Function Ext2LookupBlockExtent

Ext4Fsd/memory.c:1058–1091

BOOLEAN
Ext2LookupBlockExtent(
    IN PEXT2_VCB    Vcb,
    IN PEXT2_MCB    Mcb,
    IN ULONG        Start,
    IN PULONG       Block,
    IN PULONG       Mapped
)
{
    LONGLONG    Vbn = 0;
    LONGLONG    Lbn = 0;
    LONGLONG    Length = 0;

    BOOLEAN     rc = FALSE;

    Vbn = ((LONGLONG) Start) << BLOCK_BITS;

    if (Mcb) {
        rc = Ext2LookupMcbExtent(Vcb, Mcb, Vbn, &Lbn, &Length);
    } else {
        rc = Ext2LookupVcbExtent(Vcb, Vbn, &Lbn, &Length);
    }

    if (rc) {
        *Mapped = (ULONG)(Length >> BLOCK_BITS);
        if (Lbn != -1 && Length > 0) {
            *Block = (ULONG)(Lbn >> BLOCK_BITS);
        } else {
            *Block = 0;
        }
    }

    return rc;
}


BOOLEAN