vm_vfs.c revision 1.36
1 /* $NetBSD: vm_vfs.c,v 1.36 2020/01/15 17:55:44 ad Exp $ */ 2 3 /* 4 * Copyright (c) 2008-2011 Antti Kantee. All Rights Reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __KERNEL_RCSID(0, "$NetBSD: vm_vfs.c,v 1.36 2020/01/15 17:55:44 ad Exp $"); 30 31 #include <sys/param.h> 32 33 #include <sys/buf.h> 34 #include <sys/vnode.h> 35 36 #include <uvm/uvm.h> 37 #include <uvm/uvm_readahead.h> 38 39 /* 40 * release resources held during async io. this is almost the 41 * same as uvm_aio_aiodone() from uvm_pager.c and only lacks the 42 * call to uvm_aio_aiodone_pages(): unbusies pages directly here. 43 */ 44 void 45 uvm_aio_aiodone(struct buf *bp) 46 { 47 struct uvm_object *uobj = NULL; 48 int i, npages = bp->b_bufsize >> PAGE_SHIFT; 49 struct vm_page **pgs; 50 vaddr_t va; 51 int pageout = 0; 52 53 KASSERT(npages > 0); 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 59 if (uobj == NULL) { 60 uobj = pgs[i]->uobject; 61 KASSERT(uobj != NULL); 62 mutex_enter(uobj->vmobjlock); 63 } else { 64 KASSERT(uobj == pgs[i]->uobject); 65 } 66 67 if (pgs[i]->flags & PG_PAGEOUT) { 68 KASSERT((pgs[i]->flags & PG_FAKE) == 0); 69 pageout++; 70 pgs[i]->flags &= ~PG_PAGEOUT; 71 pgs[i]->flags |= PG_RELEASED; 72 } 73 } 74 KASSERT(mutex_owned(uobj->vmobjlock)); 75 76 uvm_page_unbusy(pgs, npages); 77 mutex_exit(uobj->vmobjlock); 78 79 uvm_pagermapout((vaddr_t)bp->b_data, npages); 80 uvm_pageout_done(pageout); 81 82 if (BUF_ISWRITE(bp) && (bp->b_cflags & BC_AGE) != 0) { 83 mutex_enter(bp->b_objlock); 84 vwakeup(bp); 85 mutex_exit(bp->b_objlock); 86 } 87 88 putiobuf(bp); 89 90 kmem_free(pgs, npages * sizeof(*pgs)); 91 } 92 93 void 94 uvm_aio_biodone(struct buf *bp) 95 { 96 97 uvm_aio_aiodone(bp); 98 } 99 100 /* 101 * UBC 102 */ 103 104 #define PAGERFLAGS (PGO_SYNCIO | PGO_NOBLOCKALLOC | PGO_NOTIMESTAMP) 105 106 void 107 ubc_zerorange(struct uvm_object *uobj, off_t off, size_t len, int flags) 108 { 109 struct vm_page **pgs; 110 int maxpages = MIN(32, round_page(len) >> PAGE_SHIFT); 111 int npages, i; 112 113 if (maxpages == 0) 114 return; 115 116 pgs = kmem_alloc(maxpages * sizeof(pgs), KM_SLEEP); 117 mutex_enter(uobj->vmobjlock); 118 while (len) { 119 npages = MIN(maxpages, round_page(len) >> PAGE_SHIFT); 120 memset(pgs, 0, npages * sizeof(struct vm_page *)); 121 (void)uobj->pgops->pgo_get(uobj, trunc_page(off), 122 pgs, &npages, 0, VM_PROT_READ | VM_PROT_WRITE, 123 0, PAGERFLAGS | PGO_PASTEOF); 124 KASSERT(npages > 0); 125 126 mutex_enter(uobj->vmobjlock); 127 for (i = 0; i < npages; i++) { 128 struct vm_page *pg; 129 uint8_t *start; 130 size_t chunkoff, chunklen; 131 132 pg = pgs[i]; 133 if (pg == NULL) 134 break; 135 136 KASSERT(pg->uobject != NULL); 137 KASSERT(uobj->vmobjlock == pg->uobject->vmobjlock); 138 139 chunkoff = off & PAGE_MASK; 140 chunklen = MIN(PAGE_SIZE - chunkoff, len); 141 start = (uint8_t *)pg->uanon + chunkoff; 142 143 memset(start, 0, chunklen); 144 uvm_pagemarkdirty(pg, UVM_PAGE_STATUS_DIRTY); 145 146 off += chunklen; 147 len -= chunklen; 148 } 149 uvm_page_unbusy(pgs, npages); 150 } 151 mutex_exit(uobj->vmobjlock); 152 kmem_free(pgs, maxpages * sizeof(pgs)); 153 } 154 155 #define len2npages(off, len) \ 156 ((round_page(off+len) - trunc_page(off)) >> PAGE_SHIFT) 157 158 int 159 ubc_uiomove(struct uvm_object *uobj, struct uio *uio, vsize_t todo, 160 int advice, int flags) 161 { 162 struct vm_page **pgs; 163 int npages = len2npages(uio->uio_offset, todo); 164 size_t pgalloc; 165 int i, rv, pagerflags; 166 vm_prot_t prot; 167 168 pgalloc = npages * sizeof(pgs); 169 pgs = kmem_alloc(pgalloc, KM_SLEEP); 170 171 pagerflags = PAGERFLAGS; 172 if (flags & UBC_WRITE) 173 pagerflags |= PGO_PASTEOF; 174 if (flags & UBC_FAULTBUSY) 175 pagerflags |= PGO_OVERWRITE; 176 177 prot = VM_PROT_READ; 178 if (flags & UBC_WRITE) 179 prot |= VM_PROT_WRITE; 180 181 mutex_enter(uobj->vmobjlock); 182 do { 183 npages = len2npages(uio->uio_offset, todo); 184 memset(pgs, 0, pgalloc); 185 rv = uobj->pgops->pgo_get(uobj, trunc_page(uio->uio_offset), 186 pgs, &npages, 0, prot, 0, pagerflags); 187 if (rv) 188 goto out; 189 190 mutex_enter(uobj->vmobjlock); 191 for (i = 0; i < npages; i++) { 192 struct vm_page *pg; 193 size_t xfersize; 194 off_t pageoff; 195 196 pg = pgs[i]; 197 if (pg == NULL) 198 break; 199 200 KASSERT(pg->uobject != NULL); 201 KASSERT(uobj->vmobjlock == pg->uobject->vmobjlock); 202 pageoff = uio->uio_offset & PAGE_MASK; 203 204 xfersize = MIN(MIN(todo, PAGE_SIZE), PAGE_SIZE-pageoff); 205 KASSERT(xfersize > 0); 206 rv = uiomove((uint8_t *)pg->uanon + pageoff, 207 xfersize, uio); 208 if (rv) { 209 uvm_page_unbusy(pgs, npages); 210 mutex_exit(uobj->vmobjlock); 211 goto out; 212 } 213 if (uio->uio_rw == UIO_WRITE) { 214 pg->flags &= ~PG_FAKE; 215 uvm_pagemarkdirty(pg, UVM_PAGE_STATUS_DIRTY); 216 } 217 todo -= xfersize; 218 } 219 uvm_page_unbusy(pgs, npages); 220 } while (todo); 221 mutex_exit(uobj->vmobjlock); 222 223 out: 224 kmem_free(pgs, pgalloc); 225 return rv; 226 } 227
Indexes created Tue Sep 30 06:09:59 GMT 2025