* \brief Second Extended Filesystem Driver
* \todo Implement file full write support
*/
-#define DEBUG 1
+#define DEBUG 0
#define VERBOSE 0
#include "ext2_common.h"
// === PROTOYPES ===
Uint32 Ext2_int_AllocateBlock(tExt2_Disk *Disk, Uint32 PrevBlock);
void Ext2_int_DeallocateBlock(tExt2_Disk *Disk, Uint32 Block);
- int Ext2_int_AppendBlock(tExt2_Disk *Disk, tExt2_Inode *Inode, Uint32 Block);
// === CODE ===
/**
* \brief Write to a file
*/
-size_t Ext2_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer)
+size_t Ext2_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer, Uint Flags)
{
tExt2_Disk *disk = Node->ImplPtr;
- tExt2_Inode inode;
+ tExt2_Inode *inode = (void*)(Node+1);
Uint64 base;
Uint64 retLen;
Uint block;
Uint64 allocSize;
int bNewBlocks = 0;
- Debug_HexDump("Ext2_Write", Buffer, Length);
-
- Ext2_int_ReadInode(disk, Node->Inode, &inode);
+ //Debug_HexDump("Ext2_Write", Buffer, Length);
+
+ // TODO: Handle (Flags & VFS_IOFLAG_NOBLOCK)
// Get the ammount of space already allocated
// - Round size up to block size
// - block size is a power of two, so this will work
- allocSize = (inode.i_size + disk->BlockSize-1) & ~(disk->BlockSize-1);
+ allocSize = (inode->i_size + disk->BlockSize-1) & ~(disk->BlockSize-1);
+ LOG("allocSize = %llx, Offset=%llx", allocSize, Offset);
// Are we writing to inside the allocated space?
if( Offset > allocSize ) return 0;
// Within the allocated space
block = Offset / disk->BlockSize;
Offset %= disk->BlockSize;
- base = Ext2_int_GetBlockAddr(disk, inode.i_block, block);
+ base = Ext2_int_GetBlockAddr(disk, inode->i_block, block);
// Write only block (if only one)
if(Offset + retLen <= disk->BlockSize) {
// Write middle blocks
while(retLen > disk->BlockSize)
{
- base = Ext2_int_GetBlockAddr(disk, inode.i_block, block);
+ base = Ext2_int_GetBlockAddr(disk, inode->i_block, block);
VFS_WriteAt(disk->FD, base, disk->BlockSize, Buffer);
Buffer += disk->BlockSize;
retLen -= disk->BlockSize;
}
// Write last block
- base = Ext2_int_GetBlockAddr(disk, inode.i_block, block);
+ base = Ext2_int_GetBlockAddr(disk, inode->i_block, block);
VFS_WriteAt(disk->FD, base, retLen, Buffer);
if(!bNewBlocks) return Length; // Writing in only allocated space
}
else
- base = Ext2_int_GetBlockAddr(disk, inode.i_block, allocSize/disk->BlockSize-1);
+ base = Ext2_int_GetBlockAddr(disk, inode->i_block, allocSize/disk->BlockSize-1);
addBlocks:
- Log_Notice("EXT2", "File extending is untested");
-
// Allocate blocks and copy data to them
retLen = Length - (allocSize-Offset);
- while( retLen > disk->BlockSize )
+ while( retLen > 0 )
{
+ size_t blk_len = (retLen < disk->BlockSize ? retLen : disk->BlockSize);
// Allocate a block
block = Ext2_int_AllocateBlock(disk, base/disk->BlockSize);
if(!block) return Length - retLen;
// Add it to this inode
- if( !Ext2_int_AppendBlock(disk, &inode, block) ) {
+ if( Ext2_int_AppendBlock(Node, inode, block) ) {
+ Log_Warning("Ext2", "Appending %x to inode %p:%X failed",
+ block, disk, Node->Inode);
Ext2_int_DeallocateBlock(disk, block);
goto ret;
}
// Copy data to the node
base = block * disk->BlockSize;
- VFS_WriteAt(disk->FD, base, disk->BlockSize, Buffer);
+ VFS_WriteAt(disk->FD, base, blk_len, Buffer);
// Update pointer and size remaining
- inode.i_size += disk->BlockSize;
- Buffer += disk->BlockSize;
- retLen -= disk->BlockSize;
+ Buffer += blk_len;
+ retLen -= blk_len;
}
- // Last block :D
- block = Ext2_int_AllocateBlock(disk, base/disk->BlockSize);
- if(!block) goto ret;
- if( !Ext2_int_AppendBlock(disk, &inode, block) ) {
- Ext2_int_DeallocateBlock(disk, block);
- goto ret;
- }
- base = block * disk->BlockSize;
- VFS_WriteAt(disk->FD, base, retLen, Buffer);
-
- // TODO: When should the size update be committed?
