OvmfPkg/VirtioFsDxe: flush, sync, release and forget in Close() / Delete()

[mirror_edk2.git] / OvmfPkg / VirtioFsDxe / SimpleFsDelete.c

/** @file\r
  EFI_FILE_PROTOCOL.Delete() member function for the Virtio Filesystem driver.\r
\r
  Copyright (C) 2020, Red Hat, Inc.\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
**/\r
\r
#include <Library/BaseLib.h>             // RemoveEntryList()\r
#include <Library/MemoryAllocationLib.h> // FreePool()\r
\r
#include "VirtioFsDxe.h"\r
\r
EFI_STATUS\r
EFIAPI\r
VirtioFsSimpleFileDelete (\r
  IN EFI_FILE_PROTOCOL *This\r
  )\r
{\r
  VIRTIO_FS_FILE *VirtioFsFile;\r
  VIRTIO_FS      *VirtioFs;\r
  EFI_STATUS     Status;\r
\r
  VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);\r
  VirtioFs     = VirtioFsFile->OwnerFs;\r
\r
  //\r
  // All actions in this function are "best effort"; the UEFI spec requires\r
  // EFI_FILE_PROTOCOL.Delete() to release resources unconditionally. If a step\r
  // related to removing the file fails, it's only reflected in the return\r
  // status (EFI_WARN_DELETE_FAILURE rather than EFI_SUCCESS).\r
  //\r
  // Release, remove, and (if needed) forget. We don't waste time flushing and\r
  // syncing; if the EFI_FILE_PROTOCOL user cares enough, they should keep the\r
  // parent directory open until after this function call returns, and then\r
  // force a sync on *that* EFI_FILE_PROTOCOL instance, using either the\r
  // Flush() member function, or the Close() member function.\r
  //\r
  // If any action fails below, we still try the others.\r
  //\r
  VirtioFsFuseReleaseFileOrDir (VirtioFs, VirtioFsFile->NodeId,\r
    VirtioFsFile->FuseHandle, VirtioFsFile->IsDirectory);\r
\r
  //\r
  // VirtioFsFile->FuseHandle is gone at this point, but VirtioFsFile->NodeId\r
  // is still valid. Continue with removing the file or directory. The result\r
  // of this operation determines the return status of the function.\r
  //\r
  // TODO\r
  //\r
  Status = EFI_WARN_DELETE_FAILURE;\r
\r
  //\r
  // Finally, if we've known VirtioFsFile->NodeId from a lookup, then we should\r
  // also ask the server to forget it *once*.\r
  //\r
  if (VirtioFsFile->NodeId != VIRTIO_FS_FUSE_ROOT_DIR_NODE_ID) {\r
    VirtioFsFuseForget (VirtioFs, VirtioFsFile->NodeId);\r
  }\r
\r
  //\r
  // One fewer file left open for the owner filesystem.\r
  //\r
  RemoveEntryList (&VirtioFsFile->OpenFilesEntry);\r
\r
  FreePool (VirtioFsFile);\r
  return Status;\r
}\r