OvmfPkg/VirtioFsDxe/FuseRename.c

   1 /** @file
   2   FUSE_RENAME2 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   Rename a regular file or a directory, by sending the FUSE_RENAME2 request to
  15   the Virtio Filesystem device. If the new filename exists, the request will
  16   fail.
  17
  18   The function may only be called after VirtioFsFuseInitSession() returns
  19   successfully and before VirtioFsUninit() is called.
  20
  21   @param[in,out] VirtioFs     The Virtio Filesystem device to send the
  22                               FUSE_RENAME2 request to. On output, the FUSE
  23                               request counter "VirtioFs->RequestId" will have
  24                               been incremented.
  25
  26   @param[in] OldParentNodeId  The inode number of the directory in which
  27                               OldName should be removed.
  28
  29   @param[in] OldName          The single-component filename to remove in the
  30                               directory identified by OldParentNodeId.
  31
  32   @param[in] NewParentNodeId  The inode number of the directory in which
  33                               NewName should be created, such that on
  34                               successful return, (NewParentNodeId, NewName)
  35                               refer to the same inode as (OldParentNodeId,
  36                               OldName) did on entry.
  37
  38   @param[in] NewName          The single-component filename to create in the
  39                               directory identified by NewParentNodeId.
  40
  41   @retval EFI_SUCCESS  The file or directory has been renamed.
  42
  43   @return              The "errno" value mapped to an EFI_STATUS code, if the
  44                        Virtio Filesystem device explicitly reported an error.
  45
  46   @return              Error codes propagated from VirtioFsSgListsValidate(),
  47                        VirtioFsFuseNewRequest(), VirtioFsSgListsSubmit(),
  48                        VirtioFsFuseCheckResponse().
  49 **/
  50 EFI_STATUS
  51 VirtioFsFuseRename (
  52   IN OUT VIRTIO_FS *VirtioFs,
  53   IN     UINT64    OldParentNodeId,
  54   IN     CHAR8     *OldName,
  55   IN     UINT64    NewParentNodeId,
  56   IN     CHAR8     *NewName
  57   )
  58 {
  59   VIRTIO_FS_FUSE_REQUEST         CommonReq;
  60   VIRTIO_FS_FUSE_RENAME2_REQUEST Rename2Req;
  61   VIRTIO_FS_IO_VECTOR            ReqIoVec[4];
  62   VIRTIO_FS_SCATTER_GATHER_LIST  ReqSgList;
  63   VIRTIO_FS_FUSE_RESPONSE        CommonResp;
  64   VIRTIO_FS_IO_VECTOR            RespIoVec[1];
  65   VIRTIO_FS_SCATTER_GATHER_LIST  RespSgList;
  66   EFI_STATUS                     Status;
  67
  68   //
  69   // Set up the scatter-gather lists.
  70   //
  71   ReqIoVec[0].Buffer = &CommonReq;
  72   ReqIoVec[0].Size   = sizeof CommonReq;
  73   ReqIoVec[1].Buffer = &Rename2Req;
  74   ReqIoVec[1].Size   = sizeof Rename2Req;
  75   ReqIoVec[2].Buffer = OldName;
  76   ReqIoVec[2].Size   = AsciiStrSize (OldName);
  77   ReqIoVec[3].Buffer = NewName;
  78   ReqIoVec[3].Size   = AsciiStrSize (NewName);
  79   ReqSgList.IoVec    = ReqIoVec;
  80   ReqSgList.NumVec   = ARRAY_SIZE (ReqIoVec);
  81
  82   RespIoVec[0].Buffer = &CommonResp;
  83   RespIoVec[0].Size   = sizeof CommonResp;
  84   RespSgList.IoVec    = RespIoVec;
  85   RespSgList.NumVec   = ARRAY_SIZE (RespIoVec);
  86
  87   //
  88   // Validate the scatter-gather lists; calculate the total transfer sizes.
  89   //
  90   Status = VirtioFsSgListsValidate (VirtioFs, &ReqSgList, &RespSgList);
  91   if (EFI_ERROR (Status)) {
  92     return Status;
  93   }
  94
  95   //
  96   // Populate the common request header.
  97   //
  98   Status = VirtioFsFuseNewRequest (VirtioFs, &CommonReq, ReqSgList.TotalSize,
  99              VirtioFsFuseOpRename2, OldParentNodeId);
 100   if (EFI_ERROR (Status)) {
 101     return Status;
 102   }
 103
 104   //
 105   // Populate the FUSE_RENAME2-specific fields.
 106   //
 107   Rename2Req.NewDir  = NewParentNodeId;
 108   Rename2Req.Flags   = VIRTIO_FS_FUSE_RENAME2_REQ_F_NOREPLACE;
 109   Rename2Req.Padding = 0;
 110
 111   //
 112   // Submit the request.
 113   //
 114   Status = VirtioFsSgListsSubmit (VirtioFs, &ReqSgList, &RespSgList);
 115   if (EFI_ERROR (Status)) {
 116     return Status;
 117   }
 118
 119   //
 120   // Verify the response (all response buffers are fixed size).
 121   //
 122   Status = VirtioFsFuseCheckResponse (&RespSgList, CommonReq.Unique, NULL);
 123   if (Status == EFI_DEVICE_ERROR) {
 124     DEBUG ((DEBUG_ERROR, "%a: Label=\"%s\" OldParentNodeId=%Lu OldName=\"%a\" "
 125       "NewParentNodeId=%Lu NewName=\"%a\" Errno=%d\n", __FUNCTION__,
 126       VirtioFs->Label, OldParentNodeId, OldName, NewParentNodeId, NewName,
 127       CommonResp.Error));
 128     Status = VirtioFsErrnoToEfiStatus (CommonResp.Error);
 129   }
 130   return Status;
 131 }