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| author | Laszlo Ersek <lersek@redhat.com> | 2020-12-16 22:11:10 +0100 |
|---|---|---|
| committer | mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> | 2020-12-21 17:16:23 +0000 |
| commit | 1c05df69984d3f515be991863f69c379e7dc9cba (patch) | |
| tree | 5b964410ebc347b8d6cbdc77cbd5fd72313efa6a | |
| parent | d98d7e3005cb5222af490355ec87758db318d7a3 (diff) | |
| download | edk2-1c05df69984d3f515be991863f69c379e7dc9cba.tar.gz edk2-1c05df69984d3f515be991863f69c379e7dc9cba.tar.bz2 edk2-1c05df69984d3f515be991863f69c379e7dc9cba.zip | |
OvmfPkg/VirtioFsDxe: implement EFI_FILE_PROTOCOL.Read() for regular files
Using the functions introduced previously, we can now implement
VirtioFsSimpleFileRead(); for regular files at first.
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3097
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20201216211125.19496-34-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
| -rw-r--r-- | OvmfPkg/VirtioFsDxe/SimpleFsRead.c | 75 |
1 files changed, 74 insertions, 1 deletions
diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsRead.c b/OvmfPkg/VirtioFsDxe/SimpleFsRead.c index e737d5e332..c4ad07c9ae 100644 --- a/OvmfPkg/VirtioFsDxe/SimpleFsRead.c +++ b/OvmfPkg/VirtioFsDxe/SimpleFsRead.c @@ -8,6 +8,69 @@ #include "VirtioFsDxe.h"
+/**
+ Read from a regular file.
+**/
+STATIC
+EFI_STATUS
+ReadRegularFile (
+ IN OUT VIRTIO_FS_FILE *VirtioFsFile,
+ IN OUT UINTN *BufferSize,
+ OUT VOID *Buffer
+ )
+{
+ VIRTIO_FS *VirtioFs;
+ EFI_STATUS Status;
+ VIRTIO_FS_FUSE_ATTRIBUTES_RESPONSE FuseAttr;
+ UINTN Transferred;
+ UINTN Left;
+
+ VirtioFs = VirtioFsFile->OwnerFs;
+ //
+ // The UEFI spec forbids reads that start beyond the end of the file.
+ //
+ Status = VirtioFsFuseGetAttr (VirtioFs, VirtioFsFile->NodeId, &FuseAttr);
+ if (EFI_ERROR (Status) || VirtioFsFile->FilePosition > FuseAttr.Size) {
+ return EFI_DEVICE_ERROR;
+ }
+
+ Status = EFI_SUCCESS;
+ Transferred = 0;
+ Left = *BufferSize;
+ while (Left > 0) {
+ UINT32 ReadSize;
+
+ //
+ // FUSE_READ cannot express a >=4GB buffer size.
+ //
+ ReadSize = (UINT32)MIN ((UINTN)MAX_UINT32, Left);
+ Status = VirtioFsFuseReadFileOrDir (
+ VirtioFs,
+ VirtioFsFile->NodeId,
+ VirtioFsFile->FuseHandle,
+ FALSE, // IsDir
+ VirtioFsFile->FilePosition + Transferred,
+ &ReadSize,
+ (UINT8 *)Buffer + Transferred
+ );
+ if (EFI_ERROR (Status) || ReadSize == 0) {
+ break;
+ }
+ Transferred += ReadSize;
+ Left -= ReadSize;
+ }
+
+ *BufferSize = Transferred;
+ VirtioFsFile->FilePosition += Transferred;
+ //
+ // If we managed to read some data, return success. If zero bytes were
+ // transferred due to zero-sized buffer on input or due to EOF on first read,
+ // return SUCCESS. Otherwise, return the error due to which zero bytes were
+ // transferred.
+ //
+ return (Transferred > 0) ? EFI_SUCCESS : Status;
+}
+
EFI_STATUS
EFIAPI
VirtioFsSimpleFileRead (
@@ -16,5 +79,15 @@ VirtioFsSimpleFileRead ( OUT VOID *Buffer
)
{
- return EFI_NO_MEDIA;
+ VIRTIO_FS_FILE *VirtioFsFile;
+ EFI_STATUS Status;
+
+ VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);
+
+ if (VirtioFsFile->IsDirectory) {
+ Status = EFI_NO_MEDIA;
+ } else {
+ Status = ReadRegularFile (VirtioFsFile, BufferSize, Buffer);
+ }
+ return Status;
}
|