- inode.i_size += retLen;
- Node->Size += retLen;
- Node->Flags |= VFS_FFLAG_DIRTY;
-
- retLen = 0;
-ret: // Makes sure the changes to the inode are committed
- Ext2_int_WriteInode(disk, Node->Inode, &inode);
- return Length - retLen;
+
+ret:
+ retLen = Length - retLen;
+ if( retLen )
+ {
+ // TODO: When should the size update be committed?
+ inode->i_size += retLen;
+ Node->Size += retLen;
+ Node->Flags |= VFS_FFLAG_DIRTY;
+ //Ext2_int_WriteInode(disk, Node->Inode, inode);
+ }
+ return retLen;
}
/**
Uint32 Ext2_int_AllocateBlock(tExt2_Disk *Disk, Uint32 PrevBlock)
{
int bpg = Disk->SuperBlock.s_blocks_per_group;
- Uint blockgroup = PrevBlock / bpg;
- Uint bitmap[Disk->BlockSize/sizeof(Uint)];
- Uint bitsperblock = 8*Disk->BlockSize;
- int i, j = 0;
- Uint block;
-
+ Uint firstgroup = PrevBlock / bpg;
+ Uint blockgroup = firstgroup;
+ tExt2_Group *bg;
+
+ // TODO: Need to do locking on the bitmaps
+
// Are there any free blocks?
- if(Disk->SuperBlock.s_free_blocks_count == 0) return 0;
-
- if(Disk->Groups[blockgroup].bg_free_blocks_count > 0)
+ if(Disk->SuperBlock.s_free_blocks_count == 0)
+ return 0;
+
+ // First: Check the next block after `PrevBlock`
+ int iblock = (PrevBlock + 1) % Disk->SuperBlock.s_blocks_per_group;
+ //LOG("iblock = %i, Disk=%p, blockgroup=%i", iblock, Disk, blockgroup);
+ if( iblock != 0 && Disk->Groups[blockgroup].bg_free_blocks_count > 0 )
{
- // Search block group's bitmap
- for(i = 0; i < bpg; i++)
+ //LOG("Checking %i:%i", blockgroup, iblock);
+
+ bg = &Disk->Groups[blockgroup];
+
+ const int sector_size = 512;
+ Uint8 buf[sector_size];
+ int byte = (iblock/8) % sector_size;
+ Uint8 bit = 1 << (iblock % 8);
+ int ofs = (iblock/8) / sector_size * sector_size;
+ byte %= sector_size;
+ Uint64 vol_ofs = Disk->BlockSize*bg->bg_block_bitmap+ofs;
+ VFS_ReadAt(Disk->FD, vol_ofs, sector_size, buf);
+
+ //LOG("buf@%llx[%i] = %02x (& %02x)", vol_ofs, byte, buf[byte], bit);
+
+ if( (buf[byte] & bit) == 0 )
{
- // Get the block in the bitmap block
- j = i & (bitsperblock-1);
-
- // Read in if needed
- if(j == 0) {
- VFS_ReadAt(
- Disk->FD,
- (Uint64)Disk->Groups[blockgroup].bg_block_bitmap + i / bitsperblock,
- Disk->BlockSize,
- bitmap
- );
- }
-
- // Fast Check
- if( bitmap[j/32] == 0xFFFFFFFF ) {
- j = (j + 31) & ~31;
- continue;
- }
-
- // Is the bit set?
