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  Message 1 of 13  
29 May 09 03:39
Alexei Kleimyonov
xxxxxx@rambler.ru
Join Date: 06 Apr 2009
Posts To This List: 11
Dynamic changing Parameters.Write.Length in irp stack
Hello all! The task is to dynamic change the size of writing ON DISK data. I try not to change data, that go in stack, and modify only irp with flag irp_nocache. Additional size is 0x200. So, the problem is that when i change Parameters.Write.Length in writing dispatch procedure and write in mapping file (with notepad, from example), i receive in completion procedure 0xc0000054 (FILE LOCKED). With simple writing (with far editor) all working ok. Can anybody help me?
  Message 2 of 13  
29 May 09 09:42
Alexei Kleimyonov
xxxxxx@rambler.ru
Join Date: 06 Apr 2009
Posts To This List: 11
RE: Dynamic changing Parameters.Write.Length in irp stack
No one knows? =(
  Message 3 of 13  
29 May 09 09:49
MM
xxxxxx@evitechnology.com
Join Date: 28 May 2005
Posts To This List: 359
RE: Dynamic changing Parameters.Write.Length in irp stack
Dude, it's only been about six hours, and at least here in the states most people aren't probably even at work yet. Have some patience. mm
  Message 4 of 13  
29 May 09 10:05
Aditya Shrivastava
xxxxxx@gmail.com
Join Date: 05 Oct 2006
Posts To This List: 293
RE: Dynamic changing Parameters.Write.Length in irp stack
So you are changing the writelength only, who will expand the buffer than?
  Message 5 of 13  
29 May 09 10:30
Peter Scott
xxxxxx@KernelDrivers.com
Join Date: 14 Jan 2002
Posts To This List: 506
Re: Dynamic changing Parameters.Write.Length in irp stack
xxxxx@rambler.ru wrote: > Hello all! > The task is to dynamic change the size of writing ON DISK data. I try not to change data, that go in stack, and modify only irp with flag irp_nocache. Additional size is 0x200. > > So, the problem is that when i change Parameters.Write.Length in writing dispatch procedure and write in mapping file (with notepad, from example), i receive in completion procedure 0xc0000054 (FILE LOCKED). With simple writing (with far editor) all working ok. > Can anybody help me? > Changing the length of writes going down to the underlying file system can be difficult. If you are trying to hide this additional length then things get really complicated. For instance, if you are changing this length during a PAGING request and the length goes beyond the EOF then it won't work. You need to update this length outside of the paging pathway so when you do receive the PAGING request the EOF is already adjusted. And, as Mr. Vastava asked, what are you doing about the buffer itself? Pete -- Kernel Drivers Windows File System and Device Driver Consulting www.KernelDrivers.com 866.263.9295 > --- > NTFSD is sponsored by OSR > > For our schedule of debugging and file system seminars > (including our new fs mini-filter seminar) visit: > http://www.osr.com/seminars > > To unsubscribe, visit the List Server section of OSR Online at http://www.osronline.com/page.cfm?name=ListServer
  Message 6 of 13  
29 May 09 11:03
Alexei Kleimyonov
xxxxxx@rambler.ru
Join Date: 06 Apr 2009
Posts To This List: 11
RE: Dynamic changing Parameters.Write.Length in irp stack
If writing is in the beginning of file, I save and replace the original MDL and create new, extended. In the beginning of new buffer i write my signature - 0x200 bytes length, then copy original data. pDiskDeviceExtension->oldMDL[i]=(PVOID)Irp->MdlAddress; newlen = MmGetMdlByteCount(mdl) + 0x1000; p_IO_STK->Parameters.Write.Length+=0x1000; MyBuffer=(PVOID)ExAllocatePool(NonPagedPool,newlen); MyMDL=IoAllocateMdl( MyBuffer, newlen, FALSE, FALSE, Irp ); if(MyMDL==NULL) { return ERROR_CREATE_IRP; } MmBuildMdlForNonPagedPool(MyMDL); RtlCopyMemory(MyBuffer+SIGSIZE,Buf,mylen-SIGSIZE); RtlCopyMemory(MyBuffer,SIGNATURE,REALSIZE);
  Message 7 of 13  
30 May 09 04:35
Alexei Kleimyonov
xxxxxx@rambler.ru
Join Date: 06 Apr 2009
Posts To This List: 11
RE: Dynamic changing Parameters.Write.Length in irp stack
