Sample Code
windows driver samples/ cdfs file system driver/ C++/ fspdisp.c/
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 | /*++ Copyright (c) 1989-2000 Microsoft Corporation Module Name: FspDisp.c Abstract: This module implements the main dispatch procedure/thread for the Cdfs Fsp --*/ #include "CdProcs.h" // // The Bug check file id for this module // #define BugCheckFileId (CDFS_BUG_CHECK_FSPDISP)
VOID CdFspDispatch ( _In_ PVOID Context ) /*++ Routine Description: This is the main FSP thread routine that is executed to receive and dispatch IRP requests. Each FSP thread begins its execution here. There is one thread created at system initialization time and subsequent threads created as needed. Arguments: IrpContext - IrpContext for a request to process. Return Value: None --*/ { THREAD_CONTEXT ThreadContext = {0}; PIRP_CONTEXT IrpContext = Context; NTSTATUS Status; PIRP Irp = IrpContext->Irp; PIO_STACK_LOCATION IrpSp = IoGetCurrentIrpStackLocation( Irp ); PVOLUME_DEVICE_OBJECT VolDo = NULL; // // If this request has an associated volume device object, remember it. // if (IrpSp->FileObject != NULL) { VolDo = CONTAINING_RECORD( IrpSp->DeviceObject, VOLUME_DEVICE_OBJECT, DeviceObject ); } // // Now case on the function code. For each major function code, // either call the appropriate worker routine. This routine that // we call is responsible for completing the IRP, and not us. // That way the routine can complete the IRP and then continue // post processing as required. For example, a read can be // satisfied right away and then read can be done. // // We'll do all of the work within an exception handler that // will be invoked if ever some underlying operation gets into // trouble. // while ( TRUE ) { // // Set all the flags indicating we are in the Fsp. // SetFlag( IrpContext->Flags, IRP_CONTEXT_FSP_FLAGS ); FsRtlEnterFileSystem(); CdSetThreadContext( IrpContext, &ThreadContext ); while (TRUE) { try { // // Reinitialize for the next try at completing this // request. // Status = IrpContext->ExceptionStatus = STATUS_SUCCESS; // // Initialize the Io status field in the Irp. // Irp->IoStatus.Status = STATUS_SUCCESS; Irp->IoStatus.Information = 0; // // Case on the major irp code. // switch (IrpContext->MajorFunction) { case IRP_MJ_CREATE : CdCommonCreate( IrpContext, Irp ); break ; case IRP_MJ_CLOSE : NT_ASSERT( FALSE ); break ; case IRP_MJ_READ : CdCommonRead( IrpContext, Irp ); break ; case IRP_MJ_QUERY_INFORMATION : CdCommonQueryInfo( IrpContext, Irp ); break ; case IRP_MJ_SET_INFORMATION : CdCommonSetInfo( IrpContext, Irp ); break ; case IRP_MJ_QUERY_VOLUME_INFORMATION : CdCommonQueryVolInfo( IrpContext, Irp ); break ; case IRP_MJ_DIRECTORY_CONTROL : CdCommonDirControl( IrpContext, Irp ); break ; case IRP_MJ_FILE_SYSTEM_CONTROL : CdCommonFsControl( IrpContext, Irp ); break ; case IRP_MJ_DEVICE_CONTROL : CdCommonDevControl( IrpContext, Irp ); break ; case IRP_MJ_LOCK_CONTROL : CdCommonLockControl( IrpContext, Irp ); break ; case IRP_MJ_CLEANUP : CdCommonCleanup( IrpContext, Irp ); break ; case IRP_MJ_PNP : NT_ASSERT( FALSE ); CdCommonPnp( IrpContext, Irp ); break ; default : Status = STATUS_INVALID_DEVICE_REQUEST; CdCompleteRequest( IrpContext, Irp, Status ); } } except( CdExceptionFilter( IrpContext, GetExceptionInformation() )) { Status = CdProcessException( IrpContext, Irp, GetExceptionCode() ); } // // Break out of the loop if we didn't get CANT_WAIT. // if (Status != STATUS_CANT_WAIT) { break ; } // // We are retrying this request. Cleanup the IrpContext for the retry. // SetFlag( IrpContext->Flags, IRP_CONTEXT_FLAG_MORE_PROCESSING ); CdCleanupIrpContext( IrpContext, FALSE ); } FsRtlExitFileSystem(); // // If there are any entries on this volume's overflow queue, service // them. // if (VolDo != NULL) { KIRQL SavedIrql; PVOID Entry = NULL; // // We have a volume device object so see if there is any work // left to do in its overflow queue. // KeAcquireSpinLock( &VolDo->OverflowQueueSpinLock, &SavedIrql ); if (VolDo->OverflowQueueCount > 0) { // // There is overflow work to do in this volume so we'll // decrement the Overflow count, dequeue the IRP, and release // the Event // VolDo->OverflowQueueCount -= 1; Entry = RemoveHeadList( &VolDo->OverflowQueue ); } else { VolDo->PostedRequestCount -= 1; Entry = NULL; } KeReleaseSpinLock( &VolDo->OverflowQueueSpinLock, SavedIrql ); // // There wasn't an entry, break out of the loop and return to // the Ex Worker thread. // if (Entry == NULL) { break ; } // // Extract the IrpContext , Irp, set wait to TRUE, and loop. // IrpContext = CONTAINING_RECORD( Entry, IRP_CONTEXT, WorkQueueItem.List ); Irp = IrpContext->Irp; IrpSp = IoGetCurrentIrpStackLocation( Irp ); __analysis_assert( IrpSp != 0 ); continue ; } break ; } return ; } |
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