On Wed, Feb 03, 2021 at 09:45:30PM +0800, Xiao Ni wrote:
> +static struct bio *raid10_split_bio(struct r10conf *conf,
> + struct bio *bio, sector_t sectors, bool want_first)
> +{
> + struct bio *split;
> +
> + split = bio_split(bio, sectors, GFP_NOIO, &conf->bio_split);
> + bio_chain(split, bio);
> + allow_barrier(conf);
> + if (want_first) {
> + submit_bio_noacct(bio);
> + bio = split;
> + } else
> + submit_bio_noacct(split);
> + wait_barrier(conf);
> +
> + return bio;
I'm not sure this helper makes much sense given that the two different
cases could just be open coded into the two callers.
> + /* raid10_remove_disk uses smp_mb to make sure rdev is set to
> + * replacement before setting replacement to NULL. It can read
> + * rdev first without barrier protect even replacment is NULL
> + */
Not the normal kernel comment style.
> +/* There are some limitations to handle discard bio
> + * 1st, the discard size is bigger than stripe_size*2.
> + * 2st, if the discard bio spans reshape progress, we use the old way to
> + * handle discard bio
> + */
Same here.
> +static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
> +{
> + struct r10conf *conf = mddev->private;
> + struct geom *geo = &conf->geo;
> + struct r10bio *r10_bio;
> +
> + int disk;
> + sector_t chunk;
> + unsigned int stripe_size;
> + unsigned int stripe_data_disks;
> + sector_t split_size;
> +
> + sector_t bio_start, bio_end;
Empty lines between variabe declarations also are kinda strange.
> + stripe_data_disks = geo->near_copies ?
> + geo->raid_disks / geo->near_copies +
> + geo->raid_disks % geo->near_copies :
> + geo->raid_disks;
Normal style would be an if/else here.
> +
> + bio_start = bio->bi_iter.bi_sector;
> + bio_end = bio_end_sector(bio);
> +
> + /* Maybe one discard bio is smaller than strip size or across one stripe
> + * and discard region is larger than one stripe size. For far offset layout,
While there are occasional exceptions to the 80 char line rule, a block
comment should never qualify.
> + * if the discard region is not aligned with stripe size, there is hole
> + * when we submit discard bio to member disk. For simplicity, we only
> + * handle discard bio which discard region is bigger than stripe_size*2
> + */
> + if (bio_sectors(bio) < stripe_size*2)
missing whitespaces around the *.
