From 2b24e6f63ac9e817630424c6d8f008256348dfc4 Mon Sep 17 00:00:00 2001 From: Johannes Thumshirn Date: Wed, 3 Apr 2019 11:15:19 +0200 Subject: block: bio: ensure newly added bio flags don't override BVEC_POOL_IDX With the introduction of BIO_NO_PAGE_REF we've used up all available bits in bio::bi_flags. Convert the defines of the flags to an enum and add a BUILD_BUG_ON() call to make sure no-one adds a new one and thus overrides the BVEC_POOL_IDX causing crashes. Reviewed-by: Ming Lei Reviewed-by: Hannes Reinecke Reviewed-by: Bart Van Assche Reviewed-by: Christoph Hellwig Signed-off-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- block/bio.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'block/bio.c') diff --git a/block/bio.c b/block/bio.c index 8d516d508ae3..c2592c5d70b9 100644 --- a/block/bio.c +++ b/block/bio.c @@ -2218,6 +2218,9 @@ static int __init init_bio(void) bio_slab_nr = 0; bio_slabs = kcalloc(bio_slab_max, sizeof(struct bio_slab), GFP_KERNEL); + + BUILD_BUG_ON(BIO_FLAG_LAST > BVEC_POOL_OFFSET); + if (!bio_slabs) panic("bio: can't allocate bios\n"); -- cgit v1.2.3-58-ga151