Avi Kivity wrote: > NeilBrown wrote: >> To achieve this, the "for_each" macros are now somewhat more complex. >> For example, rq_for_each_segment is: >> >> #define bio_for_each_segment_offset(bv, bio, _i, offs, _size) \ >> for (_i.i = 0, _i.offset = (bio)->bi_offset + offs, \ >> _i.size = min_t(int, _size, (bio)->bi_size - offs); \ >> _i.i < (bio)->bi_vcnt && _i.size > 0; \ >> _i.i++) \ >> if (bv = *bio_iovec_idx((bio), _i.i), \ >> bv.bv_offset += _i.offset, \ >> bv.bv_len <= _i.offset \ >> ? (_i.offset -= bv.bv_len, 0) \ >> : (bv.bv_len -= _i.offset, \ >> _i.offset = 0, \ >> bv.bv_len < _i.size \ >> ? (_i.size -= bv.bv_len, 1) \ >> : (bv.bv_len = _i.size, \ >> _i.size = 0, \ >> bv.bv_len > 0))) >> >> #define bio_for_each_segment(bv, bio, __i) \ >> bio_for_each_segment_offset(bv, bio, __i, 0, (bio)->bi_size) >> >> It does some with some explanatory text in a comment, but it is still >> a bit daunting. Any suggestions on making this more approachable >> would be very welcome. >> >> > > Well, I hesitate to state the obvious, but how about: > > #define bio_for_each_segment_offset(bv, bio, _i, offs, _size) \ > for (bio_iterator_init(&_i, ...); bio_iterator_cont(&_i, ...); > bio_iterator_advance(&_i, ...)) \ > if (bio_iterator_want_segment(&_i, ...)) > > While this doesn't remove the complexity, at least it's readable.
Violently seconded. -- tejun - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
