| 1 | /** @file
|
|---|
| 2 | EFI_FILE_PROTOCOL.Write() member function for the Virtio Filesystem driver.
|
|---|
| 3 |
|
|---|
| 4 | Copyright (C) 2020, Red Hat, Inc.
|
|---|
| 5 |
|
|---|
| 6 | SPDX-License-Identifier: BSD-2-Clause-Patent
|
|---|
| 7 | **/
|
|---|
| 8 |
|
|---|
| 9 | #include "VirtioFsDxe.h"
|
|---|
| 10 |
|
|---|
| 11 | EFI_STATUS
|
|---|
| 12 | EFIAPI
|
|---|
| 13 | VirtioFsSimpleFileWrite (
|
|---|
| 14 | IN EFI_FILE_PROTOCOL *This,
|
|---|
| 15 | IN OUT UINTN *BufferSize,
|
|---|
| 16 | IN VOID *Buffer
|
|---|
| 17 | )
|
|---|
| 18 | {
|
|---|
| 19 | VIRTIO_FS_FILE *VirtioFsFile;
|
|---|
| 20 | VIRTIO_FS *VirtioFs;
|
|---|
| 21 | EFI_STATUS Status;
|
|---|
| 22 | UINTN Transferred;
|
|---|
| 23 | UINTN Left;
|
|---|
| 24 |
|
|---|
| 25 | VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);
|
|---|
| 26 | VirtioFs = VirtioFsFile->OwnerFs;
|
|---|
| 27 |
|
|---|
| 28 | if (VirtioFsFile->IsDirectory) {
|
|---|
| 29 | return EFI_UNSUPPORTED;
|
|---|
| 30 | }
|
|---|
| 31 | if (!VirtioFsFile->IsOpenForWriting) {
|
|---|
| 32 | return EFI_ACCESS_DENIED;
|
|---|
| 33 | }
|
|---|
| 34 |
|
|---|
| 35 | Status = EFI_SUCCESS;
|
|---|
| 36 | Transferred = 0;
|
|---|
| 37 | Left = *BufferSize;
|
|---|
| 38 | while (Left > 0) {
|
|---|
| 39 | UINT32 WriteSize;
|
|---|
| 40 |
|
|---|
| 41 | //
|
|---|
| 42 | // Honor the write buffer size limit.
|
|---|
| 43 | //
|
|---|
| 44 | WriteSize = (UINT32)MIN ((UINTN)VirtioFs->MaxWrite, Left);
|
|---|
| 45 | Status = VirtioFsFuseWrite (
|
|---|
| 46 | VirtioFs,
|
|---|
| 47 | VirtioFsFile->NodeId,
|
|---|
| 48 | VirtioFsFile->FuseHandle,
|
|---|
| 49 | VirtioFsFile->FilePosition + Transferred,
|
|---|
| 50 | &WriteSize,
|
|---|
| 51 | (UINT8 *)Buffer + Transferred
|
|---|
| 52 | );
|
|---|
| 53 | if (!EFI_ERROR (Status) && WriteSize == 0) {
|
|---|
| 54 | //
|
|---|
| 55 | // Progress should have been made.
|
|---|
| 56 | //
|
|---|
| 57 | Status = EFI_DEVICE_ERROR;
|
|---|
| 58 | }
|
|---|
| 59 | if (EFI_ERROR (Status)) {
|
|---|
| 60 | break;
|
|---|
| 61 | }
|
|---|
| 62 | Transferred += WriteSize;
|
|---|
| 63 | Left -= WriteSize;
|
|---|
| 64 | }
|
|---|
| 65 |
|
|---|
| 66 | *BufferSize = Transferred;
|
|---|
| 67 | VirtioFsFile->FilePosition += Transferred;
|
|---|
| 68 | //
|
|---|
| 69 | // According to the UEFI spec,
|
|---|
| 70 | //
|
|---|
| 71 | // - 'Partial writes only occur when there has been a data error during the
|
|---|
| 72 | // write attempt (such as "file space full")', and
|
|---|
| 73 | //
|
|---|
| 74 | // - (as an example) EFI_VOLUME_FULL is returned when 'The volume is full'.
|
|---|
| 75 | //
|
|---|
| 76 | // These together imply that after a partial write, we have to return an
|
|---|
| 77 | // error. In other words, (Transferred > 0) is inconsequential for the return
|
|---|
| 78 | // value.
|
|---|
| 79 | //
|
|---|
| 80 | return Status;
|
|---|
| 81 | }
|
|---|
