#define trace_sync_bit(rw) \
(((rw) & (1 << BIO_RW_SYNC)) >> (BIO_RW_SYNC - 1))
#define trace_ahead_bit(rw) \
- (((rw) & (1 << BIO_RW_AHEAD)) << (BIO_RW_AHEAD - 0))
+ (((rw) & (1 << BIO_RW_AHEAD)) << (2 - BIO_RW_AHEAD))
/*
* The worker for the various blk_add_trace*() types. Fills out a