text: /** @file
    FUSE_UNLINK / FUSE_RMDIR wrapper for the Virtio Filesystem device.
  
    Copyright (C) 2020, Red Hat, Inc.
  
    SPDX-License-Identifier: BSD-2-Clause-Patent
  **/
  
  #include <Library/BaseLib.h> // AsciiStrSize()
  
  #include "VirtioFsDxe.h"
  
  /**
    Remove a regular file or a directory, by sending the FUSE_UNLINK or
    FUSE_RMDIR request to the Virtio Filesystem device.
  
    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_UNLINK
                             / FUSE_RMDIR request to. On output, the FUSE request
                             counter "VirtioFs->RequestId" will have been
                             incremented.
  
    @param[in] ParentNodeId  The inode number of the directory in which Name
                             should be removed.
  
    @param[in] Name          The single-component filename to remove in the
                             directory identified by ParentNodeId.
  
    @param[in] IsDir         TRUE if Name refers to a directory, FALSE otherwise.
  
    @retval EFI_SUCCESS  The file or directory has been removed.
  
    @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
  VirtioFsFuseRemoveFileOrDir (
    IN OUT VIRTIO_FS  *VirtioFs,
    IN     UINT64     ParentNodeId,
    IN     CHAR8      *Name,
    IN     BOOLEAN    IsDir
    )
  {
    VIRTIO_FS_FUSE_REQUEST         CommonReq;
    VIRTIO_FS_IO_VECTOR            ReqIoVec[2];
    VIRTIO_FS_SCATTER_GATHER_LIST  ReqSgList;
    VIRTIO_FS_FUSE_RESPONSE        CommonResp;
    VIRTIO_FS_IO_VECTOR            RespIoVec[1];
    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 = Name;
    ReqIoVec[1].Size   = AsciiStrSize (Name);
    ReqSgList.IoVec    = ReqIoVec;
    ReqSgList.NumVec   = ARRAY_SIZE (ReqIoVec);
  
    RespIoVec[0].Buffer = &CommonResp;
    RespIoVec[0].Size   = sizeof CommonResp;
    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,
               IsDir ? VirtioFsFuseOpRmDir : VirtioFsFuseOpUnlink,
               ParentNodeId
               );
    if (EFI_ERROR (Status)) {
      return Status;
    }
  
    //
    // 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 (Status == EFI_DEVICE_ERROR) {
      DEBUG ((
        DEBUG_ERROR,
        "%a: Label=\"%s\" ParentNodeId=%Lu Name=\"%a\" "
        "IsDir=%d Errno=%d\n",
        __FUNCTION__,
        VirtioFs->Label,
        ParentNodeId,
        Name,
        IsDir,
        CommonResp.Error
        ));
      Status = VirtioFsErrnoToEfiStatus (CommonResp.Error);
    }
  
    return Status;
  }
  