_pager_iodone: object is gone???"); } relpbuf(bp); } } /* * small block file system vnode pager input */ int vnode_pager_input_smlfs(vnp, m) vn_pager_t vnp; vm_page_t m; { int i; int s; struct vnode *dp, *vp; struct buf *bp; vm_offset_t kva; int fileaddr; int block; vm_offset_t bsize; int error = 0; vp = vnp->vnp_vp; bsize = vp->v_mount->mnt_stat.f_iosize; VOP_BMAP(vp, 0, &dp, 0, 0); kva = vm_pager_map_page(m); for (i = 0; i < PAGE_SIZE / bsize; i++) { if ((vm_page_bits(m->offset + i * bsize, bsize) & m->valid)) continue; fileaddr = vnode_pager_addr(vp, m->offset + i * bsize, (int *)0); if (fileaddr != -1) { bp = getpbuf(); /* build a minimal buffer header */ bp->b_flags = B_BUSY | B_READ | B_CALL; bp->b_iodone = vnode_pager_iodone; bp->b_proc = curproc; bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred; if (bp->b_rcred != NOCRED) crhold(bp->b_rcred); if (bp->b_wcred != NOCRED) crhold(bp->b_wcred); bp->b_un.b_addr = (caddr_t) kva + i * bsize; bp->b_blkno = fileaddr / DEV_BSIZE; pbgetvp(dp, bp); bp->b_bcount = bsize; bp->b_bufsize = bsize; /* do the input */ VOP_STRATEGY(bp); /* we definitely need to be at splbio here */ s = splbio(); while ((bp->b_flags & B_DONE) == 0) { tsleep((caddr_t) bp, PVM, "vnsrd", 0); } splx(s); if ((bp->b_flags & B_ERROR) != 0) error = EIO; /* * free the buffer header back to the swap buffer pool */ relpbuf(bp); HOLDRELE(vp); if (error) break; vm_page_set_clean(m, i * bsize, bsize); vm_page_set_valid(m, i * bsize, bsize); } else { vm_page_set_clean(m, i * bsize, bsize); bzero((caddr_t) kva + i * bsize, bsize); } nextblock: } vm_pager_unmap_page(kva); pmap_clear_modify(VM_PAGE_TO_PHYS(m)); if (error) { return VM_PAGER_ERROR; } return VM_PAGER_OK; } /* * old style vnode pager output routine */ int vnode_pager_input_old(vnp, m) vn_pager_t vnp; vm_page_t m; { struct uio auio; struct iovec aiov; int error; int size; vm_offset_t kva; error = 0; /* * Return failure if beyond current EOF */ if (m->offset >= vnp->vnp_size) { return VM_PAGER_BAD; } else { size = PAGE_SIZE; if (m->offset + size > vnp->vnp_size) size = vnp->vnp_size - m->offset; /* * Allocate a kernel virtual address and initialize so that * we can use VOP_READ/WRITE routines. */ kva = vm_pager_map_page(m); aiov.iov_base = (caddr_t) kva; aiov.iov_len = size; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = m->offset; auio.uio_segflg = UIO_SYSSPACE; auio.uio_rw = UIO_READ; auio.uio_resid = size; auio.uio_procp = (struct proc *) 0; error = VOP_READ(vnp->vnp_vp, &auio, 0, curproc->p_ucred); if (!error) { register int count = size - auio.uio_resid; if (count == 0) error = EINVAL; else if (count != PAGE_SIZE) bzero((caddr_t) kva + count, PAGE_SIZE - count); } vm_pager_unmap_page(kva); } pmap_clear_modify(VM_PAGE_TO_PHYS(m)); m->dirty = 0; return error ? VM_PAGER_ERROR : VM_PAGER_OK; } /* * generic vnode pager input routine */ int vnode_pager_input(vnp, m, count, reqpage) register vn_pager_t vnp; vm_page_t *m; int count, reqpage; { int i; vm_offset_t kva, foff; int size, sizea; vm_object_t object; struct vnode *dp, *vp; int bsize; int first, last; int firstaddr; int block, offset; int runpg; int runend; struct buf *bp, *bpa; int counta; int s; int failflag; int error = 0; object = m[reqpage]->object; /* all vm_page_t items are in same * object */ vp = vnp->vnp_vp; bsize = vp->v_mount->mnt_stat.f_iosize; /* get the UNDERLYING device for the file with VOP_BMAP() */ /* * originally, we did not check for an error return value -- assuming * an fs always has a bmap entry point -- that assumption is wrong!!! */ foff = m[reqpage]->offset; /* * if we can't bmap, use old VOP code */ if (VOP_BMAP(vp, 0, &dp, 0, 0)) { for (i = 0; i < count; i++) { if (i != reqpage) { vnode_pager_freepage(m[i]); } } cnt.v_vnodein++; cnt.v_vnodepgsin++; return vnode_pager_input_old(vnp, m[reqpage]); /* * if the blocksize is smaller than a page size, then use * special small filesystem code. NFS sometimes has a small * blocksize, but it can handle large reads itself. */ } else if ((PAGE_SIZE / bsize) > 1 && (vp->v_mount->mnt_stat.f_type != MOUNT_NFS)) { for (i = 0; i < count; i++) { if (i != reqpage) { vnode_pager_freepage(m[i]); } } cnt.v_vnodein++; cnt.v_vnodepgsin++; return vnode_pager_input_smlfs(vnp, m[reqpage]); } /* * if ANY DEV_BSIZE blocks are valid on a large filesystem block * then, the entire page is valid -- */ if (m[reqpage]->valid) { m[reqpage]->valid = VM_PAGE_BITS_ALL; for (i = 0; i < count; i++) { if (i != reqpage) vnode_pager_freepage(m[i]); } return VM_PAGER_OK; } /* * here on direct device I/O */ firstaddr = -1; /* * calculate the run that includes the required page */ for(first = 0, i = 0; i < count; i = runend) { firstaddr = vnode_pager_addr(vp, m[i]->offset, &runpg); if (firstaddr == -1) { if( i == reqpage && foff < vnp->vnp_size) { printf("vnode_pager_input: unexpected missing page: firstaddr: %d, foff: %d, vnp_size: %d\n", firstaddr, foff, vnp->vnp_size); panic("vnode_pager_input:..."); } vnode_pager_freepage(m[i]); runend = i + 1; first = runend; continue; } runend = i + runpg; if( runend <= reqpage) { int j; for(j = i; j < runend; j++) { vnode_pager_freepage(m[j]); } } else { if( runpg < (count - first)) { for(i=first + runpg; i < count; i++) vnode_pager_freepage(m[i]); count = first + runpg; } break; } first = runend; } /* * the first and last page have been calculated now, move input pages * to be zero based... */ if (first != 0) { for (i = first; i < count; i++) { m[i - first] = m[i]; } count -= first; reqpage -= first; } /* * calculate the file virtual address for the transfer */ foff = m[0]->offset; #if 0 printf("foff: 0x%lx, firstaddr: 0x%lx\n", foff, firstaddr); DELAY(6000000); #endif /* * calculate the size of the transfer */ size = count * PAGE_SIZE; if ((foff + size) > vnp->vnp_size) size = vnp->vnp_size - foff; /* * round up physical size for real devices */ if (dp->v_type == VBLK || dp->v_type == VCHR) size = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1); counta = 0; if (count * PAGE_SIZE > bsize) counta = (count - reqpage) - 1; bpa = 0; sizea = 0; bp = getpbuf(); if (counta) { bpa = (struct buf *) trypbuf(); if (bpa) { count -= counta; sizea = size - count * PAGE_SIZE; size = count * PAGE_SIZE; } } kva = (vm_offset_t) bp->b_data; /* * and map the pages to be read into the kva */ pmap_qenter(kva, m, count); /* build a minimal buffer header */ bp->b_flags = B_BUSY | B_READ | B_CALL; bp->b_iodone = vnode_pager_iodone; /* B_PHYS is not set, but it is nice to fill this in */ bp->b_proc = curproc; bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred; if (bp->b_rcred != NOCRED) crhold(bp->b_rcred); if (bp->b_wcred != NOCRED) crhold(bp->b_wcred); bp->b_blkno = firstaddr / DEV_BSIZE; pbgetvp(dp, bp); bp->b_bcount = size; bp->b_bufsize = size; cnt.v_vnodein++; cnt.v_vnodepgsin += count; /* do the input */ VOP_STRATEGY(bp); if (counta) { for (i = 0; i < counta; i++) { vm_page_deactivate(m[count + i]); } pmap_qenter((vm_offset_t) bpa->b_data, &m[count], counta); ++m[count]->object->paging_in_progress; bpa->b_flags = B_BUSY | B_READ | B_CALL | B_ASYNC; bpa->b_iodone = vnode_pager_iodone; /* B_PHYS is not set, but it is nice to fill this in */ bpa->b_proc = curproc; bpa->b_rcred = bpa->b_wcred = bpa->b_proc->p_ucred; if (bpa->b_rcred != NOCRED) crhold(bpa->b_rcred); if (bpa->b_wcred != NOCRED) crhold(bpa->b_wcred); bpa->b_blkno = (firstaddr + count * PAGE_SIZE) / DEV_BSIZE; pbgetvp(dp, bpa); bpa->b_bcount = sizea; bpa->b_bufsize = counta * PAGE_SIZE; cnt.v_vnodepgsin += counta; VOP_STRATEGY(bpa); } s = splbio(); /* we definitely need to be at splbio here */ while ((bp->b_flags & B_DONE) == 0) { tsleep((caddr_t) bp, PVM, "vnread", 0); } splx(s); if ((bp->b_flags & B_ERROR) != 0) error = EIO; if (!error) { if (size != count * PAGE_SIZE) bzero((caddr_t) kva + size, PAGE_SIZE * count - size); } pmap_qremove(kva, count); /* * free the buffer header back to the swap buffer pool */ relpbuf(bp); HOLDRELE(vp); finishup: for (i = 0; i < count; i++) { pmap_clear_modify(VM_PAGE_TO_PHYS(m[i])); m[i]->dirty = 0; m[i]->valid = VM_PAGE_BITS_ALL; if (i != reqpage) { /* * whether or not to leave the page activated is up in * the air, but we should put the page on a page queue * somewhere. (it already is in the object). Result: * It appears that emperical results show that * deactivating pages is best. */ /* * just in case someone was asking for this page we * now tell them that it is ok to use */ if (!error) { vm_page_deactivate(m[i]); PAGE_WAKEUP(m[i]); } else { vnode_pager_freepage(m[i]); } } } if (error) { printf("vnode_pager_input: I/O read error\n"); } return (error ? VM_PAGER_ERROR : VM_PAGER_OK); } /* * old-style vnode pager output routine */ int vnode_pager_output_old(vnp, m) register vn_pager_t vnp; vm_page_t m; { vm_offset_t kva, kva2; vm_offset_t size; struct iovec aiov; struct uio auio; struct vnode *vp; int error; vp = vnp->vnp_vp; /* * Dont return failure if beyond current EOF placate the VM system. */ if (m->offset >= vnp->vnp_size) { return VM_PAGER_OK; } else { size = PAGE_SIZE; if (m->offset + size > vnp->vnp_size) size = vnp->vnp_size - m->offset; kva2 = kmem_alloc(pager_map, PAGE_SIZE); /* * Allocate a kernel virtual address and initialize so that * we can use VOP_WRITE routines. */ kva = vm_pager_map_page(m); bcopy((caddr_t) kva, (caddr_t) kva2, size); vm_pager_unmap_page(kva); pmap_clear_modify(VM_PAGE_TO_PHYS(m)); PAGE_WAKEUP(m); aiov.iov_base = (caddr_t) kva2; aiov.iov_len = size; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = m->offset; auio.uio_segflg = UIO_SYSSPACE; auio.uio_rw = UIO_WRITE; auio.uio_resid = size; auio.uio_procp = (struct proc *) 0; error = VOP_WRITE(vp, &auio, 0, curproc->p_ucred); kmem_free_wakeup(pager_map, kva2, PAGE_SIZE); if (!error) { if ((size - auio.uio_resid) == 0) { error = EINVAL; } } return error ? VM_PAGER_ERROR : VM_PAGER_OK; } } /* * vnode pager output on a small-block file system */ int vnode_pager_output_smlfs(vnp, m) vn_pager_t vnp; vm_page_t m; { int i; int s; struct vnode *dp, *vp; struct buf *bp; vm_offset_t kva; int fileaddr; vm_offset_t bsize; int error = 0; vp = vnp->vnp_vp; bsize = vp->v_mount->mnt_stat.f_iosize; VOP_BMAP(vp, 0, &dp, 0, 0); kva = vm_pager_map_page(m); for (i = 0; !error && i < (PAGE_SIZE / bsize); i++) { if ((vm_page_bits(m->offset + i * bsize, bsize) & m->valid & m->dirty) == 0) continue; /* * calculate logical block and offset */ fileaddr = vnode_pager_addr(vp, m->offset + i * bsize, (int *)0); if (fileaddr != -1) { bp = getpbuf(); /* build a minimal buffer header */ bp->b_flags = B_BUSY | B_CALL | B_WRITE; bp->b_iodone = vnode_pager_iodone; bp->b_proc = curproc; bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred; if (bp->b_rcred != NOCRED) crhold(bp->b_rcred); if (bp->b_wcred != NOCRED) crhold(bp->b_wcred); bp->b_un.b_addr = (caddr_t) kva + i * bsize; bp->b_blkno = fileaddr / DEV_BSIZE; pbgetvp(dp, bp); ++dp->v_numoutput; /* for NFS */ bp->b_dirtyoff = 0; bp->b_dirtyend = bsize; bp->b_bcount = bsize; bp->b_bufsize = bsize; /* do the input */ VOP_STRATEGY(bp); /* we definitely need to be at splbio here */ s = splbio(); while ((bp->b_flags & B_DONE) == 0) { tsleep((caddr_t) bp, PVM, "vnswrt", 0); } splx(s); if ((bp->b_flags & B_ERROR) != 0) error = EIO; vm_page_set_clean(m, i * bsize, bsize); /* * free the buffer header back to the swap buffer pool */ relpbuf(bp); HOLDRELE(vp); } } vm_pager_unmap_page(kva); if (error) return VM_PAGER_ERROR; else return VM_PAGER_OK; } /* * generic vnode pager output routine */ int vnode_pager_output(vnp, m, count, rtvals) vn_pager_t vnp; vm_page_t *m; int count; int *rtvals; { int i, j; vm_offset_t kva, foff; int size; vm_object_t object; struct vnode *dp, *vp; struct buf *bp; vm_offset_t reqaddr; int bsize; int s; daddr_t block; struct timeval tv; int runpg; int error = 0; retryoutput: object = m[0]->object; /* all vm_page_t items are in same object */ vp = vnp->vnp_vp; /* * Make sure underlying filesystem is still mounted. */ if (vp->v_mount == NULL) return VM_PAGER_FAIL; bsize = vp->v_mount->mnt_stat.f_iosize; for (i = 0; i < count; i++) rtvals[i] = VM_PAGER_AGAIN; if ((int) m[0]->offset < 0) { printf("vnode_pager_output: attempt to write meta-data!!! -- 0x%x\n", m[0]->offset); m[0]->dirty = 0; rtvals[0] = VM_PAGER_OK; return VM_PAGER_OK; } /* * if the filesystem does not have a bmap, then use the old code */ if (VOP_BMAP(vp, (m[0]->offset / bsize), &dp, &block, 0) || (block == -1)) { rtvals[0] = vnode_pager_output_old(vnp, m[0]); m[0]->dirty = 0; cnt.v_vnodeout++; cnt.v_vnodepgsout++; return rtvals[0]; } tv = time; VOP_UPDATE(vp, &tv, &tv, 0); /* * if the filesystem has a small blocksize, then use the small block * filesystem output code */ if ((bsize < PAGE_SIZE) && (vp->v_mount->mnt_stat.f_type != MOUNT_NFS)) { for (i = 0; i < count; i++) { rtvals[i] = vnode_pager_output_smlfs(vnp, m[i]); if (rtvals[i] == VM_PAGER_OK) { pmap_clear_modify(VM_PAGE_TO_PHYS(m[i])); } } cnt.v_vnodeout++; cnt.v_vnodepgsout += count; return rtvals[0]; } for (i = 0; i < count; i++) { foff = m[i]->offset; if (foff >= vnp->vnp_size) { for (j = i; j < count; j++) rtvals[j] = VM_PAGER_BAD; count = i; break; } } if (count == 0) { return rtvals[0]; } foff = m[0]->offset; reqaddr = vnode_pager_addr(vp, foff, &runpg); if( runpg < count) count = runpg; /* * calculate the size of the transfer */ size = count * PAGE_SIZE; if ((foff + size) > vnp->vnp_size) size = vnp->vnp_size - foff; /* * round up physical size for real devices */ if (dp->v_type == VBLK || dp->v_type == VCHR) size = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1); bp = getpbuf(); kva = (vm_offset_t) bp->b_data; /* * and map the pages to be read into the kva */ pmap_qenter(kva, m, count); /* build a minimal buffer header */ bp->b_flags = B_BUSY | B_WRITE | B_CALL; bp->b_iodone = vnode_pager_iodone; /* B_PHYS is not set, but it is nice to fill this in */ bp->b_proc = curproc; bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred; if (bp->b_rcred != NOCRED) crhold(bp->b_rcred); if (bp->b_wcred != NOCRED) crhold(bp->b_wcred); bp->b_blkno = reqaddr / DEV_BSIZE; pbgetvp(dp, bp); ++dp->v_numoutput; /* for NFS */ bp->b_dirtyoff = 0; bp->b_dirtyend = size; bp->b_bcount = size; bp->b_bufsize = size; cnt.v_vnodeout++; cnt.v_vnodepgsout += count; /* do the output */ VOP_STRATEGY(bp); s = splbio(); /* we definitely need to be at splbio here */ while ((bp->b_flags & B_DONE) == 0) { tsleep((caddr_t) bp, PVM, "vnwrite", 0); } splx(s); if ((bp->b_flags & B_ERROR) != 0) error = EIO; pmap_qremove(kva, count); /* * free the buffer header back to the swap buffer pool */ relpbuf(bp); HOLDRELE(vp); if (!error) { for (i = 0; i < count; i++) { pmap_clear_modify(VM_PAGE_TO_PHYS(m[i])); m[i]->dirty = 0; rtvals[i] = VM_PAGER_OK; } } else if (count != 1) { error = 0; count = 1; goto retryoutput; } if (error) { printf("vnode_pager_output: I/O write error\n"); } return (error ? VM_PAGER_ERROR : VM_PAGER_OK); }