/* $NetBSD: genfs_vnops.c,v 1.41 2001/11/30 15:18:39 christos Exp $ */ /* * Copyright (c) 1982, 1986, 1989, 1993 * 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. * */ #include __KERNEL_RCSID(0, "$NetBSD: genfs_vnops.c,v 1.41 2001/11/30 15:18:39 christos Exp $"); #include "opt_nfsserver.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef NFSSERVER #include #include #include #include #include #endif #define MAX_READ_AHEAD 16 /* XXXUBC 16 */ int genfs_poll(v) void *v; { struct vop_poll_args /* { struct vnode *a_vp; int a_events; struct proc *a_p; } */ *ap = v; return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); } int genfs_fsync(v) void *v; { struct vop_fsync_args /* { struct vnode *a_vp; struct ucred *a_cred; int a_flags; off_t offlo; off_t offhi; struct proc *a_p; } */ *ap = v; struct vnode *vp = ap->a_vp; int wait; wait = (ap->a_flags & FSYNC_WAIT) != 0; vflushbuf(vp, wait); if ((ap->a_flags & FSYNC_DATAONLY) != 0) return (0); else return (VOP_UPDATE(vp, NULL, NULL, wait ? UPDATE_WAIT : 0)); } int genfs_seek(v) void *v; { struct vop_seek_args /* { struct vnode *a_vp; off_t a_oldoff; off_t a_newoff; struct ucred *a_ucred; } */ *ap = v; if (ap->a_newoff < 0) return (EINVAL); return (0); } int genfs_abortop(v) void *v; { struct vop_abortop_args /* { struct vnode *a_dvp; struct componentname *a_cnp; } */ *ap = v; if ((ap->a_cnp->cn_flags & (HASBUF | SAVESTART)) == HASBUF) PNBUF_PUT(ap->a_cnp->cn_pnbuf); return (0); } int genfs_fcntl(v) void *v; { struct vop_fcntl_args /* { struct vnode *a_vp; u_int a_command; caddr_t a_data; int a_fflag; struct ucred *a_cred; struct proc *a_p; } */ *ap = v; if (ap->a_command == F_SETFL) return (0); else return (EOPNOTSUPP); } /*ARGSUSED*/ int genfs_badop(v) void *v; { panic("genfs: bad op"); } /*ARGSUSED*/ int genfs_nullop(v) void *v; { return (0); } /*ARGSUSED*/ int genfs_einval(v) void *v; { return (EINVAL); } /*ARGSUSED*/ int genfs_eopnotsupp(v) void *v; { return (EOPNOTSUPP); } /* * Called when an fs doesn't support a particular vop but the vop needs to * vrele, vput, or vunlock passed in vnodes. */ int genfs_eopnotsupp_rele(v) void *v; { struct vop_generic_args /* struct vnodeop_desc *a_desc; / * other random data follows, presumably * / } */ *ap = v; struct vnodeop_desc *desc = ap->a_desc; struct vnode *vp; int flags, i, j, offset; flags = desc->vdesc_flags; for (i = 0; i < VDESC_MAX_VPS; flags >>=1, i++) { if ((offset = desc->vdesc_vp_offsets[i]) == VDESC_NO_OFFSET) break; /* stop at end of list */ if ((j = flags & VDESC_VP0_WILLPUT)) { vp = *VOPARG_OFFSETTO(struct vnode**,offset,ap); switch (j) { case VDESC_VP0_WILLPUT: vput(vp); break; case VDESC_VP0_WILLUNLOCK: VOP_UNLOCK(vp, 0); break; case VDESC_VP0_WILLRELE: vrele(vp); break; } } } return (EOPNOTSUPP); } /*ARGSUSED*/ int genfs_ebadf(v) void *v; { return (EBADF); } /* ARGSUSED */ int genfs_enoioctl(v) void *v; { return (ENOTTY); } /* * Eliminate all activity associated with the requested vnode * and with all vnodes aliased to the requested vnode. */ int genfs_revoke(v) void *v; { struct vop_revoke_args /* { struct vnode *a_vp; int a_flags; } */ *ap = v; struct vnode *vp, *vq; struct proc *p = curproc; /* XXX */ #ifdef DIAGNOSTIC if ((ap->a_flags & REVOKEALL) == 0) panic("genfs_revoke: not revokeall"); #endif vp = ap->a_vp; simple_lock(&vp->v_interlock); if (vp->v_flag & VALIASED) { /* * If a vgone (or vclean) is already in progress, * wait until it is done and return. */ if (vp->v_flag & VXLOCK) { vp->v_flag |= VXWANT; simple_unlock(&vp->v_interlock); tsleep((caddr_t)vp, PINOD, "vop_revokeall", 0); return (0); } /* * Ensure that vp will not be vgone'd while we * are eliminating its aliases. */ vp->v_flag |= VXLOCK; simple_unlock(&vp->v_interlock); while (vp->v_flag & VALIASED) { simple_lock(&spechash_slock); for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) { if (vq->v_rdev != vp->v_rdev || vq->v_type != vp->v_type || vp == vq) continue; simple_unlock(&spechash_slock); vgone(vq); break; } if (vq == NULLVP) simple_unlock(&spechash_slock); } /* * Remove the lock so that vgone below will * really eliminate the vnode after which time * vgone will awaken any sleepers. */ simple_lock(&vp->v_interlock); vp->v_flag &= ~VXLOCK; } vgonel(vp, p); return (0); } /* * Lock the node. */ int genfs_lock(v) void *v; { struct vop_lock_args /* { struct vnode *a_vp; int a_flags; } */ *ap = v; struct vnode *vp = ap->a_vp; return (lockmgr(&vp->v_lock, ap->a_flags, &vp->v_interlock)); } /* * Unlock the node. */ int genfs_unlock(v) void *v; { struct vop_unlock_args /* { struct vnode *a_vp; int a_flags; } */ *ap = v; struct vnode *vp = ap->a_vp; return (lockmgr(&vp->v_lock, ap->a_flags | LK_RELEASE, &vp->v_interlock)); } /* * Return whether or not the node is locked. */ int genfs_islocked(v) void *v; { struct vop_islocked_args /* { struct vnode *a_vp; } */ *ap = v; struct vnode *vp = ap->a_vp; return (lockstatus(&vp->v_lock)); } /* * Stubs to use when there is no locking to be done on the underlying object. */ int genfs_nolock(v) void *v; { struct vop_lock_args /* { struct vnode *a_vp; int a_flags; struct proc *a_p; } */ *ap = v; /* * Since we are not using the lock manager, we must clear * the interlock here. */ if (ap->a_flags & LK_INTERLOCK) simple_unlock(&ap->a_vp->v_interlock); return (0); } int genfs_nounlock(v) void *v; { return (0); } int genfs_noislocked(v) void *v; { return (0); } /* * Local lease check for NFS servers. Just set up args and let * nqsrv_getlease() do the rest. If NFSSERVER is not in the kernel, * this is a null operation. */ int genfs_lease_check(v) void *v; { #ifdef NFSSERVER struct vop_lease_args /* { struct vnode *a_vp; struct proc *a_p; struct ucred *a_cred; int a_flag; } */ *ap = v; u_int32_t duration = 0; int cache; u_quad_t frev; (void) nqsrv_getlease(ap->a_vp, &duration, ND_CHECK | ap->a_flag, NQLOCALSLP, ap->a_p, (struct mbuf *)0, &cache, &frev, ap->a_cred); return (0); #else return (0); #endif /* NFSSERVER */ } int genfs_mmap(v) void *v; { return 0; } /* * generic VM getpages routine. * Return PG_BUSY pages for the given range, * reading from backing store if necessary. */ int genfs_getpages(v) void *v; { struct vop_getpages_args /* { struct vnode *a_vp; voff_t a_offset; struct vm_page **a_m; int *a_count; int a_centeridx; vm_prot_t a_access_type; int a_advice; int a_flags; } */ *ap = v; off_t newsize, diskeof, memeof; off_t offset, origoffset, startoffset, endoffset, raoffset; daddr_t lbn, blkno; int s, i, error, npages, orignpages, npgs, run, ridx, pidx, pcount; int fs_bshift, fs_bsize, dev_bshift; int flags = ap->a_flags; size_t bytes, iobytes, tailbytes, totalbytes, skipbytes; vaddr_t kva; struct buf *bp, *mbp; struct vnode *vp = ap->a_vp; struct vnode *devvp; struct genfs_node *gp = VTOG(vp); struct uvm_object *uobj = &vp->v_uobj; struct vm_page *pg, *pgs[MAX_READ_AHEAD]; struct ucred *cred = curproc->p_ucred; /* XXXUBC curproc */ boolean_t async = (flags & PGO_SYNCIO) == 0; boolean_t write = (ap->a_access_type & VM_PROT_WRITE) != 0; boolean_t sawhole = FALSE; boolean_t overwrite = (flags & PGO_OVERWRITE) != 0; UVMHIST_FUNC("genfs_getpages"); UVMHIST_CALLED(ubchist); UVMHIST_LOG(ubchist, "vp %p off 0x%x/%x count %d", vp, ap->a_offset >> 32, ap->a_offset, *ap->a_count); /* XXXUBC temp limit */ if (*ap->a_count > MAX_READ_AHEAD) { panic("genfs_getpages: too many pages"); } error = 0; origoffset = ap->a_offset; orignpages = *ap->a_count; GOP_SIZE(vp, vp->v_size, &diskeof); if (flags & PGO_PASTEOF) { newsize = MAX(vp->v_size, origoffset + (orignpages << PAGE_SHIFT)); GOP_SIZE(vp, newsize, &memeof); } else { memeof = diskeof; } KASSERT(ap->a_centeridx >= 0 || ap->a_centeridx <= orignpages); KASSERT((origoffset & (PAGE_SIZE - 1)) == 0 && origoffset >= 0); KASSERT(orignpages > 0); /* * Bounds-check the request. */ if (origoffset + (ap->a_centeridx << PAGE_SHIFT) >= memeof) { if ((flags & PGO_LOCKED) == 0) { simple_unlock(&uobj->vmobjlock); } UVMHIST_LOG(ubchist, "off 0x%x count %d goes past EOF 0x%x", origoffset, *ap->a_count, memeof,0); return EINVAL; } /* * For PGO_LOCKED requests, just return whatever's in memory. */ if (flags & PGO_LOCKED) { uvn_findpages(uobj, origoffset, ap->a_count, ap->a_m, UFP_NOWAIT|UFP_NOALLOC|UFP_NORDONLY); return ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0; } /* vnode is VOP_LOCKed, uobj is locked */ if (write && (vp->v_flag & VONWORKLST) == 0) { vn_syncer_add_to_worklist(vp, filedelay); } /* * find the requested pages and make some simple checks. * leave space in the page array for a whole block. */ if (vp->v_type == VREG) { fs_bshift = vp->v_mount->mnt_fs_bshift; dev_bshift = vp->v_mount->mnt_dev_bshift; } else { fs_bshift = DEV_BSHIFT; dev_bshift = DEV_BSHIFT; } fs_bsize = 1 << fs_bshift; orignpages = MIN(orignpages, round_page(memeof - origoffset) >> PAGE_SHIFT); npages = orignpages; startoffset = origoffset & ~(fs_bsize - 1); endoffset = round_page((origoffset + (npages << PAGE_SHIFT) + fs_bsize - 1) & ~(fs_bsize - 1)); endoffset = MIN(endoffset, round_page(memeof)); ridx = (origoffset - startoffset) >> PAGE_SHIFT; memset(pgs, 0, sizeof(pgs)); uvn_findpages(uobj, origoffset, &npages, &pgs[ridx], UFP_ALL); /* * if the pages are already resident, just return them. */ for (i = 0; i < npages; i++) { struct vm_page *pg = pgs[ridx + i]; if ((pg->flags & PG_FAKE) || (write && (pg->flags & PG_RDONLY))) { break; } } if (i == npages) { UVMHIST_LOG(ubchist, "returning cached pages", 0,0,0,0); raoffset = origoffset + (orignpages << PAGE_SHIFT); npages += ridx; goto raout; } /* * if PGO_OVERWRITE is set, don't bother reading the pages. */ if (flags & PGO_OVERWRITE) { UVMHIST_LOG(ubchist, "PGO_OVERWRITE",0,0,0,0); for (i = 0; i < npages; i++) { struct vm_page *pg = pgs[ridx + i]; pg->flags &= ~(PG_RDONLY|PG_CLEAN); } npages += ridx; goto out; } /* * the page wasn't resident and we're not overwriting, * so we're going to have to do some i/o. * find any additional pages needed to cover the expanded range. */ npages = (endoffset - startoffset) >> PAGE_SHIFT; if (startoffset != origoffset || npages != orignpages) { /* * we need to avoid deadlocks caused by locking * additional pages at lower offsets than pages we * already have locked. unlock them all and start over. */ for (i = 0; i < orignpages; i++) { struct vm_page *pg = pgs[ridx + i]; if (pg->flags & PG_FAKE) { pg->flags |= PG_RELEASED; } } uvm_page_unbusy(&pgs[ridx], orignpages); memset(pgs, 0, sizeof(pgs)); UVMHIST_LOG(ubchist, "reset npages start 0x%x end 0x%x", startoffset, endoffset, 0,0); npgs = npages; uvn_findpages(uobj, startoffset, &npgs, pgs, UFP_ALL); } simple_unlock(&uobj->vmobjlock); /* * read the desired page(s). */ totalbytes = npages << PAGE_SHIFT; bytes = MIN(totalbytes, MAX(diskeof - startoffset, 0)); tailbytes = totalbytes - bytes; skipbytes = 0; kva = uvm_pagermapin(pgs, npages, UVMPAGER_MAPIN_WAITOK | UVMPAGER_MAPIN_READ); s = splbio(); mbp = pool_get(&bufpool, PR_WAITOK); splx(s); mbp->b_bufsize = totalbytes; mbp->b_data = (void *)kva; mbp->b_resid = mbp->b_bcount = bytes; mbp->b_flags = B_BUSY|B_READ| (async ? B_CALL : 0); mbp->b_iodone = (async ? uvm_aio_biodone : 0); mbp->b_vp = vp; LIST_INIT(&mbp->b_dep); /* * if EOF is in the middle of the range, zero the part past EOF. * if the page including EOF is not PG_FAKE, skip over it since * in that case it has valid data that we need to preserve. */ if (tailbytes > 0) { size_t tailstart = bytes; if ((pgs[bytes >> PAGE_SHIFT]->flags & PG_FAKE) == 0) { tailstart = round_page(tailstart); tailbytes -= tailstart - bytes; } UVMHIST_LOG(ubchist, "tailbytes %p 0x%x 0x%x", kva, tailstart, tailbytes,0); memset((void *)(kva + tailstart), 0, tailbytes); } /* * now loop over the pages, reading as needed. */ if (write) { lockmgr(&gp->g_glock, LK_EXCLUSIVE, NULL); } else { lockmgr(&gp->g_glock, LK_SHARED, NULL); } bp = NULL; for (offset = startoffset; bytes > 0; offset += iobytes, bytes -= iobytes) { /* * skip pages which don't need to be read. */ pidx = (offset - startoffset) >> PAGE_SHIFT; while ((pgs[pidx]->flags & (PG_FAKE|PG_RDONLY)) == 0) { size_t b; KASSERT((offset & (PAGE_SIZE - 1)) == 0); b = MIN(PAGE_SIZE, bytes); offset += b; bytes -= b; skipbytes += b; pidx++; UVMHIST_LOG(ubchist, "skipping, new offset 0x%x", offset, 0,0,0); if (bytes == 0) { goto loopdone; } } /* * bmap the file to find out the blkno to read from and * how much we can read in one i/o. if bmap returns an error, * skip the rest of the top-level i/o. */ lbn = offset >> fs_bshift; error = VOP_BMAP(vp, lbn, &devvp, &blkno, &run); if (error) { UVMHIST_LOG(ubchist, "VOP_BMAP lbn 0x%x -> %d\n", lbn, error,0,0); skipbytes += bytes; goto loopdone; } /* * see how many pages can be read with this i/o. * reduce the i/o size if necessary to avoid * overwriting pages with valid data. */ iobytes = MIN((((off_t)lbn + 1 + run) << fs_bshift) - offset, bytes); if (offset + iobytes > round_page(offset)) { pcount = 1; while (pidx + pcount < npages && pgs[pidx + pcount]->flags & PG_FAKE) { pcount++; } iobytes = MIN(iobytes, (pcount << PAGE_SHIFT) - (offset - trunc_page(offset))); } /* * if this block isn't allocated, zero it instead of reading it. * if this is a read access, mark the pages we zeroed PG_RDONLY. */ if (blkno < 0) { int holepages = (round_page(offset + iobytes) - trunc_page(offset)) >> PAGE_SHIFT; UVMHIST_LOG(ubchist, "lbn 0x%x -> HOLE", lbn,0,0,0); sawhole = TRUE; memset((char *)kva + (offset - startoffset), 0, iobytes); skipbytes += iobytes; for (i = 0; i < holepages; i++) { if (write) { pgs[pidx + i]->flags &= ~PG_CLEAN; } else { pgs[pidx + i]->flags |= PG_RDONLY; } } continue; } /* * allocate a sub-buf for this piece of the i/o * (or just use mbp if there's only 1 piece), * and start it going. */ if (offset == startoffset && iobytes == bytes) { bp = mbp; } else { s = splbio(); bp = pool_get(&bufpool, PR_WAITOK); splx(s); bp->b_data = (char *)kva + offset - startoffset; bp->b_resid = bp->b_bcount = iobytes; bp->b_flags = B_BUSY|B_READ|B_CALL; bp->b_iodone = uvm_aio_biodone1; bp->b_vp = vp; bp->b_proc = NULL; LIST_INIT(&bp->b_dep); } bp->b_lblkno = 0; bp->b_private = mbp; if (devvp->v_type == VBLK) { bp->b_dev = devvp->v_rdev; } /* adjust physical blkno for partial blocks */ bp->b_blkno = blkno + ((offset - ((off_t)lbn << fs_bshift)) >> dev_bshift); UVMHIST_LOG(ubchist, "bp %p offset 0x%x bcount 0x%x blkno 0x%x", bp, offset, iobytes, bp->b_blkno); VOP_STRATEGY(bp); } loopdone: if (skipbytes) { s = splbio(); if (error) { mbp->b_flags |= B_ERROR; mbp->b_error = error; } mbp->b_resid -= skipbytes; if (mbp->b_resid == 0) { biodone(mbp); } splx(s); } if (async) { UVMHIST_LOG(ubchist, "returning 0 (async)",0,0,0,0); lockmgr(&gp->g_glock, LK_RELEASE, NULL); return 0; } if (bp != NULL) { error = biowait(mbp); } s = splbio(); pool_put(&bufpool, mbp); splx(s); uvm_pagermapout(kva, npages); raoffset = startoffset + totalbytes; /* * if this we encountered a hole then we have to do a little more work. * for read faults, we marked the page PG_RDONLY so that future * write accesses to the page will fault again. * for write faults, we must make sure that the backing store for * the page is completely allocated while the pages are locked. */ if (!error && sawhole && write) { for (i = 0; i < npages; i++) { if (pgs[i] == NULL) { continue; } pgs[i]->flags &= ~PG_CLEAN; UVMHIST_LOG(ubchist, "mark dirty pg %p", pgs[i],0,0,0); } error = GOP_ALLOC(vp, startoffset, npages << PAGE_SHIFT, 0, cred); UVMHIST_LOG(ubchist, "gop_alloc off 0x%x/0x%x -> %d", startoffset, npages << PAGE_SHIFT, error,0); } lockmgr(&gp->g_glock, LK_RELEASE, NULL); simple_lock(&uobj->vmobjlock); /* * see if we want to start any readahead. * XXXUBC for now, just read the next 128k on 64k boundaries. * this is pretty nonsensical, but it is 50% faster than reading * just the next 64k. */ raout: if (!error && !async && !write && ((int)raoffset & 0xffff) == 0 && PAGE_SHIFT <= 16) { off_t rasize; int racount; /* XXXUBC temp limit, from above */ racount = MIN(1 << (16 - PAGE_SHIFT), MAX_READ_AHEAD); rasize = racount << PAGE_SHIFT; (void) VOP_GETPAGES(vp, raoffset, NULL, &racount, 0, VM_PROT_READ, 0, 0); simple_lock(&uobj->vmobjlock); /* XXXUBC temp limit, from above */ racount = MIN(1 << (16 - PAGE_SHIFT), MAX_READ_AHEAD); (void) VOP_GETPAGES(vp, raoffset + rasize, NULL, &racount, 0, VM_PROT_READ, 0, 0); simple_lock(&uobj->vmobjlock); } /* * we're almost done! release the pages... * for errors, we free the pages. * otherwise we activate them and mark them as valid and clean. * also, unbusy pages that were not actually requested. */ if (error) { for (i = 0; i < npages; i++) { if (pgs[i] == NULL) { continue; } UVMHIST_LOG(ubchist, "examining pg %p flags 0x%x", pgs[i], pgs[i]->flags, 0,0); if (pgs[i]->flags & PG_FAKE) { pgs[i]->flags |= PG_RELEASED; } } uvm_lock_pageq(); uvm_page_unbusy(pgs, npages); uvm_unlock_pageq(); simple_unlock(&uobj->vmobjlock); UVMHIST_LOG(ubchist, "returning error %d", error,0,0,0); return error; } out: UVMHIST_LOG(ubchist, "succeeding, npages %d", npages,0,0,0); uvm_lock_pageq(); for (i = 0; i < npages; i++) { pg = pgs[i]; if (pg == NULL) { continue; } UVMHIST_LOG(ubchist, "examining pg %p flags 0x%x", pg, pg->flags, 0,0); if (pg->flags & PG_FAKE && !overwrite) { pg->flags &= ~(PG_FAKE); pmap_clear_modify(pgs[i]); } if (write) { pg->flags &= ~(PG_RDONLY); } if (i < ridx || i >= ridx + orignpages || async) { UVMHIST_LOG(ubchist, "unbusy pg %p offset 0x%x", pg, pg->offset,0,0); if (pg->flags & PG_WANTED) { wakeup(pg); } if (pg->flags & PG_FAKE) { KASSERT(overwrite); uvm_pagezero(pg); } if (pg->flags & PG_RELEASED) { uvm_pagefree(pg); continue; } uvm_pageactivate(pg); pg->flags &= ~(PG_WANTED|PG_BUSY|PG_FAKE); UVM_PAGE_OWN(pg, NULL); } } uvm_unlock_pageq(); simple_unlock(&uobj->vmobjlock); if (ap->a_m != NULL) { memcpy(ap->a_m, &pgs[ridx], orignpages * sizeof(struct vm_page *)); } return 0; } /* * generic VM putpages routine. * Write the given range of pages to backing store. * * => "offhi == 0" means flush all pages at or after "offlo". * => object should be locked by caller. we may _unlock_ the object * if (and only if) we need to clean a page (PGO_CLEANIT), or * if PGO_SYNCIO is set and there are pages busy. * we return with the object locked. * => if PGO_CLEANIT or PGO_SYNCIO is set, we may block (due to I/O). * thus, a caller might want to unlock higher level resources * (e.g. vm_map) before calling flush. * => if neither PGO_CLEANIT nor PGO_SYNCIO is set, then we will neither * unlock the object nor block. * => if PGO_ALLPAGES is set, then all pages in the object will be processed. * => NOTE: we rely on the fact that the object's memq is a TAILQ and * that new pages are inserted on the tail end of the list. thus, * we can make a complete pass through the object in one go by starting * at the head and working towards the tail (new pages are put in * front of us). * => NOTE: we are allowed to lock the page queues, so the caller * must not be holding the page queue lock. * * note on "cleaning" object and PG_BUSY pages: * this routine is holding the lock on the object. the only time * that it can run into a PG_BUSY page that