/**
Set the size of a file.
This is a helper function for SetFileInfo().
@param[in] Instance A pointer to the description of the volume
the file belongs to.
@param[in] File A pointer to the description of the file.
@param[in] NewSize The requested new size for the file.
@retval EFI_SUCCESS The size was set.
@retval EFI_OUT_OF_RESOURCES An allocation needed to process the request failed.
**/
STATIC
EFI_STATUS
SetFileSize (
IN BOOTMON_FS_INSTANCE *Instance,
IN BOOTMON_FS_FILE *BootMonFsFile,
IN UINTN NewSize
)
{
EFI_STATUS Status;
UINT32 OldSize;
LIST_ENTRY *RegionToFlushLink;
LIST_ENTRY *NextRegionToFlushLink;
BOOTMON_FS_FILE_REGION *Region;
EFI_FILE_PROTOCOL *File;
CHAR8 *Buffer;
UINTN BufferSize;
UINT64 StoredPosition;
OldSize = BootMonFsFile->Info->FileSize;
//
// In case of file truncation, force the regions waiting for writing to
// not overflow the new size of the file.
//
if (NewSize < OldSize) {
for (RegionToFlushLink = GetFirstNode (&BootMonFsFile->RegionToFlushLink);
!IsNull (&BootMonFsFile->RegionToFlushLink, RegionToFlushLink);
)
{
NextRegionToFlushLink = GetNextNode (&BootMonFsFile->RegionToFlushLink, RegionToFlushLink);
Region = (BOOTMON_FS_FILE_REGION*)RegionToFlushLink;
if (Region->Offset > NewSize) {
RemoveEntryList (RegionToFlushLink);
FreePool (Region->Buffer);
FreePool (Region);
} else {
Region->Size = MIN (Region->Size, NewSize - Region->Offset);
}
RegionToFlushLink = NextRegionToFlushLink;
}
} else if (NewSize > OldSize) {
// Increasing a file's size is potentially complicated as it may require
// moving the image description on media. The simplest way to do it is to
// seek past the end of the file (which is valid in UEFI) and perform a
// Write.
File = &BootMonFsFile->File;
// Save position
Status = File->GetPosition (File, &StoredPosition);
if (EFI_ERROR (Status)) {
return Status;
}
// Set position at the end of the file
Status = File->SetPosition (File, OldSize);
if (EFI_ERROR (Status)) {
return Status;
}
BufferSize = NewSize - OldSize;
Buffer = AllocateZeroPool (BufferSize);
if (Buffer == NULL) {
return EFI_OUT_OF_RESOURCES;
}
Status = File->Write (File, &BufferSize, Buffer);
FreePool (Buffer);
if (EFI_ERROR (Status)) {
return Status;
}
// Restore saved position
Status = File->SetPosition (File, StoredPosition);
if (EFI_ERROR (Status)) {
return Status;
}
}
BootMonFsFile->Info->FileSize = NewSize;
return EFI_SUCCESS;
}
// Set the file's size (NB "size", not "physical size"). If the change amounts
// to an increase, simply do a write followed by a flush.
// (This is a helper function for SetFileInfo.)
STATIC
EFI_STATUS
SetFileSize (
IN BOOTMON_FS_INSTANCE *Instance,
IN BOOTMON_FS_FILE *BootMonFsFile,
IN UINTN NewSize
)
{
UINT64 StoredPosition;
EFI_STATUS Status;
EFI_FILE_PROTOCOL *File;
CHAR8 Buffer;
UINTN BufferSize;
UINT32 OldSize;
OldSize = BootMonFsFile->HwDescription.Region[0].Size;
if (OldSize == NewSize) {
return EFI_SUCCESS;
}
Buffer = 0;
BufferSize = sizeof (Buffer);
File = &BootMonFsFile->File;
if (!(BootMonFsFile->OpenMode & EFI_FILE_MODE_WRITE)) {
return EFI_ACCESS_DENIED;
}
if (NewSize <= OldSize) {
OldSize = NewSize;
} else {
// Increasing a file's size is potentially complicated as it may require
// moving the image description on media. The simplest way to do it is to
// seek past the end of the file (which is valid in UEFI) and perform a
// Write.
// Save position
Status = File->GetPosition (File, &StoredPosition);
if (EFI_ERROR (Status)) {
return Status;
}
Status = File->SetPosition (File, NewSize - 1);
if (EFI_ERROR (Status)) {
return Status;
}
Status = File->Write (File, &BufferSize, &Buffer);
if (EFI_ERROR (Status)) {
return Status;
}
// Restore saved position
Status = File->SetPosition (File, NewSize - 1);
if (EFI_ERROR (Status)) {
return Status;
}
Status = File->Flush (File);
if (EFI_ERROR (Status)) {
return Status;
}
}
return EFI_SUCCESS;
}