After merging the iolatency policy, we potentially now have 4 policies being registered, but only support 3. This causes one of them to fail loading. Takashi reports that BFQ no longer works for him, because it fails to load due to policy registration failure. Bump to 5 policies, and also add a warning for when we have exceeded the global amount. If we have to touch this again, we should switch to a dynamic scheme instead.
Unified · Split
| @@ -1510,8 +1510,10 @@ int blkcg_policy_register(struct blkcg_policy *pol) · 1509 unmodified lines | ||
| 1510 | 1510 | for (i = 0; i < BLKCG_MAX_POLS; i++) |
| 1511 | 1511 | if (!blkcg_policy[i]) |
| 1512 | 1512 | break; |
| 1513 | − if (i >= BLKCG_MAX_POLS) | |
| 1513 | + if (i >= BLKCG_MAX_POLS) { | |
| 1514 | + pr_warn("blkcg_policy_register: BLKCG_MAX_POLS too small\n"); | |
| 1514 | 1515 | goto err_unlock; |
| 1516 | + } | |
| 1515 | 1517 | |
| 1516 | 1518 | /* Make sure cpd/pd_alloc_fn and cpd/pd_free_fn in pairs */ |
| 1517 | 1519 | if ((!pol->cpd_alloc_fn ^ !pol->cpd_free_fn) || |
| @@ -54,7 +54,7 @@ struct blk_stat_callback; · 53 unmodified lines | ||
| 54 | 54 | * Maximum number of blkcg policies allowed to be registered concurrently. |
| 55 | 55 | * Defined here to simplify include dependency. |
| 56 | 56 | */ |
| 57 | −#define BLKCG_MAX_POLS 3 | |
| 57 | +#define BLKCG_MAX_POLS 5 | |
| 58 | 58 | |
| 59 | 59 | typedef void (rq_end_io_fn)(struct request *, blk_status_t); |
| 60 | 60 | |