[fireball] 33476: - Factor out device reading code into a separate function. - Fix a bug which led to reading a wrong sector in case of DeltaEnd != 0 operation.
Author: fireball Date: Mon May 12 11:30:20 2008 New Revision: 33476
URL: http://svn.reactos.org/svn/reactos?rev=33476&view=rev Log: - Factor out device reading code into a separate function. - Fix a bug which led to reading a wrong sector in case of DeltaEnd != 0 operation.
Modified: branches/nocc/ntoskrnl/cache/copysup.c
Modified: branches/nocc/ntoskrnl/cache/copysup.c URL: http://svn.reactos.org/svn/reactos/branches/nocc/ntoskrnl/cache/copysup.c?re... ============================================================================== --- branches/nocc/ntoskrnl/cache/copysup.c [iso-8859-1] (original) +++ branches/nocc/ntoskrnl/cache/copysup.c [iso-8859-1] Mon May 12 11:30:20 2008 @@ -26,6 +26,45 @@
/* FUNCTIONS ******************************************************************/
+NTSTATUS +NTAPI +DoDeviceRead(PFILE_OBJECT FileObject, + LARGE_INTEGER SectorBase, + PCHAR SystemBuffer, + ULONG AlignSize, + ULONG *LengthRead) +{ + IO_STATUS_BLOCK IoStatusBlock = {{0}}; + NTSTATUS Status; + KEVENT Event; + PMDL Mdl; + + /* Create an MDL for the transfer */ + Mdl = IoAllocateMdl(SystemBuffer, AlignSize, TRUE, FALSE, NULL); + MmBuildMdlForNonPagedPool(Mdl), + Mdl->MdlFlags |= (MDL_PAGES_LOCKED | MDL_IO_PAGE_READ); + + /* Setup the event */ + KeInitializeEvent(&Event, NotificationEvent, FALSE); + + /* Read the page */ + Status = IoPageRead(FileObject, Mdl, &SectorBase, &Event, &IoStatusBlock); + if (Status == STATUS_PENDING) + { + /* Do the wait */ + KeWaitForSingleObject(&Event, Suspended, KernelMode, FALSE, NULL); + Status = IoStatusBlock.Status; + } + + /* Free the MDL */ + IoFreeMdl(Mdl); + + /* Save how much we read, if needed */ + if (LengthRead) *LengthRead = IoStatusBlock.Information; + + return Status; +} + BOOLEAN NTAPI CcCopyRead(IN PFILE_OBJECT FileObject, @@ -38,10 +77,8 @@ NTSTATUS Status; ULONG AlignBase, AlignSize, DeltaBase; LARGE_INTEGER SectorBase; - IO_STATUS_BLOCK IoStatusBlock = {{0}}; - KEVENT Event; PCHAR SystemBuffer; - PMDL Mdl; + ULONG LengthRead; BOOLEAN DirectRead = FALSE; DPRINT("CcCopyRead(FileObject 0x%p, FileOffset %I64x, " "Length %lx, Wait %d, Buffer 0x%p, IoStatus 0x%p)\n", @@ -81,22 +118,9 @@ DeltaBase = 0; }
- /* Create an MDL for the transfer */ - Mdl = IoAllocateMdl(SystemBuffer, AlignSize, TRUE, FALSE, NULL); - MmBuildMdlForNonPagedPool(Mdl), - Mdl->MdlFlags |= (MDL_PAGES_LOCKED | MDL_IO_PAGE_READ); - - /* Setup the event */ - KeInitializeEvent(&Event, NotificationEvent, FALSE); - - /* Read the page */ - Status = IoPageRead(FileObject, Mdl, &SectorBase, &Event, &IoStatusBlock); - if (Status == STATUS_PENDING) - { - /* Do the wait */ - KeWaitForSingleObject(&Event, Suspended, KernelMode, FALSE, NULL); - Status = IoStatusBlock.Status; - } + /* Do actual read from the device */ + Status = DoDeviceRead(FileObject, SectorBase, SystemBuffer, AlignSize, &LengthRead); + if (!NT_SUCCESS(Status)) DPRINT1("Status: %lx\n", Status); ASSERT(NT_SUCCESS(Status));
