/** @file | |
FUSE_INIT 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_INIT request to the Virtio Filesystem device, for starting the | |
FUSE session. | |
From virtio-v1.1-cs01-87fa6b5d8155, 5.11.5 Device Initialization: "On | |
initialization the driver first discovers the device's virtqueues. The FUSE | |
session is started by sending a FUSE_INIT request as defined by the FUSE | |
protocol on one request virtqueue." | |
The function may only be called after VirtioFsInit() returns successfully and | |
before VirtioFsUninit() is called. | |
@param[in,out] VirtioFs The Virtio Filesystem device to send the FUSE_INIT | |
request to. The FUSE request counter | |
"VirtioFs->RequestId" is set to 1 on output. The | |
maximum write buffer size exposed in the FUSE_INIT | |
response is saved in "VirtioFs->MaxWrite", on | |
output. | |
@retval EFI_SUCCESS The FUSE session has been started. | |
@retval EFI_UNSUPPORTED FUSE interface version or feature negotiation | |
failed. | |
@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 | |
VirtioFsFuseInitSession ( | |
IN OUT VIRTIO_FS *VirtioFs | |
) | |
{ | |
VIRTIO_FS_FUSE_REQUEST CommonReq; | |
VIRTIO_FS_FUSE_INIT_REQUEST InitReq; | |
VIRTIO_FS_IO_VECTOR ReqIoVec[2]; | |
VIRTIO_FS_SCATTER_GATHER_LIST ReqSgList; | |
VIRTIO_FS_FUSE_RESPONSE CommonResp; | |
VIRTIO_FS_FUSE_INIT_RESPONSE InitResp; | |
VIRTIO_FS_IO_VECTOR RespIoVec[2]; | |
VIRTIO_FS_SCATTER_GATHER_LIST RespSgList; | |
EFI_STATUS Status; | |
// | |
// Initialize the FUSE request counter. | |
// | |
VirtioFs->RequestId = 1; | |
// | |
// Set up the scatter-gather lists. | |
// | |
ReqIoVec[0].Buffer = &CommonReq; | |
ReqIoVec[0].Size = sizeof CommonReq; | |
ReqIoVec[1].Buffer = &InitReq; | |
ReqIoVec[1].Size = sizeof InitReq; | |
ReqSgList.IoVec = ReqIoVec; | |
ReqSgList.NumVec = ARRAY_SIZE (ReqIoVec); | |
RespIoVec[0].Buffer = &CommonResp; | |
RespIoVec[0].Size = sizeof CommonResp; | |
RespIoVec[1].Buffer = &InitResp; | |
RespIoVec[1].Size = sizeof InitResp; | |
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, | |
VirtioFsFuseOpInit, | |
0 | |
); | |
if (EFI_ERROR (Status)) { | |
return Status; | |
} | |
// | |
// Populate the FUSE_INIT-specific fields. | |
// | |
InitReq.Major = VIRTIO_FS_FUSE_MAJOR; | |
InitReq.Minor = VIRTIO_FS_FUSE_MINOR; | |
InitReq.MaxReadahead = 0; | |
InitReq.Flags = VIRTIO_FS_FUSE_INIT_REQ_F_DO_READDIRPLUS; | |
// | |
// 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\" Errno=%d\n", | |
__func__, | |
VirtioFs->Label, | |
CommonResp.Error | |
)); | |
Status = VirtioFsErrnoToEfiStatus (CommonResp.Error); | |
} | |
return Status; | |
} | |
// | |
// Check FUSE interface version / feature compatibility. | |
// | |
if ((InitResp.Major < InitReq.Major) || | |
((InitResp.Major == InitReq.Major) && (InitResp.Minor < InitReq.Minor)) || | |
((InitResp.Flags & VIRTIO_FS_FUSE_INIT_REQ_F_DO_READDIRPLUS) == 0) || | |
(InitResp.MaxWrite < SIZE_4KB)) | |
{ | |
return EFI_UNSUPPORTED; | |
} | |
// | |
// Save the maximum write buffer size for FUSE_WRITE requests. | |
// | |
VirtioFs->MaxWrite = InitResp.MaxWrite; | |
return EFI_SUCCESS; | |
} |