diff mbox series

[v2,2/3] block: bio: ensure newly added bio flags don't override BVEC_POOL_IDX

Message ID 20190322131346.20169-3-jthumshirn@suse.de (mailing list archive)
State New, archived
Headers show
Series add flag for tracking bio allocation | expand

Commit Message

Johannes Thumshirn March 22, 2019, 1:13 p.m. UTC 
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 <jthumshirn@suse.de>
---
 block/bio.c               |  3 +++
 include/linux/blk_types.h | 25 ++++++++++++++-----------
 2 files changed, 17 insertions(+), 11 deletions(-)

Comments

Christoph Hellwig March 22, 2019, 2:01 p.m. UTC | #1 
Looks fine,

Reviewed-by: Christoph Hellwig <hch@lst.de>
Hannes Reinecke March 22, 2019, 2:07 p.m. UTC | #2 
On 3/22/19 2:13 PM, Johannes Thumshirn wrote:
> 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 <jthumshirn@suse.de>
> ---
>   block/bio.c               |  3 +++
>   include/linux/blk_types.h | 25 ++++++++++++++-----------
>   2 files changed, 17 insertions(+), 11 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes
diff mbox series

Patch

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 */