@@ -110,14 +134,11 @@ ExFreePool(SystemBuffer); }
- /* Free the MDL */ - IoFreeMdl(Mdl); - /* Check if we read less than the caller wanted */ - if (IoStatusBlock.Information < Length) + if (LengthRead < Length) { /* Only then do we write the real size */ - IoStatus->Information = IoStatusBlock.Information; + IoStatus->Information = LengthRead; } else { @@ -142,7 +163,7 @@ UNIMPLEMENTED; while (TRUE); } - + BOOLEAN NTAPI CcCopyWrite(IN PFILE_OBJECT FileObject, @@ -157,7 +178,7 @@ IO_STATUS_BLOCK IoStatusBlock; KEVENT Event; PCHAR SystemBuffer; - PMDL Mdl, ReadMdl; + PMDL Mdl; BOOLEAN DirectWrite = FALSE; DPRINT("CcCopyWrite(FileObject 0x%p, FileOffset %I64x, " "Length %lx, Wait %d, Buffer 0x%p)\n", @@ -242,63 +263,28 @@ // if (DeltaBase) { - /* Create an MDL for the read transfer */ - ReadMdl = IoAllocateMdl(SystemBuffer, PAGE_SIZE, TRUE, FALSE, NULL); - MmBuildMdlForNonPagedPool(ReadMdl), - ReadMdl->MdlFlags |= (MDL_PAGES_LOCKED | MDL_IO_PAGE_READ); - /* We have an offset from a page boundary, so we need to do a read */ - ReadSector = SectorBase; - Status = IoPageRead(FileObject, - ReadMdl, - &ReadSector, - &Event, - &IoStatusBlock); - if (Status == STATUS_PENDING) - { - /* Do the wait */ - KeWaitForSingleObject(&Event, Suspended, KernelMode, FALSE, NULL); - Status = IoStatusBlock.Status; - } + Status = DoDeviceRead(FileObject, SectorBase, SystemBuffer, + PAGE_SIZE, NULL);
/* This shouldn't fail */ ASSERT(NT_SUCCESS(Status)); - - /* Free the MDL */ - IoFreeMdl(ReadMdl); }
/* Now check if we read up to a page boundary, or have an offset */ if ((DeltaEnd))// && (Length > PAGE_SIZE)) { - /* Create an MDL for the read transfer */ - ReadMdl = IoAllocateMdl(SystemBuffer + ROUND_DOWN(Length, PAGE_SIZE), - PAGE_SIZE, - TRUE, - FALSE, - NULL); - MmBuildMdlForNonPagedPool(ReadMdl), - ReadMdl->MdlFlags |= (MDL_PAGES_LOCKED | MDL_IO_PAGE_READ); - /* We have an offset from a page boundary, so we need to do a read */ + ReadSector = SectorBase; ReadSector.QuadPart += ROUND_DOWN(Length, PAGE_SIZE); - Status = IoPageRead(FileObject, - ReadMdl, - &SectorBase, - &Event, - &IoStatusBlock); - if (Status == STATUS_PENDING) - { - /* Do the wait */ - KeWaitForSingleObject(&Event, Suspended, KernelMode, FALSE, NULL); - Status = IoStatusBlock.Status; - } + Status = DoDeviceRead(FileObject, + ReadSector, + SystemBuffer + ROUND_DOWN(Length, PAGE_SIZE), + PAGE_SIZE, + NULL);
/* This shouldn't fail */ ASSERT(NT_SUCCESS(Status)); - - /* Free the MDL */ - IoFreeMdl(ReadMdl); }
/* Okay, now we have the original data, write our modified data on top */
-
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