I will try to create and send IRP_MJ_SET_INFORMATION with FileAllocationInformation from DispatchWrite to increase the size of file to 0x1000. I think i should do this when receive IRP_MJ_WRITE with flag IRP_NOCACHE. Can anybody give me example, how to do it correctly? This code doesn't work: KeInitializeEvent(&event2, SynchronizationEvent, FALSE); MyIrp = IoAllocateIrp(DeviceObject->StackSize,FALSE); if(!MyIrp) { return ERROR_CREATE_IRP; } MyBuffer=(PVOID)ExAllocatePool(NonPagedPool,sizeof(FILE_ALLOCATION_INFORMATION)); MyIrp->AssociatedIrp.SystemBuffer=MyBuffer; MyIrp->UserEvent = &event2; MyIrp->UserBuffer=MyBuffer; MyIrp->Cancel=FALSE; MyIrp->UserIosb = &IoStatusBlock; MyIrp->Tail.Overlay.Thread = PsGetCurrentThread(); MyIrp->Tail.Overlay.OriginalFileObject = p_IO_STK->FileObject; MyIrp->RequestorMode = UserMode; MyIrp->Flags = 0x830; IoSetNextIrpStackLocation(MyIrp); p_IO_NextSTK = IoGetCurrentIrpStackLocation(MyIrp); p_IO_NextSTK->DeviceObject = DeviceObject; p_IO_NextSTK->FileObject=p_IO_STK->FileObject; p_IO_NextSTK =IoGetNextIrpStackLocation(MyIrp); p_IO_NextSTK->MajorFunction=IRP_MJ_SET_INFORMATION; p_IO_NextSTK->MinorFunction = 0; p_IO_NextSTK->DeviceObject = DeviceObject; p_IO_NextSTK->FileObject=p_IO_STK->FileObject; p_IO_NextSTK->Parameters.SetFile.FileInformationClass=FileAllocationInform ation; p_IO_NextSTK->Parameters.SetFile.Length=sizeof(FILE_ALLOCATION_INFORMATION ); p_IO_NextSTK->Parameters.SetFile.ReplaceIfExists=FALSE; p_IO_NextSTK->Parameters.SetFile.AdvanceOnly=TRUE; ((PFILE_ALLOCATION_INFORMATION)MyBuffer)->AllocationSize.QuadPart=0; IoSetCompletionRoutine(MyIrp, OnCreateSetCompletion, &DeviceObject, TRUE, TRUE, TRUE); IoCallDriver(((PSFILTER_DEVICE_EXTENSION) DeviceObject->DeviceExtension)->AttachedToDeviceObject,MyIrp); KeWaitForSingleObject(&event2, Executive, KernelMode, TRUE, 0);
  Message 8 of 13  
30 May 09 04:51
Maxim S. Shatskih
xxxxxx@storagecraft.com
Join Date: 23 Feb 2000
Posts To This List: 3623
Re: Dynamic changing Parameters.Write.Length in irp stack
>I will try to create and send IRP_MJ_SET_INFORMATION with FileAllocationInformation from >DispatchWrite to increase the size of file to 0x1000. > I think i should do this when receive IRP_MJ_WRITE with flag IRP_NOCACHE. Major doubts that you can change the file size from within the paging IO path. -- Maxim S. Shatskih Windows DDK MVP xxxxx@storagecraft.com http://www.storagecraft.com
  Message 9 of 13  
30 May 09 09:14
Alexei Kleimyonov
xxxxxx@rambler.ru
Join Date: 06 Apr 2009
Posts To This List: 11
RE: Dynamic changing Parameters.Write.Length in irp stack
What can you advise me?
  Message 10 of 13  
30 May 09 18:18
Alexei Kleimyonov
xxxxxx@rambler.ru
Join Date: 06 Apr 2009
Posts To This List: 11
RE: Dynamic changing Parameters.Write.Length in irp stack
I tried many variants but unsuccessfully (
  Message 11 of 13  
31 May 09 06:41
Alexei Kleimyonov
xxxxxx@rambler.ru
Join Date: 06 Apr 2009
Posts To This List: 11
RE: Dynamic changing Parameters.Write.Length in irp stack
I tried to change only Parameters.ByteOffset.QuadPart and send my signature with additional IRP_MJ_WRITE. My irp wrote information successfully, but the main writing gave me again 0xc0000054 (((
  Message 12 of 13  
01 Jun 09 04:07
Malcolm Smith
xxxxxx@operamail.com
Join Date: 12 Sep 2007
Posts To This List: 71
Re: Dynamic changing Parameters.Write.Length in irp stack
xxxxx@rambler.ru wrote: > I tried to change only Parameters.ByteOffset.QuadPart and send my signature with additional IRP_MJ_WRITE. My irp wrote information successfully, but the main writing gave me again 0xc0000054 ((( > Sorry to be the one to point it out, but you're on completely the wrong track. You cannot do this by fudging writes to the filesystem. The filesystem maintains its own concept of file sizes. The exact behavior you will see is determined by the filesystem, but will typically either be a write dropped silently on the floor (truncated), or STATUS_FILE_LOCK_CONFLICT. I posted to this list a while back explaining when this occurs and why. If you want to change the length of the file, your filter needs to own caching, since file size information is communicated privately between the filesystem (cache owner) and the cache. If you own the cache, and only send noncached IO to the filesystem, you are then free to maintain one set of sizes to the user and another set to the filesystem. Owning the cache is not for the faint of heart. Writing the class of filter you are attempting is the hardest class according to many. You have been warned. Good luck, - M -- This posting is provided "AS IS" with no warranties, and confers no rights.
  Message 13 of 13  
01 Jun 09 05:37
Maxim S. Shatskih
xxxxxx@storagecraft.com
Join Date: 23 Feb 2000
Posts To This List: 3623
Re: Dynamic changing Parameters.Write.Length in irp stack
> Owning the cache is not for the faint of heart. Writing the class of > filter Such a filter is called "layered FSD". It is a full FSD, but uses noncached IO of the underlying filesystem to perform its operations. -- Maxim S. Shatskih Windows DDK MVP xxxxx@storagecraft.com http://www.storagecraft.com
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