OvmfPkg/VirtioFsDxe/FuseUnlink.c

   1 /** @file
   2   FUSE_UNLINK / FUSE_RMDIR wrapper for the Virtio Filesystem device.
   3
   4   Copyright (C) 2020, Red Hat, Inc.
   5
   6   SPDX-License-Identifier: BSD-2-Clause-Patent
   7 **/
   8
   9 #include <Library/BaseLib.h> // AsciiStrSize()
  10
  11 #include "VirtioFsDxe.h"
  12
  13 /**
  14   Remove a regular file or a directory, by sending the FUSE_UNLINK or
  15   FUSE_RMDIR request to the Virtio Filesystem device.
  16
  17   The function may only be called after VirtioFsFuseInitSession() returns
  18   successfully and before VirtioFsUninit() is called.
  19
  20   @param[in,out] VirtioFs  The Virtio Filesystem device to send the FUSE_UNLINK
  21                            / FUSE_RMDIR request to. On output, the FUSE request
  22                            counter "VirtioFs->RequestId" will have been
  23                            incremented.
  24
  25   @param[in] ParentNodeId  The inode number of the directory in which Name
  26                            should be removed.
  27
  28   @param[in] Name          The single-component filename to remove in the
  29                            directory identified by ParentNodeId.
  30
  31   @param[in] IsDir         TRUE if Name refers to a directory, FALSE otherwise.
  32
  33   @retval EFI_SUCCESS  The file or directory has been removed.
  34
  35   @return              The "errno" value mapped to an EFI_STATUS code, if the
  36                        Virtio Filesystem device explicitly reported an error.
  37
  38   @return              Error codes propagated from VirtioFsSgListsValidate(),
  39                        VirtioFsFuseNewRequest(), VirtioFsSgListsSubmit(),
  40                        VirtioFsFuseCheckResponse().
  41 **/
  42 EFI_STATUS
  43 VirtioFsFuseRemoveFileOrDir (
  44   IN OUT VIRTIO_FS  *VirtioFs,
  45   IN     UINT64     ParentNodeId,
  46   IN     CHAR8      *Name,
  47   IN     BOOLEAN    IsDir
  48   )
  49 {
  50   VIRTIO_FS_FUSE_REQUEST         CommonReq;
  51   VIRTIO_FS_IO_VECTOR            ReqIoVec[2];
  52   VIRTIO_FS_SCATTER_GATHER_LIST  ReqSgList;
  53   VIRTIO_FS_FUSE_RESPONSE        CommonResp;
  54   VIRTIO_FS_IO_VECTOR            RespIoVec[1];
  55   VIRTIO_FS_SCATTER_GATHER_LIST  RespSgList;
  56   EFI_STATUS                     Status;
  57
  58   //
  59   // Set up the scatter-gather lists.
  60   //
  61   ReqIoVec[0].Buffer = &CommonReq;
  62   ReqIoVec[0].Size   = sizeof CommonReq;
  63   ReqIoVec[1].Buffer = Name;
  64   ReqIoVec[1].Size   = AsciiStrSize (Name);
  65   ReqSgList.IoVec    = ReqIoVec;
  66   ReqSgList.NumVec   = ARRAY_SIZE (ReqIoVec);
  67
  68   RespIoVec[0].Buffer = &CommonResp;
  69   RespIoVec[0].Size   = sizeof CommonResp;
  70   RespSgList.IoVec    = RespIoVec;
  71   RespSgList.NumVec   = ARRAY_SIZE (RespIoVec);
  72
  73   //
  74   // Validate the scatter-gather lists; calculate the total transfer sizes.
  75   //
  76   Status = VirtioFsSgListsValidate (VirtioFs, &ReqSgList, &RespSgList);
  77   if (EFI_ERROR (Status)) {
  78     return Status;
  79   }
  80
  81   //
  82   // Populate the common request header.
  83   //
  84   Status = VirtioFsFuseNewRequest (
  85              VirtioFs,
  86              &CommonReq,
  87              ReqSgList.TotalSize,
  88              IsDir ? VirtioFsFuseOpRmDir : VirtioFsFuseOpUnlink,
  89              ParentNodeId
  90              );
  91   if (EFI_ERROR (Status)) {
  92     return Status;
  93   }
  94
  95   //
  96   // Submit the request.
  97   //
  98   Status = VirtioFsSgListsSubmit (VirtioFs, &ReqSgList, &RespSgList);
  99   if (EFI_ERROR (Status)) {
 100     return Status;
 101   }
 102
 103   //
 104   // Verify the response (all response buffers are fixed size).
 105   //
 106   Status = VirtioFsFuseCheckResponse (&RespSgList, CommonReq.Unique, NULL);
 107   if (Status == EFI_DEVICE_ERROR) {
 108     DEBUG ((
 109       DEBUG_ERROR,
 110       "%a: Label=\"%s\" ParentNodeId=%Lu Name=\"%a\" "
 111       "IsDir=%d Errno=%d\n",
 112       __FUNCTION__,
 113       VirtioFs->Label,
 114       ParentNodeId,
 115       Name,
 116       IsDir,
 117       CommonResp.Error
 118       ));
 119     Status = VirtioFsErrnoToEfiStatus (CommonResp.Error);
 120   }
 121
 122   return Status;
 123 }