OvmfPkg/VirtioFsDxe/FuseMkDir.c

   1 /** @file
   2   FUSE_MKDIR 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   Send a FUSE_MKDIR request to the Virtio Filesystem device, for creating a
  15   directory.
  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_MKDIR
  21                            request to. On output, the FUSE request counter
  22                            "VirtioFs->RequestId" will have been incremented.
  23
  24   @param[in] ParentNodeId  The inode number of the direct parent directory of
  25                            the directory to create.
  26
  27   @param[in] Name          The single-component filename of the directory to
  28                            create, under the parent directory identified by
  29                            ParentNodeId.
  30
  31   @param[out] NodeId       The inode number of the new directory.
  32
  33   @retval EFI_SUCCESS  The directory has been created.
  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 VirtioFsFuseMkDir (
  44   IN OUT VIRTIO_FS  *VirtioFs,
  45   IN     UINT64     ParentNodeId,
  46   IN     CHAR8      *Name,
  47   OUT UINT64        *NodeId
  48   )
  49 {
  50   VIRTIO_FS_FUSE_REQUEST              CommonReq;
  51   VIRTIO_FS_FUSE_MKDIR_REQUEST        MkDirReq;
  52   VIRTIO_FS_IO_VECTOR                 ReqIoVec[3];
  53   VIRTIO_FS_SCATTER_GATHER_LIST       ReqSgList;
  54   VIRTIO_FS_FUSE_RESPONSE             CommonResp;
  55   VIRTIO_FS_FUSE_NODE_RESPONSE        NodeResp;
  56   VIRTIO_FS_FUSE_ATTRIBUTES_RESPONSE  AttrResp;
  57   VIRTIO_FS_IO_VECTOR                 RespIoVec[3];
  58   VIRTIO_FS_SCATTER_GATHER_LIST       RespSgList;
  59   EFI_STATUS                          Status;
  60
  61   //
  62   // Set up the scatter-gather lists.
  63   //
  64   ReqIoVec[0].Buffer = &CommonReq;
  65   ReqIoVec[0].Size   = sizeof CommonReq;
  66   ReqIoVec[1].Buffer = &MkDirReq;
  67   ReqIoVec[1].Size   = sizeof MkDirReq;
  68   ReqIoVec[2].Buffer = Name;
  69   ReqIoVec[2].Size   = AsciiStrSize (Name);
  70   ReqSgList.IoVec    = ReqIoVec;
  71   ReqSgList.NumVec   = ARRAY_SIZE (ReqIoVec);
  72
  73   RespIoVec[0].Buffer = &CommonResp;
  74   RespIoVec[0].Size   = sizeof CommonResp;
  75   RespIoVec[1].Buffer = &NodeResp;
  76   RespIoVec[1].Size   = sizeof NodeResp;
  77   RespIoVec[2].Buffer = &AttrResp;
  78   RespIoVec[2].Size   = sizeof AttrResp;
  79   RespSgList.IoVec    = RespIoVec;
  80   RespSgList.NumVec   = ARRAY_SIZE (RespIoVec);
  81
  82   //
  83   // Validate the scatter-gather lists; calculate the total transfer sizes.
  84   //
  85   Status = VirtioFsSgListsValidate (VirtioFs, &ReqSgList, &RespSgList);
  86   if (EFI_ERROR (Status)) {
  87     return Status;
  88   }
  89
  90   //
  91   // Populate the common request header.
  92   //
  93   Status = VirtioFsFuseNewRequest (
  94              VirtioFs,
  95              &CommonReq,
  96              ReqSgList.TotalSize,
  97              VirtioFsFuseOpMkDir,
  98              ParentNodeId
  99              );
 100   if (EFI_ERROR (Status)) {
 101     return Status;
 102   }
 103
 104   //
 105   // Populate the FUSE_MKDIR-specific fields.
 106   //
 107   MkDirReq.Mode = (VIRTIO_FS_FUSE_MODE_PERM_RWXU |
 108                    VIRTIO_FS_FUSE_MODE_PERM_RWXG |
 109                    VIRTIO_FS_FUSE_MODE_PERM_RWXO);
 110   MkDirReq.Umask = 0;
 111
 112   //
 113   // Submit the request.
 114   //
 115   Status = VirtioFsSgListsSubmit (VirtioFs, &ReqSgList, &RespSgList);
 116   if (EFI_ERROR (Status)) {
 117     return Status;
 118   }
 119
 120   //
 121   // Verify the response (all response buffers are fixed size).
 122   //
 123   Status = VirtioFsFuseCheckResponse (&RespSgList, CommonReq.Unique, NULL);
 124   if (EFI_ERROR (Status)) {
 125     if (Status == EFI_DEVICE_ERROR) {
 126       DEBUG ((
 127         DEBUG_ERROR,
 128         "%a: Label=\"%s\" ParentNodeId=%Lu Name=\"%a\" "
 129         "Errno=%d\n",
 130         __FUNCTION__,
 131         VirtioFs->Label,
 132         ParentNodeId,
 133         Name,
 134         CommonResp.Error
 135         ));
 136       Status = VirtioFsErrnoToEfiStatus (CommonResp.Error);
 137     }
 138
 139     return Status;
 140   }
 141
 142   //
 143   // Output the NodeId of the new directory.
 144   //
 145   *NodeId = NodeResp.NodeId;
 146   return EFI_SUCCESS;
 147 }