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 (
  99              VirtioFs,
 100              &CommonReq,
 101              ReqSgList.TotalSize,
 102              VirtioFsFuseOpRename2,
 103              OldParentNodeId
 104              );
 105   if (EFI_ERROR (Status)) {
 106     return Status;
 107   }
 108
 109   //
 110   // Populate the FUSE_RENAME2-specific fields.
 111   //
 112   Rename2Req.NewDir  = NewParentNodeId;
 113   Rename2Req.Flags   = VIRTIO_FS_FUSE_RENAME2_REQ_F_NOREPLACE;
 114   Rename2Req.Padding = 0;
 115
 116   //
 117   // Submit the request.
 118   //
 119   Status = VirtioFsSgListsSubmit (VirtioFs, &ReqSgList, &RespSgList);
 120   if (EFI_ERROR (Status)) {
 121     return Status;
 122   }
 123
 124   //
 125   // Verify the response (all response buffers are fixed size).
 126   //
 127   Status = VirtioFsFuseCheckResponse (&RespSgList, CommonReq.Unique, NULL);
 128   if (Status == EFI_DEVICE_ERROR) {
 129     DEBUG ((
 130       DEBUG_ERROR,
 131       "%a: Label=\"%s\" OldParentNodeId=%Lu OldName=\"%a\" "
 132       "NewParentNodeId=%Lu NewName=\"%a\" Errno=%d\n",
 133       __FUNCTION__,
 134       VirtioFs->Label,
 135       OldParentNodeId,
 136       OldName,
 137       NewParentNodeId,
 138       NewName,
 139       CommonResp.Error
 140       ));
 141     Status = VirtioFsErrnoToEfiStatus (CommonResp.Error);
 142   }
 143
 144   return Status;
 145 }