- if( bitmap[j/32] & (1 << (j%32)) )
- continue;
-
- // Ooh! We found one
- break;
- }
- if( i < bpg ) {
- Warning("[EXT2 ] Inconsistency detected, Group Free Block count is non-zero when no free blocks exist");
- goto checkAll; // Search the entire filesystem for a free block
- // Goto needed for neatness
+ // Free block - nice and contig allocation
+ buf[byte] |= bit;
+ VFS_WriteAt(Disk->FD, vol_ofs, sector_size, buf);
+
+ bg->bg_free_blocks_count --;
+ Disk->SuperBlock.s_free_blocks_count --;
+ #if EXT2_UPDATE_WRITEBACK
+ Ext2_int_UpdateSuperblock(Disk);
+ #endif
+ return PrevBlock + 1;
}
-
- // Mark as used
- bitmap[j/32] |= (1 << (j%32));
- VFS_WriteAt(
- Disk->FD,
- (Uint64)Disk->Groups[blockgroup].bg_block_bitmap + i / bitsperblock,
- Disk->BlockSize,
- bitmap
- );
- block = i;
- Disk->Groups[blockgroup].bg_free_blocks_count --;
- #if EXT2_UPDATE_WRITEBACK
- //Ext2_int_UpdateBlockGroup(Disk, blockgroup);
- #endif
+ // Used... darnit
+ // Fall through and search further
}
- else
+
+ // Second: Search for a group with free blocks
+ while( blockgroup < Disk->GroupCount && Disk->Groups[blockgroup].bg_free_blocks_count == 0 )
+ blockgroup ++;
+ if( Disk->Groups[blockgroup].bg_free_blocks_count == 0 )
{
- checkAll:
- Log_Warning("EXT2", "TODO - Implement using blocks outside the current block group");
+ LOG("Roll over");
+ blockgroup = 0;
+ while( blockgroup < firstgroup && Disk->Groups[blockgroup].bg_free_blocks_count == 0 )
+ blockgroup ++;
+ }
+ if( Disk->Groups[blockgroup].bg_free_blocks_count == 0 ) {
+ Log_Notice("Ext2", "Ext2_int_AllocateBlock - Out of blockss on %p, but superblock says some free",
+ Disk);
return 0;
}
+ //LOG("BG%i has free blocks", blockgroup);
+
+ // Search the bitmap for a free block
+ bg = &Disk->Groups[blockgroup];
+ int ofs = 0;
+ do {
+ const int sector_size = 512;
+ Uint8 buf[sector_size];
+ Uint64 vol_ofs = Disk->BlockSize*bg->bg_block_bitmap+ofs;
+ VFS_ReadAt(Disk->FD, vol_ofs, sector_size, buf);
+
+ int byte, bit;
+ for( byte = 0; byte < sector_size && buf[byte] == 0xFF; byte ++ )
+ ;
+ if( byte < sector_size )
+ {
+ //LOG("buf@%llx[%i] = %02x", vol_ofs, byte, buf[byte]);
+ for( bit = 0; bit < 8 && buf[byte] & (1 << bit); bit ++)
+ ;
+ ASSERT(bit != 8);
+ buf[byte] |= 1 << bit;
+ VFS_WriteAt(Disk->FD, vol_ofs, sector_size, buf);
+
+ bg->bg_free_blocks_count --;
+ Disk->SuperBlock.s_free_blocks_count --;
+
+ #if EXT2_UPDATE_WRITEBACK
+ Ext2_int_UpdateSuperblock(Disk);
+ #endif
+
+ Uint32 ret = blockgroup * Disk->SuperBlock.s_blocks_per_group + byte * 8 + bit;
+ LOG("Allocated 0x%x", ret);
+ return ret;
+ }
+ } while(ofs < Disk->SuperBlock.s_blocks_per_group / 8);
- // Reduce global count
- Disk->SuperBlock.s_free_blocks_count --;
- #if EXT2_UPDATE_WRITEBACK
- Ext2_int_UpdateSuperblock(Disk);
- #endif
-
- return block;
+ Log_Notice("Ext2", "Ext2_int_AllocateBlock - Out of block in group %p:%i but header reported free",
