The call to frontswap_init() was added within enable_swap_info(), which was called not only during sys_swapon, but also to reinsert the swap_info into the swap_list in case of failure of try_to_unuse() within sys_swapoff. This means that frontswap_init() might be called more than once for the same swap area.
While as far as I could see no frontswap implementation has any problem with it (and in fact, all the ones I found ignore the parameter passed to frontswap_init), this could change in the future. To prevent future problems, move the call to frontswap_init() to outside the code shared between sys_swapon and sys_swapoff. Cc: Konrad Rzeszutek Wilk <konrad.w...@oracle.com> Cc: Dan Magenheimer <dan.magenhei...@oracle.com> Signed-off-by: Cesar Eduardo Barros <ces...@cesarb.net> --- mm/swapfile.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index 886db96..088daf4 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1471,7 +1471,6 @@ static void _enable_swap_info(struct swap_info_struct *p, int prio, swap_list.head = swap_list.next = p->type; else swap_info[prev]->next = p->type; - frontswap_init(p->type); } static void enable_swap_info(struct swap_info_struct *p, int prio, @@ -1480,6 +1479,7 @@ static void enable_swap_info(struct swap_info_struct *p, int prio, { spin_lock(&swap_lock); _enable_swap_info(p, prio, swap_map, frontswap_map); + frontswap_init(p->type); spin_unlock(&swap_lock); } -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/