OvmfPkg/BaseMemEncryptSevLib: skip the pre-validated system RAM

[mirror_edk2.git] / OvmfPkg / VirtioFsDxe / FuseForget.c

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