1 /*- 2 * Copyright (c) 2011 The FreeBSD Foundation 3 * Copyright (c) 2014-2020 François Tigeot <ftigeot@wolfpond.org> 4 * All rights reserved. 5 * 6 * Portions of this software were developed by Konstantin Belousov 7 * under sponsorship from the FreeBSD 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 AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE 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 24 * OR 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 32 #include <vm/vm.h> 33 #include <vm/vm_page.h> 34 #include <vm/vm_page2.h> 35 #include <vm/vm_pager.h> 36 37 #include <linux/err.h> 38 #include <linux/shmem_fs.h> 39 40 struct page * 41 shmem_read_mapping_page(vm_object_t object, vm_pindex_t pindex) 42 { 43 vm_page_t m; 44 int rv; 45 46 VM_OBJECT_LOCK(object); 47 m = vm_page_grab(object, pindex, VM_ALLOC_NORMAL | VM_ALLOC_RETRY); 48 if (m->valid != VM_PAGE_BITS_ALL) { 49 if (vm_pager_has_page(object, pindex)) { 50 rv = vm_pager_get_page(object, &m, 1); 51 m = vm_page_lookup(object, pindex); 52 if (m == NULL) 53 return ERR_PTR(-ENOMEM); 54 if (rv != VM_PAGER_OK) { 55 vm_page_free(m); 56 return ERR_PTR(-ENOMEM); 57 } 58 } else { 59 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 60 m->valid = VM_PAGE_BITS_ALL; 61 m->dirty = 0; 62 } 63 } 64 vm_page_wire(m); 65 vm_page_wakeup(m); 66 VM_OBJECT_UNLOCK(object); 67 68 return (struct page *)m; 69 } 70 71 struct page * 72 shmem_read_mapping_page_gfp(struct vm_object *mapping, 73 pgoff_t index, gfp_t gfp_mask) 74 { 75 return shmem_read_mapping_page(mapping, index); 76 } 77