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/*
* fs_ext2/super.c
* Per-volume functions, including SimpleFileSystem interface
*
* Copyright (c) 2006 Christoph Pfisterer
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* See LICENSE.txt for details about the copyright status of
* the ext2 file system driver.
*/
#include "fs_ext2.h"
#define DEBUG_LEVEL 0
// functions
EFI_STATUS EFIAPI Ext2OpenVolume(IN EFI_FILE_IO_INTERFACE *This,
OUT EFI_FILE **Root);
//
// read the superblock and setup the Simple File System interface
//
EFI_STATUS Ext2ReadSuper(IN EXT2_VOLUME_DATA *Volume)
{
EFI_STATUS Status;
// NOTE: in the error case, the caller frees SuperBlock and BlockBuffer
// read the superblock from disk
Volume->SuperBlock = AllocatePool(sizeof(struct ext2_super_block));
Status = Volume->DiskIo->ReadDisk(Volume->DiskIo, Volume->MediaId,
BLOCK_SIZE,
sizeof(struct ext2_super_block),
Volume->SuperBlock);
if (EFI_ERROR(Status))
return Status;
// check the superblock
if (Volume->SuperBlock->s_magic != EXT2_SUPER_MAGIC)
return EFI_UNSUPPORTED;
if (Volume->SuperBlock->s_rev_level != EXT2_GOOD_OLD_REV &&
Volume->SuperBlock->s_rev_level != EXT2_DYNAMIC_REV)
return EFI_UNSUPPORTED;
if (Volume->SuperBlock->s_rev_level == EXT2_DYNAMIC_REV &&
(Volume->SuperBlock->s_feature_incompat & ~(EXT2_FEATURE_INCOMPAT_FILETYPE | EXT3_FEATURE_INCOMPAT_RECOVER)))
return EFI_UNSUPPORTED;
if (Volume->SuperBlock->s_rev_level == EXT2_DYNAMIC_REV &&
(Volume->SuperBlock->s_feature_incompat & EXT3_FEATURE_INCOMPAT_RECOVER))
Print(L"Ext2 WARNING: This ext3 file system needs recovery, trying to use it anyway.\n");
Volume->BlockSize = 1024 << Volume->SuperBlock->s_log_block_size;
Volume->IndBlockCount = Volume->BlockSize / sizeof(__u32);
Volume->DIndBlockCount = Volume->IndBlockCount * Volume->IndBlockCount;
if (Volume->SuperBlock->s_rev_level == EXT2_GOOD_OLD_REV) {
Volume->InodeSize = EXT2_GOOD_OLD_INODE_SIZE;
#if DEBUG_LEVEL
Print(L"Ext2ReadSuper: EXT2_GOOD_OLD_REV, %d byte inodes\n", Volume->InodeSize);
#endif
} else {
Volume->InodeSize = Volume->SuperBlock->s_inode_size;
#if DEBUG_LEVEL
Print(L"Ext2ReadSuper: EXT2_DYNAMIC_REV, %d byte inodes\n", Volume->InodeSize);
#endif
}
Volume->RootInode = NULL;
Volume->DirInodeList = NULL;
Volume->BlockBuffer = AllocatePool(Volume->BlockSize);
Volume->BlockInBuffer = INVALID_BLOCK_NO;
#if DEBUG_LEVEL
Print(L"Ext2ReadSuper: successful, BlockSize %d\n", Volume->BlockSize);
#endif
// setup the SimpleFileSystem protocol
Volume->FileSystem.Revision = EFI_FILE_IO_INTERFACE_REVISION;
Volume->FileSystem.OpenVolume = Ext2OpenVolume;
return EFI_SUCCESS;
}
//
// Ext2OpenVolume
//
EFI_STATUS EFIAPI Ext2OpenVolume(IN EFI_FILE_IO_INTERFACE *This,
OUT EFI_FILE **Root)
{
EFI_STATUS Status;
EXT2_VOLUME_DATA *Volume;
EXT2_INODE_HANDLE InodeHandle;
#if DEBUG_LEVEL
Print(L"Ext2OpenVolume\n");
#endif
Volume = EXT2_VOLUME_FROM_FILE_SYSTEM(This);
// open the root inode, keep it around until the FS is unmounted
if (Volume->RootInode == NULL) {
Status = Ext2InodeOpen(Volume, EXT2_ROOT_INO, NULL, NULL, &Volume->RootInode);
if (EFI_ERROR(Status))
return Status;
}
// create a new inode handle
Status = Ext2InodeHandleReopen(Volume->RootInode, &InodeHandle);
if (EFI_ERROR(Status))
return Status;
// wrap it in a file structure
Status = Ext2FileFromInodeHandle(&InodeHandle, Root);
// NOTE: file handle takes ownership of inode handle
return Status;
}
//
// read given block into the volume's block buffer
//
EFI_STATUS Ext2ReadBlock(IN EXT2_VOLUME_DATA *Volume, IN UINT32 BlockNo)
{
EFI_STATUS Status;
// check buffer
if (BlockNo == Volume->BlockInBuffer)
return EFI_SUCCESS;
#if DEBUG_LEVEL == 2
Print(L"Ext2ReadBlock: %d\n", BlockNo);
#endif
// remember buffer state
Volume->BlockInBuffer = BlockNo;
// special treatment for "holes" a.k.a. sparse files
if (BlockNo == 0) {
ZeroMem(Volume->BlockBuffer, Volume->BlockSize);
return EFI_SUCCESS;
}
// read from disk
Status = Volume->DiskIo->ReadDisk(Volume->DiskIo, Volume->MediaId,
(UINT64)BlockNo * Volume->BlockSize,
Volume->BlockSize,
Volume->BlockBuffer);
if (EFI_ERROR(Status)) {
Volume->BlockInBuffer = INVALID_BLOCK_NO;
return Status;
}
return EFI_SUCCESS;
}
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