Commit 2b24e6f6 authored by Johannes Thumshirn's avatar Johannes Thumshirn Committed by Jens Axboe

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: default avatarMing Lei <ming.lei@redhat.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 2bc13b83
......@@ -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");
......
......@@ -215,21 +215,24 @@ struct bio {
/*
* bio flags
*/
#define BIO_NO_PAGE_REF 0 /* don't put release vec pages */
#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
enum {
BIO_NO_PAGE_REF, /* don't put release vec pages */
BIO_SEG_VALID, /* bi_phys_segments valid */
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 */
......
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