audk/OvmfPkg/VirtioFsDxe/SimpleFsDelete.c

117 lines
3.6 KiB
C

/** @file
EFI_FILE_PROTOCOL.Delete() member function for the Virtio Filesystem driver.
Copyright (C) 2020, Red Hat, Inc.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Library/BaseLib.h> // RemoveEntryList()
#include <Library/MemoryAllocationLib.h> // FreePool()
#include "VirtioFsDxe.h"
EFI_STATUS
EFIAPI
VirtioFsSimpleFileDelete (
IN EFI_FILE_PROTOCOL *This
)
{
VIRTIO_FS_FILE *VirtioFsFile;
VIRTIO_FS *VirtioFs;
EFI_STATUS Status;
VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);
VirtioFs = VirtioFsFile->OwnerFs;
//
// All actions in this function are "best effort"; the UEFI spec requires
// EFI_FILE_PROTOCOL.Delete() to release resources unconditionally. If a step
// related to removing the file fails, it's only reflected in the return
// status (EFI_WARN_DELETE_FAILURE rather than EFI_SUCCESS).
//
// Release, remove, and (if needed) forget. We don't waste time flushing and
// syncing; if the EFI_FILE_PROTOCOL user cares enough, they should keep the
// parent directory open until after this function call returns, and then
// force a sync on *that* EFI_FILE_PROTOCOL instance, using either the
// Flush() member function, or the Close() member function.
//
// If any action fails below, we still try the others.
//
VirtioFsFuseReleaseFileOrDir (
VirtioFs,
VirtioFsFile->NodeId,
VirtioFsFile->FuseHandle,
VirtioFsFile->IsDirectory
);
//
// VirtioFsFile->FuseHandle is gone at this point, but VirtioFsFile->NodeId
// is still valid. Continue with removing the file or directory. The result
// of this operation determines the return status of the function.
//
if (VirtioFsFile->IsOpenForWriting) {
UINT64 ParentNodeId;
CHAR8 *LastComponent;
//
// Split our canonical pathname into most specific parent directory
// (identified by NodeId), and single-component filename within that
// directory. If This stands for the root directory "/", then the following
// function call will gracefully fail.
//
Status = VirtioFsLookupMostSpecificParentDir (
VirtioFs,
VirtioFsFile->CanonicalPathname,
&ParentNodeId,
&LastComponent
);
if (!EFI_ERROR (Status)) {
//
// Attempt the actual removal. Regardless of the outcome, ParentNodeId
// must be forgotten right after (unless it stands for the root
// directory).
//
Status = VirtioFsFuseRemoveFileOrDir (
VirtioFs,
ParentNodeId,
LastComponent,
VirtioFsFile->IsDirectory
);
if (ParentNodeId != VIRTIO_FS_FUSE_ROOT_DIR_NODE_ID) {
VirtioFsFuseForget (VirtioFs, ParentNodeId);
}
}
if (EFI_ERROR (Status)) {
//
// Map any failure to the spec-mandated warning code.
//
Status = EFI_WARN_DELETE_FAILURE;
}
} else {
Status = EFI_WARN_DELETE_FAILURE;
}
//
// Finally, if we've known VirtioFsFile->NodeId from a lookup, then we should
// also ask the server to forget it *once*.
//
if (VirtioFsFile->NodeId != VIRTIO_FS_FUSE_ROOT_DIR_NODE_ID) {
VirtioFsFuseForget (VirtioFs, VirtioFsFile->NodeId);
}
//
// One fewer file left open for the owner filesystem.
//
RemoveEntryList (&VirtioFsFile->OpenFilesEntry);
FreePool (VirtioFsFile->CanonicalPathname);
if (VirtioFsFile->FileInfoArray != NULL) {
FreePool (VirtioFsFile->FileInfoArray);
}
FreePool (VirtioFsFile);
return Status;
}