1 /* 2 * Copyright 2008, Ingo Weinhold, ingo_weinhold@gmx.de. 3 * Copyright 2004-2007, Axel Dörfler, axeld@pinc-software.de. 4 * Distributed under the terms of the MIT License. 5 */ 6 7 #include "vnode_store.h" 8 9 #include <stdlib.h> 10 #include <string.h> 11 12 #include <file_cache.h> 13 #include <vfs.h> 14 #include <vm.h> 15 16 #include "IORequest.h" 17 18 19 status_t 20 VMVnodeCache::Init(struct vnode *vnode) 21 { 22 status_t error = VMCache::Init(CACHE_TYPE_VNODE); 23 if (error != B_OK) 24 return error; 25 26 fVnode = vnode; 27 fFileCacheRef = NULL; 28 29 vfs_vnode_to_node_ref(fVnode, &fDevice, &fInode); 30 31 return B_OK; 32 } 33 34 35 bool 36 VMVnodeCache::HasPage(off_t offset) 37 { 38 // We always pretend to have the page - even if it's beyond the size of 39 // the file. The read function will only cut down the size of the read, 40 // it won't fail because of that. 41 return true; 42 } 43 44 45 status_t 46 VMVnodeCache::Read(off_t offset, const iovec *vecs, size_t count, 47 uint32 flags, size_t *_numBytes) 48 { 49 size_t bytesUntouched = *_numBytes; 50 51 status_t status = vfs_read_pages(fVnode, NULL, offset, vecs, count, 52 flags, _numBytes); 53 54 size_t bytesEnd = *_numBytes; 55 56 if (offset + bytesEnd > virtual_end) 57 bytesEnd = virtual_end - offset; 58 59 // If the request could be filled completely, or an error occured, 60 // we're done here 61 if (status != B_OK || bytesUntouched == bytesEnd) 62 return status; 63 64 bytesUntouched -= bytesEnd; 65 66 // Clear out any leftovers that were not touched by the above read - we're 67 // doing this here so that not every file system/device has to implement 68 // this 69 for (int32 i = count; i-- > 0 && bytesUntouched != 0;) { 70 size_t length = min_c(bytesUntouched, vecs[i].iov_len); 71 72 addr_t address = (addr_t)vecs[i].iov_base + vecs[i].iov_len - length; 73 if ((flags & B_PHYSICAL_IO_REQUEST) != 0) 74 vm_memset_physical(address, 0, length); 75 else 76 memset((void*)address, 0, length); 77 78 bytesUntouched -= length; 79 } 80 81 return B_OK; 82 } 83 84 85 status_t 86 VMVnodeCache::Write(off_t offset, const iovec *vecs, size_t count, 87 uint32 flags, size_t *_numBytes) 88 { 89 return vfs_write_pages(fVnode, NULL, offset, vecs, count, flags, _numBytes); 90 } 91 92 93 status_t 94 VMVnodeCache::WriteAsync(off_t offset, const iovec* vecs, size_t count, 95 size_t numBytes, uint32 flags, AsyncIOCallback* callback) 96 { 97 return vfs_asynchronous_write_pages(fVnode, NULL, offset, vecs, count, 98 numBytes, flags, callback); 99 } 100 101 102 status_t 103 VMVnodeCache::Fault(struct vm_address_space *aspace, off_t offset) 104 { 105 return B_BAD_HANDLER; 106 } 107 108 109 bool 110 VMVnodeCache::CanWritePage(off_t offset) 111 { 112 // all pages can be written 113 return true; 114 } 115 116 117 status_t 118 VMVnodeCache::AcquireUnreferencedStoreRef() 119 { 120 struct vnode *vnode; 121 status_t status = vfs_get_vnode(fDevice, fInode, false, &vnode); 122 123 // If successful, update the store's vnode pointer, so that release_ref() 124 // won't use a stale pointer. 125 if (status == B_OK) 126 fVnode = vnode; 127 128 return status; 129 } 130 131 132 void 133 VMVnodeCache::AcquireStoreRef() 134 { 135 vfs_acquire_vnode(fVnode); 136 } 137 138 139 void 140 VMVnodeCache::ReleaseStoreRef() 141 { 142 vfs_put_vnode(fVnode); 143 } 144 145