it does not own is if * some other process has started I/O on the page (e.g. either * a pagein, or a pageout). if the PG_BUSY page is being paged * in, then it can not be dirty (!PG_CLEAN) because no one has * had a chance to modify it yet. if the PG_BUSY page is being * paged out then it means that someone else has already started * cleaning the page for us (how nice!). in this case, if we * have syncio specified, then after we make our pass through the * object we need to wait for the other PG_BUSY pages to clear * off (i.e. we need to do an iosync). also note that once a * page is PG_BUSY it must stay in its object until it is un-busyed. * * note on page traversal: * we can traverse the pages in an object either by going down the * linked list in "uobj->memq", or we can go over the address range * by page doing hash table lookups for each address. depending * on how many pages are in the object it may be cheaper to do one * or the other. we set "by_list" to true if we are using memq. * if the cost of a hash lookup was equal to the cost of the list * traversal we could compare the number of pages in the start->stop * range to the total number of pages in the object. however, it * seems that a hash table lookup is more expensive than the linked * list traversal, so we multiply the number of pages in the * range by an estimate of the relatively higher cost of the hash lookup. */ int genfs_putpages(v) void *v; { struct vop_putpages_args /* { struct vnode *a_vp; voff_t a_offlo; voff_t a_offhi; int a_flags; } */ *ap = v; struct vnode *vp = ap->a_vp; struct uvm_object *uobj = &vp->v_uobj; off_t startoff = ap->a_offlo; off_t endoff = ap->a_offhi; off_t off; int flags = ap->a_flags; int n = MAXBSIZE >> PAGE_SHIFT; int i, s, error, npages, nback; int freeflag; struct vm_page *pgs[n], *pg, *nextpg, *tpg, curmp, endmp; boolean_t wasclean, by_list, needs_clean; boolean_t async = (flags & PGO_SYNCIO) == 0; UVMHIST_FUNC("genfs_putpages"); UVMHIST_CALLED(ubchist); KASSERT(flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)); KASSERT((startoff & PAGE_MASK) == 0 && (endoff & PAGE_MASK) == 0); KASSERT(startoff < endoff || endoff == 0); UVMHIST_LOG(ubchist, "vp %p pages %d off 0x%x len 0x%x", vp, uobj->uo_npages, startoff, endoff - startoff); if (uobj->uo_npages == 0) { if (LIST_FIRST(&vp->v_dirtyblkhd) == NULL && (vp->v_flag & VONWORKLST)) { vp->v_flag &= ~VONWORKLST; LIST_REMOVE(vp, v_synclist); } simple_unlock(&uobj->vmobjlock); return 0; } /* * the vnode has pages, set up to process the request. */ error = 0; wasclean = TRUE; off = startoff; if (endoff == 0 || flags & PGO_ALLPAGES) { endoff = trunc_page(LLONG_MAX); } by_list = (uobj->uo_npages <= ((endoff - startoff) >> PAGE_SHIFT) * UVM_PAGE_HASH_PENALTY); /* * start the loop. when scanning by list, hold the last page * in the list before we start. pages allocated after we start * will be added to the end of the list, so we can stop at the * current last page. */ freeflag = (curproc == uvm.pagedaemon_proc) ? PG_PAGEOUT : PG_RELEASED; curmp.uobject = uobj; curmp.offset = (voff_t)-1; curmp.flags = PG_BUSY; endmp.uobject = uobj; endmp.offset = (voff_t)-1; endmp.flags = PG_BUSY; if (by_list) { pg = TAILQ_FIRST(&uobj->memq); TAILQ_INSERT_TAIL(&uobj->memq, &endmp, listq); PHOLD(curproc); } else { pg = uvm_pagelookup(uobj, off); } nextpg = NULL; while (by_list || off < endoff) { /* * if the current page is not interesting, move on to the next. */ KASSERT(pg == NULL || pg->uobject == uobj); KASSERT(pg == NULL || (pg->flags & (PG_RELEASED|PG_PAGEOUT)) == 0 || (pg->flags & PG_BUSY) != 0); if (by_list) { if (pg == &endmp) { break; } if (pg->offset < startoff || pg->offset >= endoff || pg->flags & (PG_RELEASED|PG_PAGEOUT)) { pg = TAILQ_NEXT(pg, listq); continue; } off = pg->offset; } else if (pg == NULL || pg->flags & (PG_RELEASED|PG_PAGEOUT)) { off += PAGE_SIZE; if (off < endoff) { pg = uvm_pagelookup(uobj, off); } continue; } /* * if the current page needs to be cleaned and it's busy, * wait for it to become unbusy. */ if (flags & PGO_FREE) { pmap_page_protect(pg, VM_PROT_NONE); } if (flags & PGO_CLEANIT) { needs_clean = pmap_clear_modify(pg) || (pg->flags & PG_CLEAN) == 0; pg->flags |= PG_CLEAN; } else { needs_clean = FALSE; } if (needs_clean && pg->flags & PG_BUSY) { KASSERT(curproc != uvm.pagedaemon_proc); UVMHIST_LOG(ubchist, "busy %p", pg,0,0,0); if (by_list) { TAILQ_INSERT_BEFORE(pg, &curmp, listq); UVMHIST_LOG(ubchist, "curmp next %p", TAILQ_NEXT(&curmp, listq), 0,0,0); } pg->flags |= PG_WANTED; pg->flags &= ~PG_CLEAN; UVM_UNLOCK_AND_WAIT(pg, &uobj->vmobjlock, 0, "genput", 0); simple_lock(&uobj->vmobjlock); if (by_list) { UVMHIST_LOG(ubchist, "after next %p", TAILQ_NEXT(&curmp, listq), 0,0,0); pg = TAILQ_NEXT(&curmp, listq); TAILQ_REMOVE(&uobj->memq, &curmp, listq); } else { pg = uvm_pagelookup(uobj, off); } continue; } /* * if we're cleaning, build a cluster. * the cluster will consist of pages which are currently dirty, * but they will be returned to us marked clean. * if not cleaning, just operate on the one page. */ if (needs_clean) { wasclean = FALSE; memset(pgs, 0, sizeof(pgs)); pg->flags |= PG_BUSY; UVM_PAGE_OWN(pg, "genfs_putpages"); /* * first look backward. */ npages = MIN(n >> 1, off >> PAGE_SHIFT); nback = npages; uvn_findpages(uobj, off - PAGE_SIZE, &nback, &pgs[0], UFP_NOWAIT|UFP_NOALLOC|UFP_DIRTYONLY|UFP_BACKWARD); if (nback) { memmove(&pgs[0], &pgs[npages - nback], nback * sizeof(pgs[0])); } n -= nback; /* * then plug in our page of interest. */ pgs[nback] = pg; /* * then look forward to fill in the remaining space in * the array of pages. */ npages = MIN(n, (endoff - off) >> PAGE_SHIFT) - 1; uvn_findpages(uobj, off + PAGE_SIZE, &npages, &pgs[nback + 1], UFP_NOWAIT|UFP_NOALLOC|UFP_DIRTYONLY); npages += nback + 1; } else { pgs[0] = pg; npages = 1; } /* * apply FREE or DEACTIVATE options if requested. */ if (flags & (PGO_DEACTIVATE|PGO_FREE)) { uvm_lock_pageq(); } for (i = 0; i < npages; i++) { tpg = pgs[i]; KASSERT(tpg->uobject == uobj); if (flags & PGO_DEACTIVATE && (tpg->pqflags & PQ_INACTIVE) == 0 && tpg->wire_count == 0) { (void) pmap_clear_reference(tpg); uvm_pagedeactivate(tpg); } else if (flags & PGO_FREE) { pmap_page_protect(tpg, VM_PROT_NONE); if (tpg->flags & PG_BUSY) { tpg->flags |= freeflag; if (freeflag == PG_PAGEOUT) { uvmexp.paging++; uvm_pagedequeue(tpg); } } else { nextpg = TAILQ_NEXT(tpg, listq); uvm_pagefree(tpg); } } } if (flags & (PGO_DEACTIVATE|PGO_FREE)) { uvm_unlock_pageq(); } if (needs_clean) { /* * start the i/o. if we're traversing by list, * keep our place in the list with a marker page. */ if (by_list) { TAILQ_INSERT_AFTER(&uobj->memq, pg, &curmp, listq); } simple_unlock(&uobj->vmobjlock); error = GOP_WRITE(vp, pgs, npages, flags); simple_lock(&uobj->vmobjlock); if (by_list) { pg = TAILQ_NEXT(&curmp, listq); TAILQ_REMOVE(&uobj->memq, &curmp, listq); } if (error == ENOMEM) { for (i = 0; i < npages; i++) { tpg = pgs[i]; if (tpg->flags & PG_PAGEOUT) { tpg->flags &= ~PG_PAGEOUT; uvmexp.paging--; } tpg->flags &= ~PG_CLEAN; uvm_pageactivate(tpg); } uvm_page_unbusy(pgs, npages); } if (error) { break; } if (by_list) { continue; } } /* * find the next page and continue if there was no error. */ if (by_list) { if (nextpg) { pg = nextpg; nextpg = NULL; } else { pg = TAILQ_NEXT(pg, listq); } } else { off += PAGE_SIZE; if (off < endoff) { pg = uvm_pagelookup(uobj, off); } } } if (by_list) { TAILQ_REMOVE(&uobj->memq, &endmp, listq); PRELE(curproc); } /* * if we're cleaning and there was nothing to clean, * take us off the syncer list. if we started any i/o * and we're doing sync i/o, wait for all writes to finish. */ if ((flags & PGO_CLEANIT) && wasclean && startoff == 0 && endoff == trunc_page(LLONG_MAX) && LIST_FIRST(&vp->v_dirtyblkhd) == NULL && (vp->v_flag & VONWORKLST)) { vp->v_flag &= ~VONWORKLST; LIST_REMOVE(vp, v_synclist); } if (!wasclean && !async) { s = splbio(); while (vp->v_numoutput != 0) { vp->v_flag |= VBWAIT; UVM_UNLOCK_AND_WAIT(&vp->v_numoutput, &uobj->vmobjlock, FALSE, "genput2",0); simple_lock(&uobj->vmobjlock); } splx(s); } simple_unlock(&uobj->vmobjlock); return error; } int genfs_gop_write(struct vnode *vp, struct vm_page **pgs, int npages, int flags) { int s, error, run; int fs_bshift, dev_bshift; vaddr_t kva; off_t eof, offset, startoffset; size_t bytes, iobytes, skipbytes; daddr_t lbn, blkno; struct vm_page *pg; struct buf *mbp, *bp; struct vnode *devvp; boolean_t async = (flags & PGO_SYNCIO) == 0; UVMHIST_FUNC("genfs_gop_write"); UVMHIST_CALLED(ubchist); UVMHIST_LOG(ubchist, "vp %p pgs %p npages %d flags 0x%x", vp, pgs, npages, flags); GOP_SIZE(vp, vp->v_size, &eof); if (vp->v_type == VREG) { fs_bshift = vp->v_mount->mnt_fs_bshift; dev_bshift = vp->v_mount->mnt_dev_bshift; } else { fs_bshift = DEV_BSHIFT; dev_bshift = DEV_BSHIFT; } error = 0; pg = pgs[0]; startoffset = pg->offset; bytes = MIN(npages << PAGE_SHIFT, eof - startoffset); skipbytes = 0; KASSERT(bytes != 0); kva = uvm_pagermapin(pgs, npages, UVMPAGER_MAPIN_WRITE | UVMPAGER_MAPIN_WAITOK); s = splbio(); vp->v_numoutput += 2; mbp = pool_get(&bufpool, PR_WAITOK); UVMHIST_LOG(ubchist, "vp %p mbp %p num now %d bytes 0x%x", vp, mbp, vp->v_numoutput, bytes); splx(s); mbp->b_bufsize = npages << PAGE_SHIFT; mbp->b_data = (void *)kva; mbp->b_resid = mbp->b_bcount = bytes; mbp->b_flags = B_BUSY|B_WRITE|B_AGE| (async ? B_CALL : 0); mbp->b_iodone = uvm_aio_biodone; mbp->b_vp = vp; LIST_INIT(&mbp->b_dep); bp = NULL; for (offset = startoffset; bytes > 0; offset += iobytes, bytes -= iobytes) { lbn = offset >> fs_bshift; error = VOP_BMAP(vp, lbn, &devvp, &blkno, &run); if (error) { UVMHIST_LOG(ubchist, "VOP_BMAP() -> %d", error,0,0,0); skipbytes += bytes; bytes = 0; break; } iobytes = MIN((((off_t)lbn + 1 + run) << fs_bshift) - offset, bytes); if (blkno == (daddr_t)-1) { skipbytes += iobytes; continue; } /* if it's really one i/o, don't make a second buf */ if (offset == startoffset && iobytes == bytes) { bp = mbp; } else { s = splbio(); vp->v_numoutput++; bp = pool_get(&bufpool, PR_WAITOK); UVMHIST_LOG(ubchist, "vp %p bp %p num now %d", vp, bp, vp->v_numoutput, 0); splx(s); bp->b_data = (char *)kva + (vaddr_t)(offset - pg->offset); bp->b_resid = bp->b_bcount = iobytes; bp->b_flags = B_BUSY|B_WRITE|B_CALL; bp->b_iodone = uvm_aio_biodone1; bp->b_vp = vp; LIST_INIT(&bp->b_dep); } bp->b_lblkno = 0; bp->b_private = mbp; if (devvp->v_type == VBLK) { bp->b_dev = devvp->v_rdev; } /* adjust physical blkno for partial blocks */ bp->b_blkno = blkno + ((offset - ((off_t)lbn << fs_bshift)) >> dev_bshift); UVMHIST_LOG(ubchist, "vp %p offset 0x%x bcount 0x%x blkno 0x%x", vp, offset, bp->b_bcount, bp->b_blkno); VOP_STRATEGY(bp); } if (skipbytes) { UVMHIST_LOG(ubchist, "skipbytes %d", skipbytes, 0,0,0); s = splbio(); if (error) { mbp->b_flags |= B_ERROR; mbp->b_error = error; } mbp->b_resid -= skipbytes; if (mbp->b_resid == 0) { biodone(mbp); } splx(s); } if (async) { UVMHIST_LOG(ubchist, "returning 0 (async)", 0,0,0,0); return 0; } UVMHIST_LOG(ubchist, "waiting for mbp %p", mbp,0,0,0); error = biowait(mbp); uvm_aio_aiodone(mbp); UVMHIST_LOG(ubchist, "returning, error %d", error,0,0,0); return error; } void genfs_node_init(struct vnode *vp, struct genfs_ops *ops) { struct genfs_node *gp = VTOG(vp); lockinit(&gp->g_glock, PINOD, "glock", 0, 0); gp->g_op = ops; } void genfs_size(struct vnode *vp, off_t size, off_t *eobp) { int bsize; bsize = 1 << vp->v_mount->mnt_fs_bshift; *eobp = (size + bsize - 1) & ~(bsize - 1); }