Function Ext2DoExtentExpand

Ext4Fsd/ext4/extents.c:104–147

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