Hi Namjae,
> >
> >> > + if (hint_clu == sbi->num_clusters) {
> >> > hint_clu = EXFAT_FIRST_CLUSTER;
> >> > p_chain->flags = ALLOC_FAT_CHAIN;
> >> > }
> > This is normal case, so let exfat rewind to the first cluster.
> >
> >> > + /* check cluster validation */
> >> > + if (!is_valid_cluster(sbi, hint_clu)) {
> >> > + exfat_err(sb, "hint_cluster is invalid (%u)", hint_clu);
> >> > + ret = -EIO;
> >> There is no problem with allocation when invalid hint clu.
> >> It is right to handle it as before instead returning -EIO.
> > We think all other case are real error case, so, error print and
> > return EIO.
> Why ?
>
> > May I confirm is there any normal case in here?
> Could you please explain more ? I can't understand what you are saying.
> >
`hint_clu` has the following cases.
1. Create a new cluster chain: `hint_clu == EXFAT_EOF_CLUSTER`
2. Append a new cluster to a cluster chain: `hint_clu = last_clu + 1`
2.1 ` hint_clu == sbi-> num_clusters`
2.2 `EXFAT_FIRST_CLUTER <= hint_clu < sbi-> num_clusters`
This commit splits case 2 to 2.1 and 2.2, and handles case 2.1 before calling is_valid_cluster().
So is_valid_cluster() is always true, even removing the check of is_valid_cluster() is fine.
But considering that this check can find bugs in future code updates, we keep this check and return -EIO.
If not returned EIO and continue, bug may not be revealed.
