audk/OvmfPkg/VirtioFsDxe/FuseOpen.c

140 lines
4.0 KiB
C

/** @file
FUSE_OPEN wrapper for the Virtio Filesystem device.
Copyright (C) 2020, Red Hat, Inc.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include "VirtioFsDxe.h"
/**
Send a FUSE_OPEN request to the Virtio Filesystem device, for opening a
regular file.
The function may only be called after VirtioFsFuseInitSession() returns
successfully and before VirtioFsUninit() is called.
@param[in,out] VirtioFs The Virtio Filesystem device to send the FUSE_OPEN
request to. On output, the FUSE request counter
"VirtioFs->RequestId" will have been incremented.
@param[in] NodeId The inode number of the regular file to open.
@param[in] ReadWrite If TRUE, open the regular file in read-write mode.
If FALSE, open the regular file in read-only mode.
@param[out] FuseHandle The open handle to the regular file, returned by the
Virtio Filesystem device.
@retval EFI_SUCCESS The regular file has been opened.
@return The "errno" value mapped to an EFI_STATUS code, if the
Virtio Filesystem device explicitly reported an error.
@return Error codes propagated from VirtioFsSgListsValidate(),
VirtioFsFuseNewRequest(), VirtioFsSgListsSubmit(),
VirtioFsFuseCheckResponse().
**/
EFI_STATUS
VirtioFsFuseOpen (
IN OUT VIRTIO_FS *VirtioFs,
IN UINT64 NodeId,
IN BOOLEAN ReadWrite,
OUT UINT64 *FuseHandle
)
{
VIRTIO_FS_FUSE_REQUEST CommonReq;
VIRTIO_FS_FUSE_OPEN_REQUEST OpenReq;
VIRTIO_FS_IO_VECTOR ReqIoVec[2];
VIRTIO_FS_SCATTER_GATHER_LIST ReqSgList;
VIRTIO_FS_FUSE_RESPONSE CommonResp;
VIRTIO_FS_FUSE_OPEN_RESPONSE OpenResp;
VIRTIO_FS_IO_VECTOR RespIoVec[2];
VIRTIO_FS_SCATTER_GATHER_LIST RespSgList;
EFI_STATUS Status;
//
// Set up the scatter-gather lists.
//
ReqIoVec[0].Buffer = &CommonReq;
ReqIoVec[0].Size = sizeof CommonReq;
ReqIoVec[1].Buffer = &OpenReq;
ReqIoVec[1].Size = sizeof OpenReq;
ReqSgList.IoVec = ReqIoVec;
ReqSgList.NumVec = ARRAY_SIZE (ReqIoVec);
RespIoVec[0].Buffer = &CommonResp;
RespIoVec[0].Size = sizeof CommonResp;
RespIoVec[1].Buffer = &OpenResp;
RespIoVec[1].Size = sizeof OpenResp;
RespSgList.IoVec = RespIoVec;
RespSgList.NumVec = ARRAY_SIZE (RespIoVec);
//
// Validate the scatter-gather lists; calculate the total transfer sizes.
//
Status = VirtioFsSgListsValidate (VirtioFs, &ReqSgList, &RespSgList);
if (EFI_ERROR (Status)) {
return Status;
}
//
// Populate the common request header.
//
Status = VirtioFsFuseNewRequest (
VirtioFs,
&CommonReq,
ReqSgList.TotalSize,
VirtioFsFuseOpOpen,
NodeId
);
if (EFI_ERROR (Status)) {
return Status;
}
//
// Populate the FUSE_OPEN-specific fields.
//
OpenReq.Flags = (ReadWrite ?
VIRTIO_FS_FUSE_OPEN_REQ_F_RDWR :
VIRTIO_FS_FUSE_OPEN_REQ_F_RDONLY);
OpenReq.Unused = 0;
//
// Submit the request.
//
Status = VirtioFsSgListsSubmit (VirtioFs, &ReqSgList, &RespSgList);
if (EFI_ERROR (Status)) {
return Status;
}
//
// Verify the response (all response buffers are fixed size).
//
Status = VirtioFsFuseCheckResponse (&RespSgList, CommonReq.Unique, NULL);
if (EFI_ERROR (Status)) {
if (Status == EFI_DEVICE_ERROR) {
DEBUG ((
DEBUG_ERROR,
"%a: Label=\"%s\" NodeId=%Lu ReadWrite=%d "
"Errno=%d\n",
__func__,
VirtioFs->Label,
NodeId,
ReadWrite,
CommonResp.Error
));
Status = VirtioFsErrnoToEfiStatus (CommonResp.Error);
}
return Status;
}
//
// Output the open handle.
//
*FuseHandle = OpenResp.FileHandle;
return EFI_SUCCESS;
}