OvmfPkg/VirtioFsDxe/FuseStatFs.c

   1 /** @file
   2   FUSE_STATFS 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 "VirtioFsDxe.h"
  10
  11 /**
  12   Send the FUSE_STATFS request to the Virtio Filesysem device, for retrieving
  13   the attributes of the host-side filesystem that contains NodeId.
  14
  15   The function may only be called after VirtioFsFuseInitSession() returns
  16   successfully and before VirtioFsUninit() is called.
  17
  18   @param[in,out] VirtioFs  The Virtio Filesystem device to send the FUSE_STATFS
  19                            request to. On output, the FUSE request counter
  20                            "VirtioFs->RequestId" will have been incremented.
  21
  22   @param[in] NodeId        The inode whose containing filesystem is to be
  23                            queried for its attributes.
  24
  25   @param[out] FilesysAttr  The VIRTIO_FS_FUSE_STATFS_RESPONSE object describing
  26                            the filesystem that underlies NodeId.
  27
  28   @retval EFI_SUCCESS  FilesysAttr has been filled in.
  29
  30   @return              The "errno" value mapped to an EFI_STATUS code, if the
  31                        Virtio Filesystem device explicitly reported an error.
  32
  33   @return              Error codes propagated from VirtioFsSgListsValidate(),
  34                        VirtioFsFuseNewRequest(), VirtioFsSgListsSubmit(),
  35                        VirtioFsFuseCheckResponse().
  36 **/
  37 EFI_STATUS
  38 VirtioFsFuseStatFs (
  39   IN OUT VIRTIO_FS                    *VirtioFs,
  40   IN     UINT64                       NodeId,
  41   OUT VIRTIO_FS_FUSE_STATFS_RESPONSE  *FilesysAttr
  42   )
  43 {
  44   VIRTIO_FS_FUSE_REQUEST         CommonReq;
  45   VIRTIO_FS_IO_VECTOR            ReqIoVec[1];
  46   VIRTIO_FS_SCATTER_GATHER_LIST  ReqSgList;
  47   VIRTIO_FS_FUSE_RESPONSE        CommonResp;
  48   VIRTIO_FS_IO_VECTOR            RespIoVec[2];
  49   VIRTIO_FS_SCATTER_GATHER_LIST  RespSgList;
  50   EFI_STATUS                     Status;
  51
  52   //
  53   // Set up the scatter-gather lists.
  54   //
  55   ReqIoVec[0].Buffer = &CommonReq;
  56   ReqIoVec[0].Size   = sizeof CommonReq;
  57   ReqSgList.IoVec    = ReqIoVec;
  58   ReqSgList.NumVec   = ARRAY_SIZE (ReqIoVec);
  59
  60   RespIoVec[0].Buffer = &CommonResp;
  61   RespIoVec[0].Size   = sizeof CommonResp;
  62   RespIoVec[1].Buffer = FilesysAttr;
  63   RespIoVec[1].Size   = sizeof *FilesysAttr;
  64   RespSgList.IoVec    = RespIoVec;
  65   RespSgList.NumVec   = ARRAY_SIZE (RespIoVec);
  66
  67   //
  68   // Validate the scatter-gather lists; calculate the total transfer sizes.
  69   //
  70   Status = VirtioFsSgListsValidate (VirtioFs, &ReqSgList, &RespSgList);
  71   if (EFI_ERROR (Status)) {
  72     return Status;
  73   }
  74
  75   //
  76   // Populate the common request header.
  77   //
  78   Status = VirtioFsFuseNewRequest (
  79              VirtioFs,
  80              &CommonReq,
  81              ReqSgList.TotalSize,
  82              VirtioFsFuseOpStatFs,
  83              NodeId
  84              );
  85   if (EFI_ERROR (Status)) {
  86     return Status;
  87   }
  88
  89   //
  90   // Submit the request.
  91   //
  92   Status = VirtioFsSgListsSubmit (VirtioFs, &ReqSgList, &RespSgList);
  93   if (EFI_ERROR (Status)) {
  94     return Status;
  95   }
  96
  97   //
  98   // Verify the response (all response buffers are fixed size).
  99   //
 100   Status = VirtioFsFuseCheckResponse (&RespSgList, CommonReq.Unique, NULL);
 101   if (Status == EFI_DEVICE_ERROR) {
 102     DEBUG ((
 103       DEBUG_ERROR,
 104       "%a: Label=\"%s\" NodeId=%Lu Errno=%d\n",
 105       __FUNCTION__,
 106       VirtioFs->Label,
 107       NodeId,
 108       CommonResp.Error
 109       ));
 110     Status = VirtioFsErrnoToEfiStatus (CommonResp.Error);
 111   }
 112
 113   return Status;
 114 }