Function Ext2NewBlock

Ext4Fsd/ext3/generic.c:961–1171

}

NTSTATUS
Ext2NewBlock(
    IN PEXT2_IRP_CONTEXT    IrpContext,
    IN PEXT2_VCB            Vcb,
    IN ULONG                GroupHint,
    IN ULONG                BlockHint,
    OUT PULONG              Block,
    IN OUT PULONG           Number
)
{
    struct super_block      *sb = &Vcb->sb;
    PEXT2_GROUP_DESC        gd;
    struct buffer_head     *gb = NULL;
    struct buffer_head     *bh = NULL;
    ext4_fsblk_t            bitmap_blk;

    RTL_BITMAP              BlockBitmap;

    ULONG                   Group = 0;
    ULONG                   Index = 0xFFFFFFFF;
    ULONG                   dwHint = 0;
    ULONG                   Count = 0;
    ULONG                   Length = 0;

    NTSTATUS                Status = STATUS_DISK_FULL;

    *Block = 0;

    ExAcquireResourceExclusiveLite(&Vcb->MetaBlock, TRUE);

    /* validate the hint group and hint block */
    if (GroupHint >= Vcb->sbi.s_groups_count) {
        DbgBreak();
        GroupHint = Vcb->sbi.s_groups_count - 1;
    }

    if (BlockHint != 0) {
        GroupHint = (BlockHint - EXT2_FIRST_DATA_BLOCK) / BLOCKS_PER_GROUP;
        dwHint = (BlockHint - EXT2_FIRST_DATA_BLOCK) % BLOCKS_PER_GROUP;
    }

    Group = GroupHint;

Again:

    if (bh)
        fini_bh(&bh);

    if (gb)
        fini_bh(&gb);

    gd = ext4_get_group_desc(sb, Group, &gb);
    if (!gd) {
        DbgBreak();
        Status = STATUS_INSUFFICIENT_RESOURCES;
        goto errorout;
    }