OvmfPkg/VirtioFsDxe/FuseFlush.c

   1 /** @file
   2   FUSE_FLUSH 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   Flush changes queued on the local virtualization host to the remote storage
  13   server's memory (not storage device), over the network, by sending the
  14   FUSE_FLUSH request to the Virtio Filesystem device.
  15
  16   The function may only be called after VirtioFsFuseInitSession() returns
  17   successfully and before VirtioFsUninit() is called.
  18
  19   @param[in,out] VirtioFs  The Virtio Filesystem device to send the FUSE_FLUSH
  20                            request to. On output, the FUSE request counter
  21                            "VirtioFs->RequestId" will have been incremented.
  22
  23   @param[in] NodeId        The inode number of the regular file to flush.
  24
  25   @param[in] FuseHandle    The open handle to the regular file to flush.
  26
  27   @retval EFI_SUCCESS  The regular file has been flushed.
  28
  29   @return              The "errno" value mapped to an EFI_STATUS code, if the
  30                        Virtio Filesystem device explicitly reported an error.
  31
  32   @return              Error codes propagated from VirtioFsSgListsValidate(),
  33                        VirtioFsFuseNewRequest(), VirtioFsSgListsSubmit(),
  34                        VirtioFsFuseCheckResponse().
  35 **/
  36 EFI_STATUS
  37 VirtioFsFuseFlush (
  38   IN OUT VIRTIO_FS  *VirtioFs,
  39   IN     UINT64     NodeId,
  40   IN     UINT64     FuseHandle
  41   )
  42 {
  43   VIRTIO_FS_FUSE_REQUEST         CommonReq;
  44   VIRTIO_FS_FUSE_FLUSH_REQUEST   FlushReq;
  45   VIRTIO_FS_IO_VECTOR            ReqIoVec[2];
  46   VIRTIO_FS_SCATTER_GATHER_LIST  ReqSgList;
  47   VIRTIO_FS_FUSE_RESPONSE        CommonResp;
  48   VIRTIO_FS_IO_VECTOR            RespIoVec[1];
  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   ReqIoVec[1].Buffer = &FlushReq;
  58   ReqIoVec[1].Size   = sizeof FlushReq;
  59   ReqSgList.IoVec    = ReqIoVec;
  60   ReqSgList.NumVec   = ARRAY_SIZE (ReqIoVec);
  61
  62   RespIoVec[0].Buffer = &CommonResp;
  63   RespIoVec[0].Size   = sizeof CommonResp;
  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              VirtioFsFuseOpFlush,
  83              NodeId
  84              );
  85   if (EFI_ERROR (Status)) {
  86     return Status;
  87   }
  88
  89   //
  90   // Populate the FUSE_FLUSH-specific fields.
  91   //
  92   FlushReq.FileHandle = FuseHandle;
  93   FlushReq.Unused     = 0;
  94   FlushReq.Padding    = 0;
  95   FlushReq.LockOwner  = 0;
  96
  97   //
  98   // Submit the request.
  99   //
 100   Status = VirtioFsSgListsSubmit (VirtioFs, &ReqSgList, &RespSgList);
 101   if (EFI_ERROR (Status)) {
 102     return Status;
 103   }
 104
 105   //
 106   // Verify the response (all response buffers are fixed size).
 107   //
 108   Status = VirtioFsFuseCheckResponse (&RespSgList, CommonReq.Unique, NULL);
 109   if (Status == EFI_DEVICE_ERROR) {
 110     DEBUG ((
 111       DEBUG_ERROR,
 112       "%a: Label=\"%s\" NodeId=%Lu FuseHandle=%Lu "
 113       "Errno=%d\n",
 114       __FUNCTION__,
 115       VirtioFs->Label,
 116       NodeId,
 117       FuseHandle,
 118       CommonResp.Error
 119       ));
 120     Status = VirtioFsErrnoToEfiStatus (CommonResp.Error);
 121   }
 122
 123   return Status;
 124 }