+ Disk, blockgroup);
+ return 0;
}
/**
*/
void Ext2_int_DeallocateBlock(tExt2_Disk *Disk, Uint32 Block)
{
+ Log_Warning("Ext2", "TODO: Impliment Ext2_int_DeallocateBlock");
}
/**
* \brief Append a block to an inode
*/
-int Ext2_int_AppendBlock(tExt2_Disk *Disk, tExt2_Inode *Inode, Uint32 Block)
+int Ext2_int_AppendBlock(tVFS_Node *Node, tExt2_Inode *Inode, Uint32 Block)
{
+ tExt2_Disk *Disk = Node->ImplPtr;
int nBlocks;
int dwPerBlock = Disk->BlockSize / 4;
Uint32 *blocks;
Uint32 id1, id2;
nBlocks = (Inode->i_size + Disk->BlockSize - 1) / Disk->BlockSize;
+
+ LOG("Append 0x%x to inode [%i]", Block, nBlocks);
// Direct Blocks
if( nBlocks < 12 ) {
// Single Indirect
if( nBlocks < dwPerBlock)
{
+ LOG("Indirect 1 %i", nBlocks);
// Allocate/Get Indirect block
if( nBlocks == 0 ) {
Inode->i_block[12] = Ext2_int_AllocateBlock(Disk, Inode->i_block[0]);
if( !Inode->i_block[12] ) {
+ Log_Warning("Ext2", "Allocating indirect block failed");
free(blocks);
return 1;
}
blocks[nBlocks] = Block;
VFS_WriteAt(Disk->FD, Inode->i_block[12]*Disk->BlockSize, Disk->BlockSize, blocks);
+ Node->Flags |= VFS_FFLAG_DIRTY;
free(blocks);
return 0;
}
- nBlocks += dwPerBlock;
+ nBlocks -= dwPerBlock;
// Double Indirect
if( nBlocks < dwPerBlock*dwPerBlock )
{
+ LOG("Indirect 2 %i/%i", nBlocks/dwPerBlock, nBlocks%dwPerBlock);
// Allocate/Get Indirect block
if( nBlocks == 0 ) {
Inode->i_block[13] = Ext2_int_AllocateBlock(Disk, Inode->i_block[0]);
if( !Inode->i_block[13] ) {
+ Log_Warning("Ext2", "Allocating double indirect block failed");
free(blocks);
return 1;
}
memset(blocks, 0, Disk->BlockSize);
+ Node->Flags |= VFS_FFLAG_DIRTY;
}
else
VFS_ReadAt(Disk->FD, Inode->i_block[13]*Disk->BlockSize, Disk->BlockSize, blocks);
id1 = Ext2_int_AllocateBlock(Disk, Inode->i_block[0]);
if( !id1 ) {
free(blocks);
+ Log_Warning("Ext2", "Allocating double indirect block (l2) failed");
return 1;
}
blocks[nBlocks/dwPerBlock] = id1;
if( nBlocks == 0 ) {
Inode->i_block[14] = Ext2_int_AllocateBlock(Disk, Inode->i_block[0]);
if( !Inode->i_block[14] ) {
+ Log_Warning("Ext2", "Allocating triple indirect block failed");
free(blocks);
return 1;
}
memset(blocks, 0, Disk->BlockSize);
+ Node->Flags |= VFS_FFLAG_DIRTY;
}
else
VFS_ReadAt(Disk->FD, Inode->i_block[14]*Disk->BlockSize, Disk->BlockSize, blocks);
{
id1 = Ext2_int_AllocateBlock(Disk, Inode->i_block[0]);
if( !id1 ) {
+ Log_Warning("Ext2", "Allocating triple indirect block (l2) failed");
free(blocks);
return 1;
}
if( nBlocks % dwPerBlock == 0 ) {
id2 = Ext2_int_AllocateBlock(Disk, id1);
if( !id2 ) {
+ Log_Warning("Ext2", "Allocating triple indirect block (l3) failed");
free(blocks);
return 1;
}
return 0;
}
- Warning("[EXT2 ] Inode %i cannot have a block appended to it, all indirects used");
+ Log_Warning("Ext2", "Inode ?? cannot have a block appended to it, all indirects used");
free(blocks);
return 1;
}
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