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- /** @file
- Disk utilities
- Copyright (c) 2021 Pedro Falcato All rights reserved.
- SPDX-License-Identifier: BSD-2-Clause-Patent
- **/
- #include "Ext4Dxe.h"
- /**
- Reads from the partition's disk using the DISK_IO protocol.
- @param[in] Partition Pointer to the opened ext4 partition.
- @param[out] Buffer Pointer to a destination buffer.
- @param[in] Length Length of the destination buffer.
- @param[in] Offset Offset, in bytes, of the location to read.
- @return Success status of the disk read.
- **/
- EFI_STATUS
- Ext4ReadDiskIo (
- IN EXT4_PARTITION *Partition,
- OUT VOID *Buffer,
- IN UINTN Length,
- IN UINT64 Offset
- )
- {
- return EXT4_DISK_IO (Partition)->ReadDisk (
- EXT4_DISK_IO (Partition),
- EXT4_MEDIA_ID (Partition),
- Offset,
- Length,
- Buffer
- );
- }
- /**
- Reads blocks from the partition's disk using the DISK_IO protocol.
- @param[in] Partition Pointer to the opened ext4 partition.
- @param[out] Buffer Pointer to a destination buffer.
- @param[in] NumberBlocks Length of the read, in filesystem blocks.
- @param[in] BlockNumber Starting block number.
- @return Success status of the read.
- **/
- EFI_STATUS
- Ext4ReadBlocks (
- IN EXT4_PARTITION *Partition,
- OUT VOID *Buffer,
- IN UINTN NumberBlocks,
- IN EXT4_BLOCK_NR BlockNumber
- )
- {
- UINT64 Offset;
- UINTN Length;
- ASSERT (NumberBlocks != 0);
- ASSERT (BlockNumber != EXT4_BLOCK_FILE_HOLE);
- Offset = MultU64x32 (BlockNumber, Partition->BlockSize);
- Length = NumberBlocks * Partition->BlockSize;
- // Check for overflow on the block -> byte conversions.
- // Partition->BlockSize is never 0, so we don't need to check for that.
- if (DivU64x64Remainder (Offset, BlockNumber, NULL) != Partition->BlockSize) {
- return EFI_INVALID_PARAMETER;
- }
- if (Length / NumberBlocks != Partition->BlockSize) {
- return EFI_INVALID_PARAMETER;
- }
- return Ext4ReadDiskIo (Partition, Buffer, Length, Offset);
- }
- /**
- Allocates a buffer and reads blocks from the partition's disk using the DISK_IO protocol.
- This function is deprecated and will be removed in the future.
- @param[in] Partition Pointer to the opened ext4 partition.
- @param[in] NumberBlocks Length of the read, in filesystem blocks.
- @param[in] BlockNumber Starting block number.
- @return Buffer allocated by AllocatePool, or NULL if some part of the process
- failed.
- **/
- VOID *
- Ext4AllocAndReadBlocks (
- IN EXT4_PARTITION *Partition,
- IN UINTN NumberBlocks,
- IN EXT4_BLOCK_NR BlockNumber
- )
- {
- VOID *Buf;
- UINTN Length;
- // Check that number of blocks isn't empty, because
- // this is incorrect condition for opened partition,
- // so we just early-exit
- if ((NumberBlocks == 0) || (BlockNumber == EXT4_BLOCK_FILE_HOLE)) {
- return NULL;
- }
- Length = NumberBlocks * Partition->BlockSize;
- // Check for integer overflow
- if (Length / NumberBlocks != Partition->BlockSize) {
- return NULL;
- }
- Buf = AllocatePool (Length);
- if (Buf == NULL) {
- return NULL;
- }
- if (Ext4ReadBlocks (Partition, Buf, NumberBlocks, BlockNumber) != EFI_SUCCESS) {
- FreePool (Buf);
- return NULL;
- }
- return Buf;
- }
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