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vm_vfs.c revision 1.12 
      1 /*	$NetBSD: vm_vfs.c,v 1.12 2009/10/07 10:23:50 pooka Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2008 Antti Kantee.  All Rights Reserved.
      5  *
      6  * Development of this software was supported by the
      7  * Finnish Cultural Foundation.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
     19  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     21  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     24  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     28  * SUCH DAMAGE.
     29  */
     30 
     31 #include <sys/cdefs.h>
     32 __KERNEL_RCSID(0, "$NetBSD: vm_vfs.c,v 1.12 2009/10/07 10:23:50 pooka Exp $");
     33 
     34 #include <sys/param.h>
     35 
     36 #include <sys/buf.h>
     37 #include <sys/vnode.h>
     38 
     39 #include <uvm/uvm.h>
     40 #include <uvm/uvm_readahead.h>
     41 
     42 /*
     43  * release resources held during async io.  this is almost the
     44  * same as uvm_aio_aiodone() from uvm_pager.c and only lacks the
     45  * call to uvm_aio_aiodone_pages(): unbusies pages directly here.
     46  */
     47 void
     48 uvm_aio_aiodone(struct buf *bp)
     49 {
     50 	int i, npages = bp->b_bufsize >> PAGE_SHIFT;
     51 	struct vm_page **pgs;
     52 	vaddr_t va;
     53 
     54 	pgs = kmem_alloc(npages * sizeof(*pgs), KM_SLEEP);
     55 	for (i = 0; i < npages; i++) {
     56 		va = (vaddr_t)bp->b_data + (i << PAGE_SHIFT);
     57 		pgs[i] = uvm_pageratop(va);
     58 		pgs[i]->flags &= ~PG_PAGEOUT;
     59 	}
     60 
     61 	uvm_pagermapout((vaddr_t)bp->b_data, npages);
     62 	uvm_page_unbusy(pgs, npages);
     63 
     64 	if (BUF_ISWRITE(bp) && (bp->b_cflags & BC_AGE) != 0) {
     65 		mutex_enter(bp->b_objlock);
     66 		vwakeup(bp);
     67 		mutex_exit(bp->b_objlock);
     68 	}
     69 
     70 	putiobuf(bp);
     71 
     72 	kmem_free(pgs, npages * sizeof(*pgs));
     73 }
     74 
     75 void
     76 uvm_aio_biodone(struct buf *bp)
     77 {
     78 
     79 	uvm_aio_aiodone(bp);
     80 }
     81 
     82 /*
     83  * UBC
     84  */
     85 
     86 void
     87 uvm_vnp_zerorange(struct vnode *vp, off_t off, size_t len)
     88 {
     89 	struct uvm_object *uobj = &vp->v_uobj;
     90 	struct vm_page **pgs;
     91 	int maxpages = MIN(32, round_page(len) >> PAGE_SHIFT);
     92 	int rv, npages, i;
     93 
     94 	pgs = kmem_zalloc(maxpages * sizeof(pgs), KM_SLEEP);
     95 	while (len) {
     96 		npages = MIN(maxpages, round_page(len) >> PAGE_SHIFT);
     97 		memset(pgs, 0, npages * sizeof(struct vm_page *));
     98 		mutex_enter(&uobj->vmobjlock);
     99 		rv = uobj->pgops->pgo_get(uobj, off, pgs, &npages, 0, 0, 0, 0);
    100 		KASSERT(npages > 0);
    101 
    102 		for (i = 0; i < npages; i++) {
    103 			uint8_t *start;
    104 			size_t chunkoff, chunklen;
    105 
    106 			chunkoff = off & PAGE_MASK;
    107 			chunklen = MIN(PAGE_SIZE - chunkoff, len);
    108 			start = (uint8_t *)pgs[i]->uanon + chunkoff;
    109 
    110 			memset(start, 0, chunklen);
    111 			pgs[i]->flags &= ~PG_CLEAN;
    112 
    113 			off += chunklen;
    114 			len -= chunklen;
    115 		}
    116 		uvm_page_unbusy(pgs, npages);
    117 	}
    118 	kmem_free(pgs, maxpages * sizeof(pgs));
    119 
    120 	return;
    121 }
    122 
    123 /* dumdidumdum */
    124 #define len2npages(off, len)						\
    125   (((((len) + PAGE_MASK) & ~(PAGE_MASK)) >> PAGE_SHIFT)			\
    126     + (((off & PAGE_MASK) + (len & PAGE_MASK)) > PAGE_SIZE))
    127 
    128 int
    129 ubc_uiomove(struct uvm_object *uobj, struct uio *uio, vsize_t todo,
    130 	int advice, int flags)
    131 {
    132 	struct vm_page **pgs;
    133 	int npages = len2npages(uio->uio_offset, todo);
    134 	size_t pgalloc;
    135 	int i, rv, pagerflags;
    136 
    137 	pgalloc = npages * sizeof(pgs);
    138 	pgs = kmem_zalloc(pgalloc, KM_SLEEP);
    139 
    140 	pagerflags = PGO_SYNCIO | PGO_NOBLOCKALLOC | PGO_NOTIMESTAMP;
    141 	if (flags & UBC_WRITE)
    142 		pagerflags |= PGO_PASTEOF;
    143 	if (flags & UBC_FAULTBUSY)
    144 		pagerflags |= PGO_OVERWRITE;
    145 
    146 	do {
    147 		mutex_enter(&uobj->vmobjlock);
    148 		rv = uobj->pgops->pgo_get(uobj, uio->uio_offset & ~PAGE_MASK,
    149 		    pgs, &npages, 0, VM_PROT_READ | VM_PROT_WRITE, 0,
    150 		    pagerflags);
    151 		if (rv)
    152 			goto out;
    153 
    154 		for (i = 0; i < npages; i++) {
    155 			size_t xfersize;
    156 			off_t pageoff;
    157 
    158 			pageoff = uio->uio_offset & PAGE_MASK;
    159 			xfersize = MIN(MIN(todo, PAGE_SIZE), PAGE_SIZE-pageoff);
    160 			uiomove((uint8_t *)pgs[i]->uanon + pageoff,
    161 			    xfersize, uio);
    162 			if (uio->uio_rw == UIO_WRITE)
    163 				pgs[i]->flags &= ~PG_CLEAN;
    164 			todo -= xfersize;
    165 		}
    166 		uvm_page_unbusy(pgs, npages);
    167 	} while (todo);
    168 
    169  out:
    170 	kmem_free(pgs, pgalloc);
    171 	return rv;
    172 }
    173