/* $NetBSD: uvm_vnode.c,v 1.55 2001/11/10 07:37:01 lukem Exp $ */ /* * Copyright (c) 1997 Charles D. Cranor and Washington University. * Copyright (c) 1991, 1993 * The Regents of the University of California. * Copyright (c) 1990 University of Utah. * * 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 Charles D. Cranor, * Washington University, 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. * * @(#)vnode_pager.c 8.8 (Berkeley) 2/13/94 * from: Id: uvm_vnode.c,v 1.1.2.26 1998/02/02 20:38:07 chuck Exp */ /* * uvm_vnode.c: the vnode pager. */ #include __KERNEL_RCSID(0, "$NetBSD: uvm_vnode.c,v 1.55 2001/11/10 07:37:01 lukem Exp $"); #include "fs_nfs.h" #include "opt_uvmhist.h" #include "opt_ddb.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * functions */ void uvn_detach __P((struct uvm_object *)); int uvn_get __P((struct uvm_object *, voff_t, struct vm_page **, int *, int, vm_prot_t, int, int)); int uvn_put __P((struct uvm_object *, voff_t, voff_t, int)); void uvn_reference __P((struct uvm_object *)); int uvn_findpage __P((struct uvm_object *, voff_t, struct vm_page **, int)); /* * master pager structure */ struct uvm_pagerops uvm_vnodeops = { NULL, uvn_reference, uvn_detach, NULL, uvn_get, uvn_put, }; /* * the ops! */ /* * uvn_attach * * attach a vnode structure to a VM object. if the vnode is already * attached, then just bump the reference count by one and return the * VM object. if not already attached, attach and return the new VM obj. * the "accessprot" tells the max access the attaching thread wants to * our pages. * * => caller must _not_ already be holding the lock on the uvm_object. * => in fact, nothing should be locked so that we can sleep here. * => note that uvm_object is first thing in vnode structure, so their * pointers are equiv. */ struct uvm_object * uvn_attach(arg, accessprot) void *arg; vm_prot_t accessprot; { struct vnode *vp = arg; struct uvm_object *uobj = &vp->v_uobj; struct vattr vattr; int result; struct partinfo pi; voff_t used_vnode_size; UVMHIST_FUNC("uvn_attach"); UVMHIST_CALLED(maphist); UVMHIST_LOG(maphist, "(vn=0x%x)", arg,0,0,0); used_vnode_size = (voff_t)0; /* * first get a lock on the uobj. */ simple_lock(&uobj->vmobjlock); while (vp->v_flag & VXLOCK) { vp->v_flag |= VXWANT; UVMHIST_LOG(maphist, " SLEEPING on blocked vn",0,0,0,0); UVM_UNLOCK_AND_WAIT(uobj, &uobj->vmobjlock, FALSE, "uvn_attach", 0); simple_lock(&uobj->vmobjlock); UVMHIST_LOG(maphist," WOKE UP",0,0,0,0); } /* * if we're mapping a BLK device, make sure it is a disk. */ if (vp->v_type == VBLK && bdevsw[major(vp->v_rdev)].d_type != D_DISK) { simple_unlock(&uobj->vmobjlock); UVMHIST_LOG(maphist,"<- done (VBLK not D_DISK!)", 0,0,0,0); return(NULL); } KASSERT(vp->v_type == VREG || vp->v_type == VBLK); /* * set up our idea of the size * if this hasn't been done already. */ if (vp->v_size == VSIZENOTSET) { vp->v_flag |= VXLOCK; simple_unlock(&uobj->vmobjlock); /* drop lock in case we sleep */ /* XXX: curproc? */ if (vp->v_type == VBLK) { /* * We could implement this as a specfs getattr call, but: * * (1) VOP_GETATTR() would get the file system * vnode operation, not the specfs operation. * * (2) All we want is the size, anyhow. */ result = (*bdevsw[major(vp->v_rdev)].d_ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&pi, FREAD, curproc); if (result == 0) { /* XXX should remember blocksize */ used_vnode_size = (voff_t)pi.disklab->d_secsize * (voff_t)pi.part->p_size; } } else { result = VOP_GETATTR(vp, &vattr, curproc->p_ucred, curproc); if (result == 0) used_vnode_size = vattr.va_size; } /* relock object */ simple_lock(&uobj->vmobjlock); if (vp->v_flag & VXWANT) { wakeup(vp); } vp->v_flag &= ~(VXLOCK|VXWANT); if (result != 0) { simple_unlock(&uobj->vmobjlock); UVMHIST_LOG(maphist,"<- done (VOP_GETATTR FAILED!)", 0,0,0,0); return(NULL); } vp->v_size = used_vnode_size; } simple_unlock(&uobj->vmobjlock); UVMHIST_LOG(maphist,"<- done, refcnt=%d", vp->v_usecount, 0, 0, 0); return uobj; } /* * uvn_reference * * duplicate a reference to a VM object. Note that the reference * count must already be at least one (the passed in reference) so * there is no chance of the uvn being killed or locked out here. * * => caller must call with object unlocked. * => caller must be using the same accessprot as was used at attach time */ void uvn_reference(uobj) struct uvm_object *uobj; { VREF((struct vnode *)uobj); } /* * uvn_detach * * remove a reference to a VM object. * * => caller must call with object unlocked and map locked. */ void uvn_detach(uobj) struct uvm_object *uobj; { vrele((struct vnode *)uobj); } /* * uvn_put: flush page data to backing store. * * => object must be locked on entry! VOP_PUTPAGES must unlock it. * => flags: PGO_SYNCIO -- use sync. I/O * => note: caller must set PG_CLEAN and pmap_clear_modify (if needed) */ int uvn_put(uobj, offlo, offhi, flags) struct uvm_object *uobj; voff_t offlo; voff_t offhi; int flags; { struct vnode *vp = (struct vnode *)uobj; int error; LOCK_ASSERT(simple_lock_held(&vp->v_interlock)); error = VOP_PUTPAGES(vp, offlo, offhi, flags); LOCK_ASSERT(!simple_lock_held(&vp->v_interlock)); return error; } /* * uvn_get: get pages (synchronously) from backing store * * => prefer map unlocked (not required) * => object must be locked! we will _unlock_ it before starting any I/O. * => flags: PGO_ALLPAGES: get all of the pages * PGO_LOCKED: fault data structures are locked * => NOTE: offset is the offset of pps[0], _NOT_ pps[centeridx] * => NOTE: caller must check for released pages!! */ int uvn_get(uobj, offset, pps, npagesp, centeridx, access_type, advice, flags) struct uvm_object *uobj; voff_t offset; struct vm_page **pps; /* IN/OUT */ int *npagesp; /* IN (OUT if PGO_LOCKED) */ int centeridx; vm_prot_t access_type; int advice, flags; { struct vnode *vp = (struct vnode *)uobj; int error; UVMHIST_FUNC("uvn_get"); UVMHIST_CALLED(ubchist); UVMHIST_LOG(ubchist, "vp %p off 0x%x", vp, (int)offset, 0,0); error = VOP_GETPAGES(vp, offset, pps, npagesp, centeridx, access_type, advice, flags); return error; } /* * uvn_findpages: * return the page for the uobj and offset requested, allocating if needed. * => uobj must be locked. * => returned pages will be BUSY. */ void uvn_findpages(uobj, offset, npagesp, pgs, flags) struct uvm_object *uobj; voff_t offset; int *npagesp; struct vm_page **pgs; int flags; { int i, count, npages, rv; count = 0; npages = *npagesp; if (flags & UFP_BACKWARD) { for (i = npages - 1; i >= 0; i--, offset -= PAGE_SIZE) { rv = uvn_findpage(uobj, offset, &pgs[i], flags); if (flags & UFP_DIRTYONLY && rv == 0) { break; } count++; } } else { for (i = 0; i < npages; i++, offset += PAGE_SIZE) { rv = uvn_findpage(uobj, offset, &pgs[i], flags); if (flags & UFP_DIRTYONLY && rv == 0) { break; } count++; } } *npagesp = count; } int uvn_findpage(uobj, offset, pgp, flags) struct uvm_object *uobj; voff_t offset; struct vm_page **pgp; int flags; { struct vm_page *pg; boolean_t dirty; UVMHIST_FUNC("uvn_findpage"); UVMHIST_CALLED(ubchist); UVMHIST_LOG(ubchist, "vp %p off 0x%lx", uobj, offset,0,0); if (*pgp != NULL) { UVMHIST_LOG(ubchist, "dontcare", 0,0,0,0); return 0; } for (;;) { /* look for an existing page */ pg = uvm_pagelookup(uobj, offset); /* nope? allocate one now */ if (pg == NULL) { if (flags & UFP_NOALLOC) { UVMHIST_LOG(ubchist, "noalloc", 0,0,0,0); return 0; } pg = uvm_pagealloc(uobj, offset, NULL, 0); if (pg == NULL) { if (flags & UFP_NOWAIT) { UVMHIST_LOG(ubchist, "nowait",0,0,0,0); return 0; } simple_unlock(&uobj->vmobjlock); uvm_wait("uvn_fp1"); simple_lock(&uobj->vmobjlock); continue; } if (UVM_OBJ_IS_VTEXT(uobj)) { uvmexp.vtextpages++; } else { uvmexp.vnodepages++; } UVMHIST_LOG(ubchist, "alloced %p", pg,0,0,0); break; } else if (flags & UFP_NOCACHE) { UVMHIST_LOG(ubchist, "nocache",0,0,0,0); return 0; } /* page is there, see if we need to wait on it */ if ((pg->flags & PG_BUSY) != 0) { if (flags & UFP_NOWAIT) { UVMHIST_LOG(ubchist, "nowait",0,0,0,0); return 0; } pg->flags |= PG_WANTED; UVM_UNLOCK_AND_WAIT(pg, &uobj->vmobjlock, 0, "uvn_fp2", 0); simple_lock(&uobj->vmobjlock); continue; } /* skip PG_RDONLY pages if requested */ if ((flags & UFP_NORDONLY) && (pg->flags & PG_RDONLY)) { UVMHIST_LOG(ubchist, "nordonly",0,0,0,0); return 0; } /* stop on clean pages if requested */ if (flags & UFP_DIRTYONLY) { dirty = pmap_clear_modify(pg) || (pg->flags & PG_CLEAN) == 0; pg->flags |= PG_CLEAN; if (!dirty) { return 0; } } /* mark the page BUSY and we're done. */ pg->flags |= PG_BUSY; UVM_PAGE_OWN(pg, "uvn_findpage"); UVMHIST_LOG(ubchist, "found %p", pg,0,0,0); break; } *pgp = pg; return 1; } /* * uvm_vnp_setsize: grow or shrink a vnode uobj * * grow => just update size value * shrink => toss un-needed pages * * => we assume that the caller has a reference of some sort to the * vnode in question so that it will not be yanked out from under * us. */ void uvm_vnp_setsize(vp, newsize) struct vnode *vp; voff_t newsize; { struct uvm_object *uobj = &vp->v_uobj; voff_t pgend = round_page(newsize); UVMHIST_FUNC("uvm_vnp_setsize"); UVMHIST_CALLED(ubchist); simple_lock(&uobj->vmobjlock); UVMHIST_LOG(ubchist, "vp %p old 0x%x new 0x%x", vp, vp->v_size, newsize, 0); /* * now check if the size has changed: if we shrink we had better * toss some pages... */ if (vp->v_size > pgend && vp->v_size != VSIZENOTSET) { (void) uvn_put(uobj, pgend, 0, PGO_FREE); } else { simple_unlock(&uobj->vmobjlock); } vp->v_size = newsize; } /* * uvm_vnp_zerorange: set a range of bytes in a file to zero. */ void uvm_vnp_zerorange(vp, off, len) struct vnode *vp; off_t off; size_t len; { void *win; /* * XXXUBC invent kzero() and use it */ while (len) { vsize_t bytelen = len; win = ubc_alloc(&vp->v_uobj, off, &bytelen, UBC_WRITE); memset(win, 0, bytelen); ubc_release(win, 0); off += bytelen; len -= bytelen; } }