With the introduction of BIO_ALLOCED we've used up all available bits in
bio::bi_flags.

Make sure no-one adds a new one and thus overrides the BVEC_POOL_IDX

Signed-off-by: Johannes Thumshirn <[email protected]>
---
 block/bio.c               |  3 +++
 include/linux/blk_types.h | 25 ++++++++++++++-----------
 2 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index a79b2bbcffd0..87a515e93bee 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -2198,6 +2198,9 @@ 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");
 
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 472059e92071..1d28992a20f0 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -215,19 +215,22 @@ struct bio {
 /*
  * bio flags
  */
-#define BIO_CLONED     2       /* doesn't own data */
-#define BIO_BOUNCED    3       /* bio is a bounce bio */
-#define BIO_USER_MAPPED 4      /* contains user pages */
-#define BIO_NULL_MAPPED 5      /* contains invalid user pages */
-#define BIO_QUIET      6       /* Make BIO Quiet */
-#define BIO_CHAIN      7       /* chained bio, ->bi_remaining in effect */
-#define BIO_REFFED     8       /* bio has elevated ->bi_cnt */
-#define BIO_THROTTLED  9       /* This bio has already been subjected to
+enum {
+       BIO_CLONED,             /* doesn't own data */
+       BIO_BOUNCED,            /* bio is a bounce bio */
+       BIO_USER_MAPPED,        /* contains user pages */
+       BIO_NULL_MAPPED,        /* contains invalid user pages */
+       BIO_QUIET,              /* Make BIO Quiet */
+       BIO_CHAIN,              /* chained bio, ->bi_remaining in effect */
+       BIO_REFFED,             /* bio has elevated ->bi_cnt */
+       BIO_THROTTLED,          /* This bio has already been subjected to
                                 * throttling rules. Don't do it again. */
-#define BIO_TRACE_COMPLETION 10        /* bio_endio() should trace the final 
completion
+       BIO_TRACE_COMPLETION,   /* bio_endio() should trace the final completion
                                 * of this bio. */
-#define BIO_QUEUE_ENTERED 11   /* can use blk_queue_enter_live() */
-#define BIO_TRACKED 12         /* set if bio goes through the rq_qos path */
+       BIO_QUEUE_ENTERED,      /* can use blk_queue_enter_live() */
+       BIO_TRACKED,            /* set if bio goes through the rq_qos path */
+       BIO_FLAG_LAST
+};
 
 /* See BVEC_POOL_OFFSET below before adding new flags */
 
-- 
2.16.4

Reply via email to