reactos/drivers/filesystems/ext2/src/ext4/extents.c

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/*
* COPYRIGHT: See COPYRIGHT.TXT
* PROJECT: Ext2 File System Driver for WinNT/2K/XP
* FILE: extents.c
* PROGRAMMER: Matt Wu <mattwu@163.com>
* HOMEPAGE: http://www.ext2fsd.com
* UPDATE HISTORY:
*/
/* INCLUDES *****************************************************************/
#include "ext2fs.h"
/* GLOBALS *****************************************************************/
extern PEXT2_GLOBAL Ext2Global;
/* DEFINITIONS *************************************************************/
#ifdef ALLOC_PRAGMA
#endif
NTSTATUS
Ext2MapExtent(
IN PEXT2_IRP_CONTEXT IrpContext,
IN PEXT2_VCB Vcb,
IN PEXT2_MCB Mcb,
IN ULONG Index,
IN BOOLEAN Alloc,
OUT PULONG Block,
OUT PULONG Number
)
{
EXT4_EXTENT_HEADER *eh;
struct buffer_head bh_got = {0};
int flags, rc;
ULONG max_blocks = 0;
memset(&bh_got, 0, sizeof(struct buffer_head));
eh = get_ext4_header(&Mcb->Inode);
if (eh->eh_magic != EXT4_EXT_MAGIC) {
if (Alloc) {
/* now initialize inode extent root node */
ext4_ext_tree_init(IrpContext, NULL, &Mcb->Inode);
} else {
/* return empty-mapping when inode extent isn't initialized */
if (Block)
*Block = 0;
if (Number) {
LONGLONG _len = _len = Mcb->Inode.i_size;
if (Mcb->Fcb)
_len = Mcb->Fcb->Header.AllocationSize.QuadPart;
*Number = (ULONG)((_len + BLOCK_SIZE - 1) >> BLOCK_BITS);
}
return STATUS_SUCCESS;
}
}
/* IrpContext is NULL when called during journal initialization */
if (IsMcbDirectory(Mcb) || IrpContext == NULL ||
IrpContext->MajorFunction == IRP_MJ_WRITE || !Alloc){
flags = EXT4_GET_BLOCKS_IO_CONVERT_EXT;
max_blocks = EXT_INIT_MAX_LEN;
} else {
flags = EXT4_GET_BLOCKS_IO_CREATE_EXT;
max_blocks = EXT_UNWRITTEN_MAX_LEN;
}
if (Alloc) {
if (Number && !*Number) {
if (max_blocks > *Number) {
max_blocks = *Number;
}
} else {
max_blocks = 1;
}
}
if ((rc = ext4_ext_get_blocks(
IrpContext,
NULL,
&Mcb->Inode,
Index,
max_blocks,
&bh_got,
Alloc,
flags)) < 0) {
DEBUG(DL_ERR, ("Block insufficient resources, err: %d\n", rc));
return Ext2WinntError(rc);
}
if (Alloc)
Ext2SaveInode(IrpContext, Vcb, &Mcb->Inode);
if (Number)
*Number = rc ? rc : 1;
if (Block)
*Block = (ULONG)bh_got.b_blocknr;
return STATUS_SUCCESS;
}
NTSTATUS
Ext2DoExtentExpand(
IN PEXT2_IRP_CONTEXT IrpContext,
IN PEXT2_VCB Vcb,
IN PEXT2_MCB Mcb,
IN ULONG Index,
IN OUT PULONG Block,
IN OUT PULONG Number
)
{
EXT4_EXTENT_HEADER *eh;
struct buffer_head bh_got;
int rc, flags;
if (IsMcbDirectory(Mcb) || IrpContext->MajorFunction == IRP_MJ_WRITE) {
