Re: [PATCH v3] bcache: avoid oversized read request in cache missing code path

On 5/20/21 4:05 PM, Christoph Hellwig wrote:

This fix is pretty gross. Adding pages to bios can fail for all kinds of reasons, so the fix is to use bio_add_page and check its return value, and if it needs another bio keep looping and chaining more bios.

OK, I will try this idea and avoid to access BIO_MAX_VECS directly.

And maybe capping the readahead to some sane upper bound still makes sense, but it should never look at BIO_MAX_VECS for that.

Thanks for the hint.

Coly Li