vm_vfs.c revision 1.38
1 /* $NetBSD: vm_vfs.c,v 1.38 2020/02/23 15:46:42 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 1.38 2020/02/23 15:46:42 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 rw_enter(uobj->vmobjlock, RW_WRITER); 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(rw_write_held(uobj->vmobjlock)); 75 76 uvm_page_unbusy(pgs, npages); 77 rw_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 /* 94 * UBC 95 */ 96 97 #define PAGERFLAGS (PGO_SYNCIO | PGO_NOBLOCKALLOC | PGO_NOTIMESTAMP) 98 99 void 100 ubc_zerorange(struct uvm_object *uobj, off_t off, size_t len, int flags) 101 { 102 struct vm_page **pgs; 103 int maxpages = MIN(32, round_page(len) >> PAGE_SHIFT); 104 int npages, i; 105 106 if (maxpages == 0) 107 return; 108 109 pgs = kmem_alloc(maxpages * sizeof(pgs), KM_SLEEP); 110 rw_enter(uobj->vmobjlock, RW_WRITER); 111 while (len) { 112 npages = MIN(maxpages, round_page(len) >> PAGE_SHIFT); 113 memset(pgs, 0, npages * sizeof(struct vm_page *)); 114 (void)uobj->pgops->pgo_get(uobj, trunc_page(off), 115 pgs, &npages, 0, VM_PROT_READ | VM_PROT_WRITE, 116 0, PAGERFLAGS | PGO_PASTEOF); 117 KASSERT(npages > 0); 118 119 rw_enter(uobj->vmobjlock, RW_WRITER); 120 for (i = 0; i < npages; i++) { 121 struct vm_page *pg; 122 uint8_t *start; 123 size_t chunkoff, chunklen; 124 125 pg = pgs[i]; 126 if (pg == NULL) 127 break; 128 129 KASSERT(pg->uobject != NULL); 130 KASSERT(uobj->vmobjlock == pg->uobject->vmobjlock); 131 132 chunkoff = off & PAGE_MASK; 133 chunklen = MIN(PAGE_SIZE - chunkoff, len); 134 start = (uint8_t *)pg->uanon + chunkoff; 135 136 memset(start, 0, chunklen); 137 uvm_pagemarkdirty(pg, UVM_PAGE_STATUS_DIRTY); 138 139 off += chunklen; 140 len -= chunklen; 141 } 142 uvm_page_unbusy(pgs, npages); 143 } 144 rw_exit(uobj->vmobjlock); 145 kmem_free(pgs, maxpages * sizeof(pgs)); 146 } 147 148 #define len2npages(off, len) \ 149 ((round_page(off+len) - trunc_page(off)) >> PAGE_SHIFT) 150 151 int 152 ubc_uiomove(struct uvm_object *uobj, struct uio *uio, vsize_t todo, 153 int advice, int flags) 154 { 155 struct vm_page **pgs; 156 int npages = len2npages(uio->uio_offset, todo); 157 size_t pgalloc; 158 int i, rv, pagerflags; 159 vm_prot_t prot; 160 161 pgalloc = npages * sizeof(pgs); 162 pgs = kmem_alloc(pgalloc, KM_SLEEP); 163 164 pagerflags = PAGERFLAGS; 165 if (flags & UBC_WRITE) 166 pagerflags |= PGO_PASTEOF; 167 if (flags & UBC_FAULTBUSY) 168 pagerflags |= PGO_OVERWRITE; 169 170 prot = VM_PROT_READ; 171 if (flags & UBC_WRITE) 172 prot |= VM_PROT_WRITE; 173 174 rw_enter(uobj->vmobjlock, RW_WRITER); 175 do { 176 npages = len2npages(uio->uio_offset, todo); 177 memset(pgs, 0, pgalloc); 178 rv = uobj->pgops->pgo_get(uobj, trunc_page(uio->uio_offset), 179 pgs, &npages, 0, prot, 0, pagerflags); 180 if (rv) 181 goto out; 182 183 rw_enter(uobj->vmobjlock, RW_WRITER); 184 for (i = 0; i < npages; i++) { 185 struct vm_page *pg; 186 size_t xfersize; 187 off_t pageoff; 188 189 pg = pgs[i]; 190 if (pg == NULL) 191 break; 192 193 KASSERT(pg->uobject != NULL); 194 KASSERT(uobj->vmobjlock == pg->uobject->vmobjlock); 195 pageoff = uio->uio_offset & PAGE_MASK; 196 197 xfersize = MIN(MIN(todo, PAGE_SIZE), PAGE_SIZE-pageoff); 198 KASSERT(xfersize > 0); 199 rv = uiomove((uint8_t *)pg->uanon + pageoff, 200 xfersize, uio); 201 if (rv) { 202 uvm_page_unbusy(pgs, npages); 203 rw_exit(uobj->vmobjlock); 204 goto out; 205 } 206 if (uio->uio_rw == UIO_WRITE) { 207 pg->flags &= ~PG_FAKE; 208 uvm_pagemarkdirty(pg, UVM_PAGE_STATUS_DIRTY); 209 } 210 todo -= xfersize; 211 } 212 uvm_page_unbusy(pgs, npages); 213 } while (todo); 214 rw_exit(uobj->vmobjlock); 215 216 out: 217 kmem_free(pgs, pgalloc); 218 return rv; 219 } 220
Indexes created Tue Sep 30 17:09:57 GMT 2025