From: Jens Axboe <axboe@kernel.dk>
Date: Mon, 9 Jan 2023 17:45:56 +0000 (-0700)
Subject: block: add a BUILD_BUG_ON() for adding more bio flags than we have space
X-Git-Tag: for-6.3/block-2023-02-16~143
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=a3df2e456c0f9db4cc7f2013eb0beb853945b937;p=linux-block.git

block: add a BUILD_BUG_ON() for adding more bio flags than we have space

We have BIO_FLAG_LAST in the enum for bio specific flags, but it's
not used to check that we're not exceeding the size of them. Add
such a check.

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/block/bio.c b/block/bio.c
index ab59a491a883..d7fbc7adfc50 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1792,6 +1792,8 @@ static int __init init_bio(void)
 {
 	int i;
 
+	BUILD_BUG_ON(BIO_FLAG_LAST > 8 * sizeof_field(struct bio, bi_flags));
+
 	bio_integrity_init();
 
 	for (i = 0; i < ARRAY_SIZE(bvec_slabs); i++) {