On Mon, Feb 10, 2025 at 05:03:19PM +0800, Ming Lei wrote:
> PAGE_SIZE is applied in some block device queue limits, this way is
> very fragile and is wrong:
Can you rephrase this? what is "some block device queue limits"?
> }
>
> diff --git a/block/blk.h b/block/blk.h
> index 90fa5f28ccab..cbfa8a3d4e42 100644
> --- a/block/blk.h
> +++ b/block/blk.h
> @@ -359,7 +359,7 @@ static inline bool bio_may_need_split(struct bio *bio,
> const struct queue_limits *lim)
> {
> return lim->chunk_sectors || bio->bi_vcnt != 1 ||
> - bio->bi_io_vec->bv_len + bio->bi_io_vec->bv_offset > PAGE_SIZE;
> + bio->bi_io_vec->bv_len + bio->bi_io_vec->bv_offset > BLK_MIN_SEGMENT_SIZE;
please avoid the overly long line here. And maybe split up the
condition to actually be readable? I.e.
if (lim->chunk_sectors)
return true;
if (bio->bi_vcnt != 1)
return true;
if (bio->bi_io_vec->bv_len + bio->bi_io_vec->bv_offset >
BLK_MIN_SEGMENT_SIZE)
return true;
return false;
> + BLK_MIN_SEGMENT_SIZE = 4096, /* min(PAGE_SIZE) */
That's a very sparse and cryptic comment. Please write down an
actual explanation.