flags = EXT4_GET_BLOCKS_IO_CONVERT_EXT;
} else {
flags = EXT4_GET_BLOCKS_IO_CREATE_EXT;
}
memset(&bh_got, 0, sizeof(struct buffer_head));
eh = get_ext4_header(&Mcb->Inode);
if (eh->eh_magic != EXT4_EXT_MAGIC) {
ext4_ext_tree_init(IrpContext, NULL, &Mcb->Inode);
}
if ((rc = ext4_ext_get_blocks( IrpContext, NULL, &Mcb->Inode, Index,
*Number, &bh_got, 1, flags)) < 0) {
DEBUG(DL_ERR, ("Expand Block insufficient resources, Number: %u,"
" err: %d\n", *Number, rc));
DbgBreak();
return Ext2WinntError(rc);
}
if (Number)
*Number = rc ? rc : 1;
if (Block)
*Block = (ULONG)bh_got.b_blocknr;
Ext2SaveInode(IrpContext, Vcb, &Mcb->Inode);
return STATUS_SUCCESS;
}
NTSTATUS
Ext2ExpandExtent(
PEXT2_IRP_CONTEXT IrpContext,
PEXT2_VCB Vcb,
PEXT2_MCB Mcb,
ULONG Start,
ULONG End,
PLARGE_INTEGER Size
)
{
ULONG Count = 0, Number = 0, Block = 0;
NTSTATUS Status = STATUS_SUCCESS;
if (End <= Start)
return Status;
while (End > Start + Count) {
Number = End - Start - Count;
Status = Ext2DoExtentExpand(IrpContext, Vcb, Mcb, Start + Count,
&Block, &Number);
if (!NT_SUCCESS(Status)) {
Status = STATUS_INSUFFICIENT_RESOURCES;
break;
}
if (Number == 0) {
Status = STATUS_INSUFFICIENT_RESOURCES;
break;
}
if (Block && IsZoneInited(Mcb)) {
if (!Ext2AddBlockExtent(Vcb, Mcb, Start + Count, Block, Number)) {
DbgBreak();
ClearFlag(Mcb->Flags, MCB_ZONE_INITED);
Ext2ClearAllExtents(&Mcb->Extents);
}
}
Count += Number;
}
Size->QuadPart = ((LONGLONG)(Start + Count)) << BLOCK_BITS;
/* save inode whatever it succeeds to expand or not */
Ext2SaveInode(IrpContext, Vcb, &Mcb->Inode);
return Status;
}
NTSTATUS
Ext2TruncateExtent(
PEXT2_IRP_CONTEXT IrpContext,
PEXT2_VCB Vcb,
PEXT2_MCB Mcb,
PLARGE_INTEGER Size
)
{
NTSTATUS Status = STATUS_SUCCESS;
ULONG Extra = 0;
ULONG Wanted = 0;
ULONG End;
ULONG Removed;
int err;
/* translate file size to block */
End = Vcb->max_data_blocks;
Wanted = (ULONG)((Size->QuadPart + BLOCK_SIZE - 1) >> BLOCK_BITS);
/* calculate blocks to be freed */
Extra = End - Wanted;
err = ext4_ext_truncate(IrpContext, &Mcb->Inode, Wanted);
if (err == 0) {
if (!Ext2RemoveBlockExtent(Vcb, Mcb, Wanted, Extra)) {
ClearFlag(Mcb->Flags, MCB_ZONE_INITED);
Ext2ClearAllExtents(&Mcb->Extents);
}
Extra = 0;
} else {
Status = STATUS_INSUFFICIENT_RESOURCES;
}
if (!NT_SUCCESS(Status)) {
Size->QuadPart += ((ULONGLONG)Extra << BLOCK_BITS);
}
if (Mcb->Inode.i_size > (loff_t)(Size->QuadPart))
Mcb->Inode.i_size = (loff_t)(Size->QuadPart);
/* Save modifications on i_blocks field and i_size field of the inode. */
Ext2SaveInode(IrpContext, Vcb, &Mcb->Inode);
return Status;
}