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authorJohannes Thumshirn <jthumshirn@suse.de>2019-04-03 11:15:19 +0200
committerJens Axboe <axboe@kernel.dk>2019-04-04 09:30:37 -0600
commit2b24e6f63ac9e817630424c6d8f008256348dfc4 (patch)
tree04e523e6f47a8d5b251f86ad827e2ab3ee8c7640 /block/bio.c
parent2bc13b83e6298486371761de503faeffd15b7534 (diff)
downloadlwn-2b24e6f63ac9e817630424c6d8f008256348dfc4.tar.gz
lwn-2b24e6f63ac9e817630424c6d8f008256348dfc4.zip
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 <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bio.c')
-rw-r--r--block/bio.c3
1 files changed, 3 insertions, 0 deletions
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");