diff options
Diffstat (limited to 'mm/frontswap.c')
| -rw-r--r-- | mm/frontswap.c | 31 |
1 files changed, 23 insertions, 8 deletions
diff --git a/mm/frontswap.c b/mm/frontswap.c index 2760b0f98822..538367ef1372 100644 --- a/mm/frontswap.c +++ b/mm/frontswap.c @@ -121,8 +121,13 @@ struct frontswap_ops *frontswap_register_ops(struct frontswap_ops *ops) int i; for (i = 0; i < MAX_SWAPFILES; i++) { - if (test_and_clear_bit(i, need_init)) + if (test_and_clear_bit(i, need_init)) { + struct swap_info_struct *sis = swap_info[i]; + /* __frontswap_init _should_ have set it! */ + if (!sis->frontswap_map) + return ERR_PTR(-EINVAL); ops->init(i); + } } /* * We MUST have frontswap_ops set _after_ the frontswap_init's @@ -156,20 +161,30 @@ EXPORT_SYMBOL(frontswap_tmem_exclusive_gets); /* * Called when a swap device is swapon'd. */ -void __frontswap_init(unsigned type) +void __frontswap_init(unsigned type, unsigned long *map) { struct swap_info_struct *sis = swap_info[type]; - if (frontswap_ops) { - BUG_ON(sis == NULL); - if (sis->frontswap_map == NULL) - return; + BUG_ON(sis == NULL); + + /* + * p->frontswap is a bitmap that we MUST have to figure out which page + * has gone in frontswap. Without it there is no point of continuing. + */ + if (WARN_ON(!map)) + return; + /* + * Irregardless of whether the frontswap backend has been loaded + * before this function or it will be later, we _MUST_ have the + * p->frontswap set to something valid to work properly. + */ + frontswap_map_set(sis, map); + if (frontswap_ops) frontswap_ops->init(type); - } else { + else { BUG_ON(type > MAX_SWAPFILES); set_bit(type, need_init); } - } EXPORT_SYMBOL(__frontswap_init); |