On 3/21/19 1:30 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@xxxxxxx>
---
block/bio.c | 8 ++++++++
include/linux/blk_types.h | 31 +++++++++++++++++--------------
2 files changed, 25 insertions(+), 14 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index 4db1008309ed..8c689aed46a0 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -2126,12 +2126,20 @@ static void __init biovec_init_slabs(void)
}
}
+static inline void bio_flag_buildtime_check(void)
+{
+ BUILD_BUG_ON(BIO_FLAG_LAST > BVEC_POOL_OFFSET);
+}
+
static int __init init_bio(void)
{
bio_slab_max = 2;
bio_slab_nr = 0;
bio_slabs = kcalloc(bio_slab_max, sizeof(struct bio_slab),
GFP_KERNEL);
+
+ bio_flag_buildtime_check();
+
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 d66bf5f32610..0273bad71a96 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -215,20 +215,23 @@ struct bio {
/*
* bio flags
*/
-#define BIO_SEG_VALID 1 /* bi_phys_segments valid */
-#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
- * throttling rules. Don't do it again. */
-#define BIO_TRACE_COMPLETION 10 /* 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 */
+enum {
+ BIO_SEG_VALID = 1, /* bi_phys_segments valid */
+ BIO_CLONED = 2, /* doesn't own data */
+ BIO_BOUNCED = 3, /* bio is a bounce bio */
+ BIO_USER_MAPPED = 4, /* contains user pages */
+ BIO_NULL_MAPPED = 5, /* contains invalid user pages */
+ BIO_QUIET = 6, /* Make BIO Quiet */
+ BIO_CHAIN = 7, /* chained bio, ->bi_remaining in effect */
+ BIO_REFFED = 8, /* bio has elevated ->bi_cnt */
+ BIO_THROTTLED = 9, /* This bio has already been subjected to
+ * throttling rules. Don't do it again. */
+ BIO_TRACE_COMPLETION = 10, /* bio_endio() should trace the final completion
+ * of this bio. */
+ BIO_QUEUE_ENTERED = 11, /* can use blk_queue_enter_live() */
+ BIO_TRACKED = 12, /* set if bio goes through the rq_qos path */
+ BIO_FLAG_LAST
+};
/* See BVEC_POOL_OFFSET below before adding new flags */
Where's the point of the enum if all values are initialized?
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
