audk/OvmfPkg/VirtioFsDxe/FuseForget.c

86 lines
2.6 KiB
C

/** @file
FUSE_FORGET wrapper for the Virtio Filesystem device.
Copyright (C) 2020, Red Hat, Inc.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include "VirtioFsDxe.h"
/**
Make the Virtio Filesysem device drop one reference count from a NodeId that
the driver looked up by filename.
Send the FUSE_FORGET request to the Virtio Filesysem device for this. Unlike
most other FUSE requests, FUSE_FORGET doesn't elicit a response, not even the
common VIRTIO_FS_FUSE_RESPONSE header.
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_FORGET
request to. On output, the FUSE request counter
"VirtioFs->RequestId" will have been incremented.
@param[in] NodeId The inode number that the client learned by way of
lookup, and that the server should now un-reference
exactly once.
@retval EFI_SUCCESS The FUSE_FORGET request has been submitted.
@return Error codes propagated from VirtioFsSgListsValidate(),
VirtioFsFuseNewRequest(), VirtioFsSgListsSubmit().
**/
EFI_STATUS
VirtioFsFuseForget (
IN OUT VIRTIO_FS *VirtioFs,
IN UINT64 NodeId
)
{
VIRTIO_FS_FUSE_REQUEST CommonReq;
VIRTIO_FS_FUSE_FORGET_REQUEST ForgetReq;
VIRTIO_FS_IO_VECTOR ReqIoVec[2];
VIRTIO_FS_SCATTER_GATHER_LIST ReqSgList;
EFI_STATUS Status;
//
// Set up the scatter-gather list (note: only request).
//
ReqIoVec[0].Buffer = &CommonReq;
ReqIoVec[0].Size = sizeof CommonReq;
ReqIoVec[1].Buffer = &ForgetReq;
ReqIoVec[1].Size = sizeof ForgetReq;
ReqSgList.IoVec = ReqIoVec;
ReqSgList.NumVec = ARRAY_SIZE (ReqIoVec);
//
// Validate the scatter-gather list (request only); calculate the total
// transfer size.
//
Status = VirtioFsSgListsValidate (VirtioFs, &ReqSgList, NULL);
if (EFI_ERROR (Status)) {
return Status;
}
//
// Populate the common request header.
//
Status = VirtioFsFuseNewRequest (VirtioFs, &CommonReq, ReqSgList.TotalSize,
VirtioFsFuseOpForget, NodeId);
if (EFI_ERROR (Status)) {
return Status;
}
//
// Populate the FUSE_FORGET-specific fields.
//
ForgetReq.NumberOfLookups = 1;
//
// Submit the request. There's not going to be a response.
//
Status = VirtioFsSgListsSubmit (VirtioFs, &ReqSgList, NULL);
return Status;
}