On Tue, Aug 19, 2025 at 09:49:15AM -0700, Keith Busch wrote: > /* > * If the queue doesn't support SG gaps and adding this > * offset would create a gap, disallow it. > @@ -339,8 +343,16 @@ int bio_split_rw_at(struct bio *bio, const struct queue_limits *lim, > * Individual bvecs might not be logical block aligned. Round down the > * split size so that each bio is properly block size aligned, even if > * we do not use the full hardware limits. > + * > + * Misuse may submit a bio that can't be split into a valid io. There > + * may either be too many discontiguous vectors for the max segments > + * limit, or contain virtual boundary gaps without having a valid block > + * sized split. Catch that condition by checking for a zero byte > + * result. > */ > bytes = ALIGN_DOWN(bytes, bio_split_alignment(bio, lim)); > + if (!bytes) If this is just misuse it could be a WARN_ON_ONCE. But I think we can also trigger this when validating passthrough commands that need to be built to hardware limits. So maybe don't speak about misuse here? Otherwise looks good: Reviewed-by: Christoph Hellwig <hch@xxxxxx>
